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991.
Maria T. Giardi 《Planta》1993,190(1):107-113
The presence of heterogeneity in phosphorylated PSII core populations in grana membranes of spinach (Spinacia oleracea L.) was previously demonstrated (Giardi et al., 1991, Biochem. Biophys. Res. Commun. 176, 1298–1304). The effect of photoinhibitory conditions on the distribution of these phosphorylated PSII core populations in thylakoids and PSII particles has been investigated. The sensitivity of the PSII core to strong illumination depended on the phosphorylation state of D1 and D2 proteins as well as on the content of the 9-kDa PsbH phosphoprotein. When D1 and D2 proteins are under-phosphorylated, the 9-kDa phosphoprotein is tightly bound to the PSII core; thus, a partial protection from photoinhibition is observed. Of the different PSII core populations isolated from membranes photoinhibited for 10 min, the highly phosphorylated populations lack internal antennae CP43 and CP47; perhaps these migrate out to the non-appressed regions of thylakoids. The degradation of the D1 protein seems to follow the disassembly of the PSII core.  相似文献   
992.
To promote the rational use of cabozantinib (CBZ), this paper studied the influence of several nutritional supplements on the interaction between CBZ and bovine serum albumin (BSA), an appropriate alternative model for human serum albumin (HSA) that is one of the important transporter proteins in plasma, by fluorescence spectroscopy and UV–vis spectroscopy. The results showed that CBZ could quench the fluorescence of BSA via a dynamic–static quenching process, and the six nutritional supplements did not change the quenching mode of BSA by CBZ. However, all of them could reduce the binding constant of the CBZ–BSA system at 293 K and increase the polarity around tryptophan residues. Among them, nicotinamide and vitamin B12 (VB12) had a greater effect on the binding constants of the CBZ–BSA system. In the meantime, the thermodynamic parameters of the CBZ–BSA system were examined, indicating that the interaction of CBZ with BSA was spontaneous and dominated by hydrophobic forces. Further research discovered that the combining of CBZ with BSA was primarily located within Site I of BSA, and the binding distance r was 2.48 nm. Consequently, while taking CBZ, patients should use VB12 and nicotinamide carefully, which may interfere with the transport of drugs.  相似文献   
993.
The genetic peculiarity of the Basque population has long been noted. We aim to describe Basque distinctiveness in space and assess the internal Basque heterogeneity. All these aspects are relevant to the question of the origin of Basques. After a thorough literature search, a data base was created containing all the available data on gene frequencies in the Iberian Peninsula and France. Twenty-nine systems, comprising 71 alleles, were used to carry out a principal component (PC) analysis. The results show a sharp peak in the first PC in the Basque area, which remains even when the geographic scope is widened to include western Europe. As demonstrated by “wombling” analysis, the steeper slope in the first PC is found to the east of the Basque area, along the Pyrenees. Measures of genetic heterogeneity (such as FST values) within the Basque country, as compared to those for non-Basques, do not show a particular internal substructuration in the Basque population. The genetic results support a scenario in which the Basques are the product of in situ differentiation around the time of the Last Glacial Maximum (18,000 B .P .), in agreement with archaeological and linguistic data. Isolation from the surrounding populations has allowed the differentiation to last for millennia, but has erased the differences existing among Basques. © 1994 Wiley-Liss, Inc.  相似文献   
994.
Although the tussock growth form of caespitose graminoids is widespread, the effect of this growth form on light interception and carbon gain of tillers has received little attention. Daily incident photosynthetic photon flux density (PFDinc) and carbon gain in monospecific stands of tussock grasses were compared with those of a hypothetical distribution with the equivalent tiller density per total ground area, but evenly distributed rather than clumped in tussocks. This was computed for two tussock grasses Pseudoroegneria spicata (Pursh) A. Löve (bluebunch wheatgrass) and Agropyron desertorum (Fisch, ex Link) Schult. (creasted wheatgrass) at different plant densities. Daily PFDinc and net photosynthesis (A) were greater if tillers were distributed uniformly rather than clumped in tussocks, except when the density of tussocks was so great as to approach a uniform canopy. When tussock density per ground area was low, much of the difference between tussock and uniform tiller densities in PFDinc and A was due to shading within the tussocks; up to 50–60% of the potential carbon gain was lost in A. desertorum due to shading within tussocks. In a matrix of tussocks, the light field for establishing seedlings was very heterogeneous; potential A ranged from 7 to 96% relative to an isolated seedling. The mean of daily PFDinc and A for seedlings in a tussock stand were nearly identical to the values in corresponding stands of uniform tiller distributions. It is hypothesized that the loss of A resulting from clumping tillers into tussocks is offset by benefits of protecting sequestered belowground resources from invasion by seedlings of competitors.  相似文献   
995.
