Although Mg-based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers,their high operating temperature and slow kinetics are the main challenges for...Although Mg-based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers,their high operating temperature and slow kinetics are the main challenges for practical application.Here,a Mg-Ni based hydride,Mg_(2)NiH_(4) nanoparticles(~100 nm),with dual modification strategies of nanosizing and alloying is successfully prepared via a gas-solid preparation process.It is demonstrated that Mg_(2)NiH_(4) nanoparticles form a unique chain-like structure by oriented stacking and exhibit impressive hydrogen storage performance:it starts to release H2 at~170℃ and completes below 230℃ with a saturated capacity of 3.32 wt%and desorbs 3.14 wt% H_(2) within 1800 s at 200℃.The systematic characterizations of Mg_(2)NiH_(4) nanoparticles at different states reveal the dehydrogenation behavior and demonstrate the excellent structural and hydrogen storage stabilities during the de/hydrogenated process.This research is believed to provide new insights for optimizing the kinetic performance of metal hydrides and novel perspectives for designing highly active and stable hydrogen storage alloys.展开更多
The processability and ultimate quality of coffee(Coffea arabica)are determined by the composition of the matured fruits.The basis of genetic variation in coffee fruit quality could be explained by studying color form...The processability and ultimate quality of coffee(Coffea arabica)are determined by the composition of the matured fruits.The basis of genetic variation in coffee fruit quality could be explained by studying color formation during fruit maturation.Transcriptome profiling was conducted on matured fruits of four C.arabica varieties(orange colored fruits(ORF);purple colored fruits(PF);red colored fruits(RF)and yellow colored fruits(YF))to identify key color-regulating genes,biosynthesis pathways and transcription factors implicated in fruit color formation.A total of 39,938 genes were identified in the transcriptomes of the four C.arabica varieties.In all,2745,781 and 1224 differentially expressed genes(DEGs)were detected in YF_vs_PF,YF_vs_RF and YF_vs_ORF,respectively,with 1732 DEGs conserved among the three pairwise groups.Functional annotation of the DEGs led to the detection of 28 and 82 key genes involved in the biosynthesis of carotenoids and anthocyanins,respectively.Key transcription factors bHLH,MYB,NAC,MADS,and WRKY implicated in fruit color regulation were detected.The high expression levels of gene-LOC113688784(PSY),gene-LOC113730013(b-CHY),gene-LOC113728842(CCD7),gene-LOC113689681(NCED)and gene-LOC113729473(ABA2)in YF may have accounted for the yellow coloration.The differential expression of several anthocyanin and carotenoid-specific genes in the fruits substantially account for the purple(PF),red(RF),and orange(ORF)colorations.This study provides important insights into fruit color formation and variations in C.arabica and will help to develop coffee varieties with specific color and quality traits.展开更多
Two-dimensional Ti_(3)C_(2)T_(x) MXenes exposing different active facets are introduced into MgH_(2), and their catalytic effects are systematically investigated in depth through experimental and theoretical approache...Two-dimensional Ti_(3)C_(2)T_(x) MXenes exposing different active facets are introduced into MgH_(2), and their catalytic effects are systematically investigated in depth through experimental and theoretical approaches. Excluding factors such as interlayer space, surface functional groups and experimental contingency, the exposed facets is considered to be the dominant factor for catalytic activity of Ti_(3)C_(2)T_(x) towards MgH_(2).More exposed edge facets of Ti_(3)C_(2)T_(x) displays higher catalytic activity than that with more exposed basal facets, which also leads to different rate-controlling steps of MgH_(2) in the de/hydrogenation process. The low work function, strong hydrogen affinity and high content of in situ metallic Ti for the edge facet contribute the high catalytic activity. This work will give insights into the structural design of two-dimensional Ti_(3)C_(2)T_(x) MXene used for enhancing the catalytic activity in various fields.展开更多
Background Nitrate leaching to groundwater and surface water and ammonia volatilization from dairy farms have negative impacts on the environment.Meanwhile,the increasing demand for dairy products will result in more ...Background Nitrate leaching to groundwater and surface water and ammonia volatilization from dairy farms have negative impacts on the environment.Meanwhile,the increasing demand for dairy products will result in more pollution if N losses are not controlled.Therefore,a more efficient,and environmentally friendly production system is needed,in which nitrogen use efficiency(NUE)of dairy cows plays a key role.To genetically improve NUE,extensively recorded and cost-effective proxies are essential,which can be obtained by including mid-infrared(MIR)spectra of milk in prediction models for NUE.This study aimed to develop and validate the best prediction model of NUE,nitrogen loss(NL)and dry matter intake(DMI)for individual dairy cows in China.Results A total of 86 lactating Chinese Holstein cows were used in this study.After data editing,704 records were obtained for calibration and validation.Six prediction models with three different machine learning algorithms and three kinds of pre-processed MIR spectra were developed for each trait.Results showed that the coefficient of determination(R2)of the