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   22227篇
  免费   1154篇
  国内免费   228篇
耳鼻咽喉   283篇
儿科学   561篇
妇产科学   518篇
基础医学   2402篇
口腔科学   646篇
临床医学   1844篇
内科学   6111篇
皮肤病学   362篇
神经病学   2339篇
特种医学   924篇
外科学   3426篇
综合类   62篇
一般理论   4篇
预防医学   825篇
眼科学   289篇
药学   1289篇
中国医学   36篇
肿瘤学   1688篇
  2023年   231篇
  2022年   479篇
  2021年   854篇
  2020年   501篇
  2019年   635篇
  2018年   772篇
  2017年   592篇
  2016年   620篇
  2015年   716篇
  2014年   882篇
  2013年   1147篇
  2012年   1761篇
  2011年   1714篇
  2010年   956篇
  2009年   916篇
  2008年   1444篇
  2007年   1364篇
  2006年   1300篇
  2005年   1223篇
  2004年   1081篇
  2003年   890篇
  2002年   852篇
  2001年   271篇
  2000年   249篇
  1999年   243篇
  1998年   165篇
  1997年   134篇
  1996年   130篇
  1995年   112篇
  1994年   77篇
  1993年   90篇
  1992年   131篇
  1991年   105篇
  1990年   100篇
  1989年   80篇
  1988年   86篇
  1987年   85篇
  1986年   57篇
  1985年   65篇
  1984年   57篇
  1983年   44篇
  1982年   27篇
  1981年   25篇
  1980年   20篇
  1979年   45篇
  1978年   25篇
  1977年   25篇
  1976年   25篇
  1975年   30篇
  1974年   28篇
排序方式: 共有10000条查询结果,搜索用时 59 毫秒
61.
62.
Annals of Surgical Oncology - The liver-first approach in patients with synchronous colorectal liver metastases (CRLM) has gained wide consensus but its role is still to be clarified. We aimed to...  相似文献   
63.
64.
BackgroundSleeve gastrectomy (SG) has become the most prevalent bariatric-metabolic surgical approach in the United States. Its popularity among surgeons and patients is mainly due to a better safety profile and less overall morbidity, with broad benefits from a systemic and metabolic perspective.ObjectiveComprehensively describe the short-term multiorgan metabolic effects of rapid weight loss after SG.SettingAcademic hospital, United States.MethodsWe retrospectively reviewed the charts of patients that underwent SG at our institution between 2012 and 2016. We analyzed the required variables to calculate multiple risk scores, such as cardiovascular, hypertension, and diabetes risk scores. Furthermore, the renal and hepatic functions and the metabolic and hematologic profiles were assessed at 12 months of follow-up.ResultsA total of 1002 patients were included in the analysis. The percentage of excess body mass index loss was, on average, 65% at 12 months of follow-up. We observed a positive cardio-renal-hepatic improvement, demonstrated by a substantial reduction of the 10-year cardiovascular risk. We noticed an improvement of renal function, which was more significant in chronic kidney disease (stage ≥2), and a significant improvement on liver function tests (measured by decreased aspartate aminotransferase and alanine transaminase) at 12 months of follow-up. Our data also show a positive impact on decreasing the risk of developing hypertension and type 2 diabetes. There was a positive impact on the lipid profile, with the exception of low-density lipoprotein.ConclusionThere are significant short-term benefits on multiorgan metabolic parameters after rapid weight loss in severely obese patients undergoing sleeve gastrectomy.  相似文献   
65.
66.
67.
We present a modeling framework designed for patient-specific computational hemodynamics to be performed in the context of large-scale studies. The framework takes advantage of the integration of image processing, geometric analysis and mesh generation techniques, with an accent on full automation and high-level interaction. Image segmentation is performed using implicit deformable models taking advantage of a novel approach for selective initialization of vascular branches, as well as of a strategy for the segmentation of small vessels. A robust definition of centerlines provides objective geometric criteria for the automation of surface editing and mesh generation. The framework is available as part of an open-source effort, the Vascular Modeling Toolkit, a first step towards the sharing of tools and data which will be necessary for computational hemodynamics to play a role in evidence-based medicine.  相似文献   
68.
