Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and poten...Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and potential links to other high-energy astrophysical events make them particularly valuable for probing a wide range of fundamental physics(e.g.,ref.[1]).展开更多
The accuracy and repeatability of computer aided cervical vertebra landmarking (CACVL) were investigated in cephalogram.120 adolescents (60 boys,60 girls) aged from 9.1 to 17.2 years old were randomly selected.Twenty-...The accuracy and repeatability of computer aided cervical vertebra landmarking (CACVL) were investigated in cephalogram.120 adolescents (60 boys,60 girls) aged from 9.1 to 17.2 years old were randomly selected.Twenty-seven landmarks from the second to fifth cervical vertebrae on the lat-eral cephalogram were identified.In this study,the system of CACVL was developed and used to iden-tify and calculate the landmarks by fast marching method and parabolic curve fitting.The accuracy and repeatability in CACVL group were compared with those in two manual landmarking groups [orthodon-tic experts (OE) group and orthodontic novices (ON) group].The results showed that,as for the accu-racy,there was no significant difference between CACVL group and OE group no matter in x-axis or y-axis (P>0.05),but there was significant difference between CACVL group and ON group,as well as OE group and ON group in both axes (P<0.05).As for the repeatability,CACVL group was more reli-able than OE group and ON group in both axes.It is concluded that CACVL has the same or higher ac-curacy,better repeatability and less workload than manual landmarking methods.It’s reliable for cervi-cal parameters identification on the lateral cephalogram and cervical vertebral maturation prediction in orthodontic practice and research.展开更多
Liver is the central hub regulating energy metabolism during feeding-fasting transition.Evidence suggests that fasting and refeeding induce dynamic changes in liver size,but the underlying mechanisms remain unclear.Ye...Liver is the central hub regulating energy metabolism during feeding-fasting transition.Evidence suggests that fasting and refeeding induce dynamic changes in liver size,but the underlying mechanisms remain unclear.Yes-associated protein(YAP)is a key regulator of organ size.This study aims to explore the role of YAP in fasting-and refeeding-induced changes in liver size.Here,fasting significantly reduced liver size,which was recovered to the normal level after refeeding.Moreover,hepatocyte size was decreased and hepatocyte proliferation was inhibited after fasting.Conversely,refeeding promoted hepatocyte enlargement and proliferation compared to fasted state.Mechanistically,fasting or refeeding regulated the expression of YAP and its downstream targets,as well as the proliferation-related protein cyclin D1(CCND1).Furthermore,fasting significantly reduced the liver size in AAV-control mice,which was mitigated in AAV Yap(5SA)mice.Yap overexpression also prevented the effect of fasting on hepatocyte size and proliferation.Besides,the recovery of liver size after refeeding was delayed in AAV Yap shRNA mice.Yap knockdown attenuated refeeding-induced hepatocyte enlargement and proliferation.In summary,this study demonstrated that YAP plays an important role in dynamic changes of liver size during fasting-refeeding transition,which provides new evidence for YAP in regulating liver size under energy stress.展开更多
Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investiga...Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.展开更多
Fasting is a popular dietary strategy because it grants numerous advantages,and redox regulation is one mecha-nism involved.However,the precise redox changes with respect to the redox species,organelles and tissues re...Fasting is a popular dietary strategy because it grants numerous advantages,and redox regulation is one mecha-nism involved.However,the precise redox changes with respect to the redox species,organelles and tissues remain unclear,which hinders the understanding of the metabolic mechanism,and exploring the precision redox map under various dietary statuses is of great significance.Twelve redox-sensitive C.elegans strains stably expressing genetically encoded redox fluorescent probes(Hyperion sensing H_(2)O_(2) and Grx1-roGFP2 sensing GSH/GSSG)in three organelles(cytoplasm,mitochondria and endoplasmic reticulum(ER))were constructed in two tissues(body wall muscle and neurons)and were confirmed to respond to redox challenge.The H_(2)O_(2) and GSSG/GSH redox changes in two tissues and three organelles were obtained by confocal microscopy during fasting,refeeding,and satiation.We found that under fasting condition,H_(2)O_(2) decreased in most compartments,except for an increase in mitochondria,while GSSG/GSH increased in the cytoplasm of body muscle and the ER of neurons.After refeeding,the redox changes in H_(2)O_(2) and GSSG/GSH caused by fasting were reversed in most organelles of the body wall muscle and neurons.In the sati-ated state,H_(2)O_(2) increased markedly in the cytoplasm,mitochondria and ER of muscle and the ER of neurons,while GSSG/GSH exhibited no change in most organelles of the two tissues except for an increase in the ER of muscle.Our study systematically and precisely presents the redox characteristics under different dietary states in living animals and provides a basis for further investigating the redox mechanism in metabolism and optimizing dietary guidance.展开更多
