The three-dimensional displacements caused by ocean loading effects are significant enough to impact spatial geodetic measurements on sub-daily or longer timescales,particularly in the vertical direction.Currently,mos...The three-dimensional displacements caused by ocean loading effects are significant enough to impact spatial geodetic measurements on sub-daily or longer timescales,particularly in the vertical direction.Currently,most tide models incorporate the distribution of vertical displacement loading tides;however,their accuracy has not been assessed for the equatorial and Indian Ocean regions.Global Positioning System(GPS)observations provide high-precision data on sea-level changes,enabling the assessment of the accuracy and reliability of vertical displacement tide models.However,because the tidal period of the K_(2) constituent is almost identical to the orbital period of GPS constellations,the estimation of the K_(2) tidal constituent from GPS observations is not satisfactory.In this study,the principle of smoothness is employed to correct the systematic error in K_(2) estimates in GPS observations through quadratic fitting.Using the adjusted harmonic constants from 31 GPS stations for the equatorial and Indian Ocean,the accuracy of eight major constituents from five global vertical displacement tide models(FES2014,EOT11a,GOT4.10c,GOT4.8,and NAO.99b)is evaluated for the equatorial and Indian Ocean.The results indicate that the EOT11a and FES2014 models exhibit higher accuracy in the vertical displacement tide models for the equatorial and Indian Ocean,with root sum squares errors of 2.29 mm and 2.34 mm,res-pectively.Furthermore,a brief analysis of the vertical displacement tide distribution characteristics of the eight major constituents for the equatorial and Indian Ocean was conducted using the EOT11a model.展开更多
Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine mont...Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine months daily WWS for severe acute respiratory syndrome coronavirus 2(SARSCoV-2)from 12 wastewater treatment plants(WWTPs),covering approximately 80%of the population,to monitor infection dynamics in Hong Kong,China.We found that the SARS-CoV-2 virus concentration in wastewater was correlated with the daily number of reported cases and reached two pandemic peaks three days earlier during the study period.In addition,two different methods were established to estimate the prevalence/incidence rates from wastewater measurements.The estimated results from wastewater were consistent with findings from two independent citywide clinical surveillance programmes(rapid antigen test(RAT)surveillance and serology surveillance),but higher than the cases number reported by the Centre for Health Protection(CHP)of Hong Kong,China.Moreover,the effective reproductive number(R_(t))was estimated from wastewater measurements to reflect both citywide and regional transmission dynamics.Our findings demonstrate that large-scale intensive WWS from WWTPs provides cost-effective and timely public health information,especially when the clinical surveillance is inadequate and costly.This approach also provides insights into pandemic dynamics at higher spatiotemporal resolutions,facilitating the formulation of effective control policies and targeted resource allocation.展开更多
Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from...Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.展开更多
Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production.It has been difficult to meet the needs of the field wit...Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production.It has been difficult to meet the needs of the field with the usual prediction model of mechanical properties of hotrolled strip.Insufficient data and difficult parameter adjustment limit deep learning models based on multi-layer networks in practical applications;besides,the limited discrete process parameters used make it impossible to effectively depict the actual strip processing process.In order to solve these problems,this research proposed a new sampling approach for mechanical characteristics input data of hot-rolled strip based on the multi-grained cascade forest(gcForest)framework.According to the characteristics of complex process flow and abnormal sensitivity of process path and parameters to product quality in the hot-rolled strip production,a three-dimensional continuous time series process data sampling method based on time-temperature-deformation was designed.The basic information of strip steel(chemical composition and typical process parameters)is fused with the local process information collected by multi-grained scanning,so that the next link’s input has both local and global features.Furthermore,in the multi-grained scanning structure,a sub sampling scheme with a variable window was designed,so that input data with different dimensions can get output characteristics of the same dimension after passing through the multi-grained scanning structure,allowing the cascade forest structure to be trained normally.Finally,actual production data of three steel grades was used to conduct the experimental evaluation.The results revealed that the gcForest-based mechanical property prediction model outperforms the competition in terms of comprehensive performance,ease of parameter adjustment,and ability to sustain high prediction accuracy with fewer samples.展开更多