best model in within-herd validation was 0.66 for NUE,0.58 for NL and 0.63 for DMI.For external validation,reasonable prediction results were only observed for NUE,with R2 ranging from 0.58 to 0.63,while the R2 of the other two traits was below 0.50.The infrared waves from 973.54 to 988.46 cm−1 and daily milk yield were the most important variables for prediction.Conclusion The results showed that individual NUE can be predicted with a moderate accuracy in both within-herd and external validations.The model of NUE could be used for the datasets that are similar to the calibration dataset.The prediction models for NL and 3-day moving average of DMI(DMI_a)generated lower accuracies in within-herd validation.Results also indicated that information of MIR spectra variables increased the predictive ability of models.Additionally,pre-processed MIR spectra do not result in higher accuracy than original MIR spectra in the external validation.These models will be applied to large-scale data to further investigate the genetic architecture of N efficiency and further reduce the adverse impacts on the environment after more data is collected.展开更多
BACKGROUND The global prevalence of type 2 diabetes mellitus(T2DM)is increasing.T2DM is associated with alterations of the gut microbiota,which can be affected by age,illness,and genetics.Previous studies revealed tha...BACKGROUND The global prevalence of type 2 diabetes mellitus(T2DM)is increasing.T2DM is associated with alterations of the gut microbiota,which can be affected by age,illness,and genetics.Previous studies revealed that there are discriminating microbiota compositions between the Dai and the Han populations.However,the specific gut microbiota differences between the two populations have not been elucidated.AIM To compare the gut microbiota differences in subjects with and without T2DM in the Dai and Han populations.METHODS A total of 35 subjects of the Han population(including 15 healthy children,8 adult healthy controls,and 12 adult T2DM patients)and 32 subjects of the Dai population(including 10 healthy children,10 adult healthy controls,and 12 adult T2DM patients)were enrolled in this study.Fasting venous blood samples were collected from all the subjects for biochemical analysis.Fecal samples were collected from all the subjects for DNA extraction and 16S rRNA sequencing,which was followed by analyses of the gut microbiota composition.RESULTS No significant difference in alpha diversity was observed between healthy children and adults.The diversity of gut microbiota was decreased in T2DM patients compared to the healthy adults in both the Dai and Han populations. There was a significant difference in gut microbiota between healthy children and healthy adults in the Hanpopulation with an increased abundance of Bacteroidetes and decreased Firmicutes in children. However, thisdifference was less in the Dai population. Significant increases in Bacteroidetes in the Han population and Proteobacteriain the Dai population and decreases in Firmicutes in both the Han and Dai population were observed inT2DM patients compared to healthy adults. Linear discriminant analysis Effect Size analysis also showed that thegut microbiota was different between the Han and Dai populations in heathy children, adults, and T2DM patients.Four bacteria were consistently increased and two consistently decreased in the Han population compared to theDai population.CONCLUSION Differences in gut microbiota were found between the Han and Dai populations. A significant increase inBacteroidetes was related to the occurrence of T2DM in the Han population, while a significant increase in Proteobacteriawas related to the occurrence of T2DM in the Dai population.展开更多
The initial healing stages of bone fracture is a complex physiological process involving a series of spatially and temporally overlapping events,including pathogen clearance,immunological modulation,and osteogenesis.I...The initial healing stages of bone fracture is a complex physiological process involving a series of spatially and temporally overlapping events,including pathogen clearance,immunological modulation,and osteogenesis.In this study,we have developed a piezoelectric and aligned nanofibrous scaffold composed of ZnO@PCL/PVDF with multiple antibacterial,immunomodulatory,and osteogenic effects using electrospinning technology.This scaffold’s piezoelectric signal output under ultrasound(US)control can be similar to the physiological electrical signals of healthy bone tissue,creating a truly biomimetic electrical microenvironment in the bone defect.In vitro studies have shown that ZnO@PCL/PVDF scaffold significantly enhances the proliferation,migration,and osteogenic differentiation of MC3T3-E1 cells under piezoelectric drive provided by ultrasound.Furthermore,the scaffold exhibits inhibitory effects on the growth of E.coli and S.aureus,as well as the ability to induce M2 macrophage polarization,indicating potent antibacterial and immunomodulatory properties.In vivo experiments demonstrated that the ZnO@PCL/PVDF scaffold can accelerate the repair of mandibular defects in rats,effectively inhibit bacterial colonization,and reduce inflammatory responses.Altogether,this study confirms that the newly developed ZnO@PCL/PVDF scaffold effectively promotes bone repair by truly mimicking the endogenous electrical microenvironment and precisely regulating the temporospatial disorders of initial bone healing,thus providing a simple and effective solution for bone defects.展开更多
