The future of Sino-U.S.strategic engagement has become a focus of international attention since the second inauguration of U.S.President Donald Trump this January.Previously,Trump claimed intentions to boost domestic ...The future of Sino-U.S.strategic engagement has become a focus of international attention since the second inauguration of U.S.President Donald Trump this January.Previously,Trump claimed intentions to boost domestic manufacturing.If his plan continues,the U.S.may seek a certain degree of cooperation with China in trade in order to benefit from China’s vast market and complete industrial chain.The two countries can negotiate on lowering tariffs and other trade barriers and leveraging China’s manufacturing capacity to reduce the risk of decoupling in bilateral trade.展开更多
Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacill...Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.展开更多
Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer susta...Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer sustainable.This trial aims at evaluating the effects of the dietary inclusion of Hermetia illucens oil(HIO)vs.hydrogenated palm fat(HPF)on digestive parameters,oxidative stress,and milk production performance of dairy cows.Results Twenty-six Valdostana Red Pied cows were randomly divided into two groups and fed with hay ad libitum and a concentrate containing 3%(as fed)of either HPF or HIO.The trial lasted 50 d,including two weeks of diet adaptation.Individual feed intake and milk yield were monitored three and four times a week,respectively.Fecal samples were collected at the end(d 50)of the trial to determine total-tract nutrients apparent digestibility.Individual blood samples were collected to evaluate blood plasma metabolites(d 0 and d 50)and oxidative stress parameters(d 0,d 26 and d 50).Milk samples were collected at d 0,d 14,d 26,d 38 and d 50 for chemical composition analysis.Feed efficiency was estimated through feed conversion ratio and residual feed intake(RFI).Data were analyzed by SAS software using a mixed model.The diet had no effect on nutrients intake and apparent total-tract digestibility.However,the dietary inclusion of HIO led to higher milk production(+0.82 kg/cow/d;P<0.05)and slightly lower RFI(−0.008;P<0.001)when compared to the HPF diet.Milk composition and the nutritional metabolic status of the cows remained unaffected by diet.Serum antioxidant capacity was comparable between the two groups,while lower derivatives of reactive oxygen metabolite concentrations were observed in the HIO-fed cows when compared to the HPF-fed ones(−37.13 Carratelli Units;P<0.001).Conclusions The dietary inclusion of HIO instead of HPF did not negatively affect feed palatability and total-tract apparent digestibility of nutrients in dairy cows.Furthermore,it increased feed efficiency by supporting a higher milk production together with an improved antioxidant status.The results suggest that HIO could be an eligible option as an innovative energy source for dairy cows.展开更多
The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Musch...The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. （Brassicaceae）, have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes （LEAFY and G3pdh） and two chloroplast intergenic spacers （petN-psbM and psbM-trnD） were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum （Maxim.） Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.展开更多
In this study, volatile compounds present in Toona sinensis (A. Juss.) Roem (TS) were investigated and their characteristic aromatic components were identified using Headspace Solid-phase Microextraction (HS-SPME) fol...In this study, volatile compounds present in Toona sinensis (A. Juss.) Roem (TS) were investigated and their characteristic aromatic components were identified using Headspace Solid-phase Microextraction (HS-SPME) followed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O). The optimum conditions for extracting the volatiles from TS were achieved with the experimental parameters including the use of a 65 μm polydimethylsiloxane/divinyl benzene (PDMS/DVB) fibre, an extraction temperature of 40℃ and an extraction time of 30 min. Under these conditions, 56 volatile compounds were separated and 53 were identified by GC-MS. Among them, 21 sulfide compounds (42.146%) and 27 terpenes(55.984%) were found to be the major components. The sample was analyzed by GC-O and 26 elutes were sniffed and their sensory descriptions evaluated by an odor panelists. Analysis of the data indicated, two compounds cis and trans isomers of 2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene were major contributors to the characteristic aroma of TS.展开更多
