Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast （cp） genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was co...Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast （cp） genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species. The complete cp genome ofM. grandiflora was 159623 bp in length and contained a pair of inverted repeats （IR） of 26563 bp separated by large and small single copy （LSC, SSC） regions of 87757 and 18740 bp, respectively. A total of 129 genes were successfully annotated, 18 of which included introns. The identity, number and GC content of M. grandiflora cp genes were similar to those of other Magnoliaceae species genomes. Analysis revealed 218 simple sequence repeat （SSR） loci, most composed of A or T, contributing to a bias in base composition. The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M. grandiflora cp genome vectors. In addition, results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycfl gene. Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony （MP） and max- imum likelihood （ML） methods provided strong support for the phylogenetic position of Magnolia. The availability of the complete cp genome sequence of M. grandiflora provides valuable information for breeding of desirable varieties, cp genetic engineering, developing useful molecular markers and phylogenetic analyses in Magnoliaceae.展开更多
In this work,Nb^(5+)and Cu^(2+)were selected to partially substitute Zr4+in Gd_(2)Zr_(2)O_(7)for studying the phase structure,microscopic morphology and thermal properties.Gd_(2)(Zr_(1-3 x/2)Nb_(x)CU_(x/2))_(2)O_(7)(x...In this work,Nb^(5+)and Cu^(2+)were selected to partially substitute Zr4+in Gd_(2)Zr_(2)O_(7)for studying the phase structure,microscopic morphology and thermal properties.Gd_(2)(Zr_(1-3 x/2)Nb_(x)CU_(x/2))_(2)O_(7)(x=0,0.05,0.1,0.15,0.2,0.25)ceramic materials were synthesized by high-temperature solid-state reaction method.The results show that the Gd_(2)(Zr_(1-3 x/2)Nb_(x)Cu_(x)/2)_(2)O_(7)ceramics present cubic pyrochlore structure with clear grain boundaries and dense cell structure.And the thermal expansion coefficient of Gd_(2)(Zr_(1-3 x/2)Nb_(x)Cu_(x/2))_(2)O_(7)ceramics gradually decreases because of the incorporation of Nb^(5+)and Cu^(2+)into Zr-site in Gd_(2)Zr_(2)O_(7).Meanwhile,its thermal conductivity decreases firstly and then increases with the doping of Nb^(5+)and Cu^(2+),which reaches the lowest value for the composition of Gd_(2)(Zr_(0.85)Nb_(0.1)Cu_(0.05))_(2)O_(7).展开更多
Objective:To investigate the association of body mass index(BMI),waist circumference(WC),and waist-to-height ratio(WHtR)with the long-term prognosis of ST-elevation myocardial infarction(STEMI)patients and to determin...Objective:To investigate the association of body mass index(BMI),waist circumference(WC),and waist-to-height ratio(WHtR)with the long-term prognosis of ST-elevation myocardial infarction(STEMI)patients and to determine whether the combination of obesity indices can be used for risk stratification.Method:A multifactorial Cox regression analysis was performed using 3-year follow-up data from 220 STEMI patients to explore the relationship between obesity indicators and major adverse cardiovascular events(MACEs).The incidence of MACEs was also compared by combining BMI and WHtR.Results:WC was found to reduce the risk of MACEs within 25 months after myocardial infarction[hazard ratio(HR)=0.95,95%confidence interval(CI)=0.92-0.98,P<0.001].However,this effect was not significant beyond 25 months(HR=0.98,95%CI=0.97-1.07,P=0.49).Neither BMI nor WHtR were significantly associated with the risk of MACEs.The incidence of MACEs was highest in patients with low body weight(BMI<18.5 kg/m^(2))and WHtR>0.5,and lowest in obese patients(BMI≥28 kg/m^(2))with WHtR>0.5.Conclusions:BMI,WC,and WHtR were not significantly associated with the long-term prognosis of STEMI patients.However,the combination of BMI and WHtR can be useful for further stratifying patient risk.展开更多
CoCu-based catalysts are widely used in CO_(x) hydrogenation reactions to produce higher alcohols due to the C–C coupling ability of Co and the ability of Cu to produce alcohols.This work describes the role of easily...CoCu-based catalysts are widely used in CO_(x) hydrogenation reactions to produce higher alcohols due to the C–C coupling ability of Co and the ability of Cu to produce alcohols.This work describes the role of easily happened CO_(2)dissociation on the CoCu surface during the reaction,using different silica support to tune the metal–support interaction,reaches different selectivity to ethanol.CoCu supported on mesoporous silica MCM-41 shows ethanol selectivity as high as 85.3%,the ethanol space-time yield(STY)is 0.229 mmol/(gmetal∙h),however,poor selectivity to ethanol as low as 28.8%is observed on CoCu supported on amorphous silica.The different selectivity is due to the different intensities of CO_(2)dissociation on the catalysts.The adsorbed O*produced via CO_(2)dissociation can occupy the cobalt hollow sites on CoCu surfaces,which are also the adsorption sites of C1 intermediates for further C–C coupling.展开更多
