首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   30984篇
  免费   2835篇
  国内免费   223篇
耳鼻咽喉   141篇
儿科学   535篇
妇产科学   285篇
基础医学   9069篇
口腔科学   497篇
临床医学   2786篇
内科学   5024篇
皮肤病学   906篇
神经病学   935篇
特种医学   497篇
外国民族医学   13篇
外科学   1781篇
综合类   4476篇
预防医学   1294篇
眼科学   221篇
药学   1793篇
  3篇
中国医学   494篇
肿瘤学   3292篇
  2024年   3篇
  2023年   291篇
  2022年   340篇
  2021年   633篇
  2020年   670篇
  2019年   788篇
  2018年   724篇
  2017年   777篇
  2016年   810篇
  2015年   1078篇
  2014年   1562篇
  2013年   1929篇
  2012年   1663篇
  2011年   2275篇
  2010年   1970篇
  2009年   2218篇
  2008年   2022篇
  2007年   2021篇
  2006年   1835篇
  2005年   1597篇
  2004年   1414篇
  2003年   1312篇
  2002年   1075篇
  2001年   857篇
  2000年   736篇
  1999年   610篇
  1998年   458篇
  1997年   415篇
  1996年   377篇
  1995年   445篇
  1994年   347篇
  1993年   263篇
  1992年   143篇
  1991年   139篇
  1990年   71篇
  1989年   48篇
  1988年   25篇
  1987年   13篇
  1986年   11篇
  1985年   15篇
  1984年   18篇
  1983年   7篇
  1982年   9篇
  1981年   11篇
  1980年   2篇
  1979年   6篇
  1978年   4篇
  1976年   2篇
  1973年   1篇
  1906年   1篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
Serum thymus and activation‐regulated chemokine/CCL17 (sTARC) is known as a good indicator for atopic dermatitis severity. Herein, we investigate whether sTARC correlates with severity and therapeutic response for alopecia areata (AA) in our 121 patients. The sTARC mean of AA totalis and universalis was significantly higher than mild AA. Next, we compared sTARC of diffuse AA (n = 14) and severity‐controlled patchy AA (n = 32) and found that sTARC in diffuse AA (564.2 ± 400.0 pg/mL) was significantly higher than that of the patchy type (344.0 ± 239.8 pg/mL), suggesting a potential role of TARC in active progression of diffuse AA. Ten patients with diffuse AA were treated with i.v. corticosteroid pulse therapy. Then, we tested whether sTARC can predict prognosis after the pulse therapy and found that baseline sTARC in the poor responders (1025.5 ± 484.8 pg/mL) was significantly higher than that in the good responders (complete remission at 24 months after the pulse therapy, 347.8 ± 135.7 pg/mL), indicating sTARC as a response biomarker in the corticosteroid pulse therapy for diffuse AA. Finally, to investigate TARC production in the affected hair follicles, we performed immunohistochemical double staining of TARC and CD68 using scalp skin specimens of diffuse AA with high titers of sTARC. The results showed their co‐localization in the infiltrating cells around the AA hair follicles, suggesting that TARC is mainly produced from CD68+ histiocytes. In conclusion, sTARC is a disease activity and response biomarker in AA, providing new insight beyond the T‐helper 1/2 paradigm to solve the immunological pathogenesis of AA.  相似文献   
5.
Vitiligo is an acquired disorder in which depigmented macules result from mostly autoimmune loss of melanocytes. The initiating process in vitiligo has still been uncertain. Here, we report the case of a 19‐year‐old man with undetermined/unclassified vitiligo with a new periphery‐spreading vitiligo lesion on the right dorsal hand after rigorous sun exposure. Histopathological evaluation showed noticeable infiltration of CD68+ macrophages, moderate infiltration of CD3+ T cells, little infiltration of CD8+ T cells and CD11c+ myeloid dendritic cells, HMB45/CD11c double‐positive cells, and Melan‐A/MART1+ deposits in the dermis. We surmised that melanocyte‐derived deposits were mostly phagocytosed by CD68+ macrophages and were faintly phagocytosed by CD11c+ myeloid dendritic cells, referring distribution of CD68+ mononuclear cells and melanocyte biomarkers. Complete repigmentation was achieved following topical application of hydrocortisone butyrate propionate 0.1% ointment. We summarize that prompt clearance of debris by macrophages would be essential to an excellent prognosis of complete repigmentation.  相似文献   
6.
7.
We describe a 34‐year‐old Japanese man with syringotropic CD8+ mycosis fungoides (MF) accompanied by hypohidrosis who was treated with vorinostat and retinoids. Interestingly, immunohistochemical staining for dermcidin revealed a decrease of sweat in the eccrine glands, and a sweat test by the iodine starch method proved hypohidrosis in the MF‐affected areas. Six months after treatment with this combination therapy, the patient's advanced MF was under control.  相似文献   
8.
Objective: The role of inflammation in cognitive alterations in a post-operative setting is still not fully understood. Surgical interventions can cause systemic inflammations which eventually can induce neuroinflammation. However, the main causes of functional changes after surgery are still elusive. In this study, we investigated the role of CD38, a TNFα-inducible NADH+ cyclase and hydrolase. We assume that CD38 overexpression impairs mitochondrial ATP synthesis. Within the hippocampus, the resulting cellular death could lead to cognitive impairment.