The grass carp(Ctenopharyngodon idella) is one of the most important cultivated fish species in China.Mounting evidences suggests that microRNAs(miRNAs) may be key regulators of skeletal muscle among the grass carp,bu...The grass carp(Ctenopharyngodon idella) is one of the most important cultivated fish species in China.Mounting evidences suggests that microRNAs(miRNAs) may be key regulators of skeletal muscle among the grass carp,but the knowledge of the identity of myogenic miRNAs and role of miRNAs during skeletal muscle anabolic state remains limited.In the present study,we choose 8 miRNAs previously reported to act as muscle growth-related miRNAs for fasting-refeeding research.We investigated postprandial changes in the expression of 8 miRNAs following a single satiating meal in grass carp juveniles who had been fasting for one week and found that 7 miRNAs were sharply up-regulated within 1 or 3 h after refeeding,suggesting that they may be promising candidate miRNAs involved in a fast-response signaling system that regulates fish skeletal muscle growth.展开更多
文摘Fast radio bursts(FRBs)are extremely energetic,millisecond-duration flashes of radio waves that represent one of the most intriguing phenomena in astronomy.Their cosmological distances,immense energy outputs,and potential links to other high-energy astrophysical events make them particularly valuable for probing a wide range of fundamental physics(e.g.,ref.[1]).
基金supported by grants from National Natural Sciences Foundation of China (No. 30801314)China Hubei Provincial Science and Technology Department (No.2008CBD088)
文摘The accuracy and repeatability of computer aided cervical vertebra landmarking (CACVL) were investigated in cephalogram.120 adolescents (60 boys,60 girls) aged from 9.1 to 17.2 years old were randomly selected.Twenty-seven landmarks from the second to fifth cervical vertebrae on the lat-eral cephalogram were identified.In this study,the system of CACVL was developed and used to iden-tify and calculate the landmarks by fast marching method and parabolic curve fitting.The accuracy and repeatability in CACVL group were compared with those in two manual landmarking groups [orthodon-tic experts (OE) group and orthodontic novices (ON) group].The results showed that,as for the accu-racy,there was no significant difference between CACVL group and OE group no matter in x-axis or y-axis (P>0.05),but there was significant difference between CACVL group and ON group,as well as OE group and ON group in both axes (P<0.05).As for the repeatability,CACVL group was more reli-able than OE group and ON group in both axes.It is concluded that CACVL has the same or higher ac-curacy,better repeatability and less workload than manual landmarking methods.It’s reliable for cervi-cal parameters identification on the lateral cephalogram and cervical vertebral maturation prediction in orthodontic practice and research.
基金supported by the National Key R&D Program of China(2022YFA1104900)the Natural Science Foundation of China(Grant number:82025034,81973392)+3 种基金the Shenzhen Science and Technology Program(KQTD20190929174023858,China)the 111 project(Grant number:B16047,China)the Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(Grant number:2017BT01Y093,China)the National Engineering and Technology Research Center for New drug Druggability Evaluation(Seed Program of Guangdong Province,Grant number:2017B090903004,China)。
文摘Liver is the central hub regulating energy metabolism during feeding-fasting transition.Evidence suggests that fasting and refeeding induce dynamic changes in liver size,but the underlying mechanisms remain unclear.Yes-associated protein(YAP)is a key regulator of organ size.This study aims to explore the role of YAP in fasting-and refeeding-induced changes in liver size.Here,fasting significantly reduced liver size,which was recovered to the normal level after refeeding.Moreover,hepatocyte size was decreased and hepatocyte proliferation was inhibited after fasting.Conversely,refeeding promoted hepatocyte enlargement and proliferation compared to fasted state.Mechanistically,fasting or refeeding regulated the expression of YAP and its downstream targets,as well as the proliferation-related protein cyclin D1(CCND1).Furthermore,fasting significantly reduced the liver size in AAV-control mice,which was mitigated in AAV Yap(5SA)mice.Yap overexpression also prevented the effect of fasting on hepatocyte size and proliferation.Besides,the recovery of liver size after refeeding was delayed in AAV Yap shRNA mice.Yap knockdown attenuated refeeding-induced hepatocyte enlargement and proliferation.In summary,this study demonstrated that YAP plays an important role in dynamic changes of liver size during fasting-refeeding transition,which provides new evidence for YAP in regulating liver size under energy stress.
