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Runar Collander
Paul Runar Collander (1 May 1894 Vyborg – 25 May 1973 Helsinki) was a Finnish botanist. He was an adjunct professor of plant physiology at the University of Helsinki from 1935 to 1939, and professor of botany from 1939 to 1961. He gained international acclaim for his research on the effect of molecular size and solubility ratios on the ability of substances to penetrate the cell membrane. He presented the "lipoid filter theory" of permeability and further developed it. Collander also wrote several works on the history of botany The history of botany examines the human effort to understand life on Earth by tracing the historical development of the discipline of botany—that part of natural science dealing with organisms traditionally treated as plants. Rudimentary b .... Selected works * References 1894 births 1973 deaths 20th-century Finnish botanists Academic staff of the University of Helsinki Scientists from Vyborg Plant physiologists {{botanis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vyborg
Vyborg (; rus, Вы́борг, links=1, r=Výborg, p=ˈvɨbərk; fi, Viipuri ; sv, Viborg ; german: Wiborg ) is a town in, and the administrative center of, Vyborgsky District in Leningrad Oblast, Russia. It lies on the Karelian Isthmus near the head of the Vyborg Bay, to the northwest of St. Petersburg, east of the Finnish capital Helsinki, and south of Russia's border with Finland, where the Saimaa Canal enters the Gulf of Finland. The population of Vyborg is as follows: Located in the boundary zone between the East Slavic/Russian and Finnish worlds, formerly well known as one of the few medieval towns in Finland, Vyborg has changed hands several times in history, most recently in 1944 when the Soviet Union captured it from Finland during World War II. Finland evacuated the entire population of the city and resettled them within the rest of the country. On March 25, 2010, Dmitry Medvedev named Vyborg the "City of Military Glory". In Russia, a city can be award ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cell Membrane
The cell membrane (also known as the plasma membrane (PM) or cytoplasmic membrane, and historically referred to as the plasmalemma) is a biological membrane that separates and protects the interior of all cells from the outside environment (the extracellular space). The cell membrane consists of a lipid bilayer, made up of two layers of phospholipids with cholesterols (a lipid component) interspersed between them, maintaining appropriate membrane fluidity at various temperatures. The membrane also contains membrane proteins, including integral proteins that span the membrane and serve as membrane transporters, and peripheral proteins that loosely attach to the outer (peripheral) side of the cell membrane, acting as enzymes to facilitate interaction with the cell's environment. Glycolipids embedded in the outer lipid layer serve a similar purpose. The cell membrane controls the movement of substances in and out of cells and organelles, being selectively permeable to ions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Academic Staff Of The University Of Helsinki
An academy (Attic Greek: Ἀκαδήμεια; Koine Greek Ἀκαδημία) is an institution of secondary or tertiary higher learning (and generally also research or honorary membership). The name traces back to Plato's school of philosophy, founded approximately 385 BC at Akademia, a sanctuary of Athena, the goddess of wisdom and skill, north of Athens, Greece. Etymology The word comes from the ''Academy'' in ancient Greece, which derives from the Athenian hero, ''Akademos''. Outside the city walls of Athens, the gymnasium was made famous by Plato as a center of learning. The sacred space, dedicated to the goddess of wisdom, Athena, had formerly been an olive grove, hence the expression "the groves of Academe". In these gardens, the philosopher Plato conversed with followers. Plato developed his sessions into a method of teaching philosophy and in 387 BC, established what is known today as the Old Academy. By extension, ''academia'' has come to mean the accumulation, dev ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1973 Deaths
Events January * January 1 - The United Kingdom, the Republic of Ireland and Denmark enter the European Economic Community, which later becomes the European Union. * January 15 – Vietnam War: Citing progress in peace negotiations, U.S. President Richard Nixon announces the suspension of offensive action in North Vietnam. * January 17 – Ferdinand Marcos becomes President for Life of the Philippines. * January 20 – Richard Nixon is sworn in for a second term as President of the United States. Nixon is the only person to have been sworn in twice as President ( 1969, 1973) and Vice President of the United States ( 1953, 1957). * January 22 ** George Foreman defeats Joe Frazier to win the heavyweight world boxing championship. ** A Royal Jordanian Boeing 707 flight from Jeddah crashes in Kano, Nigeria; 176 people are killed. * January 27 – U.S. involvement in the Vietnam War ends with the signing of the Paris Peace Accords. February * February 8 – A militar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1894 Births
Events January–March * January 4 – A military alliance is established between the French Third Republic and the Russian Empire. * January 7 – William Kennedy Dickson receives a patent for motion picture film in the United States. * January 9 – New England Telephone and Telegraph installs the first battery-operated telephone switchboard, in Lexington, Massachusetts Lexington is a suburban town in Middlesex County, Massachusetts, United States. It is 10 miles (16 km) from Downtown Boston. The population was 34,454 as of the 2020 census. The area was originally inhabited by Native Americans, and was firs .... * February 12 ** French anarchist Émile Henry (anarchist), Émile Henry sets off a bomb in a Paris café, killing one person and wounding twenty. ** The barque ''Elisabeth Rickmers'' of Bremerhaven is wrecked at Haurvig, Denmark, but all crew and passengers are saved. * February 15 ** In Korea, peasant unrest erupts in the Donghak Peasant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Suomen Kansallisbiografia
