And drugs and alcohol truly can ablate some of your symptoms in the short term.
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SonaCare has two focused ultrasound devices on the market, one to treat diseased cells in soft tissue and another to ablate prostate tissue.
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"The shower is rich in small particles, which do not produce enough light to be easily seen as they ablate ("burn up")," Bill Cooke of NASA's Meteoroid Environments Office told Gizmodo.
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They found that it is theoretically possible for a pulsed laser to ablate the space debris, creating a force that can remove the object from orbit, using a space-based laser.
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Lasers are used to cut or ablate bones and teeth in dentistry.
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Phototherapeutic keratectomy (PTK) can be used to excise or ablate the abnormal corneal tissue. Patients with superficial corneal opacities are suitable candidates for this procedure.
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Exposure to repeated nuclear blasts raises the problem of ablation (erosion) of the pusher plate. Calculations and experiments indicated that a steel pusher plate would ablate less than 1 mm, if unprotected. If sprayed with an oil it would not ablate at all (this was discovered by accident; a test plate had oily fingerprints on it and the fingerprints suffered no ablation). The absorption spectra of carbon and hydrogen minimize heating.
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A newer procedure uses a carbon dioxide laser to ablate the vermillion border. This treatment is relatively quick and easy to perform, but it requires a skilled operator. Anesthesia is usually required. Secondary infection and scarring can occur with laser ablation.
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Thus, these nanoscale graphene sheets require a laser power on the lower end of the range used with gold nanoparticles to photothermally ablate tumors. In 2012, Yang et al. incorporated the promising results regarding nanoscale reduced graphene oxide reported by Robinson et al. into another in vivo mice study.
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Hedin CA, Pindborg JJ, Axéll T: Depigmentation of smoker's melanosis after smoking-stop. J Oral Pathol Med 1993;22:228-230. A dental laser can target and ablate the melanocytes, thus reducing the production of melanin in the gingival tissue. Following laser depigmentation, the gingiva heals by secondary intention.
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The procedure involves endovascular access via the femoral artery with advancement of a catheter-mounted device into the renal artery. The device uses radiofrequency or ultrasound to ablate the renal nerves. Typically, numerous ablations are applied at a different longitudinal and rotational positions to ensure maximal denervation. The procedure does not involve a permanent implant.
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LSI's ability to ablate proteins at atmospheric pressure in order to form a multiple of charged ions with a mass resolution of 100,000 when coupled with a quadrupole orbitrap mass spectrometer. The advantages of using LSI includes a solvent-free ionization technique, fast data acquisition, simply to use, and the improved fragmentation through multiple charging.
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The second step of the procedure uses an excimer laser (193 nm) to remodel the corneal stroma. The laser vaporizes the tissue in a finely controlled manner without damaging the adjacent stroma. No burning with heat or actual cutting is required to ablate the tissue. The layers of tissue removed are tens of micrometers thick.
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Foreman suggests aleukemic leukemia meaning the marrow wouldn't be making normal cells. House tells them to ablate the patient's bone marrow, despite the team's arguments that this could kill the patient. He faxes this information and information on the patient's condition to Taub and Thirteen for their opinions. They both are shown to ignore the fax.
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One technology proposed to help deal with fragments from in size is the laser broom, a proposed multimegawatt land-based laser that could deorbit debris: the side of the debris hit by the laser would ablate and create a thrust that would change the eccentricity of the remains of the fragment until it would re-enter harmlessly.
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While in operation the plasma can thermally ablate the walls of the thruster cavity and support structure, which can eventually lead to system failure. Design and materials advancement may solve this problem. Due to their extremely low thrust, plasma engines are not suitable for launch-to-orbit on Earth. On average, these rockets provide about 2 pounds of thrust maximum.
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In linguistic morphology, an uninflected word is a word that has no morphological markers (inflection) such as affixes, ablate, consonant gradation, etc., indicating declension or conjugation. If a word has an uninflected form, this is usually the form used as the lemma for the word.Glasgow.com In English and many other languages, uninflected words include prepositions, interjections, and conjunctions, often called invariable words.
