全文获取类型
收费全文 | 46425篇 |
免费 | 3216篇 |
国内免费 | 147篇 |
专业分类
耳鼻咽喉 | 492篇 |
儿科学 | 1162篇 |
妇产科学 | 1122篇 |
基础医学 | 6011篇 |
口腔科学 | 1010篇 |
临床医学 | 4344篇 |
内科学 | 9397篇 |
皮肤病学 | 750篇 |
神经病学 | 4565篇 |
特种医学 | 1581篇 |
外科学 | 7339篇 |
综合类 | 499篇 |
现状与发展 | 1篇 |
一般理论 | 38篇 |
预防医学 | 3868篇 |
眼科学 | 1111篇 |
药学 | 3168篇 |
中国医学 | 155篇 |
肿瘤学 | 3175篇 |
出版年
2023年 | 266篇 |
2022年 | 534篇 |
2021年 | 1099篇 |
2020年 | 674篇 |
2019年 | 1009篇 |
2018年 | 1277篇 |
2017年 | 888篇 |
2016年 | 928篇 |
2015年 | 1097篇 |
2014年 | 1623篇 |
2013年 | 2055篇 |
2012年 | 3294篇 |
2011年 | 3415篇 |
2010年 | 1917篇 |
2009年 | 1732篇 |
2008年 | 3034篇 |
2007年 | 3211篇 |
2006年 | 2975篇 |
2005年 | 2904篇 |
2004年 | 2763篇 |
2003年 | 2614篇 |
2002年 | 2380篇 |
2001年 | 567篇 |
2000年 | 501篇 |
1999年 | 556篇 |
1998年 | 510篇 |
1997年 | 452篇 |
1996年 | 418篇 |
1995年 | 348篇 |
1994年 | 327篇 |
1993年 | 288篇 |
1992年 | 302篇 |
1991年 | 272篇 |
1990年 | 236篇 |
1989年 | 183篇 |
1988年 | 202篇 |
1987年 | 208篇 |
1986年 | 181篇 |
1985年 | 196篇 |
1984年 | 186篇 |
1983年 | 188篇 |
1982年 | 208篇 |
1981年 | 189篇 |
1980年 | 165篇 |
1979年 | 123篇 |
1978年 | 134篇 |
1977年 | 133篇 |
1976年 | 101篇 |
1975年 | 113篇 |
1974年 | 102篇 |
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
Lauren Tingey Britta Mullany Rachel Chambers Ranelda Hastings Angelita Lee Anthony Parker 《AIDS care》2015,27(9):1087-1097
Potential for widespread transmission of HIV/AIDS among American Indian (AI) adolescents exists, yet no evidence-based interventions (EBIs) have been adapted and evaluated with this population. Intensive psychoeducation may improve knowledge and decision-making which could potentially translate to reductions in HIV risk behaviors. A peer group randomized controlled comparison of an adapted EBI vs. control was delivered over an eight-day summer basketball camp in one reservation-based tribal community to adolescents ages 13–19. Outcome data were gathered immediately post-camp and at 6 and 12 months follow-up. Self-selected peer groups were randomized to intervention (n = 138) or control (n = 129) conditions for a total sample of 267 participants (56.2% female), mean age 15.1 years (SD = 1.7). Intervention participants had better condom use self-efficacy post-camp (Adjusted Mean Difference [AMD] = ?0.75, p < 0.005) and at 6 (AMD = ?0.44, p < 0.005) and 12 months (AMD = ?0.23, p < 0.05) follow-up. Intervention participants also had higher HIV prevention and transmission knowledge (post-camp: AMD = 0.07, p < 0.01; 6 months: AMD = 0.06, p < 0.01) were more likely to believe condoms prevent sexually transmitted infections (post-camp: RR = 1.41, p < 0.005; 6 months: RR = 1.34, p < 0.05), to talk with an adult about HIV/AIDS (post-camp: RR=1.78, p < 0.005; 6 months: RR = 1.14, p < 0.005), had higher partner negotiation efficacy related to substance use during sex (post-camp: AMD = 0.37, p < 0.01), and were more likely to intend to use a condom (post-camp: RR = 1.39, p < 0.01). The adapted intervention had short- and medium-term impacts on AI adolescent risk for HIV/AIDS, but attenuated at 12 months. Intervention delivery through a community-based camp is feasible and acceptable with strong retention. Additional study is needed to evaluate the adapted intervention's impact on sexual risk behaviors and if booster sessions and parent involvement translate to long-term impacts. 相似文献
2.
3.
4.
5.
Alessia Scarselli Silvia Di Cesare Claudia Capponi Simona Cascioli Maria L. Romiti Gigliola Di Matteo Alessandra Simonetti Paolo Palma Andrea Finocchi Barbarella Lucarelli Rita M. Pinto Ippolita Rana Giuseppe Palumbo Maurizio Caniglia Paolo Rossi Rita Carsetti Caterina Cancrini Alessandro Aiuti 《Journal of clinical immunology》2015,35(4):373-383
6.
Pedro Lopez Matheus Daros Pinto Ronei Silveira Pinto 《Ultrasound in medicine & biology》2019,45(2):612-616
In the work described here, our aim was to determine, in an elderly population, changes in muscle thickness (MT), cross-sectional area (CSA) and echo intensity (EI) of the quadriceps muscles at four time points (0, 5, 10 and 15 min; i.e., T0, T5, T10 and T15, respectively) after changing from a standing to supine position. Twenty-one elderly participants (14 men: 68.1 ± 4.6 y; 8 women: 66.8 ± 4.1 y) were evaluated at four time points. Rectus femoris CSA (RFCSA), MT and EI of the quadriceps femoris (QF) muscles were assessed. EI significantly increased from T0 to T5, T10 and T15 (p < 0.001), whereas no differences were observed between T5 and T15 in the rectus femoris (RFEI), vastus intermedius (VIEI) and quadriceps femoris (QFEI). No differences were observed between any time points in the RFCSA and MT of QF muscles. In summary, these results suggest that periods >5 min are not necessary to obtain consistent MT and EI measurements of quadriceps femoris muscles in the elderly population. 相似文献
7.
8.
9.
Paula Cristina Galati Paula Garcia Chiarello Belinda Pinto Simões 《Nutrition and cancer》2016,68(1):86-93
Changes in resting energy expenditure (REE) of cancer patients vary depending on type of tumor, treatment time point and kind of treatment. Little is known about REE of acute leukemia adult patients after treatment, especially with results related to body weight or fat free mass (FFM). This study aimed to assess changes in REE of acute leukemia adult patients before and after the first remission induction. Evaluation of REE was performed by indirect calorimetry and predicted REE was calculated by Harris-Benedict equation. Weight and height were measured and compared to a control group of healthy individuals. FFM was assessed by bioelectrical impedance for adjusting REE values. We evaluated 18 patients and 26 healthy individuals. At diagnosis, patients presented REE, REE/weight, and REE/FFM higher than the controls. Reductions of REE, REE/weight, and REE/FFM were also observed in patients after the first cycle of chemotherapy. The predicted REE for the patients group showed significant lower value compared with measured REE. Before the first cycle of chemotherapy REE was increased but undergoes a reduction after treatment, reaching values similar to the controls. For predictive Harris-Benedict equation, stress factors should be added to avoid underestimation of REE before and after chemotherapy. 相似文献
10.