Sleep quality is closely linked to people’s health,and during the COVID-19 pandemic,the sleep patterns of residents in China were notably poor.The lockdown in China led to an increase in social media use,prompting qu...Sleep quality is closely linked to people’s health,and during the COVID-19 pandemic,the sleep patterns of residents in China were notably poor.The lockdown in China led to an increase in social media use,prompting questions about its impact on sleep.Therefore,this study investigates the association between social media use and sleep quality among Chinese residents during the COVID-19 outbreak,highlighting the potential mediating role of social media addiction.Data were collected via questionnaires through a cross-sectional survey with 779 valid responses.Variance analysis was used to test for differences in social media use among different demographic variables.Bivariate correlation analysis was employed to explore the relationships between variables,while regression analysis investigated the correlations between various media factors and sleep quality.Additionally,Bootstrap sampling was utilized to analyze the potential mediating influence of social media addiction in the relationship between social media use and sleep.The study's findings reveal a significant correlation between social media use,particularly before bedtime,and sleep quality(p<0.01),with pre-sleep activity notably linked to poorer overall sleep scores(β=0.141,p=0.004).Although the daily use of social media did not directly impact most individuals’sleep quality,specific platforms like news apps,short video apps,dating apps,and content community platforms were associated with higher levels of social media addiction,subsequently negatively affecting sleep quality.Specifically,the use of news apps(B=0.068,95%CI[0.000,0.019]),short video apps(B=0.112,95%CI[0.001,0.031]),dating apps(B=0.147,95%CI[0.000,0.028]),and content community platforms(B=0.106,95%CI[0.001,0.028])was found to increase the risk of social media addiction,subsequently leading to adverse effects on sleep quality.The study underscores a notable link between social media use and sleep quality,suggesting that mindful social media habits,particularly before bedtime,and reducing addiction-associated apps could enhance sleep quality.展开更多
Background:Recently,researchers have been attracted in identifying the crucial genes related to cancer,which plays important role in cancer diagnosis and treatment.However,in performing the cancer molecular subtype cl...Background:Recently,researchers have been attracted in identifying the crucial genes related to cancer,which plays important role in cancer diagnosis and treatment.However,in performing the cancer molecular subtype classification task from cancer gene expression data,it is challenging to obtain those significant genes due to the high dimensionality and high noise of data.Moreover,the existing methods always suffer from some issues such as premature convergence.Methods:To address those problems,we propose a new ant colony optimization(ACO)algorithm called DACO to classify the cancer gene expression datasets,identifying the essential genes of different diseases.In DACO,first,we propose the initial pheromone concentration based on the weight ranking vector to accelerate the convergence speed;then,a dynamic pheromone volatility factor is designed to prevent the algorithm from getting stuck in the local optimal solution;finally,the pheromone update rule in the Ant Colony System is employed to update the pheromone globally and locally.To demonstrate the performance of the proposed algorithm in classification,different existing approaches are compared with the proposed algorithm on eight high-dimensional cancer gene expression datasets.Results:The experiment results show that the proposed algorithm performs better than other effective methods in terms of classification accuracy and the number of feature sets.It can be used to address the classification problem effectively.Moreover,a renal cell carcinoma dataset is employed to reveal the biological significance of the proposed algorithm from a number of biological analyses.Conclusion:The results demonstrate that CAPS may play a crucial role in the occurrence and development of renal clear cell carcinoma.展开更多
Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a...Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a transcriptome deep sequencing(RNA-seq)analysis of the rice cultivar Nipponbare(Nip)and the tocopherol-deficient mutant small grain and dwarf 1-2(sgd1-2).We identified 563 differentially expressed genes that were enriched in Gene Ontology categories associated with metabolism,stress,cellular responses,and transcriptional regulation.We determined that the total fatty acid composition of Nip and sgd1-2 was comparable,although cell membrane penetrability in sgd1-2 was significantly higher than in Nip under optimal growth conditions,indicating that tocopherol deficiency induces cell membrane damage.The expression levels of dehydration-responsive element binding 1(DREB1)genes and free proline content in sgd1-2 were also higher than those in Nip.We also showed that the DELLA protein SLENDER RICE1(SLR1)accumulated in sgd1-2,resulting in significant changes in the global transcriptome.Our study confirms that the lack of tocopherol accumulation in rice induced ectopic stress responses and limited growth by enhancing SLR1 abundance through increasing SLR1 transcript levels.These results provide new insights into tocopherol during rice development.展开更多
6-(5-Carboxyl-2-methoxyphenyl)-apigenin (1), a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata (Desv.) Spring. Its structure was established by spectroscopic methods. Compound 1 ...6-(5-Carboxyl-2-methoxyphenyl)-apigenin (1), a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata (Desv.) Spring. Its structure was established by spectroscopic methods. Compound 1 represents the first example of the flavonoids possessing a benzoic acid substituent at C-6.展开更多
