Chapter Eight

Chapter Eight

Microbiology

Passage 1

Introduction to Pharmaceutical Microbiology—

Microorganisms and Medicine

Despite continuing poverty in many parts of the world and the devastating effects of HIV and AIDS infection on the African continent and elsewhere, the health of the world's population is progressively improving.This is reflected in the increase in life expectancy that has been recorded for the great majority of the countries reporting statistics to the World Health Organization over the last 40 years. In Central America, for example, the life expectancy has increased from 55 years in 1960 to 71 years in 2000, and the increase in North (but not sub-Saharan) Africa is even greater, form 47 to 68 years.Much of this improvement is due to better nutrition and sanitation, but improved health care and the greater availability of effective medicines with which ti treat common diseases are also major contributing factors. Substantial inroads have been made in the prevention and treatment of cancer, cardiovascular disease and other major cause of death in Western society, and of infections and diarrhoeal disease that remain the big killers in developing countries. Several infectious diseases have been eradicated completely, and others from substantial parts of the world. The global eradication of smallpox in 1997 is well documented, but 2002 saw three of the world's continents declared free of polio, and the prospects are good for the total elimination of polio, measles an Chagas diseases.

The development of the many vaccines and other medicines that have been so crucial to the improvement in world health has been the result of the large investment in research by the major international pharmaceutical companies. This has led to the manufacture of pharmaceuticals becoming one of most consistently successful and important industries in many counties, not only in the traditional strongholds of North America, Western Europe and Japan but, increasingly, in Eastern Europe, the Indian subcontinent and the Far East.Worldwide sales of medicines and medical devices are estimated to have exceeded ＄U.S. 401 billion (approximately ￡250 billion) in 2002, and this figure is rising by 8％per annum. In the UK alone, the value of pharmaceutical exports is currently ￡10.03 billion each year, a figure that translates to more than ￡150,000 for each employee in the industry.

The growth of the pharmaceutical industry in recent decades has been paralleled by rising standards for product quality and more rigorous regulation of manufacturing procedures. In order to receive a manufacturing licence,a modern medicine must be shown to be effective, safe and of good quality. Most medicines consist of an active ingredient that is formulated with a variety of other materials (excipients) that are necessary to ensure that the medicine is effective, and remains stable, palatable and safe during storage and use.While the efficacy and safety aspects of the active ingredient are within the domain of the pharmacologist and toxicologist, respectively, many other disciplines contribute to the efficacy, safety and quality of the manufactured products as a whole. Analytical chemists and pharmacists take lead responsibility for ensuring that the components of the medicine are present in the correct physical form and concentration, but quality is not judged solely on the physicochemical properties of the product: microorganisms also have the potential to influence efficacy and safety.

It is obvious that medicines contaminated with potentially pathogenic (disease-causing) microorganisms are a safety hazard, so medicines administered by vulnerable routes (e.g. injections) or to vulnerable areas of the body (e.g. The eyes) are manufactured as sterile products.What is less predictable is that microorganisms can, in addition to initiating infections, cause product spoilage by chemically decomposing the active ingredient or the excipients. This may lead to the product being under-strength, physically or chemically unstable or possibly contaminated with toxic materials. Thus, it is cleat that pharmaceutical microbiology must encompass the subjects of sterilization and preservation against microbial spoilage, and a pharmacist with responsibility for the safe, hygienic manufacture and use of medicines must know where microorganisms arise in the environment, i.e. The sources of microbial contamination, and the factors that predispose to, or prevent, product spoilage. In these respects, the pharmaceutical microbiology has a lot in common with food and cosmetics microbiologists, and there is substantial scope for transfer of knowledge between these disciplines.

Disinfection and the properties of chemicals (biocides) used as antiseptics,disinfectants and preservatives are subjects of which pharmacists and other persons responsible for the manufacture of medicines should have a knowledge,both from the perspective of biocide use in product formulation and manufacture,and because antiseptics and disinfectants are pharmaceutical products in their own right. However , they are not the only antimicrobial substances that are relevant to medicine;antibiotics are major importance and represent a product category that regularly features among the top five most frequently prescribed. The term "antibiotic" is used in several different ways: originally an antibiotics was defined as a naturally occurring substance that was produced by one microorganism that inhibited the growth of, or killed, other microorganisms,

i.e. an antibiotic was a natural product, a microbial metabolite. More recently the term has come to encompass certain synthetic agents that are usually used systemically (throughout the body) to treat infection.A knowledge of the manufacture, quality control and, in the light of current concerns about resistance of microorganisms, the use of antibiotics, are other areas of knowledge that contribute to the discipline of pharmaceutical microbiology.

Commercial antibiotic production began with the manufacture of penicillin in the 1940s, and for many years antibiotics were the only significant example of a medicinal product that was made using microorganisms. Following the adoption in the 1950s of microorganisms to facilitate the manufacture of steroids and the development of recombinant DNA technology in the last three decades of the 20th century, the use of microorganisms in the manufacture of medicines has gathered great momentum. It led to more than 100 biotechnology-derived products on the market by the new millennium and another 300 or more in clinical trials. While it is true to say that traditionally the principal pharmaceutical interest in microorganisms is that of controlling them, exploiting microbial metabolism in the manufacture of medicines is a burgeoning area of knowledge that will become increasingly important, not only in the pharmacy curriculum but also in those of other disciplines employed in the pharmaceutical industry.

Looking ahead to the early decades of the 21st century, it is clear that an understanding of the physiology and genetics of microorganisms will also become more important, not just in the production of new therapeutic agents but in the understanding of infections and other diseases. Several of the traditional diseases that were major cause of death before the antibiotic era, e.g. tuberculosis and diphtheria, are now re-emerging in resistant form-even in developed

countries-adding to the problems posed by infections in which antibiotic resistance has long been a problem, and those like Creutzfeldt-Jakob disease, West Nile virus and severe acute respiratory syndrome (SARS) that have only been recognized in recent years.

Not only has the development of resistance to established antibiotics become a challenge, so too has the ability of microorganisms to take advantage of changing practices and procedures in medicine and surgery.Microorganisms are found almost everywhere in our surroundings and they posses the potential to reproduce extremely rapidly; it is quite possible for cell division to occur every 20 minutes under favourable conditions. These characteristics mean that they can adapt readily to a changing environment and colonize new niches. One feature of modern surgery is the ever-increasing use of plastic, ceramic and metal devices that are introduced into the body for a wide variety of purpose, including the commonly encountered urinary or venous catheters and the less common intra-ocular lenses, heart valves, pacemakers and hip prostheses. Many bacteria have the potential to produce substances or structures that help them to attach to these devices, even

while combating the immune system of the device in question—often leading to great discomfort for the patient and substantial monetary cost to the health-care service. It has recently been estimated that, on average,a hospital-acquired infection results in an extra 14 days in hospital, a 10％increase in the chance of dying and more than ￡3,000 additional expenditure on health care. The development of strategies for eliminating, or at least restricting, the severity or consequences of these device-relate infections is a challenge for pharmacist and microbiologists within the industry, and for many other health-care professionals.

In addition to an improved understanding of the mechanisms of antibiotic resistance, of the links between antibiotic resistance and misuse, and of the factors influencing the initiation of infections in the body, our insights into the role of microorganisms in other disease states have broadened significantly in recent years.Until about 1980 it was probably true to say that there was little or no recognition of the possibility that microorganisms might have a role to play in human diseases other than clear-cut infections. In recent years, however ,our preception of the scope pf microorganisms as agents of disease has been changed by the discovery that Helicobacter pylori is intimately involved in the development of gastric or duodenal ulcers and stomach cancer; by the finding that viruses can cause cancers of the liver, blood and cervix; and by the suspected involvement of microorganisms in diverse conditions like parkinsonism and Alzheimer's disease.

Clearly, a knowledge of the mechanisms whereby microorganisms are able to resist antibiotics,colonize medical devices and cause or predispose humans to other disease states is essential in the development not only of new antibiotics, but of other medicines and health-care practices that minimize the risks of these adverse situations developing.

