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   11120篇
  免费   612篇
  国内免费   344篇
耳鼻咽喉   311篇
儿科学   440篇
妇产科学   188篇
基础医学   224篇
口腔科学   310篇
临床医学   1312篇
内科学   1608篇
皮肤病学   43篇
神经病学   691篇
特种医学   978篇
外国民族医学   1篇
外科学   3438篇
综合类   1424篇
预防医学   202篇
眼科学   118篇
药学   363篇
  7篇
中国医学   170篇
肿瘤学   248篇
  2024年   9篇
  2023年   176篇
  2022年   275篇
  2021年   421篇
  2020年   418篇
  2019年   333篇
  2018年   299篇
  2017年   322篇
  2016年   332篇
  2015年   401篇
  2014年   814篇
  2013年   683篇
  2012年   554篇
  2011年   646篇
  2010年   533篇
  2009年   572篇
  2008年   572篇
  2007年   585篇
  2006年   549篇
  2005年   454篇
  2004年   422篇
  2003年   306篇
  2002年   307篇
  2001年   266篇
  2000年   208篇
  1999年   160篇
  1998年   141篇
  1997年   130篇
  1996年   148篇
  1995年   100篇
  1994年   98篇
  1993年   101篇
  1992年   83篇
  1991年   76篇
  1990年   62篇
  1989年   58篇
  1988年   48篇
  1987年   47篇
  1986年   44篇
  1985年   48篇
  1984年   43篇
  1983年   30篇
  1982年   51篇
  1981年   27篇
  1980年   29篇
  1979年   22篇
  1978年   34篇
  1977年   20篇
  1976年   7篇
  1975年   5篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
目的 探讨基于正交试验的肾造瘘管不同固定方案的比较效果。方法 将14Fr硅胶肾造瘘管固定在聚乙烯展板和拉力显示器上,以固定材料、固定方法、面积为3个影响因素,每个因素3个水平,每组进行3次试验再求平均值作为最后拉力值F,共进行9个固定方案共27次试验。利用L9(33)正交试验矩阵研究不同材料(医用橡皮膏、医用透气胶带、医用无纺布胶带)、固定方法(交叉固定法、“工”字固定法和改良“工”字固定法)及面积(16 cm2、24 cm2、32 cm2)对肾造瘘管固定强度的影响。结果 正交试验所选的3种影响因素中,对拉力值影响显著性排序为:材料>方法>面积;3种固定材料中,医用橡皮膏固定强度最大。结论 肾造瘘管固定方案中,最佳固定组合为以医用橡皮膏结合改良“工”字法固定,可为临床管道固定方案的选择提供参考。  相似文献   
2.
A male in his late 50s had been complaining of headaches and dizziness for 25 years. He also had episodes of losing consciousness, but had not sought treatment because of financial hardship. He was found in the ocean. Autopsy revealed foamy liquid leaking from his nose and mouth, and pleural effusions. The trachea and bronchi contained the same foamy liquid. The lungs were swollen and edematous, and leaked a large amount of foamy liquid. His cause of death was diagnosed as drowning. In the brain, the veins on the frontal lobe and the temporal pole, each on the right cerebral hemisphere, were dilated. A vascular lesion measuring 5 × 5 × 8 cm was found on the bottom of the right frontal lobe, and was located between the right middle cerebral artery and those veins. This vascular lesion extended to the brain parenchyma, and the basal ganglia of the right cerebrum was displaced outward and upward. The vascular lesions in the brain showed blood vessels of various sizes and shapes, and some of the vessel walls were thickened. The vascular lesion on the right frontal lobe was diagnosed as an arteriovenous malformation (AVM). According to the police investigation, the harbor where his body was found was a place he often came for fishing and walking. The possibility of suicide cannot be ruled out. Moreover, it was considered that his AVM might have rendered him unconscious, causing him to fall into the ocean.  相似文献   
3.
BACKGROUND Surgery for gastric cancer is a complex procedure and lymphadenectomy is often mandatory.Postoperative mortality and morbidity after curative gastric cancer surgery is not insignificant.AIM To evaluate the factors determining mortality and morbidity in a population of patients undergoing R0 resection and D2 lymphadenectomy for gastric cancer.METHODS A retrospective analysis of clinical data and pathological characteristics(age,sex,primary site of the tumor,Lauren histotype,number of positive lymph nodes resected,number of negative lymph nodes resected,and depth of invasion as defined by the standard nomenclature)was conducted in patients with gastric cancer.For each patient we calculated the Kattan’s score.We arbitrarily divided the study population of patients into two groups based on the nomogram score(<100 points or≥100 points).Prespecified subgroups in these analyses were defined according to age(≤65 years or>65 years),and number of lymph nodes retrieved(≤35 lymph nodes or>35 lymph nodes).Uni-and multivariate analysis of clinical and pathological findings were performed to identify the factors affecting postoperative mortality and morbidity.RESULTS One-hundred and eighty-six patients underwent a curative R0 resection with D2 lymphadenectomy.Perioperative mortality rate was 3.8%(7 patients);a higher mortality rate was observed in patients aged>65 years(P=0.002)and in N+patients(P=0.04).Following univariate analysis,mortality was related to a Kattan’s score≥100 points(P=0.04)and the presence of advanced gastric cancer(P=0.03).Morbidity rate was 21.0%(40 patients).Surgical complications were observed in 17 patients(9.1%).A higher incidence of morbidity was observed in patients where more than 35 lymph nodes were harvested(P=0.0005).CONCLUSION Mortality and morbidity rate are higher in N+and advanced gastric cancer patients.The removal of more than 35 lymph nodes does not lead to an increase in mortality.  相似文献   
4.
5.
