Dietary parboiled rice(PR)has a low risk of disease,but little is known about the contribution of PR to the prevention of hyperlipidemia.The potential role and underlying mechanisms of PR in hyperlipidemia were evalua...Dietary parboiled rice(PR)has a low risk of disease,but little is known about the contribution of PR to the prevention of hyperlipidemia.The potential role and underlying mechanisms of PR in hyperlipidemia were evaluated in this study.Male C57BL/6J mice were fed with a normal diet,high-fat diet(HFD)containing refined rice(HFDRR)or PR(HFDPR).It was found that PR intervention improved lipid accumulation in mice.Transcriptomic data analysis revealed that 27 genes were up-regulated(mostly involved in lipid breakdown)and 86 genes were down-regulated(mostly involved in inflammatory responses)in the HFDPR group compared to the HFDRR group.And 15 differentially expressed genes(DEGs)were validated by quantitative real-time PCR(RT-qPCR),while protein interaction network showed that protein tyrosine phosphatase receptor type C(PTPRC)has a central role.The gut microbiota of mice was also altered after different dietary treatments,with higher ratio of Firmicutes and Bacteroidetes,increased abundances of Ruminococcaceae,Lachnospiraceae,Christensenellaceae,Porphyromonadaceae,Rikenellaceae and Prevotellaceae,and decreased abundances of Lactobacillaceae,Peptostreptococcaceae,Erysipelotrichaceae and Actinobacteria in the HFDRR group.In addition,it was observed that PPAR signaling pathway may act as a bridge between DEGs and differential gut microbiota.These results suggested that PR can prevent hyperlipidemia by modulating liver genes and gut microbiota.展开更多
The characteristic secondary metabolites in tea(theanine,caffeine,and catechins)are important factors contributing to unique tea flavors.However,there has been relatively little research on molecular markers related t...The characteristic secondary metabolites in tea(theanine,caffeine,and catechins)are important factors contributing to unique tea flavors.However,there has been relatively little research on molecular markers related to these metabolites.Thus,we conducted a genome-wide association analysis of the levels of these tea flavor-related metabolites in three seasons.The theanine,caffeine,and catechin levels in Population 1 comprising 191 tea plant germplasms were examined,which revealed that their heritability exceeded 0.5 in the analyzed seasons,with the following rank order(highest to lowest heritabilities):(+)-catechin>(−)-gallocatechin gallate>caffeine=(−)-epicatechin>(−)-epigallocatechin-3-gallate>theanine>(−)-epigallocatechin>(−)-epicatechin-3-gallate>catechin gallate>(+)-gallocatechin.The SNPs detected by amplified-fragment SNP and methylation sequencing divided Population 1 into three groups and seven subgroups.An association analysis yielded 307 SNP markers related to theanine,caffeine,and catechins that were common to all three seasons.Some of the markers were pleiotropic.The functional annotation of 180 key genes at the SNP loci revealed that FLS,UGT,MYB,and WD40 domain-containing proteins,as well as ATP-binding cassette transporters,may be important for catechin synthesis.KEGG and GO analyses indicated that these genes are associated with metabolic pathways and secondary metabolite biosynthesis.Moreover,in Population 2(98 tea plant germplasm resources),30 candidate SNPs were verified,including 17 SNPs that were significantly or extremely significantly associated with specific metabolite levels.These results will provide a foundation for future research on important flavor-related metabolites and may help accelerate the breeding of new tea varieties.展开更多
Nanocomposite is proved to be an effective method to improve thermoelectric performance.In the present study,graphene is introduced into p-type skutterudite La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)by plasma-enhanced chem...Nanocomposite is proved to be an effective method to improve thermoelectric performance.In the present study,graphene is introduced into p-type skutterudite La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)by plasma-enhanced chemical vapor deposition(PECVD)method to form skutterudite/graphene nanocomposites.It is demonstrated that the graphene has no obvious effect on the electrical conductivity of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12),but the Seebeck coefficient is slightly improved at high temperature,thereby leading to high power factor.Furthermore,due to the enhancement of phonon scattering by the graphene,the lattice thermal conductivity is reduced significantly.Ultimately,the maximum z T value of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)/graphene is higher than that of graphene-free alloy and reaches to 1.0 at 723 K.Such an approach raised by us enriches prospects for future practical application.展开更多
