Extreme heat events contribute to high mortality[1,2]and overwhelm emergency medical services through increased ambulance calls and overcrowded emergency departments.[3]Because morbidity and mortality are directly rel...Extreme heat events contribute to high mortality[1,2]and overwhelm emergency medical services through increased ambulance calls and overcrowded emergency departments.[3]Because morbidity and mortality are directly related to both the degree and duration of hyperthermia,timely recognition and management of heat exhaustion and heat stroke are critical for preventing death and reducing healthcare burdens.展开更多
Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potentia...Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.展开更多
Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance b...Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.展开更多
In recent years the crucial role of CD4^(+)T cells in tumor immunomodulation has garnered increasing recognition.While conventional cancer immunotherapy research has predominantly focused on the cytotoxic function of ...In recent years the crucial role of CD4^(+)T cells in tumor immunomodulation has garnered increasing recognition.While conventional cancer immunotherapy research has predominantly focused on the cytotoxic function of CD8+T cells,emerging evidence has now shown that CD4^(+)T cells enhance antitumor immunity by delivering co-stimulatory signals,secreting cytokines,and promoting cytotoxic T lymphocyte(CTL)activation and display unique immunoregulatory capabilities through direct tumor cell killing or remodeling of the tumor microenvironment.The high heterogeneity and functional plasticity of CD4^(+)T cell subsets significantly influence clinical responses to immunotherapy with underlying mechanisms involving multi-level regulatory networks,including epigenetic modulation and metabolic reprogramming.Deciphering the functional heterogeneity of CD4^(+)T cells and the interactions with the tumor microenvironment will provide essential mechanistic insights for next-generation immunotherapies,such as immune checkpoint inhibitors and chimeric antigen receptor T(CAR-T)therapies,thereby advancing personalized treatment paradigms.展开更多
Main Exhauster is one of the main equipment of sintering production. It needs to consume a lot of electricity. Therefore, the system＇ s reconstruction for energy-saving will effectively reduce electricity for the pro...Main Exhauster is one of the main equipment of sintering production. It needs to consume a lot of electricity. Therefore, the system＇ s reconstruction for energy-saving will effectively reduce electricity for the production. The paper takes an iron and steel enterprise that had successfully transformed the synchronous motors of main exhauster of sintering as an example, which describes the application of high-voltage variable frequency speed regulation system in main exhauster of Sintering, so as to provide a reference for other iron and steel enterprises.展开更多
文摘Extreme heat events contribute to high mortality[1,2]and overwhelm emergency medical services through increased ambulance calls and overcrowded emergency departments.[3]Because morbidity and mortality are directly related to both the degree and duration of hyperthermia,timely recognition and management of heat exhaustion and heat stroke are critical for preventing death and reducing healthcare burdens.
文摘Exercise produces a decrease in pain sensitivity via an effect called exercise-induced hypoalgesia(EIH).Transcranial direct current stimulation(tDCS),acting on similar analgesic mechanisms as EIH,represents a potential complementary intervention that may amplify the effects of exercise on pain.This study aimed to explore if anodal tDCS could enhance the effect of exercise on pain compared to exercise alone.A total of 35 healthy participants aged 19–37 years completed a familiarisation session followed by two separate sessions where active and sham tDCS was applied in a randomised cross-over design.The familiarisation session involved familiarisation to the pain assessment and exercise tasks,while the subsequent tDCS sessions involved pain sensitivity assessment,exercise and either anodal tDCS or sham tDCS.tDCS doses were applied at 2 mA over the primary motor cortex for 10 min,with the reference electrode placed over the contralateral supraorbital area.The exercise task involved a sustained isometric grip strength contraction at 35%of maximal voluntary contraction(MVC)until volitional exhaustion.Pain sensitivity was evaluated as pressure pain threshold before tDCS,after tDCS,and after exercise.Across both tDCS conditions,pain threshold was higher after exercise when compared to pre-and post-tDCS measurement.This increase in pain threshold did not differ between active and sham tDCS conditions.Our findings suggest that the hypoalgesic effects of active anodal tDCS over the motor cortex prior to exercise are no greater than the effects of sham tDCS prior to exercise.
