Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 47.014
Filtrar
1.
BMC Anesthesiol ; 24(1): 124, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38561683

RESUMO

BACKGROUND: This study aimed to investigate the impact of intraoperative hypothermia on the recovery period of anesthesia in elderly patients undergoing abdominal surgery. METHODS: A prospective observational study was conducted based on inclusion and exclusion criteria. A total of 384 elderly patients undergoing abdominal surgery under general anesthesia were enrolled in a grade A tertiary hospital in Chengdu, Sichuan Province from October 2021 and October 2022. After anesthesia induction, inflatable warming blankets were routinely used for active heat preservation, and nasopharyngeal temperature was monitored to observe the occurrence of intraoperative hypothermia. Patients were divided into hypothermia group and nonhypothermia group according to whether hypothermia occurred during the operation. Anesthesia recovery time and the incidence of adverse events or unwanted events during anesthesia recovery between the two groups were compared. RESULTS: The numbers (percentage) of 384 patients who underwent abdominal surgery developed intraoperative hypothermia occurred in 240 (62.5%) patients, all of whom had mild hypothermia. There were statistically significant differences between mild hypothermia after active warming and nonhypothermia in the occurrence of shivering (χ2 = 5.197, P = 0.023) and anesthesia recovery time (Z = -2.269, P = 0.02) in elderly patients undergoing abdominal surgery during anesthesia recovery, and there were no statistically significant differences in hypoxemia, nausea or vomiting, hypertension, hypokalemia, hypocalcemia, analgesic drug use,postoperative wound infection or postoperative hospitalization days. CONCLUSIONS: The incidence of intraoperative mild hypothermia after active warming was high in elderly patients who underwent abdominal surgery. Mild hypothermia increased the incidence of shivering and prolonged anesthesia recovery time in elderly patients undergoing abdominal surgery.


Assuntos
Hipotermia , Humanos , Idoso , Hipotermia/epidemiologia , Hipotermia/etiologia , Temperatura Corporal , Anestesia Geral/efeitos adversos , Tremor por Sensação de Frio , Infecção da Ferida Cirúrgica/etiologia
2.
J Biomech Eng ; 146(8)2024 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-38491980

RESUMO

Radio frequency ablation has emerged as a widely accepted treatment for atherosclerotic plaques. However, monitoring the temperature field distribution in the blood vessel wall during this procedure presents challenges. This limitation increases the risk of endothelial cell damage and inflammatory responses, potentially leading to lumen restenosis. The aim of this study is to accurately reconstruct the transient temperature distribution by solving a stochastic heat transfer model with uncertain parameters using an inverse heat transfer algorithm and temperature measurement data. The nonlinear least squares optimization method, Levenberg-Marquardt (LM), was employed to solve the inverse heat transfer problem for parameter estimation. Then, to improve the convergence of the algorithm and reduce the computational resources, a method of parameter sensitivity analysis was proposed to select parameters mainly affecting the temperature field. Furthermore, the robustness and accuracy of the algorithm were verified by introducing random noise to the temperature measurements. Despite the high level of temperature measurement noise (ξ = 5%) and larger initial guess deviation, the parameter estimation results remained closely aligned with the actual values, with an overall ERMS consistently below 0.05. The absolute errors between the reconstruction temperature at the measurement points TC1, TC2, and TC3, and the actual temperature, remained within 0.33 °C, 2.4 °C, and 1.17 °C, respectively. The Levenberg-Marquardt algorithm employed in this study proficiently tackled the ill-posed issue of inversion process and obtained a strong consistency between the reconstructed temperature the actual temperature.


Assuntos
Placa Aterosclerótica , Ablação por Radiofrequência , Humanos , Temperatura , Temperatura Alta , Temperatura Corporal , Algoritmos
3.
Artigo em Inglês | MEDLINE | ID: mdl-38541370

RESUMO

This study compared physiological responses to two work/rest cycles of a 2:1 work-to-rest ratio in a hot environment. In a randomized crossover design, fourteen participants completed 120 min of walking and rest in the heat (36.3 ± 0.6 °C, 30.2 ± 4.0% relative humidity). Work/rest cycles were (1) 40 min work/20 min rest [40/20], or (2) 20 min work/10 min rest [20/10], both completing identical work. Core temperature (Tc), skin temperature (Tsk), heart rate (HR), nude body mass, and perception of work were collected. Comparisons were made between trials at equal durations of work using three-way mixed model ANOVA. Tc plateaued in [20/10] during the second hour of work (p = 0.93), while Tc increased in [40/20] (p < 0.01). There was no difference in maximum Tc ([40/20]: 38.08 ± 0.35 °C, [20/10]: 37.99 ± 0.27 °C, p = 0.22) or end-of-work Tsk ([40/20]: 36.1 ± 0.8 °C, [20/10]: 36.0 ± 0.7 °C, p = 0.45). End-of-work HR was greater in [40/20] (145 ± 25 b·min-1) compared to [20/10] (141 ± 27 b·min-1, p = 0.04). Shorter work/rest cycles caused a plateau in Tc while longer work/rest cycles resulted in a continued increase in Tc throughout the work, indicating that either work structure could be used during shorter work tasks, while work greater than 2 h in duration may benefit from shorter work/rest cycles to mitigate hyperthermia.