China’s“three-child policy”,implemented in response to population aging,has made the protection of maternal and infant health an urgent priority.In this environmental and medical big-data era,the Zhejiang Environme...China’s“three-child policy”,implemented in response to population aging,has made the protection of maternal and infant health an urgent priority.In this environmental and medical big-data era,the Zhejiang Environmental and Birth Health Research Alliance(ZEBRA)maternity cohort was established with the aim of identifying risk factors for perinatal morbidity and mortality from the perspectives of both observational epidemiology and experimental etiology.Compared with conventional birth cohorts,the inclusion of a maternity cohort allows greater scope for research and places an emphasis on maternal health.In particular,it allows us to focus on pregnant women with a history of pregnancy-related illnesses and those planning to have a second or third child.There are currently many pressing issues in perinatal health,including the risk associations between exogenous together with endogenous factors and the occurrence of perinatal abnormalities,pregnancy complications,and adverse pregnancy outcomes.It is crucial to explore the interaction between environmental exposures and genetic factors affecting perinatal health if we are to improve it.It is also worthwhile to assess the feasibility of the early stage prediction of major perinatal abnormalities.We hope to study this in the ZEBRA cohort and also seek nationwide and international collaborations to establish a multicenter cohort consortium,with the ultimate goal of contributing epidemiological evidence to literature and providing evidence-based insights for global maternal and child healthcare.展开更多
Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mi...Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mineral element,can directly affect plant growth and development at different N levels.It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants.However,there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels.In this experiment,the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P.polyphylla var.yunnanensis infested by AMF as the test material.It was found that nitrogen addition increased the biomass,chlorophyll content,and nutrient content of above-and below-ground plant parts and increased the content of saponin content of P.polyphylla var.yunnanensis to some extent,but AMF inoculation increased the saponin content of P.polyphylla var.yunnanensis more significantly.AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway,including 3-hydroxy-3-methylglutaryl coenzyme A synthase(HMGS),squalene epoxidase 1(SE1),and cycloartenol synthase(CAS),which is in according with the accumulation of saponin in plants.It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.展开更多
目的:采用Meta分析的方法,对光学相干断层扫描血管成像技术(OCTA)测量无糖尿病视网膜病变(NDR)的患者黄斑区的血流密度(VD)及浅层中心凹无血管区(FAZ)面积进行系统评价,探讨糖尿病早期视网膜的微循环特征。方法:在PubMed、Embase、Web o...目的:采用Meta分析的方法,对光学相干断层扫描血管成像技术(OCTA)测量无糖尿病视网膜病变(NDR)的患者黄斑区的血流密度(VD)及浅层中心凹无血管区(FAZ)面积进行系统评价,探讨糖尿病早期视网膜的微循环特征。方法:在PubMed、Embase、Web of Science、Cochrane Library数据库中全面检索发表于2011-01-01/2021-01-05之间关于OCTA分析NDR患者黄斑区不同区域血流密度的研究。比较NDR组与正常对照组(同期年龄、性别与NDR组患者相匹配的健康人群)在浅层旁中心凹血流密度(spafVD)、浅层中心凹周围血流密度(spefVD)、深层旁中心凹血流密度(dpafVD)、深层中心凹周围血流密度(dpefVD)、浅层FAZ面积、最佳矫正视力(BCVA)。结果:研究纳入文献13篇,共1227眼(正常对照组558眼,NDR组669眼)。Meta分析结果显示:与正常对照组相比,NDR组spafVD(MD=-1.90,95%CI:-2.43~-1.37,P<0.00001)、spefVD(MD=-1.29,95%CI:-2.14~-0.44,P=0.003)、dpafVD(MD=-2.18,95%CI:-2.69~-1.67,P<0.00001)、dpefVD(MD=-2.37,95%CI:-3.27~-1.46,P<0.00001)显著降低,其中dpefVD降低更明显;浅层FAZ面积(MD=0.04,95%CI:0.03~0.06,P<0.00001)增大;两组BCVA比较无差异(MD=0.00,95%CI:-0.01~0.02,P=0.44)。结论:黄斑区深层中心凹周围区毛细血管损伤是糖尿病患者视网膜微循环障碍的最早期表现,也是糖尿病视网膜病变临床随访的关键指标。展开更多
With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study...With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.展开更多
In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user syste...In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user protection.The optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization problem.The Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of subtraction.Then,an iterative power allocation algorithm is proposed to solve the optimization problem.The simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network.展开更多
Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors tha...Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly.展开更多
Efficiency is an important factor in quantitative and qualitative analysis of radionuclides, and the gamma point source efficiency is related to the radial angle,detection distance, and gamma-ray energy. In this work,...Efficiency is an important factor in quantitative and qualitative analysis of radionuclides, and the gamma point source efficiency is related to the radial angle,detection distance, and gamma-ray energy. In this work, on the basis of a back-propagation(BP) neural network model,a method to determine the gamma point source efficiency is developed and validated. The efficiency of the point sources ^(137)Cs and ^(60)Co at discrete radial angles, detection distances, and gamma-ray energies is measured, and the BP neural network prediction model is constructed using MATLAB. The gamma point source efficiencies at different radial angles, detection distances, and gamma-ray energies are predicted quickly and accurately using this nonlinear prediction model. The results show that the maximum error between the predicted and experimental values is 3.732% at 661.661 keV, 11π/24, and 35 cm, and those under other conditions are less than 3%. The gamma point source efficiencies obtained using the BP neural network model are in good agreement with experimental data.展开更多
