Halo device

The optimal treatment remains controversial. Most of the patients can effectively be treated by immobilizing them in a halo device and only few, especially the long-standing ones, require posterior surgical fusion (Prols et al. 1973, Apuzzo et al. 1978, Ekong et al. 1981, Tator et al. 1982). 

Note, for many synthetic transformations, it is convenient to ntiUse halo- or alkoxy-diazines, in lien of the (oxidation level) equivalent carbonyl compounds. Often this device facilitates solnbiUty a final hydrolysis converts to the carbonyl form. 

Furan also undergoes cycloadditions with allenes," " with benzyne" and with simpler dienophiles, like acrylonitrile and acrylate various Lewis acidic catalysts can assist" in some cases, zinc iodide is one such, hafnium tetrachloride another, and improved endo exo ratios are obtained in an ionic liquid as reaction solvent. Maleate and fumarate esters react if the addition is conducted under high pressure. This device can also be used to increase markedly the reactivity of 2-methoxyfuran and 2-acetoxyfuran towards dienophiles. At higher reaction temperatures alkynes and even electron-rich alkenes will add to furan. 3- or 5-Halo-furans react faster in these cycloadditions. ... 

We solved the problem by using a three-membered ring (epoxide) for (2) and an a-halo carbonyl compound for (3) two apparently different devices which in fact rely on the same principle. The atoms marked + in (2) and (3) are easily made nucleophilic —by enolisation (i) for example—and the common principle is to use a preliminary nucleophilic attack on a heteroatom to reverse the natural polarity of the atom from nucleophilic to electrophilic. Halogenation (i, E = Br) of a ketone provides a reagent for (3) and epoxidation... 

DISPOSAL AND STORAGE METHODS absorb in dry earth, sand or vermiculite, and place in a secured sanitary landfill dissolve in flammable solvent, such as alcohol, and atomize in a suitable combustion chamber equipped with appropriate effluent gas cleaning device store in a cool, dry location with adequate ventilation separate from oxidizing materials, halo-carbons, and water. 

A halo is a medical device used to stabilize the cervical spine, especially after traumatic injuries to the neck or after spine surgery. The apparatus includes a halo vest, stabilization bars, and a metal ring encircling the patient s head and fixated to the skull with multiple pins. The halo allows for proper alignment of the neck and spinal cord to help treat and prevent further damage to the spine. Lightweight carbon halos are a significant improvement over metal because they must be worn for several months. 

GULL WING lead A surface mounted device iead which flares outward from the device body. haloing a light area around holes or other machined areas on or below the surface of the base laminate. 

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