Pharmacokinetics, sometimes abbreviated as PK, is a branch of pharmacology dedicated to determining the fate of substances administered to a living organism. The substances of interest include any chemical xenobiotic such as, pharmaceutical drugs, food additives, cosmetic ingredients, etc. It attempts to analyze chemical metabolism and to discover the fate of a chemical from the moment that it is administered up to the point at which it is eliminated from the body. Pharmacokinetics is the study of how an organism affects a drug, both together influence dosing and adverse effects, as seen in PK/PD models. Pharmacokinetic properties of chemicals are affected by the route of administration and these may affect the absorption rate. Models have been developed to simplify conceptualization of the processes that take place in the interaction between an organism and a chemical substance. The various compartments that the model is divided into are commonly referred to as the ADME scheme, absorption - the process of a substance entering the blood circulation.
Distribution - the dispersion or dissemination of substances throughout the fluids, metabolism – the recognition by the organism that a foreign substance is present and the irreversible transformation of parent compounds into daughter metabolites. Excretion - the removal of the substances from the body, in rare cases, some drugs irreversibly accumulate in body tissue. The two phases of metabolism and excretion can be grouped together under the title elimination, the study of these distinct phases involves the use and manipulation of basic concepts in order to understand the process dynamics. All these concepts can be represented through mathematical formulas that have a graphical representation. The model outputs for a drug can be used in industry or in the application of pharmacokinetic concepts. Clinical pharmacokinetics provides many performance guidelines for effective and efficient use of drugs for human-health professionals, in practice, it is generally considered that steady state is reached when a time of 4 to 5 times the half-life for a drug after regular dosing is started.
Noncompartmental methods estimate the exposure to a drug by estimating the area under the curve of a concentration-time graph, compartmental methods estimate the concentration-time graph using kinetic models. Noncompartmental methods are more versatile in that they do not assume any specific compartmental model. The final outcome of the transformations that a drug undergoes in an organism, a number of functional models have been developed in order to simplify the study of pharmacokinetics. These models are based on a consideration of an organism as a number of related compartments, the simplest idea is to think of an organism as only one homogenous compartment. However, these models do not always reflect the real situation within an organism
Rats are various medium-sized, long-tailed rodents of the superfamily Muroidea. True rats are members of the genus Rattus, the most important of which to humans are the black rat, Rattus rattus, many members of other rodent genera and families are referred to as rats, and share many characteristics with true rats. Rats are typically distinguished from mice by their size, when someone discovers a large muroid rodent, its common name includes the term rat, while if it is smaller, the name includes the term mouse. The muroid family is broad and complex, and the common terms rat, the terms are not confined to members of the Rattus and Mus genera, for example, the pack rat and cotton mouse. The best-known rat species are the black rat and the brown rat, the group is generally known as the Old World rats or true rats, and originated in Asia. Rats are bigger than most Old World mice, which are their relatives, the term rat is used in the names of other small mammals which are not true rats. Examples include the North American pack rats, a number of species loosely called kangaroo rats, Rats such as the bandicoot rat are murine rodents related to true rats, but are not members of the genus Rattus.
Male rats are called bucks, unmated females are called does, pregnant or parent females are called dams, a group of rats is referred to as a mischief. The common species are opportunistic survivors and often live with and near humans and they may cause substantial food losses, especially in developing countries. However, the distributed and problematic commensal species of rats are a minority in this diverse genus. Many species of rats are island endemics and some have become endangered due to loss or competition with the brown. Wild rodents, including rats, can carry many different zoonotic pathogens, such as Leptospira, Toxoplasma gondii, another zoonotic disease linked to the rat is the foot-and-mouth disease. The average lifespan of any given rat depends on species is being discussed. The black and brown rats diverged from other Old World rats during the beginning of the Pleistocene in the forests of Asia, specially bred rats have been kept as pets at least since the late 19th century. Pet rats are typically variants of the brown rat, but black rats.
Pet rats behave differently from their wild counterparts depending on how many generations they have kept as pets. Pet rats do not pose any more of a risk than pets such as cats or dogs. Tamed rats are generally friendly and can be taught to perform selected behaviors, in 1895, Clark University in Worcester, Massachusetts established a population of domestic albino brown rats to study the effects of diet and for other physiological studies
Modern humans are the only extant members of Hominina tribe, a branch of the tribe Hominini belonging to the family of great apes. Several of these hominins used fire, occupied much of Eurasia and they began to exhibit evidence of behavioral modernity around 50,000 years ago. In several waves of migration, anatomically modern humans ventured out of Africa, the spread of humans and their large and increasing population has had a profound impact on large areas of the environment and millions of native species worldwide. Humans are uniquely adept at utilizing systems of communication for self-expression and the exchange of ideas. Humans create complex structures composed of many cooperating and competing groups, from families. Social interactions between humans have established a wide variety of values, social norms, and rituals. These human societies subsequently expanded in size, establishing various forms of government, today the global human population is estimated by the United Nations to be near 7.5 billion.
