Exposure to high fluoride concentrat Source Biometals SO 2005 Jun 18 3 207 12[PMIDT15984565]
Diva Decloaker 10X Pretreatment Reagent 说明书
Intended Use:For In Vitro Diagnostic UseHeat induced antigen retrieval of formalin-fixed paraffin-embedded (FFPE) tissues for immunohistochemistry (IHC) procedures. The clinical interpretation of any staining or its absence should be complimented by morphological studies using proper controls and should be evaluated within the context of the patient's clinical history and other diagnostic tests by a qualified pathologist.Summary & Explanation:Diva Decloaker is a heat retrieval solution that is compatible with virtually all antibodies and eliminates the need for multiple buffers including citrate buffer, EDTA or high pH tris buffers. Antibody titers are doubled and tripled when compared to citrate buffer, pH 6.0. Diva Decloaker incorporates Assure™ tech nology, a color-coded high temperatures pH indicator solution. The end-user is assured by visual inspection that the solution is at the correct dilution and pH. This product is specially formulated for superior pH stability at high temperatures and will help prevent the possibility of losing pH sensitive antigens. Diva Decloaker is non-toxic, non-flammable, odorless and sodium azide and thimerosal free.Known Applications:Immunohistochemistry (formalin-fixed paraffin-embedded tissues) Supplied As:100mlDiva Decloaker, 10X concentrate (DV2004LX)500mlDiva Decloaker, 10X concentrate (DV2004MX)Materials and Reagents (Needed But Not Provided): Microscope slides, positively chargedDesert Chamber* (Drying oven)Positive and negative tissue controlsXylene (Could be substituted with xylene substitute*)Ethanol or reagent alcoholDecloaking Chamber* (Pressure cooker)Deionized or distilled waterWash buffer*(TBS/PBS)Enzyme digestion*Avidin-Biotin Blocking Kit*(Labeled Streptavidin Kits Only) Peroxidase block*Protein block*Primary antibody*Negative control reagents*Detection kits*Detection components*Chromogens*Hematoxylin*Bluing reagent*Mounting medium** Biocare Medical Products: Refer to a Biocare Medical catalog for further information regarding catalog number and ordering information. Certain reagents listed above are based on specific application and detection system used. Storage and Stability:Store at room temperature. Do not use after expiration date printed on vial. If reagents are stored under conditions other than those specified in the package insert, they must be verified by the user. Diluted reagents should be used promptly; any remaining reagent should be stored at room temperature.Protocol Recommendations:1. Deparaffinize tissues and hydrate to water. If necessary, block for endogenous peroxidase and wash in DI water.2. Dilute concentrated Diva Decloaker at a ratio of 1:10 (1 ml Diva to 9 ml of deionized water).3. Place slides into 1X retrieval solution in a slide container (e.g. Coplin Jar, Tissue -Tek™ staining dish or metal slide canister).4. Retrieve sections under pressure using Biocare's Decloaking Chamber. Follow the recommendations on the antibody data sheet and Decloaking Chamber User Manual.5. Check solution for appropriate color change. (See Technical Note #1)6. Gently rinse by gradually adding DI water to the solution, then remove slides and rinse with DI water.Technical Notes:1. Concentrated Diva Decloaker is a bright yellow color. RTU or 1X solution is a pale yellow color. When the solution reaches 80-125°C, the solution turns yellow and indicates that the high temperature solution is at correct pH. Should the pH rise above 7.0, the solution turns a fuschia red color. Should the pH drop too low, thesolution turns a pink color.2. If using Biocare’s Desert Chamber Pro (a programmable turbo-action drying oven), dry sections at 25ºC overnight or at 37ºC for 30-60 minutes and then dry slides at 60ºC for 30 minutes.3. Use positive char ged slides (use Biocare’s Kling-On HIER Slides) and cut tissues at 4-5 microns. Do not use any adhesives in the water bath. Poor fixation and processing of tissues will cause tissue sections to fall off the slides, especially fatty tissues such as breast. Tissues should be fixed a minimum of 6-12 hours.4. Protocol time and temperatures for HIER can vary depending on the Decloaking Chamber model used. Please refer to the relevant Decloaking Chamber manual for appropriate protocol times and temperatures.Limitations:The protocols for a specific application can vary. These include, but are not limited to: fixation, heat-retrieval method, incubation times, tissue section thickness and detection kit used. Due to the superior sensitivity of these unique reagents, the recommended incubation times and titers listed are not applicable to other detection systems, asresults may vary. The data sheet recommendations and protocols are based on exclusive use of Biocare products. Ultimately, it is the responsibility of the investigator to determine optimal conditions. The clinical interpretation of any positive or negative staining should be evaluated within the context of clinical presentation, morphology and other histopathological criteria by a qualified pathologist. The clinical interpretation of any positive or negative staining should be complemented by morphological studies using proper positive and negative internal and external controls as well as other diagnostic tests.Catalog Number: DV2004 LX, MX Description: 100, 500 ml, concentrateQuality Control:Refer to CLSI Quality Standards for Design and Implementation of Immunohistochemistry Assays; Approved Guideline-Second edition (I/LA28-A2). CLSI Wayne, PA, USA (). 2011 Precautions:1. This product is not classified as hazardous. The preservative used in this reagent is Proclin 300 and the concentration is less than 0.25%. Overexposure to Proclin 300 can cause skin and eye irritation and irritation to mucous membranes and upper respiratory tract. The concentration of Proclin 300 in this product does not meet the OSHA criteria for a hazardous substance. Wear disposable gloves when handling reagents.2. Specimens, before and after fixation, and all materials exposed to them should be handled as if capable of transmitting infection and disposed of with proper precautions. Never pipette reagents by mouth and avoid contacting the skin and mucous membranes with reagents and specimens. If reagents or specimens come in contact with sensitive areas, wash with copious amounts of water.3. Microbial contamination of reagents may result in an increase in nonspecific staining.4. Incubation times or temperatures other than those specified may give erroneous results. The user must validate any such change.5. Do not use reagent after the expiration date printed on the vial.6. The SDS is available upon request and is located at /.7. Consult OSHA, federal, state or local regulations for disposal of any toxic substances. Proclin is a trademark of Rohm and Haas Company, or of its subsidiaries or affiliates.Troubleshooting:Follow the antibody specific protocol recommendations according to data sheet provided. If atypical results occur, contact Biocare's Technical Support at 1-800-542-2002.。
萤石介绍 Fluorite
FluoriteFluorite (also called fluorspar) is a halide mineral composed of calcium fluoride CaF2. Fluorite may occur as a vein deposit, especially with metallic minerals, where it often forms a part of the gangue (the surrounding “host-rock” in which valuable minerals occur) and may be associated with galena, sphalerite, barite, quartz and calcite. It is a common mineral in deposits of hydrothermal origin and has been noted as a primary mineral in granites and other igneous rocks and as a common minor constituent of dolostone and limestone.Fluorite is a widely occurring mineral which is found in large deposits in many areas of the world. ProductionIn 2009 the world reserves of fluorite were estimated at 230 Mt (million tonne), with the largest deposits being in South Africa (about 42 Mt), Mexico (32 Mt) and China (21 Mt). Present world production is around 5.5 Mt and three countries China (approx 59%), Mexico (18%) and Mongolia/CIS (10%) accounting for 87%.Roskill states that mined production of fluorite accounts for approximately 92% of world consumption and the balance derived from fluor-apatite as a by-product of phosphate fertiliser manufacturing.The role of the leading producer China has changed significantly over the last 20 years. Chinese exports of fluorite began to increase from the mid 1980s and by the early 1990's, China was established as the major source of supply for many countries.Mine production elsewhere declined in response to Chinese low prices and diminishing consumption in fluorochemicals in the main industrialised countries. Following a period in the mid to late 1990s when fluorite producers elsewhere sought to protect their markets by mean of anti-dumping measures, the Chinese government introduced a number of actions, including export quotas and taxes, which significantly reduced supply of fluorite to the international market.However this has now been largely offset by increased production in Mongolia and Mexico and by exports of fluorite derivatives from China. Nevertheless increased production is being considered outside of China, both with the re-opening of old mines and the development of new deposits.Some of the more significant world deposits of Fluorite being mined outside of China are as follows:Las Cuevas (Mexico): The Las Cuevas hosts the richest known fluorite resource in the world. The deposit is of hydrothermal/epithermal origin and the grade of the various ore bodies varies between 73 and 95% fluorite. Production output is 420,000 tpa (tonne per annum) of metallurgical grade concentrate and 580,000 tpa of acid grade concentrate. This is the largest fluorite mine in the world and more than double the size of the next largest.Vergenoeg (South Africa): This is a hematite-fluorite resource of grade approximately 40.0%. Production output in 2009 was 150,000 tpa obtained on a 70% recovery.Bor-Ondor/Urgun/Eranduer (Mongolia): These 3 deposits account for a large percentage of the fluorite mined and processed in Mongolia. However there are numerous mines, both underground and open cut and a large amount of artisinal activities.Okorusu (Namibia): This deposit has a grade of approximately 35% and is presently producing 120,000 tpa of acidspar grade fluorine. Significant improvement in the yields occurred by removing the mineral fluor-apatite which requires separate processing.UsesThere are two principal types of industrial use for natural fluorite, corresponding to different grades of purity:Metallurgical grade fluorite: called metspar which contains less than 97% (typically 85% or more) CaF2. This is used for flux in steel production and in the manufacturing of ceramics, opalescent glass, enamels and cooking utensils.Acid grade fluorite: called acidspar which contains 97% or more CaF2. This is used to make hydrogen fluoride and hydrofluoric acid; manufacture of fluorochemicals, which includes fluorocarbons, fluoropolymers and fluoroelastomers; manufacture of AlF3 and synthetic cryolite used in aluminium smelting.Market and GrowthThe present world demand for fluorite is approximately 5.5 Mt and as follows:- Acidspar for Fluorochemicals from HF: 50.3%.- Acidspar for Aluminium: 17.4%.- Metspar for Iron/steel: 30.8%.- Metspar for Miscellaneous: 1.5%.Since the 2000/01 economic recession and industry effects of restrictions on the use of fluorocarbons fluorite demand has shown an uneven recovery at an annual rate of 3.3% from 2002 to 2008 when demand was exceeded for the first time.。
