Cold Environmental Temperatures Research Articles

Design of Temperature Monitoring and Stabilization System Based on Microcontroller for Outdoor Jacket in Cold Regions

The design of a temperature monitoring and stabilization system on a microcontroller based cold region outdoor jacket by utilizing microcontroller technology, by ensuring user comfort while in a cold temperature environment. This research is shown specifically in cold areas, with the aim of preventing hypothermia commonly experienced by climbers or humans, who are active in cold areas. The results of the system research on outdoor jackets that can monitor and stabilize the user's body temperature automatically, especially in cold areas. This system uses an ESP32 microcontroller, which is equipped with the Blynk application to control and monitor temperature using a smartphone. When the ambient temperature drops below 20°C, the system automatically activates the carbon fiber heating pad to maintain a stable body temperature. The jacket is designed to function offline, where the system will rely on the temperature sensor to activate the carbon fibre heating pad if the temperature drops below 20°C. Test results show that the system works well, providing efficient results in power consumption, responsive to temperature changes, and effective in maintaining temperature stability. The resulting jacket is comfortable and safe so that it does not interfere with outdoor jacket users in various conditions.

Development and Evaluation of Insulation Materials for Deepwater Cementing.

Marine oil and gas resources are abundant in deepwater regions, where the shallow seabed harbors natural gas hydrate layers due to the cold temperature and high-pressure environment. Hydrates are prone to thermal decomposition, which can compromise the integrity of cement sealing and even lead to accidents like blowouts. While current low-hydrated heat cement systems mitigate hydrate decomposition from cement hydration heat during the waiting period for cementing, they do not address heat transfer from deep strata to shallow hydrate layers through fluid circulation in the tubing during deep oil and gas development. Rather than utilizing costly pipe insulation technology, adjusting the thermal conductivity of well cement emerges as a cost-effective approach to prevent heat loss in the wellbore to the hydrate layer and thus inhibit hydrate decomposition. The critical aspect lies in utilizing insulation functional materials. This study delves into the functional and structural design of insulation materials suitable for cement slurry systems in well cementing, outlining the preparation methods and processes for two insulation materials (SDBW and SDBW-II) tailored for deepwater well cementing. SDBW and SDBW-II are both nuclear shell structural materials. The core is made of high-strength hollow microspheres, produced by using a reverse suspension polymerization method to form spheres followed by high-temperature sintering. The shell consists of a wear-resistant BPA epoxy resin layer, with the surface of SDBW-II also containing highly reflective glass microspheres. Incorporating 20% of material SDBW into the cement reduces the thermal conductivity of the cement stone from 0.8 to 0.31 W·(m·K)-1 while achieving a compressive strength of 6 MPa after 24 h at 20 °C. Material SDBW-II offers both thermal resistance and reflection functions, increasing reflectivity (R) from 0.3 to 0.5. By adding 20% of this material to the cement, under the same conditions, although the compressive strength decreases to 4.2 MPa, the thermal conductivity can be reduced to 0.27 W·(m·K)-1. Furthermore, there is no significant change within 180 days, demonstrating long-term thermal insulation stability. These developed insulation materials can effectively improve the thermal insulation performance of the cement sheath, thereby maintaining the stability of the upper natural gas hydrate layer in the oil and gas production process of deepwater wells, providing an innovative solution for the long-term operation of deepwater oil and gas wells.

Low temperature effect on cyclic behavior of shape memory alloy U-shaped dampers

Although Nickel-Titanium (NiTi) shape memory alloys (SMAs) have been widely studied as seismic response mitigation devices in civil structures, their temperature sensitivity due to the coupled thermo-mechanical behavior prevents their practical implementation in cold temperature environments. This paper investigated the effects of varying ambient temperatures (particularly low ambient temperature) on the hysteretic behavior and self-centering (SC) ability of shape memory alloy U-shaped dampers (SMAUDs) that were made of NiTi showing superelasticity (SE) at room temperature. Thermo-mechanical properties of SMAUDs were identified through differential scanning calorimetry (DSC) tests. Cyclic loading experiments on SMAUDs were conducted at a wide ambient temperature range from −40 °C to 20 °C. The variations in the hysteretic characteristics of the SMAUDs, including partial superelasticity (SE), strength, stiffness, SC, and energy dissipation capabilities, at different ambient temperatures were investigated. In general, the decreasing ambient temperature leads to the degradation of the SC ability. At ambient temperatures below the phase transformation temperature, the SMAUDs lose the SE but still maintain certain levels of strength and energy dissipation, which is different from common axial-type SMA elements. Meanwhile, the SMAUDs can restore their SC ability and strength after the recovery from low temperatures to room temperature, making them suitable for use in a cold environment.

