Metabolic syndrome(Met S)is a chronic disease associated with the disturbance of gut microbiota homeostasis.Metabolites derived from gut microbes play essential roles in Met S prevention and therapy.Here,we focused on...Metabolic syndrome(Met S)is a chronic disease associated with the disturbance of gut microbiota homeostasis.Metabolites derived from gut microbes play essential roles in Met S prevention and therapy.Here,we focused on the inhibitory effect of the extract of millet bran protein(EMBP)on a high-fat diet(HFD)-induced Met S,aiming to identify gut microbiota and their metabolites that involve in the anti-Met S activity of EMBP.The obesity,chronic inflammation,insulin resistance in Met S mouse models were abolished after EMBP treatment.The protective mechanism of EMBP against HFD-induced Met S may depend on improved gut barrier function.Using microbiome analysis,we found that EMBP supplementation improved gut microbiome dysbiosis in Met S mice,specifically upregulating Bacteroides acidifaciens.The fecal microbiota transplantation(FMT)also demonstrated this phenomenon.In addition,metabolomic analysis showed that EMBP mediates metabolic profiling reprogramming in Met S mice.Notably,a microbiota-derived metabolite,gamma-aminobutyric acid(GABA),is enriched by EMBP.In addition,exogenous GABA treatment produced a similar protective effect to EMBP by improving NRF2-dependent gut barrier function to protect HFDinduced Met S.The results suggest that EMBP suppress host Met S by remodeling of gut microbiota as an effective candidate for next-generation medicine food dual purpose dietary supplement to intervene in MetS.展开更多
Intercropping cereals and legumes is practiced widely in the world for improving yields and economic benefits. Shorter legume crops in intercropping are shaded by taller cereals, substantially reducing legume growth a...Intercropping cereals and legumes is practiced widely in the world for improving yields and economic benefits. Shorter legume crops in intercropping are shaded by taller cereals, substantially reducing legume growth and yield. Reducing shade in intercropping by shortening the plant height of cereals by seedling defoliation has been proposed as a practical approach to increase crop yields and land productivity. A two-year field experiment was conducted to investigate the effect of defoliation of cereal crops at seedling stage on the growth and yield of peanut(Arachis hypogaea L.) intercropped with corn(Zea mays L.) or millet(Setaria italica L.). In comparison with non-defoliation controls, defoliation reduced final plant height by 29 cm on average for corn and 18 cm for millet. Photosynthetically active radiation on peanut in intercropping systems with corn or millet intercropping was respectively 27.0% and 22.8% higher than those in controls, significantly improving the light environment of intercropped peanut. Net photosynthetic rates of peanut were on average 25.5% higher in corn and peanut intercropping and 19.6% higher in millet and peanut intercropping than those in non-defoliation controls. Total biomass of intercropped peanut increased owing to increased root growth. Across two years, yield of peanut intercropped with corn was 27.7% and with millet 32.8% higher than those of controls. Defoliation of cereal crops did not affect corn yield but significantly decreased millet yield by 24.5%. Our results suggest that applying seedling defoliation in intercropped corn could increase peanut yield without compromising corn yield in an intercropping system.展开更多
[ Objective ] This study aimed to obtain Phytolacca acinosa Roxb. polyploids and provide high-efficiency raw materials for the preparation of biological pesticides. [Method] Terminal bud growing points of Phytolacca a...[ Objective ] This study aimed to obtain Phytolacca acinosa Roxb. polyploids and provide high-efficiency raw materials for the preparation of biological pesticides. [Method] Terminal bud growing points of Phytolacca acinosa Roxb. seedlings were treated with 0.1%, 0.2%, 0.3% colchicine and 1% agar solution for 24, 48 and 72 h, respectively, while Phytolacca acinosa Roxb. without treatment was adopted as the control. The mutagenic effect of various concentrations of colchicine was calculated. Phytolacca acinosa Roxb. mutants were identified using morphological, anatomical and cytological methods. [ Result] Induction with 0. 2% colchicine for 48 h led to the highest mntagenic effect. Compared with the control, leaf width and leaf thickness of mutants were enhanced by 40. 15% and 33. 25%, respectively; vertical and horizontal diameter of stomata of mutants were enhanced by 30.25% and 60.82%, respectively ; the stomata density of mutants was improved by 150%. Identification of meiotic chromosome of pollen mother cells using compression method showed that the chromosome number of microspore cells of Phytolacca acinosa Roxb. mutants was n = 2 x = 36, while that of the control was n = x = 18, indicating that the mutants were tetraploids. [ Conclusion ] Phytolacca acinosa Roxb. polyploids were induced using the traditional liquid droplet method, which was easy and direct with simple operation and good effect to acquire a large number of polyploid materials within a short time.展开更多