Vocabulary

Alzheimer's disease 阿尔茨海默症

biocide 杀生物剂，杀虫剂，灭菌剂，生物杀生剂

cardiovascular disease 心血管疾病

cervix [拉]颈，子宫颈

Chagas disease 查加斯病，南美洲锥虫病

Creutzfeldt-Jakob disease 克罗伊茨菲尔特-雅各布病

diarrhoeal 痢疾病

duodenal ulcers 十二指肠溃疡

heart valves 心脏瓣膜

Helicobacter pylori 幽门螺旋杆菌

hip prosthes 髋关节假体，人工髋关节

intra-ocular lenses 眼内透镜，人造晶状体，眼内镜片

measles 麻疹，风疹，包虫病

pacemaker 起搏器，心律调整器

parkinsonism 帕金森综合症；震颤（性）麻痹

polio 脊髓灰质炎，小儿麻痹症

severe acute respiratory syndrome，SARS 严重急性呼吸器官综合

征；传染性非典型肺炎

smallpox 天花

tuberculosis 结核病，肺结核

urinary 泌尿的，含尿的；泌尿器的

venous 静脉的，在静脉中的

West Nile virus 西尼罗病毒，西尼罗病毒，西尼罗河脑炎病毒

药学微生物学介绍

——微生物和医药

虽然世界上许多地区依然贫困，在非洲大陆和其他地方艾滋病的感染依然严重，但是全球人类的健康在不断改善。这表现为人类预期寿命的增长，人类预期寿命是在过去40年间绝大多数国家记录并上报给世界卫生组织的统计数据。例如，在美国中部，人类的预期寿命从1960年的55岁增加到2000年的71岁，在北非（不包括亚撒哈拉地区）这一增长更加明显，从47岁增加到了68岁。这一进步主要归功于营养和公共卫生的改善，但是卫生保健的改善和治疗一般疾病的有效药物的广泛利用也是主要因素。在西方社会，已经对癌症、心血管疾病和其他引起死亡的主要疾病的预防和治疗才去了实质性的措施，而感染和痢疾仍是发展中国家的头号杀手。一些传染性疾病和那些来自世界上主要地区的传染性疾病都已经完全根除。1977年在全球范围内消灭了天花，2002年世界上三个大洲宣布消灭了脊髓灰质炎，这些前景对于完全消除脊髓灰质炎、麻疹和南美洲锥虫病都是十分有益的。

许多疫苗和其他药物在改善人类健康方面具有重要作用，这些疫苗和药物的研制是大部分国际医药公司在科研上巨大投资的结果。这使得药品生产在许多国家成为最能持续获得成功、最重要的产业之一，不包括传统的北美中心地、西欧和日本，而且东欧、印第安次大陆和远东也日益加入其中。全世界药品和医疗器械的销售额在2002年估计已经超过4010亿美元（约2500亿英镑），这一数字以每年8％的增幅上涨。仅在美国，现在每年的药物出口额达100.3银棒，相当于企业员工每人创造的兼职超过15万英镑。

制药工业在最近几十年的发展是与不断提高的产业质量标准和更加严格的生产操作规程想并行的。为了获得生产许可，现代医药必须显示出高效、安全和高品质的特征。大多数药物由活性成分和其他物质（辅料）按照配方制成的辅料，在储存和使用过程中对于保证药物的有效性、稳定性、适口性和安全性是必需的。虽然活性成分的有效性和安全性分别是药理学家和毒理学家的研究领域，但总体来讲许多其他学科对加工产品的有效性、安全性和质量都有所贡献。分析化学家和药剂师的只要责任是保证药物组分在药品中以正确的物理形式和浓度出现，但是质量不仅由产品的理化性质决定，微生物也具备影响药品效力和安全性的潜在

能力。

显然药物被潜在的致病（能引起疾病的）微生物污染是一种安全性的危害，所以轻易感染途径（例如：注射）给药或给予易感染部位（例如：眼睛）的药物都是以无菌制品的方式产生。除了引起感染之外，人们更难预见的是微生物能够以化学方法分解活性成分或辅料而引起产品变质。这会导致药物效力下降，物理或化学上的不稳定或可能被有毒的物质污染。因此，药物微生物学必须包括灭菌和防止微生物造成的腐败，药剂师负责药品的安全性，卫生生产和使用药品必须知道环境中微生物在哪里出现，也就是微生物污染的根源以及造成药品腐败的因素或者防止药品腐败的措施等。在这些方面，药物微生物学家和食品及化妆品微生物学家有许多相同之处，很多知识可在这些学科之间进行传递。

化学试剂（灭菌剂）由于其杀菌作用和性质可用作防腐剂，药剂师和其他负责生产消毒剂和防腐剂的人员应该具备相关知识，包括来自于灭菌剂产品组成和生产的各个方面，还因为防腐剂和消毒剂就其本身而言也是一种药物制剂。但它们不是唯一与药物相关的抗微生物制剂；抗生素是一大类重要的代表性药物，其在五大最常用处方中具有规律性的特征。在几个不同方面使用“抗生素”这一术语：最初抗生素被定义为由一种微生物自然产生的能够抑制其他微生物的生长或将其杀死的物质，也就是抗生素是微生物的自然代谢产物。近来这一术语已经包含某些用于治疗全身感染的合成制剂。药物微生物学不但包含生产和质量控制的相关知识，而且根据近来对微生物耐药性的关注，抗生素的合理使用也成为该门学科涉及的领域之一。

商品化的抗生素制品始于20世纪40年代青霉素的生产许多年来抗生素仍然是利用微生物生产药用产品的唯一重要实例。在20世纪50年代开始利用微生物促进类固醇的生产，20世

纪最后30年发展了重组ＤＮＡ技术，随后利用微生物生产药物获得了长足的发展。直至新千年１００多种的生物技术来源药品上市，另外其他３００多种或更多的药品进入临床试验阶段。虽然传统上制药业将兴趣主要集中在控制为生物上，利用微生物代谢产物来生产药物还处于萌芽阶段，但必将变得日益重要，这不仅体现在药学课程上，而且体现在那些从事制药工业涉及的其他学科上。

展望２１世纪的前几十年，不仅在新的治疗药物的产生方面，而且在理解感染和其他疾病的原因方面阐明微生物的生理学和遗传学将变得更加重要。在抗生素时代之前，一些曾经是主要死因的传统疾病，例如肺结核和白喉，现在甚至在发达国家又出现了其抗性形式，这加剧了长期存在的由于抗生素耐药性所带来的感染问题，以及那些类似痉挛性假性硬化、罗脑河炎病毒和严重性急性呼吸综合征（ＳＡＲＳ）等近来人们才有所认识的疾病问题。

不仅只有对已有的抗生素产生的耐药性成为一大挑战，而且微生物具有在内科和外科领域利用不断改变的实践和操作的能力也成为一大挑战。在环境中到处都有微生物存在，它们具有极其快速的复制潜力，再合适的条件下，完全可能没每２０ｍｉｎ细胞分裂一次。这些特点意味着微生物能快速适应不断变化的环境，并且拓展新的合适的生态环境。现代外科手术的特征之一是使用塑料制品、陶瓷制品和金属装置植入体内不断增多，其目的多种多样，包括常见的泌尿系统或静脉导管以及不常见的人工晶体、心脏瓣膜、起搏器和人工髋关节。许多戏剧化呢能够产生有助于其扶着在这些设备上的物质或结构，甚至于免疫系统抗争。因此，细菌的移升现象常使我们有必要去除去或替换上述这些设备，它们往往引起患者的不适并使保健服务花费大量金钱。最近的评估显示，平均来讲医院内获得性感染会导致患者多住院治疗１４天，死亡几率几乎增加１０％，并且在卫生保健上的额外支出超过３０００英镑。如何去除或者将这些因设备引起感染的严重性和后果降至最小是对该产业中药剂师和微生物

学家的挑战，同时也是对其他卫生保健同行的挑战。

近年来，除了更好的理解抗生素耐药性机制、抗生素耐药性与滥用的联系、影响引发机体感染的因子之外，人们对微生物在其他疾病状态下的作用有了进一步的了解。直到大概1980

年，人们才对微生物在人类疾病中除引起感染外的其他可能角色有所认识。然而近年来，人们对微生物作为病原菌范围的理解通过以下事实已有所改变：发现幽门螺旋杆菌或十二指肠溃疡及胃癌的发生密切相关；检测到能够引起肝癌、血癌和宫颈癌的病毒；在不同条件下有可疑微生物与帕金森综合症和阿尔茨海默病相关。

显然，了解微生物对抗生素产生耐药性的机制以及附着在医疗用具上引起感染或引起人类其他疾病的机制不仅对新型抗生素的研制是重要的，而且对于其他药物和能将这些不利情形的危害减少到最小的卫生保健措施而言也同样是重要的。

Passage 2

Microbiology Today

The late 1800s became know as the golden age of microbiology. Advances came rapidly and life was dramatically improved. But the advances that have continued to be made during the twentieth century have been no less striking. Let's look briefly at four key areas: chemotherapy,immunology, virology, and genetic engineering.