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RFA is used to treat uterine fibroids using the heat energy of radio frequency waves to ablate the fibroid tissue. The Acessa device obtained FDA approval in 2012 and is now on third-generation technology, the Acessa ProVu. The device is inserted via a laparoscopic probe and guided inside the fibroid tissue using an ultrasound probe. The heat shrinks the fibroids.
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The procedures are not guaranteed to work, and in a minority may exacerbate the problem. Anterior Stromal Puncture with a 20-25 gauge needle is an effective and simple treatment. An option for minimally invasive and long-term effective therapy is laser phototherapeutic keratectomy. Laser PTK involves the surgical laser treatment of the cornea to selectively ablate cells on the surface layer of the cornea.
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These findings supported further clinical development of INCB009471 and they have since progressed to phase IIb clinical trials. As of 2009 the study of this compound is inactive and no further studies are planned at this time. Not only small molecules but also proteins delivered by gene therapy have been suggested to ablate CCR5 function, an approach that has also been employed for other HIV targets.
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Parkin activation requires phosphorylation of serine Ser65 in Ubl by serine/threonine kinase, PINK1. Addition of a charged phosphate destabilises hydrophobic interactions between Ubl and neighbouring subregions, reducing autoinhibitory effects of this N-terminus domain. Ser65Ala missense mutations were found to ablate Ub-parkin binding whilst inhibiting parkin recruitment to damaged mitochondria. PINK1 also phosphorylates Ub at Ser65, accelerating its discharge from E2 and enhancing its affinity for parkin.
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However, as Thirteen receives a message from the community clinic she applied to, she ignores it and looks at House's fax. Taub looks at the fax as he talks to a rather silly patient. They both call House as the team is about to ablate the patient's marrow. They reason that the patient's body went to hell hours after the worms were gone because the worms were helping him.
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Commonly used arthroscopic tools are the hook probe, used to assess the integrity and consistency of the hip, radiofrequency probes that ablate soft tissue and can also smoothen tissue surfaces, and various shavers or burrs that can take away diseased tissue. If the acetabular labrum requires repair, specially designed anchors may be used. This is by no means a comprehensive list as new instruments are being developed constantly.
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Ion source for ambient mass spectrometry employing a combination of laser desorption and electrospray. The sample target is on the left. Laser-based ambient ionization is a two-step process in which a pulsed laser is used to desorb or ablate material from a sample and the plume of material interacts with an electrospray or plasma to create ions. Lasers with ultraviolet and infrared wavelengths and nanosecond to femtosecond pulse widths have been used.
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The technique uses pulsed radio frequency energy delivered via catheter at frequencies of 300–750 kHz for 30 to 60 seconds. Thermal pulsed radio frequency takes advantage of high current delivered focally by an electrode to ablate the tissue of interest. Generally the tissue/electrode temperature reached is 60 to 75 °C resulting in focal tissue destruction. Thermal pulse radio frequency ablation has also been used for lesioning of peripheral nerves to reduce chronic pain.
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Soft-tissue laser surgery is used in a variety of applications in humans (general surgery, neurosurgery, ENT, dentistry, orthodontics, and oral and maxillofacial surgery as well as veterinary surgical fields. The primary uses of lasers in soft tissue surgery are to cut, ablate, vaporize, and coagulate. There are several different laser wavelengths used in soft tissue surgery. Different laser wavelengths and device settings (such as pulse duration and power) produce different effects on the tissue.
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Catheter ablation involves advancing several flexible catheters into the patient's blood vessels, usually either in the femoral vein, internal jugular vein, or subclavian vein. The catheters are then advanced towards the heart. Electrical impulses are then used to induce the arrhythmia and local heating or freezing is used to ablate (destroy) the abnormal tissue that is causing it. Originally, a DC impulse was used to create lesions in the intra- cardiac conduction system.
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Laser ablation electrospray ionization (LAESI) mass spectrometry is an ambient ionization technique applicable to plant and animal tissue imaging, live-cell imaging, and most recently to cell-by-cell imaging. This technique uses a mid-IR laser to ablate the sample which creates a cloud of neutral molecules. This cloud is then hit with the electrospray from above to cause ionization. The desorbed ions are then able to pass into the mass spectrometer for analysis.
