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891.
892.
In any case of intra-abdominal trauma or hemorrhage a preoperative IVP is essential to determine the renal status. Preoperative catheter occlusion of the renal artery in these vascular tumors may be attempted to decrease blood loss. Stigmas of tuberous sclerosis should be sought in patients with vascular renal tumors, especially if they are bilateral. Conservation of renal tissue in tuberous sclerotic patients harboring renal angiomyolipomas is important.  相似文献   
893.
Using metallic microelectrodes, intracellular measurements were performed of changes in O2 concentration for spherical oocytes of hens by their replacement from normal (PO2=150 torr) to hyperoxic (to 600 torr) conditions, and vice versa. The curves of O2 influx and efflux were recorded in pulse regime of the working electrode polarization. The character of these curves can be expressed by the following equations: m(t)==c==e=y1t+y0 and m (t) =e-y1t+v0+c, where v1 is determined by the coefficient of cell membrane permeability for O2. Valid differences were shown between values of v1 for oxygen influx and efflux which vanish after the action of cyanides. It is suggested that O2 transport into the cell involves a base component which may be physical diffusion, and an additional component which can be depressed by cyanides.  相似文献   
894.
895.
A potassium-mercury lamp in a sapphire envelope was constructed. Under the proper conditions of pressure and temperature the potassium resonance lines radiate efficiently at the infrared absorption lines of Nd3+in YAG. Spectral tests indicate that a threefold improvement in pumping efficiency should be obtained compared with a tungsten filament lamp. CW room-temperature laser tests result in an output of 10 watts for an input of 420 watts for a 2.4 percent overall efficiency. This compares with a 1 percent overall efficiency for the tungsten filament lamp.  相似文献   
896.
897.
The major problem of this experiment was to determine the effect of a win or loss in a competitive reaction time (RT) task on the prediction of success on the following trial. Each of the 15 experimental pairs of college students was matched with a pair of control Ss who also engaged in a competitive RT task but predicted a sequence of events identical to the sequence of wins and losses generated by the experimental pair. During the last 70 trials the event on a given trial had a substantial effect on the prediction on the subsequent trial, an effect which was different for the 2 groups. For the experimental group the effect of a win was considerably greater than that of a loss, and the degree of asymmetry was positively related to the proportion of win events. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
898.
The a priori biologic significance of the histocompatibility complex with its excessive polymorphism remains unknown. Teleologically, however, the role of the HLA system may be viewed as vital for survival of the species and the individual by providing the host with a recognition system of and defenses against viruses, microorganisms, parasites, plant antigens, neoplastic cells, and others. HLA testing, in addition to its usefulness in donor selection for transplantation, has been recently applied to the diagnosis and differentiation of specific diseases, the prediction of disease development (risk prediction), and as a basis for prognostic evaluations. An increasing number of diseases is being shown to be linked by specific HLA antigens and certain common denominators, such as arthritides, autoimmune components or infections, suggesting common etiologic or pathogenic mechanisms or both. These diseases with HLA associations can be separated into those that appear certain, probable, or only statistically possible.  相似文献   
899.
Previous experiments in this laboratory demonstrated a progressive decrease in cell-mediated cytotoxicity (CMC) against allogeneic tumor cells by immune spleen cells from mice repeatedly immunized with those tumor cells. In the present study, immune spleen cells, obtained at specified intervals during the course of multiple immunizations of BALB/c mice with EL-4 lymphoma cells, were tested for CMC against EL-4 target cells pretreated with anti-EL-4 serum which had been obtained from singly or repeatedly immunized animals. Cytolysis of EL-4 cells was measured by a 51Cr-release assay. The results indicate that blocking of CMC in an allogeneic tumor model may occur by two pathways. First, antigen or antigen-antibody complexes present in the immunized animal may bind in vivo to the antigen receptor sites of of sensitized effector cells that are used in the in vitro CMC assay, thereby blocking their interaction with tumor cells. Second, immune serum that is added to the in vitro CMC assay may contain highly avid antibodies, as well as antigen-antibody complexes, that bind to tumor cells and thereby block interaction with sensitized effector cells. The identification of these elements may be of prognostic significance in certain clinical situations.  相似文献   
900.
A study of 100 selected Wisconsin family physicians demonstrated that younger physicians generally had more contact with younger patients, middle-aged physicians had an even distribution of patient age contacts, and older physicians had more contact with older patients. The increase in older patients became pronounced for 56 to 60-year-old physicians. Generally a ten-year increase in physician age was accompanied by a five-year increase in patient age. The rising average age of the American population, combined with the direct physician-patient age relationship demonstrated here suggest that geriatrics will become increasingly relevant not only in the continuum of medical education but also for the individual practicing physician.  相似文献   
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