全文获取类型
收费全文 | 46218篇 |
免费 | 2353篇 |
国内免费 | 373篇 |
专业分类
耳鼻咽喉 | 487篇 |
儿科学 | 840篇 |
妇产科学 | 1315篇 |
基础医学 | 5595篇 |
口腔科学 | 1744篇 |
临床医学 | 3577篇 |
内科学 | 12928篇 |
皮肤病学 | 971篇 |
神经病学 | 4000篇 |
特种医学 | 1216篇 |
外科学 | 6950篇 |
综合类 | 172篇 |
一般理论 | 9篇 |
预防医学 | 2518篇 |
眼科学 | 740篇 |
药学 | 2559篇 |
中国医学 | 116篇 |
肿瘤学 | 3207篇 |
出版年
2024年 | 40篇 |
2023年 | 326篇 |
2022年 | 792篇 |
2021年 | 1487篇 |
2020年 | 802篇 |
2019年 | 1149篇 |
2018年 | 1578篇 |
2017年 | 1043篇 |
2016年 | 1131篇 |
2015年 | 1327篇 |
2014年 | 1810篇 |
2013年 | 2410篇 |
2012年 | 3705篇 |
2011年 | 3642篇 |
2010年 | 2066篇 |
2009年 | 1785篇 |
2008年 | 3105篇 |
2007年 | 3206篇 |
2006年 | 3005篇 |
2005年 | 2974篇 |
2004年 | 2669篇 |
2003年 | 2396篇 |
2002年 | 2112篇 |
2001年 | 318篇 |
2000年 | 235篇 |
1999年 | 319篇 |
1998年 | 388篇 |
1997年 | 340篇 |
1996年 | 302篇 |
1995年 | 291篇 |
1994年 | 235篇 |
1993年 | 178篇 |
1992年 | 168篇 |
1991年 | 128篇 |
1990年 | 131篇 |
1989年 | 121篇 |
1988年 | 84篇 |
1987年 | 79篇 |
1986年 | 92篇 |
1985年 | 84篇 |
1984年 | 84篇 |
1983年 | 82篇 |
1982年 | 101篇 |
1981年 | 78篇 |
1980年 | 82篇 |
1979年 | 49篇 |
1978年 | 54篇 |
1977年 | 43篇 |
1976年 | 40篇 |
1975年 | 37篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Marco Antonio Palma Rocio Ortiz Carlos Alvarez-Dardet Maria T. Ruiz 《Social science & medicine (1982)》2009
The possible effect of Government Consumption (a component of Gross Domestic Product (GDP)) on attainment of the hunger Millennium Development Goal (MDG1) was analyzed by evaluating the effect of macroeconomic, social, demographic and policy variables on average undernourished population. Eighty-four developing countries with data available on undernourished population were included in an ecological study. Regression models were applied to explore possible determinants of Undernourished between 1990 and 2004 and consequent achievement of the projected 2004 MDG1. In 2004, 1.4% of the overall undernourished population in the studied countries [70.16 million people] was in excess of the projected level required to meet MDG1. The multiple linear regression showed significant associations between Undernourished and poverty levels, the Gini Index, rural population and Government Consumption. The multiple logistic regression showed significant associations between achievement of projected 2004 MDG1 levels and Government Consumption and the Gini Index. The significant associations between Undernourished and Government Consumption suggest that the effects of GDP components on social conditions call for more thorough research and that policymakers such as governments and international financial institutions need to ensure that changes in distributive and redistributive policies do not negatively affect the possibility of achieving MDG1. 相似文献
53.
Antonio E Martin-Ucar Apostolos Nakas John G Edwards David A Waller 《European journal of cardio-thoracic surgery》2007,31(5):765-70; discussion 770-1
OBJECTIVE: To compare the outcomes of extrapleural pneumonectomy (EPP) and radical pleurectomy/decortication (P/D) for N2 malignant pleural mesothelioma (MM). PATIENTS AND METHODS: In a retrospective case-control study we analysed the results of the 57 patients [49 male and 8 female, median age 59 (range 14-70) years] who underwent radical surgery for MM found to have pathological N2 disease over a 7-year-period. EPP was performed on 45 and P/D on 12 patients. Prognostic factors, postoperative course, pathological data and postoperative survival were analysed. RESULTS: Those in the P/D group were significantly older (median age 62 vs 58 years, p=0.03) than in the EPP group. There was no difference in postoperative hospital stay (p=0.1) nor T stage (p=0.7) between the groups. There were no significant differences in the proportion of patients undergoing some adjuvant therapy in each group (p=0.2). Mean survival from diagnosis was 15 months in the EPP group and 16 months for those who underwent P/D (p=0.4). CONCLUSIONS: Preservation of the lung during radical surgery for N2 MM does not compromise survival even in an older group population. We therefore now have ceased to perform EPP in cases of N2 disease and we make every effort to accurately stage patients with mediastinoscopy to identify them. 相似文献
54.
