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Bogumił Brzezinski
Bogumił Kazimierz Brzezinski (born 22 May 1943) is a Polish chemist, professor of chemistry science who specialises in the field of infrared spectroscopy and hydrogen bonds. Co-worker of Prof. Georg Zundel. He is co-author of nearly 400 original scientific publications. Career In 1967 he graduated from the Faculty of Mathematics, Physics and Chemistry at the Adam Mickiewicz University in Poznań with M.Sc. degree. Brzezinski defended his Ph.D. in 1972 and D.Sc. in 1982. He is a Professor since 1991. He was Vice-Dean of the Faculty of Chemistry UAM in the years 1990–1996. Currently Prof. Brzezinski is the head of the Department of Biochemistry since 1998. In the years 1975–1977 Brzezinski was Alexander von Humboldt Fellow at the Faculty of Biophysic of University of Munich in Germany. Many times he was visiting Professor of Humboldt University (Faculty of Biophysic Charite) in Berlin. Research areas * Biochemistry, bioorganic and organic chemistry. * Ionophores (monensi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Poland
Poland, officially the Republic of Poland, is a country in Central Europe. It extends from the Baltic Sea in the north to the Sudetes and Carpathian Mountains in the south, bordered by Lithuania and Russia to the northeast, Belarus and Ukraine to the east, Slovakia and the Czech Republic to the south, and Germany to the west. The territory has a varied landscape, diverse ecosystems, and a temperate climate. Poland is composed of Voivodeships of Poland, sixteen voivodeships and is the fifth most populous member state of the European Union (EU), with over 38 million people, and the List of European countries by area, fifth largest EU country by area, covering . The capital and List of cities and towns in Poland, largest city is Warsaw; other major cities include Kraków, Wrocław, Łódź, Poznań, and Gdańsk. Prehistory and protohistory of Poland, Prehistoric human activity on Polish soil dates to the Lower Paleolithic, with continuous settlement since the end of the Last Gla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionophores
In chemistry, an ionophore () is a chemical species that reversibly binds ions. Many ionophores are lipid-soluble entities that transport ions across the cell membrane. Ionophores catalyze ion transport across hydrophobic membranes, such as liquid polymeric membranes (carrier-based ion selective electrodes) or lipid bilayers found in the living cells or synthetic vesicles (liposomes). Structurally, an ionophore contains a hydrophilic center and a hydrophobic portion that interacts with the membrane. Some ionophores are synthesized by microorganisms to import ions into their cells. Synthetic ion carriers have also been prepared. Ionophores selective for cations and anions have found many applications in analysis. These compounds have also shown to have various biological effects and a synergistic effect when combined with the ion they bind. Classification Biological activities of metal ion-binding compounds can be changed in response to the increment of the metal concentrat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1941 Births
The Correlates of War project estimates this to be the deadliest year in human history in terms of conflict deaths, placing the death toll at 3.49 million. However, the Uppsala Conflict Data Program estimates that the subsequent year, 1942, was the deadliest such year. Death toll estimates for both 1941 and 1942 range from 2.28 to 7.71 million each. Events Below, the events of World War II have the "WWII" prefix. January * January–August – 10,072 men, women and children with mental and physical disabilities are asphyxiated with carbon monoxide in a gas chamber, at Hadamar Euthanasia Centre in Germany, in the first phase of mass killings under the Aktion T4 program here. * January 1 – Thailand's Prime Minister Plaek Phibunsongkhram decrees January 1 as the official start of the Thai solar calendar new year (thus the previous year that began April 1 had only 9 months). * January 3 – A decree (''Normalschrifterlass'') promulgated in Germany by Martin Bormann ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Proton Sponge
1,8-Bis(dimethylamino)naphthalene is an organic compound with the formula CH(NMe) (Me = methyl). It is classified as a peri-naphthalene, i.e. a 1,8-disubstituted derivative of naphthalene. Owing to its unusual structure, it exhibits exceptional basicity. It is often referred by the trade name Proton Sponge, a trademark of Sigma-Aldrich. Structure and properties This compound is a diamine in which the two dimethylamino groups are attached on the same side ( peri position) of a naphthalene ring. This molecule has several very interesting properties; one is its very high basicity; another is its spectroscopic properties. With a p''K'' of 12.34 for its conjugate acid in aqueous solution, 1,8-bis(dimethylamino)naphthalene is one of the strongest organic bases. However, it only absorbs protons slowly—hence the trade name. The high basicity is attributed to the relief of strain upon protonation and/or the strong interaction between the nitrogen lone pairs. Additionally, although many a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Arginine
Arginine is the amino acid with the formula (H2N)(HN)CN(H)(CH2)3CH(NH2)CO2H. The molecule features a guanidinium, guanidino group appended to a standard amino acid framework. At physiological pH, the carboxylic acid is deprotonated (−CO2−) and both the amino and guanidino groups are protonated, resulting in a cation. Only the -arginine (symbol Arg or R) enantiomer is found naturally. Arg residues are common components of proteins. It is Genetic code, encoded by the DNA codon table, codons CGU, CGC, CGA, CGG, AGA, and AGG. The guanidine group in arginine is the Precursor (chemistry), precursor for the biosynthesis of nitric oxide. Like all amino acids, it is a white, water-soluble solid. The one-letter symbol R was assigned to arginine for its phonetic similarity. History Arginine was first isolated in 1886 from Lupinus luteus, yellow lupin seedlings by the German chemist Ernst Schulze (chemist), Ernst Schulze and his assistant Ernst Steiger. He named it from the Greek ''árg ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acid–base Reaction
