背景:青壮年股骨颈骨内固定后并发股骨头坏死的预防在骨科领域仍是一项挑战,针对青壮年股骨颈骨折内固定术后并发股骨头坏死的发病机制仍是充满讨论的话题。目的:对青壮年股骨颈骨折内固定后股并发股骨头坏死的发病机制做一综述。方法:...背景:青壮年股骨颈骨内固定后并发股骨头坏死的预防在骨科领域仍是一项挑战,针对青壮年股骨颈骨折内固定术后并发股骨头坏死的发病机制仍是充满讨论的话题。目的:对青壮年股骨颈骨折内固定后股并发股骨头坏死的发病机制做一综述。方法:通过计算机检索2010-2021年PubMed、EMbase、万方数据库、维普和中国知网上关于青壮年股骨颈骨折内固定后股骨坏死的相关文献。检索中文关键词为"股骨颈骨折、股骨头坏死、有限元分析、力学、应力、螺钉、植入物、血供、分子生物学、基因"。检索英文关键词为"Femoral neck fracture,femoral head necrosis,finite element analysis,mechanics,stress,screws,implants,blood supply,molecular biology,genes"。结果与结论:青壮年股骨颈骨折内固定后内固定取出与否均可导致股骨头坏死的发生。内固定取出时易造成微骨折,甚至再骨折;内固定不取出时,伴随着内固定的长期置留,内固定物周围形成大量的硬化骨,其可能是青壮年股骨颈骨折术后股骨头坏死并快速塌陷的重要力学机制之一。通过文献分析不同骨折模型及不同类型内固定物,可知倒三角结构虽然是最优治疗方式,但其仍不可避免应力的集中,导致硬化骨的形成,最终导致股骨头的坏死塌陷。因此提出在内固定周围形成硬化骨之前,适时的取钉并置入一种新型高强度、可降解、多微孔结构及又可促进成骨血管化的内置物,避免应力集中在内固定周围,用以抑制硬化骨的形成,从而可终止股骨头坏死的发生。展开更多
Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disp...Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China＇s inbound tourism economy during 1996-2008 with the methods of a-convergence, club convergence and r-convergence. The results indicate that 1） inbound tourism receipts per capita （ITRPC） of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2） ITRPC of the whole country was characterized by convergence; 3） the eastern region presented club con- vergence, but the central and western regions did not show this trend; 4） the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism de- velopment, and there was no difference among the 31 provinces （municipalities） in the mainland of China; 5） but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the terti- ary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy.展开更多
The Center is a research organ co-established on November 11, 1994, by the CAS Lanzhou Branch, Lanzhou University, and the Gansu Provincial S&T Commission with the approval of the People’s Government of Gansu Pro...The Center is a research organ co-established on November 11, 1994, by the CAS Lanzhou Branch, Lanzhou University, and the Gansu Provincial S&T Commission with the approval of the People’s Government of Gansu Province. The Center’s administrative office is in the compound of the CAS Lanzhou Branch. Its main research orientations and contents include interactions between the hydrosphere, atmosphere, biosphere, lithosphere and cryopedosphere in northwest China, especially centered on rich natural resource deposits and the fragile eco-system of hinderland China. Targeted at展开更多
目的通过Meta分析评价髋关节表面置换与全髋关节置换治疗小于60岁中年终末期髋关节疾病患者的临床疗效和安全性。方法检索2010年10月至2020年10月已发表的关于髋关节表面置换与全髋关节置换的临床对照研究。所检索的数据库包括Pubmed、E...目的通过Meta分析评价髋关节表面置换与全髋关节置换治疗小于60岁中年终末期髋关节疾病患者的临床疗效和安全性。方法检索2010年10月至2020年10月已发表的关于髋关节表面置换与全髋关节置换的临床对照研究。所检索的数据库包括Pubmed、Embase、Cochrane图书馆、万方数据库、中国知网等。中文检索的关键词为表面置换、全髋置换;英文检索的关键词为hip resur-facing,total hip replacement,total hip arthroplasty。提取数据后,采用Review Manager 5.3软件进行数据分析,比较髋关节表面置换与全髋关节置换治疗60岁以下中年患者的疗效差异。结果共检索到相关文献2586篇,并最终纳入20篇相关文献,其中髋关节表面置换3020例,全髋关节置换2407例。Meta分析结果显示,髋关节表面置换的HHS评分[MD=2.49,95%CI(0.66,4.32),P<0.001]和UCLA活动评分[MD=0.64,95%CI(0.11,1.17),P=0.02]高于全髋关节置换,两者差异有统计学意义。而两组的VAS疼痛评分[MD=0.19,95%CI(-0.30,0.69),P=0.44]比较差异无统计学意义。髋关节表面置换的钴离子浓度[MD=-0.72,95%CI(-1.42,-0.02),P=0.04]和铬离子浓度[MD=-0.28,95%CI(-0.39,-0.17),P<0.001]低于全髋关节置换,两者差异有统计学意义。髋关节表面置换的翻修率[OR=0.45,95%CI(0.25,0.80),P=0.007]和并发症发生率[OR=0.35,95%CI(0.12,0.98),P<0.05]低于全髋关节置换,两者差异有统计学意义。髋关节表面置换的手术时间[MD=17.58,95%CI(11.81,23.35),P<0.001]高于全髋关节置换,术中失血量[MD=-41.05,95%CI(-59.87,-22.24),P<0.001]低于全髋关节置换,两者差异有统计学意义。结论对于小于60岁中年终末期髋关节疾病患者,与全髋关节置换相比,髋关节表面置换术后有更好的HHS及UCLA活动评分,减少了术中失血量、血清金属离子浓度、术后翻修率及并发症发生率,提高了患者的生活质量。展开更多
