生物认证_生物学_自然科学_专业资料-文档资料
rsem和bowtie2的简介生物学自然科学专业资料
目录
CONTENTS
• RSEM简介 • Bowtie2简介 • RSEM和Bowtie2的比较 • RSEM和Bowtie2在生物学中的
应用 • 总结与展望
01
RSEM简介
RSEM是什么
RSEM的用途
基因表达量估计
RSEM可以对单一样本或多样本进 行基因表达量估计，提供每个基 因的转录本数量。
VS
Bowtie2
Bowtie2主要用于将测序得到的短读比对 到参考基因组。它的应用场景包括基因组 测序、重测序、小RNA测序等。
优缺点比较
RSEM
RSEM的优点在于其精确的量化能力和对低 表达基因的良好检测。它能够有效地处理各 种测序数据，并提供准确的基因表达水平估 计。然而，RSEM的计算复杂度较高，需要 较长时间来处理大规模数据集。
Bowtie2是一个用于将测序得到的短读（short reads）比对（mapping）到参考基因 组的软件。它使用Burrows-Wheeler变换（BWT）和后缀数组索引（SAM/BAM）来
高效地比对短读，并支持各种测序平台的数据。
应用场景比较
RSEM
RSEM主要用于RNA-Seq数据的量化， 即用于估计基因或转录本的表达水平。 它可以处理单端或双端测序数据，并能 处理各种测序平台的数据。
Bowtie2的用途
用于基因组测序数据的预处理，将测序得到的短读比对至参考基因组，为后续的基因组变异分析和基因表达分析提供基础数 据。
可用于单分子测序、全基因组测序、全外显子测序等不同类型的测序数据。
Bowtie2的优势与局限性
速度快
Bowtie2使用高效的算法，能够在短时间内完成大量数据的比对。
蒲丰试验
蒲丰试验
一天,法国数学家蒲丰请许多朋友到家里,做了一次试验。
蒲丰在桌子上铺好一张大白纸,白纸上画满了等距离的平行线,他又拿出很多等长的小针,小针的长度都是平行线的一半。
蒲丰说:“请大家把这些小针往这张白纸上随便仍吧!”客人们按他说的做了。
蒲丰的统计结果是：大家共掷2212次,其中小针与纸上平行线相交704次,2210÷704≈3.142。
蒲丰说：“这个数是π的近似值。
每次都会得到圆周率的近似值,而且投掷的次数越多,求出的圆周率近似值越精确。
”这就是著名的“蒲丰试验”。
植物识别记
植物识别记
今天，爸爸带我到农田里去玩。
到了农田，我们发现很多植物都结出果实来了，我指着一个小叶子，有黄色的花的植物问爸爸：这是什么东西？”爸爸说：这个是花生。
”爸爸指着一个叶子紧密的植物考我：这是什么植物？”我摇摇头，表示不知道，爸爸让我在仔细看看，我看见那叶子下面有几个西瓜，便神气十足地说：是西瓜！”爸爸说：对了，现在正是西瓜成熟的好季节。
”爸爸又考我：这是什么？”我一看，它长着胡须”，心想：这肯定就是玉米。
于是，我不假思索的回答：肯定是玉米!”爸爸说：对了，这就是玉米。
”我说：他长着白胡子，好像在招呼我们过来。
”我们向前走去，这只这一个大叶子的植物说：这肯定是丝瓜！”爸爸说：藤上挂的才是丝瓜，这是冬瓜。
”原来如此！”我恍然大悟。
天色渐渐暗了，我和爸爸值得恋恋不舍地回家。
农田了的植物可真不少，还有许多我不认识的，以后我要多多观察，细心发现。
文章。
遗传学_生物学_自然科学_专业资料
第一章绪论本章习题1.解释下列名词：遗传学、遗传、变异。
遗传学：是研究生物遗传和变异的科学，是生物学中一门十分重要的理论科学，直接探索生命起源和进化的机理。
同时它又是一门紧密联系生产实际的基础科学，是指导植物、动物和微生物育种工作的理论基础；并与医学和人民保健等方面有着密切的关系。
遗传：是指亲代与子代相似的现象。
如种瓜得瓜、种豆得豆。
变异：是指亲代与子代之间、子代个体之间存在着不同程度差异的现象。
如高秆植物品种可能产生矮杆植株：一卵双生的兄弟也不可能完全一模一样。
2.简述遗传学研究的对象和研究的任务。
答：遗传学研究的对象主要是微生物、植物、动物和人类等，是研究它们的遗传和变异。
遗传学研究的任务是阐明生物遗传变异的现象及表现的规律；深入探索遗传和变异的原因及物质基础，揭示其内在规律；从而进一步指导动物、植物和微生物的育种实践，提高医学水平，保障人民身体健康。
3.为什么说遗传、变异和选择是生物进化和新品种选育的三大因素？答：生物的遗传是相对的、保守的，而变异是绝对的、发展的。
没有遗传，不可能保持性状和物种的相对稳定性；没有变异就不会产生新的性状，也不可能有物种的进化和新品种的选育。
遗传和变异这对矛盾不断地运动，经过自然选择，才形成形形色色的物种。
同时经过人工选择，才育成适合人类需要的不同品种。
因此，遗传、变异和选择是生物进化和新品种选育的三大因素。
4. 为什么研究生物的遗传和变异必须联系环境？答：因为任何生物都必须从环境中摄取营养，通过新陈代谢进行生长、发育和繁殖，从而表现出性状的遗传和变异。
生物与环境的统一，是生物科学中公认的基本原则。
所以，研究生物的遗传和变异，必须密切联系其所处的环境。
本章习题1.解释下列名词:原核细胞、真核细胞、染色体、染色单体、着丝点、细胞周期、同源染色体、异源染色体、无丝分裂、有丝分裂、单倍体、二倍体、联会、胚乳直感、果实直感。
原核细胞：一般较小，约为1~10mm。
细胞壁是由蛋白聚糖（原核生物所特有的化学物质）构成，起保护作用。
第八章呼吸Respiration
肺通气量和肺泡通气量
呼吸频率 潮气量 肺通气量 肺泡通气量 (次/min) (ml) (ml/min) (ml/min)
16
500
8000
8
1000
8000
32
250
8000
5600 6800 3200
第二节 呼吸气体在体内的交换与运输
2.1 呼吸气体的交换
第八章 呼吸(Respiration)
呼吸： 机体与环境之间的气体交换。
外呼吸(external respiration)： 外界环境与血液在肺部实现的气体交换。
内呼吸(internal respiration)： 血液通过组织液与组织细胞之间的气体交换。
呼吸环节：
1 外呼吸 2 气体在血中的运输 3 内呼吸
1.2 肺通气原理
动力：呼吸肌的运动
吸气肌收缩
胸廓扩大
肺扩大
吸气肌舒张
吸气 大气压>肺内压
胸廓缩小
肺缩小 肺内压>大气压
呼气
呼吸肌运动(原动力) 胸内压变化(间接动力) 肺内压与大气压差变化(直接动力)
肺通气
1.3 肺容量 (pulmonary capacity)
①潮气量(tidal volume, TV)： 平静呼吸时，每次吸入或呼出的气量。400-500ml
①以HCO3-形式运输
碳酸酐酶
CO2+H2O
H2CO3
H++HCO3-
H++HbO2
组织 肺
HHb++O2
CO2+H2O +HbO2
组织 肺
HCO3-+ HHb++O2
USP 88 生物实验
88BIOLOGICAL REACTIVITY TESTS, IN VIVOThe following tests are designed to determine the biological response of animals to elastomerics, plastics, and other polymeric material with direct or indirect patient contact, or by the injection of specific extracts prepared from the material under test. It is essential to make available the specific surface area for extraction. When the surface area of the specimen cannot be determined, use g of elastomer or g of plastic or other material for every mL of extraction fluid. Also, it is essential to exercise care in the preparation of the materials to be injected or instilled to prevent contamination with microorganisms and other foreign matter. Three tests are described. The Systemic Injection Test and the Intracutaneous Test are used for elastomeric materials, especially to elastomeric