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Effect of chemical composition on zircon radiation damage dating:Implications for low-temperature thermochronology

Geoscience Frontiers 2023年第6期14卷 368-379页

作者： Mingpu Fan Xiaoming Liu Shengsi Sun Yunpeng Dong John c.ayers M.Santosh State Key Laboratory of continental Dynamics Department of GeologyNorthwest UniversityXi’an 710069China Vanderbilt University Department of Earth&Environmental SciencesPMB 3518052301 Vanderbilt PlaceNashvilleTN 37235-1805USA School of Earth Science and Resources China University of GeosciencesBeijing 100083China Department of Earth Science University of AdelaideAdelaideSA 5005Australia Yonsei Frontier Lab Yonsei UniversitySeoul 03722Republic of Korea

Zircon radiation damage dating is a low-temperature thermochronological method that can reveal the cooling histories of magmatic intrusions and discriminate sedimentary provenance in combination with other dating *** method has broad application prospects because of its advantages of nondestructive,high efficiency,and capable of double(or multiple)dating,involving only multiple measurements by Raman spectrometer and laser ablation-inductively coupled plasma-mass ***,several factors,such as zircon chemical composition and the non-uniformity of radiation damage annealing kinetics,can cause poor precision when using this method and thus restricts its wide *** study examined the effect of chemical composition(P,Ti,Dy,Th,U,and Hf)on Raman spectra using synthetic zircon crystals grown in a lithium-molybdate *** results show that the full width at half-maximum(FWHM)of the v_(3)(SiO_(4))band has positive linear correlations with the concentrations of P,Ti,Dy,Th,and U in decreasing order of influence,while the FWHM is unaffected by Hf at concentrationscreases at concentrations>10 wt.%.Furthermore,the Raman shift is negatively correlated with Th,U,and Dy concentrations,positively correlated with Hf,and shows no obvious correlation with Ti and ***,our study shows that chemical composition is a non-ignorable factor for calculating zircon radiation damage age using Raman spectroscopy,especially for zircon with relatively high concentrations of P,rare earth elements(REEs),Th,U,and *** obtained multiple linear regression equation provides a potential means for estimating the FWHM at zero dose and implication for improving the dating precision of this *** addition,the observed effects of REEs,Th,U,and Hf on the Raman shift of the v_(3)(SiO_(4))band indicate that chemical composition in zircon might affect the estimation of the P-T conditions of geological processes when using entrapped zircon inclusions in host mi

关键词： Synthetic zircon Raman spectroscopy chemical composition Radiation damage dating cooling age

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The <i>phka</i>1 deficient I/LnJ mouse exhibits endurance exercise deficiency with no compensatory changes in glycolytic gene expression

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Open Journal of Molecular and Integrative Physiology 2013年第2期3卷 87-94页

作者： Ashley M. Mefford claci c. ayers Naomi S. Rowland Nancy A. Rice Department of Biology Western Kentucky University Bowling Green USA

During exercise, phosphorylase kinase (PhK) is the key regulatory enzyme responsible for maintaining glycogenolytic flux to sustain muscle contraction. The absence of PhK in skeletal muscle results in glycogen storage disease (GSD) Type IX which is characterized by muscle weakness and rapid fatigue upon exercise. In this study, we have used the phka1 deficient I/LnJ mouse model of GSD to investigate the physiological and genetic adaptations that occur in response to voluntary exercise. When quantified over training periods of either 1, 2, or 5 weeks, I/LnJ mice ran significantly less time/day and distance/day than agematched c57/Bl6 mice. cumulatively after five weeks, adult I/LnJ mice ran ~1/2 the total time and distance of wild-type mice, 116 ± 6 hours and 211 ±23 kmversus 194 ± 3 hours and 418 ±4 km, respectively. After 5 weeks, c57/Bl6 mice demonstrated an increase in endurance as a result of aerobic training;this observed physiological adaptation was not present in I/LnJ mice. The decrease in total distance run by I/LnJ mice was not due to a reduction in speed;juvenile and adult I/LnJ mice ran ~75% - 80% as fast as c57/Bl6 mice. When transcription of glycolytic genes glucose transporter 4 (scla1), pyruvate dehydrogenase (pdha1), and phosphofructokinase (pfk) were quantified at the end of each training period, no significant differences in expression levels were found between mouse strains, suggesting that non-glycolytic mechanisms work to maintain the muscle function observed in the I/LnJ mice.

