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   25545篇
  免费   2290篇
  国内免费   1089篇
耳鼻咽喉   207篇
儿科学   375篇
妇产科学   194篇
基础医学   2843篇
口腔科学   540篇
临床医学   2646篇
内科学   4319篇
皮肤病学   543篇
神经病学   1460篇
特种医学   1129篇
外国民族医学   4篇
外科学   3799篇
综合类   3543篇
现状与发展   1篇
一般理论   2篇
预防医学   1646篇
眼科学   449篇
药学   2103篇
  30篇
中国医学   1027篇
肿瘤学   2064篇
  2024年   321篇
  2023年   457篇
  2022年   879篇
  2021年   1181篇
  2020年   1011篇
  2019年   816篇
  2018年   760篇
  2017年   746篇
  2016年   753篇
  2015年   1040篇
  2014年   1262篇
  2013年   1362篇
  2012年   1980篇
  2011年   1941篇
  2010年   1400篇
  2009年   1161篇
  2008年   1410篇
  2007年   1435篇
  2006年   1354篇
  2005年   1133篇
  2004年   943篇
  2003年   961篇
  2002年   801篇
  2001年   629篇
  2000年   498篇
  1999年   376篇
  1998年   177篇
  1997年   147篇
  1996年   117篇
  1995年   107篇
  1994年   91篇
  1993年   76篇
  1992年   167篇
  1991年   147篇
  1990年   145篇
  1989年   127篇
  1988年   89篇
  1987年   106篇
  1986年   101篇
  1985年   86篇
  1984年   63篇
  1983年   50篇
  1982年   32篇
  1980年   32篇
  1979年   60篇
  1978年   35篇
  1977年   30篇
  1973年   31篇
  1972年   29篇
  1968年   32篇
排序方式: 共有10000条查询结果,搜索用时 0 毫秒
41.
Uterus transplantation (UTx) has become an alternative to gestational surrogacy and adoption for women with uterine factor infertility (UFI). Brännström et al achieved the first human delivery after UTx in 2014, and to date a total of 8 babies have been born after UTx from living donors. This outcome has attracted much attention worldwide, and many countries are now preparing for UTx.There are an estimated 60,000 women of reproductive age with UFI in Japan, and these patients cannot have biological children because gestational surrogacy is forbidden in Japan. We have performed UTx research from 2009 using cynomolgus macaque, in preparation for clinical application of UTx for these patients to have a child, and we have accumulated a large amount of data. However, the UTx procedure still has many medical, ethical, and social issues that require discussion prior to clinical application. The Japan Society for Uterus Transplantation was established in 2014 for further discussion of these issues in Japan.UTx is still in the experimental stage overseas, and the safety and efficacy remain unclear, despite several clinical applications. Despite the many issues to be resolved, this organ transplantation technology will provide new hope for women with UFI, and further development of the technology is important for future reproductive and transplant medicine.In this article, we summarize the current status of UTx and the situation regarding future clinical application in Japan.  相似文献   
42.
43.
Atrophy and fatty infiltration of lower extremity muscle after spinal cord injury (SCI) predisposes individuals to metabolic syndrome and related diabetes and cardiovascular disease. The objective of this study was to prospectively measure changes in muscle atrophy and fat content of distal lower extremity muscles and explore related factors in a cohort of adults with chronic SCI and diverse impairments. Muscle cross-sectional area and density were calculated from peripheral quantitative computed tomography scans of the 66% site of the calf from 70 participants with chronic SCI (50 male, mean age 49 years, C2-T12, American Spinal Injury Association Impairment Scale A-D) at study enrollment and annually for 2 years. Mixed-model repeated measures analysis of variance (rANOVA) examined longitudinal changes in muscle area and density, and regression analyses explored factors related to muscle changes using 16 potential correlates selected a priori. A high degree of individual variation in muscle area and density change was observed over 2 years (range: 8.5 to???22.6?cm2; 6.4 to??8.6?mg/cm3). Repeated measures analysis of variance revealed significant reductions in muscle area (estimated mean difference [95% confidence intervals] ?1.76 [?3.29?to ?0.23]) cm2, p?=?0.025) and density (?1.04 [?1.94 to??0.14] mg/cm3, p?<?0.024); however, changes in area were not significant with outliers removed. Regression analyses explained a small proportion of the variability in muscle density change; however, none of the preselected variables were significantly related to changes in muscle density after post hoc sensitivity analyses. Lower extremity muscle size and fat content may not reach a “steady-state” after chronic SCI. Progressive atrophy and fatty infiltration of lower extremity muscle may have adverse implications for metabolic syndrome and cardiovascular disease risk and related mortality after chronic SCI.  相似文献   
44.
