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1.
BMC Sports Sci Med Rehabil ; 16(1): 174, 2024 Aug 19.
Artículo en Inglés | MEDLINE | ID: mdl-39160597

RESUMEN

BACKGROUND: Soccer coaches often employ small-sided games (SSGs) to elicit both physiological and technical responses from players. However, numerous contextual factors can influence the outcomes of these games. This comparative study aimed to investigate how environmental temperature (< 21ºC and > 29ºC) impacts heart rate responses, perception of effort, and technical performance in young male football players during SSGs. METHODS: This study compares temperatures below 21ºC (∼ 20.4 ± 0.4ºC) with temperatures above 29ºC (∼ 29.7 ± 0.6ºC). This repeated measures study design involved 60 male football players at a trained/developmental level, selected from under-16 and under-19 teams. It aimed to assess the effects of the 3v3 format, conducted repeatedly under conditions of 21ºC and above 29ºC. Throughout the games, mean heart rate responses (HRmean), measured via heart rate sensors; rate of perceived exertion (RPE), assessed using the CR-10 Borg scale; and successful passes and lost balls, tracked through an ad hoc observational analysis tool, were monitored. RESULTS: No significant interactions were observed (time*age group) in meanHR (F = 0.159; p = 0.691; [Formula: see text]=0.003), RPE (F=0.646; p=0.425; [Formula: see text]=0.011), number of passes completed (F=0.204; p=0.654; [Formula: see text]=0.003), and number of lost balls (F = 0.157; p = 0.694; [Formula: see text]=0.003). Overall, significantly higher heart rate responses in mean HR (p<0.001) and RPE (p<0.001) were observed at temperatures above 29ºC, while significantly more passes were completed at temperatures below 21ºC (p<0.001). CONCLUSIONS: Heat conditions significantly intensified the psychophysiological responses in players, concurrently leading to a significant impairment in the number of passes. Coaches should contemplate implementing mitigation strategies to avert performance declines during heat conditions when utilizing SSGs.

2.
Wien Klin Wochenschr ; 136(17-18): 507-514, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39158652

RESUMEN

Exposure to extreme heat is associated with both increased morbidity and mortality, especially in older people. Health burdens associated with heat include heat stroke, diabetes mellitus, hypertension, ischemic heart diseases, heart failure and arrhythmia, pulmonary diseases but also injuries, problems with activities of daily living, and mental disorders. In Europe, there are remarkable spatial differences in heat exposure between urban and less populated areas. In Austria, for example, there is a significant gradual association between population density and the number of heat days, where the gradient of urbanization also follows the gradient of sea level. The European population is continuously ageing, especially in rural areas. Older adults are especially vulnerable to negative health consequences resulting from heat exposure, due to a lack of physiological, social, cognitive, and behavioral resources. Older people living in urban areas are particularly at risk, due to the urban heat island effect, the heat-promoting interplay between conditions typically found in cities, such as a lack of vegetation combined with a high proportion of built-up areas; however, older people living in rural regions often have less infrastructure to cope with extreme heat, such as fewer cooling centers and emergency services. Additionally, older adults still engaged in agricultural or forestry activities may be exposed to high temperatures without adequate protection or hydration. More research is required to examine factors responsible for heat vulnerability in older adults and the interactions and possibilities for increasing resilience in older urban and rural populations to the health consequences of heat.


Asunto(s)
Trastornos de Estrés por Calor , Población Rural , Población Urbana , Humanos , Anciano , Población Urbana/estadística & datos numéricos , Población Rural/estadística & datos numéricos , Europa (Continente)/epidemiología , Trastornos de Estrés por Calor/epidemiología , Anciano de 80 o más Años , Femenino , Masculino , Calor/efectos adversos , Factores de Riesgo , Calor Extremo/efectos adversos , Poblaciones Vulnerables/estadística & datos numéricos , Persona de Mediana Edad
3.
Br J Sports Med ; 58(15): 860-869, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38950917

