背景:国内外研究已证实新型镁合金的生物安全性,但尚未有关于镁合金颅骨固定系统相关研究的报道。目的:探讨新型生物可降解镁合金颅骨固定系统植入健康新西兰大白兔后的安全性和有效性。方法:将30只新西兰大白兔随机分2组,每组15只,空...背景:国内外研究已证实新型镁合金的生物安全性,但尚未有关于镁合金颅骨固定系统相关研究的报道。目的:探讨新型生物可降解镁合金颅骨固定系统植入健康新西兰大白兔后的安全性和有效性。方法:将30只新西兰大白兔随机分2组,每组15只,空白对照组不进行任何处理,实验组建立新型生物可降解镁合金颅骨固定系统植入模型。术后14,30,90,180 d,检测两组血常规、凝血功能、肝肾功能、血清镁等指标;术后180 d,通过B超、CT及直视下观察实验组固定系统吸收情况及周围产气情况,采集实验组颅骨固定系统周围及空白对照组相同部位肌肉、颅骨、硬脑膜、脑等组织标本,进行组织切片观察。结果与结论:(1)实验组术后不同时间点的白细胞、血小板、血红蛋白、血尿素氮、谷丙转氨酶、血清镁浓度与空白对照组比较无差异,两组各指标均维持在较稳定的状态;(2)颅部B超提示新型生物可降解镁合金固定系统周围无明显气体,可看出固定系统在逐步吸收,术后180 d CT三维重建显示该系统已吸收近50%,人造颅缝愈合顺利;(3)组织学观察显示,新型生物可降解镁合金固定系统未引起局部肌肉、颅骨、硬脑膜、脑组织的炎症与异物反应;(4)结果表明,新型生物可降解镁合金固定系统具有良好的组织相容性,植入新西兰兔体内安全有效。展开更多
Force analysis using a compact tension model, as recommended by ASTM, was carried out on a crack stop hole. The stress before, and after, drilling the hole was compared in terms of stress concentration and stress grad...Force analysis using a compact tension model, as recommended by ASTM, was carried out on a crack stop hole. The stress before, and after, drilling the hole was compared in terms of stress concentration and stress gradient. The optimum drilling location and diameter were studied through analysis of different locations and diameters. By analyzing the effects of flank holes and an additional hole, drilling advice was proposed and fatigue testing of the cracks in a steel bridge deck with a crack stop hole was conducted. The results show that the stress at the crack tip with a crack stop hole decreased, and the major principal stress around the hole was distributed accordingly. The optimum position of the crack stop hole centre was where the centre of the crack stop hole was situated behind the crack and the hole edge coincided with the crack tip. Therefore, hole diameters larger than 8 mm, or those weakening the section by 10%, were suggested as the best diameters. In terms of multi-hole crack stopping, a flank hole was not recommended. The optimum horizontal position of flank holes was at a distance of 1/4 of a single hole diameter from, and in front of, the single hole. Besides, the experiment showed that crack stop hole could only prevent cracks from growing and had no influence on crack growth rate.展开更多
Cultivated strawberry(Fragaria×ananassa)originated from four diploid ancestors:F.vesca,F.viridis,F.iinumae and F.nipponica.Among them,F.vesca is the dominant subgenome for cultivated strawberry.It is not well und...Cultivated strawberry(Fragaria×ananassa)originated from four diploid ancestors:F.vesca,F.viridis,F.iinumae and F.nipponica.Among them,F.vesca is the dominant subgenome for cultivated strawberry.It is not well understood how differences in gene expression between diploid and octoploid strawberry contribute to differences during fruit development.In this study,we used comprehensive transcriptomic analyses of F.vesca and F.×ananassa to investigate gene expression at the different stages of fruit development.In total,we obtained 3508(turning stage)and 3958(red stage)differentially expressed genes with pairwise comparisons between diploid and octoploid.The genes involved in flavonoid biosynthesis were almost upregulated in the turning stages of octoploid,and we also discovered a ripe fruit-specific module associated with several flavonoid biosynthetic genes,including FveMYB10,FveMYB9/11,and Fve RAP,using weighted gene coexpression network analysis(WGCNA).Furthermore,we identified the species-specific regulated networks in the octoploid and diploid fruit.Notably,we found that the WAK and F-box genes were enriched in the octoploid and diploid fruits,respectively.This study elucidates new findings on flavonoid biosynthesis and fruit size of strawberry with important implications for future molecular breeding in cultivated strawberry.展开更多
