The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is pres...The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.展开更多
The increase in forest-wildfire events around the world has revived the old debate regarding the practice of salvage logging and its effectiveness in comparison to the unlogged, natural regeneration of burned forests....The increase in forest-wildfire events around the world has revived the old debate regarding the practice of salvage logging and its effectiveness in comparison to the unlogged, natural regeneration of burned forests. Since the logging of burned trees may have undesirable outcomes in soil systems, such as soil compaction and nutrient losses, these changes could further cause disturbances to soil microbial-community activity. The aim of this study was to examine chemical and biological changes in soil under two post-fire practices: salvage logging and unlogged, natural regeneration of burned areas, in the recently burned Byria Forest in Israel. Results indicated that salvage logging had a short- lived effect on soil chemical and biological properties that was confined mostly to the first year after logging. Soil moisture was greatly affected by salvage logging, and drier conditions were found in the logged compared to the unlogged burned areas. Moreover, logging had a negative effect on microbial biomass, with reduced biomass in the logged compared to unlogged areas, which was more evident during the first year after fire. These findings support the recommendations in the literature to postpone post-fire practices such as logging or, in turn, to combine the two practices in order to create a mosaic of burned-logged and burned-naturally regenerated areas.展开更多
The goal of this study was to determine whether climate has affected vegetation regrowth over the past decade (2000 to 2010) in post-fire forest ecosystems of the United States and Canada. Our methodology detected tre...The goal of this study was to determine whether climate has affected vegetation regrowth over the past decade (2000 to 2010) in post-fire forest ecosystems of the United States and Canada. Our methodology detected trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) timeseries within forest areas that burned between 1984 and 1999. The trends in summed growing season EVI (composited to 8 km spatial resolution) within all burned area perimeters showed that nearly 1.6% post-fire forest area declined in vegetation greenness cover significantly (p < 0.05) over the past decade. Nearly 62% of all post-fire forest area showed a non significant EVI regrowth trend from 2000 to 2010. Regression results detected numerous significantly negative trend pixels in post-fire areas from 1994-1999 to indicate that forest regrowth has not yet occurred to any measurable level in many recent wildfire areas across the continent. We found several noteworthy relationships between annual temperature and precipitation patterns and negative post-fire forest EVI trends across North America. Change patterns in the climate moisture index (CMI), growing degree days (GDD), and the standardized precipitation index (SPI) were associated with post-fire forest EVI trends. We conclude that temperature warming-induced change and variability of precipitation at local and regional scales may have altered the trends of large post-fire forest regrowth and could be impacting the resilience of post-fire forest ecosystems in North America.展开更多
We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood ...We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.展开更多
We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground...We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground roots on each contour. The main roots at the south-facing slope (SS) developed in a long and straight form, and those on the north-facing slope (NS) in a twisted form. The side roots developed more than the main roots on the Ridge. The depth of taproots decreased in the following order: SS > NS > Ridge. The roots on the SS developed in a pile-form root structure whereas those in the Ridge and NS developed concentrically near the root collar. The amount of root development decreased in the following order: SS > NS > Ridge. The ratio of fine roots from the whole-root development decreased in the following order: Ridge > SS > NS. These results can guide considerations of growth differences according to the planting contour conditions for future establishment of P. densiflora artificial plantations.展开更多
Cardiac arrest(CA)is a critical condition in the field of cardiovascular medicine.Despite successful resuscitation,patients continue to have a high mortality rate,largely due to post CA syndrome(PCAS).However,the inju...Cardiac arrest(CA)is a critical condition in the field of cardiovascular medicine.Despite successful resuscitation,patients continue to have a high mortality rate,largely due to post CA syndrome(PCAS).However,the injury and pathophysiological mechanisms underlying PCAS remain unclear.Experimental animal models are valuable tools for exploring the etiology,pathogenesis,and potential interventions for CA and PCAS.Current CA animal models include electrical induction of ventricular fibrillation(VF),myocardial infarction,high potassium,asphyxia,and hemorrhagic shock.Although these models do not fully replicate the complexity of clinical CA,the mechanistic insights they provide remain highly relevant,including post-CA brain injury(PCABI),post-CA myocardial dysfunction(PAMD),systemic ischaemia/reperfusion injury(IRI),and the persistent precipitating pathology.Summarizing the methods of establishing CA models,the challenges encountered in the modeling process,and the mechanisms of PCAS can provide a foundation for developing standardized CA modeling protocols.展开更多
Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't...Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't get too many visitors anyway.But after being abandoned for over 35 years,it actually doesn't look half bad.展开更多
Polyvinyl chloride(PVC)is one of the most widely used plastic materials worldwide,particularly in long-life applications such as construction materials.However,recycling options for PVC waste remain limited,as convent...Polyvinyl chloride(PVC)is one of the most widely used plastic materials worldwide,particularly in long-life applications such as construction materials.However,recycling options for PVC waste remain limited,as conventional methods often degrade material quality or generate environmentally hazardous byproducts.In this study,we demonstrate an efficient process to convert PVC into new polymers with variable aromatic groups,using triethylsilane as the reductant in different solvents.This approach enables the production of polymers analogous to functionalized polyethylene(PE),which are typically challenging to obtain through conventional copolymerization or direct post-modification of C-H bonds in PE.The resulting polymers exhibit tunable thermal and mechanical properties depending on the introduced aromatic groups,which not only enhance the sustainable valorization of PVC waste,but also provide an opportunity for the synthesis of new functionalized polymers.展开更多
The effects of post heat treatment on the microstructure,aging kinetics,and room/elevated temperature mechanical properties of additively manufactured Inconel 718 superalloy were investigated.Scanning electron microsc...The effects of post heat treatment on the microstructure,aging kinetics,and room/elevated temperature mechanical properties of additively manufactured Inconel 718 superalloy were investigated.Scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),and X-ray diffraction(XRD),as well as hardness,tensile,and creep testing were used for characterization.At temperatures higher than 1100°C,homogenization treatment resulted in the appearance of equiaxed grains by recrystallization and diminishing the dislocation density.The precipitation activation energy for the homogenized and aged condition was obtained as 203.2 kJ/mol,which was higher than the value of~160 kJ/mol for the as-built IN718 superalloy.Therefore,direct aging resulted in a faster aging response,which led to a significant improvement in tensile properties,as rationalized by the strengthening mechanisms.Direct aging treatment resulted in a higher elevated-temperature ultimate tensile strength(UTS)as well as the optimum creep life and the lowest minimum creep rate in comparison with other heat treatment routes,which were attributed to the presence of fine and uniformly dispersed strengthening precipitates in conjunction with the high dislocation density.展开更多
Cardiac arrest is associated with high rates of mortality and significant long-term neurological disability in survivors.Timely and accurate assessment following successful resuscitation is critical for optimizing out...Cardiac arrest is associated with high rates of mortality and significant long-term neurological disability in survivors.Timely and accurate assessment following successful resuscitation is critical for optimizing outcomes.Imaging plays a central role in this evaluation process,providing crucial insights into the etiology of arrest,the extent of cerebral and cardiac injury,and guiding both acute management and long-term prognostication.A structured,multimodal imaging approach utilizing tools such as computed tomography,magnetic resonance imaging,echocardiography,and angiography is increasingly recognized as es-sential in the post-cardiac arrest setting.This review aims to consolidate current evidence related to the use of various imaging modalities across neurological,cardiac and systemic contexts.Particular emphasis is placed on the prognostic value and optimal timing of neuroimaging,the detection of potentially reversible causes of arrest,such as coronary occlusion or pulmonary embolism,and the emerging role of whole-body imaging in evaluating patients with non-traumatic out-of-hospital cardiac arrest.展开更多
High-voltage electrical post equipment is generally installed on steel supports,which amplifies the seismic inputs and degrades the seismic performance of equipment.This study proposed a variable cross-section damped ...High-voltage electrical post equipment is generally installed on steel supports,which amplifies the seismic inputs and degrades the seismic performance of equipment.This study proposed a variable cross-section damped steel support frame(VCDFS)with viscous dampers to reduce seismic responses of both tall and low-rise electrical equipment.The VCDFS contains a trapezoidal damper layer to generate rocking motions,enabling the diagonal viscous dampers to dissipate seismic inputs.A theoretical model of post equipment with VCDFS is established,and an optimal design procedure is proposed.The analysis shows that the remaining static stiffness ratio λ_(k) is the key parameter that determines the effectiveness of the VCDFS.The VCDFS reduces the average displacement and stress response of a post insulator by 39.4%and 44.6%,respectively,together with a significant decrease in the dynamic amplification factor.Therefore,it is recommended to use the VCDFS instead of the conventional latticed-steel frame in earthquake zones.展开更多
Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,wit...Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,with~1 in 8 people,equivalent to 970 million individuals suffering from a mental disorder in 2019(https://vizhub.healthdata.org/gbd-results).Anxiety and depressive disorders are predominant,contributing significantly to the burden of mental health issues,according to the World Health Organization.The COVID-19 pandemic has further exacerbated this situation.It led to a notable upsurge in anxiety and major depressive disorders in 2020.Estimates indicate a 26%rise in anxiety and a 28%increase in depression within that year(https://www.who.int/publications/i/item/WHO-2019-nCoVSci_Brief-Mental_health-2022.1)[1].展开更多
This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-...This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-hole drilling(DHD)methods,and investigated the microstructure and mechanical properties.During the PWHT at 600℃,a phase transformation(β→α)occurred in the EBW joint and affected the residual stress distribution and mechanical properties.The surface residual stress was mainly compressive stress,while the internal residual stress was mainly tensile stress in the welded joint.For the as-welded joint,the absolute value of surface residual stress was higher than the absolute value of internal residual stress.After PWHT,the residual stress in the treated joint was substantially reduced compared to the as-welded joint,particularly the surface stress,which relieved from−425 to−90 MPa.However,the residual stress relief effect had minimal positive impact on the internal region at 600℃.PWHT resulted in a shift of the joint fracture location from the fusion zone(FZ)to the base metal(BM),and therefore exerted no noticeable effect on the joint strength,but increased the joint elongation significantly.This study provides valuable insights into the regulation of residual stress distribution of ultra-thick titanium alloy plates.展开更多
Diffusion-bonded Ti_(2)AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize ...Diffusion-bonded Ti_(2)AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize the microstructure, contributing to strength improvement and appropriate ductility sacrifice. An available method by the introduction of fine size (both 20-100 nm) and a high fraction (59.7% and 13.7%) of O and α_(2) phases using both solution at 1000℃ for 1 h and aging at 750℃ for 5 h can result in excellent tensile strength (992 MPa and 858 MPa) at room temperature and 650℃, respectively, which increases 5.3% and 44.5% than that of as-received sample. The aging treatment can contribute to lamellar O and α2 grains precipitated from the B_(2) parent, which results in limited dislocation slip systems and slip spaces to resist plastic deformation. Moreover, the crack propagation and fracture surfaces are also comparatively analyzed to reveal the fracture behaviors in the samples with high and low strength. This study can provide a new method for the mechanical property optimization of the welded Ti_(2)AlNb alloys.展开更多
The diagnosis and treatment processes for long COVID have been relatively slow to develop for several reasons,such as a lack of consensus about its definition among medical professionals and researchers,and restricted...The diagnosis and treatment processes for long COVID have been relatively slow to develop for several reasons,such as a lack of consensus about its definition among medical professionals and researchers,and restricted access to knowledge from the relevant pandemics of the past.Legacies of viral pandemics unfortunately do not include sufficient research on how the acute symptoms of infection evolved into chronic health conditions.More so,the idea of surviving a viral pandemic with long-lasting symptoms is not new,yet it is curiously disjointed as a medical concept throughout documented histories on the subject.Individuals with long-term conditions that are rooted in acute viral infections,such as COVID-19,require a coordinated system of care that includes comprehensive rehabilitation.This commentary will discuss the philosophical underpinnings of the historical scarcity of documented incidences of individuals with chronic virus symptoms and the need for a shift in post-viral infection treatment approaches.展开更多
Chak-hao,the Forbidden Rice from Manipur,India,is an aromatic,purplish-black rice variety that has been awarded a geographical indication tag to preserve and promote its traditional cultivation in Manipur,India.Althou...Chak-hao,the Forbidden Rice from Manipur,India,is an aromatic,purplish-black rice variety that has been awarded a geographical indication tag to preserve and promote its traditional cultivation in Manipur,India.Although Chak-hao is a hardy landrace with field tolerance to biotic stress,its grains are highly susceptible to storage pest infestations,particularly those caused by the rice weevil(Sitophilus oryzae).This severely compromises its commercial storage quality,as pest damage reduces both nutritional value and quantity.展开更多
