全文获取类型
收费全文 | 45510篇 |
免费 | 2975篇 |
国内免费 | 925篇 |
专业分类
耳鼻咽喉 | 359篇 |
儿科学 | 1148篇 |
妇产科学 | 1201篇 |
基础医学 | 5048篇 |
口腔科学 | 792篇 |
临床医学 | 3954篇 |
内科学 | 10765篇 |
皮肤病学 | 700篇 |
神经病学 | 4150篇 |
特种医学 | 1690篇 |
外国民族医学 | 2篇 |
外科学 | 6109篇 |
综合类 | 2081篇 |
现状与发展 | 1篇 |
一般理论 | 1篇 |
预防医学 | 2376篇 |
眼科学 | 589篇 |
药学 | 3876篇 |
8篇 | |
中国医学 | 959篇 |
肿瘤学 | 3601篇 |
出版年
2023年 | 402篇 |
2022年 | 1048篇 |
2021年 | 1605篇 |
2020年 | 1021篇 |
2019年 | 1101篇 |
2018年 | 1222篇 |
2017年 | 1016篇 |
2016年 | 1056篇 |
2015年 | 1354篇 |
2014年 | 1764篇 |
2013年 | 2167篇 |
2012年 | 2831篇 |
2011年 | 2866篇 |
2010年 | 1720篇 |
2009年 | 1575篇 |
2008年 | 2412篇 |
2007年 | 2463篇 |
2006年 | 2264篇 |
2005年 | 2139篇 |
2004年 | 1962篇 |
2003年 | 1695篇 |
2002年 | 1524篇 |
2001年 | 1412篇 |
2000年 | 1336篇 |
1999年 | 1238篇 |
1998年 | 449篇 |
1997年 | 332篇 |
1996年 | 354篇 |
1995年 | 272篇 |
1994年 | 253篇 |
1993年 | 210篇 |
1992年 | 670篇 |
1991年 | 566篇 |
1990年 | 537篇 |
1989年 | 548篇 |
1988年 | 457篇 |
1987年 | 419篇 |
1986年 | 400篇 |
1985年 | 315篇 |
1984年 | 260篇 |
1983年 | 211篇 |
1982年 | 116篇 |
1979年 | 211篇 |
1978年 | 129篇 |
1977年 | 110篇 |
1974年 | 122篇 |
1973年 | 125篇 |
1972年 | 122篇 |
1971年 | 110篇 |
1969年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
131.
微创穿刺术治疗基底节区脑出血临床随机对照研究 总被引:50,自引:3,他引:47
目的评价比较微创穿刺血肿粉碎清除术与内科保守治疗两种方法治疗基底节区脑出血(25~40m l)的疗效异同。方法采用多中心、随机对照试验的方法,42个参研医院共随机入选465例基底节区脑出血患者,根据纳入与排除标准共排除88例,其中资料不全者16例;不符合入选标准者72例,分别为Glasgow评分≤8分(64例)、术前出血量>40m l(7例)、从发病到达急诊室时间>72h(1例)。评价治疗14d时两组患者神经功能缺损程度和日常生活活动能力、治疗3个月时的日常生活活动能力以及3个月和住院期间病死率。结果最终符合入组标准的病例数为377例,其中微创治疗组195例,对照组182例。微创治疗组患者于治疗14d时,神经功能改善明显优于对照组(χ2=7.931,P=0.02);治疗3个月时达良好功能状态的患者比例明显多于对照组(35.91%vs21.82%;χ2=8.294P=0.004)。微创治疗组病,残率明显低于对照组(40.88%vs63.03%,χ2=16.948,P<0.01);两组病死率间差异无显著性意义(6.67%vs8.79%)。结论与单纯内科保守治疗相比,应用微创穿刺血肿粉碎清除术治疗基底节区小血肿不增加病死率,并可明显提高脑出血患者的日常生活活动能力,降低病残率。 相似文献
132.
L. Angrisani F. Favretti F. Furbetta L. Busetto S.B. Doldi E. Lattuada M. Paganelli M. Lucchese N. Basso F.D. Capizzi A. Iuppa G. Lesti N. Di Lorenzo C. Giardiello L. Di Cosmo A. Veneziani S. Lacitignola M. Alkilani P. Forestieri M. Toppino A. Gardinazzi F. Puglisi A. Cascardo P. Bernante G. Silecchia B. Marzano A. Adorni V. Borrelli M. Lorenzo 《Surgery for obesity and related diseases》2005,1(3)
133.
Massimo Chello Costanza Goffredo Giuseppe Patti Dario Candura Rosetta Melfi Stefano Mastrobuoni Germano Di Sciascio Elvio Covino 《European journal of cardio-thoracic surgery》2005,28(6):805-810
Objective: Endothelial dysfunction represents a critical early component of organ injury following cardiopulmonary bypass. Recent studies demonstrate that the treatment with atorvastatin is associated with a significant improvement of endothelial function independently of its efficacy on cholesterol levels. Therefore, we investigated the effects of preoperative atorvastatin treatment on endothelium function after coronary surgery. Methods: Forty patients undergoing coronary surgery were randomized to treatment with atorvastatin (20 mg/die; N = 20) or placebo (N = 20) 3 weeks before surgery. Twenty normal patients served as control group. The flow-mediated dilations (FMD) of the brachial artery after both reactive hyperemia (endothelium dependent) and nitroglycerin administration (endothelium independent) were evaluated at baseline, at 48 h, and 5 days postoperatively. Results: At baseline, the endothelium-dependent FMD was significantly attenuated in coronary versus normal patients (normal 10.3 ± 1.8% vs coronary 4.1 ± 1.6%, p < 0.01). At 48 h postoperatively all patients exhibited a reduced FMD compared with baseline values: the endothelium-dependent dilatation showed a drop of 60.1 + 15% in the patients of the placebo group compared with 45.8 + 16.6% (p < 0.05) those in the atorvastatin group. At the univariate analysis, no significant correlation was found between serum levels of either total cholesterol or HDL cholesterol and FMD. The nitroglycerin-induced dilation was not significantly influenced by extracorporeal circulation as well as by atorvastatin treatment. Conclusions: The endothelial dysfunction following cardiopulmonary bypass is improved by the treatment with atorvastatin, by a mechanism unrelated to the drug efficacy of controlling serum cholesterol levels. 相似文献
134.
