全文获取类型
收费全文 | 374910篇 |
免费 | 34754篇 |
国内免费 | 26048篇 |
专业分类
耳鼻咽喉 | 2844篇 |
儿科学 | 4893篇 |
妇产科学 | 4198篇 |
基础医学 | 41090篇 |
口腔科学 | 6130篇 |
临床医学 | 52899篇 |
内科学 | 50714篇 |
皮肤病学 | 4139篇 |
神经病学 | 18177篇 |
特种医学 | 13789篇 |
外国民族医学 | 225篇 |
外科学 | 33125篇 |
综合类 | 70019篇 |
现状与发展 | 86篇 |
一般理论 | 31篇 |
预防医学 | 27589篇 |
眼科学 | 10672篇 |
药学 | 40726篇 |
435篇 | |
中国医学 | 24382篇 |
肿瘤学 | 29549篇 |
出版年
2024年 | 1281篇 |
2023年 | 5465篇 |
2022年 | 14421篇 |
2021年 | 18321篇 |
2020年 | 14423篇 |
2019年 | 11694篇 |
2018年 | 12179篇 |
2017年 | 11689篇 |
2016年 | 10789篇 |
2015年 | 16846篇 |
2014年 | 20962篇 |
2013年 | 19074篇 |
2012年 | 28386篇 |
2011年 | 31909篇 |
2010年 | 21513篇 |
2009年 | 17523篇 |
2008年 | 21421篇 |
2007年 | 21142篇 |
2006年 | 20163篇 |
2005年 | 19249篇 |
2004年 | 12719篇 |
2003年 | 12251篇 |
2002年 | 10023篇 |
2001年 | 8539篇 |
2000年 | 8325篇 |
1999年 | 8397篇 |
1998年 | 5305篇 |
1997年 | 5095篇 |
1996年 | 3960篇 |
1995年 | 3716篇 |
1994年 | 3137篇 |
1993年 | 2026篇 |
1992年 | 2427篇 |
1991年 | 2128篇 |
1990年 | 1792篇 |
1989年 | 1556篇 |
1988年 | 1284篇 |
1987年 | 1185篇 |
1986年 | 955篇 |
1985年 | 676篇 |
1984年 | 369篇 |
1983年 | 271篇 |
1982年 | 142篇 |
1981年 | 169篇 |
1980年 | 115篇 |
1979年 | 154篇 |
1978年 | 73篇 |
1977年 | 53篇 |
1974年 | 42篇 |
1972年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
本文报道八个双炔失碳酯类似物的小鼠抗早孕、抗着床试验结果,同时考查了生物活性与油水分布系数之间的关系,发现抗早孕活性与油水分布系数之间为线性相关。双炔失碳半琥珀酸酯的抗早孕效果优于已用于临床的双炔失碳丙酸酯。 相似文献
962.
In this study, the anti-tumour activity of selenium-protein polysaccharide (SPP), a water extract of the rich selenium Agaricus blazei, was tested both in vivo and in vitro. The results of in vivo experiments show that SPP at doses of 50 and 100 mg/kg inhibits proliferation of implanted Sarcoma 180 by 22 and 37.69%, respectively, and promotes lymphocyte transformation and natural killer (NK) cells activity in tumour bearing mice. During the in vitro experiment, we treated the tumour and non-tumour bearing mice with SPP, and prepared serum treated with SPP (SerumSPP). The results show that SerumSPP, whether from tumour or non-tumour bearing mice, significantly inhibits K562 cells proliferation and induces their apoptosis, and also significantly increases caspase-3 activity of K562 cells. However, the difference in anti-tumour activity of SerumSPP between tumour and non-tumour bearing mice is significantly different (p<0.01). The results, according to the studies both in vivo and in vitro, imply that SPP extracted from rich selenium A. blazei can inhibit growth of implanted Sarcoma 180 and promote lymphocyte transformation and NK cells activity in vivo. Additionally, SerumSPP can inhibit proliferation and cause apoptotic morphological changes and the fragmentation of internucleosomal DNA, and increase caspase-3 activity of K562 cells in vitro, which indicates that apoptosis of K562 cells induced by SerumSPP may be related to up-regulation of caspase-3. 相似文献
963.
本文收集了我省十年(1974—1983)来诊断为恶性淋巴瘤的病例,按免疫功能分类复查了全部切片,最后确诊为非何杰金氏恶性淋巴瘤(NHL)528例,进行了分析。本组NHL在首发部位、类型分布等方面与国内外有所不同。本组NHL首发于淋巴结外的占64.02%,明显高于国内其它省、市,而滤泡型淋巴瘤则低于国内多数地区。T细胞淋巴瘤占14.84%,较国内、外均低。并提出提高制片质量和广泛开展及应用免疫学技术的重要性。 相似文献
964.
