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Virologists
Virology is the scientific study of biological viruses. It is a subfield of microbiology that focuses on their detection, structure, classification and evolution, their methods of infection and exploitation of host cells for reproduction, their interaction with host organism physiology and immunity, the diseases they cause, the techniques to isolate and culture them, and their use in research and therapy. The identification of the causative agent of tobacco mosaic disease (TMV) as a novel pathogen by Martinus Beijerinck (1898) is now acknowledged as being the official beginning of the field of virology as a discipline distinct from bacteriology. He realized the source was neither a bacterial nor a fungal infection, but something completely different. Beijerinck used the word "virus" to describe the mysterious agent in his 'contagium vivum fluidum' ('contagious living fluid'). Rosalind Franklin proposed the full structure of the tobacco mosaic virus in 1955. Virology began ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Virus
A virus is a submicroscopic infectious agent that replicates only inside the living cells of an organism. Viruses infect all life forms, from animals and plants to microorganisms, including bacteria and archaea. Since Dmitri Ivanovsky's 1892 article describing a non-bacterial pathogen infecting tobacco plants and the discovery of the tobacco mosaic virus by Martinus Beijerinck in 1898,Dimmock p. 4 more than 9,000 virus species have been described in detail of the millions of types of viruses in the environment. Viruses are found in almost every ecosystem on Earth and are the most numerous type of biological entity. The study of viruses is known as virology, a subspeciality of microbiology. When infected, a host cell is often forced to rapidly produce thousands of copies of the original virus. When not inside an infected cell or in the process of infecting a cell, viruses exist in the form of independent particles, or ''virions'', consisting of (i) the genetic material, i. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiology
Microbiology () is the scientific study of microorganisms, those being unicellular (single cell), multicellular (cell colony), or acellular (lacking cells). Microbiology encompasses numerous sub-disciplines including virology, bacteriology, protistology, mycology, immunology, and parasitology. Eukaryotic microorganisms possess membrane-bound organelles and include fungi and protists, whereas prokaryotic organisms—all of which are microorganisms—are conventionally classified as lacking membrane-bound organelles and include Bacteria and Archaea. Microbiologists traditionally relied on culture, staining, and microscopy. However, less than 1% of the microorganisms present in common environments can be cultured in isolation using current means. Microbiologists often rely on molecular biology tools such as DNA sequence based identification, for example the 16S rRNA gene sequence used for bacteria identification. Viruses have been variably classified as organisms, as they have ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Martinus Beijerinck
Martinus Willem Beijerinck (, 16 March 1851 – 1 January 1931) was a Dutch microbiologist and botanist who was one of the founders of virology and environmental microbiology. He is credited with the discovery of viruses, which he called "''contagium vivum fluidum''". Life Early life and education Born in Amsterdam, Beijerinck studied at the Technical School of Delft, where he was awarded the degree of Chemical Engineer in 1872. He obtained his Doctor of Science degree from the University of Leiden in 1877. At the time, Delft, then a Polytechnic, did not have the right to confer doctorates, so Leiden did this for them. He became a teacher in microbiology at the Agricultural School in Wageningen (now Wageningen University) and later at the ''Polytechnische Hogeschool Delft'' (Delft Polytechnic, currently Delft University of Technology) (from 1895). He established the Delft School of Microbiology. His studies of agricultural and industrial microbiology yielded fundamental disco ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wendell Stanley
Wendell Meredith Stanley (16 August 1904 – 15 June 1971) was an American biochemist, virologist and Nobel laureate. Biography Stanley was born in Ridgeville, Indiana, and earned a BSc in Chemistry at Earlham College in Richmond, Indiana. He then studied at the University of Illinois, gaining an MS in science in 1927 followed by a PhD in chemistry two years later. His later accomplishments include writing the book "Chemistry: A Beautiful Thing" and being a Pulitzer Prize nominee. Research As a member of National Research Council he moved temporarily for academic work with Heinrich Wieland in Munich before he returned to the States in 1931. On return he was approved as an assistant at The Rockefeller Institute for Medical Research. He remained with the Institute until 1948, becoming an Associate Member in 1937, and a Member in 1940. In 1948, he became Professor of Biochemistry at the University of California, Berkeley and built the Virus Laboratory and a free-standing De ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Germ Theory Of Disease
The germ theory of disease is the currently accepted scientific theory for many diseases. It states that microorganisms known as pathogens or "germs" can lead to disease. These small organisms, too small to be seen without magnification, invade humans, other animals, and other living hosts. Their growth and reproduction within their hosts can cause disease. "Germ" refers to not just a bacterium but to any type of microorganism, such as protists or fungi, or even non-living pathogens that can cause disease, such as viruses, prions, or viroids. Diseases caused by pathogens are called infectious diseases. Even when a pathogen is the principal cause of a disease, environmental and hereditary factors often influence the severity of the disease, and whether a potential host individual becomes infected when exposed to the pathogen. Pathogens are disease-carrying agents that can pass from one individual to another, both in humans and animals. Infectious diseases are caused by biological a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
History Of Virology
