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   233篇
  免费   52篇
  国内免费   1篇
  2024年   1篇
  2023年   4篇
  2022年   13篇
  2021年   20篇
  2020年   14篇
  2019年   17篇
  2018年   16篇
  2017年   21篇
  2016年   14篇
  2015年   11篇
  2014年   14篇
  2013年   20篇
  2012年   12篇
  2011年   7篇
  2010年   6篇
  2009年   3篇
  2008年   8篇
  2007年   11篇
  2006年   4篇
  2005年   8篇
  2004年   10篇
  2003年   3篇
  2002年   3篇
  2001年   7篇
  2000年   2篇
  1999年   3篇
  1998年   5篇
  1997年   5篇
  1996年   1篇
  1995年   2篇
  1994年   1篇
  1993年   3篇
  1992年   1篇
  1990年   1篇
  1988年   2篇
  1987年   2篇
  1986年   3篇
  1985年   2篇
  1984年   1篇
  1982年   2篇
  1979年   1篇
  1978年   1篇
  1976年   1篇
排序方式: 共有286条查询结果,搜索用时 687 毫秒
91.
92.
Chemical communication plays an essential role in several social and reproductive behaviors of many animals. In lizards, the main sources of semiochemicals are femoral or pre‐anal gland secretions and feces. In male lizards Psammodromus algirus, there are age‐related differences in the chemical composition of femoral gland secretions and in the reproductive strategies, with older males defending territories and females, while younger males adopting sneak‐mating strategies. Females flee more often from mating advances of young males than from those of old males, which are more successful in obtaining matings. This suggests that age discrimination of males may be important for females. We tested here whether females showed differential chemosensory responses to chemical cues (femoral gland secretion and feces) of males of two age classes, and whether females use information from substrate scent marks of males of different ages to select where to stay. We found that females elicited more tongue‐flicks to the secretion and feces of old males than to control or secretion and feces of young males. Also, the time spent by females on a scented paper depended on the treatment, suggesting that females tended to spend more time on scent marks made with femoral secretions of old males. Adult females seemed capable to discriminate between young and old males based on chemical cues alone and showed more interest in scents of old males. However, substrate scent marks did not seem to entirely determine site selection by females, suggesting that females might need additional cues to perform the choice. These results can be explained by the different age‐dependent reproductive strategies of males, which can affect differentially to females.  相似文献   
93.
The injury and dysfunction of the femoral head microvascular endothelial cells are associated with the pathogenesis of glucocorticoid‐induced osteonecrosis of the femoral head (ONFH). Reports indicate that icariin (ICA) can enhance vascular roles and also inhibit endothelial cell dysfunction. However, it still remains unclear whether ICA can promote angiogenesis in glucocorticoid‐induced ONFH. In this study, we investigate this hypothesis through in vitro and in vivo experiments. Results showed that 0.1 mg/mL hydrocortisone significantly suppressed bone microvascular endothelial cells (BMECs) proliferation while ICA at 10?5 mol/L reversed this inhibition. ICA significantly promoted BMECs migration, tube formation, the angiogenesis‐related cytokines expression and the activation of Akt. Furthermore, ICA enhanced Bcl‐2 expression but diminished Bax expression. According to in vivo results, rats with ICA treatment exhibited a lower ratio of empty lacunae, higher volume of blood vessels and more CD31‐positive cells. This study revealed that ICA promotes angiogenesis of BMECs in vitro and improves femoral head blood vessel volume of rats treated with glucocorticoid, suggesting the efficacy of ICA in the prevention of glucocorticoid‐induced ONFH.  相似文献   
94.

Background

Avascular necrosis (AVN) of femoral head is a progressive bone disease due to ischemia of femoral head; patients experience pain and they can not do normal activity. There is not an effective way to treat the cause of this disease. In recent studies, treatment of this disease using pluripotent stem cell–derived mesenchyme is safe and effective, but this method needs more investigation. In this study, the safety and efficacy of CD133+ cells were evaluated as a novel method of stem cell therapy to treat AVN.

Methods

In this prospective quasi-experimental study, the participants were selected among patients with AVN who were referred to the Royan Cell Therapy Center. Autologous bone marrow–derived CD133+ cells were injected into the necrotic site of the femoral head during core decompression (CD). The Visual Analogue Scale (VAS), Harris Hip Score (HHS), Western Ontario and McMaster Universities Arthritis Index (WOMAC) and walking distance (WD) were measured before and 2, 6 and 12 months after CD.

