全文获取类型
收费全文 | 254336篇 |
免费 | 23387篇 |
国内免费 | 15824篇 |
专业分类
耳鼻咽喉 | 2514篇 |
儿科学 | 2796篇 |
妇产科学 | 3148篇 |
基础医学 | 30646篇 |
口腔科学 | 4529篇 |
临床医学 | 31779篇 |
内科学 | 36755篇 |
皮肤病学 | 3523篇 |
神经病学 | 13068篇 |
特种医学 | 10080篇 |
外国民族医学 | 115篇 |
外科学 | 25856篇 |
综合类 | 40782篇 |
现状与发展 | 62篇 |
一般理论 | 28篇 |
预防医学 | 17200篇 |
眼科学 | 6917篇 |
药学 | 27568篇 |
255篇 | |
中国医学 | 14603篇 |
肿瘤学 | 21323篇 |
出版年
2024年 | 893篇 |
2023年 | 3806篇 |
2022年 | 9920篇 |
2021年 | 12740篇 |
2020年 | 9494篇 |
2019年 | 8265篇 |
2018年 | 8755篇 |
2017年 | 8108篇 |
2016年 | 7867篇 |
2015年 | 11994篇 |
2014年 | 14681篇 |
2013年 | 13852篇 |
2012年 | 20236篇 |
2011年 | 21783篇 |
2010年 | 14101篇 |
2009年 | 11277篇 |
2008年 | 14649篇 |
2007年 | 13847篇 |
2006年 | 13259篇 |
2005年 | 12472篇 |
2004年 | 8434篇 |
2003年 | 7937篇 |
2002年 | 6576篇 |
2001年 | 5217篇 |
2000年 | 5102篇 |
1999年 | 5010篇 |
1998年 | 3025篇 |
1997年 | 2998篇 |
1996年 | 2328篇 |
1995年 | 2241篇 |
1994年 | 1999篇 |
1993年 | 1223篇 |
1992年 | 1621篇 |
1991年 | 1429篇 |
1990年 | 1155篇 |
1989年 | 1086篇 |
1988年 | 922篇 |
1987年 | 795篇 |
1986年 | 596篇 |
1985年 | 485篇 |
1984年 | 243篇 |
1983年 | 198篇 |
1982年 | 129篇 |
1981年 | 146篇 |
1980年 | 105篇 |
1979年 | 124篇 |
1978年 | 58篇 |
1977年 | 53篇 |
1976年 | 46篇 |
1974年 | 48篇 |
排序方式: 共有10000条查询结果,搜索用时 31 毫秒
21.
Tumor metastasis to the pancreas is a rare but recognized cause of acute pancreatitis. Autopsy series have reported a 24-40% of pancreatic involvement in small cell lung cancer. However, only a very few cases of tumor-induced acute pancreatitis have been described. Budd-Chiari syndrome complicating lung cancer is a rarely reported condition. We report a 68-year-old woman with extensive small cell lung cancer with the unusual initial presentation of both acute pancreatitis and acute Budd-Chiari syndrome. This patient suffered from progressive epigastralgia for 3 weeks. Severe epigastralgia with radiation to back and progressive jaundice developed 2 days prior to admission. After admission, the liver enlarged rapidly and the ascites increased markedly. Chest roentgenogram showed a mass lesion over the left lower lung field. Poorly differentiated carcinoma cells were found in ascites and bone marrow. The patient died on the ninth day of hospitalization before chemotherapy was initiated. Prompt diagnosis of extensive-stage small cell lung cancer may allow early chemotherapy treatment which favorably influences recovery when the pancreatitis is mild. Although prolonged survival might have been expected had this patient recovered from pancreatitis and received chemotherapy, diagnosis was delayed due to difficulty in immunohistochemical diagnosis of the tumor and the unusual clinical presentation. The use of stains employing antibodies against neurofilament and neuron-specific enolase cell antigens is important for early diagnosis of poorly differentiated metastatic tumor cells. 相似文献
22.
BACKGROUND AND PURPOSE: This report describes the results of matched-unrelated-donor transplant for leukemia or myelodysplasia in the first 23 recipient children at a single medical center in Taiwan. METHODS: Between August 1994 and February 2003, 23 consecutive children with leukemia or myelodysplasia underwent matched-unrelated-donor bone marrow transplantation (BMT). The preparative regimen consisted of fractionated total body irradiation and cyclophosphamide in 6 patients; busulfan in combination with etoposide and cyclophosphamide in 4 patients who received cranial irradiation before transplantation; and busulfan and cyclophosphamide in 13 patients. RESULTS: Engraftment was achieved in 91.3% of cases. Acute graft-versus-host disease (GVHD) occurred in 18 of 21 patients who engrafted (85.7%). Event-free survival for all patients was 24.46 +/- 9.24%. The 12 children with standard-risk disease had better event-free survival than the 11 children with high-risk disease (46.88 +/- 15.03% vs 0%, p < or = 0.001). CONCLUSIONS: The major obstacles to successful matched-unrelated-donor BMT are acute GVHD, relapse and infection. Early transplantation and patient selection, prophylactic and therapeutic maneuvers for GVHD, as well as appropriate donor selection and virus prophylaxis may improve the results. 相似文献
23.
