Reynolds-averaged Navier-Stokes(RANS)turbulence modeling can lead to the excessive turbulence level around the interface in two-phase flow,which causes the unphysical motion of the interface in sloshing simulation.In ...Reynolds-averaged Navier-Stokes(RANS)turbulence modeling can lead to the excessive turbulence level around the interface in two-phase flow,which causes the unphysical motion of the interface in sloshing simulation.In order to avoid the unphysical motion of the interface,a novel eddy-viscosity eliminator based on sigmoid functions is designed to reduce the excessive turbulence level,and the eddy-viscosity eliminator based on polynomials is extracted from the cavitation simulations.Surface elevations by combining the eddy-viscosity eliminators and classical two-equation closure models are compared with the experiments,the ones by using the adaptive asymptotic model(AAM)and the ones by using the modified two-equation closure models.The root-mean-squared error(RMSE)is introduced to quantify the accuracies of surface elevations and the forces.The relation between the turbulence level in the transition layer and RMSEs of surface elevations is studied.Besides,the parametric analysis of the eddy-viscosity eliminators is carried out.The studies suggest that(1)the excessive turbulence level in the transition layer around the interface has a significant influence on the accuracies of surface elevations and the forces;(2)the eddy-viscosity eliminators can effectively reduce the excessive turbulence level in the transition layer to avoid the unphysical motion of the interface;(3)the k-ωSST model combined with the eddy-viscosity eliminators is appropriate for predicting surface elevations and forces in RANS simulations of sloshing flow.展开更多
Numerical simulation method is applied in the study oftwo - phase flow dynamics in the eliminator of air wash-er. The carrier phase (air) is treated in Eulerian frame,the water droplets are tracked in the Lagrangian f...Numerical simulation method is applied in the study oftwo - phase flow dynamics in the eliminator of air wash-er. The carrier phase (air) is treated in Eulerian frame,the water droplets are tracked in the Lagrangian frame.A three - dimensional unsteady two - phase flow model isdeveloped. With the help of FLUENT software, air-stream velocity field and water droplets trajectories havebeen illustrated when their mixture passing through tra-ditional folded eliminator. The result of the simulationcan be used to investigate the mechanism of展开更多
Foodstuffs, fruits and vegetables stored in a refrigerator often produce a peculiar smell which affects preservation. But an electronic ozone eliminator in a refrigerator can help eliminate the smell. Ozone, a strong ...Foodstuffs, fruits and vegetables stored in a refrigerator often produce a peculiar smell which affects preservation. But an electronic ozone eliminator in a refrigerator can help eliminate the smell. Ozone, a strong oxidents, has incomparable advantages including no dead space, is nonpoisonous and a powerful anti-bacteria agent. It has been highly praised by health experts worldwide for its great effect in sterilization of air and food and vegetables. In recent years, it has been used in hospitals and surgical rooms, and for kitchen utilities. Some manufacturers have developed refrigerators with an展开更多
Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience...Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience-dependent mechanisms.The pruning process involves multiple molecular signals and a series of regulatory activities governing the“eat me”and“don't eat me”states.Under physiological conditions,the interaction between glial cells and neurons results in the clearance of unnecessary synapses,maintaining normal neural circuit functionality via synaptic pruning.Alterations in genetic and environmental factors can lead to imbalanced synaptic pruning,thus promoting the occurrence and development of autism spectrum disorder,schizophrenia,Alzheimer's disease,and other neurological disorders.In this review,we investigated the molecular mechanisms responsible for synaptic pruning during neural development.We focus on how synaptic pruning can regulate neural circuits and its association with neurological disorders.Furthermore,we discuss the application of emerging optical and imaging technologies to observe synaptic structure and function,as well as their potential for clinical translation.Our aim was to enhance our understanding of synaptic pruning during neural development,including the molecular basis underlying the regulation of synaptic function and the dynamic changes in synaptic density,and to investigate the potential role of these mechanisms in the pathophysiology of neurological diseases,thus providing a theoretical foundation for the treatment of neurological disorders.展开更多
ISO releases two standards for textiles.Recently,two international standards,ISO 8159:2025,Textiles-Morphology of fibres and yarns-Vocabulary,and ISO 17971:2025,Textiles-Smart textiles-Test method for determining the ...ISO releases two standards for textiles.Recently,two international standards,ISO 8159:2025,Textiles-Morphology of fibres and yarns-Vocabulary,and ISO 17971:2025,Textiles-Smart textiles-Test method for determining the screen-touch properties of fabrics,were officially released.They are of positive significance for eliminating technical ambiguities in exchanges on textile products and filling the gaps in international standards.展开更多
