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   780篇
  免费   56篇
  国内免费   4篇
耳鼻咽喉   14篇
儿科学   31篇
妇产科学   48篇
基础医学   105篇
口腔科学   9篇
临床医学   73篇
内科学   162篇
皮肤病学   12篇
神经病学   117篇
特种医学   57篇
外科学   78篇
综合类   2篇
预防医学   37篇
眼科学   5篇
药学   25篇
肿瘤学   65篇
  2024年   3篇
  2023年   6篇
  2022年   18篇
  2021年   25篇
  2020年   10篇
  2019年   26篇
  2018年   30篇
  2017年   10篇
  2016年   23篇
  2015年   17篇
  2014年   25篇
  2013年   48篇
  2012年   46篇
  2011年   31篇
  2010年   20篇
  2009年   31篇
  2008年   35篇
  2007年   65篇
  2006年   53篇
  2005年   40篇
  2004年   36篇
  2003年   21篇
  2002年   26篇
  2001年   10篇
  2000年   9篇
  1999年   9篇
  1998年   7篇
  1997年   3篇
  1995年   6篇
  1994年   6篇
  1993年   6篇
  1992年   10篇
  1991年   14篇
  1990年   12篇
  1989年   8篇
  1988年   8篇
  1987年   14篇
  1986年   9篇
  1985年   10篇
  1984年   7篇
  1983年   8篇
  1982年   6篇
  1981年   3篇
  1980年   5篇
  1979年   4篇
  1976年   4篇
  1975年   4篇
  1972年   2篇
  1967年   4篇
  1960年   1篇
排序方式: 共有840条查询结果,搜索用时 15 毫秒
71.
Platelet activation is found in inflammatory conditions and implicated in the pathogenesis of chronic medical conditions, such as atherosclerosis, coronary vascular disease, cerebrovascular disease, and diabetes mellitus (DM). HbA1c is inversely related to vitamin D25 levels in individuals with and without DM. This study aimed to determine the relation between platelet aggregation, vitamin D and HbA1c among healthy individuals and those with Type 2 DM (T2DM). The direct effect of vitamin D1, 25 (calcitriol) on platelet aggregation was also investigated. The study included four groups: A. normoglycemic Control group: HbA1c<5.7%; B. Pre-diabetes (DM): 5.7% ≥ HbA1c ≤ 6.4%; C. DM on aspirin therapy: HbA1c>6.4%(+)Asp.; and D. DM not on aspirin therapy: HbA1c > 6.4%(?)Asp. Platelet aggregation was tested with and without calcitriol or saline pre-treatment, using collagen or adenosine diphosphate (ADP) as agonists. Platelet aggregation was higher in DM(?)Asp group compared to normoglycemic and DM(+)Asp, and higher, but not significant compared to pre-DM. The entire study population exhibited negative correlation between HbA1c and serum concentration of vitamin D25. Excluding DM(+)Asp, aggregation induced by collagen was significantly higher in patients with insufficient (<76 nmol/L) vitamin D25 compared to sufficient (≥76 nmol/L) vitamin D25. In this cohort, a negative correlation was found between serum concentrations of vitamin D25 and collagen-induced percent maximum (%max) aggregation and area under curve (AUC) aggregation. In the DM(?)Asp group, collagen-induced aggregation was reduced by approximately 25% after calcitriol treatment. Calcitriol decreased ADP-induced aggregation of control and DM(+)Asp groups to approximately 85% of saline treatment. We conclude that glycemic control is inversely associated with high platelet aggregation and low vitamin D25 levels. This elevated aggregation could be regulated by a novel, direct effect of calcitriol, indicating a beneficial effect of vitamin D on vascular complications related to diabetes. We offer a possible non-genomic mechanism for the vitamin D/Vitamin D receptor (VDR) pathway.  相似文献   
72.

Objective

To examine the efficacy and safety of Curalin supplement in patients with type 2 diabetes.

Research design and methods

Adult patients with type 2 diabetes were randomized 1:1 to receive Curalin supplement or placebo. The primary endpoint was HbA1c decrease at 1 month. The secondary endpoint was a decrease in HbA1c by more than 0.5% and 1% and a change in 7 daily blood glucose measurements. A satisfaction questionnaire was used as an exploratory endpoint. Safety variables and adverse events were assessed.

Results

After 1 month of intervention, HbA1c was reduced by 0.94% in the Curalin arm versus 0.4% in the placebo arm (P = 0.008). 72% of Curalin patients had decreased HbA1c levels >0.5% versus 35% in the placebo arm (P < 0.05). The Treatment Satisfaction Questionnaire indicated that Curalin arm patients reported higher overall satisfaction.

