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21.
William S. Thayer Emanuel Rubin 《Biochimica et Biophysica Acta (BBA)/Molecular Cell Research》1982,721(4):328-335
Previous studies have established that hepatic mitochondria and submitochondrial particles from rats, fed ethanol chronically, display diminished respiratory activities and alterations in the contents of specific electron transfer chain components. The latter include a decrease of about 50% in cytochrome b content. Titrations of respiratory activity in submitochondrial particles with antimycin, a stoichiometric inhibitor of electron flow through the cytochrome b-c1 region of the respiratory chain, indicated a comparable decrease (35%) in the amount of antimycin required to elicit maximal inhibition (‘titer’) after chronic ethanol treatment. Measurements of antimycin binding to submitochondrial particles by fluorescence quenching demonstrated a similar diminution in the number of tight binding sites per mg protein. By contrast, hepatocytes isolated from control and ethanol-fed rats exhibited nearly identical rates of oxygen utilization under a variety of conditions. However, antimycin titrations of respiratory activity in isolated hepatocytes revealed a 60% decrease in the antimycin titer, but no change in the maximal extent of inhibition after chronic ethanol treatment. Direct measurements of cytochrome b which could be reduced in the presence of antimycin in hepatocytes confirmed a comparable decrease (42%) after chronic ethanol treatment. The results demonstrate that molecular alterations in the cytochrome b region of the respiratory chain caused by ethanol feeding are present in intact liver cells, but suggest that substrate accessibility, rather than the respiratory chain, limits the rate of oxygen utilization in isolated hepatocytes. The data also suggest that mitochondria account for at least 80% of total oxygen utilization by liver cells from both control and ethanol-fed rats. 相似文献
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A map of 22 loci on human chromosome 22. 总被引:7,自引:0,他引:7
J P Dumanski E Carlbom V P Collins M Nordenskj?ld B S Emanuel M L Budarf H E McDermid R Wolff P O'Connell R White 《Genomics》1991,11(3):709-719
We constructed a genetic linkage map of the entire long arm of human chromosome 22 with 30 polymorphic markers, defining 22 loci. The map consists of a continuous linkage group 110 cM long, when male and female recombination fractions are combined; average distance between the loci is 5.2 cM. All loci were placed on the map with high support against alternative orders (odds in excess of 1000:1). The order of loci presented in our map is in full agreement with that of the previous linkage maps of chromosome 22 and with the physical assignment of markers. Two markers included in this map, KI-831 (D22S212) and pEFZ31 (D22S32), allowed us to better define the region of the (11;22) translocation breakpoint specific for Ewing sarcoma. Ten additional polymorphic markers were placed on the 22-loci map with odds lower than 1000:1 against alternative locations. In total, we have introduced 29 new markers on the linkage map of chromosome 22. 相似文献
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Emanuel Martín Campoy María Eugenia Mansilla María Isabel Colombo 《Cellular microbiology》2013,15(6):922-941
Coxiella burnetii is a Gram‐negative intracellular bacterium. As previously described, both the endocytic and the autophagic pathways contribute to the maturation of Coxiella replicative vacuoles (CRVs). The large CRVs share the properties of both phagolysosomal and autophagolysosomal compartments. Vamp3, Vamp7 and Vamp8 are v‐SNAREs involved in the endocytic pathway which participate mainly in the fusion between endosomes and lysosomes. In the present study we observed that Vamp7 interacts with C. burnetii at different infection times (1 h–48 h p.i.). We have determined that a truncated mutant of Vamp7 (Vamp7 NT) and a siRNA against this SNARE protein affects the optimal development of CRVs, suggesting that Vamp7 mediates fusion events that are required for the biogenesis of CRVs. Indeed, we have observed that overexpression of Vamp7 NT inhibited the heterotypic fusion with lysosomes and the homotypic fusion between individual Coxiella phagosomes and CRVs. Moreover, we have detected in the vacuole membrane, at different infection times, the Vamp7 partners (Vti1a and Vti1b). Interestingly, treatment with chloramphenicol reduced the colocalization between C. burnetii and Vamp7, Vti1a or Vti1b, indicating that the recruitment of these SNAREs proteins is a bacteria‐driven process that favours the CRV biogenesis, likely by facilitating the interaction with the endolysosomal compartment. 相似文献
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Woyneshet Gelaye Nana Aba Williams Stella Kepha Augusto Messa Junior Pedro Emanuel Fleitas Helena Marti-Soler Destaw Damtie Sissay Menkir Alejandro J. Krolewiecki Lisette van Lieshout Wendemagegn Enbiale 《PLoS neglected tropical diseases》2021,15(2)
BackgroundSoil-transmitted helminths (STH) are common in low and middle income countries where there is lack of access to clean water and sanitation. Effective diagnosis and treatment are essential for the control of STH infections. However, among STH parasites, Strongyloides stercoralis is the most neglected species, both in diagnostics and control strategies. Diagnostic methods cover different approaches, each with different sensitivities and specificities, such as serology, molecular techniques and microscopy based techniques. Of the later, the Baermann technique is the most commonly used procedure. In the literature, several ways have been described to perform the Baermann method, which illustrates the overall lack of a ‘(gold) reference standard’ method for the diagnosis of S. stercoralis infection. In this study we have evaluated the performance of three Baermann techniques in order to improve the reference standard for the microscopic diagnosis of S. stercoralis infection thereby facilitating individual case detection, mapping of the disease and proper evaluation of treatment responses.Methods/Principal findingsA community based cross sectional study was conducted at Zenzelima, Bahir Dar Zuria Ethiopia. A total of 437 stool samples were collected and analyzed by the following procedures: conventional Baermann (CB), modified Baermann (MB), and modified Baermann with charcoal pre-incubation (MBCI). The diagnostic sensitivity and Negative Predictive Value (NPV) of each technique was calculated using the combination of all the three techniques as a composite reference standard. Our result indicated that larvae of S. stercoralis were detected in 151 (34.6%) stool samples. The prevalence of S. stercoralis infection based on the three diagnostic methods was 9.6%, 8.0%, and 31.3% by CB, MB, and MBCI respectively. The sensitivity and NPV for CB, MB, and MBCI were 26.7% and 70.8%, 22.1% and 69.6%, and 87.0% and 93.2%, respectively. The MBCI showed significant difference (P- value = <0.001) in the sensitivity and NPV values when compared with CB and MB values. The agreement between CB, MB, and MBCI with the composite reference standard was 31.8%, 26.7%, 89.6%, respectively.Conclusion/SignificanceOur results suggest the superior performance of MBCI. It is relatively easy to implement, simple to perform and comparatively cheaper. The CB is by far the commonly used method in routine diagnostic although this technique significantly underestimates the true burden of the disease and thereby contributing to the exclusion of S. stercoralis from the control strategies. Therefore, MBCI is recommended as a routine microscopy-based diagnostic test for S. stercoralis infection, particularly in settings where molecular procedures are not available. 相似文献
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Detecting trends in tree growth: not so simple 总被引:1,自引:0,他引:1
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