Background:Mammalian cells possess molecular clocks,the adequate functioning of which is decisive for metabolic health.Exercise is known to modulate these clocks,potentially having distinct effects on metabolism depen...Background:Mammalian cells possess molecular clocks,the adequate functioning of which is decisive for metabolic health.Exercise is known to modulate these clocks,potentially having distinct effects on metabolism depending on the time of day.This study aimed to investigate the impact of morning vs.evening moderate-intensity aerobic exercise on glucose regulation and energy metabolism in healthy men and women.It also aimed to elucidate molecular mechanisms within skeletal muscle.Methods:Using a randomized crossover design,healthy men(n=18)and women(n=17)performed a 60-min bout of moderate-intensity aerobic exercise in the morning and evening.Glucose regulation was continuously monitored starting 24 h prior to the exercise day and continuing until 48 h post-exercise for each experimental condition.Energy expenditure and substrate oxidation were measured by indirect calorimetry during exercise and at rest before and after exercise for 30 min.Skeletal muscle biopsies were collected immediately before and after exercise to assess mitochondrial function,transcriptome,and mitochondrial proteome.Results:Results indicated similar systemic glucose,energy expenditure,and substrate oxidation during and after exercise in both sexes.Notably,transcriptional analysis,mitochondrial function,and mitochondrial proteomics revealed marked sexual dimorphism and time of day variations.Conclusion:The sexual dimorphism and time of day variations observed in the skeletal muscle in response to exercise may translate into observable systemic effects with higher exercise-intensity or chronic exercise interventions.This study provides a foundational molecular framework for precise exercise prescription in the clinical setting.展开更多
BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHOD...BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHODS:It was a prospective,blind,randomised controlled study involving 109 medical students without previous CPR training.In a standardized mannequin scenario,after the step of dispatcher-assisted cardiac arrest recognition,the participants performed compression-only resuscitation guided over the telephone by either:(1)the pre-recorded instructional audio(n=57);or(2)verbal dispatcher assistance(n=52).The simulation video records were reviewed to assess the CPR performance using a 13-item checklist.The interval from call reception to the first compression,total number and rate of compressions,total number and duration of pauses after the first compression were also recorded.RESULTS:There were no significant differences between the recording-assisted and dispatcher-assisted groups based on the overall performance score(5.6±2.2 vs.5.1±1.9,P>0.05)or individual criteria of the CPR performance checklist.The recording-assisted group demonstrated provided(170.2±48.0 vs.156.2±60.7).CONCLUSION:When provided by untrained persons in the simulated settings,the compression-only resuscitation guided by the pre-recorded instructional audio is no less efficient than dispatcher-assisted CPR.Future studies are warranted to further assess feasibility of using instructional audio aid as a potential alternative to dispatcher assistance.展开更多
A unified perturbation theory is developed here for calculating solitary waves of all heights by series expansion of base flow variables in powers of a small base parameter to eighteenth order for the one-parameter fa...A unified perturbation theory is developed here for calculating solitary waves of all heights by series expansion of base flow variables in powers of a small base parameter to eighteenth order for the one-parameter family of solutions in exact form, with all the coefficients determined in rational numbers. Comparative studies are pursued to investigate the effects due to changes of base parameters on （i） the accuracy of the theoretically predicted wave properties and （ii） the rate of convergence of perturbation expansion. Two important results are found by comparisons between the theoretical predictions based on a set of parameters separately adopted for expansion in turn. First, the accuracy and the convergence of the perturbation expansions, appraised versus the exact solution provided by an earlier paper [1] as the standard reference, are found to depend, quite sensitively, on changes in base parameter. The resulting variations in the solution are physically displayed in various wave properties with differences found dependent on which property （e.g. the wave amplitude, speed, its profile, excess mass, momentum, and energy）, on what range in value of the base, and on the rank of the order n in the expansion being addressed. Secondly, regarding convergence, the present perturbation series is found definitely asymptotic in nature, with the relative error δ （n） （the relative mean-square difference between successive orders n of wave elevations） reaching a minimum, δm at a specific order, n = n both depending on the base adopted, e.g. nm,α= 11-12 based on parameter α （wave amplitude）, nm,δ = 15 on δ （amplitude-speed square ratio）, and nm.ε= 17 on ε （ wave number squared）. The asymptotic range is brought to completion by the highest order of n = 18 reached in this work.展开更多
