全文获取类型
收费全文 | 21486篇 |
免费 | 2009篇 |
国内免费 | 894篇 |
专业分类
耳鼻咽喉 | 314篇 |
儿科学 | 326篇 |
妇产科学 | 266篇 |
基础医学 | 2158篇 |
口腔科学 | 437篇 |
临床医学 | 2759篇 |
内科学 | 2554篇 |
皮肤病学 | 631篇 |
神经病学 | 1003篇 |
特种医学 | 764篇 |
外国民族医学 | 9篇 |
外科学 | 1455篇 |
综合类 | 3789篇 |
现状与发展 | 3篇 |
一般理论 | 3篇 |
预防医学 | 2064篇 |
眼科学 | 618篇 |
药学 | 2502篇 |
43篇 | |
中国医学 | 1308篇 |
肿瘤学 | 1383篇 |
出版年
2024年 | 39篇 |
2023年 | 277篇 |
2022年 | 1016篇 |
2021年 | 1389篇 |
2020年 | 1057篇 |
2019年 | 709篇 |
2018年 | 798篇 |
2017年 | 883篇 |
2016年 | 716篇 |
2015年 | 1184篇 |
2014年 | 1458篇 |
2013年 | 1479篇 |
2012年 | 2168篇 |
2011年 | 2218篇 |
2010年 | 1442篇 |
2009年 | 1153篇 |
2008年 | 1279篇 |
2007年 | 1113篇 |
2006年 | 879篇 |
2005年 | 766篇 |
2004年 | 520篇 |
2003年 | 407篇 |
2002年 | 303篇 |
2001年 | 226篇 |
2000年 | 205篇 |
1999年 | 145篇 |
1998年 | 67篇 |
1997年 | 54篇 |
1996年 | 33篇 |
1995年 | 38篇 |
1994年 | 28篇 |
1993年 | 16篇 |
1992年 | 47篇 |
1991年 | 59篇 |
1990年 | 26篇 |
1989年 | 23篇 |
1988年 | 20篇 |
1987年 | 14篇 |
1986年 | 17篇 |
1985年 | 16篇 |
1984年 | 6篇 |
1982年 | 6篇 |
1979年 | 10篇 |
1974年 | 5篇 |
1973年 | 6篇 |
1971年 | 7篇 |
1970年 | 7篇 |
1969年 | 7篇 |
1968年 | 7篇 |
1966年 | 7篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
11.
目的探讨河豚鱼中毒的治疗方法及影响预后的因素。方法回顾性分析我院1996年1月-2006年4月收治的15例河豚鱼中毒的病例资料。结果15例均有恶心、呕吐,腹痛,口唇、舌尖、指端麻木,四肢乏力,外周血白细胞计数增高,肝功能损害5例,心电图可见房室传导阻滞6例。1例于中毒后16h死于呼吸循环衰竭。结论目前河豚鱼中毒尚无特效解毒剂,死亡率50%,死亡主要原因为脑干麻痹,导致呼吸循环衰竭。主张尽早清除毒物,应用维生素B1,B6,B12等以及士的宁注射治疗神经肌肉麻痹,有呼吸衰竭者尽快行气管插管机械通气辅助呼吸。 相似文献
12.
M M Husain W M McDonald P M Doraiswamy G S Figiel C Na P R Escalona O B Boyko C B Nemeroff K R Krishnan 《Psychiatry research》1991,40(2):95-99
The basal ganglia are recognized as putative mediators of certain cognitive and behavioral symptoms of major depression. Moreover, patients with basal ganglia lesions have repeatedly exhibited significant affective symptomatology, including apathy, depressive mood, and psychosis. Using high resolution, axial T2 intermediate magnetic resonance images, and a systematic sampling stereologic method, we assessed putamen nuclei volumes in 41 patients with major depression (DSM-III) and 44 healthy volunteer controls of similar age. Depressed patients had significantly smaller putamen nuclei compared with controls. Age was negatively correlated with putamen size in both groups. These results are the first demonstration of diminished putamen volumes in depression and further support a role for basal ganglia structures in the etiopathogenesis of depression. 相似文献
13.
K B Ates S Boyacio?lu I Ta? A Gencer G Temu?in B Sahin 《Gastrointestinal radiology》1991,16(2):178-180
Bleeding into a pancreatic pseudocyst is a rare but life-threatening entity. Early diagnosis is crucial in its management. There are reports suggesting that computed tomography (CT), scintigraphy, endoscopic retrograde cholangiopancreatography (ERCP), and angiography could be the diagnostic maneuvers. In this report, we present a case of arterial bleeding into a pancreatic pseudocyst, which was diagnosed by the turbulent echo-currents seen in real-time ultrasonography. 相似文献
14.
