全文获取类型
收费全文 | 26812篇 |
免费 | 3012篇 |
国内免费 | 865篇 |
专业分类
耳鼻咽喉 | 79篇 |
儿科学 | 622篇 |
妇产科学 | 239篇 |
基础医学 | 6611篇 |
口腔科学 | 375篇 |
临床医学 | 1955篇 |
内科学 | 4619篇 |
皮肤病学 | 424篇 |
神经病学 | 1980篇 |
特种医学 | 387篇 |
外国民族医学 | 4篇 |
外科学 | 1785篇 |
综合类 | 3401篇 |
现状与发展 | 13篇 |
一般理论 | 1篇 |
预防医学 | 1880篇 |
眼科学 | 324篇 |
药学 | 2403篇 |
10篇 | |
中国医学 | 1500篇 |
肿瘤学 | 2077篇 |
出版年
2024年 | 85篇 |
2023年 | 701篇 |
2022年 | 694篇 |
2021年 | 1668篇 |
2020年 | 1272篇 |
2019年 | 1104篇 |
2018年 | 1002篇 |
2017年 | 1141篇 |
2016年 | 1171篇 |
2015年 | 1141篇 |
2014年 | 1491篇 |
2013年 | 1977篇 |
2012年 | 1393篇 |
2011年 | 1386篇 |
2010年 | 1238篇 |
2009年 | 1197篇 |
2008年 | 1131篇 |
2007年 | 1098篇 |
2006年 | 1033篇 |
2005年 | 908篇 |
2004年 | 801篇 |
2003年 | 666篇 |
2002年 | 629篇 |
2001年 | 606篇 |
2000年 | 486篇 |
1999年 | 401篇 |
1998年 | 400篇 |
1997年 | 327篇 |
1996年 | 336篇 |
1995年 | 312篇 |
1994年 | 262篇 |
1993年 | 241篇 |
1992年 | 218篇 |
1991年 | 222篇 |
1990年 | 161篇 |
1989年 | 163篇 |
1988年 | 177篇 |
1987年 | 157篇 |
1986年 | 152篇 |
1985年 | 177篇 |
1984年 | 198篇 |
1983年 | 111篇 |
1982年 | 167篇 |
1981年 | 104篇 |
1980年 | 93篇 |
1979年 | 82篇 |
1978年 | 49篇 |
1977年 | 45篇 |
1976年 | 56篇 |
1973年 | 22篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
61.
肺癌患者红细胞免疫功能和T淋巴细胞亚群的检测及临床意义 总被引:10,自引:0,他引:10
作者对62例肺癌患者进行红细胞免疫功能及T淋巴细胞亚群测定,并与20例正常人对照。结果显示:肺癌组红细胞膜C3b受体活性(RBC-C3bRR)、CD3 、CD4 、CD4 /CD8 比值均低于正常人(P<0.05~0.01),红细胞膜的吸附免疫复合物(RBC-ICR)、CD8 均高于正常人(P<0.05~0.01),因此认为红细胞免疫及T淋巴细胞亚群测定对肺癌的诊断、治疗及病情预后估计有一定价值。 相似文献
62.
肺结核病人红细胞免疫功能及T淋巴细胞亚群的变化 总被引:1,自引:0,他引:1
①目的探讨红细胞免疫功能及T淋巴细胞亚群变化与肺结核的关系。②方法对44例肺结核病人和44例健康人的红细胞免疫功能、血清循环免疫复合物、T淋巴细胞亚群、NK细胞水平的变化进行了检测,并与对照组比较。③结果肺结核病人红细胞C3b受体花环率(E-C3bRR),CD4,CD4/CD8,NK细胞水平明显降低,CD8水平明显升高,与对照组相比,差异均有极显著意义(t=9.76~22.24,P均<0.01);复治组较初治组变化更明显(t=4.27~15.32,P均<0.01)。E-C3bRR与CD4,CD4/CD8,NK细胞水平呈正相关(r=0.2692~0.5479,P<0.05,0.01),与CD8呈显著负相关(r=-0.374,P<0.01)。④结论红细胞免疫功能、T淋巴细胞亚群及NK细胞的异常与肺结核的发病及病情变化有一定关系。 相似文献
63.
Disorders in the postnatal nervous, immune, and endocrine regulation systems were revealed in the progeny of rats irradiated
during the preimplantation period of embryogenesis. These disorders persist till adult age. The direction of disorders confirms
the hypothesis about memorization of changed proliferative properties of embryonal cells during the development of the (pro)endocrine
system of a new organism. Memorization results in distortion of postnatal nervous immunoendocrine regulation: hypertrophy
of the endocrine component and coadaptive underdevelopment of the nervous and immune components.
Translated fromByulleten' Eksperimental'noi Biologii i Meditsiny, Vol. 126, No. 8, pp. 164–166, August, 1998 相似文献
64.
