全文获取类型
收费全文 | 1269篇 |
免费 | 97篇 |
国内免费 | 6篇 |
专业分类
耳鼻咽喉 | 23篇 |
儿科学 | 31篇 |
妇产科学 | 29篇 |
基础医学 | 111篇 |
口腔科学 | 13篇 |
临床医学 | 79篇 |
内科学 | 253篇 |
皮肤病学 | 24篇 |
神经病学 | 120篇 |
特种医学 | 44篇 |
外科学 | 346篇 |
综合类 | 30篇 |
预防医学 | 70篇 |
眼科学 | 14篇 |
药学 | 49篇 |
中国医学 | 4篇 |
肿瘤学 | 132篇 |
出版年
2023年 | 12篇 |
2022年 | 24篇 |
2021年 | 53篇 |
2020年 | 43篇 |
2019年 | 39篇 |
2018年 | 58篇 |
2017年 | 29篇 |
2016年 | 30篇 |
2015年 | 31篇 |
2014年 | 55篇 |
2013年 | 51篇 |
2012年 | 78篇 |
2011年 | 94篇 |
2010年 | 43篇 |
2009年 | 42篇 |
2008年 | 66篇 |
2007年 | 72篇 |
2006年 | 52篇 |
2005年 | 55篇 |
2004年 | 44篇 |
2003年 | 46篇 |
2002年 | 47篇 |
2001年 | 25篇 |
2000年 | 23篇 |
1999年 | 21篇 |
1998年 | 10篇 |
1997年 | 7篇 |
1996年 | 5篇 |
1995年 | 6篇 |
1994年 | 5篇 |
1993年 | 8篇 |
1992年 | 13篇 |
1991年 | 11篇 |
1990年 | 11篇 |
1989年 | 18篇 |
1988年 | 10篇 |
1987年 | 12篇 |
1986年 | 15篇 |
1985年 | 7篇 |
1984年 | 9篇 |
1983年 | 7篇 |
1979年 | 10篇 |
1978年 | 4篇 |
1977年 | 9篇 |
1976年 | 5篇 |
1975年 | 4篇 |
1974年 | 11篇 |
1973年 | 9篇 |
1971年 | 7篇 |
1968年 | 4篇 |
排序方式: 共有1372条查询结果,搜索用时 15 毫秒
41.
42.
Papasavvas E Moore EC Sun J Azzoni L Pistilli M Mounzer K Shull J Kostman JR Montaner LJ 《AIDS research and human retroviruses》2008,24(9):1203-1208
We investigated the association between plasma HIV-1 RNA, immune activation, and polyclonal T cell function in viremic subjects whether on or off antiretroviral therapy (ART). The surface expression of activation/functional molecules on T cells and monocytes as well as cytokine secretion and T cell proliferation were assessed in 23 HIV-1(-) and 79 HIV-1(+)-infected subjects with different levels of viral suppression and CD4(+) T cell count >250 cells/mm(3) for >6 months. Viral replication was associated with increased T cell and monocyte activation irrespective of ART. In subjects with a detectable viral load on ART, we found a positive association with anti-CD3/CD28-induced T cell proliferation compared to patients with undetectable viral load (<400 copies/ml). No difference among groups was observed for anti-CD3/CD28-mediated IFN-gamma responses. The presence of an unexpected positive association between polyclonal T cell proliferation and viral load in subjects with levels of T cell IFN-gamma responses comparable to those of uninfected subjects is of potential relevance to an increase in T cell activation response before the loss of polyclonal cytokine secretion and proliferation observed with disease progression. This finding suggests that T cell hyperresponsiveness may play a role in the pathogenesis of immune comorbidities on ART. 相似文献
43.
Youakim Saliba Ralph Karam Viviane Smayra Georges Aftimos Joel Abramowitz Lutz Birnbaumer Nassim Farès 《Journal of the American Society of Nephrology : JASN》2015,26(8):1855-1876
Transient receptor potential canonical (TRPC) Ca2+-permeant channels, especially TRPC3, are increasingly implicated in cardiorenal diseases. We studied the possible role of fibroblast TRPC3 in the development of renal fibrosis. In vitro, a macromolecular complex formed by TRPC1/TRPC3/TRPC6 existed in isolated cultured rat renal fibroblasts. However, specific blockade of TRPC3 with the pharmacologic inhibitor pyr3 was sufficient to inhibit both angiotensin II- and 1-oleoyl-2-acetyl-sn-glycerol–induced Ca2+ entry in these cells, which was detected by fura-2 Ca2+ imaging. TRPC3 blockade or Ca2+ removal inhibited fibroblast proliferation and myofibroblast differentiation by suppressing the phosphorylation of extracellular signal-regulated kinase (ERK1/2). In addition, pyr3 inhibited fibrosis and inflammation-associated markers in a noncytotoxic manner. Furthermore, TRPC3 knockdown by siRNA confirmed these pharmacologic findings. In adult male Wistar rats or wild-type mice subjected to unilateral ureteral obstruction, TRPC3 expression increased in the fibroblasts of obstructed kidneys and was associated with increased Ca2+ entry, ERK1/2 phosphorylation, and fibroblast proliferation. Both TRPC3 blockade in rats and TRPC3 knockout in mice inhibited ERK1/2 phosphorylation and fibroblast activation as well as myofibroblast differentiation and extracellular matrix remodeling in obstructed kidneys, thus ameliorating tubulointerstitial damage and renal fibrosis. In conclusion, TRPC3 channels are present in renal fibroblasts and control fibroblast proliferation, differentiation, and activation through Ca2+-mediated ERK signaling. TRPC3 channels might constitute important therapeutic targets for improving renal remodeling in kidney disease. 相似文献
44.