RESUMEN

Several International Federations (IFs) employ specific policies to protect athletes' health from the danger of heat. Most policies rely on the measurement of thermal indices such as the Wet Bulb Globe Temperature (WBGT) to estimate the risk of heat-related illness. This review summarises the policies implemented by the 32 IFs of the 45 sports included in the Paris 2024 Olympic Games. It provides details into the venue type, measured parameters, used thermal indices, measurement procedures, mitigation strategies and specifies whether the policy is a recommendation or a requirement. Additionally, a categorisation of sports' heat stress risk is proposed. Among the 15 sports identified as high, very high or extreme risk, one did not have a heat policy, three did not specify any parameter measurement, one relied on water temperature, two on air temperature and relative humidity, seven on WBGT (six measured on-site and one estimated) and one on the Heat Stress Index. However, indices currently used in sports have been developed for soldiers or workers and may not adequately reflect the thermal strain endured by athletes. Notably, they do not account for the athletes' high metabolic heat production and their level of acclimation. It is, therefore, worthwhile listing the relevance of the thermal indices used by IFs to quantify the risk of heat stress, and in the near future, develop an index adapted to the specific needs of athletes.


Asunto(s)
Trastornos de Estrés por Calor , Calor , Deportes , Humanos , Trastornos de Estrés por Calor/prevención & control , Deportes/fisiología , Deportes/clasificación , Calor/efectos adversos , Atletas/clasificación , Paris , Política de Salud
4.
Br J Sports Med ; 58(15): 870-881, 2024 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-38955507

RESUMEN

The upcoming Paris 2024 Olympic and Paralympic Games could face environmental challenges related to heat, air quality and water quality. These challenges will pose potential threats to athletes and impact thousands of stakeholders and millions of spectators. Recognising the multifaceted nature of these challenges, a range of strategies will be essential for mitigating adverse effects on participants, stakeholders and spectators alike. From personalised interventions for athletes and attendees to comprehensive measures implemented by organisers, a holistic approach is crucial to address these challenges and the possible interplay of heat, air and water quality factors during the event. This evidence-based review highlights various environmental challenges anticipated at Paris 2024, offering strategies applicable to athletes, stakeholders and spectators. Additionally, it provides recommendations for Local Organising Committees and the International Olympic Committee that may be applicable to future Games. In summary, the review offers solutions for consideration by the stakeholders responsible for and affected by the anticipated environmental challenges at Paris 2024.


Asunto(s)
Atletas , Deportes , Humanos , Aniversarios y Eventos Especiales , Calor/efectos adversos , Contaminación del Aire/prevención & control , Contaminación del Aire/efectos adversos , Participación de los Interesados , Paris , Deportes para Personas con Discapacidad
5.
Br J Sports Med ; 58(18): 1044-1051, 2024 Sep 09.
Artículo en Inglés | MEDLINE | ID: mdl-39029949

RESUMEN

OBJECTIVE: To evaluate the efficacy of the Fédération Internationale de Football Association (FIFA) cooling break policy against alternative cooling configurations in attenuating thermal strain during simulated football in the heat. METHODS: 12 males (age: 27±6 years, V̇O2peak: 61±7 mL/kg/min) completed five 90 min intermittent treadmill football match simulations in 40°C and 41% relative humidity (32°C wet-bulb globe temperature) with different cooling configurations: regular match without cooling breaks (REG), 3 min breaks without cooling (BRKno-cool), 3 min breaks with cooling (BRKcool: current FIFA policy; chilled fluid ingestion and ice towel across neck and shoulders), 5 min extended half-time without cooling breaks (ExtHTonly) and 3 min cooling breaks with 5 min ExtHT (ExtHTcool). Rectal temperature (Tre), heart rate, whole-body sweat rate (WBSR) and rating of perceived exertion (RPE) were recorded. Data are presented as mean (95% CIs). RESULTS: Final Tre was lower in BRKno-cool (0.20°C (0.01, 0.39), p=0.038), BRKcool (0.39°C (0.21, 0.57), p<0.001) and ExtHTcool (0.40°C (0.22, 0.58), p<0.001) than REG (39.1°C (38.8, 39.3)). Mean Tre was lower in ExtHTcool (38.2°C (38.0, 38.4)) than BRKcool (38.3°C (38.1, 38.5), p=0.018), BRKno-cool and ExtHTonly (38.4°C (38.2, 38.6), p<0.001) and REG (38.5°C (38.3, 38.7), p<0.001). Mean heart rate was lower during BRKcool (6 beats/min (4, 7), p<0.001) and ExtHTcool (7 beats/min (6, 8), p<0.001) compared with REG. WBSR was comparable across trials (p≥0.07) and RPE was attenuated during BRKcool (0.4 (0.1, 0.7), p=0.004) and ExtHTcool (0.5 (0.2, 0.7), p=0.002), compared with REG. CONCLUSION: BRKcool and ExtHTcool attenuated thermal, cardiovascular and perceptual strain during a simulated football match in the heat. Additional strategies may be required in field settings or under harsher conditions.