In common usage, the word generally refers to the only extant species of the genus Homo—anatomically and behaviorally modern Homo sapiens. In scientific terms, the meanings of hominid and hominin have changed during the recent decades with advances in the discovery, there is a distinction between anatomically modern humans and Archaic Homo sapiens, the earliest fossil members of the species. The English adjective human is a Middle English loanword from Old French humain, ultimately from Latin hūmānus, the words use as a noun dates to the 16th century. The native English term man can refer to the species generally, the species binomial Homo sapiens was coined by Carl Linnaeus in his 18th century work Systema Naturae. The generic name Homo is a learned 18th century derivation from Latin homō man, the species-name sapiens means wise or sapient. Note that the Latin word homo refers to humans of either gender, the genus Homo evolved and diverged from other hominins in Africa, after the human clade split from the chimpanzee lineage of the hominids branch of the primates.
The closest living relatives of humans are chimpanzees and gorillas, with the sequencing of both the human and chimpanzee genome, current estimates of similarity between human and chimpanzee DNA sequences range between 95% and 99%. The gibbons and orangutans were the first groups to split from the leading to the humans. The splitting date between human and chimpanzee lineages is placed around 4–8 million years ago during the late Miocene epoch, during this split, chromosome 2 was formed from two other chromosomes, leaving humans with only 23 pairs of chromosomes, compared to 24 for the other apes. There is little evidence for the divergence of the gorilla, chimpanzee. Each of these species has been argued to be an ancestor of hominins
A chemical compound is an entity consisting of two or more atoms, at least two from different elements, which associate via chemical bonds. Many chemical compounds have a numerical identifier assigned by the Chemical Abstracts Service. For example, water is composed of two atoms bonded to one oxygen atom, the chemical formula is H2O. A compound can be converted to a different chemical composition by interaction with a chemical compound via a chemical reaction. In this process, bonds between atoms are broken in both of the compounds, and bonds are reformed so that new associations are made between atoms. Schematically, this reaction could be described as AB + CD → AC + BD, where A, B, C, and D are each unique atoms, and AB, CD, AC, and BD are each unique compounds. A chemical element bonded to a chemical element is not a chemical compound since only one element. Examples are the diatomic hydrogen and the polyatomic molecule sulfur. Chemical compounds have a unique and defined chemical structure held together in a spatial arrangement by chemical bonds.
Pure chemical elements are not considered chemical compounds, failing the two or more atom requirement, though they often consist of molecules composed of multiple atoms. There is varying and sometimes inconsistent nomenclature differentiating substances, which include truly non-stoichiometric examples, from chemical compounds, other compounds regarded as chemically identical may have varying amounts of heavy or light isotopes of the constituent elements, which changes the ratio of elements by mass slightly. Characteristic properties of compounds include that elements in a compound are present in a definite proportion, for example, the molecule of the compound water is composed of hydrogen and oxygen in a ratio of 2,1. In addition, compounds have a set of properties. The physical and chemical properties of compounds differ from those of their constituent elements, mixtures can be created by mechanical means alone, but a compound can be created only by a chemical reaction. Some mixtures are so combined that they have some properties similar to compounds.
Other examples of compound-like mixtures include intermetallic compounds and solutions of metals in a liquid form of ammonia. Compounds may be described using formulas in various formats, for compounds that exist as molecules, the formula for the molecular unit is shown. For polymeric materials, such as minerals and many metal oxides, the elements in a chemical formula are normally listed in a specific order, called the Hill system
Endo–exo isomerism is a special type of isomerism found in organic compounds with a substituent on a bridged ring system. The prefix endo is reserved for the isomer with the substituent located closest, or syn, the prefix exo is reserved for the isomer with the substituent located farthest, or anti, to the longest bridge. Here longest and shortest refer to the number of atoms that comprise the bridge and this type of molecular geometry is found in norbornane systems such as dicyclopentadiene. The terms endo and exo are used in a sense in discussions of the stereoselectivity in Diels–Alder reactions. IUPAC, Compendium of Chemical Terminology, 2nd ed. Online corrected version, exo, anti
Feces or faeces are the solid or semisolid metabolic waste from an animals digestive tract, discharged through the anus or cloaca during a process called defecation. Urine and feces together are called excreta, collected feces has various uses, namely as fertilizer or soil conditioner in agriculture, as a fuel source, or for medicinal purposes. After an animal has digested eaten material, the remains of material are discharged from its body as waste. Although it is lower in energy than the food from which it is derived, feces may retain a large amount of energy and this means that of all food eaten, a significant amount of energy remains for the decomposers of ecosystems. Many organisms feed on feces, from bacteria to fungi to insects such as dung beetles, some may specialize in feces, while others may eat other foods as well. Feces serve not only as a food, but as a supplement to the usual diet of some animals. Feces and urine, which reflect light, are important to raptors such as kestrels.