The teleseismic receiver functions of digital seismic network of Ningxia and its adjacent area are calculated with two different Gauss filter factors. The accuracy and stability of the receiver functions are discussed...The teleseismic receiver functions of digital seismic network of Ningxia and its adjacent area are calculated with two different Gauss filter factors. The accuracy and stability of the receiver functions are discussed. The h-k stacking method is applied to estimate the crustal thickness and velocity ratio beneath seismic stations. The results indicate that there are sharp changes of crustal thickness and velocity ratio in the studied region. This region is located in the northeastern margin of Tibet, and also a junction of several first-grade blocks. The large contrast of crustal structure in this region is considered to be resulted from the interaction of these blocks. Our results are helpful to construct the completed model of the formation and evolution of the Tibet. Some local structures are also discussed combining with the geological faults.展开更多
Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical con...Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical converter with double push rods is proposed in this paper, which can simultaneously output two electromagnetic forces, can push or pull the valve core and sleeve according to the current direction and realize rapid operation of load. According to the electromagnetic principle and the magnetic circuit analysis method, the mathematical model and equivalent circuit of the electromechanical converter with double push rods are established. Through the finite element simulation model of the electromechanical converter with double push rods with the same magnetization directions, the changing rules of its magnetic field distribution and force–displacement behaviors are studied and analyzed. According to the analysis results, the electromagnetic mechanical parameters and mechanical structure of the electromechanical converter with double push rods are determined, and the prototype is made. The test platform for the push-pull characteristics of the electromechanical converter with double push rods is built, and its static and dynamic characteristics are tested and analyzed. The results show that the thrust and pull output characteristics of the internal and external push rods are basically consistent with the simulation output, and proportional to the current density of the coil;the push-pull hysteresis of internal and external push rods output force is less than 5%;and the dynamic time response characteristics of the displacement and force are obtained. The hysteresis e ect of output force is improved e ectively through the H bridge drive control circuit modulated by PWM. Compared with the displacement response of a singlewinding electromagnet with a similar volume, it can e ectively improve the dynamic displacement response. Followup work will further optimize the structure of the electromechanical converter and test the corresponding pilot valve. The research results provide a new theory for improving the output characteristics of electro-hydraulic pilot valve and have an extremely high engineering application value and broad application prospect.展开更多
Inflammatory stimulation plays a significant role in the development and worsening of insulin-resistant diabetes.Therefore,it is crucial to identify therapeutic agents that can alleviate insulin resistance by targetin...Inflammatory stimulation plays a significant role in the development and worsening of insulin-resistant diabetes.Therefore,it is crucial to identify therapeutic agents that can alleviate insulin resistance by targeting inflammation.Here,we present evidence that Bakuchiol(BL),a monoterpene phenolic compound first discovered from Psoralea corylifolia L.as traditional Chinese medicine,can effectively improve insulin resistance in diabetic mice through anti-inflammation.Our findings demonstrate that BL alleviates inflammation by inhibiting the toll-like receptor 4/nuclear factorκB/mitogen-activated protein kinase axis,consequently enhancing insulin receptor signaling through the c-Jun N-terminal kinase/suppressors of cytokine signaling 3/insulin receptor substrate1 pathway and improving glucolipid homeostasis.Furthermore,the insulin recovery achieved with BL(60 mg/kg)was comparable to that of metformin(200 mg/kg).These results provide further support for considering BL as a potential treatment option for insulin-resistant diabetes mellitus.展开更多
