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   412篇
  免费   157篇
  国内免费   13篇
  2024年   3篇
  2023年   31篇
  2022年   19篇
  2021年   56篇
  2020年   34篇
  2019年   39篇
  2018年   25篇
  2017年   26篇
  2016年   27篇
  2015年   46篇
  2014年   60篇
  2013年   37篇
  2012年   36篇
  2011年   41篇
  2010年   8篇
  2009年   8篇
  2008年   13篇
  2007年   12篇
  2006年   13篇
  2005年   12篇
  2004年   7篇
  2003年   5篇
  2002年   4篇
  2001年   1篇
  1999年   4篇
  1998年   3篇
  1997年   1篇
  1996年   2篇
  1995年   1篇
  1993年   2篇
  1991年   1篇
  1990年   2篇
  1989年   1篇
  1985年   1篇
  1980年   1篇
排序方式: 共有582条查询结果,搜索用时 109 毫秒
81.
Glucagon-like peptide-1 (GLP-1) has been proved to have effects of anti-hyperglycemia and β-cell preservation. However, it is still unclear whether there are differences between early and late GLP-1 intervention in type 2 diabetes mellitus (T2DM). We divided the mice into 5 groups: early treated group (n = 7, 8-week old, fasting glucose > 10 mmol/l), late treated group (n = 7, 10-week old, fasting glucose > 20 mmol/l), early control group (n = 7), late control group (n = 7) and wild type group (n = 7). Treated group was injected with liraglutide (a GLP-1 analog) 300 μg/kg bid for 4 weeks, while control group was given saline at the same time. The results showed that compared with control group, food intake and body weight gain were reduced in both early and late treated group (p < 0.05), and there was no significance between the two treated groups. Early liraglutide intervention showed better improvements in glucose control, acute insulin response to glucose (AIRg) and disposition index (before vs. after treatment, AIRg 1.01 ± 0.53 vs. 2.98 ± 0.63, disposition index 10.81 ± 0.89 vs. 27.4 ± 2.15) than late intervention (AIRg 0.99 ± 0.02 vs. 1.41 ± 0.32, disposition index 3.47 ± 0.38 vs. 6.43 ± 1.62, p = 0.001). The histopathology of the pancreas showed the estimated β-cell mass (BCM) was increased more in early treated group than that in late one (0.03 vs. 0.01 g). Expressions of the proliferation related genes PDX-1, MafA and GLP-1 receptor (GLP-1R) in early treated group were 1.81, 2.57 and 1.59 times as much as that in late treated group. In conclusion, early liraglutide intervention was better in glucose control, β-cell function improvement and β-cell mass preservation.  相似文献   
82.
There is a paucity of literature comparing patient and staff dose during coronary angiography (CA), implantable cardiac devices, permanent pacemakers (PPM) and electrophysiology (EP) procedures and little noting dose to staff other than cardiologists. This study sought to compare patient and occupational dose during a range of fluoroscopically guided cardiac procedures. Radiation dose levels for the patients (n = 1651), cardiologists (n = 24), scrub (n = 32) and scout nurses (n = 35) were measured in a prospective single-centre study between February 2017 and August 2019. A comparison of dose during CA, device implantation, PPM insertion and EP studies was performed. Three angiographic units were used, with dosimeters worn on the temple of staff. Results indicated that occupational dose during PPM was significantly higher than other procedures. The cardiologist had the highest mean dose during biventricular implantable cardioverter-defibrillators; levels were approximately five times that of ‘normal’ pacemaker insertions. Transcatheter aortic valve implantations (TAVI) were associated with relatively high mean doses for both staff and patients and had a statistically significant higher (>2 times) mean patient dose area product than all other categories. TAVI workups were also related to higher mean cardiologist and scrub nurse dose. It was observed that the mean scrub nurse dose can exceed that of the cardiologist. The highest mean dose for Scout nurses were recorded during EP studies. Given the significantly higher temple dose associated with PPM insertion, cardiologists should consider utilizing ceiling mounted lead shields, lead glasses and/or skull caps where possible. Efforts should also be made to minimize the use of DSA during TAVI and TAVI workups to reduce cardiologist, nurse and patient dose.  相似文献   
83.
84.
85.
As psychiatric genetics enters an era where gene identification is finally yielding robust, replicable genetic associations and polygenic risk scores, it is important to consider next steps and delineate how that knowledge will be applied to ultimately ameliorate suffering associated with substance use and psychiatric disorders. Much of the post‐genome‐wide association study discussion has focused on the potential of genetic information to elucidate the underlying biology and use this information for the development of more effective pharmaceutical treatments. In this review we focus on additional areas of research that should follow gene identification. By taking genetic findings into longitudinal, developmental studies, we can map the pathways by which genetic risk manifests across development, elucidating the early behavioral manifestations of risk, and studying how various environments and interventions moderate that risk across developmental stages. The delineation of risk across development will advance our understanding of mechanism, sex differences and risk and resilience processes in different racial/ethnic groups. Here, we review how the extant twin study literature can be used to guide these efforts. Together, these new lines of research will enable us to develop more informed, tailored prevention and intervention efforts.  相似文献   
86.
目的:探讨低位胆道恶性梗阻性黄疸患者术前胆红素异常的处理策略,以提高该类患者的临床疗效。方法:回顾性分析西京医院肝胆外科2008年1月1日-2017年12月31日收治的符合研究条件的134例低位胆道恶性梗阻性黄疸(术前总胆红素≥171μmol/L)患者,按胆红素水平分为中、重度黄疸组,分析和比较两组术前黄疸的处理方法、术后肝功能、并发症情况等。结果:两组患者胆道引流后总胆红素水平均明显低于引流前,而肝功能Child-Pugh分级比较差异均无统计学意义(P0.05);两组行术前胆道引流患者与未行胆道引流患者的围手术期情况比较均无统计学差异(P0.05);两组行术前胆道引流患者与未行胆道引流患者的手术并发症的发生情况比较均无统计学差异(P0.05)。结论:对于低位胆道恶性梗阻性黄疸患者,无论中度黄疸还是重度黄疸,原则上术前不必行胆道引流。对于伴有脏器功能不全、急性炎症或其他暂不宜手术的患者,可先行胆道引流处理,限期手术。若行术前胆道引流,采用PTCD方式,更为简单安全有效。  相似文献   
87.
目的:分析有无心脏外科支持的经皮冠状动脉介入术(PCI)病例的特点及转归差异。方法:回顾性分析2308例行PCI术患者的病例资料,根据心脏外科支持情况分为支持组(2031例)、无支持组(277例),比较两组患者的基线资料、PCI术相关指标及主要不良心血管事件(MACE)的发生情况。结果:与支持组比较,无支持组患者的医疗费用明显增加,急诊PCI、危险因素中AMI病史、PCI史、疾病诊断中STEMI的比例明显降低,LVEF明显升高,差异均有统计学意义(P0.05)。支持组以三支及以上冠脉病变以及B、C型复杂病变形态多见,支架置入数、左主干病变比例明显增多,靶血管IVUS比例检查比例、术中总并发症发生率明显降低,与无支持组比较差异均有统计学意义(P0.05)。两组PCI术后MACE的发生率比较差异均无统计学意义(P0.05)。结论:有无心脏外科支持的PCI患者的临床特点存在较大差异,无心脏外科支持的PCI患者以急诊手术为主,且靶血管病变相对较轻。对于低风险病例实施PCI手术是安全可行的,具有较高成功率,预后尚可。  相似文献   
88.