Quantitative (82)Rb PET/CT: development and validation of myocardial perfusion database. 总被引:1,自引:0,他引:1
Cesar A Santana Russell D Folks Ernest V Garcia Liudmila Verdes Rupan Sanyal Jon Hainer Marcelo F Di Carli Fabio P Esteves 《Journal of nuclear medicine》2007,48(7):1122-1128
The use of myocardial perfusion (82)Rb PET/CT studies continues to increase but its accuracy using database quantification methods for the diagnosis of coronary artery disease (CAD) has not been established. METHODS: A sex-independent normal database and criteria for abnormality for rest-stress (82)Rb PET/CT myocardial perfusion imaging were developed and validated by evaluation of 281 patients (136 females: mean age +/- SD, 63.3 +/- 13.3 y; 145 males: mean age +/- SD, 63.9 +/- 12.8 y) who underwent a rest-adenosine stress (82)Rb PET/CT study. These patients were divided into 3 groups: (a) healthy group: 30 patients, with <5% likelihood of CAD (low likelihood [LLK]) based on sequential Bayesian analysis; these patients were used to generate the normal distribution; (b) pilot group: 174 patients; these patients were used to determine the optimal criteria for detecting and localizing the perfusion abnormality; and (c) validation group: 76 patients (23 with LLK of CAD and 53 who underwent coronary angiography; these patients were used for prospective validation. RESULTS: Of the 53 patients who underwent coronary angiography, 8 had <50% stenosis and 45 patients had at least one stenosis > or =50% in one major artery. Fifteen patients had single-vessel disease, 17 had double-vessel disease, and 13 had triple-vessel disease. The prospective validation shows a normalcy rate of 78% (18/23) for global CAD. The analyses by individual arteries show a normalcy rate of 96% (22/23) for the left anterior descending coronary artery, 96% for the left circumflex coronary artery (22/23), and 100% for the right coronary artery (23/23). The overall sensitivity for detection of CAD (> or =50% stenosis) was 93% (42/45). The overall specificity for detection of the absence of CAD (< or =50% stenosis) was 75% (6/8). Also, the positive predictive value for global CAD was 95% (42/44), the negative predictive value was 67% (6/9), and the accuracy was 91% (48/53). CONCLUSION: The quantitative (82)Rb PET/CT database created and validated in this study is highly accurate for the detection and localization of CAD. Physicians should consider using the quantitative output of these algorithms as decision support tools to aid with image interpretation. 相似文献
135.
136.
G. Fatati M. L. Amerio M. Bacci F. Brunetti A. Caretto L. Casali S. Coaccioli F. D’Andrea E. Del Toma M. Di Sapio D. Domeniconi M. Kob F. Leonardi E. Mirri P. Nanni A. Paci P. Pallini G. Ronzani A. R. Sabbatini S. G. Sukkar M. Tagliaferri G. Vincenzoni M. A. Fusco 《Mediterranean journal of nutrition and metabolism》2009,1(3):203-206
137.
138.
运用文献计量分分析法对本刊1992-1995年16期所刊文章作了分析。结果:致突变的文章较多;每篇文章作者平均3.94人,大多集中在高等院校及科研机构,地区分布较广,高产作家尚少;平均引文8.22篇,引文以中、英文期刊为主;文献半衰期为中文4.16年,英文6.93年;有8种核心期刊;自引率较高。与创刊后的前12期(1989-1992)相比:一次性文献比重明显增加,致畸文章比重增加,高产作家相对增多,英文引文增加,英文半衰期缩短近二年半,提示刊物水平有提高趋势。 相似文献
139.
The role of aminophylline in the re-formation of peritoneal adhesions was considered in 23 rats. Since the adhesions were obtained, the animals were subsequently divided into three groups, the first one containing seven units, the others containing eight animals each. During the four days prior the surgery, allopurinol at the dose of 50 mg/kg/die was added to the regular ground laboratory chow in the animals of the second group; aminophylline at the dose of 40 mg/kg/die was administered four hours and immediately prior the surgery, to the animals of the third group. The adhesions that we observed, were graded and evaluated assigning them a score. At the moment of the lysis of adhesions, we observed the score of 2.71 +/- 1.11 in the first group, 3.12 +/- 1.13 in the second group, and 2.75 +/- 1.03 in the third one. Matching each group one another no statistically significant difference was found. At the end the experiment, we observed a score of 3.71 +/- 0.49 for the adhesions in the first group, 2 +/- 0.75 in the second group, and 3.87 +/- 0.35 in the third one. Matching these scores with those observed at the moment of their lysis, they appeared significantly higher in the animals of the first group (p less than 0.02) and of the third group (p less than 0.05), but they were lower in the second group (p less than 0.05). Such results indicate that the re-formation of peritoneal adhesions following their lysis is constant, that allopurinol decreases the intensity of the process, while aminophylline increases it. 相似文献
140.