Tissue engineering is an interdisciplinary field that integrates medical,biological,and engineering expertise to restore or regenerate the functionality of healthy tissues and organs.The three fundamental pillars of t...Tissue engineering is an interdisciplinary field that integrates medical,biological,and engineering expertise to restore or regenerate the functionality of healthy tissues and organs.The three fundamental pillars of tissue engineering are scaffolds,cells,and biomolecules.Electrospun nanofibers have been successfully used as scaffolds for a variety of tissue engineering applications because they are biomimetic of the natural,fibrous extracellular matrix(ECM)and contain a three-dimensional(3D)network of interconnected pores.In this review,we provide an overview of the electrospinning process,its principles,and the application of the resultant electrospun nanofibers for tissue engineering.We first briefly introduce the electrospinning process and then cover its principles and standard equipment for biomaterial fabrication.Next,we highlight the most important and recent advances related to the applications of electrospun nanofibers in tissue engineering,including skin,blood vessels,nerves,bone,cartilage,and tendon/ligament applications.Finally,we conclude with current advancements in the fabrication of electrospun nanofiber scaffolds and their biomedical applications in emerging areas.展开更多
Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects.Exopolysaccharides from lactic acid bacter...Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects.Exopolysaccharides from lactic acid bacteria(LAB-EPS)are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and metabolism.Numerous studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in livestock.They are biodegradable,nontoxic and bio-compatible,which are considered as ideal alternatives to antibiotics.This review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals,and thus provide scientific justification for commercial applications of LAB-EPS in livestock.展开更多
Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,f...Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,finer resolution and spatially continuous imper-vious areas information remains scarce in the Arctic.In this study,we developed an accurate and complete circumpolar Arctic Man-made impervious areas(CAMI)map at a resolution of 10 m by combining Sentinel-1 C-band Synthetic Aperture Radar,Sentinel-2 multispectral images,OpenStreetMap,and ArcticDEM via Google Earth Engine platform.A random forest classifier model was trained and used to generate corresponding impervious areas map for the year 2020.The evaluation results suggested that CAMI was the most accurate with an overall accuracy of 86.36%and kappa coefficient of 70.73%as against the three existing impervious areas products.Based on the generated map and OpenStreetMap,we estimated that total imper-vious areas area in the Arctic has achieved 807.80 km2,of which roads,industrial and resident land were three major land use types,accounting for 54.08%,17.85%and 10.34%,respectively.The CAMI map will support for new application and provide advanced insight into the infrastructure vulnerability evaluation and environmental sustainability in the Arctic.展开更多
The Arctic,located at the northernmost part of the Earth,plays a disproportionately crucial role in regulating global climate and affecting the surface energy balance[1].Over the past decades,a multitude of environmen...The Arctic,located at the northernmost part of the Earth,plays a disproportionately crucial role in regulating global climate and affecting the surface energy balance[1].Over the past decades,a multitude of environmental changes have been observed in the terrestrial section of the Arctic,including permafrost thawing,land ice retreat,and vegetation greening/browning.These changes not only threat the delicate network of the high-latitude biomes,but also influence human communities far beyond the Arctic limits[2].展开更多
BACKGROUND: For many years, yeast cell walls (YCW) and mannan oligosaccharides (MOS) have been used as alternatives to antibiotics and health feed additives to enhance the growth performance and health of food an...BACKGROUND: For many years, yeast cell walls (YCW) and mannan oligosaccharides (MOS) have been used as alternatives to antibiotics and health feed additives to enhance the growth performance and health of food animals. In the present study, the inhibitory effects of YCW and MOS on the adhesion of enteropathogenic bacteria to intestinal epithelial cells were tested. METHODS: YCW and MOS were extracted from Saccharomyces cerevisiae (XM 0315), and the morphology of YCW and MOS bound to pathogenic bacteria was observed by scanning electron microscopy (SEM). Real-time fluorescent quantitative PCR was used to quantitatively analyze the effects of YCW and MOS on the adhesion of Escherichia coli (CVCC3367) and Salmonella pullorum (CVCC520) to Caco-2 cells. RESULTS: The results showed that YCW inhibited E. coli and S. pullorum binding to Caco-2 cells by 95% and 74%, respectively, whereas MOS prevented E. coli and S. pullorum binding by 67% and 50%, respectively. CONCLUSIONS: These data suggest that YCW has a stronger ability than MOS to inhibit pathogenic bacteria from adhering to Caco-2 cells in vitro.展开更多
