In this paper, we study the second-order nonlinear differential systems of Liénard-type x˙=1a(x)[ h(y)−F(x) ], y˙=−a(x)g(x). Necessary and sufficient conditions to ensure that all nontrivial solutions are oscil...In this paper, we study the second-order nonlinear differential systems of Liénard-type x˙=1a(x)[ h(y)−F(x) ], y˙=−a(x)g(x). Necessary and sufficient conditions to ensure that all nontrivial solutions are oscillatory are established by using a new nonlinear integral inequality. Our results substantially extend and improve previous results known in the literature.展开更多
Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-...Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.展开更多
Data stream clustering is integral to contemporary big data applications.However,addressing the ongoing influx of data streams efficiently and accurately remains a primary challenge in current research.This paper aims...Data stream clustering is integral to contemporary big data applications.However,addressing the ongoing influx of data streams efficiently and accurately remains a primary challenge in current research.This paper aims to elevate the efficiency and precision of data stream clustering,leveraging the TEDA(Typicality and Eccentricity Data Analysis)algorithm as a foundation,we introduce improvements by integrating a nearest neighbor search algorithm to enhance both the efficiency and accuracy of the algorithm.The original TEDA algorithm,grounded in the concept of“Typicality and Eccentricity Data Analytics”,represents an evolving and recursive method that requires no prior knowledge.While the algorithm autonomously creates and merges clusters as new data arrives,its efficiency is significantly hindered by the need to traverse all existing clusters upon the arrival of further data.This work presents the NS-TEDA(Neighbor Search Based Typicality and Eccentricity Data Analysis)algorithm by incorporating a KD-Tree(K-Dimensional Tree)algorithm integrated with the Scapegoat Tree.Upon arrival,this ensures that new data points interact solely with clusters in very close proximity.This significantly enhances algorithm efficiency while preventing a single data point from joining too many clusters and mitigating the merging of clusters with high overlap to some extent.We apply the NS-TEDA algorithm to several well-known datasets,comparing its performance with other data stream clustering algorithms and the original TEDA algorithm.The results demonstrate that the proposed algorithm achieves higher accuracy,and its runtime exhibits almost linear dependence on the volume of data,making it more suitable for large-scale data stream analysis research.展开更多
The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalit...The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalities(e.g.,high voltage,flexibility,stretchability,self-healing,electrochromism and photo/thermal response)to PMSCs is essential for building multifunctional PMSCs and their smart selfpowered integrated microsystems.In this review,we summarized the latest advances in PMSCs from various functional microdevices to their smart integrated microsystems.Primarily,the functionalities of PMSCs are characterized by three major factors to emphasize their electrochemical behavior and unique scope of application.These include but are not limited to high-voltage outputs(realized through asymmetric configuration,novel electrolyte and modular integration),mechanical resilience that includes various feats of flexibility or stretchability,and response to stimuli(self-healing,electrochromic,photo-responsive,or thermal-responsive properties).Furthermore,three representative integrated microsystems including energy harvester-PMSC,PMSC-energy consumption,and all-in-one selfpowered microsystems are elaborately overviewed to understand the emerging intelligent interaction models.Finally,the key perspectives,challenges and opportunities of PMSCs for powering smart microelectronics are proposed in brief.展开更多
Objective:The aim of this study was to prospectively compare double-tract reconstruction(DTR)and esophagogastrostomy(EG)after proximal gastrectomy(PG)regarding the incidence of reflux esophagitis,quality of life(QOL),...Objective:The aim of this study was to prospectively compare double-tract reconstruction(DTR)and esophagogastrostomy(EG)after proximal gastrectomy(PG)regarding the incidence of reflux esophagitis,quality of life(QOL),nutritional status and surgical safety.Methods:This study was a randomized controlled trial.Patients eligible for PG were enrolled and randomly assigned to the EG group and DTR group.The characteristics of patients,parameters for surgical safety,incidence of reflux esophagitis,nutrition status and QOL were collected and compared between the two groups.Univariate analysis and multivariate analysis were performed to determine the significant factors affecting the incidence of reflux esophagitis after PG.Results:Thirty-seven patients of the EG group and 36 patients of the DTR group were enrolled.The incidence of reflux esophagitis was significantly lower in the DTR group than in the EG group(8.3%vs.32.4%,P=0.019).The DTR group demonstrated a more favorable QOL than the EG group after PG.The nutritional status was balanced within the EG group and the DTR group.The operation time was longer in the DTR group than in the EG group(191 min vs.221 min,P=0.001),while surgical safety was similar in the two groups.Conclusions:Our research demonstrated that DTR is superior to EG after PG in terms of the incidence of reflux esophagitis and provides a more satisfactory QOL without increasing surgical complications or sacrificing nutritional status.展开更多
Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oats...Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oatsβ-glucan oligosaccharides(OGOS),Astragalus polysaccharides(APS),Astragalus oligosaccharides(AOS),xanthan gum oligosaccharides(XGOS),gellan gum oligosaccharides(GGOS),curdlan oligosaccharides(COS),and pullulan oligosaccharides(POS)were used to investigate NDC specifi city in modulating butyrate-producing bacteria and butyrate production in 48 h in vitro fermentation studies in combination with fecal inocula from 7 healthy donors and 11 patients with type 2 diabetes(T2D).We observed that the amount of these ten NDCs utilized depended on NDC structure and inter-individual gut microbial differences.XGOS and GGOS fermentations signifi cantly increased butyrate-producing bacteria(especially f_Lachnospiraceae)and butyric acid production.Furthermore,XGOS and GGOS fermentations showed a better ability to consistently modulate gut microbiota composition and metabolic properties between individuals of healthy donors or T2D patients when compared to inulin,FOS,APS,AOS,OGS,OGOS,COS and POS fermentation.This research indicated that xanthan gum and gellan gum oligosaccharides have strong specifi city to enhance butyrate-producing bacteria and butyrate production.展开更多
Patients with posterior circulation infarction underwent CT angiography and magnetic resonance angiography. Intracranial and extracranial vasculopathy was evaluated according to age group and location of stroke. Patie...Patients with posterior circulation infarction underwent CT angiography and magnetic resonance angiography. Intracranial and extracranial vasculopathy was evaluated according to age group and location of stroke. Patients aged 〉 60 years and 〈 60 years had similar rates of vertebral artery dominance and vertebrobasilar artery developmental or origin anomalies. Vertebrobasilar artery stenosis or occlusion and tortuosity occurred more frequently in patients aged 〉 60 years than 〈 60 years. The rates of vertebrobasilar artery anomalies and tortuosity were high in patients with posterior circulation infarction. Vertebrobasilar artery tortuosity occurred more frequently in patients aged 〉 60 years, whereas vertebrobasilar artery developmental anomalies occurred with similar frequency in patients aged 〈 60 years and 〉 60 years. Patients with infarction of the brainstem or cerebellum were more ~ikely to have vertebral artery stenosis or occlusion, basi^ar artery stenosis or occlusion, vertebral artery dominance or tortuosity, and basilar artery tortuosity, and patients with infarction of the thalamus, medial temporal, or occipital lobes were more likely to have stenosis or occlusion of the vertebral or basilar arteries. Vertebrobasilar artery tortuosity, vertebral artery dominance （hypoplasia）, and congenital variations of the vertebrobasilar system may lead to posterior circulation infarction at different locations in different age groups.展开更多
It is difficult to rapidly design the process parameters of copper alloys by using the traditional trial-and-error method and simultaneously improve the conflicting mechanical and electrical properties.The purpose of ...It is difficult to rapidly design the process parameters of copper alloys by using the traditional trial-and-error method and simultaneously improve the conflicting mechanical and electrical properties.The purpose of this work is to develop a new type of Cu-Ni-Co-Si alloy saving scarce and expensive Co element,in which the Co content is less than half of the lower limit in ASTM standard C70350 alloy,while the properties are as the same level as C70350 alloy.Here we adopted a strategy combining Bayesian optimization machine learning and experimental iteration and quickly designed the secondary deformation-aging parameters(cold rolling deformation 90%,aging temperature 450℃,and aging time 1.25 h)of the new copper alloy with only 32 experiments(27 basic sample data acquisition experiments and 5 iteration experiments),which broke through the barrier of low efficiency and high cost of trial-and-error design of deformation-aging parameters in precipitation strengthened copper alloy.The experimental hardness,tensile strength,and electrical conductivity of the new copper alloy are HV(285±4),(872±3)MPa,and(44.2±0.7)%IACS(international annealed copper standard),reaching the property level of the commercial lead frame C70350 alloy.This work provides a new idea for the rapid design of material process parameters and the simultaneous improvement of mechanical and electrical properties.展开更多
Alloys designed with the traditional trial and error method have encountered several problems,such as long trial cycles and high costs.The rapid development of big data and artificial intelligence provides a new path ...Alloys designed with the traditional trial and error method have encountered several problems,such as long trial cycles and high costs.The rapid development of big data and artificial intelligence provides a new path for the efficient development of metallic materials,that is,machine learning-assisted design.In this paper,the basic strategy for the machine learning-assisted rational design of alloys was introduced.Research progress in the property-oriented reversal design of alloy composition,the screening design of alloy composition based on models established using element physical and chemical features or microstructure factors,and the optimal design of alloy composition and process parameters based on iterative feedback optimization was reviewed.Results showed the great advantages of machine learning,including high efficiency and low cost.Future development trends for the machine learning-assisted rational design of alloys were also discussed.Interpretable modeling,integrated modeling,high-throughput combination,multi-objective optimization,and innovative platform building were suggested as fields of great interest.展开更多
BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation duri...BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.展开更多
The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanicai approach. Firstly, on the microscopic level, a representative volume element （...The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanicai approach. Firstly, on the microscopic level, a representative volume element （RVE） is selected to reflect the microstructures of the composite materials and the constituents are assumed to be elastic perfectly-plastic. Based on the homogenization theory and the static limit theorem, an optimization formulation to directly calculate the macroscopic strength domain of the RVE is obtained. The finite element modeling of the static limit analysis is formulated as a nonlinear mathematical programming and solved by the sequential quadratic programming method, where the temperature parameter method is used to construct the self-stress field. Secondly, Hill＇s yield criterion is adopted to connect the micromechanicai and macromechanical analyses. And the limit loads of composite structures are worked out on the macroscopic scale. Finally, some examples and comparisons are shown.展开更多
Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared...Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared by the conventional precipitation method. Among various procedures for ethanol induced method, it was found that incorporation of ethanol in the precipitation process was the better. After incorporation of ethanol, the crystal size of CuO decreased and the reduction of copper species became easier. The better activity of Cu-Fe-Zr catalysts prepared by ethanol induced procedures was probably caused by the higher dispersion of Cu species.展开更多
Forkhead box P3 (FOXP3) is a “master regulator” of regulatory T cells (Tregs), which are a subset of T cells that can suppress the antigen-specific immune reaction and that play important roles in host tolerance and...Forkhead box P3 (FOXP3) is a “master regulator” of regulatory T cells (Tregs), which are a subset of T cells that can suppress the antigen-specific immune reaction and that play important roles in host tolerance and immune homeostasis. It is well known that FOXP3 forms complexes with several proteins and can be regulated by various post-translational modifications (PTMs) such as acetylation, phosphorylation, ubiquitination, and methylation. As a consequence, the PTMs change the stability of FOXP3 and its capability to regulate gene expression, and eventually affect Treg activity. Although FOXP3 per se is not an ideal drug target, deacetylases, acetyltransferases, kinases, and other enzymes that regulate the PTMs of FOXP3 are potential targets to modulate FOXP3 and Treg activity. However, FOXP3 is not the only substrate for most of these enzymes;thus, unwanted ‘‘on target/off FOXP3” side effects must be considered when inhibitors to these enzymes are used. In this review, we summarize recent progress in the study of FOXP3 cofactors and PTM proteins, and potential clinical applications in autoimmunity and cancer immunity.展开更多
Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ra...Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.展开更多
Chinese rice wine making is a typical simultaneous saccharification and fermentation （SSF） process. During the fermentation process, temperature is one of the key parameters which decide the quality of Chinese rice ...Chinese rice wine making is a typical simultaneous saccharification and fermentation （SSF） process. During the fermentation process, temperature is one of the key parameters which decide the quality of Chinese rice wine. To optimize the SSF process for Chinese rice wine brewing, the effects of temperature on the kinetic parameters of yeast growth and ethanol production at various temperatures were determined in batch cultures using a mathematical model. The kinetic parameters as a function of temperature were evaluated using the software Origin8.0. Combing these functions with the mathematical model, an appropriate form of the model equations for the SSF considering the effects of temperature were developed. The kinetic parameters were found to fit the experimental data satisfactorily with the developed temperature-dependent model. The temperature profile for maximizing the ethanol production for rice wine fermentation was determined by genetic algorithm. The optimum temperature profile began at a low temperature of 26℃ up to 30 h. The operating temperature increased rapidly to 31.9 ℃, and then decreased slowly to 18℃ at 65 h. Thereafter, the temperature was maintained at 18 ℃ until the end of fermentation. A maximum ethanol production of 89.3 g.L 1 was attained. Conceivably, our model would facilitate the improvement of Chinese rice wine production at the industrial scale.展开更多
This paper discusses the new progress and field application of CO2 flooding in low permeability reservoirs enhanced oil recovery. The study shows that CO2 flooding can improve the oil recovery rate of low permeability...This paper discusses the new progress and field application of CO2 flooding in low permeability reservoirs enhanced oil recovery. The study shows that CO2 flooding can improve the oil recovery rate of low permeability oilfield by more than 10%. The practice shows that the liquid CO2 injection in low permeability reservoir is easier than water injection, and the reservoir generally has better CO2 storage.展开更多
