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Radiation-induced Cancer
Exposure to ionizing radiation is known to increase the future incidence of cancer, particularly leukemia. The mechanism by which this occurs is well understood, but quantitative models predicting the level of risk remain controversial. The most widely accepted model posits that the incidence of cancers due to ionizing radiation increases linearly with effective radiation dose at a rate of 5.5% per sievert; if correct, natural background radiation is the most hazardous source of radiation to general public health, followed by medical imaging as a close second. Additionally, the vast majority of non-invasive cancers are non-melanoma skin cancers caused by ultraviolet radiation (which lies on the boundary between ionizing and non-ionizing radiation). Non-ionizing radio frequency radiation from mobile phones, electric power transmission, and other similar sources have been investigated as a possible carcinogen by the WHO's International Agency for Research on Cancer, but to date ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ionizing Radiation
Ionizing radiation (or ionising radiation), including nuclear radiation, consists of subatomic particles or electromagnetic waves that have sufficient energy to ionize atoms or molecules by detaching electrons from them. Some particles can travel up to 99% of the speed of light, and the electromagnetic waves are on the high-energy portion of the electromagnetic spectrum. Gamma rays, X-rays, and the higher energy ultraviolet part of the electromagnetic spectrum are ionizing radiation, whereas the lower energy ultraviolet, visible light, nearly all types of laser light, infrared, microwaves, and radio waves are non-ionizing radiation. The boundary between ionizing and non-ionizing radiation in the ultraviolet area is not sharply defined, as different molecules and atoms ionize at different energies. The energy of ionizing radiation starts between 10 electronvolts (eV) and 33 eV. Typical ionizing subatomic particles include alpha particles, beta particle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiograph
Radiography is an imaging technique using X-rays, gamma rays, or similar ionizing radiation and non-ionizing radiation to view the internal form of an object. Applications of radiography include medical radiography ("diagnostic" and "therapeutic") and industrial radiography. Similar techniques are used in airport security (where "body scanners" generally use backscatter X-ray). To create an image in conventional radiography, a beam of X-rays is produced by an X-ray generator and is projected toward the object. A certain amount of the X-rays or other radiation is absorbed by the object, dependent on the object's density and structural composition. The X-rays that pass through the object are captured behind the object by a detector (either photographic film or a digital detector). The generation of flat two dimensional images by this technique is called projectional radiography. In computed tomography (CT scanning) an X-ray source and its associated detectors rotate around th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Becquerel
The becquerel (; symbol: Bq) is the unit of radioactivity in the International System of Units (SI). One becquerel is defined as the activity of a quantity of radioactive material in which one nucleus decays per second. For applications relating to human health this is a small quantity, and SI multiples of the unit are commonly used. The becquerel is named after Henri Becquerel, who shared a Nobel Prize in Physics with Pierre and Marie Skłodowska Curie in 1903 for their work in discovering radioactivity. Definition 1 Bq = 1 s−1 A special name was introduced for the reciprocal second (s−1) to represent radioactivity to avoid potentially dangerous mistakes with prefixes. For example, 1 µs−1 would mean 106 disintegrations per second: 1·(10−6 s)−1 = 106 s−1, whereas 1 µBq would mean 1 disintegration per 1 million seconds. Other names considered were hertz (Hz), a special name already in use for the reciprocal second, and Four ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Curie (unit)
The curie (symbol Ci) is a non- SI unit of radioactivity originally defined in 1910. According to a notice in ''Nature'' at the time, it was to be named in honour of Pierre Curie, but was considered at least by some to be in honour of Marie Curie as well, and is in later literature considered to be named for both. It was originally defined as "the quantity or mass of radium emanation in equilibrium with one gram of radium (element)", but is currently defined as 1 Ci = decays per second after more accurate measurements of the activity of 226Ra (which has a specific activity of ). In 1975 the General Conference on Weights and Measures gave the becquerel (Bq), defined as one nuclear decay per second, official status as the SI unit of activity. Therefore: : 1 Ci = = 37 GBq and : 1 Bq ≅ ≅ 27 pCi While its continued use is discouraged by National Institute of Standards and Technology (NIST) and other bodies, the curie is still widely used througho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thyroid Cancer
Thyroid cancer is cancer that develops from the tissues of the thyroid gland. It is a disease in which cells grow abnormally and have the potential to spread to other parts of the body. Symptoms can include swelling or a lump in the neck. Cancer can also occur in the thyroid after spread from other locations, in which case it is not classified as thyroid cancer. Risk factors include radiation exposure at a young age, having an enlarged thyroid, and family history. The four main types are papillary thyroid cancer, follicular thyroid cancer, medullary thyroid cancer, and anaplastic thyroid cancer. Diagnosis is often based on ultrasound and fine needle aspiration. Screening people without symptoms and at normal risk for the disease is not recommended as of 2017. Treatment options may include surgery, radiation therapy including radioactive iodine, chemotherapy, thyroid hormone, targeted therapy, and watchful waiting. Surgery may involve removing part or all of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chernobyl Disaster
The Chernobyl disaster was a nuclear accident that occurred on 26 April 1986 at the No. 4 nuclear reactor, reactor in the Chernobyl Nuclear Power Plant, near the city of Pripyat in the north of the Ukrainian Soviet Socialist Republic, Ukrainian SSR in the Soviet Union. It is one of only two nuclear energy accidents rated at seven—the maximum severity—on the International Nuclear Event Scale, the other being the 2011 Fukushima nuclear disaster in Japan. The initial emergency response, together with later decontamination of the environment, involved more than Chernobyl liquidators, 500,000 personnel and cost an estimated 18 billion Soviet rouble, roubles—roughly US$68 billion in 2019, adjusted for inflation. The accident occurred during a safety test meant to measure the ability of the steam turbine to power the emergency feedwater pumps of an RBMK, RBMK-type nuclear reactor in the event of a simultaneous loss of external power and major coolant leak. During a pla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chernobyl Radiation Map 1996