Chemotherapy

Probably the most significant advance in medical microbiology during the 1900s was the development of chemotherapy(treatment of disease with chemicals called drugs).

Nineteenth-century microbiologists discovered ways to prevent many infections, but not until the twentieth century did they acquire the ability to treat infections once they had stared.

The German physician-chemist Paul Ehrlich is called the father of chemotherapy because he articulated its guiding principle, that of selective toxicity. For a drug to be effective against infection, it must be selectively harmless to the affected human. Ehrlich conceived of drugs as being"magic bullets," agents that would strike and kill the microbe but miss the host completely. Ehrlich gave the fledgling science of chemotherapy its first success in 1908 by discovering a drug for the treatment of syphilis. He called his drug salvarsan, from the Latin word meaning "to save ." For more than 20 years syphilis was the only infectious disease that could be treated by chemotherapy.

Stimulated by Ehrlich's success, research in chemotherapy expanded. Sulfa drugs were the first major class of drug to come into widespread clinical use. Sulfas are synthetic drugs(organic chemicals manufactured in the laboratory). They were discovered in the 1930s when a German chemical company, I.G. Farben, began systematically testing various compounds as possible chemotherapeutic agents.

Antibiotics (chemotherapeutic agents produced by microorganisms) were discovered at about the same time. They proved to be more effective than the sulfas. The first medically useful antibiotic,penicillin, was discovered by the Scottish microbiologist Alexander Fleming

(1881-1995)in 1929. But it not come into widespread clinical use for another decade because of technical problems in purifying and mass-produc-ng it.In the 1940s however,during World War Ⅱ,intensive research made penicillin readily available.The dramatic effectiveness of penicillin gave it the well-deserved title "wonder drug."

Immunology

In the days of Pasteur and Koch, immunology was a branch of microbiology devoted to developing vaccines for preventing infectious diseases. Today, immunology is an independent and fast-developing science. Immune system is extremely complicated, delicate, and prone to defects. In following chapter we'll discuss the immune system, how its defects can cause disease, and the clinical applications of immune reactions and how they can be used to diagnose disease.

Virology

Virology, the study of viruses, began in 1892 when the Russian microbiologist Dmitri Iwanowski discovered the tobacco mosaic virus. Iwanowski was studying a disease of tobacco plants through filters that retained the smallest bacteria.He found the filtered juice still caused disease. Because bacteria were believed to be the smallest microorganisms,Iwanowski first thought his methodology might be flawed. But repeated experimentation convinced him that minute disease-causing agents were passing through the filter. He called these tiny agents "filterable viruses."They could not be seen,even under the most powerful microscope of that time. Until the electron microscope was developed in the 1930s, we knew viruses existed, but little more.

Genetic Engineering

Two properties of microorganisms have led to particularly exciting developments in the second half of the twentieth century. First, the metabolism and genetic properties of microorganisms are remarkably similar to those of plants and animals, including humans. Thus, what we learn about microorganisms is often directly applicable to higher forms of life. In fact, much of our knowledge of the fundamental properties of all living things came first from studies on bacteria can double their numbers every 20 minutes. The number of human being on Earth.We can thus study enormous numbers of organisms in an extremely short period of time and undertake experiments that would be impossible using larger, slower-growing organisms.

Intensive laboratory studies on microorganisms have led to the developments that would be impossible using larger,slower-growing organisms.

Intensive laboratory studies on microorganisms have led to the development of a remarkable set of techniques, collectively called genetic engineering or recombinant DNA technology.With

this technology researchers can manipulate DNA, the cell's genetic material, outside the organism from which it was obtained and reintroduce the modified DNA into another cell where it will exert its effect. The DNA can be taken from any organism, and fragments of itt from different organisms can be joined together. The organism that is most frequently used as the host for manipulated DNA is the bacterium Escherichia coli.For example,industry use E .coli to produce human insulin for the treatment of diabetes and human growth hormone for the treatment of pituitary dwarfism.

The potential of recombinant DNA technology seems almost limitless. We'll examine genetic engineering techniques and its use in following chapter.

The Future

As an active experimental science, microbiology is little more than a hundred years old. Its pattern of accelerating progress seems likely to continue. And the need is great. Medical microbiology and virology will need to solve pressing problems of resistance of pathogens to antibiotics and evolution of new disease.Daily we read about newly discovered strains of bacterial pathogens with increased resistance to known antibiotics. New antibiotics and other chemotherapeutic agents may be the answer, although some researchers emphasize enhancement

of the natural immune system.Whatever route researchers follow, they will depend heavily on recombinant DNA technology.

The other area that will expand rapidly in the future is environmental microbiology.We will rely increasingly on bioremediation (use of microorganisms to degrade toxic chemicals ) to clean up our environment.

The world of microorganisms is huge and diverse. The vast majority-probably more than 90 percent or micro-organisms hasn't yet been identified or named.Some of these unknown microorganisms may benefit us.Many new microorganisms are needed to attack the problems the twenty-first century will surely bring. But whether or not you plan to make microbiology your career, we hope you enjoy the trip through the world of microbes we are about to undertake.

微生物学的今天

众所周知，19世纪晚期是微生物学的黄金时期，进展飞速，同时人们的生活得到了显著的改善。但是这种一直持续到20世纪的发展势头又带来了更多的震惊。让我们来简要地看看这四个关键领域：化学疗法、免疫学、病毒学而后基因工程。

化学疗法

也学在20世纪医学微生物学领域更重大的发展要算是化学疗法的发展（用来治疗疾病的化学物质称为药物）。19世纪微生物学家就发现了预防感染的多种途径，但是直到20世纪他们才具备治疗感染的能力。

保罗欧利希是德国的内科医生兼化学家，他由于清楚地阐明了化学治疗的指导原理即选择毒性而被尊称为化学治疗之父。因为能够有效对抗感染的药物必须具有选择性毒性。也就是说，该种药物对引起感染的微生物而言必须是致命性的或有抑制作用的，而对被感染的人而言则

是相对无害的。欧利希把药物想成是“魔术弹”，它能够侵袭并杀死微生物，但却会完全错过宿主。欧利希提出了化学疗法的雏形，并在1908年发现治疗梅毒的药物而首次获得成功。他称这种药物为萨尔佛散，源自拉丁语，意为“解救”。20多年来，梅毒是唯一能够用化学疗法治疗的感染性疾病。

欧利希的成功极大地刺激了化学疗法这一研究工作的开展。磺胺类药物是第一个在临床上广泛使用的药物大类，属于合成药物（在实验室中生产的有机化合物），在20世纪30年代由德国一家化学药品公司I.G.Farben 首次公之于世，并对可能作为化学治疗药物的多种化合物开始了系统性的实验工作。

大约在同一时期发现了抗生素（由微生物产生的化学治疗药物），并证明它们比磺胺类药物更加有效。青霉素是第一个在医学上应用的抗生素，它是苏格兰微生物学家亚历山大弗莱明（1881-1955）于1929年首次发现的。但是由于在纯化和大量生产上的技术问题青霉素在接下来的10年中没有被广泛用于临床。然而，在20世纪40年代第二次世界大战期间，技术攻关使得青霉素被广泛使用。青霉素的这一戏剧性的效应带给它当之无愧的头衔“特效药”。免疫学

在巴斯德和科赫时代，免疫学作为微生物学的一个分支致力于研制预防感染性疾病的疫苗。今天，免疫学成为一门独立的并快速发展的学科。免疫系统是极其复杂精密的，且易于发生缺陷。在下面的章节里，我们将讨论免疫系统、免疫系统的缺陷如何导致疾病以及免疫反应的临床应用和疾病诊断中的应用。