Xiangjiaba hydropowcr station is one of the complicated geological conditions of its dam foundation, parameters of rock masses are very important issues. To cascade power stations on the Jinsha River, China. Due to th...Xiangjiaba hydropowcr station is one of the complicated geological conditions of its dam foundation, parameters of rock masses are very important issues. To cascade power stations on the Jinsha River, China. Due to the evaluating the rock mass quality and determining the mechanical address these issues, several groups of rock borehole shear tests （RBSTs） were conducted on the black mudstone in the dam foundation of Xiangjiaba hydropower station in the second construction phase. Forty three groups of shear strengths of black mudstone samples were obtained from RBSTs, and the shear strength parameters （c and f） were calculated using the least squares method. In addition, the limitations and merits of RBST employed in the Xiangjiaba hydropower station were discussed. Test results indicate that the shear strength parameters obtained from RBST have a good correlation with the results from sotmd wave test in borehole. It is believed that RBST has a good adaptability and applicability in geotechnical engineering.展开更多
Background： Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fraction...Background： Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods： To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet（HFD） or a high energy diet（HED） were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results： Rumen bacterial diversity was mainly affected by diet and individual cow（P 〉 0.05） rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers（using LEf Se analysis） were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions： Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.展开更多
文摘In this paper, we study the second-order nonlinear differential systems of Liénard-type x˙=1a(x)[ h(y)−F(x) ], y˙=−a(x)g(x). Necessary and sufficient conditions to ensure that all nontrivial solutions are oscillatory are established by using a new nonlinear integral inequality. Our results substantially extend and improve previous results known in the literature.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3803101)the National Natural Science Foundation of China(Nos.52022011,51974028,and 52090041)+1 种基金the Xiaomi Young Scholars ProgramChina National Postdoctoral Program for Innovative Talents(No.BX20230042)。
文摘Solid solution-strengthened copper alloys have the advantages of a simple composition and manufacturing process,high mechanical and electrical comprehensive performances,and low cost;thus,they are widely used in high-speed rail contact wires,electronic component connectors,and other devices.Overcoming the contradiction between low alloying and high performance is an important challenge in the development of solid solution-strengthened copper alloys.Taking the typical solid solution-strengthened alloy Cu-4Zn-1Sn as the research object,we proposed using the element In to replace Zn and Sn to achieve low alloying in this work.Two new alloys,Cu-1.5Zn-1Sn-0.4In and Cu-1.5Zn-0.9Sn-0.6In,were designed and prepared.The total weight percentage content of alloying elements decreased by 43%and 41%,respectively,while the product of ultimate tensile strength(UTS)and electrical conductivity(EC)of the annealed state increased by 14%and 15%.After cold rolling with a 90%reduction,the UTS of the two new alloys reached 576 and 627MPa,respectively,the EC was 44.9%IACS and 42.0%IACS,and the product of UTS and EC(UTS×EC)was 97%and 99%higher than that of the annealed state alloy.The dislocations proliferated greatly in cold-rolled alloys,and the strengthening effects of dislocations reached 332 and 356 MPa,respectively,which is the main reason for the considerable improvement in mechanical properties.
基金This research was funded by the National Natural Science Foundation of China(Grant No.72001190)by the Ministry of Education’s Humanities and Social Science Project via the China Ministry of Education(Grant No.20YJC630173)by Zhejiang A&F University(Grant No.2022LFR062).
文摘Data stream clustering is integral to contemporary big data applications.However,addressing the ongoing influx of data streams efficiently and accurately remains a primary challenge in current research.This paper aims to elevate the efficiency and precision of data stream clustering,leveraging the TEDA(Typicality and Eccentricity Data Analysis)algorithm as a foundation,we introduce improvements by integrating a nearest neighbor search algorithm to enhance both the efficiency and accuracy of the algorithm.The original TEDA algorithm,grounded in the concept of“Typicality and Eccentricity Data Analytics”,represents an evolving and recursive method that requires no prior knowledge.While the algorithm autonomously creates and merges clusters as new data arrives,its efficiency is significantly hindered by the need to traverse all existing clusters upon the arrival of further data.This work presents the NS-TEDA(Neighbor Search Based Typicality and Eccentricity Data Analysis)algorithm by incorporating a KD-Tree(K-Dimensional Tree)algorithm integrated with the Scapegoat Tree.Upon arrival,this ensures that new data points interact solely with clusters in very close proximity.This significantly enhances algorithm efficiency while preventing a single data point from joining too many clusters and mitigating the merging of clusters with high overlap to some extent.We apply the NS-TEDA algorithm to several well-known datasets,comparing its performance with other data stream clustering algorithms and the original TEDA algorithm.The results demonstrate that the proposed algorithm achieves higher accuracy,and its runtime exhibits almost linear dependence on the volume of data,making it more suitable for large-scale data stream analysis research.