The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-...The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni,Zr-Sn,and Ni-Sn.The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting.Solubilities of x<0:07 at 973 K and x<0:13 at 1173 K were clearly indicated.An intermediate-Heusler phase with a partly filled Ni void was observed,which is believed to be beneficial to the lowered lattice thermal conductivity.The highest ZT value~0:71 at 973 K was obtained for ZrNi_(1.11)Sn_(1.04).The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.展开更多
Benefiting from the unique"Phonon-Glass,Electron-Crystal"(PGEC)characteristic,Zintl phases have been considered as a kind of promising thermoelectric materials.For the typical AM2X2 compounds with the CaAl2S...Benefiting from the unique"Phonon-Glass,Electron-Crystal"(PGEC)characteristic,Zintl phases have been considered as a kind of promising thermoelectric materials.For the typical AM2X2 compounds with the CaAl2Si2-type structure,YbMg_(2)Bi2 has shown competitive thermoelectric performance recently.Nevertheless,the optimization of YbMg_(2)Bi2 compounds is primarily focused on the substitution on Yb or Mg site.Herein,the Bi site is substituted by isoelectric Sb and the effect on the thermoelectric transport behavior is investigated.The partial substitution reduces the carrier concentration and induces the lattice deformation caused by the different atomic radius and mass between Bi and Sb,further leading to the decreased power factor and thermal conductivity.Fortunately,the reduction extent of the thermal conductivity outperforms that of power factor.Finally,the Sb substitution successfully results in a better thermoelectric performance compared with that of the pristine YbMg_(2)Bi1.98.Especially,the calculated energy conversion efficiency(a)of YbMg_(2)Bi1.88Sb0.1 which also possesses a relatively high output power density reaches the maximum value of 9.8% when Th=873 K,and Tc=300 K,respectively.This work demonstrates that the idea of substitution on anionic site should be a new strategy to achieve better ZT values for AM2X2 compounds.展开更多
Methyl-hydroxy-cyclohexadienyl radicals(OTAs)are the key products of the photooxidation of toluene,with implications for the fate of toluene.Hence,we investigated the photooxidation mechanisms and kinetics of three ma...Methyl-hydroxy-cyclohexadienyl radicals(OTAs)are the key products of the photooxidation of toluene,with implications for the fate of toluene.Hence,we investigated the photooxidation mechanisms and kinetics of three main OTAs(o-OTA,m-OTA,and p-OTA)with NO_(2)using quantum chemical calculations as well as the fate of OTAs under the different concentration ratios of NO_(2)and O_(2).The mechanism results show that the pathway of Habstraction by NO_(2)to anti-HONO(anti-H-abstraction)is more favorable than the syn-Habstraction pathway,because the strong interaction between OTAs and NO_(2)is formed in the transition states of the anti-H-abstraction pathways.The branching ratios of the antiH-abstraction pathways are more than 99%in the temperature range of 216-298 K.The total rate constant of the OTA-NO_(2)reaction is 9.9×10^(-12)cm^(3)/(molecule·sec)at 298 K,which is contributed about 90%by o-OTA+NO_(2),and the main products are o-cresol and anti-HONO.The half-lives of the OTA-NO_(2)reaction in some polluted areas of China are 35 times longer than those of the OTA-O_(2)reaction.In the atmosphere,the NO_(2^(-))and O_(2^(-))initiated reactions of OTAs have the same ability to form cresols as[NO_(2)]is up to 142.1 ppmV,which is impossible to achieve.It implies that under the experimental condition,the[NO_(2)]/[O_(2)]should be controlled to be less than 7.8×10^(-5)to simulate real atmospheric oxidation of toluene.Our results reveal that for the photooxidation of toluene,the yield of cresol is not affected by the concentration of NO_(2)under the atmospheric environment.展开更多