基金supported by the Agency for Defense Development Grant Funded by the Korean Government(Grant No.912822501).
文摘Unmanned combat aerial vehicles require lightweight,stealth-capable exhaust systems.However,traditional metallic nozzles increase radar detectability and reduce range,while advanced composites offer high performance but are expensive.Therefore,to improve the operational range and survivability of unmanned combat aerial vehicles,a lightweight,high-temperature-resistant,oxidation-resistant,and low-observable composite exhaust nozzle is developed to replace conventional metallic straight-type nozzles.The nozzle features a double serpentine shape to reduce radar and infrared signatures and is manufactured as a monolithic structure using the filament winding process,accommodating the complex geometry and large size(length:1.8 m,width:0.8 m).The exhaust nozzle consists of a ceramic matrix composite made of silicon carbide fibers and a silicon oxycarbide matrix,which absorbs and scatters radio frequency signals while withstanding prolonged exposure to high-temperature(700℃)oxidizing environments typical of engine exhaust gases.The polysiloxane resin used to produce the silicon oxycarbide matrix poses significant challenges owing to its low tackiness and high viscosity variations depending on the presence of nanoparticles,making filament winding difficult.These challenges are addressed by optimizing resin viscosity and winding pattern design.As a result,the tensile strength of the composite specimens fabricated with the optimized viscosity increases by 228.03% before pyrolysis and 97.68%after pyrolysis,compared with that of the non-optimized specimens.In addition,the density and tensile strength of the composite processed via three cycles of polymer infiltration and pyrolysis increased by 13.08% and 80.37%,respectively,compared to those of the non-densified composite.High-temperature oxidation and flame tests demonstrate exceptional thermal and oxidative stability.Furthermore,when compared with carbon fiber-reinforced ceramic matrix composites,the developed composite exhibits a permittivity at least two levels lower and a reflection loss below7 dB within the frequency range of 9.3-10.9 GHz,underscoring its superior electromagnetic stealth performance.
基金supported by The National Key Research and Development Program of China(Grant No.2021YFA0910100)Healthy Zhejiang One Million People Cohort(Grant No.K-20230085)+6 种基金supported by National Natural Science Foundation of China(Grant Nos.82304946 and 82573745)Post-doctoral Innovative Talent Support Program(Grant No.BX2023375)567 Foundation of Zhejiang Province(Grant No.LMS25H160006)supported by the National Natural Science Foundation of China(Grant No.82473489)the Medical Science and Technology Project of Zhejiang Province(Grant No.WKJ-ZJ-2202)the Natural Science Foundation of Zhejiang Province(Grant No.LBD24H290001)supported by the National Natural Science Foundation of China(Grant No.82403546).
文摘In recent years the crucial role of CD4^(+)T cells in tumor immunomodulation has garnered increasing recognition.While conventional cancer immunotherapy research has predominantly focused on the cytotoxic function of CD8+T cells,emerging evidence has now shown that CD4^(+)T cells enhance antitumor immunity by delivering co-stimulatory signals,secreting cytokines,and promoting cytotoxic T lymphocyte(CTL)activation and display unique immunoregulatory capabilities through direct tumor cell killing or remodeling of the tumor microenvironment.The high heterogeneity and functional plasticity of CD4^(+)T cell subsets significantly influence clinical responses to immunotherapy with underlying mechanisms involving multi-level regulatory networks,including epigenetic modulation and metabolic reprogramming.Deciphering the functional heterogeneity of CD4^(+)T cells and the interactions with the tumor microenvironment will provide essential mechanistic insights for next-generation immunotherapies,such as immune checkpoint inhibitors and chimeric antigen receptor T(CAR-T)therapies,thereby advancing personalized treatment paradigms.
文摘Main Exhauster is one of the main equipment of sintering production. It needs to consume a lot of electricity. Therefore, the system＇ s reconstruction for energy-saving will effectively reduce electricity for the production. The paper takes an iron and steel enterprise that had successfully transformed the synchronous motors of main exhauster of sintering as an example, which describes the application of high-voltage variable frequency speed regulation system in main exhauster of Sintering, so as to provide a reference for other iron and steel enterprises.
