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   2407394篇
  免费   200680篇
  国内免费   7936篇
耳鼻咽喉   34770篇
儿科学   72922篇
妇产科学   63353篇
基础医学   337425篇
口腔科学   68487篇
临床医学   219934篇
内科学   469462篇
皮肤病学   48433篇
神经病学   201333篇
特种医学   97526篇
外国民族医学   927篇
外科学   364377篇
综合类   66484篇
一般理论   990篇
预防医学   192665篇
眼科学   56824篇
药学   182695篇
  47篇
中国医学   7673篇
肿瘤学   129683篇
  2018年   25399篇
  2017年   20285篇
  2016年   21669篇
  2015年   25569篇
  2014年   36563篇
  2013年   53445篇
  2012年   72597篇
  2011年   76594篇
  2010年   45500篇
  2009年   43309篇
  2008年   71658篇
  2007年   76010篇
  2006年   76892篇
  2005年   74858篇
  2004年   71369篇
  2003年   68861篇
  2002年   67724篇
  2001年   113515篇
  2000年   117387篇
  1999年   98883篇
  1998年   26980篇
  1997年   24585篇
  1996年   24334篇
  1995年   25087篇
  1994年   23557篇
  1993年   21735篇
  1992年   79564篇
  1991年   76645篇
  1990年   73765篇
  1989年   70982篇
  1988年   65946篇
  1987年   64889篇
  1986年   61390篇
  1985年   58450篇
  1984年   44197篇
  1983年   37567篇
  1982年   22808篇
  1981年   20250篇
  1979年   41240篇
  1978年   28904篇
  1977年   24225篇
  1976年   22684篇
  1975年   23855篇
  1974年   29532篇
  1973年   27961篇
  1972年   26166篇
  1971年   24110篇
  1970年   22704篇
  1969年   21041篇
  1968年   19093篇
排序方式: 共有10000条查询结果,搜索用时 17 毫秒
1.
2.
3.
Modified-release opioids are often prescribed for the management of moderate to severe acute pain following total hip and knee arthroplasty, despite recommendations against their use due to increasing concerns regarding harm. The primary objective of this multicentre study was to examine the impact of modified-release opioid use on the incidence of opioid-related adverse events compared with immediate-release opioid use, among adult inpatients following total hip or knee arthroplasty. Data for total hip and knee arthroplasty inpatients receiving an opioid analgesic for postoperative analgesia during hospitalisation were collected from electronic medical records of three tertiary metropolitan hospitals in Australia. The primary outcome was the incidence of opioid-related adverse events during hospital admission. Patients who received modified with or without immediate-release opioids were matched to those receiving immediate-release opioids only (1:1) using nearest neighbour propensity score matching with patient and clinical characteristics as covariates. This included total opioid dose received. In the matched cohorts, patients given modified-release opioids (n = 347) experienced a higher incidence of opioid-related adverse events overall, compared with those given immediate-release opioids only (20.5%, 71/347 vs. 12.7%, 44/347; difference in proportions 7.8% [95%CI 2.3–13.3%]). Modified-release opioid use was associated with an increased risk of harm when used for acute pain during hospitalisation after total hip or knee arthroplasty.  相似文献   
4.
Post-induction hypotension is common and associated with postoperative complications. We hypothesised that pneumatic leg compression reduces post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy. In this double-blind randomised study, patients were allocated randomly to the pneumatic leg compression group (n = 50) or control (n = 50). In the intervention group, pneumatic leg compression was initiated before induction of anaesthesia. In the control group, pneumatic leg compression was initiated 20 min after anaesthesia induction. The primary outcome was the incidence of post-induction hypotension in these groups. Post-induction hypotension was defined as systolic blood pressure < 90 mmHg during the first 20 min after induction. Haemodynamic variables and area under the curve of post-induction systolic blood pressure over time were assessed. Complications associated with pneumatic leg compression were recorded, including: peripheral neuropathy; compartment syndrome; extensive bullae beneath the leg sleeves; and pulmonary thromboembolism. The incidence of post-induction hypotension decreased in the pneumatic leg compression group compared with that in the control group; 5 (10%) vs. 29 (58%), respectively, p < 0.001. In the pneumatic leg compression group, the lowest systolic, diastolic and mean blood pressures 20 min after induction of anaesthesia were significantly greater than the control group. Pneumatic leg compression resulted in an increased area under the curve of systolic blood pressure in the first 20 min after induction, p = 0.001. There were no pneumatic leg compression-related complications. Pneumatic leg compression reduced post-induction hypotension in elderly patients undergoing robot-assisted laparoscopic prostatectomy, suggesting that it is an effective and safe intervention to prevent post-induction hypotension among elderly patients undergoing general anaesthesia.  相似文献   
5.
