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51.
The protective effect of affinity purified antigen has been investigated in an experimental model for malaria which shows a well marked recrudescence of parasitaemia, a feature of the disease in man. A monoclonal antibody (MoAb) recognizing an epitope common to two genetically distinct cloned lines of Plasmodium chabaudi (AS and CB), was used to purify a Mr250,000 polymorphic schizont antigen (PSA) from these parasites. The purified preparations were then examined for the presence of specific and cross-reactive epitopes by immunoprecipitation with a panel of MoAb raised against P. chabaudi AS. When tested previously on smears of parasitized blood by immunofluorescence, or against lysates of parasitized erythrocytes by immunoprecipitation, most of these MoAb had been found to be AS specific. When either AS or CB affinity purified Mr250,000 PSA was used as the target, these same MoAb immunoprecipitated both antigens, and in some cases, a number of associated polypeptides (AP) which copurify with the Mr250,000 PSA. Subsequently, mice were immunized with either the purified AS or CB antigens in Freund's complete adjuvant (FCA). Prechallenge sera were compared by indirect immunofluorescence and immunoprecipitation. Sera from mice immunized with AS antigen reacted strongly with AS and cross-reacted with CB parasite preparations. Pre-challenge serum from CB antigen immunized mice reacted well with CB, but only faintly with AS preparations. In mice immunized with the AS antigen and then challenged with either AS or CB parasites, the initial parasitaemias were delayed in appearance and the height of the peak parasitaemia reduced, an effect which was most pronounced after challenge with homologous parasites. Only homologous challenge of the mice immunized with CB antigen produced statistically significant modification of the initial parasitaemia. In the immunized mice challenged with homologous parasites, the delayed appearance and slightly reduced peak of the primary parasitaemia was associated with delayed resolution of the patent parasitaemia and significant enhancement of the recrudescence. 相似文献
52.
C_3基因在BXSB小鼠主要脏器中的表达 总被引:1,自引:1,他引:0
用同位素标记cDNA探针的分子杂交方法检测了BXSB小鼠肝、肾、脾、胸腺各脏器中补体C_3mRNA的表达情况,结果表明3~4月龄雄性BXSB小鼠肝、肾、脾各脏器C_3mRNA的表达量较正常对照鼠显著增加。C_3基因的过度表达可能参与BXSB小鼠SLE多脏器非感染性炎症的发生,同时提示该鼠存在M系统的大量扩增及活化。 相似文献
53.
Distraction osteogenesis in the Cbfa-1+/- mouse. 总被引:2,自引:0,他引:2
S Isefuku C J Joyner A A C Reed A H R W Simpson 《Journal of orthopaedic research》2004,22(6):1276-1282
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55.
Clonal deletion and anergy are two major mechanisms of self-tolerance. However, the molecular mechanisms underlying clonal deletion and anergy, as well as the threshold of TCR affinity/avidity required for these processes, are not known. Expression of the V beta 8.1 TCR correlates with the reactivity of the T cells to the minor lymphocyte stimulating locus-1a (Mls-1a) and T cells expressing this TCR are deleted in the thymus of Mls-1a mice. Similarly, in TCR V beta 8.1 transgenic mice, the number of CD4+CD8-T cells is reduced in Mls-1a mice. However, small numbers of CD4+CD8-T cells remain in the periphery of adult Mls-1a transgenic mice. We have generated T cell clones from TCR V beta 8.1 transgenic mice by stimulation of lymph node T cells with C57BL/6 alloantigens. Interestingly, CD4+CD8-V beta 8.1+ clones isolated from the transgenic mice of Mls-1a background responded to the self-antigen Mls-1a, to which they did not respond in primary assay. Reactive patterns of the clones were compared with clones derived from Mls-1b mice. Proliferation and cytokine production of the clones from Mls-1a mice to the self-antigen Mls-1a were generally reduced when compared with clones from Mls-1b mice. More importantly, T cell clones from Mls-1a mice required more Mls-1a antigen for their activation, and were more susceptible to the inhibitory effects of anti-CD4 antibody on the proliferative responses to Mls-1a than those from Mls-1b mice. These results suggest that the T cell receptor on clones derived from Mls-1a mice have functional but reduced affinity/avidity for self-antigen Mls-1a. 相似文献
56.
应用小鼠骨髓细胞长周期培养(LTBMC)体系,观察重组人白细胞介素-1α(rhIL-1α)对造血细胞增殖的影响。结果显示,经rhlL-1α作用后,小鼠LTBMC中悬浮细胞数增多,其中粒单系祖细胞(CFU-GM)数量也明显增加,维持时间延长。表明rhIL-1α能促进小鼠造血细胞在体外LTBMC中增殖并分化,而且与剂量有关系。rhIL-1α加入的时间,以骨髓细胞2次接种时同时加入为好,延迟加入则作用减弱。本实验对骨髓干、祖细胞体外扩增和自体骨髓移植等方面的研究有一定意义。 相似文献
57.
58.
本文对新型有机磷农药,25%乙基硫环磷进行了Ames及微核两项诱变性试验研究。Ames试验中,无论是否加入S9活化系统,25%乙基硫环磷均未能诱发回变菌落数的增加;微核试验的各剂量组PCE微核率也较低,(2‰~3‰),与阴性对照相比无显著性差异。 相似文献
59.
取32只2~3个月的BALB/C小白鼠,随机分为4组,每组8只,第1组为对照组,其余3个组为实验组,实验组小白鼠左腿皮下注射苯0.3ml(15ml/kg体重).注射后分别于24h,48h,72h脱颈处死。观察中毒前、后末梢血象、骨髓细胞、骨髓细胞构成的变化。结果表明,苯中毒时骨髓变化先于末梢血象的变化,骨髓的病变为造血细胞变性、坏死,大量毛细血管扩张、充血,骨髓细胞构成降低,而且骨髓细胞构成中细胞成分降低早于外周血粒细胞减少。 相似文献
60.
本文着重检测了不同免疫缺陷的纯合子615-nu、615-bg、615-nu/bg、Ba1b/c-nu和表现型正常的杂合子615/PBI小鼠的巨噬细胞细胞毒活性、吞噬功能,并与它们的NK细胞活性和T、B细胞功能进行了对比分析。实验结果表明:这些不同免疫缺陷的615小鼠其相应的免疫缺陷的性质是确定的。615-nu、615-nu/bg、Ba1b/c-nu的巨噬细胞毒活性与615/PBI无明显差别,但吞噬指数较正常升高,而615-bg的巨噬细胞细胞毒活性和吞噬功能则都显著低于615/PBI的。 相似文献