Purpose

Today's orthotics should be designed to apply the external orthosis moment to the knee joint solely during the stance phase instead of the entire gait cycle. The aim of this study was to validate the reliability of a simple device for measuring forces at the leg–orthosis interface and describe the behavior of an innovating dynamic unloader knee brace built to interrupt its mechanical action during large knee flexion (swing phase of gait).

Methods

A compression testing machine was used to apply known (standard) forces to the device (modeled forces) and the results were compared.

Results

The low absolute mean bias (4%), the narrow agreement limits associated with the Bland and Altman analysis as well as the significant linear correlation (r=0.99; p<0.001) validate the agreement between standard and modeled forces. Likewise, the low standard error of measurement between trials (1.3%) and the intraclass correlation coefficient (1.00) reflect high test-retest reliability.

Conclusion

These results demonstrate the validity of the proposed device for measuring constraints induced by the dynamic unloader knee brace. An example of an application is provided through an orthosis moment calculation using kinematic data, which reveal a changeable mechanical action, necessary to improve comfort resulting in potentially better compliance.  相似文献   
89.
目的:系统评价有氧运动、抗阻运动、有氧联合抗阻运动三种不同干预方式对糖尿病前期人群血糖的影响。方法:制定文献检索策略,检索PubMed、EMBASE、EBSCO外文数据库以及CNKI、Wanfang中文数据库,以手工查阅检出文献和相关参考文献作为补充,查找符合纳入标准的随机对照试验进行质量评价,运用RevMan5.2统计软件对纳入的数据进行Meta分析,运动干预组和对照组间指标采用均数差(MD)评价。结果:共纳入原始文献8篇,与对照组相比,不同运动干预方式的综合效应对空腹血糖指标无显著性影响,与按不同干预方式进行亚组分析结果一致;有氧运动及有氧联合抗阻运动对餐后2h血糖指标有显著性降低的作用(P < 0.05);有氧运动对胰岛素抵抗指数有显著降低作用。结论:对糖尿病前期人群,运动干预对餐后2 h血糖、胰岛素抵抗指数的影响与运动方式有关,但对空腹血糖的作用尚不能确定。  相似文献   
90.
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