Plague,caused by Yersinia pestis,is a natural focus infectious disease.In China,plague is classified as category A,with the highest risk and hazard among the infectious diseases.Qinghai used to be considered as one of...Plague,caused by Yersinia pestis,is a natural focus infectious disease.In China,plague is classified as category A,with the highest risk and hazard among the infectious diseases.Qinghai used to be considered as one of the most serious areas of plague in China.In recent years,thank to the measures in eight aspects summarized as the“Qinghai model”which were adopted to prevent and control the human plague in Qinghai,Qinghai has not experienced any plague case reported for eight years.In early 2020,coronavirus disease 2019(COVID-19)outbroke in China.The Qinghai model on plague was employed to deal with the COVID-19 emergency in Qinghai Province.The Qinghai Center for Disease Control and Prevention(Qinghai CDC)and hospitals,along with the departments of public security,animal husbandry and other departments,quickly tracked and treated the patients with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and started surveillance programs on close contacts timely.At present,the cure rate of patients has reached 100%,and close contacts have been effectively quarantined and tested to avoid the spread of COVID-19.The findings from the study suggest that the prevention and control measures undertaken in Qinghai Province might be effective in dealing with the category A infectious diseases such as COVID-19 and other diseases.展开更多
A combinational therapeutic system that simultaneously administrates various pathways is preferred for anti-cancer treatment.In the present study,we successfully constructed a co-delivery system,multivesicular liposom...A combinational therapeutic system that simultaneously administrates various pathways is preferred for anti-cancer treatment.In the present study,we successfully constructed a co-delivery system,multivesicular liposomes(MVLs)co-encapsulating doxorubicin(DOX)and luminespib(AUY922).A simple and accurate dual-wavelength spectrophotometric method was established for the determination of DOX and AUY922 in liposomal formulation.MVL-loading drugs were prepared by a multi-emulsion solvent evaporation method,which exhibited excellent physicochemical properties,such as particle size of 3–8μm and high entrapment efficiency above 95%for DOX and 73%for AUY922.The synergetic cytotoxic effect for these two drugs was evaluated in MDA-MB-231 cells.The in vitro antitumor studies demonstrated the superior anti-proliferation activity of DOX and AUY922 with a combination index of 0.43,indicating a great synergistic effect.The experimental data suggested that combinational use of DOX and AUY922 within liposomes could be an effective way to develop efficient treatments of cancers.展开更多
基金The Shandong Provincial Natural Science Foundation under contract No.ZR2023QD045the National Natural Science Foundation of China under contract Nos 42406026,42076024 and 42106032supported by the Taishan Scholar Program under contract No.tstp20221148。
文摘The three-dimensional displacements caused by ocean loading effects are significant enough to impact spatial geodetic measurements on sub-daily or longer timescales,particularly in the vertical direction.Currently,most tide models incorporate the distribution of vertical displacement loading tides;however,their accuracy has not been assessed for the equatorial and Indian Ocean regions.Global Positioning System(GPS)observations provide high-precision data on sea-level changes,enabling the assessment of the accuracy and reliability of vertical displacement tide models.However,because the tidal period of the K_(2) constituent is almost identical to the orbital period of GPS constellations,the estimation of the K_(2) tidal constituent from GPS observations is not satisfactory.In this study,the principle of smoothness is employed to correct the systematic error in K_(2) estimates in GPS observations through quadratic fitting.Using the adjusted harmonic constants from 31 GPS stations for the equatorial and Indian Ocean,the accuracy of eight major constituents from five global vertical displacement tide models(FES2014,EOT11a,GOT4.10c,GOT4.8,and NAO.99b)is evaluated for the equatorial and Indian Ocean.The results indicate that the EOT11a and FES2014 models exhibit higher accuracy in the vertical displacement tide models for the equatorial and Indian Ocean,with root sum squares errors of 2.29 mm and 2.34 mm,res-pectively.Furthermore,a brief analysis of the vertical displacement tide distribution characteristics of the eight major constituents for the equatorial and Indian Ocean was conducted using the EOT11a model.
基金financially supported by the Health and Medical Research Fund(COVID1903015)the Food and Health Bureau,the Government of the Hong Kong Special Administrative Region(SAR),China+1 种基金supported by the AIR@InnoHK(KL,GML,and JTW)Health@InnoHK(MP and LLMP)administered by the Innovation and Technology Commission of the Government of the Hong Kong SAR.