基金the National Natural Science Foundation of China,China (Grant Nos.22125903,51872283,22109040)the“Transformational Technologies for Clean Energy and Demonstration”Strategic Priority Research Program of the Chinese Academy of Sciences (Grant No.XDA21000000)+4 种基金the Dalian Innovation Support Plan for High Level Talents,China (2019RT09)DICP,China (DICP I202032)the Dalian National Laboratory For Clean Energy (DNL),CAS,DNL Cooperation Fund,CAS,China (DNL202016,DNL202019)the Top-Notch Talent Program of Henan Agricultural University,China (30500947)the Joint Fund of the Yulin University and the Dalian National Laboratory for Clean Energy,China (YLU-DNL Fund 2021002,YLU-DNL Fund 2021009)。
文摘The popularization of portable,implantable and wearable microelectronics has greatly stimulated the rapid development of high-power planar micro-supercapacitors(PMSCs).Particularly,the introduction of new functionalities(e.g.,high voltage,flexibility,stretchability,self-healing,electrochromism and photo/thermal response)to PMSCs is essential for building multifunctional PMSCs and their smart selfpowered integrated microsystems.In this review,we summarized the latest advances in PMSCs from various functional microdevices to their smart integrated microsystems.Primarily,the functionalities of PMSCs are characterized by three major factors to emphasize their electrochemical behavior and unique scope of application.These include but are not limited to high-voltage outputs(realized through asymmetric configuration,novel electrolyte and modular integration),mechanical resilience that includes various feats of flexibility or stretchability,and response to stimuli(self-healing,electrochromic,photo-responsive,or thermal-responsive properties).Furthermore,three representative integrated microsystems including energy harvester-PMSC,PMSC-energy consumption,and all-in-one selfpowered microsystems are elaborately overviewed to understand the emerging intelligent interaction models.Finally,the key perspectives,challenges and opportunities of PMSCs for powering smart microelectronics are proposed in brief.
基金supported by the Beijing Municipal Administration of Hospitals Incubating Program(No.PX2019039)。
文摘Objective:The aim of this study was to prospectively compare double-tract reconstruction(DTR)and esophagogastrostomy(EG)after proximal gastrectomy(PG)regarding the incidence of reflux esophagitis,quality of life(QOL),nutritional status and surgical safety.Methods:This study was a randomized controlled trial.Patients eligible for PG were enrolled and randomly assigned to the EG group and DTR group.The characteristics of patients,parameters for surgical safety,incidence of reflux esophagitis,nutrition status and QOL were collected and compared between the two groups.Univariate analysis and multivariate analysis were performed to determine the significant factors affecting the incidence of reflux esophagitis after PG.Results:Thirty-seven patients of the EG group and 36 patients of the DTR group were enrolled.The incidence of reflux esophagitis was significantly lower in the DTR group than in the EG group(8.3%vs.32.4%,P=0.019).The DTR group demonstrated a more favorable QOL than the EG group after PG.The nutritional status was balanced within the EG group and the DTR group.The operation time was longer in the DTR group than in the EG group(191 min vs.221 min,P=0.001),while surgical safety was similar in the two groups.Conclusions:Our research demonstrated that DTR is superior to EG after PG in terms of the incidence of reflux esophagitis and provides a more satisfactory QOL without increasing surgical complications or sacrificing nutritional status.
基金supported by the National Key R&D Program of China(2021YFC2101100)Project funded by China Postdoctoral Science Foundation(2021M701463)+2 种基金the National Key R&D Program of China(2017YFD0400302)the National first-class discipline program of light industry technology and engineering(LITE2018-17)the Program of Introducing Talents of Discipline to Universities(111-2-06).