Asunto(s)
Frecuencia Cardíaca , Calor , Fútbol , Sudoración , Humanos , Masculino , Adulto , Frecuencia Cardíaca/fisiología , Sudoración/fisiología , Fútbol/fisiología , Fútbol/lesiones , Adulto Joven , Regulación de la Temperatura Corporal/fisiología , Temperatura Corporal/fisiología , Prueba de Esfuerzo , Esfuerzo Físico/fisiología , Trastornos de Estrés por Calor/prevención & control , Frío
6.
Womens Health (Lond) ; 20: 17455057241259171, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-39066467

RESUMEN

BACKGROUND: We sought to improve the current understanding of how climate change impacts women's reproductive health in sub-Saharan Africa. OBJECTIVES: We investigated the relationship between maternal heat exposure and miscarriage (pregnancy ending before 20 weeks gestation) in a South African setting. DESIGN: Population-based cohort study. METHODS: Our study involved data for pregnancies collected via a health and demographic surveillance system in rural KwaZulu-Natal, South Africa between 2012 and 2016. Data from the South African Weather Service were used to compute maternal exposure to heat during the following time windows for each pregnancy: during the month preceding conception (T1) and during the week preceding the study outcome (either a miscarriage or no miscarriage, T2). Heat exposure was operationalized as a continuous variable and defined as the number of days that a mother was exposed to a mean daily temperature of > 26.6°C (A "hot day," equivalent to a mean daily temperature of > 80°F) during T1 or T2. Binary logistic regression was used to investigate the relationship between maternal heat exposure and miscarriage. RESULTS: A total of 105/3477 pregnancies included in our analysis ended in miscarriage (3.0%). Each additional hot day during T1 was associated with a 26% higher odds of miscarriage (odds ratio: 1.26; 95% confidence interval: 1.15-1.38). No significant associations were observed between maternal heat exposure during T2 and the odds of miscarriage (odds ratio: 0.94, 95% confidence interval: 0.73-1.20). The relationship between maternal heat exposure during T1 and the odds of miscarriage was J-shaped. CONCLUSION: There is a clear relationship between maternal heat exposure during the month preceding conception and miscarriage in our sub-Saharan African setting. Given the lack of feasible strategies to reduce pregnancy loss associated with prevailing high temperatures in sub-Saharan Africa, progressive climate change will likely exacerbate existing challenges for women's reproductive health in this region.


Asunto(s)
Aborto Espontáneo , Calor , Población Rural , Humanos , Femenino , Sudáfrica/epidemiología , Embarazo , Aborto Espontáneo/epidemiología , Adulto , Calor/efectos adversos , Población Rural/estadística & datos numéricos , Estudios de Cohortes , Exposición Materna/efectos adversos , Exposición Materna/estadística & datos numéricos , Adulto Joven , Cambio Climático
7.
Physiol Rep ; 12(11): e16107, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38849294

