One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between...One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between the gut microbiome and genetic factors.Dysbiosis of the gut flora and elevated polymeric immunoglobulin receptor(pIgR)levels have been observed in both patients and mouse models.Moreover,there is a direct relationship between pIgR expression and transaminase levels in patients with AIH.In this study,we aimed to explore how pIgR influences the secretion of regenerating islet-derived 3 beta(Reg3b)and the flora composition in AIH using in vivo experiments involving patients with AIH and a concanavalin A-induced mouse model of AIH.Reg3b expression was reduced in pIgR gene(Pigr)-knockout mice compared to that in wild-type mice,leading to increased microbiota disruption.Conversely,exogenous pIgR supplementation increased Reg3b expression and maintained microbiota homeostasis.RNA sequencing revealed the participation of the interleukin(IL)-17 signaling pathway in the regulation of Reg3b through pIgR.Furthermore,the introduction of external pIgR could not restore the imbalance in gut microbiota in AIH,and the decrease in Reg3b expression was not apparent following the inhibition of signal transducer and activator of transcription 3(STAT3).In this study,pIgR facilitated the upregulation of Reg3b via the STAT3 pathway,which plays a crucial role in preserving the balance of the intestinal microbiota in AIH.Through this research,we discovered new molecular targets that can be used for the diagnosis and treatment of AIH.展开更多
Isogeometric analysis(IGA)is introduced to establish the direct link between computer-aided design and analysis.It is commonly implemented by Galerkin formulations(isogeometric Galerkin,IGA-G)through the use of nonuni...Isogeometric analysis(IGA)is introduced to establish the direct link between computer-aided design and analysis.It is commonly implemented by Galerkin formulations(isogeometric Galerkin,IGA-G)through the use of nonuniform rational B-splines(NURBS)basis functions for geometric design and analysis.Another promising approach,isogeometric collocation(IGA-C),working directly with the strong form of the partial differential equation(PDE)over the physical domain defined by NURBS geometry,calculates the derivatives of the numerical solution at the chosen collocation points.In a typical IGA,the knot vector of the NURBS numerical solution is only determined by the physical domain.A new perspective on the IGAmethod is proposed in this study to improve the accuracy and convergence of the solution.Solving the PDE with IGA can be regarded as fitting the load function defined on the NURBS geometry(right-hand side)with derivatives of the NURBS numerical solution(left-hand side).Moreover,the design of the knot vector has a close relationship to theNURBS functions to be fitted in the area of data fitting in geometric design.Therefore,the detected feature points of the load function are integrated into the initial knot vector of the physical domainto construct thenewknot vector of thenumerical solution.Then,they are connected seamlessly with the IGA-C framework for its great potential combining the accuracy and smoothness merits with the computational efficiency,which we call isogeometric collocation by fitting load function(IGACL).In numerical experiments,we implement our method to solve 1D,2D,and 3D PDEs and demonstrate the improvement in accuracy by comparing it with the standard IGA-C method.We also verify the superiority in the accuracy of our knot selection scheme when employed in the IGA-G method,which we call isogeometric Galerkin by fitting load function(IGA-GL).展开更多
Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA has...Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.展开更多
In this paper, a new filled function with only one parameter is proposed. The main advantages of the new filled function are that it not only can be analyzed easily, but also can be approximated uniformly by a continu...In this paper, a new filled function with only one parameter is proposed. The main advantages of the new filled function are that it not only can be analyzed easily, but also can be approximated uniformly by a continuously differentiable function. Thus, a minimizer of the proposed filled function can be obtained easily by using a local optimization algorithm. The obtained minimizer is taken as the initial point to minimize the objective function and a better minimizer will be found. By repeating the above processes, we will find a global minimizer at last. The results of numerical experiments show that the new proposed filled function method is effective.展开更多
Poly(L-lactic acid)(PLLA)is a thermoplastic material with complete degradability,high biocompatibility and excellent mechanical properties.It can replace petroleum-based polymers are currently being used in the fields...Poly(L-lactic acid)(PLLA)is a thermoplastic material with complete degradability,high biocompatibility and excellent mechanical properties.It can replace petroleum-based polymers are currently being used in the fields of packaging,agriculture,textiles,medical and so on.However,PLLA’s extremely flammability greatly limits its wider application.An bio-based flame retardant L-APP/PLLA composites was prepared by melt blending of the L-APP and PLLA.The morphology,impact properties,thermal properties and flame retardant properties of composites were investigated by field emission scanning electron microscope(SEM),impact tester,differential scanning calorimeter(DSC),thermogravimetric analyzer(TGA),limiting oxygen indexer(LOI)and horizontalvertical burning tester.The results showed that the degree of crystallization(X_(c))and LOI of L-APP/PLLA composites increased as increasing of L-APP content.What’s more,the impact strength first increased and then decreased,the glass transition temperature(T_(g))and melting temperature(T_(m))do not changed significantly.The impact strength of composites was 9.1 kJ/m^(2) at a 5 wt%loading for L-APP,which was the highest level.When the content of L-APP was 20%,the LOI was 30.8%,the Xc was 42.3%and the UL-94 level was V-0.This research can promote the value-added utilization of lignin and the application of PLLA in the fields of flame retardant materials.展开更多
