Hepatic ischemia-reperfusion injury(HIRI)is a major clinical cause of morbidity and mortality in liver surgery and transplantation.Many studies have found that nitric oxide(NO)plays an important role in the HIRI and i...Hepatic ischemia-reperfusion injury(HIRI)is a major clinical cause of morbidity and mortality in liver surgery and transplantation.Many studies have found that nitric oxide(NO)plays an important role in the HIRI and its increase or decrease can affect the progression and outcome of HIRI.However,the role of NO in HIRI is controversial and complicated.NO derived by endothelial NO synthase(eNOS)shows a protective role in HIRI,while excessive NO derived by inducible NO synthase(iNOS)accelerates inflammation and increases oxidative stress,further aggravating HIRI.Nevertheless,the overexpression of eNOS may exacerbate HIRI and iNOS-derived NO in some cases reduces HIRI.Here we review the new progress in the understanding of the roles of NO during HIRI:(1)NO possesses different roles in HIRI by increasing NO bioavailability,down-regulating leukotriene C4 synthase,inhibiting the activation of the nuclear factorκB(NFκB)pathway,enhancing cell autophagy,and reducing inflammatory cytokines and reactive oxygen species(ROS).And NO has both protective and deleterious effects by regulating apoptotic factors;(2)eNOS promotes NO production and suppresses its own overexpression,exerting a hepatoprotective effect reversely.Its activation is regulated by the PI3K/Akt and KLF2/AMPK pathways;and(3)iNOS derived NO mainly has deteriorating effects on HIRI,while it may have a protective function under some conditions.Their expression should reach a balance to reduce the adverse side and make NO protective in the treatment of HIRI.Thus,it can be inferred that NO modulating drugs may be a new direction in the treatment of HIRI or may be used as an adjunct to mitigate HIRI for the purpose of protecting the liver.展开更多
The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been investigated.The results show that the viscosity increases and crosslinking reaction occurs simultaneously...The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been investigated.The results show that the viscosity increases and crosslinking reaction occurs simultaneously together with the increase of temperature,thus causing the variation of storage modulus(G')and loss modulus(G")in the repeated frequency sweeps with residual time.This research has pointed out that the superposition is valid for monitoring the complex behavior composed of the viscosity increasing and crosslink occurring process by tracing the variation behavior of the crossover points of G'and G"with time,revealing the same time-temperature dependence of the two reactions in the isothermal process.A normalized master curve has been proposed to describe the melt behavior at a given temperature.展开更多
Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy;chemistry;medicine;and materials science because of their unique physical and chemical properties.Great efforts have been mad...Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy;chemistry;medicine;and materials science because of their unique physical and chemical properties.Great efforts have been made in the past decades to find more effective synthetic methods for this important class of boron compounds.However;existing synthetic methods suffer from low efficiency and low selectivity.Herein;we report a facile one-pot synthesis of[(CH_(3))3S]_(2)B_(12)H_(12) with moderate yields at mild conditions.The mechanisms for the multi-step chemoselective synthesis of B_(12)H_(12)^(2-)without other by-products are elucidated based on theoretical results and our previous work.The Lewis base used in B–H bond condensation reaction;which acts as a hydrogen or to balance the newly generated polyhedral borane charges;is proposed and studied in detail.The current study has led to a more effective and selective synthetic method for B_(12)H_(12)^(2-) and has also implicated the syntheses of other new polyhedral boranes.展开更多
Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI framework.This paper describes a da...Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI framework.This paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD technology.The general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting regression.This offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for validation.It is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics model.Given high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various forms.Importantly,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.展开更多
Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,...Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well understood.Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2-)(B_(12)H_(12)^(2-)) anions by employing commercially available and inexpensive starting materials.Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms.We have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial role.The current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12)H_(12)^(2-) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral boranes.This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.展开更多
