全文获取类型
收费全文 | 1828篇 |
免费 | 99篇 |
国内免费 | 21篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 66篇 |
妇产科学 | 23篇 |
基础医学 | 204篇 |
口腔科学 | 16篇 |
临床医学 | 132篇 |
内科学 | 305篇 |
皮肤病学 | 21篇 |
神经病学 | 333篇 |
特种医学 | 379篇 |
外科学 | 203篇 |
综合类 | 42篇 |
预防医学 | 46篇 |
眼科学 | 32篇 |
药学 | 77篇 |
中国医学 | 1篇 |
肿瘤学 | 57篇 |
出版年
2023年 | 5篇 |
2022年 | 7篇 |
2021年 | 31篇 |
2020年 | 30篇 |
2019年 | 19篇 |
2018年 | 22篇 |
2017年 | 20篇 |
2016年 | 33篇 |
2015年 | 32篇 |
2014年 | 38篇 |
2013年 | 57篇 |
2012年 | 69篇 |
2011年 | 66篇 |
2010年 | 48篇 |
2009年 | 68篇 |
2008年 | 99篇 |
2007年 | 107篇 |
2006年 | 97篇 |
2005年 | 87篇 |
2004年 | 65篇 |
2003年 | 75篇 |
2002年 | 65篇 |
2001年 | 38篇 |
2000年 | 45篇 |
1999年 | 43篇 |
1998年 | 59篇 |
1997年 | 56篇 |
1996年 | 46篇 |
1995年 | 33篇 |
1994年 | 51篇 |
1993年 | 26篇 |
1992年 | 29篇 |
1991年 | 28篇 |
1990年 | 27篇 |
1989年 | 38篇 |
1988年 | 33篇 |
1987年 | 39篇 |
1986年 | 33篇 |
1985年 | 21篇 |
1984年 | 25篇 |
1983年 | 21篇 |
1982年 | 15篇 |
1981年 | 27篇 |
1980年 | 9篇 |
1979年 | 12篇 |
1978年 | 12篇 |
1977年 | 12篇 |
1976年 | 13篇 |
1975年 | 14篇 |
1965年 | 1篇 |
排序方式: 共有1948条查询结果,搜索用时 187 毫秒
921.
922.
Niels A van der Gaag Steve MM de Castro Erik AJ Rauws Marco J Bruno Casper HJ van Eijck Ernst J Kuipers Josephus JGM Gerritsen Jan-Paul Rutten Jan Willem Greve Erik J Hesselink Jean HG Klinkenbijl Inne HM Borel Rinkes Djamila Boerma Bert A Bonsing Cees J van Laarhoven Frank JGM Kubben Erwin van der Harst Meindert N Sosef Koop Bosscha Ignace HJT de Hingh Laurens Th de Wit Otto M van Delden Olivier RC Busch Thomas M van Gulik Patrick MM Bossuyt Dirk J Gouma 《BMC surgery》2007,7(1):3
Background
Surgery in patients with obstructive jaundice caused by a periampullary (pancreas, papilla, distal bile duct) tumor is associated with a higher risk of postoperative complications than in non-jaundiced patients. Preoperative biliary drainage was introduced in an attempt to improve the general condition and thus reduce postoperative morbidity and mortality. Early studies showed a reduction in morbidity. However, more recently the focus has shifted towards the negative effects of drainage, such as an increase of infectious complications. Whether biliary drainage should always be performed in jaundiced patients remains controversial. The randomized controlled multicenter DROP-trial (DRainage vs. Operation) was conceived to compare the outcome of a 'preoperative biliary drainage strategy' (standard strategy) with that of an 'early-surgery' strategy, with respect to the incidence of severe complications (primary-outcome measure), hospital stay, number of invasive diagnostic tests, costs, and quality of life.Methods/design
Patients with obstructive jaundice due to a periampullary tumor, eligible for exploration after staging with CT scan, and scheduled to undergo a "curative" resection, will be randomized to either "early surgical treatment" (within one week) or "preoperative biliary drainage" (for 4 weeks) and subsequent surgical treatment (standard treatment). Primary outcome measure is the percentage of severe complications up to 90 days after surgery. The sample size calculation is based on the equivalence design for the primary outcome measure. If equivalence is found, the comparison of the secondary outcomes will be essential in selecting the preferred strategy. Based on a 40% complication rate for early surgical treatment and 48% for preoperative drainage, equivalence is taken to be demonstrated if the percentage of severe complications with early surgical treatment is not more than 10% higher compared to standard treatment: preoperative biliary drainage. Accounting for a 10% dropout, 105 patients are needed in each arm resulting in a study population of 210 (alpha = 0.95, beta = 0.8).Discussion
The DROP-trial is a randomized controlled multicenter trial that will provide evidence whether or not preoperative biliary drainage is to be performed in patients with obstructive jaundice due to a periampullary tumor.923.
