Background Exogenous gonadotropin-controlled ovarian stimulation is the critical step in animal reproductive management,such as pig,sheep,bovine and other species.It helps synchronize ovulation or stimulate multiple o...Background Exogenous gonadotropin-controlled ovarian stimulation is the critical step in animal reproductive management,such as pig,sheep,bovine and other species.It helps synchronize ovulation or stimulate multiple ovu-lations.However,a number of evidence indicated an unexpected decrease in pregnancy outcomes following ovarian stimulation.This study aimed to explore the underlying mechanism of the pregnancy defect and develop a practical rescue strategy.Results Compared with those in the control group,gilts that underwent ovarian stimulation showed a decrease in pregnancy rate,farrowing rate,and total number of piglets born.Stimulated gilts also showed an increase in estra-diol(E_(2))levels.The supraphysiologicalE_(2) level was correlated with the decrease in the number of piglets born.Furthermore,we found that high levels ofE_(2) impair uterine receptivity,as shown by the overproliferation of endo-metrial epithelial cells.In vitro mechanistic studies demonstrated that high levels ofE_(2) hyperactivate FGF-FGFR-ERK signaling cascade in the uterine endometrium,and in turn induces overproliferation of endometrial epithelial cells.Of note,N-acetyl-L-cysteine(NAC)supplementation effectively inhibits ERK hyperphosphorylation and ameliorates endometrial epithelial overproliferation.Importantly,in vivo experiments indicated that dietary NAC supplementa-tion,compared with ovarian stimulation group,improves the uterine receptivity in gilts,and significantly increases the pregnancy rate and total number of piglets born.Conclusions Ovarian stimulation-induced supraphysiological levels ofE_(2) impairs uterine receptivity by hyperactivat-ing FGF-FGFR-ERK signaling cascade,thereby reducing pregnancy rate and litter size.Supplementing NAC to a con-ventional diet for gilts ameliorates hyperactivated ERK signaling and improves uterine receptivity,thus rescuing adverse pregnancy outcomes following ovarian stimulation.展开更多
Infancy and toddlerhood are critical phases of life,as the gut microbiota is established here,which influences current and future health.During this period,the microbiota was relatively less stable and highly responsi...Infancy and toddlerhood are critical phases of life,as the gut microbiota is established here,which influences current and future health.During this period,the microbiota was relatively less stable and highly responsive to environmental factors.Therefore,it is important to understand how dietary factors affect this complex stage of microbial assembly.The effect of feeding practices(breast milk/formula) on microbial colonization in early infancy has been actively studied;however,studies on the effect of diet on the gut microbiota during the complementary feeding period are sparse.The introduction of complementary foods provides abundant new dietary compounds for the gut microbiota,which induces a shift in gut microbiota and metabolism from milk-adapted toward a more mature and diverse adult-like community.Herein,we discuss the impact of dietary nutrients(carbohydrates,proteins,fats,vitamins,and minerals) on microbiome of infants and toddlers.Furthermore,this review summarizes the effects of complementary feeding patterns,specific foods(such as cereals;legumes and nuts;vegetables and fruits;meats;dairy products),food additives,and malnutrition(undernutrition or overnutrition) on gut microbiota of this populations.These findings might deepen our comprehension of the complex interactions between diets and the development and establishment of the gut microbiota.This may facilitate the tailoring of interventions aimed at promoting beneficial modifications within the gut microbial community.Furthermore,the insights gained could inform the design and implementation of safe and efficacious complementary feeding practices.展开更多
Interfacial disorders in semiconductor quantum wells(QWs)determine material properties and device performance and have attracted great research efforts using different experimental methods.However,so far,there has bee...Interfacial disorders in semiconductor quantum wells(QWs)determine material properties and device performance and have attracted great research efforts using different experimental methods.However,so far,there has been no way to quantify the lateral length distribution of the interfacial disorders in QWs.Since photoluminescence(PL)is sensitive to exciton localization,the evolutions of PL energy and linewidth under external perpendicular magnetic fields have served as effective measurement methods for QW analysis;however,the evolution of PL intensity has not played a matching role.In this paper,we develop a theoretical model correlating the PL intensity with the interfacial disorders of type-I QWs under an external perpendicular magnetic field.We verify the model's rationality and functionality using In Ga(N)As/Ga As single QWs.In addition,we derive the Urbach energy and determine the lateral length distribution of interfacial disorders.The results show that the magnetic field-dependent PL intensity,as described by our model,serves as a valid probe for quantifying the interface flatness.The model also reveals that the mechanism of magnetic-field-induced intensity enhancement is a joint effect of interfacial disorder-induced exciton localization and the transfer of excitons from dark to bright states.These insights may benefit performance improvements of type-I QW materials and devices.展开更多
Related to ABI3 and VP1(RAV)transcription factors belong to the AP2 and B3 superfamily.RAVs genes have been reported to be involved in plant growth and development regulation.This study screened three RAV genes from M...Related to ABI3 and VP1(RAV)transcription factors belong to the AP2 and B3 superfamily.RAVs genes have been reported to be involved in plant growth and development regulation.This study screened three RAV genes from Medicago truncatula and named one of them MtRAV1.The MtRAV1 overexpressing plants exhibits traits such as plant dwarfing,delayed flowering,reduced leaf and floral organs,increased branching,and reduced pods and seeds.Gene expression analysis results showed that overexpression of Mt RAV1 inhibited the expression of Flowering Locus T(MtFTa1),Suppressor of Overexpression of CO1(MtSOC1),GA3-oxidase1(MtGA3OX1),DWARF14(MtD14)and Carotenoid Cleavage Dioxygenase7(MtCCD7).To further investigate the regulation pathway involved by MtRAV1,RNA-sequencing(RNA-seq)and DNA affinity purification sequencing(DAP-seq)analysis were conducted.RNA-seq results indicated that MtRAV1 might affect plant growth and development by regulating some genes in photosynthesis,circadian rhythm and plant hormone signaling pathways,especially the auxin signaling pathway.Conjoint analysis of DAP-seq and RNA-seq revealed that Mt RAV1 might inhibit the expression of Ferredoxin(Mt Fd-l3),Light-harvesting Chlorophyll a/b Binding Protein 1(Mt Lhcb-l2)and Small Auxin Up-regulated RNA(Mt SAUR-l),which related to photosystem II and auxin signaling pathway.Summarily,MtRAV1 was preliminarily proven to be a key growth inhibitory factor in M.truncatula.展开更多
