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Fluorescein
Fluorescein is an organic compound and dye based on the xanthene tricyclic structural motif, formally belonging to Triarylmethane dye, triarylmethine dyes family. It is available as a dark orange/red powder slightly soluble in water and alcohol. It is used as a fluorescent Flow tracer, tracer in many applications. The color of its aqueous solutions is green by reflection and orange by transmission (its spectral properties are dependent on pH of the solution), as can be noticed in spirit level, bubble levels, for example, in which fluorescein is added as a colorant to the Alcohol (chemistry), alcohol filling the tube in order to increase the visibility of the air bubble contained within. More concentrated solutions of fluorescein can even appear red (because under these conditions nearly all incident emission is re-absorbed by the solution). It is on the WHO Model List of Essential Medicines, World Health Organization's List of Essential Medicines. Uses Fluorescein sodium, t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corneal Abrasion
Corneal abrasion is a scratch to the surface of the cornea of the eye. Symptoms include pain, redness, light sensitivity, and a feeling like a foreign body is in the eye. Most people recover completely within three days. Most cases are due to minor trauma to the eye such as that which can occur with contact lens use or from fingernails. About 25% of cases occur at work. Diagnosis is often by slit lamp examination after fluorescein dye has been applied. More significant injuries like a corneal ulcer, globe rupture, recurrent erosion syndrome, and a foreign body within the eye should be ruled out. Prevention includes the use of eye protection. Treatment is typically with antibiotic ointment. In those who wear contact lenses a fluoroquinolone antibiotic is often recommended. Paracetamol (acetaminophen), NSAIDs, and eye drops such as cyclopentolate that Cycloplegia, paralyse the pupil can help with pain. Evidence does not support the usefulness of eye patching for those with simple ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herpetic Corneal Infection
Herpetic simplex keratitis is a form of keratitis caused by recurrent herpes simplex virus (HSV) infection in the cornea. It begins with infection of epithelial cells on the surface of the eye and retrograde infection of nerves serving the cornea. Primary infection typically presents as swelling of the conjunctiva and eyelids ( blepharoconjunctivitis), accompanied by small white itchy lesions on the corneal surface. The effect of the lesions varies, from minor damage to the epithelium ( superficial punctate keratitis), to more serious consequences such as the formation of dendritic ulcers. Infection is unilateral, affecting one eye at a time. Additional symptoms include dull pain deep inside the eye, mild to acute dryness, and sinusitis. Most primary infections resolve spontaneously in a few weeks. Healing can be aided by the use of oral and topical antivirals. Subsequent recurrences may be more severe, with infected epithelial cells showing larger dendritic ulceration, and le ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Corneal Ulcer
Corneal ulcer, often resulting from keratitis is an inflammatory or, more seriously, infective condition of the cornea involving disruption of its epithelial layer with involvement of the corneal stroma. It is a common condition in humans particularly in the tropics and in farming. In developing countries, children afflicted by vitamin A deficiency are at high risk for corneal ulcer and may become blind in both eyes persisting throughout life. In ophthalmology, a corneal ulcer usually refers to having an infection, while the term corneal abrasion refers more to a scratch injury. Types Superficial and deep corneal ulcers Corneal ulcers are a common human eye disease. They are caused by trauma, particularly with vegetable matter, as well as chemical injury, contact lenses and infections. Other eye conditions can cause corneal ulcers, such as entropion, distichiasis, corneal dystrophy, and keratoconjunctivitis sicca (dry eye). Many micro-organisms cause infective corneal ulce ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xanthene
Xanthene (9''H''-xanthene, 10''H''-9-oxaanthracene) is the organic compound with the formula CH2 6H4sub>2O. It is a yellow solid that is soluble in common organic solvents. Xanthene itself is an obscure compound, but many of its derivatives are useful dyes. Xanthene dyes Dyes that contain a xanthene core include bikaverin, fluorescein, eosins, and rhodamines. Xanthene dyes tend to be fluorescent, yellow to pink to bluish red, brilliant dyes. Many xanthene dyes can be prepared by condensation of derivates of phthalic anhydride with derivates of resorcinol Resorcinol (or resorcin) is a phenolic compound. It is an organic compound with the formula C6H4(OH)2. It is one of three isomeric benzenediols, the 1,3-isomer (or ''meta- (chemistry), meta''-isomer). Resorcinol crystallizes from benzene as co ... or 3-aminophenol. Further reading * See also * Xanthone * Xanthydrol References {{Reflist Dyes Fungicides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorescent
Fluorescence is one of two kinds of photoluminescence, the emission of light by a substance that has absorbed light or other electromagnetic radiation. When exposed to ultraviolet radiation, many substances will glow (fluoresce) with colored visible light. The color of the light emitted depends on the chemical composition of the substance. Fluorescent materials generally cease to glow nearly immediately when the radiation source stops. This distinguishes them from the other type of light emission, phosphorescence. Phosphorescent materials continue to emit light for some time after the radiation stops. This difference in duration is a result of quantum spin effects. Fluorescence occurs when a photon from incoming radiation is absorbed by a molecule, exciting it to a higher energy level, followed by the emission of light as the molecule returns to a lower energy state. The emitted light may have a longer wavelength and, therefore, a lower photon energy than the absorbed rad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spirit Level