目的:在大肠杆菌中表达人B组轮状病毒WH-2株VP7蛋白并制备其兔抗血清。方法:根据B组轮状病毒(GBRV)WH-2株vp7基因的全序列设计引物,用PCR的方法扩增得到vp7基因的编码区。将其克隆到原核GST融合表达载体pGEX-KG内,转化大肠杆菌E.coliDH5α,IPTG诱导表达人B组轮状病毒WH-2株VP7蛋白,经SDS-PAGE分离纯化表达的蛋白免疫新西兰兔,制备人B组轮状病毒WH-2株VP7蛋白抗血清。结果:经鉴定确认,vp7基因以正确的方式插入到载体中,此重组表达载体经IPTG诱导后,可表达相对分子量为53.4 kDa的GST-VP7融合蛋白。制备的抗血清经同样诱导表达的表达载体pGEX-KG表达产物吸收后1:500倍稀释后用Western Blot分析,与53.4 kDa的GST-VP7融合蛋白获得特异性显色信号。结论:人B组轮状病毒WH-2株VP7蛋白成功在大肠杆菌中GST融合表达,所表达的蛋白和制备的抗体不但为研究结构与功能提供了物质基础,也为GBRV所引起的疾病预防、诊断和治疗等流行病学研究和临床诊断奠定了基础,具有重要实际应用价值。 相似文献
15.
11β-羟类固醇脱氢酶与2型糖尿病 总被引:12,自引:0,他引:12
11β-羟类固醇脱氢酶(11β-HSDs)催化氢化可的松(皮质酮)和可的松(脱氢皮质酮)的相互转化,对调节局部糖皮质激素的活性起着重要作用,而糖皮质激素可诱导胰岛素抵抗。肝、脂肪等组织内11β-HSD活性的改变与肥胖、2型糖尿病等疾病密切相关。 相似文献
16.
Summary In this study the technique of labelling the cell membrane with DPH fluorescence polarization was used to observe the membrane
fluidity of B lymphocytic cell lines and tonsillar cells from healthy persons; the modulation effect on membrane-fluidity
induced by McAbs against isotypic and idiotypic determinants of IgM from patients with leukemia was studied as well. The expression
of the corresponding isotypic and idiotypic determinants of IgM on the cell membrane was determined. The results show that
the membrane fluidity of leukemic cell lines is remarkably higher than that of tonsillar cells from healthy persons, and McAbs
against isotypic determinants of leukemic IgM can enhance the membrane fluidity of all kinds of cells mentioned above. However,
the anti-idiotypic monoclonal antibody increased only the membrane fluidity of leukemic cell lines. These results indicated
that there was a close relationship between the effect of McAbs on cell membrane fluidity and the expression of corresponding
isotypic and idiotypic determinants of IgM on the cell membrane. 相似文献
17.
采自贵州省猪尾鼠的吸虱具有特殊的形态。李氏欣奇虱独自成为一科。双叶盲鼠虱隶拟血虱科。拟血虱科中的拟血虱属和钩板虱属均寄生于鼹科,裂虱属和盲鼠虱属则寄生于睡鼠科和刺山鼠科。后者曾被置于睡鼠科。研究食虫目动物的吸虱将可能对吸虱与其宿主动物的偕同进化提供更多的证据。 相似文献
18.
采访与写作是新闻记者的一种社会性活动,社会的政治经济动向、科教文化潮流、外交军事突变以及各种风云人物的活动都是这一工作反映的内容。要写出一篇好的作品.必须要有一定的社交能力、应变能力、观察能力及写作能力.这是脑力劳动和体力劳动的综合行为。当记者在枯燥的材料堆里翻开资料,当他与一个初次采访的人物去谈话.在面临危险的环境中找新闻时…….是何种动机支配着记者去克服困难.完成这些采访任务的呢?心理学认为动机是直接推动个体活动以达到一定目的的内部动力。 相似文献
19.
The physico-chemical methods for the study of the binding of ligands to tubulin are examined in-depth, emphasizing the assumptions on which they are based and their limitations. The criteria of specificity and linkage to protein self-association are presented. It is shown that, of the direct equilibrium binding techniques, Hummel-Dreyer gel permeation chromatography and rapid ultracentrifugation are applicable only when binding is not linked to protein self-association. Disc filtration is valid only when the reverse unbinding reaction is very low. Binding linked to protein self-association can be measured by batch gel permeation or by dialysis equilibrium. The indirect techniques, such as fluorescence perturbation or difference absorption spectroscopy are discussed in terms of the assumptions on which they are based. They are shown to be used best only after characterization of the binding by direct techniques. Equilibrium binding parameters can also be deduced from careful kinetic experiments. Comparison of calorimetrically measured enthalpies of binding to van't Hoff enthalpies derived from equilibrium measurements indicates that the method of choice is calorimetric, while comparison with van't Hoff analysis can reveal the existence of reaction steps not detected by equilibrium measurements. Use of other indirect approaches, such as titration of an enzymic activity, can also lead to the detection of additional steps. The criteria are set up for the proper data analysis of ligand binding linked to protein self-association and the selection of the proper mode of linkage. It is shown how the thermodynamic contributions of various moieties of a ligand can be established by a rational structural modification of the ligand and the proper analysis of the binding measurements, in which all non-specific entropic contributions are taken into account. It is demonstrated also how a similar analysis of binding data can lead to conclusions about the reaction pathway from a comparison of equilibrium thermodynamic measurements on judiciously modified ligand molecules. 相似文献
20.