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   17932篇
  免费   1210篇
  国内免费   51篇
耳鼻咽喉   84篇
儿科学   524篇
妇产科学   424篇
基础医学   2124篇
口腔科学   230篇
临床医学   2590篇
内科学   3755篇
皮肤病学   208篇
神经病学   1689篇
特种医学   352篇
外科学   1835篇
综合类   474篇
一般理论   18篇
预防医学   2373篇
眼科学   376篇
药学   945篇
中国医学   18篇
肿瘤学   1174篇
  2023年   86篇
  2022年   92篇
  2021年   286篇
  2020年   181篇
  2019年   265篇
  2018年   314篇
  2017年   233篇
  2016年   272篇
  2015年   330篇
  2014年   496篇
  2013年   753篇
  2012年   1147篇
  2011年   1337篇
  2010年   681篇
  2009年   611篇
  2008年   1175篇
  2007年   1287篇
  2006年   1187篇
  2005年   1166篇
  2004年   1145篇
  2003年   1040篇
  2002年   997篇
  2001年   248篇
  2000年   258篇
  1999年   253篇
  1998年   245篇
  1997年   179篇
  1996年   165篇
  1995年   157篇
  1994年   130篇
  1993年   123篇
  1992年   161篇
  1991年   136篇
  1990年   142篇
  1989年   145篇
  1988年   128篇
  1987年   133篇
  1986年   120篇
  1985年   115篇
  1984年   113篇
  1983年   110篇
  1982年   90篇
  1981年   102篇
  1980年   84篇
  1979年   86篇
  1978年   80篇
  1977年   52篇
  1976年   43篇
  1975年   48篇
  1974年   49篇
排序方式: 共有10000条查询结果,搜索用时 15 毫秒
1.
2.
Trabecular bone score (TBS) is used for fracture prediction in adults, but its utility in children is limited by absence of appropriate reference values. We aimed to develop reference ranges for TBS by age, sex, and population ancestry for youth ages 5 to 20 years. We also investigated the association between height, body mass index (BMI), and TBS, agreement between TBS and lumbar spine areal bone mineral density (aBMD) and bone mineral apparent density (BMAD) Z-scores, tracking of TBS Z-scores over time, and precision of TBS measurements. We performed secondary analysis of spine dual-energy X-ray absorptiometry (DXA) scans from the Bone Mineral Density in Childhood Study (BMDCS), a mixed longitudinal cohort of healthy children (n = 2014) evaluated at five US centers. TBS was derived using a dedicated TBS algorithm accounting for tissue thickness rather than BMI. TBS increased only during ages corresponding to pubertal development with an earlier increase in females than males. There were no differences in TBS between African Americans and non-African Americans. We provide sex-specific TBS reference ranges and LMS values for calculation of TBS Z-scores by age and means and SD for calculation of Z-scores by pubertal stage. TBS Z-scores were positively associated with height Z-scores at some ages. TBS Z-scores explained only 27% and 17% of the variance of spine aBMD and BMAD Z-scores. Tracking of TBS Z-scores over 6 years was lower (r = 0.47) than for aBMD or BMAD Z-scores (r = 0.74 to 0.79), and precision error of TBS (2.87%) was greater than for aBMD (0.85%) and BMAD (1.22%). In sum, TBS Z-scores provide information distinct from spine aBMD and BMAD Z-scores. Our robust reference ranges for TBS in a well-characterized pediatric cohort and precision error estimates provide essential tools for clinical assessment using TBS and determination of its value in predicting bone fragility in childhood and adolescence. © 2022 American Society for Bone and Mineral Research (ASBMR).  相似文献   
3.
4.
Aim: Older residents in Japan requiring rehabilitation often reside in health‐care facilities for the elderly (HCFE) prior to being discharged to home. The return home can be very stressful for both the elder and family caregiver. The purpose of this study was to clarify the differences in plans for home life between the residents of a HCFE who were scheduled for discharge home and their family caregivers. Method: Semistructured interviews were conducted with eight pairs of elders and caregivers. Results: Differences were seen in several areas, including dietary preferences, recognition of the elder’s independence, preconceptions or not knowing about the elder’s pleasurable activities, and the way of care. Conclusions: Differences with regard to enjoyable activities for the elderly arose from a lack of understanding of the lives of the elderly on the part of their families.  相似文献   
5.
Stephenson  Joan 《JAMA》2006,295(15):1763
  相似文献   
6.
The final events of Wolfe Tone’s short and stormy life are fairly common knowledge. He was captured on board the French flagshipHoche when the vessel surrendered to a superior British naval force off Lough Swilly on October 10, 1798. Despite his protests that he was entitled to normal prisoner-of-war treatment, he was brought in irons a month later to Dublin. A court martial was hurriedly convened and he was found guilty of treason on Saturday November 10 and condemned to be hanged two days later. According to the generally accepted version of subsequent events he cut his own throat early on the Monday morning. The assistant surgeon of the 5th Dragoon Guards dressed the wound “ — but only with a view to prolong life until the fatal hour of one o’clock”. This surgeon was Benjamin Lentaigne, a Royalist emigre from France. Despite the pleas of John Philpott Curran, a leading advocate of the day, the military authorities refused to allow any consultation with a civil surgeon. Was this just bloody mindedness or was there an even more sinister reason? Two possibilities come to mind. One was that the wound had been so incompetently treated that a consultant would have been forced to make adverse comments, the other that the throat wound was not due to a cutting injury but, to a bullet fired either deliberately or accidently and a knife or razor was then used to try and camouflage the original trauma. In 1812 Lentaigne published a pamphlet in Latin in which he made reference to an unusual neck would stating that “— the bullet passed through his throat...” There is no direct evidence that the victim was Tone, why did the writer not make this clear? It may be he was reluctant to expose the medico-military inefficiency or callousness or to jeopardise his son’s career. Whatever the true facts, the verdict must remain the Scots one of “Not proven”.  相似文献   
7.
8.
Data on 232 members of a single pedigree, descended from two pairs of original parents, were made available to the participants of Genetic Analysis Workshop 8 (GAW8). In addition to information concerning age and sex, measurements for 10 quantitative traits and genotypes at 22 polymorphic marker loci were also provided for a subset of 193 of these family members. © 1993 Wiley-Liss, Inc.  相似文献   
9.
Dimethyl isosorbide (DMI), which is currently under investigation for its potential use as a pharmaceutical vehicle and drug permeation enhancer, is a water-miscible liquid with relatively low viscosity. The solubilization behavior of DMI as a cosolvent for nonpolar drugs was characterized via dielectric constant measurements of binary solvent systems containing DMI and either water, propylene glycol (PG), or polyethylene glycol (PEG). Evidence from the dielectric constant profiles and NMR studies suggest that DMI undergoes complexation with water and PG, but not with PEG, through hydrogen bonding interactions. The solvent complexation exhibited a major effect on the solubilities of prednisone, dexamethasone, and prednisolone in the mixed solvent systems. Maximum solubility of each drug was found to occur near a DMI/water or DMI/PG concentration ratio of 1:2. In the DMI–PEG mixed system, while there is no apparent interaction between DMI and PEG molecules, the solubility of prednisone was found to increase with decreasing dielectric constant.  相似文献   
10.
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