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991.
The major penetrating membrane glycoprotein (band 3) was isolated from En(a-) and normal human erythrocytes. The two proteins differed only in carbohydrate composition. Band 3 from En(a-) erythrocytes contained greater amounts of galactose and N-acetyl-glucosamine. The loss of the sialoglycoprotein sialotetrasaccharides in the En(a-) cell is not compensated by the appearance of these units in band 3 of En(a-) erythrocytes. 相似文献
992.
The decline (half-life) of maternally acquired antibodies of two different specificities (diphtheria and tetanus) was studied in rats. Essentially similar half-lives for antibody of each specificity were found in young rats from the same litter. In contrast, half-lives varied from 2 to 10 days in individuals of different litters. Significant differences in half-lives were demonstrated in young rats possessing markedly different initial titres of antibodies of the two specificities. It was established that there was a relationship between the half-life and the initial titre of antibody of each specificity which could be described by a rectangular hyperbola. These findings are in close aggreement with previous studies in human infants. 相似文献
993.
994.
MJ Brownstein EA Mroz JS Kizer M Palkovits SE Leeman 《Canadian Metallurgical Quarterly》1976,116(2):299-305
Using a sensitive radioimmunoassay we have studied the regional distribution of substance P. The level of substance P is higher in the mesencephalon, hypothalamus and preoptic area than in other regions of the brain. Substance P is found in especially high concentrations in the reticular part of the substantia nigra and the interpeduncular nucleus. It is present in large amounts in several septal, preoptic and hypothalamic nuclei as well. 相似文献
995.
The patterns of expression of eight multilocous isozyme systems were investigated in the differentiated adult tissues and the early embryonic stages (0-210 hours after fertilization) of the green sunfish, Lepomis cyanellus. Enzymes encoded by approximately 23 gene loci were resolved by starch-gel electrophoresis and detected by specific histochemical staining. The developmental patterns of these isozyme systems appear to be the result of the diffential expression of the multiple gene loci. Isozymic forms of glucoseophosphate isomerase (GPI-A2), malate dehydrogenase (MDH-A2), and creatine kinase (CK-C2) were present in most differentiated tissues, in the unfertilized eggs, and in all stages of embryonic development. Closely homologous forms of these isozymes (GPI-B2, MDH-B2, and CK-A2) were expressed predominantly in skeletal muscle and were first detected at around the time of hatching (38-42 hours). The similar temporal and spatial patterns of gene expressions for the GPI, LDH, MDH, and CK loci suggest that the duplicates loci encoding enzymes, diverged in their regulation to patterns of differential gene expression which are similar for each enzyme system. 相似文献
996.
Geometric superresolution by code division multiplexing 总被引:2,自引:0,他引:2
In many highly resolved optical systems the resolution is limited not by the optics but by the CCD's nonzero pixel size. As a result, overall resolution is decreased. Here we propose a novel approach to enhancing resolution beyond the limit set by the CCD's pixels. This method does not involve additional mechanical elements, such as those used for microscans. In this scheme neither the CCD nor additional elements are moved. The geometric superresolving procedure is based on code-division multiplexing, with all its inherent benefits, such as relative noise immunity to single-tone interference. A setup is proposed for coherent and incoherent illumination, with slight modifications for the latter. A theoretical analysis of the setup is presented and compared with empirical results. This scheme is shown to enhance one-dimensional image resolution with the use of only a simple mask that doubles image resolution. This method can easily be expanded to two-dimensional images and to resolution-enhancement factors greater than 2. 相似文献
997.
998.
999.
1000.
A.A. Roche A.K. Behme Jr. J.S. Solomon 《International Journal of Adhesion and Adhesives》1982,2(4):249-254
A three-point flexure test was used to evaluate the effects of chemical surface treatments on the performance of adhesively-bonded structures of Ti6A14V. A single adherend/adhesive structure rather than a double adherend sandwich configuration is shown to be sensitive to pre-bonding adherend surface treatments. Data is presented which relates mechanical properties with chemically treated adherend surfaces. Photoelastic isochromatic fringes were recorded simultaneously with the flexure test as a means to monitor stress distribution, failure initiation, and crack propagation. 相似文献