(3S)-2-Oxo-5,12-dimethoxy-3-hydroxy-3-methylbenz[f]indoline (1), a new benzoxindole alkaloid, along with two known alkaloids, was isolated from the root barks of Goniothalamus cheliensis Hu. The structure was eluc...(3S)-2-Oxo-5,12-dimethoxy-3-hydroxy-3-methylbenz[f]indoline (1), a new benzoxindole alkaloid, along with two known alkaloids, was isolated from the root barks of Goniothalamus cheliensis Hu. The structure was elucidated by spectroscopic evidences, and the absolute configuration was determined by CD spectrum.展开更多
It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. Th...It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.展开更多
Two discriminant methods,partial least squares-discriminant analysis(PLS-DA)and Fisher's discriminant analysis(FDA),were combined with Fourier transform infrared imaging(FTIRI)to differentiate healthy and osteoart...Two discriminant methods,partial least squares-discriminant analysis(PLS-DA)and Fisher's discriminant analysis(FDA),were combined with Fourier transform infrared imaging(FTIRI)to differentiate healthy and osteoarthritic articular cartilage in a canine model.Osteoarthritic cartilage had been developed for up to two years after the anterior cruciate ligament(ACL)transection in one knee.Cartilage specimens were sectioned into 10μm thickness for FTIRI.A PLS-DA model was developed after spectral pre-processing.All IR spectra extracted from FTIR images were calculated by PLS-DA with the discriminant accuracy of 90%.Prior to FDA,principal component analysis(PCA)was performed to decompose the IR spectral matrix into informative princi pal component matrices.Based on the different discriminant mechanism,the discriminant accuracy(96%)of PCA-FDA with high convenience was higher than that of PLS-DA.No healthy cartilage sample was mis assigned by these two methods.The above mentioned suggested that both integrated technologies of FTIRI-PLS-DA and,especially,FTIRI-PCA-FDA could become a promising tool for the discrimination of healthy and osteoarthritic cartilage specimen as well as the diagnosis of cartilage lesion at microscopic level.The results of the study would be helpful for better understanding the pathology of osteoarthritics.展开更多
Agricultural monitoring is essential for adequate management of food production and distribution.Crop land and crop type classification,using remote sensing time series,form an important tool to capture the agricultur...Agricultural monitoring is essential for adequate management of food production and distribution.Crop land and crop type classification,using remote sensing time series,form an important tool to capture the agricultural production information.The recently launched Sentinel-2 satellites provide unprecedented monitoring capacities in terms of spatial resolution,swath width,and revisit frequency.The Sentinel-2 for Agriculture(Sen2-Agri)system has been developed to fully exploit those capacities,by providing four relevant earth observation products for agricultural monitoring.Under the Dragon 4 Program,the crop mapping with various satellite images and a specific focus on the Yellow River irrigated agricultural area in the Ningxia Hui Autonomous Region in China was carried out with the Sentinel-2 for Agriculture system(Sent2Agri).9 types of crops were classified and the crop type map in 2017 was produced based on 35 scenes Sentinel 2A/B images.The overall accuracy computed from the error confusion matrix is 88%,which includes the cropped and uncropped types.After the removal of the uncropped area,the overall accuracy for a cropped decrease to 73%.In order to further improve the crop classification accuracy,the training dataset should be further improved and tuned.展开更多
Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,poste...Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.展开更多
Polymeric nitrogen as a new class of high energy density materials has promising applications.We develop a new scheme of crystal structure searching in a confined space using external confining potentials fitted from ...Polymeric nitrogen as a new class of high energy density materials has promising applications.We develop a new scheme of crystal structure searching in a confined space using external confining potentials fitted from firstprinciples calculations.As a showcase,this method is employed to systematically explore novel polymeric nitrogen structures confined in single-walled carbon nanotubes.Several quasi-one-dimensional single-bonded polymeric nitrogen structures are realized,two of them are composed of nanotubes instead of chains.These new polymeric nitrogen phases are mechanically stable at ambient pressure and temperature according to phonon calculations and ab initio molecular dynamics simulations.It is revealed that the stabilization of zigzag and armchair chains confined in carbon nanotubes are mostly attributed to the charge transfer from carbon to nitrogen.However,for the novel nitrogen nanotube systems,electrons overlapping in the middle space provide strong Coulomb repulsive forces,which not only induce charge transfer from the middle to the sides but also stabilize the polymeric nitrogen.Our work provides a new strategy for designing novel high-energy-density polymeric nitrogen materials,as well as other new materials with the help of confined space inside porous systems,such as nanotubes,covalent organic frameworks,and zeolites.展开更多
Microbial transformation is a useful tool for structure modification of active natural products.Z-Butylidenephthalide is the main active constituent of Angelica sinensis.In the present work,a pair of new oxidized meta...Microbial transformation is a useful tool for structure modification of active natural products.Z-Butylidenephthalide is the main active constituent of Angelica sinensis.In the present work,a pair of new oxidized metabolites,namely(-)(11R)-(Z)-11-hydroxy-butylidenephthalide(1a)and(+)(11S)-(Z)-11-hydroxy-butylidenephthalide(1b),were obtained from microbial transformation for region-selective 11-hydroxylation of Z-butylidenephthalide by Aspergillus niger CGMCC 3.739.Their structures,including absolute configurations,were elucidated by extensive analysis of HR-ESI-MS,NMR spectra,and the modified Mosher’s method.This is the first study on the microbial transformation of Z-butylidenephthalide,and these findings offer a tool for region-selective 11-hydroxylation of Z-butylidenephthalide.展开更多
In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured s...In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.展开更多