Piston 液体昆虫喷霰说明书
PRODUCT NAME:Piston DESCRIPTION A liquid insecticide EPA REGISTRATIONNUMBER: 91234-19COMPANY IDENTIFICATION:Atticus, LLC5000 CentreGreen Way, Suite 100 Cary, NC 27513WARNINGHarmful if swallowedHarmful if inhaledVery toxic to aquatic lifeCommon Name Chemical Name CAS #Composition Chlorfenapyr4-bromo-2-(4-chlorophenul)-1-(ethoxymethyl)-5-(trifluromethyl)-1H-pyrrole-3-carbonitrile122453-73-021.40%Have the product container or label with you when calling a poison control center or doctor, or going for treatment. For emergency medical assistance, call SafetyCall: 1-844-685-9173. For chemical emergency: spill, leak, fire, exposure or accident, call CHEMTREC: 1-800-424-9300.IF SWALLOWED: Immediately call a doctor or poison control center. Do not induce vomiting unless told to do so by a poison control center or doctor. Have person sip a glass of water if able to swallow. Do not give anything by mount to an unconscious person.IF INHAL ED: Move person to fresh air and keep comfortable for breathing. If person is not breathing, call 911 or an ambulance; then give artificial respiration, preferably by mouth to mouth, if possible. Call a doctor or poison control center if you feel unwell.Flash Point: > 110°C (> 230°F)Fire and Explosion Hazards: Thermal decomposition may produce toxic fumes (see Section 10).Extinguishing Medium: Water fog, foam, dry chemical or carbon dioxide (CO2).Fire Fighting Equipment: Firefighters should be equipped with self-contained positive pressure breathing apparatus and full bunker gear. Fire Fighting Instructions: Evacuate area of all unnecessary personnel and fight fire from a safe distance upwind. Contain contaminated water / firefighting water; do not allow to enter drains or waterways. Foam or dry chemical fire extinguishing systems are preferred to prevent environmental damage from excessive water runoff.NFPA Ratings: Health – 1 / Flammability – 1 / Reactivity - 0Personal Precautions:I solate area and keep unnecessary and unprotected personnel from entering. Wear suitable personal protective clothing and equipment as described in Section 8 of this document. Environmental Precautions: Prevent material from entering public sewer systems or any waterways. Do not flush to drain. Large spills to soil or similar surfaces may necessitate removal of topsoil. The affected area should be removed and placed in an appropriate container for disposal. Spill Cleanup: Dike spill using suitable absorbent or impervious materials such as sand, cat litter, commercial clay, gel or similar absorbents. Collect and contain contaminated absorbent and place in an appropriate container for disposal. Pump any free liquid into an appropriate closed container and decontaminate tools and equipment following cleanup. Collect washings for disposal.7Handling: Avoid breathing vapors or spray mist. Avoid contact with skin, eyes or clothing. Wash hands thoroughly with soap and water after handling and before eating, drinking, chewing gum, using tobacco, or using the toilet. Remove and wash contaminated clothing before reuse. Storage: Keep this product in its tightly closed original container, when not in use. Do not store below 32°F. Do not store in direct sunlight. Store in a cool, dry (preferably locked) area that is inaccessible to children and animals.Engineering Controls: Facilities storing or utilizing this material should be equipped with an eyewash station and a safety shower.Protective Clothing: Mixers, loaders, applicators, and other handlers must wear long-sleeved shirts, long pants, shoes plus socks, and chemical resistant gloves made of any waterproof material (such as barrier laminate, butyl rubber or nitrile rubber, neoprene, or polyvinyl chloride (PVC), or viton <14 mils).General: Follow manufacturer’s instructions for cleaning/maintaining PPE. If no such instructions for washables, use detergent and hot water. Keep and was PPE separately from other laundry. Discard clothing and other absorbent materials that have been drenched or heavily contaminated with the product’s concentrate. Do not reuse them.PHYSICAL STATE:Opaque white liquidODOR:Mild sweetFLASHPOINT:N/A (will not flash)PH: 5.86 (corrected to 25°C) 1% dispersion DENSITY: 1.10 g/cm3 (at 25°C) SOLUBILITY:SolubleCONDITIONS TO AVOID: Excessive heat, do not store near heat or flame. CHEMICAL STABILITY: Stable under all normal use and storage conditions. INCOMPATIBILITY WITH OTHER MATERIALS: Strong oxidizing agents HAZARDOUS DECOMPOSITION PRODUCTS: This product is chemically stable and no hazardous reactions should occur if stored and handled as prescribed / indicated. When thermally decomposed, may release oxides of carbon and nitrogen, hydrogen bromide, hydrochloric acid, hydrofluoric acid, hydrogen fluoride, halogenated hydrocarbons, and hydrocarbons. HAZARDOUS POL YMERIZATION: Will not occur.ORAL TOXICITY (RAT LD50):560-567 mg/kgDERMAL TOXICITY (RAT LD50):> 2,000 mg/kgINHALATION TOXICITY (RAT LC50): 2.284 mg/LEYE IRRITATION:Non-irritatingSKIN IRRITATION:Non-irritatingSKIN SENSITIZATION:Guinea Pig – Not a contactsensitizer CARCINOGENICITY:EPA:Not Listed NTP:Not Listed ACGIH:Not Listed OSHA:Not Listed IARC:Not ListedMUTAGENIC TOXICITY: No evidence of mutagenic effects during in vivo and in vitro assays.REPRODUCTIVE TOXICITY: Not known to cause reproductive or birth defects at normal exposure levels.This pesticide is toxic to aquatic organisms, birds, and wildlife.The following information is for the active ingredient, Chlorfenapyr: AQUATIC TOXICITYRainbow Trout (96-hour LC50): 7.44 μg/LBluegill (96-hour LC50): 11.6 μg/LDaphnia (96-hour LC50): 6.11 μg/LAlgae (EC50): 132 μg/LAVIAN TOXICITYBobwhite Quail (LD50): 34 mg/kgMallard Duck (LD50): 10 mg/kgOTHER TOXICITYHoney Bee (LD50): 0.2 μg/beePESTICIDE DISPOSAL: Wastes resulting from the use of this product may be disposed of on-site or at an approved waste disposal facility. CONTAINER DISPOSAL: Nonrefillable container. Do not reuse or refill this container. Refer to the product label for specific container disposal instructions.US DOT (shipped by land):Containers < 1.3 gallons (5 Liters):Not regulated by DOT.Containers > 1.3 gallons (5 Liters):DOT Shipping Name:UN3082, Environmentally HazardousSubstance, Liquid, N.O.S.(contains Chlorfenapyr), 9, PG III Emergency Response Guide:171Marine Pollutant:YesIMDG (shipped by vessel):UN3082, Environmentally Hazardous Substance, Liquid, N.O.S. (contains Chlorfenapyr), 9, PG III, Marine PollutantIATA (shipped by air):UN3082, Environmentally Hazardous Substance, Liquid, N.O.S. (contains Chlorfenapyr), 9, PG IIIFIFRA –This chemical is a pesticide product registered by the Environmental Protection Agency and is subject to certain labeling requirements under federal pesticide law. These requirements differ from the classification criteria and hazard information required for safety data sheets, and for workplace labels of non-pesticide chemicals. The following is the hazard information as required on the pesticide label: PRECAUTIONARY STATEMENTSHAZARDS TO HUMANS AND DOMESTIC ANIMALS CAUTION. Harmful if swallowed, inhaled or absorbed through skin. Causes moderate eye irritation. Avoid breathing vapors or spray mist. Avoid contact with skin, eyes or clothing. Wash thoroughly with soap and water after handling and before eating, drinking, chewing gum or using tobacco. Remove contaminated clothing and wash clothing before reuse.See inside label booklet for additional precautionary statements. Environmental HazardsThis product is toxic to toxic to aquatic organisms, birds, and wildlife. Do not apply directly to water or to areas where surface water is present. Avoid spraying ponds or aquaria containing fish. Runoff from treated areas may be hazardous to aquatic organisms in neighboring areas.All pesticides are governed under the Federal I nsecticide, Fungicide, and Rodenticide Act (F FRA). The regulatory information presented below is pertinent only when this product is handled outside of the normal use and application as a pesticide. This product is excluded from listing requirements under EPA/TSCA.SARA Title III – Section 302 Extremely Hazardous SubstancesNot listedSARA Title III – Section 311/312 Hazard CategoriesImmediateSARA Title III – Section 312 Threshold Planning QuantityThe threshold planning quantity (TPQ) for this product treated as a mixture is 10,000 lbs. This product contains no ingredients with a TPQ of less than 10,000 lbs.SARA Title III – Section 313 Reportable IngredientsNoneCERCLA Reportable Quantity (RQ) –NoneCALIFORNIA PROP 65 STATUS –This product does not contain any chemicals known to the state of California to cause cancer or reproductive harm.CANADA –This product has been classified in accordance with the hazard criteria of the Controlled Products Regulations (CPR) and the SDS contains all of the information required by CPR.This Safety Data Sheet (SDS) serves different purposes than and DOES NOT REPLACE OR MOD I FY THE EPA APPROVED PRODUCT LABELING (attached to and accompanying the product container). This SDS provides important health, safety, and environmental information for employers, employees, emergency responders and others handling large quantities of the product in activities generally other than product use, while the labeling provides that information specifically for product use in the ordinary course.To the extent consistent with applicable law, neither Atticus, LLC nor Seller be liable for any incidental, consequential or special damages resulting from the use or handling of this product. TO THE EXTENT CONSISTENT WITH APPLICABLE LAW, THE EXCLUSIVE REMEDY OF THE USER OR BUYER, AND THE EXCLUS VE L AB L TY OF ATT CUS, LLC AND SELLER FOR ANY AND ALL CLA MS, LOSSES, NJUR ES OR DAMAGES (I NCLUD I NG CLA I MS BASED ON BREACH OF WARRANTY, CONTRACT, NEGLI GENCE, TORT, STRI CT LI ABI LI TY OR OTHERW SE) RESUL T NG FROM THE USE OR HANDL NG OF THIS PRODUCT, SHALL BE THE RETURN OF THE PURCHASE PRICE OF THE PRODUCT OR, AT THE ELECTION OF ATTICUS, LLC OR SELLER, THE REPLACEMENT OF THE PRODUCT.SDS Version: 1.0Effective Date: 9/29/2016。
KODAK VISION3 500T色度电影5219 7219 SO-219商品说明书