Assuntos
Temperatura Corporal , Temperatura Alta , Humanos , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Frequência Cardíaca/fisiologia , Temperatura Cutânea , Temperatura
4.
Zhonghua Wei Zhong Bing Ji Jiu Yi Xue ; 36(2): 205-207, 2024 Feb.
Artigo em Chinês | MEDLINE | ID: mdl-38442940

RESUMO

OBJECTIVE: A warming fixation device for premature infants was made and its clinical application effect was discussed. METHODS: The warming fixation device for premature infants was designed and used in clinic. Sixty premature infants admitted to the neonatal ward of Baoding Hospital, Beijing Children's Hospital, Capital Medical University from January to June 2022 were selected as the control group, and 60 premature infants admitted from July to December 2022 were selected as the experimental group. In the control group, umbilical vein catheterization or central vein catheterization were performed using Astro Boy heating box, restraint band or artificial restraint. The preterm infants in the experimental group were radiated into the Astro Boy warm box with self-designed preterm warming fixation device for catheterization. The time of catheterization, the number of limb protrusion, the number of participants in catheterization operation, and the body temperature from 20 minutes of catheterization operation to the end of catheterization operation were recorded in the two groups. The frequency of hypothermia (< 36.5 centigrade) was calculated, and the differences in various indexes between the two groups were compared. RESULTS: (1) The warming fixation device for premature babies consists of two parts: warm sleeping bag and soft pad. The warm sleeping bag includes 4 parts: head, arm, chest and abdomen, and lower limbs. The chest and abdomen were designed with rectangular covering cloth, which can be opened to facilitate umbilical vein puncture for premature infants. There were 3 groups of restraint belts on the rectangular soft pad, which can respectively fix the arms, chest and abdomen of the warm sleeping bag and the lower limbs. During the catheterization operation, use Velcro to secure the warm sleeping bag to the cushioned surface, and select the area of exposed skin according to the piercing site. (2) There were no significant differences in gender, body weight and gestational age between the experimental group and the control group [male: 48.3% vs. 46.7%, body weight (kg): 1.86±0.06 vs. 1.82±0.06, gestational age (weeks): 31.33±0.31 vs. 32.25±0.34, all P > 0.05]. Compared with the control group, the catheterization time of experimental group was significantly shortened (minutes: 21.30±0.43 vs. 30.02±0.64, P < 0.01), the number of limb protrusion was significantly reduced (0 time: 70.0% vs. 33.3%, 1 time: 26.7% vs. 50.0%, P < 0.01), and the number of participants in catheterization operation was significantly reduced (people: 1.77±0.06 vs. 2.37±0.06, P < 0.01). The frequency of hypothermia in experimental group was significantly lower than that in the control group [6.12% (6/98) vs. 26.50% (31/117), χ2 = 15.536, P < 0.01]. CONCLUSIONS: The warming fixation device for premature infants is convenient to use, which can effectively shorten the tube placement time, save human resources, and reduce the incidence of hypothermia in premature infants.


Assuntos
Hipotermia , Recém-Nascido Prematuro , Recém-Nascido , Lactente , Criança , Humanos , Masculino , Idade Gestacional , Temperatura Corporal , Peso Corporal
5.
Comput Biol Med ; 172: 108262, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38479196

RESUMO

Given the increasing aging population and rising living standards in China, developing an accurate and straightforward thermoregulation model for the elderly has become increasingly essential. To address this need, an existing one-segment four-node thermoregulation model for the young was selected as the base model. This study developed the base model considering age-related physical and physiological changes to predict mean skin temperatures of the elderly. Measured data for model optimization were collected from 24 representative healthy Chinese elderly individuals (average age: 67 years). The subjects underwent temperature step changes between neutral and warm conditions with a temperature range of 25-34 °C. The model's demographic representation was first validated by comparing the subjects' physical characteristics with Chinese census data. Secondly, sensitivity analysis was performed to investigate the influences of passive system parameters on skin and core temperatures, and adjustments were implemented using measurement or literature data specific to the Chinese elderly. Thirdly, the active system was modified by resetting the body temperature set points. The active parameters to control thermoregulation activities were further optimized using the TPE (Tree-structured Parzen Estimator) hyperparameter tuning method. The model's accuracy was further verified using independent experimental data for a temperature range of 18-34 °C for Chinese elderly. By comprehensively considering age-induced thermal response changes, the proposed model has potential applications in designing and optimizing thermal management systems in buildings, as well as informing energy-efficient strategies tailored to the specific needs of the Chinese elderly population.


