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   22921篇
  免费   1609篇
  国内免费   975篇
耳鼻咽喉   176篇
儿科学   1958篇
妇产科学   600篇
基础医学   3584篇
口腔科学   196篇
临床医学   1500篇
内科学   2014篇
皮肤病学   233篇
神经病学   1987篇
特种医学   399篇
外国民族医学   5篇
外科学   948篇
综合类   5039篇
现状与发展   4篇
一般理论   1篇
预防医学   1379篇
眼科学   210篇
药学   2924篇
  3篇
中国医学   1289篇
肿瘤学   1056篇
  2023年   217篇
  2022年   381篇
  2021年   586篇
  2020年   510篇
  2019年   516篇
  2018年   505篇
  2017年   625篇
  2016年   638篇
  2015年   769篇
  2014年   1273篇
  2013年   1519篇
  2012年   1376篇
  2011年   1560篇
  2010年   1244篇
  2009年   1148篇
  2008年   1216篇
  2007年   1182篇
  2006年   1195篇
  2005年   960篇
  2004年   885篇
  2003年   776篇
  2002年   676篇
  2001年   586篇
  2000年   512篇
  1999年   453篇
  1998年   337篇
  1997年   318篇
  1996年   353篇
  1995年   313篇
  1994年   282篇
  1993年   291篇
  1992年   245篇
  1991年   186篇
  1990年   182篇
  1989年   151篇
  1988年   159篇
  1987年   139篇
  1986年   126篇
  1985年   171篇
  1984年   164篇
  1983年   72篇
  1982年   129篇
  1981年   129篇
  1980年   86篇
  1979年   64篇
  1978年   57篇
  1977年   45篇
  1976年   43篇
  1975年   30篇
  1970年   27篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
《Pancreatology》2022,22(7):880-886
BackgroundPremature intracellular trypsinogen activation has long been considered a key initiator of acute pancreatitis (AP). Cathepsin B (CTSB) activates trypsinogen, while cathepsin L (CTSL) inactivates trypsin(ogen), and both proteins play a role in the onset of AP.MethodsAP was induced by 7 hourly intraperitoneal injections of cerulein (50 μg/kg) in wild-type and pancreas-specific conditional Ctsb knockout (CtsbΔpan), Ctsl knockout (CtslΔpan), and Ctsb;Ctsl double-knockout (CtsbΔpan;CtslΔpan) mice. Pancreatic samples were collected and analyzed by histology, immunohistochemistry, real-time PCR, and immunoblots. Trypsin activity was measured in pancreatic homogenates. Peripheral blood was collected, and serum amylase activity was measured.ResultsDouble deletion of Ctsb and Cstl did not affect pancreatic development or mouse growth. After 7 times cerulein injections, double Ctsb and Ctsl deficiency in mouse pancreases increased trypsin activity to the same extent as that in Ctsl-deficient mice, while Ctsb deficiency decreased trypsin activity but did not affect the severity of AP. CtsbΔpan;CtslΔpan mice had comparable serum amylase activity and histopathological changes and displayed similar levels of proinflammatory cytokines, apoptosis, and autophagy activity compared with wild-type, CtsbΔpan, and CtslΔpan mice.ConclusionDouble deletion of Ctsb and Ctsl in the mouse pancreas altered intrapancreatic trypsin activity but did not affect disease severity and inflammatory response after cerulein-induced AP.  相似文献   
3.
4.
目的研究新生儿肺炎(NP)患儿血清高敏C反应蛋白(hs-CRP)、降钙素原(PCT)、白细胞介素-6(IL-6)水平表达及其意义。方法选取2017年1月-2018年2月韶关市曲江区妇幼保健计划生育服务中心诊治的NP患儿80例,按细菌感染情况分为观察1组和观察2组,各40例。选择同期40例健康新生儿作为对照组。测定并比较三组的hs-CRP、PCT和IL-6水平。结果观察1组血清PCT、hs-CRP和IL-6水平明显高于观察2组和对照组,差异均有统计学意义(P<0.05)。观察1组血清PCT、hs-CRP和1L-6检测阳性率明显高于观察2组和对照组,差异均有统计学意义(P<0.05),且观察1组血清PCT、hs-CRP和1L-6诊断NP的敏感度均明显高于观察2组,差异均有统计学意义(P<0.05);观察组各指标特异度与观察2组比较差异无统计学意义(P>0.05)。结论血清hs-CRP、PCT、IL-6水平可作为NP患儿的辅助鉴别指标,为抗生素的合理使用和疗效提供依据。  相似文献   
5.
ObjectivesThis study aimed to determine the effect of lower leg compression during cesarean section (CS) on post-spinal hypotension (PSH) and neonatal hemodynamic parameters.MethodsThis study is a nonrandomized controlled clinical trial conducted in the cesarean delivery unit of the National Medical institute, Damanhour, Egypt. The sample included 120 parturients (60 intervention and 60 control). The researchers developed three tools for data collection: sociodemographic data and reproductive history interview schedule, electronic monitoring of maternal hemodynamic parameters, and neonatal hemodynamic assessment sheet. All parturients received ordinary pre-operative care. For the intervention group, a long elastic stocking (ordinary pressure 20–30 mmHg, 1 mmHg = 0.133 kPa) was applied on both legs during cesarean section. The control group received the same care without the elastic stocking.ResultsSystolic blood pressure, diastolic blood pressure, and mean arterial blood pressure were significantly higher in the intervention group throughout the entire operation period except in the last 5–15 min. Heart rate was significantly lower in the intervention group. Only 13.3% of the intervention group took ephedrine compared with 45% of the control group. Apgar score was higher among neonates of intervention group compared with the control group at 1 min. Neonatal acidosis was significantly higher in the control group than in the contral group.ConclusionLower leg compression technique can effectively reduce PSH and neonatal acidosis.  相似文献   
6.
《Immunity》2022,55(8):1343-1353
  相似文献   
7.
Aeromonas species can cause gastroenteritis, soft tissue infections, hepatobiliary tract and other infections. While most reported soft tissue infections have been attributed to Aeromonas hydrophila, we report a case of necrotizing fasciitis caused by Aeromonas veronii biovar sobria. Prompt and accurate diagnosis cum treatment could help save children with Aeromonas soft tissue infections from developing a bacteremia with extended morbidity and mortality.  相似文献   
8.
9.
10.
The primary aim of this study was to evaluate the accuracy of sonographic estimation of fetal weight when performed at due date by first-line sonographers. This was a prospective study including 500 singleton pregnancies. Ultrasound examinations were performed by residents on delivery day. Estimated fetal weights (EFWs) were calculated and compared with the corresponding birth weights. The median absolute difference between EFW and birth weight was 200 g (100–330). This difference was within ±10% in 75.2% of the cases. The median absolute percentage error was 5.53% (2.70%–10.03%). Linear regression analysis revealed a good correlation between EFW and birth weight (r = 0.79, p < 0.0001). According to Bland–Altman analysis, bias was −85.06 g (95% limits of agreement: −663.33 to 494.21). In conclusion, EFWs calculated by residents were as accurate as those calculated by experienced sonographers. Nevertheless, predictive performance remains limited, with a low sensitivity in the diagnosis of macrosomia.  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