Visual curve completion is a fundamental problem in understanding the principles of the human visual system. This problem is usually divided into two problems: a grouping problem and a shape problem.On one hand, thoug...Visual curve completion is a fundamental problem in understanding the principles of the human visual system. This problem is usually divided into two problems: a grouping problem and a shape problem.On one hand, though perception of the visually completed curve is clearly a global task(for example,a human perceives the Kanizsa triangle only when seeing all three black objects), conventional methods for solving the grouping problem are generally based on local Gestalt laws. On the other hand, the shape of the visually completed curve is usually recovered by minimizing shape energy in existing methods.However, not only do these methods lack mechanisms to adjust the shape of the recovered visual curve using perceptual, psychophysical, and neurophysiological knowledge, but it is also difficult to calculate an explicit representation of the visually completed curve. In this paper, we present a systematic computational model for generating a visually completed curve. Firstly, based on recent studies of perception, psychophysics, and neurophysiology, we formulate a grouping procedure based on the human visual system by seeking a minimum Hamiltonian cycle in a graph, solving the grouping problem in a global manner. Secondly, we employ a B′ezier curve-based model to represent the visually completed curve. Not only is an explicit representation deduced, but we also present a means to integrate knowledge from related areas, such as perception, psychophysics, and neurophysiology, and so on. The proposed computational model has been validated using many modal and amodal completion examples, and desirable results were obtained.展开更多
A number of studies have suggested that coronavirus disease 2019(COVID-19)can cause liver damage.However,clinical features and outcome of COVID-19 in patients with liver injury remain to be further investigated.In thi...A number of studies have suggested that coronavirus disease 2019(COVID-19)can cause liver damage.However,clinical features and outcome of COVID-19 in patients with liver injury remain to be further investigated.In this study,the clinical data of 265 COVID-19 patients admitted to seven tertiary hospitals were collected.Based on a threshold for transaminase or total bilirubin levels at two times the normal upper limit,patients were divided into mild or moderate/severe liver injury groups.Among the 265 patients,183 patients showed liver injury within 48 hours of admission.Aspartate aminotransferase levels were predominantly elevated in the liver injury group,but albumin levels were reduced.Moreover,fibrinogen and D-dimer were significantly increased.Furthermore,68%of the patients with moderate/severe liver injury had one or more underlying diseases.Almost half of these patients developed acute respiratory distress syndrome(44%)and secondary infections(46%).These patients showed increased interleukin-6 and interleukin-10 levels and a decrease in PaO2 and the oxygenation index.In addition,levels of alanine aminotransferase,aspartate aminotransferase,and albumin were correlated with the oxygenation index,D-dimer and lymphocyte counts.Furthermore,a novel prognostic assessment model based on liver function was established,which accuracy reached 88%and was able to accurately assess the prognosis of COVID-19 patients.展开更多
Diffusion curves can be used to generate vector graphics images with smooth variation by solving Poisson equations. However, using the classical diffusion curve model, it is difficult to ensure that the generated diff...Diffusion curves can be used to generate vector graphics images with smooth variation by solving Poisson equations. However, using the classical diffusion curve model, it is difficult to ensure that the generated diffusion image satisfies desired constraints. In this paper, we develop a model for producing a diffusion image by solving a diffusion equation with diffusion coefficients, in which color layers and coefficient layers are introduced to facilitate the generation of the diffusion image. Doing so allows us to impose various constraints on the diffusion image, such as diffusion strength, diffusion direction,diffusion points, etc., in a unified computational framework. Various examples are presented in this paper to illustrate the capabilities of our model.展开更多
基金supported by the National Natural Science Foundation of China(82070593)the Zhejiang Provincial Natural Science Foundation(LD21H030002)+1 种基金the Department of Science and Technology of Zhejiang Province(ZY2019008)the Youth Program of the National Natural Science Foundation of China(82200632).