This article discusses the evolving real-world practice using nitazoxanide,nonsteroidal anti-inflammatory drugs(NSAIDs)and/or azithromycin(Kelleni’s protocol)to manage the evolving manifestations of severe acute resp...This article discusses the evolving real-world practice using nitazoxanide,nonsteroidal anti-inflammatory drugs(NSAIDs)and/or azithromycin(Kelleni’s protocol)to manage the evolving manifestations of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron EG.5.1,its descendant HV.1 as well as BA.2.86 and its descendant JN.1 subvariants in Egypt in 2024.These subvariants are well-known for their highly evolved immune-evasive properties and the manifestations include some peculiar manifestations as persistent cough besides high fever in young children as well as high fever,persistent severe cough,change of voice,loss of taste and smell,epigastric pain,nausea,vomiting,diarrhea,generalized malaise and marked bone aches in adults including the high-risk groups.It’s suggested that the ongoing SARS-CoV-2 evolution is continuing to mostly affect the high-risk groups of patients,to some of whom we’ve also successfully prescribed nitazoxanide and/or NSAIDs for post-exposure prophylaxis of all household contacts.We also continue to recommend starting the immune-modulatory antiviral Kelleni’s protocol as soon as possible in the course of infection and adjusting it in a personalized manner to be more aggressive from the beginning for the high risk patients,at least until the currently encountered surge of infections subsides.展开更多
Background Quantitative flow ratio(QFR) holds significant value in guiding drug-coated balloon(DCB) treatment and enhancing outcomes. However, the predictive capability of post-angioplasty QFR for long-term clinical e...Background Quantitative flow ratio(QFR) holds significant value in guiding drug-coated balloon(DCB) treatment and enhancing outcomes. However, the predictive capability of post-angioplasty QFR for long-term clinical events in patients with de novo lesions who receive DCB treatment remains uncertain. The aim of this study was to explore the potential significance of post-angioplasty QFR measurements in predicting clinical outcomes in patients underwent DCB treatment for de novo lesions.Methods Patients who underwent DCB-only intervention for de novo lesions were enrolled. QFR was conducted after DCB treatment. The patients were then categorized based on post-angioplasty QFR. The primary endpoint was major adverse cardiac events(MACE), encompassing all-cause death, cardiovascular death, nonfatal myocardial infarction, stroke, and target vessel revascularization.Results A total of 553 patients with 561 lesions were included. The median follow-up period was 505 days, during which 66(11.8%) MACEs occurred. Based on post-procedural QFR grouping, there were 259 cases in the high QFR group(QFR > 0.93) and302 cases in the low QFR group(QFR ≤ 0.93). Kaplan-Meier analysis revealed a significantly higher cumulative incidence of MACE in the low QFR group(log-rank P = 0.004). The multivariate Cox proportional hazards model demonstrated a significant inverse correlation between QFR and the occurrence of MACEs(HR = 0.522, 95%CI: 0.289-0.942, P = 0.031). Landmark analysis indicated that high QFR had a significant reducing effect on the cumulative incidence of MACEs within 1 year(log-rank P = 0.016)and 1-5 years(log-rank P = 0.026).Conclusions In patients who underwent DCB-only treatment for de novo lesions, higher post-procedural QFR values(> 0.93)were identified as an independent protective factor against adverse prognosis.展开更多
In order to investigate the micro-process and inner mechanism of rock failure under impact loading, the laboratory tests were carried out on an improved split Hopkinson pressure bar （SHPB） system with synchronized m...In order to investigate the micro-process and inner mechanism of rock failure under impact loading, the laboratory tests were carried out on an improved split Hopkinson pressure bar （SHPB） system with synchronized measurement devices including a high-speed camera and a dynamic strain meter. The experimental results show that the specimens were in the state of good stress equilibrium during the post failure stage even when visible cracks were forming in the specimens. Rock specimens broke into strips but still could bear the external stress and keep force balance. Meanwhile, numerical tests with particle flow code （PFC） revealed that the failure process of rocks can be described by the evolution of micro-fractures. Shear cracks emerged firstly and stopped developing when the external stress was not high enough. Tensile cracks, however, emerged when the rock specimen reached its peak strength and played an important role in controlling the ultimate failure during the post failure stage.展开更多
基金National Outstanding Youth Science Foundation (59825105).
文摘The authors study the structure, functions and data organization for the hazard analysis system of urban post-earthquake fire on the platform of GIS. A general hazard analysis model of the post-earthquake fire is presented. Taking Shanghai central district as background, a system for hazard analysis of the post-earthquake fire and auxiliary decision-against fire is developed.
