全文获取类型
收费全文 | 66190篇 |
免费 | 5270篇 |
国内免费 | 1760篇 |
专业分类
耳鼻咽喉 | 756篇 |
儿科学 | 886篇 |
妇产科学 | 1455篇 |
基础医学 | 9911篇 |
口腔科学 | 1602篇 |
临床医学 | 6046篇 |
内科学 | 12813篇 |
皮肤病学 | 1146篇 |
神经病学 | 4875篇 |
特种医学 | 2205篇 |
外国民族医学 | 6篇 |
外科学 | 9534篇 |
综合类 | 4466篇 |
现状与发展 | 1篇 |
一般理论 | 33篇 |
预防医学 | 4128篇 |
眼科学 | 1591篇 |
药学 | 5840篇 |
1篇 | |
中国医学 | 833篇 |
肿瘤学 | 5092篇 |
出版年
2023年 | 345篇 |
2022年 | 579篇 |
2021年 | 1072篇 |
2020年 | 659篇 |
2019年 | 1114篇 |
2018年 | 1687篇 |
2017年 | 1262篇 |
2016年 | 1312篇 |
2015年 | 1397篇 |
2014年 | 1931篇 |
2013年 | 2302篇 |
2012年 | 3251篇 |
2011年 | 3314篇 |
2010年 | 1943篇 |
2009年 | 1778篇 |
2008年 | 2723篇 |
2007年 | 2849篇 |
2006年 | 2634篇 |
2005年 | 2332篇 |
2004年 | 2121篇 |
2003年 | 1929篇 |
2002年 | 1819篇 |
2001年 | 4737篇 |
2000年 | 4657篇 |
1999年 | 4059篇 |
1998年 | 1496篇 |
1997年 | 1109篇 |
1996年 | 670篇 |
1995年 | 550篇 |
1994年 | 513篇 |
1993年 | 458篇 |
1992年 | 1967篇 |
1991年 | 1703篇 |
1990年 | 1553篇 |
1989年 | 1507篇 |
1988年 | 1317篇 |
1987年 | 1203篇 |
1986年 | 1075篇 |
1985年 | 910篇 |
1984年 | 602篇 |
1983年 | 479篇 |
1982年 | 264篇 |
1981年 | 191篇 |
1980年 | 152篇 |
1979年 | 298篇 |
1978年 | 85篇 |
1974年 | 80篇 |
1973年 | 102篇 |
1972年 | 77篇 |
1970年 | 78篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
61.
R. Bataille X. G. Zhang J. Wijdenes J-F Schved B. Klein 《Medical oncology (Northwood, London, England)》1993,10(4):185-188
Because IL-6 has been involved in the pathogenesis of acute monoblastic leukemia, we investigated thein vitro anti-proliferative effect and thein vivo anti-tumoral effect of an anti-IL-6 murine monoclonal antibody (mAb) in a patient with MSB type acute leukemia. In the current study, we clearly show the IL-6 dependence of monoblastic cell viability and proliferationin vitro in short-term cultures of malignant cells and the clinical activity of the anti-IL-6 murine mAb. The complete neutralization of IL-6in vivo was associated with a transient but complete disappearance of malignant monoblastic cells in the peripheral blood, with improvement or even normalization of several other biological parameters of disease activity, No immunization against the anti-IL-6 murine mAb was observed. 相似文献
62.
Penetration of Schistosoma japonicum cercaria into host skin. 总被引:1,自引:0,他引:1
The anterior part of Schistosoma japonicum cercaria is a specialized head organ which can slightly stretch out and retract. There are three different types of large unicellular glands in cercarial body, consisting of one head gland, 2 pairs of pre- and 3 pairs of postacetabular glands. These glands differ in position, gross feature, histochemistry and functions. Both polysaccharase and protease activities are demonstrated in the secretions from these glands. Mode of cercarial penetration is described in detail and the penetration is effected by a combination of lytic secretions and mechanical movements. The schematic representation of the process of cercarial penetration is presented. The dynamic distributions of schistosomula in skin at different time intervals after skin penetration in various mammalian hosts are shown. Some newly transformed schistosomula die while penetrating into the skin of 7 mammalian species and the mortality rate varies with the host species, and that can also be affected by the age of cercariae following emergence from the snail. Some physiological aspects between cercariae and newly transformed schistosomula are compared. In contrast to cercariae, schistosomula are saline-adapted and water-intolerant. They were modified histochemically and antigenically.