With the deepening understanding for the concept of sustainable development,the utilization of minerals is no longer limited to the traditional way.In this study,an environment friendly method for preparing Fe-Al_(2)O...With the deepening understanding for the concept of sustainable development,the utilization of minerals is no longer limited to the traditional way.In this study,an environment friendly method for preparing Fe-Al_(2)O_(3)composites by using natural minerals was investigated.Additionally,the effects of CeO_(2)on the properties of composites were studied.The mechanical properties of Fe-Al_(2)O_(3)composites prepared by natural minerals are affected by the brittleness of glass phase.The strength and toughness of the glass phase in the composite are improved successfully by using rare earth oxides,indicating that the natural rare earths in Bayan Obo minerals have an enhanced influence on the properties of composite materials.The results show that the properties of glass phase can be significantly improved by addition of CeO_(2).At the optimal addition of 3 wt%CeO_(2),the composite achieves the density of 4.21 g/cm^(3),flexural strength of 401 MPa,Vickers hardness of 13.07 GPa and fracture toughness of 6.58 MPa·m^(1/2).The composite has excellent mechanical properties,which can be used in engineering as a cheap structural material.This study aims at reducing waste emissions,improving energy efficiencies and avoiding waste of rare earth resources during the preparation of composite materials.展开更多
Er_(x)Ti_(0.1)Zr_(0.9-x)O_(2-1.5 x)(x=0.04,0.05,0.06,0.07,0.08) ceramics were synthesized by a solid-state reaction method.The influence of the Er^(3+) addition on the phase composition,Vickers hardness,fracture tough...Er_(x)Ti_(0.1)Zr_(0.9-x)O_(2-1.5 x)(x=0.04,0.05,0.06,0.07,0.08) ceramics were synthesized by a solid-state reaction method.The influence of the Er^(3+) addition on the phase composition,Vickers hardness,fracture toughness,and thermal conductivity of this ceramic material was investigated.The X-ray diffraction results reveal that the c-ZrO_(2) content increases from 1.85 vol% to 33.89 vol%,and the percentage of t-ZrO_(2) decreases from 98.15 vol% to 66.11 vol% with the increase in Er^(3+) content from 4 mol% to 8 mol%.Moreover,the addition of Er^(3+) is beneficial to the volume expansion of the unit cell.At the same time,the incorporation of Er^(3+) weakens the coordination of oxygen ions around the metal cations,resulting in a corresponding decrease in the tetragonality of the t-ZrO_(2).The Vickers hardness and fracture toughness of the Er_(x)Ti_(0.1)Zr_(0.9-x)O_(2-1.5)_(x) ceramics show increasing and decreasing trends,respectively.The thermal conductivity has a significant decline due to point defects caused by the Er^(3+) doping.The 8 ETZ ceramic exhibits the highest Vickers hardness(12.7 GPa),the lowest fracture toughness(7.6 MPa·m^(1/2)),and the lowest average thermal conductivity(1.85 W/(m·K)) in the temperature range of 200-1000℃.All of the above properties are higher than those of the Y_(2)O_(3)-stabilized ZrO_(2) ceramic.展开更多
The influences of equimolar substitution of yttria by gadolinia on the phase constituent and stability for Y203- Ta2Os-Zr02 ceramics have been investigated. The ceramics with the Gd content lower than 8 tool% exhibit ...The influences of equimolar substitution of yttria by gadolinia on the phase constituent and stability for Y203- Ta2Os-Zr02 ceramics have been investigated. The ceramics with the Gd content lower than 8 tool% exhibit pure tetragonal phase as well as high tetragonal phase stability. However, the high Gd containing ceramics consist of t-Zr02, m-Zr02 and monoclinic GdTa04 and show complicated phase evolution behaviors. The fractions of monoclinic Zr02 and GdTa04 increase with increasing Gd content, indicating that the excessive substitution of Gd for Y results in a reduction in the tetragonal phase stability. In addition, the lower Gd containing ceramics show an almost invariable tetragonality, while the higher Gd containing ceramics reveal a composition-dependent tetragonality. Accordingly, an association of the tetragonal phase stability and tetragonality with the Gd concentration is established, which provides us a clue to understand the phase stability of these ceramics.展开更多
