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Dilatation
Dilation (or dilatation) may refer to: Physiology or medicine * Cervical dilation, the widening of the cervix in childbirth, miscarriage etc. * Coronary dilation, or coronary reflex * Dilation and curettage, the opening of the cervix and surgical removal of the contents of the uterus * Dilation and evacuation, the dilation of the cervix and evacuation of the contents of the uterus * Esophageal dilatation, a procedure for widening a narrowed esophagus * Pupillary dilation (also called mydriasis), the widening of the pupil of the eye * Vasodilation, the widening of luminal diameter in blood vessels Mathematics * Dilation (affine geometry), an affine transformation * Dilation (metric space), a function from a metric space into itself * Dilation (operator theory), a dilation of an operator on a Hilbert space * Dilation (morphology), an operation in mathematical morphology * Scaling (geometry), including: ** Homogeneous dilation (homothety), the scalar multiplication operator on a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Esophageal Dilatation
Esophageal dilatation is a therapeutic endoscopic procedure that enlarges the lumen of the esophagus. Indications It can be used to treat a number of medical conditions that result in narrowing of the esophageal lumen, or decrease motility in the distal esophagus. These include the following: * Peptic stricture * Eosinophilic esophagitis * Schatzki rings * Achalasia * Scleroderma esophagus * Rarely esophageal cancer Types of dilators There are three major classes of dilators: * Mercury-weighted bougies are blindly inserted bougies placed into the esophagus by the treating physician. They are passed in sequentially increasing sizes to dilate the obstructed area. They must be used with precaution in patients with narrow strictures, as they may curl proximal to the obstruction. * Bougie over guidewire dilators are used at the time of gastroscopy or fluoroscopy. An endoscopy is usually performed first to evaluate the anatomy, and a guidewire is passed into the stomach past the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Time Dilation
In physics and relativity, time dilation is the difference in the elapsed time as measured by two clocks. It is either due to a relative velocity between them ( special relativistic "kinetic" time dilation) or to a difference in gravitational potential between their locations (general relativistic gravitational time dilation). When unspecified, "time dilation" usually refers to the effect due to velocity. After compensating for varying signal delays due to the changing distance between an observer and a moving clock (i.e. Doppler effect), the observer will measure the moving clock as ticking slower than a clock that is at rest in the observer's own reference frame. In addition, a clock that is close to a massive body (and which therefore is at lower gravitational potential) will record less elapsed time than a clock situated further from the said massive body (and which is at a higher gravitational potential). These predictions of the theory of relativity have been repeat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scale Invariance
In physics, mathematics and statistics, scale invariance is a feature of objects or laws that do not change if scales of length, energy, or other variables, are multiplied by a common factor, and thus represent a universality. The technical term for this transformation is a dilatation (also known as dilation), and the dilatations can also form part of a larger conformal symmetry. *In mathematics, scale invariance usually refers to an invariance of individual functions or curves. A closely related concept is self-similarity, where a function or curve is invariant under a discrete subset of the dilations. It is also possible for the probability distributions of random processes to display this kind of scale invariance or self-similarity. *In classical field theory, scale invariance most commonly applies to the invariance of a whole theory under dilatations. Such theories typically describe classical physical processes with no characteristic length scale. *In quantum field the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thermal Expansion
Thermal expansion is the tendency of matter to change its shape, area, volume, and density in response to a change in temperature, usually not including phase transitions. Temperature is a monotonic function of the average molecular kinetic energy of a substance. When a substance is heated, molecules begin to vibrate and move more, usually creating more distance between themselves. Substances which contract with increasing temperature are unusual, and only occur within limited temperature ranges (see examples below). The relative expansion (also called strain) divided by the change in temperature is called the material's coefficient of linear thermal expansion and generally varies with temperature. As energy in particles increases, they start moving faster and faster weakening the intermolecular forces between them, therefore expanding the substance. Overview Predicting expansion If an equation of state is available, it can be used to predict the values of the thermal ex ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cervical Dilation
Cervical dilation (or cervical dilatation) is the opening of the cervix, the entrance to the uterus, during childbirth, miscarriage, induced abortion, or gynecological surgery. Cervical dilation may occur naturally, or may be induced surgically or medically. In childbirth In the later stages of pregnancy, the cervix may already have opened up to 1–3 cm (or more in rarer circumstances), but during labor, repeated uterine contractions lead to further widening of the cervix to about 6 centimeters. From that point, pressure from the presenting part (head in vertex births or bottom in breech births), along with uterine contractions, will dilate the cervix to 10 centimeters, which is "complete." Cervical dilation is accompanied by effacement, the thinning of the cervix. General guidelines for cervical dilation: * Latent phase: 0–3 centimeters * Active Labor: 4–7 centimeters * Transition: 8–10 centimeters * Complete: 10 centimeters. Delivery of the infant takes place sh ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coronary Dilation
