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   3365篇
  免费   204篇
  国内免费   19篇
耳鼻咽喉   47篇
儿科学   218篇
妇产科学   71篇
基础医学   461篇
口腔科学   30篇
临床医学   244篇
内科学   633篇
皮肤病学   93篇
神经病学   133篇
特种医学   239篇
外科学   342篇
综合类   202篇
预防医学   294篇
眼科学   54篇
药学   275篇
中国医学   49篇
肿瘤学   203篇
  2023年   20篇
  2022年   41篇
  2021年   106篇
  2020年   55篇
  2019年   49篇
  2018年   81篇
  2017年   52篇
  2016年   68篇
  2015年   91篇
  2014年   119篇
  2013年   146篇
  2012年   194篇
  2011年   217篇
  2010年   146篇
  2009年   102篇
  2008年   167篇
  2007年   179篇
  2006年   169篇
  2005年   142篇
  2004年   103篇
  2003年   104篇
  2002年   91篇
  2001年   96篇
  2000年   92篇
  1999年   67篇
  1998年   57篇
  1997年   45篇
  1996年   44篇
  1995年   34篇
  1994年   22篇
  1993年   32篇
  1992年   43篇
  1991年   46篇
  1990年   51篇
  1989年   56篇
  1988年   49篇
  1987年   34篇
  1986年   36篇
  1985年   42篇
  1984年   19篇
  1983年   19篇
  1982年   18篇
  1979年   24篇
  1978年   24篇
  1977年   20篇
  1975年   16篇
  1973年   21篇
  1971年   17篇
  1970年   16篇
  1969年   16篇
排序方式: 共有3588条查询结果,搜索用时 46 毫秒
101.
Since total homocysteine (tHcy) level is markedly elevated in patients with chronic renal failure (CRF), it has been presented as a potential factor contributing to the high risk of cardiovascular disease (CVD) in CRF. Our aim was to examine the significance of elevated tHcy level and other cardiovascular risk factors for carotid atherosclerosis in patients with CRF. In this cross-sectional study, 135 study patients with CRF (52 +/- 11 years) included 58 patients with moderate to severe predialysis CRF, 36 dialysis patients and 41 renal transplant recipients. In addition, 58 control subjects were examined. The association of tHcy level and classic risk factors for atherosclerosis with common carotid artery intima-media thickness (IMT) or carotid artery plaque score was examined. We found no association between tHcy and carotid IMT or a high carotid plaque score in the CRF patient groups. No consistent association was found between elevated tHcy and coronary artery disease, cerebrovascular disease or peripheral arterial disease. Renal function, described as creatinine clearance, was the strongest determinant for tHcy level. Significant predictors of carotid atherosclerosis were age, duration of hypertension and elevated low-density lipoprotein cholesterol level. In conclusion, the present study shows no apparent association between tHcy level and atheromatous carotid findings in patients with CRF. However, because of the changing renal function in the course of renal disease, the strong confounding effect of renal function may not be adequately controlled for the analysis of the significance of elevated tHcy level for CVD in patients with CRF.  相似文献   
102.
BACKGROUND: Post-kala-azar dermal leishmaniasis (PKDL), an established sequela of visceral leishmaniasis (VL), is proposed to facilitate anthroponotic transmission of VL, especially during interepidemic periods. Immunopathological mechanisms responsible for Indian PKDL are still poorly defined. METHODS: Our study attempted to characterize the immune profiles of patients with PKDL or VL relative to that of healthy control subjects by immunophenotyping, intracellular cytokine staining of peripheral blood mononuclear cells, and enzyme-linked immunosorbent assay for serum cytokines and immunoglobulin G (IgG) subclasses. RESULTS: Patients with PKDL had significantly raised percentages of peripheral CD3+CD8+ cells compared with control subjects, a difference that persisted after cure. Patients with PKDL showed an intact response to phytohemagglutinin, with the percentages of lymphocytes expressing interferon (IFN)-gamma, interleukin (IL)-2, IL-4, and IL-10 being comparable to those in control subjects. Patients with VL had decreased IFN-gamma and IL-2 expression, which was restored after cure, and increased IL-10 expression, which persisted after cure. In their response to Leishmania donovani antigen, patients with PKDL showed a 9.6-fold increase in the percentage of IL-10-expressing CD3+CD8+ lymphocytes compared with control subjects, and this percentage decreased with treatment. Patients with PKDL had raised levels of IgG3 and IgG1 (surrogate markers for IL-10), concomitant with increased serum levels of IL-10. CONCLUSIONS: IL-10-producing CD3+CD8+ lymphocytes are important protagonists in the immunopathogenesis of Indian PKDL.  相似文献   
103.
104.
Minireview: malonyl CoA, AMP-activated protein kinase, and adiposity   总被引:14,自引:0,他引:14  
Ruderman NB  Saha AK  Kraegen EW 《Endocrinology》2003,144(12):5166-5171
  相似文献   
105.

