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Lightning Injuries
Lightning injuries are injuries caused by a lightning strike. Initial symptoms may include heart asystole and respiratory arrest. While the asystole may resolve spontaneously fairly rapidly, the respiratory arrest is typically more prolonged. Other symptoms may include burns and blunt injuries. Of those who survive, about 75% have ongoing health problems as a result, such as cataracts and hearing loss. If death occurs it is typically from either an abnormal heart rhythm or respiratory failure. Lightning injuries are divided into direct strikes, side splash, contact injury, and ground current. Ground current make up about half of cases and occurs when the lightning strikes nearby and travels to the person through the ground. Side splash makes up about a third of cases and occurs when lightning strikes nearby and jumps through the air to the person. Contact injury occurs when the person is touching the object that is hit. Direct strikes make up about 5% of injuries. The mechanism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Emergency Medicine
Emergency medicine is the medical speciality concerned with the care of illnesses or injuries requiring immediate medical attention. Emergency physicians (often called “ER doctors” in the United States) continuously learn to care for unscheduled and undifferentiated patients of all ages. As first-line providers, in coordination with Emergency Medical Services, they are primarily responsible for initiating resuscitation and stabilization and performing the initial investigations and interventions necessary to diagnose and treat illnesses or injuries in the acute phase. Emergency physicians generally practise in hospital emergency departments, pre-hospital settings via emergency medical services, and intensive care units. Still, they may also work in primary care settings such as urgent care clinics. Sub-specializations of emergency medicine include; disaster medicine, medical toxicology, point-of-care ultrasonography, critical care medicine, emergency medical services, hy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Central Pulse (medicine)
In medicine, a pulse represents the tactile arterial palpation of the cardiac cycle (heartbeat) by trained fingertips. The pulse may be palpated in any place that allows an artery to be compressed near the surface of the body, such as at the neck (carotid artery), wrist (radial artery), at the groin (femoral artery), behind the knee (popliteal artery), near the ankle joint (posterior tibial artery), and on foot (dorsalis pedis artery). Pulse (or the count of arterial pulse per minute) is equivalent to measuring the heart rate. The heart rate can also be measured by listening to the heart beat by auscultation, traditionally using a stethoscope and counting it for a minute. The radial pulse is commonly measured using three fingers. This has a reason: the finger closest to the heart is used to occlude the pulse pressure, the middle finger is used get a crude estimate of the blood pressure, and the finger most distal to the heart (usually the ring finger) is used to nullify the effec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ruptured Eardrum
A perforated eardrum (tympanic membrane perforation) is a hole in the eardrum. It can be caused by infection (otitis media), trauma, overpressure (loud noise), inappropriate ear clearing, and changes in middle ear pressure. An otoscope can be used to view the eardrum to diagnose a perforation. Perforations may heal naturally, or require surgery. Presentation A perforated eardrum leads to conductive hearing loss, which is usually temporary. Other symptoms may include tinnitus, ear pain, vertigo, or a discharge of mucus. Nausea and/or vomiting secondary to vertigo may occur. Causes A perforated eardrum can have one of many causes, such as: * infection (otitis media). This infection may then spread through the middle ear, and may reoccur. * trauma. This may be caused by trying to clean ear wax with sharp instruments. It may also occur due to surgical complications. * overpressure (loud noise or shockwave from an explosion). * inappropriate ear clearing. * flying with a seve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrical Charge
Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by Maxwell's equations. Various common phenomena are related to electricity, including lightning, static electricity, electric heating, electric discharges and many others. The presence of an electric charge, which can be either positive or negative, produces an electric field. The movement of electric charges is an electric current and produces a magnetic field. When a charge is placed in a location with a non-zero electric field, a force will act on it. The magnitude of this force is given by Coulomb's law. If the charge moves, the electric field would be doing work on the electric charge. Thus we can speak of electric potential at a certain point in space, which is equal to the work done by an external agent in carrying a unit of positiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ozone
Ozone (), or trioxygen, is an inorganic molecule with the chemical formula . It is a pale blue gas with a distinctively pungent smell. It is an allotrope of oxygen that is much less stable than the diatomic allotrope , breaking down in the lower atmosphere to (dioxygen). Ozone is formed from dioxygen by the action of ultraviolet (UV) light and electrical discharges within the Earth's atmosphere. It is present in very low concentrations throughout the latter, with its highest concentration high in the ozone layer of the stratosphere, which absorbs most of the Sun's ultraviolet (UV) radiation. Ozone's odour is reminiscent of chlorine, and detectable by many people at concentrations of as little as in air. Ozone's O3 structure was determined in 1865. The molecule was later proven to have a bent structure and to be weakly diamagnetic. In standard conditions, ozone is a pale blue gas that condenses at cryogenic temperatures to a dark blue liquid and finally a violet-black soli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Static Electricity
Static electricity is an imbalance of electric charges within or on the surface of a material or between materials. The charge remains until it is able to move away by means of an electric current or electrical discharge. Static electricity is named in contrast with current electricity, where the electric charge flows through an electrical conductor or space, and transmits energy. A static electric charge can be created whenever two surfaces contact and have worn and separated, and at least one of the surfaces has a high resistance to electric current (and is therefore an electrical insulator). The effects of static electricity are familiar to most people because people can feel, hear, and even see the spark as the excess charge is neutralized when brought close to a large electrical conductor (for example, a path to ground), or a region with an excess charge of the opposite polarity (positive or negative). The familiar phenomenon of a static shockmore specifically, an electros ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Shock Wave