Antonio Gigante Claudia Bevilacqua Andrea Ricevuto Monica Mattioli-Belmonte Francesco Greco 《Knee surgery, sports traumatology, arthroscopy》2007,15(1):88-92
The implantation of chondrocytes, seeded on matrices such as hyaluronic acid or collagen membranes, is a method that is being widely used for the treatment of chondral defects. The aim of the present study was to evaluate the distribution, viability and phenotype expression of the cells seeded on a collagen membrane just at the time of the implantation. Twelve patients who were suffering from articular cartilage lesions were treated by the MACI® procedure. The residual part of each membrane was tested by colorimetric assay (MTT) and histochemical and ultrastructural analyses were carried out. In all of the samples a large number of viable cells, quite homogenously distributed, was detected. The cells expressed the markers of the differentiated hyaline chondrocytes. These data reassure in that the MACI procedure provides a suitable engineered tissue for cartilage repair, in line with the clinical evidences emerging in the literature. 相似文献
55.
Vincenzo Neri Antonio Ambrosi Giuseppe Di Lauro Tiziano Pio Valentino 《JSLS, Journal of the Society of Laparoendoscopic Surgeons》2006,10(1):66-69
OBJECTIVES: The aim of this study was to evaluate the safety and effectiveness of laparoscopic-assisted sigmoid colectomy for diverticulitis and to assess its postoperative advantages. METHODS: From 1999 to 2001, 5 patients were selectively operated on with a laparoscopic-assisted procedure for uncomplicated sigmoid diverticulitis. In the preceding period (September 1997 through December 1998), 4 patients underwent open procedures for the same pathology. The surgical indication with the same criteria was restrictive: at least 2 acute episodes had occurred that were treated with hospital admission and that were separated by an adequate period (2 months) of medical therapy. RESULTS: No conversions of laparoscopy to an open procedure were necessary. Age, sex, weight, morbidity, and mortality were similar between the 2 groups. Operative time was 180 minutes for laparoscopy and 120 minutes for laparotomy. Postoperative resumption of peristalsis was 24 hours versus 4 days, resumption of alimentation was on the second postoperative day versus the fifth postoperative day, and hospital stay was 7 days versus 12 days for laparoscopy and laparotomy, respectively. CONCLUSION: This study shows the feasibility and the advantages of elective laparoscopic-assisted colonic resection for uncomplicated sigmoid diverticulitis. The advantages of the laparoscopic approach are the lower need for analgesics and the more precocious ambulation, canalization, resumption of alimentation, and the shorter hospital stay. 相似文献
56.
Juli Busquets Jose Castellote Jaume Torras Juan Fabregat Emilio Ramos Laura Llado Antonio Rafecas Esmeralda de la Banda Juan Figueras 《Journal of gastrointestinal surgery》2007,11(4):458-463
Background Cold ischemia time and the presence of postoperative hepatic arterial thrombosis have been associated with biliary complications
(BC) after liver transplantation. An ABO-incompatible blood group has also been suggested as a factor for predisposal towards
BC. However, the influence of Rh nonidentity has not been studied previously.
Materials Three hundred fifty six liver transplants were performed from 1995 to 2000 at our hospital. BC incidence and risk factors
were studied in 345 patients.
Results Seventy patients (20%) presented BC after liver transplantation. Bile leakage (24/45%) and stenotic anastomosis (21/30%) were
the most frequent complications. Presence of BC in Rh-nonidentical graft–host cases (23/76, 30%) was higher than in Rh-identical
grafts (47/269, 17%) (P = 0.01). BC was also more frequent in grafts with arterial thrombosis (9/25, 36% vs 60/319, 19%; P = 0.03) and grafts with cold ischemia time longer than 430 min (26/174, 15% vs 44/171, 26%; P = 0.01). Multivariate logistic regression confirmed that Rh graft–host nonidentical blood groups [RR = 2(1.1–3.6); P = 0.02], arterial thrombosis [RR = 2.6(1.1–6.4); P = 0.02] and cold ischemia time longer than 430 min [RR = 1.8(1–3.2); P = 0.02] were risk factors for presenting BC.
Conclusion Liver transplantation using Rh graft–host nonidentical blood groups leads to a greater incidence of BC. 相似文献
57.
Factors affecting aseptic loosening of 4750 total hip arthroplasties: multivariate survival analysis
Barbara Bordini Susanna Stea Manuela De Clerico Sergio Strazzari Antonio Sasdelli Aldo Toni 《BMC musculoskeletal disorders》2007,8(1):69
Background
Total hip arthroplasty is a successful surgery, that fails at a rate of approximately 10% at ten years from surgery. Causes for failure are mainly aseptic loosening of one or both components partially due to wear of articular surfaces and partially to design. The present analysis aimed to identify risk factors and quantify their effects on aseptic failure. 相似文献58.
We propose a new self-organizing neural model that performs principal components analysis. It is also related to the adaptive subspace self-organizing map (ASSOM) network, but its training equations are simpler. Experimental results are reported, which show that the new model has better performance than the ASSOM network. 相似文献
59.
60.
David Jiménez Castro Gema Díaz David Martí Carlos Escobar Javier Ortega Sergio García-Rull Joaquin Picher Antonio Sueiro 《Blood coagulation & fibrinolysis》2007,18(2):173-177
This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization. 相似文献