In combination with the augmented reality (AR) technology and Hololens device, an electric power work assist system is developed to provide a more realistic and convenient training experience for electric power traini...In combination with the augmented reality (AR) technology and Hololens device, an electric power work assist system is developed to provide a more realistic and convenient training experience for electric power training. The training effect was improved, and help guidance information was provided in the actual operation of electric power work. Experimental results show that difficulty of electric power work is reduced and the efficiency of actual work is improved.展开更多
The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of g...The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of gaseous pollutants.Therefore,this paper established a numerical model of the electrostatic oil mist purifier and applied it to a two-stage electrostatic precipitator.Then the model was used to investigate the corona discharge characteristics under different relative humidity conditions in the charged zone,the particle deposition characteristics,the purification efficiency,the ozone concentration distribution,and the oil vapor concentration distribution in the collection zone.The results indicate that,with a constant temperature,the corona current decreases as relative humidity increase,and there is a quadratic relationship between relative humidity and current.The variation in relative humidity has little impact on the purification efficiency.The maximum ozone concentration occurs near the electrode line,and its concentration is influenced by the discharge current and inlet airflow velocity.The oil vapor concentration reaches its maximum value at the side plates,with a value of 19 ppb,while it reaches the minimum value at the collecting zone electrode plate,with a value of 2 ppb.The temperature is the main factor affecting the volatilization of the oil film,with higher temperatures resulting in higher oil vapor.展开更多
Augmented reality(AR)display,which superimposes virtual images on ambient scene,can visually blend the physical world and the digital world and thus opens a new vista for human–machine interaction.AR display is consi...Augmented reality(AR)display,which superimposes virtual images on ambient scene,can visually blend the physical world and the digital world and thus opens a new vista for human–machine interaction.AR display is considered as one of the next-generation display technologies and has been drawing huge attention from both academia and industry.Current AR display systems operate based on a combination of various refractive,reflective,and diffractive optical elements,such as lenses,prisms,mirrors,and gratings.Constrained by the underlying physical mechanisms,these conventional elements only provide limited light-field modulation capability and suffer from issues such as bulky volume and considerable dispersion,resulting in large size,severe chromatic aberration,and narrow field of view of the composed AR display system.Recent years have witnessed the emerging of a new type of optical elements—metasurfaces,which are planar arrays of subwavelength electromagnetic structures that feature an ultracompact footprint and flexible light-field modulation capability,and are widely believed to be an enabling tool for overcoming the limitations faced by current AR displays.Here,we aim to provide a comprehensive review on the recent development of metasurface-enabled AR display technology.We first familiarize readers with the fundamentals of AR display,covering its basic working principle,existing conventional-optics-based solutions,as well as the associated pros and cons.We then introduce the concept of optical metasurfaces,emphasizing typical operating mechanisms,and representative phase modulation methods.We elaborate on three kinds of metasurface devices,namely,metalenses,metacouplers,and metaholograms,which have empowered different forms of AR displays.Their physical principles,device designs,and the performance improvement of the associated AR displays are explained in details.In the end,we discuss the existing challenges of metasurface optics for AR display applications and provide our perspective on future research endeavors.展开更多
Interleukin(IL)-17A,a pro-inflammatory cytokine,is a fundamental function in the onset and advancement of multiple immune diseases.To uncover the primary compounds with IL-17A inhibitory activity,a large-scale screeni...Interleukin(IL)-17A,a pro-inflammatory cytokine,is a fundamental function in the onset and advancement of multiple immune diseases.To uncover the primary compounds with IL-17A inhibitory activity,a large-scale screening of the library of traditional Chinese medicine constituents and microbial secondary metabolites was conducted using splenic cells from IL-17A-GFP reporter mice cultured under Th17-priming conditions.Our results indicated that some aureane-type sesquiterpene tetraketides isolated from a wetland mud-derived fungus,Myrothecium gramineum,showed remarkable IL-17A inhibitory activity.Nine new aureane-type sesquiterpene tetraketides,myrogramins A-I(1,4-11),and two known ones(2 and 3)were isolated and identified from the strain.Compounds 1,3,4,10,and 11 exhibited significant IL-17A inhibitory activity.Among them,compound 3,with a high fermentation yield dosedependently inhibited the generation of IL-17A and suppressed glycolysis in splenic cells under Th17-priming conditions.Strikingly,compound 3 suppressed immunopathology in both IL-17A-mediated animal models of experimental autoimmune encephalomyelitis and pulmonary hypertension.Our results revealed that aureane-type sesquiterpene tetraketides are a novel class of immunomodulators with IL-17A inhibitory activity,and hold great promise applications in treating IL-17A-mediated immune diseases.展开更多