July 2015 • H-1-5219tTECHNICAL DATA / COLOR NEGATIVE FILMKODAK VISION3 500T ColorNegative Film 5219 / 7219 / SO-219KODAK VISION3 500T Color Negative Film 5219 / 7219 / SO-219 gives you control and flexibility at every phase of the filmmaking process—from capture through post, in both digital and traditional workflows.VISION3 500T Film has outstanding skin tones and color reproduction, while adding technical innovations that improve product performance and increase product versatility. The proprietary, advanced Dye Layering Technology (DLT) provides noticeably reduced grain in shadows, allowing you to pull out an amazing amount of shadow detail. The proprietary Sub-Micron Technology enables 2 stops of extended highlight latitude, so you can follow the action into bright light-in a single shot-without worrying about blown-out details.VISION3 500T Film is designed to extend thecapabilities of the DI (digital intermediate) process. The improved grain provides better to signal to noisecapabilities allowing the colorist to provide greater detail in shadows, while the extended highlight latitude enables improved digital "dodging and burning" to provide more details in highlights.BASEKODAK VISION3 500T Color Negative Films 5219 and 7219 have an acetate safety base with rem-jet backing.KODAK VISION3 500T Color Negative Film SO-219 has an ESTAR Safety Base with rem-jet backingSTORAGEStore unexposed film at 13°C (55°F) or lower. Forextended storage, store at -18°C (0°F) or lower. Process exposed film promptly.Store processed film according to the recommendations in ISO 18911:2010, Imaging Materials - Processed Safety Photographic Films - Storage Practices .This relates to optimized film handling rather than preservation; static, dust-attraction and curl-related problems are generally minimized at the higher relative humidity. After usage, the film should be returned to theShort T erm(less than 6 months)Long T erm(more than 6 months)Unexposed film in original, sealed package 13°C (55°F)RH below 60%-18 to -23°C (0 to-10°F)RH below 50%Exposed film, unprocessed -18 to -23°C (0 to-10°F)RH below 20%Not recommended.Process film promtly.Process film21°C (70°F)RH 20 to 50%2°C (36°F)RH 20 to 30%appropriate medium- or long-term storage conditions as soon as possible.Warm-upT imesT o prevent film telescoping, moisture condensation, and spotting, allow your film to warm to room temperature before use:For more information about film storage and handling, see ANSI/PIMA ISO-18911, SMPTE RP131-2002, and KODAK Publicatio No. H-845, The EssentialReference Guide for Filmmakers , available online at /go/referenceguide.DARKROOM RECOMMENDATIONSDo not use a safelight. Handle unprocessed film in total darkness.EXPOSUREExposure IndexesTungsten (3200K) - 500 Daylight - 320 (with 85 filter)Use these indexes with incident- or reflected-light exposure meters and cameras marked for ISO or ASA speeds or exposure indexes. These indexes apply for meter readings of average subjects made from the camera position or for readings made from a gray card of18-percent reflectance held close to and in front of the subject. For unusually light- or dark-colored subjects, decrease or increase the exposure indicated by the meter accordingly.Film Package Typical Warm-up Time (Hours)14°C (25°F) Rise55°C (100°F) RiseSuper 81 1 1/216 mm 1 1 1/235 mm35Color BalanceThese films are balanced for exposure with tungsten illumination (3200K). You can also expose them with tungsten lamps that have slightly higher or lower color temperatures (+/- 200K) without correction filters, since final color balancing can be done in printing.* These are approximate corrections only. Make final corrections duringprinting.† These are starting-point recommendations for trial exposures. If the kind of lamp is unknown, a KODAK Color Compensating Filter CC30R + CC20Y can be used with an exposure index (EI) of 250.Note: Consult the manufacturer of high-intensity ultraviolet lamps for safety information on ultraviolet radiation and ozone generation.Exposure Table—Tungsten LightAt 24 frames per second (fps), 180-degree shutteropening, use this table for average subjects that contain a combination of light, medium, and dark colors:Reciprocity CharacteristicsYou do not need to make any filter corrections or exposure adjustments for exposure times from 1/1000 of a second to 1 second.Light Source KODAK Filters on Camera *Exposure Index T ungsten (3000 K)None 500T ungsten (3200 K)None 500KINO FLO 29KINO FLO 32None500Daylight (5500 K)WRATTEN 2 OpticalFilter / 85320Metal Halide WRATTEN 2 OpticalFilter / 85320H.M.I.WRATTEN 2 OpticalFilter / 85320KINO FLO 55WRATTEN 2 OpticalFilter / 85320Fluorescent, Warm White †CC30R + CC05M320Fluorescent, Cool White †CC40R160Lens Aperture f /1.4f /2f /2.8f /4f /5.6f /8f /11f /16Footcandles Required510204080160320640PROCESSINGProcess in Process ECN-2.Most commercial motion-picture laboratories provide a processing service for these films. See KODAK Publication No. H-24.07, Processing KODAK Color Negative Motion Picture Films, Module 7 available online at/go/h24, for more information on the solution formulas and the procedure for machineprocessing these films. There are also pre-packaged kits available for preparing the processing solutions. For more information on the KODAK ECN-2 Kit Chemicals, check Kodak's Motion Picture Films for Professional Use price catalog, also available online at /go/motion.IDENTIFICATIONAfter processing, the product code numbers 5219 (35 mm), 7219 (16 mm), or SO-219 (16, 35, and 65 mm; edgeprint shows 0219) emulsion, roll, and strip number identification, KEYKODE Numbers, and manufacturer/film identification code (EJ) are visible along the length of the film.POST PRODUCTIONScanningThe wider exposure latitude in KODAK VISION3 Films differentiate film capture from the limited dynamic range of digital capture. Digital "dodging and burning," a very powerful tool in the colorists' toolkit, is now even more powerful—up to two stops more image information can be extracted from scene highlights in VISION3 Films.If traditional 10-bit scanner data encoding schemes are used to digitize films having this extended density range, highlight information captured on these film could be lost. Kodak has recommendations for extracting the full density range stored on high dynamic range films in a technical document titled Scanning Recommendations for Extended Dynamic Range Camera Films , available online at /go/scanning.Laboratory Aim Densities (LAD)T o maintain optimum quality and consistency in the final prints, the laboratory must carefully control the color timing, printing, and duplicating procedures. T o aid in color timing and curve placement, negative originals should be timed relative to Laboratory Aim Density (LAD) Control Film supplied by Eastman Kodak Company. The LADControl Film provides both objective sensitometric control and subjective verification of the duplicating procedures used by the laboratory.In the LAD Control Method, the electronic color analyzer used for color timing is set-up with the LAD Control Film to produce a gray video display of the LAD patch, corresponding to 1.0 neutral density (gray) on the print. The negative printing original is then scene-to-scene timed. There are specific LAD values for each type of print or duplicating film that the original can be printed on. Forprint films, the LAD patch is printed to a neutral gray of 1.0 visual density. For duplicating films, the specified aims are at the center of the usable straight-line portion of the sensitometric curve of the film.Due to normal variations in exposure and processing of color negative films, particular scenes may not print exactly at the same printer lights as the LAD Control Film. The LAD Control Film is intended as a set-up tool for electronic color analyzers and printers. It is NOT a reference that every scene must match. Normalfilm-to-film and scene-to-scene exposure variability is accommodated by the color timing (grading) process, on an electronic color analyzer set up with the LAD Control Film. Normally exposed and processed color negatives will typically print well within the range of an additive printer setup with the LAD Control Film, although SIGNIFICANT or UNEXPECTED departures from this center point balance may indicate an exposure/filtration problem with the cinematography or with the process control. Some specialized films and/or specialized negative processing techniques (push-processing, pull-processing,"skip-bleach" processing, etc.) may require more extreme adjustment from the LAD printing condition to attain desired results.More information is contained in KODAK Publication H-61, Laboratory Aim Density, available online at/go/lad.Film-to-Tape TransfersWhen you transfer the film directly to tape, you can set up the telecine using KODAK T elecine Analysis Film (TAF) supplied by Eastman Kodak Company. The TAF consists of a neutral density scale and an eight-bar color test pattern with a LAD gray surround.The TAF gray scale provides the telecine operator (colorist) with an effective way to adjust subcarrier balance and to center the telecine controls before timing and transferring a film. The TAF color bars provide the utility of electronic color bars, even though they do not precisely match the electronically generated color bars. Using the TAF will help obtain optimum quality and consistency in the film-to-tape transfer. For more information regarding TAF, see KODAK Publication No. H-606, KODAK Telecine Tool Kit and Reference Manual, available online at /go/telecine. IMAGE STRUCTUREFor more information on image-structure characteristics, see KODAK Publication No. H-845, The Essential Reference Guide for Filmmakers available online at / go/referenceguide.Note: The sensitometric curves and data in this publication represent product tested under the conditions of exposure and processing specified. They are representative of production coatings, and therefore do not apply directly to a particular box or roll of photographic material. They do not represent standards or specifications that must be met by Eastman Kodak Company. The company reserves the right to change and improve product characteristics at any time.Modulation Transfer FunctionThe "perceived" sharpness of any film depends on various components of the motion picture production system. The camera and projector lenses and film printers, among other factors, all play a role. But the specific sharpness of a film can be measured and is charted in the Modulation Transfer Function Curve.This graph shows a measure of the visual sharpness of this film. The x-axis, "Spatial Frequency," refers to the number of sine waves per millimeter that can be resolved. The y-axis, "Response," corresponds to film sharpness. The longer and flatter the line, the more sine waves per millimeter that can be resolved with a high degree of sharpness—and, the sharper the film.rms Granularity:Read with a microdensitometer, (red, green, blue) using a 48-micrometer aperture.The "perception" of the graininess of any film is highly dependent on scene content, complexity, color, and density. Other factors, such as film age, processing, exposure conditions, and telecine transfer may also have significant effects.To find the rms Granularity value for a given density, find the density on the left vertical scale and follow horizontally to the characteristic curve and then go vertically (up or down) to the granularity curve. At that point, followhorizontally to the Granularity Sigma D scale on the right. Read the number and multiply by 1000 for the rms value. Note: This curve represents granularity based on modified measuring techniques. Sensitometric and Diffuse RMS Granularity curves are produced on different equipment. Aslight variation in curve shape may be noticed.SensitometryThe curves describe this film's response to red, green, and blue light. Sensitometric curves determine the change indensity on the film for a given change in log exposure.Note: The exposure scale for VISION3 5219 / 7219 Film is longer than previous VISION and VISON2 Films. Because of the extended highlight latitude we have expanded the exposure scale from a 0-4 increment to a 0-5 scale. In addition to the longer exposure scale, we are plotting 21 steps instead of 20.Spectral SensitivityThese curves depict the sensitivity of this film to the spectrum of light. They are useful for determining,KODAK VISION3 500T Color Negative Film 5219 / 7219 / SO-219Revised 7-15Printed in U.S.A.KODAK VISION3 500T ColorNegative Film 5219 / 7219 / SO-219Spectral Dye DensityThese curves depict the spectral absorptions of the dyes formed when the film is processed. They are useful for adjusting or optimizing any device that scans or prints the film.Spectral Dye Density CurvesNote: Cyan, Magenta, and Yellow Dye Curves arepeak-normalized.MORE INFORMATIONOutside the United States and Canada, please contact your Kodak representative. You can also visit our web site at /go/motion for further information. You may want to bookmark our location so you can find us easily the next time.H-2Cinematographer’s Field GuideH-845The Essential Reference Guide for Filmmakers H-24Manual for Processing KODAK Motion Picture Films, Process ECN-2 Specifications, Module 7H-61LAD—Laboratory Aim DensityH-606KODAK Telecine Tool Kit and Reference ManualSIZES AVAILABLEStandard Products Available*for AATON A-MINIMA CamerasIdentification No.Length in Metres (Feet)Core Description Perforations 65 mm SP332305 (1000)PEmulsion InKS-4740 (KS-1866)35 mm SP41730 (100)S-83 100-ft. spoolBH-4740 (BH-1866)35 mm SP71861 (200)U BH-4740 (BH-1866)35 mm SP718122 (400)U BH-4740 (BH-1866)35 mm SP718305 (1000)U BH-4740 (BH-1866)35 mm SP239710 (2000)YBH-4740 (BH-1866)16 mm SP45530 (100)R-90 100-ft. spoolWinding B 1R-7605 (1R-2994)16 mm SP445*61 (200)A-MIN Winding A 1R-7605 (1R-2994)16 mm SP457122 (400)T Winding B 1R-7605 (1R-2994)16 mm SP458244 (800)TWinding B1R-7605 (1R-2994)16 mm SP44930 (100)R-90 100-ft. spool 2R-7605 (2R-2994)16 mm SP578122 (400)S-153 400-ft. spool2R-7605 (2R-2994)16 mm SP451122 (400)T2R-7605 (2R-2994)16 mm SP434122 (400)S-153 400-ft. spool2R-7620 (2R-3000)S8 mm SP46415 (50)Super 8 cartridgeKodak, Eastman, Keykode, Vision, and Wratten are trademarks.。
