全文获取类型
收费全文 | 21654篇 |
免费 | 2270篇 |
国内免费 | 44篇 |
专业分类
耳鼻咽喉 | 284篇 |
儿科学 | 608篇 |
妇产科学 | 510篇 |
基础医学 | 3603篇 |
口腔科学 | 416篇 |
临床医学 | 2308篇 |
内科学 | 4062篇 |
皮肤病学 | 274篇 |
神经病学 | 2079篇 |
特种医学 | 920篇 |
外国民族医学 | 1篇 |
外科学 | 2713篇 |
综合类 | 679篇 |
一般理论 | 11篇 |
预防医学 | 2320篇 |
眼科学 | 302篇 |
药学 | 1557篇 |
中国医学 | 55篇 |
肿瘤学 | 1266篇 |
出版年
2022年 | 115篇 |
2021年 | 268篇 |
2020年 | 204篇 |
2019年 | 310篇 |
2018年 | 395篇 |
2017年 | 281篇 |
2016年 | 301篇 |
2015年 | 389篇 |
2014年 | 503篇 |
2013年 | 734篇 |
2012年 | 1193篇 |
2011年 | 1233篇 |
2010年 | 676篇 |
2009年 | 622篇 |
2008年 | 1075篇 |
2007年 | 1095篇 |
2006年 | 1076篇 |
2005年 | 1085篇 |
2004年 | 1041篇 |
2003年 | 960篇 |
2002年 | 941篇 |
2001年 | 483篇 |
2000年 | 514篇 |
1999年 | 462篇 |
1998年 | 312篇 |
1997年 | 211篇 |
1996年 | 220篇 |
1995年 | 228篇 |
1994年 | 204篇 |
1993年 | 177篇 |
1992年 | 327篇 |
1991年 | 360篇 |
1990年 | 300篇 |
1989年 | 336篇 |
1988年 | 276篇 |
1987年 | 298篇 |
1986年 | 269篇 |
1985年 | 282篇 |
1984年 | 271篇 |
1983年 | 226篇 |
1982年 | 201篇 |
1981年 | 143篇 |
1980年 | 111篇 |
1979年 | 209篇 |
1978年 | 152篇 |
1977年 | 153篇 |
1976年 | 130篇 |
1974年 | 145篇 |
1973年 | 128篇 |
1972年 | 96篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Xiumei Jiang Xiaowei Zhang Patrick Gray Jiwen Zheng Timothy R. Croley Peter P. Fu 《journal of environmental science and health part c-environmental carcinogenesis & ecotoxicology reviews》2019,37(2):116-131
Gold nanoparticles (Au NPs) hold great promise in food, industrial and biomedical applications due to their unique physicochemical properties. However, influences of the gastrointestinal tract (GIT), a likely route for Au NPs administration, on the physicochemical properties of Au NPs has been rarely evaluated. Here, we investigated the influence of GIT fluids on the physicochemical properties of Au NPs (5, 50, and 100?nm) and their implications on intestinal epithelial permeability in vitro. Au NPs aggregated in fasted gastric fluids and generated hydroxyl radicals in the presence of H2O2. Cell studies showed that GIT fluids incubation of Au NPs affected the cellular uptake of Au NPs but did not induce cytotoxicity or disturb the intestinal epithelial permeability. 相似文献
3.
Erin C. Tully Jackson M. Gray Sherryl H. Goodman Stephen Nowicki Jr. 《Early child development and care》2016,186(12):1939-1951
Children who expect they can bring about good outcomes and avoid bad outcomes tend to experience more personal successes. Little is known about factors that contribute to these ‘control expectancies’. The purpose of the present study was to determine whether children's internal control expectancies occur in the context of parents’ internal control expectancies, low family strain, and high family cohesiveness and whether these factors are more strongly related to daughters’ than sons’ control expectancies. A community sample of 85 children aged 9–11 years and their parents (85 mothers; 63 fathers) completed rating scales. Fathers’ more internal control expectancies and mothers’ reports of fewer family strains were associated with daughters’ but not sons’ greater internal control expectancies, and greater family cohesiveness was related to both daughters’ and sons’ internal control orientations. These findings suggest that family factors may contribute to children's, particularly daughters’, development of internal control expectancies. 相似文献
4.
5.
6.
