Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law s...Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize glasses.Early simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency regime.It is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D glasses.Here,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model glasses.It is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size increases.Furthermore,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes examined.Therefore,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies.展开更多
BACKGROUND Mitral valvuloplasty using artificial chordae tendineae represents an effective surgical approach for treating mitral regurgitation.Achieving precise measurements of artificial chordae tendineae length(CL)i...BACKGROUND Mitral valvuloplasty using artificial chordae tendineae represents an effective surgical approach for treating mitral regurgitation.Achieving precise measurements of artificial chordae tendineae length(CL)is an important factor in the procedure;however,no objective index currently exists to facilitate this measurement.Therefore,preoperative assessment of CL is critical for surgical planning and support.Four-dimensional x-ray micro-computed tomography(4D-CT)may be useful for accurate CL measurement considering that it allows for dynamic three-dimensional(3D)evaluation compared to that with transthoracic echocardiography,a conventional inspection method.AIM To investigate the behavior and length of mitral chordae tendineae during systole using 4D-CT.METHODS Eleven adults aged>70 years without mitral valve disease were evaluated.A 64-slice CT scanner was used to capture 20 phases in the cardiac cycle in electrocardiographic synchronization.The length of the primary chordae tendineae was measured from early systole to early diastole using the 3D image.The primary chordae tendineae originating from the anterior papillary muscle and attached to the A1-2 region and those from the posterior papillary muscle and attached to the A2-3 region were designated as cA and cP,respectively.The behavior and maximum lengths[cA(ma),cP(max)]were compared,and the correlation with body surface area(BSA)was evaluated.RESULTS In all cases,the mitral anterior leaflet chordae tendineae could be measured.In most cases,the cA and cP chordae tendineae could be measured visually.The mean cA(max)and cP(max)were 20.2 mm±1.95 mm and 23.5 mm±4.06 mm,respectively.cP(max)was significantly longer.The correlation coefficients(r)with BSA were 0.60 and 0.78 for cA(max)and cP(max),respectively.Both cA and cP exhibited constant variation in CL during systole,with a maximum 1.16-fold increase in cA and a 1.23-fold increase in cP from early to mid-systole.For cP,CL reached a plateau at 15%and remained elongated until end-systole,whereas for cA,after peaking at 15%,CL shortened slightly and then moved toward its peak again as end-systole approached.CONCLUSION The study suggests that 4D-CT is a valuable tool for accurate measurement of both the length and behavior of chordae tendineae within the anterior leaflet of the mitral valve.展开更多
Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(...Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(MRI)provides comprehensive flow information and is a promising alternative.This study evaluated the efficacy of 4D flow MRI as a noninvasive method for diagnosing CSPH and high-risk varices in patients with liver cirrhosis.Methods:This prospective study enrolled consecutive patients diagnosed with liver cirrhosis at a tertiary referral center between October 2020 and March 2021.Each participant underwent abdominal 4D flow MRI.Hemodynamic parameters within the portal vein,including the average and peak flow velocities,normalized flow volume(Q_(normal)),and regurgitant fraction(R%),were extracted and compared between healthy individuals and patients with CSPH and between participants with high-and low-risk varices.Subsequently,these parameters were incorporated into