全文获取类型
收费全文 | 13319篇 |
免费 | 977篇 |
国内免费 | 57篇 |
专业分类
耳鼻咽喉 | 120篇 |
儿科学 | 229篇 |
妇产科学 | 183篇 |
基础医学 | 1829篇 |
口腔科学 | 407篇 |
临床医学 | 1338篇 |
内科学 | 3156篇 |
皮肤病学 | 195篇 |
神经病学 | 1178篇 |
特种医学 | 378篇 |
外科学 | 2016篇 |
综合类 | 124篇 |
一般理论 | 13篇 |
预防医学 | 1205篇 |
眼科学 | 248篇 |
药学 | 873篇 |
中国医学 | 12篇 |
肿瘤学 | 849篇 |
出版年
2023年 | 122篇 |
2022年 | 245篇 |
2021年 | 458篇 |
2020年 | 217篇 |
2019年 | 379篇 |
2018年 | 391篇 |
2017年 | 280篇 |
2016年 | 302篇 |
2015年 | 353篇 |
2014年 | 489篇 |
2013年 | 629篇 |
2012年 | 996篇 |
2011年 | 969篇 |
2010年 | 552篇 |
2009年 | 518篇 |
2008年 | 827篇 |
2007年 | 886篇 |
2006年 | 839篇 |
2005年 | 894篇 |
2004年 | 829篇 |
2003年 | 701篇 |
2002年 | 643篇 |
2001年 | 122篇 |
2000年 | 95篇 |
1999年 | 112篇 |
1998年 | 153篇 |
1997年 | 113篇 |
1996年 | 96篇 |
1995年 | 94篇 |
1994年 | 69篇 |
1993年 | 68篇 |
1992年 | 52篇 |
1991年 | 41篇 |
1990年 | 46篇 |
1989年 | 46篇 |
1988年 | 49篇 |
1987年 | 54篇 |
1986年 | 55篇 |
1985年 | 42篇 |
1984年 | 52篇 |
1983年 | 47篇 |
1982年 | 52篇 |
1981年 | 29篇 |
1980年 | 30篇 |
1979年 | 31篇 |
1978年 | 14篇 |
1977年 | 25篇 |
1976年 | 23篇 |
1973年 | 14篇 |
1970年 | 16篇 |
排序方式: 共有10000条查询结果,搜索用时 11 毫秒
91.
92.
93.
94.
95.
Ethan J. Halpern Jacob P. Deutsch Maria M. Hannaway Adrian T. Estepa Anand S. Kenia Kenneth J. Neuburger David C. Levin 《The American journal of emergency medicine》2013,31(10):1479-1485
ObjectiveThe objective of the study is to evaluate cardiac risk factors and risk scores for prediction of coronary artery disease (CAD) and adverse outcomes in an emergency department (ED) population judged to be at low to intermediate risk for acute coronary syndrome.MethodsInformed consent was obtained from consecutive ED patients who presented with chest pain and were evaluated with coronary computed tomography angiography (cCTA). Cardiac risk factors, clinical presentation, electrocardiogram, and laboratory studies were recorded; the Thrombolysis in Myocardial Infarction (TIMI) and Global Registry of Acute Coronary Events (GRACE) scores were tabulated. Coronary computed tomography angiography findings were rated on a 6-level plaque burden scale and classified for significant CAD (stenosis ≥ 50%). Adverse cardiovascular outcomes were recorded at 30 days.ResultsAmong 250 patients evaluated by cCTA, 143 (57%) had no CAD, 64 (26%) demonstrated minimal plaque (< 30% stenosis), 26 (10%) demonstrated mild plaque (< 50% stenosis), 9 (4%) demonstrated moderate single vessel disease (50%-70% stenosis), 2 (1%) demonstrated moderate multivessel disease, and 6 (2%) demonstrated severe disease (> 70% stenosis). Six patients developed adverse cardiovascular outcomes. Among traditional cardiac risk factors, only age (older) and sex (male) were significant independent predictors of CAD. Correlation with CAD was poor for the TIMI (r = 0.12) and GRACE (r = 0.09-0.23) scores. The TIMI and GRACE scores were not useful to predict adverse outcomes. Coronary computed tomography angiography identified severe CAD in all subjects with adverse outcomes.ConclusionAmong ED patients who present with chest pain judged to be at low to intermediate risk for acute coronary syndrome, traditional risk factors are not useful to stratify risk for CAD and adverse outcomes. Coronary computed tomography angiography is an excellent predictor of CAD and outcome. 相似文献
96.
OBJECTIVE: To communicate results of laparoscopic treatment of pancreatic pseudocyst (PP) and resection of benign lesions of the pancreas. Perioperative data, surgical outcomes, techniques and insights from 54 cases are presented. SUMMARY BACKGROUND DATA: Although laparoscopic therapy for other solid organs has been widely adopted, reports of therapeutic laparoscopy of the pancreas have been few and of limited numbers, and its role in pancreatic disease is still unclear. METHODS: Eighteen men and 11 women were selected for laparoscopic PP surgery. Four distinct laparoscopic approaches were used. An additional 9 men and 16 women underwent laparoscopic distal pancreatectomy (LDP) using a technique similar to the lesser sac approach. RESULTS: Laparoscopic PP surgery was completed successfully in 28 of 29 patients. The overall mean operative time was 2.8 hours and the mean postoperative length of stay was 4.4 days. Of the techniques described, the authors prefer cyst gastrostomy by the lesser sac approach or the minilaparoscopic cystic gastrostomy. LDP was attempted in 25 patients and completed successfully in 23. One underwent a successful hand-assisted enucleation of an insulinoma. In 12 cases the spleen was preserved. Mean operative time was 3.7 hours, and mean postoperative length of stay was 4.1 days. CONCLUSIONS: In the authors' experience, minimally invasive treatment of PP produces good results and avoids difficulties linked with percutaneous drainage or endoscopic internal procedures. However, combining upper endoscopy with intragastric laparoscopic surgery offers advantages of both. LDP compares well to open procedures and often allows preservation of the spleen. 相似文献
97.