基金supported in part by National Natural Science Foundation of China(No.51277106)in part by the National Basic Research Program of China(973 Program)(No.2011CB209405)
文摘Very fast transient over-voltage （VFTO）, induced by disconnector operations in gas- insulated switchgears, has become the limiting dielectric stress at ultra-high voltage levels. Much work has been done to investigate single-strike waveforms of VFTO. However, little study has been carried out investigating the repeated strike process, which would influence VFTO significantly. In this paper, we carried out 450 effective experiments in an ultra-high voltage test circuit, and conducted calculations through the Monte Carlo simulation method, to investigate the repeated strike process. Firstly, the mechanism of the repeated strike process is proposed, based on the ex- perimentai results. Afterwards, statistical breakdown characteristics of disconnectors are obtained and analyzed. Finally, simulations of the repeated strike process are conducted, which indicate that the dielectric strength recovery speed and polarity effect factor have a joint effect on VFTO. This study enhances the understanding of the nature of VFTO, and may help to optimize the disconnector designed to minimize VFTO.
基金supported by the National Key R&D Program(2022YFA1303000 and 2017YFA0504000)the National Natural Science Foundation of China(91849203,31900893)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB39000000).
文摘Fasting is a popular dietary strategy because it grants numerous advantages,and redox regulation is one mecha-nism involved.However,the precise redox changes with respect to the redox species,organelles and tissues remain unclear,which hinders the understanding of the metabolic mechanism,and exploring the precision redox map under various dietary statuses is of great significance.Twelve redox-sensitive C.elegans strains stably expressing genetically encoded redox fluorescent probes(Hyperion sensing H_(2)O_(2) and Grx1-roGFP2 sensing GSH/GSSG)in three organelles(cytoplasm,mitochondria and endoplasmic reticulum(ER))were constructed in two tissues(body wall muscle and neurons)and were confirmed to respond to redox challenge.The H_(2)O_(2) and GSSG/GSH redox changes in two tissues and three organelles were obtained by confocal microscopy during fasting,refeeding,and satiation.We found that under fasting condition,H_(2)O_(2) decreased in most compartments,except for an increase in mitochondria,while GSSG/GSH increased in the cytoplasm of body muscle and the ER of neurons.After refeeding,the redox changes in H_(2)O_(2) and GSSG/GSH caused by fasting were reversed in most organelles of the body wall muscle and neurons.In the sati-ated state,H_(2)O_(2) increased markedly in the cytoplasm,mitochondria and ER of muscle and the ER of neurons,while GSSG/GSH exhibited no change in most organelles of the two tissues except for an increase in the ER of muscle.Our study systematically and precisely presents the redox characteristics under different dietary states in living animals and provides a basis for further investigating the redox mechanism in metabolism and optimizing dietary guidance.
基金Foundation items： This study was supported by the National Natural Science Foundation of China （31230076 31340054）, the Natural Science Foundation of Hunan province （14JJ2135）and the State Key Laboratory of Freshwater Ecology and Biotechnology （2012FB01 ）
文摘The grass carp(Ctenopharyngodon idella) is one of the most important cultivated fish species in China.Mounting evidences suggests that microRNAs(miRNAs) may be key regulators of skeletal muscle among the grass carp,but the knowledge of the identity of myogenic miRNAs and role of miRNAs during skeletal muscle anabolic state remains limited.In the present study,we choose 8 miRNAs previously reported to act as muscle growth-related miRNAs for fasting-refeeding research.We investigated postprandial changes in the expression of 8 miRNAs following a single satiating meal in grass carp juveniles who had been fasting for one week and found that 7 miRNAs were sharply up-regulated within 1 or 3 h after refeeding,suggesting that they may be promising candidate miRNAs involved in a fast-response signaling system that regulates fish skeletal muscle growth.
文摘利用FIASCO(Fast Isolation by AFLP Sequences Containing repeats)技术建立拟穴青蟹Scylla paramamosain基因组文库,并与生物素标记的(CA)15寡核苷酸探针杂交,联合磁珠富集法构建拟穴青蟹微卫星富集文库。测序194个阳性菌落,分析其中的150条序列,结果表明:两碱基重复类型占90%以上,其中重复拷贝数在30以上的占27.45%;含微卫星座位189个,其中完美型146个、非完美型28个和复合型15个。设计125对引物扩增一个拟穴青蟹野生群体(含20个个体),其中的19对引物能稳定扩增且片段大小基本符合理论长度。遗传变异分析表明,17个位点表现出高度多态性,16个位点显著偏离Hardy-Weinberg平衡(P<0.05),4组两两位点间存在连锁不平衡现象(P<0.0026,经Bonferroni法校正),7个微卫星位点可能存在无效等位基因。若排除混合微卫星位点的引物对以及扩增位点PIC(polymorphism information content)值在0.5以下的引物对,则13对引物能用于拟穴青蟹群体遗传学等研究。
