全文获取类型
收费全文 | 425917篇 |
免费 | 291307篇 |
国内免费 | 46596篇 |
专业分类
耳鼻咽喉 | 4165篇 |
儿科学 | 6506篇 |
妇产科学 | 3840篇 |
基础医学 | 108122篇 |
口腔科学 | 5398篇 |
临床医学 | 81330篇 |
内科学 | 118064篇 |
皮肤病学 | 7258篇 |
神经病学 | 29878篇 |
特种医学 | 16154篇 |
外国民族医学 | 70篇 |
外科学 | 58164篇 |
综合类 | 84655篇 |
现状与发展 | 55篇 |
一般理论 | 26篇 |
预防医学 | 55263篇 |
眼科学 | 22452篇 |
药学 | 77130篇 |
259篇 | |
中国医学 | 56271篇 |
肿瘤学 | 28760篇 |
出版年
2023年 | 4802篇 |
2022年 | 9694篇 |
2021年 | 12015篇 |
2020年 | 12443篇 |
2019年 | 18128篇 |
2018年 | 18953篇 |
2017年 | 19541篇 |
2016年 | 18025篇 |
2015年 | 20831篇 |
2014年 | 22711篇 |
2013年 | 22742篇 |
2012年 | 27450篇 |
2011年 | 30167篇 |
2010年 | 27742篇 |
2009年 | 33707篇 |
2008年 | 23230篇 |
2007年 | 19600篇 |
2006年 | 18457篇 |
2005年 | 17418篇 |
2004年 | 16341篇 |
2003年 | 15295篇 |
2002年 | 14522篇 |
2001年 | 15247篇 |
2000年 | 10229篇 |
1999年 | 14949篇 |
1998年 | 15334篇 |
1997年 | 15221篇 |
1996年 | 15902篇 |
1995年 | 16003篇 |
1994年 | 15660篇 |
1993年 | 14063篇 |
1992年 | 13433篇 |
1991年 | 12689篇 |
1990年 | 11636篇 |
1989年 | 11412篇 |
1988年 | 10856篇 |
1987年 | 10215篇 |
1986年 | 9659篇 |
1985年 | 8659篇 |
1984年 | 6641篇 |
1983年 | 6624篇 |
1982年 | 7663篇 |
1981年 | 7169篇 |
1980年 | 6839篇 |
1979年 | 6672篇 |
1978年 | 5832篇 |
1977年 | 6133篇 |
1976年 | 5752篇 |
1975年 | 5495篇 |
1974年 | 5039篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
41.
42.
Large granular lymphocyte expansions in patients with Felty's syndrome: analysis using anti-T cell receptor V beta-specific monoclonal antibodies. 总被引:5,自引:0,他引:5 下载免费PDF全文
S J Bowman M Bhavnani G C Geddes V Corrigall A W Boylston G S Panayi J S Lanchbury 《Clinical and experimental immunology》1995,101(1):18-24
Felty's syndrome (FS), the association of rheumatoid arthritis (RA) and idiopathic neutropenia, remains an unexplained phenomenon. HLA-DR4 is found in over 90% of cases. Patients with FS may have a T cell lymphocytosis of CD3+CD8+CD57+ large granular lymphocytes (LGL syndrome). In this study of 47 patients with FS, 19% had clear evidence for LGL expansions, while in total 42% had variable evidence for the LGL syndrome using currently available techniques. Of these T cell expansions, 76% were clonal, as demonstrated by Southern blotting and analysis with T cell receptor (TCR) beta chain constant region probes. This technique may fail to detect clonal populations in some patients. Cytofluorographic analysis using antibodies specific for TCR V beta chains identified patients with clonal LGL expansions with results comparable to those obtained with Southern blotting. No evidence for shared V beta usage among expansions from different patients was seen. The role of LGL in RA and FS is currently unclear, but this technique offers a practical and accessible means of identifying patients with LGL expansions, as a starting point for further investigation. 相似文献
43.
44.