closures for which the appropriate Biological Reactivity Tests, In Vitro 87have indicated significant biological reactivity. These two tests are used for plastics and other polymers, in addition to a third test, the Implantation Test, to test the suitability of these materials intended for use in fabricating containers and accessories thereto, for use in parenteral preparations, and for use in medical devices, implants, and other systems.These three tests are applied to materials or medical devices, if there is a need for classification of plastics and other polymers based on in vivo biological reactivity testing.For the purpose of this chapter, these definitions apply: the Sample is the specimen under test or an extract prepared from such a specimen. A Blank consists of the same quantity of the same extracting medium that is used for the extraction of the specimen under test, treated in the same manner as the extracting medium containing the specimen under test. A Negative Control1 is a specimen that gives no reaction under the conditions of the test.CLASSIFICATION OF PLASTICSSix Plastic Classes are defined (see Table 1). This classification is based on responsesto a series of in vivo tests for which extracts, materials, and routes of administrationare specified. These tests are directly related to the intended end-use of the plastic articles. The choice of extractants is representative of the vehicles in preparations with which the plastics are likely to be in contact. The Table 1 classification facilitates communication among suppliers, users, and manufacturers of plastics by summarizing the tests to be performed for containers for injections and medical devices if a need for classification exists.Table 1. Classification of PlasticsPlasticClasses a Tests to be ConductedI II III IV V VI Test Material Animal Dose Procedure bx x x x x xExtract of Sample in SodiumChloride Injection Mouse50 mL/kg A (IV)x x x x x xRabbit orGuinea PigmL/animalat each of 10 or 6sites B (IC)x x x x xExtract of Sample in 1 in 20Solution of Alcohol inSodium Chloride Injection Mouse50 mL/kg A (IP)x x x x xRabbit orGuinea PigmL/animalat each of 10 or 6sites B (IC)x x xExtract of Sample inPolyethylene Glycol 400Mouse10 g/kg A (IP)x xRabbit orGuinea PigmL/animalat each of 10 or 6sites B (IC)x x x xExtract of Sample inVegetable Oil Mouse50 mL/kg A (IP)x x xRabbit orGuinea PigmL/animalat each of 10 or 6sites B (IC)x x Implant strips of Sample Rabbit 4 strips/animal Cx x Implant Sample Rat 2 Samples/animal Ca Tests required for each class are indicated by “x” in appropriate columns.b Legend: A (IP)—Systemic Injection Test (intraperitoneal); B (IC)—Intracutaneous Test (intracutaneous); C—Implantation Test (intramuscular or subcutaneous implantation).With the exception of the Implantation Test, the procedures are based on the use of extracts that, depending on the heat resistance of the material, are prepared at one of three standard temperatures: 50, 70, and 121. Therefore, the class designation of a plastic must be accompanied by an indication of the temperature of extraction .,IV-121, which represents a class IV plastic extracted at 121, or I-50, which represents a class I plastic extracted at 50).Plastics may be classified as USP Plastic Classes I–VI only on the basis of the response criteria prescribed in Table 1.This classification does not apply to plastics that are intended for use as containers for oral or topical products, or that may be used as an integral part of a drug formulation. Table 1 does not apply to natural elastomers, which are to be tested in Sodium Chloride Injection and vegetable oils only.The Systemic Injection Test and the Intracutaneous Test are designed to