Coal is the dominant energy source in China,and coal-fired power accounts for about half of coal consumption.However,air pollutant emissions from coal-fired power plants cause severe ecological and environmental probl...Coal is the dominant energy source in China,and coal-fired power accounts for about half of coal consumption.However,air pollutant emissions from coal-fired power plants cause severe ecological and environmental problems.This paper focuses on near-zero emission technologies and applications for clean coal-fired power.The long-term operation states of near-zero emission units were evaluated,and synergistic and special mercury(Hg)control technologies were researched.The results show that the principle technical route of near-zero emission,which was applied to 101 of China’s coal-fired units,has good adaptability to coal properties.The emission concentrations of particulate matter(PM),SO2,and NOx were below the emission limits of gas-fired power plants and the compliance rates of the hourly average emission concentrations reaching near-zero emission in long-term operation exceeded 99%.With the application of near-zero emission technologies,the generating costs increased by about 0.01 CNY∙(kW∙h)-1.However,the total emissions of air pollutants decreased by about 90%,resulting in effective improvement of the ambient air quality.Furthermore,while the Hg emission concentrations of the near-zero emission units ranged from 0.51 to 2.89μg∙m^-3,after the modified fly ash(MFA)special Hg removal system was applied,Hg emission concentration reached as low as 0.29μg∙m^-3.The operating cost of this system was only 10%-15%of the cost of mainstream Hg removal technology using activated carbon injection.Based on experimental studies carried out in a 50000 m^3∙h^-1 coal-fired flue gas pollutant control pilot platform,the interaction relationships of multi-pollutant removal were obtained and solutions were developed for emissions reaching different limits.A combined demonstration application for clean coal-fired power,with the new“1123”eco-friendly emission limits of 1,10,20 mg∙m^-3,and 3μg∙m^-3,respectively,for PM,SO2,NOx,and Hg from near-zero emission coal-fired power were put forward and realized,providing engineering and technical support for the national enhanced pollution emission standards.展开更多
To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing,six typical land use types were selected and studied from August 2009 to September 2011.Statistical ana...To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing,six typical land use types were selected and studied from August 2009 to September 2011.Statistical analysis on the distribution of pollutant concentrations in all water samples shows that pollutant concentrations fluctuate greatly in rainfall-runoff,and the concentrations of the same pollutant also vary greatly in different rainfall events.In addition,it indicates that the event mean concentrations （EMCs） of total suspended solids （TSS） and chemical oxygen demand （COD） from urban traffic roads （UTR） are significantly higher than those from residential roads （RR）,commercial areas （CA）,concrete roofs （CR）,tile roofs （TRoof）,and campus catchment areas （CCA）;and the EMCs of total phosphorus （TP） and NH3-N from UTR and CA are 2.35-5 and 3 times of the class-III standard values specified in the Environmental Quality Standards for Surface Water （GB 3838-2002）.The EMCs of Fe,Pb and Cd are also much higher than the class-III standard values.The analysis of pollution load producing coefficients （PLPC） reveals that the main pollution source of TSS,COD and TP is UTR.The analysis of correlations between rainfall factors and EMCs/PLPC indicates that rainfall duration is correlated with EMCs/PLPC of TSS for TRoof and TP for UTR,while rainfall intensity is correlated with EMCs/PLPC of TP for both CR and CCA.The results of this study provide a reference for better management of non-point source pollution in urban regions.展开更多
China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs)to achieve ultra-low emission.The potential fo...China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs)to achieve ultra-low emission.The potential for further particulate matter(PM)emission reduction to achieve near-zero emission for CFPPs has become a hotspot issue.In this study,PM emission from some ultra-low emission CFPPs adopting advanced air pollutant control technologies in China was reviewed.The results revealed that the average filterable particulate matter(FPM)concentration,measured as the total particulate matter(TPM)according to the current national monitoring standard,was(1.67±0.86)mg/m^(3),which could fully achieve the ultra-low emission standard for key regions(5 mg/m^(3)),but that achieving the near-zero emission standard was difficult(1 mg/m^(3)).However,the condensable particulate matter(CPM),with an average concentration of(1.06±1.28)mg/m^(3),was generally ignored during monitoring,which led to about 38.7%underestimation of the TPM.Even considering both FPM and CPM,the TPM emission from current CFPPs would contribute to less than 5%of atmospheric PM_(2.5) concentrations in the key cities and regions in China.Therefore,further reduction in FPM emission proposed by the near-zero emission plan of CFPPs may have less environmental benefit than emission control of other anthropogenic sources.However,it is suggested that the management of CPM emission should be strengthened,and a national standard for CPM emission monitoring based on the indirect dilution method should be established for CFPPs.Those measurements are helpful for optimal operation of air pollutant control devices and continuously promoting further emission reduction.展开更多
