全文获取类型
收费全文 | 8961篇 |
免费 | 605篇 |
国内免费 | 78篇 |
专业分类
耳鼻咽喉 | 138篇 |
儿科学 | 247篇 |
妇产科学 | 138篇 |
基础医学 | 1200篇 |
口腔科学 | 276篇 |
临床医学 | 831篇 |
内科学 | 2114篇 |
皮肤病学 | 243篇 |
神经病学 | 464篇 |
特种医学 | 455篇 |
外科学 | 1060篇 |
综合类 | 52篇 |
现状与发展 | 1篇 |
预防医学 | 718篇 |
眼科学 | 204篇 |
药学 | 681篇 |
中国医学 | 87篇 |
肿瘤学 | 735篇 |
出版年
2024年 | 13篇 |
2023年 | 106篇 |
2022年 | 268篇 |
2021年 | 456篇 |
2020年 | 242篇 |
2019年 | 303篇 |
2018年 | 317篇 |
2017年 | 258篇 |
2016年 | 361篇 |
2015年 | 400篇 |
2014年 | 428篇 |
2013年 | 495篇 |
2012年 | 759篇 |
2011年 | 677篇 |
2010年 | 427篇 |
2009年 | 286篇 |
2008年 | 529篇 |
2007年 | 497篇 |
2006年 | 423篇 |
2005年 | 435篇 |
2004年 | 366篇 |
2003年 | 324篇 |
2002年 | 257篇 |
2001年 | 148篇 |
2000年 | 144篇 |
1999年 | 124篇 |
1998年 | 43篇 |
1997年 | 29篇 |
1996年 | 25篇 |
1995年 | 16篇 |
1994年 | 24篇 |
1993年 | 25篇 |
1992年 | 46篇 |
1991年 | 53篇 |
1990年 | 33篇 |
1989年 | 38篇 |
1988年 | 38篇 |
1987年 | 23篇 |
1986年 | 18篇 |
1985年 | 26篇 |
1984年 | 12篇 |
1983年 | 10篇 |
1982年 | 12篇 |
1981年 | 10篇 |
1979年 | 15篇 |
1978年 | 10篇 |
1977年 | 10篇 |
1973年 | 9篇 |
1969年 | 10篇 |
1966年 | 11篇 |
排序方式: 共有9644条查询结果,搜索用时 0 毫秒
21.
IL-8 mRNA in human gingival epithelial cells (HGECs) is up-regulated by Fusobacterium nucleatum, and up-/down-regulated by Porphyromonas gingivalis in a complex interaction in the early stages (< or = 4 h) after infection. The mechanisms involved in this regulation in response to F. nucleatum and/or P. gingivalis infection, and identification of co-regulated cytokine genes, are the focus of this investigation. Heat, formalin or protease treatment of F. nucleatum cells attenuated the IL-8 mRNA up-regulation. NF-kappaB, mitogen-activated protein kinase (MAPK) p38 and MAPK kinase/extracellular signal-regulated kinase (MEK/ERK) pathways were involved in IL-8 mRNA induction by F. nucleatum. Pretreatment of P. gingivalis with heat, formalin or protease enhanced IL-8 mRNA induction. NF-kappaB, MARK p38, and MEK/ERK pathways were also involved in this induction. In contrast, down-regulation of IL-8 mRNA by P. gingivalis involved MEK/ERK, but not NF-kappaB or MAPK p38 pathways. cDNA arrays analysis revealed that mRNA down-regulation by P. gingivalis is a specific reaction that only a number of genes, e.g. IL-1beta, IL-8, macrophage inflammatory protein-2alpha, and migration inhibitory factor-related protein-14, are affected based on examination of 278 cytokine/receptor genes. These data indicate that F. nucleatum and P. gingivalis trigger specific and differential gene regulation pathways in HGECs. 相似文献
22.