红细胞不同温度长期冻存后形态和免疫功能的变化及其临床意义 总被引:1,自引:0,他引:1
目的 探讨一种简便、有效的红细胞长期保存的方法。方法 红细胞在-40℃、80℃及-196℃(液氮)不同温度下长期保存18个月后,分别测定冻存前后红细胞平均体积(MCV)、红细胞渗透脆性(RFT)及红细胞免疫功能(RBC-C3bRR、ERPN)。结果 红细胞-40℃长期冻存后,MCV和RFT较冻存前显著提高(P<0.05),RBC-C3bRRt ERPN较冻存前显著降低(P<0.05)。红细胞-80℃、-196℃长期冻存后,MCV、RFT、RBC-C3bRR及ERPN较冻存前无明显改变(P>0.05)。结论 红细胞经-80℃、-196℃长期冻存后,其形态、结构和免疫功能保存良好。-80℃低温冻存是一种简便、有效的红细胞长期保存的方法。 相似文献
65.
Effects of enteral feedback inhibition on motility,luminal flow,and absorption of nutrients in proximal gut of minipigs 总被引:2,自引:0,他引:2
Andreas Huge Eckhard Weber Prof. Dr. Hans-Jörg Ehrlein 《Digestive diseases and sciences》1995,40(5):1024-1034
We wanted to clarify whether the postprandial intestinal feedback control activated by nutrients in the distal gut exerts different effects on motility, transit of digesta, and absorption of nutrients in the proximal gut. Additionally, interrelationships among motility, transit, and absorption were to be elucidated because these relationships have only been investigated in the fasted state. In five minipigs, a 150-cm segment of the proximal jejunum was isolated by two cannulas. Motility of the jejunal segment was recorded by multiple strain gauges and analyzed by computerized methods. Markers (Cr- and Cu-EDTA) were used for the measurement of the flow rate, transit time, and absorption of nutrients. After a meal, the test segment was perfused with 2 kcal/min of an elemental diet over a period of 90 min. A feedback inhibition was activated by infusion of nutrients into the midgut at rates of 1–4 kcal/min. Saline was infused as control. With increasing energy loads infused into the midgut, the motility index and the length of contraction waves decreased, whereas the incidence of stationary contractions increased, ie, the motility changed from a propulsive to a segmenting pattern. These modulations of motility were associated with a linear decrease in the flow rate and a linear increase in transit time. Flow and transit were linearly correlated with each other. Additionally, the reduction in flow rate and the delay in luminal transit were associated with a linear increase in the absorption of nutrients. However, the increase in absorption induced by the feedback mechanism was small (7.3–13.4%) compared to the marked inhibition of the motility parameters (54–64%), the flow rate (59%), and the delay of transit (5.8-fold). Feedback control primarily modulated motor patterns and luminal flow, whereas the small increase in absorption was only a side effect due to the longer contact time of the nutrients with the mucosa.The study was supported by the Deutsche Forschungsgemeinschaft, grant Eh 64/6-3. 相似文献
66.
Jill Taylor Randall Weinberg Bernard Languet Philippe Desmettre Enzo Paoletti 《Vaccine》1988,6(6):497-503
The natural host of fowlpox virus is limited to avian species. When inoculated into non-avian tissue culture cells, however, fowlpox virus can initiate an abortive infection. A fowlpox virus was engineered to express rabies virus glycoprotein. On inoculation of the recombinant virus into either avian (permissive) or non-avian (non-permissive) cells, the rabies glycoprotein was expressed as a membrane-associated antigen. Inoculation of the fowlpox virus recombinant into six different species of mammal resulted in specific immune responses to both fowlpox antigens and to rabies glycoprotein. In mice, cats and dogs the immune response was sufficient to protect against a live rabies virus challenge. The results demonstrate the utility of a fowlpox virus vector in immunizing non-avian species against rabies in the absence of productive viral replication of the fowlpox vector. 相似文献
67.
68.
The in vitro capacity of sympathetic superior cervical ganglia (SCG) to take up [3H]choline from the extracellular medium, to synthesize acetylcholine from [3H]choline, and to release [3H]acetylcholine in response to a high K+ concentration, were examined in rats throughout a 24-h cycle. Both the release of [3H]acetylcholine and the synthesis of [3H]acetylcholine from [3H]choline exhibited significant diurnal variations, showing maxima during the first half of the night. After these maxima, nocturnal acetylcholine release and synthesis decayed to daytime levels and remained low until the end of the night. [3H]Choline uptake by rat SCG did not vary significantly throughout a 24-h period. A 1.5-h exposure of rats to darkness at the 5th hour of light phase of the daily photoperiod did not change significantly any parameter studied. A 20-min, 5-Hz, electrical stimulation of the preganglionic trunk of SCG excised from rats at noon increased significantly subsequent K+-induced [3H]acetylcholine release but did not change [3H]acetylcholine synthesis. In decentralized SCG of rats subjected to a unilateral SCG decentralization and a contralateral sham-operation 7 days earlier, [3H]acetylcholine release and synthesis were highly reduced or abolished at the decentralized side, while [3H]choline uptake remained unaltered. The present results suggest that an activation of preganglionic rat SCG neurons takes place during the first half of the scotophase. 相似文献
69.
Institute of Biochemistry, Academy of Sciences of the Uzbek SSR, Tashkent. (Presented by Academician of the Academy of Medical Sciences of the USSR Yu. A. Pankov.) Translated from Byulleten' Éksperimental'noi Biologii i Meditsiny, Vol. 113, No. 2, pp. 168–170, February, 1992. 相似文献
70.