24.
25.
X Dong M He X Song B Lu Y Yang S Zhang N Zhao L Zhou Y Li X Zhu R Hu 《Diabetic medicine》2007,24(12):1482-1486
AIMS: Our aim was to assess performances of the Cockcroft-Gault and simplified Modification of Diet in Renal Disease (MDRD) formulae in estimating glomerular filtration rate (GFR) in Chinese diabetic populations and their association with vascular risks. METHODS: A total of 1009 patients with Type 2 diabetes were categorized into low estimated GFR groups (GFR < 60 ml/min/1.73 m(2)) and control groups by the two equations. The performances of these formulae were assessed at different stages of kidney function. Carotid artery intima-media thickness (IMT) and the prevalence of diabetic retinopathy or albuminuria were compared among the groups. The ability of these formulae to identify established vascular risk markers using sensitivity, specificity, positive and negative predictive values were also compared. RESULTS: The prevalence of low estimated GFR was 32.7% with the Cockcroft-Gault formula and 5.2% with the MDRD formula, respectively. In low estimated GFR subjects by the MDRD formula, IMT was significantly thicker than those by the Cockcroft-Gault formula (1.2 mm vs. 1.0 mm; P < 0.05), with a higher prevalence of albuminuria (78.4 vs. 52.8%, P < 0.05) and diabetic retinopathy (46.5 vs. 30.5%; P < 0.05). The Cockcroft-Gault formula gave a specificity of 71.7% and a sensitivity of 37.0%, and the MDRD formula gave a specificity of 96.6% and a sensitivity of 7.9% in estimating low GFR relevant for established vascular risks. CONCLUSIONS: These formulae performed differently in Chinese diabetic populations. The simplified MDRD formula is minimally superior to the Cockcroft-Gault formula for its high specificity and positive predictive values in estimating low GFR relevant for vascular risks. 相似文献
26.
A study on the pathologic findings after recession and resection of extraocular muscles in rabbits was performed. Fibrosis of the extraocular muscles increased with time, which showed no difference between the recessed and resected muscles. Inflammation and foreign body reaction decreased with time, which showed no difference between the recessed and resected muscles. Adhesions of extraocular muscles to the sclera were observed from one month after the operation. The resected muscles showed milder adhesion to the sclera than the recessed ones. The operated extraocular muscles showed atrophies at one month, which showed no difference between the recessed and resected muscles. According to our results, when reoperation is needed, fibrosis of the extraocular muscles after recession and resection should be considered when making a decision on the amount of muscle to be recessed and resected. 相似文献
27.
28.
29.
医院感染是指病人在入院时不存在,也不处于潜伏期,而是在医院内发生的感染,也包括在医院里获得治疗,出院后发病的病人感染[1].癌症病人是一个特殊的群体,是医院感染的易感和高危人群,由于疾病本身引起消瘦无力、营养不良、甚至恶病质,免疫力低下、再加上接受放射线治疗后引起骨髓功能抑制、消化道功能障碍、皮肤反应及其他副反应等危险因素,医院感染发生率高,因此放疗科的医院感染控制是非常重要的工作.本文通过对我院放疗科病房2003年8月-2004年4月住院病人137例中发生医院感染病例12例进行分析,总结出一些控制医院感染的方法,现将其介绍如下.…… 相似文献
30.
Sharon Craven Lori Dewar Xianjun Yang Jeff Ginsberg Frederick Ofosu 《Blood coagulation & fibrinolysis》2007,18(3):219-225
Up to 20% of patients develop venographically proven deep-vein thrombosis after elective orthopedic surgery even under the cover of heparin or low molecular weight heparin. The extent to which the chronic inflammation of osteoarthritis requiring elective orthopedic surgery alters in-vivo coagulation and whether any specific alteration influences the development of postoperative thrombosis are unknown. This study compared the concentrations of activated factor VII (FVIIa), tissue factor pathway inhibitor (TFPI), activated factor X (FXa)-TFPI, thrombin-antithrombin, and prothrombin fragment 1+2 (F1+2) in plasmas of 535 healthy individuals (ages 17-76) with those in the preoperative plasmas of 306 arthritis patients (ages 30-92) scheduled for elective knee or hip replacement surgery. C-reactive protein was also measured in the plasmas of approximately 15% of the participants. Age-adjusted concentrations of FVIIa, F1+2, and C-reactive protein were higher in patients than controls, while the concentrations of thrombin-antithrombin, TFPI and FXa-TFPI were similar. Chronic inflammation in the patients was thus associated with increased coagulation in vivo. Without compensatory increases in the concentrations of TFPI (natural inhibitor of prothrombinase), the elevated concentrations of FVIIa in the preoperative plasmas and the trauma associated with surgery may enhance the risk for developing postoperative deep-vein thrombosis. 相似文献