The objective of this study was to compare the test-retest precision error for peripheral quantitative computed tomography (pQCT)-derived marrow density and marrow area segmentation at the tibia using 3 software packages. A secondary analysis of pQCT data in young adults (n?=?18, mean?±?standard deviation 25.4?±?3.2?yr), older adults (n?=?47, 71.8?±?8.2?yr), and individuals with spinal cord injury (C1–T12 American Spinal Injury Association Impairment Scale, classes A–C; n?=?19, 43.5?±?8.6?yr) was conducted. Repeat scans of the tibial shaft (66%) were performed using pQCT (Stratec XCT2000). Test-retest precision errors (root mean square standard deviation and root mean square coefficient of variation [RMSCV%]) for marrow density (mg/cm3) and marrow area (mm2) were reported for the watershed-guided manual segmentation method (SliceOmatic version 4.3 [Sliceo-WS]) and the 2 threshold-based edge detection methods (Stratec version 6.0 [Stratec-TB] and BoneJ version 1.3.14 [BoneJ-TB]). Bland-Altman plots and 95% limits of agreement were computed to evaluate test-retest discrepancies within and between methods of analysis and subgroups. RMSCV% for marrow density segmentation was >5% for all methods across subgroups (Stratec-TB: 12.2%–28.5%, BoneJ-TB: 14.5%–25.2%, and Sliceo-WS: 10.9%–23.0%). RMSCV% for marrow area segmentation was within 5% for all methods across subgroups (Stratec-TB: 1.9%–4.4%, BoneJ-TB: 2.6%–5.1%, and Sliceo-WS: 2.4%–4.5%), except using BoneJ-TB in older adults. Intermethod discrepancies in marrow density appeared to be present across the range of marrow density values and did not differ by subgroup. Intermethod discrepancies varied to a greater extent for marrow area and were found to be more frequently at mid- to higher-range values for those with spinal cord injury. Precision error for pQCT-derived marrow density segmentation exceeded 5% for all methods of analysis across a range of bone mineral densities and fat infiltration, whereas precision error for marrow area segmentation ranged from 2% to 5%. Further investigation is necessary to determine alternative acquisition and analysis methods for pQCT-derived marrow segmentation.  相似文献   
45.
Segment 7 is considered an unfavorable portion for laparoscopic hepatectomy because of technical difficulties in exposure and controlling bleeding. We compared intermittent Pringle with continuous half-Pringle maneuver in laparoscopic liver resections of tumors in segment 7. A retrospective analysis was conducted in a total of 36 consecutive patients with tumors in segment 7 undergoing laparoscopic liver resections between July 2011 and February 2016 (16 in the Pringle group versus 20 in the half-Pringle group). The two groups were well matched in baseline characteristics. The operative time (274.5?±?34.3 versus 237.6?±?41.8 min), overall declamping time (28.4?±?8.6 versus 2.3?±?2.5 min), and ischemic duration (69.7?±?16.5 versus 52.7?±?13.2 min) were significantly longer in the Pringle group (P?<?0.05). The amount of intraoperative blood loss (612.5?±?222.3 versus 417.4?±?163.8 mL) and transfusion (335.2?±?58.7 versus 224.8?±?76.2 mL) was significantly greater in the Pringle group (P?<?0.05). The Pringle group was associated with significantly lower postoperative albumin and higher C-reactive protein levels on postoperative days 1, 3, and 7 (P?<?0.05). Laparoscopic hepatectomy for tumors in segment 7 can be performed safely and effectively with successful exposure of surgical field and proper hepatic blood flow occlusion. Continuous half-Pringle maneuver offers the advantages of less operative time and blood loss, less injury, and better recovery.  相似文献   
46.
目的总结Remebot机器人辅助下立体定向脑组织活检术的护理配合方法。方法对19例患者行Remebot机器人辅助下立体定向脑组织活检术,其护理配合包括完善术前准备,合理布局手术间、正确安置体位、术中密切监护等,术后加强仪器设备的管理、特殊器械的维护和保养等。结果 19例均顺利完成手术,手术时间28~48min,平均35.5min;术后无一例发生并发症。结论 Remebot机器人辅助下立体定向脑组织活检术是一种高效、精准的新型手术方式,充分的术前准备、高质量的手术配合以及妥善的术后处理是手术成功的重要保证。  相似文献   
47.
48.
49.
50.
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