Urban populations are increasingly exposed to extreme heat due to climate change and rapid urbanization,heightening health risks in cities worldwide.Accurate heat exposure assessment is essential for public health pla...Urban populations are increasingly exposed to extreme heat due to climate change and rapid urbanization,heightening health risks in cities worldwide.Accurate heat exposure assessment is essential for public health planning and risk reduction.Most existing approaches rely on a single threshold temperature(e.g.,35℃of daily max temperature),applied uniformly to the entire population.However,this one-size-fits-all assumption overlooks substantial differences in heat sensitivity across population subgroups.In this study,we address this limitation by quantifying subgroup-specific temperature-mortality relationships and using corresponding minimum mortality temperatures(MMTs)to assess heat exposure.Results show that the population-wide MMT was 27.5℃,but it varied greatly across population subgroups.The elderly population(≥65)had an MMT of 24.6℃,much lower than the 28.6℃observed in younger individuals(<65).Females also exhibited a lower MMT that males(25℃versus 28.2℃).However,educational attainment did not significantly affect MMT.Using a uniform MMT resulted in substantial underestimation of heat exposure,ranging from 25.3%in 1990 to 13.9%in 2020,reflecting demographic shifts over time.Spatially,nearly half of the city experienced underestimated heat risk,especially in central and northeastern regions where heat-vulnerable populations are concentrated.These findings underscore the need for more nuanced heat exposure assessments that account for demographic and spatial variability,paving the way for targeted public health interventions to protect the most vulnerable urban populations.展开更多
Elderly individuals disproportionately face heat exposure risk compared to other demographic groups,with projected amplification in the future.The vast disparities between Global North and South countries necessitate ...Elderly individuals disproportionately face heat exposure risk compared to other demographic groups,with projected amplification in the future.The vast disparities between Global North and South countries necessitate a comprehensive understanding of the underlying factors influencing future heat exposure vulnerabilities.Here,we use factor decomposition method to quantify the contribution of climate change,population,and aging to heat exposure risk under four shared socioeconomic pathways(SSP)(SSP126,SSP245,SSP370,SSP585)from 2000 to 2100 at 20-year intervals.Results demonstrate a projected global escalation in heat exposure risk by 16 and 76 times under SSP126 and SSP585,respectively,with the North generally suffering lower risk than the South.Climate change emerges as a pivotal driver of future heat exposure risk in the North while aging notably influences the South.Despite climate change is projected to reduce heat exposure risk by up to 10%in the North under SSP1-2.6 by the end of the 21st century,aging remains a critical risk factor.展开更多
[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The ...[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The temperature was increased from(18± 0.5) ℃ by 0.08 ℃/min and respectively kept at(32±0.5) ℃ for 2, 4 and 6 h. The respiration rate, related biochemical indicators and heat shock protein 70(Hsp 70) mR-NA expression were investigated. [Result] At(32±0.5) ℃, the activities of total protein, albumin, globulin, urea nitrogen, ceatinine, malondialde-hyde, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase fluctuated dramatically from 2 h to 6 h. Meanwhile, the respi-ration rate and Hsp 70 m RNA expression in heart, liver and spleen were significantly increased from 2 h to 6 h. In comparison, the lower respira-tion rate and tiny fluctuations in activities of biochemical indicators were consistent with the lower Hsp 70 expression. [Conclusion] During the process of heat stress, A. schrencki seems to be sensitive to such temperature, and manifests generally consistent gill breathing, biochemical indica-tors and Hsp70 gene expression, implying better heat tolerance.展开更多
When studying the thermal adaptation of building occupants,understanding the effects of different thermal experiences on adaptation is necessary,particularly for moderate and severe heat exposure.However,this area has...When studying the thermal adaptation of building occupants,understanding the effects of different thermal experiences on adaptation is necessary,particularly for moderate and severe heat exposure.However,this area has seen limited research.Further,skin temperature,a common parameter for quantifying thermal sensation,may insufficiently reflect the automatic thermoregulation of the human body.This study investigates the effects of long-term heat exposure on the human body using multiple physiological and subjective indexes.Two heat exposure experiments were conducted on healthy male participants from northern and southern China.Participant responses,including skin temperature,heart rate,heart rate variability,blood volume pulse(BVP),subjective thermal comfort thermal sensation,thermal acceptability,and normalized high and low frequency values were collected and compared The results indicated that the subjective responses of northern and southern participants were not significantly different;however,the subjective physiological symptoms and self-reported discomfort of the latter were less than those of the former,indicating that the southern participants had superior heat tolerance.Additionally,the physiological responses of all the participants were largely similar.However,southern participants showed slightly higher normalized high frequency and BVP values,indicating that they have more active vagus nerves and better vasodilation.They also showed a wider acceptable temperature range and better acclimation to heat exposure.Notably,the mean skin temperature could not effectively predict thermal sensation during heat exposure;this was more accurately achieved using the rate of change of skin temperature.These findings suggest that long-term thermal experiences can affect building occupants’thermal adaptability.展开更多