Conclusions

Curalin treatment significantly reduced HbA1c over a 1-month period and was well-tolerated.  相似文献   
73.
The recent discovery of incessant spontaneous fluctuations in human brain activity (also termed resting state fMRI) has been a focus of intense research in brain imaging. The spontaneous BOLD activity shows organized anatomical specialization as well as disruption in a number of brain pathologies. The link between the spontaneous fMRI fluctuations and human behavior is therefore of acute interest and importance. Here we report that a highly significant correlation exists between spontaneous BOLD fluctuations and eye movements which occur subliminally and spontaneously in the absence of any visual stimulation. Of the various eye movement parameters tested, we found robust and anatomically consistent correlations with both the amplitude and velocity of spontaneous eye movements. Control experiments ruled out a contribution of spatial and visual attention as well as smooth pursuit eye movements to the effect. The consistent anatomical specificity of the correlation patterns and their tight temporal link at the proper hemodynamic delay argues against a non-neuronal explanation of the effect, such as cardiac or respiratory cycles. Our results thus demonstrate a link between resting state and spontaneously emerging subconscious oculo-motor behavior.  相似文献   
74.
We previously showed that moxifloxacin (MXF) exerts protective anti-inflammatory effects in immunosuppressed mice infected with Candida albicans by inhibiting interleukin-8 (IL-8) and tumor necrosis factor alpha (TNF-alpha) production in the lung. Immunohistochemistry demonstrated inhibition of nuclear factor (NF)-kappaB translocation in lung epithelium and macrophages in MXF-treated mice. In the present study we investigated the effects of MXF on the production of proinflammatory cytokines (i.e., IL-8, TNF-alpha, and IL-1beta) by activated human peripheral blood monocytes and THP-1 cells and analyzed the effects of the drug on the major signal transduction pathways associated with inflammation: NF-kappaB and the mitogen-activated protein kinases ERK and c-Jun N-terminal kinase (JNK). The levels of IL-8, TNF-alpha, and IL-1beta secretion rose 20- and 6.7-fold in lipopolysaccharide (LPS)-activated monocytes and THP-1 cells, respectively. MXF (5 to 20 microg/ml) significantly inhibited cytokine production by 14 to 80% and 15 to 73% in monocytes and THP-1 cells, respectively. In THP-1 cells, the level of NF-kappaB nuclear translocation increased fourfold following stimulation with LPS-phorbol myristate acetate (PMA), and this was inhibited (38%) by 10 microg of MXF per ml. We then assayed the degradation of inhibitor (I)-kappaB by Western blotting. LPS-PMA induced degradation of I-kappaB by 73%, while addition of MXF (5 microg/ml) inhibited I-kappaB degradation by 49%. Activation of ERK1/2 and the 46-kDa p-JNK protein was enhanced by LPS and LPS-PMA and was significantly inhibited by MXF (54 and 42%, respectively, with MXF at 10 microg/ml). We conclude that MXF suppresses the secretion of proinflammatory cytokines in human monocytes and THP-1 cells and that it exerts its anti-inflammatory effects in THP-1 cells by inhibiting NF-kappaB, ERK, and JNK activation. Its anti-inflammatory properties should be further assessed in clinical settings.  相似文献   
75.
Beta defensins comprise a family of cationic, cysteine-rich antimicrobial peptides, predominantly expressed at epithelial surfaces. Previously we identified a unique five-cysteine defensin-related peptide (Defr1) that, when synthesized, is a mixture of dimeric isoforms and exhibits potent antimicrobial activity against Escherichia coli and Pseudomonas aeruginosa. Here we report that Defr1 displays antimicrobial activity against an extended panel of multidrug-resistant nosocomial pathogens for which antimicrobial treatment is limited or nonexistent. Defr1 fractions were collected by high-pressure liquid chromatography and analyzed by gel electrophoresis and mass spectrometry. Antimicrobial activity was initially investigated with the type strain Pseudomonas aeruginosa PAO1. All fractions tested displayed equivalent, potent antimicrobial activity levels comparable with that of the unfractionated Defr1. However, use of an oxidized, monomeric six-cysteine analogue (Defr1 Y5C), or of reduced Defr1, gave diminished antimicrobial activity. These results suggest that the covalent dimer structure of Defr1 is crucial to antimicrobial activity; this hypothesis was confirmed by investigation of a synthetic one-cysteine variant (Defr1-1cys). This gave an activity profile similar to that of synthetic Defr1 but only in an oxidized, dimeric form. Thus, we have shown that covalent, dimeric molecules based on the Defr1 beta-defensin sequence demonstrate antimicrobial activity even in the absence of the canonical cysteine motif.  相似文献   
76.
MAPKs and inhibitory-kappaB kinase (IKK) were suggested to link various conditions thought to develop in adipose tissue in obesity (oxidative, endoplasmic reticulum stress, inflammation) with insulin resistance. Yet whether in obesity these kinases are affected in a fat-depot-differential manner is unknown. We assessed the expression and phosphorylation of these kinases in paired omental and abdominal-sc fat biopsies from 48 severely obese women (body mass index > 32 kg/m(2)). Protein and mRNAs of p38MAPK, ERK, c-Jun kinase-1, and IKKbeta were increased 1.5-2.5-fold in omental vs. sc fat. The phosphorylated (activated) forms of these kinases were also increased to similar magnitudes as the total expression. However, phosphorylation of insulin receptor substrate-1 on Ser312 (equivalent of murine Ser307) was not increased in omental, compared with sc, fat. Consistently, fat tissue fragments stimulated with insulin demonstrated that tyrosine phosphorylation and signal transduction to Akt/protein kinase B in omental fat was not inferior to that observable in sc fat. Comparison with lean women (body mass index 23.2 +/- 2.9 kg/m(2)) revealed similar ERK2 and IKKbeta expression and phosphorylation in both fat depots. However, as compared with lean controls, obese women exhibited 480 and 270% higher amount of the phosphorylated forms of p38MAPK and c-Jun kinase, respectively, in omental, but not sc, fat, and this expression level correlated with clinical parameters of glycemia and insulin sensitivity. Increased expression of stress-activated kinases and IKK and their phosphorylated forms in omental fat occurs in obesity, potentially contributing to differential roles of omental and sc fat in the pathophysiology of obesity.  相似文献   
77.