荧光高效液相色谱法 英文
荧光高效液相色谱法英文Fluorescence High Performance Liquid Chromatography (FL-HPLC) is an analytical technique that separates and measures compounds based ontheir fluorescent properties. It is a highly sensitive and selective technique that has gained popularity in areas such as pharmaceutical development, environmental monitoring, and food safety analysis.Fundamental Principle The fundamental principle of fluorescence detection in HPLC is based on the interaction of light with fluorescent compounds, which absorb light at a certain wavelength and emit light at a longer wavelength. When a sample is injected into an HPLC system, it is separated into its constituent components by a stationary phase, such as a column filled with a packing material. The separated components pass through a detector, where they are excited by a light source at a specific wavelength. As the excited moleculesreturn to their ground state, they emit light at alonger wavelength which is detected by a photomultiplier or diode array detector.Instrumentation FL-HPLC systems consist of the following components:1. mobile phase delivery system2. column3. injector4. detector5. data acquisition and processing system.The mobile phase delivery system includes pumps that deliver solvent or buffer solutions to the column at a constant flow rate. The column contains a stationary phase that separates the sample intoits individual components. The injector introduces the sample into the column in precise amounts. The detector detects the emission of light from the fluorescent compound, and the data acquisition and processing system collects and analyzes the detected signals.Applications FL-HPLC is highly sensitive and selective for the detection of fluorescent compounds, making it suitable for the analysis of trace amounts of compounds in complex matrices. It has found applications in the following areas:1. Pharmaceutical analyses: FL-HPLC is used to analyze active pharmaceutical ingredients and impurities in drug formulations.2. Food and beverage analyses: FL-HPLC is used to analyze vitamins, amino acids, and other nutrients in food and beverages.3. Environmental analyses: FL-HPLC is used to analyze pollutants and toxins in soil, water, and air.Advantages and limitations FL-HPLC has several advantages over conventional HPLC:1. High sensitivity: FL-HPLC is highly sensitive, and can detect trace amounts of compounds.2. High selectivity: FL-HPLC can selectively detect fluorescent compounds, which can be advantageous in a complex matrix.3. Versatility: FL-HPLC can be used to detect a wide range of compounds, including those that are difficult to detect using other methods.However, there are also some limitations to FL-HPLC:1. Limited applicability: FL-HPLC is only applicable to compounds that are fluorescent, which limits its use in some areas.2. Background fluorescence: Background fluorescence from the matrix can interfere with the detection of fluorescent compounds.3. Instrumentation costs: FL-HPLC instrumentation is more expensive than conventional HPLC instrumentation.Conclusion FL-HPLC is a powerful tool for the analysis of fluorescent compounds. Its high sensitivity and selectivity make it an attractive option for the detection of trace amounts of compounds in complex matrices. However, its limitations must also be considered when selecting an analytical method. With continued development, FL-HPLC has the potential to become even more powerful as an analytical tool in a variety of fields.。
亚临界水色谱
advantages of PHW-LC
(1) higher separation speeds (lower backpressure);
(2) use of longer columns; (3) improved column efficiency; (4) extended detector selection.
It has also proved possible to directly link superheated water extractions to SHWC by using a cold sorbent trap to focus the sample, that no solvent is used in the extraction or separation stage. The trap is then thermally desorbed either on-line or off- line to inject the sample.
Ideally the sample solvent should be water, because it can be assumed that stronger solvent would cause band broadening.However, there may be an advantage in using a stronger eluent as the injection solvent as long as it is more retained on the column than the analytes.
亚临界水色谱
superheated water chromatography (SHWC) pressurised water chromatography subcritical water chromatography
每一个人都想有一个健康的身体英语作文
每一个人都想有一个健康的身体英语作文全文共6篇示例，供读者参考篇1Certainly! Here is an essay of approximately 2000 words on the topic "Everyone Wants to Have a Healthy Body," written from the perspective of an elementary school student:Everyone Wants to Have a Healthy BodyHi there! My name is Emma, and I'm a 10-year-old girl who loves playing outside, reading books, and learning about the world. Today, I want to talk to you about something really important – being healthy!I think everyone wants to have a healthy body. After all, when we're healthy, we feel great! We have lots of energy to run around, play sports, and do all the fun things we love. We don't have to worry about getting sick or feeling yucky. And we can focus on school, our hobbies, and spending time with our friends and family.But what does it mean to be healthy? Well, there are a few key things we need to do to keep our bodies in tip-top shape.First, we have to eat the right kinds of food. That means lots of fruits and veggies, whole grains, lean proteins like chicken and fish, and healthy fats like avocados and nuts. My favorite healthy snacks are apples, carrots, and yogurt! It's also important to drink plenty of water and limit sugary drinks and junk food.Next, we need to stay active and exercise regularly. This could mean playing sports like soccer or basketball, going for bike rides or hikes, or even just running around the playground at school. Exercise is so much fun, and it helps keep our hearts, lungs, and muscles strong.Getting enough sleep is also super important for our health. When we sleep, our bodies recharge and repair themselves. That's why it's recommended that kids my age get around 10-11 hours of sleep every night. I try to go to bed early so I can wake up feeling refreshed and ready to take on the day!Another key part of being healthy is taking care of our mental and emotional well-being. We all experience stress, anxiety, and tough emotions sometimes, but it's important to find healthy ways to cope. Things like talking to a trusted adult, writing in a journal, practicing deep breathing or meditation, and spending time outdoors can really help.And finally, it's crucial to go for regular check-ups with our doctors and dentists. They can help catch any health problems early and make sure we're growing and developing properly.Now, you might be wondering why being healthy is so important. Well, there are lots of reasons!For one, when we're healthy, we have more energy and stamina to do the things we love. Whether it's playing our favorite sport, going on adventures with our friends, or just running around outside, being healthy means we can fully enjoy all the fun activities we love.Being healthy also helps us learn and focus better in school. When we're well-rested, well-nourished, and feeling good, it's easier to pay attention in class, retain information, and do our best work.Plus, developing healthy habits now sets us up for a lifetime of wellness. The choices we make as kids can have a big impact on our health as we grow older. By learning to take care of our bodies and minds from a young age, we're more likely to continue those positive behaviors as teenagers and adults.And let's not forget – when we're healthy, we just feel better overall! We have more energy, a positive outlook, and a generalsense of well-being. It's like our bodies are telling us, "Great job taking care of me! Keep up the good work!"It's also important to remember that everyone's journey to health looks a little different. Some people might need to focus more on getting enough sleep, while others might need to work on eating more veggies or staying active. And that's okay! The key is finding what works best for our unique bodies and lifestyles.Another thing to keep in mind is that being healthy isn't just about our physical bodies – it's about our minds and emotions, too. Taking care of our mental health by managing stress, practicing self-care, and surrounding ourselves with positive people is just as important as taking care of our physical health.At the end of the day, being healthy is about feeling our best and living life to the fullest. When we're healthy, we have the energy and vitality to chase our dreams, explore the world around us, and make the most of every single day.So let's all make a commitment to take care of our bodies and minds. Let's fuel ourselves with nutritious foods, stay active and get plenty of exercise, prioritize rest and relaxation, and practice good habits like proper hygiene and regular check-ups.Remember, we only get one body, and it's up to us to treat it with love and respect. When we do, our bodies will reward us with years of health, happiness, and the ability to live our best lives.Who's with me? Let's make health a priority and embrace all the amazing benefits that come with it. Our future selves will thank us!