文摘The increase in forest-wildfire events around the world has revived the old debate regarding the practice of salvage logging and its effectiveness in comparison to the unlogged, natural regeneration of burned forests. Since the logging of burned trees may have undesirable outcomes in soil systems, such as soil compaction and nutrient losses, these changes could further cause disturbances to soil microbial-community activity. The aim of this study was to examine chemical and biological changes in soil under two post-fire practices: salvage logging and unlogged, natural regeneration of burned areas, in the recently burned Byria Forest in Israel. Results indicated that salvage logging had a short- lived effect on soil chemical and biological properties that was confined mostly to the first year after logging. Soil moisture was greatly affected by salvage logging, and drier conditions were found in the logged compared to the unlogged burned areas. Moreover, logging had a negative effect on microbial biomass, with reduced biomass in the logged compared to unlogged areas, which was more evident during the first year after fire. These findings support the recommendations in the literature to postpone post-fire practices such as logging or, in turn, to combine the two practices in order to create a mosaic of burned-logged and burned-naturally regenerated areas.
文摘The goal of this study was to determine whether climate has affected vegetation regrowth over the past decade (2000 to 2010) in post-fire forest ecosystems of the United States and Canada. Our methodology detected trends in the monthly MODerate resolution Imaging Spectroradiometer (MODIS) Enhanced Vegetation Index (EVI) timeseries within forest areas that burned between 1984 and 1999. The trends in summed growing season EVI (composited to 8 km spatial resolution) within all burned area perimeters showed that nearly 1.6% post-fire forest area declined in vegetation greenness cover significantly (p < 0.05) over the past decade. Nearly 62% of all post-fire forest area showed a non significant EVI regrowth trend from 2000 to 2010. Regression results detected numerous significantly negative trend pixels in post-fire areas from 1994-1999 to indicate that forest regrowth has not yet occurred to any measurable level in many recent wildfire areas across the continent. We found several noteworthy relationships between annual temperature and precipitation patterns and negative post-fire forest EVI trends across North America. Change patterns in the climate moisture index (CMI), growing degree days (GDD), and the standardized precipitation index (SPI) were associated with post-fire forest EVI trends. We conclude that temperature warming-induced change and variability of precipitation at local and regional scales may have altered the trends of large post-fire forest regrowth and could be impacting the resilience of post-fire forest ecosystems in North America.
文摘We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.
基金supported by a research Grant from Yeungnam University in 2015the National Research Foundation of Korea Grant(NRF No.2016M3C1B6929073)funded by the Ministry of Science,ICT and Future Planning of the Republic of Korea
文摘We estimated the growth volume of artificially reforested Pinus densiflora in a post-fire area on three different contour conditions by comparing and analyzing the vertical and horizontal distributions of below-ground roots on each contour. The main roots at the south-facing slope (SS) developed in a long and straight form, and those on the north-facing slope (NS) in a twisted form. The side roots developed more than the main roots on the Ridge. The depth of taproots decreased in the following order: SS > NS > Ridge. The roots on the SS developed in a pile-form root structure whereas those in the Ridge and NS developed concentrically near the root collar. The amount of root development decreased in the following order: SS > NS > Ridge. The ratio of fine roots from the whole-root development decreased in the following order: Ridge > SS > NS. These results can guide considerations of growth differences according to the planting contour conditions for future establishment of P. densiflora artificial plantations.
基金supported by the National Key Research and Development Program(2021YFC3002205)the Postgraduate Research and Innovation Program of Tianjin Municipal Education Commission(2022BKY113),China.
文摘Cardiac arrest(CA)is a critical condition in the field of cardiovascular medicine.Despite successful resuscitation,patients continue to have a high mortality rate,largely due to post CA syndrome(PCAS).However,the injury and pathophysiological mechanisms underlying PCAS remain unclear.Experimental animal models are valuable tools for exploring the etiology,pathogenesis,and potential interventions for CA and PCAS.Current CA animal models include electrical induction of ventricular fibrillation(VF),myocardial infarction,high potassium,asphyxia,and hemorrhagic shock.Although these models do not fully replicate the complexity of clinical CA,the mechanistic insights they provide remain highly relevant,including post-CA brain injury(PCABI),post-CA myocardial dysfunction(PAMD),systemic ischaemia/reperfusion injury(IRI),and the persistent precipitating pathology.Summarizing the methods of establishing CA models,the challenges encountered in the modeling process,and the mechanisms of PCAS can provide a foundation for developing standardized CA modeling protocols.
