Химия. Экология. Медицина



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MEDICINE AND PHARMACEUTICAL SCIENCE

Ashna, group 24. Science adviser is Larisa Lukyanova.


MEDICINE the word medicine is derived from LATIN arc medicina meaning THE ART OF HEALING. MEDICINE is the field of applied APPLIED SCIENCE to the art of healing by diagnosis,treatment, and prevention of disease.

It encompasses a variety of health carepractices evolved to maintain and restore health by the prevention and treatment of illness in human beings.Contemporary medicine applies health science,biomedical research,genetics and medical technology to diagnose and treat and prevent injury and disease, typically through medication or surgery, but also through therapies as diverse as psychotherapy,external splints and traction, prostheses, biologics,pharmaceutials,ionizing radiation.

PHARMACEUTICAL SCIENCE are a group of interdisciplinary areas of study concerned with the design, action, delivery, disposition, inorganic, physical,biochemical and analytical biology (anatomy and physiology, biochemistry,cell biology, and molecular biology),epidemiology, statistics, chemometrics,mathematics, physics, and chemical engineering, and applies their principles to the study of drugs. The pharmaceutical sciences are further subdivided into several specific specialties, with four main branches:

Pharmacology: the study of the biochemical and physiological effects of drugs onhuman beings.

Pharmacodynamics: the study of the cellular and molecular interactions of drugs with their receptors.

Pharmacokinetics: the study of the factors that control the concentration of drug at various sites in the body.

Pharmaceutical toxicology: the study of the harmful or toxic effects of drugs.

Pharmacogenomics: the study of the inheritance of characteristic patterns of interaction between drugs and organisms.

Pharmaceutical chemistry: the study of drug design to optimize pharmacokinetics and pharmacodynamics and synthesis of new drug molecules.

Pharmaceutics: the study and design of drug formulation for optimum delivery stability, pharmacokinetics, and patient acceptance.

Pharmacognosy: the study of medicines derived from natural sources.

Medicine and pharmaceutical science play very important role in human life.



HYDROGEN

Fameya Zoabi, group 25. Science adviser is Olga Levashova.


Hydrogen is a chemical element with chemical symbol H and atomic number 1. With an atomic weight of 1.00794 u, hydrogen is the lightest element and its monatomic form (H) is the most abundant chemical substance, constituting roughly 75% of the Universe's baryonic mass. Non-remnant stars are mainly composed of hydrogen in its plasma state.

At standard temperature and pressure, hydrogen is a colorless, odorless, tasteless, non-toxic, nonmetallic, highly combustible diatomic gas with the molecular formula H2. Most of the hydrogen on Earth is in molecules such as water and organic compounds because hydrogen readily forms covalent compounds with most non-metallic elements.

Hydrogen plays a particularly important role in acid–base chemistry with many reactions exchanging protons between soluble molecules. In ionic compounds, it can take a negative charge (an anion known as a hydride and written as H), or as a positively charged species H+. The latter cation is written as though composed of a bare proton, but in reality, hydrogen cations in ionic compounds always occur as more complex species.

The most common isotope of hydrogen is protium (name rarely used, symbol 1H) with a single proton and no neutrons. As the simplest atom known, the hydrogen atom has been of theoretical use. For example, as the only neutral atom with an analytic solution to the Schrödinger equation, the study of the energetics and bonding of the hydrogen atom played a key role in the development of quantum mechanics.

Hydrogen gas was first artificially produced in the early 16th century, via the mixing of metals with acids. In 1766–81, Henry Cavendish was the first to recognize that hydrogen gas was a discrete substance, and that it produces water when burned, a property which later gave it its name: in Greek, hydrogen means "water-formr".

Industrial production is mainly from the steam reforming of natural gas, and less often from more energy-intensive hydrogen production methods like the electrolysis of water. Most hydrogen is employed near its production site, with the two largest uses being fossil fuel processing (e.g., hydrocracking) and ammonia production, mostly for the fertilizer market.

Hydrogen is a concern in metallurgy as it can embrittle many metals, complicating the design of pipelines and storage tanks.

Combustion

Hydrogen gas (dihydrogen or molecular hydrogen) is highly flammable and will burn in air at a very wide range of concentrations between 4% and 75% by volume. The enthalpy of combustion for hydrogen is −286 kJ/mol:

2 H2(g) + O2(g) → 2 H2O(l) + 572 kJ (286 kJ/mol)

Hydrogen gas forms explosive mixtures with air if it is 4–74% concentrated and with chlorine if it is 5–95% concentrated. The mixtures may be ignited by spark, heat or sunlight. The hydrogen autoignition temperature, the temperature of spontaneous ignition in air, is 500 °C (932 °F). Pure hydrogen-oxygen flames emit ultraviolet light and with high oxygen mix are nearly invisible to the naked eye, as illustrated by the faint plume of the Space Shuttle Main Engine compared to the highly visible plume of a Space Shuttle Solid Rocket Booster. The detection of a burning hydrogen leak may require a flame detector; such leaks can be very dangerous. Hydrogen flames in other conditions are blue, resembling blue natural gas flames. The destruction of the Hindenburg airship was an infamous example of hydrogen combustion; the cause is debated, but the visible orange flames were the result of a rich mixture of hydrogen to oxygen combined with carbon compounds from the airship skin.

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