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   5053篇
  免费   428篇
  国内免费   12篇
耳鼻咽喉   91篇
儿科学   115篇
妇产科学   110篇
基础医学   634篇
口腔科学   109篇
临床医学   540篇
内科学   973篇
皮肤病学   21篇
神经病学   376篇
特种医学   181篇
外科学   961篇
综合类   74篇
一般理论   4篇
预防医学   524篇
眼科学   111篇
药学   322篇
中国医学   12篇
肿瘤学   335篇
  2024年   10篇
  2023年   73篇
  2022年   128篇
  2021年   268篇
  2020年   137篇
  2019年   204篇
  2018年   209篇
  2017年   161篇
  2016年   176篇
  2015年   189篇
  2014年   229篇
  2013年   256篇
  2012年   428篇
  2011年   409篇
  2010年   212篇
  2009年   170篇
  2008年   278篇
  2007年   265篇
  2006年   263篇
  2005年   225篇
  2004年   189篇
  2003年   162篇
  2002年   136篇
  2001年   52篇
  2000年   42篇
  1999年   42篇
  1998年   27篇
  1997年   19篇
  1996年   35篇
  1995年   28篇
  1994年   13篇
  1993年   18篇
  1992年   42篇
  1991年   49篇
  1990年   36篇
  1989年   21篇
  1988年   20篇
  1987年   37篇
  1986年   22篇
  1985年   16篇
  1984年   14篇
  1983年   21篇
  1982年   11篇
  1979年   16篇
  1978年   13篇
  1977年   9篇
  1976年   10篇
  1974年   15篇
  1973年   12篇
  1968年   9篇
排序方式: 共有5493条查询结果,搜索用时 15 毫秒
71.
CardioVascular and Interventional Radiology - Genicular artery embolisation (GAE) is a novel treatment for patients with knee osteoarthritis (OA). Cadaveric dissection was undertaken to provide a...  相似文献   
72.
Garske LA  Bell SC 《Chest》2002,121(4):1363-1364
Hypertrophic pulmonary osteoarthropathy (HPOA) may complicate the advanced lung disease that is associated with cystic fibrosis, resulting in severe joint pain and early-morning stiffness. Symptoms are usually controlled with the administration of nonsteroidal anti-inflammatory drugs, physiotherapy, and, on occasions, oral corticosteroids. This report describes a case of refractory HPOA with complete remission following the administration of IV pamidronate, which is a potent inhibitor of osteoclastic bone resorption. Symptom relief resulted for up to 3 months, but repeated courses of pamidronate have been required to maintain symptom control.  相似文献   
73.
74.
We utilized synthetic photochemistry to generate novel sp3-rich scaffolds and report the design, synthesis, and biological testing of a diverse series of amides based on the 1-(amino-methyl)-2-benzyl-2-aza-bicyclo[2.1.1]hexane scaffold. Preliminary antimalarial screening of the library provided promising compounds with activity in the 1–5 μM range with an enhanced hit rate. Further evaluation (solubility, drug metabolism and pharmacokinetics (DMPK), and toxicity) of a selected compound (9) suggested that this series represents an excellent opportunity for further optimization with the framework offering multiple opportunities for the addition of uniquely vectorally positioned extra functionality.  相似文献   
75.
The noninvasive quantification of axonal morphology is an exciting avenue for gaining understanding of the function and structure of the central nervous system. Accurate non‐invasive mapping of micron‐sized axon radii using commonly applied neuroimaging techniques, that is, diffusion‐weighted MRI, has been bolstered by recent hardware developments, specifically MR gradient design. Here the whole brain characterization of the effective MR axon radius is presented and the inter‐ and intra‐scanner test–retest repeatability and reproducibility are evaluated to promote the further development of the effective MR axon radius as a neuroimaging biomarker. A coefficient‐of‐variability of approximately 10% in the voxelwise estimation of the effective MR radius is observed in the test–retest analysis, but it is shown that the performance can be improved fourfold using a customized along‐tract analysis.  相似文献   
76.