As a typical compatible solute, proline is accumulated in plants under environmental stresses. Proline transporter(Pro T) plays an important role in proline distribution between plant organs. Using a candidate gene ap...As a typical compatible solute, proline is accumulated in plants under environmental stresses. Proline transporter(Pro T) plays an important role in proline distribution between plant organs. Using a candidate gene approach, we cloned a c DNA sequence for Pro T from common bean(Phaseolus vulgaris L.) and designated the gene Pv Pro T. The deduced amino acid sequence of Pv Pro T showed high similarity to Bet/Pro T proteins from other leguminous plants, and the highest similarity was observed with mothbean(Vigna aconitifolia L.) Vu Pro T.Relative quantification of the m RNA level of Pv Pro T using real-time PCR analysis showed that the Pv Pro T transcript level was higher in leaves than in stems and roots of common bean plants subjected to drought and salt stress. Under 20%(w/w) PEG-6000 treatment,drought-resistant plants expressed a higher level of Pv Pro T transcripts than droughtsensitive plants. Although heterologous expression of Pv Pro T in the Escherichia coli mutant mkh13 showed that Pv Pro T exhibited uptake activities for proline and betaine, no betaine content was detected in the common bean. These findings suggest that Pv Pro T plays an important role in the transportation of proline in common bean plants exposed to drought and salt stress.展开更多
The ultrahigh vacuum scanning tunneling microscope(STM)was used to characterize the GaSb_(1-x)Bi_(x) films of a few nanometers thickness grown by the molecular beam epitaxy(MBE)on the GaSb buffer layer of 100 nm with ...The ultrahigh vacuum scanning tunneling microscope(STM)was used to characterize the GaSb_(1-x)Bi_(x) films of a few nanometers thickness grown by the molecular beam epitaxy(MBE)on the GaSb buffer layer of 100 nm with the GaSb(100)substrates.The thickness of the GaSb_(1-x)Bi_(x) layers of the samples are 5 and 10 nm,respectively.For comparison,the GaSb buffer was also characterized and its STM image displays terraces whose surfaces are basically atomically flat and their roughness is generally less than 1 monolayer(ML).The surface of 5 nm GaSb_(1-x)Bi_(x) film reserves the same terraced morphology as the buffer layer.In contrast,the morphology of the 10 nm GaSb_(1-x)Bi_(x) film changes to the mound-like island structures with a height of a few MLs.The result implies the growth mode transition from the two-dimensional mode as displayed by the 5 nm film to the Stranski-Krastinov mode as displayed by the 10 nm film.The statistical analysis with the scanning tunneling spectroscopy(STS)measurements indicates that both the incorporation and the inhomogeneity of Bi atoms increase with the thickness of the GaSb_(1-x)Bi_(x) layer.展开更多
The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 su...The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 suppressed the anomalous rapid oxidation of the substrate Ti_3AlC_2 occurred near 600℃ by forming a protective B_2O_3 glass layer, and also improved the oxidation resistance of the MAX phase at intermediatetemperature.展开更多
This special issue is focused on grain legumes,which belong to the Fabaceae family.Legumes are the second largest family of plants in the world after the grasses and are key components of manmade and natural ecosystem...This special issue is focused on grain legumes,which belong to the Fabaceae family.Legumes are the second largest family of plants in the world after the grasses and are key components of manmade and natural ecosystems[1–3].They provide the environmental service of nitrogen fixation,so essential to soil construction and fertility maintenance,and are thus essential to agricultural systems[4,5].Different species of legumes range from huge trees to shrubs展开更多
Common bacterial blight(CBB), caused by Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans(Xff), is a worldwide disease of common bean(Phaseolus vulgaris L.).Longyundou 5, a Chinese cultivar in...Common bacterial blight(CBB), caused by Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans(Xff), is a worldwide disease of common bean(Phaseolus vulgaris L.).Longyundou 5, a Chinese cultivar in the Mesoamerican gene pool of common bean, displays resistance to the Xff strain XSC3-1. To identify the genetic mechanisms behind this resistance,we crossed Long 5 with a susceptible genotype to develop a mapping population of F2 plants.Plant resistance to CBB was identified at 14 and 21 days after inoculation with Xff strain XSC3-1.A major QTL at 14 and 21 days after inoculation was mapped on chromosome Pv10 with LOD scores of 6.41 and 5.35, respectively. This locus was associated with SAP6, a previouslyidentified and much-used dominant marker, but in a 4.2 cM interval between new codominant markers BMp10s174 and BMp10s244. Ten candidate genes were found between markers BMp10s174 and BMp10s244 on chromosome Pv10 and could encode defense response proteins responding to CBB pathogens. Four pairs each of epistatic QTL for CBB resistance were detected at 14 and 21 days after inoculation. Phenotypic variation explained by the epistatic QTL ranged from 7.19% to 12.15% and 7.72% to 8.80% at 14 and 21 days after inoculation, respectively. These results confirmed the importance of epistasis in CBB resistance in common bean. The adjacent markers found may be more efficient for marker assisted selection in common bean breeding for CBB resistance owing to their closer linkage to the target QTL.展开更多
InAs/GaSb type-II superlattce (T2SL) photodetector structures at the MWIR regime were grown by molecular beam epitaxy. The growth temperature and group-V soaking times were optimized with respect to interface and tran...InAs/GaSb type-II superlattce (T2SL) photodetector structures at the MWIR regime were grown by molecular beam epitaxy. The growth temperature and group-V soaking times were optimized with respect to interface and transport quality. Novel strain compensation schemes with insertion of InSb layers were proposed and tested to be efficient to tune the overall strain between tensile and compressive without degradation of interface and optical quality. The effect of the proposed methods is modeled by analytic functions.? Band structure calculations were also carried out for the proposed T2SL structures to assist optimizing sample designs. Single pixel photodiodes with a low dark current were demonstrated.展开更多
Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-con...Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.展开更多