文摘Deep in the Tengger Desert of Inner Mongolia autonomous region,surrounded by sand as far as the eye can see,lies the world's loneliest post office.Measuring only 15 square meters,the wooden post office doesn't get too many visitors anyway.But after being abandoned for over 35 years,it actually doesn't look half bad.
基金the Beijing Natural Science Foundation(Z240029)the National Natural Science Foundation of China(22472004)+2 种基金China National Petroleum Corporation-Peking University Strategic Cooperation Project of Fundamental Researchthe New Cornerstone Science Foundationsupport from the Tencent Foundation through the Xplorer Prize.
文摘Polyvinyl chloride(PVC)is one of the most widely used plastic materials worldwide,particularly in long-life applications such as construction materials.However,recycling options for PVC waste remain limited,as conventional methods often degrade material quality or generate environmentally hazardous byproducts.In this study,we demonstrate an efficient process to convert PVC into new polymers with variable aromatic groups,using triethylsilane as the reductant in different solvents.This approach enables the production of polymers analogous to functionalized polyethylene(PE),which are typically challenging to obtain through conventional copolymerization or direct post-modification of C-H bonds in PE.The resulting polymers exhibit tunable thermal and mechanical properties depending on the introduced aromatic groups,which not only enhance the sustainable valorization of PVC waste,but also provide an opportunity for the synthesis of new functionalized polymers.
文摘The effects of post heat treatment on the microstructure,aging kinetics,and room/elevated temperature mechanical properties of additively manufactured Inconel 718 superalloy were investigated.Scanning electron microscopy(SEM),electron backscattered diffraction(EBSD),and X-ray diffraction(XRD),as well as hardness,tensile,and creep testing were used for characterization.At temperatures higher than 1100°C,homogenization treatment resulted in the appearance of equiaxed grains by recrystallization and diminishing the dislocation density.The precipitation activation energy for the homogenized and aged condition was obtained as 203.2 kJ/mol,which was higher than the value of~160 kJ/mol for the as-built IN718 superalloy.Therefore,direct aging resulted in a faster aging response,which led to a significant improvement in tensile properties,as rationalized by the strengthening mechanisms.Direct aging treatment resulted in a higher elevated-temperature ultimate tensile strength(UTS)as well as the optimum creep life and the lowest minimum creep rate in comparison with other heat treatment routes,which were attributed to the presence of fine and uniformly dispersed strengthening precipitates in conjunction with the high dislocation density.
文摘Cardiac arrest is associated with high rates of mortality and significant long-term neurological disability in survivors.Timely and accurate assessment following successful resuscitation is critical for optimizing outcomes.Imaging plays a central role in this evaluation process,providing crucial insights into the etiology of arrest,the extent of cerebral and cardiac injury,and guiding both acute management and long-term prognostication.A structured,multimodal imaging approach utilizing tools such as computed tomography,magnetic resonance imaging,echocardiography,and angiography is increasingly recognized as es-sential in the post-cardiac arrest setting.This review aims to consolidate current evidence related to the use of various imaging modalities across neurological,cardiac and systemic contexts.Particular emphasis is placed on the prognostic value and optimal timing of neuroimaging,the detection of potentially reversible causes of arrest,such as coronary occlusion or pulmonary embolism,and the emerging role of whole-body imaging in evaluating patients with non-traumatic out-of-hospital cardiac arrest.
基金Guangdong Basic and Applied Basic Research Foundation under Grant Nos.2022A1515110561 and 2023A1515010072Natural Science Foundation of China under Grant Nos.52308488 and 52378499。
文摘High-voltage electrical post equipment is generally installed on steel supports,which amplifies the seismic inputs and degrades the seismic performance of equipment.This study proposed a variable cross-section damped steel support frame(VCDFS)with viscous dampers to reduce seismic responses of both tall and low-rise electrical equipment.The VCDFS contains a trapezoidal damper layer to generate rocking motions,enabling the diagonal viscous dampers to dissipate seismic inputs.A theoretical model of post equipment with VCDFS is established,and an optimal design procedure is proposed.The analysis shows that the remaining static stiffness ratio λ_(k) is the key parameter that determines the effectiveness of the VCDFS.The VCDFS reduces the average displacement and stress response of a post insulator by 39.4%and 44.6%,respectively,together with a significant decrease in the dynamic amplification factor.Therefore,it is recommended to use the VCDFS instead of the conventional latticed-steel frame in earthquake zones.