基金supported by the National Natural Science Foundation of China (30970307, 81130069)the Innovation Research Team of the University of Ministry of Education of China (IRT1150)
文摘Magnolia grandiflora is an important medicinal, ornamental and horticultural plant species. The chloroplast （cp） genome of M. grandiflora was sequenced using a 454 sequencing platform and the genome structure was compared with other related species. The complete cp genome ofM. grandiflora was 159623 bp in length and contained a pair of inverted repeats （IR） of 26563 bp separated by large and small single copy （LSC, SSC） regions of 87757 and 18740 bp, respectively. A total of 129 genes were successfully annotated, 18 of which included introns. The identity, number and GC content of M. grandiflora cp genes were similar to those of other Magnoliaceae species genomes. Analysis revealed 218 simple sequence repeat （SSR） loci, most composed of A or T, contributing to a bias in base composition. The types and abundances of repeat units in Magnoliaceae species were relatively conserved and these loci will be useful for developing M. grandiflora cp genome vectors. In addition, results indicated that the cp genome size in Magnoliaceae species and the position of the IR border were closely related to the length of the ycfl gene. Phylogenetic analyses based on 66 shared genes from 30 species using maximum parsimony （MP） and max- imum likelihood （ML） methods provided strong support for the phylogenetic position of Magnolia. The availability of the complete cp genome sequence of M. grandiflora provides valuable information for breeding of desirable varieties, cp genetic engineering, developing useful molecular markers and phylogenetic analyses in Magnoliaceae.
基金the National Natural Science Foundation of China(51762036)。
文摘In this work,Nb^(5+)and Cu^(2+)were selected to partially substitute Zr4+in Gd_(2)Zr_(2)O_(7)for studying the phase structure,microscopic morphology and thermal properties.Gd_(2)(Zr_(1-3 x/2)Nb_(x)CU_(x/2))_(2)O_(7)(x=0,0.05,0.1,0.15,0.2,0.25)ceramic materials were synthesized by high-temperature solid-state reaction method.The results show that the Gd_(2)(Zr_(1-3 x/2)Nb_(x)Cu_(x)/2)_(2)O_(7)ceramics present cubic pyrochlore structure with clear grain boundaries and dense cell structure.And the thermal expansion coefficient of Gd_(2)(Zr_(1-3 x/2)Nb_(x)Cu_(x/2))_(2)O_(7)ceramics gradually decreases because of the incorporation of Nb^(5+)and Cu^(2+)into Zr-site in Gd_(2)Zr_(2)O_(7).Meanwhile,its thermal conductivity decreases firstly and then increases with the doping of Nb^(5+)and Cu^(2+),which reaches the lowest value for the composition of Gd_(2)(Zr_(0.85)Nb_(0.1)Cu_(0.05))_(2)O_(7).
基金National Natural Science Foundation of China(Grant/Award Number:81970304)Tianjin Municipal Science and Technology Commission(Grant/Award Numbers:18ZXZNSY00290 and 19JCQNJC11500).
文摘Objective:To investigate the association of body mass index(BMI),waist circumference(WC),and waist-to-height ratio(WHtR)with the long-term prognosis of ST-elevation myocardial infarction(STEMI)patients and to determine whether the combination of obesity indices can be used for risk stratification.Method:A multifactorial Cox regression analysis was performed using 3-year follow-up data from 220 STEMI patients to explore the relationship between obesity indicators and major adverse cardiovascular events(MACEs).The incidence of MACEs was also compared by combining BMI and WHtR.Results:WC was found to reduce the risk of MACEs within 25 months after myocardial infarction[hazard ratio(HR)=0.95,95%confidence interval(CI)=0.92-0.98,P<0.001].However,this effect was not significant beyond 25 months(HR=0.98,95%CI=0.97-1.07,P=0.49).Neither BMI nor WHtR were significantly associated with the risk of MACEs.The incidence of MACEs was highest in patients with low body weight(BMI<18.5 kg/m^(2))and WHtR>0.5,and lowest in obese patients(BMI≥28 kg/m^(2))with WHtR>0.5.Conclusions:BMI,WC,and WHtR were not significantly associated with the long-term prognosis of STEMI patients.However,the combination of BMI and WHtR can be useful for further stratifying patient risk.
基金the National Key R&D Program of China(No.2021YFA1500704)the National Natural Science Foundation of China(No.22121004)+2 种基金the Haihe Laboratory of Sustainable Chemical Transformations(No.CYZC202107)the Program of Introducing Talents of Discipline to Universities(No.BP0618007)the XPLORER PRIZE for financial support.