Purpose:To analyse the hereditary features of a Chinese pedigree with familial vitreous amyloidosis in Liaoning Province,China,and to investigate the correlation between the clinical appearance of the disease and tran...Purpose:To analyse the hereditary features of a Chinese pedigree with familial vitreous amyloidosis in Liaoning Province,China,and to investigate the correlation between the clinical appearance of the disease and transthyretin(TTR)gene mutation,including the locus and type of TTR gene mutation.Methods:Five patients (10 eyes) from one Chinese family were diagnosed with vitreous amyloidosis between July 1996 and April 2009.Family members were followed up subsequently,and peripheral venous blood was obtained from 13 subjects (including 2 patients,and 11 controls without clinical signs of disease).DNA samples were extracted and 4 exons of the TTR gene were amplified by polymerase chain reaction (PCR).The gene fragments were subjected to sequencing analysis.The results were analyzed with DNAMAN Windows 5.2.2.0 and Chromas sequence chart analysis software,TTR gene exons were compared between affected patients and normal controls.Results:Family pedigree analysis revealed that patients were distributed in three generations.Male and female subjects had equal prevalence,and only one parent of affected patients had signs of disease.TTR gene exon sequencing showed that the sequence of patients was identical to that of normal individuals.No TTR gene mutations were noted in 10 unaffected family members.However,a TTR Gly-54 point mutation in the 2nd exon was detected in two patients and 1 unaffected family member (one of the patients' daughters).Vitreous samples in 4 cases (7 eyes) showed positive Congo red staining,suggesting that these family members suffered from familial vitreous amyloidosis.Conclusion:This pedigree affected with familial vitreous amyloidosis was characterized by autosomal dominant inheritance;.a TTR Gly-54 point mutation in the 2nd exon is presumed to be the cause.This Gly-54 point mutation of the TTR gene is a novel mutation in vitreous amyloidosis.展开更多
基金supported by the National Key R&D Program of China(No.2022YFB3803801)National Natural Science Foundation of China(52071177,21975125 and 52171214)the Priority Academic Program Development(PAPD)of Jiangsu Higher Education Institutions.
文摘Although Mg-based hydrides are extensively considered as a prospective material for solid-state hydrogen storage and clean energy carriers,their high operating temperature and slow kinetics are the main challenges for practical application.Here,a Mg-Ni based hydride,Mg_(2)NiH_(4) nanoparticles(~100 nm),with dual modification strategies of nanosizing and alloying is successfully prepared via a gas-solid preparation process.It is demonstrated that Mg_(2)NiH_(4) nanoparticles form a unique chain-like structure by oriented stacking and exhibit impressive hydrogen storage performance:it starts to release H2 at~170℃ and completes below 230℃ with a saturated capacity of 3.32 wt%and desorbs 3.14 wt% H_(2) within 1800 s at 200℃.The systematic characterizations of Mg_(2)NiH_(4) nanoparticles at different states reveal the dehydrogenation behavior and demonstrate the excellent structural and hydrogen storage stabilities during the de/hydrogenated process.This research is believed to provide new insights for optimizing the kinetic performance of metal hydrides and novel perspectives for designing highly active and stable hydrogen storage alloys.
基金financially supported by the Yunnan Science and Technology Introducing project(International Science and Technology Cooperation):Construction Project of Coffee Scientific and Technological Demonstration Districts in Mountainous Areas of Northern Laos(2019IB013)High-end Foreign Experts Program of Yunnan Thousand Talents Program(2019013)Yunnan provincial key programs(2019ZG00901,202002AA10007).
文摘The processability and ultimate quality of coffee(Coffea arabica)are determined by the composition of the matured fruits.The basis of genetic variation in coffee fruit quality could be explained by studying color formation during fruit maturation.Transcriptome profiling was conducted on matured fruits of four C.arabica varieties(orange colored fruits(ORF);purple colored fruits(PF);red colored fruits(RF)and yellow colored fruits(YF))to identify key color-regulating genes,biosynthesis pathways and transcription factors implicated in fruit color formation.A total of 39,938 genes were identified in the transcriptomes of the four C.arabica varieties.In all,2745,781 and 1224 differentially expressed genes(DEGs)were detected in YF_vs_PF,YF_vs_RF and YF_vs_ORF,respectively,with 1732 DEGs conserved among the three pairwise groups.Functional annotation of the DEGs led to the detection of 28 and 82 key genes involved in the biosynthesis of carotenoids and anthocyanins,respectively.Key transcription factors bHLH,MYB,NAC,MADS,and WRKY implicated in fruit color regulation were detected.The high expression levels of gene-LOC113688784(PSY),gene-LOC113730013(b-CHY),gene-LOC113728842(CCD7),gene-LOC113689681(NCED)and gene-LOC113729473(ABA2)in YF may have accounted for the yellow coloration.The differential expression of several anthocyanin and carotenoid-specific genes in the fruits substantially account for the purple(PF),red(RF),and orange(ORF)colorations.This study provides important insights into fruit color formation and variations in C.arabica and will help to develop coffee varieties with specific color and quality traits.