BACKGROUND:Glutamine(Gin)pretreatment can protect neural cells from injuries due to heat,ischemia,hypoxia,endotoxemia,and inflammatory factors.OBJECTIVE:To observe the effects of Gin pretreatment on learning and memor...BACKGROUND:Glutamine(Gin)pretreatment can protect neural cells from injuries due to heat,ischemia,hypoxia,endotoxemia,and inflammatory factors.OBJECTIVE:To observe the effects of Gin pretreatment on learning and memory,survival time,and rectal temperature in heat-exposed rats.DESIGN,TIME AND SETTING:The present randomized grouping,neurobehavioral experiment was performed at the Laboratory of Department of Pharmacology,Basic School of Medicine,Wuhan University between March and September 2007.MATERIALS:Twenty-four healthy,Wistar rats were included in this study.SPX-160B biochemistry incubator(Shanghai Experimental Equipment Co.,Ltd.,China),probe electronic thermometer(11000 type,Maikepai Science and Technology Co.,Ltd.,China),Y-type maze box used in conjunction with MG-2 maze stimulator(Zhangjiagang Biomedical Instrument Factory,China),L-Gln(Batch No.061218,5 g/bottle,prepared into 10%aqueous solution,Amresco Company,USA)were used.METHODS:Twenty-four rats were randomly and evenly divided into 3 groups:heat-exposed,Gln low-lose,and Gln high-dose.Following learning and memory testing with the Y-maze,rats in the heat-exposed group were subjected to heat injury(40.5-41.5℃)in a biochemistry incubator.Rectal temperature was measured every 5 minutes.Thirty-five minutes after heat exposure,rats were removed and placed in the Y-type maze to test learning and memory again.Subsequently,the rats were returned to the same environment of thermal stimulation until they died.Rat survival time was recorded.Subsequent to learning and memory testing,rats in the Gin low-dose and high-dose groups received an i.p.injection of Gin(0.4 g/kg and 0.8 g/kg,respectively),and were exposed to heat injury.The remaining experimental procedures remained the same as for the heat-exposed group.MAIN OUTCOME MEASURES:Rat learning and memory,rectal temperature,and survival time in heat exposure environment.RESULTS:(1)In the Y-maze experiment,the frequency for the heat-exposed group rats to move 15 successive times through the maze without any mistakes was 13 times greater prior to heat exposure.Thirty-five minutes after heat exposure,rat learning and memory were significantly decreased,i.e.,frequency was 9/15 correct trials(P〈0.01).Following Gln pretreatment,rat learning and memory noticeably improved The frequency of Gln low-dose and high-dose rats maintained 13/15 correct trials,which was not different compared with before heat exposure(P〉0.05).(2)The heat-exposed group required 14 minutes to reach the rectal temperature of 39.5℃.After 2 hours of Gln pretreatment,the Gln low-dose and high-dose groups needed 18 and 20 minutes,respectively(P〈0.05).(3)Following 2 hours ofGln pretreatment,the survival time of the Gln low-dose and high-dose groups was 66 and 69 minutes,which was prolonged by 18.2%(P〈0.05)and 21.7%(P〈0.01),respectively,compared with the heat-exposed group(54 minutes).CONCLUSION:A 2-hour Gln pretreatment can noticeably improve learning and memory,delay ascending speed of body temperature,and prolong survival time in heat-exposed rats in a dose-dependent manner.展开更多
Over 100 human thermal indices have been developed to predict the combined thermal impact on the body.In principle,these indices based on energy thermal budget equations should not only be the most complex but also be...Over 100 human thermal indices have been developed to predict the combined thermal impact on the body.In principle,these indices based on energy thermal budget equations should not only be the most complex but also be the most accurate.However,the simple indices based on algebraic or statistical models[e.g.,the wet-bulb globe temperature(WBGT)]continue to be the most popular.A new heat stress index,the enthalpy dry-bulb temperature(EnD)for indoor environments is developed and validated in this study.The EnD index is unique in that it uses the air specific enthalpy,not the wet-bulb temperature,to measure the latent heat transfer from the skin to the surrounding environment.Theoretically,the EnD index can be treated as the equivalent temperature based on the convective heat transfer coefficient h_(c).Comparison is made between the EnD index and the widely used WBGT index based on the experimental data taken from three independent studies available in the scientific literature.The results show that the EnD index can reduce the overestimation of the dry-bulb air temperature and thus reduce heat stress in most cases,especially for hot and humid environments.It can be concluded that the EnD index has the potential to replace the WBGT index as the standard heat stress index in the future.展开更多
Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongl...Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongly influences MHW identification.Following a recent work suggesting that there should be a communicating baseline for long-term ocean temperature trends(LTT)and MHWs,we provided an effective and quantitative solution to calculate LTT and MHWs simultaneously by using the ensemble empirical mode decomposition(EEMD)method.The long-term nonlinear trend of SST obtained by EEMD shows superiority over the traditional linear trend in that the data extension does not alter prior results.The MHWs identified from the detrended SST data exhibited low sensitivity to the baseline choice,demonstrating the robustness of our method.We also derived the total heat exposure(THE)by combining LTT and MHWs.The THE was sensitive to the fixed-period baseline choice,with a response to increasing SST that depended on the onset time of a perpetual MHW state(identified MHW days equal to the year length).Subtropical areas,the Indian Ocean,and part of the Southern Ocean were most sensitive to the long-term global warming trend.展开更多