Shylo R. Johnson Dennis Slate Kathleen M. Nelson Amy J. Davis Samual A. Mills John T. Forbes Kurt C. VerCauteren Amy T. Gilbert Richard B. Chipman 《Viruses》2021,13(2)
Since the 1990s, oral rabies vaccination (ORV) has been used successfully to halt the westward spread of the raccoon rabies virus (RV) variant from the eastern continental USA. Elimination of raccoon RV from the eastern USA has proven challenging across targeted raccoon (Procyon lotor) and striped skunk (Mephitis mephitis) populations impacted by raccoon RV. Field trial evaluations of the Ontario Rabies Vaccine Bait (ONRAB) were initiated to expand ORV products available to meet the rabies management goal of raccoon RV elimination. This study describes the continuation of a 2011 trial in West Virginia. Our objective was to evaluate raccoon and skunk response to ORV occurring in West Virginia for an additional two years (2012–2013) at 75 baits/km2 followed by three years (2014–2016) of evaluation at 300 baits/km2. We measured the change in rabies virus-neutralizing antibody (RVNA) seroprevalence in targeted wildlife populations by comparing levels pre- and post-ORV during each year of study. The increase in bait density from 75/km2 to 300/km2 corresponded to an increase in average post-ORV seroprevalence for raccoon and skunk populations. Raccoon population RVNA levels increased from 53% (300/565, 95% CI: 50–57%) to 82.0% (596/727, 95% CI: 79–85%) during this study, and skunk population RVNA levels increased from 11% (8/72, 95% CI: 6–20%) to 39% (51/130, 95% CI: 31–48%). The RVNA seroprevalence pre-ORV demonstrated an increasing trend across study years for both bait densities and species, indicating that multiple years of ORV may be necessary to achieve and maintain RVNA seroprevalence in target wildlife populations for the control and elimination of raccoon RV in the eastern USA. 相似文献
7.
Raphael Mohr Robert Schierwagen Carolynne Schwarze-Zander Christoph Boesecke Jan-Christian Wasmuth Jonel Trebicka Jürgen Kurt Rockstroh 《Medicine》2015,94(50)
Liver-related death in human immunodeficiency virus (HIV)-infected individuals is about 10 times higher compared with the general population, and the prevalence of significant liver fibrosis in those with HIV approaches 15%. The present study aimed to assess risk factors for development of hepatic fibrosis in HIV patients receiving a modern combination anti-retroviral therapy (cART).This cross-sectional prospective study included 432 HIV patients, of which 68 (16%) patients were anti-hepatitis C virus (HCV) positive and 23 (5%) were HBsAg positive.Health trajectory including clinical characteristics and liver fibrosis stage assessed by transient elastography were collected at inclusion. Liver stiffness values >7.1 kPa were considered as significant fibrosis, while values >12.5 kPa were defined as severe fibrosis. Logistic regression and Cox regression uni- and multivariate analyses were performed to identify independent factors associated with liver fibrosis.Significant liver fibrosis was detected in 10% of HIV mono-infected, in 37% of HCV co-infected patients, and in 18% of hepatitis B virus co-infected patients. The presence of diabetes mellitus (odds ratio [OR] = 4.6) and FIB4 score (OR = 2.4) were independently associated with presence of significant fibrosis in the whole cohort. Similarly, diabetes mellitus (OR = 5.4), adiposity (OR = 4.6), and the FIB4 score (OR = 3.3) were independently associated with significant fibrosis in HIV mono-infected patients. Importantly, cumulative cART duration protected, whereas persistent HIV viral replication promoted the development of significant liver fibrosis along the duration of HIV infection.Our findings strongly indicate that besides known risk factors like metabolic disorders, HIV may also have a direct effect on fibrogenesis. Successful cART leading to complete suppression of HIV replication might protect from development of liver fibrosis. 相似文献
8.
Fluid role boundaries: exploring the contribution of the advanced nurse practitioner to multi‐professional palliative care
下载免费PDF全文
![点击此处可从《Journal of clinical nursing》网站下载免费的PDF全文](/ch/ext_images/free.gif)
9.
10.
Jennifer B. Gray Neal D. Gray 《International journal of mental health and addiction》2006,4(4):307-318
Some researchers speculate that as many as 10% of users worldwide suffer from “problematic” use of the internet, possibly stemming from an internet dependency. Research is in its early stages, making it an uncertain issue for mental health professionals. This paper provides: (1) a critical review of research on problematic internet use for the mental health and addictions professional; and (2) practical implications, including suggestions on treatment and prevention, given its uncertain clinical classification. 相似文献