Assuntos
Temperatura Alta , Modelos Biológicos , Humanos , Idoso , Regulação da Temperatura Corporal/fisiologia , Temperatura Corporal/fisiologia , Temperatura Cutânea , China
6.
Vet Med Sci ; 10(3): e1423, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38520702

RESUMO

OBJECTIVE: This study aimed to compare rectal temperature (RT) with temperatures measured in the pinna, cornea, medial canthus, gingiva, metacarpal pad and axillary region of cats in a home environment. ANIMALS STUDIED: Five healthy mixed-breed cats (two females and three males) owned by a veterinarian were used. PROCEDURES: All temperature measurements were conducted by the owner by using an infrared camera in the same room and initiated with the pinna, followed by the cornea, medial canthus, gingiva and metacarpal pad. Subsequently, axillary temperature (AT) and RT were recorded by a digital thermometer, respectively. The time taken for a single AT and RT measurements was recorded. RESULTS: The average measurement time for RT was 17.34 ± 0.89 s, with a range of 8-32 s, whereas AT measurements took an average of 46.72 ± 1.16 s, with a range of 29-69 s. AT emerged as a superior alternative measurement site compared to others, exhibiting the lowest bias and the highest proportion of readings within the limits of clinical agreement. The mean difference between RT and AT, with 95% limits of agreement for the differences, was -0.26 (-1.13 to 0.61). CONCLUSIONS: Anatomical regions were not all interchangeable with the rectum for assessing body temperature (BT), with AT recording the highest level of agreement with RT. When RT is not possible, AT could be considered as an alternative for monitoring BT in clinically healthy cats that live in a home environment.


Assuntos
Temperatura Corporal , Termômetros , Masculino , Feminino , Gatos , Animais , Temperatura , Termômetros/veterinária , Reto , Axila
7.
Sci Rep ; 14(1): 6406, 2024 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-38493262

RESUMO

A complete assessment of animal welfare requires not just an understanding of negative emotional states, such as fear and anxiety, but also of positive states, such as calmness and happiness. However, few studies have identified accurate and reliable indicators of positive emotional states in dogs. This study aimed to identify parameters that may serve as indicators of short-term emotional states in dogs. Using a cross-over design, 60 dogs living at a research facility were exposed to six different 10-min scenarios expected to elicit responses varying in emotional valence and arousal. A range of behavioural and physiological parameters were collected and their relationship to anticipated emotional valence and arousal was analysed using linear and logistic mixed models. Cortisol, adrenocorticotropic hormone, heart rate variability, panting, whining, and body shake all demonstrated significant differences based on arousal levels, but only within negative valence scenarios. Scores from a qualitative behavioural assessment (QBA) were associated with both emotional valence and arousal and were considered the best indicator of positive valence. Activity, ear temperature, and sitting were associated with positive high arousal, although this may have been influenced by differing levels of movement induced during these scenarios. Meanwhile, heart rate, secretory immunoglobulin A, standing and lying all showed similar changes associated with arousal for both positive and negative valence scenarios. This study provides a critical first step towards identifying evidence-based indicators of short-term emotional states in dogs, while highlighting considerations that should be made when employing these parameters, including the influence of coder bias, food provision, exercise, and external temperature. Overall, it is recommended future dog emotion and welfare research use a combination of parameters including indicators of both emotional valence and arousal.


Assuntos
Emoções , Medo , Animais , Cães , Temperatura Corporal/fisiologia , Emoções/fisiologia , Alimentos , Vocalização Animal , Estudos Cross-Over
8.
Transl Psychiatry ; 14(1): 138, 2024 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-38453903

