全文获取类型
收费全文 | 27493篇 |
免费 | 2229篇 |
国内免费 | 703篇 |
专业分类
耳鼻咽喉 | 142篇 |
儿科学 | 747篇 |
妇产科学 | 616篇 |
基础医学 | 1106篇 |
口腔科学 | 312篇 |
临床医学 | 2838篇 |
内科学 | 5396篇 |
皮肤病学 | 240篇 |
神经病学 | 1670篇 |
特种医学 | 434篇 |
外科学 | 2940篇 |
综合类 | 3806篇 |
预防医学 | 6352篇 |
眼科学 | 205篇 |
药学 | 2403篇 |
13篇 | |
中国医学 | 147篇 |
肿瘤学 | 1058篇 |
出版年
2024年 | 79篇 |
2023年 | 600篇 |
2022年 | 1419篇 |
2021年 | 1552篇 |
2020年 | 1409篇 |
2019年 | 1095篇 |
2018年 | 1149篇 |
2017年 | 1109篇 |
2016年 | 1274篇 |
2015年 | 1148篇 |
2014年 | 2624篇 |
2013年 | 2388篇 |
2012年 | 2046篇 |
2011年 | 2208篇 |
2010年 | 1566篇 |
2009年 | 1360篇 |
2008年 | 1295篇 |
2007年 | 1225篇 |
2006年 | 990篇 |
2005年 | 812篇 |
2004年 | 585篇 |
2003年 | 457篇 |
2002年 | 365篇 |
2001年 | 331篇 |
2000年 | 275篇 |
1999年 | 172篇 |
1998年 | 119篇 |
1997年 | 142篇 |
1996年 | 104篇 |
1995年 | 89篇 |
1994年 | 77篇 |
1993年 | 66篇 |
1992年 | 62篇 |
1991年 | 54篇 |
1990年 | 40篇 |
1989年 | 27篇 |
1988年 | 31篇 |
1987年 | 17篇 |
1986年 | 8篇 |
1985年 | 12篇 |
1984年 | 11篇 |
1983年 | 6篇 |
1982年 | 8篇 |
1981年 | 5篇 |
1980年 | 6篇 |
1979年 | 2篇 |
1977年 | 4篇 |
1976年 | 1篇 |
1906年 | 1篇 |
排序方式: 共有10000条查询结果,搜索用时 13 毫秒
11.
The purpose of the present study was to reduce background tracks by removing a given surface layer of the 250 μm thick lexan polycarbonate foils before exposure to alpha particles. Ethylenediamine solution was used for taking layers from the surface of the foils. 相似文献
12.
集训新兵躯体化症状特点及其相关因素分析 总被引:5,自引:1,他引:5
目的:探讨集训新兵躯体化症状特点及其相关因素。方法:用成人EPQ和症状自评量表(SCL-90)在集训过程中对1432名新兵进行了躯体化症状和个性评定。结果:集训第一个月末新兵躯体化症状的检出率最高(12.25%),集训第二个月末为9.81%,集训前为8.66%。逐步回归分析表明,影响躯体化症状的主要因素依次为情绪不稳、有过受伤史、缺少体育锻炼、非主动要求参军等。结论:集训期间躯体化症状呈非线性下降趋势,集训前躯体化症状受多种因素影响。 相似文献
13.
N. Drakoulis I. Cascorbi J. Brockmöller C. R. Gross I. Roots 《Journal of molecular medicine (Berlin, Germany)》1994,72(3):240-248
Genetic differences in the metabolism of carcinogens may codetermine individual predisposition to cancer. Cytochrome P-4501A1 (CYP1A1) metabolically activates precarcinogens in cigarette smoke, such as benzo(a)pyrene, which is also an inducer of CYP1A1. Two point mutations have been reported, m1 in the 3-flanking region (6235T to C), and m2 within exon 7 (4889A to G), the latter leading to an isoleucine to valine exchange. In the Japanese population ml and m2 are correlated with lung cancer, suggesting an increased susceptibility to cigarette smoking related lung cancer. We studied 142 lung cancer and 171 reference patients in an ethnically homogeneous German group for m1 and m2 mutations by restriction fragment length polymorphism and allele-specific polymerase chain reaction, respectively. No statistically significant difference was found in the distribution of m1 alleles between lung cancer and controls; the frequency was 8.5% and 7.3% of the alleles, respectively (odds ratio = 1.17). A trend to an overrepresentation of ml alleles was observed among 52 squamous cell carcinoma patients (odds ratio = 1.65). In contrast, the frequency of m2 alleles in lung cancer patients was twofold higher (6.7%) than in the reference group (3.2%; odds ratio = 2.16; 95% confidence limits 0.96–5.11, P = 0.033); the odds ratio of m2 alleles in squamous cell carcinoma was 2.51 (95% confidence limits 0.85–7.05, P = 0.05). There was a close genetic linkage of m2 to m1 (10 of 11 reference patients), but a significantly higher number of cancer patients showed no linkage compared to the controls (odds ratio = 8.89, 95% confidence limits 0.83–433, P = 0.04). Thus no association was found between presence of ml alleles and lung cancer, but, in contrast, m2 alleles proved as a hereditary risk factor, especially if not linked with m1 alleles.Abbreviations Ah
aryl hydrocarbon
- CYP1A1
cytochrome P4501A1
-
CYP1A1
CYP1A1 gene
- PCR
polymerase chain reaction
- PY
pack years
- RFLP
restriction fragment length polymorphism
Correspondence to: N. Drakoulis 相似文献
14.
15.
16.
17.
Francisco A. Ferri Joel S. Frieder David Gutierrez Blanco David Romero Funes Camila Ortiz Gomez Emanuele Lo Menzo Samuel Szomstein Raul J. Rosenthal 《Surgery for obesity and related diseases》2021,17(2):284-291
BackgroundSleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.ObjectiveComprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.SettingAcademic hospital, United States.MethodsWe retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.ResultsA total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.ConclusionThere are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy. 相似文献
18.
19.
This study investigated the risk of insomnia and hypnotics use among emergency physicians. This cross-sectional study recruited physicians working in Taiwanese hospitals in 2015 and the general population as the participants. Data from 1,097 emergency physicians obtained from the National Health Insurance Research Database were grouped into the case group, whereas 14,112 nonemergency physicians and 4,388 people from the general population were categorized into the control groups. This study used logistic regression and conditional logistic regression to compare the risks of insomnia between emergency and nonemergency physicians and between emergency physicians and the general population, respectively. The prevalence of insomnia among emergency physicians, nonemergency physicians and general population was 5.56%, 4.08%, and 1.73%, respectively. Compared with nonemergency physicians and the general population, emergency physicians had a significantly higher risk of insomnia. The proportions of emergency physicians, nonemergency physicians, and general population using hypnotics were 19.96%, 18.24%, and 13.26%, respectively. Among emergency physicians who used hypnotics, 49.77%, 25.57%, and 24.66% used only benzodiazepines, only nonbenzodiazepines, and both benzodiazepines and nonbenzodiazepines, respectively. Nonpharmacological interventions to improve insomnia and reminder of safe use of hypnotics to emergency physicians can serve as references for hospitals in developing health-promoting activities. 相似文献
20.