Purpose

The aim of the current study was to evaluate the therapeutic effects of omega-3 plant sterol esters (n-3-PSE) on lipid profile and other coronary heart disease risk factors in subjects with mixed hyperlipidemia.

Methods

Ninety-one patients with mixed hyperlipidemia were randomized in a double blind fashion to receive either placebo (corn oil) or n-3-PSE. Twenty four patients dropped out or were excluded from the efficacy analysis due to protocol violation. The primary efficacy endpoint was mean change in plasma low-density lipoprotein cholesterol (LDL-C) levels after 12 weeks of treatment. Other efficacy measures included plasma lipids, lipoproteins, and high-sensitivity C-reactive protein (hsCRP) levels. Participants who completed the double-blind study were given the option to continue into an open-label, 12-weeks follow up phase.

Results

n-3-PSE treatment did not result in a significant change in LDL-C levels. Triglyceride levels were reduced significantly by 19% (51 mg/dL, p?<?0.0001) in the n-3-PSE group in comparison with the placebo group (p?=?0.025). Diastolic blood pressure and hsCRP were reduced by 7% (5.9 mmHg) and 7.8% (0.6 mg/L), respectively, and were significantly different from the placebo group (p?=?0.036 and p?=?0.018, respectively).

Conclusions

In patients with mixed hyperlipidemia, n-3-PSE treatment may offer a safe and effective therapy for triglyceride level reduction while avoiding the typical increase in LDL-C levels associated with n-3 fatty acid treatment. The observed reduction in blood pressure and inflammation markers warrants further evaluation. The positive effect of n-3-PSE treatment was preserved at the end of the follow up phase.  相似文献   
78.
79.
Primary biliary cirrhosis (PBC) and systemic sarcoidosis are granulomatous diseases of unknown etiology whose hepatic manifestations may infrequently be imitative of one another. Described herein is the first reported case in the medical literature of systemic sarcoidosis developing after liver transplantation for PBC. The presented patient, who suffered from typical clinical, laboratory, and pathologic manifestations of PBC, developed decompensated liver cirrhosis within a course of 8 years, necessitating orthotopic liver transplantation. A year and a half after transplantation, the patient developed diffuse, biopsy-proven, dermatologic and pulmonary manifestations of systemic sarcoidosis, which promptly responded to corticosteroid treatment. In retrospect, the patient's longstanding liver disease was probably caused by an unrecognizable, isolated hepatic form of sarcoidosis or an overlap between PBC and sarcoidosis. This patient illustrates the complexity that may be rarely encountered in differentiating between PBC and hepatic sarcoidosis. Discussed are the clinical, laboratory, and pathologic overlaps between hepatic sarcoidosis and PBC, and clues that may aid in the diagnosis and differentiation between the 2 disorders. Hepatologists and liver transplantation specialists should be aware of the rare possibility of hepatic sarcoidosis imitating PBC, and exacerbating systemically after liver transplantation.  相似文献   
80.
Infection is one of the leading causes of mortality in dialysis patients, second only to cardiovascular disease. This retrospective study assessed the efficacy and clinical outcomes of influenza vaccination among hemodialysis (HD) patients. In the 2014–2015 season, 104 of 164 (63.6%) HD patients were vaccinated for influenza by the outpatient community health system facilities. Significantly more patients, 159 of 170 (93.8%), were vaccinated in 2015–2016 by the hospital dialysis unit staff during an inpatient HD session (P <0.001). A trend toward fewer complications from influenza infection was observed in vaccinated patients. Among HD patients with diabetes (who comprised 56% of the study population), the incidence of influenza was 17% among nonvaccinated patients vs. 6.3% among those who were vaccinated (P =0.026). The inpatient vaccination policy resulted in a greater rate of vaccination. HD patients with diabetes benefit from influenza vaccination, with a significantly lower incidence of influenza 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