Laser additive manufacturing(LAM)is a promising technology for processing bulk metallic glass(BMG)with freeform geometries or unlimited size.However,the inherently brittle Fe-based BMGs produced by LAM have always bee...Laser additive manufacturing(LAM)is a promising technology for processing bulk metallic glass(BMG)with freeform geometries or unlimited size.However,the inherently brittle Fe-based BMGs produced by LAM have always been plagued by the micro-cracking induced by the large thermal stresses during the LAM process.To solve this dilemma,316L stainless steel(SS)with excellent toughness and similar elemental composition was carefully selected as the second phase to form Fe-based BMG composites(BMGCs).The obtained Fe-based BMGCs are equipped with a heterogeneous structure,i.e.,the 316L SS phase is wrapped by the metallic glass and forms a unique"fishbone"structure with a micron-scale.Excitedly,the special structure nicely improves a plastic strain of the Fe-based BMGC with a strength of 2355 MPa to~17%,achieving a record-breaking achievement among Fe-based amorphous with critical dimensions over 1mm.展开更多
Type 2 diabetes mellitus(T2DM)is a common endocrine and progressive metabolic disorder disease,which seriously threatens peoples’lives and health.Due to the high cost of clinical treatments and obvious side effects,l...Type 2 diabetes mellitus(T2DM)is a common endocrine and progressive metabolic disorder disease,which seriously threatens peoples’lives and health.Due to the high cost of clinical treatments and obvious side effects,looking for effective bioactive ingredients in the diet is an important strategy to prevent or even reduce the risk of diabetes.Epidemiological studies have suggested that dietary flavonoids have a potential antidiabetic effect,but the underlying mechanism remains unclear.Accumulating evidences indicates that gut microbiota has become an important target of dietary interventions.It plays essential roles in the digestion and absorption of flavonoids and affects the occurrence and progression of T2DM.This review systematically summarized the progress of dietary flavonoids targeting gut microbiota to ameliorate T2DM and analyzed possible molecular mechanisms.It suggests that flavonoids may prevent T2DM for healthy people and ameliorate health situations for T2DM patients.In addition,microbiota-based nutrition aims to provide personalized nutritional guidance to alter an individual’s microbiota and further improve response to dietary flavonoids,which will benefit to achieve a more effective diet for the prevention and management of T2DM.展开更多
基金financially supported by Key Project of State Key R&D Program,China (2022YFF1100200)the Program for Science&Technology Innovation Platform of Hunan Province (2019TP102)+3 种基金Natural Science Foundation of Hunan Province (2021JJ31075,2019JJ50984)Natural Science Foundation of Changsha City (kq2014275)Scientific Innovation Fund for Postgraduates of Central South University of Forestry and Technology (CX20200699,CX202102067)Postgraduate Scientific Research Innovation Project of Hunan Province (CX20201018,CX20210899,CX20220701 and CX20220720)。
文摘Dietary parboiled rice(PR)has a low risk of disease,but little is known about the contribution of PR to the prevention of hyperlipidemia.The potential role and underlying mechanisms of PR in hyperlipidemia were evaluated in this study.Male C57BL/6J mice were fed with a normal diet,high-fat diet(HFD)containing refined rice(HFDRR)or PR(HFDPR).It was found that PR intervention improved lipid accumulation in mice.Transcriptomic data analysis revealed that 27 genes were up-regulated(mostly involved in lipid breakdown)and 86 genes were down-regulated(mostly involved in inflammatory responses)in the HFDPR group compared to the HFDRR group.And 15 differentially expressed genes(DEGs)were validated by quantitative real-time PCR(RT-qPCR),while protein interaction network showed that protein tyrosine phosphatase receptor type C(PTPRC)has a central role.The gut microbiota of mice was also altered after different dietary treatments,with higher ratio of Firmicutes and Bacteroidetes,increased abundances of Ruminococcaceae,Lachnospiraceae,Christensenellaceae,Porphyromonadaceae,Rikenellaceae and Prevotellaceae,and decreased abundances of Lactobacillaceae,Peptostreptococcaceae,Erysipelotrichaceae and Actinobacteria in the HFDRR group.In addition,it was observed that PPAR signaling pathway may act as a bridge between DEGs and differential gut microbiota.These results suggested that PR can prevent hyperlipidemia by modulating liver genes and gut microbiota.