In 1997, IGCP Project No. 410 was established to appraise known records of Ordovician biotas, in order to evaluate one of the greatest-ever diversifications of life on Earth, between 489 and 443 million years ago. Dat...In 1997, IGCP Project No. 410 was established to appraise known records of Ordovician biotas, in order to evaluate one of the greatest-ever diversifications of life on Earth, between 489 and 443 million years ago. Data collection and analysis of biodiversity were coordinated through seven regional teams, and a global“clade” team.展开更多
In this study,a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group,or both.This techni...In this study,a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group,or both.This technique is based on derivatizing first the carboxylic group(s) of the multifunctional compound using an alcohol (e.g.,methanol,1-butanol) in the presence of a relatively strong Lewisacid (BF3) as a catalyst.This esterification reaction quickly and quantitatively converts carboxylic acids to their ester forms.The second step is based on silylation of the ester compounds using bis(trimethylsilyl) trifluoroacetamide (BSTFA) as the derivatizing agent.For compounds bearing ketone groups in addition to carboxylic and hydroxyl groups,a third step was used based on PFBHA derivatizationof the carbonyls.Different parameters including temperature,reaction time,and effect due to artifacts were optimized.A GC/MS in EI and in methane-CI mode was used for the analysis of these compounds.The new approach was tested on a number of multifunctional compounds.The interpretation of their EI (70 eV) and CI mass spectra shows that critical information is gained leading to unambiguous identification of unknown compounds.For example,when derivatized only with BF3-methanol,their mass spectra comprise primary ions at m/z M ·+ +1,M ·+ +29,and M ·+ - 31 for compounds bearing only carboxylic groups and M ·+ +1,M ·+ +29,M ·+ -31,and M ·+ -17 for those bearing hydroxyl andcarboxylic groups.However,when a second derivatization (BSTFA) was used,compounds bearing hydroxyl and carboxylic groups simultaneously show,in addition to the ions observed before,ions at m/z M ·+ +73,M ·+ -15,M ·+ -59,M ·+ -75,M ·+ -89,and 73.To the best of our knowledge,this technique describes systematically for the first time a method for identifying multifunctional oxygenated compounds containing simultaneously one or more hydroxyl and carboxylic acid groups.展开更多
Plant height has been a major target for selection of high-yielding varieties in wheat.Two height-reducing loci(Rht-B1 and Rht-D1)have been widely used since the Green Revolution.However,these genes also negatively af...Plant height has been a major target for selection of high-yielding varieties in wheat.Two height-reducing loci(Rht-B1 and Rht-D1)have been widely used since the Green Revolution.However,these genes also negatively affect other agronomic traits such as kernel weight.Identifying alternative height-reducing loci could benefit wheat improvement.This study focused on the genetics of plant height in 260 historical and contemporary winter wheat accessions via genome-wide association studies using 38,693 single nucleotide polymorphism(SNP)markers generated through genotyping by sequencing,two Kompetitive Allele Specific Polymorphismmarkers,and phenotypic data recorded in two seasons(2016 and 2018).The 260 accessions showed wide variation in plant height.Most accessions developed after 1960 were shorter than earlier accessions.The broad-sense heritability for plant height was high(H2=0.82),whichwas also supported by a high correlation(r=0.82,P<0.0001)between heights from the two years.We detected a total of 16 marker–trait associations(MTAs)for plant height at–lg(P)≥4.0 on chromosomes 1A,2B,2D,3B,4D,5A,5D,6A,6B,7A,and 7D.We detected three of the MTAs(QPLH-2D,QPLH-4B.2,and QPLH-4D)consistently in individual-year and combined-year analyses.These MTAs individually explained 10%–16%of phenotypic variation.The heightreducing alleles at these threeMTAs appeared after 1960 and increased in frequency thereafter.Among the genes near these loci were gibberellic acid insensitive(GAI)and GRAS transcription factor(GIBBERELLIC-ACID INSENSITIVE(GAI),REPRESSOR of GAI(RGA),and SCARECROW(SCR)).The evidence from this study and previous reports suggests that QPLH-2D is Rht8.A gene encoding a GRAS transcription factor is located near QPLH-2D.Validation of the QPLH-2D locus and associated candidate genes awaits further study.展开更多