Objective:To evaluate the effectiveness of direct-acting antivirals(DAAs)in patients with chronic hepatitis C,assess changes in liver function and hepatic fibrosis following treatment,and identify independent predicto...Objective:To evaluate the effectiveness of direct-acting antivirals(DAAs)in patients with chronic hepatitis C,assess changes in liver function and hepatic fibrosis following treatment,and identify independent predictors of treatment failure.Methods:This retrospective cohort study included patients who received DAA therapy at Hospital Kuala Lumpur between January 2020 and December 2023.Sustained virologic response(SVR)was assessed at least 12 weeks post-treatment by reverse transcription-polymerase chain reaction for hepatitis C virus(HCV)RNA.Demographic,clinical,and laboratory data were collected and analyzed.Multiple logistic regression analysis was performed to identify independent predictors of treatment failure.Results:A total of 335 patients in the study.The overall SVR rate was 89%.After achieving SVR,significant improvements were observed in liver enzyme levels and non-invasive liver fibrosis scores,whereas the overall Model for End-Stage Liver Disease(MELD)scores remained unchanged.Significant independent predictors of treatment failure included non-compliance with DAA therapy[adjusted odds ratio(aOR)68.3;95%confidence interval(95%CI)16.3-285.0;P<0.001],treatment with sofosbuvir/velpatasvir(aOR 6.1;95%CI 1.4-26.5;P=0.015),MELD score of 10-15(aOR 4.6;95%CI 1.1-18.2;P=0.031),HCV genotype 3 infection(aOR 4.5;95%CI 1.1-17.6;P=0.031),and elevated serum total bilirubin level(aOR 1.1;95%CI 1.0-1.1;P=0.003).Conclusions:DAA therapy yielded a high SVR rate,and treatment failure was strongly associated with non-adherence to therapy and advanced liver disease.These findings underscore the necessity of adherence support,early diagnosis,and individualized clinical management to optimize treatment outcomes in patients with chronic hepatitis C.展开更多
Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability...Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability. Even without apparent inflammation, injury sites are associated with increased inflammatory markers. This review focuses on how it might be possible to reduce neuropathic pain by reducing inflammation. Physiologically, pain is resolved by a combination of the out-migration of pro-inflammatory cells from the injury site, the down-regulation of the genes underlying the inflammation, up-regulating genes for anti-inflammatory mediators, and reducing nociceptive neuron hyperexcitability. While various techniques reduce chronic neuropathic pain, the best are effective on < 50% of patients, no technique reliably or permanently eliminates neuropathic pain. This is because most techniques are predominantly aimed at reducing pain, not inflammation. In addition, while single factors reduce pain, increasing evidence indicates significant and longer-lasting pain relief requires multiple factors acting simultaneously. Therefore, it is not surprising that extensive data indicate that the application of platelet-rich plasma provides more significant and longer-lasting pain suppression than other techniques, although its analgesia is neither complete nor permanent. However, several case reports indicate that platelet-rich plasma can induce permanent neuropathic pain elimination when the platelet concentration is significantly increased and is applied to longer nerve lengths. This review examines the primary triggers of the development and maintenance of neuropathic pain and techniques that reduce chronic neuropathic pain. The application of plateletrich plasma holds great promise for providing complete and permanent chronic neuropathic pain elimination.展开更多
The comprehensive evaluation of six properties for equipment product is an important basis for their quality control,and their correlative relationship among six properties will affect their quality level.To understan...The comprehensive evaluation of six properties for equipment product is an important basis for their quality control,and their correlative relationship among six properties will affect their quality level.To understand their correlative relationship among six properties,this paper firstly combines group evaluation with decision-making trial and evaluation laboratory(DEMATEL)model,and develops the optimization model based on group consensus to form six influent relationship matrices.Secondly,group consensus matrix is used to design super network hierarchy matrix,and the weights of six properties with relevant environment is also proposed.Thirdly,the elimination and choice translating reality(ELECTRE)model is used to make comprehensive evaluation,and an example is used to compare the results under two kinds of conditions,and illustrate the effect of the weights of six properties on the priority of equipment products.展开更多
During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their el...During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.展开更多
Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si...Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si alloys fabricated by laser powder-bed fusion(L-PBF).The results indicate that the eutectic Mg_(2) Si phase possesses a strong ability to reduce crack susceptibility.It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidifica-tion.The crack-free L-PBFed Al-x Mg_(2) Si alloys(x=6 wt.%,9 wt.%,and 12 wt.%)exhibit the combination of low crack susceptibility index(CSI),superior ability for liquid filling,and grain refinement.Particularly,the L-PBFed Al-9Mg_(2) Si alloy shows improved mechanical properties(e.g.yield strength of 397 MPa and elongation of 7.3%).However,the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg_(2) Si alloy with a large solidification range and low eutectic content for liquid filling.Correspondingly,the L-PBFed Al-3Mg_(2) Si alloy shows poor bearing capacity of mechanical properties.The precise tuning of Mg_(2) Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy.展开更多
The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing...The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing was revealed.The combined fracturing process of a coal seam and its roof under different in situ stress and fracture spacing conditions was analysed through true triaxial physical tests and numerical simulations.The results showed that the pre-fracturing of the roof had a pressure relief effect on the coal seam,and the secondary pressure relief of the coal seam could be completed at a lower fracture initiation pressure.To ensure the continued presence of the stress shadow effect in actual projects,the fracture spacing should be maintained within the critical range influencing the fracture extension.If the vertical stress is high,a call on increasing the fracture spacing can be taken;otherwise,it must be reduced.In the early phase of fracturing,energy is mostly concentrated at the tip and surface of the fracture;however,the proportion of surface energy for subsequent fracturing is gradually reduced,and the energy is mostly used to open the formation and work on the surrounding matrix.Hydraulic fracturing creates new fractures to interconnect originally heterogeneously distributed gas zones,enabling the entire coal seam to first establish interconnected pressure equilibration,then undergo gradientcontrolled depressurization.Hydraulic fracturing can homogenize the stress field and gas pressure field in the original coal seam via communication pressure equalization and reduction decompression,reduce the elastic and extension energies,increase the minimum failure energy required for instability;and realize the elimination of gas outbursts.Our findings provide some theoretical support for the efficient development of coalbed methane and the prevention and control of dynamic gas disasters in coal mines.展开更多
A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measur...A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature,pH,and nickel ion concentration,is also established,which significantly improves process efficiency and coating quality.Experimental results indicate that the system is capable of realizing stable operation over extended periods.A nonporous nickel-phosphorus coating with a thickness greater than 200μm is successfully obtained,with high phosphorus content,robust adhesion,and superior machinability.展开更多
Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,...Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,gastrointestinal dysfunction,and increased recurrence rates.When these concerns develop,traditional Chinese medicine(TCM)may have advantages.TCM is based on the concept of completeness and aims to eliminate pathogens and strengthen the body.It has the potential to prevent this condition while also boosting the rate of Helicobacter pylori eradication.This review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways,which reflects the flexibility of TCM in treating diseases and the advantages of multi-level,multipathway,and multi-target treatments for HPAG.展开更多
Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfor...Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.展开更多
基金financially supported by the National Natural Science Foundation of China(Grant Nos.11802176,11802301)。
文摘Reynolds-averaged Navier-Stokes(RANS)turbulence modeling can lead to the excessive turbulence level around the interface in two-phase flow,which causes the unphysical motion of the interface in sloshing simulation.In order to avoid the unphysical motion of the interface,a novel eddy-viscosity eliminator based on sigmoid functions is designed to reduce the excessive turbulence level,and the eddy-viscosity eliminator based on polynomials is extracted from the cavitation simulations.Surface elevations by combining the eddy-viscosity eliminators and classical two-equation closure models are compared with the experiments,the ones by using the adaptive asymptotic model(AAM)and the ones by using the modified two-equation closure models.The root-mean-squared error(RMSE)is introduced to quantify the accuracies of surface elevations and the forces.The relation between the turbulence level in the transition layer and RMSEs of surface elevations is studied.Besides,the parametric analysis of the eddy-viscosity eliminators is carried out.The studies suggest that(1)the excessive turbulence level in the transition layer around the interface has a significant influence on the accuracies of surface elevations and the forces;(2)the eddy-viscosity eliminators can effectively reduce the excessive turbulence level in the transition layer to avoid the unphysical motion of the interface;(3)the k-ωSST model combined with the eddy-viscosity eliminators is appropriate for predicting surface elevations and forces in RANS simulations of sloshing flow.