Let n be a positive integer. For any integer a, we say that is idempotent modulo n if a2≡a(mod n). The n-modular Erdös-Burgess constant is the smallest positive integer l such that any l integers contain one...Let n be a positive integer. For any integer a, we say that is idempotent modulo n if a2≡a(mod n). The n-modular Erdös-Burgess constant is the smallest positive integer l such that any l integers contain one or more integers, whose product is idempotent modulo n. We gave a sharp lower bound of the n-modular Erdös-Burgess constant, in particular, we determined the n-modular Erdös-Burgess constant in the case when n was a prime power or a product of pairwise distinct primes.展开更多
Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well docu...Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well documented.Here,we examined the light interception and use efficiency in maize-peanut intercropping with different maize plant densities in two row configurations in semiarid dryland agriculture over a two-year period.The field experiment comprised four cropping systems,i.e.,monocropped maize,monocropped peanut,maize-peanut intercropping with two rows of maize and four rows of peanut,intercropping with four rows of maize and four rows of peanut,and three maize plant densities(3.0,4.5 and 6.0 plants m^(-1) row)in both monocropped and intercropping maize.The mean total light interception in intercropping across years and densities was 779 MJ·m^(-2),5.5%higher than in monocropped peanut(737 MJ·m^(-2))and 7.6%lower than in monocropped maize(843 MJ·m^(-2)).Increasing maize density increased light interception in monocropped maize but did not affect the total light interception in the intercrops.Across years the LUE of maize was 2.9 g·MJ–1 and was not affected by cropping system but increased with maize plant density.The LUE of peanut was enhanced in intercropping,especially in a wetter year.The yield advantage of maize-peanut intercropping resulted mainly from the LUE of peanut.These results will help to optimize agronomic management and system design and provide evidence for system level light use efficiency in intercropping.展开更多
Molecular targeted therapy has become an emerging promising strategy in cancer treatment,and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment.Our previous study fir...Molecular targeted therapy has become an emerging promising strategy in cancer treatment,and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment.Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran(FMBP)exhibited excellent targeting anti-colorectal cancer(CRC)activity in vivo and in vitro,whereas its underlying target remains unclear.The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78(cs GRP78)abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP,indicating it serves as a potential target of FMBP against CRC.Further,we demonstrated that the combination of FMBP with the nucleotide binding domain(NBD)of cs GRP78interfered with the downstream activation of signal transducer and activator of transcription 3(STAT3)in CRC cells,thus promoting the intracellular accumulation of reactive oxygen species(ROS)and cell grown inhibition.These phenomena were further confirmed in nude mice tumor model.Collectively,our study highlights cs GRP78 acts as an underlying target of FMBP against CRC,uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.展开更多
Light is one of the most important natural resources for plant growth. Light interception （LI） and use efficiency （LUE） are often affected by the structure of canopy caused by growing pattern and agronomy manageme...Light is one of the most important natural resources for plant growth. Light interception （LI） and use efficiency （LUE） are often affected by the structure of canopy caused by growing pattern and agronomy managements. Agro-nomy practices, such as the ridge-furrow system and plastic film cover, might affect the leaf morphology and then light transmission within the canopy, thus change light extinction coefficient （k）, and LI and LUE. The objective of this study is to quantify LI and LUE in rain-fed maize （Zea Mays L.）, a major cropping system in Northeast China, under different combinations of ridge-furrow and film covering ratios. The tested ridge-furrow system （DRF： ＂double ridges and furrows＂） was asymmetric and alternated with wide ridge （0.70 m in width and 0.15 m in height）, narrow furrow （0.10 m）, narrow ridge （0.40 m in width and 0.20 m in height）, and narrow furrow （0.10 m）. Field ex-periments were conducted in 2013 and 2014 in Jilin Province, Northeast China. Four treatments were tested： no ridges and plastic film cover （control, NRF）, ridges without film cover （DRF0）, ridges with 58% film cover （DRF58）, and ridges with 100% film cover （DRFl00）. DRF0 significantly increased LI by 9% compared with NRF, while film cover showed a marginal improvement. Specific leaf area in DRF experiments with film cover was significantly lower than in NRF, and leaf angle was 16% higher than in NRF, resulting in a 4% reduction in k. LUE of maize was not increased by DRF0, but was significantly enhanced by covering film in other DRF experiments, especially by 22% in DRF100. The increase of LUE by film cover was due to a greater biomass production and a lower assimilation portioning to vegetative organs, which caused a higher harvest index. The results could help farmers to optimize maize managements, especially in the region with decreased solar radiation under climate change.展开更多
Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resourc...Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resource use efficiency,lower input requirements,natural suppression of pests,pathogens and weeds,and building a soil with more organic carbon and nitrogen.Information is needed which species combinations perform best under different circumstances and which management is suitable to bring out the best from intercropping in a given production situation.The literature is replete with case studies on intercropping from across the globe,but evidence synthesis is needed to make this information accessible.Meta-analysis requires a careful choice of metric that is appropriate for answering the question at hand,and which lends itself for a robust meta-analysis.This paper reviews some metrics that may be used in the quantitative synthesis of literature data on intercropping.展开更多
Oxygen-assisted high temperature solid-state reaction approach was employed for the fabrication of Pr activated Ba(Mg_(0.28)Zr_(0.16)Ta_(0.56))O_(3)transparent ceramic phosphor.Retiveld refinement of X-ray diffraction...Oxygen-assisted high temperature solid-state reaction approach was employed for the fabrication of Pr activated Ba(Mg_(0.28)Zr_(0.16)Ta_(0.56))O_(3)transparent ceramic phosphor.Retiveld refinement of X-ray diffraction pattern was carried out to reveal the lattice parameters and crystal structural information.Under the blue-light excitation ofλ=473 nm,the phosphor exhibits a sharp intense red emission centered at645 nm,accompanied by several other weak peaks.PL evolution with temperature shows a significant luminescence quenching behavior,and the underlying multi-phonon interaction with optical center is revealed by proposing an unprecedent theoretical calculation work.Such a phonon effect is further confirmed from the red-shift of peak position with temperature,and the involved phonon energy of50.7 meV is determined from Raman scattering measurement.More interestingly,the fitted results of transient-state PL spectra show a fluctuation of luminescence lifetime at various temperatures,further indicating a significant effect of phonon vibration in the system.展开更多
Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound me...Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound measurement data were collected from 24 hospitals in 18 provinces of China from 1st September through 31st October of 2019.The estimated fetal weight(EFW)was calculated based on head circumference,abdominal circumference,and femur length using Hadlock formula 3.Fetal growth curves were estimated using a two-level linear regression model with cubic splines.All participants were divided into two groups:the northern group(n=5829)and the southern group(n=3246)based on the geographical division of China and male fetus group(n=4775)and female fetus group(n=4300)based on fetal gender.The EFW was compared by fetal gender and geographical group.All statistical models were adjusted for maternal sociodemographic characteristics.Results:A total of 9075 participants with 31,700 ultrasound measurement records were included in this study.Male fetuses demonstrated significantly larger EFW compared to female ones starting at 16 weeks of gestation and extending to delivery(global testP<0.01).The overall geographic difference in EFW was significant(global testP=0.03),and week-specific comparisons showed that the northern group had a greater EFW starting at 15 weeks of gestation and extending to 29 weeks of gestation,although this difference did not extend to the time of delivery.TheZ-score of EFW confirmed that our Chinese fetal growth charts differed from previously published standards.Conclusion:This study provides EFW and ultrasound biometric reference measurements for Chinese fetuses and reveals differences from other fetal growth charts.The chart is worth promoting in more regions of China but should be tested prudently before use.展开更多
基金supported by National Natural Science Foundation of China(32270420,32072220)National Key Research and Development Project(2020YFD1001405)+2 种基金Shanxi Province Science Foundation(202103021224011)Shanxi Key Laboratory for Research and Development of Regional PlantsShanxi Province“136”Revitalization Medical Project Construction Funds。
文摘Metabolic syndrome(Met S)is a chronic disease associated with the disturbance of gut microbiota homeostasis.Metabolites derived from gut microbes play essential roles in Met S prevention and therapy.Here,we focused on the inhibitory effect of the extract of millet bran protein(EMBP)on a high-fat diet(HFD)-induced Met S,aiming to identify gut microbiota and their metabolites that involve in the anti-Met S activity of EMBP.The obesity,chronic inflammation,insulin resistance in Met S mouse models were abolished after EMBP treatment.The protective mechanism of EMBP against HFD-induced Met S may depend on improved gut barrier function.Using microbiome analysis,we found that EMBP supplementation improved gut microbiome dysbiosis in Met S mice,specifically upregulating Bacteroides acidifaciens.The fecal microbiota transplantation(FMT)also demonstrated this phenomenon.In addition,metabolomic analysis showed that EMBP mediates metabolic profiling reprogramming in Met S mice.Notably,a microbiota-derived metabolite,gamma-aminobutyric acid(GABA),is enriched by EMBP.In addition,exogenous GABA treatment produced a similar protective effect to EMBP by improving NRF2-dependent gut barrier function to protect HFDinduced Met S.The results suggest that EMBP suppress host Met S by remodeling of gut microbiota as an effective candidate for next-generation medicine food dual purpose dietary supplement to intervene in MetS.