A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in t...A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan展开更多
The following paper reports on a comparative study of the effects of two types of carbon nanotubes,namely multiwall(MWCNT)and single-wall(SWCNT)carbon nanotube,on the properties of 3D-printed parts produced with acryl...The following paper reports on a comparative study of the effects of two types of carbon nanotubes,namely multiwall(MWCNT)and single-wall(SWCNT)carbon nanotube,on the properties of 3D-printed parts produced with acrylonitrile-butadiene-styrene(ABS)nanocomposites with various CNT loadings of5-10 wt.%.Quasi-static tensile properties and Vicat softening temperature of 3D-printed parts were enhanced with the increasing CNT content.The highest enhancement in tensile properties was observed for the ABS/CNT nanocomposites at 10 wt.%filler loading.3D-printed ABS/SWCNT composites showed higher tensile modulus,better creep stability and higher Vicat temperature.However,the strength of ABS/SWCNT 3D samples is relatively lower than that of ABS/MWCNT.In addition,3D-printed parts exhibited anisotropic electrical conductive behaviour,which has a conductivity of through-layer of about2-3 orders of magnitude higher than cross-layer.The highest conductivity of 3D-printed samples reached25.2 S/m,and 9.3 S/m for ABS/MWCNT and ABS/SWCNT composites at 10 wt.%,respectively.The results obtained,i.e.the successful fuse filament fabrication and the consequent electromechanical properties,confirm that these 3D printable nanocomposite could be properly utilized for the production,and application up to about 90°C,of thermoelectric devices and/or resistors for flexible circuits.展开更多
文摘The future of Sino-U.S.strategic engagement has become a focus of international attention since the second inauguration of U.S.President Donald Trump this January.Previously,Trump claimed intentions to boost domestic manufacturing.If his plan continues,the U.S.may seek a certain degree of cooperation with China in trade in order to benefit from China’s vast market and complete industrial chain.The two countries can negotiate on lowering tariffs and other trade barriers and leveraging China’s manufacturing capacity to reduce the risk of decoupling in bilateral trade.
基金supported by research grants from the Guangdong Province Basic and Applied Basic Research Fund Project(2022A1515110447)Open Fund Project of the State Key Laboratory of Applied Microbiology in South China(SKLAM006-2022)+1 种基金74th batch of general funding from the China Postdoctoral Science Foundation(2023M740774)Guangdong Provincial People’s Hospital,Postdoctoral Research Launch Fund(BY012022017)。
文摘Epidemiological studies have indicated that branched-chain amino acids(BCAAs)increased and gut microbiota disordered in type 2 diabetes mellitus(T2DM).This study aimed to investigate the mechanism of Lactiplantibacillus plantarum strain 84-3(Lp84-3)combined with Staphylococcus aureus bacteriophage on ameliorating T2DM.Here we perform a case-control study and identify that Staphylococcus_phage was inversely correlated with fasting blood glucose(FBG).It revealed that Lp84-3 could inhibit the growth of S.aureus,and Lp84-3 contains BCAAs degradation enzymes in its genome.Furthermore,Lp84-3 alone or combined with S.aureus bacteriophage interventions can improve blood glucose,insulin resistance,triglycerides,interleukin-1β,tumor necrosis factor-α(TNF-α),BCAAs,and acetyllactate synthase(ALS)in db/db mice.Lp84-3 and S.aureus bacteriophage decreased S.aureus,Malacoplasma iowae,and Oscillibacter sp.,and increased some beneficial such as L.plantarum and Muribaculaceae bacterium.Transcriptomic analyses revealed that Lp84-3 and S.aureus bacteriophage activated the PI3K/AKT/GLUT4 signaling pathway and upregulated key genes of Il22,Hgf,Col6a1,Gh,Itga10,Fgf23,and Prl involved in glucose metabolism in hypothalamus.Collectively,Lp84-3 and S.aureus bacteriophage alleviate T2DM by modulating gut microbiota and enhancing glucose metabolism in hypothalamus,supporting its potential use as a promising functional compound microecological agent for alleviating T2DM.
基金funded by the HiGa project,supported within the Green Era Hub call by the Green Development and Demonstration Programme,GUDP,under the Ministry of Food,Agriculture and Fisheries of Denmark,the Flanders Innovation&Entrepreneurship(VLAIO)the Italian Ministry of Agriculture,Food Sovereignty and Forests(CUP:D23 C23000570005).