Seeds may be found in feces, animals who eat fruit are known as frugivores. An advantage for a plant in having fruit is that animals will eat the fruit and this mode of seed dispersal is highly successful, as seeds dispersed around the base of a plant are unlikely to succeed and often are subject to heavy predation. Provided the seed can withstand the pathway through the system, it is not only likely to be far away from the parent plant. This cycling of matter is known as the biogeochemical cycle, the distinctive odor of feces is due to bacterial action. Gut flora produce compounds such as indole and thiols and these are the same compounds that are responsible for the odor of flatulence. Consumption of foods prepared with spices may result in the spices being undigested, the perceived bad odor of feces has been hypothesized to be a deterrent for humans, as consuming or touching it may result in sickness or infection. Human perception of the odor may be contrasted by an animals perception of it, for example.
In humans and depending on the individual and the circumstances, defecation may occur daily, extensive hardening of the feces may cause prolonged interruption in the routine and is called constipation. Human fecal matter varies significantly in appearance, depending on diet, normally it is semisolid, with a mucus coating. The brown coloration comes from a combination of bile and bilirubin, in newborn babies, initially fecal matter is yellow-green after the meconium. This coloration comes from the presence of bile alone, throughout the life of an ordinary human, one may experience many types of feces
A tablet is a pharmaceutical dosage form. Tablets may be defined as the solid unit dosage form of medicament or medicaments with or without suitable excipients and it comprises a mixture of active substances and excipients, usually in powder form, pressed or compacted from a powder into a solid dose. The compressed tablet is the most popular form in use today. About two-thirds of all prescriptions are dispensed as solid dosage forms, a tablet can be formulated to deliver an accurate dosage to a specific site, it is usually taken orally, but can be administered sublingually, rectally or intravaginally. The tablet is just one of the forms that an oral drug can take such as syrups, suspensions. Medicinal tablets were made in the shape of a disk of whatever color their components determined. Tablets are often stamped with symbols and numbers, sizes of tablets to be swallowed range from a few millimeters to about a centimeter. Pills are thought to date back to around 1500 BC, earlier medical recipes, such as those from 4000 BC, were for liquid preparations rather than solids.
The first references to pills were found on papyruses in ancient Egypt, medicinal ingredients, such as plant powders or spices, were mixed in and formed by hand to make little balls, or pills. In ancient Greece, such medicines were known as katapotia, and the Roman scholar Pliny, Pills have always been difficult to swallow and efforts long have been made to make them go down easier. In medieval times, people coated pills with slippery plant substances, another approach, used as recently as the 19th century, was to gild them in gold and silver, although this often meant that they would pass through the digestive tract with no effect. In the 1800s sugar-coating and gelatin-coating was invented, as were gelatin capsules, in 1843, the British painter and inventor William Brockedon was granted a patent for a machine capable of Shaping Pills and Black Lead by Pressure in Dies. The device was capable of compressing powder into a tablet without use of an adhesive, pills include tablets and variants thereof like caplets—essentially anything with medication that can be digested, minus the liquid forms, colloquially falls into the pill category. A caplet is a smooth, oval-shaped medicinal tablet in the shape of a capsule.
Many caplets have a running down the middle so they may be split in half easier. An orally disintegrating tablet or orodispersible tablet, is a dosage form available for a limited range of over-the-counter. In the tablet-pressing process, it is important that all ingredients be fairly dry, powdered or granular, somewhat uniform in particle size, content uniformity ensures that the same API dose is delivered with each tablet. Some APIs may be tableted as pure substances, but this is rarely the case, normally, a pharmacologically inactive ingredient termed a binder is added to help hold the tablet together and give it strength
The density, or more precisely, the volumetric mass density, of a substance is its mass per unit volume. The symbol most often used for density is ρ, although the Latin letter D can be used. Mathematically, density is defined as mass divided by volume, ρ = m V, where ρ is the density, m is the mass, and V is the volume. In some cases, density is defined as its weight per unit volume. For a pure substance the density has the numerical value as its mass concentration. Different materials usually have different densities, and density may be relevant to buoyancy, purity and iridium are the densest known elements at standard conditions for temperature and pressure but certain chemical compounds may be denser. Thus a relative density less than one means that the floats in water. The density of a material varies with temperature and pressure and this variation is typically small for solids and liquids but much greater for gases. Increasing the pressure on an object decreases the volume of the object, increasing the temperature of a substance decreases its density by increasing its volume.