Genetic improvement of drought resistance is one of the main breeding goals for common bean,so molecular markers must be identified to facilitate drought resistance breeding.In this study,we evaluated the proline,treh...Genetic improvement of drought resistance is one of the main breeding goals for common bean,so molecular markers must be identified to facilitate drought resistance breeding.In this study,we evaluated the proline,trehalose,raffinose,and stachyose contents of 210 common bean accessions under two watering conditions and found large variations in all four.The coefficients of variation ranged from 21.21%for proline content to 78.69%for stachyose content under well-watered conditions,and from 20.11%for proline content to 50.08%for trehalose content under drought stress.According to our genome-wide association analysis,32 quantitative trait loci were associated with drought resistance,seven of which overlapped with known loci.Four hotspot regions were identified at Pv01,Pv07 and Pv11.A set of candidate genes was identified,including genes encoding MYB,bZIP,bHLH,ERF,and protein kinases.Among these genes,Phvul.001G189400,Phvul.007G273000 and Phvul.008G270500 were annotated as bZIP,ERF and WRKY,respectively.These genes are reportedly involved in drought stress responses in Arabidopsis thaliana and were induced by drought stress in common bean.Significant SNPs in six candidate gene regions formed different haplotypes,and phenotypic analysis revealed significant differences among the haplotypes.These results provide new insight into the genetic basis of drought resistance in common bean and reveal candidate genes and superior natural variations that will be useful for improving common bean.展开更多
Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 21...Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 210 common bean accessions showed large variation in 11 agronomic traits at the adult stage(plant height,pod number per plant,seed number per pod,seed number per plant,seed yield per plant,pod length,harvest index,pod harvest index,days to maturity,hundred-seed weight,and seed yield)under two water conditions.The coefficient of variation ranged from 6.21% for pod harvest index to51.00% for seed number per plant under well-watered conditions,and from 4.05% for days to maturity to 40.72% for seed number per plant under drought stress.In a genome-wide association study,119quantitative-trait loci were associated with drought resistance,including 41 adjacent to known loci.Among these loci,12 were found to be associated with at least two traits.Three major loci were identified at Pv01 and Pv02.A set of candidate genes were found that encode MYBs,AREBs,WKRYs,and protein kinases.These results reveal promising alleles that control drought resistance,shedding light on the genetic basis of drought resistance and accelerating future efforts for drought resistance improvement in common bean.展开更多
Strain and stress were simulated using finite element method(FEM)for threeⅢ-V-on-Insulator(Ⅲ-VOI)structures,i.e.,InP/SiO2/Si,InP/Al2O3/SiO2/Si,and GaAs/Al2O3/SiO2/Si,fabricated by ion-slicing as the substrates for o...Strain and stress were simulated using finite element method(FEM)for threeⅢ-V-on-Insulator(Ⅲ-VOI)structures,i.e.,InP/SiO2/Si,InP/Al2O3/SiO2/Si,and GaAs/Al2O3/SiO2/Si,fabricated by ion-slicing as the substrates for optoelectronic devices on Si.The thermal strain/stress imposes no risk for optoelectronic structures grown on InPOI at a normal growth temperature using molecular beam epitaxy.Structures grown on GaAsOI are more dangerous than those on InPOI due to a limited critical thickness.The intermedia Al2O3 layer was intended to increase the adherence while it brings in the largest risk.The simulated results reveal thermal stress on Al2O3 over 1 GPa,which is much higher than its critical stress for interfacial fracture.InPOI without an Al2O3 layer is more suitable as the substrate for optoelectronic integration on Si.展开更多
The characteristics of highway transport and the application of information technology in highway transport service are combined; the information flows＇ promotion and substitution on highway transport are analyzed; a...The characteristics of highway transport and the application of information technology in highway transport service are combined; the information flows＇ promotion and substitution on highway transport are analyzed; and the highway transport development strategy based on information flow impact is proposed.展开更多
基金National Natural Science Foundation of China(31930103)National Center of Technology Innovation for Pigs(NCTIP-XD/B03)+2 种基金Ningbo Major Science and Technology Project(2021Z112)National Key R&D Program(2022YFD1300303)Beijing Innovation Consortium of Livestock Research System BAIC05-2024.
文摘Background Exogenous gonadotropin-controlled ovarian stimulation is the critical step in animal reproductive management,such as pig,sheep,bovine and other species.It helps synchronize ovulation or stimulate multiple ovu-lations.However,a number of evidence indicated an unexpected decrease in pregnancy outcomes following ovarian stimulation.This study aimed to explore the underlying mechanism of the pregnancy defect and develop a practical rescue strategy.Results Compared with those in the control group,gilts that underwent ovarian stimulation showed a decrease in pregnancy rate,farrowing rate,and total number of piglets born.Stimulated gilts also showed an increase in estra-diol(E_(2))levels.The supraphysiologicalE_(2) level was correlated with the decrease in the number of piglets born.Furthermore,we found that high levels ofE_(2) impair uterine receptivity,as shown by the overproliferation of endo-metrial epithelial cells.In vitro mechanistic studies demonstrated that high levels ofE_(2) hyperactivate FGF-FGFR-ERK signaling cascade in the uterine endometrium,and in turn induces overproliferation of endometrial epithelial cells.Of note,N-acetyl-L-cysteine(NAC)supplementation effectively inhibits ERK hyperphosphorylation and ameliorates endometrial epithelial overproliferation.Importantly,in vivo experiments indicated that dietary NAC supplementa-tion,compared with ovarian stimulation group,improves the uterine receptivity in gilts,and significantly increases the pregnancy rate and total number of piglets born.Conclusions Ovarian stimulation-induced supraphysiological levels ofE_(2) impairs uterine receptivity by hyperactivat-ing FGF-FGFR-ERK signaling cascade,thereby reducing pregnancy rate and litter size.Supplementing NAC to a con-ventional diet for gilts ameliorates hyperactivated ERK signaling and improves uterine receptivity,thus rescuing adverse pregnancy outcomes following ovarian stimulation.