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High intensity focused ultrasound (HIFU) was first used in the 1940s and 1950s in efforts to destroy tumors in the central nervous system. Since then, HIFU has been shown to be effective at destroying malignant tissue in the brain, prostate, spleen, liver, kidney, breast, and bone. HIFU for prostate cancer utilizes ultrasound to ablate/destroy the tissue of the prostate. During the HIFU procedure, sound waves are used to heat the prostate tissue, thus destroying the cancerous cells.
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The live cornea has a thin layer removed therefrom, leaving an exposed internal surface thereon. Then, either the surface or thin layer is exposed to the laser beam along a predetermined pattern to ablate desired portions. The thin layer is then replaced onto the surface. Ablating a central area of the surface or thin layer makes the cornea less curved, while ablating an annular area spaced from the center of the surface or layer makes the cornea more curved.
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If at any step during the EP study the electrophysiologist finds the source of the abnormal electrical activity, they may try to ablate the cells that are misfiring. This is done using high-energy radio frequencies (similar to microwaves) to effectively heat up the abnormal cells, to form scar tissue. This can be painful with pain felt in the heart itself, the neck and shoulder areas. A more recent method of ablation is cryoablation, which is considered less risky and less painful.
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Minimaze procedures are minimally invasive versions of the original Cox maze procedure but without cardiac incisions. These procedures do not require a median sternotomy (vertical incision in the breastbone) or cardiopulmonary bypass (heart-lung machine). They use laser, cryothermy, radiofrequency, or acoustic energy to ablate atrial tissue near the pulmonary veins and make other required ablations to mimic the maze. Minimally invasive surgical (endoscopic) maze procedures are now routinely conducted at hospitals around the US. This approach was developed in the early 2000s.
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The D-T fuel would be placed in a small capsule, designed to rapidly ablate when heated and thereby maximize compression and shock wave formation. This capsule would be placed within an engineered shell, the hohlraum, which acted similar to the bomb casing. However, the hohlraum did not have to be heated by x-rays; any source of energy could be used as long as it delivered enough energy to cause the hohlraum itself to heat up and start giving off x-rays.
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Targeted radiofrequency ablation (also written t-RFA) is a minimally invasive procedure to treat severe pain and discomfort caused from metastatic tumors in the vertebral body of the spine. This procedure uses radiofrequency energy to target and ablate a specific spinal tumor, causing it shrink and reduce the pressure on the surrounding nerves and tissues. The procedure minimizes damage to the vertebrae and surrounding tissues. It is used as a palliative therapy rather with the intention of treating the cancer itself.
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However, the violet CTP systems are often cheaper than thermal ones, and thermal CTP systems do not need to be operated under yellow light. Thermal CTP involves the use of thermal lasers to expose or remove areas of coating while the plate is being imaged. This depends on whether the plate is negative, or positive working. These lasers are generally at a wavelength of 830 nm, but vary in their energy usage depending on whether they are used to expose or ablate material.
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Endometrial ablation is a surgical procedure that is used to remove (ablate) or destroy the endometrial lining of the uterus in women who have heavy menstrual bleeding. Endometrial ablation should never be performed on women who wish to have children. Endometrial ablation is most often employed in women who suffer from excessive menstrual bleeding, who have failed medical therapy and do not wish to undergo a hysterectomy. Heavy menstrual bleeding is most commonly due to dysfunctional uterine bleeding or adenomyosis.
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The annexins are a family of calcium-dependent phospholipid- binding proteins. Members of the annexin family contain 4 internal repeat domains, each of which includes a type II calcium-binding site. The calcium- binding sites are required for annexins to aggregate and cooperatively bind anionic phospholipids and extracellular matrix proteins. This gene encodes a divergent member of the annexin protein family in which all four homologous type II calcium-binding sites in the conserved tetrad core contain amino acid substitutions that ablate their function.