基金supported by the National Natural Science Foundation of China (51801100,51771092,21975125,51801099)Natural Science Foundation of the Jiangsu Higher Education Institutions of China (18KJB430014)+1 种基金Six Talent Peaks Project in Jiangsu Province (2018,XNY-020)the Priority Academic Program Development (PAPD) of Jiangsu Higher Education Institutions。
文摘Two-dimensional Ti_(3)C_(2)T_(x) MXenes exposing different active facets are introduced into MgH_(2), and their catalytic effects are systematically investigated in depth through experimental and theoretical approaches. Excluding factors such as interlayer space, surface functional groups and experimental contingency, the exposed facets is considered to be the dominant factor for catalytic activity of Ti_(3)C_(2)T_(x) towards MgH_(2).More exposed edge facets of Ti_(3)C_(2)T_(x) displays higher catalytic activity than that with more exposed basal facets, which also leads to different rate-controlling steps of MgH_(2) in the de/hydrogenation process. The low work function, strong hydrogen affinity and high content of in situ metallic Ti for the edge facet contribute the high catalytic activity. This work will give insights into the structural design of two-dimensional Ti_(3)C_(2)T_(x) MXene used for enhancing the catalytic activity in various fields.
基金supported by the earmarked fund for China Agriculture Research System (CARS-36)the Key Research Project of Henan Province (221111111100)+3 种基金the Key Research Project of Ningxia Hui Autonomous Region (2022BBF02017)the Program for Changjiang Scholar and Innovation Research Team in University (IRT_15R62)China Scholarship Council (No.201913043)Hainan University.
文摘Background Nitrate leaching to groundwater and surface water and ammonia volatilization from dairy farms have negative impacts on the environment.Meanwhile,the increasing demand for dairy products will result in more pollution if N losses are not controlled.Therefore,a more efficient,and environmentally friendly production system is needed,in which nitrogen use efficiency(NUE)of dairy cows plays a key role.To genetically improve NUE,extensively recorded and cost-effective proxies are essential,which can be obtained by including mid-infrared(MIR)spectra of milk in prediction models for NUE.This study aimed to develop and validate the best prediction model of NUE,nitrogen loss(NL)and dry matter intake(DMI)for individual dairy cows in China.Results A total of 86 lactating Chinese Holstein cows were used in this study.After data editing,704 records were obtained for calibration and validation.Six prediction models with three different machine learning algorithms and three kinds of pre-processed MIR spectra were developed for each trait.Results showed that the coefficient of determination(R2)of the best model in within-herd validation was 0.66 for NUE,0.58 for NL and 0.63 for DMI.For external validation,reasonable prediction results were only observed for NUE,with R2 ranging from 0.58 to 0.63,while the R2 of the other two traits was below 0.50.The infrared waves from 973.54 to 988.46 cm−1 and daily milk yield were the most important variables for prediction.Conclusion The results showed that individual NUE can be predicted with a moderate accuracy in both within-herd and external validations.The model of NUE could be used for the datasets that are similar to the calibration dataset.The prediction models for NL and 3-day moving average of DMI(DMI_a)generated lower accuracies in within-herd validation.Results also indicated that information of MIR spectra variables increased the predictive ability of models.Additionally,pre-processed MIR spectra do not result in higher accuracy than original MIR spectra in the external validation.These models will be applied to large-scale data to further investigate the genetic architecture of N efficiency and further reduce the adverse impacts on the environment after more data is collected.
基金supported by the National Natural Science Foundation of China[Grant No.42041004]the“Innovation Star”Project for Outstanding Postgraduates of Gansu Province[Grant No.2022CXZX-107]the Central Universities[Grant No.lzujbky-2019-kb30].