Serca Uncoupling May Facilitate Cold Acclimation in Dark-Eyed Juncos (Junco hyemalis) without Regulation by Sarcolipin or Phospholamban.

Homeothermic endotherms defend their body temperature in cold environments using a number of behavioral and physiological mechanisms. Maintaining a stable body temperature primarily requires heat production through shivering or non-shivering thermogenesis (NST). Although the use of NST is well established in mammalian systems, the mechanisms and extent to which NST is used in birds are poorly understood. In mammals, one well-characterized mechanism of NST is through uncoupling of Ca2+ transport from ATP hydrolysis by sarco/endoplasmic reticulum ATPase (SERCA) in the skeletal muscle, which generates heat and may contribute to Ca2+ signaling for fatigue resistance and mitochondrial biogenesis. Two small proteins-sarcolipin (SLN) and phospholamban (PLN)-are known to regulate SERCA in mammals, but recent work shows inconsistent responses of SLN to cold acclimation in birds. In this study, we measured SERCA uncoupling in the pectoralis flight muscle of control (18°C) and cold-acclimated (-8°C) dark-eyed juncos (Junco hyemalis) that exhibited suppressed SLN transcription in the cold. We measured SERCA activity and Ca2+ uptake rates for the first time in cold-acclimated birds and found greater SERCA uncoupling in the muscle of juncos in the cold. However, SERCA uncoupling was not related to SLN or PLN transcription or measures of mitochondrial biogenesis. Nonetheless, SERCA uncoupling reduced an individual's risk of hypothermia in the cold. Therefore, while SERCA uncoupling in the cold could be indicative of NST, it does not appear to be mediated by known regulatory proteins in these birds. These results prompt interesting questions about the significance of SLN and PLN in birds and the role of SERCA uncoupling in response to environmental conditions.

Physiological adaptations to semi‐aquatic habits: the thermogenic macronutrient intake of the Eurasian otter

Abstract Maintaining thermal homeostasis in water is a major challenge for semi‐aquatic mammals, which entails morphological, behavioural and physiological adaptations. Foraging strategies and dietary‐induced thermogenesis (DIT) contribute to regulating body temperature in cold environments. As DIT differs among macronutrients, semi‐aquatic mammals may be expected to regulate their macronutrient ratios to enhance their capability of thermoregulating. We estimated the nutritional intake target of a widespread semi‐aquatic mustelid, Eurasian otter Lutra lutra by reviewing the available literature on otters' diet throughout Europe and assessing the nutritional composition of non‐commercial fish species forming the bulk of otter diet through laboratory analyses. The macronutrient intake target for the otter was assessed as 61% protein and 39% lipid energy ratios. The mean percent protein energy was higher than that reported for typical hypercarnivores and tended to increase with decreasing water temperatures. The additional source of heat provided by the thermogenic effect induced by protein digestion may contribute to balance heat loss, compensating for the costs associated with protein overconsumption. If, as suggested by fossil records, semi‐aquatic habits appeared after the development of otter's ‘fish specialist’ dentition, the thermogenic effect of its fish‐based diet may have promoted the tight relationship occurring between otters and water habitats.

Survival strategies of marine mammals in extreme environments: A study of whales and seals

Extreme environments, characterized by challenges such as sub-zero temperatures, limited sunlight and scarce resources, pose great challenges to organisms, including marine mammals. Marine mammals have evolved to live in extreme environments.These mammals are highly tolerant of cold and stress and can continue to breathe for long periods of time. The method used in this article is literature study by analyzing several articles. Marine mammals such as seals have a thick layer of fat. This adaptation reduces heat loss and helps maintain body temperature in cold environments. Cetaceans, like whales, have undergone fundamental morphological and molecular changes to adapt to the aquatic environment. Characteristic of these whales are their baleen plates and ability to communicate through vocal signals, forage socially, and migrate across much of the globe.