基金Supported by Development Foundation of Dong Hua Univetsity
文摘Numerical simulation method is applied in the study oftwo - phase flow dynamics in the eliminator of air wash-er. The carrier phase (air) is treated in Eulerian frame,the water droplets are tracked in the Lagrangian frame.A three - dimensional unsteady two - phase flow model isdeveloped. With the help of FLUENT software, air-stream velocity field and water droplets trajectories havebeen illustrated when their mixture passing through tra-ditional folded eliminator. The result of the simulationcan be used to investigate the mechanism of
文摘Foodstuffs, fruits and vegetables stored in a refrigerator often produce a peculiar smell which affects preservation. But an electronic ozone eliminator in a refrigerator can help eliminate the smell. Ozone, a strong oxidents, has incomparable advantages including no dead space, is nonpoisonous and a powerful anti-bacteria agent. It has been highly praised by health experts worldwide for its great effect in sterilization of air and food and vegetables. In recent years, it has been used in hospitals and surgical rooms, and for kitchen utilities. Some manufacturers have developed refrigerators with an
基金supported by the National Natural Science Foundation of China,No.31760290,82160688the Key Development Areas Project of Ganzhou Science and Technology,No.2022B-SF9554(all to XL)。
文摘Synaptic pruning is a crucial process in synaptic refinement,eliminating unstable synaptic connections in neural circuits.This process is triggered and regulated primarily by spontaneous neural activity and experience-dependent mechanisms.The pruning process involves multiple molecular signals and a series of regulatory activities governing the“eat me”and“don't eat me”states.Under physiological conditions,the interaction between glial cells and neurons results in the clearance of unnecessary synapses,maintaining normal neural circuit functionality via synaptic pruning.Alterations in genetic and environmental factors can lead to imbalanced synaptic pruning,thus promoting the occurrence and development of autism spectrum disorder,schizophrenia,Alzheimer's disease,and other neurological disorders.In this review,we investigated the molecular mechanisms responsible for synaptic pruning during neural development.We focus on how synaptic pruning can regulate neural circuits and its association with neurological disorders.Furthermore,we discuss the application of emerging optical and imaging technologies to observe synaptic structure and function,as well as their potential for clinical translation.Our aim was to enhance our understanding of synaptic pruning during neural development,including the molecular basis underlying the regulation of synaptic function and the dynamic changes in synaptic density,and to investigate the potential role of these mechanisms in the pathophysiology of neurological diseases,thus providing a theoretical foundation for the treatment of neurological disorders.
文摘ISO releases two standards for textiles.Recently,two international standards,ISO 8159:2025,Textiles-Morphology of fibres and yarns-Vocabulary,and ISO 17971:2025,Textiles-Smart textiles-Test method for determining the screen-touch properties of fabrics,were officially released.They are of positive significance for eliminating technical ambiguities in exchanges on textile products and filling the gaps in international standards.