基金the National Natural Science Foundation of China,No.82160402Special Fund for Training Leading Medical Talents in Yunnan Province,China,No.L-2019022。
文摘BACKGROUND The global prevalence of type 2 diabetes mellitus(T2DM)is increasing.T2DM is associated with alterations of the gut microbiota,which can be affected by age,illness,and genetics.Previous studies revealed that there are discriminating microbiota compositions between the Dai and the Han populations.However,the specific gut microbiota differences between the two populations have not been elucidated.AIM To compare the gut microbiota differences in subjects with and without T2DM in the Dai and Han populations.METHODS A total of 35 subjects of the Han population(including 15 healthy children,8 adult healthy controls,and 12 adult T2DM patients)and 32 subjects of the Dai population(including 10 healthy children,10 adult healthy controls,and 12 adult T2DM patients)were enrolled in this study.Fasting venous blood samples were collected from all the subjects for biochemical analysis.Fecal samples were collected from all the subjects for DNA extraction and 16S rRNA sequencing,which was followed by analyses of the gut microbiota composition.RESULTS No significant difference in alpha diversity was observed between healthy children and adults.The diversity of gut microbiota was decreased in T2DM patients compared to the healthy adults in both the Dai and Han populations. There was a significant difference in gut microbiota between healthy children and healthy adults in the Hanpopulation with an increased abundance of Bacteroidetes and decreased Firmicutes in children. However, thisdifference was less in the Dai population. Significant increases in Bacteroidetes in the Han population and Proteobacteriain the Dai population and decreases in Firmicutes in both the Han and Dai population were observed inT2DM patients compared to healthy adults. Linear discriminant analysis Effect Size analysis also showed that thegut microbiota was different between the Han and Dai populations in heathy children, adults, and T2DM patients.Four bacteria were consistently increased and two consistently decreased in the Han population compared to theDai population.CONCLUSION Differences in gut microbiota were found between the Han and Dai populations. A significant increase inBacteroidetes was related to the occurrence of T2DM in the Han population, while a significant increase in Proteobacteriawas related to the occurrence of T2DM in the Dai population.
基金funded by National Natural Science Foundation of China(Nos.82151312,82272493,and 82072406)the Beijing Science Nova Program(No.20220484155)+1 种基金the Natural Science Foundation of Shaanxi Province(No.2023-YBSF-426)Beijing Jishuitan Hospital Elite Young Scholar Programme(No.XKGG2021).
文摘The initial healing stages of bone fracture is a complex physiological process involving a series of spatially and temporally overlapping events,including pathogen clearance,immunological modulation,and osteogenesis.In this study,we have developed a piezoelectric and aligned nanofibrous scaffold composed of ZnO@PCL/PVDF with multiple antibacterial,immunomodulatory,and osteogenic effects using electrospinning technology.This scaffold’s piezoelectric signal output under ultrasound(US)control can be similar to the physiological electrical signals of healthy bone tissue,creating a truly biomimetic electrical microenvironment in the bone defect.In vitro studies have shown that ZnO@PCL/PVDF scaffold significantly enhances the proliferation,migration,and osteogenic differentiation of MC3T3-E1 cells under piezoelectric drive provided by ultrasound.Furthermore,the scaffold exhibits inhibitory effects on the growth of E.coli and S.aureus,as well as the ability to induce M2 macrophage polarization,indicating potent antibacterial and immunomodulatory properties.In vivo experiments demonstrated that the ZnO@PCL/PVDF scaffold can accelerate the repair of mandibular defects in rats,effectively inhibit bacterial colonization,and reduce inflammatory responses.Altogether,this study confirms that the newly developed ZnO@PCL/PVDF scaffold effectively promotes bone repair by truly mimicking the endogenous electrical microenvironment and precisely regulating the temporospatial disorders of initial bone healing,thus providing a simple and effective solution for bone defects.
基金funding from various sources,including the Zhejiang Province Health Innovative Talent Project(A0466)the International Cooperation Seed Program of Women’s Hospital,Zhejiang University(GH2022B008-01 and GH2024005)+3 种基金the Australian Research Council(DP210102076)the Australian National Health and Medical Research Council(APP2000581)the UK Research and Innovation(UKRI)Centre for Application of Artificial Intelligence to the Study of Environmental Risks(AI4ER,EP/S022961/1)the Start-up Grant from Yong Loo Lin School of Medicine,National University of Singapore(NUHSRO/2024/045/Startup/06),and the US-China Fulbright Program.
文摘China’s“three-child policy”,implemented in response to population aging,has made the protection of maternal and infant health an urgent priority.In this environmental and medical big-data era,the Zhejiang Environmental and Birth Health Research Alliance(ZEBRA)maternity cohort was established with the aim of identifying risk factors for perinatal morbidity and mortality from the perspectives of both observational epidemiology and experimental etiology.Compared with conventional birth cohorts,the inclusion of a maternity cohort allows greater scope for research and places an emphasis on maternal health.In particular,it allows us to focus on pregnant women with a history of pregnancy-related illnesses and those planning to have a second or third child.There are currently many pressing issues in perinatal health,including the risk associations between exogenous together with endogenous factors and the occurrence of perinatal abnormalities,pregnancy complications,and adverse pregnancy outcomes.It is crucial to explore the interaction between environmental exposures and genetic factors affecting perinatal health if we are to improve it.It is also worthwhile to assess the feasibility of the early stage prediction of major perinatal abnormalities.We hope to study this in the ZEBRA cohort and also seek nationwide and international collaborations to establish a multicenter cohort consortium,with the ultimate goal of contributing epidemiological evidence to literature and providing evidence-based insights for global maternal and child healthcare.
基金supported by the Key R&D Program of Yunnan Province,China(Grant No.202103AC100003202101AS070228)+2 种基金the Major Special Project of the Ministry of Science and Technology(2021YFD10002022021YFD1601003)and the National Natural Science Foundation of China(Grant No.31860075),thank you.