Methods: Seventy-nine Wistar-HAN rats were subjected for three hours either to partial hepatectomy under sevoflurane anaesthesia (‘surgery’), sevoflurane anaesthesia alone (‘anaesthesia’) or control. Rats were randomly selected to determine levels of CD38, TNFα, IL-6, and ATP, for GFAP immunohistochemistry and for Morris Water Maze testing.

Results: Plasma TNFα and IL-6 levels were significantly higher in the surgery group in the immediate post-operative phase. GFAP expression and hippocampal CD38 concentration were significantly elevated 24 h after the intervention in the surgery group as compared to anaesthesia alone and controls. ATP levels did not differ significantly between the three groups. No treatment differences in spatial cognition parameters were found.

Conclusions: Surgery in the form of partial hepatectomy activated the peripheral immune system and induced hippocampal glial activation and a CD38 increase. These changes, however, were not associated with rats’ cognitive impairment ≥24 h after surgery.  相似文献   
9.
10.
Purpose: MRL-lpr/lpr mice, a model for various autoimmune diseases, were repeatedly irradiated with 0.5 Gy of γ-rays, and changes in their autoimmune manifestations were investigated.

Materials and methods: MRL-lpr/lpr mice at 13 weeks of age were maintained in plastic cages and exposed whole-body to 0.5 Gy γ-ray irradiation from a 137Cs source 5 times per week for 4 weeks, from the time they were 13 weeks old until they reached 17 weeks old. Changes of autoimmune manifestations were examined 3 weeks later at the 20th week.

Results: Splenomegaly, lymphadenopathy, and proteinuria in MRL-lpr/lpr mice were clearly ameliorated by a total dose of 10 Gy (0.5 Gy/day×5 days/week for 4 weeks). Histologically severe disease-specific damage to the kidney and the salivary gland, i.e., glomerulonephritis and sialoadenitis, was also improved after irradiation. CD3+ CD4? CD8? CD45R/B220+ T cell numbers, which proliferate abnormally in MRL-lpr/lpr mice, were significantly decreased by the irradiation, possibly through induction of apoptosis. The elevated NO2? and NO3? (NOx?) production by macrophages of MRL-lpr/lpr mice was lowered by the irradiation. The irradiation also prolonged the life span of MRL-lpr/lpr mice. These phenomena may contribute to the amelioration of autoimmune manifestations in MRL-lpr/lpr mice exposed to repeated small-doses of γ-rays.

Conclusions: Repeated small-dose γ-ray exposure ameliorates the autoimmune manifestations in MRL-lpr/lpr model mice.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号