文摘Butyrate and butyrate-producing bacteria are important indicators of gut microbial metabolism in human health.Ten non-digestible carbohydrates(NDCs),including inulin,fructooligosaccharide(FOS),oatsβ-glucans(OGS),oatsβ-glucan oligosaccharides(OGOS),Astragalus polysaccharides(APS),Astragalus oligosaccharides(AOS),xanthan gum oligosaccharides(XGOS),gellan gum oligosaccharides(GGOS),curdlan oligosaccharides(COS),and pullulan oligosaccharides(POS)were used to investigate NDC specifi city in modulating butyrate-producing bacteria and butyrate production in 48 h in vitro fermentation studies in combination with fecal inocula from 7 healthy donors and 11 patients with type 2 diabetes(T2D).We observed that the amount of these ten NDCs utilized depended on NDC structure and inter-individual gut microbial differences.XGOS and GGOS fermentations signifi cantly increased butyrate-producing bacteria(especially f_Lachnospiraceae)and butyric acid production.Furthermore,XGOS and GGOS fermentations showed a better ability to consistently modulate gut microbiota composition and metabolic properties between individuals of healthy donors or T2D patients when compared to inulin,FOS,APS,AOS,OGS,OGOS,COS and POS fermentation.This research indicated that xanthan gum and gellan gum oligosaccharides have strong specifi city to enhance butyrate-producing bacteria and butyrate production.
基金supported by Bureau of Science and Technology of Zhengzhou City, No.12199TGG494-12
文摘Patients with posterior circulation infarction underwent CT angiography and magnetic resonance angiography. Intracranial and extracranial vasculopathy was evaluated according to age group and location of stroke. Patients aged 〉 60 years and 〈 60 years had similar rates of vertebral artery dominance and vertebrobasilar artery developmental or origin anomalies. Vertebrobasilar artery stenosis or occlusion and tortuosity occurred more frequently in patients aged 〉 60 years than 〈 60 years. The rates of vertebrobasilar artery anomalies and tortuosity were high in patients with posterior circulation infarction. Vertebrobasilar artery tortuosity occurred more frequently in patients aged 〉 60 years, whereas vertebrobasilar artery developmental anomalies occurred with similar frequency in patients aged 〈 60 years and 〉 60 years. Patients with infarction of the brainstem or cerebellum were more ~ikely to have vertebral artery stenosis or occlusion, basi^ar artery stenosis or occlusion, vertebral artery dominance or tortuosity, and basilar artery tortuosity, and patients with infarction of the thalamus, medial temporal, or occipital lobes were more likely to have stenosis or occlusion of the vertebral or basilar arteries. Vertebrobasilar artery tortuosity, vertebral artery dominance （hypoplasia）, and congenital variations of the vertebrobasilar system may lead to posterior circulation infarction at different locations in different age groups.
基金supported by the National Key Research and Development Program of China(No.2021YFB 3803101)the National Natural Science Foundation of China(Nos.52090041,52022011,and 51974028)。
文摘It is difficult to rapidly design the process parameters of copper alloys by using the traditional trial-and-error method and simultaneously improve the conflicting mechanical and electrical properties.The purpose of this work is to develop a new type of Cu-Ni-Co-Si alloy saving scarce and expensive Co element,in which the Co content is less than half of the lower limit in ASTM standard C70350 alloy,while the properties are as the same level as C70350 alloy.Here we adopted a strategy combining Bayesian optimization machine learning and experimental iteration and quickly designed the secondary deformation-aging parameters(cold rolling deformation 90%,aging temperature 450℃,and aging time 1.25 h)of the new copper alloy with only 32 experiments(27 basic sample data acquisition experiments and 5 iteration experiments),which broke through the barrier of low efficiency and high cost of trial-and-error design of deformation-aging parameters in precipitation strengthened copper alloy.The experimental hardness,tensile strength,and electrical conductivity of the new copper alloy are HV(285±4),(872±3)MPa,and(44.2±0.7)%IACS(international annealed copper standard),reaching the property level of the commercial lead frame C70350 alloy.This work provides a new idea for the rapid design of material process parameters and the simultaneous improvement of mechanical and electrical properties.
基金financially supported by the National Key Research and Development Program of China(No.2021YFB3803101)National Natural Science Foundation of China(Nos.51974028 and 52022011)the Beijing Municipal Science and Technology Commission(No.Z191100001119125)。
文摘Alloys designed with the traditional trial and error method have encountered several problems,such as long trial cycles and high costs.The rapid development of big data and artificial intelligence provides a new path for the efficient development of metallic materials,that is,machine learning-assisted design.In this paper,the basic strategy for the machine learning-assisted rational design of alloys was introduced.Research progress in the property-oriented reversal design of alloy composition,the screening design of alloy composition based on models established using element physical and chemical features or microstructure factors,and the optimal design of alloy composition and process parameters based on iterative feedback optimization was reviewed.Results showed the great advantages of machine learning,including high efficiency and low cost.Future development trends for the machine learning-assisted rational design of alloys were also discussed.Interpretable modeling,integrated modeling,high-throughput combination,multi-objective optimization,and innovative platform building were suggested as fields of great interest.