提要本研究是在大鼠VD_3+Nicotine引起的心血管钙超载模型上观察心钠素(ANF)治疗(10ug ·kg~-1/d),对钙超载的影响。结果发现,钙超载组动物主动脉、心肌组织钙含量较对照组分别增高24倍(54.4±2.2vs 2.3±0.04fumol/gww)和9倍(16.9±2.1vs1.8±0.1umol/gww)。ANF治疗能显著抑制钙超载的发生,主动脉和心肌组织钙含量较钙超载组分别降低92%(3.8±0.4 umol/gww)和66%(5.6±0.6umol/gww)。离体滋流的钙超载血管环较对照组对去甲肾上腺素收缩反应增强;对乙酰胆碱舒张反应减弱,对硝普钠舒张反应无影响。ANF能显著改善钙超载所致的血管反应性障碍。实验结果表明,ANF具有显著的防治心血管钙超载的作用。 相似文献
45.
Shoji Kubo Hiroaki Kinoshita Kazuhiro Hirohashi Takatsugu Yamamoto 《Journal of Hepato-Biliary-Pancreatic Surgery》1995,2(1):85-89
A case of cystadenocarcinoma of the liver is reported. The patient was a 73-year-old woman in whom a tumor was detected in
the lateral segment of the liver during a health examination. Ultrasonograms and computed tomograms showed a multilocular
cystic mass. Magnetic resonance imaging (MRI) showed a multilocular lowintensity mass, including a high-intensity portion
and a portal branch compressed by the tumor. MRI with gadolinium showed an enhanced cyst wall. The cystic part of the tumor
became smaller and the solid part became larger over a 1-month period, indicating that the tumor was malignant. Subsegmentectomy
(S3) was performed and cystadenocarcinoma with cystadenoma was diagnosed by histopathological examination. Identification of
changes in the appearance of a tumor should be helpful for the differential diagnosis of cystadenoma and cystadenocarcinoma. 相似文献
46.
This study examined the immunoregulatory role of recombinant interleukin 4 (IL-4), also known as B-cell stimulating factor 1, on the generation of cytotoxic effector cells from normal and leukaemic human blood mononuclear cells. When tested on cells from normal individuals, the addition of IL-4 to mixed lymphocyte cultures led to a dose-dependent proliferation of T-helper cells (CD3, 4 positive) with a concomitant decrease in phenotypic and functional cytotoxic T cells and natural killer (NK) cells. IL-4 also inhibited the interleukin-2 (IL-2)-induced generation of lymphokine-activated killer (LAK) activity when added at the beginning of mixed lymphocyte culture. When tested on mature leukaemic NK cells, IL-4 also inhibited the ability of IL-2 to induce LAK function using a short-term culture system. These results show that IL-4 acts on both normal and leukaemic cells and suggests that it acts at more than one level during the development of LAK function. 相似文献
47.
In der Behandlung von Frakturen spielt die Analgesie eine wesentliche Rolle. Es stellt sich daher die Frage, ob in der Klinik h?ufig eingesetzte Analgetika wie Tramadol oder Diclofenac negative Wirkungen auf die Knochenbruchheilung haben. 相似文献
48.
49.
50.
H. Nilsson J. Johansson K. Svanberg S. Svanberg G. Jori E. Reddi A. Segalla D. Gust A. L. Moore T. A. Moore 《British journal of cancer》1997,76(3):355-364
The biodistribution of two recently developed tumour markers, trimethylated (CP(Me)3) and trimethoxylated (CP(OMe)3) carotenoporphyrin, was investigated by means of laser-induced fluorescence (LIF) after i.v. injection into 38 tumour-bearing (MS-2 fibrosarcoma) female Balb/c mice. At 3, 24, 48 or 96 h after administration, the carotenoporphyrin fluorescence was measured in tumoral and peritumoral tissue, as well as in the abdominal, thoracic and cranial cavities. The fluorescence was induced by a nitrogen laser-pumped dye laser, emitting light at 425 nm, and analysed by a polychromator equipped with an image-intensified CCD camera. The fluorescence was evaluated at 490, 655 and 720 nm: the second and third wavelengths represent the carotenoporphyrin (CP)-related peaks, whereas the first one is close to the peak of the tissue autofluorescence. The tumour and the liver were the two tissue types showing the strongest carotenoporphyrin-related fluorescence, whereas the cerebral cortex and muscle consistently exhibited weak substance-related fluorescence. In most tissue types, the fluorescence intensities decreased over time. A few exceptions were observed, notably the liver, in which the intensity remained remarkably constant over the time period investigated. 相似文献