文摘Background Scant information is currently available on the use of insect oils in ruminant diets.Insect oils could be used as alternatives to certain conventional plant lipid sources that are considered no longer sustainable.This trial aims at evaluating the effects of the dietary inclusion of Hermetia illucens oil(HIO)vs.hydrogenated palm fat(HPF)on digestive parameters,oxidative stress,and milk production performance of dairy cows.Results Twenty-six Valdostana Red Pied cows were randomly divided into two groups and fed with hay ad libitum and a concentrate containing 3%(as fed)of either HPF or HIO.The trial lasted 50 d,including two weeks of diet adaptation.Individual feed intake and milk yield were monitored three and four times a week,respectively.Fecal samples were collected at the end(d 50)of the trial to determine total-tract nutrients apparent digestibility.Individual blood samples were collected to evaluate blood plasma metabolites(d 0 and d 50)and oxidative stress parameters(d 0,d 26 and d 50).Milk samples were collected at d 0,d 14,d 26,d 38 and d 50 for chemical composition analysis.Feed efficiency was estimated through feed conversion ratio and residual feed intake(RFI).Data were analyzed by SAS software using a mixed model.The diet had no effect on nutrients intake and apparent total-tract digestibility.However,the dietary inclusion of HIO led to higher milk production(+0.82 kg/cow/d;P<0.05)and slightly lower RFI(−0.008;P<0.001)when compared to the HPF diet.Milk composition and the nutritional metabolic status of the cows remained unaffected by diet.Serum antioxidant capacity was comparable between the two groups,while lower derivatives of reactive oxygen metabolite concentrations were observed in the HIO-fed cows when compared to the HPF-fed ones(−37.13 Carratelli Units;P<0.001).Conclusions The dietary inclusion of HIO instead of HPF did not negatively affect feed palatability and total-tract apparent digestibility of nutrients in dairy cows.Furthermore,it increased feed efficiency by supporting a higher milk production together with an improved antioxidant status.The results suggest that HIO could be an eligible option as an innovative energy source for dairy cows.
基金supported by the Chinese National Natural Science Foundation (grants no.30625004,40771073 to HS)the Yunnan Natural Science Foundation (2008CC013 to HS)+4 种基金the US National Science Foundation (grant no. DEB-0321846,to DEB)the John D. and Catherine T. MacArthur Foundation (grant to JW,RR,and GM)the Innovation Project of the Chinese Academy of Sciences (KSCX2-YW-Z-030)a Mercer Fellowship from the Arnold Arboretum (to JPY)supported by the National Geographic Society (grant no.7405-03)
文摘The Hengduan Mountains region of south-west China is a noted biodiversity,hotspot, but the geographic origins and historical assembly of its rich endemic flora, including the sky-island species ofSolms-laubachia Muschl. （Brassicaceae）, have been little studied. Previous molecular studies on the phylogeny of Solms-laubachia showed it to be paraphyletic, leading to considerable expansion not only of its taxonomic limits, but also its geographic range, with the inclusion of taxa from outside the Hengduan region. However, these studies provided little resolution of interspecific relationships, preventing inferences about historical biogeography within the clade. In the present study, new sequence data from two nuclear genes （LEAFY and G3pdh） and two chloroplast intergenic spacers （petN-psbM and psbM-trnD） were combined with existing markers to increase phylogenetic signals. Phaeonychium villosum （Maxim.） Al-Shehbaz was found to be nested within Solms-laubachia s.l. In general, phylogenetic relationships appear to be a good predictor of geography, with the Hengduan Mountain endemics embedded in a paraphyletic grade of species from the western Himalayas and central Asia, but they also imply morphological homoplasy, lncongruence was detected between the nuclear and chloroplast gene trees, perhaps resulting from incomplete lineage sorting of ancestral polymorphisms. The crown age ofSolms-laubachia s.l. was estimated to be approximately 1.42-3.68 mya, using Bayesian relaxed molecular clock analysis. Historical biogeographic analysis using a parametric dispersalextinction-cladogenesis model inferred central Asia and the western Himalayas as most probable ancestral range of Solms-laubachia s.l., and estimated higher rates of eastward expansion than westward during the diversification of descendant lineages. In summary, our results suggest that Solms-laubachia s.l. originated during the Pliocene in central Asia, and subsequently migrated eastward into the Hengduan Mountains, colonizing sky-island, alpine scree-slope habitats that may have provided novel ecological opportunity and accelerated speciation, ultimately establishing this region as the present center of diversity of the genus.