Physiological mechanisms associated with the use of a passive heat intervention: positive implications for soccer substitutes

PurposeSoccer substitutes are exposed to periods of limited activity before entering match-play, likely negating benefits of active warm-ups. This study aimed to determine the effects of using a passive heat intervention following a pre-match, and half-time warm-up, on muscle and core temperature in soccer players during ambient (18 °C) and cold (2 °C) conditions.MethodsOn four occasions, 8 male players, completed a pre-match warm-up, followed by 45 min of rest. Following this, participants completed a half-time re-warm-up followed by an additional 45 min of rest, simulating a full match for an unplaying substitute. During periods of rest, participants wore either standardised tracksuit bottoms (CON), or heated trousers (HEAT), over typical soccer attire.ResultsVastus lateralis temperature declined less in HEAT compared to CON following the 1st half in 2 °C (Δ − 4.39 ± 0.81 vs. − 6.21 ± 1.32 °C, P = 0.002) and 18 °C (Δ − 2.48 ± 0.71 vs. − 3.54 ± 0.88 °C, P = 0.003). These findings were also observed in the 2nd half for the 2 °C (Δ − 4.36 ± 1.03 vs. − 6.26 ± 1.04 °C, P = 0.002) and 18 °C (Δ − 2.85 ± 0.57 vs. − 4.06 ± 1 °C, P = 0.018) conditions. In addition, core temperature declined less in HEAT compared to CON following the 1st (Δ − 0.41 ± 0.25 vs. − 0.84 ± 0.41 °C, P = 0.037) and 2nd (Δ − 0.25 ± 0.33 vs. − 0.64 ± 0.34 °C, P = 0.028) halves of passive rest in 2 °C, with no differences in the 18 °C condition. Perceptual data confirmed that participants were more comfortable in HEAT vs. CON in 2 °C (P < 0.01).ConclusionsFollowing active warm-ups, heated trousers attenuate the decline in muscle temperature in ambient and cold environments.

Thermal Management of a LiFEPO4 Battery Pack in a Cold Temperature Environment Using Phase Change Materials (PCMs)

Thermal Management of a LiFEPO4 Battery Pack in a Cold Temperature Environment Using Phase Change Materials (PCMs)

Transcriptome Analysis Revealed Potential Genes of Skeletal Muscle Thermogenesis in Mashen Pigs and Large White Pigs under Cold Stress.

Pigs are susceptible to cold stress due to the absence of brown fat caused by the partial deletion of uncoupling protein 1 during their evolution. Some local pig breeds in China exhibit potential cold adaptability, but research has primarily focused on fat and intestinal tissues. Skeletal muscle plays a key role in adaptive thermogenesis in mammals, yet the molecular mechanism of cold adaptation in porcine skeletal muscle remains poorly understood. This study investigated the cold adaptability of two pig breeds, Mashen pigs (MS) and Large White pigs (LW), in a four-day cold (4 °C) or normal temperature (25 °C) environment. We recorded phenotypic changes and collected blood and longissimus dorsi muscle for transcriptome sequencing. Finally, the PRSS8 gene was randomly selected for functional exploration in porcine skeletal muscle satellite cells. A decrease in body temperature and body weight in both LW and MS pigs under cold stress, accompanied by increased shivering frequency and respiratory frequency, were observed. However, the MS pigs demonstrated stable physiological homeostasis, indicating a certain level of cold adaptability. The LW pigs primarily responded to cold stress by regulating their heat production and glycolipid energy metabolism. The MS pigs exhibited a distinct response to cold stress, involving the regulation of heat production, energy metabolism pathways, and robust mitochondrial activity, as well as a stronger immune response. Furthermore, the functional exploration of PRSS8 in porcine skeletal muscle satellite cells revealed that it affected cellular energy metabolism and thermogenesis by regulating ERK phosphorylation. These findings shed light on the diverse transcriptional responses of skeletal muscle in LW and MS pigs under cold stress, offering valuable insights into the molecular mechanisms underlying cold adaptation in pigs.

