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Parvalbumin
Parvalbumin (PV) is a calcium-binding protein with low molecular weight (typically 9–11 kDa). In humans, it is encoded by the ''PVALB'' gene. It is a member of the albumin family; it is named for its size (''parv-'', from Latin ' which means "small") and its ability to coagulate. It has three EF hand motifs and is structurally related to calmodulin and troponin C. Parvalbumin is found in fast-contracting muscles, where its levels are highest, as well as in the brain and some endocrine tissues. Parvalbumin is a small, stable protein containing EF-hand type calcium binding sites. It is involved in calcium signaling. Typically, this protein is broken into three domains, domains AB, CD and EF, each individually containing a helix-loop-helix motif. The AB domain houses a two amino-acid deletion in the loop region, whereas domains CD and EF contain the N-terminal and C-terminal, respectively. Calcium binding proteins like parvalbumin play a role in many physiological processes, nam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pharmacovigilance
Pharmacovigilance (PV, or PhV), also known as drug safety, is the pharmaceutical science relating to the "collection, detection, assessment, monitoring, and prevention" of adverse effects with pharmaceutical products. The etymological roots for the word "pharmacovigilance" are: (Greek for drug) and (Latin for to keep watch). As such, pharmacovigilance heavily focuses on adverse drug reactions (ADR), which are defined as any response to a drug which is noxious and unintended. That definition includes lack of efficacy: that means that the doses normally used for prevention, diagnosis, or treatment of a disease—or, especially in the case of device, for the modification of physiological disorder function. In 2010, the European Union expanded PV to include medication errors such as overdose, misuse, and abuse of a drug as well as drug exposure during pregnancy and breastfeeding. These are monitored even in the absence of an adverse event, because they may result in an adve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paceville
Paceville ( sometimes abbreviated PV) is a district in St Julian's which is the main nightlife hub in Malta, being heavily populated with nightclubs, bars, strip clubs, pubs and restaurants. It is hence also known as 'Malta's Sin City'. Paceville is located between Spinola Point and Dragonara Point, delimiting Spinola Bay and St. George's Bay respectively. In 2016, it was estimated that Paceville's population stood around 1,939, of which 1,160 were foreigners. Origins Early years Paceville traces its origins in the 1910s and 1920s when prominent lawyer and developer Dr Giuseppe Pace (1890–1971) built a few seaside residences in the area of St. Julian's known as 'il-Qaliet', the small bay between the Dragonara Peninsula and Portomaso. Some of these residencies are still there today, although they are now surrounded by the multi-storey apartments and hotels in the area. Pace's houses were initially rented out to a number of British servicemen who were stationed in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Per Vaginam
In mammals and other animals, the vagina (: vaginas or vaginae) is the elastic, muscular reproductive organ of the female genital tract. In humans, it extends from the vulval vestibule to the cervix (neck of the uterus). The vaginal introitus is normally partly covered by a thin layer of mucosal tissue called the hymen. The vagina allows for copulation and birth. It also channels menstrual flow, which occurs in humans and closely related primates as part of the menstrual cycle. To accommodate smoother penetration of the vagina during sexual intercourse or other sexual activity, vaginal moisture increases during sexual arousal in human females and other female mammals. This increase in moisture provides vaginal lubrication, which reduces friction. The texture of the vaginal walls creates friction for the penis during sexual intercourse and stimulates it toward ejaculation, enabling fertilization. Along with pleasure and bonding, women's sexual behavior with other people can ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principal Value
In mathematics, specifically complex analysis, the principal values of a multivalued function are the values along one chosen branch (mathematical analysis), branch of that Function (mathematics), function, so that it is Single-valued function, single-valued. A simple case arises in taking the square root of a positive real number. For example, 4 has two square roots: 2 and −2; of these the positive root, 2, is considered the principal root and is denoted as \sqrt. Motivation Consider the complex logarithm function . It is defined as the complex number such that :e^w = z. Now, for example, say we wish to find . This means we want to solve :e^w = i for w. The value i\pi/2 is a solution. However, there are other solutions, which is evidenced by considering the position of in the complex plane and in particular its argument (complex analysis), argument \arg i. We can rotate counterclockwise \pi/2 radians from 1 to reach initially, but if we rotate further another 2\pi we rea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paravirtualization
In computing, virtualization (abbreviated v12n) is a series of technologies that allows dividing of physical computing resources into a series of virtual machines, operating systems, processes or containers. Virtualization began in the 1960s with IBM CP/CMS. The control program CP provided each user with a simulated stand-alone System/360 computer. In hardware virtualization, the ''host machine'' is the machine that is used by the virtualization and the ''guest machine'' is the virtual machine. The words ''host'' and ''guest'' are used to distinguish the software that runs on the physical machine from the software that runs on the virtual machine. The software or firmware that creates a virtual machine on the host hardware is called a ''hypervisor'' or ''virtual machine monitor''. Hardware virtualization is not the same as hardware emulation. Hardware-assisted virtualization facilitates building a virtual machine monitor and allows guest OSes to be run in isolation. Desktop v ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semaphore (programming)