文摘In this study, volatile compounds present in Toona sinensis (A. Juss.) Roem (TS) were investigated and their characteristic aromatic components were identified using Headspace Solid-phase Microextraction (HS-SPME) followed by Gas Chromatography-Mass Spectrometry (GC-MS) and Gas Chromatography-Olfactometry (GC-O). The optimum conditions for extracting the volatiles from TS were achieved with the experimental parameters including the use of a 65 μm polydimethylsiloxane/divinyl benzene (PDMS/DVB) fibre, an extraction temperature of 40℃ and an extraction time of 30 min. Under these conditions, 56 volatile compounds were separated and 53 were identified by GC-MS. Among them, 21 sulfide compounds (42.146%) and 27 terpenes(55.984%) were found to be the major components. The sample was analyzed by GC-O and 26 elutes were sniffed and their sensory descriptions evaluated by an odor panelists. Analysis of the data indicated, two compounds cis and trans isomers of 2-Mercapto-3,4-dimethyl-2,3-dihydrothiophene were major contributors to the characteristic aroma of TS.
基金funded by the Spanish Ministry of Culture and Sport,Consejo Superior de Deportes,Plan de Recuperación,Transformación y Resiliencia,Unión Europea,Next Generation EUAyudas Europeas a Proyectos de Investigaci on Aplicada a la Actividad Física Beneficiosa para la Salud y la Medicina Deportiva(EXP_77437)+9 种基金by the Spanish Ministry of Science and Innovation(PID2022-141506OB-I00)the European Regional Development Funds(ERDF)by the University of Granada Plan Propio de Investigación-Excellence actions:Unit of Excellence on Exercise Nutrition and Health(UCEENS)supported by the Spanish Ministry of Education,Culture and Sport(FPU19/03745 and FPU20/05530,respectively)supported by the Juan de la Cierva Formación Grant FJC2020-044453-I funded by Ministerio de Ciencia e Innovaci on/Agencia Estatal de Investigaci on MCIN/AEI/10.13039/501100011033European Union Next Generation,Plan de Recuperación,Transformación y Resilencia(EU/PRTR)“Ramón y Cajal fellowship 2013-2017”funded by MCIN/AEI/10.13039/501100011033 and“El Fondo Social Europeo invierte en tu futuro”partially supported by the Grant PID2020-114054RA-I001001100482funded by MCIN/AEI/10.13039/501100011033supported by a grant from the MCIN/AEI/10.13039/501100011033,Spain,and the ERDF(PID2021-126788OB-I00).
文摘Background:Mammalian cells possess molecular clocks,the adequate functioning of which is decisive for metabolic health.Exercise is known to modulate these clocks,potentially having distinct effects on metabolism depending on the time of day.This study aimed to investigate the impact of morning vs.evening moderate-intensity aerobic exercise on glucose regulation and energy metabolism in healthy men and women.It also aimed to elucidate molecular mechanisms within skeletal muscle.Methods:Using a randomized crossover design,healthy men(n=18)and women(n=17)performed a 60-min bout of moderate-intensity aerobic exercise in the morning and evening.Glucose regulation was continuously monitored starting 24 h prior to the exercise day and continuing until 48 h post-exercise for each experimental condition.Energy expenditure and substrate oxidation were measured by indirect calorimetry during exercise and at rest before and after exercise for 30 min.Skeletal muscle biopsies were collected immediately before and after exercise to assess mitochondrial function,transcriptome,and mitochondrial proteome.Results:Results indicated similar systemic glucose,energy expenditure,and substrate oxidation during and after exercise in both sexes.Notably,transcriptional analysis,mitochondrial function,and mitochondrial proteomics revealed marked sexual dimorphism and time of day variations.Conclusion:The sexual dimorphism and time of day variations observed in the skeletal muscle in response to exercise may translate into observable systemic effects with higher exercise-intensity or chronic exercise interventions.This study provides a foundational molecular framework for precise exercise prescription in the clinical setting.
文摘BACKGROUND:To assess the effectiveness of the telephone chest-compression-only cardiopulmonary resuscitation(CPR)guided by a pre-recorded instructional audio when compared with dispatcher-assisted resuscitation.METHODS:It was a prospective,blind,randomised controlled study involving 109 medical students without previous CPR training.In a standardized mannequin scenario,after the step of dispatcher-assisted cardiac arrest recognition,the participants performed compression-only resuscitation guided over the telephone by either:(1)the pre-recorded instructional audio(n=57);or(2)verbal dispatcher assistance(n=52).The simulation video records were reviewed to assess the CPR performance using a 13-item checklist.The interval from call reception to the first compression,total number and rate of compressions,total number and duration of pauses after the first compression were also recorded.RESULTS:There were no significant differences between the recording-assisted and dispatcher-assisted groups based on the overall performance score(5.6±2.2 vs.5.1±1.9,P>0.05)or individual criteria of the CPR performance checklist.The recording-assisted group demonstrated provided(170.2±48.0 vs.156.2±60.7).CONCLUSION:When provided by untrained persons in the simulated settings,the compression-only resuscitation guided by the pre-recorded instructional audio is no less efficient than dispatcher-assisted CPR.Future studies are warranted to further assess feasibility of using instructional audio aid as a potential alternative to dispatcher assistance.