RESUMO

Whole genome analysis has identified rare copy number variations (CNV) that are strongly involved in the pathogenesis of psychiatric disorders, and 3q29 deletion has been found to have the largest effect size. The 3q29 deletion mice model (3q29-del mice) has been established as a good pathological model for schizophrenia based on phenotypic analysis; however, circadian rhythm and sleep, which are also closely related to neuropsychiatric disorders, have not been investigated. In this study, our aims were to reevaluate the pathogenesis of 3q29-del by recreating model mice and analyzing their behavior and to identify novel new insights into the temporal activity and temperature fluctuations of the mouse model using a recently developed small implantable accelerometer chip, Nano-tag. We generated 3q29-del mice using genome editing technology and reevaluated common behavioral phenotypes. We next implanted Nano-tag in the abdominal cavity of mice for continuous measurements of long-time activity and body temperature. Our model mice exhibited weight loss similar to that of other mice reported previously. A general behavioral battery test in the model mice revealed phenotypes similar to those observed in mouse models of schizophrenia, including increased rearing frequency. Intraperitoneal implantation of Nano-tag, a miniature acceleration sensor, resulted in hypersensitive and rapid increases in the activity and body temperature of 3q29-del mice upon switching to lights-off condition. Similar to the 3q29-del mice reported previously, these mice are a promising model animals for schizophrenia. Successive quantitative analysis may provide results that could help in treating sleep disorders closely associated with neuropsychiatric disorders.


Assuntos
Deficiências do Desenvolvimento , Deficiência Intelectual , Humanos , Criança , Camundongos , Animais , Deficiências do Desenvolvimento/genética , Deleção Cromossômica , Variações do Número de Cópias de DNA , Temperatura Corporal , Deficiência Intelectual/genética , Modelos Animais de Doenças , Fenótipo
9.
AJNR Am J Neuroradiol ; 45(4): 424-431, 2024 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-38453412

RESUMO

BACKGROUND AND PURPOSE: Although the application of cryoablation to metastatic spinal tumors has been attempted, spinal cryoablation has the unique complication of cryogenic spinal cord injury. This study aimed to elucidate the conditions for the development of cryogenic spinal cord injury. MATERIALS AND METHODS: Fifteen canines were used in this study. A metal probe was inserted into the 13th thoracic vertebral body. Cryoablation was performed for 10 minutes by freezing the probe in liquid nitrogen. The control canine underwent probe insertion only. Spinal cord monitoring, epidural temperature measurement, motor function assessment, and pathologic examination of the spinal cord were performed. RESULTS: During the 10 minutes of cryoablation, the epidural temperature decreased and reached the lowest epidural temperature (LET) at the end of cryoablation. The LETs (degrees celsius [°C]) of each canine were -37, -30, -27, -8, -3, -2, 0, 1, 4, 8, 16, 18, 20, and 25, respectively. As the epidural temperature decreased, waveform amplitudes also decreased. At the end of cryoablation (10 minutes after the start of cryoablation), abnormal waves were observed in 92.9% (13/14) of canines. With epidural rewarming, the amplitude of the waveforms tended to recover. After epidural rewarming (2 hours after the start of cryoablation), abnormal waves were observed in 28.6% (4/14) of canines. The LETs (°C) of the canines with abnormal waves after epidural rewarming were -37, -30, -27, and -8. None of the canines with normal waves after epidural rewarming had any motor impairment. In contrast, all canines with remaining abnormal waves after epidural rewarming had motor impairment. In the pathologic assessment, cryogenic changes were found in canines with LETs (°C) of -37 -30, -27, -8, 0, and 1. CONCLUSIONS: This study showed that 10-minute spinal cryoablation with LETs (°C) of -37, -30, -27, -8, 0, and 1 caused cryogenic spinal cord injury. There was no evidence of cryogenic spinal cord injury in canines with LET of ≥4°C. The epidural temperature threshold for cryogenic spinal cord injury is between 1 and 4°C, suggesting that the epidural temperature should be maintained above at least 4°C to prevent cryogenic spinal cord injury.


Assuntos
Neoplasias do Sistema Nervoso Central , Criocirurgia , Hipotermia Induzida , Traumatismos da Medula Espinal , Neoplasias da Medula Espinal , Neoplasias da Coluna Vertebral , Animais , Cães , Neoplasias da Coluna Vertebral/patologia , Criocirurgia/efeitos adversos , Traumatismos da Medula Espinal/etiologia , Traumatismos da Medula Espinal/cirurgia , Temperatura Corporal , Medula Espinal/patologia , Neoplasias da Medula Espinal/patologia , Neoplasias do Sistema Nervoso Central/patologia
10.
Toxins (Basel) ; 16(3)2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38535782

