首页 | 本学科首页   官方微博 | 高级检索  
文章检索
  按 检索   检索词:      
出版年份:   被引次数:   他引次数: 提示:输入*表示无穷大
  收费全文   84610篇
  免费   6263篇
  国内免费   224篇
耳鼻咽喉   690篇
儿科学   2478篇
妇产科学   1572篇
基础医学   11653篇
口腔科学   1725篇
临床医学   9322篇
内科学   17571篇
皮肤病学   1193篇
神经病学   8164篇
特种医学   2613篇
外国民族医学   2篇
外科学   11622篇
综合类   1134篇
一般理论   83篇
预防医学   7796篇
眼科学   2051篇
药学   5760篇
  1篇
中国医学   98篇
肿瘤学   5569篇
  2023年   397篇
  2022年   611篇
  2021年   1620篇
  2020年   1001篇
  2019年   1575篇
  2018年   1958篇
  2017年   1457篇
  2016年   1587篇
  2015年   1813篇
  2014年   2734篇
  2013年   3753篇
  2012年   5922篇
  2011年   6029篇
  2010年   3366篇
  2009年   3022篇
  2008年   5470篇
  2007年   5912篇
  2006年   5847篇
  2005年   5581篇
  2004年   5292篇
  2003年   4808篇
  2002年   4686篇
  2001年   914篇
  2000年   734篇
  1999年   948篇
  1998年   1030篇
  1997年   874篇
  1996年   734篇
  1995年   708篇
  1994年   595篇
  1993年   550篇
  1992年   594篇
  1991年   544篇
  1990年   490篇
  1989年   445篇
  1988年   488篇
  1987年   433篇
  1986年   457篇
  1985年   435篇
  1984年   478篇
  1983年   492篇
  1982年   501篇
  1981年   489篇
  1980年   440篇
  1979年   376篇
  1978年   368篇
  1977年   288篇
  1976年   250篇
  1975年   219篇
  1974年   233篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
3.
4.
5.
Journal of Neuro-Oncology - Adjuvant radiation is often used in patients with low grade gliomas with high-risk characteristics with a recommended dose of 45–54 Gy. We used the...  相似文献   
6.
Introduction: Percutaneous renal mass biopsy has evolved over the last decade with improvements on previous pitfalls including low tissue yield, high non-diagnostic rates, and complications. As understanding of tumor biology and natural history of renal cortical neoplasms has improved, percutaneous renal mass biopsy is poised to have an expanding role in an area characterized by individualized management and refined risk stratification.

Areas covered: This review summarizes the evolution of renal mass biopsy to its current state with respect to outcomes, indications, and clinical guidelines.

Expert opinion: With improved understanding of differential biological potential of renal cortical neoplasms combined with technical improvements in diagnostic yield and accuracy, utilization of renal mass biopsy is becoming an important adjunct to patient care in a broad range of clinical scenarios, including active surveillance, thermal ablation, and use of primary systemic therapy in localized and advanced settings.  相似文献   

7.
8.
ABSTRACT

Close observation of the interactions between a traumatised mother and her infant son provides information on the modes of transmission of psychic trauma in the mother–infant dyad. Following the presentation of a current literature review on the theme, the subject of “radioactive residue” and counter-transference in the transmission of psychic trauma from mother to infant will be illustrated through a clinical case study that focuses on a Haitian mother and her two-year-old infant son who has been referred to a “transitional care nursery” in urban Paris. The encounter with this mother–infant dyad is analysed through observing the quality of the interactions that take place between the mother and infant in order to determine how a particularly traumatic narrative impacts the mother–infant relationship, in addition to relations with the clinician. Mother and infant respond to one another through the emission and reception of “radioactive residues” as hypothesized by Gampel. This clinical case study shows that there is a need to consider transcultural factors and collective experience and history when analysing traumatic events. Additionally, the case study shows that counter-transference can be an effective clinical tool for gaining access to an infant's experience as the recipient of a traumatic narrative.  相似文献   
9.
The majority of hip fractures in the elderly are the result of a fall from standing or from a lower height. Current injury models focus mostly on femur strength while neglecting subject-specific loading. This article presents an injury modeling strategy for hip fractures related to sideways falls that takes subject-specific impact loading into account. Finite element models (FEMs) of the human body were used to predict the experienced load and the femoral strength in a single model. We validated these models for their predicted peak force, effective pelvic stiffness, and fracture status against matching ex vivo sideways fall impacts (n = 11) with a trochanter velocity of 3.1 m/s. Furthermore, they were compared to sideways impacts of volunteers with lower impact velocities that were previously conducted by other groups. Good agreement was found between the ex vivo experiments and the FEMs with respect to peak force (root mean square error [RMSE] = 10.7%, R2 = 0.85) and effective pelvic stiffness (R2 = 0.92, RMSE = 12.9%). The FEMs were predictive of the fracture status for 10 out of 11 specimens. Compared to the volunteer experiments from low height, the FEMs overestimated the peak force by 25% for low BMI subjects and 8% for high BMI subjects. The effective pelvic stiffness values that were derived from the FEMs were comparable to those derived from impacts with volunteers. The force attenuation from the impact surface to the femur ranged between 27% and 54% and was highly dependent on soft tissue thickness (R2 = 0.86). The energy balance in the FEMS showed that at the time of peak force 79% to 93% of the total energy is either kinetic or was transformed to soft tissue deformation. The presented FEMs allow for direct discrimination between fracture and nonfracture outcome for sideways falls and bridge the gap between impact testing with volunteers and impact conditions representative of real life falls. © 2019 American Society for Bone and Mineral Research.  相似文献   
10.
Animal and human studies suggest fish oil and green tea may have protective effect on prostate cancer. Fatty acid synthase (FAS) has been hypothesized to be linked to chemoprotective effects of both compounds. This study evaluated the independent and joint effects of fish oil (FO) and green tea supplement (epigallocatechin-3-gallate, EGCG) on FAS and Ki-67 levels in prostate tissue. Through a double-blinded, randomized controlled trial with 2 × 2 factorial design, 89 men scheduled for repeat prostate biopsy following an initial negative prostate biopsy were randomized into either FO alone (1.9 g DHA + EPA/day), EGCG alone (600 mg/day), a combination of FO and EGCG, or placebo. We used linear mixed-effects models to test the differences of prostate tissue FAS and Ki-67 by immunohistochemistry between pre- and post-intervention within each group, as well as between treatment groups. Results did not show significant difference among treatment groups in pre-to-post-intervention changes of FAS (P = 0.69) or Ki-67 (P = 0.26). Comparing placebo group with any of the treatment groups, we did not find significant difference in FAS or Ki-67 changes (all P > 0.05). Results indicate FO or EGCG supplementation for a short duration may not be sufficient to produce biologically meaningful changes in FAS or Ki-67 levels in prostate tissue.  相似文献   
设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号