In most materials, heating the bottom of a results in convection of the heat from the bottom to the top. This causes it to rise relative to more dense unheated material, the reciprocal of the density of a substance is occasionally called its specific volume, a term sometimes used in thermodynamics. Density is a property in that increasing the amount of a substance does not increase its density. Archimedes knew that the irregularly shaped wreath could be crushed into a cube whose volume could be calculated easily and compared with the mass, upon this discovery, he leapt from his bath and ran naked through the streets shouting, Eureka. As a result, the term eureka entered common parlance and is used today to indicate a moment of enlightenment, the story first appeared in written form in Vitruvius books of architecture, two centuries after it supposedly took place. Some scholars have doubted the accuracy of this tale, saying among other things that the method would have required precise measurements that would have been difficult to make at the time, from the equation for density, mass density has units of mass divided by volume.
As there are units of mass and volume covering many different magnitudes there are a large number of units for mass density in use. The SI unit of kilogram per metre and the cgs unit of gram per cubic centimetre are probably the most commonly used units for density.1,000 kg/m3 equals 1 g/cm3. In industry, other larger or smaller units of mass and or volume are often more practical, see below for a list of some of the most common units of density
An acetylcholine receptor is an integral membrane protein that responds to the binding of acetylcholine, a neurotransmitter. Like other transmembrane receptors, acetylcholine receptors are classified according to their pharmacology, although all acetylcholine receptors, by definition, respond to acetylcholine, they respond to other molecules as well. Nicotinic acetylcholine receptors are particularly responsive to nicotine, the nicotine ACh receptor is a Na+, K+ and Ca2+ ion channel. Muscarinic acetylcholine receptors are particularly responsive to muscarine and muscarinic are two main kinds of cholinergic receptors. Molecular biology has shown that the nicotinic and muscarinic receptors belong to distinct protein superfamilies, nicotinic receptors are of two types, Nm and Nn. Nm is located in the junction which causes the contraction of skeletal muscles by way of end-plate potential. Nn causes depolarization in autonomic ganglia resulting in post ganglionic impulse, nicotinic receptors cause the release of catecholamine from the adrenal medulla, and site specific excitation or inhibition in brain.
Both Nm and Nn are Na+ and Ca++ channel linked but Nn is linked with an extra K+ channel, the subunit composition is highly variable across different tissues. Each subunit contains four regions which span the membrane and consist of approximately 20 amino acids, region II which sits closest to the pore lumen, forms the pore lining. Binding of acetylcholine to the N termini of each of the two alpha subunits results in the 15° rotation of all M2 helices. In the intermediate region of the receptor, within the pore lumen, the nAChR is found at the edges of junctional folds at the neuromuscular junction on the postsynaptic side, it is activated by acetylcholine release across the synapse. In contrast, the mAChRs are not ion channels, but belong instead to the superfamily of G-protein-coupled receptors that activate other ionic channels via a second messenger cascade, the muscarine cholinergic receptor activates a G-protein when bound to extracellular ACh. The alpha subunit of the G-protein deactivates adenylate cyclase while the beta-gamma subunit activates the K-channels and this causes a decrease in cardiac activity.