关键词： Phosphorylase Kinase Glycogen Storage Disease Exercise Skeletal Muscle I/LnJ

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二辉橄榄岩中元素分配与质量平衡的关系

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地质科学译丛 1994年第3期11卷 6-12页

作者： John c.ayers 刘春芳 Department of Gcology Vanderbm UniversityNashvilleTN 37235USA

对二辉橄榄岩中,矿物成分与实际矿物丰度的相关性应用质量平衡方程及相之间的分配系数进行了研究。与斜方辉石和橄榄石相比,由于单斜辉石强烈富集不相容元素,所以当其实际矿物丰度接近零时,单斜辉石的成分便发生显著改变;当单斜辉石的... 详细信息

对二辉橄榄岩中,矿物成分与实际矿物丰度的相关性应用质量平衡方程及相之间的分配系数进行了研究。与斜方辉石和橄榄石相比,由于单斜辉石强烈富集不相容元素,所以当其实际矿物丰度接近零时,单斜辉石的成分便发生显著改变;当单斜辉石的质量分数小于0.2时,其成分变量如元素浓度(La)、元素比值(La/Yb)及内插浓度(Nb/Nb)并不代表全岩成分;在缺乏其它富集不相容元素的矿物时,单斜辉石的La/Yb总是比其寄主二辉橄榄岩高,而它的HFSE/HFSE却总比寄主二辉橄榄岩低。所以,只根据单斜辉石分析结果便认为二辉橄榄岩全岩REE富集或HFSE亏损的观点可能是错误的。

关键词：二辉橄榄元素分配质量平衡

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脂肪分布与血压水平及血压变异性的关系

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中华高血压杂志 2016年第7期24卷 631-631页

作者：刘莉叶鹏 Yano Y Vongpatanasin W ayers c Turer A chandra A carnethon MR Greenland P de Lemos JA Neeland IJ

该研究旨在探索脂肪分布与家庭、诊室血压水平及血压变异性的相关性。达拉斯心脏研究受试者来自一个多种族的人群,均在5个月内于3个不同场合（2次在家庭和1次在诊室）接受了5次血压测量检查,通过磁共振成像定量测定内脏脂肪组织、

关键词：血压变异性脂肪分布内脏脂肪组织诊室血压磁共振成像血压测量平均血压平均收缩压定量测定达拉斯

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心肌肌钙蛋白I与肺高血压患者疾病严重程度和预后的相关性

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中华高血压杂志 2013年第5期21卷 431-431页

作者： Vélez-Martínez M ayers c Mishkin JD Bartolome SB García cK Torres F Drazner MH de Lemos JA Turer AT chin KM 刘莉叶鹏

先前的研究表明，心肌肌钙蛋白I（cardiac troponin I，cTnI）可作为肺高血压预后的重要标志物，然而传统的试验测定方法敏感性较差，即便是高危患者中也如此。该研究使用一项新的高敏分析方法检测255例肺高血压患者的cTnI水平，辅以人... 详细信息

先前的研究表明，心肌肌钙蛋白I（cardiac troponin I，cTnI）可作为肺高血压预后的重要标志物，然而传统的试验测定方法敏感性较差，即便是高危患者中也如此。该研究使用一项新的高敏分析方法检测255例肺高血压患者的cTnI水平，辅以人口统计学、血肌酐、6min步行距离、血流动力学、心脏磁共振成像和脑钠尿肽水平等其他指标。

关键词：心肌肌钙蛋白1 高血压患者血压预后疾病严重程度相关性 troponin 心脏磁共振成像肺

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达拉斯心脏中心关于MR成像上腹主动脉粥样硬化与心血管事件关系的研究