This paper aims to investigate the dynamics of buoyancy-driven microflow in a narrow annular space inside a liquid floated gyroscope(LFG). Several theoretical models with a non-uniform thermal boundary for fluid flow ...This paper aims to investigate the dynamics of buoyancy-driven microflow in a narrow annular space inside a liquid floated gyroscope(LFG). Several theoretical models with a non-uniform thermal boundary for fluid flow in annular channels are given to analyze the effects of various parameters, such as the clearance size h, roughness height re, and rough density ε, on the flow and temperature profiles as well as on the fluid-drag torque. In the narrow annular regime, the relationship between the temperature and the angular displacement of the outer wall is defined as a cosine function, and the surface roughness of the inner wall is structured as a series of surface protrusions with a circular shape. With the increase of clearance size h, the flow velocity gradually increases to a stable level, and the drag torque increases initially and then decreases to a stable level. Furthermore, the increase of roughness height re and roughness density ε intensifies the frictional effect of fluid on the inner-wall surface. However, these two parameters have no significant effect on the flow velocity. This study can provide theoretical references for precision manufacturing and precision improvement of gyro instruments.展开更多
Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on th...Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements,we establish an oxygen(O_(2))balance index(OBI),i.e.,the ratio of the O_(2)production from the ecosystem to the O_(2)consumption by human behavior,based on the net primary productivity(NPP),fuel consumption,gross domestic production(GDP),population data,and so on.The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development.The estimated OBI values are then validated by statistical data from 27 counties in China,and it is found that the OBI reflects the ecological environment status well.Moreover,the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O_(2)production and consumption in highly developed regions,especially in the cities,in contrast to good O_(2)balance in areas with high-quality ecological status and less industrialization.The findings from this study have quantitatively captured the regional ecological quality,providing guidance for sustainable natural and socioeconomic developments in local areas of China.展开更多
基金the Declaration of Helsinki and has received ethical approval from the Biomedical Research Ethics Committee of Nanjing Normal University(IRB Number:NNU2022060054).
文摘Sleep quality is closely linked to people’s health,and during the COVID-19 pandemic,the sleep patterns of residents in China were notably poor.The lockdown in China led to an increase in social media use,prompting questions about its impact on sleep.Therefore,this study investigates the association between social media use and sleep quality among Chinese residents during the COVID-19 outbreak,highlighting the potential mediating role of social media addiction.Data were collected via questionnaires through a cross-sectional survey with 779 valid responses.Variance analysis was used to test for differences in social media use among different demographic variables.Bivariate correlation analysis was employed to explore the relationships between variables,while regression analysis investigated the correlations between various media factors and sleep quality.Additionally,Bootstrap sampling was utilized to analyze the potential mediating influence of social media addiction in the relationship between social media use and sleep.The study's findings reveal a significant correlation between social media use,particularly before bedtime,and sleep quality(p<0.01),with pre-sleep activity notably linked to poorer overall sleep scores(β=0.141,p=0.004).Although the daily use of social media did not directly impact most individuals’sleep quality,specific platforms like news apps,short video apps,dating apps,and content community platforms were associated with higher levels of social media addiction,subsequently negatively affecting sleep quality.Specifically,the use of news apps(B=0.068,95%CI[0.000,0.019]),short video apps(B=0.112,95%CI[0.001,0.031]),dating apps(B=0.147,95%CI[0.000,0.028]),and content community platforms(B=0.106,95%CI[0.001,0.028])was found to increase the risk of social media addiction,subsequently leading to adverse effects on sleep quality.The study underscores a notable link between social media use and sleep quality,suggesting that mindful social media habits,particularly before bedtime,and reducing addiction-associated apps could enhance sleep quality.
基金supported by the Langfang Science and Technology Plan Project(No.2018013151)from Hebei Petro China Central Hospital.
文摘Background:Recently,researchers have been attracted in identifying the crucial genes related to cancer,which plays important role in cancer diagnosis and treatment.However,in performing the cancer molecular subtype classification task from cancer gene expression data,it is challenging to obtain those significant genes due to the high dimensionality and high noise of data.Moreover,the existing methods always suffer from some issues such as premature convergence.Methods:To address those problems,we propose a new ant colony optimization(ACO)algorithm called DACO to classify the cancer gene expression datasets,identifying the essential genes of different diseases.In DACO,first,we propose the initial pheromone concentration based on the weight ranking vector to accelerate the convergence speed;then,a dynamic pheromone volatility factor is designed to prevent the algorithm from getting stuck in the local optimal solution;finally,the pheromone update rule in the Ant Colony System is employed to update the pheromone globally and locally.To demonstrate the performance of the proposed algorithm in classification,different existing approaches are compared with the proposed algorithm on eight high-dimensional cancer gene expression datasets.Results:The experiment results show that the proposed algorithm performs better than other effective methods in terms of classification accuracy and the number of feature sets.It can be used to address the classification problem effectively.Moreover,a renal cell carcinoma dataset is employed to reveal the biological significance of the proposed algorithm from a number of biological analyses.Conclusion:The results demonstrate that CAPS may play a crucial role in the occurrence and development of renal clear cell carcinoma.
