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   4187篇
  免费   285篇
  国内免费   19篇
耳鼻咽喉   27篇
儿科学   151篇
妇产科学   98篇
基础医学   607篇
口腔科学   76篇
临床医学   459篇
内科学   940篇
皮肤病学   80篇
神经病学   385篇
特种医学   126篇
外科学   473篇
综合类   17篇
一般理论   3篇
预防医学   309篇
眼科学   57篇
药学   327篇
中国医学   9篇
肿瘤学   347篇
  2023年   43篇
  2022年   66篇
  2021年   146篇
  2020年   83篇
  2019年   104篇
  2018年   107篇
  2017年   72篇
  2016年   116篇
  2015年   118篇
  2014年   135篇
  2013年   198篇
  2012年   275篇
  2011年   299篇
  2010年   158篇
  2009年   127篇
  2008年   248篇
  2007年   252篇
  2006年   244篇
  2005年   230篇
  2004年   194篇
  2003年   178篇
  2002年   186篇
  2001年   73篇
  2000年   56篇
  1999年   64篇
  1998年   48篇
  1997年   32篇
  1996年   20篇
  1995年   19篇
  1994年   34篇
  1993年   14篇
  1992年   45篇
  1991年   34篇
  1990年   30篇
  1989年   28篇
  1988年   32篇
  1987年   21篇
  1986年   25篇
  1985年   22篇
  1984年   22篇
  1983年   25篇
  1982年   17篇
  1981年   14篇
  1979年   18篇
  1978年   13篇
  1977年   13篇
  1976年   11篇
  1973年   10篇
  1972年   11篇
  1966年   10篇
排序方式: 共有4491条查询结果,搜索用时 15 毫秒
81.

Background

The EINSTEIN-Jr program will evaluate rivaroxaban for the treatment of venous thromboembolism (VTE) in children, targeting exposures similar to the 20 mg once-daily dose for adults.

Methods

This was a multinational, single-dose, open-label, phase I study to describe the pharmacodynamics (PD), pharmacokinetics (PK) and safety of a single bodyweight-adjusted rivaroxaban dose in children aged 0.5–18 years. Children who had completed treatment for a venous thromboembolic event were enrolled into four age groups (0.5–2 years, 2–6 years, 6–12 years and 12–18 years) receiving rivaroxaban doses equivalent to 10 mg or 20 mg (either as a tablet or oral suspension). Blood samples for PK and PD analyses were collected within specified time windows.

Results

Fifty-nine children were evaluated. In all age groups, PD parameters (prothrombin time, activated partial thromboplastin time and anti-Factor Xa activity) showed a linear relationship versus rivaroxaban plasma concentrations and were in line with previously acquired adult data, as well as in vitro spiking experiments. The rivaroxaban pediatric physiologically based pharmacokinetic model, used to predict the doses for the individual body weight groups, was confirmed. No episodes of bleeding were reported, and treatment-emergent adverse events occurred in four children and all resolved during the study.

Conclusions

Bodyweight-adjusted, single-dose rivaroxaban had predictable PK/PD profiles in children across all age groups from 0.5 to 18 years. The PD assessments based on prothrombin time and activated partial thromboplastin time demonstrated that the anticoagulant effect of rivaroxaban was not affected by developmental hemostasis in children.

Trial registration

ClinicalTrials.gov number, NCT01145859.
  相似文献   
82.
Background: Self-rated health (SRH) measures one’s current general health and is a widely used health indicator. Sleep problems, somatic health complaints, and unmet needs in interpersonal relationships are suspected to influence SRH, but studies in primary health care settings are sparse.

Objective: To examine the associations between patients’ self-rated health and their sleep problems, somatic health complaints, and unmet needs in interpersonal relationships.

Design: We collected data via questionnaires for this cross-sectional study from general practice.

Setting: Primary health care in Norway.

Subjects: 1302 consecutive patients participated.

Main outcome measures: The questionnaire included a single question about SRH, the Bergen Insomnia Scale (BIS), five questions on somatic health complaints, and three questions from the Basic Psychological Needs Scale (BPNS) pertaining to the relationships domain. We analyzed our data using ordinal logistic regression models.