基金the National Natural Science Foundation of China, No. 3067104130870642
文摘BACKGROUND： Transplantation of human umbilical cord blood-derived mesenchymal stem cells （MSCs） has been shown to benefit spinal cord injury （SCI） repair. However, mechanisms of microenvironmental regulation during differentiation of transplanted MSCs remain poorly understood. OBJECTIVE： To observe changes in nerve growth factor （NGF）, brain-derived neurotrophic factor （BDNF）, and interleukin-8 （IL-8） expression following transplantation of human umbilical cord-derived MSCs, and to explore the association between microenvironment and neural functional recovery following MSCs transplantation. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment was performed at the Department of Orthopedics, First Affiliated Hospital of Soochow University from April 2005 to March 2007. MATERIALS： Human cord blood samples were provided by the Department of Gynecology and Obstetrics, First Affiliated Hospital of Soochow University. Written informed consent was obtained. METHODS： A total of 62 Wister rats were randomly assigned to control （n = 18）, model （n = 22, SCI ＋ PBS）, and transplantation （n = 22, SCI ＋ MSCs） groups. The rat SCI model was established using the weight compression method. MSCs were isolated from human umbilical cord blood and cultured in vitro for several passages. 5-bromodeoxyuridine （BrdU）-Iabeled MSCs （24 hours before injection） were intravascularly transplanted. MAIN OUTCOME MEASURES： The rats were evaluated using the Basso, Beattie and Bresnahan （BBB） locomotor score and inclined plane tests. Transplanted cells were analyzed following immunohistochemistry. Enzyme-linked immunosorbant assay was performed to determine NGF, BDNF, and IL-8 levels prior to and after cell transplantation. RESULTS： A large number of BrdU-positive MSCs were observed in the SCI region of the transplantation group, and MSCs were evenly distributed in injured spinal cord tissue 1 week after transplantation. BBB score and inclined plane test results revealed significant functional improvement in the transplantation group compared to the model group （P 〈 0.05）, which was maintained for 2-3 weeks. Compared to the model group, NGF and BDNF levels were significantly increased in the injured region following MSCs transplantation at 3 weeks （P 〈 0.05）, but IL-8 levels remained unchanged （P 〉 0.05）. CONCLUSION： MSCs transplantation increased NGF and BDNF expression in injured spinal cord tissue. MSCs could promote neurological function recovery in SCI rats by upregulating NGF expression and improving regional microenvironments.
基金supported by the National Natural Science Foundation of China (No.50809003)the National Foundation for Excellent Doctorial Dissertation of China (200025).
文摘The load-bearing capacity of ductile composite structures comprised of periodic composites is studied by a combined micro/macromechanicai approach. Firstly, on the microscopic level, a representative volume element （RVE） is selected to reflect the microstructures of the composite materials and the constituents are assumed to be elastic perfectly-plastic. Based on the homogenization theory and the static limit theorem, an optimization formulation to directly calculate the macroscopic strength domain of the RVE is obtained. The finite element modeling of the static limit analysis is formulated as a nonlinear mathematical programming and solved by the sequential quadratic programming method, where the temperature parameter method is used to construct the self-stress field. Secondly, Hill＇s yield criterion is adopted to connect the micromechanicai and macromechanical analyses. And the limit loads of composite structures are worked out on the macroscopic scale. Finally, some examples and comparisons are shown.
基金Natural Science Foundation of State Key Laboratory of Coal Conversion(No09-610)
文摘Ethanol induced method was applied to prepare Cu-Fe-Zr catalysts for conversion of syngas to higher alcohols. The catalytic performance of the catalysts induced by ethanol was superior to that of the catalyst prepared by the conventional precipitation method. Among various procedures for ethanol induced method, it was found that incorporation of ethanol in the precipitation process was the better. After incorporation of ethanol, the crystal size of CuO decreased and the reduction of copper species became easier. The better activity of Cu-Fe-Zr catalysts prepared by ethanol induced procedures was probably caused by the higher dispersion of Cu species.
基金grant supports from the Breast Cancer Research Foundation and the National Institutes of Health to M.I.Greene(RO1CA219034)
文摘Forkhead box P3 (FOXP3) is a “master regulator” of regulatory T cells (Tregs), which are a subset of T cells that can suppress the antigen-specific immune reaction and that play important roles in host tolerance and immune homeostasis. It is well known that FOXP3 forms complexes with several proteins and can be regulated by various post-translational modifications (PTMs) such as acetylation, phosphorylation, ubiquitination, and methylation. As a consequence, the PTMs change the stability of FOXP3 and its capability to regulate gene expression, and eventually affect Treg activity. Although FOXP3 per se is not an ideal drug target, deacetylases, acetyltransferases, kinases, and other enzymes that regulate the PTMs of FOXP3 are potential targets to modulate FOXP3 and Treg activity. However, FOXP3 is not the only substrate for most of these enzymes;thus, unwanted ‘‘on target/off FOXP3” side effects must be considered when inhibitors to these enzymes are used. In this review, we summarize recent progress in the study of FOXP3 cofactors and PTM proteins, and potential clinical applications in autoimmunity and cancer immunity.