基金This work was supported by Key-Area Research and Development Program of Guangdong Province[2020B020220004]the earmarked fund for the National Modern Agro-industry Technology Research System(CARS-19)+5 种基金the National Natural Science Foundation of China(31600550)Science and Technology program of Guangdong Province(2016A030303032 and 2019B030316026)Discipline team building projects of Guangdong Academy of Agricultural Sciences in the 13th Five-Year Period(201619TD)Special funds for scientific innovation strategy-construction of high level Academy of Agriculture Science(R2017PY-QY009)Integrated demonstration of key techniques for the industrial development of featured crops in rocky desertification areas of Yunnan-Guangxi-Guizhou provinces(SMH2019-2021)the Central Public-interest Scientific Institution Basal Research Fund for Chinese Academy of Tropical Agricultural Sciences(1630052019022).
文摘The characteristic secondary metabolites in tea(theanine,caffeine,and catechins)are important factors contributing to unique tea flavors.However,there has been relatively little research on molecular markers related to these metabolites.Thus,we conducted a genome-wide association analysis of the levels of these tea flavor-related metabolites in three seasons.The theanine,caffeine,and catechin levels in Population 1 comprising 191 tea plant germplasms were examined,which revealed that their heritability exceeded 0.5 in the analyzed seasons,with the following rank order(highest to lowest heritabilities):(+)-catechin>(−)-gallocatechin gallate>caffeine=(−)-epicatechin>(−)-epigallocatechin-3-gallate>theanine>(−)-epigallocatechin>(−)-epicatechin-3-gallate>catechin gallate>(+)-gallocatechin.The SNPs detected by amplified-fragment SNP and methylation sequencing divided Population 1 into three groups and seven subgroups.An association analysis yielded 307 SNP markers related to theanine,caffeine,and catechins that were common to all three seasons.Some of the markers were pleiotropic.The functional annotation of 180 key genes at the SNP loci revealed that FLS,UGT,MYB,and WD40 domain-containing proteins,as well as ATP-binding cassette transporters,may be important for catechin synthesis.KEGG and GO analyses indicated that these genes are associated with metabolic pathways and secondary metabolite biosynthesis.Moreover,in Population 2(98 tea plant germplasm resources),30 candidate SNPs were verified,including 17 SNPs that were significantly or extremely significantly associated with specific metabolite levels.These results will provide a foundation for future research on important flavor-related metabolites and may help accelerate the breeding of new tea varieties.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.51622101,51771065,and 51471061)
文摘Nanocomposite is proved to be an effective method to improve thermoelectric performance.In the present study,graphene is introduced into p-type skutterudite La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)by plasma-enhanced chemical vapor deposition(PECVD)method to form skutterudite/graphene nanocomposites.It is demonstrated that the graphene has no obvious effect on the electrical conductivity of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12),but the Seebeck coefficient is slightly improved at high temperature,thereby leading to high power factor.Furthermore,due to the enhancement of phonon scattering by the graphene,the lattice thermal conductivity is reduced significantly.Ultimately,the maximum z T value of La_(0.8)Ti_(0.1)Ga_(0.1)Fe_3CoSb_(12)/graphene is higher than that of graphene-free alloy and reaches to 1.0 at 723 K.Such an approach raised by us enriches prospects for future practical application.