文摘Objective:To evaluate the effectiveness of direct-acting antivirals(DAAs)in patients with chronic hepatitis C,assess changes in liver function and hepatic fibrosis following treatment,and identify independent predictors of treatment failure.Methods:This retrospective cohort study included patients who received DAA therapy at Hospital Kuala Lumpur between January 2020 and December 2023.Sustained virologic response(SVR)was assessed at least 12 weeks post-treatment by reverse transcription-polymerase chain reaction for hepatitis C virus(HCV)RNA.Demographic,clinical,and laboratory data were collected and analyzed.Multiple logistic regression analysis was performed to identify independent predictors of treatment failure.Results:A total of 335 patients in the study.The overall SVR rate was 89%.After achieving SVR,significant improvements were observed in liver enzyme levels and non-invasive liver fibrosis scores,whereas the overall Model for End-Stage Liver Disease(MELD)scores remained unchanged.Significant independent predictors of treatment failure included non-compliance with DAA therapy[adjusted odds ratio(aOR)68.3;95%confidence interval(95%CI)16.3-285.0;P<0.001],treatment with sofosbuvir/velpatasvir(aOR 6.1;95%CI 1.4-26.5;P=0.015),MELD score of 10-15(aOR 4.6;95%CI 1.1-18.2;P=0.031),HCV genotype 3 infection(aOR 4.5;95%CI 1.1-17.6;P=0.031),and elevated serum total bilirubin level(aOR 1.1;95%CI 1.0-1.1;P=0.003).Conclusions:DAA therapy yielded a high SVR rate,and treatment failure was strongly associated with non-adherence to therapy and advanced liver disease.These findings underscore the necessity of adherence support,early diagnosis,and individualized clinical management to optimize treatment outcomes in patients with chronic hepatitis C.
文摘Nerve trauma commonly results in chronic neuropathic pain. This is by triggering the release of proinflammatory mediators from local and invading cells that induce inflammation and nociceptive neuron hyperexcitability. Even without apparent inflammation, injury sites are associated with increased inflammatory markers. This review focuses on how it might be possible to reduce neuropathic pain by reducing inflammation. Physiologically, pain is resolved by a combination of the out-migration of pro-inflammatory cells from the injury site, the down-regulation of the genes underlying the inflammation, up-regulating genes for anti-inflammatory mediators, and reducing nociceptive neuron hyperexcitability. While various techniques reduce chronic neuropathic pain, the best are effective on < 50% of patients, no technique reliably or permanently eliminates neuropathic pain. This is because most techniques are predominantly aimed at reducing pain, not inflammation. In addition, while single factors reduce pain, increasing evidence indicates significant and longer-lasting pain relief requires multiple factors acting simultaneously. Therefore, it is not surprising that extensive data indicate that the application of platelet-rich plasma provides more significant and longer-lasting pain suppression than other techniques, although its analgesia is neither complete nor permanent. However, several case reports indicate that platelet-rich plasma can induce permanent neuropathic pain elimination when the platelet concentration is significantly increased and is applied to longer nerve lengths. This review examines the primary triggers of the development and maintenance of neuropathic pain and techniques that reduce chronic neuropathic pain. The application of plateletrich plasma holds great promise for providing complete and permanent chronic neuropathic pain elimination.
文摘The comprehensive evaluation of six properties for equipment product is an important basis for their quality control,and their correlative relationship among six properties will affect their quality level.To understand their correlative relationship among six properties,this paper firstly combines group evaluation with decision-making trial and evaluation laboratory(DEMATEL)model,and develops the optimization model based on group consensus to form six influent relationship matrices.Secondly,group consensus matrix is used to design super network hierarchy matrix,and the weights of six properties with relevant environment is also proposed.Thirdly,the elimination and choice translating reality(ELECTRE)model is used to make comprehensive evaluation,and an example is used to compare the results under two kinds of conditions,and illustrate the effect of the weights of six properties on the priority of equipment products.
基金supported by Catalan Government,Nos.2014SGR344(to JT),2017SGR704(to JT),2021SGR01214(to MAL)MCIN/AEI/10.13039/501100011033/by“ERDF A way of making Europe,”Nos.SAF2015-67143(to JT),PID2019-106332GB-I00(to JT and MAL)and PID2022-141252NB-I00(to MAL).