Background

Dialysis-requiring acute kidney injury (D-AKI) is a serious complication in hospitalized heart failure (HF) patients. However, data on national trends are lacking after 2002.

Methods

We used the Nationwide Inpatient Sample (2002–2013) to identify HF hospitalizations with and without D-AKI. We analyzed trends in incidence, in-hospital mortality, length of stay (LoS), and cost. We calculated adjusted odds ratios (aORs) for predictors of D-AKI and for outcomes including in-hospital mortality and adverse discharge (discharge to skilled nursing facilities, nursing homes, etc).

Results

We identified 11,205,743 HF hospitalizations. Across 2002–2013, the incidence of D-AKI doubled from 0.51% to 1.09%. We found male sex, younger age, African-American and Hispanic race, and various comorbidities and procedures, such as sepsis and mechanical ventilation, to be independent predictors of D-AKI in HF hospitalizations. D-AKI was associated with higher odds of in-hospital mortality (aOR 2.49, 95% confidence interval [CI] 2.36–2.63; P?<?.01) and adverse discharge (aOR 2.04, 95% CI 1.95–2.13; P?<?.01). In-hospital mortality and attributable risk of mortality due to D-AKI decreased across 2002–2013. LoS and cost also decreased across this period.

Conclusions

The incidence of D-AKI in HF hospitalizations doubled across 2002–2013. Despite declining in-hospital mortality, LoS, and cost, D-AKI was associated with worse outcomes.  相似文献   
106.
107.
108.
109.
110.
Toll‐like receptors (TLRs) recognize pathogen‐associated molecular patterns and results in innate immune system activation that results in elicitation of the adaptive immune response. One crucial modulator of the adaptive immune response is CD40. However, whether these molecules influence each other's expression and functions is not known. Therefore, we examined the effects of TLRs on CD40 expression on macrophages, the host cell for the protozoan parasite L eishmania major. While polyinosinic‐polycytidylic acid [poly (I:C)], a TLR‐3 ligand, lipopolysaccharide (LPS), a TLR‐4 ligand, imiquimod, a TLR‐7/8 ligand and cytosine–phosphate–guanosine (CpG), a TLR‐9 ligand, were shown to enhance CD40 expression, CD40 stimulation enhanced only TLR‐9 expression. Therefore, we tested the synergism between CD40 and CpG in anti‐leishmanial immune response. In L eishmania‐infected macrophages, CpG was found to reduce CD40‐induced extracellular stress‐regulated kinase (ERK)1/2 activation; with the exception of interleukin (IL)‐10, these ligands had differential effects on CD40‐induced IL‐1α, IL‐6 and IL‐12 production. CpG significantly enhanced the anti‐leishmanial function of CD40 with differential effects on IL‐4, IL‐10 and interferon (IFN)‐γ production in susceptible BALB/c mice. Thus, we report the first systematic study on CD40–TLR cross‐talk that regulated the experimental L . major infection.  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