In chemistry, an acid–base reaction is a chemical reaction that occurs between an acid and a base. It can be used to determine pH via titration. Several theoretical frameworks provide alternative conceptions of the reaction mechanisms and their application in solving related problems; these are called the acid–base theories, for example, Brønsted–Lowry acid–base theory. Their importance becomes apparent in analyzing acid–base reactions for gaseous or liquid species, or when acid or base character may be somewhat less apparent. The first of these concepts was provided by the French chemist Antoine Lavoisier, around 1776. – Table of discoveries attributes Antoine Lavoisier as the first to posit a scientific theory in relation to oxyacids. It is important to think of the acid–base reaction models as theories that complement each other. For example, the current Lewis model has the broadest definition of what an acid and base are, with the Brønsted–Lowry the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gossypol
Gossypol () is a natural phenol derived from the cotton plant (genus ''Gossypium''). Gossypol is a phenolic aldehyde that permeates cells and acts as an inhibitor for several dehydrogenase enzymes. It is a yellow pigment. The structure exhibits atropisomerism, with the two enantiomers having different biochemical properties. Among other applications, it has been tested as a male oral contraceptive in China. In addition to its putative contraceptive properties, gossypol has also long been known to possess antimalarial properties. History Utilization of cotton-seed oil in the 19th century was complicated by the fact that it stained everything. In 1882-1883 James Longmore from Liverpool took several patents on separating the colorant by partial saponification of the oil, and in 1886 he presented his findings to the local section of the Society of Chemical Industry. He is often considered the discoverer of gossypol, even though he only isolated it in crude form. The name was co ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cation
An ion () is an atom or molecule with a net electrical charge. The charge of an electron is considered to be negative by convention and this charge is equal and opposite to the charge of a proton, which is considered to be positive by convention. The net charge of an ion is not zero because its total number of electrons is unequal to its total number of protons. A cation is a positively charged ion with fewer electrons than protons (e.g. K+ ( potassium ion)) while an anion is a negatively charged ion with more electrons than protons (e.g. Cl− ( chloride ion) and OH− ( hydroxide ion)). Opposite electric charges are pulled towards one another by electrostatic force, so cations and anions attract each other and readily form ionic compounds. Ions consisting of only a single atom are termed ''monatomic ions'', ''atomic ions'' or ''simple ions'', while ions consisting of two or more atoms are termed polyatomic ions or ''molecular ions''. If only a + or − is present, it indic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Metal
A metal () is a material that, when polished or fractured, shows a lustrous appearance, and conducts electrical resistivity and conductivity, electricity and thermal conductivity, heat relatively well. These properties are all associated with having electrons available at the Fermi level, as against nonmetallic materials which do not. Metals are typically ductile (can be drawn into a wire) and malleable (can be shaped via hammering or pressing). A metal may be a chemical element such as iron; an alloy such as stainless steel; or a molecular compound such as polythiazyl, polymeric sulfur nitride. The general science of metals is called metallurgy, a subtopic of materials science; aspects of the electronic and thermal properties are also within the scope of condensed matter physics and solid-state chemistry, it is a multidisciplinary topic. In colloquial use materials such as steel alloys are referred to as metals, while others such as polymers, wood or ceramics are nonmetallic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Bond
A chemical bond is the association of atoms or ions to form molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons as in covalent bonds, or some combination of these effects. Chemical bonds are described as having different strengths: there are "strong bonds" or "primary bonds" such as covalent, ionic and metallic bonds, and "weak bonds" or "secondary bonds" such as dipole–dipole interactions, the London dispersion force, and hydrogen bonding. Since opposite electric charges attract, the negatively charged electrons surrounding the nucleus and the positively charged protons within a nucleus attract each other. Electrons shared between two nuclei will be attracted to both of them. "Constructive quantum mechanical wavefunction interference" stabilizes the paired nuclei (see Theories of chemical bonding). Bonded nuclei maintain an optima ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ion Channels
Ion channels are pore-forming membrane proteins that allow ions to pass through the channel pore. Their functions include establishing a resting membrane potential, shaping action potentials and other electrical signals by gating the flow of ions across the cell membrane, controlling the flow of ions across secretory and epithelial cells, and regulating cell volume. Ion channels are present in the membranes of all cells. Ion channels are one of the two classes of ionophoric proteins, the other being ion transporters. The study of ion channels often involves biophysics, electrophysiology, and pharmacology, while using techniques including voltage clamp, patch clamp, immunohistochemistry, X-ray crystallography, fluoroscopy, and RT-PCR. Their classification as molecules is referred to as channelomics. Basic features There are two distinctive features of ion channels that differentiate them from other types of ion transporter proteins: # The rate of ion transport thr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antibacterial Activity
The shelf life of a product can be extended either by adding artificial preservatives or by taking hygienic measures during the manufacturing process. As the consumer trend today is towards preservative-free foods with a long shelf-life, industry is being forced to rethink its manufacturing methods. Instead of adding preservative agents, increased hygienic precautions can be taken during production. A clean and hygienic manufacturing environment is an essential prerequisite in order to keep contamination-related reject rates low. The utilization of surfaces in the manufacturing environment with antibacterial properties can significantly reduce contamination risks. The determination of the antibacterial activity ( microbicidy) of surfaces is described in the following norms: ISO 22196 and JIS Z 2801.JIS Z 2801:2000 Antimicrobial products- test for antimicrobial activity and efficacy The Japanese norm JIS Z 2801 was published in 2000 and published again in 2007 as the internationally ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