文摘One-third of patients with autoimmune hepatitis(AIH)have cirrhosis at the time of diagnosis.The relevance of these variables,although unknown,is believed to be critical in AIH because of suspected interactions between the gut microbiome and genetic factors.Dysbiosis of the gut flora and elevated polymeric immunoglobulin receptor(pIgR)levels have been observed in both patients and mouse models.Moreover,there is a direct relationship between pIgR expression and transaminase levels in patients with AIH.In this study,we aimed to explore how pIgR influences the secretion of regenerating islet-derived 3 beta(Reg3b)and the flora composition in AIH using in vivo experiments involving patients with AIH and a concanavalin A-induced mouse model of AIH.Reg3b expression was reduced in pIgR gene(Pigr)-knockout mice compared to that in wild-type mice,leading to increased microbiota disruption.Conversely,exogenous pIgR supplementation increased Reg3b expression and maintained microbiota homeostasis.RNA sequencing revealed the participation of the interleukin(IL)-17 signaling pathway in the regulation of Reg3b through pIgR.Furthermore,the introduction of external pIgR could not restore the imbalance in gut microbiota in AIH,and the decrease in Reg3b expression was not apparent following the inhibition of signal transducer and activator of transcription 3(STAT3).In this study,pIgR facilitated the upregulation of Reg3b via the STAT3 pathway,which plays a crucial role in preserving the balance of the intestinal microbiota in AIH.Through this research,we discovered new molecular targets that can be used for the diagnosis and treatment of AIH.
基金supported by the National Natural Science Foundation of China under Grant Nos.61872316,62272406,61932018the National Key R&D Plan of China under Grant No.2020YFB1708900.
文摘Isogeometric analysis(IGA)is introduced to establish the direct link between computer-aided design and analysis.It is commonly implemented by Galerkin formulations(isogeometric Galerkin,IGA-G)through the use of nonuniform rational B-splines(NURBS)basis functions for geometric design and analysis.Another promising approach,isogeometric collocation(IGA-C),working directly with the strong form of the partial differential equation(PDE)over the physical domain defined by NURBS geometry,calculates the derivatives of the numerical solution at the chosen collocation points.In a typical IGA,the knot vector of the NURBS numerical solution is only determined by the physical domain.A new perspective on the IGAmethod is proposed in this study to improve the accuracy and convergence of the solution.Solving the PDE with IGA can be regarded as fitting the load function defined on the NURBS geometry(right-hand side)with derivatives of the NURBS numerical solution(left-hand side).Moreover,the design of the knot vector has a close relationship to theNURBS functions to be fitted in the area of data fitting in geometric design.Therefore,the detected feature points of the load function are integrated into the initial knot vector of the physical domainto construct thenewknot vector of thenumerical solution.Then,they are connected seamlessly with the IGA-C framework for its great potential combining the accuracy and smoothness merits with the computational efficiency,which we call isogeometric collocation by fitting load function(IGACL).In numerical experiments,we implement our method to solve 1D,2D,and 3D PDEs and demonstrate the improvement in accuracy by comparing it with the standard IGA-C method.We also verify the superiority in the accuracy of our knot selection scheme when employed in the IGA-G method,which we call isogeometric Galerkin by fitting load function(IGA-GL).