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国际医学放射学杂志 2013年第6期 581-581页

作者： c.D.Maroules E.Rosero c.ayers MS R.M.Peshock A.Khera 高炜 Departments of Radiology Anesthesiology Clinical Sciences and Internal Medicine Division of Cardiology and the Donald W.Reynolds Cardiovascular Clinical Research Center University of Texas Southwestern Medical Center 5323 Harry Hines BlvdDallas TX 75390-8896

摘要目的在MR成像上确定两个腹主动脉粥样硬化的测量值,以预测未来的心血管事件发生的风险性。材料与方法本研究得到机构审查委员会的批准,并遵守HIPAA法

关键词：心血管粥样硬化腹主动脉主动脉腹部 MR 达拉斯

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高磷喂食诱导运动不耐受并损害小鼠的脂肪酸代谢

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中华高血压杂志 2019年第2期27卷 148-148页

作者：刘青叶鹏 Peri-Okonny PA Baskin KK Iwamoto G Mitchell JH Smith SA Kim HK Szweda LI Bassel-Duby R Fujikawa T castorena cM Richardson J Shelton JM ayers c Berry JD Malladi VS Hu Mc Moe OW Scherer PE Vongpatanasin W

无机磷酸盐(inorganic phosphate,Pi)广泛用作西方饮食中的防腐剂和增味剂。缺乏身体活动是西方社会的共同特征,与心血管病的发病率和死亡率增加有关。目前尚不清楚饮食中Pi过量是否会导致运动不耐受和身体活动缺乏。为了确定人体中Pi... 详细信息

无机磷酸盐(inorganic phosphate,Pi)广泛用作西方饮食中的防腐剂和增味剂。缺乏身体活动是西方社会的共同特征,与心血管病的发病率和死亡率增加有关。目前尚不清楚饮食中Pi过量是否会导致运动不耐受和身体活动缺乏。为了确定人体中Pi过量和体力活动之间的关联,研究者在调整了相关变量后,评估DHS-2(达拉斯心脏研究第2阶段)参与者的血清Pi与活动记录测定的身体活动水平以及心脏磁共振成像的左心室功能之间的关系。

关键词：无机磷酸盐不耐受脂肪酸代谢运动小鼠损害喂食身体活动

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Understanding chemical Reactivity in Extended Systems：Exploring Models of chemical Softness in carbon Nanotubes

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物理化学学报 2018年第6期34卷 631-638页

作者： cáRDENAS carlos MUNOZ Macarena cONTRERAS Julia ayers Paul W. GóMEZ Tatiana FUENTEALBA Patricio Departamento de Flsica Facultad de Ciencias Universidad de Chile Casilla 653 Santiago Chile centro para el Desarrollo de la Nanociencias y Nanotecnologia CEDENNA Avenida Ecuador 3493 Santiago Chile Nucleo de Matematicas Fisica y Estad

chemical reactivity towards electron transfer is captured by the Fukui ***,this is not well defined when the system or its ions have degenerate or pseudo-degenerate ground *** such a case,the first-order chemical response is not independent of the perturbation and the correct response has to be computed using the mathematical formalism of perturbation theory for degenerate ***-degeneracy is ubiquitous in nanostructures with high symmetry and totally extended *** the size of these systems,using degenerate-state perturbation theory is impractical because it requires the calculation of many excited *** we present an alternative to compute the chemical response of extended systems using models of local softness in terms of the local density of *** local softness is approximately equal to the density of states at the Fermi ***,such approximation leaves out the contribution of inner *** order to include and weight the contribution of the states around the Fermi level,a model inspired by the long-range behavior of the local softness is *** wall capped carbon nanotubes(SWccNT) illustrate the limitation of the frontier orbital theory in extended ***,we have used a c360 SWccNT to test the proposed model and how it compares with available models based on the local density of ***,a simple Hü ckel approximation captures the main features of chemical response of these *** results suggest that density-of-states models of the softness along simple tight binding Hamiltonians could be used to explore the chemical reactivity of more complex system,such a surfaces and nanoparticles.