determine the systemic and local, respectively, biological responses of animals to plastics and other polymers by the single-dose injection of specific extracts prepared from a Sample. The Implantation Test is designed to evaluate the reaction of living tissue to the plastic and other polymers by the implantation of the Sample itself into animal tissue. The proper preparation and placement of the specimens under aseptic conditions are important in the conduct of the Implantation Test.These tests are designed for application to plastics and other polymers in the condition in which they are used. If the material is to be exposed to any cleansing or sterilization process prior to its end-use, then the tests are to be conducted on a Sample prepared from a specimen preconditioned by the same processing.Factors such as material composition, processing and cleaning procedures, contacting media, inks, adhesives, absorption, adsorption and permeability of preservatives, and conditions of storage may also affect the suitability of a material for a specific use. Evaluation of such factors should be made by appropriate additional specific tests to determine the suitability of a material for its intended use.USP R EFERENCE S TANDARDS 11—USP High-Density Polyethylene RS.Extracting Media—SODIUM CHLORIDE INJECTION (see monograph). Use Sodium Chloride Injection containing % of NaCl.1 IN 20 SOLUTION OF ALCOHOL IN SODIUM CHLORIDE INJECTION.POLYETHYLENE GLYCOL 400 (see monograph).VEGETABLE OIL— Use freshly refined Sesame Oil (see monograph) or Cottonseed Oil (see monograph) or other suitable vegetable oils.DRUG PRODUCT VEHICLE (where applicable).WATER FOR INJECTION (see monograph).NOTE—The Sesame Oil or Cottonseed Oil or other suitable vegetable oil meets the following additional requirements. Obtain, if possible, freshly refined oil. Use three properly prepared animals, and inject the oil intracutaneously in a dose of mL into each of 10 sites per animal, and observe the animals at 24, 48, and 72 h following injection. Rate the observations at each site on the numerical scale indicated in Table 2. For the 3 rabbits or guinea pigs (30 or 18 injection sites), at any observation time, the average response for erythema is not greater than and for edema is not greater than , and no site shows a tissue reaction larger than 10 mm in overall diameter. The residue of oil at the injection site should not be misinterpreted as edema. Edematous tissue blanches when gentle pressure is applied.Table 2. Evaluation of Skin Reactions aErythema and Eschar Formation Score No erythema0 Very slight erythema (barely perceptible)1 Well-defined erythema2 Moderate to severe erythema3 Severe erythema (beet-redness) to slight eschar formation (injuries indepth)4 Edema Formation b Score No edema0 Very slight edema (barely perceptible)1 Slight edema (edges of area well defined by definite raising)2 Moderate edema (raised approximately1 mm)3 Severe edema (raised more than 1 mm and extending beyond the area of exposure)4a Draize JH, Woodward G, Calvery HO. Methods for the study of irritation and toxicity of substances applied topically to the skin and mucous membranes. JErythema and Eschar Formation Score Pharmacol Exp Ther 1944;82:377–390.b Excludes noninflammatory (mechanical) edema from the blank or extraction fluid. Apparatus— The apparatus for the tests includes the following.AUTOCLAVE— Use an autoclave capable of maintaining a temperature of 121 ± , equipped with a thermometer, a pressure gauge, a vent cock, a rack adequate to accommodate the test containers above the water level, and a water cooling system that will allow for cooling of the test containers to about, but not below, 20 immediately following