全文获取类型
收费全文 | 14526篇 |
免费 | 1361篇 |
国内免费 | 884篇 |
专业分类
耳鼻咽喉 | 89篇 |
儿科学 | 81篇 |
妇产科学 | 62篇 |
基础医学 | 738篇 |
口腔科学 | 196篇 |
临床医学 | 1151篇 |
内科学 | 851篇 |
皮肤病学 | 151篇 |
神经病学 | 415篇 |
特种医学 | 269篇 |
外科学 | 445篇 |
综合类 | 2763篇 |
现状与发展 | 1篇 |
预防医学 | 1315篇 |
眼科学 | 235篇 |
药学 | 5074篇 |
28篇 | |
中国医学 | 2627篇 |
肿瘤学 | 280篇 |
出版年
2024年 | 73篇 |
2023年 | 195篇 |
2022年 | 365篇 |
2021年 | 489篇 |
2020年 | 490篇 |
2019年 | 428篇 |
2018年 | 456篇 |
2017年 | 502篇 |
2016年 | 521篇 |
2015年 | 545篇 |
2014年 | 971篇 |
2013年 | 1062篇 |
2012年 | 1112篇 |
2011年 | 1136篇 |
2010年 | 862篇 |
2009年 | 732篇 |
2008年 | 696篇 |
2007年 | 853篇 |
2006年 | 750篇 |
2005年 | 651篇 |
2004年 | 525篇 |
2003年 | 482篇 |
2002年 | 421篇 |
2001年 | 386篇 |
2000年 | 324篇 |
1999年 | 241篇 |
1998年 | 191篇 |
1997年 | 188篇 |
1996年 | 161篇 |
1995年 | 136篇 |
1994年 | 127篇 |
1993年 | 93篇 |
1992年 | 101篇 |
1991年 | 76篇 |
1990年 | 58篇 |
1989年 | 51篇 |
1988年 | 52篇 |
1987年 | 36篇 |
1986年 | 35篇 |
1985年 | 31篇 |
1984年 | 32篇 |
1983年 | 25篇 |
1982年 | 26篇 |
1981年 | 17篇 |
1980年 | 15篇 |
1979年 | 12篇 |
1978年 | 10篇 |
1977年 | 7篇 |
1976年 | 7篇 |
1974年 | 5篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
91.
Mikls Miltnyi Andrew E. Czeizel Lidia Balogh Zoltn Detre 《American journal of medical genetics. Part A》1992,43(5):789-790
We describe two sibs with tetraectrodactyly and oligomeganephronic renal hypoplasia. The parents were unaffected. This syndrome of apparently autosomal recessive origin appears to be the first Mendelian form of the acrorenal developmental field defect identified so far. © 1992 Wiley-Liss, Inc. 相似文献
92.
Exposure of cell cultures to organophosphorous compounds such as VX can result in cell death. However, it is not clear whether VX-induced cell death is necrotic or involves programmed cell death mechanisms. Activation of caspases, a family of cysteine proteases, is often involved in cell death, and in particular, caspase-3 activation appears to be a key event in programmed cell death processes including apoptosis. In this study, we investigated VX-induced neuronal cell death, as well as the underlying mechanism in terms of its effect on caspase-3 activity. Primary cortical neuronal cultures were prepared from gestational days 17 to 19 Sprague Dawley rat fetuses. At maturation, the cells were treated with varying concentrations of VX and cell death was evaluated by lactate dehydrogenase (LDH) release. VX induced an increase in LDH release in a concentration-dependent manner. Morphological VX-induced cell death was also characterized by using nuclear staining with propidium iodide and Hoechst 33342. VX induced a concentration- and time-dependent increase in caspase-3 activation. Caspase-3 activation was also confirmed by the proteolytic cleavage of poly(ADP-ribose)polymerase (PARP), an endogenous caspase-3 substrate. These data suggested that in rat cortical neurons, VX-induced cell death via a programmed cell death pathway that involves changes in caspase-3 protease. 相似文献
93.
复方中药注射液对小白鼠艾氏腹水癌细胞膜表面的(Na~+-K~+)-ATP酶和微绒毛影响的电镜观察 总被引:2,自引:0,他引:2
本实验应用电镜细胞化学和扫描电镜技术,观察到小白鼠艾氏腹水癌细胞在复方中药注射液的连续作用下,膜表面(Na~+-K~+)-ATP酶活性减弱,微绒毛减退等变化,同时观察到该复方中药注射液对癌细胞增殖的抑制作用,抑瘤率可达87%,癌细胞增殖和(Na~+-K~+)-ATP酶活性及微绒毛的多少有平行关系。讨论了该复方中药抑制癌细胞增殖与膜表面(Na~+-K~+)-ATP酶活性和微绒毛变化的关系。 相似文献
94.
H1N2新亚型流感病毒神经氨酸酶基因来源的进一步研究 总被引:1,自引:0,他引:1
对流感病毒H1N2亚型重组株A/哈防/1/88、A/哈防/12/92以及H3N2亚型病毒株A/雅防/2/87、A/京防/57/898和A/粤防/1/92神经氨酸酶(NA)基因核苷酸全序列的测定,进一步弄清了A/哈防/1/88病毒株的NA基因确来自当时人群中流行的H3N2亚型病毒株,很可能是来自A/雅防/2/87类病毒株;而A/哈防/12/92病毒株的NA基因可能是与A/哈防/1/88病毒株的NA基 相似文献
95.