In computer science, a semaphore is a variable or abstract data type used to control access to a common resource by multiple threads and avoid critical section problems in a concurrent system such as a multitasking operating system. Semaphores are a type of synchronization primitive. A trivial semaphore is a plain variable that is changed (for example, incremented or decremented, or toggled) depending on programmer-defined conditions. A useful way to think of a semaphore as used in a real-world system is as a record of how many units of a particular resource are available, coupled with operations to adjust that record ''safely'' (i.e., to avoid race conditions) as units are acquired or become free, and, if necessary, wait until a unit of the resource becomes available. Though semaphores are useful for preventing race conditions, they do not guarantee their absence. Semaphores that allow an arbitrary resource count are called counting semaphores, while semaphores that are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Page View
In web analytics and website management, a pageview or page view, abbreviated in business to PV and occasionally called page impression, is a request to load a single HTML file (web page) of an Internet site. On the World Wide Web, a page request would result from a web surfer clicking on a link on another page pointing to the page in question. In contrast, a hit refers to a request for any file from a web server. Therefore, there may be many hits per page view since an HTML page can contain multiple files such as images, videos, JavaScripts, cascading style sheets (CSS), etc. On balance, page views refer to a number of pages viewed or clicked on the site during the given time. Page views may be counted as part of web analytics. For the owner of the site, this information can be useful to see if any change in the "page" (such as the information or the way it is presented) results in more visits. If there are any advertisements on the page, the publishers would also be inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perovskite
Perovskite (pronunciation: ) is a calcium titanium oxide mineral composed of calcium titanate (chemical formula ). Its name is also applied to the class of compounds which have the same type of crystal structure as , known as the perovskite (structure), perovskite structure, which has a general chemical formula . Many different cations can be embedded in this structure, allowing the development of diverse engineered materials. History The mineral was discovered in the Ural Mountains of Russia by Gustav Rose in 1839 and is named after Russian mineralogist Lev Perovski (1792–1856). Perovskite's notable crystal structure was first described by Victor Goldschmidt in 1926 in his work on tolerance factors. The crystal structure was later published in 1945 from X-ray diffraction data on barium titanate by Helen Dick Megaw. Occurrence Found in the Earth's Mantle (geology), mantle, perovskite's occurrence at Khibiny Mountains, Khibina Massif is restricted to the silica under-saturat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peroxide Value
Detection of peroxide gives the initial evidence of rancidity in unsaturated fats and oils. Other methods are available, but peroxide value is the most widely used. It gives a measure of the extent to which an oil sample has undergone primary oxidation; extent of secondary oxidation may be determined from p-anisidine test.Chemistry And Technology Of Oils And FatChemistry And Technology Of Oils And Fats By Dr. M.M. Chakrabarty The double bonds found in fats and oils play a role in autoxidation. Oils with a high degree of Unsaturated fat, unsaturation are most susceptible to autoxidation. The best test for autoxidation (oxidative rancidity) is determination of the peroxide value. Peroxides are intermediates in the autoxidation reaction. Autoxidation is a Free radical addition, free radical reaction involving oxygen that leads to deterioration of fats and oils which form off-flavours and off-odours. Peroxide value, concentration of peroxide in an oil or fat, is useful for assessing t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protecting Group
A protecting group or protective group is introduced into a molecule by chemical modification of a functional group to obtain chemoselectivity in a subsequent chemical reaction. It plays an important role in multistep organic synthesis. In many preparations of delicate organic compounds, specific parts of the molecules cannot survive the required reagents or chemical environments. These parts (functional groups) must be protected. For example, lithium aluminium hydride is a highly reactive reagent that usefully reduces esters to alcohols. It always reacts with carbonyl groups, and cannot be discouraged by any means. When an ester must be reduced in the presence of a carbonyl, hydride attack on the carbonyl must be prevented. One way to do so converts the carbonyl into an acetal, which does not react with hydrides. The acetal is then called a protecting group for the carbonyl. After the hydride step is complete, aqueous acid removes the acetal, restoring the carbonyl. This step ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ideal Gas Equation
The ideal gas law, also called the general gas equation, is the equation of state of a hypothetical ideal gas. It is a good approximation of the behavior of many gases under many conditions, although it has several limitations. It was first stated by Benoît Paul Émile Clapeyron in 1834 as a combination of the empirical Boyle's law, Charles's law, Avogadro's law, and Gay-Lussac's law. The ideal gas law is often written in an empirical form: pV = nRT where p, V and T are the pressure, volume and temperature respectively; n is the amount of substance; and R is the ideal gas constant. It can also be derived from the microscopic kinetic theory, as was achieved (independently) by August Krönig in 1856 and Rudolf Clausius in 1857. Equation The state of an amount of gas is determined by its pressure, volume, and temperature. The modern form of the equation relates these simply in two main forms. The temperature used in the equation of state is an absolute temperature: the ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