the heating cycle.OVEN— Use an oven, preferably a forced-circulation model, that will maintainoperating temperatures of 50or 70within ±2.EXTRACTION CONTAINERS— Use only containers, such as ampuls or screw-cap culture test tubes, of Type I glass. If used, culture test tubes are closed with screw caps having suitable elastomeric liners. The exposed surface of the elastomeric liner is completely protected with an inert solid disk – mm in thickness. A suitable disk may be fabricated from a polytef resin.Preparation of Apparatus— Cleanse all glassware thoroughly with chromic acid cleansing mixture, or if necessary, with hot nitric acid, followed by prolonged rinsing with water. Clean cutting utensils by an appropriate method ., successive cleaning with acetone and methylene chloride) prior to use in subdividing a specimen. Clean all other equipment by thorough scrubbing with a suitable detergent and prolonged rinsing with water.Render containers and equipment used for extraction, and in transfer and administration of test material, sterile and dry by a suitable process. [NOTE—If ethylene oxide is used as the sterilizing agent, allow adequate time for complete degassing. ]Procedure—PREPARATION OF SAMPLE— Both the Systemic Injection Test and the Intracutaneous Test may be performed using the same extract, if desired, or separate extracts may be made for each test. Select and subdivide into portions a Sample of the size indicated in Table 3. Remove particulate matter, such as lint and free particles, by treating each subdivided Sample or Negative Control as follows. Place the Sample into a clean, glass-stoppered, 100-mL graduated cylinder of Type I glass, and add about 70 mL of Water for Injection. Agitate for about 30 s, and drain off the water. Repeat this step, and dry those pieces prepared for the extraction with Vegetable Oil in an oven at a temperature not exceeding 50. [NOTE—Do not clean the Sample with a dry or wet cloth or by rinsing or washing with an organic solvent, surfactant, etc. ]Table 3. Surface Area of Specimen To Be Used aForm of Material Thickness Amount of Sample for each 20 mLof Extracting Medium Subdivided intoFilm or sheet< mm Equivalent of 120 cm2 total surfacearea (both sides combined)Strips of about5 × cm–1 mm Equivalent of 60 cm2 total surface area (both sides combined)Tubing < mm(wall)Length (in cm) = 120 cm2/(sum ofID and OD circumferences)Sections of about5 × cm–1 mm(wall)Length (in cm) = 60 cm2/(sum of IDand OD circumferences)Slabs, tubing, and molded items>1 mm Equivalent of 60 cm2 total surfacearea (all exposed surfacescombined)Pieces up toabout 5 × cmElastomers>1 mm Equivalent of 25 cm2 total surfacearea (all exposed surfacescombined)Do not subdivide ba When surface area cannot be determined due to the configuration of the specimen, use g of elastomer or g of plastic or other polymers for every 1 mL of extracting fluid.b Molded elastomeric closures are tested intact.PREPARATION OF EXTRACTS— Place a properly prepared Sample to be tested in an extraction container, and add 20 mL of the appropriate extracting medium. Repeat these directions for each extracting medium required for testing. Also, prepare one 20-mL blank of each medium for parallel injections and comparisons. Extract byheating in an autoclave at 121for 60 min, in an oven at 70for 24 h, or at 50for 72 h. Allow adequate time for the liquid within the container to reach the extraction temperature. [NOTE—The extraction conditions should not in any instance cause physical changes such as fusion or melting of the Sample pieces, which result in a decrease in the available surface area. A slight adherence of the pieces can be tolerated. Always add the cleaned pieces individually