BACKGROUND Patients affected by cystic fibrosis can present with metabolic alkalosis such as Bartter's syndrome.In this case report we want to underline this differential diagnosis and we aimed focusing on the sus...BACKGROUND Patients affected by cystic fibrosis can present with metabolic alkalosis such as Bartter's syndrome.In this case report we want to underline this differential diagnosis and we aimed focusing on the suspect of cystic fibrosis,also in case of a negative newborn screening.CASE SUMMARY In a hot August–with a mean environmental temperature of 36℃–an 8-mo-old female patient presented with severe dehydration complicated by hypokalemic metabolic alkalosis,in absence of fever,diarrhea and vomiting.Differential diagnosis between cystic fibrosis and tubulopathies causing metabolic alkalosis(Bartter's Syndrome)was considered.We started intravenous rehydration with subsequent improvement of clinical conditions and serum electrolytes normalization.We diagnosed a mild form of cystic fibrosis(heterozygous mutations:G126 D and F508 del in the cystic fibrosis transmembrane conductance regulator gene).The trigger factor of this condition had been heat exposure.CONCLUSION When facing a patient with hypokalemic metabolic alkalosis,cystic fibrosis presenting with Pseudo-Bartter's syndrome should be considered in the differential diagnosis,even if the newborn screening was negative.展开更多
Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition characterized by painful nodules, abscesses, and scarring, primarily affecting areas rich in apocrine glands. Environmental and occupational risk...Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition characterized by painful nodules, abscesses, and scarring, primarily affecting areas rich in apocrine glands. Environmental and occupational risk factors, including prolonged exposure to heat, friction, and certain chemicals, have been identified as exacerbating conditions for HS. Yet, there remains a lack of tailored recommendations for modifying work environments to alleviate these triggers. This review presents novel suggestions for work modifications to reduce HS flare-ups, such as implementing breathable, friction-reducing workwear, ergonomic adjustments to minimize pressure on affected areas, and introducing low-irritant hygiene protocols in workplaces with chemical exposure. These recommendations are grounded in emerging evidence linking specific occupational exposures to the exacerbation of HS symptoms. The novelty of this approach lies in its proactive stance, shifting from reactive management of HS symptoms to preventative environmental modifications. Future studies should explore the long-term efficacy of these modifications and investigate the potential for personalized work environment adjustments based on individual patient profiles. Targeted workplace interventions may significantly improve the quality of life for HS patients, highlighting the need for multidisciplinary collaboration between dermatologists, occupational health specialists, and employers.展开更多
Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on in...Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on indoor workplace productivity in timber office buildings has not been extensively researched.Therefore,further investigation to reduce the work capacity decline towards the end of the century is needed.Here,heat exposure in a net zero-carbon timber building near Brussels,Belgium,was evaluated using a reproducible comparative approach with different internal thermal mass levels.The analysis indicated that strategies with increased thermal mass were more effective in limiting the effects of heat exposure on workplace productivity.The medium and high thermal mass strategies reduced workplace productivity loss to 0.1%in the current,0.3%and 0.2%in the midfuture,and 4.9%and 3.9%for future scenarios.In comparison,baseline with low thermal mass yielded a decline of 2.3%,3.3%,and 8.2%.The variation in maximum and minimum wet-bulb globe temperatures were also lower for medium and high thermal mass strategies than for low thermal mass baseline.The study findings lead to the formulation of design guidelines,identification of research gaps,and recommendations for future work.展开更多
Background and Objectives:There is no evidence on antioxidant-rich diet s in preventing hypertension in heat-exposed workers.We aimed to evaluate the effects of formula supplemented with vitamin C(V it C)and ha w thor...Background and Objectives:There is no evidence on antioxidant-rich diet s in preventing hypertension in heat-exposed workers.We aimed to evaluate the effects of formula supplemented with vitamin C(V it C)and ha w thorn beverage on reducing blood pressure(BP)and oxidative stress levels in heat-exposed workers.Methods and S tudy Design:In the 40-day cluster-randomized controlled trial,four heat-exposed shift-teams were e n-rolled and randomly assigned to the intervention and control groups.The intervention group was given one V it C tablet(130 mg)and a 500 mL hawthorn beverage containing 278.7 mg flavonoids daily whereas the control group was given 500 mL of slightly salted water daily;both groups were provided education on a healthy diet.BP and creatinine-corrected urinary 8-isoprostane-prostaglandin F2α(8-iso-PGF2α/Cr)concentrations were assessed at baseline,Day 17(only BP)and Day 41,respectively.Results:Compared with the control group,the systolic BP(SBP),diastolic BP(DBP),and log10-transformed 8-iso-PGF2α/Cr in the intervention group decreased by 7.41 mmHg,7.93 mmHg and 0.232,respectively,from baseline to day 41(all p<0.05).When comparing BP le v els at baseline,DBP in the intervention group was reduced by 5.46 mmHg wh en compared to control(p<0.05)among participants with lower baseline BP;SBP and DBP experienced reductions of 9.74 and 9.22 mmHg among participants with higher baseline BP(both p<0.05).Conclusions:S upplementation of V it C and flavonoids rich hawthorn beverage to heat-exposed workers prevented elevated BP caused by heat exposure which may be at tri b uted to its oxidative stress inhibition effects.展开更多