相似文献
63.
B Delbosc X Piquot P Herve M Montard 《Bulletin des sociétés d'ophtalmologie de France》1990,90(4):421-427
Using organ-culture preservation human corneas were preserved up to 5 weeks in a modified tissue culture medium at 37 degrees C. The endothelial viability was examined after staining with trypan-blue 0.3%, after determination of endothelial cell density and cell loss and by light microscopy after staining with trypan-blue 0.3% and alizarin red 1%. The biochemical analysis of the medium (pH, glucose, lactate) has allowed the evaluation of three kinds of storage. The influence of time preservation on the endothelial viability and the metabolic conditions are determined. At the end of this study a clinical trial is proposed. 相似文献
64.
65.
66.
Implantation of porcine bone morphogenetic protein (pBMP) in the muscle induces differentiation of mesenchymal-type cells and results in endochondral bone formation. pBMP was isolated from porcine demineralized bone matrix and purified by hydroxyapatite chromatography, Sephadex G75 gel filtration, preparative sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), preparative isoelectric focusing (IEF), and chromatofocusing fast protein liquid chromatography (FPLC). Porcine BMP has an MW of 26 K and a range of pI from 4.65 to 4.73 determined by SDS-PAGE and IEF, respectively. Reconstitution with the citrate buffer supernatant fraction enables as little as 50 micrograms of the soluble pBMP fractions to induce osteogenesis in an in vivo assay. Chemical modification studies indicate that the osteoinductive potential of the pBMP molecule depends on tyrosine, carboxyl groups, and disulfide bonds and can be increased by modification of sulfhydryl groups. Modification of arginine and tryptophan has no effect on bioactivity. By pepsin-limited proteolysis, fragments of pBMP with an MW of 6-14 K show definite, although reduced, BMP activity. 相似文献
67.
X F Sun H Zhang X C Wu Y M Han G Q Hou M S Xian 《Acta oncologica (Stockholm, Sweden)》1992,31(1):37-40
The microcirculatory architecture of normal tissue, transitional mucosa and adenocarcinoma of the human colon was investigated with microvascular corrosion casting (MVCC) combined with scanning electron microscopy (SEM). The study showed that the capillaries within the normal mucosa were arranged in a regular hexagonal pattern around the mucosal glands and that the microvessels of transitional mucosa mostly had lost the typical hexagonal pattern and become slightly wider in diameter. The microvessels in the tumor periphery were increased in number and disorganized, and presented large variation in morphology with claw-like formations, widened sinuses, diverticula and appendixoid patterns. Microvessels were lacking in the central areas of tumors. These morphological alterations may serve as additional indicators of tumor development. 相似文献
68.
69.
70.
Tetraethylammonium (TEA) effects on K currents were examined on either side of the membrane of hippocampal CA1 neurons by means of whole-cell voltage-clamp recording and intracellular perfusion. Recording media contained ion channel blockers to allow the selective activation of voltage-dependent K currents which consisted of a rapidly decaying component (A-current) and a delayed component. Voltage protocols were applied to separate the A-current from the delayed component. Results show that 10 mM extracellular TEA suppressed 50 +/- 11% (S.D., n = 4) of the delayed current at different levels of depolarization but had little effect on the A-current. In contrast 10 mM TEA applied by intracellular perfusion suppressed the A-current by 42 +/- 10% (S.D., n = 4) in addition to inhibiting the delayed currently 55 +/- 15% (S.D., n = 4). Both the intracellular and extracellular actions of TEA on K currents showed no voltage- nor time-dependency. The results suggest that voltage-dependent transient current (A-current) is mediated through a separate group of ionic channels distinct from those that sustained the delayed current. Furthermore, the asymmetrical effects of intracellular and extracellular TEA on the transient current are similar to those described for the A-current in molluscan neurons. This observation supports the notion that the structure of the ion channel mediating the A-current is closely conserved across different species. 相似文献