基金supported by the National Natural Science Foundation of China (32122067 and 32021005)supported by the Fundamental Research Funds for the Central Universities (JUSRP622013)。
文摘Infancy and toddlerhood are critical phases of life,as the gut microbiota is established here,which influences current and future health.During this period,the microbiota was relatively less stable and highly responsive to environmental factors.Therefore,it is important to understand how dietary factors affect this complex stage of microbial assembly.The effect of feeding practices(breast milk/formula) on microbial colonization in early infancy has been actively studied;however,studies on the effect of diet on the gut microbiota during the complementary feeding period are sparse.The introduction of complementary foods provides abundant new dietary compounds for the gut microbiota,which induces a shift in gut microbiota and metabolism from milk-adapted toward a more mature and diverse adult-like community.Herein,we discuss the impact of dietary nutrients(carbohydrates,proteins,fats,vitamins,and minerals) on microbiome of infants and toddlers.Furthermore,this review summarizes the effects of complementary feeding patterns,specific foods(such as cereals;legumes and nuts;vegetables and fruits;meats;dairy products),food additives,and malnutrition(undernutrition or overnutrition) on gut microbiota of this populations.These findings might deepen our comprehension of the complex interactions between diets and the development and establishment of the gut microbiota.This may facilitate the tailoring of interventions aimed at promoting beneficial modifications within the gut microbial community.Furthermore,the insights gained could inform the design and implementation of safe and efficacious complementary feeding practices.
基金supported by the National Natural Science Foundation of China(Grant Nos.12227901,12393830,and 12274429)the STCSM(Grant No.22QA1410600)。
文摘Interfacial disorders in semiconductor quantum wells(QWs)determine material properties and device performance and have attracted great research efforts using different experimental methods.However,so far,there has been no way to quantify the lateral length distribution of the interfacial disorders in QWs.Since photoluminescence(PL)is sensitive to exciton localization,the evolutions of PL energy and linewidth under external perpendicular magnetic fields have served as effective measurement methods for QW analysis;however,the evolution of PL intensity has not played a matching role.In this paper,we develop a theoretical model correlating the PL intensity with the interfacial disorders of type-I QWs under an external perpendicular magnetic field.We verify the model's rationality and functionality using In Ga(N)As/Ga As single QWs.In addition,we derive the Urbach energy and determine the lateral length distribution of interfacial disorders.The results show that the magnetic field-dependent PL intensity,as described by our model,serves as a valid probe for quantifying the interface flatness.The model also reveals that the mechanism of magnetic-field-induced intensity enhancement is a joint effect of interfacial disorder-induced exciton localization and the transfer of excitons from dark to bright states.These insights may benefit performance improvements of type-I QW materials and devices.
基金supported by the Key Projects in Science and Technology of Inner Mongolia,China(2021ZD0031)the China Agriculture Research System of MOF and MARA(CARS-34)+1 种基金the Performance Incentive and Guidance Special Project of Scientific Research Institution,Chongqing Science and Technology Committee,China(cstc2022jxjl80019)the Natural Science Foundation of Chongqing,China(CSTB2022NSCQ-BHX0744)。
文摘Related to ABI3 and VP1(RAV)transcription factors belong to the AP2 and B3 superfamily.RAVs genes have been reported to be involved in plant growth and development regulation.This study screened three RAV genes from Medicago truncatula and named one of them MtRAV1.The MtRAV1 overexpressing plants exhibits traits such as plant dwarfing,delayed flowering,reduced leaf and floral organs,increased branching,and reduced pods and seeds.Gene expression analysis results showed that overexpression of Mt RAV1 inhibited the expression of Flowering Locus T(MtFTa1),Suppressor of Overexpression of CO1(MtSOC1),GA3-oxidase1(MtGA3OX1),DWARF14(MtD14)and Carotenoid Cleavage Dioxygenase7(MtCCD7).To further investigate the regulation pathway involved by MtRAV1,RNA-sequencing(RNA-seq)and DNA affinity purification sequencing(DAP-seq)analysis were conducted.RNA-seq results indicated that MtRAV1 might affect plant growth and development by regulating some genes in photosynthesis,circadian rhythm and plant hormone signaling pathways,especially the auxin signaling pathway.Conjoint analysis of DAP-seq and RNA-seq revealed that Mt RAV1 might inhibit the expression of Ferredoxin(Mt Fd-l3),Light-harvesting Chlorophyll a/b Binding Protein 1(Mt Lhcb-l2)and Small Auxin Up-regulated RNA(Mt SAUR-l),which related to photosystem II and auxin signaling pathway.Summarily,MtRAV1 was preliminarily proven to be a key growth inhibitory factor in M.truncatula.
基金the National Science and Technology Support Program of China(2015BAA05B02).
