being closed – закрываемый, закрывающийся, будучи закрыт(-ым) (= когда закрыли)
having closed – закрыв
having been closed – так как (после того как) был закрыт
closed – закрытый, закрываемый, когда (так как) закрыт
Participle I expresses simultaneous action with the main verb.
· While making the experiment, he broke some glassware.
· The substance being investigated can be used in our further work.
Perfect participle expresses the action preceding the action expressed by the main verb:
· Having investigated all the properties they could state that those gases were harmful.
· Having been cooled to a very low temperature many substances acquire quite new properties.
Participle II has the meaning of the passive voice.
· When asked about his work, he couldn’t say anything.
· A piece of iron placed in the container with acid diminishes in mass.
NB! Pay attention to the translation of some special cases of Participle II.
· The question involved is to be solved today.
Вопрос, о котором идет речь, должен быть решен сегодня.
Данный вопрос должен быть решен сегодня.
· The discovery followed by many experiments resulted in new investigations in chemistry.
Открытие, за которым последовало много экспериментов, привело к новым исследованиям в области химии.
· When (if) heated, water turns into steam.
При нагревании (когда воду нагревают) вода превращается в пар
Ex.1. Choose the correct form of the Participle.
1. Magnesium is not attacked by water despite favorable potential unless (having been amalgamated, amalgamated, having amalgamated). 2. Many ethers take up oxygen from the atmosphere (having formed, forming, having been formed) peroxy ethers. 3. When (heating, heated, having heated) concentrated sulphuric acid reacts with metals. 4. When (prepared, having prepared, preparing) a substance on a commercial scale the method chosen must utilize inexpensive and readily available materials. 5. (cooling, having cooled, cooled) the concentrated solution of naphthalene in hexane we obtained white precipitate of pure naphthalene. 6. Neutral water when (saturated, having saturated, having been saturated) with 02 is a fairly good (oxidizing, oxidized) agent. 7. Organo-metallic compounds are exceedingly reactive (having been, having being been, being) vigorously hydrolyzed by water. 8. (Being, having been, been) very brittle antimony can be easily pulverized.
ABSOLUTE PARTICIPIAL CONSTRUCTION
Study the following sentences:
Weather permitting, we shall go to the country.
Если погода позволит, мы поедем за город.
This being so urgent, we must reconsider our decision.
Так как это очень срочно, мы должны пересмотреть свое решение.
My mother was cooking dinner, my sister helping her.
Моя мама готовила обед, а сестра помогала ей.
We could not come to any conclusions, there being many objections to it.
Мы не могли прийти ни к какому заключению, так как (поскольку) этому имелось много возражений.
Things packed, we started off.
После того, как (когда) вещи были упакованы, мы поехали.
1. The subject of the construction in the subordinate clause expressed by a noun or by a pronoun differs from the subject of the main clause.
2. The Construction is always separated from the main clause by a comma.
3. The Construction may be situated either at the beginning of the sentence or at the end of it.
4. The Construction is translated into Russian with the help of conjunctions поскольку, так как, ввиду того что, когда, после того как (at the beginning of a sentence), причем, а, в то время как, но (at the end of a sentence).
Ex.2. Translate the following sentences, pay attention to the forms and functions of the Participles.
a) 1. Phosphorus dissolves in alcohol, ether, benzene and carbon disulphide, the best solvent being the latter. 2. The charge of the electron having been determined, it was easy to calculate its mass. 3. Arsenic and its compounds have been known from ancient times, the metal being found in free state as well as combined. 4. The liquid being heated to a very high temperature, the substance it contained dissolved entirely. 5. Chlorine is fairly soluble in water, the solution having the same color as the gas. 6. Water being poured upon lumps of burnt lime, large quantities of heat are evolved. 7. Every liquid has a definite vapour pressure, this pressure increasing with rising of temperature. 8. A liquid starts boiling at a certain temperature and under a given pressure, heat causing the liquid to vaporize.