基金supported by funding from the Natural Science Foundation of Jiangsu Province(BK20190239)Huai’an Academy of Agricultural Sciences Initiation and Development of Scientific Research Fund for High-Level Introduced Talents(0062019016B)the Scientific Research Fund Development Project of Huai’an Academy of Agricultural Sciences(HNY202102).
文摘Although tocopherols are essential for rice development,the molecular details by which their absence affects development remain to be determined.To study how tocopherols function during rice development,we performed a transcriptome deep sequencing(RNA-seq)analysis of the rice cultivar Nipponbare(Nip)and the tocopherol-deficient mutant small grain and dwarf 1-2(sgd1-2).We identified 563 differentially expressed genes that were enriched in Gene Ontology categories associated with metabolism,stress,cellular responses,and transcriptional regulation.We determined that the total fatty acid composition of Nip and sgd1-2 was comparable,although cell membrane penetrability in sgd1-2 was significantly higher than in Nip under optimal growth conditions,indicating that tocopherol deficiency induces cell membrane damage.The expression levels of dehydration-responsive element binding 1(DREB1)genes and free proline content in sgd1-2 were also higher than those in Nip.We also showed that the DELLA protein SLENDER RICE1(SLR1)accumulated in sgd1-2,resulting in significant changes in the global transcriptome.Our study confirms that the lack of tocopherol accumulation in rice induced ectopic stress responses and limited growth by enhancing SLR1 abundance through increasing SLR1 transcript levels.These results provide new insights into tocopherol during rice development.
基金the National Basic Research Program of China(No.2006CB504100).
文摘6-(5-Carboxyl-2-methoxyphenyl)-apigenin (1), a new flavonoid, was isolated from the 60% ethanol extract of Selaginella uncinata (Desv.) Spring. Its structure was established by spectroscopic methods. Compound 1 represents the first example of the flavonoids possessing a benzoic acid substituent at C-6.
文摘(3S)-2-Oxo-5,12-dimethoxy-3-hydroxy-3-methylbenz[f]indoline (1), a new benzoxindole alkaloid, along with two known alkaloids, was isolated from the root barks of Goniothalamus cheliensis Hu. The structure was elucidated by spectroscopic evidences, and the absolute configuration was determined by CD spectrum.
基金Supported by the National Key Science&Technology Projects during 13th Five-Year Plan(2016ZX05053-003)Young Scholars Development fund of SWPU(201499010121)
文摘It has been known that the productivity of artesian wells is strongly dependent on the rheological properties of crude oils. This work targets two deep artesian wells(>5000 m) that are producing heavy crude oil. The impacts of well conditions including temperature, pressure and shear rate, on the crude oil rheology were comprehensively investigated and correlated using several empirical rheological models. The experimental data indicate that this heavy oil is very sensitive to temperature as result of microstructure change caused by hydrogen bonding. The rheological behavior of the heavy oil is also significantly impacted by the imposed pressure, i.e., the viscosity flow activation energy(Eμ) gently increases with the increasing pressure. The viscosity–shear rate data are well fitted to the power law model at low temperature. However, due to the transition of fluid feature at high temperature(Newtonian fluid), the measured viscosity was found to slightly deviate from the fitting data. Combining the evaluated correlations, the viscosity profile of the heavy crude oil in these two deep artesian wells as a function of well depth was predicted using the oilfield producing data.
基金the National Natural Science Foundation of China for the grant of 61378087Natural Science Foundation of Jiangsu Province(BK20151478)+1 种基金Zhi-Hua Mao is grateful to the Open Funds for Graduate Innovation Lab of Nanjing University of Aeronautics and Astronautics(kfjj20150309)and Fundamental Research Funds for the Central Universities.The raw data acquisition in FTIRI was mostly carried out in the lab of Professor Yang Xia at Oakland University(Rochester,Michigan,USA).Professor Xia was supported by an NIH grant R01-AR052353 during the time of the data acquisition.
文摘Two discriminant methods,partial least squares-discriminant analysis(PLS-DA)and Fisher's discriminant analysis(FDA),were combined with Fourier transform infrared imaging(FTIRI)to differentiate healthy and osteoarthritic articular cartilage in a canine model.Osteoarthritic cartilage had been developed for up to two years after the anterior cruciate ligament(ACL)transection in one knee.Cartilage specimens were sectioned into 10μm thickness for FTIRI.A PLS-DA model was developed after spectral pre-processing.All IR spectra extracted from FTIR images were calculated by PLS-DA with the discriminant accuracy of 90%.Prior to FDA,principal component analysis(PCA)was performed to decompose the IR spectral matrix into informative princi pal component matrices.Based on the different discriminant mechanism,the discriminant accuracy(96%)of PCA-FDA with high convenience was higher than that of PLS-DA.No healthy cartilage sample was mis assigned by these two methods.The above mentioned suggested that both integrated technologies of FTIRI-PLS-DA and,especially,FTIRI-PCA-FDA could become a promising tool for the discrimination of healthy and osteoarthritic cartilage specimen as well as the diagnosis of cartilage lesion at microscopic level.The results of the study would be helpful for better understanding the pathology of osteoarthritics.