文摘Coal is the dominant energy source in China,and coal-fired power accounts for about half of coal consumption.However,air pollutant emissions from coal-fired power plants cause severe ecological and environmental problems.This paper focuses on near-zero emission technologies and applications for clean coal-fired power.The long-term operation states of near-zero emission units were evaluated,and synergistic and special mercury(Hg)control technologies were researched.The results show that the principle technical route of near-zero emission,which was applied to 101 of China’s coal-fired units,has good adaptability to coal properties.The emission concentrations of particulate matter(PM),SO2,and NOx were below the emission limits of gas-fired power plants and the compliance rates of the hourly average emission concentrations reaching near-zero emission in long-term operation exceeded 99%.With the application of near-zero emission technologies,the generating costs increased by about 0.01 CNY∙(kW∙h)-1.However,the total emissions of air pollutants decreased by about 90%,resulting in effective improvement of the ambient air quality.Furthermore,while the Hg emission concentrations of the near-zero emission units ranged from 0.51 to 2.89μg∙m^-3,after the modified fly ash(MFA)special Hg removal system was applied,Hg emission concentration reached as low as 0.29μg∙m^-3.The operating cost of this system was only 10%-15%of the cost of mainstream Hg removal technology using activated carbon injection.Based on experimental studies carried out in a 50000 m^3∙h^-1 coal-fired flue gas pollutant control pilot platform,the interaction relationships of multi-pollutant removal were obtained and solutions were developed for emissions reaching different limits.A combined demonstration application for clean coal-fired power,with the new“1123”eco-friendly emission limits of 1,10,20 mg∙m^-3,and 3μg∙m^-3,respectively,for PM,SO2,NOx,and Hg from near-zero emission coal-fired power were put forward and realized,providing engineering and technical support for the national enhanced pollution emission standards.
基金supported by the Major Projects on Control and Rectification of Water Body Pollution(No.2008ZX07315-001)
文摘To investigate the distribution of pollutant concentrations and pollution loads in stormwater runoff in Chongqing,six typical land use types were selected and studied from August 2009 to September 2011.Statistical analysis on the distribution of pollutant concentrations in all water samples shows that pollutant concentrations fluctuate greatly in rainfall-runoff,and the concentrations of the same pollutant also vary greatly in different rainfall events.In addition,it indicates that the event mean concentrations （EMCs） of total suspended solids （TSS） and chemical oxygen demand （COD） from urban traffic roads （UTR） are significantly higher than those from residential roads （RR）,commercial areas （CA）,concrete roofs （CR）,tile roofs （TRoof）,and campus catchment areas （CCA）;and the EMCs of total phosphorus （TP） and NH3-N from UTR and CA are 2.35-5 and 3 times of the class-III standard values specified in the Environmental Quality Standards for Surface Water （GB 3838-2002）.The EMCs of Fe,Pb and Cd are also much higher than the class-III standard values.The analysis of pollution load producing coefficients （PLPC） reveals that the main pollution source of TSS,COD and TP is UTR.The analysis of correlations between rainfall factors and EMCs/PLPC indicates that rainfall duration is correlated with EMCs/PLPC of TSS for TRoof and TP for UTR,while rainfall intensity is correlated with EMCs/PLPC of TP for both CR and CCA.The results of this study provide a reference for better management of non-point source pollution in urban regions.
基金supported by the National Key Research and Development Project(No.2019YFC0214800)the Science and Technology Innovation Project of China Energy Investment Corporation Limited(No.51609225)Tsinghua-Foshan Innovation Special Fund(No.2020THFS0102)。
文摘China has established the largest clean coal-fired power generation system in the world by accomplishing the technological transformation of coal-fired power plants(CFPPs)to achieve ultra-low emission.The potential for further particulate matter(PM)emission reduction to achieve near-zero emission for CFPPs has become a hotspot issue.In this study,PM emission from some ultra-low emission CFPPs adopting advanced air pollutant control technologies in China was reviewed.The results revealed that the average filterable particulate matter(FPM)concentration,measured as the total particulate matter(TPM)according to the current national monitoring standard,was(1.67±0.86)mg/m^(3),which could fully achieve the ultra-low emission standard for key regions(5 mg/m^(3)),but that achieving the near-zero emission standard was difficult(1 mg/m^(3)).However,the condensable particulate matter(CPM),with an average concentration of(1.06±1.28)mg/m^(3),was generally ignored during monitoring,which led to about 38.7%underestimation of the TPM.Even considering both FPM and CPM,the TPM emission from current CFPPs would contribute to less than 5%of atmospheric PM_(2.5) concentrations in the key cities and regions in China.Therefore,further reduction in FPM emission proposed by the near-zero emission plan of CFPPs may have less environmental benefit than emission control of other anthropogenic sources.However,it is suggested that the management of CPM emission should be strengthened,and a national standard for CPM emission monitoring based on the indirect dilution method should be established for CFPPs.Those measurements are helpful for optimal operation of air pollutant control devices and continuously promoting further emission reduction.
基金supported by an earmarked fund for China Agriculture Research System (No. CARS-09)the Agricultural Science and Technology Innovation Program (ASTIP) of CAASthe Higher Education Institution Key Research Project Plan of Henan Province (No. 15A210042)
文摘As a typical compatible solute, proline is accumulated in plants under environmental stresses. Proline transporter(Pro T) plays an important role in proline distribution between plant organs. Using a candidate gene approach, we cloned a c DNA sequence for Pro T from common bean(Phaseolus vulgaris L.) and designated the gene Pv Pro T. The deduced amino acid sequence of Pv Pro T showed high similarity to Bet/Pro T proteins from other leguminous plants, and the highest similarity was observed with mothbean(Vigna aconitifolia L.) Vu Pro T.Relative quantification of the m RNA level of Pv Pro T using real-time PCR analysis showed that the Pv Pro T transcript level was higher in leaves than in stems and roots of common bean plants subjected to drought and salt stress. Under 20%(w/w) PEG-6000 treatment,drought-resistant plants expressed a higher level of Pv Pro T transcripts than droughtsensitive plants. Although heterologous expression of Pv Pro T in the Escherichia coli mutant mkh13 showed that Pv Pro T exhibited uptake activities for proline and betaine, no betaine content was detected in the common bean. These findings suggest that Pv Pro T plays an important role in the transportation of proline in common bean plants exposed to drought and salt stress.