Kimball P Wagner B King A Fisher RA Dawson S Cotterell A Posner M 《Clinical transplantation》2002,16(4):290-294
Renal transplant recipients with positive flow cytometric crossmatches (FCXM) face greater risk of early rejection and graft failure. It is clear that the pharmacologic needs of this high risk group have not been identified. We retrospectively compared the impact of two drug regimens upon early rejection and 5 yr actuarial survival among 324 primary cadaveric transplant recipients with positive and negative FCXM. Patients received either Regimen I (OKT3 induction, cyclosporine and steroids) or Regimen II (mycophenolate mofetil with cyclosporine or Prograf). Recipient gender, age, disease etiology, ethnic distribution and cytotoxic panel reactive antibody (PRA) were equivalent between regimens (p=ns). With Regimen I, the incidence of rejection was greater for FCXM positive vs. FCXM negative patients (51 vs. 21%, p=0.001). In contrast, with Regimen II the incidence of rejection for FCXM positive and FCXM negative patients was equivalent (18 vs. 12%, p=ns) and lower than patients treated with Regimen I (p < 0.01). Ethnic variation was only observed with Regimen I in which African Americans with positive FCXM had more rejections than Caucasians (60 vs. 45%, p < 0.05). Five-year actuarial survival was lower for FCXM positive vs. FCXM negative patients treated with Regimen I (40 vs. 75%, p=0.0006) or Regimen 2 (60 vs. 90%, p=0.001). Allograft survival was equivalent (p=ns) among FCXM positive individuals receiving Regimen I or II. However, allograft survival among FCXM negative individuals improved with Regimen II (p < 0.05). Ethnic variation in survival was not observed with either regimen (p=ns). 相似文献
98.
A modified technique for repair of the anomalous origin of the right pulmonary artery from the ascending aorta. 总被引:2,自引:0,他引:2
Edvin Prifti Giacomo Frati Adrian Crucean Vittorio Vanini 《European journal of cardio-thoracic surgery》2002,22(1):148-150
We report a modified technique of right pulmonary artery implantation to the main pulmonary artery with interposition of a tube created from the great arterial wall for an anomalous origin of the right pulmonary artery from the right lateral aspect of the ascending aorta. This technique offers extra autologous tissue length and reduced tension at the anastomotic site. It also offers the possibility to place the anomalous right pulmonary artery anterior to the ascending aorta, avoiding the aortic compression. This technique was employed successfully in a 15-week-old female. 相似文献
99.
Katherine A Hillman Tanya M Johnson Paul J D Winyard Geoffrey Burnstock Robert J Unwin Adrian S Woolf 《Experimental nephrology》2002,10(1):34-42
BACKGROUND: Purinergic receptors are cell-surface molecules that bind extracellular nucleotides, notably ATP. The P2X family includes seven nonselective ion channels with one member, P2X(7), implicated in cytolytic pore formation and cell death. MATERIALS AND METHODS: We sought P2X(7) expression in mouse nephrogenesis and cpk/cpk renal cyst growth, conditions in which both proliferation and apoptosis are prominent. RESULTS: P2X(7) immunolocalized to condensed metanephric mesenchyme: both proliferation and apoptosis were detected in this compartment, assessed by proliferating cell nuclear antigen expression and propidium iodide-stained pyknotic nuclei respectively. Later in nephrogenesis, P2X(7) was detected in collecting ducts, a pattern persisting to maturity. A mesenchymal to epithelial shift of P2X(7) expression was also documented in ureter development. In cpk/cpk kidneys, P2X(7)-expressing collecting duct cysts dominated histology from two weeks until four weeks after birth, when animals die from uremia. In polycystic kidneys pyknotic nuclei were rarely identified in P2X(7)-expressing epithelia, but were detected between cysts, consistent with a non-apoptotic role for P2X(7) in cyst enlargement. CONCLUSION: P2X(7) is expressed during normal nephrogenesis and in a model of congenital polycystic kidney disease. Further experiments are necessary to define possible functions of P2X(7) in these settings. 相似文献
100.
The most widely accepted treatment for comminuted fractures of the radial head is either the excision or open reduction and internal fixation. The purpose of the present study is to evaluate the value of an ‘on-table’ reconstruction technique in severely comminuted fractures of the radial head. In this study, two patients with a Mason type-III and four patients with a Mason type-IV radial-head fracture were treated with ‘on-table’ reconstruction and fixation using low-profile mini-plates. After a mean follow-up of 112 months (47-154 months), the mean elbow motion was 0-6-141° extension flexion with 79° of pronation and 70° of supination. The mean Broberg and Morrey functional rating score was 97.0 points, the Mayo Elbow Performance Index was 99.2 points and the mean Disabilities of the Arm, Shoulder, and Hand (DASH) Outcome Measure score was 1.94 points. One patient had symptoms of degenerative changes, with a slight joint-space narrowing. There were no radiographic signs of devitalisation at final examination. Comminuted fractures of the radial head, which would otherwise require excision, can be successfully treated with an ‘on-table’ reconstruction technique. 相似文献