a logistic regression(LR)model refined using L1 regularization and validated using five-fold cross-validation.The diagnostic efficacy was evaluated using receiver operating characteristic(ROC)curves.Results:Eighty-two participants were enrolled(71 patients diagnosed with liver cirrhosis and 11 healthy individuals serving as controls).Among hemodynamic parameters,patients with CSPH exhibited a notable increase in Q_(normal)of 0.66±0.19 ml*m^(2)/[cycle*kg](P=0.001)and an R%of 1.98(2.05)(P=0.002).Similarly,patients with high-risk varices showed a higher Q_(normal)of 0.61±0.15 ml*m^(2)/[cycle*kg](P<0.001)and R%of 1.88(2.81)(P=0.006).ROC analysis revealed an area under the curve(AUC)for Q_(normal)of 0.93 and 0.91 for R%for diagnosing CSPH,while the LR model showcased a superior AUC of 0.95.For high-risk varices,Q_(normal)and R%showed AUC values of 0.75 and 0.70,respectively,whereas the LR model showed a higher AUC of 0.84.Conclusion:As a noninvasive imaging modality,4D flow MRI exhibits considerable potential for the diagnosis of CSPH and high-risk gastroesophageal varices;thus,it may minimize the reliance on invasive procedures in patients with cirrhosis.展开更多
本研究根据公开发表的烟草K326基因组和烟草430K SNP固相芯片检测数据,以7份种质两两组合之间每条染色体上20个多态标记为目标,基于多重PCR扩增的精准定位测序分型技术(mGPS,Genotyping by Pinpoint Sequencing of multiplex PCR produc...本研究根据公开发表的烟草K326基因组和烟草430K SNP固相芯片检测数据,以7份种质两两组合之间每条染色体上20个多态标记为目标,基于多重PCR扩增的精准定位测序分型技术(mGPS,Genotyping by Pinpoint Sequencing of multiplex PCR products)开发出烟草1.8K育种液相芯片(YT1.8K.1)。利用该芯片对上述7份种质两两之间杂交的21个杂交组合进行基因分型检测,每个杂交组合之间的平均差异位点数为650个,能同时满足每个组合定向改良筛选高遗传背景回复率单株的需要。利用该芯片对23个烟草品种进行基因型分型检测和聚类分析,聚类分类结果与品种系谱基本吻合;利用该芯片从367个BC2F1群体中筛选出5个背景回复率高于94.96%的单株,高于理论均值87.5%,表明该育种芯片可应用于烟草种质资源聚类分析、定向改良育种的遗传背景筛选。展开更多
为了建立水禽细小病毒(WPV)快速检测方法,根据序列比对结果在水禽细小病毒NS基因SF3保守区域内设计特异性引物,建立SYBR Green Ⅰ荧光定量PCR通用检测方法。该方法的扩增效率(E)为90.0%,相关系数(R~2)=0.99,标准曲线方程为y=-3.607x+38....为了建立水禽细小病毒(WPV)快速检测方法,根据序列比对结果在水禽细小病毒NS基因SF3保守区域内设计特异性引物,建立SYBR Green Ⅰ荧光定量PCR通用检测方法。该方法的扩增效率(E)为90.0%,相关系数(R~2)=0.99,标准曲线方程为y=-3.607x+38.77;除WPV出现S形扩增曲线外,新城疫病毒(NDV)、H9亚型禽流感病毒(H9 AIV)、鸭坦布苏病毒(DTMUV)、鸭肝炎病毒(DHAV)、鸭肠炎病毒(DEV)、鸭呼肠孤病毒(DRV)样品均未出现S形阳性扩增曲线;批内变异系数(CV)为0.15%~0.23%,批间变异系数为0.09%~0.28%。结果表明,SYBR Green Ⅰ荧光定量PCR检测方法重复性好、灵敏度高和特异性强。临床样品检测结果表明,SYBR Green Ⅰ荧光定量PCR与普通PCR的符合率达98.4%,灵敏度是普通PCR的1 000倍。SYBR Green Ⅰ荧光定量PCR检测方法不仅能定性检测WPV,还可以进行定量检测,可用于种鸭场、种鹅场的WPV净化检测,也可用于WPV临床大量样品的快速检测。展开更多
基金the support from the National Natural Science Foundation of China(Grant Nos.12374202 and 12004001)Anhui Projects(Grant Nos.2022AH020009,S020218016,and Z010118169)Hefei City(Grant No.Z020132009)。
文摘Glasses are known to possess low-frequency excess modes beyond the Debye prediction.For decades,it has been assumed that evolution of low-frequency density of excess modes D(ω) with frequency ω follows a power-law scaling:D(ω)~ω~γ.However,it remains debated on the value of γ at low frequencies below the first phonon-like mode in finitesize glasses.Early simulation studies reported γ=4 at low frequencies in two-(2D),three-(3D),and four-dimensional(4D)glasses,whereas recent observations in 2D and 3D glasses suggested γ=3.5 in a lower-frequency regime.It is uncertain whether the low-frequency scaling of D(ω)~ω^(3.5) could be generalized to 4D glasses.Here,we conduct numerical simulation studies of excess modes at frequencies below the first phonon-like mode in 4D model glasses.It is found that the system size dependence of D(ω) below the first phonon-like mode varies with spatial dimensions:D(ω) increases in2D glasses but decreases in 3D and 4D glasses as the system size increases.Furthermore,we demonstrate that the ω^(3.5)scaling,rather than the ω~4 scaling,works in the lowest-frequency regime accessed in 4D glasses,regardless of interaction potentials and system sizes examined.Therefore,our findings in 4D glasses,combined with previous results in 2D and 3D glasses,suggest a common low-frequency scaling of D(ω)~ ω^3.5) below the first phonon-like mode across different spatial dimensions,which would inspire further theoretical studies.