基金This work was financially supported by the following funds:National Natural Science Foundation of China(51803055)Hunan Provincial Natural Foundation of China(2019JJ50472)+5 种基金Scientific Research Fund of Hunan Provincial Education Department of China(18C0979,19A391)Opening Fund of National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources(KF201802)Hunan Province Key Field R&D Program Project(2019GK2246)Key Scientific Research Project of Huaihua University(HHUY2019-04)Hunan Provincial Key Research and Development Program(2018GK2062)Science and Technology Plan Project of Huaihua City(2020R3101).
文摘Polyvinyl alcohol (PVA) has been widely used in the fields of medical, food and packaging due to its excellentbiocompatibility, good fiber-forming and film-forming properties. However, the high flammability of PVA hasgreatly limited its wider applications. The flame-retardant PVA was prepared by melt blending of a bio-basedflame retardant (prepared from lignin, phosphoric acid and carbamide) with thermoplastic PVA (TPVA). Thechemical structure, morphology, thermal properties, mechanical properties, fire property and fluidity of thisflame retardant PVA were investigated by Fourier transform infrared spectrometer(FTIR), field emission scanning electron microscope(SEM), thermogravimetric analyzer(TGA), impact tester, universal testing machine,horizontal-vertical burning tester, limiting oxygen indexer(LOI) and melt flow rate meter(MFR). The resultsshowed that the prepared flame retardant had good compatibility with the PVA substrate;The impact strength,melt flow rate, fire property and char residue of this PVA material increased with the content of bio-based flameretardant. When the content of flame retardant was of 20%, the five indices including impact strength, meltflow rate, UL-94 level, LOI and char residual were 11.3 KJ/m^(2), 21.2 g/10 min, V-0 UL-94 level, 33.1%, and19.2%, respectively. This research can promote the high-value utilization of lignin and the application ofPVA in the fields of fire protection.
文摘In this paper, a new filled function with only one parameter is proposed. The main advantages of the new filled function are that it not only can be analyzed easily, but also can be approximated uniformly by a continuously differentiable function. Thus, a minimizer of the proposed filled function can be obtained easily by using a local optimization algorithm. The obtained minimizer is taken as the initial point to minimize the objective function and a better minimizer will be found. By repeating the above processes, we will find a global minimizer at last. The results of numerical experiments show that the new proposed filled function method is effective.
基金This work was financially supported by the following funds:Hunan Provincial Natural Foundation of China(2019JJ50472)Opening Fund of National&Local Joint Engineering Laboratory for New Petro-chemical Materials and Fine Utilization of Resources(KF201802)+4 种基金Hunan Province Key Field R&D Program Project(2019GK2246)Education Department of Hunan Province Key Project(19A391)Key scientific research project of Huaihua University(HHUY2019-04)Special Project of Innovative Provincial Construction in Hunan Province(2020RC1013)Huaihua Key Laboratory for Preparation of Ceramic Materials and Devices and Science and Technology Plan Project of Huaihua City(2020R3101).
文摘Poly(L-lactic acid)(PLLA)is a thermoplastic material with complete degradability,high biocompatibility and excellent mechanical properties.It can replace petroleum-based polymers are currently being used in the fields of packaging,agriculture,textiles,medical and so on.However,PLLA’s extremely flammability greatly limits its wider application.An bio-based flame retardant L-APP/PLLA composites was prepared by melt blending of the L-APP and PLLA.The morphology,impact properties,thermal properties and flame retardant properties of composites were investigated by field emission scanning electron microscope(SEM),impact tester,differential scanning calorimeter(DSC),thermogravimetric analyzer(TGA),limiting oxygen indexer(LOI)and horizontalvertical burning tester.The results showed that the degree of crystallization(X_(c))and LOI of L-APP/PLLA composites increased as increasing of L-APP content.What’s more,the impact strength first increased and then decreased,the glass transition temperature(T_(g))and melting temperature(T_(m))do not changed significantly.The impact strength of composites was 9.1 kJ/m^(2) at a 5 wt%loading for L-APP,which was the highest level.When the content of L-APP was 20%,the LOI was 30.8%,the Xc was 42.3%and the UL-94 level was V-0.This research can promote the value-added utilization of lignin and the application of PLLA in the fields of flame retardant materials.