Cavitation within the tip vortex(TV)flow remains a challenging issue in the design of high-speed and low-noise hydraulic machinery.In this paper,the TV cavitating flow around an elliptical hydrofoil is calculated by u...Cavitation within the tip vortex(TV)flow remains a challenging issue in the design of high-speed and low-noise hydraulic machinery.In this paper,the TV cavitating flow around an elliptical hydrofoil is calculated by using large eddy simulation(LES)combined with a modified Schnerr-Sauer(S-S)cavitation model.The original S-S cavitation model is modified by taking into account the typical effect of vortex flow.The partial pressure term which can describe the vortex quantitatively and qualitatively is confirmed asρ_(m)ω^(2) x r _(c)^(2) ,and is considered into the R-P equation of the modified S-S cavitation model.Comparison between the numerical and experimental results shows good agreement in the form and evolution of cavities,including attached cavities(AC)and tip vortex cavities(TVC).The vorticity transport equation is utilized to investigate the dynamic mechanisms of the vortex development around the TVC.Further analyses indicate that cavitation in the TV flow influences the pressure in the core of the cavity and the local flow patterns.Typical vortex structures in the TV cavitating flow include TV,secondary vortex(SV)and wake vortex(WV).The direction and magnitude of the rotation effect can be described by axial vorticity which is drawn on the iso-surface of Q=1×105 s−2.The development of the TV cavitating flow can be divided into two stages:Stage I,the development and fusion of TV,SV,stage II,the dissipation of SV.The stretching term dominates the evolution of TV,and the dilatation term is the main reason in the mergence process of SV.展开更多
Ferulic acid(FA)is a phenolic phytochemical with antioxidant and anti-inflammatory pharmacological effects.In recent years,the neuroprotective effects of FA have been studied extensively.Many researchers have attempte...Ferulic acid(FA)is a phenolic phytochemical with antioxidant and anti-inflammatory pharmacological effects.In recent years,the neuroprotective effects of FA have been studied extensively.Many researchers have attempted to use FA to prevent and treat neurological diseases and have made some progress.This paper mainly collated the study of the protective effect of FA on stroke and summarized the protective effect of FA on ischemic stroke and the potential protective effects of FA on neurovascular units.展开更多
文摘Hepatic ischemia-reperfusion injury(HIRI)is a major clinical cause of morbidity and mortality in liver surgery and transplantation.Many studies have found that nitric oxide(NO)plays an important role in the HIRI and its increase or decrease can affect the progression and outcome of HIRI.However,the role of NO in HIRI is controversial and complicated.NO derived by endothelial NO synthase(eNOS)shows a protective role in HIRI,while excessive NO derived by inducible NO synthase(iNOS)accelerates inflammation and increases oxidative stress,further aggravating HIRI.Nevertheless,the overexpression of eNOS may exacerbate HIRI and iNOS-derived NO in some cases reduces HIRI.Here we review the new progress in the understanding of the roles of NO during HIRI:(1)NO possesses different roles in HIRI by increasing NO bioavailability,down-regulating leukotriene C4 synthase,inhibiting the activation of the nuclear factorκB(NFκB)pathway,enhancing cell autophagy,and reducing inflammatory cytokines and reactive oxygen species(ROS).And NO has both protective and deleterious effects by regulating apoptotic factors;(2)eNOS promotes NO production and suppresses its own overexpression,exerting a hepatoprotective effect reversely.Its activation is regulated by the PI3K/Akt and KLF2/AMPK pathways;and(3)iNOS derived NO mainly has deteriorating effects on HIRI,while it may have a protective function under some conditions.Their expression should reach a balance to reduce the adverse side and make NO protective in the treatment of HIRI.Thus,it can be inferred that NO modulating drugs may be a new direction in the treatment of HIRI or may be used as an adjunct to mitigate HIRI for the purpose of protecting the liver.
基金the National Key R&D Program of China(No.2017YFB0307600)the National Natural Science Foundation of China(No.21574140).
文摘The rheological property evolution of polyamide 1012(PA1012)in the isothermal process in molten state has been investigated.The results show that the viscosity increases and crosslinking reaction occurs simultaneously together with the increase of temperature,thus causing the variation of storage modulus(G')and loss modulus(G")in the repeated frequency sweeps with residual time.This research has pointed out that the superposition is valid for monitoring the complex behavior composed of the viscosity increasing and crosslink occurring process by tracing the variation behavior of the crossover points of G'and G"with time,revealing the same time-temperature dependence of the two reactions in the isothermal process.A normalized master curve has been proposed to describe the melt behavior at a given temperature.
基金supported by the National Natural Science Foundation of China(22171246,U1804253 to X.Chen,and 21773214 to D.Wei)L.S.Wang wishes to thank the US National Science Foundation for support under grant CHE-2403841.
文摘Polyhedral boranes are a class of well-known boron molecular clusters widely used in energy;chemistry;medicine;and materials science because of their unique physical and chemical properties.Great efforts have been made in the past decades to find more effective synthetic methods for this important class of boron compounds.However;existing synthetic methods suffer from low efficiency and low selectivity.Herein;we report a facile one-pot synthesis of[(CH_(3))3S]_(2)B_(12)H_(12) with moderate yields at mild conditions.The mechanisms for the multi-step chemoselective synthesis of B_(12)H_(12)^(2-)without other by-products are elucidated based on theoretical results and our previous work.The Lewis base used in B–H bond condensation reaction;which acts as a hydrogen or to balance the newly generated polyhedral borane charges;is proposed and studied in detail.The current study has led to a more effective and selective synthetic method for B_(12)H_(12)^(2-) and has also implicated the syntheses of other new polyhedral boranes.
基金Project supported by the National Natural Science Foundation of China (Grant No.52241102).