Coronary reflex is the change of coronary diameter in response to chemical, neurological or mechanical stimulation of the coronary arteries. The coronary reflexes are stimulated differently from the rest of the vascular system. Causes of coronary constriction Chemical * N-nitro L-arginine * indomethacin * glibenclamide * tetraethylammonium chloride * caffeine Other * Cold Causes of coronary dilation Cocaine abuse frequently can cause a coronary spasm, resulting in a spontaneous myocardial infarction A myocardial infarction (MI), commonly known as a heart attack, occurs when blood flow decreases or stops to the coronary artery of the heart, causing damage to the heart muscle. The most common symptom is chest pain or discomfort which .... Chemical * Versed (Midazolam): a coronary dilator. In midazolam's presence, dilation was unaffected by N-nitro L-arginine, indomethacin and glibenclamide. * Tetraethylammonium chloride, an inhibitor of the BKCa K+ channel (a high con ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilation And Curettage
Dilation (or dilatation) and curettage (D&C) refers to the dilation (widening/opening) of the cervix and surgical removal of part of the lining of the uterus and/or contents of the uterus by scraping and scooping ( curettage). It is a gynecologic procedure used for diagnostic and therapeutic purposes, and is the most commonly used method for first-trimester miscarriage or abortion. D&C normally refers to a procedure involving a curette, also called ''sharp curettage''. However, some sources use the term ''D&C'' to refer to any procedure that involves the processes of dilation and removal of uterine contents, which includes the more common ''suction curettage'' procedures of manual and electric vacuum aspiration. Clinical uses D&Cs may be performed in pregnant and non-pregnant patients, for different clinical indications. During pregnancy or postpartum A D&C may be performed early in pregnancy to remove pregnancy tissue, either in the case of a non-viable pregnancy, suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vasodilation
Vasodilation is the widening of blood vessels. It results from relaxation of smooth muscle cells within the vessel walls, in particular in the large veins, large arteries, and smaller arterioles. The process is the opposite of vasoconstriction, which is the narrowing of blood vessels. When blood vessels dilate, the flow of blood is increased due to a decrease in vascular resistance and increase in cardiac output. Therefore, dilation of arterial blood vessels (mainly the arterioles) decreases blood pressure. The response may be intrinsic (due to local processes in the surrounding tissue) or extrinsic (due to hormones or the nervous system). In addition, the response may be localized to a specific organ (depending on the metabolic needs of a particular tissue, as during strenuous exercise), or it may be systemic (seen throughout the entire systemic circulation). Endogenous substances and drugs that cause vasodilation are termed vasodilators. Such vasoactivity is ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
ICD-10-PCS
The ICD-10 Procedure Coding System (ICD-10-PCS) is an international system of medical classification used for procedural coding. The Centers for Medicare and Medicaid Services, the agency responsible for maintaining the inpatient procedure code set in the U.S., contracted with 3M Health Information Systems in 1995 to design and then develop a procedure classification system to replace Volume 3 of ICD-9-CM. ICD-9-CM contains a procedure classification; ICD-10-CM does not. ICD-10-PCS is the result. ICD-10-PCS was initially released in 1998. It has been updated annually since that time. Section structure Each code consists of seven alphanumeric characters. The first character is the 'section'. The second through seventh characters mean different things in each section. Each character can be any of 34 possible values the ten digits 0-9 and the 24 letters A-H, J-N and P-Z may be used in each character. The letters O and I are excluded to avoid confusion with the numbers 0 and 1. There ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homothetic Transformation
In mathematics, a homothety (or homothecy, or homogeneous dilation) is a transformation of an affine space determined by a point ''S'' called its ''center'' and a nonzero number ''k'' called its ''ratio'', which sends point X to a point X' by the rule : \overrightarrow=k\overrightarrow for a fixed number k\ne 0. Using position vectors: :\mathbf x'=\mathbf s + k(\mathbf x -\mathbf s). In case of S=O (Origin): :\mathbf x'=k\mathbf x, which is a uniform scaling and shows the meaning of special choices for k: :for k=1 one gets the ''identity'' mapping, :for k=-1 one gets the ''reflection'' at the center, For 1/k one gets the ''inverse'' mapping defined by k. In Euclidean geometry homotheties are the similarities that fix a point and either preserve (if k>0) or reverse (if k<0) the direction of all vectors. Together with the translations, all homotheties of an affi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilate (musical Project)
Dilate was an ambient solo project begun in 1996 by composer and synthesizer player Victor Wulf, formerly of the sound collage and industrial music band Vampire Rodents. Wulf released the studio album's '' Cyclos'' and ''Octagon'' for Hypnotic Records in 1996 and 1997 respectively. History Dilate was started by composer Victor Wulf after parting ways with the sound collage project Vampire Rodents in 1993. Wulf had already been began composing since 1977, worked with independent film scoring in Belgium, Canada, Japan, and the United States and performed in Vampire Rodents on the albums '' War Music'' and ''Premonition'', released in 1990 and 1992. Dilate released its debut album '' Cyclos'' in early 1996 for Hypnotic Records, a sublabel of Cleopatra Records. The album was somewhat well-received critically, with AllMusic awarding the album four out of five stars and the music magazine ''Keyboard'' stating "he synthesizers swell majestically, but never sound corny or contrived" ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dilate (Ani DiFranco Album)
''Dilate'' is the seventh studio album by American singer-songwriter Ani DiFranco, released in 1996. ''Dilate'' is her highest-selling and most critically acclaimed record, with US sales of over 480,000 units according to SoundScan. In 2011, ''Slant Magazine'' placed the album at No. 67 on its list of "The 100 Best Albums of 1990s". Track listing Personnel *Ani DiFranco – synthesizer, acoustic guitar, bass, guitar, bongos, electric guitar, steel guitar, Hammond organ, vocals, thumb piano *Michael Ramos – Hammond organ *Andy Stochansky – drums *David Travers-Smith – trumpet Production *Ani DiFranco – record producer, mixing, sampling, arranger, sequencing, artwork, design *Robin Aubé – engineer *Bob Doidge – engineer *Andrew Gilchrist – engineer *Mark Hallman Mark Hallman (born August 1, 1951) is an American producer, songwriter, engineer and multi-instrumentalist. He has worked with Carole King (appearing on six of her albums as a performer and produ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