文摘BACKGROUND Mitral valvuloplasty using artificial chordae tendineae represents an effective surgical approach for treating mitral regurgitation.Achieving precise measurements of artificial chordae tendineae length(CL)is an important factor in the procedure;however,no objective index currently exists to facilitate this measurement.Therefore,preoperative assessment of CL is critical for surgical planning and support.Four-dimensional x-ray micro-computed tomography(4D-CT)may be useful for accurate CL measurement considering that it allows for dynamic three-dimensional(3D)evaluation compared to that with transthoracic echocardiography,a conventional inspection method.AIM To investigate the behavior and length of mitral chordae tendineae during systole using 4D-CT.METHODS Eleven adults aged>70 years without mitral valve disease were evaluated.A 64-slice CT scanner was used to capture 20 phases in the cardiac cycle in electrocardiographic synchronization.The length of the primary chordae tendineae was measured from early systole to early diastole using the 3D image.The primary chordae tendineae originating from the anterior papillary muscle and attached to the A1-2 region and those from the posterior papillary muscle and attached to the A2-3 region were designated as cA and cP,respectively.The behavior and maximum lengths[cA(ma),cP(max)]were compared,and the correlation with body surface area(BSA)was evaluated.RESULTS In all cases,the mitral anterior leaflet chordae tendineae could be measured.In most cases,the cA and cP chordae tendineae could be measured visually.The mean cA(max)and cP(max)were 20.2 mm±1.95 mm and 23.5 mm±4.06 mm,respectively.cP(max)was significantly longer.The correlation coefficients(r)with BSA were 0.60 and 0.78 for cA(max)and cP(max),respectively.Both cA and cP exhibited constant variation in CL during systole,with a maximum 1.16-fold increase in cA and a 1.23-fold increase in cP from early to mid-systole.For cP,CL reached a plateau at 15%and remained elongated until end-systole,whereas for cA,after peaking at 15%,CL shortened slightly and then moved toward its peak again as end-systole approached.CONCLUSION The study suggests that 4D-CT is a valuable tool for accurate measurement of both the length and behavior of chordae tendineae within the anterior leaflet of the mitral valve.
基金supported by the Key Research and Development Program of Jiangsu Province(BE2023767)Research Personnel Cultivation Programme of Zhongda Hospital,Southeast University(CZXMGSP-RC125)+2 种基金the Fundamental Research Fund of Southeast University(3290002303A2)Changjiang Scholars Talent Cultivation Project of Zhongda Hospital of Southeast University(2023YJXYYRCPY03)the Basic Research Fund,First Affiliated Hospital of Gannan Medical University(QD095).