目的 从烧伤合并内毒素血症致多器官损害家兔血清中分离纯化内毒素结合蛋白 ,并初步对比研究它们的生物学活性。方法 兔血清蛋白质通过二步离子交换层析 (Bio Rex 70Resin、Mono Q)及凝胶过滤分离纯化 ,并经流式细胞分析实验、绵羊红细胞凝聚实验、氨基末端氨基酸残基测序等方法鉴定 ,再将所获蛋白质作用于体外培养的人单核细胞 (U937) ,观测其分泌TNFα等细胞因子的生物效应。结果 获得两种具有促进内毒素 (LPS)与外周血单核细胞 (PBMC)结合的蛋白质 ,其中一种相对分子质量为 6 0× 10 4 ,其N端 10个氨基酸序列为TNPGLITRIT ,证实为兔内毒素结合蛋白 (LBP) ;另一种蛋白质相对分子质量为 4 8× 10 4 ,其N端 10个氨基酸序列为GSQGTFTSEE ,与NCBI蛋白质库中的氨基酸序列进行比较 ,未发现相同序列 ,命名为p48。结论 p48与LBP具有相似的生物学功能 ,p48的生物学活性稍弱于LBP。提示体内除LBP外 ,p48也同样起着介导LPS的毒性作用。这可能是近年国外研究中阻断LBP的活性后 ,机体毒性反应并无明显减轻的原因之一。 相似文献
96.
Dunckley H Dodd R Greville WD Hersee J Le T Taverniti A Wallace R Strickland J Hogbin JP Truong J Velickovic ZM 《Tissue antigens》2004,63(6):584-586
Anew human leukocyte antigen-B allele, B*1565, has been identified during routine typing of cord blood samples. Subsequently, two individuals from the same family as the first cord blood sample plus two unrelated Australian Bone Marrow Donor Registry samples have been found to carry this novel allele. 相似文献
97.
The novel HLA-Cw*1802 allele is associated with B*5703 in the Bubi population from Equatorial Guinea
C. Vilches M. Bunce R. de Pablo M. E. Moreno S. Puente L. Sanz M. Kreisler 《Tissue antigens》1997,49(6):644-648
The HLA-Cw*1801 specificity, a Cw7/Cw4 hybrid allele, has recently been described in association with B*8101 (formerly B"DT"). In this study, the new Cw*1802 variant, differing from Cw*1801 at exon 5. is found associated with B*5703 in Bubi individuals from Equatorial Guinea. Confirmatory complete coding regions of B*5703 and B*3910 are also reported. 相似文献
98.
99.
Bloom's syndrome. XIX. Cytogenetic and population evidence for genetic heterogeneity 总被引:1,自引:0,他引:1
Cells with abnormally high rates of sister-chromatid exchange (SCE) are uniquely characteristic of Bloom's syndrome (BS). However, in one in five persons a minor population of cells with a low-SCE phenotype circulates in the blood. The origin and significance of the low-SCE cells in BS have never been understood, although they are assumed to arise by somatic mutation. In the present investigation, the enigmatic high-SCE/low-SCE mosaicism was investigated by comparing the incidence in several subpopulations of persons in the Bloom's Syndrome Registry who exhibit the two types of cells, and a striking negative correlation emerged: in persons with BS whose parents share a common ancestor, the case in approximately half of registered persons, low-SCE cells are found only rarely; conversely, the mosaicism occurs almost exclusively in persons with BS whose parents are not known to share a common ancestor. Because those who share a common ancestor are predominantly homozygous-by-descent at the mutated BS locus, the negative correlation is interpreted to mean that the emergence of low-SCE cells in BS in some way depends on the pre-existence of compound heterozygosity. A corollary to this is that BS is genetically heterogeneous. 相似文献
100.
金芪降糖片联合西药治疗糖尿病对患者血浆ET-1和sICAM-1水平的影响 总被引:2,自引:0,他引:2
目的:探讨金芪降糖片对糖尿病患者血浆ET-1和sICAM-1水平的影响及临床应用价值。方法:金芪降糖片和降糖类西药同时服用治疗糖尿病,并与只服西药治疗组进行比较。采用酶联免疫法检测两组患者治疗前后血浆中血管内皮细胞活性因子ET-1和sICAM-1水平,同时观察血糖和血脂、HbA1c等各项指标的变化。结果:金芪组治疗后血糖和血脂、HbA1c均有显著变化(P〈0.05),对照组仅血糖有明显变化(P〈0.05);金芪组治疗后ET-1和sICAM-1均显著降低,分别为P〈0.05和P〈0.01,对照组两者水平皆无明显变化(P〉0.05)。结论:金芪降糖片通过降低糖尿病患者血浆中ET-1和s/CAM-1水平,从而保护患者的血管内皮细胞,在西药常规治疗糖尿病的基础上,再加以中药辨证施治,可以提高临床对糖尿病的疗效。 相似文献