控制植物开花的途径有光周期现象、GA、春化途径、自主途径,在光周期途径中,CO基因促进开花通过直接上调FT和SOC1基因表达,FT(FLOWERING LOCUS T)是光周期途径植物开花时间决定关键基因,并认为FT基因表达产物可能就是长期追寻的开花刺...控制植物开花的途径有光周期现象、GA、春化途径、自主途径,在光周期途径中,CO基因促进开花通过直接上调FT和SOC1基因表达,FT(FLOWERING LOCUS T)是光周期途径植物开花时间决定关键基因,并认为FT基因表达产物可能就是长期追寻的开花刺激物质,这种开花刺激物质经过叶片到茎尖的长距离运输,最终引起茎顶端花器官分化的起始。本研究以莲瓣兰大雪素作为实验材料,用RACE方法快速地克隆全长cDNA,生物信息学分析全长cDNA为662bp,含有编码框和3′UTR,具有完整的开放阅读框(ORF)522bp,编码173氨基酸的蛋白质。通过系统发育分析获得一个FT同源基因。本研究为进一步对这个基因的功能研究奠定了基础。展开更多
Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related pe...Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.展开更多
基金国家自然科学基金(编号:NSFC 31060166 and NSFC31460053)云南省中青年学术技术带头人后备人才基金(编号:2012HB 018)资助
文摘控制植物开花的途径有光周期现象、GA、春化途径、自主途径,在光周期途径中,CO基因促进开花通过直接上调FT和SOC1基因表达,FT(FLOWERING LOCUS T)是光周期途径植物开花时间决定关键基因,并认为FT基因表达产物可能就是长期追寻的开花刺激物质,这种开花刺激物质经过叶片到茎尖的长距离运输,最终引起茎顶端花器官分化的起始。本研究以莲瓣兰大雪素作为实验材料,用RACE方法快速地克隆全长cDNA,生物信息学分析全长cDNA为662bp,含有编码框和3′UTR,具有完整的开放阅读框(ORF)522bp,编码173氨基酸的蛋白质。通过系统发育分析获得一个FT同源基因。本研究为进一步对这个基因的功能研究奠定了基础。
文摘Purpose： The aims of this study were to assess differences of limb symmetry index （LSI） in strength- and coordination-related tasks between high-level, competitive, noninjured ski racers of different age-related performance levels and to prospectively assess limb differences as a possible risk factor for traumatic and overuse injury in youth ski racers. Methods： The study （Study 1） included 285 high-level competitive ski racers （125 females, 160 males） of 3 age-related performance levels and based on the school system： 95 youth （10-14 years, secondary modem school）, 107 adolescent （15-19 years, grammar school）, and 83 elite athletes （20-34 years）. To investigate the second aim （Study 2）, 67 of the 95 youth athletes were included and any traumatic or overuse injuries were prospectively recorded over 2 seasons. All athletes performed 4 unilateral tests （strength related： one-leg counter movement jump （OL-CMJ） and one-leg isometric/isokinetic press strength test （OL-ILS）; coordination related： one-leg stability test （OL-ST） and one-leg speedy jump test （OL-SJ））. The LSI was calculated by dividing the dominant leg by the nondominant leg and multiplying by 100. Kruskal-Wallis H tests and binary logistic regression analyses were conducted. Results： There were significant differences between the LSI of the 3 age-related performance-level groups only in the strength-related tests： the OL-CMJ （X^2（2, 285） = 9.09; p = 0.01） and the OL-ILS （X^2（2,285） = 14.79; p 〈 0.01）. The LSI for OL-ILS was found to be a significant risk factor for traumatic injury in youth ski racers （Wald = 7.08; p 〈 0.01）. No significant risk factors were found for overuse injuries. Conclusion： Younger athletes display slightly greater LSI values only in the strength-related tests. The cut-off value of limb differences of 〈 10% for return to sport decisions seems to be appropriate for elite athletes, but for youth and adolescent athletes it has to be critically discussed. It seems to be necessary to define thresholds based on specific performance tasks （strength vs. coordination related） rather than on generalizations, and age-related performance levels must be considered. Limb differences in unilateral leg extension strength represent a significant injury risk factor in youth ski racers.2018 Published by Elsevier B.V. on behalf of Shanghai University of Sport. This is an open access article under the CC BY-NC-ND license. （http：//creativecommons.org/licenses/by-nc-nd/4.0/）.