b) 1. When freshly prepared this substance is colorless. 2. Having obtained the necessary compound we could finish our experiment. 3. The sodium atom has eleven electrons, the eleventh one occupying a position in the third shell. 4. Oxygen combines with most elements, the product formed being called an oxide. 5. Inert gases are among substances unaffected by oxygen. 6. The amount of heat liberated by very slow oxidation is the same as that liberated by rapid combustion. 7. The gas being colorless, we did not notice its formation. 8. When exposed to air at room temperature phosphorus begins to oxidize.
c) 1. Так как скорость света чрезвычайно велика, ее невозможно измерить простыми способами. 2. Никогда не трогайте фосфор незащищенными руками, так как тепла тела достаточно, чтоб он воспламенился. 3. Водород горит почти бесцветным пламенем, при этом образуется вода. 4. При температурах, близких к абсолютному нулю, все тела становятся хрупкими, а жидкости и газы становятся плотными. 5. Когда формула соединения известна, мы можем подсчитать его молекулярный вес. 6. Если добавить в воду немного соли, она становится хорошим проводником. 7. Поскольку водород – самый легкий из элементов, его плотность – наименьшая по сравнению со всеми существующими веществами. 8. Когда раствор не содержит в избытке ни кислоты, ни основного гидроксида, мы называем такой раствор нейтральным.
1. Why did this direction of chemistry become a separate branch not so long ago compared to other directions?
2. What are the future perspectives of pharmaceutical chemistry: will it be beneficial to humanity or not?
Pharmaceutical chemistry and Medicinal chemistry are disciplines at the intersection of chemistry, especially synthetic organic chemistry, and pharmacology as well as various other biological specialties, where it is involved with design, chemical synthesis and development for market of pharmaceutical agents (drugs). Pharmaceutical chemistry encompasses drug design, drug synthesis, and the evaluation of drug efficacy (how effective it is in treating a condition) and drug safety. Prior to the nineteenth century, schools of pharmacy trained pharmacists and physicians how to prepare medicinal remedies from natural organic products or inorganic materials. Herbal medications and folk remedies dating back to ancient Egyptian, Greek, Roman, and Asian societies were administered without any knowledge of their biological mechanism of action. It was not until the early 1800s that scientists began extracting chemicals from plants with purported therapeutic properties to isolate the active components and identify them. By discovering and structurally characterizing compounds with medicinal activity, chemists are able to design new drugs with enhanced potency and decreased adverse side effects.
Drug discovery is the core of pharmaceutical chemistry. The drug discovery process includes all the stages of drug development, from targeting a disease or medical condition to toxicity studies in animals, or even, by some definitions, testing the drug on human subjects. Typically, conditions that affect a larger percentage of the population receive more attention and more research funding. Antiulcer drugs and cholesterol-reducing agents are currently the therapeutic areas of greatest emphasis. To develop a drug to target a specific disease, researchers try to understand the biological mechanism responsible for that condition. The biochemical pathways leading up to the disease being understood, scientists attempt to design drugs that will block one or several of the steps of the disease progress. Alternatively, drugs that boost the body's own defense mechanism may be appropriate.
Computers have transformed the drug discovery process. Rational drug design involves computer-assisted approaches to designing molecules with desired chemical properties. Molecular modeling software depicts three-dimensional images of a chemical which helps to demonstrate the size and shape of the drug, and the location of any charged groups. Chemists can vary the atoms or groups within the model and predict the effect the transformation has on the molecular properties of the drug. In this way, new compounds can be designed. Advances in technology have made it possible for medicinal chemists to synthesize a vast number of compounds in a relatively short time, a process referred to as combinatorial chemistry.
Every chemical that is synthesized must be tested for biological activity. In vitro testing involves biological assays outside a living system. New technologies have made it possible to assay large numbers of compounds in a short period. High-throughput drug screening allows pharmaceutical chemists to test between 1,000 and 100,000 chemicals in a single day! A compound that demonstrates some biological activity will undergo further tests, or it may be chemically modified to enhance its activity. Once a drug shows promise in vitro as a therapeutic agent, it must also be screened for toxic properties. To investigate drug toxicity, animal studies are performed. These studies also estimate mutagenicity, that is, whether the compound under investigation damages genetic material.
