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   6484篇
  免费   285篇
  国内免费   102篇
耳鼻咽喉   66篇
儿科学   78篇
妇产科学   212篇
基础医学   511篇
口腔科学   208篇
临床医学   481篇
内科学   2092篇
皮肤病学   88篇
神经病学   417篇
特种医学   272篇
外科学   1384篇
综合类   31篇
现状与发展   1篇
一般理论   3篇
预防医学   244篇
眼科学   132篇
药学   247篇
中国医学   3篇
肿瘤学   401篇
  2024年   6篇
  2023年   74篇
  2022年   157篇
  2021年   283篇
  2020年   164篇
  2019年   230篇
  2018年   274篇
  2017年   159篇
  2016年   198篇
  2015年   187篇
  2014年   312篇
  2013年   363篇
  2012年   534篇
  2011年   573篇
  2010年   376篇
  2009年   336篇
  2008年   484篇
  2007年   499篇
  2006年   461篇
  2005年   348篇
  2004年   279篇
  2003年   195篇
  2002年   170篇
  2001年   50篇
  2000年   36篇
  1999年   23篇
  1998年   28篇
  1997年   14篇
  1996年   10篇
  1995年   7篇
  1994年   17篇
  1993年   4篇
  1992年   6篇
  1991年   2篇
  1990年   2篇
  1989年   2篇
  1984年   2篇
  1982年   1篇
  1979年   1篇
  1978年   1篇
  1975年   2篇
  1969年   1篇
排序方式: 共有6871条查询结果,搜索用时 15 毫秒
81.
82.
83.
84.
85.
86.
Background and Aim: We investigated the role of the prophylactic administration of the antioxidant 2‐mercaptoethane sulfonate (mesna) on the hepatocyte‐regenerating capacity following partial hepatectomy (PH) with concurrent Pringle maneuver. Methods: Wistar rats were subjected to PH (70% hepatectomy), 30 min Pringle maneuver, PH plus Pringle with or without mesna pretreatment (400 mg/kg, per os, 3 h before Pringle), or sham operation. At 24 h, 48 h, 72 h, and 1 week after operation, relative liver weight, hepatocyte mitotic activity (mitotic index), the histopathological score and serum aspartate aminotransferase, and alanine aminotransferase concentrations were assessed. At 1 h after operation, oxidative stress markers (glutathione to glutathione disulfide ratio, malondialdehyde concentration, and superoxide dismutase activity) and nuclear factor‐κB (NF‐κB) activity were assessed. Results: Hepatectomy stimulated the regenerating process and induced mild oxidative stress and the activation of NF‐κB in hepatocytes, while causing tissue injury in the remnant liver. When PH was performed under Pringle maneuver, hepatocyte mitotic activity was substantially suppressed, although Pringle alone initiated a delayed regenerating response. Furthermore, Pringle maneuver deteriorated oxidative stress markers, markedly increased NF‐κB activity, and aggravated tissue injury, as compared to hepatectomy alone. Mesna pretreatment prevented the Pringle‐induced antimitotic effect and the induction of oxidative stress, inhibited the activation of NF‐κB, while attenuating liver injury after PH under Pringle. Conclusion: The excessive activation of NF‐κB is related to the suppression of hepatocyte‐regenerating activity following PH with concurrent liver ischemia. Mesna pretreatment protects the liver against the Pringle‐induced antimitotic effect after PH via the prevention of oxidative stress and the inhibition of NF‐κB activation.  相似文献   
87.
88.
89.
AIM:To analyze retrospectively the records of 294 conse-cutive patients operated upon for gallbladder stones, to determine the predictive factors of synchronous common bile duct (CBD) stones and validate prospectively the generated model. METHODS: The prognostic estimation of a biochemical test and ultrasonography alone to differentiate between the absence and presence of choledocholithiasis was assessed using receiver operating characteristics curve analysis. Multivariate analysis was employed using discriminant analysis for establishment of a best model.Prospective validation of the model was made. RESULTS: Discriminant forward stepwise analysis disclosed that high values (≥2×normal) of SGOT,ALP, conjugated bilirubin and CBD diameter on ultrasound ≥10 mm were all prognostic factors of CBD lithiasis in univariate and multivariate analysis, P<0.01. History was not included in the model.Prospective validation of the model was performed by multivariate analysis using Visual General Stepwise Regression. Positive predictive value, when considering all these predictors,was 93.3%,while the negative predictive value was 88.8%.Sensitivity of the model was 96.5% and specificity 80%. CONCLUSION: The above model can be objectively applied to predict the presence of CBD stones.  相似文献   
90.
Long-term outcome of pneumatic dilation in the treatment of achalasia   总被引:8,自引:0,他引:8  
OBJECTIVE: Achalasia is a well-defined esophageal motor disorder for which pneumatic dilation is an established therapeutic method. Even though it has been used for several years, there are limited data on the long-term outcomes of patients treated with this procedure. Hence, we aimed to evaluate the long-term efficacy of pneumatic dilation to control the symptoms of achalasia. METHODS: The medical records of all patients treated in our unit for achalasia with pneumatic dilation were reviewed. We identified the long-term result of the initial procedure, the date of the first dilation, and the time interval between dilation and retreatment. RESULTS: Of 260 patients who were treated with pneumatic dilation, 153 (67 men, 86 women) were followed up for more than 5 yr. The mean follow-up period was 11.09 +/- 3.91 yr, and the success rate of the dilation was 75.8%. Among these patients, 35 (19 men, 16 women) had follow-up periods of more than 15 yr. The mean follow-up time of those patients was 16.56 +/- 1.09 yr, and the success rate was 51.4%. Kaplan-Meier survival analysis showed that, overall, 50% of patients develop recurring symptoms after 10.92 yr. CONCLUSIONS: Although 51.4% of patients continued to be in clinical remission more than 15 yr after the initial pneumatic dilation, the long-term success rate of pneumatic dilation seems to drop progressively with time.  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