基金Natural Science Foundation project(No.41271429)FP7 Project(SIGMA)ESA Project(Dragon 4 and S2A)。
文摘Agricultural monitoring is essential for adequate management of food production and distribution.Crop land and crop type classification,using remote sensing time series,form an important tool to capture the agricultural production information.The recently launched Sentinel-2 satellites provide unprecedented monitoring capacities in terms of spatial resolution,swath width,and revisit frequency.The Sentinel-2 for Agriculture(Sen2-Agri)system has been developed to fully exploit those capacities,by providing four relevant earth observation products for agricultural monitoring.Under the Dragon 4 Program,the crop mapping with various satellite images and a specific focus on the Yellow River irrigated agricultural area in the Ningxia Hui Autonomous Region in China was carried out with the Sentinel-2 for Agriculture system(Sent2Agri).9 types of crops were classified and the crop type map in 2017 was produced based on 35 scenes Sentinel 2A/B images.The overall accuracy computed from the error confusion matrix is 88%,which includes the cropped and uncropped types.After the removal of the uncropped area,the overall accuracy for a cropped decrease to 73%.In order to further improve the crop classification accuracy,the training dataset should be further improved and tuned.
基金funded by National Nature Foundation of China ( 11532004,1140204,11832008)
文摘Objective Mitral valve(MV)plays an importance role in regulating blood flow from left atrium to left ventricle and preventing backflow to left atrium.Mitral Valve consist of four important parts;anterior leaflet,posterior leaflet,chordae tendineae,and papillary muscles,which all work in harmony.The material properties alteration on the leaflet causes MV malfunction,and leading to valve diseases such as regurgitation and stenosis.The alteration may be caused by several factors such as calcification,genetic disorders,and infection,which usually have an influence to the mechanical properties,and thus affecting the mechanical behavior of MV.In consequence,some of the patients need MV replacement or repair to restore the normal function of MV.The important point for succeeding such a medical treatment depends on the technique,design,and material used in the treatment shall help rebuild the normal mechanical environment and behavior of MV.Therefore,the mechanical and materials characteristics of MV become a magnetism to explore.In this study,we present an integrated experimental and mathematical constitutive study base in collagen distribution aiming at the mechanical property differences in various region on MV.Methods and materials Both the size and composition of porcine valves are similar to human’s,so the porcine heart valve is often being used in experimental research.Mitral valve was isolated from fresh eight porcine hearts(250-500 gr),and perfused in PBS solution to maintain moist.Anterior and posterior leaflets were separated and dissected into 4 part(two 8~*8 mm rough zone and two clear zone samples)and 2 part(8~*8 mm belly and edge of the clear zone)respectively.Tracking markers(glass bean)were stickled on specimen with superglue(cyanoacrylate adhesive).Then,the specimen was mounted onto biaxial tester machine(CeIIScale,Biotester),and the tests are run by force control.During mechanical test,the specimen is immersed into PBS solution in physiological temperature(37℃).Every test procedure contains 8 preconditioning cycles and 8 loading cycles.The mechanical behavior was determined from the relationship between first Piola-Kirchoff stress and stretch.Constitutive model was reconstructed and material parameters were fitted from biaxial tensile result.Histological analyses were performed in the specimen before and after test.First,a piece of the specimen was cut and immersed in fixation solution(4%paraformaldehyde),then it was dehydrated in graded alcohol solution,and next embedding in paraffin wax block.Paraffin block was then cut and stained with VVG and Picro-sirius red.The collagen fibril orientation was observed from those histological results.Results The experimental results of the clear zone of MV’s first Piola-Kirchhoff stress and stretch curve are similar to those of the recent study from others,while result of the rough zone shows a different trend.This can be explained by differences in collagen distribution between clear zone and rough zone of MV.Our result thus allows for a refinement of computational models for more accurately predicting MV condition,where tissue heterogeneity plays an important role in the MV function.
基金financial support from the National Natural Science Foundation of China(Grant Nos.12125404,11974162,and 11834006)the Fundamental Research Funds for the Central Universities。
文摘Polymeric nitrogen as a new class of high energy density materials has promising applications.We develop a new scheme of crystal structure searching in a confined space using external confining potentials fitted from firstprinciples calculations.As a showcase,this method is employed to systematically explore novel polymeric nitrogen structures confined in single-walled carbon nanotubes.Several quasi-one-dimensional single-bonded polymeric nitrogen structures are realized,two of them are composed of nanotubes instead of chains.These new polymeric nitrogen phases are mechanically stable at ambient pressure and temperature according to phonon calculations and ab initio molecular dynamics simulations.It is revealed that the stabilization of zigzag and armchair chains confined in carbon nanotubes are mostly attributed to the charge transfer from carbon to nitrogen.However,for the novel nitrogen nanotube systems,electrons overlapping in the middle space provide strong Coulomb repulsive forces,which not only induce charge transfer from the middle to the sides but also stabilize the polymeric nitrogen.Our work provides a new strategy for designing novel high-energy-density polymeric nitrogen materials,as well as other new materials with the help of confined space inside porous systems,such as nanotubes,covalent organic frameworks,and zeolites.