基金supported by the National Natural Science Foundation of China(51771065 and 51871082)the Natural Science Foundation of Heilongjiang Province of China(ZD2020E003)。
基金This work was funded by the National Natural Science Foundation of China(51971081,11674078,and 51871081)the National Key Research&Development Program of China(2017YFA0303600)+2 种基金the National Natural Science Foundation of Guangdong Province of China(2018A0303130033)Shenzhen Fundamental Research Projects(JCYJ20170811155832192)Shenzhen Science and Technology Innovation Plan(KQISCX20180328165435202).
文摘The solubility range of interstitial Ni in the ZrNi1+xSn half-Heusler phase is a controversial issue,but it has an impact on the thermoelectric properties.In this study,two isothermal section phase diagrams of the Zr-Ni-Sn ternary system at 973K and 1173 K were experimentally constructed based on the binary phase diagrams of Zr-Ni,Zr-Sn,and Ni-Sn.The thermodynamic equilibrium phases were obtained after a long time of heating treatment on the raw alloys prepared by levitation melting.Solubilities of x<0:07 at 973 K and x<0:13 at 1173 K were clearly indicated.An intermediate-Heusler phase with a partly filled Ni void was observed,which is believed to be beneficial to the lowered lattice thermal conductivity.The highest ZT value~0:71 at 973 K was obtained for ZrNi_(1.11)Sn_(1.04).The phase boundary mapping provides an important instruction for the further optimization of ZrNiSn-based materials and other systems.
基金supported financially by the National Natural Science Foundation of China(Nos.51771065 and 51871082)。
文摘Benefiting from the unique"Phonon-Glass,Electron-Crystal"(PGEC)characteristic,Zintl phases have been considered as a kind of promising thermoelectric materials.For the typical AM2X2 compounds with the CaAl2Si2-type structure,YbMg_(2)Bi2 has shown competitive thermoelectric performance recently.Nevertheless,the optimization of YbMg_(2)Bi2 compounds is primarily focused on the substitution on Yb or Mg site.Herein,the Bi site is substituted by isoelectric Sb and the effect on the thermoelectric transport behavior is investigated.The partial substitution reduces the carrier concentration and induces the lattice deformation caused by the different atomic radius and mass between Bi and Sb,further leading to the decreased power factor and thermal conductivity.Fortunately,the reduction extent of the thermal conductivity outperforms that of power factor.Finally,the Sb substitution successfully results in a better thermoelectric performance compared with that of the pristine YbMg_(2)Bi1.98.Especially,the calculated energy conversion efficiency(a)of YbMg_(2)Bi1.88Sb0.1 which also possesses a relatively high output power density reaches the maximum value of 9.8% when Th=873 K,and Tc=300 K,respectively.This work demonstrates that the idea of substitution on anionic site should be a new strategy to achieve better ZT values for AM2X2 compounds.