基金supported by the National Natural Science Foundation of China(Nos.61474073,61874069 and 61804157).
文摘The ultrahigh vacuum scanning tunneling microscope(STM)was used to characterize the GaSb_(1-x)Bi_(x) films of a few nanometers thickness grown by the molecular beam epitaxy(MBE)on the GaSb buffer layer of 100 nm with the GaSb(100)substrates.The thickness of the GaSb_(1-x)Bi_(x) layers of the samples are 5 and 10 nm,respectively.For comparison,the GaSb buffer was also characterized and its STM image displays terraces whose surfaces are basically atomically flat and their roughness is generally less than 1 monolayer(ML).The surface of 5 nm GaSb_(1-x)Bi_(x) film reserves the same terraced morphology as the buffer layer.In contrast,the morphology of the 10 nm GaSb_(1-x)Bi_(x) film changes to the mound-like island structures with a height of a few MLs.The result implies the growth mode transition from the two-dimensional mode as displayed by the 5 nm film to the Stranski-Krastinov mode as displayed by the 10 nm film.The statistical analysis with the scanning tunneling spectroscopy(STS)measurements indicates that both the incorporation and the inhomogeneity of Bi atoms increase with the thickness of the GaSb_(1-x)Bi_(x) layer.
基金partially supported by the National Natural Science Foundation of China (No. 51102125, No. 51571205 and 51602140)the Foundation of Liaoning Educational Committee of China (No. LYB201618)partially by Foundation of Liaoning Province of China (No. 20170520130)
文摘The oxidation behavior of Ti_3AlC_2-20 TiB_2 composite was studied at 500℃–900℃ in air. The composite showed a very low oxidation rate and followed a logarithmic oxidation law. The in-situ incorporation of TiB_2 suppressed the anomalous rapid oxidation of the substrate Ti_3AlC_2 occurred near 600℃ by forming a protective B_2O_3 glass layer, and also improved the oxidation resistance of the MAX phase at intermediatetemperature.
文摘This special issue is focused on grain legumes,which belong to the Fabaceae family.Legumes are the second largest family of plants in the world after the grasses and are key components of manmade and natural ecosystems[1–3].They provide the environmental service of nitrogen fixation,so essential to soil construction and fertility maintenance,and are thus essential to agricultural systems[4,5].Different species of legumes range from huge trees to shrubs
基金supported by the National Natural Science Foundation of China (31471559)the China Agriculture Research System (CARS-09)+2 种基金the National Key Technology R&D Program of China (2013BAD01B03-18a)the Evans Allen Fund of the U.S. Department of Agriculturethe Agricultural Science and Technology Innovation Program (ASTIP) of the Chinese Academy of Agricultural Sciences
文摘Common bacterial blight(CBB), caused by Xanthomonas axonopodis pv. phaseoli and Xanthomonas fuscans subsp. fuscans(Xff), is a worldwide disease of common bean(Phaseolus vulgaris L.).Longyundou 5, a Chinese cultivar in the Mesoamerican gene pool of common bean, displays resistance to the Xff strain XSC3-1. To identify the genetic mechanisms behind this resistance,we crossed Long 5 with a susceptible genotype to develop a mapping population of F2 plants.Plant resistance to CBB was identified at 14 and 21 days after inoculation with Xff strain XSC3-1.A major QTL at 14 and 21 days after inoculation was mapped on chromosome Pv10 with LOD scores of 6.41 and 5.35, respectively. This locus was associated with SAP6, a previouslyidentified and much-used dominant marker, but in a 4.2 cM interval between new codominant markers BMp10s174 and BMp10s244. Ten candidate genes were found between markers BMp10s174 and BMp10s244 on chromosome Pv10 and could encode defense response proteins responding to CBB pathogens. Four pairs each of epistatic QTL for CBB resistance were detected at 14 and 21 days after inoculation. Phenotypic variation explained by the epistatic QTL ranged from 7.19% to 12.15% and 7.72% to 8.80% at 14 and 21 days after inoculation, respectively. These results confirmed the importance of epistasis in CBB resistance in common bean. The adjacent markers found may be more efficient for marker assisted selection in common bean breeding for CBB resistance owing to their closer linkage to the target QTL.
文摘InAs/GaSb type-II superlattce (T2SL) photodetector structures at the MWIR regime were grown by molecular beam epitaxy. The growth temperature and group-V soaking times were optimized with respect to interface and transport quality. Novel strain compensation schemes with insertion of InSb layers were proposed and tested to be efficient to tune the overall strain between tensile and compressive without degradation of interface and optical quality. The effect of the proposed methods is modeled by analytic functions.? Band structure calculations were also carried out for the proposed T2SL structures to assist optimizing sample designs. Single pixel photodiodes with a low dark current were demonstrated.