Scientists and government regulatory agencies having determined the drug candidate to be relatively safe, it can enter into clinical trials. The clinical stage involves four phases of testing on human volunteers. Phase I clinical trials evaluate drug tolerance and safety in a small group of healthy adult volunteers. Phase II trials continue to assess the drug safety and effectiveness in a larger population. Phase III and phase IV clinical trials involve even larger populations. During phase III trials, which can last two to eight years, a drug is often brought to market. Phase IV studies continue after the drug is being marketed.
The field of pharmaceutical chemistry is diverse and involves many areas of expertise. Natural-product and analytical chemists isolate and identify active components from plant and other natural sources. Theoretical chemists construct molecular models of existing drugs to evaluate their properties.
WHAT DO PHARMACEUTICAL CHEMISTS DO?
Scientists in pharmaceutical chemistry are principally industrial scientists, working as part of an interdisciplinary team that uses their chemistry abilities, especially their synthetic abilities, to use chemical principles to design effective therapeutic agents. Their work involves chemical aspects of identification, and then systematic thorough synthetic alteration of new chemical entities to make them suitable for therapeutic use. It includes synthetic and computational aspects of the study of existing drugs and agents in development in relation to their bioactivities (biological activities and properties), i.e., understanding their structure-activity relationships (SAR). Pharmaceutical chemists are focused on quality aspects of medicines and aim to assure fitness for purpose of medicinal products.
Graduate level programs in pharmaceutical chemistry can be found in traditional medicinal chemistry or pharmaceutical sciences departments, both of which are traditionally associated with schools of pharmacy, and in some chemistry departments. Most entry-level workers in pharmaceutical chemistry do not have formal training but receive the necessary pharmaceutical and pharmacologic background after employment – at entry into their work in a pharmaceutical company, where the company provides its particular understanding or model of training through active involvement in practical synthesis on therapeutic projects.
Ex.1. Match the following words on the left with the appropriate synonyms on the right:
illness or disease
to imply or claim to be
to apply or dispense
medication or cure
a route or a course
Ex. 2. Some of the following sentences can be incorrect. Find the mistakes and correct them.
1. In early times schools of pharmacy trained people how to prepare medicinal remedies only from natural organic products.
2. Knowing structural characteristics of compounds with medicinal activity, chemists are able to design new drugs with better properties and fewer adverse side effects.
3. To develop a drug to target a specific disease, researchers try to understand the possible adverse effects of this drug that can be responsible for that condition.
4. Every chemical that is synthesized must be tested in vitro and in vivo.
5. Most entry-level workers in pharmaceutical chemistry shouldn’t have any training and have no necessary pharmaceutical and pharmacologic background after employment.
Ex. 3. Complete the following passage using the words from the box.
How do chemists "discover" drugs? Often there is an existing (1) … for a condition, and scientists will evaluate how that drug exerts its actions. Once the drug's structure is known, the drug can serve as a prototype or "lead compound" for designing more effective (2) … of similar chemical structure. (3) … compounds are molecules that have some (4) … with respect to the condition under investigation. However, the lead compound may not be effective in (5) … the disease, or it may produce undesirable (6) …. Lead optimization involves chemical modifications to the lead compound to produce a more (7) … drug, or one with fewer or decreased (8) … effects. Compounds used as medicines are most often organic (9) … , which are often divided into the broad classes of small organic molecules (e.g., atorvastatin, clopidogrel) and "biologics” (erythropoietin, insulin, glargine), the latter of which are most often medicinal (10) … of proteins (natural and recombinant antibodies, hormones, etc.). Inorganic and organometallic compounds are also useful as drugs (e.g., lithium and platinum-based agents such as lithium carbonate).
Ex. 4. Speak on the history of pharmaceutical chemistry.
Dwell on the main stages of drug design and testing.
Specify the main areas of activity for pharmaceutical chemists.
1. What in your opinion caused the emergence of a totally new and separate speciality as environmental chemistry?
2. Do you think we possess enough theoretical knowledge and a sufficient instrumental basis for the effective functioning of this branch of chemistry?
