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A J Barwijuk K Swietochowska R Pia?cik K Jaroszewicz Z Skrzydlewski 《Acta physiologica Polonica》1989,40(4):404-408
The total phospholipids and their various classes in erythrocytes and blood plasma were determined quantitatively by means of two-dimensional thin-layer chromatography. The total amount of phospholipids in neonate plasma was approximately half of that found in adult plasma, however, the amount of phospholipids in erythrocytes of the neonate was significantly higher. The differences were observed in some classes of phospholipids in the plasma and erythrocytes of neonates as well as adult human beings. 相似文献
4.
Genetic determinants of glutamine synthetase inDrosophila melanogaster: A gene for glutamine synthetase I resides in the 21B3-6 region 总被引:1,自引:0,他引:1
Corrado Caggese Ruggiero Caizzi Maria Pia Bozzetti Paolo Barsanti Ferruccio Ritossa 《Biochemical genetics》1988,26(9-10):571-584
Recombinational and deletion mapping of electrophoretic variants of the glutamine synthetase I isozyme (GSI) in Drosophila melanogaster locates the gene in the 21B region on the second chromosome. We have conducted a genetic analysis of the region extending cytologically from 21A to 21B4-6. Recessive lethal mutations were generated by ethyl methanesulfonate (EMS) and ethyl nitrosourea (ENU) mutagenesis and by hybrid dysgenesis (HD). These lethals fall into seven functional groups, which were partially ordered by complementation with cytologically defined deficiencies of this region generated by hybrid dysgenesis. Two of the EMS- and two of the ENU-induced lethals fulfill biochemical criteria expected for null alleles of the GSI gene. 相似文献
5.
Metabolic and energetic aspects of the growth of Clostridium butyricum on glucose in chemostat culture 总被引:8,自引:0,他引:8
The influence of a number of environmental parameters on the fermentation of glucose, and on the energetics of growth of Clostridium butyricum in chemostat culture, have been studied. With cultures that were continuously sparged with nitrogen gas, glucose was fermented primarily to acetate and butyrate with a fixed stoichiometry. Thus, irrespective of the growth rate, input glucose concentration specific nutrient limitation and, within limits, the culture pH value, the acetate/butyrate molar ratio in the culture extracellular fluids was uniformly 0.74±0.07. Thus, the efficiency with which ATP was generated from glucose catabolism also was constant at 3.27±0.02 mol ATP/mol glucose fermented. However, the rate of glucose fermentation at a fixed growth rate, and hence the rate of ATP generation, varied markedly under some conditions leading to changes in the Y
glucose and Y
ATP values. In general, glucose-sufficient cultures expressed lower yield values than a correponding glucose-limited culture, and this was particularly marked with a potassium-limited culture. However, with a glucose-limited culture increasing the input glucose concentration above 40g glucose·l-1 also led to a significant decrease in the yield values that could be partially reversed by increasing the sparging rate of the nitrogen gas. Finally glucose-limited cultures immediately expressed an increased rate of glucose fermentation when relieved of their growth limitation. Since the rate of cell synthesis did not increase instantaneously, again the yield values with respect to glucose consumed and ATP generated transiently decreased.Two conditions were found to effect a change in the fermentation pattern with a lowering of the acetate/butyrate molar ratio. First, a significant decrease in this ratio was observed when a glucose-limited culture was not sparged with nitrogen gas; and second, a substantial (and progressive) decrease was observed to follow addition of increasing amounts of mannitol to a glucose-limited culture. In both cases, however, there was no apparent change in the Y
ATP value.These results are discussed with respect to two imponder-ables, namely the mechanism(s) by which C. butyricum might partially or totally dissociate catabolism from anabolism, and how it might dispose of the excess reductant [as NAD(P)H] that attends both the formation of acetate from glucose and the fermentation of mannitol. With regards to the latter, evidence is presented that supports the conclusion that the ferredoxin-mediated oxidation of NAD(P)H, generating H2, is neither coupled to, nor driven by, an energy-yielding reaction. 相似文献
6.