文摘During the development of the nervous system,there is an overproduction of neurons and synapses.Hebbian competition between neighboring nerve endings and synapses performing different activity levels leads to their elimination or strengthening.We have extensively studied the involvement of the brain-derived neurotrophic factor-Tropomyosin-related kinase B receptor neurotrophic retrograde pathway,at the neuromuscular junction,in the axonal development and synapse elimination process versus the synapse consolidation.The purpose of this review is to describe the neurotrophic influence on developmental synapse elimination,in relation to other molecular pathways that we and others have found to regulate this process.In particular,we summarize our published results based on transmitter release analysis and axonal counts to show the different involvement of the presynaptic acetylcholine muscarinic autoreceptors,coupled to downstream serine-threonine protein kinases A and C(PKA and PKC)and voltage-gated calcium channels,at different nerve endings in developmental competition.The dynamic changes that occur simultaneously in several nerve terminals and synapses converge across a postsynaptic site,influence each other,and require careful studies to individualize the mechanisms of specific endings.We describe an activity-dependent balance(related to the extent of transmitter release)between the presynaptic muscarinic subtypes and the neurotrophin-mediated TrkB/p75NTR pathways that can influence the timing and fate of the competitive interactions between the different axon terminals.The downstream displacement of the PKA/PKC activity ratio to lower values,both in competing nerve terminals and at postsynaptic sites,plays a relevant role in controlling the elimination of supernumerary synapses.Finally,calcium entry through L-and P/Q-subtypes of voltage-gated calcium channels(both channels are present,together with the N-type channel in developing nerve terminals)contributes to reduce transmitter release and promote withdrawal of the most unfavorable nerve terminals during elimination(the weakest in acetylcholine release and those that have already become silent).The main findings contribute to a better understanding of punishment-rewarding interactions between nerve endings during development.Identifying the molecular targets and signaling pathways that allow synapse consolidation or withdrawal of synapses in different situations is important for potential therapies in neurodegenerative diseases.
基金financially supported by the National Natural Science Foundation of China(Grant No.52071343)the Leading Innovation and Entrepreneurship Team of Zhejiang Province-Automotive Light Alloy Innovation Team(No.2022R01018).
文摘Large solidification ranges and coarse columnar grains in the additively manufacturing of Al-Mg-Si alloys are normally involved in hot cracks during solidification.In this work,we develop novel crack-free Al-Mg_(2) Si alloys fabricated by laser powder-bed fusion(L-PBF).The results indicate that the eutectic Mg_(2) Si phase possesses a strong ability to reduce crack susceptibility.It can enhance the grain growth restriction factor in the initial stage of solidification and promote eutectic filling in the terminal stage of solidifica-tion.The crack-free L-PBFed Al-x Mg_(2) Si alloys(x=6 wt.%,9 wt.%,and 12 wt.%)exhibit the combination of low crack susceptibility index(CSI),superior ability for liquid filling,and grain refinement.Particularly,the L-PBFed Al-9Mg_(2) Si alloy shows improved mechanical properties(e.g.yield strength of 397 MPa and elongation of 7.3%).However,the cracks are more likely to occur in the region near the columnar grain boundaries of the L-PBFed Al-3Mg_(2) Si alloy with a large solidification range and low eutectic content for liquid filling.Correspondingly,the L-PBFed Al-3Mg_(2) Si alloy shows poor bearing capacity of mechanical properties.The precise tuning of Mg_(2) Si eutectic content can offer an innovative strategy for eliminating cracks in additively manufactured Al-Mg-Si alloy.
基金financially supported by the National Key R&D Program(Nos.2023YFC3009000 and 2023YFC3006804)the National Natural Science Foundation of China(Nos.52130409,52121003,51874314,and 52274190).
