Temperature最新文献

{"title":"Extracting thermodynamic properties from van ’t Hoff plots with emphasis on temperature-sensing ion channels","authors":"Jakob T. Bullerjahn, Sonya M. Hanson","doi":"10.1080/23328940.2023.2265962","DOIUrl":"https://doi.org/10.1080/23328940.2023.2265962","url":null,"abstract":"ABSTRACTTransient receptor potential (TRP) ion channels are among the most well-studied classes of temperature-sensing molecules. Yet, the molecular mechanism and thermodynamic basis for the temperature sensitivity of TRP channels remains to this day poorly understood. One hypothesis is that the temperature-sensing mechanism can simply be described by a difference in heat capacity between the closed and open channel states. While such a two-state model may be simplistic it nonetheless has descriptive value, in the sense that it can be used to compare overall temperature sensitivity between different channels and mutants. Here, we introduce a mathematical framework based on the two-state model to reliably extract temperature-dependent thermodynamic potentials and heat capacities from measurements of equilibrium constants at different temperatures. Our framework is implemented in an open-source data analysis package that provides a straightforward way to fit both linear and nonlinear van ’t Hoff plots, thus avoiding some of the previous, potentially erroneous, assumptions when extracting thermodynamic variables from TRP channel electrophysiology data.KEYWORDS: TRP channelstemperature sensorsvan ’t Hoff plotsthermodynamicsspline fitting AcknowledgmentsWe thank Dr. Andrés Jara-Oseguera for fruitful discussions and critical comments on the manuscript. The Flatiron Institute is a division of the Simons Foundation.Disclosure statementNo potential conflict of interest was reported by the author(s).Additional informationFundingThis work was supported by the Max-Planck-Gesellschaft (JTB) and the Simons Foundation (SMH).","PeriodicalId":36837,"journal":{"name":"Temperature","volume":"11 1","pages":"0"},"PeriodicalIF":0.0,"publicationDate":"2023-11-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"135974543","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Validation of upper thermal thresholds for outdoor sports using thermal physiology modelling.","authors":"Takahiro Oyama, Minoru Fujii, Kenichi Nakajima, Jun'ya Takakura, Yasuaki Hijioka","doi":"10.1080/23328940.2023.2210477","DOIUrl":"10.1080/23328940.2023.2210477","url":null,"abstract":"<p><p>Thermal safety guidelines with upper thresholds aim to protect athletes' health, yet evidence-based sport-specific thresholds remain unestablished. Experimenting with athletes in severely hot conditions raises ethical concerns, so we used a thermo-physiological model to validate the thresholds of guidelines for outdoor sports. First, the reproducibility of the joint system thermoregulation model (JOS-3) of core temperature has been validated for 18 sports experiments (<i>n</i> = 213) and 11 general exercise experiments (<i>n</i> = 121) using the Bland - Altman analysis. Then, core temperatures were predicted using the JOS-3 in conditions corresponding to the upper thresholds, and if the 90^th-99.7^th percentile core temperature value (corresponding to 0.3%-10% of the participants) exceeded 40°C, the thresholds were judged as potentially hazardous. Finally, we proposed revisions for sports with potentially hazardous thresholds. As a result, the JOS-3 could simulate core temperature increases in most experiments (27/29) for six sports and general exercises with an accuracy of 0.5°C. The current upper thresholds for marathons, triathlons, and football are potentially hazardous. Suggested revisions, based on specified percentiles, include: Football: revise from wet bulb globe temperature (WBGT) 32°C to 29-31°C or not revise. Marathon: revise from WBGT 28°C to 24-27°C. Triathlon: revise from WBGT 32.2°C to 23-26°C. If conducting sports events under the revised upper thresholds proves difficult, taking measures for a possible high incidence of heat illness becomes crucial, such as placing additional medical resources, assisting heat acclimatization and cooling strategies for participants, and rule changes such as shorter match times and increased breaks.</p>","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"92-106"},"PeriodicalIF":0.0,"publicationDate":"2023-05-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10989705/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45583782","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Seasonal influence on cognitive and psycho-physiological responses to a single 11-h day of work in outdoor mine industry workers.","authors":"Sarah M Taggart, Olivier Girard, Grant J Landers, Ullrich K H Ecker, Karen E Wallman","doi":"10.1080/23328940.2023.2208516","DOIUrl":"10.1080/23328940.2023.2208516","url":null,"abstract":"<p><p>This study investigated the seasonal effects that working outdoors had on various parameters in mining industry workers over the course of a work-shift. Workers (<i>n</i> = 27) were assessed in summer (33.3 ± 4.2°C, 38 ± 18% RH; <i>n</i> = 13, age = 46 ± 14 y, BMI = 29.1 ± 5.7 kg/m²) and winter (23.6 ± 5.1°C, 39 ± 20% RH; <i>n</i> = 14, age = 44 ± 12 y, BMI = 31.2 ± 4.1 kg/m²). Core temperature and heart-rate were measured continuously (analyzed at five time