Exposure to extreme heat can severely harm crop growth and development,and it is essential to assess such exposure accurately to minimize risks to crop production.However,the actual distribution of crops and its chang...Exposure to extreme heat can severely harm crop growth and development,and it is essential to assess such exposure accurately to minimize risks to crop production.However,the actual distribution of crops and its changes have neither been examined in sufficient detail nor integrated into the assessments of exposure to ensure their accuracy.By examining the distribution of maize at a high resolution through species distribution modeling,we assessed the past and future exposure of maize to temperatures above 37℃worldwide.Such exposure is likely to be widespread and severe,mainly in the subtropics,and may even expand to the mid-latitudes to encompass some major maize-producing areas.Many areas at both high and low latitudes may become exposed for the first time in the next 20 years.By the 2050 s,the total area exposed could increase by up to 185%to 308.18 million ha,of which the area exposed for over 60 days may increase nearly sevenfold.The average length of exposure may increase by 69%to 27 days,and areas optimally suited to maize planting may see the fastest increase by up to 772%.Extreme heat can threaten global maize production severely,and measures to mitigate that threat and to adapt to it are urgently needed.展开更多
Climate change has increased interest in the effects of the thermal environment on cardiovascular health.Most studies have focused on mortality data.However,pre-hospital care data are better able to evaluate these eff...Climate change has increased interest in the effects of the thermal environment on cardiovascular health.Most studies have focused on mortality data.However,pre-hospital care data are better able to evaluate these effects,as they can register the full spectrum of the disease in real time.This scoping review aims to synthesize the epidemiological evidence regarding the effects of the thermal environment on cardiovascular morbidity in the pre-hospital setting,evaluated through ambulance calls.A staged literature search was performed using the PubMed database for the period between 1st January 2000 and 30th March 2023,using the MeSH terms“Weather”AND“Emergency Medical Services”.A total of 987 publications were identified that examined the correlation between the thermal environment and ambulance call-outs for cardiovascular causes.The studies were mostly ecological time series,with significant variability in the methodological aspects employed.An increase in the number of ambulance call-outs has been observed in association with low temperatures,both for overall cardiovascular pathologies and for certain pathological subtypes.For high temperatures,no effect has been observed in overall call-outs,although an increase has been observed during heat waves.The demand for ambulances for cardiac arrests is increased by both low and high temperatures and during heat waves.Ambulance call-outs for cardiovascular causes increase with low temperatures and heat waves,with no significant increase in the overall demand associated with high temperatures.Ambulance call-outs for cardiac arrests are the only subtype that is increased by high temperatures.展开更多
Small brown planthopper, Laodelphax striatellus （Fall6n） numbers usually drop sharply in the summer and revive quickly in the autumn. However, it is unclear whether and how the high temperature plays a role in this ...Small brown planthopper, Laodelphax striatellus （Fall6n） numbers usually drop sharply in the summer and revive quickly in the autumn. However, it is unclear whether and how the high temperature plays a role in this process. The effects of durations of heat exposure （33~C） on life-history traits were examined here. Exposure of adults for 1 day during the oviposition stage led to a very low survival of nymphs. The average longevity ofL. striatellus exposed for 1-31 days from oviposition was significantly longer than that of the control （27℃）. Short-term （1-5 days） heat exposure of the third instar nymphs did not significantly influence eclosion, but exposure of the fourth instar nymphs significantly increased eclosion. Lifespan from egg to adult was significantly lengthened when the third instar nymphs were exposed to heat for 2-15 days, or the fourth instar were exposed for 10 days. The preoviposition period was prolonged by heat exposure of the third or fourth instar nymphs. Short-term heat exposure of less than 3 days of the third or fourth instar nymphs did not restrict fecundity, but when the exposure duration exceeded 5 days the total eggs per female and hatchability decreased. Exposure to high temperature increased the brachypter rate of adults. In summary, low survival and slowing development under heat exposure resulted in population decline in the summer, and the relatively high fecundity and brachypter rate led to quick revival in autumn. Temperature in the summer determines the rise and fall in numbers ofL. striatellus.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.42225104)CAS Project for Young Scientists in Basic Research(Grant No.YSBR-086).