Oncogenic role of an uncharacterized cold-induced zinc finger protein 726 in breast cancer.

The unobtrusive cold environmental temperature can be linked to the development of cancer. This study, for the first time, envisaged cold stress-mediated induction of a zinc finger protein 726 (ZNF726) in breast cancer. However, the role of ZNF726 in tumorigenesis has not been defined. This study investigated the putative role of ZNF726 in breast cancer tumorigenic potency. Gene expression analysis using multifactorial cancer databases predicted overexpression of ZNF726 in various cancers, including breast cancer. Experimental observations found that malignant breast tissues and highly aggressive MDA-MB-231 cells showed an elevated ZNF726 expression as compared to benign and luminal A type (MCF-7), respectively. Furthermore, ZNF726 silencing decreased breast cancer cell proliferation, epithelial-mesenchymal transition, and invasion accompanied by the inhibition of colony-forming ability. Concordantly, ZNF726 overexpression significantly demonstrated opposite outcomes than ZNF726 knockdown. Taken together, our findings propose cold-inducible ZNF726 as a functional oncogene demonstrating its prominent role in facilitating breast tumorigenesis. An inverse correlation between environmental temperature and total serum cholesterol was observed in the previous study. Furthermore, experimental outcomes illustrate that cold stress elevated cholesterol content hinting at the involvement of the cholesterol regulatory pathway in cold-induced ZNF726 gene regulation. This observation was bolstered by a positive correlation between the expression of cholesterol-regulatory genes and ZNF726. Exogenous cholesterol treatment elevated ZNF726 transcript levels while knockdown of ZNF726 decreased the cholesterol content via downregulating various cholesterol regulatory gene expressions (e.g., SREBF1/2, HMGCoR, LDLR). Moreover, an underlying mechanism supporting cold-driven tumorigenesis is proposed through interdependent regulation of cholesterol regulatory pathway and cold-inducible ZNF726 expression.

Whole Blood Fatty Acid Profiles of Cold-Stunned Juvenile Green, Kemp’s Ridley, and Loggerhead Sea Turtles

When subjected to cold environmental temperatures, cheloniid sea turtles can experience debilitating lethargy, anorexia, and potential mortality in a phenomenon known as cold-stunning. Every year, hundreds to thousands of cold-stunned sea turtles are transported to rehabilitation centers for medical and nutritional care. The objective of this study was to investigate one aspect of nutritional status in cold-stunned sea turtles: fatty acid profiles. Blood was collected from eleven green (Chelonia mydas), twelve Kemp’s ridley (Lepidochelys kempii), and three loggerhead (Caretta caretta) juvenile sea turtles found cold-stunned along the coast of North Carolina, USA. Whole blood (~160 µL) was dried onto specialized paper spot cards, frozen, and subsequently analyzed via gas chromatography to quantify fatty acid percentages. Significant differences among species were identified for 19 out of 36 individual fatty acids analyzed and six out of seven fatty acid groups evaluated (P &lt; 0.5). The whole blood fatty acid profiles of cold-stunned green and Kemp’s ridley sea turtles were similar to prior published profiles of healthy conspecifics. Marginal numerical differences noted upon visual comparison included that cold-stunned sea turtles had lower proportions of total polyunsaturated fatty acids (PUFA) and monoenes and higher proportions of total saturated fatty acids relative to healthy conspecifics. These differences may reflect acute impacts of cold-stunning on circulating plasma fatty acids or may be the result of natural seasonal variations. These data provide practical information to aid in the diet design of sea turtles in rehabilitation settings.

Resistance to mild cold stress is greater in both wild-type and long-lived GHR-KO female mice.