篇2Everyone Wants a Healthy BodyI think every kid (and grown-up too!) wants to have a healthy body. It's so important to take care of ourselves and treat our bodies right. Being healthy makes us feel good, gives us energy to play and learn, and keeps us from getting sick. It's no fun being stuck in bed with a cold or stomach ache!What does it mean to have a healthy body? Well, there are lots of things we need to do. First, we have to eat good foods that give our bodies nutrients. My mom always tells me to "eat the rainbow" by having fruits and veggies of different colors on my plate. The brighter the color, the better! Oranges, strawberries, broccoli, carrots – they are all so yummy and packed with vitamins.We also need to drink lots of water to stay hydrated. Our bodies are made up mostly of water, so we have to keep refilling the tank. I try to have a water bottle with me wherever I go and take little sips throughout the day. Juice, soda, and sugary drinks are treats, not everyday beverages.Exercise is another key part of being healthy. At least 60 minutes of physical activity every day helps our hearts, lungs, muscles and bones stay strong. I love running around at recess, riding my bike, swimming at the pool, and playing sports like soccer and basketball. Moving our bodies makes us feel energized and happy.Getting enough sleep is important too. Kids my age need9-12 hours of sleep every night. Sleep is the time when our bodies recharge and repair themselves. If I don't get proper rest, I'm grumpy and have a hard time paying attention in class. Having a calming bedtime routine of taking a bath, reading stories, and quiet activities before bed helps ensure I get my zzzs.Hygiene habits like bathing, brushing teeth, and washing hands are also vital. We need to keep ourselves clean to wash away germs and dirt that could make us sick. I make sure to soap up well in the shower, brush twice a day with fluoride toothpaste, and lather up with warm water and soap after using thebathroom, before eating, or when my hands look dirty. Little things make a big difference!Seeing the doctor and dentist for check-ups is smart too. The doctor keeps track of my growth, gives me any necessary vaccines, and checks that all my body parts and systems are developing properly. The dentist looks at my teeth and gums to watch for any cavities or problems. It's better to catch issues early before they become bigger problems.It's not always easy to make healthy choices, I'll admit. Sometimes I crave a big slice of cake or just want to veg out in front of the TV instead of moving around. My parents remind me that it's all about balance and moderation. Having occasional treats and rest periods is okay, as long as most of the time I'm making nutritious food picks, staying active, and practicing good self-care.I see kids at school who are overweight and sedentary, and it makes me sad. Being too heavy or inactive puts their bodies at risk for issues like diabetes, joint problems, heart disease and low self-esteem. I want all my friends and classmates to feel strong, capable and confident. Making unhealthy choices as a child can lead to unhealthy habits that stick around as you become an adult.On the flip side, taking care of your health when you're young sets you up for a lifetime of feeling your best. The human body is an incredible machine, but like anything, it needs the proper quality fuel, exercise and maintenance to run smoothly. I hope all kids understand how important it is to respect their bodies through healthy behaviors. Let's get moving, eat nutritious foods, and take good care of ourselves. A healthy body is something to feel proud of and cherish!篇3Everyone Wants a Healthy BodyHi there! My name is Emily, and I'm a 10-year-old girl who loves to play outside, read books, and learn new things. Today, I want to talk to you about something really important – having a healthy body.I'm sure you've heard adults say things like "Eat your veggies, they're good for you!" or "Go outside and get some fresh air, it'll do you good." But have you ever wondered why they say these things? Well, it's because they want us to have healthy bodies!You see, our bodies are like amazing machines that need the right fuel and care to work properly. Just like a car needs gas, oil,and regular maintenance, our bodies need good food, exercise, and rest to stay strong and healthy.Let me tell you why having a healthy body is so important.First of all, when you have a healthy body, you feel good! You have lots of energy to run, jump, and play with your friends. You can concentrate better in class, and you don't get sick as often. Doesn't that sound great?On the other hand, if you don't take care of your body, you might feel tired, grumpy, or even get sick more often. Nobody wants to miss out on fun activities or stay home from school because they're not feeling well, right?So, how do we keep our bodies healthy? Well, there are a few important things we need to do.One of the most important things is to eat healthy foods. That means lots of fruits, vegetables, whole grains, lean proteins (like chicken or fish), and low-fat dairy products. These foods give our bodies the nutrients they need to grow, repair themselves, and have energy.But we also need to limit things like candy, chips, soda, and other junk foods. These foods are high in sugar, salt, andunhealthy fats, which can make us gain too much weight and even cause health problems down the road.Another key to having a healthy body is to stay active and exercise regularly. Exercise helps our hearts, lungs, and muscles stay strong. It also helps us maintain a healthy weight and gives us more energy.You don't need to be a super athlete to exercise – just 60 minutes of physical activity every day is enough! This can include things like playing tag, jumping rope, riding your bike, swimming, or even just dancing around your living room.Getting enough sleep is also really important for a healthy body. When we sleep, our bodies rest and recharge for the next day. Most kids our age need between 9 and 12 hours of sleep every night.If we don't get enough sleep, we might feel grumpy, have a hard time paying attention in school, or even get sick more easily.Finally, it's important to take care of our mental health, too. That means finding ways to manage stress, like talking to a trusted adult when we're feeling worried or upset, or doingactivities that help us relax, like reading, drawing, or listening to music.A healthy mind and a healthy body go hand in hand!I know it can be tough sometimes to make healthy choices, especially when there are so many tempting unhealthy foods and activities around us. But trust me, it's worth it!When you take care of your body, you'll have more energy, feel better, and be able to do all the things you love. Plus, you'll be setting yourself up for a lifetime of good health.So, let's all make a pact to take care of our amazing bodies. Eat those veggies, get active and play outside, get plenty of sleep, and don't forget to take care of your mind, too.Your body is your best friend, and it deserves to be healthy and happy. Let's work together to make that happen!篇4The Importance of Having a Healthy BodyHello, everyone! Today, I want to talk about something really important - having a healthy body. We all know that a healthy body is super cool and it makes us feel great! So, let's learn why it's so important to take care of our bodies.Firstly, having a healthy body means we can do all the things we love. Imagine if we feel sick all the time, we won't be able to play sports, run around with our friends, or even go to school. But when we have a healthy body, we have so much energy to do all these activities and more! We can play soccer, basketball, dance, and have lots of fun. So, it's important to eat nutritious food, exercise regularly, and get enough sleep to keep our bodies healthy.Secondly, a healthy body helps us focus and do well in school. When we are fit and healthy, our brains work better too. We can concentrate more in class, understand our lessons easily, and remember things better. It's like having a superpower! So, let's make sure we eat a balanced diet with lots of fruits and vegetables, drink plenty of water, and get enough rest. This way, we can become super smart!Moreover, having a healthy body keeps us away from diseases. When we take care of ourselves, we build a strong immune system. This means that our body can fight off germs and viruses that try to make us sick. We won't have to miss school or fun activities because of being unwell. We can enjoy life to the fullest without worrying about getting sick. So, let'swash our hands regularly, cover our mouths when we cough or sneeze, and avoid touching our faces with dirty hands.In addition, a healthy body makes us feel happy and confident. When we look after our health, we feel good about ourselves. We have a positive attitude, and we can face challenges with a smile. We can also make friends easily because everyone loves to be around happy and confident people. So, let's take care of our bodies and spread happiness to others too!Lastly, having a healthy body means we can live a long and fulfilling life. When we make healthy choices from a young age, we set ourselves up for a bright future. We can grow up to be strong and active adults who can achieve their dreams. We can travel the world, pursue our passions, and make a difference in the world. It's like having a superhero life! So, let's start building healthy habits now and enjoy a wonderful journey throughout our lives.In conclusion, having a healthy body is super important for all of us. It allows us to do the things we love, excel in school, stay away from illnesses, be happy and confident, and live an amazing life. So, let's remember to eat well, exercise regularly, get enough rest, and take care of our bodies. Together, we can be the healthiest and happiest versions of ourselves!Remember, my friends, a healthy body is a happy body!篇5Everyone Wants to Have a Healthy BodyHi there! My name is Emily and I'm 10 years old. Today I want to talk to you about why it's so important to have a healthy body. It's something that every single person wants, whether they are a kid like me or a grown-up adult.Having a healthy body means feeling good, having lots of energy to play and learn, and not getting sick very often. When your body is healthy, you can run around outside with your friends, concentrate on your schoolwork, and pretty much do anything you want without feeling tired or achy. It's the best feeling in the world!On the other hand, when your body isn't healthy, it's no fun at all. You might have to stay inside resting instead of going out to play. You could get headaches or stomach aches that make it hard to pay attention in class. Worst of all, you might have to go to the doctor and get pills or even shots! No kid wants that.So how can we keep our bodies healthy and avoid getting sick or rundown? Well, there are lots of things we can do, and I'll go over some of the most important ones.First, we need to eat healthy foods. That means plenty of fruits and vegetables, whole grains, lean protein like chicken or fish, and healthy fats like avocados or nuts. Junk food like chips, candy, and soda is okay once in a while as a treat, but we shouldn't have it too often because it doesn't give our bodies what they need to grow and have energy.My mom always tells me that a healthy meal has foods from all the different food groups - a protein like chicken, a vegetable like broccoli, a fruit like an apple, some whole grains like brown rice, and a bit of healthy fat like the avocado in our salad. Eating a balanced diet with all those nutrients is key.Another crucial thing for staying healthy is getting enough exercise and physical activity. Experts recommend at least 60 minutes of exercise or active play for kids each day. That could be riding bikes, playing sports, running around at recess, or anything that gets your body moving!Exercise is so important because it strengthens our muscles, hearts, and lungs. It also helps us maintain a healthy weight andsleep better at night. Being active is just as vital as eating right when it comes to having a healthy body.My favorite way to exercise is playing soccer with my friends after school. We run around chasing the ball for an hour or more without even realizing we're working out. Tag, jump rope, dancing, and hiking are also really fun ways to stay active.In addition to diet and exercise, we need to take care of our bodies