RESUMEN

July 2023 has been confirmed as Earth's hottest month on record, and it was characterized by extraordinary heatwaves across southern Europe. Field data collected under real heatwave periods could add important evidence to understand human adaptability to extreme heat. However, field studies on human physiological responses to heatwave periods remain limited. We performed field thermo-physiological measurements in a healthy 37-years male undergoing resting and physical activity in an outdoor environment in the capital of Sicily, Palermo, during (July 21; highest level of local heat-health alert) and following (August 10; lowest level of local heat-health alert) the peak of Sicily's July 2023 heatwave. Results indicated that ~40 min of outdoor walking and light running in 33.8°C Wet Bulb Globe Temperature (WBGT) conditions (July 21) resulted in significant physiological stress (i.e., peak heart rate: 209 bpm; core temperature: 39.13°C; mean skin temperature: 37.2°C; whole-body sweat losses: 1.7 kg). Importantly, significant physiological stress was also observed during less severe heat conditions (August 10; WBGT: 29.1°C; peak heart rate: 190 bpm; core temperature: 38.48°C; whole-body sweat losses: 2 kg). These observations highlight the physiological strain that current heatwave conditions pose on healthy young individuals. This ecologically-valid empirical evidence could inform more accurate heat-health planning.


Asunto(s)
Calor Extremo , Frecuencia Cardíaca , Humanos , Masculino , Adulto , Sicilia , Frecuencia Cardíaca/fisiología , Calor Extremo/efectos adversos , Sudoración/fisiología , Temperatura Corporal/fisiología , Regulación de la Temperatura Corporal/fisiología , Temperatura Cutánea/fisiología , Calor/efectos adversos
9.
Environ Res ; 257: 119347, 2024 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-38844034

RESUMEN

BACKGROUND: As climate change increases the frequency and intensity of extreme heat events, there is an urgent need to quantify the heat-related health burden. However, most past studies have focussed on a single health outcome (mainly mortality) or on specific heatwaves, thus providing limited knowledge of the total pressure heat exerts on health services. OBJECTIVES: This study aims to quantify the heat-related mortality and morbidity burden for five different health outcomes including all-cause mortality, hospitalizations, emergency department (ED) visits, ambulance transports and calls to a health hotline, using the province of Quebec (Canada) as a case study. METHODS: A two-step statistical analysis was employed to estimate regional heat-health relationships using Distributed Lag Non-Linear Models (DLNM) and pooled estimates using a multivariate meta-regression. Heat burden was quantified by attributable fraction (AF) and attributable number (AN) for two temperature ranges: all heat (above the minimum mortality/morbidity temperature) and extreme heat (above the 95th percentile of temperature). RESULTS: Higher temperatures were associated with greater risk ratios for all health outcomes studied, but at different levels. Significant AF ranging from 2 to 3% for the all heat effect and 0.4-1.0% for extreme heat were found for all health outcomes, except for hospitalizations that had an AF of 0.1% for both heat exposures. The estimated burden of all heat (and extreme heat) every summer across the province was 470 (200) deaths, 225 (170) hospitalizations, 36 000 (6 200) ED visits, 7 200 (1 500) ambulance transports and 15 000 (3 300) calls to a health hotline, all figures significant. DISCUSSION: This new knowledge on the total heat load will help public health authorities to target appropriate actions to reduce its burden now and in the future. The proposed state-of-the-art framework can easily be applied to other regions also experiencing the adverse effects of extreme heat.


Asunto(s)
Hospitalización , Calor , Quebec/epidemiología , Humanos , Hospitalización/estadística & datos numéricos , Calor/efectos adversos , Servicio de Urgencia en Hospital/estadística & datos numéricos , Trastornos de Estrés por Calor/mortalidad , Trastornos de Estrés por Calor/epidemiología , Morbilidad , Calor Extremo/efectos adversos , Mortalidad/tendencias , Anciano
11.
Am J Ind Med ; 67(6): 556-561, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38698682

