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   147562篇
  免费   6178篇
  国内免费   428篇
耳鼻咽喉   2259篇
儿科学   4562篇
妇产科学   3075篇
基础医学   19569篇
口腔科学   4918篇
临床医学   9193篇
内科学   36731篇
皮肤病学   4258篇
神经病学   11922篇
特种医学   3812篇
外国民族医学   2篇
外科学   19129篇
综合类   738篇
一般理论   45篇
预防医学   13264篇
眼科学   3079篇
药学   9890篇
中国医学   658篇
肿瘤学   7064篇
  2023年   958篇
  2022年   902篇
  2021年   3236篇
  2020年   1660篇
  2019年   3385篇
  2018年   5631篇
  2017年   3359篇
  2016年   3202篇
  2015年   3585篇
  2014年   4217篇
  2013年   6149篇
  2012年   10724篇
  2011年   11326篇
  2010年   5823篇
  2009年   4219篇
  2008年   9134篇
  2007年   9672篇
  2006年   8994篇
  2005年   8834篇
  2004年   7834篇
  2003年   7315篇
  2002年   6937篇
  2001年   3945篇
  2000年   4541篇
  1999年   3445篇
  1998年   674篇
  1997年   463篇
  1996年   446篇
  1995年   385篇
  1994年   293篇
  1993年   276篇
  1992年   1329篇
  1991年   1105篇
  1990年   1005篇
  1989年   819篇
  1988年   697篇
  1987年   657篇
  1986年   678篇
  1985年   567篇
  1984年   445篇
  1983年   345篇
  1979年   361篇
  1975年   287篇
  1974年   326篇
  1973年   375篇
  1972年   315篇
  1971年   327篇
  1970年   307篇
  1969年   302篇
  1968年   276篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
961.
IntroductionTo analyse the influence of socioeconomic status on the clinical profile of patients undergoing non-traumatic lower-limb amputation.MethodsRetrospective study of 697 lower-limb amputee patients in an Angiology and Vascular Surgery Department during a 5-year period. Patients were classified according to their socioeconomic status (low, medium and high). We analysed demographic (age and gender) and clinical variables (cause of amputation, comorbidity, cardiovascular risk factors and amputation level).ResultsMean age was 70.5 ± 11.9 years, and the median was 72 years. The low socioeconomic status group presented a higher frequency of amputations in men. Cardiovascular risks factors were more frequent in this socioeconomic group, and the difference was statistically significant for diabetes (85.8% low, 69.3% medium, 65% high; P<.01) and obesity (31.4% low, 22.6% medium, 12.5% high, P<.01). Diabetic retinopathy was the only comorbidity with a significant association with low socioeconomic status (21.1% low, 15.3% medium, 12.5% high, P<.03). Regarding the cause for amputation, there was no difference in terms of socioeconomic status. The low socioeconomic level showed a higher frequency of major amputation, which was a significant difference (63.6% low, 41.2% medium, 55% high, P<.04) and a higher predisposition for this amputation level.ConclusionsThe low socioeconomic status has been shown to determine an unfavourable vascular risk profile in lower-limb non-traumatic amputees and a higher predisposition of a major amputation. This socioeconomic level demonstrates a negative influence on these patients’ diabetes, obesity and diabetic retinopathy.  相似文献   
962.
963.
IntroductionThe number of citations is considered as an indirect indicator of the merit of an article, journal or researcher, although it is not an infallible method to determine scientific quality. Our goal is to determine the characteristics of the articles most cited about pancreas and laparoscopy.MethodsWe performed a search of all articles published in any journal about pancreas and laparoscopy until September 2019 and selected the 100 most cited papers. We recorded number of citations, journal, year of publication, quartil, impact factor, institution, country, authors type of paper, type of surgery, topic and area.ResultsThe top 100 citations account 10,970 citations in total. The journal with the most articles is Surgical Endoscopy and 2007 is the year with the highest number of articles in the top 100 citations. The percentage of publications from America and Europe are similar.Case series is the most frequently paper, outcomes/morbidity is the most frequently discussed topic, and distal pancreatectomy is the most frequently type of surgery.ConclusionsThis bibliometric study on pancreas and laparoscopy is conditioned by the time factor, since laparoscopy has arrived later at pancreatic surgery, probably due to the morbidity and mortality associated with pancreatic surgery and the need for a high specialization in this field. The literature is recent and scarce. More and better-quality studies are needed in this field.  相似文献   
964.
965.
966.