基金funded by National Key Research and Development Program of China(2016YFD0300202)China Agriculture Research System(CARS-08-G09)+1 种基金National Natural Science Foundation of China(32071551)Liao Ning Revitalization Talents Program(XLYC1907089)。
文摘Intercropping cereals and legumes is practiced widely in the world for improving yields and economic benefits. Shorter legume crops in intercropping are shaded by taller cereals, substantially reducing legume growth and yield. Reducing shade in intercropping by shortening the plant height of cereals by seedling defoliation has been proposed as a practical approach to increase crop yields and land productivity. A two-year field experiment was conducted to investigate the effect of defoliation of cereal crops at seedling stage on the growth and yield of peanut(Arachis hypogaea L.) intercropped with corn(Zea mays L.) or millet(Setaria italica L.). In comparison with non-defoliation controls, defoliation reduced final plant height by 29 cm on average for corn and 18 cm for millet. Photosynthetically active radiation on peanut in intercropping systems with corn or millet intercropping was respectively 27.0% and 22.8% higher than those in controls, significantly improving the light environment of intercropped peanut. Net photosynthetic rates of peanut were on average 25.5% higher in corn and peanut intercropping and 19.6% higher in millet and peanut intercropping than those in non-defoliation controls. Total biomass of intercropped peanut increased owing to increased root growth. Across two years, yield of peanut intercropped with corn was 27.7% and with millet 32.8% higher than those of controls. Defoliation of cereal crops did not affect corn yield but significantly decreased millet yield by 24.5%. Our results suggest that applying seedling defoliation in intercropped corn could increase peanut yield without compromising corn yield in an intercropping system.
文摘[ Objective ] This study aimed to obtain Phytolacca acinosa Roxb. polyploids and provide high-efficiency raw materials for the preparation of biological pesticides. [Method] Terminal bud growing points of Phytolacca acinosa Roxb. seedlings were treated with 0.1%, 0.2%, 0.3% colchicine and 1% agar solution for 24, 48 and 72 h, respectively, while Phytolacca acinosa Roxb. without treatment was adopted as the control. The mutagenic effect of various concentrations of colchicine was calculated. Phytolacca acinosa Roxb. mutants were identified using morphological, anatomical and cytological methods. [ Result] Induction with 0. 2% colchicine for 48 h led to the highest mntagenic effect. Compared with the control, leaf width and leaf thickness of mutants were enhanced by 40. 15% and 33. 25%, respectively; vertical and horizontal diameter of stomata of mutants were enhanced by 30.25% and 60.82%, respectively ; the stomata density of mutants was improved by 150%. Identification of meiotic chromosome of pollen mother cells using compression method showed that the chromosome number of microspore cells of Phytolacca acinosa Roxb. mutants was n = 2 x = 36, while that of the control was n = x = 18, indicating that the mutants were tetraploids. [ Conclusion ] Phytolacca acinosa Roxb. polyploids were induced using the traditional liquid droplet method, which was easy and direct with simple operation and good effect to acquire a large number of polyploid materials within a short time.
基金supported by NSFC(Grant No.61303023,11301381,11501561).
文摘Let n be a positive integer. For any integer a, we say that is idempotent modulo n if a2≡a(mod n). The n-modular Erdös-Burgess constant is the smallest positive integer l such that any l integers contain one or more integers, whose product is idempotent modulo n. We gave a sharp lower bound of the n-modular Erdös-Burgess constant, in particular, we determined the n-modular Erdös-Burgess constant in the case when n was a prime power or a product of pairwise distinct primes.