文摘Wastewater surveillance(WWS)can leverage its wide coverage,population-based sampling,and high monitoring frequency to capture citywide pandemic trends independent of clinical surveillance.Here we conducted a nine months daily WWS for severe acute respiratory syndrome coronavirus 2(SARSCoV-2)from 12 wastewater treatment plants(WWTPs),covering approximately 80%of the population,to monitor infection dynamics in Hong Kong,China.We found that the SARS-CoV-2 virus concentration in wastewater was correlated with the daily number of reported cases and reached two pandemic peaks three days earlier during the study period.In addition,two different methods were established to estimate the prevalence/incidence rates from wastewater measurements.The estimated results from wastewater were consistent with findings from two independent citywide clinical surveillance programmes(rapid antigen test(RAT)surveillance and serology surveillance),but higher than the cases number reported by the Centre for Health Protection(CHP)of Hong Kong,China.Moreover,the effective reproductive number(R_(t))was estimated from wastewater measurements to reflect both citywide and regional transmission dynamics.Our findings demonstrate that large-scale intensive WWS from WWTPs provides cost-effective and timely public health information,especially when the clinical surveillance is inadequate and costly.This approach also provides insights into pandemic dynamics at higher spatiotemporal resolutions,facilitating the formulation of effective control policies and targeted resource allocation.
基金Supported by the National Key Research and Development Program of China(No.2017YFC1404402)the National Natural Science Foundation of China(Nos.41620104001,41806131)+1 种基金the Scientific and Technological Innovation Project of the Qingdao National Laboratory for Marine Science and Technology(No.2016ASKJ02)the China Postdoctoral Science Foundation(No.2018M632722)。
文摘Illumina sequencing and quantitative PCR(qPCR)based on the 16 S ribosomal RNA(rRNA)gene were conducted to characterize the vertical distribution of bacterial and archaeal communities in the sediments of two sites from the South Yellow Sea.Both bacterial and archaeal communities showed a clear stratified distribution with sediment depth.The microbial communities in the upper layers were distinct from those in the deeper layers;the relative abundances of sequences of Thaumarchaeota,Gammaproteobacteria,and Actinobacteria were higher in the upper than in the deeper sediments,whereas the sequences of Bathyarchaeia,Lokiarchaeota,Euryarchaeota,Chloroflexi,and Deltaproteobacteria were relatively more abundant in the deeper sediments.Sediment depth and total organic carbon(TOC)can significantly influence both the bacterial and archaeal communities.Furthermore,bacterial and archaeal groups potentially involved in nitrogen,sulfur,and methane metabolism were detected in both sites.In our study,both ammonia-oxidizing bacteria(Nitrospira)and ammonia-oxidizing archaea(Candidatus Nitrosopumilus)were responsible for ammonia oxidization.Additionally,sulfur-reducing bacteria SEEP-SRB1 forming consortia with anaerobic methane-oxidizing archaea ANME-2 a-2 b were capable of anaerobic methane oxidation(AOM)in the 3400-02 sediment samples.
基金financially supported by the National Natural Science Foundation of China(No.52004029)the Fundamental Research Funds for the Central Universities,China(No.FRF-TT-20-06).
文摘Higher requirements for the accuracy of relevant models are put throughout the transformation and upgrade of the iron and steel sector to intelligent production.It has been difficult to meet the needs of the field with the usual prediction model of mechanical properties of hotrolled strip.Insufficient data and difficult parameter adjustment limit deep learning models based on multi-layer networks in practical applications;besides,the limited discrete process parameters used make it impossible to effectively depict the actual strip processing process.In order to solve these problems,this research proposed a new sampling approach for mechanical characteristics input data of hot-rolled strip based on the multi-grained cascade forest(gcForest)framework.According to the characteristics of complex process flow and abnormal sensitivity of process path and parameters to product quality in the hot-rolled strip production,a three-dimensional continuous time series process data sampling method based on time-temperature-deformation was designed.The basic information of strip steel(chemical composition and typical process parameters)is fused with the local process information collected by multi-grained scanning,so that the next link’s input has both local and global features.Furthermore,in the multi-grained scanning structure,a sub sampling scheme with a variable window was designed,so that input data with different dimensions can get output characteristics of the same dimension after passing through the multi-grained scanning structure,allowing the cascade forest structure to be trained normally.Finally,actual production data of three steel grades was used to conduct the experimental evaluation.The results revealed that the gcForest-based mechanical property prediction model outperforms the competition in terms of comprehensive performance,ease of parameter adjustment,and ability to sustain high prediction accuracy with fewer samples.