The internal diameter of the ureteral access sheath limits the size of stones that can be removed during flexible ureteroscopy. We describe a technique that allows removal of larger stones, which are entrapped and removed en bloc with the access sheath. This new technique was shown to be efficient and safe. 相似文献
924.
Rakesh Gupta Roop Singh RC Siwach SS Sangwan Narender K Magu Rahul Diwan 《Indian Journal of Orthopaedics》2007,41(3):224-229
Background:
Optimized functional results are difficult to achieve following hand injuries. This prospective study was undertaken to evaluate the functional outcome after surgical stabilization of metacarpal and phalangeal fractures.Materials and Methods:
Forty-five fractures of digits of hand in 31 patients were managed by surgical stabilization. Five fractures were fixed with closed reduction and percutaneous Kirschner wire fixation; 10 with external fixator; 26 with open reduction and Kirschner wire fixation; and four with open reduction and plate and screw or screw fixation.Results:
Final evaluation of the patients was done at the end of three months. It was based on total active range of motion for digital functional assessment as suggested by the American Society for surgery of hand. Overall results were excellent to good in 87%. Better total active range of motion (excellent grade) was observed in metacarpal fractures (47%) versus phalanx fractures (31%); closed fractures (57%) versus open fractures (27%); and single digit involvement (55%) versus multiple digits (29%). Excellent total active range of motion was observed with all four plate and screw/ screw fixation technique (100%) and closed reduction and percutaneous kirschner wire fixation (60%). Twenty-two complications were observed in 10 patients with finger stiffness being the most common.Conclusion:
Surgical stabilization of metacarpal and phalangeal fractures of hand seems to give good functional outcome. Closed fractures and fractures with single digit involvement have shown a better grade of total active range of motion. 相似文献925.
926.
Suboptimal processing strategy and working-memory impairments predict abstraction deficit in schizophrenia 总被引:1,自引:0,他引:1
Silver H Goodman C Bilker WB Knoll G Gur R Povar G 《Journal of clinical and experimental neuropsychology》2007,29(8):823-830
We studied the relationship between abstraction and other, more basic, cognitive functions in 78 schizophrenia patients and 57 healthy controls. Patients' performance was impaired compared to that of healthy individuals. Regression analysis showed significant contributions of task latency, spatial working memory, and verbal working memory to abstraction performance. The model explained 56.9% of the variance. The latency contribution included linear and quadratic components indicating optimal strategies for normal abstraction performance. Abnormal (suboptimal) processing strategies and working-memory dysfunctions predict impaired abstraction in schizophrenia. The model presented may enable differentiation between impaired and compensating components in schizophrenia patients with an abstraction deficit. 相似文献
927.
RC Siwach Virender Singh Kadyan SS Sangwan Rajiv Gupta 《Indian Journal of Orthopaedics》2007,41(1):62-66
Aim:
To evaluate the functional and radiological outcome of primary total hip replacement (THR) using modular total hip system at 2-10 years follow-up.Materials and Methods:
The cohort comprised 100 operated cases for total hip replacement using modular hip system, with an average follow-up of 6.02 years ranging from 2-10 years. In 61 cases cemented THR, in 36 cases hybrid and in three cases uncemented THR was done. Harris hip score was used for clinical evaluation. Osteolysis was recorded in three acetabular zones described by DeLee and Charnley and the seven femoral zones described by Gruen et al.Results:
The average age at operation was 52.46±9.58 years. Mean follow-up duration was 6.02 years ranging from 2-10 years. Four patients died due to causes unrelated to surgery. At the last follow-up mean Harris Hip score was 83.5. Radiolucent lines were present in 39(39%) acetabular and 32 (32%) femoral components. Osteolysis was most common in Zone 7 of the femoral and Zone II and III of the acetabular component. Eight hips have been revised, five for aseptic loosening as proved by negative culture at revision and three hips for posttraumatic periprosthetic femoral fracture. One girdle stone resection was done for deep infection. Out of 96 hips available at latest follow-up, 87 primary arthroplasties were intact and functioning well.Conclusion:
The results of our study support the continued use of the modular hip system. The acetabular loosening was more common than femoral in our study. 相似文献928.