基金This research was funded by the National Key R&D Program of China(2016YFD0300202)the China Institute of Water Resources and Hydropower Research Team Construction and Talent Development Project(JZ0145B752017)+1 种基金the International Cooperation and Exchange of the National Science Foundation of China(31461143025)The work was partly funded by the European Union through the Horizon 2020 Program for Research and Innovation under grant agreement No.727217(ReMIX:redesigning European cropping systems based on species MIXtures).
文摘Intercropping increases crop yields by optimizing light interception and/or use efficiency.Although intercropping combinations and metrics have been reported,the effects of plant density on light use are not well documented.Here,we examined the light interception and use efficiency in maize-peanut intercropping with different maize plant densities in two row configurations in semiarid dryland agriculture over a two-year period.The field experiment comprised four cropping systems,i.e.,monocropped maize,monocropped peanut,maize-peanut intercropping with two rows of maize and four rows of peanut,intercropping with four rows of maize and four rows of peanut,and three maize plant densities(3.0,4.5 and 6.0 plants m^(-1) row)in both monocropped and intercropping maize.The mean total light interception in intercropping across years and densities was 779 MJ·m^(-2),5.5%higher than in monocropped peanut(737 MJ·m^(-2))and 7.6%lower than in monocropped maize(843 MJ·m^(-2)).Increasing maize density increased light interception in monocropped maize but did not affect the total light interception in the intercrops.Across years the LUE of maize was 2.9 g·MJ–1 and was not affected by cropping system but increased with maize plant density.The LUE of peanut was enhanced in intercropping,especially in a wetter year.The yield advantage of maize-peanut intercropping resulted mainly from the LUE of peanut.These results will help to optimize agronomic management and system design and provide evidence for system level light use efficiency in intercropping.
基金supported by National Natural Science Foundation of China(Nos.31500630,31770382,32072220,and 81803238)“1331 Project”Key Innovation Center and Team,National Key Research and Development Project(No.2020YFD1001405,China)+1 种基金Shanxi Key Laboratory for Research and Development of Regional Plants,Higher Education Institution Project of Shanxi Province:Ecological Remediation of Soil Pollution Disciplines Group(No.20181401,China)the Open Project Program of Xinghuacun College of Shanxi University[Shanxi Institute of Brewing Technology and Industry(Preparation)](No.XCSXUKF-202004,China)。
文摘Molecular targeted therapy has become an emerging promising strategy in cancer treatment,and screening the agents targeting at cancer cell specific targets is very desirable for cancer treatment.Our previous study firstly found that a secretory peroxidase of class III derived from foxtail millet bran(FMBP)exhibited excellent targeting anti-colorectal cancer(CRC)activity in vivo and in vitro,whereas its underlying target remains unclear.The highlight of present study focuses on the finding that cell surface glucose-regulated protein 78(cs GRP78)abnormally located on CRC is positively correlated with the anti-CRC effects of FMBP,indicating it serves as a potential target of FMBP against CRC.Further,we demonstrated that the combination of FMBP with the nucleotide binding domain(NBD)of cs GRP78interfered with the downstream activation of signal transducer and activator of transcription 3(STAT3)in CRC cells,thus promoting the intracellular accumulation of reactive oxygen species(ROS)and cell grown inhibition.These phenomena were further confirmed in nude mice tumor model.Collectively,our study highlights cs GRP78 acts as an underlying target of FMBP against CRC,uncovering the clinical potential of FMBP as a targeted agent for CRC in the future.