45.
Hajj Hussein IA Tohme R Barada K Mostafa MH Freund JN Jurjus RA Karam W Jurjus A 《World journal of gastroenterology : WJG》2008,14(25):4028-4039
AIM:To develop a novel model of colitis in rats, using a combination of iodoacetamide and enteropathogenic E. coli(EPEC), and to elucidate the pathophysiologic processes implicated in the development of ulcerative colitis (UC).
METHODS: Hale Sprague-Dawley rats (/7 = 158) were inoculated intrarectally on a weekly basis with 4 different combinations: (a) 1% methylcellulose (HC), (b) 100 μL of 6% iodoacetamide (IA) in 1% HC, (c) 200 p.L containing 4×10^8 colony factor units (CFU) of EPEC, and (d) combined treatment of (IA) followed by bacteria (13) after 2 d. Thirty days post treatment, each of the four groups was divided into two subgroups; the inoculation was stopped for one subgroup and the other subgroup continued with biweekly inoculation until the end of the experiment. Colitis was evaluated by the clinical course of the disease, the macroscopic and microscopic alterations, activity of myeloperoxidase (HPO), and by TNF-α gene expression. RESULTS: Findings indicative of UC were seen in the combined treatment (IA + B) as well as the IA continued treatment groups: the animals showed slow rate of increase in body weight, diarrhea, bloody stools, high colonic ulcer score, as well as histological alterations characteristic of UC, with an extensive inflammatory reaction. During the course of the experiment, the MPO activity was consistently elevated and the TNF-α gene expression was upregulated compared to the control animals.
CONCLUSION: The experimental ulcerative colitis model used in the present study resembles, to a great extent, the human disease. It is reproducible with characteristics indicative of chronicity. 相似文献
METHODS: Hale Sprague-Dawley rats (/7 = 158) were inoculated intrarectally on a weekly basis with 4 different combinations: (a) 1% methylcellulose (HC), (b) 100 μL of 6% iodoacetamide (IA) in 1% HC, (c) 200 p.L containing 4×10^8 colony factor units (CFU) of EPEC, and (d) combined treatment of (IA) followed by bacteria (13) after 2 d. Thirty days post treatment, each of the four groups was divided into two subgroups; the inoculation was stopped for one subgroup and the other subgroup continued with biweekly inoculation until the end of the experiment. Colitis was evaluated by the clinical course of the disease, the macroscopic and microscopic alterations, activity of myeloperoxidase (HPO), and by TNF-α gene expression. RESULTS: Findings indicative of UC were seen in the combined treatment (IA + B) as well as the IA continued treatment groups: the animals showed slow rate of increase in body weight, diarrhea, bloody stools, high colonic ulcer score, as well as histological alterations characteristic of UC, with an extensive inflammatory reaction. During the course of the experiment, the MPO activity was consistently elevated and the TNF-α gene expression was upregulated compared to the control animals.
CONCLUSION: The experimental ulcerative colitis model used in the present study resembles, to a great extent, the human disease. It is reproducible with characteristics indicative of chronicity. 相似文献
46.
47.
48.
49.
Aging represents a major risk factor for prostate cancer; however, mechanisms responsible for this relationship remain unclear. Preclinical and some clinical investigations support the protective role of selenium against prostate cancer possibly through the reduction of oxidative stress. While increased levels of oxidative stress together with decreases in selenium and the major cellular antioxidant glutathione (GSH) are common in tissues of old animals, there is little data available on these parameters in the prostate. In the present study we have compared the levels of selenium, GSH and protein-bound GSH (GSSP) in blood and prostate tissues in young (4-month), mature (12-month), old (18 month), and very old (24 month) male F344 rats. Each prostate lobe (dorsolateral, DL; anterior, AL; ventral, VL) was analyzed separately based upon their differing potential for prostate cancer development. At all ages, selenium levels were lowest in DL相似文献
50.
Viviane Kovess‐Masfety Jordi Alonso Matthias Angermeyer Evelyn Bromet Giovanni de Girolamo Peter de Jonge Koen Demyttenaere Silvia E. Florescu Michael J. Gruber Oye Gureje Chiyi Hu Yueqin Huang Elie G. Karam Robert Jin Jean‐Pierre Lpine Daphna Levinson Katie A. McLaughlin María E. Medina‐Mora Siobhan O'Neill Yutaka Ono Jos A. Posada‐Villa Nancy A. Sampson Kate M. Scott Victoria Shahly Dan J. Stein Maria C. Viana Zahari Zarkov Ronald C. Kessler 《Depression and anxiety》2013,30(4):395-406