文摘Introduction:Noninvasive diagnoses of clinically significant portal hypertension(CSPH)and high-risk gastroesophageal varices are clinically relevant but challenging.Four-dimensional(4D)flow magnetic resonance imaging(MRI)provides comprehensive flow information and is a promising alternative.This study evaluated the efficacy of 4D flow MRI as a noninvasive method for diagnosing CSPH and high-risk varices in patients with liver cirrhosis.Methods:This prospective study enrolled consecutive patients diagnosed with liver cirrhosis at a tertiary referral center between October 2020 and March 2021.Each participant underwent abdominal 4D flow MRI.Hemodynamic parameters within the portal vein,including the average and peak flow velocities,normalized flow volume(Q_(normal)),and regurgitant fraction(R%),were extracted and compared between healthy individuals and patients with CSPH and between participants with high-and low-risk varices.Subsequently,these parameters were incorporated into a logistic regression(LR)model refined using L1 regularization and validated using five-fold cross-validation.The diagnostic efficacy was evaluated using receiver operating characteristic(ROC)curves.Results:Eighty-two participants were enrolled(71 patients diagnosed with liver cirrhosis and 11 healthy individuals serving as controls).Among hemodynamic parameters,patients with CSPH exhibited a notable increase in Q_(normal)of 0.66±0.19 ml*m^(2)/[cycle*kg](P=0.001)and an R%of 1.98(2.05)(P=0.002).Similarly,patients with high-risk varices showed a higher Q_(normal)of 0.61±0.15 ml*m^(2)/[cycle*kg](P<0.001)and R%of 1.88(2.81)(P=0.006).ROC analysis revealed an area under the curve(AUC)for Q_(normal)of 0.93 and 0.91 for R%for diagnosing CSPH,while the LR model showcased a superior AUC of 0.95.For high-risk varices,Q_(normal)and R%showed AUC values of 0.75 and 0.70,respectively,whereas the LR model showed a higher AUC of 0.84.Conclusion:As a noninvasive imaging modality,4D flow MRI exhibits considerable potential for the diagnosis of CSPH and high-risk gastroesophageal varices;thus,it may minimize the reliance on invasive procedures in patients with cirrhosis.
文摘本研究根据公开发表的烟草K326基因组和烟草430K SNP固相芯片检测数据,以7份种质两两组合之间每条染色体上20个多态标记为目标,基于多重PCR扩增的精准定位测序分型技术(mGPS,Genotyping by Pinpoint Sequencing of multiplex PCR products)开发出烟草1.8K育种液相芯片(YT1.8K.1)。利用该芯片对上述7份种质两两之间杂交的21个杂交组合进行基因分型检测,每个杂交组合之间的平均差异位点数为650个,能同时满足每个组合定向改良筛选高遗传背景回复率单株的需要。利用该芯片对23个烟草品种进行基因型分型检测和聚类分析,聚类分类结果与品种系谱基本吻合;利用该芯片从367个BC2F1群体中筛选出5个背景回复率高于94.96%的单株,高于理论均值87.5%,表明该育种芯片可应用于烟草种质资源聚类分析、定向改良育种的遗传背景筛选。
文摘为了建立水禽细小病毒(WPV)快速检测方法,根据序列比对结果在水禽细小病毒NS基因SF3保守区域内设计特异性引物,建立SYBR Green Ⅰ荧光定量PCR通用检测方法。该方法的扩增效率(E)为90.0%,相关系数(R~2)=0.99,标准曲线方程为y=-3.607x+38.77;除WPV出现S形扩增曲线外,新城疫病毒(NDV)、H9亚型禽流感病毒(H9 AIV)、鸭坦布苏病毒(DTMUV)、鸭肝炎病毒(DHAV)、鸭肠炎病毒(DEV)、鸭呼肠孤病毒(DRV)样品均未出现S形阳性扩增曲线;批内变异系数(CV)为0.15%~0.23%,批间变异系数为0.09%~0.28%。结果表明,SYBR Green Ⅰ荧光定量PCR检测方法重复性好、灵敏度高和特异性强。临床样品检测结果表明,SYBR Green Ⅰ荧光定量PCR与普通PCR的符合率达98.4%,灵敏度是普通PCR的1 000倍。SYBR Green Ⅰ荧光定量PCR检测方法不仅能定性检测WPV,还可以进行定量检测,可用于种鸭场、种鹅场的WPV净化检测,也可用于WPV临床大量样品的快速检测。