in other ways too. Getting enough sleep is super important - doctors say kids my age need between 9-12 hours per night! When we don't get enough shut-eye, we feel grumpy and have a hard time concentrating.Good hygiene habits like bathing regularly, washing our hands, and brushing our teeth also play a role in keeping our bodies healthy. We use soap and water to rinse away dirt and germs that could make us sick. Deodorant, combing our hair, and clipping our nails are other ways to stay clean.Sometimes we still get sick even when we do all the right things. When that happens, we need to take care of ourselves by resting, drinking plenty of fluids, and maybe taking medicine if the doctor recommends it. Getting plenty of rest allows our bodies to use their amazing healing powers to fight off illnesses so we feel better soon.Having good mental health is part of total body health too. If we feel very worried, sad, anxious or angry for long periods, it's hard for our bodies to function properly. Things like talking to a counselor, doing calming activities like yoga or meditation, and spending time with friends can help improve our mentalwell-being.Taking care of our bodies is a lifelong job that starts when we're little kids. If we build healthy habits like nutritious eating, exercise, hygiene and self-care at a young age, it will be easier to keep them up as we get older.Adults often struggle with unhealthy habits because they didn't learn the importance of things like vegetable-eating or daily activity when they were young. That's why it's key for kids to start prioritizing their health now so it becomes second nature.Having a healthy body also helps prevent serious medical issues down the road like obesity, diabetes, heart disease, and other problems. By taking care of ourselves while we're still young, we set ourselves up for a lifetime of wellness and energy.There are so many fun activities that require us to be physically fit too. If you want to excel at sports, go hiking or rockclimbing, or even just keep up with rambunctious kids or grandkids someday, you'll need to take care of your body.As you can probably tell, having a healthy mind and body is super important to me. I love feeling energetic and strong so I can learn, play, and live life to the fullest. Getting sick or hurt is no fun at all!That's why I make an effort to eat my veggies, stay active through sports and playing, get enough sleep, and take care of my hygiene. I also try to keep my mind healthy by sharing my feelings, doing activities I enjoy, and not worrying too much.I know I'm still a kid and my parents help a lot when it comes to making healthy choices. But I'm trying to build good habits now so staying fit and well becomes automatic as I get older.Every single person wants to have a healthy body, even if they don't think about it much. It allows us to feel our best, full of energy and vitality. It prevents us from getting sick and developing diseases. And it enables us to live life to the fullest - being active, spending time with loved ones, working at jobs we enjoy, and pursuing hobbies and interests.So there you have it - my perspective as a 10-year-old kid on why having a healthy mind and body is so crucial. I hope readingthis essay helps you appreciate how lucky we are when we're feeling strong and well. And I hope it inspires you to make your health a top priority through good habits like I'm trying to do. Taking care of our bodies is one of the most important things we can do for ourselves at any age!篇6Having a Healthy Body is Super Important!Hi everyone! My name is Alex, and I'm 10 years old. Today, I want to talk about something that's really, really important –having a healthy body! I think every single person in the whole wide world wants to be healthy and strong, don't you agree?Being healthy means that your body works the way it's supposed to. It means you have lots of energy to play, run, jump, and have fun. It also means you don't get sick very often, which is awesome because nobody likes being stuck in bed with a yucky cold or a nasty flu.But being healthy is about more than just not being sick. It's about feeling good – both physically and mentally. When your body is healthy, you feel happy, energetic, and ready to take on the world! You can concentrate better in school, play harder on the playground, and just enjoy life to the fullest.So, how can we make sure our bodies stay healthy? Well, there are a few things we need to do.First and foremost, we need to eat the right foods. That means lots of fruits and veggies, whole grains, lean proteins like chicken and fish, and healthy fats like those found in nuts and avocados. These foods give our bodies the nutrients they need to grow strong and fight off illnesses.On the other hand, we should try to limit things like candy, chips, soda, and other junk foods. They might taste really good, but they're not good for our bodies at all. Too much of that stuff can make us feel sluggish, gain weight, and even lead to serious health problems down the road.Next, we need to stay active and exercise regularly. Exercise is like giving our bodies a super-powered tune-up! It makes our hearts stronger, our muscles bigger, and our bones denser. It also helps us sleep better, cope with stress, and just feel happier overall.Some great ways to exercise are playing sports like soccer, basketball, or swimming. But even simple things like running around the playground, riding your bike, or going for a family walk count as exercise too!Getting enough sleep is also crucial for a healthy body. When we sleep, our bodies have a chance to rest, repair, and recharge for the next day. Aim for at least 9-11 hours of sleep every night if you're a kid like me.Lastly, it's important to take care of our mental health too. Feeling stressed, worried, or sad can take a toll on our physical health as well. That's why it's so important to talk to a trusted adult, like a parent or teacher, if you're feeling overwhelmed or down.Things like practicing deep breathing, doing yoga, or just taking some quiet time to yourself can also help us stay calm and centered.Now, I know what some of you might be thinking – "But Alex, being healthy is so hard! It's way more fun to sit around playing video games and eating junk food all day!"I get it, trust me. Sometimes, it can be really tempting to just veg out and not worry about being active or eating right. But trust me, your future self will thank you for taking care of your body now!Think about it – when you're a grown-up, you'll want to have enough energy to keep up with your kids or grandkids. You'llwant to be able to go on adventures, travel the world, and just live life to the fullest without being slowed down by health problems.Plus, taking care of your body now can help prevent all sorts of nasty diseases like heart disease, diabetes, and even some cancers. That's a pretty big deal if you ask me!So, let's all make a pact right here, right now to take care of our bodies and make healthy choices. It might not always be easy, but it's so worth it in the long run.We only get one body, and it's our job to treat it with love and respect. When we do that, our bodies will reward us with energy, strength, and good health for many, many years to come.Who's with me? Let's get moving, eat our veggies, and make being healthy the coolest thing ever!。
太阳能板安装指南说明书
• Keeping within the maximum permitted loadMake sure the support structure adheres to maximum permissible load requirements as prescribed by local ordinances, particularly in regions of high snow accumulations and high wind velocities. Take notice to possible bowing of the modules under high loads. Avoid installing fasteners, cable ties, etc. between the module backside and support structure (i.e. on mounting rails) as any sharp edges can damage module.• Grounding of the module and frameThe company installing the PV module frame is also responsible for the professional grounding. If the building is already equipped with an exterior lightning protection system the PVinstallation must be integrated in thep rotection system against direct effects of lightning. Country specific standards must be adhered to.A grounding method authorized by UL is mandatory in the US and Canada.Example UL:The modules can be connected to the grounding holes using a layin lug and a screw with serrated washer, washer and nut.Drawings:Ground connection using a cable lug, a bolt, a serrated washer, a washer and a nut.1) Layin lug3) Serrated washer 5) Nut2) Bolt 4) WasherWe recommend using the components as listed below. Any UL approved PV grounding method and components are also acceptable in the US and Canada.Table: Recommended componentsItem DescriptionManufacturer/ ManufacturerDistributor Part NumberGrounding Lug LayIn Lug IlscoGBL4 Bolt#632, SS McMaster Carr 92314A148 Serrated washer M5, SSMcMaster Carr 91120A140 Washer ID 9/64’’, OD 3/8’’, SS McMaster Carr 92141A007Nut#632, SSMcMaster Carr91841A007• Fire safetyThe roof construction and installation may affect the fire safety of a building; improper installation may contribute to hazards in the event of fire. For roof application, the modules should be mounted over a fire resistant covering rated for the application. The module is “nonexplosionprotected equipment”. Hence it must not be installed in the proximity of highly flammable gases and vapors (e.g. filling stations, gas containers, paint spraying equipment). The module must not be installed near open flames or flammable materials.• Suitable environmental conditionsThe module is intended for use in temperate climatic conditions.The module must not be subjected to concentrated light. It must not be immersed in water or constantly exposed to water spray (e.g. from fountains). There is risk of corrosion with exposure to salt (it is recommended that modules are installed at least 500 m or 1700 ft from the sea) and sulfur (sulfur sources, volcanoes). The module may not be exposed to extremely corrosive chemicals (e.g. emissions from manufacturing plants).• Suitable installationMake sure the module meets the technical requirements of the system as a whole. Ensure that other system components do not exert damaging mechanical or electrical influences on the modules. When connected in series, modules must all have the same amperage. When connected in parallel, the modules must all have the same voltage. The modules must not be connected together to create a voltage higher than the permitted system voltage. Modules must not be fitted as overhead glazing or vertical glazing (façade). Ensure that the mounting system can also withstand the anticipated wind and snow loads. There are openings at the base of the module frame to allow water fromprecipitation to drain. Ensure that these openings are not blocked nor partially blocked by the module installation method.Carefully read through these installation instructions before installing, operating or servicing the photovoltaic (PV) system. Failure to follow these instructions may result in bodily injury or damage to property. Keep these instructions! Working on a PV system requires specialized knowledge and must therefore be carried out only by appropriately qualified and authorized personnel. Keep children away!Warning noticesDanger of death from electric shock!Solar modules generate electricity as soon as they are exposed to light. The voltage of a single module is less than 50VDC. When several modules are connected in series, the summed voltage can be dangerously high. When the modules are connected in parallel the currents are summed together. Although touch protection is provided in the form of the fully insulated plug contacts, the following points must be observed when handling the solar modules to avoid the risk of fire, arcing and fatal electric shock:• T he installation of higher voltage systems should be done by qualified, licensed professionals.