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A wide variety of artifacts may be found when monitoring the ECG in a neonatal intensive care unit. Many of the artifacts resemble arrhythmias, and unless they are recognized as artifacts they may lead to serious errors of diagnosis and therapy. Many of the artifacts are caused by patient movement such as seizures, tremulousness, or hiccups. Others may be introduced by the monitor itself or be caused by electrical equipment in the vicinity. A group of ECG tracings is presented to illustrate the various artifacts encountered. Features that distinguish the artifacts from the arrhythmias they mimic are described, as are suggestions for elimination of the artifacts. 相似文献
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The LD50 values were utilized to assess the relative rate of absorption of two very poorly soluble drugs. Formulations of these drugs were studied by micronization; addition of surfactant, alkaline or buffering agents, and/or bile salts; coprecipitation; melt or fusion techniques; or granulation with hydrophilic agents. Differences in toxicities were demonstrated from formulations compared to pure drugs by the LD50 method. This study shows that the LD50 is a practical, rapid method of achieving comparative evaluations of drug formulations. 相似文献
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Persisting primitive papilla epithelialis is described in a 22-year-old woman. The papilla has blurred borders, a central papilla eminence and a yellowish colour. In addition pigmentary pseudoretinopathy with perivascular pigment deposits and hypermetropia with aplasia maculae occurred. This picture can be confused classically with pappilloedema. 相似文献
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Tablets were prepared using pan-coating, congealing, plasticization with organic solvents and direct compression methods. The tablets were evaluated using the official dissolution test, and an analysis of the active ingredient was accomplished by employing gas-liquid chromatography. The formulation and dissolution characteristics of sustained release tablets, employing the matrix concept to regulate drug release, were studied. Particle size distribution of plastic material influenced the release rates from porous inert matrices, and it was found that incomplete drug release occurred from these preparations. Three-layer slowly-eroding sustained release tablets, using a swellable gum (carbomer) were formulated; by adjusting the proportion of the gum quantitative release of the drug was attained. Approximation of linearity for drug release-time relationship was achieved from three-layer slowly-eroding tablets containing different concentrations of drug in the middle and outer layers. Administration of the above tablets, containing 30 mg of methadone, produced analgesia in male albino rats for approximately 60 h, without undesirable effects. 相似文献
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