Retinoids in embryonal development   总被引:30,自引:0,他引:30  
The key role of vitamin A in embryonal development is reviewed. Special emphasis is given to the physiological action of retinoids, as evident from the retinoid ligand knockout models. Retinoid metabolism in embryonic tissues and teratogenic consequences of retinoid administration at high doses are presented. Physiological and pharmacological actions of retinoids are outlined and explained on the basis of their interactions as ligands of the nuclear retinoid receptors. Immediate target genes and the retinoid response elements of their promoters are summarized. The fundamental role of homeobox genes in embryonal development and the actions of retinoids on their expression are discussed. The similarity of the effects of retinoid ligand knockouts to effects of compound retinoid receptor knockouts on embryogenesis is presented. Although much remains to be clarified, the emerging landscape offers exciting views for future research.  相似文献   
69.
Germline p53 mutations are associated with cancer predisposition in Li-Fraumeni families as well as in individuals with component tumors of the syndrome. In the majority of cases these mutations have been shown to be inherited rather than de novo. We screened 59 children with primary bone or soft tissue sarcomas. Germline p53 mutations were identified in 2 patients. Interestingly, analysis revealed that both mutations were de novo. Although the frequency of germline p53 mutations in primary pediatric sarcoma patients is low, there is evidence for the importance of considering pediatric patients for testing for de novo mutations.  相似文献   
70.
In an earlier posturographic investigation (Collins and De Luca 1993) it was proposed that open-loop and closed-loop control mechanisms are involved in the regulation of undisturbed, upright stance. In this study, stabilogram-diffusion analysis was used to examine how visual input affects the operational characteristics of these control mechanisms. Stabilogram-diffusion analysis leads to the extraction of repeatable center-of-pressure (COP) parameters that can be directly related to the resultant steady-state behavior and functional interaction of the neuromuscular mechanisms underlying the maintenance of erect posture. Twenty-five healthy male subjects (aged 19–30 years) were included in the study. An instrumented force platform was used to measure the time-varying displacements of the COP under each subject's feet during quiet standing. The subjects were tested under eyes-open and eyes-closed conditions. The COP trajectories were analyzed as one-dimensional and two-dimensional random walks, according to stabilogram-diffusion analysis. Using this technique, it was found that visual input affects the performance of the postural control system in one of two different ways — either it significantly modifies the steady-state behavior of the open-loop postural control mechanisms, or it significantly alters the characteristics of the other closed-loop feedback mechanisms that are involved in balance control. This result is interpreted as an indication that the visual system is integrated into the postural control system in one of two different ways. The experimental population was roughly evenly divided between these two schemes. For the first group (13 of 25 subjects), visual input principally caused a decrease in the effective stochastic activity of the open-loop control mechanisms in both the mediolateral and anteroposterior directions. For the second group (12 of 25 subjects), visual input caused an increase in the effective stochastic activity and uncorrelated behavior of the closed-loop control mechanisms in the anteroposterior direction only. On the basis of these results, it is hypothesized that visual input, in both schemes, serves to decrease the stiffness of the musculoskeletal system. In the former case, this may be accomplished by decreasing the level of muscular activity across the joints of the lower limb, whereas, in the latter case, reduced stiffness may be achieved by reducing the gain(s) of the other postural feedback mechanisms, i.e., the proprioceptive and/or vestibular systems. Using stabilogram-diffusion analysis, it was also found that the two groups of subjects behaved similarly under eyes-closed conditions. This result suggests that the open-loop postural control mechanisms and reflex-based feedback systems, respectively, of healthy, young individuals are organized in functionally equivalent ways.  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