Chernobyl ( , ; russian: Чернобыль, ) or Chornobyl ( uk, Чорнобиль, ) is a partially abandoned city in the Chernobyl Exclusion Zone, situated in the Vyshhorod Raion of northern Kyiv Oblast, Ukraine. Chernobyl is about north of Kyiv, and southwest of the Belarusian city of Gomel. Before its evacuation, the city had about 14,000 residents, while around 1,000 people live in the city today. First mentioned as a ducal hunting lodge in 1193, the city has changed hands multiple times over the course of history. Jews moved into the city in the 16th century, and a now-defunct monastery was established in the area in 1626. By the end of the 18th century, Chernobyl was a major centre of Hasidic Judaism under the Twersky Dynasty, who left Chernobyl after the city was subject to pogroms in the early 20th century. The Jewish community was later murdered during the Holocaust. Chernobyl was chosen as the site of Ukraine's first nuclear power plant in 1972, located ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
US Capitol
The United States Capitol, often called The Capitol or the Capitol Building, is the seat of the legislative branch of the United States federal government, which is formally known as the United States Congress. It is located on Capitol Hill at the eastern end of the National Mall in Washington, D.C. Though no longer at the geographic center of the federal district, the Capitol forms the origin point for the street-numbering system of the district as well as its four quadrants. Central sections of the present building were completed in 1800. These were partly destroyed in the 1814 Burning of Washington, then were fully restored within five years. The building was later enlarged by extending the wings for the chambers for the bicameral legislature, the House of Representatives in the south wing and the Senate in the north wing. The massive dome was completed around 1866 just after the American Civil War. Like the principal buildings of the executive and judicial branches, the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cosmic Radiation
Cosmic rays are high-energy particles or clusters of particles (primarily represented by protons or atomic nuclei) that move through space at nearly the speed of light. They originate from the Sun, from outside of the Solar System in our own galaxy, and from distant galaxies. Upon impact with Earth's atmosphere, cosmic rays produce showers of secondary particles, some of which reach the surface, although the bulk is deflected off into space by the magnetosphere or the heliosphere. Cosmic rays were discovered by Victor Hess in 1912 in balloon experiments, for which he was awarded the 1936 Nobel Prize in Physics. Direct measurement of cosmic rays, especially at lower energies, has been possible since the launch of the first satellites in the late 1950s. Particle detectors similar to those used in nuclear and high-energy physics are used on satellites and space probes for research into cosmic rays. Data from the Fermi Space Telescope (2013) have been interpreted as evide ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cancer And Spaceflight
Astronauts are exposed to approximately 50-2,000 millisieverts (mSv) while on six-month-duration missions to the International Space Station (ISS), the Moon and beyond. The risk of cancer caused by ionizing radiation is well documented at radiation doses beginning at 100mSv and above. Related radiological effect studies have shown that survivors of the atomic bomb explosions in Hiroshima and Nagasaki, nuclear reactor workers and patients who have undergone therapeutic radiation treatments have received low-linear energy transfer (LET) radiation (x-rays and gamma rays) doses in the same 50-2,000 mSv range. Composition of space radiation While in space, astronauts are exposed to radiation which is mostly composed of high-energy protons, helium nuclei (alpha particles), and high-atomic-number ions (HZE ions), as well as secondary radiation from nuclear reactions from spacecraft parts or tissue. The ionization patterns in molecules, cells, tissues and the resulting biological e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American College Of Radiology
The American College of Radiology (ACR), founded in 1923, is a professional medical society representing nearly 40,000 diagnostic radiologists, radiation oncologists, interventional radiologists, nuclear medicine physicians and medical physicists. The ACR has 54 chapters in the United States, Canada and the Council of Affiliated Regional Radiation Oncology Societies (CARROS). Medical imaging accreditation The ACR has accredited more than 39,000 medical imaging facilities in 10 imaging modalities since 1987, including: * Breast MRI * Breast Ultrasound *Computed Tomography *Mammography * Magnetic Resonance Imaging *Nuclear Medicine * Positron Emission Tomography * Radiation Oncology Practice * Stereotactic Breast Biopsy *Ultrasound ACR Appropriateness Criteria The ACR Appropriateness Criteria (ACR AC) are evidence-based guidelines that assist referring physicians and other providers in making the most appropriate imaging or treatment decision for a specific clinical condition. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Medscape
Medscape is a website providing access to medical information for clinicians; the organization also provides continuing education for physicians and health professionals. It references medical journal articles, Continuing Medical Education (CME), a version of the National Library of Medicine's MEDLINE database, medical news, and drug information (Medscape Drug Reference, or MDR). At one time Medscape published seven electronic peer reviewed journals. History Medscape launched May 22, 1995 by SCP Communications, Inc. under the direction of its CEO Peter Frishauf. In 1999, George D. Lundberg became the editor-in-chief of Medscape. For seventeen years before joining Medscape he had served as Editor of the ''Journal of the American Medical Association''. In September 1999, Medscape, Inc. went public and began trading on NASDAQ under the symbol MSCP. In 2000, Medscape merged with MedicaLogic, Inc., another public company. MedicaLogic filed for bankruptcy within 18 months and sol ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