points), while perceptual measures, cognitive and manual dexterity performance were assessed at various times over an 11-h shift at the start of a 14-day swing. Hydration was assessed (urine specific gravity) pre- and post-shift. Working memory was impaired in summer compared to winter (-10%; <i>p</i> = 0.039), however did not change throughout the shift. Processing efficiency was significantly reduced at 12 pm (-12%; <i>p</i> = 0.005) and 5 pm (-21%; <i>p</i> < 0.001) compared to 9 am, irrespective of season (<i>p</i> > 0.05). Manual dexterity (dominant-hand) improved over the shift (+13%, <i>p</i> = 0.002), but was not different between seasons. Perceived fatigue had no main effect of season or shift. Core temperature, heart-rate, thermal sensation and rating of perceived exertion increased throughout the shift, with only core temperature and thermal sensation showing a seasonal effect (summer: +0.33°C, +18%, respectively; <i>p</i> < 0.002). Notably, 23% of workers in summer and 64% in winter started work significantly dehydrated, with 54% and 64% in summer and winter, respectively, finishing work with significant to serious dehydration. Impairment in working memory in summer combined with high levels of dehydration over the work-shift reinforces the need for workplace education on the importance of hydration and risk of occupation heat stress. <b>Abbreviations:</b> Core temperature: T_c; Fly-in fly-out: FIFO; Ratings of perceived exertion: RPE; Relative humidity: RH; Urinary specific gravity: USG; Wet bulb globe temperature: WBGT.</p>","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"465-478"},"PeriodicalIF":0.0,"publicationDate":"2023-05-12","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732613/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46910152","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About the Cover","authors":"E. Ostby","doi":"10.1016/b978-0-12-336156-1.50007-0","DOIUrl":"https://doi.org/10.1016/b978-0-12-336156-1.50007-0","url":null,"abstract":"","PeriodicalId":36837,"journal":{"name":"Temperature","volume":"10 1","pages":"W1 - W1"},"PeriodicalIF":0.0,"publicationDate":"2023-04-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45156923","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elevations in serum brain-derived neurotrophic factor following occupational heat stress are not influenced by age or common chronic disease.","authors":"Nicholas Goulet, James J McCormick, Kelli E King, Sean R Notley, Gary S Goldfield, Naoto Fujii, Tatsuro Amano, Glen P Kenny","doi":"10.1080/23328940.2023.2176107","DOIUrl":"10.1080/23328940.2023.2176107","url":null,"abstract":"<p><p>With global warming, workers are increasingly exposed to strenuous occupations in hot environments. Given age- and disease-associated declines in thermoregulatory function, older workers are at an elevated risk of developing heat-related injuries. Brain-derived neurotrophic factor (BDNF) is thought to confer neuroprotection during acute exercise, however, the influence of environmental heat on BDNF responses during prolonged work remains unclear. Therefore, we evaluated serum BDNF concentrations before and after 180 min of moderate-intensity treadmill walking (200 W/m2) and after 60 min of post-exercise recovery in temperate (wet-bulb globe temperature (WBGT) 16°C) and hot (WBGT 32°C) environments in 13 healthy young men (mean [SD; 22 [3] years), 12 healthy older men (59 [4] years), 10 men with hypertension (HTN) (60 [4] years), and 9 men with type 2 diabetes (T2D) (60 [5] years). In the temperate condition, all but one participant (1 HTN) completed the 180 min of exercise. While exercise tolerance in the heat was lower in older men with HTN (117 min [45]) and T2D (123 min [42]) compared to healthy older men (159 min [31]) (both p ≤ 0.049), similar end-exercise rectal temperatures (38.9°C [0.4]) were observed across groups, paralleled by similar elevations in serum BDNF across groups at end-exercise (+1106 pg/mL [203]) and end-recovery (+938 pg/mL [146]; all p ≤ 0.01) in the heat. No changes in serum BDNF were observed in the temperate condition. Our findings indicate similar BDNF responses in individuals with HTN or T2D compared to their healthy counterparts, despite exhibiting reduced tolerance to heat.</p>","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"454-464"},"PeriodicalIF":0.0,"publicationDate":"2023-02-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732602/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"47346735","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Hot water immersion acutely reduces peripheral glucose uptake in young healthy males: An exploratory crossover randomized controlled trial.","authors":"Matthew J Maley, Andrew P Hunt, Ian B Stewart, Steven Weier, Justin Holland, Christof A Leicht, Geoffrey M Minett","doi":"10.1080/23328940.2022.2161242","DOIUrl":"10.1080/23328940.2022.2161242","url":null,"abstract":"<p><p>Whether glucose concentration increases during heat exposure because of reduced peripheral tissue uptake or enhanced appearance is currently unknown. This study aimed to report glucose concentrations in both capillary and venous blood in response to a glucose challenge during passive heating (PH) to assess whether heat exposure affects glucose uptake in healthy males. Twelve healthy male participants