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   2786篇
  免费   151篇
  国内免费   21篇
耳鼻咽喉   28篇
儿科学   91篇
妇产科学   49篇
基础医学   276篇
口腔科学   263篇
临床医学   240篇
内科学   574篇
皮肤病学   20篇
神经病学   156篇
特种医学   88篇
外科学   474篇
综合类   21篇
一般理论   1篇
预防医学   359篇
眼科学   14篇
药学   220篇
中国医学   1篇
肿瘤学   83篇
  2023年   5篇
  2022年   6篇
  2021年   41篇
  2020年   31篇
  2019年   45篇
  2018年   50篇
  2017年   41篇
  2016年   44篇
  2015年   38篇
  2014年   70篇
  2013年   149篇
  2012年   153篇
  2011年   174篇
  2010年   90篇
  2009年   78篇
  2008年   187篇
  2007年   199篇
  2006年   184篇
  2005年   196篇
  2004年   191篇
  2003年   198篇
  2002年   183篇
  2001年   40篇
  2000年   25篇
  1999年   56篇
  1998年   48篇
  1997年   45篇
  1996年   38篇
  1995年   21篇
  1994年   28篇
  1993年   28篇
  1992年   22篇
  1991年   26篇
  1990年   18篇
  1989年   10篇
  1988年   13篇
  1987年   8篇
  1986年   7篇
  1985年   17篇
  1984年   17篇
  1983年   12篇
  1982年   19篇
  1981年   24篇
  1980年   14篇
  1979年   10篇
  1978年   12篇
  1976年   7篇
  1975年   6篇
  1974年   5篇
  1966年   4篇
排序方式: 共有2958条查询结果,搜索用时 406 毫秒
91.
92.
A novel virtual screening methodology called fragment‐ and negative image‐based (F‐NiB) screening is introduced and tested experimentally using phosphodiesterase 10A (PDE10A) as a case study. Potent PDE10A‐specific small‐molecule inhibitors are actively sought after for their antipsychotic and neuroprotective effects. The F‐NiB combines features from both fragment‐based drug discovery and negative image‐based (NIB) screening methodologies to facilitate rational drug discovery. The selected structural parts of protein‐bound ligand(s) are seamlessly combined with the negative image of the target's ligand‐binding cavity. This cavity‐ and fragment‐based hybrid model, namely its shape and electrostatics, is used directly in the rigid docking of ab initio generated ligand 3D conformers. In total, 14 compounds were acquired using the F‐NiB methodology, 3D quantitative structure–activity relationship modeling, and pharmacophore modeling. Three of the small molecules inhibited PDE10A at ~27 to ~67 μM range in a radiometric assay. In a larger context, the study shows that the F‐NiB provides a flexible way to incorporate small‐molecule fragments into the drug discovery.  相似文献   
93.
94.
95.
Objective : To resolve if TBX22 mutations cause isolated tongue-tie in the Finnish population. Design : Mutation analysis of the coding region of the TBX22 gene in 50 Finnish isolated tongue-tie patients and 61 control samples. Results : One putative sequence variation was identified from two male patients, but whether this represents a polymorphism or causative mutation remains unknown. Conclusions : Mutations in the coding region of the TBX22 gene are not a major cause of ankyloglossia in the Finnish population and do not explain the sex difference or inheritance of tongue-tie.  相似文献   
96.
Missing a canine is of serious concern in social life of a patient in most of societies. While conventional fixed partial dentures and implant-supported restorations may often be the treatment of choice, fiber-reinforced composite (FRC) resins offer a conservative, fast and cost-effective alternative for single and multiple teeth replacement. This clinical report presents two cases where FRC technology was successfully used to restore canine edentulous area in terms of esthetic-cosmetic values and functionality.  相似文献   
97.
P Jaako  S Debnath  K Olsson  D Bryder  J Flygare  S Karlsson 《Blood》2012,120(11):2225-2228
Diamond-Blackfan anemia (DBA) is a congenital erythroid hypoplasia caused by a functional haploinsufficiency of genes encoding for ribosomal proteins. Recently, a case study reported a patient who became transfusion-independent in response to treatment with the amino acid L-leucine. Therefore, we have validated the therapeutic effect of L-leucine using our recently generated mouse model for RPS19-deficient DBA. Administration of L-leucine significantly improved the anemia in Rps19-deficient mice (19% improvement in hemoglobin concentration; 18% increase in the number of erythrocytes), increased the bone marrow cellularity, and alleviated stress hematopoiesis. Furthermore, the therapeutic response to L-leucine appeared specific for Rps19-deficient hematopoiesis and was associated with down-regulation of p53 activity. Our study supports the rationale for clinical trials of L-leucine as a therapeutic agent for DBA.  相似文献   
98.
ObjectiveThe clinical presentation of coeliac disease has changed and patients are often overweight at diagnosis. There is concern that patients might gain further weight while on a gluten-free diet (GFD). The aim of the study was to evaluate the impact of a GFD on the body mass index (BMI) in a nationwide cohort of coeliac patients and to determine variables predictive of favourable or unfavourable BMI changes.MethodsWe prospectively investigated weight and disease-related issues in 698 newly detected adults diagnosed due to classical or extraintestinal symptoms or by screening. BMI at diagnosis and after one year on a GFD were assessed and compared with that in the general population.ResultsAt diagnosis, 4% of subjects were underweight, 57% normal, 28% overweight and 11% obese. On a GFD, 69% of underweight patients gained and 18% of overweight and 42% of obese lost weight; in the rest BMI remained stable. Changes were similar in both symptom- and screen-detected patients. The coeliac group had a more favourable BMI pattern than the general population. Favourable BMI changes were associated with subjects' self-rated expertise on GFD and young age at diagnosis, but not dietary counselling received.ConclusionsBMI improved similarly in screen- and symptom-detected coeliac disease patients on a GFD.  相似文献   
99.
100.
Objective--To evaluate whether electroencephalography (EEG) recovery could be considered a reliable marker of brain injury after experimental hypothermic circulatory arrest (HCA). Design--Cortical electrical activity was registered before and after a 75-min period of HCA in 27 pigs that survived 7 days after the experiment. The sum of EEG bursts was counted as a percentage of the sum of artifact-free bursts and suppressions, and this percentage was used as a measure of EEG activity in the analysis. Results--Brain infarction developed in 13 animals (48.1%), in 12 cases (44.4%) having involved the cortex, in 1 case the thalamus (3.7%) and in another the hippocampus (3.7%). The mean EEG burst percentage significantly correlated with the total brain histopathological score (ρ?=??0.588, P?=?0.001). EEG burst percentage from the 2?h 20?min to the 7?h 20?min interval correlated with the total brain histopathological score and with the cortex, brainstem and cerebellum scores. The mean EEG burst percentage rate was higher, but not significantly, among the animals without brain infarction (38.5% vs 32.4%), but such a difference was significant at the 3?h 20?min postoperative interval (P?=?0.02). The mean EEG burst percentage significantly correlated with brain glucose concentration at the 1?h interval (ρ?=?0.387; P?=?0.046), brain lactate concentration at the 2?h interval (ρ?=??0.431; P?=?0.025), and the brain lactate/glucose ratio at the 1?h 30?min interval from the start of rewarming (ρ?=??0.433; P?=?0.024). Conclusion--A decreased EEG burst percentage seems to be associated with an increased risk of developing histologically evident brain ischemic injury in the cortex, brainstem and cerebellum after experimental HCA.  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