基金Supported by the National Key Research and Development Program of China(2016YFD0300202)International Cooperation and Exchange Program of National Natural Science Foundation of China(31461143025)“948”Program(2011-G19)
文摘Light is one of the most important natural resources for plant growth. Light interception （LI） and use efficiency （LUE） are often affected by the structure of canopy caused by growing pattern and agronomy managements. Agro-nomy practices, such as the ridge-furrow system and plastic film cover, might affect the leaf morphology and then light transmission within the canopy, thus change light extinction coefficient （k）, and LI and LUE. The objective of this study is to quantify LI and LUE in rain-fed maize （Zea Mays L.）, a major cropping system in Northeast China, under different combinations of ridge-furrow and film covering ratios. The tested ridge-furrow system （DRF： ＂double ridges and furrows＂） was asymmetric and alternated with wide ridge （0.70 m in width and 0.15 m in height）, narrow furrow （0.10 m）, narrow ridge （0.40 m in width and 0.20 m in height）, and narrow furrow （0.10 m）. Field ex-periments were conducted in 2013 and 2014 in Jilin Province, Northeast China. Four treatments were tested： no ridges and plastic film cover （control, NRF）, ridges without film cover （DRF0）, ridges with 58% film cover （DRF58）, and ridges with 100% film cover （DRFl00）. DRF0 significantly increased LI by 9% compared with NRF, while film cover showed a marginal improvement. Specific leaf area in DRF experiments with film cover was significantly lower than in NRF, and leaf angle was 16% higher than in NRF, resulting in a 4% reduction in k. LUE of maize was not increased by DRF0, but was significantly enhanced by covering film in other DRF experiments, especially by 22% in DRF100. The increase of LUE by film cover was due to a greater biomass production and a lower assimilation portioning to vegetative organs, which caused a higher harvest index. The results could help farmers to optimize maize managements, especially in the region with decreased solar radiation under climate change.
文摘Intercropping is the planned cultivation of species mixtures on agricultural land.Intercropping has many attributes that make it attractive for developing a more sustainable agriculture,such as high yield,high resource use efficiency,lower input requirements,natural suppression of pests,pathogens and weeds,and building a soil with more organic carbon and nitrogen.Information is needed which species combinations perform best under different circumstances and which management is suitable to bring out the best from intercropping in a given production situation.The literature is replete with case studies on intercropping from across the globe,but evidence synthesis is needed to make this information accessible.Meta-analysis requires a careful choice of metric that is appropriate for answering the question at hand,and which lends itself for a robust meta-analysis.This paper reviews some metrics that may be used in the quantitative synthesis of literature data on intercropping.
基金Project supported by the National Natural Science Foundation of China of China(51902144)the Natural Science Foundation of Jiangsu Province(CN)(BK20191003)。
文摘Oxygen-assisted high temperature solid-state reaction approach was employed for the fabrication of Pr activated Ba(Mg_(0.28)Zr_(0.16)Ta_(0.56))O_(3)transparent ceramic phosphor.Retiveld refinement of X-ray diffraction pattern was carried out to reveal the lattice parameters and crystal structural information.Under the blue-light excitation ofλ=473 nm,the phosphor exhibits a sharp intense red emission centered at645 nm,accompanied by several other weak peaks.PL evolution with temperature shows a significant luminescence quenching behavior,and the underlying multi-phonon interaction with optical center is revealed by proposing an unprecedent theoretical calculation work.Such a phonon effect is further confirmed from the red-shift of peak position with temperature,and the involved phonon energy of50.7 meV is determined from Raman scattering measurement.More interestingly,the fitted results of transient-state PL spectra show a fluctuation of luminescence lifetime at various temperatures,further indicating a significant effect of phonon vibration in the system.
基金supported by the National Key R&D Program of China(2018YFC1002900)。
文摘Objective:To build a reference fetal growth chart for the Chinese population based on fetal ultrasound measurements.Methods:This was a multicenter,population-based retrospective cohort study.Longitudinal ultrasound measurement data were collected from 24 hospitals in 18 provinces of China from 1st September through 31st October of 2019.The estimated fetal weight(EFW)was calculated based on head circumference,abdominal circumference,and femur length using Hadlock formula 3.Fetal growth curves were estimated using a two-level linear regression model with cubic splines.All participants were divided into two groups:the northern group(n=5829)and the southern group(n=3246)based on the geographical division of China and male fetus group(n=4775)and female fetus group(n=4300)based on fetal gender.The EFW was compared by fetal gender and geographical group.All statistical models were adjusted for maternal sociodemographic characteristics.Results:A total of 9075 participants with 31,700 ultrasound measurement records were included in this study.Male fetuses demonstrated significantly larger EFW compared to female ones starting at 16 weeks of gestation and extending to delivery(global testP<0.01).The overall geographic difference in EFW was significant(global testP=0.03),and week-specific comparisons showed that the northern group had a greater EFW starting at 15 weeks of gestation and extending to 29 weeks of gestation,although this difference did not extend to the time of delivery.TheZ-score of EFW confirmed that our Chinese fetal growth charts differed from previously published standards.Conclusion:This study provides EFW and ultrasound biometric reference measurements for Chinese fetuses and reveals differences from other fetal growth charts.The chart is worth promoting in more regions of China but should be tested prudently before use.
