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   650篇
  免费   26篇
  国内免费   14篇
儿科学   35篇
妇产科学   3篇
基础医学   84篇
口腔科学   6篇
临床医学   52篇
内科学   88篇
皮肤病学   5篇
神经病学   183篇
特种医学   97篇
外科学   77篇
综合类   5篇
预防医学   22篇
眼科学   2篇
药学   20篇
肿瘤学   11篇
  2023年   2篇
  2021年   4篇
  2019年   3篇
  2018年   3篇
  2017年   8篇
  2016年   9篇
  2015年   11篇
  2014年   15篇
  2013年   28篇
  2012年   36篇
  2011年   44篇
  2010年   23篇
  2009年   35篇
  2008年   35篇
  2007年   46篇
  2006年   30篇
  2005年   33篇
  2004年   34篇
  2003年   24篇
  2002年   22篇
  2001年   14篇
  2000年   9篇
  1999年   18篇
  1998年   25篇
  1997年   18篇
  1996年   18篇
  1995年   14篇
  1994年   9篇
  1993年   9篇
  1991年   5篇
  1990年   6篇
  1989年   11篇
  1988年   11篇
  1987年   11篇
  1986年   3篇
  1985年   9篇
  1984年   6篇
  1983年   11篇
  1982年   8篇
  1981年   3篇
  1980年   4篇
  1979年   3篇
  1978年   2篇
  1975年   3篇
  1970年   2篇
  1965年   1篇
  1963年   1篇
  1959年   1篇
  1927年   1篇
  1921年   2篇
排序方式: 共有690条查询结果,搜索用时 0 毫秒
11.
12.
13.
Deimann  W; Seitz  M; Gemsa  D; Fahimi  HD 《Blood》1984,64(2):491-498
The development of peroxidase (PO) reaction in the nuclear envelope (NE) and endoplasmic reticulum (ER) of monocytes differentiating in vitro and its relationship with arachidonic acid metabolism were studied. The PO, as visualized by the diaminobenzidine (DAB) technique, appeared in the NE and ER of the majority of monocytes within 24 hours of culture, with a substantial decrease thereafter. The influence of three major groups of agents--inhibitors of PO, of prostanoids, and of protein biosynthesis--upon the development of the PO reaction was examined. When aminotriazole, a PO inhibitor, was added to the culture medium, the appearance of PO was suppressed in the monocytes. The cyclooxygenase blocker, indomethacin, however, did not influence the development of PO. Also the blockers of protein synthesis, puromycin, cycloheximide, and actinomycin D, did not affect the appearance of PO. The prostanoids released from the monocytes, ie, prostaglandin E and thromboxane B2, were determined by radioimmunoassay and showed a time sequence of secretion that corresponded to the appearance of PO in the cells: a marked increase within the first 24 hours with a substantial decrease thereafter. The presence of the PO inhibitors aminotriazole and sodium azide in the culture medium produced a suppression of prostanoid release from the monocytes comparable with that of indomethacin. The data suggest that the PO in the NE and ER of differentiating monocytes in vitro (1) is associated with arachidonic acid metabolism, and (2) is not formed by de novo protein synthesis but rather by an activation process.  相似文献   
14.

Background

The aim of this study was to demonstrate noninferiority of everolimus with reduced cyclosporine (CsA) vs mycophenolate mofetil (MMF) with reduced CsA in improving renal function.

Methods

In this 1-year randomized, open-label, noninferiority study in maintenance heart transplant recipients with impaired renal function 70 patients received everolimus (n = 36) or MMF (n = 34) in combination with reduced CsA. The planned sample size was not reached as the study was prematurely discontinued due to slow recruitment.

Results

Noninferiority of the everolimus regimen could not be shown: In the total population MMF seemed to be favorable on renal function assessed by serum creatinine and filtration rates, but not in the subset of patients who reached the intended reduced CsA level. Incidence rates of rejection episodes were significantly higher under MMF at month 6 (P = .0332).