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Lasers are designed to target debris between one and ten centimeters in diameter. Collisions with such debris are commonly of such high velocity that considerable damage and numerous secondary fragments are the result. The laser broom is intended to be used at high enough power to penetrate through the atmosphere with enough remaining power to ablate material from the target. The ablating material imparts a small thrust that lowers its orbital perigee into the upper atmosphere, thereby increasing drag so that its remaining orbital life is short.
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One closed cycle gas core rocket design (often called the nuclear lightbulb) contains the fissioning gas in a quartz enclosure that is separate from the propellant. First, the hydrogen coolant runs through the nozzle and inside the walls of the quartz enclosure for cooling. Next, the coolant is run along the outside of the quartz fuel enclosure. Since the fissile gas would be directly in contact with the walls, the operating temperature is not as great as other designs because the walls would eventually ablate away.
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Direct laser engraving of flexographic printing cylinders and plates has been an established process since the 1970s. This first began with the use of a carbon dioxide laser used to selectively ablate or evaporate a variety of rubber plate and sleeve materials to produce a print-ready surface without the use of photography or chemicals. With this process there is no integral ablation mask as with direct photopolymer laser imaging (discussed below). Instead a high-power carbon dioxide laser head burns away, or ablates, unwanted material.
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Similar to other A-B toxins, diphtheria toxin is adept at transporting exogenous proteins across mammalian cell membranes, which are usually impermeable to large proteins. This unique ability can be repurposed to deliver therapeutic proteins, instead of the catalytic domain of the toxin. This toxin has also been used in neuroscientific and cancer research to ablate specific populations of cells which express the diphtheria toxin receptor (heparin-binding EGF-like growth factor). Administration of the toxin into the organism which does not naturally express this receptor (e.g.
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Dominant and recessive tolerance are forms of a peripheral tolerance (the other tolerance beside peripheral is a central tolerance). Where so called recessive tolerance is associated with anergized lymphocytes as described above, in the dominant form of tolerance, specialized T-reg cells which actively ablate the immune response are developed from the naive T lymphocyte. Similarly to recessive tolerance, unopposed NFAT signalling is also important for T-reg induction. In this case, the NFAT pathway activates another transcription factor - FOXP3 that is a marker of T-regs and participates in their genetic program.
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Meteoroids that produce meteorites ablate as they pass through the atmosphere and lose mass. Thus, the total mass of a meteorite fall will always be lower than that of the original meteoroid (neglecting the mass of any terrestrial oxygen added to meteorites during the formation of their fusion crust). The upper limit to the "total known mass" of a meteorite is therefore the mass of the meteorite fall. Several factors can cause the "total known mass" of a meteorite to be less than the mass of the fall.
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The first patent for this approach, which later became known as LASIK surgery, was granted by the US Patent Office to Gholam Ali. Peyman, MD on June 20, 1989.US Patent #4,840,175, "METHOD FOR MODIFYING CORNEAL CURVATURE" It involves cutting a flap in the cornea and pulling it back to expose the corneal bed, then using an excimer laser to ablate the exposed surface to the desired shape, and then replacing the flap. The name LASIK was coined in 1991 by University of Crete and the Vardinoyannion Eye.
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Transurethral needle ablation (also called TUNA or transurethral radiofrequency ablation) is a technique that uses low energy radio frequency delivered through two needles to ablate excess prostate tissue. A cystoscope/catheter deploys the needles toward the obstructing prostate tissue is inserted into the urethra directly through the penis under local anesthetic before the procedure begins. The energy from the probe heats the abnormal prostate tissue without damaging the urethra. The resulting scar tissue later atrophies, reducing the size of the prostate which in turn reduces the constriction of the urethra.
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While the process is technically a process of electrocoagulation, the term "electrocautery" is sometimes loosely, nontechnically and incorrectly used to describe it. The process of vaporization can be used to ablate tissue targets, or, by linear extension, used to transect or cut tissue. While the processes of vaporization/ cutting and desiccation/coagulation are best accomplished with relatively low voltage, continuous or near continuous waveforms, the process of fulguration is performed with relatively high voltage modulated waveforms. Fulguration is a superficial type of coagulation, typically created by arcing modulated high voltage current to tissue that is rapidly desiccated and coagulated.