病毒学

病毒学是研究病毒的，始于1892年俄国微生物学家德米特里?约瑟霍维奇?伊万诺夫斯基发现烟草花叶病毒。伊万诺夫斯基当时正在研究一种被称作烟草花叶病的烟草属植物疾病。为了鉴定其病因，他将患病植物的叶汁挤出并用能够节流最小细菌的滤器过滤，但发现滤过的叶汁仍然可使植物发病。因为当时认为细菌是最小的微生物，所以伊万诺夫斯基首先想到可能是自己的实验方法存在缺陷，但是反复试验使他确信微笑的致病物质是可以通过这种滤器的。他将这种很小的物质称作“可滤过病毒”。它们及时在当时最好的显微镜下也不可见，直到20世纪30年代发明了电子显微镜，我们才知道了病毒的存在，但仍然知之甚少。

基因工程

20世纪后50年，微生物的两大特征带来了激动人心的发展。首先，微生物的代谢和遗传特性与植物和动物，包括人类，非常相似。因此，我们从微生物获悉的知识经常可以直接应用于高等生物。事实上，我们对所有生物基本性质的认识大多首先源自对细菌的研究。其次，微生物，特别是细菌尤其适合实验研究：容易培养且生长迅速。在适当的条件下，一些细菌每20分钟就能倍增一代。在1毫升细菌培养液中，单个细菌的数目就能超过地球上人类的总数。因此，我们能够在非常短的实验周期内研究大量的生物体，这对于大型而生长缓慢的生物体是不能实现的。

基于微生物的实验室密集型研究发展起来一系列值得关注的技术，统称为基因工程或重组ＤＮＡ技术。应用这种技术，研究人员能够在体外对DNA——细胞的遗传物质进行操作，并且将被修饰的DNA导入其他细胞以发挥效应。DNA能够取自任何生物体，来自不同生物体的ＤＮＡ片段能够重新整合。对DNA进行操作常用的宿主是大肠杆菌。例如：工业上使用大肠杆菌生产人胰岛素治疗糖尿病，生产人生长激素治疗垂体性侏儒症。

重组DNA技术的发展潜力似乎是无限的。我们将在下面的章节进一步介绍基因工程技术。展望

微生物学作为一门活跃发展的实验性科学，历史不超过100年，其加速发展的势头似乎仍在继续，需求也很大。医学微生物学和病毒学需要迫切解决一下两大问题，包括病原菌对抗生素的耐药性问题和由病毒变异而带来的新的疾病。每天我们通过各种渠道得知新发现的细菌

病原体对已知的抗生素产生耐药的情况。新的抗生素和其他化学治疗药物也许就是答案，尽管有些研究人员在强调要增强人们的固有免疫系统。无论研究人员遵循什么样的研究途径，他们都离不开重组DNA技术。

将来快速发展的另一个领域就是环境微生物学。我们将日益依赖生物除污（使用微生物来降解有毒的化学物质）手段来净化我们的环境。

微生物的世界是巨大且多变的。绝大多数，也许是超过90％的微小生物还没有被鉴定或命名。这些未知的微生物或许对我们人类大有益处。许多新型微生物需要解决21世纪将要面对的问题。你可以自己思考你的事业，这需要奉献和兴趣。但无论你是否打算将微生物学作为你的事业，我们都希望你能够尽情徜徉在我们将要从事的微生物世界中。

Passage 3

Control of Bacterial Infection

Deaths from bacterial diseases have become a rare occurrence in the developed world in the last 50 years as a result of a number of measures designed to reduce the spread of (and even eradicate) pathogenic bacteria in our environment and to improve the health of the population. The importance of sanitation, good housing and nutrition in reducing the incidence of bacterial disease cannot be emphasized enough. Even before the introduction of vaccines and antibiotics, the reduction of diseases such as tuberculosis had occurred owing to public health measures which prevented the spread of the causative microorganism, Mycobacterium tuberculosis, between individuals. In the developing countries,where there is a lack of sanitation and a large incidence of malnutrition, bacterial diseases are still a major cause of death.

Vaccination has proved to be a useful way of protecting the individual, and the population,from a number of bacterial diseases. Vaccination, or active immunization, is the artificial introduction of antigens from a microbe into an individual, in a controlled way, leading to the stimulation of the immune system without the symptoms of the full-blown disease. This leads to the production of memory cells within the host so that on a second encounter with the microbe the immune system can generate a rapid antibody response thereby preventing infection. Vaccines may be whole cells or cellular fractions or inactivated bacterial toxins(toxoids). Both live and dead bacteria are use in vaccines. Live vaccines are more useful as they mimic more effectively the natural disease process,causing long-lasting immunity. However , the bacteria must be attenuated in some way so that they do not cause disease in the host. Although vaccines have been particularly useful in the control of disease such as diphtheria, tetanus and tuberculosis, there are many bacteria for which it has proven difficult to produce a safe, effective vaccine.Finally, passive immunization, the introduction of antibodies to a particular microbe, is used occasionally to protect against infection.

Molecules that inhibit the growth of or kill bacteria are called antibacterial agents. If these compounds are isolated from microbes they are called antibiotics. There are many millions of antibiotics, produced mainly by soil bacteria and fungi,that are active against bacteria but only a few can be used to control human bacterial disease. These few have the property of being toxic to bacteria but have no significant effect on the human host. The reason for this so-called selective toxicity is that the sites at which these antibiotics act are either unique to bacteria such as peptidoglycans or very different between prokaryotes and eukaryotes such as ribosomes and nucleic acid synthesis.

Some of the factors that affect antibiotic therapy are listed below:

●The antibiotic must reach the site of infection in the host.

●The antibiotic has to reach its target site in the cell. This is easier for antibiotics such as penicillin, which act on peptidoglycan than for those, like tetracycline, which must penetrate through the plasma membrane to reach their target sites, the ribosomes.

●Gram-negative bacteria are often intrinsically resistant to the action of antibiotics due to the presence of the outer membrane which acts as an additional barrier for the antibiotic to cross and protects the peptidoglycan.

●Broad-spectrum antibiotics are effective against a wide range of different Gram-positive bacteria and Gram-negative bacteria whereas other antibiotics may have only a narrow range.

●All the pathogenic bacteria must be eradicated from the host by either inhibiting the growth of the microbes (bacteriostatic antibiotics), which can then be removed by the immune systems, or by killing them directly (bactericidal antibiotics).

Antibiotics have proved to be of great benefit to humankind and have ensured that people no longer need die from diseases such as streptococcal scarlet fever or as a result of wound infections. However, there is a problem. Bacteria can become resistant to the action of antibiotics.However, there is a problem. Bacteria can become resistant to the action of antibiotics. The mechanisms by which they do this include the production of enzymes that break down the antibiotic, reduction in permeability to the antibiotic and alterations to the target site. Antibiotic resistance may arise by mutation but more often the genes for antibiotic resistance are transferred between bacteria by conjugation, transduction and transformation. Antibiotic resistance carried by plasmids has caused particular concern as these plasmids may carry genes that confer resistance ti many different antibiotics at the same time. Multiply-resistant bacteria are therefore becoming a problem, particularly in the hospital environment, and the fear is that it will not be long before there is a bacterial strain that is untreatable by all known antibiotics.

对细菌感染的控制

近50年来，在发达国家因为细菌感染而引起的死亡病例已很少出现了，这是由于在这些国家已实施了一系列措施来降低环境中病原茵的传播，甚至通过一些手段来根除这些病原菌，还有通过提高人们的健康水平，提高了人们对病原茵的抵抗能力。良好的卫生条件，住房和营养水平对减少细菌感染病的发生极为重要。甚至在疫苗和抗生素引进之前，由于采取了一些公共卫生措施阻止了致病茵在个体之间的传播，从而减少了细菌病的发生，比如结核杆菌引起的结核病。在发展中国家，由于卫生条件恶劣和营养不良，细菌感染引起的疾病仍是引起人死亡的一个主要原因。

预防接种被证实是保护个人和群体免受众多细菌感染的一种有效的手段。预防接种或主动免疫接种，就是指把来自某微生物的一种抗原人工接种到人体内，通过某种控制方法使其免疫系统产生免疫应答但不会导致人体致病。通过产生的免疫应答促使体内产生免疫记忆细胞，当再次遇到这种病原微生物时，其免疫系统则能快速地产生抗体反应，因而能够预防病菌感染。疫苗可以是完整的细胞也可以是细胞裂解物或灭活的细菌毒素（类毒素）。活的和死的细茵都可被用来做成疫苗。活茵疫苗可以更加有效地模拟自然致病过程，产生持久的免疫效应因而用途更为广泛。然而这种细菌必须通过某种方式减活，使其进入人体后不会致病。尽管疫苗对控制某些疾病如白喉、破伤风和结核病等特别有效，但实验证实仍有许多细菌很难被做成安全且有效的疫苗。另外，有时用被动免疫接种（即把抗体引入某种特定的微生物）来保护人体免受感染。