基金supported by the National Natural Science Foundation of China(T2241028)STI2030-Major Projects[2021ZD0203000(2021ZD0203003)].
文摘Mental health disorders have emerged as a critical global health challenge,profoundly impacting individuals,communities,and societies worldwide.The prevalence of mental health problems has been steadily increasing,with~1 in 8 people,equivalent to 970 million individuals suffering from a mental disorder in 2019(https://vizhub.healthdata.org/gbd-results).Anxiety and depressive disorders are predominant,contributing significantly to the burden of mental health issues,according to the World Health Organization.The COVID-19 pandemic has further exacerbated this situation.It led to a notable upsurge in anxiety and major depressive disorders in 2020.Estimates indicate a 26%rise in anxiety and a 28%increase in depression within that year(https://www.who.int/publications/i/item/WHO-2019-nCoVSci_Brief-Mental_health-2022.1)[1].
基金supported by the National Key Research and Development Program of China(No.2023YFC2810700)the Youth Innovation Promotion Association of the Chinese Academy of Sciences(2021193)the Science and Technology Cooperation Project between Jilin Province and Chinese Academy of Sciences(No.2024SYHZ0032).
文摘This study analyzed through-thickness distribution of residual stress in a 106 mm ultra-thick TC4 titanium alloy electron beam welded(EBW)joint after post weld heat treatment(PWHT)using X-ray diffraction(XRD)and deep-hole drilling(DHD)methods,and investigated the microstructure and mechanical properties.During the PWHT at 600℃,a phase transformation(β→α)occurred in the EBW joint and affected the residual stress distribution and mechanical properties.The surface residual stress was mainly compressive stress,while the internal residual stress was mainly tensile stress in the welded joint.For the as-welded joint,the absolute value of surface residual stress was higher than the absolute value of internal residual stress.After PWHT,the residual stress in the treated joint was substantially reduced compared to the as-welded joint,particularly the surface stress,which relieved from−425 to−90 MPa.However,the residual stress relief effect had minimal positive impact on the internal region at 600℃.PWHT resulted in a shift of the joint fracture location from the fusion zone(FZ)to the base metal(BM),and therefore exerted no noticeable effect on the joint strength,but increased the joint elongation significantly.This study provides valuable insights into the regulation of residual stress distribution of ultra-thick titanium alloy plates.
基金support by the National Key R&D Program of China(No.2022YFB3402200)the Program of Shanghai Academic Research Leader(No.22XD1421600).
文摘Diffusion-bonded Ti_(2)AlNb-based alloys commonly present a low strength compared with the deformed or aged ones. In this study, the post heat treatment including solution and aging treatments is proposed to optimize the microstructure, contributing to strength improvement and appropriate ductility sacrifice. An available method by the introduction of fine size (both 20-100 nm) and a high fraction (59.7% and 13.7%) of O and α_(2) phases using both solution at 1000℃ for 1 h and aging at 750℃ for 5 h can result in excellent tensile strength (992 MPa and 858 MPa) at room temperature and 650℃, respectively, which increases 5.3% and 44.5% than that of as-received sample. The aging treatment can contribute to lamellar O and α2 grains precipitated from the B_(2) parent, which results in limited dislocation slip systems and slip spaces to resist plastic deformation. Moreover, the crack propagation and fracture surfaces are also comparatively analyzed to reveal the fracture behaviors in the samples with high and low strength. This study can provide a new method for the mechanical property optimization of the welded Ti_(2)AlNb alloys.
文摘The diagnosis and treatment processes for long COVID have been relatively slow to develop for several reasons,such as a lack of consensus about its definition among medical professionals and researchers,and restricted access to knowledge from the relevant pandemics of the past.Legacies of viral pandemics unfortunately do not include sufficient research on how the acute symptoms of infection evolved into chronic health conditions.More so,the idea of surviving a viral pandemic with long-lasting symptoms is not new,yet it is curiously disjointed as a medical concept throughout documented histories on the subject.Individuals with long-term conditions that are rooted in acute viral infections,such as COVID-19,require a coordinated system of care that includes comprehensive rehabilitation.This commentary will discuss the philosophical underpinnings of the historical scarcity of documented incidences of individuals with chronic virus symptoms and the need for a shift in post-viral infection treatment approaches.