基金supported by the National Natural Science Foundation of China (Grant Nos. 61272300, 61379072, 61379069)the Key Technologies R&D Program of China (No. 2014BAK09B04)
文摘Visual curve completion is a fundamental problem in understanding the principles of the human visual system. This problem is usually divided into two problems: a grouping problem and a shape problem.On one hand, though perception of the visually completed curve is clearly a global task(for example,a human perceives the Kanizsa triangle only when seeing all three black objects), conventional methods for solving the grouping problem are generally based on local Gestalt laws. On the other hand, the shape of the visually completed curve is usually recovered by minimizing shape energy in existing methods.However, not only do these methods lack mechanisms to adjust the shape of the recovered visual curve using perceptual, psychophysical, and neurophysiological knowledge, but it is also difficult to calculate an explicit representation of the visually completed curve. In this paper, we present a systematic computational model for generating a visually completed curve. Firstly, based on recent studies of perception, psychophysics, and neurophysiology, we formulate a grouping procedure based on the human visual system by seeking a minimum Hamiltonian cycle in a graph, solving the grouping problem in a global manner. Secondly, we employ a B′ezier curve-based model to represent the visually completed curve. Not only is an explicit representation deduced, but we also present a means to integrate knowledge from related areas, such as perception, psychophysics, and neurophysiology, and so on. The proposed computational model has been validated using many modal and amodal completion examples, and desirable results were obtained.
基金the Key Laboratory of Diagnosis and Controlment for The Development of Chronic Liver Disease of Zhejiang Provinceand Zhejiang Emergency Project(Grant number:2020C03123).
文摘A number of studies have suggested that coronavirus disease 2019(COVID-19)can cause liver damage.However,clinical features and outcome of COVID-19 in patients with liver injury remain to be further investigated.In this study,the clinical data of 265 COVID-19 patients admitted to seven tertiary hospitals were collected.Based on a threshold for transaminase or total bilirubin levels at two times the normal upper limit,patients were divided into mild or moderate/severe liver injury groups.Among the 265 patients,183 patients showed liver injury within 48 hours of admission.Aspartate aminotransferase levels were predominantly elevated in the liver injury group,but albumin levels were reduced.Moreover,fibrinogen and D-dimer were significantly increased.Furthermore,68%of the patients with moderate/severe liver injury had one or more underlying diseases.Almost half of these patients developed acute respiratory distress syndrome(44%)and secondary infections(46%).These patients showed increased interleukin-6 and interleukin-10 levels and a decrease in PaO2 and the oxygenation index.In addition,levels of alanine aminotransferase,aspartate aminotransferase,and albumin were correlated with the oxygenation index,D-dimer and lymphocyte counts.Furthermore,a novel prognostic assessment model based on liver function was established,which accuracy reached 88%and was able to accurately assess the prognosis of COVID-19 patients.
基金supported by the National Natural Science Foundation of China (No. 61379072)the National Key R&D Program of China (No. 2016YFB1001501)the Fundamental Research Funds for the Central Universities (No. 2017XZZX009-03)
文摘Diffusion curves can be used to generate vector graphics images with smooth variation by solving Poisson equations. However, using the classical diffusion curve model, it is difficult to ensure that the generated diffusion image satisfies desired constraints. In this paper, we develop a model for producing a diffusion image by solving a diffusion equation with diffusion coefficients, in which color layers and coefficient layers are introduced to facilitate the generation of the diffusion image. Doing so allows us to impose various constraints on the diffusion image, such as diffusion strength, diffusion direction,diffusion points, etc., in a unified computational framework. Various examples are presented in this paper to illustrate the capabilities of our model.