基金financially supported by Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(No.2017BT01Z032)Natural Science Foundation of Guangdong Province,China(No.2019B151502064)+1 种基金National Natural Science Foundation of China(Nos.42077189 and 4201001008)Innovation Team Project of Guangdong Provincial Department of Education(No.2017KCXTD012)
文摘Methyl-hydroxy-cyclohexadienyl radicals(OTAs)are the key products of the photooxidation of toluene,with implications for the fate of toluene.Hence,we investigated the photooxidation mechanisms and kinetics of three main OTAs(o-OTA,m-OTA,and p-OTA)with NO_(2)using quantum chemical calculations as well as the fate of OTAs under the different concentration ratios of NO_(2)and O_(2).The mechanism results show that the pathway of Habstraction by NO_(2)to anti-HONO(anti-H-abstraction)is more favorable than the syn-Habstraction pathway,because the strong interaction between OTAs and NO_(2)is formed in the transition states of the anti-H-abstraction pathways.The branching ratios of the antiH-abstraction pathways are more than 99%in the temperature range of 216-298 K.The total rate constant of the OTA-NO_(2)reaction is 9.9×10^(-12)cm^(3)/(molecule·sec)at 298 K,which is contributed about 90%by o-OTA+NO_(2),and the main products are o-cresol and anti-HONO.The half-lives of the OTA-NO_(2)reaction in some polluted areas of China are 35 times longer than those of the OTA-O_(2)reaction.In the atmosphere,the NO_(2^(-))and O_(2^(-))initiated reactions of OTAs have the same ability to form cresols as[NO_(2)]is up to 142.1 ppmV,which is impossible to achieve.It implies that under the experimental condition,the[NO_(2)]/[O_(2)]should be controlled to be less than 7.8×10^(-5)to simulate real atmospheric oxidation of toluene.Our results reveal that for the photooxidation of toluene,the yield of cresol is not affected by the concentration of NO_(2)under the atmospheric environment.
基金the National Natural Science Foundation of China(No.51971047)the project of Liaoning Province’s“Rejuvenating Liaoning talents plan”(No.XLYC1907046)+2 种基金Dalian High-Level Talent Innovation Support Program(No.2020RJ07)Supported by State Key Lab of Advanced Metals and Materials(No.2021-ZD10)the Joint Research Fund Liaoning-Shenyang National Laboratory for Materials Science(No.2019JH3/30100032)。
文摘Laser additive manufacturing(LAM)is a promising technology for processing bulk metallic glass(BMG)with freeform geometries or unlimited size.However,the inherently brittle Fe-based BMGs produced by LAM have always been plagued by the micro-cracking induced by the large thermal stresses during the LAM process.To solve this dilemma,316L stainless steel(SS)with excellent toughness and similar elemental composition was carefully selected as the second phase to form Fe-based BMG composites(BMGCs).The obtained Fe-based BMGCs are equipped with a heterogeneous structure,i.e.,the 316L SS phase is wrapped by the metallic glass and forms a unique"fishbone"structure with a micron-scale.Excitedly,the special structure nicely improves a plastic strain of the Fe-based BMGC with a strength of 2355 MPa to~17%,achieving a record-breaking achievement among Fe-based amorphous with critical dimensions over 1mm.
基金supported by the Natural Science Foundation of Hunan Province,China(No.2021JJ31075)Natural Science Foundation Project of Changsha City(KQ2014275)+2 种基金the Program for Science&Technology Innovation Platform of Hunan Province(2019TP1029)Scientific Innovation Fund for Post-graduates of Central South University of Forestry and Technology(CX202101027)Postgraduate Scientific Research Innnovation Project of Hunan Province(CX20210862).
文摘Type 2 diabetes mellitus(T2DM)is a common endocrine and progressive metabolic disorder disease,which seriously threatens peoples’lives and health.Due to the high cost of clinical treatments and obvious side effects,looking for effective bioactive ingredients in the diet is an important strategy to prevent or even reduce the risk of diabetes.Epidemiological studies have suggested that dietary flavonoids have a potential antidiabetic effect,but the underlying mechanism remains unclear.Accumulating evidences indicates that gut microbiota has become an important target of dietary interventions.It plays essential roles in the digestion and absorption of flavonoids and affects the occurrence and progression of T2DM.This review systematically summarized the progress of dietary flavonoids targeting gut microbiota to ameliorate T2DM and analyzed possible molecular mechanisms.It suggests that flavonoids may prevent T2DM for healthy people and ameliorate health situations for T2DM patients.In addition,microbiota-based nutrition aims to provide personalized nutritional guidance to alter an individual’s microbiota and further improve response to dietary flavonoids,which will benefit to achieve a more effective diet for the prevention and management of T2DM.