RESUMO

There is a limited research focus on evaluating the detrimental effects of prolonged zearalenone (ZEN) intake on dairy cows' health under controlled conditions. This experiment was conducted to evaluate whether the length of exposure to a ZEN-contaminated total mixed ration (TMR) at a level of 9.45 mg per day can negatively influence animal health parameters, such as milk composition, rumen and fecal fermentation, and the chewing activity of lactating dairy cows. For this experiment, we used 18 lactating Simmental cows that were fed a diet of 60% forage and 40% concentrate (on dry matter basis) for 26 consecutive days. The first 4 days were for adaptation prior to the first sampling day (day 0). The sampling events took place on day 0 (baseline) without ZEN, followed by day 1, day 7, day 14, and day 21 (with toxin). Dry matter intake (DMI) and ruminating chews per minute increased on the third week of ZEN inclusion; meanwhile, ruminating, eating, and drinking times were not affected. Most milk composition variables were also unaffected. Rumen fluid osmolality increased on day 21 and total short-chain fatty acids (SCFA) of ruminal fluid decreased on day 7. Fecal SCFA increased on day 21 and the acetate-to-propionate ratio increased from day 1 onwards, showing the influence of toxin intake. Animal health parameters, like heart rate, respiratory rate, and body temperature, were negatively influenced by ZEN intake, all increasing consistently on days 4 and 6, 9 and 12, and 16 and 18, respectively. The liver enzyme glutamate dehydrogenase decreased in response to ZEN intake on day 7. A total daily ZEN intake at the level of 9.45 mg did not show detrimental effects on DMI. Nevertheless, certain health parameters were negatively affected, including body temperature, respiratory rate, and heart rate, starting from the 7th day of ZEN intake, with additional signs of possible loss of water balance on the last sampling day.


Assuntos
Líquidos Corporais , Zearalenona , Feminino , Animais , Bovinos , Lactação , Leite , Temperatura Corporal
11.
Sensors (Basel) ; 24(6)2024 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-38544207

RESUMO

The remote monitoring of vital signs and healthcare provision has become an urgent necessity due to the impact of the COVID-19 pandemic on the world. Blood oxygen level, heart rate, and body temperature data are crucial for managing the disease and ensuring timely medical care. This study proposes a low-cost wearable device employing non-contact sensors to monitor, process, and visualize critical variables, focusing on body temperature measurement as a key health indicator. The wearable device developed offers a non-invasive and continuous method to gather wrist and forehead temperature data. However, since there is a discrepancy between wrist and actual forehead temperature, this study incorporates statistical methods and machine learning to estimate the core forehead temperature from the wrist. This research collects 2130 samples from 30 volunteers, and both the statistical least squares method and machine learning via linear regression are applied to analyze these data. It is observed that all models achieve a significant fit, but the third-degree polynomial model stands out in both approaches. It achieves an R2 value of 0.9769 in the statistical analysis and 0.9791 in machine learning.


Assuntos
Temperatura Corporal , Dispositivos Eletrônicos Vestíveis , Humanos , Punho/fisiologia , Temperatura , Pandemias
12.
Med Sci Monit ; 30: e943463, 2024 Mar 21.
Artigo em Inglês | MEDLINE | ID: mdl-38509664

RESUMO

BACKGROUND Intraoperative and postoperative hypothermia of patients can be caused by the use of anesthetic drugs and the complicated and time-consuming procedures of interventional surgery. This retrospective study included 184 patients to investigate the incidence and factors associated with hypothermia during intraoperative anesthesia in a single center in China between January and October 2023. MATERIAL AND METHODS A convenient sampling method was used to select 184 patients who underwent general anesthesia intervention in a tertiary hospital in Sichuan Province from January to October 2023 as the study population. The independent factors influencing the occurrence of intraoperative hypothermia were analyzed. A survey was conducted to collect 5 demographic factors, 4 preoperative-related factors, and 10 surgically related factors. According to the occurrence of intraoperative hypothermia, the independent influencing factors of unplanned hypothermia during perioperative period were further analyzed. RESULTS Among 184 patients, 64 (34.78%) experienced perioperative unplanned hypothermia, of which 5 (7.81%) cases occurred before the start of surgery, 7 (10.94%) occurred before the start of surgery after anesthesia, and 52 (81.25%) occurred during surgery. Logistic regression analysis showed that body temperature at the beginning of surgery (P<0.001), set operating room temperature (P<0.001), duration of anesthesia (P=0.006), and age (P=0.001) were independent influencing factors for unplanned hypothermia during perioperative period. CONCLUSIONS The incidence of intraoperative hypothermia is high in patients undergoing general anesthesia interventions. Age, duration of anesthesia, set operating room temperature, and body temperature at the beginning of the operation were independent influencing factors for the occurrence of unplanned hypothermia during the perioperative period.