基金The project partly supported by the National Natural Science Foundation of China(19925414,10474045)
文摘A unified perturbation theory is developed here for calculating solitary waves of all heights by series expansion of base flow variables in powers of a small base parameter to eighteenth order for the one-parameter family of solutions in exact form, with all the coefficients determined in rational numbers. Comparative studies are pursued to investigate the effects due to changes of base parameters on （i） the accuracy of the theoretically predicted wave properties and （ii） the rate of convergence of perturbation expansion. Two important results are found by comparisons between the theoretical predictions based on a set of parameters separately adopted for expansion in turn. First, the accuracy and the convergence of the perturbation expansions, appraised versus the exact solution provided by an earlier paper [1] as the standard reference, are found to depend, quite sensitively, on changes in base parameter. The resulting variations in the solution are physically displayed in various wave properties with differences found dependent on which property （e.g. the wave amplitude, speed, its profile, excess mass, momentum, and energy）, on what range in value of the base, and on the rank of the order n in the expansion being addressed. Secondly, regarding convergence, the present perturbation series is found definitely asymptotic in nature, with the relative error δ （n） （the relative mean-square difference between successive orders n of wave elevations） reaching a minimum, δm at a specific order, n = n both depending on the base adopted, e.g. nm,α= 11-12 based on parameter α （wave amplitude）, nm,δ = 15 on δ （amplitude-speed square ratio）, and nm.ε= 17 on ε （ wave number squared）. The asymptotic range is brought to completion by the highest order of n = 18 reached in this work.
文摘In 1997, IGCP Project No. 410 was established to appraise known records of Ordovician biotas, in order to evaluate one of the greatest-ever diversifications of life on Earth, between 489 and 443 million years ago. Data collection and analysis of biodiversity were coordinated through seven regional teams, and a global“clade” team.
文摘In this study,a new analytical technique was developed for the identification and quantification of multifunctional compounds containing simultaneously at least one hydroxyl or one carboxylic group,or both.This technique is based on derivatizing first the carboxylic group(s) of the multifunctional compound using an alcohol (e.g.,methanol,1-butanol) in the presence of a relatively strong Lewisacid (BF3) as a catalyst.This esterification reaction quickly and quantitatively converts carboxylic acids to their ester forms.The second step is based on silylation of the ester compounds using bis(trimethylsilyl) trifluoroacetamide (BSTFA) as the derivatizing agent.For compounds bearing ketone groups in addition to carboxylic and hydroxyl groups,a third step was used based on PFBHA derivatizationof the carbonyls.Different parameters including temperature,reaction time,and effect due to artifacts were optimized.A GC/MS in EI and in methane-CI mode was used for the analysis of these compounds.The new approach was tested on a number of multifunctional compounds.The interpretation of their EI (70 eV) and CI mass spectra shows that critical information is gained leading to unambiguous identification of unknown compounds.For example,when derivatized only with BF3-methanol,their mass spectra comprise primary ions at m/z M ·+ +1,M ·+ +29,and M ·+ - 31 for compounds bearing only carboxylic groups and M ·+ +1,M ·+ +29,M ·+ -31,and M ·+ -17 for those bearing hydroxyl andcarboxylic groups.However,when a second derivatization (BSTFA) was used,compounds bearing hydroxyl and carboxylic groups simultaneously show,in addition to the ions observed before,ions at m/z M ·+ +73,M ·+ -15,M ·+ -59,M ·+ -75,M ·+ -89,and 73.To the best of our knowledge,this technique describes systematically for the first time a method for identifying multifunctional oxygenated compounds containing simultaneously one or more hydroxyl and carboxylic acid groups.
基金The authors thank the National Small Grains Collection,USDA for providing seed of historical wheat accessions.Financial support from USDA Hatch Grant 1013073 to MM via Purdue College of Agriculture is greatly appreciated.