to the extracting medium. If culture tubes are used for autoclave extractions with Vegetable Oil, seal screw caps adequately with pressure-sensitive tape. ]Cool to about room temperature but not below 20, shake vigorously for several minutes, and decant each extract immediately, using aseptic precautions, into a dry, sterile vessel. Store the extracts at a temperature of 20–30, and do not use for tests after 24 h. Of importance are the contact of the extracting medium with the available surface area of the plastic and the time and temperature during extraction, the proper cooling, agitation, and decanting process, and the aseptic handling and storage of the extracts following extraction.SYSTEMIC INJECTION TESTThis test is designed to evaluate systemic responses to the extracts of materials under test following injection into mice. Alternate routes of injection may be used with justification.Test Animals— Use healthy, not previously used albino mice weighing 17–23 g. For each test group use only mice of the same source. Allow water and food, commonly used for laboratory animals and of known composition, ad libitum. Procedure—[NOTE—Agitate each extract vigorously prior to withdrawal of injection doses to ensure even distribution of the extracted matter. ] Inject each of the five mice in a test group with the Sample or the Blank as outlined in Table 4, except to dilute each g of the extract of the Sample prepared with Polyethylene Glycol 400, and the corresponding Blank, with volumes of Sodium Chloride Injection to obtain a solution having a concentration of about 200 mg of polyethylene glycol per mL.Table 4. Injection Procedure—Systemic Injection TestExtract or Blank Dose per kg Route aExtract or Blank Dose per kg Route a Sodium ChlorideInjection50 mL IV1 in 20 solution ofAlcohol in Sodium Chloride Injection50 mL IV Polyethylene Glycol 40010 g IP Drug product vehicle (where applicable)50 mL IV50 mL IP Vegetable Oil50 mL IPa IV = intravenous (aqueous sample and blank); IP = intraperitoneal (oleaginous sample and blank).Observe the animals immediately after injection, again 4 h after injection, and then at least at 24, 48, and 72 h. If during the observation period none of the animals treated with the extract of the Sample shows a significantly greater biological reactivity than the animals treated with the Blank, the Sample meets the requirements of this test. If two or more mice die, or if abnormal behavior such as convulsions or prostration occurs in two or more mice, or if a body weight loss greater than 2 g occurs in three or more mice, the Sample does not meet the requirements of the test. If any animals treated with the Sample show only slight signs of biological reactivity, and not more than one animal shows gross symptoms of biological reactivity or dies, repeat the test using groups of 10 mice. On the repeat test, all 10 animals treated with the Sample show no significant biological reactivity above the Blank animals during the observation period.INTRACUTANEOUS TESTThis test is designed to evaluate local responses to the extracts of materials under test following intracutaneous injection into rabbits or guinea pigs.Test Animals— Select healthy, rabbits or guinea pigs with fur that can be clipped closely and skin that is free from mechanical irritation or trauma. In handling the animals, avoid touching the injection sites during observation periods, except to discriminate between edema and an oil residue.Procedure—[NOTE—Agitate each extract vigorously prior to withdrawal of injection doses to ensure even distributionof the extracted matter. ] On the day of the test, closely clip the fur on the animal's back on both sides of the spinal column over a