文摘Urban populations are increasingly exposed to extreme heat due to climate change and rapid urbanization,heightening health risks in cities worldwide.Accurate heat exposure assessment is essential for public health planning and risk reduction.Most existing approaches rely on a single threshold temperature(e.g.,35℃of daily max temperature),applied uniformly to the entire population.However,this one-size-fits-all assumption overlooks substantial differences in heat sensitivity across population subgroups.In this study,we address this limitation by quantifying subgroup-specific temperature-mortality relationships and using corresponding minimum mortality temperatures(MMTs)to assess heat exposure.Results show that the population-wide MMT was 27.5℃,but it varied greatly across population subgroups.The elderly population(≥65)had an MMT of 24.6℃,much lower than the 28.6℃observed in younger individuals(<65).Females also exhibited a lower MMT that males(25℃versus 28.2℃).However,educational attainment did not significantly affect MMT.Using a uniform MMT resulted in substantial underestimation of heat exposure,ranging from 25.3%in 1990 to 13.9%in 2020,reflecting demographic shifts over time.Spatially,nearly half of the city experienced underestimated heat risk,especially in central and northeastern regions where heat-vulnerable populations are concentrated.These findings underscore the need for more nuanced heat exposure assessments that account for demographic and spatial variability,paving the way for targeted public health interventions to protect the most vulnerable urban populations.
基金supported by the National Key R&D Program of China(Grant No.2022YFF1303101)the open fund project of the State Key Laboratory of Regional and Urban Ecology(Grant No.SKLURE2023-2-4).
文摘Elderly individuals disproportionately face heat exposure risk compared to other demographic groups,with projected amplification in the future.The vast disparities between Global North and South countries necessitate a comprehensive understanding of the underlying factors influencing future heat exposure vulnerabilities.Here,we use factor decomposition method to quantify the contribution of climate change,population,and aging to heat exposure risk under four shared socioeconomic pathways(SSP)(SSP126,SSP245,SSP370,SSP585)from 2000 to 2100 at 20-year intervals.Results demonstrate a projected global escalation in heat exposure risk by 16 and 76 times under SSP126 and SSP585,respectively,with the North generally suffering lower risk than the South.Climate change emerges as a pivotal driver of future heat exposure risk in the North while aging notably influences the South.Despite climate change is projected to reduce heat exposure risk by up to 10%in the North under SSP1-2.6 by the end of the 21st century,aging remains a critical risk factor.
基金Supported by the Project of Science and Technology Innovation(CXCZ2017331)Natural Science Foundation of Fujian Province(2021J01085 and 2020J01539)National Innovation and En-trepreneurship Program for College Students(202110389008)。
文摘[Objective] The paper was to understand the physiological, enzymatic and molecular changes of Acipenser schrencki induced by heat exposure. [Method] The effects of heat exposure on A. schrencki were investigated. The temperature was increased from(18± 0.5) ℃ by 0.08 ℃/min and respectively kept at(32±0.5) ℃ for 2, 4 and 6 h. The respiration rate, related biochemical indicators and heat shock protein 70(Hsp 70) mR-NA expression were investigated. [Result] At(32±0.5) ℃, the activities of total protein, albumin, globulin, urea nitrogen, ceatinine, malondialde-hyde, aspartate aminotransferase, alanine aminotransferase and lactate dehydrogenase fluctuated dramatically from 2 h to 6 h. Meanwhile, the respi-ration rate and Hsp 70 m RNA expression in heart, liver and spleen were significantly increased from 2 h to 6 h. In comparison, the lower respira-tion rate and tiny fluctuations in activities of biochemical indicators were consistent with the lower Hsp 70 expression. [Conclusion] During the process of heat stress, A. schrencki seems to be sensitive to such temperature, and manifests generally consistent gill breathing, biochemical indica-tors and Hsp70 gene expression, implying better heat tolerance.
基金This study was supported by the National Key Research and Development Program of China during the 13th Five-Year Plan(No.2018YFC07004)the Science Foundation for Young Scholars of Shanxi Province(No.2017JQ5086).
文摘When studying the thermal adaptation of building occupants,understanding the effects of different thermal experiences on adaptation is necessary,particularly for moderate and severe heat exposure.However,this area has seen limited research.Further,skin temperature,a common parameter for quantifying thermal sensation,may insufficiently reflect the automatic thermoregulation of the human body.This study investigates the effects of long-term heat exposure on the human body using multiple physiological and subjective indexes.Two heat exposure experiments were conducted on healthy male participants from northern and southern China.Participant responses,including skin temperature,heart rate,heart rate variability,blood volume pulse(BVP),subjective thermal comfort thermal sensation,thermal acceptability,and normalized high and low frequency values were collected and compared The results indicated that the subjective responses of northern and southern participants were not significantly different;however,the subjective physiological symptoms and self-reported discomfort of the latter were less than those of the former,indicating that the southern participants had superior heat tolerance.Additionally,the physiological responses of all the participants were largely similar.However,southern participants showed slightly higher normalized high frequency and BVP values,indicating that they have more active vagus nerves and better vasodilation.They also showed a wider acceptable temperature range and better acclimation to heat exposure.Notably,the mean skin temperature could not effectively predict thermal sensation during heat exposure;this was more accurately achieved using the rate of change of skin temperature.These findings suggest that long-term thermal experiences can affect building occupants’thermal adaptability.