基金Supported by the National Basic Research Program of China under Grant No 2014CB643902the Key Program of Natural Science Foundation of China under Grant No 61334004+3 种基金the National Natural Science Foundation of China under Grant No 61404152the Strategic Priority Research Program of the Chinese Academy of Sciences under Grant No XDA5-1the Foundation of National Laboratory for Infrared Physics,the Key Research Program of the Chinese Academy of Sciences under Grant No KGZDEW-804the Creative Research Group Project of Natural Science Foundation of China under Grant No 61321492
文摘Optical gains of type-Ⅱ In Ga As/Ga As Bi quantum wells（QWs） with W, N, and M shapes are analyzed theoretically for near-infrared laser applications. The bandgap and wave functions are calculated using the self-consistent k·p Hamiltonian, taking into account valence band mixing and the strain effect. Our calculations show that the M-shaped type-Ⅱ QWs are a promising structure for making 1.3 um lasers at room temperature because they can easily be used to obtain 1.3 um for photoluminescence with a proper thickness and have large wave-function overlap for high optical gain.
基金supported by the National Key Research and Development Program of China(2019YFD1001300 and 2019YFD1001305)the Fundamental Research Funds for the Central Universities,China(SWUKQ22042)+1 种基金the China Agriculture Research System of MOF and MARA(CARS-08)the Agricultural Science and Technology Innovation Program of Chinese Academy of Agricultural Sciences。
文摘Genetic improvement of drought resistance is one of the main breeding goals for common bean,so molecular markers must be identified to facilitate drought resistance breeding.In this study,we evaluated the proline,trehalose,raffinose,and stachyose contents of 210 common bean accessions under two watering conditions and found large variations in all four.The coefficients of variation ranged from 21.21%for proline content to 78.69%for stachyose content under well-watered conditions,and from 20.11%for proline content to 50.08%for trehalose content under drought stress.According to our genome-wide association analysis,32 quantitative trait loci were associated with drought resistance,seven of which overlapped with known loci.Four hotspot regions were identified at Pv01,Pv07 and Pv11.A set of candidate genes was identified,including genes encoding MYB,bZIP,bHLH,ERF,and protein kinases.Among these genes,Phvul.001G189400,Phvul.007G273000 and Phvul.008G270500 were annotated as bZIP,ERF and WRKY,respectively.These genes are reportedly involved in drought stress responses in Arabidopsis thaliana and were induced by drought stress in common bean.Significant SNPs in six candidate gene regions formed different haplotypes,and phenotypic analysis revealed significant differences among the haplotypes.These results provide new insight into the genetic basis of drought resistance in common bean and reveal candidate genes and superior natural variations that will be useful for improving common bean.
基金supported by the National Key Research and Development Program of China (2019YFD1001300,2019YFD1001305)the China Agriculture Research System of MOF and MARA-Food Legumes (CARS-08)the Agricultural Science and Technology Innovation Program of CAAS。
文摘Drought stress severely impairs common bean production.For facilitating drought-resistance breeding in common bean,molecular markers were identified in a genome-wide level marker–trait association study.A panel of 210 common bean accessions showed large variation in 11 agronomic traits at the adult stage(plant height,pod number per plant,seed number per pod,seed number per plant,seed yield per plant,pod length,harvest index,pod harvest index,days to maturity,hundred-seed weight,and seed yield)under two water conditions.The coefficient of variation ranged from 6.21% for pod harvest index to51.00% for seed number per plant under well-watered conditions,and from 4.05% for days to maturity to 40.72% for seed number per plant under drought stress.In a genome-wide association study,119quantitative-trait loci were associated with drought resistance,including 41 adjacent to known loci.Among these loci,12 were found to be associated with at least two traits.Three major loci were identified at Pv01 and Pv02.A set of candidate genes were found that encode MYBs,AREBs,WKRYs,and protein kinases.These results reveal promising alleles that control drought resistance,shedding light on the genetic basis of drought resistance and accelerating future efforts for drought resistance improvement in common bean.
基金Project supported by the National Key Research and Development Program of China(Grant No.2017YFE0131300)the National Natural Science Foundation of China(Grant Nos.U1732268,61874128,11622545,61851406,11705262,and 61804157)+5 种基金the Frontier Science Key Program of the Chinese Academy of Sciences(Grant No.QYZDY-SSW-JSC032)the Chinese-Austrian Cooperative Research and Development Project(Grant No.GJHZ201950)the Science and Technology Innovation Action Plan Program of Shanghai,China(Grant No.17511106202)the Program of Shanghai Academic Research Leader,China(Grant No.19XD1404600)the Sailing Program of Shanghai,China(Grant Nos.19YF1456200 and 19YF1456400)the K C Wong Education Foundation(Grant No.GJTD-2019-11).
文摘Strain and stress were simulated using finite element method(FEM)for threeⅢ-V-on-Insulator(Ⅲ-VOI)structures,i.e.,InP/SiO2/Si,InP/Al2O3/SiO2/Si,and GaAs/Al2O3/SiO2/Si,fabricated by ion-slicing as the substrates for optoelectronic devices on Si.The thermal strain/stress imposes no risk for optoelectronic structures grown on InPOI at a normal growth temperature using molecular beam epitaxy.Structures grown on GaAsOI are more dangerous than those on InPOI due to a limited critical thickness.The intermedia Al2O3 layer was intended to increase the adherence while it brings in the largest risk.The simulated results reveal thermal stress on Al2O3 over 1 GPa,which is much higher than its critical stress for interfacial fracture.InPOI without an Al2O3 layer is more suitable as the substrate for optoelectronic integration on Si.
文摘The characteristics of highway transport and the application of information technology in highway transport service are combined; the information flows＇ promotion and substitution on highway transport are analyzed; and the highway transport development strategy based on information flow impact is proposed.