文摘背景:国内外研究已证实新型镁合金的生物安全性,但尚未有关于镁合金颅骨固定系统相关研究的报道。目的:探讨新型生物可降解镁合金颅骨固定系统植入健康新西兰大白兔后的安全性和有效性。方法:将30只新西兰大白兔随机分2组,每组15只,空白对照组不进行任何处理,实验组建立新型生物可降解镁合金颅骨固定系统植入模型。术后14,30,90,180 d,检测两组血常规、凝血功能、肝肾功能、血清镁等指标;术后180 d,通过B超、CT及直视下观察实验组固定系统吸收情况及周围产气情况,采集实验组颅骨固定系统周围及空白对照组相同部位肌肉、颅骨、硬脑膜、脑等组织标本,进行组织切片观察。结果与结论:(1)实验组术后不同时间点的白细胞、血小板、血红蛋白、血尿素氮、谷丙转氨酶、血清镁浓度与空白对照组比较无差异,两组各指标均维持在较稳定的状态;(2)颅部B超提示新型生物可降解镁合金固定系统周围无明显气体,可看出固定系统在逐步吸收,术后180 d CT三维重建显示该系统已吸收近50%,人造颅缝愈合顺利;(3)组织学观察显示,新型生物可降解镁合金固定系统未引起局部肌肉、颅骨、硬脑膜、脑组织的炎症与异物反应;(4)结果表明,新型生物可降解镁合金固定系统具有良好的组织相容性,植入新西兰兔体内安全有效。
基金Projects(51278166,51478163)supported by the National Natural Science Foundation of ChinaProject(2015B17414)supported by the Fundamental Research Funds for the Central Universities,China
文摘Force analysis using a compact tension model, as recommended by ASTM, was carried out on a crack stop hole. The stress before, and after, drilling the hole was compared in terms of stress concentration and stress gradient. The optimum drilling location and diameter were studied through analysis of different locations and diameters. By analyzing the effects of flank holes and an additional hole, drilling advice was proposed and fatigue testing of the cracks in a steel bridge deck with a crack stop hole was conducted. The results show that the stress at the crack tip with a crack stop hole decreased, and the major principal stress around the hole was distributed accordingly. The optimum position of the crack stop hole centre was where the centre of the crack stop hole was situated behind the crack and the hole edge coincided with the crack tip. Therefore, hole diameters larger than 8 mm, or those weakening the section by 10%, were suggested as the best diameters. In terms of multi-hole crack stopping, a flank hole was not recommended. The optimum horizontal position of flank holes was at a distance of 1/4 of a single hole diameter from, and in front of, the single hole. Besides, the experiment showed that crack stop hole could only prevent cracks from growing and had no influence on crack growth rate.
基金the Program for High-level University Construction of the Fujian Agriculture and Forestry University,China(612014028)the Natural Science Foundation of Fujian Province,China(2018J01700)Rural Revitalization Service Team of Fujian Agriculture and Forestry University,China(11899170125)。
文摘Cultivated strawberry(Fragaria×ananassa)originated from four diploid ancestors:F.vesca,F.viridis,F.iinumae and F.nipponica.Among them,F.vesca is the dominant subgenome for cultivated strawberry.It is not well understood how differences in gene expression between diploid and octoploid strawberry contribute to differences during fruit development.In this study,we used comprehensive transcriptomic analyses of F.vesca and F.×ananassa to investigate gene expression at the different stages of fruit development.In total,we obtained 3508(turning stage)and 3958(red stage)differentially expressed genes with pairwise comparisons between diploid and octoploid.The genes involved in flavonoid biosynthesis were almost upregulated in the turning stages of octoploid,and we also discovered a ripe fruit-specific module associated with several flavonoid biosynthetic genes,including FveMYB10,FveMYB9/11,and Fve RAP,using weighted gene coexpression network analysis(WGCNA).Furthermore,we identified the species-specific regulated networks in the octoploid and diploid fruit.Notably,we found that the WAK and F-box genes were enriched in the octoploid and diploid fruits,respectively.This study elucidates new findings on flavonoid biosynthesis and fruit size of strawberry with important implications for future molecular breeding in cultivated strawberry.