文摘Arbuscular mycorrhizal fungi(AMF)are important members of the plant microbiome and affect the uptake and transfer of mineral elements by forming a symbiotic relationship with plant roots.Nitrogen(N),as an important mineral element,can directly affect plant growth and development at different N levels.It has been confirmed that inoculation with AMF can improve the efficiency of N utilization by plants.However,there are still fewer reports on the dynamic relationship between arbuscular mycorrhizal and plant secondary metabolites at different nitrogen levels.In this experiment,the physiological indexes and genes related to saponin synthesis were determined by applying different concentration gradients of nitrogen to the medicinal plant P.polyphylla var.yunnanensis infested by AMF as the test material.It was found that nitrogen addition increased the biomass,chlorophyll content,and nutrient content of above-and below-ground plant parts and increased the content of saponin content of P.polyphylla var.yunnanensis to some extent,but AMF inoculation increased the saponin content of P.polyphylla var.yunnanensis more significantly.AMF inoculation also promoted the expression of genes related to the saponin synthesis pathway,including 3-hydroxy-3-methylglutaryl coenzyme A synthase(HMGS),squalene epoxidase 1(SE1),and cycloartenol synthase(CAS),which is in according with the accumulation of saponin in plants.It also may increase the saponin content of AMF plants by altering the expression of P450s and UGTs related to saponin synthesis.
文摘目的:采用Meta分析的方法,对光学相干断层扫描血管成像技术(OCTA)测量无糖尿病视网膜病变(NDR)的患者黄斑区的血流密度(VD)及浅层中心凹无血管区(FAZ)面积进行系统评价,探讨糖尿病早期视网膜的微循环特征。方法:在PubMed、Embase、Web of Science、Cochrane Library数据库中全面检索发表于2011-01-01/2021-01-05之间关于OCTA分析NDR患者黄斑区不同区域血流密度的研究。比较NDR组与正常对照组(同期年龄、性别与NDR组患者相匹配的健康人群)在浅层旁中心凹血流密度(spafVD)、浅层中心凹周围血流密度(spefVD)、深层旁中心凹血流密度(dpafVD)、深层中心凹周围血流密度(dpefVD)、浅层FAZ面积、最佳矫正视力(BCVA)。结果:研究纳入文献13篇,共1227眼(正常对照组558眼,NDR组669眼)。Meta分析结果显示:与正常对照组相比,NDR组spafVD(MD=-1.90,95%CI:-2.43~-1.37,P<0.00001)、spefVD(MD=-1.29,95%CI:-2.14~-0.44,P=0.003)、dpafVD(MD=-2.18,95%CI:-2.69~-1.67,P<0.00001)、dpefVD(MD=-2.37,95%CI:-3.27~-1.46,P<0.00001)显著降低,其中dpefVD降低更明显;浅层FAZ面积(MD=0.04,95%CI:0.03~0.06,P<0.00001)增大;两组BCVA比较无差异(MD=0.00,95%CI:-0.01~0.02,P=0.44)。结论:黄斑区深层中心凹周围区毛细血管损伤是糖尿病患者视网膜微循环障碍的最早期表现,也是糖尿病视网膜病变临床随访的关键指标。
基金supported by the National Natural Science Foundation of China(Nos.41374130 and 41604154)
文摘With respect to the gamma spectrum, the energy resolution improves with increase in energy. The counts of full energy peak change with energy, and this approximately complies with the Gaussian distribution. This study mainly examines a method to deconvolve the LaBr_3:Ce gamma spectrum with a detector response matrix constructing algorithm based on energy resolution calibration.In the algorithm, the full width at half maximum(FWHM)of full energy peak was calculated by the cubic spline interpolation algorithm and calibrated by a square root of a quadratic function that changes with the energy. Additionally, the detector response matrix was constructed to deconvolve the gamma spectrum. Furthermore, an improved SNIP algorithm was proposed to eliminate the background. In the experiment, several independent peaks of ^(152)Eu,^(137)Cs, and ^(60)Co sources were detected by a LaBr_3:Ce scintillator that were selected to calibrate the energy resolution. The Boosted Gold algorithm was applied to deconvolve the gamma spectrum. The results showed that the peak position difference between the experiment and the deconvolution was within ± 2 channels and the relative error of peak area was approximately within 0.96–6.74%. Finally, a ^(133) Ba spectrum was deconvolved to verify the efficiency and accuracy of the algorithm in unfolding the overlapped peaks.