RESUMEN

BACKGROUND: Occupational heat stress, exacerbated by factors such as climate change and insufficient cooling solutions, endangers the health and productivity of workers, especially in low-resource workplaces. OBJECTIVE: To evaluate the effectiveness of two cooling strategies in reducing physiological strain and productivity of piece-rate workers over a 9-h work shift in a southern Thailand sawmill. METHODS: In a crossover randomized control trial design, 12 (33 ± 7 y; 1.58 ± 0.05 m; 51 ± 9 kg; n = 5 females) medically screened sawmill workers were randomly allocated into three groups comprising an established phase change material vest (VEST), an on-site combination cooling oasis (OASIS) (i.e., hydration, cold towels, fans, water dousing), and no cooling (CON) across 3 consecutive workdays. Physiological strain was measured via core temperature telemetry and heart rate monitoring. Productivity was determined by counting the number of pallets of wood sorted, stacked, and stowed each day. RESULTS: Relative to CON, OASIS lowered core temperature by 0.25°C [95% confidence interval = 0.24, 0.25] and heart rate by 7 bpm [6, 9] bpm, compared to 0.17°C [0.17, 0.18] and 10 [9,12] bpm reductions with VEST. It was inconclusive whether productivity was statistically lower in OASIS compared to CON (mean difference [MD] = 2.5 [-0.2, 5.2]), and was not statistically different between VEST and CON (MD = 1.4 [-1.3, 4.1]). CONCLUSIONS: Both OASIS and VEST were effective in reducing physiological strain compared to no cooling. Their effect on productivity requires further investigation, as even small differences between interventions could lead to meaningful disparities in piece-rate worker earnings over time.


Asunto(s)
Estudios Cruzados , Trastornos de Estrés por Calor , Humanos , Tailandia , Femenino , Adulto , Masculino , Trastornos de Estrés por Calor/prevención & control , Frecuencia Cardíaca/fisiología , Enfermedades Profesionales/prevención & control , Enfermedades Profesionales/etiología , Ropa de Protección , Eficiencia , Calor/efectos adversos , Exposición Profesional/prevención & control , Exposición Profesional/efectos adversos , Adulto Joven
12.
Int J Biometeorol ; 68(7): 1315-1326, 2024 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-38705900

RESUMEN

Winter cold wave adaptation strategies in hot climates due to climate change didn't receive the deserved attention from previous studies. Therefore, this study comprehensively investigates the impact of various windbreak parameters on mitigating winter cold stress in hot steppe-arid climate. A microclimate model for a residential campus was built and validated through on-site measurement on a typical winter day to assess thirty-two scenarios for tree characteristics and spatial configuration windbreak parameters based on PET, wind speed, and Air Temperature (AT). Moreover, four configurations, that had best results on mitigating cold stress in winter, were tested during typical summer conditions to couple the assessment of cold and hot seasons. Additionally, environmental analysis for all scenarios was conducted. The results revealed that the most effective parameters for mitigating cold stress are tree distribution, Leaf Area Density (LAD), row number, spacing, and shape. Double rows of high LAD and medium height trees with small spacing yielded the best cold stress mitigation effect. Furthermore, the windbreak reduced the cold stress in the morning and night by 19.31% and 18.06%, respectively. It reduced AT and wind speed at night by 0.79 °C and 2.56 m/s, respectively. During summer, very hot PET area was reduced by 21.79% and 19.5% at 12:00 and 15:00, respectively.


Asunto(s)
Cambio Climático , Microclima , Modelos Teóricos , Estaciones del Año , Árboles , Viento , Frío
13.
Environ Epidemiol ; 8(2): e292, 2024 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-38617431

RESUMEN

Background: Air conditioners can prevent heat-related illness and mortality, but the increased use of air conditioners may enhance susceptibility to heat-related illnesses during large-scale power failures. Here, we examined the risks of heat-related illness ambulance transport (HIAT) and mortality associated with typhoon-related electricity reduction (ER) in the summer months in the Tokyo metropolitan area. Methods: We conducted event study analyses to compare temperature-HIAT and mortality associations before and after the power outage (July to September 2019). To better understand the role of temperature during the power outage, we then examined whether the temperature-HIAT and mortality associations were modified by different power outage levels (0%, 10%, and 20% ER). We computed the ratios of relative risks to compare the risks associated with various ER values to the risks associated without ER. Results: We analyzed the data of 14,912 HIAT cases and 74,064 deaths. Overall, 93,200 power outage cases were observed when the typhoon hit. Event study results showed that the incidence rate ratio was 2.01 (95% confidence interval [CI] = 1.42, 2.84) with effects enduring up to 6 days, and 1.11 (95% CI = 1.02, 1.22) for mortality on the first 3 days after the typhoon hit. Comparing 20% to 0% ER, the ratios of relative risks of heat exposure were 2.32 (95% CI = 1.41, 3.82) for HIAT and 0.95 (95% CI = 0.75, 1.22) for mortality. Conclusions: A 20% ER was associated with a two-fold greater risk of HIAT because of summer heat during the power outage, but there was little evidence for the association with all-cause mortality.

