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   612篇
  免费   56篇
  国内免费   4篇
耳鼻咽喉   7篇
儿科学   14篇
妇产科学   7篇
基础医学   82篇
口腔科学   14篇
临床医学   55篇
内科学   172篇
皮肤病学   9篇
神经病学   21篇
特种医学   23篇
外科学   108篇
综合类   23篇
预防医学   33篇
眼科学   13篇
药学   65篇
中国医学   4篇
肿瘤学   22篇
  2023年   25篇
  2022年   20篇
  2021年   25篇
  2020年   19篇
  2019年   22篇
  2018年   35篇
  2017年   16篇
  2016年   24篇
  2015年   24篇
  2014年   35篇
  2013年   49篇
  2012年   57篇
  2011年   51篇
  2010年   33篇
  2009年   21篇
  2008年   26篇
  2007年   27篇
  2006年   20篇
  2005年   21篇
  2004年   12篇
  2003年   13篇
  2002年   11篇
  2001年   8篇
  2000年   8篇
  1999年   15篇
  1998年   6篇
  1997年   6篇
  1996年   5篇
  1993年   2篇
  1992年   3篇
  1991年   6篇
  1989年   1篇
  1988年   3篇
  1987年   1篇
  1986年   2篇
  1985年   1篇
  1984年   2篇
  1983年   1篇
  1982年   2篇
  1981年   1篇
  1979年   1篇
  1977年   2篇
  1976年   1篇
  1974年   1篇
  1973年   1篇
  1972年   1篇
  1971年   1篇
  1968年   1篇
  1965年   1篇
  1939年   1篇
排序方式: 共有672条查询结果,搜索用时 144 毫秒
11.
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   
12.
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   
13.
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   
14.
15.
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   
16.
17.
18.
19.

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   
20.

Background

Cardiopulmonary resuscitation (CPR) is a key component of emergency care following cardiac arrest. A better understanding of factors that influence CPR outcomes and their prognostic implications would help guide care. A retrospective analysis of 800 adult patients that sustained an in- or out-of-hospital cardiac arrest and underwent CPR in the emergency department of a tertiary care facility in Karachi, Pakistan, between 2008 and 15 was conducted.

Methods

Patient demographics, clinical history, and CPR characteristics data were collected. Logistic regression model was applied to assess predictors of return of spontaneous circulation and survival to discharge. Analysis was conducted using SPSS v.21.0.

Results

Four hundred sixty-eight patients met the study’s inclusion criteria, and overall return of spontaneous circulation and survival to discharge were achieved in 128 (27.4%) and 35 (7.5%) patients respectively. Mean age of patients sustaining return of spontaneous circulation was 52 years and that of survival to discharge was 49 years. The independent predictors of return of spontaneous circulation included age ≤?49 years, witnessed arrest, ≤?30 min interval between collapse-to-start, and 1–4 shocks given during CPR (aOR (95% CI) 2.2 (1.3–3.6), 1.9 (1.0–3.7), 14.6 (4.9–43.4), and 3.0 (1.4–6.4) respectively), whereas, age ≤?52 years, bystander resuscitation, and initial rhythm documented (pulseless electrical activity and ventricular fibrillation) were independent predictors of survival to discharge (aOR (95% CI) 2.5 (0.9–6.5), 1.4 (0.5–3.8), 5.3 (1.5–18.4), and 3.1 (1.0–10.2) respectively).

Conclusion

Our study notes that while the majority of arrests occur out of the hospital, only a small proportion of those arrests receive on-site CPR, which is a key contributor to unfavorable outcomes in this group. It is recommended that effective pre-hospital emergency care systems be established in developing countries which could potentially improve post-arrest outcomes. Younger patients, CPR initiation soon after arrest, presenting rhythm of pulseless ventricular tachycardia and ventricular fibrillation, and those requiring up to four shocks to revive are more likely to achieve favorable outcomes.
  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