completed two experimental sessions, where they were asked to undertake an oral glucose tolerance test (OGTT) whilst immersed in thermoneutral (CON, 35.9 (0.6) °C) and hot water (HWI, 40.3 (0.5) °C) for 120 min. Venous and capillary blood [glucose], rectal temperature, and heart rate were recorded. [Glucose] area under the curve for HWI venous (907 (104) AU) differed from CON venous (719 (88) AU, all P < 0.001). No other differences were noted (P > 0.05). Compared with CON, HWI resulted in greater rectal temperature (37.1 (0.3) °C <i>versus</i> 38.6 (0.4) °C, respectively) and heart rate (69 (12) bpm <i>versus</i> 108 (11) bpm, respectively) on cessation (P < 0.001). An OGTT results in similar capillary [glucose] during hot and thermoneutral water immersion, whereas venous [glucose] was greater during HWI when compared with CON. This indicates that peripheral tissue glucose uptake is acutely reduced in response to HWI. <b>Abbreviations</b>: AUC: Area under the curve; CON: Thermoneutral immersion trial; HWI: Hot water immersion trial; OGTT: Oral glucose tolerance test; PH: Passive heating; <math><mrow><msub><mover><mi>T</mi><mo>-</mo></mover><mrow><mrow><mrow><mi>m</mi><mi>s</mi><mi>k</mi></mrow></mrow></mrow></msub></mrow></math>: Mean skin temperature; T_rec: Rectal temperature.</p>","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"434-443"},"PeriodicalIF":0.0,"publicationDate":"2023-01-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732630/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"45472801","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The effectiveness of heat preparation and alleviation strategies for cognitive performance: A systematic review.","authors":"Kate J Donnan, Emily L Williams, Melissa J Bargh","doi":"10.1080/23328940.2022.2157645","DOIUrl":"10.1080/23328940.2022.2157645","url":null,"abstract":"<p><p>A range of occupational and performance contexts (e.g. military personnel operations, emergency services, sport) require the critical maintenance of cognitive performance in environmentally challenging environments. Several reviews exist which evaluate the effectiveness of heat preparation strategies to facilitate physical performance. To date, no review has explored the usefulness of heat preparation strategies for cognitive performance. Therefore, this systematic review aimed to evaluate a range of interventions for the maintenance of cognitive performance, during or following active or passive heat exposure. Studies to be included were assessed by two authors reviewing title, abstract, and full-text. Forty articles were identified which met the inclusion criteria. Interventions were categorised into chronic (i.e. acclimation/acclimatisation) and acute strategies (i.e. hydration, cooling, supplementation, psychological). The results indicate that medium-term consecutive heat acclimation may mitigate some cognitive deficits under heat stress, although heat acclimation effectiveness could be influenced by age. Further, pre-cooling appears the most effective cooling method for maintaining cognitive performance under heat stress, although results were somewhat ambiguous. The hydration literature showed that the most effective hydration strategies were those which individualised electrolyte fortified fluid volumes to match for sweat loss. Limited research exploring psychological interventions indicates that motivational self-talk could be facilitative for maintaining cognitive skills following exercise in hot conditions. These findings can be used to help inform strategies for maintaining critical cognitive and decision-making skills in hot environments.</p>","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"404-433"},"PeriodicalIF":0.0,"publicationDate":"2023-01-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC10732620/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"46908327","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About the cover.","authors":"","doi":"10.1080/23328940.2022.2137207","DOIUrl":"10.1080/23328940.2022.2137207","url":null,"abstract":"","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"W1"},"PeriodicalIF":0.0,"publicationDate":"2022-10-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9629057/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"40469504","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"About the cover.","authors":"","doi":"10.1080/23328940.2022.2129144","DOIUrl":"10.1080/23328940.2022.2129144","url":null,"abstract":"","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"W1"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9542886/pdf/KTMP_9_2129144.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33495835","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Working in a warming world: Translating thermal physiology to policy-relevant information.","authors":"Andreas D Flouris, Leonidas G Ioannou, Lars Nybo","doi":"10.1080/23328940.2022.2086414","DOIUrl":"10.1080/23328940.2022.2086414","url":null,"abstract":"","PeriodicalId":36837,"journal":{"name":"Temperature","volume":" ","pages":"223-226"},"PeriodicalIF":0.0,"publicationDate":"2022-09-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9542706/pdf/KTMP_9_2086414.pdf","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"33495834","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}