基金supported in part by the National Natural Science Foundation of China for Young Scholars under Grant No.61701167Young Elite Backbone Teachers in Blue and Blue Project of Jiangsu Province, China
文摘In order to improve the energy efficiency(EE)in cognitive radio(CR),this paper investigates the joint design of cooperative spectrum sensing time and the power control optimization problem for the secondary user systems to achieve the maximum energy efficiency in a cognitive network based on hybrid spectrum sharing,meanwhile considering the maximum transmit power,user quality of service(QoS)requirements,interference limitations,and primary user protection.The optimization of energy efficient sensing time and power allocation is formulated as a non-convex optimization problem.The Dinkelbach’s method is adopted to solve this problem and to transform the non-convex optimization problem in fractional form into an equivalent optimization problem in the form of subtraction.Then,an iterative power allocation algorithm is proposed to solve the optimization problem.The simulation results show the effectiveness of the proposed algorithms for energy-efficient resource allocation in the cognitive network.
基金supported by the National Natural Science Foundation of China(Nos.41374130 and 41604154)Opening Foundation of Sichuan Provincial Key Lab of Applied Nuclear Techniques in Geosciences(No.gnzds2014003)the Open Fund of Robot Technology Used for Special Environment Key Laboratory of Sichuan Province(13zxtk04)
文摘Effect factors of the absorption of the source,air,entrance window,and dead layer of a detector must be considered in the measurement of monoenergetic alpha particles,along with statistical noise and other factors that collectively cause the alpha spectrum to exhibit a well-known low-energy tail.Therefore,the estabUshment of an alpha spectrum detector response function from the perspective of a signaling system must consider the various factors mentioned above.The detector response function is the convolution of an alphaparticle pulse function,two exponential functions,and a Gaussian function,followed by calculation of the parameters of the detector response function using the weighted leastsquares fitting method as proposed in this paper.In our experiment,^(239)Pu alpha spectra were measured by a highresolution,passivated implanted planar silicon(PIPS)detector at 10 levels of vacuum and 10 source-detector distances.The spectrum-fitting results were excellent as evaluated by reduced Chi-square(x^2) and correlation coefficients.Finally,the variation of parameters with vacuum level and source-detector distance was studied.Results demonstrate that σ,τ_1,and τ_2 exhibit no obvious trend of variation with vacuum in the range 2000-20,000 mTorr,and at a confidence level of 95%,the values of τ_1 and τ_2 decline in a similar fashion with source-detector distance by the power exponential function,while the value of a declines linearly.
基金supported by the National Natural Science Foundation of China(Nos.41374130 and 41604154)Science and Technology Program of Sichuan,China(No.2017GZ0359)+1 种基金Science and Technology Support Program of Sichuan,China(No.2015JY0007)Open Foundation for Artificial Intelligence Key Laboratory of Sichuan Province of China(No.2016RYJ08)
文摘Efficiency is an important factor in quantitative and qualitative analysis of radionuclides, and the gamma point source efficiency is related to the radial angle,detection distance, and gamma-ray energy. In this work, on the basis of a back-propagation(BP) neural network model,a method to determine the gamma point source efficiency is developed and validated. The efficiency of the point sources ^(137)Cs and ^(60)Co at discrete radial angles, detection distances, and gamma-ray energies is measured, and the BP neural network prediction model is constructed using MATLAB. The gamma point source efficiencies at different radial angles, detection distances, and gamma-ray energies are predicted quickly and accurately using this nonlinear prediction model. The results show that the maximum error between the predicted and experimental values is 3.732% at 661.661 keV, 11π/24, and 35 cm, and those under other conditions are less than 3%. The gamma point source efficiencies obtained using the BP neural network model are in good agreement with experimental data.
文摘Purpose:To analyse the hereditary features of a Chinese pedigree with familial vitreous amyloidosis in Liaoning Province,China,and to investigate the correlation between the clinical appearance of the disease and transthyretin(TTR)gene mutation,including the locus and type of TTR gene mutation.Methods:Five patients (10 eyes) from one Chinese family were diagnosed with vitreous amyloidosis between July 1996 and April 2009.Family members were followed up subsequently,and peripheral venous blood was obtained from 13 subjects (including 2 patients,and 11 controls without clinical signs of disease).DNA samples were extracted and 4 exons of the TTR gene were amplified by polymerase chain reaction (PCR).The gene fragments were subjected to sequencing analysis.The results were analyzed with DNAMAN Windows 5.2.2.0 and Chromas sequence chart analysis software,TTR gene exons were compared between affected patients and normal controls.Results:Family pedigree analysis revealed that patients were distributed in three generations.Male and female subjects had equal prevalence,and only one parent of affected patients had signs of disease.TTR gene exon sequencing showed that the sequence of patients was identical to that of normal individuals.No TTR gene mutations were noted in 10 unaffected family members.However,a TTR Gly-54 point mutation in the 2nd exon was detected in two patients and 1 unaffected family member (one of the patients' daughters).Vitreous samples in 4 cases (7 eyes) showed positive Congo red staining,suggesting that these family members suffered from familial vitreous amyloidosis.Conclusion:This pedigree affected with familial vitreous amyloidosis was characterized by autosomal dominant inheritance;.a TTR Gly-54 point mutation in the 2nd exon is presumed to be the cause.This Gly-54 point mutation of the TTR gene is a novel mutation in vitreous amyloidosis.
