全文获取类型
收费全文 | 4150116篇 |
免费 | 291560篇 |
国内免费 | 9048篇 |
专业分类
耳鼻咽喉 | 56776篇 |
儿科学 | 137028篇 |
妇产科学 | 113061篇 |
基础医学 | 586147篇 |
口腔科学 | 113308篇 |
临床医学 | 379364篇 |
内科学 | 799290篇 |
皮肤病学 | 93494篇 |
神经病学 | 338210篇 |
特种医学 | 159326篇 |
外国民族医学 | 1141篇 |
外科学 | 623290篇 |
综合类 | 85768篇 |
现状与发展 | 15篇 |
一般理论 | 1603篇 |
预防医学 | 327906篇 |
眼科学 | 96002篇 |
药学 | 303648篇 |
16篇 | |
中国医学 | 8477篇 |
肿瘤学 | 226854篇 |
出版年
2019年 | 32290篇 |
2018年 | 61754篇 |
2017年 | 47335篇 |
2016年 | 54130篇 |
2015年 | 44533篇 |
2014年 | 61738篇 |
2013年 | 93194篇 |
2012年 | 130268篇 |
2011年 | 148948篇 |
2010年 | 94096篇 |
2009年 | 84922篇 |
2008年 | 139153篇 |
2007年 | 148796篇 |
2006年 | 134261篇 |
2005年 | 130819篇 |
2004年 | 127095篇 |
2003年 | 123328篇 |
2002年 | 117860篇 |
2001年 | 183320篇 |
2000年 | 188269篇 |
1999年 | 159036篇 |
1998年 | 47334篇 |
1997年 | 41637篇 |
1996年 | 41678篇 |
1995年 | 40086篇 |
1994年 | 36822篇 |
1993年 | 34620篇 |
1992年 | 124651篇 |
1991年 | 120886篇 |
1990年 | 117606篇 |
1989年 | 113949篇 |
1988年 | 104854篇 |
1987年 | 102743篇 |
1986年 | 96733篇 |
1985年 | 92709篇 |
1984年 | 69307篇 |
1983年 | 59019篇 |
1982年 | 35200篇 |
1981年 | 31681篇 |
1979年 | 62891篇 |
1978年 | 44728篇 |
1977年 | 37765篇 |
1976年 | 35549篇 |
1975年 | 37970篇 |
1974年 | 45301篇 |
1973年 | 43148篇 |
1972年 | 40606篇 |
1971年 | 38140篇 |
1970年 | 35130篇 |
1969年 | 33814篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
971.
D J Adam S Raptis R A Fitridge 《European journal of vascular and endovascular surgery》2006,31(2):151-156
BACKGROUND: This study examines trends in the presentation and surgical management of acute diabetic foot problems in a single institution. METHOD: Prospective audit of all diabetic patients who had a primary procedure for critical lower limb ischaemia (CLI) and/or foot sepsis between 1st January 1990 and 31st December 2002. Primary and secondary intervention, mortality and limb salvage rate within 6 weeks of the index procedure were recorded. RESULTS: There were 661 patients (417 men and 244 women of median age 69, range 31-99, years) with 799 affected limbs. CLI alone was present in 625 (78%) limbs, combined CLI and foot sepsis in 53 (7%) and foot sepsis alone in 121 (15%). The primary intervention was minor amputation in 323 (40%) limbs, revascularisation in 288 (36%), major amputation in 185 (23%) and sympathectomy in three limbs. Within 6 weeks, 125 (16%) limbs required secondary intervention, the peri-procedural mortality rate was 38 of 924 (4%), and the limb salvage rates for patients with CLI, combined CLI and sepsis and sepsis alone were 66, 66 and 80%, respectively. There was a significant decline in the proportion of patients presenting with CLI alone and a significant increase in the proportion presenting with combined CLI and sepsis and sepsis alone. In patients with CLI alone, there was a significant increase in the primary major amputation rate and a significant decline in the minor amputation rate with no significant change in the revascularisation rate. CONCLUSION: There has been a progressive decline in the proportion of patients presenting with CLI alone and a greater proportion of patients presenting with an element of foot sepsis. In patients with CLI alone, the primary major amputation rate has increased at the expense of a decline in minor amputation rate. 相似文献
972.
973.
LMWH contra LMWH: superior,equivalent or non‐inferior? 总被引:2,自引:2,他引:0
974.