Thi Thu Ha Hoang Carina Bengtsson Dac Cam Phung Mikael Srberg Marta Granstrm 《Clinical and Vaccine Immunology : CVI》2005,12(1):81-85
Helicobacter pylori-associated diseases, such as peptic ulcer and gastric cancer, are common in Vietnam, but the prevalence of the infection is largely unknown. A validated enzyme-linked immunosorbent assay was used for seroepidemiology with 971 samples from the general population, ages 0 to 88 years, with 546 samples from an urban population (Hanoi), and with 425 samples from a poor, rural province (Hatay). The overall seroprevalence of the infection was 746 per 1,000, with a prevalence of 788 per 1,000 in Hanoi and 692 per 1,000 in Hatay (P = 0.0007). The risk for infection in the rural area of Hatay was 40% lower than in the urban population of Hanoi, with the odds ratio being 0.59 (95% confidence interval, 0.43 to 0.81). The study shows that the prevalence of H. pylori infection is high in Vietnam and especially high in a large urban area, such as the city of Hanoi. 相似文献
23.
Autoimmune haemolytic anaemias. V. Studies on the resistance against complement haemolysis of the red cells of patients with chronic cold agglutinin disease 总被引:2,自引:1,他引:2 下载免费PDF全文
C. P. Engelfriet A. E. G. Kr. Von Dem Borne Do Beckers E. Reynierse J. J. Van Loghem 《Clinical and experimental immunology》1972,11(2):255-264
Experiments are described the results of which sustain the hypothesis that resistance against complement haemolysis, which is a characteristic of the red cells of patients with chronic cold agglutinin disease, is due to the following mechanism: when red cells react with cold auto-agglutinins in vivo, they are either haemolysed immediately, or, due to an unknown factor, escape direct haemolysis. In the latter case β1E and β1A disappear from the cell membrane. To the sites where these proteins have been attached once, no new β1E or β1A molecules can be bound. Full complement activation thus becomes impossible. 相似文献
24.
Linda Wittkop Daniel Commenges Isabelle Pellegrin Dominique Breilh Didier Neau Denis Lacoste Jean-Luc Pellegrin Geneviève Chêne François Dabis Rodolphe Thiébaut 《BMC medical research methodology》2008,8(1):68
Background
Principal component analysis (PCA) and partial least square (PLS) regression may be useful to summarize the HIV genotypic information. Without pre-selection each mutation presented in at least one patient is considered with a different weight. We compared these two strategies with the construction of a usual genotypic score. 相似文献25.
26.
Cary-Blair, a transport medium for Vibrio parahemolyticus 总被引:2,自引:0,他引:2
27.
Lai PS Takeshima Y Adachi K Van Tran K Nguyen HT Low PS Matsuo M 《Journal of human genetics》2002,47(10):0552-0555
The frequency and distribution of deletions of 19 deletion-prone exons clustered in two hot spots in the proximal and central
regions of the dystrophin gene were compared in three populations from Singaporean, Japan, and Vietnam. DNA samples obtained
from 105 Singaporean, 86 Japanese, and 34 Vietnamese Duchenne muscular dystrophy patients were examined by polymerase chain
reaction amplification. Deletions of the examined exons were found in 51.2% of Japanese patients but in 40.0% or less of the
Singaporeans and Vietnamese. About two thirds of the deletions were localized in the central region and the remaining deletions
were clustered at the proximal region. The most commonly deleted exons at the central deletion hot spot were exon 50 in the
Singaporean, exons 49 and 50 in the Japanese, and exon 51 in the Vietnamese population. At the proximal deletion hot spot,
the most commonly deleted exons were exons 6 and 8 in the Singaporeans, exons 12 and 17 in the Japanese, and exons 8 and 12
in the Vietnamese. Two cases each from Singapore and Japan had large-scale gross mutations spanning both deletion hot spots.
Our results suggest that, although the presence and frequency of the two deletion hot spots may be similar in the three Asian
populations analyzed, the distribution and frequency of deletions among the different exons can vary as a result of population-specific
intronic sequences that predispose individuals to preferential deletion breakpoints.
Received: May 20, 2002 / Accepted: July 1, 2002 相似文献
28.
29.
30.