sufficiently large test area. Avoid mechanical irritation and trauma. Remove loose hair by means of vacuum. If necessary, swab the skin lightly with diluted alcohol, and dry the skin prior to injection. More than one extract from a given material can be used per rabbit or guinea pig, if it is determined that the test results will not be affected. For each Sample use two animals and inject each intracutaneously, using one side of the animal for the Sample and the other side for the Blank, as outlined in Table 5. [NOTE—Dilute each g of the extract of the Sample prepared with Polyethylene Glycol 400, and the corresponding Blank, with volumes of Sodium Chloride Injection to obtain a solution having a concentration of about 120 mg of polyethylene glycol per mL. ]Table 5. Intracutaneous TestExtract or Blank Number of Sites(per animal)Dose(µL per site)Sample5200Blank5200Examine injection sites for evidence of any tissue reaction such as erythema, edema, and necrosis. Swab the skin lightly, if necessary, with diluted alcohol to facilitate reading of injection sites. Observe all animals at 24, 48, and 72 h after injection. Rate the observations on a numerical scale for the extract of the Sample and for the Blank, using Table 2. Reclip the fur as necessary during the observation period. The average erythema and edema scores for Sample and Blank sites are determined at every scoring interval (24, 48, and 72 h) for each rabbit or guinea pig. After the 72-hour scoring, all erythema scores plus edema scores are totalled separately for each Sample and Blank. Divide each of the totals by 12 (2 animals × 3 scoring periods × 2 scoring categories) to determine the overall mean score for each Sample versus each corresponding Blank. The requirements of the test are met if the difference between the Sample and the Blank mean score is or less. If at any observation period the average reaction to the Sample is questionably greater than the average reaction to the Blank, repeat the test using three additional rabbits or guinea pigs. Therequirements of the test are met if the difference between the Sample and the Blank mean score is or less.IMPLANTATION TESTThe implantation test is designed for the evaluation of plastic materials and other polymeric materials in direct contact with living tissue. Of importance are the proper preparation of the implant strips and their proper implantation under aseptic conditions. The intramuscular implantation test requires healthy adult New Zealand rabbits. The test specimens are placed into needles as the delivery system for implantation. Although most materials lend themselves readily to this method, there are a number of materials that are unsuitable for intramuscular implantation. For materials with physical characteristics unsuitable for routine intramuscular implantation, the subcutaneous rat implantation model is a viable alternative.Intramuscular Implantation in RabbitsPrepare for implantation 8 strips of the Sample and 4 strips of USP High-Density Polyethylene RS. Each strip should measure not less than 10 × 1 mm. The edges of the strips should be as smooth as possible to avoid additional mechanical trauma upon implantation. Strips of the specified minimum size are implanted by means of a hypodermic needle (15–19 gauge) with intravenous point and a sterile trocar. Use either presterilized needles into which the sterile plastic strips are aseptically inserted, or insert each clean strip into a needle, the cannula and hub of which are protected with an appropriate cover, and then subjected to the appropriate sterilization procedure. [NOTE—Allow for proper degassing if agents such as ethylene oxide are used. ]Test Animals— Select healthy, adult