摘要 目的:探讨术前预后营养指数(PNI)与肺鳞状细胞癌患者预后的关系及对术后复发、死亡的预测效能。方法:纳入2017年1月-2019年1月在我院接受治疗的78例肺鳞状细胞癌患者,所有患者均具有完整的临床资料及病理信息,对其进行门诊复查随访3年,除去失访病例共纳入76例患者资料,期间共有43例患者复发、37例患者死亡;按照复发及死亡情况将该76例患者分别分为复发组(n=43)及未复发组(n=33),死亡组(n=37)及存活组(n=39),分别使用单因素和多因素Logistic回归分析影响肺鳞状细胞癌患者复发及死亡的独立危险因素;采用受试者工作特征(ROC)曲线分别分析PNI在肺鳞状细胞癌患者术后复发及死亡的预测效能及最佳截断值。结果:单因素分析显示,TNM分期、吸烟年限、糖尿病、家族史、PNI是影响肺鳞状细胞癌患者术后复发的相关因素(P<0.05);性别、年龄、TNM分期、BMI、吸烟史、吸烟年限及PNI是影响肺鳞状细胞癌患者术后死亡的相关因素(P<0.05)。多因素Logistic回归模型分析显示,TNM分期为Ⅲ期、吸烟年限较长、家族史是引发肺鳞状细胞癌患者术后复发的独立危险因素,PNI为保护因素(P<0.05);另外男性、年龄较大、TNM分期为Ⅲ期、吸烟年限较长是引发肺鳞状细胞癌患者术后死亡的独立危险因素,PNI为保护因素(P<0.05);ROC分析显示PNI在预测肺鳞状细胞癌患者术后复发的曲线下面积为0.726,敏感度为0.814,特异度为0.667,最佳截断值为48;PNI在预测肺鳞状细胞癌患者术后存活的曲线下面积为0.787,敏感度为0.838,特异度为0.718,最佳截断值为50。结论:PNI对肺鳞状细胞癌患者术后复发及生存均具有较高的预测效能,提高PNI水平对改善肺鳞状细胞癌患者的预后具有积极作用。  相似文献   
996.
摘要 目的:探讨术前预后营养指数(PNI)、中性粒细胞与淋巴细胞比值(NLR)及血小板与淋巴细胞比值(PLR)对脑胶质瘤患者术后预后的评估价值。方法:回顾性分析2016年2月至2019年2月我院收治的131例脑胶质瘤患者(脑胶质瘤组)的临床资料,另选择同期86例于门诊健康体检的志愿者为对照组,收集相关资料计算PNI、NLR、PLR。比较脑胶质瘤患者不同临床病理特征PNI、NLR、PLR的差异,Kaplan-Meier法绘制不同PNI、NLR、PLR水平脑胶质瘤患者的生存曲线,单因素和多因素COX回归分析影响脑胶质瘤患者预后的相关因素,受试者工作特征曲线(ROC)分析术前PNI、NLR、PLR预测脑胶质瘤患者预后的价值。结果:脑胶质瘤组NLR、PLR高于对照组(P<0.05),PNI低于对照组(P<0.05)。世界卫生组织(WHO)分级Ⅲ 级患者NLR、PLR高于WHO分级Ⅰ~Ⅱ级患者(P<0.05),PNI低于WHO分级Ⅰ~Ⅱ级患者(P<0.05)。高NLR组、高PLR组3年生存率低于低NLR组、低PLR组(P<0.05),低PNI组3年生存率低于高PNI组(P<0.05)。WHOⅢ级、NLR(较高)、PLR(较高)是脑胶质瘤患者预后不良的危险因素(P<0.05),PNI(较高)是保护因素(P<0.05)。术前PNI、NLR、PLR联合预测脑胶质瘤患者预后的曲线下面积为0.849,高于单独指标预测的0.703、0.706、0.704。结论:脑胶质瘤患者术前PNI降低,NLR、PLR均升高,且与预后不良有关,术前PNI、NLR、PLR可作为脑胶质瘤患者预后评估的参考指标。  相似文献   
997.