Adapting to stress, including cold environmental temperature (eT), is crucial for the survival of mammals, especially small rodents. Long-lived mutant mice have enhanced stress resistance against oxidative and non-oxidative challenges. However, much less is known about the response of those long-lived mice to cold stress. Growth hormone receptor knockout (GHR-KO) mice are long-lived with reduced growth hormone signaling. We wanted to test whether GHR-KO mice have enhanced resistance to cold stress. To examine the response of GHR-KO mice to cold eT, GHR-KO mice were housed at mild cold eT (16°C) immediately following weaning. Longevity results showed that female GHR-KO and wild-type (WT) mice retained similar lifespan, while both male GHR-KO and WT mice had shortened lifespan compared to the mice housed at 23°C eT. Female GHR-KO and WT mice housed at 16°C had upregulated fibroblast growth factor 21 (FGF21), enhanced energy metabolism, reduced plasma triglycerides, and increased mRNA expression of some xenobiotic enzymes compared to females housed at 23°C and male GHR-KO and WT mice housed under the same condition. In contrast, male GHR-KO and WT mice housed at 16°C showed deleterious effects in parameters which might be associated with their shortened longevity compared to male GHR-KO and WT mice housed at 23°C. Together, this study suggests that in response to mild cold stress, sex plays a pivotal role in the regulation of longevity, and female GHR-KO and WT mice are more resistant to this challenge than the males.

Of Heat &amp; Arctic Blasts - The Risks to Human Health

The run-up to the FIFIA World Cup football tournament in Qatar and the significant rise in fuel costs has focussed the world’s attention on the environmental impact of climate change on human health. While it is true that the health impact of working outdoors in extreme heat is indeed harmful to human health and leads in increase mortality, what has been less in the news is (1) that the impact of even moderately cold environmental temperatures is by far much larger (9:1) on environmental determinants of mortality for vulnerable sections of the population, even in high-income countries such as UK or USA, and (2) that multi-factorial deprivation, fuelled by a legacy of imperialism, racism, oppression of migrants and socio-cultural exclusion in all societies vastly amplifies the adverse impact on health.&#x0D; Considerable attention has focused on institutional racism but less on how the intersection of cultural values, frameworks, and meanings shapes institutional policies and practices. [1] This article explores the impact of environmental temperatures on human health, the influence of socio-cultural inequalities, the current interventions and the case for a policy approach that includes the voice of professional and voluntary groups representing minority groups.

Effect of Cold Temperature Environment on Fruit Juice Samples during Storage

Vitamin C in different citrus juice samples were investigated; Citrus Limon, Citrus reticulate, Citrus paradise, and Citrus sinensis. Iodine titration was utilized for the determination of vitamin C in the different samples. The highest amount of vitamin C concentration observed in Citrus sinensis was 95 mg / 100 ml whereas Citrus reticulate showed low levels of 82 mg / 100 ml. The same tendency was observed in packed citrus juice, with the effect of cold temperature as though the content of vitamin C was less than in fresh citrus juice. Results revealed that; there is a loss of vitamin C content in all four storage conditions (days), Vitamin C reduces differently in citrus juice samples stored in different conditions. On the Fourth day Table 1. The rate at which vitamin C is lost depends on the temperature and time methods employed. It has been found that the hot environment provides the conditions for fast decay of vitamin C content and the room environment provides the conditions for slow decay of vitamin C content. In present analyzed samples values are different because of the fact that the composition of content vitamin c depends upon environmental factors. Hence it is always suggested to consume fresh juice rather than packed and stored one.

Prebiotic Vesicles Retain Solutes and Grow by Micelle Addition after Brief Cooling below the Membrane Melting Temperature.

Replication of RNA genomes within membrane vesicles may have been a critical step in the development of protocells on the early Earth. Cold temperatures near 0 °C improve the stability of RNA and allow efficient copying, while some climate models suggest a cold early Earth, so the first protocells may have arisen in cold-temperature environments. However, at cold temperatures, saturated fatty acids, which would have been available on the early Earth, form gel-phase membranes that are rigid and restrict mobility within the bilayer. Two primary roles of protocell membranes are to encapsulate solutes and to grow by incorporating additional fatty acids from the environment. We test here whether fatty acid membranes in the gel phase accomplish these roles. We find that gel-phase membranes of 10-carbon amphiphiles near 0 °C encapsulate aqueous dye molecules as efficiently as fluid-phase membranes do, but the contents are released if the aqueous solution is frozen at -20 °C. Gel-phase membranes do not grow measurably by micelle addition, but growth resumes when membranes are warmed above the gel-liquid transition temperature. We find that longer, 12-carbon amphiphiles do not retain encapsulated contents near 0 °C. Together, our results suggest that protocells could have developed within environments that experience temporary cooling below the membrane melting temperature, and that membranes composed of relatively short-chain fatty acids would encapsulate solutes more efficiently as temperatures approached 0 °C.