基金Huaxi Medical Education Research and Development Center of Sichuan University,No.CMB#00-721Teaching Research Program in 2007 ofEducation Department of Hubei ProvinceGeneral Program of National College Student’s Innovation Plan,No.462
文摘BACKGROUND:Glutamine(Gin)pretreatment can protect neural cells from injuries due to heat,ischemia,hypoxia,endotoxemia,and inflammatory factors.OBJECTIVE:To observe the effects of Gin pretreatment on learning and memory,survival time,and rectal temperature in heat-exposed rats.DESIGN,TIME AND SETTING:The present randomized grouping,neurobehavioral experiment was performed at the Laboratory of Department of Pharmacology,Basic School of Medicine,Wuhan University between March and September 2007.MATERIALS:Twenty-four healthy,Wistar rats were included in this study.SPX-160B biochemistry incubator(Shanghai Experimental Equipment Co.,Ltd.,China),probe electronic thermometer(11000 type,Maikepai Science and Technology Co.,Ltd.,China),Y-type maze box used in conjunction with MG-2 maze stimulator(Zhangjiagang Biomedical Instrument Factory,China),L-Gln(Batch No.061218,5 g/bottle,prepared into 10%aqueous solution,Amresco Company,USA)were used.METHODS:Twenty-four rats were randomly and evenly divided into 3 groups:heat-exposed,Gln low-lose,and Gln high-dose.Following learning and memory testing with the Y-maze,rats in the heat-exposed group were subjected to heat injury(40.5-41.5℃)in a biochemistry incubator.Rectal temperature was measured every 5 minutes.Thirty-five minutes after heat exposure,rats were removed and placed in the Y-type maze to test learning and memory again.Subsequently,the rats were returned to the same environment of thermal stimulation until they died.Rat survival time was recorded.Subsequent to learning and memory testing,rats in the Gin low-dose and high-dose groups received an i.p.injection of Gin(0.4 g/kg and 0.8 g/kg,respectively),and were exposed to heat injury.The remaining experimental procedures remained the same as for the heat-exposed group.MAIN OUTCOME MEASURES:Rat learning and memory,rectal temperature,and survival time in heat exposure environment.RESULTS:(1)In the Y-maze experiment,the frequency for the heat-exposed group rats to move 15 successive times through the maze without any mistakes was 13 times greater prior to heat exposure.Thirty-five minutes after heat exposure,rat learning and memory were significantly decreased,i.e.,frequency was 9/15 correct trials(P〈0.01).Following Gln pretreatment,rat learning and memory noticeably improved The frequency of Gln low-dose and high-dose rats maintained 13/15 correct trials,which was not different compared with before heat exposure(P〉0.05).(2)The heat-exposed group required 14 minutes to reach the rectal temperature of 39.5℃.After 2 hours of Gln pretreatment,the Gln low-dose and high-dose groups needed 18 and 20 minutes,respectively(P〈0.05).(3)Following 2 hours ofGln pretreatment,the survival time of the Gln low-dose and high-dose groups was 66 and 69 minutes,which was prolonged by 18.2%(P〈0.05)and 21.7%(P〈0.01),respectively,compared with the heat-exposed group(54 minutes).CONCLUSION:A 2-hour Gln pretreatment can noticeably improve learning and memory,delay ascending speed of body temperature,and prolong survival time in heat-exposed rats in a dose-dependent manner.
文摘Over 100 human thermal indices have been developed to predict the combined thermal impact on the body.In principle,these indices based on energy thermal budget equations should not only be the most complex but also be the most accurate.However,the simple indices based on algebraic or statistical models[e.g.,the wet-bulb globe temperature(WBGT)]continue to be the most popular.A new heat stress index,the enthalpy dry-bulb temperature(EnD)for indoor environments is developed and validated in this study.The EnD index is unique in that it uses the air specific enthalpy,not the wet-bulb temperature,to measure the latent heat transfer from the skin to the surrounding environment.Theoretically,the EnD index can be treated as the equivalent temperature based on the convective heat transfer coefficient h_(c).Comparison is made between the EnD index and the widely used WBGT index based on the experimental data taken from three independent studies available in the scientific literature.The results show that the EnD index can reduce the overestimation of the dry-bulb air temperature and thus reduce heat stress in most cases,especially for hot and humid environments.It can be concluded that the EnD index has the potential to replace the WBGT index as the standard heat stress index in the future.
基金Supported by the National Natural Science Foundation of China(Nos.41821004,42276025)the Natural Science Foundation of Shandong Province(No.ZR2021MD027)+1 种基金the National Key Research and Development Program of China(No.2022YFE0140500)the Project of“Development of China-ASEAN blue partnership”started in 2021.
文摘Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongly influences MHW identification.Following a recent work suggesting that there should be a communicating baseline for long-term ocean temperature trends(LTT)and MHWs,we provided an effective and quantitative solution to calculate LTT and MHWs simultaneously by using the ensemble empirical mode decomposition(EEMD)method.The long-term nonlinear trend of SST obtained by EEMD shows superiority over the traditional linear trend in that the data extension does not alter prior results.The MHWs identified from the detrended SST data exhibited low sensitivity to the baseline choice,demonstrating the robustness of our method.We also derived the total heat exposure(THE)by combining LTT and MHWs.The THE was sensitive to the fixed-period baseline choice,with a response to increasing SST that depended on the onset time of a perpetual MHW state(identified MHW days equal to the year length).Subtropical areas,the Indian Ocean,and part of the Southern Ocean were most sensitive to the long-term global warming trend.