Results

Overall, nine patients (six men and three women) were investigated in this study. Their mean age was 26 years old. All of them significantly improved in VAS, HHS, WOMAC and WD scores and they could do more activity without pain. Also, imaging findings demonstrated significant reductions in joint injuries. Significant complications were not seen in patients.

Discussion

This prospective quasi-experimental study demonstrated that, in patients with AVN, a single bone marrow–derived CD133+ cell injection into the necrotic site of the femoral head during CD is safe and effective in providing significant, clinically relevant pain relief and patients could do more activity over 2, 6 and 12 months. This pilot study suggested further clinical trials over an extended assessment period to approve bone marrow–derived CD133+ cell injection to treat AVN.  相似文献   
95.
Femoral head size provides important information on body size in extinct species. Although it is well‐known that femoral head size is correlated with acetabular size, the precision with which femoral head size can be estimated from acetabular size has not been quantified. The availability of accurate 3D surface models of fossil acetabular remains opens the possibility of obtaining accurate estimates of femoral head size from even fragmentary fossil remains [Hammond et al.,: Am J Phys Anthropol 150 (2013) 565–578]. Here we evaluate the relationship between spheres fit to surface models of the femoral head and acetabulum of a large sample of extant anthropoid primates. Sphere diameters are tightly correlated and scale isometrically. In spite of significant taxonomic and possibly functional differences in the relationship between femoral head size and acetabulum size, percent prediction errors of estimated femoral head size remain low regardless of the taxonomic composition of the reference sample. We provide estimates of femoral head size for a series of fossil hominins and monkeys. Am J Phys Anthropol 155:469–475, 2014. © 2014 Wiley Periodicals, Inc.  相似文献   
96.
目的:本研究通过观察微创锁定钢板接骨术治疗老年股骨近端粉碎骨折临床效果,旨在找出最佳治疗方式。方法:自2007年12月~2010年03月,应用股骨近端锁定加压钢板治疗老年股骨近端粉碎骨折23例。记录术中出血量、手术时间,术后并发症、骨折愈合时间及最后一次随访时功能恢复情况。结果:骨折临床愈合时间为12~28周,平均16周。除1例患者髋内翻畸形,1例锁定加压钢板断裂外,其他患者均达到骨性愈合。结论:股骨近端锁定钢板具有创伤小、固定可靠、骨折愈合快、功能恢复满意的特点,尤其适用于老年股骨近端粉碎骨折。  相似文献   
