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   758篇
  免费   26篇
  国内免费   18篇
耳鼻咽喉   4篇
儿科学   2篇
妇产科学   17篇
基础医学   39篇
口腔科学   55篇
临床医学   56篇
内科学   190篇
皮肤病学   24篇
神经病学   9篇
特种医学   21篇
外科学   92篇
综合类   103篇
一般理论   1篇
预防医学   53篇
眼科学   26篇
药学   40篇
中国医学   62篇
肿瘤学   8篇
  2024年   1篇
  2023年   24篇
  2022年   70篇
  2021年   80篇
  2020年   29篇
  2019年   27篇
  2018年   12篇
  2017年   20篇
  2016年   14篇
  2015年   22篇
  2014年   52篇
  2013年   56篇
  2012年   34篇
  2011年   38篇
  2010年   34篇
  2009年   23篇
  2008年   20篇
  2007年   29篇
  2006年   16篇
  2005年   23篇
  2004年   13篇
  2003年   18篇
  2002年   23篇
  2001年   14篇
  2000年   5篇
  1999年   13篇
  1998年   7篇
  1997年   11篇
  1996年   9篇
  1995年   15篇
  1994年   6篇
  1993年   2篇
  1992年   5篇
  1991年   5篇
  1990年   3篇
  1989年   5篇
  1988年   5篇
  1987年   3篇
  1986年   6篇
  1984年   3篇
  1983年   2篇
  1982年   2篇
  1980年   1篇
  1979年   1篇
  1975年   1篇
排序方式: 共有802条查询结果,搜索用时 15 毫秒
21.
本研究旨在探索不同切碎长度和发酵方式对全株饲用青贮谷子质量的影响。采用2×3双因子试验设计,切割长度分别为1.5 cm、2.5 cm和3.5 cm,发酵方式分为复合菌剂发酵和乳酸菌发酵两个类型,每处理3个重复。常温发酵40 d后取样,进行感官评定,分析基础养分,测定挥发性成分。结果表明,随着切碎长度增加,气味评分和总分总体呈降低趋势,中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量呈增加趋势,丁酸含量显著增加;相比乳酸菌发酵组,复合菌剂发酵组整体气味评分和乳酸含量较高,pH值和NDF、ADF含量较低。综上,不同切碎长度和发酵方式对于全株饲用谷子青贮质量均有显著影响。降低切碎长度和使用复合菌剂发酵均有助于促进纤维分解,减少丁酸产量,改善青贮感官评分。  相似文献   
22.
BackgroundThree-dimensional (3D) motion analysis is considered the gold standard for evaluating human movement. However, its clinical utility is limited due to cost, operating expertise, and lengthy data processing time. Numerous qualitative scoring systems have been introduced to assess trunk and lower extremity biomechanics during functional tasks. However, the reliability of qualitative scoring systems to evaluate cutting movements is understudied. Purpose/Hypotheses: To assess the inter-rater and intra-rater reliability of the Cutting Alignment Scoring Tool (CAST) among sports medicine providers and to evaluate rater agreement of each component of the CAST. The hypotheses were: 1) there would be good–to-excellent inter-rater and intra-rater reliability among sports medicine providers, 2) there would be good to almost perfect agreement for cut width and trunk lean variables and moderate to good agreement for valgus variables of the CAST.Study DesignRepeated MeasuresMethodsTen videos of a 45-degree side-step cut performed by adolescent athletes were independently rated on two occasions by six raters (2 medical doctors, 2 physical therapists, and 2 athletic trainers). The variables assessed include trunk lean to the opposite direction of the cut, increased cut width, knee valgus at initial load acceptance (static), and knee valgus throughout the task (dynamic). Variables were scored as either present, which were given a score of “1”, or not present, which were given a score of “0”. Video sequence was randomized in each rating session, and a two-week wash out period was given.ResultsThe cumulative inter-rater and intra-rater reliabilities were good (ICC: 0.808 and ICC: 0.753). Almost perfect kappa coefficients were recorded for cut width (k=0.949). Moderate kappa coefficients were found for trunk lean (k= 0.632) and fair kappa coefficients were noted for dynamic and static valgus (k=0.462 and k= 0.533 respectively).ConclusionThese findings suggest that the CAST is a reliable tool to evaluate trunk and LE alignment during a cutting task by sports medicine providers.Level of EvidenceLevel 2 Diagnosis  相似文献   
23.
24.