The production of hydroxyl radicals by adriamycin in red blood cells   总被引:2,自引:0,他引:2  
Spin trapping of the free radicals formed from the interaction between adriamycin and red blood cells resulted in the formation of a hydroxyl spin adduct. The formation of hydroxyl radicals was found to be inhibited by mannitol. Hemoglobin was found not to be obligatory for the formation of hydroxyl radicals which probably result from the reduction of hydrogen peroxide by adriamycin semiquinone.  相似文献   
998.
Some nutritional factors affecting the biosynthesis of shikonin derivatives in callus cultures of Lithospermum erythrorhizon were examined. High sucrose concentrations increased the content of shikonin derivatives, but neither glucose nor fructose was effective for shikonin derivative formation. High concentrations of nitrogen sources inhibited or retarded shikonin derivative formation and streptomycin sulphate stimulated their biosynthesis. Addition of ascorbic acid increased the content of shikonin derivatives. Among some precursors tested only l-phenylalanine had a positive effect. At high concentrations, Ca2+ and Fe2+ inhibited the biosynthesis of shikonin derivatives.  相似文献   
999.
Electrophoretically homogeneous type 1 (GP-C1 and GP-C2), type 2 (GP-C3a and GP-C3b,) and type 3 (GP-D1, and GP-D2) glycopeptides fromAspergillus niger glucoamylase II (Manjunath and Raghavendra Rao, preceding paper) were separately treated with alkaline borohydride. The (\-eliminated oligosaccharides were subjected to single and sequential digestion with specific glycosidases and the products analysed by gas liquid chromatography. The studies revealed that carbohydrate moieties were present as mannose, Man-Man-, and trisaccharide structures, namely, (a) GIc-Man-Man-, (b) Gal-Man-Man, (c) Man-Man-Man-, (d) GlcNAc-Man-Man-, and (e) Xyl-Man-Man. None of the glycopeptides contained all the trisaccharide structures (a) to (e). Type 1 glycopeptide contained structures (a), (b) and (c); type 2, (a) and (d) and type 3, (a), (b) and (e). The number of carbohydrate units (mono-, di-and trisaccharides) present in the major glycopeptides was determined and tentative structures for the glycopeptides proposed. Carbohydrate units appeared to occur in clusters of 4 to 7 in each glycopeptide, a structure unique to the carbohydrate moiety inAspergillus niger glucoamylase. Based on carbohydrate analysis and yields of glycopeptide, the number of units of each type of glycopeptide present in glucoamylase II was tentatively calculated to give two of type Man:Glc:Gal = 12–15:l:l, one of type Man:Glc:GlcN = 10-l1:1:2 and one of type Man :GIc :Gal:Xyl = 4–8:0.1:0.5-0.8:0.3-1 glycopeptides.  相似文献   
1000.
This paper addresses the nutrition and relative importance of primary production to heterotrophy of select unicellular green algae and diatoms from the same assemblage. Algal growth responses to nutrient additions varied widely. Such responses included: inhibition and enhancement of growth by amino acid additions: nonstimulation or inhibition by most sugars 10 mM concentration; glucose stimulation of 6 and inhibition of 3 species; fructose inhibition of 6- and 3- fold stimulation of one species; stimulation of most species by a vitamin mixture, some natural products, metabolite mixtures, etc. Photoassimilation of glucose and aculeate in 8 of 12 species occurred. Nine of 12 species took up only a fraction of the total carbon fixed as organic substrate. Enhancement of photosynthesis by glucose and inhibition by acetate was common. The data suggest that attached littoral and shoal marine algal assemblages may play mixed trophic roles lower levels of the detrital food web.  相似文献   
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