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141.
Subcellular Pathology of Human Neurodegenerative Disorders: Alzheimer-Type Dementia and Huntington''s Disease 总被引:1,自引:1,他引:0
A. J. Cross T. J. Crow J. M. Dawson I. N. Ferrier J. A. Johnson T. J. Peters G. P. Reynolds 《Journal of neurochemistry》1986,47(3):882-889
Activities of enzyme markers of subcellular organelles have been measured in brain tissue from subjects with Alzheimer-type dementia (ATD) and Huntington's disease (HD). Significant increases in the activity of the lysosomal enzyme beta-glucuronidase were observed in both ATD temporal cortex and HD putamen. It is suggested that beta-glucuronidase activity may be a useful biochemical indicator of cellular damage in the CNS. A significant reduction in neutral alpha-glucosidase activity was observed in ATD temporal cortex and HD putamen. This change may reflect an alteration in glycoconjugate processing and may relate to the susceptibility of neurones to the degenerative processes of ATD and HD. 相似文献
142.
Erik Ilsø Christensen 《Cell and tissue research》1986,243(1):101-108
Summary The present study was performed to investigate whether membrane recycling via the dense apical tubules in cells of renal proximal tubules could be modified after exposure to large amounts of cationized ferritin. Proximal tubules in the rat kidney were microinfused in vivo with cationized ferritin for 10 or 30 min and then fixed with glutaraldehyde by microinfusion, or proximal tubules were microinfused with ferritin for 30 min and then fixed 2 h thereafter. The tubules were processed for electron microscopy, and the surface density and the volume density of the different cell organelles involved in endocytosis were determined by morphometry. The morphometric analyses showed that after loading of the endocytic vesicles with ferritin the surface density of dense apical tubules decreased to about 50% of the original value. However, 2 h later when ferritin had accumulated in the lysosomes the surface density of dense apical tubules had returned to control values. Furthermore, cationized ferritin was virtually absent from the Golgi region, indicating that the Golgi apparatus in these cells does not participate in membrane recycling. In conclusion, the present study shows that membrane recycling in renal proximal tubule cells can in part be inhibited by loading the endocytic vacuoles with ferritin. 相似文献
143.
144.
The pathology and infectivity of an RNA virus infectious to Trichoplusia ni larvae was investigated. The enzyme-linked immunosorbent assay (ELISA) and weight depression were used as criteria for virus concentration in larval homogenates and live larvae, respectively. Infected larvae were severely stunted, weighing as little as 13 times less than uninfected individuals of the same age, yet appeared normal morphologically. The virus was found to cause only slight mortality at high concentrations. Infected larvae displayed the pathological stunting response down to a dose of 0.1 ng of virus. Larvae infected with doses 100 times lower did not show the weight response but such inapparent infections were detectable by ELISA. Because of these subtle gross pathological symptoms, particularly at low levels of infection, infected individuals could easily remain unde-tected in a group-reared colony. 相似文献
145.
Summary The sequences of changes which occur in the fine structure of root and coleorhiza cells of the rye embryo during the first 9 hours of germination are described. Quiescent cells from both tissues characteristically possess no vacuole, a cytoplasm densely packed with ribosomes, lipid droplets largely confined to a peripheral position, a greatly reduced endomembrane system, mitochondria with few cristae and nuclei in which the heterochromatin is condensed. Following imbibition the structure of root cells is elaborated slowly. Microtubules and dictyosomes appear, followed by the development of mitochondrial cristae and endoplasmic reticulum and the dispersion of lipid droplets. A similar pattern of events occurs within coleorhiza cells but at a much enhanced rate. By 6 hours the endomembrane system is highly organized but by 9 hours it has largely disappeared. These observations are discussed in relation to the penetration of the root through the coleorhiza. 相似文献
146.
Summary The development of the macrogamete ofEimeria. stiedai in the epithelial cells of the bile ducts of rabbits was studied by electron microscopy. A macrogamete was first identified by the presence of a large central nucleus with prominent nucleolus, and subsequently by the appearance of wall forming bodies. The macrogamete was limited by an outer single membrane under which there were remnants of a second membrane. The parasitophorous vacuole, in which the macrogamete was located, was often narrow and it contained no intravacuolar-tubules or -folds. As macrogametogony proceeded wall forming bodies of Type I and II, canaliculi, electron pale spaces (lipid) and polysaccharide granules increased in number. Granular endoplasmic reticulum, mitochondria and Golgi bodies were present throughout. 相似文献
147.
