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Ultraviolet Germicidal Irradiation
Ultraviolet germicidal irradiation (UVGI) is a disinfection method that uses short-wavelength ultraviolet ( ultraviolet C or UV-C) light to kill or inactivate microorganisms by destroying nucleic acids and disrupting their DNA, leaving them unable to perform vital cellular functions. UVGI is used in a variety of applications, such as food, surface, air, and water purification. UV-C light is weak at the Earth's surface since the ozone layer of the atmosphere blocks it. UVGI devices can produce strong enough UV-C light in circulating air or water systems to make them inhospitable environments to microorganisms such as bacteria, viruses, molds, and other pathogens. Recent studies have proven the ability of UVC light in inactivating the novel Coronavirus ( COVID-19). UVGI can be coupled with a filtration system to sanitize air and water. The application of UVGI to disinfection has been an accepted practice since the mid-20th century. It has been used primarily in medical sanita ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medical Sanitation
Sterilization refers to any process that removes, kills, or deactivates all forms of life (particularly microorganisms such as fungi, bacteria, spores, and unicellular eukaryotic organisms) and other biological agents such as prions present in or on a specific surface, object, or fluid. Sterilization can be achieved through various means, including heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection, sanitization, and pasteurization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic. Applications Foods One of the first steps toward modernized sterilization was made by Nicolas Appert, who discovered that application of heat over a suitable period slowed the decay of foods and various liquids, preserving them for safe consumption for a longer time than was typical. Canning of foods is an extension of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cryptosporidium
''Cryptosporidium'', sometimes informally called crypto, is a genus of apicomplexan parasitic alveolates that can cause a respiratory and gastrointestinal illness (cryptosporidiosis) that primarily involves watery diarrhea (intestinal cryptosporidiosis), sometimes with a persistent cough (respiratory cryptosporidiosis). Treatment of gastrointestinal infection in humans involves fluid rehydration, electrolyte replacement, and management of any pain. , nitazoxanide is the only drug approved for the treatment of cryptosporidiosis in immunocompetent hosts. Supplemental zinc may improve symptoms, particularly in recurrent or persistent infections or in others at risk for zinc deficiency. ''Cryptosporidium'' oocysts are 4–6 μm in diameter and exhibit partial acid-fast staining. They must be differentiated from other partially acid-fast organisms including '' Cyclospora cayetanensis''. General characteristics ''Cryptosporidium'' causes cryptosporidiosis, an infectio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Protozoa
Protozoa (singular: protozoan or protozoon; alternative plural: protozoans) are a group of single-celled eukaryotes, either free-living or parasitic, that feed on organic matter such as other microorganisms or organic tissues and debris. Historically, protozoans were regarded as "one-celled animals", because they often possess animal-like behaviours, such as motility and predation, and lack a cell wall, as found in plants and many algae. When first introduced by Georg Goldfuss (originally spelled Goldfuß) in 1818, the taxon Protozoa was erected as a class within the Animalia, with the word 'protozoa' meaning "first animals". In later classification schemes it was elevated to a variety of higher ranks, including phylum, subkingdom and kingdom, and sometimes included within Protoctista or Protista. The approach of classifying Protozoa within the context of Animalia was widespread in the 19th and early 20th century, but not universal. By the 1970s, it became usual to require ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Water Treatment
Water treatment is any process that improves the quality of water to make it appropriate for a specific end-use. The end use may be drinking, industrial water supply, irrigation, river flow maintenance, water recreation or many other uses, including being safely returned to the environment. Water treatment removes contaminants and undesirable components, or reduces their concentration so that the water becomes fit for its desired end-use. This treatment is crucial to human health and allows humans to benefit from both drinking and irrigation use. Water is the most crucial compound for life on Earth, and having drinkable water is a key worldwide concern for the twenty-first century. All living things require clean, uncontaminated water as a basic requirement. Water covers more than 71 percent of the earth’s surface, but only around 1% of it is drinkable according to international standards due to various contaminations . Waste water discharge from industries, agricultural ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marseille, France
Marseille ( , , ; also spelled in English as Marseilles; oc, Marselha ) is the prefecture of the French department of Bouches-du-Rhône and capital of the Provence-Alpes-Côte d'Azur region. Situated in the camargue region of southern France, it is located on the coast of the Gulf of Lion, part of the Mediterranean Sea, near the mouth of the Rhône river. Its inhabitants are called ''Marseillais''. Marseille is the second most populous city in France, with 870,731 inhabitants in 2019 (Jan. census) over a municipal territory of . Together with its suburbs and exurbs, the Marseille metropolitan area, which extends over , had a population of 1,873,270 at the Jan. 2019 census, the third most populated in France after those of Paris and Lyon. The cities of Marseille, Aix-en-Provence, and 90 suburban municipalities have formed since 2016 the Aix-Marseille-Provence Metropolis, an indirectly elected metropolitan authority now in charge of wider metropolitan issues, with a pop ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tuberculosis