97.
目的:分析与股骨头缺血坏死相关临床与影像资料,以期提高影像科医生对该病的认识水平,提高股骨头缺血坏死的诊断正确率,防止与其相关的髋关节疾病的误诊。方法:回顾性分析26例误诊为股骨头缺血坏死的髋关节疾患,归纳分类疾病的种类,找出原因。结果:类风湿性髋关节炎、强直性脊柱炎髋关节炎和痛风性髋关节炎、先天性髋臼发育不良、股骨颈干角发育异常、髋关节骨关节病等疾病易与股骨头缺血坏死相混淆,引起误诊。结论:病史采集不详细、思路狭窄,对类风湿、强直性脊柱炎及痛风性关节炎所致髋关节病变认识不足或不了解、股骨头缺血坏死病理过程不清楚、临床误导等因素与股骨头缺血坏死的误诊有关。  相似文献   
98.
目的:制备万古霉素脂质体抗生素缓释系统,研究该缓释系统在治疗兔人工股骨头置换术后感染中的作用,为临床的进一步应用提供理论基础和实验依据。方法 :建立兔人工股骨头置换术后感染模型,将配置好的万古霉素-脂质体药物释放系统、万骨霉素于术中即分别放入关节腔及髓腔内,同时设对照组。大体观察左侧髋关节及观察右髋关节的活动度。实验动物于人工股骨头置换术后即刻、第4、8周,分别行髋关节X线摄片检查。实验动物建立感染模型6周后,分别取关节腔内肉芽组织或假膜组织,观察细菌生长情况,计数细菌菌落。并用4%的甲醛溶液固定组织,石蜡包埋(骨组织先用EDTA脱钙处理),HE染色,光镜观察组织炎细胞浸润状况。实验动物建立感染模型术前和术后第1、3、6周后,测定血清C-反应蛋白和血沉的变化。结果:成功建立了兔人工股骨头置换术后感染模型,各组兔人工股骨头置换术后股骨头均在位,经万古霉素-脂质体药物释放系统治疗后,万古霉素-脂质体组翻修术后8周X线结果提示关节间隙清晰,无明显骨缺损即透亮线形成,而万古霉素-骨水泥组置换术前后对比片,无明显变化。对照组感染未控制者术后6周X线结果显示,关节间隙模糊,假体及股骨结合部出现轻度骨吸收。细菌培养结果显示,空白对照组中实验动物细菌感染率为100%,而加入万古霉素后,万古霉素-PMMA组的实验动物细菌感染率为33.3%,显著降低;万古霉素-脂质体组实验动物细菌感染率为16.7%,与万古霉素-PMMA组相比,感染率显著降低(P<0.05);联合应用万古霉素-PMMA和万古霉素-脂质体,与其它组相比较,感染率显著降低(P<0.05),提示这种模式具有良好的抑菌效果。病理组织切片,发现实验动物建立感染模型6周后,空白对照组中实验动物感染人工股骨头周围股骨组织明显充血及炎性细胞浸润,万古霉素-PMMA组、万古霉素-脂质体组和万古霉素-脂质体组+万古霉素-PMMA的实验动物,炎性细胞浸润明显减少,提示术后关节周围细菌感染得到了有效的抑制。与术前相比较,各组CRP均显著升高(P<0.01),而经过万古霉素-PMMA组、万古霉素-脂质体组和万古霉素-脂质体组+万古霉素-PMMA治疗的实验动物,CRP均显著低于空白对照组中实验动物(P<0.05)。结论:本实验中首先建立兔人工股骨头置换术后感染模型,并观察了万古霉素-脂质体药物释放系统对兔人工股骨头置换术后感染的效应,通过X线检查、细菌培养、病理组织切片观察以及血清C-反应蛋白和血沉变化的测定,结果表明,通过上述方法制备的万古霉素脂质体对于人工股骨头置换术后感染具有良好的预防和治疗作用,为临床的进一步应用提供了初步的实验基础和理论依据。  相似文献   
99.
不同影像方法对股骨头缺血坏死的诊断价值   总被引:2,自引:0,他引:2  
目的:研究早期股骨头无菌性坏死(aseptic necrosis of the femoral head,ANFH)的不同影像方法(X-ray、CT、MRI)诊断价值。方法:34例双侧股骨头行X线、CT和MRI检查,分析其对早期ANFH的显示能力。结果:34例患者均存在早期骨坏死表现。X线发现Ⅰ-Ⅱ期ANFH 14例,诊断准确率41.18%;CT发现Ⅰ-Ⅱ期ANFH 19例,诊断准确率57.35%;MRI发现Ⅰ-Ⅱ期ANFH 27例,诊断准确率为77.94%。结论:X线平片难以发现ANFH的早期表现,MR结合螺旋CT扫描既可发现早期病变,又可进行分期,是研究早期ANFH的可靠手段。  相似文献   
100.
目的:探讨比较运用逆行可膨胀髓内钉与股骨远端锁定钢板治疗股骨远端33A、33C1型骨折的疗效。方法:对2013年3月至2015年6月收治并符合纳入标准的43例股骨远端33A、33C1型骨折患者进行回顾性研究。按照不同的手术固定方式分为逆行可膨胀髓内钉组(n=18)和锁定钢板组(n=25),记录并比较两组手术时间、失血量、愈合时间及功能结果、术中及术后并发症。结果:所有骨折最终都获得愈合;逆行可膨胀髓内钉组在手术时间及失血量上都显著低于锁定钢板组,两组在愈合时间及功能评定方面无明显差异;5例开放性骨折的患者中1例出现浅表伤口感染,1例患者延迟愈合。结论:股骨远端逆行可膨胀髓内钉在获得与锁定钢板相当的骨折愈合时间及患肢功能的情况下,具有操作简单、手术时间短、失血量少等特点,对于股骨远端33A、33C1型骨折来说是一个较好的选择。  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