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41.
A protein mixture can be separated in a flow column by application of a transverse electrophoretic field to carry faster-migrating components of the mixture into a fixed gel bed at one side of the column, so that slower components move along in a buffer stream. The field is then reversed to returnthe faster-moving components to the buffer stream. The cycle is repeated many times to complete the separation. 相似文献
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R M Weinshilboum F A Raymond L R Elveback W H Weidman 《Science (New York, N.Y.)》1973,181(103):943-945
Dopamine-beta-hydroxylase activity is released into the blood with catecholamines from the adrenal medulla and sympathetic nerves. This enzyme activity has been measured in the blood of 317 normal children and 227 normal adults. A significant sibling-sibling correlation of serum dopamine-beta-hydroxylase values was found in the 94 sibling pairs tested. Frequency distributions of serum enzyme values in both children and adults suggest the existence of two populations with regard to serum activity of this enzyme. 相似文献
45.
Lipoprotein patterns in acrylamide gel electrophoresis 总被引:1,自引:0,他引:1
Lipoproteins of serum stained before electrophoresis gave distinct patterns in acrylamide gel of 3-percent concentration. Samples compared in parallel on gel slabs showed qualitative differences in migration rates of beta-lipoprotein bands. 相似文献
46.
L Raymond R B Weiskopf M J Halsey A Goldfien E I Eger J W Severinghaus 《Science (New York, N.Y.)》1972,176(40):1250-1252
Breathing a mixture of 75 percent helium and 25 percent oxygen instead of 75 percent nitrogen and 25 percent oxygen reduced the occurrence of dangerous cardiac arrhythmias after ligation of the circumflex coronary artery in open-chest dogs anesthetized with pentobarbital. In dogs not subjected to circumflex ligation, the sensitivity of blood pressure, heart rate, and extrasystoles to epinephrine injected intravenously was not altered by the substitution of helium for nitrogen; however, helium did reduce the baseline heart rate and the concentration of endogenous plasma catecholamines. The antiarrhythmic effect of helium may thus be mediated by changes in sympathetic activity. 相似文献
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Glacial polish, grooves, and striations discovered at an elevation of 1370 meters in the headwaters of Boone Fork on Grandfather Mountain, North Carolina, indicate the former, existence of alpine glaciation at a latitude of 36 degrees 07'N. The Boone Fork glacier was located 890 kilometers south of the previously recognized southern limit of alpine glaciation in the Appalachian Mountains, and 350 kilometers southeast of the nearest point on the Laurentide ice sheet. This find has significant implications for studies of Pleistocene geomorphology, paleobiology, and paleoclimatology in the eastern United States. 相似文献
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