文摘BACKGROUND Patients affected by cystic fibrosis can present with metabolic alkalosis such as Bartter's syndrome.In this case report we want to underline this differential diagnosis and we aimed focusing on the suspect of cystic fibrosis,also in case of a negative newborn screening.CASE SUMMARY In a hot August–with a mean environmental temperature of 36℃–an 8-mo-old female patient presented with severe dehydration complicated by hypokalemic metabolic alkalosis,in absence of fever,diarrhea and vomiting.Differential diagnosis between cystic fibrosis and tubulopathies causing metabolic alkalosis(Bartter's Syndrome)was considered.We started intravenous rehydration with subsequent improvement of clinical conditions and serum electrolytes normalization.We diagnosed a mild form of cystic fibrosis(heterozygous mutations:G126 D and F508 del in the cystic fibrosis transmembrane conductance regulator gene).The trigger factor of this condition had been heat exposure.CONCLUSION When facing a patient with hypokalemic metabolic alkalosis,cystic fibrosis presenting with Pseudo-Bartter's syndrome should be considered in the differential diagnosis,even if the newborn screening was negative.
文摘Hidradenitis suppurativa (HS) is a chronic, inflammatory skin condition characterized by painful nodules, abscesses, and scarring, primarily affecting areas rich in apocrine glands. Environmental and occupational risk factors, including prolonged exposure to heat, friction, and certain chemicals, have been identified as exacerbating conditions for HS. Yet, there remains a lack of tailored recommendations for modifying work environments to alleviate these triggers. This review presents novel suggestions for work modifications to reduce HS flare-ups, such as implementing breathable, friction-reducing workwear, ergonomic adjustments to minimize pressure on affected areas, and introducing low-irritant hygiene protocols in workplaces with chemical exposure. These recommendations are grounded in emerging evidence linking specific occupational exposures to the exacerbation of HS symptoms. The novelty of this approach lies in its proactive stance, shifting from reactive management of HS symptoms to preventative environmental modifications. Future studies should explore the long-term efficacy of these modifications and investigate the potential for personalized work environment adjustments based on individual patient profiles. Targeted workplace interventions may significantly improve the quality of life for HS patients, highlighting the need for multidisciplinary collaboration between dermatologists, occupational health specialists, and employers.
基金the Service Public de Wallonie(SPW),Belgium,under BElgian WAllonia REsearch(BEWARE)fellowships and European Union(EU)framework program for research and innovation,Marie Skłodowska-Curie Actions(MSCA)through contract no.847587 for the Project SurChauffe.the U.S.Department of Energy,Office of Science,Office of Biological and Environmental Research’s Urban Integrated Field Laboratories research activity,under Award Number DE-SC0023520.+2 种基金the members of the School of Geographical Sciences and Urban Planning at Arizona State University,and Southwest Urban Corridor Integrated Field Laboratory(SW-IFL)for their support.We would also like to thank the stakeholders of Project OCCuPANt.the Sustainable Building Design Lab at the Faculty of Applied Sciences at the University of Liege for the valuable support and use of the state-of-the-art Super COmputeR ProcessIng wOrkstatioN(SCORPION)for building performance simulations and data analysis.the IEA EBC Annex 80-Resilient Cooling of Buildings.
文摘Changing climate intensifies heat stress,resulting in a greater risk of workplace productivity decline in timber office buildings with low internal thermal mass.The impact of climate change induced heat exposure on indoor workplace productivity in timber office buildings has not been extensively researched.Therefore,further investigation to reduce the work capacity decline towards the end of the century is needed.Here,heat exposure in a net zero-carbon timber building near Brussels,Belgium,was evaluated using a reproducible comparative approach with different internal thermal mass levels.The analysis indicated that strategies with increased thermal mass were more effective in limiting the effects of heat exposure on workplace productivity.The medium and high thermal mass strategies reduced workplace productivity loss to 0.1%in the current,0.3%and 0.2%in the midfuture,and 4.9%and 3.9%for future scenarios.In comparison,baseline with low thermal mass yielded a decline of 2.3%,3.3%,and 8.2%.The variation in maximum and minimum wet-bulb globe temperatures were also lower for medium and high thermal mass strategies than for low thermal mass baseline.The study findings lead to the formulation of design guidelines,identification of research gaps,and recommendations for future work.
基金supported by the North China University of Science and Technology postgraduate funding and t h e National Natural Science Foundation Joint Fund Project for Regional Innovation and Development(No.u22A20364).