Nicotinic acetylcholine receptors can be blocked by curare and toxins present in the venoms of snakes and shellfishes, drugs such as the neuromuscular blocking agents bind reversibly to the nicotinic receptors in the neuromuscular junction and are used routinely in anaesthesia. Nicotinic receptors are the primary mediator of the effects of nicotine, in myasthenia gravis, the receptor at the neuromuscular junction is targeted by antibodies, leading to muscle weakness. Muscarinic acetylcholine receptors can be blocked by the drugs atropine and scopolamine, congenital myasthenic syndrome is an inherited neuromuscular disorder caused by defects of several types at the neuromuscular junction. Postsynaptic defects are the most frequent cause of CMS and often result in abnormalities in nicotinic acetylcholine receptors, the majority of mutations causing CMS are found in the AChR subunits genes. Out of all associated with CMS, more than half are mutations in one of the four genes encoding the adult acetylcholine receptor subunits
Abbott Laboratories is an American worldwide health care company. It has 74,000 employees and operates in more than 150 countries, the company headquarters are in Lake Bluff, Illinois. It split off the research-based pharmaceuticals into Abbvie in 2013, in 2015, revenues were $20.4 billion. Abbott has a range of branded generic pharmaceuticals, medical devices, diagnostics. The companys in-vitro diagnostics business performs immunoassays and blood screening, in 1985, the company developed the first HIV blood-screening test. Abbott Point-of-Care manufactures diagnostic products for blood analysis to provide health care professionals diagnostics information at the point of patient care, Abbott provides point-of-care cardiac assays to the emergency room. In 1888 at the age of 30, Wallace Abbott, an 1885 graduate of the University of Michigan, at the time, he was a practicing physician and owned a drug store. His innovation was the use of the part of a medicinal plant, generally an alkaloid. This approach was successful since it produced consistent and effective dosages for patients.
Abbotts first international affiliate was in London in 1907, and the added an affiliate in Montreal. Abbott started operations in Pakistan as an affiliate in 1948. Currently two manufacturing facilities located at Landhi and Korangi in Karachi continue to produce pharmaceutical products, expansion continued in 1962 when Abbott entered into a joint venture with Dainippon Pharmaceutical Co. Ltd. of Osaka, Japan, to manufacture radio-pharmaceuticals. In 1965, Abbotts expansion in Europe continued with offices in Italy, Abbott Laboratories has been present in India for over 100 years through its subsidiary Abbott India Limited and it is currently Indias largest healthcare products company. In 2009, Abbott opened a research and development facility at Research Park. In June 2014 the company entered into an agreement to take over Russian pharmaceutical manufacturer Veropharm in a deal worth $631 million. Abbott, which already employs 1,400 people in Russia, Abbotts core businesses focus on pharmaceuticals, medical devices and nutritional products, which have been supplemented through acquisitions.
Medical Devices Medical Optics Nutrition, baby nutrition, adult health products and special dietary needs The company has divested itself of less profitable businesses through sales, in 1964, it acquired Ross Laboratories, making Ross a wholly owned subsidiary of Abbott. In 2001, the company acquired Knoll, the division of BASF
Psychology is the science of behavior and mind, embracing all aspects of conscious and unconscious experience as well as thought. It is a discipline and a social science which seeks to understand individuals and groups by establishing general principles. In this field, a professional practitioner or researcher is called a psychologist and can be classified as a social, Psychologists explore behavior and mental processes, including perception, attention, intelligence, motivation, brain functioning, and personality. This extends to interaction between people, such as relationships, including psychological resilience, family resilience, and other areas. Psychologists of diverse orientations consider the unconscious mind, Psychologists employ empirical methods to infer causal and correlational relationships between psychosocial variables. Psychology has been described as a hub science, with psychological findings linking to research and perspectives from the sciences, natural sciences, humanities.
By many accounts psychology ultimately aims to benefit society, the majority of psychologists are involved in some kind of therapeutic role, practicing in clinical, counseling, or school settings. Many do scientific research on a range of topics related to mental processes and behavior. The word psychology derives from Greek roots meaning study of the psyche, the Latin word psychologia was first used by the Croatian humanist and Latinist Marko Marulić in his book, Psichiologia de ratione animae humanae in the late 15th century or early 16th century. In 1890, William James defined psychology as the science of mental life and this definition enjoyed widespread currency for decades. Also since James defined it, the more strongly connotes techniques of scientific experimentation. Folk psychology refers to the understanding of people, as contrasted with that of psychology professionals. The ancient civilizations of Egypt, China, historians note that Greek philosophers, including Thales and Aristotle, addressed the workings of the mind.
As early as the 4th century BC, Greek physician Hippocrates theorized that mental disorders had physical rather than supernatural causes, in China, psychological understanding grew from the philosophical works of Laozi and Confucius, and from the doctrines of Buddhism. This body of knowledge involves insights drawn from introspection and observation and it frames the universe as a division of, and interaction between, physical reality and mental reality, with an emphasis on purifying the mind in order to increase virtue and power. Chinese scholarship focused on the advanced in the Qing Dynasty with the work of Western-educated Fang Yizhi, Liu Zhi. Distinctions in types of awareness appear in the ancient thought of India, a central idea of the Upanishads is the distinction between a persons transient mundane self and their eternal unchanging soul. Divergent Hindu doctrines, and Buddhism, have challenged this hierarchy of selves, yoga is a range of techniques used in pursuit of this goal