把抑制细菌增长或对细菌有杀灭作用的分子制剂称为抗茵剂。若其从微生物中分离制取则称其为抗生素。有几百万种抗生素，它们主要是由土壤中的细菌和真菌分泌产生。这些抗生素能主动抵抗某些细茵，但仅有少数几种能用于治疗人类由于细菌感染而引起的疾病。这少数几种抗生素对细茵有毒杀作用，但应用于人体则没有明显的效果，这种现象即为所谓的选择性毒性。出现选择性毒性的原因是抗生素对某些细菌作用的位点是唯一的，比如胞壁肽聚糖，或者抗生素在真核生物或原核生物细胞内（如核糖体，核酸合成）作用的位点完全不同所造成的。

影响抗生素治疗的一些因素如下所列：

抗生素必须能够到达体内的感染部位。

抗生素必须到达细胞的靶部位。这对于某些抗生素来说相对比较容易做到，如青霉素，其作用位点是细菌胞壁的肽聚糖。而对另外一些抗生素如四环素则难度稍大，因为它需要穿透细胞膜才能到达其发挥作用的靶位——核糖体。

革兰阴性茵经常会自发对抗生素的作用产生耐药性。因为这种细菌有一层外膜（即革兰阴性茵的细胞壁外层）包被，其作为对抗生素穿透的附加屏障从而保护这种抗生素发挥作用的位点——胞壁的肽聚糖。

广谱抗生素对多种不同的革兰阴性茵和革兰阳性菌都有效果，然而一些其他抗生素可

能仅作用于少数致病茵。

必须从寄主体内根除所有致病茵。可以通过抑茵剂抑制病菌在体内生长，然后通过人体免疫系统将其清除掉，也可以直接通过杀菌剂将这些病菌杀死。

抗生素确实给人类带来了诸多好处，并且能确保人们不再因患上某些如由链球菌所引起的猩红热和伤口感染引起的疾病而死亡。然而，存在一个问题，即细茵慢慢会对抗坐素产生耐药性。耐药性产生的机制是由于致病茵会分泌一些酶对抗生素进行分解，以此降低抗生素的穿透力和改变其作用的靶位。某些耐药性的产生可能由于基因突变所引起，但更为普遍的是耐药基因通常可以通过接合、转导、转化在病菌间进行传递。携带有耐药基因的质粒已引起人们的特别关注，由于这些质粒可将携带的耐药性基因同时转移给许多种不同抗生素耐药菌株。因此细菌会对多种抗生素产生耐药性（多重药物耐药细菌）问题日渐成为人们所关心的热点，尤其在当今的医疗环境下。令人恐惧的是不久的将来可能会出现一种所有已知抗生素都不能对付的致病菌株。

Passage 4

The Microbial World

What Is a Microbe?

A microbe is member of large, extremely diverse, group of organisms that are Iumped together on the basis of one property- the fact that, normally, they are so small that they cannot be seen without the use of a microscope, the word is therefore used to describe viruses, bacteria, fungi, protozoa and some algae. However, there are a few exceptions, for example, the fruiting bodies of many fungi such as mushrooms are frequently visible to the naked eye;equally some algae can grow to meters in length. Generally, microbes may be considered as fairly simple organisms. Most of the bacteria and protozoa and some of the algae and fungi are single-celled microorganisms, and even the multi-cells microbes do not have a great range of cell types. Viruses are not even cells, just genetic material surrounded by a protein coat, and are incapable of independent existence.

The science of microbiology did not start until the invention of the microscope in the mid 16th century and it was not until the late 17th century that Robert Hooke and Antoine van Leeuwenhoke made their first real breakthroughs on the role of microbes in the environment and medicine were made. Louis Pasteur disproved the theory of spontaneous generation (that living

organisms spontaneously arose from inorganic material) and Robert Koch's development of pure culture techniques allowed him to show unequivocally that a bacterium was responsible for a particular disease. Since then the science has grown dramatically as microbiology impinges on all aspects of life and the environment.

Prokaryotes and Eukaryotes

Within the microbial world can be found two different categories of cell type, prokaryote and eukaryote. Bacteria are prokaryotes: they lack a distinct nuclear membrane, the organelles associated with energy generation, such as mitochondria and Golgi apparatus, which are found in eukaryotes. Although the basic mechanisms of DNA replication, RNA synthesis and protein are the same in both prokaryotes and eukaryotes, there are difference in the components and enzymes involved.

The Importance of Microbiology

Microbes impinge on all aspects of life; just a few of these are listed below.

1. The Environment.Microbes are responsible for cycling of carbon, nitrogen and

phosphorus (geochemical cycles), all essential components of living organisms. They are found in association with plants in symbiotic relationships, maintain soil fertility and may also be used to clean up the environment of toxic compounds (bio-remediation). Some microbes are devastating plant pathogens, which destroy important food crops, but others may act as biological control agents against these diseases.

2. Medicine. The disease-causing ability of some microbes such as smallpox (Variolavirus),

cholera (Vibrio cholera bacteria ) and malaria (Plasmodium protozoa) is well known. However, microorganisms have also provided us with the means of their control in the form of antibiotics and other medically important drugs.

3.Food. Microbes have been used for thousands of years, in many processes, to produce food,

from brewing and wine making, through cheese production and bread making, to the manufacture of soy sauce. At the other medically important drugs.

4.Biotechnology. Traditionally microbes have use to synthesize many important chemicals

such as acetone and acetic acid. More recently, the advent of genetic engineering techniques has led to the cloning of pharmaceutically important polypeptides into microbes, which may then be produced on a large scale.

5.Research. Microbes have been used extensively as model organisms for the investigation of

biochemical and genetical processes as they are much easier to work with than more complex animals and plants. Millions of copies of the same single cell can be produced in large numbers very quickly and at low cost to give plenty of homogeneous experimental material. An additional

advantage is that most people have no ethical objections to experiments with these microorganisms.

微生物世界

什么是微生物？

微生物是大量的、极其多样的且基于个体微小这一共性而聚集在一起有机生物群体。通常这些有机生物个体很小，不借助显微镜肉眼根本不可能看到。因此，微生物用来表示病毒、细菌、真菌、原生生物和一些藻类。但也有一些例外，如许多真菌的子实体（例如像蘑菇通常用内眼就可以看得到。还有一些藻类有时能长到几米长）。通常，人们把微生物看作非常简单的有机体。大多数细菌和原生生物、一些藻类和真菌是单细胞微生物。即使多细胞微生物也只具有为数不多的几种细胞类型。病毒甚至不能称之为完整的细胞，它在结构上仅仅是遗传物质外包被一层蛋白质外壳，并且不能独立生存。

微生物作为一门科学，直到16世纪中期随着显微镜的发明和17世纪末罗伯特虎克和列文虎克第一次做出了关于真菌、细菌和原虫的记录才开始。微生物学在环境和医学应用方面的第一次真正突破是在19世纪后期。法国科学家巴斯德不赞同“生命体自然产生的理论”（也即无生命的物质可自发生长出有生命的生物体）和柯赫建立了微生物纯培养技术使得其毫无争议地明确表明细菌是导致某种特殊疾病发生的原因，从那时起，随着微生物学对生命活动和环境等各个方面的影响，这门学科也随之快速发展。

原核坐物和真核生物

在微生物世界里有两种不同的细胞类型：原核细胞和真核细胞（原核生物细胞和真核生物细胞）。细菌属于原核生物：它们没有明显的核膜。而在真核生物细胞内可发现有与产生能量有关的细胞器，如线粒体和叶绿体，另外还有具有复杂核膜结构的细胞器如内质网和高尔基体。尽管原核生物和真核生物的DNA复制、RNA合成和蛋白质合成的基本机制相同，但在此过程中所涉及的参加反应分子和酶有所差别。