文摘Well-shaped spherical agglomerates of FePO4 particles were prepared by a novel method:chemical co-precipitation combined with spray-drying.Tap density analysis,Brunauer-Emmett-Teller analysis,characterizations of X-ray diffraction,scanning electron microscopy,and transmission electron microscopy confirmed that the micron-sized spherical agglomerates with high specific surface area and high tap density were composed of the uniform nano-sized particles.The effects of pH and reaction time on the morphology of the FePO4 particles were investigated by experimental and theoretical analyses.The analyses revealed that amorphous FePO4 was responsible for forming a well-shaped spherical agglomerate,and the ideal spherical particles were obtained at pH 3.The reaction time also played a significant role in controlling the size and surface morphology of the FePO4 particles,and smooth spherical FePO4 particles were obtained at a reaction time of 6 h.By this novel method,poly-porous spherical iron phosphate particles were prepared,which can be used with high efficiency in some special fields,especially as a precursor for synthesizing LiFePO4 and catalysts.
基金Supported by the National Natural Science Foundation of China(21276111,21206053,61305017)the Programme of Introducing Talents of Discipline to Universities(B12018)+2 种基金Fundamental Research Funds for the Central Universities(JUSRP11558)the Natural Science Foundation of Jiangsu Province(no.BK20160162)the Fundamental Research Funds for the Central Universities(JUSRP51510)
文摘Chinese rice wine making is a typical simultaneous saccharification and fermentation （SSF） process. During the fermentation process, temperature is one of the key parameters which decide the quality of Chinese rice wine. To optimize the SSF process for Chinese rice wine brewing, the effects of temperature on the kinetic parameters of yeast growth and ethanol production at various temperatures were determined in batch cultures using a mathematical model. The kinetic parameters as a function of temperature were evaluated using the software Origin8.0. Combing these functions with the mathematical model, an appropriate form of the model equations for the SSF considering the effects of temperature were developed. The kinetic parameters were found to fit the experimental data satisfactorily with the developed temperature-dependent model. The temperature profile for maximizing the ethanol production for rice wine fermentation was determined by genetic algorithm. The optimum temperature profile began at a low temperature of 26℃ up to 30 h. The operating temperature increased rapidly to 31.9 ℃, and then decreased slowly to 18℃ at 65 h. Thereafter, the temperature was maintained at 18 ℃ until the end of fermentation. A maximum ethanol production of 89.3 g.L 1 was attained. Conceivably, our model would facilitate the improvement of Chinese rice wine production at the industrial scale.
文摘This paper discusses the new progress and field application of CO2 flooding in low permeability reservoirs enhanced oil recovery. The study shows that CO2 flooding can improve the oil recovery rate of low permeability oilfield by more than 10%. The practice shows that the liquid CO2 injection in low permeability reservoir is easier than water injection, and the reservoir generally has better CO2 storage.
基金Supported by the National Basic Research Program of China(973 Program)(2011CB013502)the Youth Special Foundation of IWHR(YJ1106)
文摘Xiangjiaba hydropowcr station is one of the complicated geological conditions of its dam foundation, parameters of rock masses are very important issues. To cascade power stations on the Jinsha River, China. Due to the evaluating the rock mass quality and determining the mechanical address these issues, several groups of rock borehole shear tests （RBSTs） were conducted on the black mudstone in the dam foundation of Xiangjiaba hydropower station in the second construction phase. Forty three groups of shear strengths of black mudstone samples were obtained from RBSTs, and the shear strength parameters （c and f） were calculated using the least squares method. In addition, the limitations and merits of RBST employed in the Xiangjiaba hydropower station were discussed. Test results indicate that the shear strength parameters obtained from RBST have a good correlation with the results from sotmd wave test in borehole. It is believed that RBST has a good adaptability and applicability in geotechnical engineering.
基金supported by National Dairy Industry and Technology System(CARS-37)National Natural Science Foundation of China(31402099)
文摘Background： Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods： To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet（HFD） or a high energy diet（HED） were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results： Rumen bacterial diversity was mainly affected by diet and individual cow（P 〉 0.05） rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers（using LEf Se analysis） were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions： Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.