• D o not insert electrically conducting parts into the plugs or sockets!• D o not wear metallic jewelry while performing mechanical or electrical Instal-lation.• D o not fit solar modules and wiring with wet plugs and sockets! Tools and working conditions must be dry.• E xercise extreme caution when carrying out work on wiring and use the appropriate safety equipment (insulated tools, insulated gloves, etc.)!• D o not use damaged modules! Do not dismantle modules! Do not remove any part or label fitted by the manufacturer! Do not treat the rear of the laminate with paint, adhesives or mark it using sharp objects!D anger of death from electric shock! The inverter can produce dangerous, high voltages, even when not connected:• E xercise extreme caution when working on wiring and the inverter.• A fter switching off the inverter, it is essential to wait for the time interval specified by the manufacturer before beginning any further work. This allows the high voltage components time to discharge.• B e sure carefully to follow the inverter manufacturer’s installation instruc-tions.D anger of death from arcing! Modules generate direct current (DC) when any amount of light shines on them. When breaking a connected string of modules (e.g. when disconnecting the DC line from the inverter under load), a lethally strong arc can occur:• N ever remove the solar generator from the inverter while it is still connected to the main grid!•E nsure that the cable connections are in perfect condition (no cracking, soiling or other contamination)!Unpacking the modules and storage• O bserve the warnings on the packaging!The utmost care is required when handling the modules. Take care when unpacking, transporting, and storing them. Leave modules in packaging until they are to be installed. Carry modules with both hands. Do not use the connection socket as a handle. Do not stand modules on hard or rough ground. Do not stand modules on their corners. Ensure modules do not bow. Do not place modules on top of each other. Do not subject to load, do not stand on them, do not drop. Do not mark or work on them with sharp objects. Keep all electrical contacts clean and dry. In order to keep a record of your system, we recommend that you make a note of the serial numbers. If it is necessary to store the modules temporarily, a dry, ventilated room should be used.General safety informationEnsure that the module is used for its intended purpose only. Pay attention to the local ordinances, building standards and accident prevention regulations during installation. The safety information for other system components must also be followed.InstallationWhen installing the modules, please pay attention to:• Safety during installationDo not carry out installation work when there are strong winds. Secure yourself and other workers to avoid falling. Secure work materials to prevent articles from falling. Create a work zone to avoid accidents with other people.Quick Guide for UsersSolarWorld® solar modulesLast revised: November 2008Drawing:Bowing of the module under high mechanical front loads.See: ; 53421SolarWorld AGKurtSchumacherStraße 121453113 Bonn GermanyTelefon: +49 228 55920 0Telefax: +49 228 55920 99*********************www.solarworld.de SolarWorld Ibérica, S.L.C/La Granja 15, Bloque B1°B 28108 Alcobendas, Madrid SpainTel.: +34 91 4905999Fax: +34 91 6574967*********************www.solarworld.esSolarWorld California Inc. 4650 Adohr Lane Camarillo, CA 93012USATel.: +1 800 947 6527Fax: +1 805 388 6395 service@solarworld www.solarworld SolarWorld Korea Ltd.8551, Dunsanri, Bongdongwup,Wanjugun, Jeollabukdo 565902, KoreaTel: +82 2 2112 1871Fax: +82 2 2112 1949service@solarworld www.solarworld• R efer to section 690-8 of the National Electric Code (NEC) for an additional multiplying factor of 125% (80% derating) which may be applicable • O ver-current protection shall be in accordance with the requirements of Article 240 of the NEC • C onductor recommendations: 8-14 AWG (1.5-10 mm 2) USE2 (nonconduit)/ THWN2 (conduit ), 90°C wet rated • C able conduits should be used in locations where the wiring is accessible to children or small animals • M odification or tampering of diodes by unqualified personnel is not permitted. Please consult a SolarWorld Service Center for additional information regarding diode replacement/repair.Maintenance and cleaningGiven a sufficient tilt (at least 15°), it is generally not necessary to clean the modules (rainfall will have a selfcleaning effect). In case of heavy soiling, we recommend cleaning the modules using plenty of water (from a hose) without any cleaning agents and using a gentle cleaning implement (a sponge). Dirt must never be scraped or rubbed away when dry, as this may cause microscratches.We recommend that the system be inspected at regular intervals to ensure:1. All mounting points are tight and secure and free of corrosion.2. All cable connections are secure, tight, clean and free of corrosion.3. Cables are not damaged in any way.4. The conductivity of module frame to earth ground.Disclaimer of liabilitySince compliance with this guide and the conditions and methods of installation, operation, use and maintenance of the modules are not checked or monitored by SolarWorld AG, SolarWorld AG accepts no liability for damage arising through improper use or incorrect installation, operation, use or maintenance.Furthermore, liability for infringements of patent law or of other third party rights arising from the use of the modules is excluded unless we are automatically liable by law.1) Stainless steel serrated lock nut 2) Stainless steel washer3) Stainless steel M8 (5/16 inch) Thead bolt12313mounting area mounting area1/4 module length1/4 module length 1/8 module length1/8 module lengthdo not mount on the short side• Optimum orientation and tiltTo obtain maximum yield from the system, we recommend that you determine the best direction and tilt angle for the modules. Conditions for generating electricity are considered ideal when the sun’s rays strike the module perpendicular to its surface. To avoid performance drops in series circuits, ensure that all modules have the same orientation and tilt.• Avoidance of shadingEven partial shading will cause a yield reduction. A module is “shade free“ when the entire surface is shade free all year round and, even on the most unfavorable days of the year, receives unobstructed sunlight.• Adequate ventilationVentilation of the module backside is necessary to avoid the buildup of heat that can reduce performance.MountingEach module must be securely fastened at a minimum of 4 points. The frame has been stress tested for mounting by the long sides. The module should not be secured by its short sides.PV modules can be mounted to the substructure by clamping on (Example A) at the front side or by screwing (Example B) at the back side.Example A: ClampingExample B: BoltingThe clamping area (Example A) of the washer must cover at least 135 mm 2 or 0.21 in 2. A torque wrench must be used for assembly. In the examples shown, the tightening torque (using stainless steel M8 or 5/16 inch bolts) must be 20 Nm or 11.8 ftlbf. Use the existing holes for securing the module; do not drill any additional holes (doing so would void the warranty). Use appropriate corrosionproof fastening materials.WiringThe module is provided from the factory with preconnectorized cables. Under no circumstances should the junction box be opened.For the wiring, pay attention to:• Correct wiring schemeIn order to decrease voltage caused by indirect lightning strikes, all connecting cables should be as short as possible. Check that the wiring is correct before commissioning the system. If the measured open circuit voltage differs from the specifications, then there is a wiring fault. Ensure that the polarity is correct.• Correct plug connectionsMake connections only in dry conditions. Ensure that connections are secure and tight.• Use of suitable materialsUse special solar cable and suitable connectors only. Ensure that they are in perfect electrical and mechanical condition. Use only single wire cables. Select a suitable conductor diameter to minimize voltage drop.• Cable protectionWe recommend securing the cables to the mounting system using UVresistant cable ties. Protect exposed cables from damage using suitable precautions (e.g. laying them in plastic pipes). Avoid direct exposure to sunlight.Underwriters Laboratories Information (U.S. and Canada)• T he solar module electrical characteristics are within +/-10% of the module label indicated values of Isc ,Voc,and Pmpp under Standard Test Conditions (irradiance of 100 mW/cm 2, AM 1.5 spectrum, and a cell temperature of 25°C/77°F)•U nder normal conditions, a photovoltaic module is likely to experience conditions that produce more current and/or voltage than reported at standard testconditions. Accordingly, the values of Isc and Voc marked on this module should be multiplied by a factor of 1.25 when determining component voltage ratings, conductor capacities, fuse sizes, and size of controls connected to the PV output.SolarWorld Asia Pacific Pte. Ltd. 72 Bendemeer Road #0701, Luzerne Singapore 339941SingaporeTel.: +65 6842 3886Fax: +65 6842 3887 *********************www.solarworld.sgSolarWorld Africa Pty. 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Exposure to highfluoride concentration in drinking water will affect spermatogenesis and steroidogenesis in male albino ratsT.Pushpalatha,M.Srinivas&P.Sreenivasula Reddy*Department of Biotechnology,Sri Venkateswara University,Tirupati–517502,India;*Author for correspondence(Tel.:+91-877-2249320;Fax:+91-877-2249611;E-mail:reddy_1955@yahoo.co.in) Received30November2004;accepted10January2005;Published online:March2005Key words:sodiumfluoride,sperm,male rat,testes,steroidogenic marker enzymesAbstractSodiumfluoride(NaF)administered orally to adult male rats at a dose level of4.5ppm and9.0ppm for 75days caused significant decrease in the body weight,brain index and testicular index.A significant decrease in sperm count,sperm motility,sperm viability and sperm function(HOS positive)with increased sperm abnormalities was also observed in NaF-exposed male rats.The activity levels of testicular steroi-dogenic marker enzymes3b-hydroxysteroid dehydrogenase(3b-HSD)and17b-hydroxysteroid dehydro-genase(17b-HSD)were significantly decreased in NaF-treated rats indicating decreased steroidogenesis and in turn spermatogenesis in rats exposed to NaF.IntroductionFluoride is a wide spread natural pollutant with established toxic effects.Fluoride has a tendency to accumulate in the organisms,if the exposure persists over time,even at low concentrations (Groth1975).Excessfluoride is reported to cause severe harmful effects on plants(Boese et al.1995; Dogeroglu et al.2003),insects(Davies et al.1998), frogs(Agalokova et al.2000;Goh&Neff2003), livestock(Suttie1977,1980)and humans (Lamberg et al.1997).Most of the research on environmental toxic effects offluoride pollution has been confined to measuring potential risks in human and other mammalian models(Chinoy&Sequeira1989; Chinoy et al.1991;Kumar&Susheela1995; Barot1998;Oritz et