A spirit level, bubble level, or simply a level, is an Measuring instrument, instrument designed to indicate whether a surface is Horizontal plane, horizontal (level) or vertical direction, vertical (plumb-bob, plumb). Two basic designs exist: ''tubular'' (or ''linear'') and ''Bull's eye level, bull's eye'' (or ''circular''). Different types of spirit levels may be used by carpenters, stonemasons, bricklayers, other building trades workers, Surveyor (surveying), surveyors, millwrights and other metalworkers, and in some Photography, photographic or Videography, videographic work. History The history of the spirit level was discussed in brief in an 1887 article appearing in ''Scientific American''. Melchisédech Thévenot, a French scientist, invented the instrument some time before February 2, 1661. This date can be established from Thevenot's correspondence with scientist Christiaan Huygens. Within a year of this date the inventor circulated details of his invention to othe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eosin Y
Eosin Y, also called C.I. 45380 or C.I. Acid Red 87, is a member of the triarylmethane dyes. It is produced from fluorescein by bromination. Use Eosin Y is commonly used as the red dye in red inks. It is commonly used in histology, most notably in the H&E (Haematoxylin and Eosin) stain. Eosin Y is also widely used in the Papanicolaou stain (or Pap stain used in the Pap test The Papanicolaou test (abbreviated as Pap test, also known as Pap smear (AE), cervical smear (BE), cervical screening (BE), or smear test (BE)) is a method of cervical screening used to detect potentially precancerous and cancerous processes i ...) and the Romanowsky type cytologic stains. It is also used as a photosensitizer in organic synthesis. File:Eosin solution.jpg, Eosin Y solution for staining microscopy slides. File:Eosinophilic, basophilic, chromophobic and amphophilic staining.png, Eosinophilic staining, using eosin Y, compared to other patterns when using hematoxylin and eosin (H& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organic Compound
Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-containing compounds such as alkanes (e.g. methane ) and its derivatives are universally considered organic, but many others are sometimes considered inorganic, such as certain compounds of carbon with nitrogen and oxygen (e.g. cyanide ion , hydrogen cyanide , chloroformic acid , carbon dioxide , and carbonate ion ). Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. The study of the properties, reactions, and syntheses of organic compounds comprise the discipline known as organic chemistry. For historical reasons, a few classes of carbon-containing compounds (e.g., carbonate salts and cyanide salts), along with a few other exceptions (e.g., carbon dioxide, and even ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vomiting
Vomiting (also known as emesis, puking and throwing up) is the forceful expulsion of the contents of one's stomach through the mouth and sometimes the nose. Vomiting can be the result of ailments like food poisoning, gastroenteritis, pregnancy, motion sickness, or hangover; or it can be an after effect of diseases such as brain tumors, elevated intracranial pressure, or overexposure to ionizing radiation. The feeling that one is about to vomit is called nausea; it often precedes, but does not always lead to vomiting. Impairment due to alcohol or anesthesia can cause inhalation of vomit. In severe cases, where dehydration develops, intravenous fluid may be required. Antiemetics are sometimes necessary to suppress nausea and vomiting. Self-induced vomiting can be a component of an eating disorder such as bulimia nervosa, and is itself now classified as an eating disorder on its own, purging disorder. Complications Aspiration Vomiting is dangerous if gastric content e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nausea
Nausea is a diffuse sensation of unease and discomfort, sometimes perceived as an urge to vomit. It can be a debilitating symptom if prolonged and has been described as placing discomfort on the chest, abdomen, or back of the throat. Over 30 definitions of nausea were proposed in a 2011 book on the topic. Nausea is a non-specific symptom, which means that it has many possible causes. Some common causes of nausea are gastroenteritis and other gastrointestinal disorders, food poisoning, motion sickness, dizziness, migraine, fainting, low blood sugar, anxiety, hyperthermia, dehydration and lack of sleep. Nausea is a side effect of many medications including chemotherapy, or morning sickness in early pregnancy. Nausea may also be caused by disgust and depression. Medications taken to prevent and treat nausea and vomiting are called antiemetics. The most commonly prescribed antiemetics in the US are promethazine, metoclopramide, and the newer ondansetron. The word na ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acute (medicine)
In medicine, describing a disease as acute denotation, denotes that it is of recent wikt:onset#Noun, onset; it occasionally denotes a short wikt:duration#Noun, duration. The quantification (science), quantification of how much time constitutes "short" and "recent" varies by disease and by context, but the core denotation of "acute" is always qualitative property, qualitatively in contrast with "chronic condition, chronic", which denotes long-lasting disease (for example, in acute leukaemia and chronic leukaemia). In the context of the mass noun "acute disease", it refers to the acute phase (that is, a short course) of any disease entity. For example, in an article on ulcerative enteritis in poultry, the author says, "in acute disease there may be increased mortality rate, mortality without any obvious medical sign, signs", referring to the acute form or phase of ulcerative enteritis. Meaning variations A mild stubbed toe is an acute injury. Similarly, many acute upper respirator ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Urticaria
Hives, also known as urticaria, is a kind of skin rash with red or flesh-colored, raised, itchy bumps. Hives may burn or sting. The patches of rash may appear on different body parts, with variable duration from minutes to days, and typically do not leave any long-lasting skin change. Fewer than 5% of cases last for more than six weeks (a condition known as chronic urticaria). The condition frequently recurs. Hives frequently occur following an infection or as a result of an allergic reaction such as to medication, insect bites, or food. Psychological stress, cold temperature, or vibration may also be a trigger. In half of cases the cause remains unknown. Risk factors include having conditions such as hay fever or asthma. Diagnosis is typically based on appearance. Patch testing may be useful to determine the allergy. Prevention is by avoiding whatever it is that causes the condition. Treatment is typically with antihistamines, with the second generation antihistamines suc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