BackgroundChyle leak (CL) is a clinically relevant complication after pancreatectomy. Its incidence and the associated risk factors are ill defined, and various treatments options have been described. There is no consensus, however, regarding optimal management. The present study aims to systematically review the literature on CL after pancreatectomy.MethodsA systematic review from PubMed, Scopus and Embase database was performed. Studies using a clear definition for CL and published from January 2000 to January 2021 were included. The PRISMA guidelines were followed during all stages of this systematic review. The MINORS score was used to assess methodological quality.ResultsLiterature search found 361 reports, 99 of which were duplicates. The titles and abstracts of 262 articles were finally screened. The references from the remaining 181 articles were manually assessed. After the exclusions, 43 articles were thoroughly assessed. A total of 23 articles were ultimately included for this review. The number of patients varied from 54 to 3532. Incidence of post pancreatectomy CL varied from 1.3% to 22.1%. Main risk factors were the extent of the surgery and early oral or enteral feeding. CL dried up spontaneously or after conservative management within 14 days in 53% to 100% of the cases.ConclusionsThe extent of surgery is the most common predictor of risk of CL. Conservative treatment has been shown to be effective in most cases and can be considered the treatment of choice. We propose a management algorithm based on the current available evidence.  相似文献   
6.
BackgroundLeft-sided repair for long gap esophageal atresia (LGEA) has been described for patients with a large leftward upper pouch, no thoracic tracheoesophageal fistula (TEF) nor tracheobronchomalacia (TBM), or as salvage plan after prior failed right-sided repair. We describe our experience with left-sided MIS traction induced growth process.MethodsWe retrospectively reviewed patients who underwent Foker process for LGEA at two institutions between December 2016 and November 2021. Patient characteristics, surgical techniques, and outcomes were reviewed.Results71 patients underwent Foker process. Of 34 MIS cases, 28 patients (82%) underwent left-sided repair (median gap length 5 cm) at median age 4 months with median 3 (range 2–8) operations and median 13.5 (IQR 11–21) days on traction until esophageal anastomosis. 9 patients (32%) underwent completely MIS approach, whereas 5 patients (18%) converted to open at first operation and 14 patients (50%) converted to open later in the traction process. Traction was internal in 68%, external in 11%, and combination in 21%. Median follow-up was 15.4 (IQR 7.5–31.7) months after anastomosis. 14% had anastomotic leak managed with antibiotics and/or esophageal vacuum therapy. Median number of esophageal dilations was 3.5 (range 0–13). 18% required stricture resection. 39% underwent Nissen fundoplication. None have needed esophageal replacement.ConclusionsFor multiple reasons including the tendency of both esophageal pouches to have a leftward bias, less tracheal compression by upper pouch, and clean field of surgery for reoperative cases, we now more commonly use left-sided approach for MIS LGEA repair compared to right side, regardless of left aortic arch.Level of evidenceLevel IV Treatment Study.  相似文献   
7.
《Pancreatology》2022,22(2):270-276
Backgroundand purpose: Zinc is an essential element for human health and plays an important role in metabolic, immunological and other biological processes. The present study was conducted to investigate the association between zinc deficiency (ZD) and the perioperative clinical course in patients with pancreatic ductal adenocarcinoma (PDAC).MethodsOf 216 patients with PDAC who underwent elective pancreatectomy between 2013 and 2017 at our institution, 206 patients with sufficient clinical data were retrospectively reviewed. The perioperative variables were compared and the risk factors associated with infectious complications were identified.ResultsZD was preoperatively present in 36 (17.5%) of 206 patients with PDAC. In the patients of the ZD group, a higher proportion of males, higher preoperative modified Glasgow prognostic scores, a higher neutrophil-to-lymphocyte ratio, and a higher occurrence of postoperative infectious complications after pancreatectomy were observed, compared to the non-ZD group. By a univariate analysis, three risk factors were significantly associated with infectious complications after pancreatectomy: ZD (vs non-ZD: p = 0.002), serum albumin <3.5 g/dl (vs ≥ 3.5 g/dl: p = 0.005), and the procedure of pancreaticoduodenectomy (vs others: p = 0.013). By multivariate logistic regression analysis, the occurrence of infectious complications was significantly associated with ZD (OR 3.430, 95%CI 1.570 to 7.490, p = 0.002) and the procedure of pancreaticoduodenectomy (OR 2.030, 95%CI 1.090 to 3.770, p = 0.025).ConclusionsThe current study newly demonstrated that ZD could serve as a preoperative predictor of infectious complications after pancreatectomies in the patients with PDAC.  相似文献   
8.
目的:探讨三种不同引流方式对食管癌术后颈部吻合口瘘的引流效果。方法:收集从2013年1月到2016年9月在我科行食管癌手术并术后发生颈部吻合口瘘患者,比较入组患者所采用的不同颈部引流方式的优劣。结果:共有83例患者纳入研究,有34例进入A组,行纱布条引流组;28例进入B组,行造瘘袋引流组;21例进入C组,行胃管负压引流组。所有入组患者一般资料和手术资料对比无明显统计学差异(P>0.05)。观察指标对比结果显示,C组患者瘘口愈合时间较其他两组时间短[(15.90±4.18)天vs(14.60±4.41)天vs(9.65±3.80)天],住院时间较其他两组短[(18.10±4.17)天vs(16.20±3.78)天vs(12.30±3.29)天],换药次数较其他两组少[(37.55±8.75)天vs(14.5±3.23)天vs(10.00±2.05)天],抗生素使用时间也较其他组明显减少[(13.10±2.49)天vs(10.85±1.84)天vs(7.20±1.74)天]。结论:颈部放置负压引流有助于食管癌术后颈部吻合口瘘愈合,值得临床推广与进一步研究。  相似文献   
9.
10.
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