rabbits weighing not less than kg, and with paravertebral muscles that are sufficiently large in size to allow for implantation of the test strips. Do not use any muscular tissue other than the paravertebral site. The animals must be anesthetized with a commonly used anesthetic agent to a degree deep enough to prevent muscular movements, such as twitching. See the Association for Assessment and Accreditation of Laboratory Animal Care (AAALAC) guidelines.Procedure— Perform the test in a clean area. On the day of the test or up to 20 h before testing, clip the fur of the animals on both sides of the spinal column. Remove loose hair by means of vacuum. Swab the skin lightly with diluted alcohol, and dry the skin prior to injection.Implant four strips of the Sample into the paravertebral muscle on one side of the spine of each of two rabbits, –5 cm from the midline and parallel to the spinal column, and about cm apart from each other. In a similar fashion implant two strips of USP High-Density Polyethylene RS in the opposite muscle of each animal. Insert a sterile stylet into the needle to hold the implant strip in the tissue while withdrawing the needle. If excessive bleeding is observed after implantation of a strip, place a duplicate strip at another site.Keep the animals for a period of not less than 120 h, and sacrifice them at the end of the observation period by administering an overdose of an anesthetic agent or other suitable agents. Allow sufficient time to elapse for the tissue to be cut without bleeding. Examine macroscopically the area of the tissue surrounding the center portion of each implant strip. Use a magnifying lens and auxiliary light source. Observe the Sample and Control implant sites for hemorrhage, necrosis, discolorations, and infections, and record the observations. Measure encapsulation, if present, by recording the width of the capsule (from the periphery of the space occupied by the implant Control or Sample to the periphery of the capsule) rounded to the nearest mm. Score encapsulation according to Table 6.Table 6. Evaluation of Encapsulation in the Implantation TestCapsule Width ScoreNone 0Up to mm1– mm2– mm 3Greater than mm4Calculate the differences between average scores for the Sample and Control sites. The requirements of the test are met if the difference does not exceed , or if thedifference between the Sample and Control mean scores for more than one of the four implant sites does not exceed 1 for any implanted animal.Subcutaneous Implantation in RatsPrepare for implantation 10 sample specimens and 10 control specimens. The size and shape of the control specimens shall be as similar to that of the test specimens as practically possible. For example, specimens made of sheeting material shall be 10–12 mm in diameter and from –1 mm in thickness. The edges of the specimens should be as smooth as possible to avoid additional mechanical trauma upon implantation.Test Animals— Select healthy albino rats weighing 225–350 g at the time of implantation.Procedure— Perform the test in a clean area. Anesthetize (see AAALAC guidelines) the animal until a surgical plane is achieved. Clip the fur of the animals on both sides of the spinal column. Remove loose hair by means of vacuum. Clean the clipped area with povidone–iodine solution. Using aseptic technique, make two midline incisions (approximately cm long) through the skin at the cranial and caudal regions on the dorsal surface. Using blunt dissection, separate the fascia connecting skin to muscle to form a pocket underneath the skin lateral to each side of the incision (base of pocket approximately 20 mm from the line of implant). Insert a sterile sample into each pocket, and close