全文获取类型
收费全文 | 3494篇 |
免费 | 275篇 |
国内免费 | 46篇 |
专业分类
耳鼻咽喉 | 11篇 |
儿科学 | 170篇 |
妇产科学 | 55篇 |
基础医学 | 391篇 |
口腔科学 | 119篇 |
临床医学 | 423篇 |
内科学 | 998篇 |
皮肤病学 | 38篇 |
神经病学 | 217篇 |
特种医学 | 307篇 |
外科学 | 396篇 |
综合类 | 45篇 |
预防医学 | 247篇 |
眼科学 | 28篇 |
药学 | 177篇 |
中国医学 | 8篇 |
肿瘤学 | 185篇 |
出版年
2023年 | 18篇 |
2022年 | 31篇 |
2021年 | 79篇 |
2020年 | 45篇 |
2019年 | 84篇 |
2018年 | 99篇 |
2017年 | 61篇 |
2016年 | 64篇 |
2015年 | 77篇 |
2014年 | 119篇 |
2013年 | 152篇 |
2012年 | 197篇 |
2011年 | 234篇 |
2010年 | 152篇 |
2009年 | 127篇 |
2008年 | 187篇 |
2007年 | 227篇 |
2006年 | 177篇 |
2005年 | 174篇 |
2004年 | 151篇 |
2003年 | 141篇 |
2002年 | 141篇 |
2001年 | 38篇 |
2000年 | 23篇 |
1999年 | 33篇 |
1998年 | 91篇 |
1997年 | 105篇 |
1996年 | 96篇 |
1995年 | 56篇 |
1994年 | 47篇 |
1993年 | 57篇 |
1992年 | 30篇 |
1991年 | 20篇 |
1990年 | 29篇 |
1989年 | 47篇 |
1988年 | 46篇 |
1987年 | 41篇 |
1986年 | 44篇 |
1985年 | 39篇 |
1984年 | 17篇 |
1983年 | 20篇 |
1982年 | 24篇 |
1981年 | 19篇 |
1980年 | 26篇 |
1979年 | 11篇 |
1978年 | 12篇 |
1977年 | 17篇 |
1976年 | 16篇 |
1975年 | 14篇 |
1968年 | 6篇 |
排序方式: 共有3815条查询结果,搜索用时 46 毫秒
11.
12.
Ten thrombocytopenic patients (platelets < 10–24 × 10(9)/L) who were refractory to platelet transfusion were investigated for their responsiveness to staphylococcal protein A column therapy. Nine patients had previously been treated with steroids, intravenous immune globulin, and/or other forms of immunosuppressive therapy without improvement in their transfusion response. All patients were receiving multiple platelet transfusions without achieving 1-hour corrected count increments (CCIs) > or = 7500. Eight patients had antibodies that reacted with platelets and were directed against HLA class I antigens, ABO antigens, and/or platelet-specific alloantigens. Plasma (500-2000 mL) from each patient was passed over a protein A silica gel column and then returned to the patient. Patients received from 1 to 14 treatments. A positive response to protein A therapy was defined as at least a doubling of the pretreatment platelet count and/or two successive 10- to 120-minute posttransfusion CCIs > or = 7500. Following plasma treatments, 6 of 10 patients responded with daily platelet counts that averaged 48 +/− 11 × 10(9) per L as compared with counts of 16 +/− 7 × 10(9) per L (p < 0.0005) before treatment. Posttransfusion CCI values determined in four of these patients averaged 2480 +/− 810 and 10,010 +/− 3540 (p < 0.005) before and after treatment, respectively. In contrast, among the four unresponsive patients, platelet counts averaged 10 +/− 9 and 13 +/− 10 × 10(9) per L (p = NS), respectively, while posttransfusion CCIs were 700 +/− 1410 and 1520 +/− 2460 (p = NS), respectively.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
13.
目的 探索LDH实验检测细胞活力的可行性。方法 原代培养骨髓细胞和软骨细胞,用LDH实验测定上述两组细胞的活力,并与镜下活体观察到细胞的生长状况相比较。与目前比较成熟的测定细胞活力的MTS实验的测得的值相比较。结果 LDH实验对上述两组细胞的活力的测定结果与镜下活体观察到的结果相符合。与MTS实验的测得的结果经统计学处理无显著差异。结论 LDH实验可用于细胞活力的直接测定,而对活细胞的生存、繁殖无影响。 相似文献
14.
J Thompson Sullebarger Humberto Coto Enrique Lopez Dany Sayad Hector L Fontanet 《Catheterization and cardiovascular interventions》2003,59(2):261-265
Percutaneous transvenous mitral commissurotomy was performed successfully via the transjugular approach in a patient with severe rheumatic mitral stenosis and obstruction of the inferior vena cava due to prior liver transplantation. This case demonstrates the advantage of the jugular approach in patients with difficult anatomy. 相似文献
15.
A comprehensive anatomic and radiographic analysis of the peribursal fat plane in 12 cadavers confirmed that the fat plane seen on radiographs represents extrasynovial fat lining the subacromial bursa and documented the anatomic relations of the bursa. A three-part retrospective clinical evaluation of rotator cuff tears, calcific tendinitis, and rheumatoid arthritis was performed. Two osteoradiologists blindly graded the appearance of the peribursal fat plane with the shoulder in external versus internal rotation in 21 patients with arthrographically intact rotator cuffs and 21 patients with disrupted rotator cuffs. The peribursal fat plane was seen better with disrupted rotator cuffs. The peribursal fat plane was seen better with the shoulder in internal rotation and was seen in 60% of control subjects but only 21% of patients with rotator cuff tears. Partial or complete obliteration of this fat plane is a sensitive (79%) but less specific (60%) indicator of rotator cuff tears. Obliteration of the peribursal fat plane by inflammatory processes in adjacent tissues, including calcific tendinitis and rheumatoid arthritis, occurred with a high frequency. 相似文献
16.