Results: Our response rate was 74%. The prevalence of fair/poor SRH was 26%, with no gender differences. We revealed a significant association between increasing age and reduced SRH. The study showed that sleep problems and somatic health complaints were strongly associated with SRH, and unmet needs in relationships were also significantly and independently associated with reduced SRH in a full model analysis.

Conclusion: Sleep problems, somatic health complaints, and unmet needs in interpersonal relationships were all associated with reduced SRH. These factors are all modifiable and could be managed both within and outside a primary care setting in order to improve SRH.

  • Key Points
  • There was a high prevalence of reduced SRH in clinical general practice

  • Sleep problems, somatic health complaints, and unmet needs in interpersonal relationships were all associated with reduced SRH

  • These predictors are all modifiable with a potential to improve SRH

  相似文献   
83.
BackgroundThere is growing body of evidence from retrospective studies that renin-angiotensin system (RAS) blockade is associated with improved outcome after transcatheter aortic valve replacement (TAVR). However, it remains unknown whether the effect of RAS blockade is dose dependent. The current study sought to assess the dose-dependent effect of RAS blockade on survival and left-ventricular (LV) remodelling after TAVR.MethodsPatients who were enrolled into our observational TAVR study at our institution were retrospectively assessed according to different doses of RAS blockade: group 1 (no RAS blockade), group 2 (25% of maximum daily dose), group 3 (50% of maximum daily dose), and group 4 (full daily dose).ResultsA total of 323 patients between January 2015 and September 2019 were included. Patients with higher doses of RAS blockade showed a trend toward higher overall survival at 3-year follow-up (56% with no RAS blockade vs 66% with the 25% dose vs 79% with the 50% dose vs 78% with the full dose; P = 0.063). After adjustment for baseline characteristics, the difference in survival was significant (P = 0.042). Besides New York Heart Association class and left-ventricular ejection fraction (LVEF), RAS blockade dose was identified as independent predictor for all-cause mortality (hazard ratio [HR] 0.72; 95% confidence interval [CI], 0.54-0.97; P = 0.03). With respect to LV remodelling, a significantly larger reduction of LV mass index was observed during the follow-up with higher doses of RAS blockade.ConclusionsThe current study showed that the impact of RAS blockade treatment on clinical outcome and LV remodelling after TAVR is dose dependent.  相似文献   
84.
85.
86.
We have previously reported that prostaglandin F(2alpha) (PGF(2alpha)) stimulates interleukin-6 (IL-6), a potent bone resorptive agent, through p44/p42 mitogen-activated protein (MAP) kinase in osteoblast-like MC3T3-E1 cells. In the present study, we investigated whether Rho-kinase is implicated in the PGF(2alpha)-stimulated IL-6 synthesis in MC3T3-E1 cells. PGF(2alpha) time-dependently induced the phosphorylation of myosin phosphatase targeting subunit (MYPT-1), a Rho-kinase substrate. Y27632, a specific Rho-kinase inhibitor, significantly reduced the PGF(2alpha)-stimulated IL-6 synthesis as well as the MYPT-1 phosphorylation. Fasudil, another inhibitor of Rho-kinase, suppressed the PGF(2alpha)-stimulated IL-6 synthesis. Y27632 and fasudil failed to affect the PGF(2alpha)-induced phosphorylation of p44/p42 MAP kinase. SB203580 and BIRB0796, potent inhibitors of p38 MAP kinase, suppressed the IL-6 synthesis induced by PGF(2alpha). While SP600125, an inhibitor of stress-activated protein kinase/c-Jun N-terminal kinase (SAPK/JNK), failed to reduce the synthesis. Y27632 as well as fasudil attenuated the PGF(2alpha)-induced phosphorylation of p38 MAP kinase. These results strongly suggest that Rho-kinase regulates PGF(2alpha)-stimulated IL-6 synthesis via p38 MAP kinase activation in osteoblasts.  相似文献   
87.
Right classification of diabetes is important clinical issue. The aim of present study was to compare clinical, biochemical and immunological features, to analyze their practical use and to establish new decision tree which make the distinction between diabetes type 1, LADA, diabetes type 2 and MODY. We studied 97 not obese (mean BMI 26.3 +/- 4.9 kg/m2) patients aged 14 to 70 years, mean age 43 +/- 11.7 years, 53 women, 44 men. Mean duration of diabetes--2.3 +/- 4.3 years. We measured basal and stimulated C-peptide (6 minutes after 1 mg i.v. glucagon) (ELISA) and antibodies titers to glutamic acid decarboxylase--antiGAD65, tyrosine phosphatase-like molecule--IA2 and insulin--IAA (RIA). Autoimmune diabetes (LADA, type 1) was diagnosed with presence of one or more islet antigen antibodies. The highest frequencies had anti-GAD antibodies 33/97 (34%). The most complicated was to sort out group of patients with LADA. Comparison between this group and patients with diabetes type 2 have shown that BMI, co-existence of autoimmune disease, autoimmune markers and basal and stimulated C-peptide level measured at entry for the classification were useful in differentiation. Moreover we observed significantly lower C-peptide basal, stimulated and over basal level in group with MODY diabetes in comparison to diabetes type 2 patients. In the studied group were 5 patients with diabetes type 2 and obesity, in relatively young age. At the end there was one case of ADM (atypical diabetes mellitus). Clinical criteria for the classification of diabetes not always correlated with diagnosis. Autoimmune markers, basal and stimulated C-peptide were useful specially in differentiation between LADA and diabetes type 2 or diabetes type 1. Autoimmune diabetes co-existe with autoimmune disease. Proposed diagnostic scheme take for consideration presence of autoantibodies as well as C-peptide criteria.  相似文献   
88.
Intercellular adhesion molecule-1 (ICAM-1) is 1 of the possible factors linking obesity and diabetes with cardiovascular disease, however, the mechanism of the increase in ICAM-1 concentration in obesity remains unclear. Therefore, the aim of the present study was to assess plasma soluble ICAM-1 (sICAM-1) levels in obese subjects with normal glucose tolerance and to evaluate whether those levels may be related to insulin resistance and tumor necrosis factor-alpha (TNFalpha) system activity. The study was performed in 8 lean and 15 obese subjects. Anthropometric and biochemical parameters were measured, and insulin sensitivity was evaluated using the euglycemic hyperinsulinemic clamp technique (insulin infusion, 50 mU x kg(-1) x h(-1)). Obese subjects were markedly more hyperinsulinemic and insulin resistant and had higher plasma soluble TNF receptor 2 (sTNFR2) and sICAM-1 levels. sICAM-1 was related positively to body mass index (BMI), waist-to-hip ratio (WHR), percent of body fat, glycated hemoglobin (HbA(1c)), plasma insulin and triglycerides (TG), TNFalpha, and sTNFR2 and negatively to insulin sensitivity. Multiple regression analysis showed that only sTNFR2 and insulin sensitivity were independent predictors of sICAM-1 concentrations and were responsible for 66% of sICAM-1 variability. We conclude that an increase in plasma sICAM-1 concentration in obesity is related to TNFalpha system activation and insulin resistance.  相似文献   
89.