Antibiotic prophylaxis in surgery is one of the most effective measures for preventing surgical site infection, although its use is frequently inadequate and may even increase the risk of infection, toxicities and antimicrobial resistance. As a result of advances in surgical techniques and the emergence of multidrug-resistant organisms, the current guidelines for prophylaxis need to be revised.The Sociedad Española de Enfermedades Infecciosas (Spanish Society of Infectious Diseases and Clinical Microbiology) (SEIMC) together with the Asociación Española de Cirujanos (Spanish Association of Surgeons) (AEC) have revised and updated the recommendations for antibiotic prophylaxis in surgery to adapt them to any type of surgical intervention and to current epidemiology. This document gathers together the recommendations on antimicrobial prophylaxis in the various procedures, with doses, duration, prophylaxis in special patient groups, and in epidemiological settings of multidrug resistance to facilitate standardized management and the safe, effective and rational use of antibiotics in elective surgery.  相似文献   
967.
Enhanced Recovery After Surgery (ERAS) constitutes the application of a series of perioperative measures based on the evidence, in order to achieve a better recovery of the patient and a decrease of the complications and the mortality. These ERAS programs initially proved their advantages in the field of colorectal surgery being progressively adopted by other surgical areas within the general surgery and other surgical specialties. The main excluding factor for the application of such programs has been the urgent clinical presentation, which has caused that despite the large volume of existing literature on ERAS in elective surgery, there are few studies that have investigated the effectiveness of these programs in surgical patients in emergencies. The aim of this article is to show ERAS measures currently available according to the existing evidence for emergency surgery.  相似文献   
968.
BackgroundTo analyze whether clinical and analytical parameters differ according to histopathology in cases of acute appendicitis (AA).MethodsThis is a retrospective, observational study including patients (>14 years of age) admitted for suspicion of AA from 1 April 2014 to 31 July 2016. Histopathology was divided into complicated (including perforated and gangrenous AA) and uncomplicated appendicitis (phlegmonous). Sex, age, temperature of patients on admission to the Emergency Department, symptom duration, preoperative white blood cell (WBC) count, neutrophil percentage, mean platelet volume (MPV), platelet distribution width (PDW), C-reactive protein (CRP) and hospital stay were compared in the two groups.ResultsThree hundred and thirty-five patients were analyzed, and 284 were included. Appendicitis was uncomplicated in 194 (68.3%) and complicated in 90 (31.7%). Age, symptom duration, neutrophil percentage, CRP and hospital stay were higher in the complicated AA group (P < .05). The mean differences between uncomplicated and complicated AA were: age 13.2 years (95% CI: 8.2-18.2), symptom duration 14.1 hours (95% CI: 6.3-21.9), neutrophil percentage 5.0% (95% CI: 3.2-6.8), CRP 73.6 mg/l (95% CI: 50.0-97.2) and hospital stay 2.2 days (95% CI: 1.4-3.0), with p<0.05 for all these variables. A model based on the preoperative parameters (age, symptom duration, neutrophil percentage and CRP) was calculated to predict the likelihood of complicated AA. The receiver operating characteristic (ROC) of the model had an area under the curve of 0.80 (95% CI 0.75-0.85).ConclusionThis model is able to diagnose complicated AA without the need for imaging techniques, although it must be validated with prospective analysis.  相似文献   
969.
970.
IntroductionThere is controversy regarding the ideal pancreaticojejunostomy technique after pancreaticoduodenectomy. Many authors consider the external Wirsung stenting technique to be associated with a low incidence of fistula, morbidity and mortality. We analyse our experience with this technique.Patients and methodsA retrospective analysis of the morbidity and mortality of a series of 80 consecutive patients who had been treated surgically over a 6.5-year period for pancreatic head or periampullary tumors, performing pancreaticoduodenectomy and pancreaticojejunostomy with external Wirsung duct stenting.ResultsMean patient age was 68.3 ± 9 years, and the resectability rate was 78%. The texture of the pancreas was soft in 51.2% of patients and hard in 48.8%. Pylorus-preserving resection was performed in 43.8%. Adenocarcinoma was the most frequent tumor (68.8%), and R0 was confirmed in 70% of patients. Biochemical fistula was observed in 11.2%, pancreatic fistula grade B in 12.5% and C in 2.5%, whereas the abdominal reoperation rate was 10%. Median postoperative hospital stay was 16 days, and postoperative and 90-day mortality was 2.5%. Delayed gastric emptying was observed in 36.3% of patients, de novo diabetes in 12.5%, and exocrine insufficiency in 3. Patient survival rates after 1, 3 and 5 years were 80.2, 53.6 and 19.2%, respectively.ConclusionsAlthough our low rates of postoperative complications and mortality using external Wirsung duct stenting coincides with other more numerous recent series, it is necessary to perform a comparative analysis with other techniques, including more cases, to choose the best reconstruction technique after pancreaticoduodenectomy.  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