Assuntos
Hipotermia , Humanos , Hipotermia/etiologia , Hipotermia/complicações , Temperatura Corporal , Centros de Atenção Terciária , Estudos Retrospectivos , Anestesia Geral/efeitos adversos , Complicações Intraoperatórias/epidemiologia , Complicações Intraoperatórias/etiologia
13.
J Biol Rhythms ; 39(2): 166-182, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38317600

RESUMO

Accurate assessment of the intrinsic period of the human circadian pacemaker is essential for a quantitative understanding of how our circadian rhythms are synchronized to exposure to natural and man-made light-dark (LD) cycles. The gold standard method for assessing intrinsic period in humans is forced desynchrony (FD) which assumes that the confounding effect of lights-on assessment of intrinsic period is removed by scheduling sleep-wake and associated dim LD cycles to periods outside the range of entrainment of the circadian pacemaker. However, the observation that the mean period of free-running blind people is longer than the mean period of sighted people assessed by FD (24.50 ± 0.17 h vs 24.15 ± 0.20 h, p <0.001) appears inconsistent with this assertion. Here, we present a mathematical analysis using a simple parametric model of the circadian pacemaker with a sinusoidal velocity response curve (VRC) describing the effect of light on the speed of the oscillator. The analysis shows that the shorter period in FD may be explained by exquisite sensitivity of the human circadian pacemaker to low light intensities and a VRC with a larger advance region than delay region. The main implication of this analysis, which generates new and testable predictions, is that current quantitative models for predicting how light exposure affects entrainment of the human circadian system may not accurately capture the effect of dim light. The mathematical analysis generates new predictions which can be tested in laboratory experiments. These findings have implications for managing healthy entrainment of human circadian clocks in societies with abundant access to light sources with powerful biological effects.


Assuntos
Relógios Circadianos , Ritmo Circadiano , Humanos , Ritmo Circadiano/fisiologia , Temperatura Corporal/fisiologia , Sono/fisiologia , Luz , Fotofobia
14.
J Appl Physiol (1985) ; 136(4): 908-916, 2024 Apr 01.
Artigo em Inglês | MEDLINE | ID: mdl-38385185

RESUMO

The six cylinder thermoregulatory model (SCTM) has been validated thoroughly for resting humans. This type of modeling is helpful to predict and develop guidance for safe performance of work and recreational activities. In the context of a warming global climate, updating the accuracy of the model for intense exercise in warm environments will help a wide range of individuals in athletic, recreational, and military settings. Three sets of previously collected data were used to determine SCTM accuracy. Dataset 1: two groups [large (LG) 91.5 kg and small (SM) 67.7 kg] of individuals performed 60 min of semirecumbent cycling in temperate conditions (25.1°C) at metabolic rates of 570-700 W. Dataset 2: two LG (100 kg) and SM (65.8 kg) groups performed 60 min of semirecumbent cycling in warm/hot environmental conditions (36.2°C) at metabolic rates of 590-680 W. Dataset 3: seven volunteers completed 8-km track trials (∼30 min) in cool (17°C) and warm (30°C) environments. The volunteers' metabolic rates were estimated to be 1,268 W and 1,166 W, respectively. For all datasets, SCTM-predicted core temperatures were found to be similar to the observed core temperatures. The root mean square deviations (RMSDs) ranged from 0.06 to 0.46°C with an average of 0.2°C deviation, which is less than the acceptance threshold of 0.5°C. Thus, the present validation shows that SCTM predicts core temperatures with acceptable accuracy during intense exercise in warm environments and successfully captures core temperature differences between large and small individuals.NEW & NOTEWORTHY The SCTM has been validated thoroughly for resting humans in warm and cold environments and during water immersion. The present study further demonstrated that SCTM predicts core temperatures with acceptable accuracy during intense exercise up to 1,300 W in temperate and warm environments and captures core temperature differences between large and small individuals. SCTM is potentially useful to develop guidance for safe operation in athletic, military, and occupational settings during exposure to warm or hot environments.


Assuntos
Regulação da Temperatura Corporal , Esportes , Humanos , Regulação da Temperatura Corporal/fisiologia , Temperatura Corporal/fisiologia , Exercício Físico/fisiologia , Temperatura Baixa , Temperatura Alta
15.
Sci Rep ; 14(1): 4669, 2024 02 26.
Artigo em Inglês | MEDLINE | ID: mdl-38409133