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The broad therapeutic potential of pGSN supplementation resides in the fact that the molecule embodies a multifunctional system contributing importantly to innate immunity rather than a pharmacologic intervention with selective and specific activities. Plasma gelsolin’s primary function is to keep inflammation local and enhance the function of the innate immune system. It functions through a pleiotropic mechanism of action; severing toxic filamentous actin (F-actin), binding inflammatory mediators, and enhancing pathogen clearance. These mechanisms are quite distinct from other anti-inflammatory agents that function as antagonists of individual mediators or inhibitors of specific enzymes, and work to ablate inflammation.
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The impacting asteroid started to brighten up in the general direction of the Pegasus constellation, close to the East horizon where the Sun was starting to rise. The impactor belonged to the Apollo group of near-Earth asteroids. The asteroid had an approximate size of and a mass of about before it entered the denser parts of Earth's atmosphere and started to ablate. NASA's web page in turn acknowledges credit for its data and visual diagrams to: :Peter Brown (University of Western Ontario); William Cooke (Marshall Space Flight Center); Paul Chodas, Steve Chesley and Ron Baalke (JPL); Richard Binzel (MIT); and Dan Adamo.
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Due to the reentrant nature of atrial flutter, it is often possible to ablate the circuit that causes atrial flutter with radiofrequency catheter ablation. Catheter ablation is considered to be a first-line treatment method for many people with typical atrial flutter due to its high rate of success (>90%) and low incidence of complications. This is done in the cardiac electrophysiology lab by causing a ridge of scar tissue in the cavotricuspid isthmus that crosses the path of the circuit that causes atrial flutter. Eliminating conduction through the isthmus prevents reentry, and if successful, prevents the recurrence of the atrial flutter.
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Hattar and his co-workers discovered that, even among the subtypes of ipRGC, there can be designated sets that differentially control circadian versus pupillary behavior. In experiments with M1 ipRGCs, they discovered that the transcription factor Brn3b is expressed by M1 ipRGCs that target the OPN, but not by ones that target the SCN. Using this knowledge, they designed an experiment to cross Melanopsin-Cre mice with mice that conditionally expressed a toxin from the Brn3b locus. This allowed them to selectively ablate only the OPN projecting M1 ipRGCS, resulting in a loss of pupil reflexes.
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A similar method called atmospheric solids analysis probe [ASAP] uses the heated gas from ESI or APCI probes to vaporize sample placed on a melting point tube inserted into an ESI/APCI source. Ionization is by APCI. Laser-based ambient ionization is a two-step process in which a pulsed laser is used to desorb or ablate material from a sample and the plume of material interacts with an electrospray or plasma to create ions. Electrospray-assisted laser desorption/ionization (ELDI) uses a 337 nm UV laser or 3 µm infrared laser to desorb material into an electrospray source.
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Preparation of nanoparticles by laser in solution Laser ablation of an asteroid-like sample Laser ablation or photoablation is the process of removing material from a solid (or occasionally liquid) surface by irradiating it with a laser beam. At low laser flux, the material is heated by the absorbed laser energy and evaporates or sublimates. At high laser flux, the material is typically converted to a plasma. Usually, laser ablation refers to removing material with a pulsed laser, but it is possible to ablate material with a continuous wave laser beam if the laser intensity is high enough.
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Inhibition of the neural impulses that are believed to cause or worsen hypertension has been tried for a few decades. Surgical sympathectomy has helped but not without significant side effects. Therefore, the introduction of non-surgical means of renal denervation with radiofrequency ablation catheter was enthusiastically welcomed. Although, the initial use of radiofrequency-generated heat to ablate nerve endings in the renal arteries to aid in management of 'resistant hypertension' were encouraging, the most recent phase 3 studying looking at catheter-based renal denervation for the treatment of resistant hypertension failed to show any significant reduction in systolic blood pressure.