文摘Plant height has been a major target for selection of high-yielding varieties in wheat.Two height-reducing loci(Rht-B1 and Rht-D1)have been widely used since the Green Revolution.However,these genes also negatively affect other agronomic traits such as kernel weight.Identifying alternative height-reducing loci could benefit wheat improvement.This study focused on the genetics of plant height in 260 historical and contemporary winter wheat accessions via genome-wide association studies using 38,693 single nucleotide polymorphism(SNP)markers generated through genotyping by sequencing,two Kompetitive Allele Specific Polymorphismmarkers,and phenotypic data recorded in two seasons(2016 and 2018).The 260 accessions showed wide variation in plant height.Most accessions developed after 1960 were shorter than earlier accessions.The broad-sense heritability for plant height was high(H2=0.82),whichwas also supported by a high correlation(r=0.82,P<0.0001)between heights from the two years.We detected a total of 16 marker–trait associations(MTAs)for plant height at–lg(P)≥4.0 on chromosomes 1A,2B,2D,3B,4D,5A,5D,6A,6B,7A,and 7D.We detected three of the MTAs(QPLH-2D,QPLH-4B.2,and QPLH-4D)consistently in individual-year and combined-year analyses.These MTAs individually explained 10%–16%of phenotypic variation.The heightreducing alleles at these threeMTAs appeared after 1960 and increased in frequency thereafter.Among the genes near these loci were gibberellic acid insensitive(GAI)and GRAS transcription factor(GIBBERELLIC-ACID INSENSITIVE(GAI),REPRESSOR of GAI(RGA),and SCARECROW(SCR)).The evidence from this study and previous reports suggests that QPLH-2D is Rht8.A gene encoding a GRAS transcription factor is located near QPLH-2D.Validation of the QPLH-2D locus and associated candidate genes awaits further study.
基金The Scientific Research Foundation for the Returned Overseas Chinese Scholars State Education Ministry(2002-2004)and Shaanxi Provincial Foreign Expert Bureau (2003).
文摘A review of the period of unregulated exploitation of forests in the state of West Virginia (U.S.) and in Shaanxi Province, PRC was presented. Economic and ecological recovery from exploitation has been different in the two regions due to basic differences in nature of the forest and in the degree and persistence of exploitive pressures. After a century since unregulated exploitation, West Virginia forests are well on the road to management for sustainability and conservation. Shaanxi's recovery from overuse and unregulated exploitation is less certain; forests are still in the early phases of ecological recovery there. Full recovery to a period of sustainability will take a century or longer. Suggestions are made for measures needed to enhance the forest recovery. Keywords Forests - Shaanxi - West Virginia - Central China - Forest exploitation - Recovery CLC number S754 Document code A Article ID 1007-662X(2004)01-0049-06 Foundation item: The project was sponsored by the Scientific Research Foundation for the Returned Overseas Chinese Scholars, State Education Ministry (2002–2004) and Shaanxi Provincial Foreign Expert Bureau (2003).Biography: Jack E. Coster (1935-), male, professor of West Virginia University, Morgantown, West Virginia. U.S.A.Responsible editor: Song Funan
基金Claudia Gavazza for her support with scanning electron microscopy(SEM)analysis。
文摘The following paper reports on a comparative study of the effects of two types of carbon nanotubes,namely multiwall(MWCNT)and single-wall(SWCNT)carbon nanotube,on the properties of 3D-printed parts produced with acrylonitrile-butadiene-styrene(ABS)nanocomposites with various CNT loadings of5-10 wt.%.Quasi-static tensile properties and Vicat softening temperature of 3D-printed parts were enhanced with the increasing CNT content.The highest enhancement in tensile properties was observed for the ABS/CNT nanocomposites at 10 wt.%filler loading.3D-printed ABS/SWCNT composites showed higher tensile modulus,better creep stability and higher Vicat temperature.However,the strength of ABS/SWCNT 3D samples is relatively lower than that of ABS/MWCNT.In addition,3D-printed parts exhibited anisotropic electrical conductive behaviour,which has a conductivity of through-layer of about2-3 orders of magnitude higher than cross-layer.The highest conductivity of 3D-printed samples reached25.2 S/m,and 9.3 S/m for ABS/MWCNT and ABS/SWCNT composites at 10 wt.%,respectively.The results obtained,i.e.the successful fuse filament fabrication and the consequent electromechanical properties,confirm that these 3D printable nanocomposite could be properly utilized for the production,and application up to about 90°C,of thermoelectric devices and/or resistors for flexible circuits.