基金supported by the basic research and development fund from Institute of Earthquake Science,China Earthquake Administration(grant No.2011IESLZ05)the National Natural Science Foundation of China(grant No.40904014)
文摘The teleseismic receiver functions of digital seismic network of Ningxia and its adjacent area are calculated with two different Gauss filter factors. The accuracy and stability of the receiver functions are discussed. The h-k stacking method is applied to estimate the crustal thickness and velocity ratio beneath seismic stations. The results indicate that there are sharp changes of crustal thickness and velocity ratio in the studied region. This region is located in the northeastern margin of Tibet, and also a junction of several first-grade blocks. The large contrast of crustal structure in this region is considered to be resulted from the interaction of these blocks. Our results are helpful to construct the completed model of the formation and evolution of the Tibet. Some local structures are also discussed combining with the geological faults.
基金Supported by National Natural Science Foundation for Young Scientists of China(Grant No.51505317)Shanxi Provincial Natural Science Foundation of China(Grant No.201601D102039)
文摘Due to the influence of material characteristics and winding power, single output electromagnet has limited ability to improve the dynamic characteristic of electro-hydraulic valve. Therefore, an electromechanical converter with double push rods is proposed in this paper, which can simultaneously output two electromagnetic forces, can push or pull the valve core and sleeve according to the current direction and realize rapid operation of load. According to the electromagnetic principle and the magnetic circuit analysis method, the mathematical model and equivalent circuit of the electromechanical converter with double push rods are established. Through the finite element simulation model of the electromechanical converter with double push rods with the same magnetization directions, the changing rules of its magnetic field distribution and force–displacement behaviors are studied and analyzed. According to the analysis results, the electromagnetic mechanical parameters and mechanical structure of the electromechanical converter with double push rods are determined, and the prototype is made. The test platform for the push-pull characteristics of the electromechanical converter with double push rods is built, and its static and dynamic characteristics are tested and analyzed. The results show that the thrust and pull output characteristics of the internal and external push rods are basically consistent with the simulation output, and proportional to the current density of the coil;the push-pull hysteresis of internal and external push rods output force is less than 5%;and the dynamic time response characteristics of the displacement and force are obtained. The hysteresis e ect of output force is improved e ectively through the H bridge drive control circuit modulated by PWM. Compared with the displacement response of a singlewinding electromagnet with a similar volume, it can e ectively improve the dynamic displacement response. Followup work will further optimize the structure of the electromechanical converter and test the corresponding pilot valve. The research results provide a new theory for improving the output characteristics of electro-hydraulic pilot valve and have an extremely high engineering application value and broad application prospect.
基金supported by National Key R&D Program of China(2022YFF1100300)the Central Guidance on Local Science and Technology Development Found of Shenzhen,China(2021Szvup030).
文摘Inflammatory stimulation plays a significant role in the development and worsening of insulin-resistant diabetes.Therefore,it is crucial to identify therapeutic agents that can alleviate insulin resistance by targeting inflammation.Here,we present evidence that Bakuchiol(BL),a monoterpene phenolic compound first discovered from Psoralea corylifolia L.as traditional Chinese medicine,can effectively improve insulin resistance in diabetic mice through anti-inflammation.Our findings demonstrate that BL alleviates inflammation by inhibiting the toll-like receptor 4/nuclear factorκB/mitogen-activated protein kinase axis,consequently enhancing insulin receptor signaling through the c-Jun N-terminal kinase/suppressors of cytokine signaling 3/insulin receptor substrate1 pathway and improving glucolipid homeostasis.Furthermore,the insulin recovery achieved with BL(60 mg/kg)was comparable to that of metformin(200 mg/kg).These results provide further support for considering BL as a potential treatment option for insulin-resistant diabetes mellitus.
