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Research data for five types of gland packings are reported. Relationships are shown with due regard for the number of loadings and the number of packing layers: relative deformation of the packing due to unit load, unit load on the packing due to its relative deformation, and compression and recovery modulus arising from relative deformation of the packing.  相似文献   
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In dogs subjected to gravitational overloadings (+Gx) according to a special training schedule the wall structure of the main arteries (carotid, humeral, femoral and aorta) was studied by histological methods. The amount of catecholamines (adrenaline and noradrenaline) in the venous blood plasma and in the adrenal tissue was the index of the sympathoadrenal system condition. It was demonstrated that in trained animals the tolerance threshold to continuously increasing overloadings (+Gx) rose. It was accompanied by an elevated amount of catecholamines in blood and the adrenals In the walls of the main arteries studied a moderate hyperelastosis and a slight collagenization of the adventitia was noted. All parts of the microcirculatory bed were moderately dilated, which favoured a better blood outflow. The data obtained demonstrate adaptational changes, which can be interpreted as indices of training and reliability of the organism.  相似文献   
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The electrochemical interaction of acetylene compounds, both with and without -hydrogen, with iron in hydrochloric and sulfuric acids was investigated by potentiostatic voltammetry on a rotating disk electrode and capacitance measurements on a stationary electrode. The tendency of acetylene compounds to electrochemical reduction correlates with their ability to polymerize on iron in acidic solutions. The presence of -hydrogen atom determines the ability of an acetylene compound to polymerize on iron, thus inducing the secondary inhibition. The compound containing no -hydrogen manifests only adsorption mechanism.  相似文献   
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A role for GH in the pathogenesis of diabetic retinopathy has long been postulated. Previous clinical studies, however, have been confounded by hyperglycemia. We have identified 2 cases of retinopathy associated with exogenous GH therapy in nondiabetic patients. Cases were identified through the MedWatch drug surveillance system of the U.S. Food and Drug Administration. Causality by concomitant medications was excluded by a search of the literature and the FDA data base. The first patient, an obese, 31-yr-old male with traumatic hypothalamic injury, presented with nonproliferative retinopathy and macular edema, resulting in decreased visual acuity (OD 20/40-1; OS count fingers), which required laser surgery. Human GH had been initiated at 0.009 mg/ kg.day, 14 months earlier, and titrated to 0.017 mg/kg.day. The second patient, a nonobese, 11-yr-old girl receiving GH for the management of short stature in Turner's Syndrome, presented with neovascularization. GH doses were 0.033 mg/kg.day for the first 17 months and 0.043 mg/ kg.day for the following 5 months. Cumulative laboratory and clinical observations suggest that GH and related peptides have a role in retinal pathology independent of the degree of glucose tolerance.  相似文献   
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