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In addition, gradual protrusion of the eyes may occur, called Graves' ophthalmopathy, as may swelling of the front of the shins. Graves' disease can be diagnosed by the presence of pathomnomonic features such as involvement of the eyes and shins, or isolation of autoantibodies, or by results of a radiolabelled uptake scan. Graves' disease is treated with anti-thyroid drugs such as propylthiouracil, which decrease the production of thyroid hormones, but hold a high rate of relapse. If there is no involvement of the eyes, then use of radioactive isotopes to ablate the gland may be considered.
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Schematic of LSII Laserspray inlet ionization (LSII) is a subset of MAII and uses a matrix- assisted laser desorption/ionization (MALDI) method. It was originally called atmospheric pressure matrix-assisted laser desorption/ionization however was renamed as LSII to avoid confusion with MALDI and as it was found to be a type of inlet ionization. As all inlet ionization techniques, highly multiply charged ions are produced. A nitrogen laser is used to ablate the solid matrix/analyte into the heated inlet tube, the observed ions are generated at the surface of the matrix/analyte and so the laser is not directly involved in the ionization as was originally thought.
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Immediately following ablatio (at 5 hours), there were no noticeable differences in synaptic structure or functionality. Motor-end plate potentials were unaltered in the pre-ablated and the 5 hour ablated models, showing that PSCs are not essential for short-term maintenance of the NMJ. Approximately 13% of ablated NMJ were observed to be retracted partially or entirely one week after ablation and there was a 50% decrease in end plate potential frequency, meaning the NMJs were firing approximately half as often! This same ablation model cannot be performed in mammals, as the antibody mAB sA12 used in the frog model does not ablate mammalian PSCs.
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The Munnerlyn Formula is the theoretical formulaMunnerlyn, CR, Koons, SJ, Marshall, J. "Photorefractive keratecomy: a technique for laser refractive surgery," J. Refratc. Surg., 1988, 14, 46-52 discovered by Charles Munnerlyn, which gives the depth an excimer laser will need to ablate during LASIK surgery or similar medical interventions. The formula states that the depth of the ablation (in micrometres) per diopter of refractive change is equal to the square of the diameter of the optical ablation zone measured in millimeters, divided by three. For example, to change refraction by 4 diopters with an optical zone of 3 mm would require ablation of 12 μm.
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Diagram of a SESI ambient ionization source Extractive electrospray ionization is an spray-type, ambient ionization method that uses two merged sprays, one of which is generated by electrospray. Laser-based electrospray-based ambient ionization is a two-step process in which a pulsed laser is used to desorb or ablate material from a sample and the plume of material interacts with an electrospray to create ions. For ambient ionization, the sample material is deposited on a target near the electrospray. The laser desorbs or ablates material from the sample which is ejected from the surface and into the electrospray which produces highly charged ions.
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A 25-ton block now rests outside of the Riksmuseum in Stockholm, a 6.6 ton block outside the Geological Museum in Copenhagen, and a 3-ton block can be found in the Museum of Natural History in Kumpula, Helsinki. Accompanying Nordenskiöld in 1871 was K. J. V. Steenstrup. Due to circumstances like the shape of the boulders, which often had sharp corners or jagged edges that are not characteristic of meteorites (which ablate considerably during atmospheric entry), Steenstrup disagreed with Nordenskiöld about the origin of the boulders, and set out on an expedition of his own in 1878. In 1879, Steenstrup first identified the type 2 iron, showing that it also contained Widmanstatten structures.
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Photorefractive keratectomy (PRK) and laser-assisted sub-epithelial keratectomy (or laser epithelial keratomileusis"Laser epithelial keratomileusis (LASEK)" Accessed June 30, 2008.) (LASEK) are laser eye surgery procedures intended to correct a person's vision, reducing dependency on glasses or contact lenses. LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate (remove by vaporization) a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of the cornea is removed prior to the ablation. A computer system tracks the patient's eye position 60 to 4,000 times per second, depending on the specifications of the laser that is used.