基金financially surpported by the Fundamental Research Funds for the Central Universities(No.2232019A3-07)the National Key Research Program of China(Nos.2016YFA0201702 of 2016YFA0201700)+2 种基金the National Nature Science Foundation of China(No.31771023)the Science and Technology Commission of Shanghai Municipality(No.19441902600)the Fundamental Research Funds for the Central Universities and Graduate Student Innovation Fund of Donghua University(No.CUSF-DH-D-2020061)。
文摘Tissue engineering is an interdisciplinary field that integrates medical,biological,and engineering expertise to restore or regenerate the functionality of healthy tissues and organs.The three fundamental pillars of tissue engineering are scaffolds,cells,and biomolecules.Electrospun nanofibers have been successfully used as scaffolds for a variety of tissue engineering applications because they are biomimetic of the natural,fibrous extracellular matrix(ECM)and contain a three-dimensional(3D)network of interconnected pores.In this review,we provide an overview of the electrospinning process,its principles,and the application of the resultant electrospun nanofibers for tissue engineering.We first briefly introduce the electrospinning process and then cover its principles and standard equipment for biomaterial fabrication.Next,we highlight the most important and recent advances related to the applications of electrospun nanofibers in tissue engineering,including skin,blood vessels,nerves,bone,cartilage,and tendon/ligament applications.Finally,we conclude with current advancements in the fabrication of electrospun nanofiber scaffolds and their biomedical applications in emerging areas.
基金supported by the National Natural Science Foundation of China(NSFC No.32072773)the International Post-doctoral Exchange Fellowship Program of China and the Chinese Academy of Agricultural Sciences Postdoctoral YouNong Program of China.
文摘Over-use or misuse of antibiotics in livestock and poultry production contributes to the rising threat of antibiotic resistance in animals and has negative ecological effects.Exopolysaccharides from lactic acid bacteria(LAB-EPS)are a class of biological macromolecules which are secreted by lactic acid bacteria to the outside of the cell wall during their growth and metabolism.Numerous studies demonstrated that LAB-EPS have anti-inflammatory and antimicrobial activities and are able to regulate intestinal health and the immune system in livestock.They are biodegradable,nontoxic and bio-compatible,which are considered as ideal alternatives to antibiotics.This review aims to discuss and summarize recent research findings of LAB-EPS on regulation of intestinal health and the immune system in animals,and thus provide scientific justification for commercial applications of LAB-EPS in livestock.
基金the National Key R&D Program of China[2018YFC1407103 and 2017YFA0604401]Annual Report(2022)on Remote Sensing Monitoring of Global Ecosystems and Environment[TC210E01B].
文摘Man-made impervious areas map is of great demand in environmen-tal and urbanization studies since impervious areas are considered as a key indication of urbanization,especially for circumpolar Arctic.However,to date,finer resolution and spatially continuous imper-vious areas information remains scarce in the Arctic.In this study,we developed an accurate and complete circumpolar Arctic Man-made impervious areas(CAMI)map at a resolution of 10 m by combining Sentinel-1 C-band Synthetic Aperture Radar,Sentinel-2 multispectral images,OpenStreetMap,and ArcticDEM via Google Earth Engine platform.A random forest classifier model was trained and used to generate corresponding impervious areas map for the year 2020.The evaluation results suggested that CAMI was the most accurate with an overall accuracy of 86.36%and kappa coefficient of 70.73%as against the three existing impervious areas products.Based on the generated map and OpenStreetMap,we estimated that total imper-vious areas area in the Arctic has achieved 807.80 km2,of which roads,industrial and resident land were three major land use types,accounting for 54.08%,17.85%and 10.34%,respectively.The CAMI map will support for new application and provide advanced insight into the infrastructure vulnerability evaluation and environmental sustainability in the Arctic.