文摘背景:青壮年股骨颈骨内固定后并发股骨头坏死的预防在骨科领域仍是一项挑战,针对青壮年股骨颈骨折内固定术后并发股骨头坏死的发病机制仍是充满讨论的话题。目的:对青壮年股骨颈骨折内固定后股并发股骨头坏死的发病机制做一综述。方法:通过计算机检索2010-2021年PubMed、EMbase、万方数据库、维普和中国知网上关于青壮年股骨颈骨折内固定后股骨坏死的相关文献。检索中文关键词为"股骨颈骨折、股骨头坏死、有限元分析、力学、应力、螺钉、植入物、血供、分子生物学、基因"。检索英文关键词为"Femoral neck fracture,femoral head necrosis,finite element analysis,mechanics,stress,screws,implants,blood supply,molecular biology,genes"。结果与结论:青壮年股骨颈骨折内固定后内固定取出与否均可导致股骨头坏死的发生。内固定取出时易造成微骨折,甚至再骨折;内固定不取出时,伴随着内固定的长期置留,内固定物周围形成大量的硬化骨,其可能是青壮年股骨颈骨折术后股骨头坏死并快速塌陷的重要力学机制之一。通过文献分析不同骨折模型及不同类型内固定物,可知倒三角结构虽然是最优治疗方式,但其仍不可避免应力的集中,导致硬化骨的形成,最终导致股骨头的坏死塌陷。因此提出在内固定周围形成硬化骨之前,适时的取钉并置入一种新型高强度、可降解、多微孔结构及又可促进成骨血管化的内置物,避免应力集中在内固定周围,用以抑制硬化骨的形成,从而可终止股骨头坏死的发生。
基金Under the auspices of National Natural Science Foundation of China (No. 40971019)National Basic Research Program of China (No. 2007CB411501)
文摘Comprehending regional characteristics and influencing factors of China＇s inbound tourism economy is im- portant to make effective policies that will help inbound tourism develop harmoniously and shrink regional disparity. This paper studied the regional disparity and convergence of China＇s inbound tourism economy during 1996-2008 with the methods of a-convergence, club convergence and r-convergence. The results indicate that 1） inbound tourism receipts per capita （ITRPC） of the whole country, the eastern, central and western regions presented the rapid increasing trend; 2） ITRPC of the whole country was characterized by convergence; 3） the eastern region presented club con- vergence, but the central and western regions did not show this trend; 4） the star-hotel levels and investment in fixed assets for the tourism industry per capita had a same trend to growth rates of ITRPC, promoting inbound tourism de- velopment, and there was no difference among the 31 provinces （municipalities） in the mainland of China; 5） but the proportion of employed persons in the tourism industry accounting for total population and the proportion of the terti- ary industry accounting for GDP had a reversal trend to growth rates of ITRPC, shrinking the provincial disparity in inbound tourism economy, and there were differences between the developed provinces and the developing provinces. Based on these analyses, we put forward some suggestions for the developing provinces to speed up inbound tourism economy.
文摘The Center is a research organ co-established on November 11, 1994, by the CAS Lanzhou Branch, Lanzhou University, and the Gansu Provincial S&T Commission with the approval of the People’s Government of Gansu Province. The Center’s administrative office is in the compound of the CAS Lanzhou Branch. Its main research orientations and contents include interactions between the hydrosphere, atmosphere, biosphere, lithosphere and cryopedosphere in northwest China, especially centered on rich natural resource deposits and the fragile eco-system of hinderland China. Targeted at
文摘目的通过Meta分析评价髋关节表面置换与全髋关节置换治疗小于60岁中年终末期髋关节疾病患者的临床疗效和安全性。方法检索2010年10月至2020年10月已发表的关于髋关节表面置换与全髋关节置换的临床对照研究。所检索的数据库包括Pubmed、Embase、Cochrane图书馆、万方数据库、中国知网等。中文检索的关键词为表面置换、全髋置换;英文检索的关键词为hip resur-facing,total hip replacement,total hip arthroplasty。提取数据后,采用Review Manager 5.3软件进行数据分析,比较髋关节表面置换与全髋关节置换治疗60岁以下中年患者的疗效差异。结果共检索到相关文献2586篇,并最终纳入20篇相关文献,其中髋关节表面置换3020例,全髋关节置换2407例。Meta分析结果显示,髋关节表面置换的HHS评分[MD=2.49,95%CI(0.66,4.32),P<0.001]和UCLA活动评分[MD=0.64,95%CI(0.11,1.17),P=0.02]高于全髋关节置换,两者差异有统计学意义。而两组的VAS疼痛评分[MD=0.19,95%CI(-0.30,0.69),P=0.44]比较差异无统计学意义。髋关节表面置换的钴离子浓度[MD=-0.72,95%CI(-1.42,-0.02),P=0.04]和铬离子浓度[MD=-0.28,95%CI(-0.39,-0.17),P<0.001]低于全髋关节置换,两者差异有统计学意义。髋关节表面置换的翻修率[OR=0.45,95%CI(0.25,0.80),P=0.007]和并发症发生率[OR=0.35,95%CI(0.12,0.98),P<0.05]低于全髋关节置换,两者差异有统计学意义。髋关节表面置换的手术时间[MD=17.58,95%CI(11.81,23.35),P<0.001]高于全髋关节置换,术中失血量[MD=-41.05,95%CI(-59.87,-22.24),P<0.001]低于全髋关节置换,两者差异有统计学意义。结论对于小于60岁中年终末期髋关节疾病患者,与全髋关节置换相比,髋关节表面置换术后有更好的HHS及UCLA活动评分,减少了术中失血量、血清金属离子浓度、术后翻修率及并发症发生率,提高了患者的生活质量。