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Ablation therapy using radio frequency waves on the heart is used to cure a variety of cardiac arrhythmiae such as supraventricular tachycardia, Wolff–Parkinson–White syndrome (WPW), ventricular tachycardia, and more recently as management of atrial fibrillation. The term is often used in the context of laser ablation, a process in which a laser dissolves a material's molecular bonds. For a laser to ablate tissues, the power density or fluence must be high, otherwise thermocoagulation occurs, which is simply thermal vaporization of the tissues. Rotoablation is a type of arterial cleansing that consists of inserting a tiny, diamond-tipped, drill-like device into the affected artery to remove fatty deposits or plaque.
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Surgical smoke is the gaseous by-product produced by electrosurgery, laser tissue ablation, ultrasonic scalpel dissection, high speed drilling or burring, or any procedure done by means of a surgical device that is used to ablate, cut, coagulate, desiccate, fulgurate, or vaporize tissue. Other names for surgical smoke are cautery smoke, plume, diathermy plume, or, sometimes, aerosols produced during surgery, vapor contaminants, or air contaminants. There is evidence, although the evidence is somewhat controversial, of the dangers from toxicity or possible infectivity of surgical smoke produced by electrosurgery or ultrasonic scalpel procedures; such surgical smoke contains carcinogenic or irritant chemicals and/or bio-aerosols capable of harming patients or operating room personnel upon inhalation.
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LASEK and PRK permanently change the shape of the anterior central cornea using an excimer laser to ablate (remove by vaporization) a small amount of tissue from the corneal stroma at the front of the eye, just under the corneal epithelium. The outer layer of the cornea is removed prior to the ablation. A computer system tracks the patient's eye position 60 to 4,000 times per second, depending on the brand of laser used, redirecting laser pulses for precise placement. Most modern lasers will automatically center on the patient's visual axis and will pause if the eye moves out of range and then resume ablating at that point after the patient's eye is re-centered.
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Pyroptosis, which can now be defined as gasdermin-mediated necrotic cell death, acts as an immune defence against infection. Hence, failure to express or cleave GSDMD can block pyroptosis and disrupt the secretion of IL-1β, and eventually unable to ablate the replicative niche of intracellular bacteria. Mutation of GSDMD is associated with various genetic diseases and human cancers, including brain, breast, lung, urinary bladder, cervical, skin, oral cavity, pharynx, colon, liver, cecum, stomach, pancreatic, prostate, oesophageal, head and neck, hematologic, thyroid and uterine cancers. Recently, studies have revealed that downregulation of GSDMD promotes gastric cancer proliferation due to the failure to inactivate ERK 1/2, STAT3 and PI3K/AKT pathways, which are involved in cell survival and tumour progression.
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Axonal pathfinding and fasciculation behaviour in the embryonic ventral nerve cord of Drosophila. An investigation was conducted looking into the role of pioneer axons in the formation of both CNS and PNS axon pathways in a Drosophila embryo. Using a method to ablate specific neurons, the ablation of the aCC axon, which plays a role in pioneering the intersegmental nerve in the Drosophila PNS, resulted in the three typical follower axons becoming delayed and prone to pathfinding errors. Despite these consequences, eventually the pathway was formed in the majority of subjects. Ablation of the pioneer axons that formed the longitudinal tracts in the Drosophila CNS resulted in similar difficulties in the formation and organization of longitudinal pathways in 70% of observed segments.
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The outer casing of the secondary assembly is called the "tamper-pusher". The purpose of a tamper in an implosion bomb is to delay the expansion of the reacting fuel supply (which is very hot dense plasma) until the fuel is fully consumed and the explosion runs to completion. The same tamper material serves also as a pusher in that it is the medium by which the outside pressure (force acting on the surface area of the secondary) is transferred to the mass of fusion fuel. The proposed tamper-pusher ablation mechanism posits that the outer layers of the thermonuclear secondary's tamper-pusher are heated so extremely by the primary's X-ray flux that they expand violently and ablate away (fly off).