关键词： Local softness Fukui function Reactivity carbon nanotubes Density of states

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Thermodynamic Dual Descriptor

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物理化学学报 2018年第6期34卷 683-691页

作者： FRANcO-PéREZ Marco GáZQUEZ José L. ayers Paul W. VELA Alberto Departamento de Quimica Universidad Aut6noma Metropolitana-Iztapalapa Av. San Rafael Atlixco 186 Ciudad de Mexico 09340 Mexico. Department of chemistry McMaster University Hamilton Ontario L8S 4M1 Canada. Departamento de Quimica Centro

A new definition of the dual descriptor,namely,thethermodynamic dual descriptor,is developed within the grand canonicalpotential *** new definition is formulated to describe the same △f_r(r)=β/2c[f^+(r)-f^-(r)](c>0) physical phenomenon as the original definition proposed by Morell,Grand,and Toro-Labbé(***.A2005,109,205),which is characterized by a second-order response of the electron density towards an electron *** formulate the new definition,we performed two successive partial derivatives of the average electron density,one with respect to the average number of electrons,and the other with respect to the chemical potential of the electron *** the derivative is expressed in terms of the three-state ensemble model,in the regime of low temperatures up to temperatures of chemical interest,one finds that the thermodynamic dual descriptor can be expressed as?f_T(r)=(β/2)c[f^+(r)-f^-(r)],whereβ=1/k_BT,cis a global quantity that depends on the temperature and global electronic properties of the molecule(the first ionization potential and the electron affinity),c=1 for systems with zero fractional charge,and c=c_ω>0(albeit very close to zero)for systems with nonzero fractional charge,,and f^+(r)and f^-(r)are the nucleophilic and electrophilic Fukui functions,*** quantity within the square brackets is the original definition of the dual *** the local terms(the ones containing regioselectivity information)are equal to those of the dual descriptor,?f_T(r)has the same regioselectivity information,multiplied by the global quantity(β/2)*** implies that the regioselectivity information contained in the original dual descriptor is preserved at all temperatures different from zero,and for any value of c>*** of the most important features of this new definition is that it avoidsthe undesired Dirac delta behavior observed when the second order partial derivative of the average density is taken with respect to the average

关键词： Dual descriptor chemical stability Finite temperature chemical reactivity theory Fractional average number of electrons Amphiphilicity

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Quantitative Electrophilicity Measures

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物理化学学报 2018年第6期34卷 662-674页

作者： GONZáLEZ Marco Martínez cáRDENAS carlos RODRíGUEZ Juan I. LIU Shubin HEIDAR-ZADEH Farnaz MIRANDA-QUINTANA Ramón Alain ayers Paul W. Laboratory of computational and Theoretical chemistry Faculty of Chemistry University of Havana Havana 10400 Cuba. Departamento de Quimica and Centro de Quimica Universidade de Coimbra 3004-535 Coimbra Portugal. Departamento de Fisica Fac

Quantitative correlation of several theoretical electrophilicity measures over different families of organic compounds are examined relative to the experimental values of Mayr et ***,the ability to predict these values accurately will help to elucidate the reactivity and selectivity trends observed in charge-transfer reactions.A crucial advantage of this theoretical approach is that itprovides this information without the need of experiments,which are often demanding and ***,two different types of electrophilicity measures were ***,models derived from conceptual density functional theory(c-DFT),including Parr's original proposal and further generalizations of this index,are *** instance,the approaches of Gázquez et *** chamorro et *** considered,whereby it is possible to distinguish between processes in which a molecule gains or loses ***,we also explored two novel electrophilicity *** one hand,the potential of environmental perturbations to affect electron incorporation into a system is analyzed in terms of recent developments in *** studies highlight the importance of considering the molecular surroundings when a consistent description of chemical reactivity is *** the other hand,we test a new definition of electrophilicity that is free from inconsistencies(so-called thermodynamic electrophilicity).This approach is based on Parr's pioneering insights,though it corrects issues present in the standard working expression for the calculation of ***,we use machine-learning tools(i.e.,symbolic regression) to identify the models that best fit the experimental *** this way,the best possible description of the electrophilicity values in terms of different electronic structure quantities is ***,this straightforward approach enables one to obtain good correlations between the theoretical and experimental quantities by using the simple,yet p

关键词： Electrophilicity conceptual density functional theory Symbolic regression Genetic programming Grammatical evolution

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