Aims/hypothesis

The aim of this multicohort study was to examine whether employees exposed to social stressors at work, such as workplace bullying and violence, have an increased risk of type 2 diabetes.

Methods

The study included 45,905 men and women (40–65 years of age and free of diabetes at baseline) from four studies in Sweden, Denmark and Finland. Workplace bullying and violence were self-reported at baseline. Incident diabetes was ascertained through national health and medication records and death registers. Marginal structural Cox models adjusted for age, sex, country of birth, marital status and educational level were used for the analyses.

Results

Nine per cent of the population reported being bullied at work and 12% were exposed to workplace violence or threats of violence. Bullied participants had a 1.46 (95% CI 1.23, 1.74) times higher risk of developing diabetes compared with non-bullied participants. Exposure to violence or threats of violence was also associated with a higher risk of diabetes (HR 1.26 [95% CI 1.02, 1.56]). The risk estimates attenuated slightly when taking BMI into account, especially for bullying. The results were similar for men and women, and were consistent across cohorts.

Conclusions/interpretation

We found a higher risk of incident type 2 diabetes among employees exposed to bullying or violence in the workplace. Further research is needed to determine whether policies to reduce bullying and violence at work may reduce the incidence of type 2 diabetes in working populations. Research on the mechanisms is also highly warranted.
  相似文献   
90.
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