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   1135篇
  免费   84篇
  国内免费   8篇
耳鼻咽喉   9篇
儿科学   32篇
妇产科学   8篇
基础医学   115篇
口腔科学   28篇
临床医学   142篇
内科学   294篇
皮肤病学   28篇
神经病学   26篇
特种医学   103篇
外科学   129篇
综合类   86篇
预防医学   83篇
眼科学   14篇
药学   75篇
  1篇
中国医学   23篇
肿瘤学   31篇
  2023年   26篇
  2022年   21篇
  2021年   29篇
  2020年   24篇
  2019年   29篇
  2018年   41篇
  2017年   21篇
  2016年   27篇
  2015年   50篇
  2014年   53篇
  2013年   73篇
  2012年   77篇
  2011年   73篇
  2010年   69篇
  2009年   49篇
  2008年   50篇
  2007年   52篇
  2006年   27篇
  2005年   30篇
  2004年   18篇
  2003年   26篇
  2002年   15篇
  2001年   16篇
  2000年   5篇
  1999年   19篇
  1998年   33篇
  1997年   29篇
  1996年   34篇
  1995年   23篇
  1994年   22篇
  1993年   16篇
  1992年   5篇
  1991年   6篇
  1990年   3篇
  1989年   15篇
  1988年   19篇
  1987年   12篇
  1986年   10篇
  1985年   11篇
  1984年   11篇
  1983年   7篇
  1982年   10篇
  1981年   4篇
  1980年   8篇
  1979年   2篇
  1978年   3篇
  1977年   4篇
  1976年   8篇
  1975年   3篇
  1939年   1篇
排序方式: 共有1227条查询结果,搜索用时 312 毫秒
21.
A middle-aged patient presented with intermittent chronic abdominal pain without any obvious cause. Computed tomography detected a hernia (presumed to be the cause of the patient’s symptoms) without any obvious lump on examination. A laparoscopy was performed to repair the hernia. This revealed a left-sided unilateral ‘peritoneal recess’ at the level of the arcuate line extending medial to the linea semilunaris. No extraperitoneal sac or defect was noted in the rectus sheath or in the muscle, nor were any contents present in the recess at the time of the laparoscopy. We believe the bowel was being trapped intermittently in this space, causing the abdominal symptoms.  相似文献   
22.
Thoracic aortocaval fistula is a very rare cause of left to right shunt. Drainage of fistula into the superior vena cava (SVC) is very uncommon. Clinical symptoms depend on the size of the shunt. We report a rare case of an asymptomatic 27‐year‐old woman with congenital aortocaval fistula to the SVC with a small amount of left to right shunt that was considered for serial medical follow‐up.  相似文献   
23.
Lactobacillus crispatus is one of the most predominant species in the healthy vagina microbiota. Nevertheless, the interactions between this commensal bacterium and the immune system are largely unknown. Given the importance of the dendritic cells (DCs) in the regulation of the immunity, this study was performed to elucidate the influence of vaginal isolated L. crispatus SJ‐3C‐US from healthy Iranian women on DCs, either directly by exposure of DCs to ultraviolet‐inactivated (UVI) and heat‐killed (HK) L. crispatus SJ‐3C‐US or indirectly to its cell‐free supernatant (CFS), and the outcomes of immune response. In this work we showed that L. crispatus SJ‐3C‐US induced strong dose‐dependent activation of dendritic cells and production of high levels of IL‐10, whereas IL‐12p70 production was induced at low level in an inverse dose‐dependent manner. This stimulation skewed T cells polarization toward CD4+ CD25+ FOXP3+ Treg cells and production of IL‐10 in a dose‐dependent manner in mixed leukocyte reaction (MLR) test. The mode of bacterial inactivation did not affect the DCs activation pattern, upon encounter with L. crispatus SJ‐3C‐US. Moreover, while DCs stimulated with CFS showed moderate phenotypic maturation and IL‐10 production, it failed to skew T cells polarization toward CD4+ CD25+ FOXP3+ regulatory T cells (Treg) and production of IL‐10. This study showed that L. crispatus SJ‐3C‐US confers an anti‐inflammatory phenotype to DCs through up‐regulation of anti‐inflammatory/regulatory IL‐10 cytokine production and induction of CD4+ CD25+ FOXP3+ T cells at optimal dosage. Our findings suggest that L. crispatus SJ‐3C‐US could be a potent candidate as protective probiotic against human immune‐mediated pathologies, such as chronic inflammation, vaginitis or pelvic inflammatory disease (PID).  相似文献   
24.
25.
ObjectiveTo develop and evaluate a risk score to predict people at high risk of developing type 2 diabetes in Pakistan.MethodologyCross sectional data regarding primary prevention of diabetes in Pakistan. Diabetes risk score was developed by using simple parameters namely age, waist circumference, and family history of diabetes. Odds ratios of the model were used to assign a score value for each variable and the diabetes risk score was calculated as the sum of those scores.ResultsWe externally validated the score using two data from 1264 subjects and 856 subjects aged 25 years and above from two separate studies respectively. Validating this score using the first data from the second screening study gave an area under the receive operator characteristics curve [AROC] of 0.758. A cut point of 4 had a sensitivity of 47.0% and specificity of 88% and in the second data AROC is 0.7 with 44% sensitivity and 89% specificity.ConclusionsA simple diabetes risk score, based on a set of variables can be used for the identification of high risk individuals for early intervention to delay or prevent type 2 diabetes in Pakistani population.  相似文献   
26.
Although emollients can be sufficient to manage mild atopic dermatitis (AD), acute flares resulting in moderate‐to‐severe symptoms require treatment with anti‐inflammatory agents, such as topical corticosteroids (TCs) and topical calcineurin inhibitors (TCIs). This review examines the role of a member of the newest class of TCs, the fourth‐generation compound methylprednisolone aceponate (MPA) in AD management, with reference to the chemical structure, pharmacokinetics, efficacy in AD, safety assessed in preclinical and clinical trials and dosing considerations. MPA has an optimized efficacy/safety profile with minimal local or systemic adverse effects. In addition, it offers the opportunity for once‐daily dosing, which provides benefits in terms of patient compliance with treatment.  相似文献   
27.
28.
29.