al.2003).An epidemiological study on humans showed an association of decreasing total fertility rate with increasing environmentalfluoride levels(Freni1994). Infertility was found in an area of India where fluorosis is highly endemic(Neelam et al.1987). Susheela&Jethanandani(1996)reported decreased testosterone concentration in skeletal fluorosis patients and suggested thatfluoride tox-icity may cause adverse effects in the reproductive system of males living influorosis endemic areas. The present study describes the responses of male rats tofluoride taking sperm analysis and marker steroidogenic enzymes as reproductive indices. The concentrations offluoride used in the present study is equivalent the concentrations offluoride in nature,in some parts of Andhra Pradesh,India (Ramamohan Rao&Bhaskaran1964).Material and methodsMaintenance of the animalsWistar strain rats bred at Department of Bio-technology animal facility,Sri Venkateswara University were maintained under a controlled light:dark(12:12h)schedule at23±1°C and provided food and water ad libitum.The rat feed was purchased from Kamadhenu Agencies, Bangalore,India.Healthy young male rats of sameBioMetals(2005)18:207–212ÓSpringer2005 DOI10.1007/s10534-005-0336-2age group(40±2days)were taken from parental stock for present study.They were kept in well-cleaned sterilized cages.ChemicalSodiumfluoride(NaF)purchased from Central Drug Private Ltd.,New Delhi,was used as test chemical.Experimental designRats were divided into three groups consisting of six animals in each group.The animals of group I were allowed ad libitum access to tap water with-out NaF,while the animals of group II and group III were allowed ad libitum access to tap water containing either 4.5ppm or9.0ppm NaF for 75days.The body weights of rats were recorded at the initiation and termination of the experiment. The rats were sacrificed by cervical dislocation on 75th day of the experiment.Testes and brain tis-sues were quickly excised,weighed immediately and tissue index was calculated.The testes were also used for the determination of activity levels of selected steroidogenic marker enzymes.MethodsSperm countEpididymis was excised at autopsy and placed in 10-ml vial containing1.0ml of physiological saline at37°C.A suspension of spermatozoa was pre-pared by mincing with a sterilized razor blade on a glass slide in a few drops of physiological saline.A drop of resulting sperm suspension was used for the analysis of total sperm count.The sperms were counted using Neubauer Chamber,as described by Belsy et al.(1980).Sperm motilityCauda epididymal tissue was teased in a2ml physiological saline to release the spermatozoa. Percent motility was determined using Neubauer Chamber,as described by Belsy et al.(1980)with in5min following their isolation from cauda epididymis at37°C.Sperm viabilityThe ratio of live and dead spermatozoa was determined using1%tryphan blue by the method of Talbot&Chacon(1981).Morphological abnormalitiesSperms differing from normal structure can be considered as abnormal sperms.The morphologi-cal abnormalities in sperm were enumerated using light microscope and the percent of abnormality was calculated.Hypoosmotic swelling test(HOS-test)This test evaluates response of spermatozoa to hypoosmotic stress.The basis of this assay is, when viable sperms are exposed to hypoosmotic medium,there will be an influx offluid causing the tail to coil,which can be seen under phase contrast microscope.The sperms were exposed to hypoosmotic medium and observed for coiled tails under the microscope and the percent of coiling was estimated by the method of Jeyendran et al.(1992).Assay of testicular enzymesThe testicular tissue was homogenized in ice-cold Tris HCl buffer(pH6.8).The microsomal fraction was separated and used as enzyme source.The activity levels of3b-hydroxysteroid dehydrogenase (3b-HSD(EC 1.1.1.51)and17b-hydroxysteroid dehydrogenase(17b-HSD)(EC 1.1.1.61)were measured by the method of Bergmeyer(1974).The enzyme assays were made under the conditions following zero order kinetics after preliminary standardization regarding linearity with respect to time of incubation and enzyme concentration.The reaction mixture in a volume of 2.0ml contained:100l moles of sodium pyrophosphate buffer(pH9.0),0.5l mol of cofactor NAD for 3b-HSD and NADPH for17b-HSD,0.08l mol of substrate(dehydroepiandrosterone for3b-HSD and androstenedione for17b-HSD)and20mg equivalent of microsomal protein as enzyme source.The reactions were carried out in a quartz cuvette of1.0cm path at23±1°C.The absor-bance at340nm was measured at20s intervals for2085min in a UV–VIS spectrophotometer(Hitachi model U-2001)against controls.The enzyme activities were expressed in l mol of NAD con-verted to NADH/mg protein/min(3b-HSD)or l mol of NADPH converted to NADP/mg protein/ min(17b-HSD).Statistical analysisThe data were statistically analyzed by student’s t-test(Pillai&Sinha1968).P<0.005was considered significant.ResultsNo mortalities were observed in control or in experimental groups.No behavioral abnormalities were observed in rats exposed to NaF.A significant decrease in the total body weight was observed in male rats treated with NaF when compared with the control rats(Table1).Brain index of the rats treated with9.0ppm NaF was significantly(P<0.0001)decreased when compared with the control animals(Table1).The decline of the testicular index in9.0ppm NaF-exposed rats was more()34.50%)than the 4.5ppm NaF-exposed animals()10.00%).The average sperm count in cauda epididymal plasma was found to be42±3.23millions/gm testes in control rats.A significant(P<0.001) depletion()31.40%)in sperm count was observed in rats exposed to4.5ppm NaF,when compared with the control rats(Table1).These decrease were more()78.20%)in rats exposed to9.0ppm NaF(Table1).A significant(P<0.001)decrease in sperm motility was observed in NaF-treated rats,with a decrease in sperm viability(Table1) when compared with the control rats.All the sperms were apparently normal in control rats.Whereas in the rats exposed to NaF,many morphologically-altered sperms were observed.Two headed sperms,banana shaped head sperms,long tailed sperms and double headed sperms were the few abnormal sperms in NaF-exposed rats(Table1).A significant (P<0.001)decrease in sperm coiling percentage was observed in rats exposed to NaF(Table1). The average sperm coiling in normal sperm is 60%,whereas the sperm coiling was decreased to 43%and30%in rats exposed to4.5ppm and 9.0ppm NaF,respectively(Table1).The results presented in Figures1a and b indi-cate that3b-HSD activity levels(0.012±0.0018) were higher than the17b-HSD activity levels (0.010±0.0016)in rat testis.A significant decrease in the activity levels of3b-HSD and17b-HSD was observed in the testis of rats exposed to NaF.The decrease in the enzymes activity increased with increased dose of NaF when compared with the controls.Table1.Effect of sodiumfluoride on body weight and sperm parameters in male rats.Parameter Control 4.5ppm NaF-exposed9.0ppm NaF-exposedBody weight(g)329±1.0301.66±7.63ns()8.31)272.33±3.05*()17.22) Brain index 1.18±0.020.57±0.35*()51.27)0.55±0.08*()53.30) Testicular index 1.10±0.010.90±0.014*()10.00)0.72±0.073*()34.50) Sperm count(millions/ml)39±1.4426.73±0.90*()31.40)8.5±0.20*()78.20) Sperm viability(%)81±1.4455.7±1.83*()31.20)46.6±2.16*()43.20) Sperm motility(%)75.5±6.3648.8±1.13*()35.30)38.5±3.10*()49.00) Sperm physiological response(HOS coiling)(%)60±0.043±2.8*()28.30)30.3±2.16*()49.50) Abnormalities(%)–43.5±0.746.6±3.78a.Banana shape–40%–b.Rod shaped sperms––40%c.Two headed sperms–1%3%d.Long tailed sperms–1%1%e.Two tailed sperms–1%2%Values are mean±S.D.of six individuals.Values in parentheses are percent change from control.*Significant at P<0.001when compared with control;ns=Not significant.209DiscussionSemen analysis including sperm morphology assessment has been suggested to be a useful indication of the factors in man’s macro-envi-ronment,which can modulate or damage sper-matogenesis(Mac Leod&Gold1953).The present study was aimed to determine the reproductive toxic effects of male rat after ingestion of NaF through drinking water.The route chosen in this study for exposure was via drinking water to mimic human exposure and to reflect the impact on fertility,after chronic ingestion.The decreased sperm number and motility observed in experimental rats might be responsible for decreasing male fertility.Decrease in male reproductive potential was observed in rats and rabbits after exposure tofluoride(Kumar& Susheela1994,1995;Narayana&Chinoy1994;Zhang et al.2000;Collins et al.2001).Besides decreased sperm count,sperm motility,the sperm viability and HOS sperm coiling percentages were also adversely affected in NaF-exposed rats.These changes were greater in rats exposed to higher dose of NaF.The decreased testicular steroidogenic enzyme activity levels may lead to decreased steroidogen-esis in experimental rats,which in turn may sup-press the reproductive activities in the male rats. Oral administration of NaF caused decrease in 3b-HSD and17b-HSD along with significant diminution in plasma levels of testosterone(Ghosh et al.2002).The decrease in testicular17b-HSD activity levels with a decrease in male reproductive potential have been reported following exposure to several xenobiotics in rats(Pant et al.1995,1997; Pant&Srivastava2003).The activity level of3b-HSD which is involved in the formation of pregnenolone fromcholesterol Figure1.Effect of NaF on testicular3b-HSD(a)and17b-HSD(b)activity.Vertical bars represent mean±SD of six rats.Values are significant at*P<0.001from controls.210was significantly decreased and the decrease in en-zyme activity affects steroid synthesis in three ways;(1)by reducing the conversion of pregnenolone to progesterone,(2)by reducing the conversion of 17b-pregnenolone to17a-hydroxyprogesterone and(3)also by reducing the conversion of dehydroepiandrostenone(DHEA)to androsten-odione.Similarly the decreased activity level of 17b-HSD,which denotes the degree of formation of androgen,has been found significantly inhibited in NaF-exposed rat testis.In the present study,exposure to NaF resulted in alterations in the activity of testicular steroido-genic enzyme(3b-HSD and17b-HSD)activities, along with a decrease in sperm count,sperm motility,viability and sperm function.In line with these results,significant reduction in reproduction was observed in screech owls collected fromfluo-ride-polluted areas(Hoffman et al.1985).Though extrapolation of rat data to human is not relevant but the sodiumfluoride level in some parts of Andhra Pradesh is equivalent to the dose exposed to the rats in the present study.It can therefore be concluded that thefluoride-exposed rats though apparently normal but exhibits poor reproductive efficiency as indicated by decreased sperm quality and quantity and that these parameters can be used as a good indicators offluoride-induced reproductive toxicity in humans.AcknowledgementsThe authors thank Dr.K.V.S.Sharma,Professor of Statistics,Sri Venkateswara University for sta-tistical analysis of data.We also thank S.Uma-sankar for maintaining the rat colony in the Department.The experiments were conducted following the rules and regulations of Department of Biotechnology Ethical Committee and comply with the laws of the country.Part of the data was submitted to Sri Venkateswara University in par-tial fulfillment for the award of the degree of Master of Science in Biotechnology by MS. 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