Wang P Barrett F Martin E Milonova M Gur RE Gur RC Kohler C Verma R 《Journal of neuroscience methods》2008,168(1):224-238
Deficits in emotional expression are prominent in several neuropsychiatric disorders, including schizophrenia. Available clinical facial expression evaluations provide subjective and qualitative measurements, which are based on static 2D images that do not capture the temporal dynamics and subtleties of expression changes. Therefore, there is a need for automated, objective and quantitative measurements of facial expressions captured using videos. This paper presents a computational framework that creates probabilistic expression profiles for video data and can potentially help to automatically quantify emotional expression differences between patients with neuropsychiatric disorders and healthy controls. Our method automatically detects and tracks facial landmarks in videos, and then extracts geometric features to characterize facial expression changes. To analyze temporal facial expression changes, we employ probabilistic classifiers that analyze facial expressions in individual frames, and then propagate the probabilities throughout the video to capture the temporal characteristics of facial expressions. The applications of our method to healthy controls and case studies of patients with schizophrenia and Asperger's syndrome demonstrate the capability of the video-based expression analysis method in capturing subtleties of facial expression. Such results can pave the way for a video-based method for quantitative analysis of facial expressions in clinical research of disorders that cause affective deficits. 相似文献
929.
Acute kidney injury (AKI) develops mostly in the context of critical illness and multiple organ failure, characterized by alterations in substrate use, insulin resistance, and hypercatabolism. Optimal nutritional support of intensive care unit patients remains a matter of debate, mainly because of a lack of adequately designed clinical trials. Most guidelines are based on expert opinion rather than on solid evidence and are not fundamentally different for critically ill patients with or without AKI. In patients with a functional gastrointestinal tract, enteral nutrition is preferred over parenteral nutrition. The optimal timing of parenteral nutrition in those patients who cannot be fed enterally remains controversial. All nutritional regimens should include tight glycemic control. The recommended energy intake is 20 to 30 kcal/kg per day with a protein intake of 1.2 to 1.5 g/kg per day. Higher protein intakes have been suggested in patients with AKI on continuous renal replacement therapy (CRRT). However, the inadequate design of the trials does not allow firm conclusions. Nutritional support during CRRT should take into account the extracorporeal losses of glucose, amino acids, and micronutrients. Immunonutrients are the subject of intensive investigation but have not been evaluated specifically in patients with AKI. We suggest a protocolized nutritional strategy delivering enteral nutrition whenever possible and providing at least the daily requirements of trace elements and vitamins. 相似文献
930.
Gur M Yilmaz R Demirbag R Yildiz A Ozdogru I Bas MM Polat M 《International journal of clinical practice》2008,62(1):138-142
We aimed to investigate the association between aortic distensibility (AD) and left ventricle myocardial performance index (MPI) in patients with newly diagnosed hypertension (HT). We studied 49 patients with HT and 24 healthy control subjects. AD was calculated from the echocardiographically derived ascending aorta diameters. The MPI was calculated from both conventional flow Doppler echocardiography and tissue Doppler echocardiography recordings. Conventional Doppler E/A and tissue Doppler derived Ea/Aa were determined for all the subjects. Aortic distensibility was lower, and both conventional and tissue Doppler MPI values were higher (p<0.001 for all) in patient group compared with control group. AD was correlated with systolic blood pressure (SBP) (beta=-0.436, p=0.037), Ea/Aa (beta=0.228, p=0.038) and tissue derived MPI (beta=-0.302, p=0.043) in multiple linear regression analysis. Aortic distensibility was independently related to tissue derived MPI and Ea/Aa besides SBP. 相似文献