17.
Dr. Ronald L. Bauer MD Michael L. Palmer MD Andrea M. Bauer MSN RN CS Hector R. Nava MD Harold O. Douglass Jr. MD 《Annals of surgical oncology》1994,1(3):183-188
Background: The purpose of this study was to evaluate the tumor characteristics and treatment associated with an improved overall survival in patients with adenocarcinoma of the small intestine.
Methods: The records of all patients with primary adenocarcinoma of the small bowel seen between January 1971 and December 1991 were reviewed retrospectively. The study comprised 38 patients, 22 (58%) with duodenal tumors, 11 (29%) with jejunal tumors, and five (13%) with ileal tumors.
Results: Although not statistically significant, the patients with duodenal adenocarcinoma lived longer than the patients with jejunal or ileal lesions (p=0.77). The overall survival was 23% and seemed to correlate best with absence of lymph node metastases (p=0.04) and pancreaticoduodenectomy for localized duodenal tumors (p=0.04). The patient's age, duration of symptoms, disease-free interval, tumor location, type of recurrence, and histologic grade did not significantly influence survival.
Conclusions: The lethality of small-intestinal adenocarcinoma appears to be related to a delay in diagnosis and treatment. When a definitive surgical procedure is performed before lymph node metastases appear, the patient's chance for long-term survival is greatly improved.Presented at the 46th Annual Cancer Symposium of The Society of Surgical Oncology, Los Angeles, California, March 18–21, 1993. 相似文献
18.
Jean-Marie Boeynaems Anne De Leener Barbara Dessars Hector Rodriguez Villa-Lobos Jean-Claude Aubry Frédéric Cotton Philippe Thiry 《Clinical chemistry and laboratory medicine》2004,42(1):67-71
Polyethylene terephthalate (PET) tubes have several advantages over glass tubes: they are unbreakable, lighter and more easily disposed of. Despite a steady increase in their use and an expansion of the range of available tubes, few studies validating their use have been published in the literature. This paper describes the various studies that have been performed to compare VENOJECT glass, VENOSAFE PET and VENOSAFE PET/heparin tubes for the assay of a panel of analytes in routine clinical chemistry, immunochemistry, hormone and tumor marker analysis and trace metal determination. These studies demonstrate that VENOSAFE PET tubes are a suitable alternative to glass tubes. 相似文献
19.
Catherine E Milch David M Kent Robin Ruthazer J Hector Pope Thomas P Aufderheide Robert A McNutt Harry P Selker 《Journal of investigative medicine》2006,54(2):76-85
BACKGROUND: Many studies have shown differences in cardiac care by racial/ethnic groups without accounting for institutional factors at the location of care. OBJECTIVE: Exploratory analysis of the effect of hospital funding status (public vs private) on emergency department (ED) triage decision making for patients with symptoms suggestive of acute coronary syndromes (ACSs) and on the likelihood of ED discharge for patients with confirmed ACS. STUDY DESIGN AND SETTING: Secondary analysis of data from a randomized controlled trial of 10,659 ED patients with possible ACS in five urban academic public and five private hospitals. The main outcome measures were the sensitivity and specificity of hospital admission for the presence of ACS at public and private hospitals and the adjusted odds of a patient with ACS not being hospitalized at public versus private hospitals. RESULTS: Of 10,659 ED patients, 1,856 had confirmed ACS. For patients with suspected ACS, triage decisions at private hospitals were considerably more sensitive (99 vs 96%; p<.001) but less specific (30 vs 48%; p<.001) than at public hospitals. The difference between hospital types persisted after adjustment for multiple patient-level and hospital-level characteristics. CONCLUSION: Significant differences in triage for patients with suspected ACS exist between public and private hospital EDs, even after adjustment for multiple patient demographic, clinical, and institutional factors. Further studies are needed to clarify the causes of the differences. 相似文献
20.
Hector Rodriguez-Luna Hugo E. Vargas Adyr Moss Kunam S. Reddy Richard B. Freeman David Mulligan 《American journal of transplantation》2005,5(9):2244-2247
The Model for End-Stage Liver Disease (MELD) is used to assign priority for liver transplantation candidates. The Organ Procurement and Transplantation Network (OPTN) approved recognized exceptional diagnoses (RED's) for which MELD fails to accurately measure priority. Centers can request increased MELD points in cases not recognized by this policy (non-RED's). Our aim was to compare regional practices to justify non-RED requests for MELD adjustments. The UNOS/OPTN database was queried to extract all adult cases for which a non-RED MELD adjustment was requested from 2/27/02 until 8/27/03. The data were stratified by region and justification. Data for 29,510 listings were available. 26,947 had complete diagnosis information. There were 827 non-RED requests of which 477 (57.7%) petitions were approved by the regional review boards (RRBs). The approval rate varied significantly among regions (range: 28-75%, p<0.0001). The most common non-RED's were complications of portal hypertension (48%). The percentage of patients listed with non-RED's varied significantly among regions (0.7-8.3 %, p<0.0001), as did the proportion of patients transplanted with non-RED's (2.1-31.9%, p<0.0001). Demographics did not differ among regions requesting non-REDs.Widespread regional variations exist in the handling of requests for non-REDs. These variations point to the need for reform to standard exception criteria. 相似文献