Lonsdaleite,also known as hexagonal diamond,is an allotrope of carbon with a hexagonal crystal structure,which was discovered in the nanostructure of the Canyon Diablo meteorite.Theoretical calculations have shown tha...Lonsdaleite,also known as hexagonal diamond,is an allotrope of carbon with a hexagonal crystal structure,which was discovered in the nanostructure of the Canyon Diablo meteorite.Theoretical calculations have shown that this structure gives it exceptional physical properties that exceed those of cubic diamond,making it highly promising for groundbreaking applications in superhard cutting tools,wide-bandgap semiconductor devices,and materials for extreme environments.As a result,the controllable synthesis of hexagonal diamond has emerged as a cutting-edge research focus in materials science.This review briefly outlines the progress in this area,with a focus on the mechanisms governing its key synthesis conditions,its intrinsic physical properties,and its potential applications in various fields.展开更多
基金the National Natural Science Foundation of China(12274170 and 52225203)。
文摘Lonsdaleite,also known as hexagonal diamond,is an allotrope of carbon with a hexagonal crystal structure,which was discovered in the nanostructure of the Canyon Diablo meteorite.Theoretical calculations have shown that this structure gives it exceptional physical properties that exceed those of cubic diamond,making it highly promising for groundbreaking applications in superhard cutting tools,wide-bandgap semiconductor devices,and materials for extreme environments.As a result,the controllable synthesis of hexagonal diamond has emerged as a cutting-edge research focus in materials science.This review briefly outlines the progress in this area,with a focus on the mechanisms governing its key synthesis conditions,its intrinsic physical properties,and its potential applications in various fields.
文摘目的:检测早期乳腺癌患者循环肿瘤细胞(circulating tumor cells,CTC)计数及其TP53、磷脂酰肌醇-3激酶(PI3K)基因突变情况,探讨基因突变结果与患者临床病理特征的相关性。方法:收集30例乳腺癌和良性乳腺肿瘤确诊患者的临床资料及血液、尿液标本,采用CellSearch法检测患者外周血CTC数目;采用微滴式数字PCR(droplet digital PCR,ddPCR)技术检测患者血、CTC和尿标本中TP53(p.R248Q、p.R273H、p.R175H)和PI3K(p.E545K、p.H1047R)基因位点突变情况;分析基因突变情况与患者临床病理特征(发病年龄、肿瘤大小、组织学分级、分子分型、腋窝淋巴结转移和Ki-67指数等)间的相关性。结果:最终纳入29例患者,患者血、CTC和尿标本中共获得435个基因检测结果,其中发生基因突变的82个(18.9%)。5种基因位点的突变率不同,差异有统计学意义(P<0.001)。突变率最高的基因是TP53(p.R175H),有29个突变(6.7%);突变率最低的是PI3K(p.E545K),仅发生1个(0.2%)突变。CTC、血和尿标本间5种基因位点的突变率差异有统计学意义(P=0.007,P<0.001,P=0.002),3类样本中突变率最高的基因都是TP53(p.R175H)。乳腺癌分子分型和Ki-67指数与CTC标本中TP53(p.R248Q)基因突变相关(P=0.003,P=0.028),而腋窝淋巴结转移可能与CTC标本中TP53(p.R175H)基因突变有关(P=0.058)。结论:早期乳腺癌患者的肿瘤分子分型和Ki-67指数与CTC中TP53(p.R248Q)基因突变相关,而腋窝淋巴结转移可能与CTC中TP53(p.R175H)基因突变相关,提示CTC标本中TP53基因突变是早期乳腺癌治疗方案选择及预后判断的潜在指标。