Journal of Thrombosis and Thrombolysis - The decision by pulmonary embolism response teams (PERTs) to utilize anticoagulation (AC) with or without systemic thrombolysis (ST) or catheter-directed...  相似文献   
6.
7.
Wu  Dan  Chen  Mengya  Chen  Shile  Zhang  Shimin  Chen  Yongheng  Zhao  Qian  Xue  Ke  Xue  Feng  Chen  Xiaosong  Zhou  Min  Li  Hao  Zheng  Jie  Le  Yunchen  Cao  Hua 《Clinical rheumatology》2022,41(10):3107-3117
Clinical Rheumatology - Extrahepatic tryptophan (Trp)-kynurenine (Kyn) metabolism via indoleamine 2,3-dioxygenase 1 (IDO1) induction was found to be associated with intrinsic immune regulation....  相似文献   
8.
梅娟  马新义  张金莲  张正 《安徽医药》2022,26(9):1794-1798
目的探讨乳腺癌组织中基质金属蛋白酶-2(MMP-2)、基质金属蛋白酶-9(MMP-9)表达与人乳头状瘤病毒(HPV)16/18感染的关系及其临床病理意义。方法回顾性选取2015年3月至2018年5月蚌埠医学院第二附属医院收治的90例乳腺癌病人乳腺癌组织为研究对象(乳腺癌组),同时选取同期该院85例良性乳腺疾病切除病变周围正常乳腺组织作为对照(对照组)。实时荧光定量逆转录聚合酶链反应(qRT-PCR)检测组织中MMP-2、MMP-9 mRNA表达水平;免疫组织化学法检测组织中MMP-2、MMP-9蛋白表达;采用原位杂交法检测HPV16/18感染情况。回顾性分析乳腺癌病人临床病理资料,比较MMP-2、MMP-9表达、HPV 感染与病人临床病理特征关系。结果乳腺癌组病人MMP-2、MMP-9 mRNA 表达水平(1.58±0.13、2.14±0.11)及其蛋白阳性表达率(77.78%、80.00%)均显著高于对照组(1.00±0.05、1.02±0.07、27.06%、17.65%)(P<0.05);乳腺癌组HPV16/18-DNA阳性率[71.11%(64/90)]显著高于对照组[12.94%(11/85)](P<0.05);MMP-2、MMP-9表达及HPV16/18阳性表达均与淋巴结转移、临床分期、绝经状态、雌激素受体(ER)阳性相关(P<0.05);MMP-2、MMP-9表达与HPV感染呈正相关(P<0.05)。结论乳腺癌病人乳腺癌组织中MMP-2、MMP-9表达水平明显升高,与HPV16/18感染呈正相关,均与病人临床病理特征密切相关。HPV感染可能引起基质金属蛋白酶表达增高,从而促进乳腺癌的发生发展。  相似文献   
9.
AIM: To identify the predictive factors and laser photocoagulation associated with the use of silicone oil as endotamponade during primary diabetic vitrectomy. METHODS: The medical and surgical records of 690 patients (798 eyes) who underwent primary diabetic vitrectomy at a tertiary eye hospital in China from January 2018 to December 2018 were reviewed in this retrospective cohort study. The patients’ baseline characteristics and preoperative treatments were recorded. The binary Logistic regression model was used to evaluate the risk factors for the use of silicone oil as endotamponade agent during primary vitrectomy for proliferative diabetic retinopathy (PDR)-related complications. RESULTS: Among 690 patients with mean age of 52.1±10.5y (range: 18-85y), 299/690 (43.3%) were female. The 31.6% of the eyes received preoperative laser treatment, and 72.4% of the eyes received preoperative anti-VEGF adjuvant therapy. Non-clearing vitreous haemorrhage (VH) alone or combined with retinal detachment was the main surgical indication (89.5%) for primary vitrectomy. Silicone oil was used as endotamponade in 313 (39.2%) eyes. Lack of preoperative laser treatment [odds ratio (OR) 0.66, 95% confidence interval (CI): 0.48-0.92; P=0.015] and older age (OR 0.96, 95%CI: 0.95-0.98; P<0.001) were predictors of silicone oil tamponade during primary vitrectomy for PDR. CONCLUSION: The lack of preoperative laser treatment is a significant predictor of silicone oil tamponade during primary vitrectomy for PDR. However, the severity of PDR relevant to silicone oil use should be further evaluated.  相似文献   
10.
Inflammopharmacology - The inflammatory process is a biological response of the organism to remove injurious stimuli and initiate homeostasis. It has been recognized as a key player in the most...  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