Effect of oral administration of GABA on thermoregulation in athletes during exercise in cold environments: A preliminary study.

Backgroundγ-aminobutyric acid (GABA), a common ingredient in sports supplements and other health products, regulates body temperature in the preoptic area and anterior hypothalamus (PO/AH). To date, no study has examined the effect of GABA on thermoregulation during exercise in humans in a cold temperature environment (11 ± 0.3°C, 45% ± 2% relative humidity).MethodsWe performed a randomized, double-blind study. Ten trained male athletes consumed either a drink (3 ml/kg weight) containing GABA (1,000 mg, trial G) or an equivalent amount of placebo drink (trial C) before exercise. They rested for 20 min and then cycled at 60% of maximum output power for 40 min, pedaling at 60 rpm, and recovered for 20 min. Core temperature (Tc), skin temperature (upper arm, chest, thigh, calf), and heart rate (HR) were monitored at rest (T0), exercise begins (T20), 20 min of exercise (T40), the exercise ends (T60), and at recovery (T80).ResultsCompared to T0, Tc decreased significantly at T20 and increased significantly at T40, T60 and T80 (p < 0.01). From 35–80 min, the Tc was higher in trial G (peaked at 37.96 ± 0.25°C) than in trial C (37.89 ± 0.37°C), but it failed to reach significant difference (p > 0.05); Tsk continued to increase during exercise and was significantly higher than T0 at T40 (p < 0.05), T60 and T80 (p < 0.01). There was no significant difference in Tsk between the two trials (p > 0.05).ConclusionOur findings provide initial evidence that oral administration of GABA does not affect thermoregulation and has no adverse effects on the body as an ergogenic exercise supplement during exercise in cold environments.

Identification of Key Candidate Genes in Runs of Homozygosity of the Genome of Two Chicken Breeds, Associated with Cold Adaptation.

Simple SummaryThe search for genomic regions related to adaptive abilities preserved in the chicken gene pool of two breeds, which have not been under intensive selection pressure, is of great importance for breeding in the future. This study aimed to identify key candidate genes associated with the adaptation of chickens to cold environments (using the example of the Russian White breed) by using molecular genetic methods. A total of 12 key genes on breed-specific ROH (runs of homozygosity) islands were identified, which may be potential candidate genes associated with the high level of adaptability of chickens to cold environments in the early postnatal period. These genes were associated with lipid metabolism, maintaining body temperature in cold environments, non-shivering thermogenesis and muscle development and are perspectives for further research.It is well known that the chicken gene pools have high adaptive abilities, including adaptation to cold environments. This research aimed to study the genomic distribution of runs of homozygosity (ROH) in a population of Russian White (RW) chickens as a result of selection for adaptation to cold environments in the early postnatal period, to perform a structural annotation of the discovered breed-specific regions of the genome (compared to chickens of the Amroks breed) and to suggest key candidate genes associated with the adaptation of RW chickens to cold environments. Genotyping of individual samples was performed using Illumina Chicken 60K SNP BeadChip® chips. The search for homozygous regions by individual chromosomes was carried out using the PLINK 1.9 program and the detectRuns R package. Twelve key genes on breed-specific ROH islands were identified. They may be considered as potential candidate genes associated with the high adaptive ability of chickens in cold environments in the early postnatal period. Genes associated with lipid metabolism (SOCS3, NDUFA4, TXNRD2, IGFBP 1, IGFBP 3), maintaining body temperature in cold environments (ADIPOQ, GCGR, TRPM2), non-shivering thermogenesis (RYR2, CAMK2G, STK25) and muscle development (METTL21C) are perspectives for further research. This study contributes to our understanding of the mechanisms of adaptation to cold environments in chickens and provides a molecular basis for selection work.