文摘Accurate modeling for highly non-linear coupling of a damaged ship with liquid sloshing in waves is still of considerable interest within the computational fluid dynamics(CFD)and AI framework.This paper describes a data-driven Stacking algorithm for fast prediction of roll motion response amplitudes in beam waves by constructing a hydrodynamics model of a damaged ship based on the dynamic overlapping grid CFD technology.The general idea is to optimize various parameters varying with four types of classical base models like multi-layer perception,support vector regression,random forest,and hist gradient boosting regression.This offers several attractive properties in terms of accuracy and efficiency by choosing the standard DTMB 5415 model with double damaged compartments for validation.It is clearly demonstrated that the predicted response amplitude operator(RAO)in the regular beam waves agrees well with the experimental data available,which verifies the accuracy of the established damaged ship hydrodynamics model.Given high-quality CFD samples,therefore,implementation of the designed Stacking algorithm with its optimal combination can predict the damaged ship roll motion amplitudes effectively and accurately(e.g.,the coefficient of determination 0.9926,the average absolute error 0.0955 and CPU 3s),by comparison of four types of typical base models and their various forms.Importantly,the established Stacking algorithm provides one potential that can break through problems involving the time-consuming and low efficiency for large-scale lengthy CFD simulations.
基金supported by the National Natural Science Foundation of China(22171246,U1804253 to X.C.and 21773214 to D.W.)the National Science Foundation(CHE-2053541 to L.-S.W.)。
文摘Polyhedral boranes are a class of well-known boron molecular clusters with unique physical and chemical properties,and great efforts have been made in the past decades to find more effective synthetic methods.However,the established synthetic methods suffer from low efficiency and low selectivity because the mechanism of the B-H bond condensation reaction,critical for the synthesis of the polyhedral boranes,is not well understood.Here we report highly selective and efficient synthetic methods of the salts of the tetradecahydridoundecaborate(1-)(B_(11)H^(-)_(14)) and dodecahydrido-dodecaborates(2-)(B_(12)H_(12)^(2-)) anions by employing commercially available and inexpensive starting materials.Both theoretical and experimental investigations are carried out to elucidate the reaction mechanisms.We have found that the nature of the B-H bond condensation is the dihydrogen bonding interaction in which the positively charged hydrogens(bridged hydrogens) play a crucial role.The current study has not only led to more effective and selective synthetic methods for B_(11)H^(-)_(14) and B_(12)H_(12)^(2-) but also unveiled the nature of the B-H bond condensation and the general formation mechanisms of polyhedral boranes.This finding will facilitate the development of more effective synthetic methods for polyhedral boranes and spur their wide application.
基金supported by the National Natural Science Foundation of China(Grant No.52009001)supported by the Postdoctoral Research Foundation of China(Granr No.2020M680380)+1 种基金the Natural Science Foundation Projectof Chongqing,Chongqing Science and Technology Commission(Grant No.cstc2021jcyj-msxmX1046)the Beijing Institute of Technology Research Fund Program for Young Scholars(Grant No.XSQD-202003008).
文摘Cavitation within the tip vortex(TV)flow remains a challenging issue in the design of high-speed and low-noise hydraulic machinery.In this paper,the TV cavitating flow around an elliptical hydrofoil is calculated by using large eddy simulation(LES)combined with a modified Schnerr-Sauer(S-S)cavitation model.The original S-S cavitation model is modified by taking into account the typical effect of vortex flow.The partial pressure term which can describe the vortex quantitatively and qualitatively is confirmed asρ_(m)ω^(2) x r _(c)^(2) ,and is considered into the R-P equation of the modified S-S cavitation model.Comparison between the numerical and experimental results shows good agreement in the form and evolution of cavities,including attached cavities(AC)and tip vortex cavities(TVC).The vorticity transport equation is utilized to investigate the dynamic mechanisms of the vortex development around the TVC.Further analyses indicate that cavitation in the TV flow influences the pressure in the core of the cavity and the local flow patterns.Typical vortex structures in the TV cavitating flow include TV,secondary vortex(SV)and wake vortex(WV).The direction and magnitude of the rotation effect can be described by axial vorticity which is drawn on the iso-surface of Q=1×105 s−2.The development of the TV cavitating flow can be divided into two stages:Stage I,the development and fusion of TV,SV,stage II,the dissipation of SV.The stretching term dominates the evolution of TV,and the dilatation term is the main reason in the mergence process of SV.
文摘Ferulic acid(FA)is a phenolic phytochemical with antioxidant and anti-inflammatory pharmacological effects.In recent years,the neuroprotective effects of FA have been studied extensively.Many researchers have attempted to use FA to prevent and treat neurological diseases and have made some progress.This paper mainly collated the study of the protective effect of FA on stroke and summarized the protective effect of FA on ischemic stroke and the potential protective effects of FA on neurovascular units.