文摘Background and Objectives:There is no evidence on antioxidant-rich diet s in preventing hypertension in heat-exposed workers.We aimed to evaluate the effects of formula supplemented with vitamin C(V it C)and ha w thorn beverage on reducing blood pressure(BP)and oxidative stress levels in heat-exposed workers.Methods and S tudy Design:In the 40-day cluster-randomized controlled trial,four heat-exposed shift-teams were e n-rolled and randomly assigned to the intervention and control groups.The intervention group was given one V it C tablet(130 mg)and a 500 mL hawthorn beverage containing 278.7 mg flavonoids daily whereas the control group was given 500 mL of slightly salted water daily;both groups were provided education on a healthy diet.BP and creatinine-corrected urinary 8-isoprostane-prostaglandin F2α(8-iso-PGF2α/Cr)concentrations were assessed at baseline,Day 17(only BP)and Day 41,respectively.Results:Compared with the control group,the systolic BP(SBP),diastolic BP(DBP),and log10-transformed 8-iso-PGF2α/Cr in the intervention group decreased by 7.41 mmHg,7.93 mmHg and 0.232,respectively,from baseline to day 41(all p<0.05).When comparing BP le v els at baseline,DBP in the intervention group was reduced by 5.46 mmHg wh en compared to control(p<0.05)among participants with lower baseline BP;SBP and DBP experienced reductions of 9.74 and 9.22 mmHg among participants with higher baseline BP(both p<0.05).Conclusions:S upplementation of V it C and flavonoids rich hawthorn beverage to heat-exposed workers prevented elevated BP caused by heat exposure which may be at tri b uted to its oxidative stress inhibition effects.
基金supported by the National Key Research and Development Program of China(Grant No.2016YFA0602402)。
文摘Exposure to extreme heat can severely harm crop growth and development,and it is essential to assess such exposure accurately to minimize risks to crop production.However,the actual distribution of crops and its changes have neither been examined in sufficient detail nor integrated into the assessments of exposure to ensure their accuracy.By examining the distribution of maize at a high resolution through species distribution modeling,we assessed the past and future exposure of maize to temperatures above 37℃worldwide.Such exposure is likely to be widespread and severe,mainly in the subtropics,and may even expand to the mid-latitudes to encompass some major maize-producing areas.Many areas at both high and low latitudes may become exposed for the first time in the next 20 years.By the 2050 s,the total area exposed could increase by up to 185%to 308.18 million ha,of which the area exposed for over 60 days may increase nearly sevenfold.The average length of exposure may increase by 69%to 27 days,and areas optimally suited to maize planting may see the fastest increase by up to 772%.Extreme heat can threaten global maize production severely,and measures to mitigate that threat and to adapt to it are urgently needed.
文摘Climate change has increased interest in the effects of the thermal environment on cardiovascular health.Most studies have focused on mortality data.However,pre-hospital care data are better able to evaluate these effects,as they can register the full spectrum of the disease in real time.This scoping review aims to synthesize the epidemiological evidence regarding the effects of the thermal environment on cardiovascular morbidity in the pre-hospital setting,evaluated through ambulance calls.A staged literature search was performed using the PubMed database for the period between 1st January 2000 and 30th March 2023,using the MeSH terms“Weather”AND“Emergency Medical Services”.A total of 987 publications were identified that examined the correlation between the thermal environment and ambulance call-outs for cardiovascular causes.The studies were mostly ecological time series,with significant variability in the methodological aspects employed.An increase in the number of ambulance call-outs has been observed in association with low temperatures,both for overall cardiovascular pathologies and for certain pathological subtypes.For high temperatures,no effect has been observed in overall call-outs,although an increase has been observed during heat waves.The demand for ambulances for cardiac arrests is increased by both low and high temperatures and during heat waves.Ambulance call-outs for cardiovascular causes increase with low temperatures and heat waves,with no significant increase in the overall demand associated with high temperatures.Ambulance call-outs for cardiac arrests are the only subtype that is increased by high temperatures.
文摘Small brown planthopper, Laodelphax striatellus （Fall6n） numbers usually drop sharply in the summer and revive quickly in the autumn. However, it is unclear whether and how the high temperature plays a role in this process. The effects of durations of heat exposure （33~C） on life-history traits were examined here. Exposure of adults for 1 day during the oviposition stage led to a very low survival of nymphs. The average longevity ofL. striatellus exposed for 1-31 days from oviposition was significantly longer than that of the control （27℃）. Short-term （1-5 days） heat exposure of the third instar nymphs did not significantly influence eclosion, but exposure of the fourth instar nymphs significantly increased eclosion. Lifespan from egg to adult was significantly lengthened when the third instar nymphs were exposed to heat for 2-15 days, or the fourth instar were exposed for 10 days. The preoviposition period was prolonged by heat exposure of the third or fourth instar nymphs. Short-term heat exposure of less than 3 days of the third or fourth instar nymphs did not restrict fecundity, but when the exposure duration exceeded 5 days the total eggs per female and hatchability decreased. Exposure to high temperature increased the brachypter rate of adults. In summary, low survival and slowing development under heat exposure resulted in population decline in the summer, and the relatively high fecundity and brachypter rate led to quick revival in autumn. Temperature in the summer determines the rise and fall in numbers ofL. striatellus.