微生物的重要性

微生物影响人类生活的各个方面，举例如下：

1．对环境的影响微生物参与碳、氮和磷的物质循环（也称地球化学循环），而碳、氮和磷是活的有机体的重要组成部分。它们可以与植物共生生长，维持土壤肥力，也可被用来清除环境中的有毒化合物（即生物除污）。一些微生物是危害重要粮食作物的具有破坏作用的植物病原，但同时另外一些微生物可作为生物防治媒介来控制这些植物病害。

2．在医学上的应用某些微生物的致病能力是众所周知的，如天花病毒所致的天花、霍乱弧茵所引起的霍乱和疟原虫所传播的疟疾。然而，也可以利用微生物生产抗生素和其他重要的医疗药物来控制这些疾病。

3．在食品方面的应用千百年来人们已使用微生物通过各种加工过程来生产食物，如从乳酪生产和面包制作、酿造术和葡萄酒制作，到酱油的生产等都离不开微生物。从另一个角度来看，某些微生物可导致食物腐败变质，一些食品上经常携带有致病微生物。

4．生物技术上的应用传统意义上微生物经常被用来合成许多重要的化学制品，如丙酮、乙酸等。但最近以来，随着基因工程技术的应用，可使某些药学应用中重要的多肽片段利用微生物进行克隆，进而可进行大规模生产。

5．在科学研究中的应用由于微生物此结构更加复杂的动植物易于操作，因此被广泛用做模式生物应用于生物的生物化学和遗传特性等的研究。用这种手段可以快速生产出无数单细胞克隆且可用较低的成本得到大量均一的实验材料。另一个优点就是，基于伦理道德方面的考虑大多数人并不反对用微生物来进行实验研究。

Additional Vocabulary in Microbiology

A

acetobacter suboxydans 弱氧化醋酸杆菌

acid and alkali 酸和碱

acquired immune deficiency syndrome，AIDS 艾滋病acquired resistance 获得性耐药性

actinomadura 马杜拉放线菌属

actinomycetes 放线菌

actinomycetes bovis 牛型放线菌

actinophages 放线菌噬菌体

actinoplanes 游动放线菌属

active transport 主动运输

adenoviruses 腺病毒

adjuvant 佐剂

aerial mycelia 气生菌丝体

aerobic microorganism 好养性微生物

aflatoxin 黄曲霉毒素

agar 琼脂

agar diffusion 琼脂扩散

agar diffusion test 琼脂扩散法

agar dilution method 琼脂稀释法

agaricus 伞菌，伞菌属

agaricus bisporus 二孢蘑菇

agglutination reaction 凝聚反应

agglutinin 凝聚素

agglutinogen 凝聚原

alcohol 醇类

algal viruses 藻类病毒

alkylating agent 烷化剂

alkylpolyoxyethlene alcohol emulsifiers 碱性多样乙烯醇乳化剂allergen 变应原

allergy 变态反应

allicin 蒜素

amanita phalloides 毒鹅膏

amanitin 鹅膏素

ames test 试验法

amphotericin 两性霉素

anaerobic microorganism 厌氧性微生物anastomosis 菌丝联锁现象anisogametes 异形配子

annulus 菌环

ansamitocin 安莎美登素

anertior-posterior polarity 前后极性anthrax 炭疽

antibiotics 抗生素

antibody 抗体

antigen，Ag 抗原

antigenic determinant 抗原决定簇antigenicity 抗原性

antimicrobial test in vitro 体外抗菌实验antimicrobial test in vivo 体内抗菌实验antimicrobial agent 抗菌剂

antiseptic agent 防腐剂

antitoxin 抗毒素

antiviral state 抗病毒状态

aplanospores 不动孢子

apothecium 子囊盘

arthrospores 节孢子

artificial immunity 人工免疫

artificial active immunization 人工自动免疫artificial passive immunity 人工被动免疫ascomycetes 子囊菌纲

ascospore 子囊孢子

ascus 子囊

ashbya gossypii 棉病囊度

aspergillus 曲霉属

aspergillus flavus 黄曲霉

aspergillus nidulans 构巢曲霉素

assembly 配装

attachment and adsorption 附着和媳妇

attenuated strain 减毒菌株

auricularia 木耳属

autoclave 高压灭菌法

autonomous state 自主状态

auxangraph 生长谱

average yield of phage 噬菌体平均收获量

axial fibrils，F 轴纤丝

B

bacillus 杆菌，好气性腰包杆菌属

bacillus anthracis 炭疽芽孢杆菌

bacillus mycoides 覃状芽孢杆菌

bacillus steatothermophilus 嗜热脂肪芽孢杆菌bacillus subtilis var.niger 或B.globigii 枯草杆菌突变株bacillus thuringiensis 苏云金杆菌

bacitracin 杆菌肽

bacteremia 菌血症

bacteria chromosome 细菌染色体

bacterial antigen 细菌抗原

bacterial toxins 细菌毒素

bactericidal 杀菌的

bactericidal agent 杀菌剂

bacteriolytic agent 融菌剂

bacteriostatic 抗菌剂

bacteriostatic agent 抑菌剂

balanced growth 平衡生长

base plate 基板

basidiocarp 担子果

basidiomycetes 担子菌纲

basidiospores 担孢子

batch culture 分批培养

bifidobacterium 双歧杆菌属

bifidobacterium bifidum 两歧双歧杆菌

biological antagonism among normal microbial flora 正常菌群的拮抗作用biomass 生物量

biphasic growth 或diauxie 双向生长

bleomycin 博来霉素

blood-brain barrier 血脑屏障

boiling 煮沸法

bone marrow 骨髓

bone marrow dependent lymphocyte 骨髓依赖淋巴细胞

borrelia 疏螺旋体属

bromodeoxyuridine，BUDR 溴脱氧尿嘧啶核苷

broth dilution method 液体稀释法

budding spore 芽生孢子

burning，incineration 焚烧

bursa of fabricius 法氏囊

burst size 爆破量

butyriolbrio 丁酸弧菌属

C

calvacin 马勃素

calvatia 马勃属

candida 假丝酵母属

candida tropicalis 热带加斯酵母

capnophiles 嗜二氧化碳细菌

capsid 衣壳

capsome 衣壳粒

capsule 荚膜

carbohydrate fermentation test 单糖发酵试验

carbohydrate utilization test 碳源利用实验

carbon source 碳源物质

cattier 带菌者，载体

cellular immunity 细胞免疫

central immune organ 中枢免疫器官

cephalosporins 头孢菌素

chemical protective action 化学保护作用

Chapter1会计概论答案

第一章会计透视：会计信息及其使用者▓复习思考题 1．概述会计的性质。 会计是按照会计规范确认、计量、记录一个组织的经济活动，运用特定程序处理加工经济信息，并将处理结果传递给会计信息使用者的信息系统，是组织和总结经济活动信息的主要工具。 会计是一个信息系统，会计处理的各个环节的加工的对象是会计信息。会计信息实际上是一种广义的信息，包含三个层次： 其一，以货币化指标体现的财务信息，它是从动态、静态两个角度，对特定主体经济资源的数量（资产）、归属（负债、所有者权益）、运用效果（收益分配）、增减变化及其结果（财务状况变动及其结果）进行描述； 其二，非货币化的和非数量化的说明性信息，它们不仅仅是对主体的财务状况、经营成果等财务指标的基本说明，而且还包含了大量的主体所处的社会、文化、道德、法律等环境信息，这些信息对于使用者正确判断主体的经营能力、发展前景，往往起到至关重要的作用； 其三，其他用于主体内部管理的信息，这些信息常常由成本会计、管理会计以及内部审计人员提供，主要包括了短期（长期）决策信息、预算信息、责任中心要求及履行情况等情况，虽然与外部性较强的财务会计信息相比，它们更容易为人们所忽略，但在经济管理和财务信息质量控制方面，它们也起了不可低估的作用。不过，在当前的会计报告模式中，所反映的会计信息主要是前两个层次上的信息。 2．企业的获利能力是否为债权人的主要考虑因素？ 债权人关心那些影响自己的债权能否得到按期偿还的因素。他们会对公司的获利能力及清偿能力感兴趣。债权人会从获利能力去衡量未来的现金流量，由于企业的获利能力与现金流量并不一定同步产生，所以对短期债权人来说，企业的获利能力不能成为债权人的主要考虑因素，但对相对长期的债权人来说获利能力应该是值得更加关注的因素。 3．财务报表中体现出来的会计信息用以满足不同使用群体的需求，但并不是所有的使用者都能得到相同的满足的。在实践中，外部财务报表使用者诸如股东、供应商、银行等是如何获得有关公司的财务信息的？若要同时满足不同类别的财务报表使用者的信息需求有什么困难？ 首先，股东是公司法定的所有者，法律上财务报表是为其制作的。法律规定，公司必须定期编制并发布财务报表，为其股东公布财务信息，我国《公司法》对此也有明确的规定。 其次，供应商与公司是商业伙伴关系，不提供商业信用的供应商，由于是钱货两讫，可通过报媒和网络了解公司公开财务的财务信息，如果供应商对公司提供商业信用，供应商可要求企业提供一定的财务信息，但对这些财务信息的准确性、可靠性需要有一定的分析。