Conclusions

Overall, the results of this trial using reduced CsA in combination with either everolimus or MMF show that there is evidence to reduce the CsA level when everolimus is given concomitantly and that the benefit of MMF with reduced CsA levels is limited due to insufficient immunosuppression.  相似文献   
15.
The efficacy of everolimus with reduced cyclosporine in de novo heart transplant patients has been demonstrated convincingly in randomized studies. Moreover, everolimus-based immunosuppression in de novo heart transplant recipients has been shown in two randomized trials to reduce the increase in maximal intimal thickness based on intravascular ultrasound, indicating attenuation of cardiac allograft vasculopathy (CAV). Randomized trials of everolimus in de novo heart transplantation have also consistently shown reduced cytomegalovirus infection versus antimetabolite therapy. In maintenance heart transplantation, conversion from calcineurin inhibitors to everolimus has demonstrated a sustained improvement in renal function. In de novo patients, a renal benefit may only be achieved if there is an adequate reduction in exposure to calcineurin inhibitor therapy. Delayed introduction of everolimus may be appropriate in patients at high risk of wound healing complications, e.g. diabetic patients or patients with ventricular assist device. The current evidence base suggests that the most convincing reasons for use of everolimus from the time of heart transplantation are to slow the progression of CAV and to lower the risk of cytomegalovirus infection. A regimen of everolimus with reduced-exposure calcineurin inhibitor and steroids in de novo heart transplant patients represents a welcome addition to the therapeutic armamentarium.  相似文献   
16.
TRACK‐HD is a multicentre longitudinal observational study investigating the use of clinical assessments and 3‐Tesla magnetic resonance imaging as potential biomarkers for future therapeutic trials in Huntington's disease (HD). The cross‐sectional data from this large well‐characterized dataset provide the opportunity to improve our knowledge of how the underlying neuropathology of HD may contribute to the clinical manifestations of the disease across the spectrum of premanifest (PreHD) and early HD. Two hundred and thirty nine gene‐positive subjects (120 PreHD and 119 early HD) from the TRACK‐HD study were included. Using voxel‐based morphometry (VBM), grey and white matter volumes were correlated with performance in four domains: quantitative motor (tongue force, metronome tapping, and gait); oculomotor [anti‐saccade error rate (ASE)]; cognition (negative emotion recognition, spot the change and the University of Pennsylvania smell identification test) and neuropsychiatric measures (apathy, affect and irritability). After adjusting for estimated disease severity, regionally specific associations between structural loss and task performance were found (familywise error corrected, P < 0.05); impairment in tongue force, metronome tapping and ASE were all associated with striatal loss. Additionally, tongue force deficits and ASE were associated with volume reduction in the occipital lobe. Impaired recognition of negative emotions was associated with volumetric reductions in the precuneus and cuneus. Our study reveals specific associations between atrophy and decline in a range of clinical modalities, demonstrating the utility of VBM correlation analysis for investigating these relationships in HD. Hum Brain Mapp, 2013. © 2011 Wiley Periodicals, Inc.  相似文献   
17.
Maternally administered recombinant human granulocyte colony- stimulating factor (rhG-CSF) has been shown to cross the placenta and induce a peripheral neutrophilia and increases in the marrow and spleen neutrophil storage pools in fetal and newborn rats. In the present study, we have used this model system to investigate the efficacy of prenatally administered rhG-CSF on neonatal defense to a lethal challenge with Group B-beta hemolytic Streptococcus (GBS). Pregnant rats were injected with rhG-CSF twice daily beginning 6 days before parturition. At birth, all pups were infected with a dose of GBS that is lethal for 90% of infected pups (LD90). Survival was monitored daily for 5 days. Survival of infected pups from saline-treated mothers beyond 60 hours after infection was 10%. No difference in survival was observed among pups from mothers treated 2 and 4 days before parturition. In contrast, we determined that survival was 82.5% among infected pups from mothers treated for 6 days before parturition with rhG-CSF. Our results demonstrate that maternal administration of rhG- CSF augments neonatal defenses against a lethal bacterial challenge.  相似文献   
18.
19.

Aim

Several large surveys have highlighted the inadequate risk factor control in populations at elevated cardiovascular risk. These populations would substantially benefit from risk reduction and could demonstrate increased awareness for risk factor control. Risk factor segregation by gender has been previously described, yet its analysis in the medical field frequently omits sociodemographic variables, which could act as potential confounders.

Subject and methods

We analyzed risk factor prevalence in a population of 1,559 patients with severe coronary heart disease prior to a coronary bypass graft (CABG) surgery. Univariate correlations between risk factor type and frequency and gender were explored. Following, multivariable models were fitted to account for sociodemographic aspects associated with gender. Interaction terms were incorporated as fit. Lastly, the correlation between gender-specific risk factor profiles and their association with self-perceived health status was assessed.

Results

Our study identified gender as the main segregating variable for risk factors after multiple adjustments and inclusion of interaction terms. Obesity and hypertension displayed a significant association with the female population (OR?=?1.598, p?=?0.047 and OR?=?3.737, p?=?0.006, respectively), while smoking and elevated alcohol consumption prevailed in males (OR?=?1.77, p?=?0.038 and OR?=?2.768, p?=?0.013, respectively). Additionally, gender-specific analysis of health perception according to risk factor loads revealed that male patients rate their health in overall better terms regardless of their risk profile.

Conclusions

Our study confirmed the role of gender as the primary risk profile segregator after multiple adjustments for potential sociodemographic confounders, even in a population at elevated cardiovascular risk. Subjective health perception, which displayed marked gender differences, should be further investigated as a potential adherence and outcome modulator.  相似文献   
20.
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