The influence of cutting forces during the machining of titanium alloys has attained prime attention in selecting the optimal cutting conditions to improve the surface integrity of medical implants and biomedical devices. So far, it has not been easy to explain the chip morphology of Ti6Al4V and the thermo-mechanical interactions involved during the cutting process. This paper investigates the chip configuration of the Ti6Al4V alloy under dry milling conditions at a macro and micro scale by employing the Johnson-Cook material damage model. 2D modeling, numerical milling simulations, and post-processing were conducted using the Abaqus/Explicit commercial software. The uncut chip geometry was modeled with variable thicknesses to accomplish the macro to micro-scale cutting by adapting a trochoidal path. Numerical results, predicted for the cutting reaction forces and shearing zone temperatures, were found in close approximation to experimental ones with minor deviations. Further analyses evaluated the influence of cutting speeds and contact friction coefficients over the chip flow stress, equivalent plastic strain, and chip morphology. The methodology developed can be implemented in resolving the industrial problems in the biomedical sector for predicting the chip morphology of the Ti6Al4V alloy, fracture mechanisms of hard-to-cut materials, and the effects of different cutting parameters on workpiece integrity.  相似文献   
25.
26.
Patient matched instrumentation is a new operative tool in the field of total knee arthroplasty. Custom made cutting blocks are designed to perform distal femoral and tibial bone cuts according to a pre-operative planning. This study evaluates the Visionaire system of Smith & Nephew. Thirty-one patients, operated with the Visionaire technique, were compared to an equal control group for different clinical and radiographic outcome parameters. Between both groups, no statistical significant difference could be found in post-operative pain, satisfaction, functional outcome, hospital stay, blood loss, radiographic alignment and precision of bone cuts. Only tibial plateau backslope can be created with more precision in the Visionaire group. But there was a statistical significant difference for residual flexion deformity after a mean follow-up time of 200 days.  相似文献   
27.
Objectives: Female genital mutilation (FGM) is becoming more widely seen in the West, due to immigration and population movement. Health services are being confronted with the need to provide care for women with FGM. One of the more recent trends is the provision of clitoral reconstruction. It remains unclear, however, what constitutes good practice with regard to this type of surgery. Methods: Based on a keynote presentation about reconstructive clitoral surgery, we briefly discuss the possible consequences of FGM and the findings from recent publications on clitoral reconstruction. Recognising individual differences in women, we suggest a multidisciplinary counselling model to provide appropriate care for women requesting clitoral reconstruction. Results: The literature shows that FGM influences physical, mental and sexual health. Clitoral reconstructive surgery can lead to an increase in sexual satisfaction and orgasm in some, but not all, women. A multidisciplinary approach would enable a more satisfactory and individually tailored approach to care. The multidisciplinary team should consist of a midwife, a gynaecological surgeon, a psychologist-psychotherapist, a sexologist and a social worker. Comprehensive health counselling should be the common thread in this model of care. Our proposed care pathway starts with taking a thorough history, followed by medical, psychological and sexological consultations. Conclusions: Women with FGM requesting clitoral reconstruction might primarily be looking to improve their sexual life, to recover their identity and to reduce pain. Surgery may not always be the right answer. Thorough counselling that includes medical, psychological and sexual advice is therefore necessary as part of a multidisciplinary approach.  相似文献   
28.
The purpose of this systematic review and meta-analysis is to compare patient-specific instrumentation (PSI) versus standard instrumentation for total knee arthroplasty (TKA) with regard to coronal and sagittal alignment, operative time, intraoperative blood loss, and cost. A systematic query in search of relevant studies was performed, and the data published in these studies were extracted and aggregated. In regard to coronal alignment, PSI demonstrated improved accuracy in femorotibial angle (FTA) (P = 0.0003), while standard instrumentation demonstrated improved accuracy in hip-knee-ankle angle (HKA) (P = 0.02). Importantly, there were no differences between treatment groups in the percentages of FTA or HKA outliers (>3 degrees from target alignment) (P = 0.7). Sagittal alignment, operative time, intraoperative blood loss, and cost were also similar between groups (P > 0.1 for all comparisons).  相似文献   
29.
Patient-specific guides can improve limb alignment and implant positioning in total knee arthroplasty, although not all studies have supported this benefit. We compared the radiographs of 100 consecutively-performed patient-specific total knees to a similar group that was implanted with conventional instruments instead. The patient-specific group showed more accurate reproduction of the theoretically ideal mechanical axis, with fewer outliers, but implant positioning was comparable between groups. Our odds ratio comparison showed that the patient-specific group was 1.8 times more likely to be within the desired + 3° from the neutral mechanical axis when compared to the standard control group. Our data suggest that reliable reproduction of the limb mechanical axis may accrue from patient-specific guides in total knee arthroplasty when compared to standard, intramedullary instrumentation.  相似文献   
30.
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