Chapter Eight Time as communication

Chapter Eight Time as communication Learning objective: .By the end of the chapter, you should be able to understand time is a personal phenomenon, and how we perceive and treat it that expresses our character. .How members of different cultures value and respond to time. .Understand the three perspectives (informal time, perceptions of past, present, and future and Hall’s monochronic and polychronic classifications) and their reflection in different cultures and learn to determine a culture’s conception of time from three different perspectives mentioned above. Warm-up activities In a small group, read the following paragraph and explain what went wrong, have a discussion on the questions. Jan was in Brazil on business. Ciro a Brazilian associate, invited her to a dinner party he and his wife were giving. The invitation was for “around 8, this Friday night.”Jan arrived at Ciro’s house at exactly 8:00. Ciro and his wife were still dressing and had not even begun to prepare the food. Why did these problems take place? What are some common problems when treating appointment? What do you think theCiro and his wife’s time concept? Reading Reading1 Time Orientation When Shakespeare wrote “The inaudible and noiseless foot of Time,’’ we cannot hold or see time, we respond to it as if it had command over our lives. Because time is such a personal phenomenon, all of us perceive and treat it in a manner that expresses our character. If we arrive thirty minutes late for an important appointment and offer no apology, we send a certain message about ourselves. Telling someone how guilty we feel about our belated arrival also sen ds a message. A culture’s use of time can also provide valuable clues to how members of that culture value and respond to time. In America, we hear people saying, “Time is money” and “He who hesitates is lost.” All Chinese know the Confucian proverb, “Think three times before you act.” Reflect for a moment on how differently each of these cultures perceives time. A culture’s conception of time can be examined from three different perspectives:(1) informal time; (2) perceptions of past, present, and future; and (3) Hall’s monochronic and polychronic classifications. Informal Time: Most of the rules for informal time, such as pace and tardiness, are not explicitly taught. Like most of culture, these rules usually function below the level of consciousness. Argyle makes much the same point when he compares cultural differences in punctuality standards: How late is “late”? This varies greatly. In Britain and America only maybe 5 minutes late for a business appointment, but not 15 and certainly not 30 minutes late, which is perfectly normal in Arab countries. On the other hand in Britain it is correct to be 5-15 minutes late for an invitation to dinner. An Italian might arrive 2 hours late, an Ethiopian after, and a Javanese not at all—he had accepted only to prevent his host from losing face. Our reaction to punctuality is rooted our cultural experiences. In the United States, we have

语言学教程第八章知识点

Chapter Eight Pragmatics ?Definition ?Pragmatics is generally the study of natural language understanding, and specifically the study of how context influences the interpretation of meanings. In another word it is the study of the relationship between symbols and their interpreters. ?In 1937,the American philosopher Charles William Morris introduced the word “Pragmatics” into literature. ?莫里斯（C.Morris）和卡耐基（R.carnap）在1938年《符号基础理论》中 提出符号三分说： ?句法学（符号关系学）Syntactics 是研究符号与符号之间的关系；语义 学semantics是研究符号与符号所指对象的关系；语用学pragmatics则是研究符号与符号解释者的关系。 ?Teaching Focus ? 1. Some basic notions ? 2. Speech act theory ? 3. The theory of conversational implicature ? 4. Post-Gricean Developments ? 1. Some basic notions ? 1.1 The definition of pragmatics ? 1.2 Pragmatics and semantics ? 1.3 Context ? 1.4 Sentence and utterance ? 1.1 The definition of pragmatics ?Various definitions: ?The study of how speakers of a language use sentences to effect successful communication. ?The study of language in use. ?The study of meaning in context. ?The study o f speakers’ meaning, utterance meaning, & contextual meaning. ? 1.2 Pragmatics and semantics ?Both semantics and pragmatics study the meaning of language.

ChapterEightSemantics---WordMeani

Chapter Eight Semantics --- Word Meaning and Sentence Meaning 0. Introduction 0.1 Definition: Semantics is the study of linguistic meaning: the meaning of words, phrases, and sentences. 0.2 Sub-branches: i. Lexical semantics: Lexical semantics deals with word meaning. ii. Sentence semantics: Sentence semantics deals with sentence meaning. ii. Two types of meaning: In general, we may say that a linguistic form has two types of meaning: denotation（外延意义）and connotation（内涵意义）. A. The denotative meaning of a linguistic form is the person, object, abstract notion, event, or state which the word or sentence denotes. B. The connotation of a linguistic form has to do with its overtones of meaning, that is, what the linguistic form suggests. Such overtones may be good or bad, and thus we can speak of a positive connotation褒义内涵and a negative connotation 贬义内涵.

chapter1_参考答案

1.计算机存储数据的基本单位是（） A.bit B.Byte C.字 D.字符 2.多年来，人们习惯于以计算机主机所使用的主要元器件的发展进行分代，所谓第四代计 算机使用的主要元器件是（） A.电子管 B.晶体管 C.中小规模集成电路 D.大规模和超大规模集成电路 3.在计算机的不同发展阶段，操作系统最先出现在（） A.第一代计算机 B.第二代计算机 C.第三代计算机 D.第四代计算机 4.运算器的主要功能是进行（） A．只做加法 B．逻辑运算 C．算术运算和逻辑运算 D．算术运算 5.计算机硬件的五大基本构件包括运算器、存储器、输入设备、输出设备和（） A.显示器 B.控制器 C.磁盘驱动器 D.鼠标器 6.关于冯.诺依曼计算机，下列说法正确的是（） A.冯.诺依曼计算机的程序和数据是靠输入设备送入计算机的寄存器保存的 B.冯.诺依曼计算机工作时是由数据流驱动控制流工作的 C.冯.诺依曼计算机的基本特点可以用“存储程序”和“程序控制”高度概括 D.随着计算机技术的发展，冯.诺依曼计算机目前已经被淘汰 7.冯.诺依曼计算机的核心思想是（），冯.诺依曼计算机的工作特点是（） （1） A.采用二进制B.存储程序 C.并行计算 D.指令系统 （2） A.堆栈操作 B.存储器按内容访问 C.按地址访问并顺序执行指令 D.多指令流单数据流 8.一个完整的计算机系统包括（） A.主机、键盘、显示器 B.主机及外围设备 C.系统软件与应用软件 D.硬件系统与软件系统 9.下列软件中，不属于系统软件的是（） A．编译软件 B．操作系统 C．数据库管理系统

D．C语言程序 解析： 计算机的软件分为系统软件和应用软件。系统软件是为了计算机能正常、高效工件所配备的各种管理、监控和维护系统的程序及其有关资料。系统软件主要包括如下几个方面：（1）操作系统软件，这是软件的核心 （2）各种语言的解释程序和编译程序（如BASIC语言解释程序等） （3）各种服务性程序（如机器的调试、故障检查和诊断程序等） （4）各种数据库管理系统（FoxPro等） 10.某单位的人事档案管理程序属于（） A.工具软件 B.应用软件 C.系统软件 D.字表处理软件 11.下列选项中，描述浮点数操作速度的指标是（） A.MIPS B.CPI C.IPC D.MFLOP 12.半个世纪以来，对计算机发展的阶段有过多种描述。下列说法中，比较全面的描述是（） A.计算机经过四个发展阶段，电子管阶段、晶体管阶段、集成电路阶段、超大规模集 成电路阶段 B.计算机经过四段发展，即大型机、中型机、小型机、微型机 C.计算机经过三段发展，即大型机、微型机、网络机 D.计算机经过五段发展，即大型机、小型机、微型机、局域网、广域网 13.下列叙述错误的是（） A.把数据从内存传输到硬盘叫写盘 B.把源程序转换为目标程序的过程叫编译 C.应用软件对操作系统没有任何要求 D.计算机内部对数据的传输、存储和处理都是用二进制 14.计算机的存储单元中存储的内容是（） A.数据和指令 B.只能是指令 C.只能是数据 D.数据或指令 15.某台微型计算机的内存容量为128M，一般指的是（） A.128Mbit B.128MB C.128M字 D.128 000K 解析：内存容量是以字节为计算单位的，8个二进制位称为1个字节，1Byte＝8bit，1KB=1024B，1MB=1024KB，1GB=1024MB，1TB=1024GB。 16.在计算机领域中通常用MIPS来描述（） A.计算机的可运行性 B.计算机的运算速度