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In his 1995 book Dark Sun: The Making of the Hydrogen Bomb, author Richard Rhodes describes in detail the internal components of the "Ivy Mike" Sausage device, based on information obtained from extensive interviews with the scientists and engineers who assembled it. According to Rhodes, the actual mechanism for the compression of the secondary was a combination of the radiation pressure, foam plasma pressure, and tamper- pusher ablation theories described above; the radiation from the primary heated the polyethylene foam lining the casing to a plasma, which then re- radiated radiation into the secondary's pusher, causing its surface to ablate and driving it inwards, compressing the secondary, igniting the sparkplug, and causing the fusion reaction. The general applicability of this principle is unclear.
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Depending on the power of the laser, its influence on a working piece differs: lower power values are used for laser engraving and laser ablation, where material is partially removed by the laser. With higher powers the material becomes fluid and laser welding can be realized, or if the power is high enough to remove the material completely, then laser cutting can be performed. Modern lasers can cut steel blocks with a thickness of 10 cm and more or ablate a layer of the cornea that is only a few micrometers thick. The ability of lasers to harden liquid polymers, together with laser scanners, is used in rapid prototyping, the ability to melt polymers and metals is, with laser scanners, to produce parts by laser sintering or laser melting.
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In patients with AF where rate control drugs are ineffective and it is not possible to restore sinus rhythm using cardioversion, non-pharmacological alternatives are available. For example, to control rate it is possible to destroy the bundle of cells connecting the upper and lower chambers of the heart – the atrioventricular node – which regulates heart rate, and to implant a pacemaker instead. This "ablate and pace" technique has an important place in the treatment of AF< as it is the only reliably effective method for relieving the symptoms of the arrhythmia and can be used when other methods have failed (as they do in up to 50% of cases of persistent AF). Although this procedure results in a regular (paced) heart rhythm it does not prevent the atria from fibrillating and therefore long-term warfarin anticoagulation may still be required.
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This was done with the introduction of the channel filler – an optical element used as a refractive medium, also encountered as random-phase plate in the ICF laser assemblies. This medium was a polystyrene plastic foam filling, extruded or impregnated with a low- molecular-weight hydrocarbon (possibly methane gas), which turned to a low-Z plasma from the X-rays, and along with channeling radiation it modulated the ablation front on the high-Z surfaces; it "tamped" the sputtering effect that would otherwise "choke" radiation from compressing the secondary. The reemitted X-rays from the radiation case must be deposited uniformly on the outer walls of the secondary’s tamper and ablate it externally, driving the thermonuclear fuel capsule (increasing the density and temperature of the fusion fuel) to the point needed to sustain a thermonuclear reaction. (see Nuclear weapon design).
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Reported details about the event, such as water boiling in the muddy crater for ten minutes from the heat of the impact, presented a problem for experts. Because the impact site is at a high altitude of more than , the meteoroid may not have been slowed down as much as it ordinarily would have been by passage through the Earth's denser lower atmosphere, and kinetic energy at impact may have been unusually high for a terrestrial impact of an object of this size and mass. Most larger meteorites are cold in their bulk mass when they land on Earth, since their heated outer layers ablate from the objects before impacting. It was later confirmed that the meteorite contained a large amount of iron and possessed magnetic properties common to similar metallic objects, which contributed to its capacity to retain heat during atmospheric entry.
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The October Draconids, in the past also unofficially known as the Giacobinids, are a meteor shower whose parent body is the periodic comet 21P/Giacobini- Zinner. They are named after the constellation Draco, where they seemingly come from. Almost all meteors which fall towards Earth ablate long before reaching its surface. The Draconids are best viewed after sunset in an area with a clear dark sky. The 1933"The meteors from Giacobini's comet", Wylie, C. C., Popular Astronomy, Vol. 42, p. 44, and 1946 Draconids had Zenithal Hourly Rates of thousands of meteors visible per hour, among the most impressive meteor storms of the 20th century. Rare outbursts in activity can occur when the Earth travels through a denser part of the cometary debris stream; for example, in 1998, rates suddenly spikedArlt, R. "Summary of 1998 Draconid Outburst Observations", WGN, Journal of the International Meteor Organization, Vol.
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