基金supported by the National Key Research&Development Program of China(2019YFC1509104,2019YFC1509105,and 2018YFC1407103)Guangdong Natural Science Foundation(2022A1515010924)the Annual Report(2022)on Remote Sensing Monitoring of Global Ecosystems and Environment(TC210E01B)。
文摘The Arctic,located at the northernmost part of the Earth,plays a disproportionately crucial role in regulating global climate and affecting the surface energy balance[1].Over the past decades,a multitude of environmental changes have been observed in the terrestrial section of the Arctic,including permafrost thawing,land ice retreat,and vegetation greening/browning.These changes not only threat the delicate network of the high-latitude biomes,but also influence human communities far beyond the Arctic limits[2].
文摘BACKGROUND: For many years, yeast cell walls (YCW) and mannan oligosaccharides (MOS) have been used as alternatives to antibiotics and health feed additives to enhance the growth performance and health of food animals. In the present study, the inhibitory effects of YCW and MOS on the adhesion of enteropathogenic bacteria to intestinal epithelial cells were tested. METHODS: YCW and MOS were extracted from Saccharomyces cerevisiae (XM 0315), and the morphology of YCW and MOS bound to pathogenic bacteria was observed by scanning electron microscopy (SEM). Real-time fluorescent quantitative PCR was used to quantitatively analyze the effects of YCW and MOS on the adhesion of Escherichia coli (CVCC3367) and Salmonella pullorum (CVCC520) to Caco-2 cells. RESULTS: The results showed that YCW inhibited E. coli and S. pullorum binding to Caco-2 cells by 95% and 74%, respectively, whereas MOS prevented E. coli and S. pullorum binding by 67% and 50%, respectively. CONCLUSIONS: These data suggest that YCW has a stronger ability than MOS to inhibit pathogenic bacteria from adhering to Caco-2 cells in vitro.
基金funded by the Key Laboratory of National Health Com-mission Project(2019PT310004)the Key Laboratory for Plague Pre-vention and Control of Qinghai Province(2020-ZJ-Y23).
文摘Plague,caused by Yersinia pestis,is a natural focus infectious disease.In China,plague is classified as category A,with the highest risk and hazard among the infectious diseases.Qinghai used to be considered as one of the most serious areas of plague in China.In recent years,thank to the measures in eight aspects summarized as the“Qinghai model”which were adopted to prevent and control the human plague in Qinghai,Qinghai has not experienced any plague case reported for eight years.In early 2020,coronavirus disease 2019(COVID-19)outbroke in China.The Qinghai model on plague was employed to deal with the COVID-19 emergency in Qinghai Province.The Qinghai Center for Disease Control and Prevention(Qinghai CDC)and hospitals,along with the departments of public security,animal husbandry and other departments,quickly tracked and treated the patients with severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)and started surveillance programs on close contacts timely.At present,the cure rate of patients has reached 100%,and close contacts have been effectively quarantined and tested to avoid the spread of COVID-19.The findings from the study suggest that the prevention and control measures undertaken in Qinghai Province might be effective in dealing with the category A infectious diseases such as COVID-19 and other diseases.
基金School of Pharmaceutical Sciences,Peking University Health Science Center,Beijing 100191,China。
文摘A combinational therapeutic system that simultaneously administrates various pathways is preferred for anti-cancer treatment.In the present study,we successfully constructed a co-delivery system,multivesicular liposomes(MVLs)co-encapsulating doxorubicin(DOX)and luminespib(AUY922).A simple and accurate dual-wavelength spectrophotometric method was established for the determination of DOX and AUY922 in liposomal formulation.MVL-loading drugs were prepared by a multi-emulsion solvent evaporation method,which exhibited excellent physicochemical properties,such as particle size of 3–8μm and high entrapment efficiency above 95%for DOX and 73%for AUY922.The synergetic cytotoxic effect for these two drugs was evaluated in MDA-MB-231 cells.The in vitro antitumor studies demonstrated the superior anti-proliferation activity of DOX and AUY922 with a combination index of 0.43,indicating a great synergistic effect.The experimental data suggested that combinational use of DOX and AUY922 within liposomes could be an effective way to develop efficient treatments of cancers.