写作篇 Chapter Eight

---------------------------------------------------------------最新资料推荐------------------------------------------------------ 写作篇Chapter Eight Progressive WritingPart Eight Sentence Errors 1/ 31

遣词造句中的常见错误大学英语教学实践及历年CET-4作文考试表明，我们在作文方面普遍存在“词不达意”、“语法结构混乱”、‘‘思想表达不清”、“主题不突出”等问题。 以下是用词及句子结构方面的典型错误。

---------------------------------------------------------------最新资料推荐------------------------------------------------------ 1. 结构不完整[例1]原句：I look for ward to holidays．For example，theMid-Autumn Festival and the Spring Festival．分析：斜体部分可以是句子的一个成分，但不能独立成句。 试改：I look for ward to holidays like the MidAutumn Festival and the Spring Festival．[例2] 原句：I refused to go to the show. Because I had been up late last night and needed sleep. 分析：斜体部分是原因状语从句，不能独立存在。 试改：I refused to go to the show because I had been up late last night and needed sleep 3/ 31

Chapter 1 电路模型和电路定律

Chapter 1 电路模型和电路定律 一、填空题 1. 在电路分析计算中，必须先指定电流与电压的__ __，电压与电流的参考方向可以独立地_ __。 2. 某元件的电压、电流参考方向如图1－1a所示，相应的电压－电流关系如图1－1b所示。该元件 是__ __元件，其原参数值为__ __（写出单位）。 3. 线性电阻上电压u与电流i关系满足__ __定律，当两者取关联参考方向时其表达式为__ __。 4. 若电压与电流的参考方向取非关联，线性电阻的电压与电流关系式是__ __。 5.若电流的计算值为负，则说明其真实方向与__ __相反。 6.电感是一种记忆元件，因为i ＝__ __。 7.电感是一种储能元件，因为其储存的能量W =__ __。 8.电容是一种记忆元件，因为u＝_ ___。 9.电容是一种储能元件，因为其储存的能量W =__ __。 10.在直流电路中，电感相当于_ ___，电容相当于__ __。 11.电压源的定义式为_ ___，其端口电压与电流_ ___。 12.电流源的定义式为__ __，其发出电流与端口电压__ __。 13.基尔霍夫定律与电路的__ __有关，而与___ _无关。 14.KVL实际上是体现了_ ___与__ __无关的性质。 15.KCL实际上是体现了_____ ___的性质。 16.支路电压等于__ __节点电压之差，它与__ __无关。 17. 独立电压源的电压可以独立存在，不受外电路控制；而受控电压源的电压不能独立存在，而受_ ___的控制。 18.理想电压源的伏安特性是一条平行于__ __的直线。 19.理想电流源的伏安特性是一条平行于__ __的直线。 20.线性电阻的伏安特性是一条__ __的直线。 21.线性电感的韦安特性是一条__ __的直线。 22.线性电容的库伏特性是一条__ __的直线。 二、选择题 1.图1－2所示电路中，属于线性电阻的伏安特性曲线是图（）。 2. 图1－3所示 电路中，已知电阻 > R，i u P=，则下列正确的关系式是（）。

Chapter Eight Packing and Shipment

Chapter Eight Packing & Shipment Exercises I.Put in the missing words: Dear Sirs， We thank you ____ your Letter of Credit No.F-120 amounting ____ US $ 1,050,000 issued in our favor through The Hong Kong & ShangHai Banking Corporation. ____ regard to shipment, we regret very much to inform you that, despite strenuous efforts having been ____by us, we are still unable to book space of a vessel sailing ____Jakarta direct. The shipping companies boat told us that, ____ the time being, there is no regular boat sailing between ports in possible, for us to ship these 10,000 metric tons of sugar to Jakarta direct. In view ____ the difficult situation faced by us, you are requested to amend the L/C to allow transshipment of the ____ in Hong Kong where arrangements can easily be made ____ transshipment. Since this is something beyond ____control, your agreement ____our request and your understanding of our position will be highly appreciated. We are anxiously awaiting the amendment ____ the L/C. Yours faithfully, II.Fill in the blanks: 1)Owing ___ the delay ___ the part of the suppliers, we must ask you to

语言学第八章

Chapter Eight Exercise I. Choose the best answer. 1. What essentially distinguishes semantics and pragmatics is whether in the study of meaning ______ is considered. A. reference B. speech act C. practical usage D. context 2. “Logic and Conversation” was written by ______. A. H.P. Grice B. William James C. Stephen Levinson D. John Austin 3. According to the conversational maxim of _______ suggested by Grice, one should speak truthfully. A. quantity B. quality C. relevance D. manner 4. Speech act theory did not come into being until _____. A. in the late 50’s of the 20the century B. in the early 1950’s C. in the late 1960’s D. in the early 21st century 5. ____ is the act performed by or resulting from saying something; it is the consequence of, or the change brought about by the utterance. A. A locutionary act B. An illocutionary act C. A perlocutionary act D. A performative act 6. All of the following are characteristics of implicature EXCEPT_______. A. conventionality B. cancellability C. non-detachability D. calculability 7. The theory of meaning which relates the meaning of a word to the things it refers to or stands for is known as the ________. A. An integrated Theory B. Speech Act Theory C. The Conceptual Theory D. The Referential Theory 8. Which of the following can best describe the relationship between “They have six cows” and “They have some animals”? _______ A. presupposition B. synonym C. antonym D. entailment 9.In which of the following aspects conversational implicature theory and speech act theory are different ? A. how contextual meaning is generated. B. how much the implied meaning is dependent on the context. C. how much role the conventional meaning of words plays. D.how indeterminate the implied meaning is. 10.‘I hereby declare the starting of the war’ reflects the ______ function of language. A. informative B. interpersonal C. performative D. emotive 11.Which of the following statements is true about John Langshaw Austin ? A. He classified the following five types of speech acts performed by sentences: representative, directive, interrogative, expressive and declarative acts. B. He accounted for why people always spoke indirectly in daily conversation. C. He finally realized that there was no clear boundary between performatives and constatives. D. Austin proposed the felicity conditions to stress performatives can be true or false.

语言学Chapter Eight Pragmatics

Chapter Eight Pragmatics Aims: ? To know what is pragmatics and its main concern; ? To have a general idea about context and the notions of deixis, reference and anaphora; ? To understand the Speech Act theory, the Cooperative Principles in Conversation and Politeness Principles in Conversation. ⅠIntroduction Pragmatics is concerned with the interpretation of linguistic meaning in context. Two kinds of contexts are relevant. When we read or hear pieces of language, we normally try to understand not only what the words mean, but what the writer or speaker of those words intended to convey. Take a look at the following dialogue: 1 A: I have a fourteen-year-old son. B: Well that?s all right A: I also have a dog. B: Oh I?m sorry. In making sense of the quote above, it may help to know that A is trying to rent an apartment from B. the real meaning is beyond the literal interpretation. It seems that pragmatics is the study of …invisible? meaning, or how we recognize what is meant even when it isn?t actually said/written. In order for that to happen, speakers/writers must be able to depend on a lot of shared assumptions and expectations. The investigation of those assumptions and expectations provides us with some insights into how more gets communicated than is said. ⅡContext It can be seen from the above discussion that context plays a very import role in making sense of utterances we hear. There are different kinds of context to be considered. One kind is best described as linguistic context, also known as co-text. The context of a word is the set of other words used in the same phrase or sentence. For example, the word bank is a homonym, a form with more than one meaning. How do we usually know which meaning is intended in a particular