Tuberculosis (TB) is an infectious disease usually caused by '' Mycobacterium tuberculosis'' (MTB) bacteria. Tuberculosis generally affects the lungs, but it can also affect other parts of the body. Most infections show no symptoms, in which case it is known as latent tuberculosis. Around 10% of latent infections progress to active disease which, if left untreated, kill about half of those affected. Typical symptoms of active TB are chronic cough with blood-containing mucus, fever, night sweats, and weight loss. It was historically referred to as consumption due to the weight loss associated with the disease. Infection of other organs can cause a wide range of symptoms. Tuberculosis is spread from one person to the next through the air when people who have active TB in their lungs cough, spit, speak, or sneeze. People with Latent TB do not spread the disease. Active infection occurs more often in people with HIV/AIDS and in those who smoke. Diagnosis of ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lupus Vulgaris
Lupus vulgaris (also known as tuberculosis luposa) are painful cutaneous tuberculosis skin lesions with nodular appearance, most often on the face around the nose, eyelids, lips, cheeks, ears and neck. It is the most common ''Mycobacterium tuberculosis'' skin infection. The lesions may ultimately develop into disfiguring skin ulcers if left untreated. Signs and symptoms It begins as painless reddish-brown nodules which slowly enlarge to form irregularly shaped red plaque. File:Lupus vulgaris.jpg, Lupus vulgaris, changes in skin in hyperkeratotic forms File:Lupus vulgaris 2.jpg, Lupus vulgaris in a woman in 19th century Cause Lupus vulgaris often develops due to inadequately treated pre-existing tuberculosis. It may also develop at site of BCG vaccination. Rarely, it has been shown to be associated with tattoo marks. Histopathology Histologically, it shows presence of epithelioid cell granulomas with Langhans giant cells with or without central caseation necrosis in the der ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Niels Finsen
Niels Ryberg Finsen (15 December 1860 – 24 September 1904) was a Faroese- Icelandic physician and scientist. In 1903, he was awarded the Nobel Prize in Medicine and Physiology "in recognition of his contribution to the treatment of diseases, especially lupus vulgaris, with concentrated light radiation, whereby he has opened a new avenue for medical science." Biography Niels Finsen was born in Tórshavn, Faroe Islands, as the second-oldest of four children. His father was , who belonged to an Icelandic family with traditions reaching back to the 10th century, and his mother was Johanne Formann from Falster, Denmark. The family moved to Tórshavn from Iceland in 1858 when his father was given the position of Landfoged. When Niels was four years old his mother died, and his father married her cousin Birgitte Kirstine Formann, with whom he had six children. In 1871 his father was made '' Amtmand'' of the Faroe Islands. His father was a member of the Faroese parliament for 12 year ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nobel Prize For Medicine
The Nobel Prize in Physiology or Medicine is awarded yearly by the Nobel Assembly at the Karolinska Institute for outstanding discoveries in physiology or medicine. The Nobel Prize is not a single prize, but five separate prizes that, according to Alfred Nobel's 1895 will, are awarded "to those who, during the preceding year, have conferred the greatest benefit to humankind". Nobel Prizes are awarded in the fields of Physics, Chemistry, Physiology or Medicine, Literature, and Peace. The Nobel Prize is presented annually on the anniversary of Alfred Nobel's death, 10 December. As of 2022, 114 Nobel Prizes in Physiology or Medicine have been awarded to 226 laureates, 214 men and 12 women. The first one was awarded in 1901 to the German physiologist, Emil von Behring, for his work on serum therapy and the development of a vaccine against diphtheria. The first woman to receive the Nobel Prize in Physiology or Medicine, Gerty Cori, received it in 1947 for her role in elucidating th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mutagen
In genetics, a mutagen is a physical or chemical agent that permanently changes genetic material, usually DNA, in an organism and thus increases the frequency of mutations above the natural background level. As many mutations can cause cancer in animals, such mutagens can therefore be carcinogens, although not all necessarily are. All mutagens have characteristic mutational signatures with some chemicals becoming mutagenic through cellular processes. The process of DNA becoming modified is called mutagenesis. Not all mutations are caused by mutagens: so-called "spontaneous mutations" occur due to spontaneous hydrolysis, errors in DNA replication, repair and recombination. Discovery The first mutagens to be identified were carcinogens, substances that were shown to be linked to cancer. Tumors were described more than 2,000 years before the discovery of chromosomes and DNA; in 500 B.C., the Greek physician Hippocrates named tumors resembling a crab ''karkinos'' (from which t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sterilization (microbiology)
Sterilization refers to any process that removes, kills, or deactivates all forms of life (particularly microorganisms such as fungi, bacteria, spores, and unicellular eukaryotic organisms) and other biological agents such as prions present in or on a specific surface, object, or fluid. Sterilization can be achieved through various means, including heat, chemicals, irradiation, high pressure, and filtration. Sterilization is distinct from disinfection, sanitization, and pasteurization, in that those methods reduce rather than eliminate all forms of life and biological agents present. After sterilization, an object is referred to as being sterile or aseptic. Applications Foods One of the first steps toward modernized sterilization was made by Nicolas Appert, who discovered that application of heat over a suitable period slowed the decay of foods and various liquids, preserving them for safe consumption for a longer time than was typical. Canning of foods is an extension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