In physics, a shock wave (also spelled shockwave), or shock, is a type of propagating disturbance that moves faster than the local speed of sound in the medium. Like an ordinary wave, a shock wave carries energy and can propagate through a medium but is characterized by an abrupt, nearly discontinuous, change in pressure, temperature, and density of the medium. For the purpose of comparison, in supersonic flows, additional increased expansion may be achieved through an expansion fan, also known as a Prandtl–Meyer expansion fan. The accompanying expansion wave may approach and eventually collide and recombine with the shock wave, creating a process of destructive interference. The sonic boom associated with the passage of a supersonic aircraft is a type of sound wave produced by constructive interference. Unlike solitons (another kind of nonlinear wave), the energy and speed of a shock wave alone dissipates relatively quickly with distance. When a shock wave passes through ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capillaries
A capillary is a small blood vessel from 5 to 10 micrometres (μm) in diameter. Capillaries are composed of only the tunica intima, consisting of a thin wall of simple squamous endothelial cells. They are the smallest blood vessels in the body: they convey blood between the arterioles and venules. These microvessels are the site of exchange of many substances with the interstitial fluid surrounding them. Substances which cross capillaries include water, oxygen, carbon dioxide, urea, glucose, uric acid, lactic acid and creatinine. Lymph capillaries connect with larger lymph vessels to drain lymphatic fluid collected in the microcirculation. During early embryonic development, new capillaries are formed through vasculogenesis, the process of blood vessel formation that occurs through a '' de novo'' production of endothelial cells that then form vascular tubes. The term ''angiogenesis'' denotes the formation of new capillaries from pre-existing blood vessels and already present endo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lichtenberg Figures
A Lichtenberg figure (German ''Lichtenberg-Figuren''), or Lichtenberg dust figure, is a branching electric discharge that sometimes appears on the surface or in the interior of insulating materials. Lichtenberg figures are often associated with the progressive deterioration of high voltage components and equipment. The study of planar Lichtenberg figures along insulating surfaces and 3D electrical trees within insulating materials often provides engineers with valuable insights for improving the long-term reliability of high-voltage equipment. Lichtenberg figures are now known to occur on or within solids, liquids, and gases during electrical breakdown. Lichtenberg figures are natural phenomena which exhibit fractal properties. History Lichtenberg figures are named after the German physicist Georg Christoph Lichtenberg, who originally discovered and studied them. When they were first discovered, it was thought that their characteristic shapes might help to reveal the natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Seizures
An epileptic seizure, informally known as a seizure, is a period of symptoms due to abnormally excessive or neural oscillation, synchronous neuronal activity in the brain. Outward effects vary from uncontrolled shaking movements involving much of the body with loss of consciousness (tonic-clonic seizure), to shaking movements involving only part of the body with variable levels of consciousness (focal seizure), to a subtle momentary loss of awareness (absence seizure). Most of the time these episodes last less than two minutes and it takes some time to return to normal. Urinary incontinence, Loss of bladder control may occur. Seizures may be provoked and unprovoked. Provoked seizures are due to a temporary event such as low blood sugar, alcohol withdrawal, abusing alcohol together with prescription medication, low blood sodium, fever, brain infection, or concussion. Unprovoked seizures occur without a known or fixable cause such that ongoing seizures are likely. Unprovoked seizur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Broken Bones
A bone fracture (abbreviated FRX or Fx, Fx, or #) is a medical condition in which there is a partial or complete break in the continuity of any bone in the body. In more severe cases, the bone may be broken into several fragments, known as a ''comminuted fracture''. A bone fracture may be the result of high force impact or stress, or a minimal trauma injury as a result of certain medical conditions that weaken the bones, such as osteoporosis, osteopenia, bone cancer, or osteogenesis imperfecta, where the fracture is then properly termed a pathologic fracture. Signs and symptoms Although bone tissue contains no pain receptors, a bone fracture is painful for several reasons: * Breaking in the continuity of the periosteum, with or without similar discontinuity in endosteum, as both contain multiple pain receptors. * Edema and hematoma of nearby soft tissues caused by ruptured bone marrow evokes pressure pain. * Involuntary muscle spasms trying to hold bone fragments in place. D ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lightning Injury
Lightning injuries are injury, injuries caused by a lightning strike. Initial symptoms may include heart asystole and respiratory arrest. While the asystole may resolve spontaneously fairly rapidly, the respiratory arrest is typically more prolonged. Other symptoms may include burns and blunt injuries. Of those who survive, about 75% have ongoing health problems as a result, such as cataracts and hearing loss. If death occurs it is typically from either an arrhythmia, abnormal heart rhythm or respiratory failure. Lightning injuries are divided into direct strikes, side splash, contact injury, and ground current. Ground current make up about half of cases and occurs when the lightning strikes nearby and travels to the person through the ground. Side splash makes up about a third of cases and occurs when lightning strikes nearby and jumps through the air to the person. Contact injury occurs when the person is touching the object that is hit. Direct strikes make up about 5% of injur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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