''Suomen kansallisbiografia'' ( en, The National Biography of Finland) is a collection of more than 6,000 biographies A biography, or simply bio, is a detailed description of a person's life. It involves more than just the basic facts like education, work, relationships, and death; it portrays a person's experience of these life events. Unlike a profile or c ... of individuals and families who have made important contributions to the development of Finnish society.The National Biography of Finland (in English). References External links Suomen kansallisbiografia {{in lang, fi [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Botany
The history of botany examines the human effort to understand life on Earth by tracing the historical development of the discipline of botany—that part of natural science dealing with organisms traditionally treated as plants. Rudimentary botanical science began with empirically based plant lore passed from generation to generation in the oral traditions of paleolithic hunter-gatherers. The first written records of plants were made in the Neolithic Revolution about 10,000 years ago as writing was developed in the settled agricultural communities where plants and animals were first domesticated. The first writings that show human curiosity about plants themselves, rather than the uses that could be made of them, appear in ancient Greece and ancient India. In Ancient Greece, the teachings of Aristotle's student Theophrastus at the Lyceum in ancient Athens in about 350 BC are considered the starting point for Western botany. In ancient India, the Vŗkşăyurvĕda, attributed to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semipermeable Membrane
Semipermeable membrane is a type of biological or synthetic, polymeric membrane that will allow certain molecules or ions to pass through it by osmosis. The rate of passage depends on the pressure, concentration, and temperature of the molecules or solutes on either side, as well as the permeability of the membrane to each solute. Depending on the membrane and the solute, permeability may depend on solute size, solubility, properties, or chemistry. How the membrane is constructed to be selective in its permeability will determine the rate and the permeability. Many natural and synthetic materials which are rather thick are also semipermeable. One example of this is the thin film on the inside of the egg. Biological membranes are selectively permeable, with the passage of molecules controlled by facilitated diffusion, passive transport or active transport regulated by proteins embedded in the membrane. Biological membranes An example of a biological semi-permeable membrane is t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Solubility
In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solubility of a substance in a specific solvent is generally measured as the concentration of the solute in a saturated solution, one in which no more solute can be dissolved. At this point, the two substances are said to be at the solubility equilibrium. For some solutes and solvents, there may be no such limit, in which case the two substances are said to be " miscible in all proportions" (or just "miscible"). The solute can be a solid, a liquid, or a gas, while the solvent is usually solid or liquid. Both may be pure substances, or may themselves be solutions. Gases are always miscible in all proportions, except in very extreme situations,J. de Swaan Arons and G. A. M. Diepen (1966): "Gas—Gas Equilibria". ''Journal of Chemical Physics'', ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Helsinki
Helsinki ( or ; ; sv, Helsingfors, ) is the Capital city, capital, primate city, primate, and List of cities and towns in Finland, most populous city of Finland. Located on the shore of the Gulf of Finland, it is the seat of the region of Uusimaa in southern Finland, and has a population of . The Helsinki urban area, city's urban area has a population of , making it by far the List of urban areas in Finland by population, most populous urban area in Finland as well as the country's most important center for politics, education, finance, culture, and research; while Tampere in the Pirkanmaa region, located to the north from Helsinki, is the second largest urban area in Finland. Helsinki is located north of Tallinn, Estonia, east of Stockholm, Sweden, and west of Saint Petersburg, Russia. It has History of Helsinki, close historical ties with these three cities. Together with the cities of Espoo, Vantaa, and Kauniainen (and surrounding commuter towns, including the eastern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Molecular Size
A molecule is a group of two or more atoms held together by attractive forces known as chemical bonds; depending on context, the term may or may not include ions which satisfy this criterion. In quantum physics, organic chemistry, and biochemistry, the distinction from ions is dropped and ''molecule'' is often used when referring to polyatomic ions. A molecule may be homonuclear, that is, it consists of atoms of one chemical element, e.g. two atoms in the oxygen molecule (O2); or it may be heteronuclear, a chemical compound composed of more than one element, e.g. water (two hydrogen atoms and one oxygen atom; H2O). In the kinetic theory of gases, the term ''molecule'' is often used for any gaseous particle regardless of its composition. This relaxes the requirement that a molecule contains two or more atoms, since the noble gases are individual atoms. Atoms and complexes connected by non-covalent interactions, such as hydrogen bonds or ionic bonds, are typically not consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