14.
Int J Biometeorol ; 68(6): 1169-1178, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38602550

RESUMEN

Examining how heat affects people with Parkinson's disease is essential for informing clinical decision-making, safety, well-being, and healthcare planning. While there is evidence that the neuropathology associated with Parkinson's disease affects thermoregulatory mechanisms, little attention has been given to the association of heat sensitivity to worsening symptoms and restricted daily activities in people with this progressive disease. Using a cross-sectional study design, we examined the experiences of people diagnosed with Parkinson's disease in the heat. Two-hundred and forty-seven people completed an online survey (age: 66.0 ± 9.2 years; sex: male = 102 (41.3%), female = 145 (58.7%)), of which 195 (78.9%) reported becoming more sensitive to heat with Parkinson's disease. Motor and nonmotor symptoms worsened with heat in 182 (73.7%) and 203 (82.2%) respondents, respectively. The most commonly reported symptoms to worsen included walking difficulties, balance impairment, stiffness, tremor, fatigue, sleep disturbances, excess sweating, difficulty concentrating, and light-headedness when standing. Concerningly, over half indicated an inability to work effectively in the heat, and nearly half reported that heat impacted their ability to perform household tasks and social activities. Overall, heat sensitivity was common in people with Parkinson's disease and had a significant impact on symptomology, day-to-day activities and quality of life.


Asunto(s)
Calor , Enfermedad de Parkinson , Humanos , Enfermedad de Parkinson/fisiopatología , Masculino , Femenino , Anciano , Persona de Mediana Edad , Estudios Transversales , Calor/efectos adversos , Sensación Térmica , Actividades Cotidianas , Encuestas y Cuestionarios
15.
Int J Occup Saf Ergon ; 30(2): 587-598, 2024 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-38509715

RESUMEN

Objectives. This study explores the effects of temperature steps on thermal responses to understand abrupt temperature shifts faced by heat-exposed workers during winter. Methods. Three temperature step changes with three phases (S20: 20-40-20 °C, S30: 10-40-10 °C, S40: 0-40-0 °C) were conducted. Phase 1 took 30 min, phase 2 took 60 min and phase 3 took 40 min. Eleven participants remained sedentary throughout the experiment, and physiological responses, thermal perception and self-reported health symptoms were recorded. Results. In temperature up steps, steady skin temperature and sweating onset were delayed, and heart rate dropped by 10 bpm from S20 to S40. In temperature down steps to cold conditions, individuals transitioned from thermal comfort to discomfort and eventually cold strain. Blood pressure increased in temperature down steps, correlating with temperature step magnitudes. Thermal responses to temperature steps of equal magnitude but opposite directions were asymmetries, which weakened as step magnitude increased. Thermal perceptions responded faster than physiological changes after temperature steps, while self-reported health symptoms lagged behind physiological responses. Conclusions. These findings contribute to expanding basic data to understand the effects of temperature step magnitude and direction.