PurposeTG43 does not account for a lack of scatter and tissue and applicator heterogeneities. The advanced collapsed-cone engine (ACE) algorithm available for use in the Oncentra Brachy treatment planning system (Elekta AB, Stockholm, Sweden) can model these conditions more accurately and is evaluated for esophageal and surface mold brachytherapy treatments.Methods and MaterialsACE was commissioned for use then compared against TG43 for five esophageal and five surface mold treatment plans. Dosimetric differences between each algorithm were assessed using superimposed comparisons and dose-volume histogram statistics.ResultsEsophagus (6 Gy per fraction): Compared with TG43, ACE demonstrated up to a 0.63% and 0.05 Gy reduction in planning target volume (PTV) V100% and PTV D98, respectively. Lung D2cc and bone D2cc deviated by up to 0.09 Gy and 0.03 Gy, respectively. Lung D0.1 cc and bone D0.1 cc both deviated by up to 0.12 Gy.Surface mold (4.5 Gy per fraction): Compared with TG43, ACE demonstrated up to a 12.5% and 0.18 Gy reduction in PTV V80% and PTV D98, respectively. Bone D2cc and D0.1 cc both reduced by up to 0.2 Gy when modeled with ACE. Increasing mold size laterally increased the dosimetric differences between TG43 and ACE.ConclusionsTG43 generally overestimated dose delivered to the target volume and organs at risk for the sites investigated. Dosimetric differences observed for esophageal treatments were minimal; however, surface mold treatments would benefit from the increased dosimetric accuracy offered by ACE.Implementation should be considered for surface mold 192Ir treatment planning, but increased calculation time, additional contouring, and mass density assignment requirements should be scrutinized with regard to their potentially negative impact on current clinical practice.  相似文献   
77.
78.
79.
Behavior Genetics - Trajectories of youth antisocial behavior (ASB) are characterized by both continuity and change. Twin studies have further indicated that genetic factors underlie continuity,...  相似文献   
80.
ContextHypohydration has been shown to alter neuromuscular function. However, the longevity of these impairments remains unclear.ObjectiveTo examine the effects of graded exercise-induced dehydration on neuromuscular control 24 hours after exercise-induced hypohydration.DesignCrossover study.SettingLaboratory.Patients or Other ParticipantsA total of 23 men (age = 21 ± 2 years, height = 179.8 ± 6.4 cm, mass = 75.24 ± 7.93 kg, maximal oxygen uptake [VO2max] = 51.7 ± 5.5 mL·kg−1·min−1, body fat = 14.2% ± 4.6%).Intervention(s)Participants completed 3 randomized exercise trials: euhydrated arrival plus fluid replacement (EUR), euhydrated arrival plus no fluid (EUD), and hypohydrated arrival plus no fluid (HYD) in hot conditions (ambient temperature = 35.2°C ± 0.6°C, relative humidity = 31.3% ± 2.5%). Each trial consisted of 180 minutes of exercise (six 30-minute cycles: 8 minutes at 40% VO2max; 8 minutes, 60% VO2max; 8 minutes, 40% VO2max; 6 minutes, passive rest) followed by 60 minutes of passive recovery.Main Outcome Measure(s)We used the Landing Error Scoring System and Balance Error Scoring System (BESS) to measure movement technique and postural control at pre-exercise, postexercise and passive rest (POSTEX), and 24 hours postexercise (POST24). Differences were assessed using separate mixed-design (trial × time) repeated-measures analyses of variance.ResultsThe magnitude of hypohydration at POSTEX was different among EUR, EUD, and HYD trials (0.2% ± 1%, 3.5% ± 1%, and 5% ± 0.9%, respectively; P < .05). We observed no differences in Landing Error Scoring System scores at pre-exercise (2.9 ± 1.6, 3.0 ± 2.1, 3.0 ± 2.0), POSTEX (3.3 ± 1.5, 3.0 ± 2.0, 3.1 ± 1.9), or POST24 (3.3 ± 1.9, 3.2 ± 1.4, 3.3 ± 1.6) among the EUD, EUR, and HYD trials, respectively (P = .90). Hydration status did not affect BESS scores (P = .11), but BESS scores at POSTEX (10.4 ± 1.1) were greater than at POST24 (7.7 ± 0.9; P = .03).ConclusionsWhereas exercise-induced dehydration up to 5% body mass did not impair movement technique or postural control 24 hours after a prolonged bout of exercise in a hot environment, postural control was impaired at 60 minutes after prolonged exercise in the heat. Consideration of the length of recovery time between bouts of exercise in hot environments is warranted.  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