Direct access to NiCo-LDH nanosheets by electrochemical-scanning-mediated hydrolysis for photothermally enhanced energy storage capacity

With the wide application of supercapacitors, it has been recognized that the drop of energy storage capacity due to cold environmental temperatures limits their utilization efficiency. In this study, a binder-free Ni/Co-layered double hydroxide (LDH)-based high-performance energy storage device is constructed on Ni foam by in situ electrochemically triggered MOF hydrolysis, which exhibits a remarkably enhanced capacity under solar irradiation. Through electrochemically controlled hydrolysis, the ligands in MOFs are replaced by OH–, and the obtained NiCo-LDH retains the original hierarchical porous structure of the MOFs. Benefitting from the sufficient oxygen vacancies and large surface area, the NiCo-LDH electrode shows a high capacity of 5.4 C cm–2 at 1.25 mA cm–2, which is 64.3 times higher than that of the MOF template. Importantly, the excellent photothermal conversion ability (temperature increase of 52.9 °C within only 30 s) under solar irradiation increases the capacity to 226.0% even at sub-freezing temperature. Furthermore, the asymmetric supercapacitor fabricated using NiCo-LDH delivers an energy density increase of 329.2% in a low-temperature environment (−4 °C) after 15 min solar-light irradiation.

Evolution of incidence of chilblain-like lesions in children during the first year of COVID-19 pandemic.

BackgroundThe COVID‐19 pandemic has brought innumerable reports of chilblains. The relation between pernio‐like acral eruptions and COVID‐19 has not been fully elucidated because most reported cases have occurred in patients with negative microbiological tests for SARS‐CoV‐2.MethodsA retrospective study of 49 cases of chilblains seen during the first year of the pandemic in a children's hospital in Madrid, Spain. The incidence of these skin lesions was correlated with the number of COVID‐19 admissions and environmental temperatures. Patients were separated into two groups depending on the day of onset (strict lockdown period vs. outside the lockdown period).ResultsMost chilblains cases presented during the first and third waves of the pandemic, paralleling the number of COVID‐19 admissions. The first wave coincided with a strict lockdown, and the third wave coincided with the lowest ambient seasonal temperatures of the year. Systemic symptoms preceding chilblains were more frequent in the first wave (45.8% vs. 8.0%, p = .002), as was the co‐occurrence with erythema multiforme‐like lesions (16.7% vs. 0%, p = .033). Laboratory test and skin biopsies were performed more frequently in the first wave (75.0% vs. 12.0%, p < .001; and 25.0% vs. 0%, p = .007; respectively). Five patients developed recurrent cutaneous symptoms.ConclusionsAn increased incidence of chilblains coincided not only with the two major waves of the pandemic, but also with the strict lockdown period in the first wave and low seasonal temperatures during the third wave. Both increased sedentary behaviors and cold environmental temperatures may have played an additive role in the development of COVID‐19‐related chilblains.

Hibernation with rhythmicity: the circadian clock and hormonal adaptations of the hibernating Asiatic toads (Bufo gargarizans).

Hibernation is one of the fundamental strategies in response to cold environmental temperatures. During hibernation, the endocrine and circadian systems ensure minimal expenditure of energy for survival. The circadian rhythms of key hormones, melatonin (MT), corticosterone (CORT), triiodothyronine (T3 ), and thyroxine (T4 ), and the underlying molecular regulatory mechanisms of hibernation have been well determined in mammals but not in ectotherms. Here, a terrestrial hibernating species, Asiatic toad (Bufo gargarizans), was employed to investigate the plasma CORT, MT, T3 , and T4 ; and the retina, brain, and liver mRNA expression of the core clock genes, including circadian locomotor output cycles kaput (Clock), brain and muscle ARNT-like 1 (Bmal1), cryptochrome (Cry) 1 and 2, and period (Per) 1 and 2, at 7-time points over a 24-h period under acute cold (1 day at 4°C), and hibernation (45 days at 4°C). Our results showed that the circadian rhythms of the core clock genes were rather unaffected by acute cold exposure in the retina, unlike the brain and liver. In contrast, during hibernation, the liver clock genes displayed significant circadian oscillations, while those in the retina and brain stopped ticking. Furthermore, plasma CORT expressed circadian oscillations in both groups, and T3 in acute cold exposure group, whereas T4 and MT did not. Our results reveal that the plasma CORT and the liver sustain rhythmicity when the brain was not, indicating that the liver clock along with the adrenal clock synergistically maintains the metabolic requirements to ensure basic survival in hibernating Asiatic toads.