文摘The hydraulic fractures induced in soft coal composite reservoirs have complex extension and energy evolution characteristics.In this study,the mechanism whereby gas outbursts can be eliminated by hydraulic fracturing was revealed.The combined fracturing process of a coal seam and its roof under different in situ stress and fracture spacing conditions was analysed through true triaxial physical tests and numerical simulations.The results showed that the pre-fracturing of the roof had a pressure relief effect on the coal seam,and the secondary pressure relief of the coal seam could be completed at a lower fracture initiation pressure.To ensure the continued presence of the stress shadow effect in actual projects,the fracture spacing should be maintained within the critical range influencing the fracture extension.If the vertical stress is high,a call on increasing the fracture spacing can be taken;otherwise,it must be reduced.In the early phase of fracturing,energy is mostly concentrated at the tip and surface of the fracture;however,the proportion of surface energy for subsequent fracturing is gradually reduced,and the energy is mostly used to open the formation and work on the surrounding matrix.Hydraulic fracturing creates new fractures to interconnect originally heterogeneously distributed gas zones,enabling the entire coal seam to first establish interconnected pressure equilibration,then undergo gradientcontrolled depressurization.Hydraulic fracturing can homogenize the stress field and gas pressure field in the original coal seam via communication pressure equalization and reduction decompression,reduce the elastic and extension energies,increase the minimum failure energy required for instability;and realize the elimination of gas outbursts.Our findings provide some theoretical support for the efficient development of coalbed methane and the prevention and control of dynamic gas disasters in coal mines.
基金supported by the National Key Research and Development Program of China(Grant No.2023YFB3407200)the National Natural Science Foundation of China(Grant Nos.52375462 and 52035009).
文摘A novel method based on mid-frequency vibration is proposed to eliminate coating defects such as bubbles during electroless nickel plating.An automated control system for the plating,enabling precise and stable measurements and adjustments of critical parameters such as plating solution temperature,pH,and nickel ion concentration,is also established,which significantly improves process efficiency and coating quality.Experimental results indicate that the system is capable of realizing stable operation over extended periods.A nonporous nickel-phosphorus coating with a thickness greater than 200μm is successfully obtained,with high phosphorus content,robust adhesion,and superior machinability.
基金Supported by National Natural Science Foundation of China,No.82374323and Hunan Graduate Research Innovation Project,No.2023CX15.
文摘Helicobacter pylori-associated gastritis(HPAG)is a common condition of the gastrointestinal tract.However,extensive and long-term antibiotic use has resulted in numerous adverse effects,including increased resistance,gastrointestinal dysfunction,and increased recurrence rates.When these concerns develop,traditional Chinese medicine(TCM)may have advantages.TCM is based on the concept of completeness and aims to eliminate pathogens and strengthen the body.It has the potential to prevent this condition while also boosting the rate of Helicobacter pylori eradication.This review elaborates on the mechanism of TCM treatment for HPAG based on cellular signalling pathways,which reflects the flexibility of TCM in treating diseases and the advantages of multi-level,multipathway,and multi-target treatments for HPAG.
基金Supported by National Natural Science Foundation of China(Grant No.52275033)National Natural Science Youth Foundation of China(Grant No.52205033)Hebei Provincial Natural Science Foundation of China(Grant No.E2021203019)。
文摘Serial-parallel manipulators are of great interest to academic community in recent years,especially those composed of classical parallel mechanisms.There have been many studies around 2(3RPS)and 2(3SPR)S-PMs,but unfortunately their inverse kinematics have not yet been resolved.This paper discovers that the unknown kinematic parameters of middle platform are responsible for the unresolvable of inverse kinematics,meanwhile the unknown kinematic parameters of middle platform also have huge coupling relationships.Therefore,to break through this challenges,the huge coupling relationships are decoupled layer by layer,the kinematic parameters of middle platform are solved by combining Sylvester's elimination method,and the inverse displacements of 2(3RPS)and 2(3SPR)S-PMs are obtained subsequently.This paper not only solves the inverse kinematics of classical 2(3RPS)and 2(3SPR)S-PMs,but also reveals the essence of the inverse kinematics of general(3-DOF)+(3-DOF)6-DOF S-PMs and proposes a corresponding solution.
