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   2487062篇
  免费   180700篇
  国内免费   3628篇
耳鼻咽喉   34652篇
儿科学   81094篇
妇产科学   66292篇
基础医学   368405篇
口腔科学   67881篇
临床医学   221970篇
内科学   481861篇
皮肤病学   55796篇
神经病学   198554篇
特种医学   95210篇
外国民族医学   514篇
外科学   376395篇
综合类   48462篇
现状与发展   12篇
一般理论   884篇
预防医学   189487篇
眼科学   58142篇
药学   185261篇
  10篇
中国医学   4887篇
肿瘤学   135621篇
  2021年   20225篇
  2019年   20795篇
  2018年   29488篇
  2017年   22353篇
  2016年   25518篇
  2015年   28694篇
  2014年   39388篇
  2013年   58545篇
  2012年   81771篇
  2011年   86167篇
  2010年   51095篇
  2009年   47933篇
  2008年   81096篇
  2007年   86743篇
  2006年   87542篇
  2005年   85394篇
  2004年   81558篇
  2003年   78840篇
  2002年   76382篇
  2001年   112804篇
  2000年   115464篇
  1999年   97179篇
  1998年   28349篇
  1997年   24751篇
  1996年   24905篇
  1995年   23435篇
  1994年   21556篇
  1993年   20311篇
  1992年   73784篇
  1991年   71853篇
  1990年   70176篇
  1989年   67398篇
  1988年   61796篇
  1987年   60633篇
  1986年   56636篇
  1985年   54395篇
  1984年   40414篇
  1983年   34318篇
  1982年   20482篇
  1979年   37060篇
  1978年   26533篇
  1977年   22006篇
  1976年   20978篇
  1975年   22766篇
  1974年   27132篇
  1973年   25711篇
  1972年   24104篇
  1971年   22901篇
  1970年   21039篇
  1969年   20034篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
51.
52.
Pharmaceutical Chemistry Journal - An HPLC-MS method for simultaneous quantitative determination of a novel gestagenic pharmaceutical and two of its metabolites in rat and rabbit blood sera was...  相似文献   
53.

Purpose

Endovascular treatment with mechanical thrombectomy devices demonstrated high recanalization rates but functional outcome did not correlate with high rates of recanalization obtained. Patient selection prior to the endovascular treatment is very important in the final outcome of the patient. The primary aim of our study was to evaluate the prognostic value of posterior circulation Alberta Stroke Program Early CT Score (pc-ASPECTS) and Pons-Midbrain Index (PMI) scores in patients with Basilar Artery Occlusion (BAO) treated with successful angiographic recanalization after mechanical thrombectomy.

Methods

Retrospective single-center study including 18 patients between 2008 and 2013 who had acute basilar artery occlusion managed with endovascular treatment within 24 hours from symptoms onset and with successful angiographic recanalization. The patients were initially classified into two groups according to clinical outcome and mortality at 90 days. For analysis we also divided patients into groups based on pc-ASPECTS (≥8vs.< 8) and PMI (≥3vs.< 3) on non-contrast CT (NCCT) and CT Angiography Source Images (CTASI). Imaging data were correlated to clinical outcome and mortality rate.

Results

CTASI pc-ASPECTS, dichotomized at < 8 versus≥8, was associated with a favorable outcome (RR: 2.6; 95% CI: 1.3-5.2) and a reduced risk of death (RR: 6.5: 95% CI: 7.8-23.3). All patients that survived and were functionally independent had pc-ASPECTS score≥8. None of the 5 patients with CTASI pc-ASPECTS score less than 8 survived.

Conclusion

PC-ASPECTS on CTASI is helpful for predicting functional outcome after BAO recanalization with endovascular treatment. These results should be validated in a randomized controlled trial in order to decide whether or not to treat a patient with BAO.  相似文献   
54.
Bulletin of Experimental Biology and Medicine - Ammonium, an end-product of catabolism, in low doses can promote adaptation of metabolic pathways in erythrocytes under conditions of extreme...  相似文献   
55.
56.
57.
Introduction: Triple negative breast cancer (TNBC) is an aggressive breast cancer subtype associated with an increased risk of recurrence and cancer-related death. Unlike hormone receptor-positive or HER2-positive breast cancers, there are limited targeted therapies available to treat TNBC and cytotoxic chemotherapy remains the mainstay of treatment. Sacituzumab govitecan (IMMU-132) is an antibody-drug conjugate targeting Trop-2 expressing cells and selectively delivering SN-38, an active metabolite of irinotecan.

Areas covered: This review covers the mechanism of action, safety and efficacy of sacituzumab govitecan in patients with previously treated, metastatic TNBC. Additionally, efficacy data in other epithelial malignancies is included based on a PubMed search for ‘sacituzumab govitecan’ and ‘clinical trial’.

Expert opinion: Sacituzumab govitecan has promising anti-cancer activity in patients with metastatic TNBC previously treated with at least two prior lines of systemic therapy based on a single arm Phase I/II clinical trial. A confirmatory Phase III randomized clinical trial is ongoing. Sacituzumab govitecan has a manageable side effect profile, with the most common adverse events being nausea, neutropenia, and diarrhea. The activity of sacituzumab govitecan likely extends beyond TNBC with promising early efficacy data in many other epithelial cancers, including hormone receptor-positive breast cancer.  相似文献   

58.
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   
59.
60.
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