The proα2 (V) collagen gene (COL5A2) maps to 2q14→2q32, syntenic to the proα1 (III) collagen locus (COL3A1) 总被引:3,自引:0,他引:3
Cécile Huerre-Jeanpierre Isabelle Henry M. Bernard Pia Gallano Dominique Weil K. H. Grzeschik F. Ramirez Claudine Junien 《Human genetics》1986,73(1):64-67
Summary A recombinant probe specific for the pro2 chain of human Type V collagen has been used for the localization of the corresponding gene (COL5A2) to chromosome 2. Regional mapping by in situ hybridization and analysis of DNA from humanxrodent cell lines indicated that COL5A2 is confined within the segment 2q142q32, thus syntenic to the pro1 (III) collagen gene (COL3A1). 相似文献
7.
An examination of the essential oil of myrrh from Commiphora molmol has permitted the identification of 1(10)Z,4Z-furanodiene-6-one, 2-meth 相似文献
8.
In a study of Necturus gallbladder epithelium Benzel et al. (Benzel et al., 1980) found that low (0.2–1.2 M) and higher concentrations (1.5 M and more) of cytochalasin B (CB) caused an increase and decrease in the transepithelial electrical resistance (TER), respectively. Moreover, there were slight changes in the height and complexicity of tight junction (TJ) strands, as visualized by freeze-fracture and freeze-etching. To elucidate the mechanisms of these findings, we first demonstrated that the effect is also present in monolayers of Madin-Darby Canine Kidney strain I (MDCK-I) cells. Thus, a low concentration (0.1 ng/ml) cytochalasin B (CB) strengthened the permeability barrier, as evidenced quantitatively by increases in TER on transepithelial electrical measurements. Furthermore, indirect immunofluorescence and confocal microscopy demonstrated that this effect was paralleled with an accumulation of F-actin and the tight junction marker protein, ZO-1, at the level of TJ. Equimolar concentrations of dihydrocytochalasin B (dhCB), on the other hand, did not lead to a tightening of the epithelium. Confirming previous studies, there was a general decrease in epithelial resistance after treatment with high concentrations (1 g/ml) of CB and dhCB, which was accompanied by distinct changes in the F-actin network and distribution of ZO-1. We speculate that the divergent effects of CB and dhCB on the F-actin and ZO-1 organization might be due to specific effects on the transport of monosaccharides across the plasma membrane, or that CB and dhCB in distinct ways involve the turnover of phosphatidylinositols in the membrane, thereby modulating junctional permeability and F-actin structure. 相似文献
9.
Karien E. De Rooij Pia A. M. De Koning Gans Raymund A. C. Roos Gert-Jan B. Van Ommen Johan T. Den Dunnen 《Human genetics》1995,95(3):270-274
The mutation causing Huntington disease (HD) has been identified as an expansion of a polymorphic (CAG)
n
repeat in the 5 part of the huntingtin gene. The specific neuropathology of HD, viz. selective neuronal loss in the caudate nucleus and putamen, cannot be explained by the widespread expression of the gene. Since somatic expansion is observed in affected tissue in myotonic dystrophy, we have studied the length of the (CAG)
n
repeat in various regions of the brain. Although we have not found clear differences when comparing severely and mildly affected regions, we have observed a minor increase in repeat length upon comparison of affected brain samples with cerebellum or peripheral blood. Hence, although further somatic amplification seems to occur in affected areas of the brain, the differences between affected and unaffected regions are too small to make this mechanism an obvious candidate for the cause of differential neuronal degeneration in HD. 相似文献
10.
Abstract. The cell-specific inhibitory (chalone) activity of JB-1 ascites tumour cell proliferation has been purified using five different procedures. By combining (1) molecular weight estimations based on ultrafiltration and gel chromatography, and (2) partitioning in organic solvent and ion exchangers, it is concluded that the active factor associates, in a complex manner, with various other components involving both hydrophobic and ionic forces. The active factor appears to be a slightly acidic, hydrophobic peptide (molecular weight 500–1000 D). When assessing the activity in vivo , it appears to be highly dependent on associated serum factors. Thus, the chalone studied appears to interact both structurally and functionally with various associated factors which affect its physicochemical behaviour and biological activity. 相似文献