Environmental chemistry is the scientific study of the chemical and biochemical phenomena that occur in natural places. It should not be confused with green chemistry, the latter seeking to reduce potential pollution at its source. It can be defined as the study of the sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments; and the effect of human activity on these. Environmental chemistry is an interdisciplinary science that includes atmospheric, aquatic and soil chemistry, as well as heavily relying on analytical chemistry and being related to environmental and other areas of science.
Environmental chemistry involves first understanding how the uncontaminated environment works, which chemicals in what concentrations are present naturally, and with what effects. Without this it would be impossible to accurately study the effects humans have on the environment through the release of chemicals.
Quantitative chemical analysis is a key part of environmental chemistry, since it provides the data that frame most environmental studies. Common analytical techniques used for quantitative determinations in environmental chemistry include classical wet chemistry, such as gravimetric, titrimetric and electrochemical methods. More sophisticated approach is used in the determination of trace metals and organic compounds. Metals are commonly measured by atomic spectroscopy and mass spectrometry: Atomic Absorption Spectrometry (AAS) and Inductively Coupled Plasma Atomic Emission (ICP-AES) or Inductively Coupled Plasma Mass Spectrometric (ICP-MS) techniques. Organic compounds are commonly measured also using mass spectrometric methods, such as Gas Chromatography-Mass Spectrometry (GC/MS) and Liquid Chromatography-Mass Spectrometry (LC/MS). Non-MS methods using GCs and LCs having universal or specific detectors are still staples in the arsenal of available analytical tools. Other parameters often measured in environmental chemistry are radiochemicals. These are pollutants which emit radioactive materials, such as alpha and beta particles, posing danger to human health and the environment. Particle counters and Scintillation counters are most commonly used for these measurements, bioassays and immunoassays being utilized for toxicity evaluations of chemical effects on various organisms.
Ecological problems of the modern world are becoming more and more public and this is the reason why ecology has become very much "public term" despite its originally scientific character. It’s a great pity that homocentric system by which all natural goods are used just for human exploit is still very much present in world's philosophy, number of supporters of ecocentric system based on ecosystem rising as well. The lack of concern for our planet is the main reason why there are today so many endangered species and why pollution can be seen in all corners of the world. People still do not have so much needed ecological conscience and do not see that they are the only ones responsible for salvation of our planet. It is probably too painful to admit our own mistakes and try to fix them before it is too late. Some small steps have been already taken but it will take much more these steps on the global level in order to make the difference.
To succeed, we do not need some extreme strategy to return the world to the time before James Watt and the first industrial revolution, giving away all the benefits of modern technology. On the contrary, our modern technologies should be used in the way that would enable peaceful coexistence between ecology and industry, the emphasis being primarily set on the use of energy resources that have the lowest negative impact on the environment. These renewable energy resources are, for instance, wind, water and sun.
Current technologies could be wisely used to prevent ecological disasters and endangering animal species, as well as, entire development of ecosystem, and all we have to do is to turn technologies in these directions. At the same time ecological problems also require appropriate legislative support that should ban modern technologies that have a negative impact on the environment, and only allow those technologies that do not have, or have only a minimum negative impact on the environment. Passive observation is not sufficient, especially now when we have become witnesses of so many ecological disasters.
It is really time for one global action, and who knows maybe this is our only chance to save the Earth. So what are we waiting for?
WHAT DO ENVIRONMENTAL CHEMISTS DO?
Environmental chemists draw on a range of concepts from chemistry and various environmental sciences to assist in their study of what is happening to a chemical species in the environment. Important general concepts from chemistry include understanding chemical reactions and equations, solutions, units, sampling, and analytical techniques.
Environmental chemists are employed by environmental agencies and research bodies around the world to detect and identify the nature and source of pollutants. These can include:
· Heavy metal contamination of land by industry. These can then be transported into water bodies and be taken up by living organisms.
· Nutrients leaching from agricultural land into water courses, which can lead to algal blooms and eutrophication.
· Urban runoff of pollutants washing off impervious surfaces (roads, parking lots, and rooftops) during rain storms. Typical pollutants include gasoline, motor oil and other hydrocarbon compounds, metals, nutrients and sediment (soil).