基金This work was financially supported by grants from the National Key Research and Development Program of China(2018 YFA0903200/2018YFA0903201)the National Natural Science Foundation of China(81925037/31900284)+3 种基金Chang Jiang Scholars Program(Young Scholar)from the Ministry of Education of China(Hao Gao,2017)National High-level Personnel of Special Support Program(2017RA2259)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y036)K.C.Wong Education Foundation(Hao Gao,2016).
文摘Microbial transformation is a useful tool for structure modification of active natural products.Z-Butylidenephthalide is the main active constituent of Angelica sinensis.In the present work,a pair of new oxidized metabolites,namely(-)(11R)-(Z)-11-hydroxy-butylidenephthalide(1a)and(+)(11S)-(Z)-11-hydroxy-butylidenephthalide(1b),were obtained from microbial transformation for region-selective 11-hydroxylation of Z-butylidenephthalide by Aspergillus niger CGMCC 3.739.Their structures,including absolute configurations,were elucidated by extensive analysis of HR-ESI-MS,NMR spectra,and the modified Mosher’s method.This is the first study on the microbial transformation of Z-butylidenephthalide,and these findings offer a tool for region-selective 11-hydroxylation of Z-butylidenephthalide.
文摘In this paper, three kinds of textured ZnO thin-films (the first kind has the textured structure with both columnar and polygon, the second posses pyramid-like textured structure only, and the third has the textured structure with both crater-like and pyramid-like), were prepared by three kinds of methods, and the application of these ZnO thin-films as a front electrode in solar cell was studied, respectively. In the first method with negative bias voltage and appropriate sputtering parameters, the textured structure with columnar and polygon on the surface of ZnO thin-film are both existence for the sample prepared by direct magnetron sputtering. Using as a front electrode in solar cell, the photoelectric conversion efficiency Eff of 7.00% was obtained. The second method is that by sputtering on the ZnO:Al self-supporting substrate, and the distribution of pyramid-like was gained. Moreover, the higher (8.25%) photoelectric conversion efficiency of solar cell was got. The last method is that by acid-etching the as-deposited ZnO thin-film which possesses mainly both columnar and polygon structure, and the textured ZnO thin-film with both crater-like and pyramid-like structure was obtained, and the photoelectric conversion efficiency of solar cell is 7.10% when using it as front electrode. These results show that the textured ZnO thin-film prepared on self-supporting substrate is more suitable for using as a front electrode in amorphous silicon cells.
文摘In combination with the augmented reality (AR) technology and Hololens device, an electric power work assist system is developed to provide a more realistic and convenient training experience for electric power training. The training effect was improved, and help guidance information was provided in the actual operation of electric power work. Experimental results show that difficulty of electric power work is reduced and the efficiency of actual work is improved.
基金This work was supported by the National Nature Science Foundation of China(No.51878442).
文摘The two-stage electrostatic precipitator is widely used to purify oil mist particles.However,there is limited research on the influences of relative humidity,particle deposition characteristics,and the generation of gaseous pollutants.Therefore,this paper established a numerical model of the electrostatic oil mist purifier and applied it to a two-stage electrostatic precipitator.Then the model was used to investigate the corona discharge characteristics under different relative humidity conditions in the charged zone,the particle deposition characteristics,the purification efficiency,the ozone concentration distribution,and the oil vapor concentration distribution in the collection zone.The results indicate that,with a constant temperature,the corona current decreases as relative humidity increase,and there is a quadratic relationship between relative humidity and current.The variation in relative humidity has little impact on the purification efficiency.The maximum ozone concentration occurs near the electrode line,and its concentration is influenced by the discharge current and inlet airflow velocity.The oil vapor concentration reaches its maximum value at the side plates,with a value of 19 ppb,while it reaches the minimum value at the collecting zone electrode plate,with a value of 2 ppb.The temperature is the main factor affecting the volatilization of the oil film,with higher temperatures resulting in higher oil vapor.
基金would like to acknowl-edge the support of the National Natural Science Foundation of China(NSFC)(Grant Nos.62075078 and 62135004)support of the Knowledge Innovation Program of Wuhan-Shuguang Project(Grant No.2022010801020095).Z.L.would like to acknowledge the support of the NSFC(Grant No.62205113)the China Postdoctoral Science Foundation(Grant No.2022M721244).
文摘Augmented reality(AR)display,which superimposes virtual images on ambient scene,can visually blend the physical world and the digital world and thus opens a new vista for human–machine interaction.AR display is considered as one of the next-generation display technologies and has been drawing huge attention from both academia and industry.Current AR display systems operate based on a combination of various refractive,reflective,and diffractive optical elements,such as lenses,prisms,mirrors,and gratings.Constrained by the underlying physical mechanisms,these conventional elements only provide limited light-field modulation capability and suffer from issues such as bulky volume and considerable dispersion,resulting in large size,severe chromatic aberration,and narrow field of view of the composed AR display system.Recent years have witnessed the emerging of a new type of optical elements—metasurfaces,which are planar arrays of subwavelength electromagnetic structures that feature an ultracompact footprint and flexible light-field modulation capability,and are widely believed to be an enabling tool for overcoming the limitations faced by current AR displays.Here,we aim to provide a comprehensive review on the recent development of metasurface-enabled AR display technology.We first familiarize readers with the fundamentals of AR display,covering its basic working principle,existing conventional-optics-based solutions,as well as the associated pros and cons.We then introduce the concept of optical metasurfaces,emphasizing typical operating mechanisms,and representative phase modulation methods.We elaborate on three kinds of metasurface devices,namely,metalenses,metacouplers,and metaholograms,which have empowered different forms of AR displays.Their physical principles,device designs,and the performance improvement of the associated AR displays are explained in details.In the end,we discuss the existing challenges of metasurface optics for AR display applications and provide our perspective on future research endeavors.