文摘Chak-hao,the Forbidden Rice from Manipur,India,is an aromatic,purplish-black rice variety that has been awarded a geographical indication tag to preserve and promote its traditional cultivation in Manipur,India.Although Chak-hao is a hardy landrace with field tolerance to biotic stress,its grains are highly susceptible to storage pest infestations,particularly those caused by the rice weevil(Sitophilus oryzae).This severely compromises its commercial storage quality,as pest damage reduces both nutritional value and quantity.
文摘This article discusses the evolving real-world practice using nitazoxanide,nonsteroidal anti-inflammatory drugs(NSAIDs)and/or azithromycin(Kelleni’s protocol)to manage the evolving manifestations of severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)Omicron EG.5.1,its descendant HV.1 as well as BA.2.86 and its descendant JN.1 subvariants in Egypt in 2024.These subvariants are well-known for their highly evolved immune-evasive properties and the manifestations include some peculiar manifestations as persistent cough besides high fever in young children as well as high fever,persistent severe cough,change of voice,loss of taste and smell,epigastric pain,nausea,vomiting,diarrhea,generalized malaise and marked bone aches in adults including the high-risk groups.It’s suggested that the ongoing SARS-CoV-2 evolution is continuing to mostly affect the high-risk groups of patients,to some of whom we’ve also successfully prescribed nitazoxanide and/or NSAIDs for post-exposure prophylaxis of all household contacts.We also continue to recommend starting the immune-modulatory antiviral Kelleni’s protocol as soon as possible in the course of infection and adjusting it in a personalized manner to be more aggressive from the beginning for the high risk patients,at least until the currently encountered surge of infections subsides.
基金supported by grants from the National Natural Science Foundation of China (82070408)the Traditional Chinese Medicine Science and Technology Project of Zhejiang Province (2023ZL496)。
文摘Background Quantitative flow ratio(QFR) holds significant value in guiding drug-coated balloon(DCB) treatment and enhancing outcomes. However, the predictive capability of post-angioplasty QFR for long-term clinical events in patients with de novo lesions who receive DCB treatment remains uncertain. The aim of this study was to explore the potential significance of post-angioplasty QFR measurements in predicting clinical outcomes in patients underwent DCB treatment for de novo lesions.Methods Patients who underwent DCB-only intervention for de novo lesions were enrolled. QFR was conducted after DCB treatment. The patients were then categorized based on post-angioplasty QFR. The primary endpoint was major adverse cardiac events(MACE), encompassing all-cause death, cardiovascular death, nonfatal myocardial infarction, stroke, and target vessel revascularization.Results A total of 553 patients with 561 lesions were included. The median follow-up period was 505 days, during which 66(11.8%) MACEs occurred. Based on post-procedural QFR grouping, there were 259 cases in the high QFR group(QFR > 0.93) and302 cases in the low QFR group(QFR ≤ 0.93). Kaplan-Meier analysis revealed a significantly higher cumulative incidence of MACE in the low QFR group(log-rank P = 0.004). The multivariate Cox proportional hazards model demonstrated a significant inverse correlation between QFR and the occurrence of MACEs(HR = 0.522, 95%CI: 0.289-0.942, P = 0.031). Landmark analysis indicated that high QFR had a significant reducing effect on the cumulative incidence of MACEs within 1 year(log-rank P = 0.016)and 1-5 years(log-rank P = 0.026).Conclusions In patients who underwent DCB-only treatment for de novo lesions, higher post-procedural QFR values(> 0.93)were identified as an independent protective factor against adverse prognosis.
基金Project(2015CB060200)supported by the National Basic Research and Development Program of ChinaProjects(51322403,51274254)supported by the National Natural Science Foundation of China
文摘In order to investigate the micro-process and inner mechanism of rock failure under impact loading, the laboratory tests were carried out on an improved split Hopkinson pressure bar （SHPB） system with synchronized measurement devices including a high-speed camera and a dynamic strain meter. The experimental results show that the specimens were in the state of good stress equilibrium during the post failure stage even when visible cracks were forming in the specimens. Rock specimens broke into strips but still could bear the external stress and keep force balance. Meanwhile, numerical tests with particle flow code （PFC） revealed that the failure process of rocks can be described by the evolution of micro-fractures. Shear cracks emerged firstly and stopped developing when the external stress was not high enough. Tensile cracks, however, emerged when the rock specimen reached its peak strength and played an important role in controlling the ultimate failure during the post failure stage.