RESUMO

Substantial evidence suggests that the circadian decline of core body temperature (CBT) triggers the initiation of human sleep, with CBT continuing to decrease during sleep. Although the connection between habitual sleep and CBT patterns is established, the impact of external body cooling on sleep remains poorly understood. The main aim of the present study is to show whether a decline in body temperatures during sleep can be related to an increase in slow wave sleep (N3). This three-center study on 72 individuals of varying age, sex, and BMI used an identical type of a high-heat capacity mattress as a reproducible, non-disturbing way of body cooling, accompanied by measurements of CBT and proximal back skin temperatures, heart rate and sleep (polysomnography). The main findings were an increase in nocturnal sleep stage N3 (7.5 ± 21.6 min/7.5 h, mean ± SD; p = 0.0038) and a decrease in heart rate (- 2.36 ± 1.08 bpm, mean ± SD; p < 0.0001); sleep stage REM did not change (p = 0.3564). Subjects with a greater degree of body cooling exhibited a significant increase in nocturnal N3 and a decrease in REM sleep, mainly in the second part of the night. In addition, these subjects showed a phase advance in the NREM-REM sleep cycle distribution of N3 and REM. Both effects were significantly associated with increased conductive inner heat transfer, indicated by an increased CBT- proximal back skin temperature -gradient, rather than with changes in CBT itself. Our findings reveal a previously far disregarded mechanism in sleep research that has potential therapeutic implications: Conductive body cooling during sleep is a reliable method for promoting N3 and reducing heart rate.


Assuntos
Sono de Ondas Lentas , Humanos , Frequência Cardíaca/fisiologia , Sono/fisiologia , Regulação da Temperatura Corporal , Temperatura Corporal/fisiologia , Fases do Sono/fisiologia
16.
J Therm Biol ; 119: 103810, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38350267

RESUMO

This study aimed to assess the effect of a phase-change material (PCM) cooling blanket for cooling between exercise bouts on recovery of physiological parameters and subsequent exercise performance in the heat. Eighteen male volunteers were recruited to participate in human trials involving two exhaustive treadmill running bouts (Bout1 for 3 km and Bout2 for 1.5 km) in a climate chamber (temperature = 33 °C; relative humidity = 40%). Participants were randomly subjected to one of two cooling conditions for a 10-min period between exercise bouts: CON: natural cooling; 10-min PCM: with a PCM cooling blanket for 10 min. Several physiological parameters including mean skin temperature (Tskin), oral temperature (Toral), core temperature (Tcore), heart rate (HR), mean arterial pressure (MAP), respiratory rate (RR), peripheral capillary oxygen saturation (SpO2), average running speed and rating of perceived exertion (RPE) scale score were analyzed. The results showed that compared to the CON group, participants in the 10-min PCM group had a significant lower Tskin, Tcore, HR and RR at post-cooling, as well as greater reductions in mean skin temperature (ΔTskin) and core temperature (ΔTcore) from post-Bout1 to post-cooling. Additionally, the 10-min PCM group exhibited significantly lower peak Tcore, peak HR and RPE scale score during Bout2, while the average running speed during Bout2 was significantly higher. The present study suggests that cooling with a PCM cooling blanket can enhance physiological recovery and subsequent exercise performance in the heat.


Assuntos
Temperatura Alta , Corrida , Humanos , Masculino , Temperatura Corporal/fisiologia , Regulação da Temperatura Corporal/fisiologia , Temperatura Baixa , Exercício Físico/fisiologia , Frequência Cardíaca/fisiologia , Corrida/fisiologia , Temperatura Cutânea , Estudos Cross-Over
17.
Sensors (Basel) ; 24(4)2024 Feb 19.
Artigo em Inglês | MEDLINE | ID: mdl-38400504

RESUMO

Addressing the increasing demand for remote patient monitoring, especially among the elderly and mobility-impaired, this study proposes the "ScalableDigitalHealth" (SDH) framework. The framework integrates smart digital health solutions with latency-aware edge computing autoscaling, providing a novel approach to remote patient monitoring. By leveraging IoT technology and application autoscaling, the "SDH" enables the real-time tracking of critical health parameters, such as ECG, body temperature, blood pressure, and oxygen saturation. These vital metrics are efficiently transmitted in real time to AWS cloud storage through a layered networking architecture. The contributions are two-fold: (1) establishing real-time remote patient monitoring and (2) developing a scalable architecture that features latency-aware horizontal pod autoscaling for containerized healthcare applications. The architecture incorporates a scalable IoT-based architecture and an innovative microservice autoscaling strategy in edge computing, driven by dynamic latency thresholds and enhanced by the integration of custom metrics. This work ensures heightened accessibility, cost-efficiency, and rapid responsiveness to patient needs, marking a significant leap forward in the field. By dynamically adjusting pod numbers based on latency, the system optimizes system responsiveness, particularly in edge computing's proximity-based processing. This innovative fusion of technologies not only revolutionizes remote healthcare delivery but also enhances Kubernetes performance, preventing unresponsiveness during high usage.