基金supported by the National Key Research and Development Program of China(2018YFA0903200,2018YFA0903201,and 2020YFA0803502)the National Natural Science Foundation of China(81925037,U22A20371,31830021,32030036,and 82270055)+5 种基金the 111 Project(B16021,China)National High-level Personnel of Special Support Program(2017RA2259,China)Guangdong International Science and Technology Cooperation Base(2021A0505020015,China)Innovative and Research Teams Project of Guangdong Higher Education Institution(2021KCXTD001,China)Local Innovative and Research Teams Project of Guangdong Pearl River Talents Program(2017BT01Y036,China)Guangdong Natural Science Funds for Distinguished Young Scholar(2021B1515020065,China)。
文摘Interleukin(IL)-17A,a pro-inflammatory cytokine,is a fundamental function in the onset and advancement of multiple immune diseases.To uncover the primary compounds with IL-17A inhibitory activity,a large-scale screening of the library of traditional Chinese medicine constituents and microbial secondary metabolites was conducted using splenic cells from IL-17A-GFP reporter mice cultured under Th17-priming conditions.Our results indicated that some aureane-type sesquiterpene tetraketides isolated from a wetland mud-derived fungus,Myrothecium gramineum,showed remarkable IL-17A inhibitory activity.Nine new aureane-type sesquiterpene tetraketides,myrogramins A-I(1,4-11),and two known ones(2 and 3)were isolated and identified from the strain.Compounds 1,3,4,10,and 11 exhibited significant IL-17A inhibitory activity.Among them,compound 3,with a high fermentation yield dosedependently inhibited the generation of IL-17A and suppressed glycolysis in splenic cells under Th17-priming conditions.Strikingly,compound 3 suppressed immunopathology in both IL-17A-mediated animal models of experimental autoimmune encephalomyelitis and pulmonary hypertension.Our results revealed that aureane-type sesquiterpene tetraketides are a novel class of immunomodulators with IL-17A inhibitory activity,and hold great promise applications in treating IL-17A-mediated immune diseases.
基金supported by the National Natural Science Foundation of China(No.U1937603).
文摘This paper aims to investigate the dynamics of buoyancy-driven microflow in a narrow annular space inside a liquid floated gyroscope(LFG). Several theoretical models with a non-uniform thermal boundary for fluid flow in annular channels are given to analyze the effects of various parameters, such as the clearance size h, roughness height re, and rough density ε, on the flow and temperature profiles as well as on the fluid-drag torque. In the narrow annular regime, the relationship between the temperature and the angular displacement of the outer wall is defined as a cosine function, and the surface roughness of the inner wall is structured as a series of surface protrusions with a circular shape. With the increase of clearance size h, the flow velocity gradually increases to a stable level, and the drag torque increases initially and then decreases to a stable level. Furthermore, the increase of roughness height re and roughness density ε intensifies the frictional effect of fluid on the inner-wall surface. However, these two parameters have no significant effect on the flow velocity. This study can provide theoretical references for precision manufacturing and precision improvement of gyro instruments.
基金Supported by the National Key Research and Development Program of China(2021YFB3901002)GaoFen Project(32-Y30F08-9001-20/22)+1 种基金National Natural Science Foundation of China(41977191)Innovation Fund of Public Meteorological Service Centre,China Meteorological Administration(K2021003).
文摘Ecological assessment plays a vital role in sustainable development of the environment,and thus exploration of specific and integrated ecological assessment methods has become a critical task.In this study,based on the concept of oxygen balance and by accommodating both natural factors and socioeconomic elements,we establish an oxygen(O_(2))balance index(OBI),i.e.,the ratio of the O_(2)production from the ecosystem to the O_(2)consumption by human behavior,based on the net primary productivity(NPP),fuel consumption,gross domestic production(GDP),population data,and so on.The results show that the spatial distributions of OBI in China are intimately correlated to the regional vegetation and socioeconomic development.The estimated OBI values are then validated by statistical data from 27 counties in China,and it is found that the OBI reflects the ecological environment status well.Moreover,the average OBI values derived from 190 natural oxygen bars in China reveal extreme imbalance between O_(2)production and consumption in highly developed regions,especially in the cities,in contrast to good O_(2)balance in areas with high-quality ecological status and less industrialization.The findings from this study have quantitatively captured the regional ecological quality,providing guidance for sustainable natural and socioeconomic developments in local areas of China.