G. Adolph Ackerman 《Cell and tissue research》1972,134(2):153-166
Summary The surfaces of developing erythrocytic cells and macrophages have been examined in normal human bone marrow by means of the pyroantimonate-osmium, ruthenium red and Thorotrast techniques for inorganic cations, surface glycoprotein-phospholipid complexes and surface anionic binding sites, respectively. No differences in the degree of surface coat reactivity were noted in the erythrocytic cells at different stages of maturation while pyroantimonate binding to the plasmalemma was not evident developmentally until the final stages of erythrocytic development. Rhopheocytotic invaginations proved to be chemically distinct from the remainder of the cell surface since they did not bind Thorotrast or pyroantimonate and gave more staining with ruthenium red. Pyroantimonate does not bind to the surface of macrophages and the binding of Thorotrast by these cells is less. Macrophage-erythrocytic cell contact zones did not stain with Thorotrast but stained with ruthenium red. The significance of these observations is discussed.Supported by Grant No. AM-HE-12084-14 from the National Institutes of Health, Bethesda, Maryland. — Appreciation is expressed to Anita Topson and Marjorie Griffith for their technical assistance and to Dr. Robert Hilberg for performing the bone marrow aspirations. 相似文献
148.
Summary A transformation system for Ophiostoma ulmi (Buism.) Nannf. was developed and analyzed. Protoplasts were generated from actively budding yeastlike cells by digestion with NovoZym 234 in MgSO4 after pretreatment with 2-mercaptoethanol. Protoplast regeneration was most efficient when 0.6 M sucrose was used as the osmoticum. Several plasmids containing fusions between fungal promoters and a bacterial gene for hygromycin phosphotransferase successfully transformed O. ulmi to hygromycin resistance. One of these vectors, pPS57, which contains a promoter for isopenicillin N synthetase from Penicillium chrysogenum, consistently conferred the greatest resistance to hygromycin. Linearization of the vector and inclusion of 2-mercaptoethanol in the transformation reaction resulted in enhanced transformation efficiency. Approximately 4 × 103 transformants/g DNA per 107 protoplasts were obtained using the optimized procedure. Southern hybridization after alternating field and standard electrophoresis suggested random insertion of tandem repeats (some greater than 250 kb) into the fungal chromosomes. Antibiotic resistance was stable through mitosis. However, expression of the transforming DNA after meiosis was highly variable. 相似文献
149.
Dr. Evelyne Vila-Porcile Renée Picart Léon Olivier Andrée Tixier-Vidal Claude Tougard 《Cell and tissue research》1988,254(3):617-627
Summary Laminin (LAM), a glycoprotein component of basement membranes, has been previously detected within several subcellular compartments of prolactin (PRL) cells in the pituitary gland. The present work was aimed at comparing the subcellular localization of PRL, a specific secretory product, with that of LAM, in relation to the secretory activity of PRL cells. LAM and PRL were located in parallel, by ultrastructural immunocytochemistry, in PRL cells of lactating female Wistar rats, either stimulated by suckling, or blocked by weaning, or reactivated by suckle following short-term weaning. Variations in physiological conditions were correlated with a redistribution of PRL immunoreactivity within morphologically modified compartments. The Golgi apparatus became hypertrophied, and PRL impressively accumulated within saccules of the Golgi stacks of blocked cells. On the contrary, no apparent changes occurred in LAM distribution, at least at the Golgi level. Only a slight increase of LAM immunoreactivity was observed in rough endoplasmic reticulum after a long weaning period. PRL could be detected in most of the secretory granules and particularly in forming elements, whereas LAM was observable at the peripheral edge of some mature granules. Such a labeling was not markedly influenced by the physiological state. The prominent structures, indicative of crinophagic activity, characteristic of blocked cells, contained masses of dense material, which were always immunopositive with antibodies to PRL, but never to LAM. These observations could suggest that, in PRL cells, intracellular transport and exportation of LAM are controlled by mechanisms independent from those involved in the regulation of PRL secretion. 相似文献
150.
Summary In an effort to investigate the functional relationship between cell-specific work and intracellular degradative processes, the effect of furosemide on cellular autophagy was investigated in two different portions of the nephron, namely, the thick ascending limb of Henle's loop (TAL), which is a main target of this drug, and the proximal convoluted tubule (PCT) as a reference structure. Eight male adult rats were treated with furosemide (60 mg/kg body weight, s.c.). Eight control animals received physiological saline. 1 to 4 h after the injections the animals were killed by perfusion fixation. Small specimens of kidney tissue from the inner stripe of the outer medulla and from the outer cortex were processed for electron microscopy; they were investigated morphometrically for volume fraction and numerical density of autophagic vacuoles (AVs). A significant increase of both parameters (volume fraction: 0.42 × 10-4 to 1.09 × 10-4; numerical density: 4.2 × 105/mm3 to 15.5 × 105/mm3) was seen under the influence of furosemide in TAL cells, whereas PCT cells did not show a significant increase in volume fraction or any increase in numerical density of AVs. These data suggest that the functional unloading of TAL, via blocking of the Na+- 2Cl- — K+ co-transport by furosemide, results in adaptative structural unloading, i.e., an increased sequestration of cytoplasmic components into AVs, within a short-time interval. 相似文献