Assuntos
Conscientização , Benchmarking , Idoso , Humanos , Pressão Sanguínea , Temperatura Corporal , Monitorização Fisiológica
18.
J Therm Biol ; 119: 103790, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38354493

RESUMO

To evaluate the use of infrared thermography to assess the thermal status of heat-stressed and water-deprived Capra hircus, full-body surface temperature (TS) and six other body-thermal variables [core, rectal (TR), and skin (TSK) temperatures, respiratory and heart rates, and total body-thermal gradient (core-to-ambient, BTG)] were measured after three days of euhydration (EU), dehydration (DE), and rehydration (RE). Results revealed that the combined effect of heat stress and water deprivation had affected all tested variables including the TS, and once these animals gained access to water in the RE stage variables returned to their EU levels. Moreover, there were positive correlations between TS and all variables with the exception of BTG. From these six variables, only three variables (i.e. the TR, TSK, and BTG) during the DE stage and two variables (i.e. the TSK and BTG) throughout the experimental stages showed higher constancy (R2 ≥ 0 75, P < 0 001; agreement intervals ±1 96 95 % CI) with TS. However, BTG appeared more closely correlated with TS, representing the body-thermal status more realistically than other variables. In effect, the mean and thresholds of the BTG were predicted using the recorded TS and were within 0.02 °C of original estimates. Collectively, these findings show that infrared thermography is appropriate for assessing body-thermal status, and thus the welfare, of these animals under the three conditions studied, and conclude that full-body TS can be a surrogate proxy for BTG in these animals. Further experiments are needed to adequately examine the reproducibility of these results under biometeorologically-simulated environments and natural habitats.


Assuntos
Transtornos de Estresse por Calor , Termografia , Animais , Termografia/métodos , Desidratação/diagnóstico , Desidratação/veterinária , Privação de Água , Cabras , Reprodutibilidade dos Testes , Temperatura Corporal/fisiologia , Resposta ao Choque Térmico , Água
19.
Stress ; 27(1): 2320780, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38414377

RESUMO

Repeated stress is associated with an increased risk of developing psychiatric illnesses such as post-traumatic stress disorder (PTSD), which is more common in women, yet the neurobiology behind this sex difference is unknown. Habituation to repeated stress is impaired in PTSD, and recent preclinical studies have shown that female rats do not habituate as fully as male rats to repeated stress, which leads to impairments in cognition and sleep. Further research should examine sex differences after repeated stress in other relevant measures, such as body temperature and neural activity. In this study, we analyzed core body temperature and EEG power spectra in adult male and female rats during restraint, as well as during sleep transitions following stress. We found that core body temperature of male rats habituated to repeated restraint more fully than female rats. Additionally, we found that females had a higher average beta band power than males on both days of restraint, indicating higher levels of arousal. Lastly, we observed that females had lower delta band power than males during sleep transitions on Day 1 of restraint, however, females demonstrated higher delta band power than males by Day 5 of restraint. This suggests that it may take females longer to initiate sleep recovery compared with males. These findings indicate that there are differences in the physiological and neural processes of males and females after repeated stress. Understanding the way that the stress response is regulated in both sexes can provide insight into individualized treatment for stress-related disorders.


Assuntos
Temperatura Corporal , Caracteres Sexuais , Humanos , Ratos , Feminino , Masculino , Animais , Estresse Psicológico , Restrição Física , Cognição , Corticosterona
20.
J Exp Biol ; 227(4)2024 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-38299309

RESUMO

In nature, many organisms experience a daily range of body temperatures. Thermal performance at stable temperatures is often extrapolated to predict function in cyclical environments. However, temperature order and cyclicity may influence physiological processes. The current study compared energy intake, digestive passage time and energy budgets at a stable temperature (33°C) and two temperature cycles in lizards (Sceloporus consobrinus), to determine (1) whether stable treatments adequately project performance in a cycling environment and (2) whether temperature order influences performance. Cycles had a mean temperature of 33°C, and rotated through 30°C, 33°C and 36°C daily, with equal durations of time at each temperature but differing temperature order, with warm days and cool nights in cycle 1 and cool days and warm nights in cycle 2. For analyses, performance in the stable treatment was compared with that during cycles. If temperature is the primary factor regulating performance, then performance from the stable treatment and cycles should compare favorably. However, physiological performance varied based on temperature treatment. Energy intake and budgets were similar between the stable trial and cycle 1 but not cycle 2. However, passage time did not differ. Notably, the two cycling regimes consistently varied in performance, indicating that temperature order plays a primary role in regulating performance. Physiological data collection requires careful consideration of effects of cycling versus stable temperature treatments. Stable temperatures do not consistently represent performance in cycling regimes and consideration should be paid not only to which temperatures animals experience but also to how temperature is experienced in nature.


Assuntos
Lagartos , Animais , Temperatura , Lagartos/fisiologia , Pradaria , Temperatura Corporal , Temperatura Baixa
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...