Effects of acute liver injury on blood coagulation 总被引:1,自引:0,他引:1
R. Kerr P. Newsome† L. Germain E. Thomson P. Dawson D. Stirling C. A. Ludlam 《Journal of thrombosis and haemostasis》2003,1(4):754-759
Summary. The mechanisms leading to the hemostatic changes of acute liver injury are poorly understood. To study these further we have assessed coagulation and immune changes in patients with acute paracetamol overdose and compared the results to patients with chronic cirrhosis and normal healthy controls. The results demonstrate that in paracetamol overdose coagulation factors (F)II, V, VII and X were reduced to a similar degree and were significantly lower than FIX and FXI (mean levels 0.28, 0.16, 0.13, 0.19, 0.51 and 0.72 IU mL−1 , respectively). In cirrhosis, by contrast, FII, FV, FVII, FIX and FX were equally reduced whilst FXI was lower than the other factors (mean levels 0.64, 0.69, 0.62, 0.60, 0.66 and 0.40 IU mL−1 , respectively). FVIII was raised in paracetamol overdose patients but normal in those with cirrhosis (mean levels 1.95 and 1.01 IU mL−1 , respectively). Interleukin-6 and tumor necrosis factor-α levels were raised in both patient groups, but higher levels were found in paracetamol overdose, compared to cirrhosis. Thrombin-antithrombin and soluble tissue factor levels were higher in those with acute liver injury but normal in cirrhosis. Antithrombin levels were reduced in both acute liver injury and cirrhosis. From these data we put forward a novel mechanism for the coagulation changes in acute paracetamol induced liver injury. We propose that immune activation leads to tissue factor-initiated consumption of FII, FV, FVII and FX, but that levels of FIX and FXI are better preserved because antithrombin inhibits the thrombin induced positive feedback loop that activates these latter factors. 相似文献
975.
Zinc sulfate addition to glass-ionomer-based cements: influence on physical and antibacterial properties, zinc and fluoride release. 总被引:5,自引:0,他引:5
Prudencio W R Osinaga Rosa Helena M Grande Rafael Y Ballester Maria Regina L Simionato Célia Regina M Delgado Rodrigues Antonio Muench 《Dental materials》2003,19(3):212-217
OBJECTIVES: The aim of this study is to evaluate the effect of ZnSO(4) addition to a conventional glass ionomer and a resin-modified glass ionomer on solubility, flexural strength, zinc and fluoride (F) release, and Streptococcus mutans growth inhibition. METHODS: 5 or 10% ZnSO(4) was added to Vitremer and Ketac-Fil powders. Solubility test was performed based on ISO 7489. Flexural strength was determined by 3-point bending test based on ISO 4049. Zn release/uptake was determined by atomic emission spectrometry; F release/uptake was measured using a F-specific electrode. Both release measurements were performed for 15 d before and 15 d after recharging. Antibacterial test was conducted according to agar plate methods against S. mutans, by measuring the inhibition halos in 1-h and 15-d specimens. Data were analyzed by ANOVA. RESULTS: Solubility increased with higher ZnSO(4) content, but remained below the ISO 7489 limit. Flexural strength was not affected by ZnSO(4) addition, and Vitremer performed better than Ketac-Fil. The control materials released no zinc. Vitremer with 10% ZnSO(4) released the highest amount of zinc. Fluoride release was similar for Ketac-Fil and Vitremer. In both cases, the highest amounts were released in the first 24 h. The growth inhibition halo of S. mutans was similar for both materials with highest content of ZnSO(4) and occurred only with 1-h specimens. SIGNIFICANCE: Zinc addition decreased microorganisms growth and improved fluoride release, without significantly affecting the materials' flexural strength and solubility. 相似文献
976.
977.
K Pritchard-Jones A Kelsey G Vujanic J Imeson C Hutton C Mitchell 《Journal of clinical oncology》2003,21(17):3269-3275
PURPOSE: To identify clinical prognostic factors in children with stage I, favorable histology (FH) Wilms' tumor treated with vincristine monochemotherapy after immediate nephrectomy to define subgroups for consideration of further reduction in treatment intensity. PATIENTS AND METHODS: During two consecutive trials of the United Kingdom Children's Cancer Study Group (UKW2 and UKW3, 1986 to 2001), 242 children with stage I FH Wilms' tumor were treated with immediate nephrectomy followed by 10 weekly injections of vincristine 1.5 mg/m2. Event-free survival (EFS) and overall survival (OS) were compared by age group. RESULTS: The 4-year EFS rate was 93.2%, 87.2%, and 71.3% for children less than 2 years old, 2 to 4 years old, and 4 years old or older at diagnosis, respectively (log-rank, P =.001); the corresponding 4-year OS rate was 98.1%, 95.0%, and 87.2% (log-rank, P =.01). There were no toxicity- or procedure-related deaths. In multivariate analysis, specimen weight was not of independent prognostic value (P =.66). Among the 186 children younger than 4 years at diagnosis, there were 17 relapses and five deaths, compared with 16 relapses and eight deaths among the 56 children at least 4 years old at diagnosis. OS after relapse was surprisingly poor (61.6% at 4 years). CONCLUSION: Treatment for stage I FH Wilms' tumor is generally successful using vincristine monotherapy after immediate nephrectomy, and therefore, the risks of dactinomycin hepatopathy can be avoided. However, age at least 4 years is a significant adverse prognostic factor. This treatment schedule should be considered in any trial of treatment reduction in very young children with stage I FH Wilms' tumor, regardless of tumor size, and we suggest that the upper age limit for the reduced therapy be set at 4 years. 相似文献
978.
979.
A M Carella 《Leukemia》2003,17(6):1199-1200
980.
Burkitt’s lymphoma is a high-grade, rapidly growing B-cell neoplasm. It is recognized by its aggressive course, brief median survival, and low rates of long-term survival. The authors discuss the case of a patient who acutely presented with intraabdominal complications from a new onset of Burkitt’s lymphoma. The clinical and pathological features, staging, treatment options, and survival data are reviewed. In addition, the role of surgical intervention is carefully analyzed. 相似文献