文摘CoCu-based catalysts are widely used in CO_(x) hydrogenation reactions to produce higher alcohols due to the C–C coupling ability of Co and the ability of Cu to produce alcohols.This work describes the role of easily happened CO_(2)dissociation on the CoCu surface during the reaction,using different silica support to tune the metal–support interaction,reaches different selectivity to ethanol.CoCu supported on mesoporous silica MCM-41 shows ethanol selectivity as high as 85.3%,the ethanol space-time yield(STY)is 0.229 mmol/(gmetal∙h),however,poor selectivity to ethanol as low as 28.8%is observed on CoCu supported on amorphous silica.The different selectivity is due to the different intensities of CO_(2)dissociation on the catalysts.The adsorbed O*produced via CO_(2)dissociation can occupy the cobalt hollow sites on CoCu surfaces,which are also the adsorption sites of C1 intermediates for further C–C coupling.
基金supported by the National Key R&D Program of China(2020YFC1909105)。
文摘With the deepening understanding for the concept of sustainable development,the utilization of minerals is no longer limited to the traditional way.In this study,an environment friendly method for preparing Fe-Al_(2)O_(3)composites by using natural minerals was investigated.Additionally,the effects of CeO_(2)on the properties of composites were studied.The mechanical properties of Fe-Al_(2)O_(3)composites prepared by natural minerals are affected by the brittleness of glass phase.The strength and toughness of the glass phase in the composite are improved successfully by using rare earth oxides,indicating that the natural rare earths in Bayan Obo minerals have an enhanced influence on the properties of composite materials.The results show that the properties of glass phase can be significantly improved by addition of CeO_(2).At the optimal addition of 3 wt%CeO_(2),the composite achieves the density of 4.21 g/cm^(3),flexural strength of 401 MPa,Vickers hardness of 13.07 GPa and fracture toughness of 6.58 MPa·m^(1/2).The composite has excellent mechanical properties,which can be used in engineering as a cheap structural material.This study aims at reducing waste emissions,improving energy efficiencies and avoiding waste of rare earth resources during the preparation of composite materials.
基金Project supported by the National High Technology Research and Development Program of China(2015AA034403)the National Natural Science Foundation of China(Grant No.51762036)。
文摘Er_(x)Ti_(0.1)Zr_(0.9-x)O_(2-1.5 x)(x=0.04,0.05,0.06,0.07,0.08) ceramics were synthesized by a solid-state reaction method.The influence of the Er^(3+) addition on the phase composition,Vickers hardness,fracture toughness,and thermal conductivity of this ceramic material was investigated.The X-ray diffraction results reveal that the c-ZrO_(2) content increases from 1.85 vol% to 33.89 vol%,and the percentage of t-ZrO_(2) decreases from 98.15 vol% to 66.11 vol% with the increase in Er^(3+) content from 4 mol% to 8 mol%.Moreover,the addition of Er^(3+) is beneficial to the volume expansion of the unit cell.At the same time,the incorporation of Er^(3+) weakens the coordination of oxygen ions around the metal cations,resulting in a corresponding decrease in the tetragonality of the t-ZrO_(2).The Vickers hardness and fracture toughness of the Er_(x)Ti_(0.1)Zr_(0.9-x)O_(2-1.5)_(x) ceramics show increasing and decreasing trends,respectively.The thermal conductivity has a significant decline due to point defects caused by the Er^(3+) doping.The 8 ETZ ceramic exhibits the highest Vickers hardness(12.7 GPa),the lowest fracture toughness(7.6 MPa·m^(1/2)),and the lowest average thermal conductivity(1.85 W/(m·K)) in the temperature range of 200-1000℃.All of the above properties are higher than those of the Y_(2)O_(3)-stabilized ZrO_(2) ceramic.
基金the financial support for this research by the National Natural Science Foundation of China under Grant No.50974074the Program for New Century Excellent Talents in University under Grant No.NCET-10-0910the Natural Science Foundation of Inner Mongolia under Grant No.2011ZD09
文摘The influences of equimolar substitution of yttria by gadolinia on the phase constituent and stability for Y203- Ta2Os-Zr02 ceramics have been investigated. The ceramics with the Gd content lower than 8 tool% exhibit pure tetragonal phase as well as high tetragonal phase stability. However, the high Gd containing ceramics consist of t-Zr02, m-Zr02 and monoclinic GdTa04 and show complicated phase evolution behaviors. The fractions of monoclinic Zr02 and GdTa04 increase with increasing Gd content, indicating that the excessive substitution of Gd for Y results in a reduction in the tetragonal phase stability. In addition, the lower Gd containing ceramics show an almost invariable tetragonality, while the higher Gd containing ceramics reveal a composition-dependent tetragonality. Accordingly, an association of the tetragonal phase stability and tetragonality with the Gd concentration is established, which provides us a clue to understand the phase stability of these ceramics.