the incision with wound clips or sutures. Implant two test samples and two control samples in each of five rats. Keep the animals for a period of at least seven days, and sacrifice them at the end of the observation period by CO2 induced hypoxia or administering an overdose of an anesthetic agent. Allow sufficient time to elapse for the tissue to be cut without bleeding. Cut the skin (dorsal surface) longitudinally and lay back. Carefully examine macroscopically the area of the tissue surrounding the implant. Cut the sample in half and remove for close examination of the tissue in direct contact with the sample. Use a magnifying lens and auxiliary light source, if appropriate. Observe the Sample and Control implant sites for hemorrhage, necrosis, discolorations, and infections, and record the observations. Measure encapsulation, if present, by recording the width of thecapsule (from the periphery of the space occupied by the implant Control or Sample to the periphery of the capsule) rounded to the nearest mm. Score encapsulation according to Table 6. Calculate the differences between average scores for the Sample and Control sites. The requirements of the test are met if the difference does not exceed .SAFETY TESTS—BIOLOGICALSThe safety test set forth here is intended to detect in an article any unexpected, unacceptable biological reactivity. This in vivo test is provided for the safety assessment of biotechnology-derived products.Safety TestSelect five healthy mice not previously used for testing, weighing 17–23 g, unless otherwise directed in the individual monograph or elsewhere in this chapter, and maintained on an adequate balanced diet. Prepare a test solution as directed in the individual monograph. Unless otherwise directed in the individual monograph or elsewhere in this chapter, inject a dose of mL of the test solution into each of the mice, using a 26-gauge needle of suitable length, or of the length specified below as applicable. Observe the animals over the 48 h following the injection. If, at the end of 48 h, all of the animals survive and not more than one of the animals shows outward symptoms of a reaction not normally expected of the level of toxicity related to the article, the requirements of this test are met. If one or more animals die or if more than one of the animals shows signs of abnormal or untoward toxicity of the article under test, repeat the test using at least another 10 mice similar to those used in the initial test, but weighing 20 ± 1 g. In either case, if all of the animals survive for 48 h and show no symptoms of a reaction indicative of an abnormal or undue level of toxicity of the article, the requirements of the test are met. Body weights of mice before and at the end of the test should be obtained to detect any untoward effects. Animals that show signs of toxicity should be grossly necropsied and subjected to histopathology if necessary.For biologics, perform the test according to the procedures prescribed in the Code of Federal Regulations, Section .1USP High-Density Polyethylene RS.contacting USP.Topic/Question Contact Expert CommitteeGeneral Chapter Desmond G.Hunt, .Senior ScientificLiaison(301) 816-8341(GCPS2010) General Chapters - Packaging Storage and DistributionReference Standards RS Technical Services9USP38–NF33 Page 158 Pharmacopeial Forum: Volume No. 38(2)。
青蛙_1
——文章来源网，仅供分享学习参考
1 青蛙
在水池边，稻田里，小溪边都能看见青蛙的背影。
它的头扁扁的，像个三角形似的，嘴巴大大的，宽宽的，长长的舌头，还带着钩子。
它的眼睛大大的，鼓鼓的，只要你站着不动，它是看不见你的，你要是动了，它马上就会看见你在动。
在嘴角两边，有两个鼓瓤，只要它一动就会发出“呱呱呱‘’的声音。
它披着一件绿色的衣裳。
肚子是白白的，鼓鼓的，好像吃了好多虫子。
青蛙有4条腿，前腿较短，后腿较长。
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青蛙吃掉害虫，保卫庄稼，为人们做了不少好事，我们应该保护青蛙。
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