Asunto(s)
Frío , Frecuencia Cardíaca , Calor , Temperatura Cutánea , Humanos , Masculino , Temperatura Cutánea/fisiología , Frecuencia Cardíaca/fisiología , Adulto , Presión Sanguínea/fisiología , Sudoración/fisiología , Femenino , Percepción/fisiología , Sensación Térmica/fisiología , Adulto Joven
17.
Saudi Dent J ; 36(1): 1-10, 2024 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-38375375

RESUMEN

Objective: The aim was to evaluate the difference in the heat generated between zirconia (Zr) and steel (SS) drills, during implant site preparation. Material and methods: This systematic review followed the PRISMA methodology criteria and used the JBI Critical Assessment Guidelines for Quasi-Experimental Studies for quality assessment. The electronic search was conducted by using the PubMed/MEDLINE, Embase, and Cochrane Library databases to January 2023. The formulated population, intervention, comparison, outcome (PICO) question was "Do zirconia drills generate less heat than steel drills during implant site preparation?". The meta-analysis was based on an inverse variance (IV) method. Results: This review included 10 studies in vitro that used zirconia drills compared to steel drills with or without coatings. The meta-analysis indicated a significant difference between Zr drills and SS drills, with a lower bone temperature variation with Zr drills. Conclusions: Despite the limitations of this review, it was concluded that Zr drills had significantly less temperature variation than SS drills.

18.
Tree Physiol ; 44(4)2024 Apr 03.
Artículo en Inglés | MEDLINE | ID: mdl-38412116

RESUMEN

Residual canopy transpiration (Emin_canop) is a key physiological trait that determines trees' survival time under drought after stomatal closure and after trees have limited access to soil water. Emin_canop mainly depends on leaf minimum conductance (gmin) and vapor pressure deficit. Here we determined the seasonal variation of gmin and how gmin is related to interspecies variation in leaf cuticular and stomatal traits for nine European tree species in a mature forest. In addition, we determined the species-specific temperature responses of gmin. With this newly obtained insight, we calculated Emin_canop for the nine species for one day at our research site during the 2022 central European hot drought. Our results show that at ambient temperatures gmin ranged from 0.8 to 4.8 mmol m-2 s-1 across the nine species and was stable in most species throughout the growing season. The interspecies variation of gmin was associated with leaf cuticular and stomatal traits. Additionally, gmin exhibited strong temperature responses and increased, depending on species, by a factor of two to four in the range of 25-50 °C. For the studied species at the site, during a single hot drought day, Emin_canop standardized by tree size (stem basal area) ranged from 2.0 to 36.7 L m-2, and non-standardized Emin_canop for adult trees ranged from 0.3 to 5.3 L. Emin_canop also exhibited species-specific rapid increases under hotter temperatures. Our results suggest that trees, depending on species, need reasonable amounts of water during a drought, even when stomates are fully closed. Species differences in gmin and ultimately Emin_canop can, together with other traits, affect the ability of a tree to keep its tissue hydrated during a drought and is likely to contribute to species-specific differences in drought vulnerability.


Asunto(s)
Árboles , Agua , Árboles/fisiología , Agua/fisiología , Sequías , Hojas de la Planta/fisiología , Bosques
19.
Int J Environ Health Res ; 34(3): 1511-1524, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37319425

RESUMEN

Heat stress-related kidney injury has drawn public health attention. This study explored the temporal relationships between impaired kidney function and preceding outdoor heat exposure Taiwan. Data of participants collected through a health screening program was used to assess the association between chronic kidney disease (CKD) and average ambient temperature with various time lag structures. A total of 1,243 CKD cases and 38,831 non-CKD participants were included in the study. After adjusting for demographic, socioeconomic, lifestyle factors, and comorbidities, CKD was positively associated with the ambient temperature within 1-9 months. The 9-month average ambient temperature yielded the highest odds ratio of CKD (OR = 1.22; 95% CI = 1.09-1.37). Furthermore, females and farmers were found to be more vulnerable to CKD risk after outdoor heat exposure. These findings suggest that the prevention of heat stress-related kidney injury should consider relevant time frames and focus on vulnerable populations.


