1.IntroductionMedium Mn steel was developed be-cause the wear resistance of Hadfield steel(Mn13)is poor under low or medium im-pact and extrusion abrasion[1-4].In theforegoing investigations[2-4]we found thatwith the ...1.IntroductionMedium Mn steel was developed be-cause the wear resistance of Hadfield steel(Mn13)is poor under low or medium im-pact and extrusion abrasion[1-4].In theforegoing investigations[2-4]we found thatwith the increase of C content,theneedle-like and network carbide in mediumMn steel increased(as shown in Fig.1(a)and(c)).Although its wear resistance was largelyimproved,its impact toughness was greatlydecreased.In order to increase toughness,along-term high temperature heat-treatmentwas needed.But the treatment caused cracks展开更多
Y染色体短串联重复(Y chromosome short tandem repeat,Y-STR)在法庭科学实战应用中具有举足轻重的地位,基于Y-STR的长度分型排查嫌疑人父系谱系的技术已在多起重特大刑事案件的侦破中发挥了至关重要的作用。但当遇到长度多态Y-STR单倍...Y染色体短串联重复(Y chromosome short tandem repeat,Y-STR)在法庭科学实战应用中具有举足轻重的地位,基于Y-STR的长度分型排查嫌疑人父系谱系的技术已在多起重特大刑事案件的侦破中发挥了至关重要的作用。但当遇到长度多态Y-STR单倍型相近或者相同的数据时,难以进行谱系的精细化区分。基于二代测序技术解析Y-STR的序列信息为解决上述困境带来了新的路径,并已成功应用于实际案例。然而,当前Y-STR序列特征的基础数据积累显著不足,序列多态性的研究也较为零散,缺乏对Y-STR序列变异的系统性总结,在一定程度上限制了Y-STR序列多态性在法庭科学的深度应用。本文基于文献公开数据,归纳在法庭科学中应用较广泛的41个Y-STR基因座重复区及侧翼区的序列特征,梳理Y-STR基因座重复区和侧翼区内可定义单倍群的单核苷酸多态性,并展望序列多态性可以拓展应用的场景,以期为利用Y-STR序列多态性精细化区分男性谱系、溯源父系生物地理祖先等研究提供参考。展开更多
文摘1.IntroductionMedium Mn steel was developed be-cause the wear resistance of Hadfield steel(Mn13)is poor under low or medium im-pact and extrusion abrasion[1-4].In theforegoing investigations[2-4]we found thatwith the increase of C content,theneedle-like and network carbide in mediumMn steel increased(as shown in Fig.1(a)and(c)).Although its wear resistance was largelyimproved,its impact toughness was greatlydecreased.In order to increase toughness,along-term high temperature heat-treatmentwas needed.But the treatment caused cracks
文摘Y染色体短串联重复(Y chromosome short tandem repeat,Y-STR)在法庭科学实战应用中具有举足轻重的地位,基于Y-STR的长度分型排查嫌疑人父系谱系的技术已在多起重特大刑事案件的侦破中发挥了至关重要的作用。但当遇到长度多态Y-STR单倍型相近或者相同的数据时,难以进行谱系的精细化区分。基于二代测序技术解析Y-STR的序列信息为解决上述困境带来了新的路径,并已成功应用于实际案例。然而,当前Y-STR序列特征的基础数据积累显著不足,序列多态性的研究也较为零散,缺乏对Y-STR序列变异的系统性总结,在一定程度上限制了Y-STR序列多态性在法庭科学的深度应用。本文基于文献公开数据,归纳在法庭科学中应用较广泛的41个Y-STR基因座重复区及侧翼区的序列特征,梳理Y-STR基因座重复区和侧翼区内可定义单倍群的单核苷酸多态性,并展望序列多态性可以拓展应用的场景,以期为利用Y-STR序列多态性精细化区分男性谱系、溯源父系生物地理祖先等研究提供参考。