Preparation of [125I-Tyr27,Leu5]beta h-endorphin and its use for crosslinking of opioid binding sites in human striatum and NG108-15 neuroblastoma-glioma cells. 下载免费PDF全文
D M Helmeste R G Hammonds Jr C H Li 《Proceedings of the National Academy of Sciences of the United States of America》1986,83(13):4622-4625
A radioligand suitable for crosslinking studies to opioid receptors has been obtained by radioiodination and purification of the monoiodotyrosine-27 derivative of the synthetic human beta-endorphin (beta h-endorphin) analogue [5-leucine]beta h-endorphin. The derivative, [27-[125I]monoiodotyrosine,5-leucine]beta h-endorphin, was crosslinked to human striatal (caudate and putamen) and NG108-15 neuroblastoma-glioma cell membranes by using disuccinimidyl suberate. Sodium dodecyl sulfate/polyacrylamide gel electrophoresis under reducing conditions revealed four specifically labeled bands at 68, 40, 30, and 25 kDa for both human caudate and putamen, whereas NG108-15 cell membranes gave specifically labeled bands at 92, 56, 38, and 23 kDa. 相似文献
965.
目的探讨原发性甲状腺机能亢进症的手术探查技巧和经验教训。方法对50例原发性甲状腺机能亢进症患者临床资料进行回顾性总结分析。结果48例患者手术治疗,术后38例诊断为甲状旁腺瘤,6例为甲状旁腺增生,4例为甲状旁腺癌。48例中44例第一次手术探查成功(占88%),2例行2次手术,2例行3次手术。46例术后痊愈,2例并发多处肋骨骨折发生呼吸衰竭而死亡。结论确诊为原发性甲状腺机能亢进症伴有临床征象者均应手术治疗。术前病灶定位明确者手术较容易,定位不明确者应在“热区内”重点探查。 相似文献
966.
967.
968.
采用CHO细胞HGPRT位点突变测定系统观察了核黄素、尼克酰胺和锌等微量营养素对甲基苄基亚硝胺(MBNA)致细胞突变作用的影响。结果表明,在RPMI1640培养基中添加核黄素(2.6~13.0μmol/L)或尼克酰胺(40~120μmol/L)可显著抑制MBNA的致细胞突变作用。联合应用核黄素、尼克酰胺和锌效果更佳。提示:核黄素等微量营养素可能具有阻止细胞癌变的作用,为应用微量营养素干预治疗癌变过程提供了一定的理论依据。 相似文献
969.
本文报告等容血液稀释(简称DH)治疗高血压病75例,总有效率为90.2%,48例随访2年血压下降稳定持久,血液流变学改善,总有效率为87.5%。结果表明:HD治疗高血压病可以改善血流高粘滞状态,降低血液粘度,增强血液流动性,减少血流阻力,改善微循环灌流,从而达到降低血压和改善器官血流,达到持久降压及减少器官合并症。一次HD与降压药适量配伍,疗效更显著而持久,可维持数月至2年以上。 相似文献
970.
M. Banyai G. Lupattelli S. R. Li S. Pongratz Q. Yang P. Böck P. Angelberger I. Virgolini 《European journal of nuclear medicine and molecular imaging》1994,21(7):634-639
The binding of radiolabelled lipoproteins, iodine-123-labelled low-density. lipoprotein (LDL) and indium-111-labelled LDL, to peripheral blood mononuclear cells (MNCs) was compared in normolipaemic subjects and in patients with heterozygous familial hypercholesterolaemia (FH). 123I-LDL and 111In-LDL binding to MNCs exhibited high-affinity, highly specific, time- and temperature-dependent binding reaching saturation at concentrations above 50 nM. The number of LDL binding sites (Bmax) was significantly (P<0.01) lower in FH patients (P<0.001; 123I-LDL: Bmax 279±44 ng protein/108MNCs; 111In-LDL: Bmax 309±43 ng protein/108MNCs) as compared with controls (123I-LDL: Bmax 2874±246 ng protein/108 MNCs; 111In-LDL: Bmax 3145±339 ng protein/108 MNCs). The corresponding dissociation constants (K
d) were 16±8 nM for 123I-LDL and 12±6 nM for 123In-LDL in healthy volunteers (123In-LDL vs 111In-LDL, P<0.05). In FH patients, the K
d values were 20±8 nM for 123I-LDL and 16±6 nM for 123In-LDL (P<0.05 vs controls for both 123I-LDL and 111In-LDL). 111In-LDL binding to MNCs was inhibited (IC50) by 30±8 nM in healthy controls and 38±12 nM in FH patients (P<0.05). 123In-LDL binding to MNCs was inhibited (IC50) by 34±8 nM in healthy controls and 46±10 nM in FH patients (P<0.05). Taken together, these results suggest a reduced number of LDL receptors expressed on MNCs from FH patients. We conclude that 111In-LDL and 123I-LDL are equally well suited as a probe of receptor-mediated binding and uptake of LDL. 相似文献