全文获取类型
收费全文 | 14263篇 |
免费 | 899篇 |
国内免费 | 66篇 |
专业分类
耳鼻咽喉 | 143篇 |
儿科学 | 315篇 |
妇产科学 | 250篇 |
基础医学 | 2176篇 |
口腔科学 | 184篇 |
临床医学 | 1408篇 |
内科学 | 3389篇 |
皮肤病学 | 362篇 |
神经病学 | 1430篇 |
特种医学 | 764篇 |
外科学 | 2298篇 |
综合类 | 109篇 |
一般理论 | 2篇 |
预防医学 | 558篇 |
眼科学 | 235篇 |
药学 | 872篇 |
中国医学 | 9篇 |
肿瘤学 | 724篇 |
出版年
2023年 | 89篇 |
2022年 | 80篇 |
2021年 | 246篇 |
2020年 | 177篇 |
2019年 | 241篇 |
2018年 | 282篇 |
2017年 | 263篇 |
2016年 | 339篇 |
2015年 | 363篇 |
2014年 | 440篇 |
2013年 | 521篇 |
2012年 | 818篇 |
2011年 | 941篇 |
2010年 | 559篇 |
2009年 | 526篇 |
2008年 | 821篇 |
2007年 | 876篇 |
2006年 | 764篇 |
2005年 | 848篇 |
2004年 | 806篇 |
2003年 | 748篇 |
2002年 | 772篇 |
2001年 | 265篇 |
2000年 | 255篇 |
1999年 | 253篇 |
1998年 | 162篇 |
1997年 | 152篇 |
1996年 | 111篇 |
1995年 | 111篇 |
1994年 | 88篇 |
1993年 | 97篇 |
1992年 | 149篇 |
1991年 | 119篇 |
1990年 | 100篇 |
1989年 | 122篇 |
1988年 | 103篇 |
1987年 | 108篇 |
1986年 | 92篇 |
1985年 | 99篇 |
1984年 | 79篇 |
1983年 | 71篇 |
1982年 | 63篇 |
1981年 | 51篇 |
1979年 | 45篇 |
1978年 | 44篇 |
1977年 | 48篇 |
1976年 | 45篇 |
1975年 | 47篇 |
1974年 | 55篇 |
1971年 | 51篇 |
排序方式: 共有10000条查询结果,搜索用时 203 毫秒
41.
42.
43.
44.
45.
46.
Marcus E. Kleber Graciela Delgado Tanja B. Grammer Günther Silbernagel Jie Huang Bernhard K. Kr?mer Eberhard Ritz Winfried M?rz 《Journal of the American Society of Nephrology : JASN》2015,26(11):2831-2838
Obesity and diets rich in uric acid–raising components appear to account for the increased prevalence of hyperuricemia in Westernized populations. Prevalence rates of hypertension, diabetes mellitus, CKD, and cardiovascular disease are also increasing. We used Mendelian randomization to examine whether uric acid is an independent and causal cardiovascular risk factor. Serum uric acid was measured in 3315 patients of the Ludwigshafen Risk and Cardiovascular Health Study. We calculated a weighted genetic risk score (GRS) for uric acid concentration based on eight uric acid–regulating single nucleotide polymorphisms. Causal odds ratios and causal hazard ratios (HRs) were calculated using a two-stage regression estimate with the GRS as the instrumental variable to examine associations with cardiometabolic phenotypes (cross-sectional) and mortality (prospectively) by logistic regression and Cox regression, respectively. Our GRS was not consistently associated with any biochemical marker except for uric acid, arguing against pleiotropy. Uric acid was associated with a range of prevalent diseases, including coronary artery disease. Uric acid and the GRS were both associated with cardiovascular death and sudden cardiac death. In a multivariate model adjusted for factors including medication, causal HRs corresponding to each 1-mg/dl increase in genetically predicted uric acid concentration were significant for cardiovascular death (HR, 1.77; 95% confidence interval, 1.12 to 2.81) and sudden cardiac death (HR, 2.41; 95% confidence interval, 1.16 to 5.00). These results suggest that high uric acid is causally related to adverse cardiovascular outcomes, especially sudden cardiac death. 相似文献
47.
Kyle J. Chambers Ashton E. Lehmann Aaron Remenschneider Matthew Dedmon Josh Meier Stacey T. Gray Derrick T. Lin 《Skull base》2015,76(2):94-100
Objective To determine trends in sinonasal undifferentiated carcinoma (SNUC) survival patterns in the United States.
Design Retrospective review of national database.
Participants All cases of SNUC in the National Cancer Institute''s Surveillance Epidemiology and End Results program from 1973 to 2010 were examined.
Main Outcome Measures Age-adjusted incidence and survival rates were calculated and stratified by demographic information and treatment modality. Cohort analysis was performed to analyze survival patterns over time.
Results A total of 318 SNUC cases were identified. Age-adjusted incidence rate (IR) was 0.02 per 100,000. Incidence was greater in males (IR: 0.03) than females (IR: 0.01; p = 0.03). Overall 5- and 10-year relative survival rate was 34.9% and 31.3%, respectively. Overall median survival was 22.1 months. Median survival following surgery combined with radiation was 41.9 months. Five-year relative survival rate following surgery, radiation, or surgery combined with radiation was 38.7%, 36.0%, and 39.1%, respectively. Median survival from 1973–1986 and 1987–2010 was 14.5 and 23.5 months, respectively.
Conclusions This study provides new data regarding survival patterns of SNUC in the United States, confirming survival benefit with surgery and radiation as well as identifying a trend toward improved survival in recent decades. 相似文献
48.
49.
50.
In this investigation, the radiological status of angular measurements in the wisdom tooth area was examined. The angles of the tooth center lines of the second and third lower molars (48,47) to the occlusal plane and to one another in 25 orthodontically untreated patients (average age: 16.3 years) were measured and compared with angular values of the patients concerned measured in a dental CT. The assessment of these 3 radiological documents in an absolute comparison revealed closely corresponding angular values. However, the dental CT provided a considerably more accurate and, in addition, a three-dimensional topographical localization of lower wisdom teeth. Zusammenfassung: In der vorliegenden Untersuchung wurde der radiologische Stellenwert von Winkelmessungen im Weisheitszahnbereich überprüft. Im Fernröntgenseitenbild und Orthopantomogramm wurden die zur Okklusionsebene und zueinander gemessenen Zahnachsenwinkel des dritten und zweiten unteren Molaren (48, 47) von 25 kieferorthopädisch unbehandelten Patienten (Durchschnittsalter: 16,3 Jahre) vermessen und mit im Dental-CT gemessenen Winkelwerten des jeweiligen Patienten verglichen. Die Beurteilung dieser drei radiologischen Unterlagen ergab im absoluten Vergleich annährend sich entsprechende Winkelwerte. Das Dental-CT gestattete jedoch eine wesentlich genauere und zudem dreidimensionale topographische Lagebestimmung unterer Weisheitszähne. 相似文献