The history of virology – the scientific study of viruses and the infections they cause – began in the closing years of the 19th century. Although Louis Pasteur and Edward Jenner developed the first vaccines to protect against viral infections, they did not know that viruses existed. The first evidence of the existence of viruses came from experiments with filters that had pores small enough to retain bacteria. In 1892, Dmitri Ivanovsky used one of these filters to show that sap from a diseased tobacco plant remained infectious to healthy tobacco plants despite having been filtered. Martinus Beijerinck called the filtered, infectious substance a "virus" and this discovery is considered to be the beginning of virology. The subsequent discovery and partial characterization of bacteriophages by Frederick Twort and Félix d'Herelle further catalyzed the field, and by the early 20th century many viruses had been discovered. In 1926, Thomas Milton Rivers defined viruses as obligat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chamberland Filter
A Chamberland filter, also known as a Pasteur–Chamberland filter, is a porcelain water filter invented by Charles Chamberland in 1884. It was developed after Henry Doulton, Henry Doulton's ceramic water filter of 1827. It is similar to the Berkefeld filter in principle. Design The filter consists of a permeable unglazed porcelain tube (called bisque) that contains a ring of enameled porcelain through which the inflow pipe fits. The core of the porcelain is made up of a metal pipe with holes through which water flows out and is collected. Inflow is pressurized so filtration occurs under force. There are 13 types: ''L1'' to ''L13''. L1 filters have the coarsest pore size while L13 have the finest. Usefulness The Pasteur-Chamberland filter is as useful as other ceramic and porcelain filters. It is a good bacterial water filter used mainly as a high volume water filter.Textbook of Microbiology by Ananthanarayan and Panikar, The filter works more quickly when the water suppli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rabies
Rabies is a viral disease that causes encephalitis in humans and other mammals. Early symptoms can include fever and tingling at the site of exposure. These symptoms are followed by one or more of the following symptoms: nausea, vomiting, violent movements, uncontrolled excitement, fear of water, an inability to move parts of the body, confusion, and loss of consciousness. Once symptoms appear, the result is virtually always death, regardless of treatment. The time period between contracting the disease and the start of symptoms is usually one to three months but can vary from less than one week to more than one year. The time depends on the distance the virus must travel along peripheral nerves to reach the central nervous system. Rabies is caused by lyssaviruses, including the rabies virus and Australian bat lyssavirus. It is spread when an infected animal bites or scratches a human or other animals. Saliva from an infected animal can also transmit rabies if the saliva come ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microbiologist
A microbiologist (from Ancient Greek, Greek ) is a scientist who studies microscopic life forms and processes. This includes study of the growth, interactions and characteristics of Microorganism, microscopic organisms such as bacteria, algae, fungi, and some types of parasites and their vectors. Most microbiologists work in offices and/or research facilities, both in private biotechnology companies and in academia. Most microbiologists specialize in a given topic within microbiology such as bacteriology, parasitology, virology, or immunology. Duties Microbiologists generally work in some way to increase scientific knowledge or to utilise that knowledge in a way that improves outcomes in medicine or some industry. For many microbiologists, this work includes planning and conducting experimental research projects in some kind of laboratory setting. Others may have a more administrative role, supervising scientists and evaluating their results. Microbiologists working in the medi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Charles Chamberland
Charles Chamberland (; 12 March 1851 – 2 May 1908) was a French microbiologist from Chilly-le-Vignoble in the department of Jura who worked with Louis Pasteur. In 1884 he developed a type of filtration known today as the Chamberland filter or Chamberland-Pasteur filter, a device that made use of an unglazed porcelain bar. The filter had pores that were smaller than bacteria, thus making it possible to pass a solution containing bacteria through the filter, and having the bacteria completely removed from the solution. Chamberland was also credited for starting a research project that led to the invention of the autoclave An autoclave is a machine used to carry out industrial and scientific processes requiring elevated temperature and pressure in relation to ambient pressure and/or temperature. Autoclaves are used before surgical procedures to perform sterilizati ... device in 1879. References External links * Charles Edouard Chamberland and Louis Pasteur PasteurBre ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gamma Phage
Gamma (uppercase , lowercase ; ''gámma'') is the third letter of the Greek alphabet. In the system of Greek numerals it has a value of 3. In Ancient Greek, the letter gamma represented a voiced velar stop . In Modern Greek, this letter represents either a voiced velar fricative or a voiced palatal fricative (while /g/ in foreign words is instead commonly transcribed as γκ). In the International Phonetic Alphabet and other modern Latin-alphabet based phonetic notations, it represents the voiced velar fricative. History The Greek letter Gamma Γ is a grapheme derived from the Phoenician letter (''gīml'') which was rotated from the right-to-left script of Canaanite to accommodate the Greek language's writing system of left-to-right. The Canaanite grapheme represented the /g/ phoneme in the Canaanite language, and as such is cognate with ''gimel'' ג of the Hebrew alphabet. Based on its name, the letter has been interpreted as an abstract representation of a camel's ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tobacco Mosaic Virus
''Tobacco mosaic virus'' (TMV) is a positive-sense single-stranded RNA virus species in the genus ''Tobamovirus'' that infects a wide range of plants, especially tobacco and other members of the family Solanaceae. The infection causes characteristic patterns, such as "mosaic"-like mottling and discoloration on the leaves (hence the name). TMV was the first virus to be discovered. Although it was known from the late 19th century that a non-bacterial infectious disease was damaging tobacco crops, it was not until 1930 that the infectious agent was determined to be a virus. It is the first pathogen identified as a virus. The virus was crystallised by W.M. Stanley. It has a similar size to the largest synthetic molecule, known as PG5 History In 1886, Adolf Mayer first described the tobacco mosaic disease that could be transferred between plants, similar to bacterial infections. In 1892, Dmitri Ivanovsky gave the first concrete evidence for the existence of a non-bacterial infect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