Asunto(s)
Trastornos de Estrés por Calor , Insuficiencia Renal Crónica , Femenino , Humanos , Insuficiencia Renal Crónica/epidemiología , Riñón , Trastornos de Estrés por Calor/epidemiología , Comorbilidad , Taiwán/epidemiología
20.
Braz. dent. sci ; 27(2): 1-17, 2024. ilus, tab
Artículo en Inglés | LILACS, BBO - Odontología | ID: biblio-1570973

RESUMEN

Objective: This study aimed to evaluate the optical behavior of pressable lithia-silicate and lithia-zirconia-silicate glass ceramics toward additional heat treatment protocols. Material and Methods: 40 lithia-silicate discs (15mm x 1mm) were heat pressed following the manufacturers' instructions. Discs were divided into four groups (n=10) according to type as follows: two groups of lithia-silicate-glass ceramics; Gp(E) (IPS e.max Press; Ivoclar Vivadent AG), Gp(L) (GC Initial LiSi Press, GC), two lithia-zirconia-silicate pressable glass ceramics; Gp(C) (Celtra Press, Dentsply Sirona) and Gp(A) (VITA Ambria, VITA Zahnfabrik). Each group was subdivided into (n=5): Subgroup(T1): the thermal tempering temperature was set 9% below the pressing temperature, Subgroup(T2): the temperature was set 5% below the pressing temperature. Optical properties: color, translucency parameter (TP), and contrast ratio (CR) were evaluated by spectrophotometer (Aglient Cary 5000 UV-Vis­NIR) after pressing and after thermal tempering. Results: Thermal tempering regardless of temperature resulted in a color shift within the acceptability level as ΔE for Gp(E) (3.18±2) followed by ΔE for Gp(L) (2.47±0.19) by ΔE for Gp(C) (2.26±0.14) and the last ΔE for Gp(A) (1.62±0.13). Subgroup(T2) showed a significantly higher color shift with mean ΔE(2.55±0.63) compared to Subgroup(T1) ΔE(2.35±0.59). There was a statistically significant increase in TP after tempering for all tested groups parallelled with a decrease in CR values. Conclusion: Heat tempering of the tested lithia-silicate pressable ceramics had a significant effect on the optical outcome of these materials, being lithia-zirconia-silicate ceramics more stable and less affected optically than other lithia-silicate-glass ceramics.(AU)


Objetivo: Avaliar o comportamento óptico de cerâmicas pressionáveis de vidro de litia-silicato e litia-zircônia-silicato sob protocolos adicionais de tratamento térmico. Materiais e métodos: 40 discos de litia-silicato (15mm x 1mm) foram prensados a quente conforme instruções dos fabricantes. Material e Métodos: 40 discos de litia-silicato (15mm x 1mm) foram prensados e divididos em quatro grupos (n=10): dois de lithia-silicato-vidro, Gp(E) (IPS e.max Imprensa) e Gp(L) (GC inicial LiSi Press), e dois de vidro prensado de litia-zircônia-silicato, Gp(C) (Celtra Press) e Gp(A) (VITA Ambria). Cada grupo foi subdividido em (n=5): Subgrupo(T1): amostras temperadas a 9% abaixo da temperatura de prensagem, e Subgrupo(T2): a temperatura foi ajustada 5% abaixo da temperatura de prensagem. As propriedades ópticas, incluindo cor, translucidez (TP) e contraste (CR), foram avaliadas com um espectrofotômetro (Aglient Cary 5000 UV-Vis-NIR) após prensagem e temperagem térmica. Resultados: O tratamento térmico resultou em mudança de cor dentro do nível aceitável, com ΔE mais alto para Gp(E) (3,18±2), seguido por Gp(L) (2,47±0,19), Gp(C) (2,26±0,14), e Gp(A) (1,62±0,13). No subgrupo (T2), houve uma mudança de cor mais significativa, com ΔE médio de (2,55±0,63), comparado ao subgrupo (T1) com ΔE médio de (2,35±0,59). Houve aumento significativo na TP e redução nos valores de RC após o tratamento térmico em todos os grupos testados. Conclusão: O tratamento térmico das cerâmicas prensadas de litia-silicato teve um efeito significativo na sua qualidade ótica, com as cerâmicas de litia-zircônia-silicato mostrando-se mais estáveis e menos afetadas visualmente em comparação com outras cerâmicas de litia-silicato-vidro(AU)


Asunto(s)
Silicatos , Materiales Dentales , Calor
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