Background

Electrocardiogram (ECG) is the first available modality used in patients with chest pain and dyspnea in emergency rooms.We aimed to study differences between acute coronary syndrome (ACS) and acute pulmonary embolism (APE) in patients presented primarily with abnormal negative T waves on their admission Electrocardiogram.

Methods

This research was a retrospective study in which 297 patients (97 patients with APE and 200 with ACS) were included. The patients were admitted to the emergency ward of a tertiary heart center between 2015 and 2017. In addition to the evaluation of distribution of negative T waves, the depth of the inverted precordial T waves was measured.

Results

The mean age of patients was 62.0?±?11.4 in ACS group and 60.7?±?17.6 in APE group (P value?=?0.563). Total negative T in V3 and V4 in ACS and APE groups was 9.1?mm and 4.2?mm respectively (P value <0.001).Total magnitude of negative T in anterior leads divided by total magnitude of negative T in inferior leads for ACS and APE groups were 15.1?±?12.0 and 5.4?±?3.6 respectively (P value?=?0.001).ROC curves showed that total magnitude of negative T in V4 divided by negative T in V1 can be valuable. A cutoff point of 1.75 with sensitivity of 73.5% and specificity of 84.9% (95% CI 0.79–0.91 P?<?0.001) could differentiate APE patients from ACS patients.

Conclusion

This study suggests that total magnitude of negative T in left precordial leads divided by right precordial leads can be valuable in differentiating APE from ACS.  相似文献   
30.
目的:对中孕期非整倍体染色体异常血清学筛查不同方案的检出率进行探讨。方法选取513名2009年9月~2013年3月在攀枝花市妇幼保健院产科进行常规产前筛查的孕妇血清样本,分别采用化学发光法和时间分辨荧光免疫法对孕妇血清进行二联、三联、四联检查,比较阳性率及假阳性率。结果二联化学发光法检测唐氏综合征(DS)高危假阳性率为9.10豫,三联为7.36豫,四联为6.28豫,假阳性率呈递减趋势(字2=5.119,P约0.05);二联化学发光法筛查18-三体高危假阳性率(0.63豫)低于三联(0.82豫),差异有统计学意义(字2=4.776,P约0.05)。三联时间分辨荧光免疫法筛查DS、18-三体假阳性率(4.01豫、0.34豫)较二联(8.93豫、0.61豫)均明显降低(字2=6.992、4.776,P约0.05)。二联化学发光法检测DS、18-三体假阳性率分别为9.10豫、0.63豫,时间分辨荧光免疫法则分别为8.93豫、0.61豫,两种检测方法比较,差异无统计学意义(字2=1.787、0.000,P跃0.05);而三联时间荧光分辨法检测DS、18-三体假阳性率(4.01豫、0.34豫)均低于三联化学发光法(7.36豫、0.82豫),差异有统计学意义(字2=5.382、4.783,P约0.05)。结论化学发光法的检测系统发现筛查效率二联、三联及四联方案呈递增趋势。时间分辨荧光免疫法检测系统发现筛查效率三联高于二联方案,时间荧光分辨法三联筛查优于化学发光法。  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