Journal of thermal biology最新文献_第3页

Microhabitat selection and thermoregulation in amazonian dragonflies 亚马逊蜻蜓的微生境选择和体温调节

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103998

Suellen Furtado Vinagre , Lenize Batista Calvão , Alex Córdoba-Aguilar , Rhainer Guillermo Ferreira , e Leandro Juen

Insect eco-physiological traits are important for understanding their distribution and habitat selection, especially in the face of land use change. We estimated the average temperature of the thoracic surface of 20 Odonata (Insecta) species and classified them into thermoregulation categories according to their preferences for sunny or shaded habitats to assess their temperature variation. We tested the influence of air temperature and six morphological metrics related to thorax and abdomen size. We expected that: (i) heliothermic species would have higher thoracic temperatures compared to thermoconformer species; (ii) Zygopterans, due to their smaller body size, are less efficient at maintaining a constant body temperature relative to the air when compared to anisopterans; (iii) thorax volume would cause an increase in Odonata thoracic temperature, and abdomen length would cause a decrease. The study was conducted at 18 Amazonian streams in Eastern Amazonia. We observed differences of 2.5 °C in thoracic temperature between heliothermic and thermoconformer species, as predicted in the first hypothesis. Both suborders, Zygoptera and Anisoptera, use different morphological and environmental variables to control temperature. While Zygoptera thoracic temperature oscillated near and below air temperature (−1.28 ± 0.62), Anisoptera maintained temperatures above air temperature (1.81 ± 1.96). Air temperature influenced only the increase in Zygoptera thoracic temperature, supporting our second hypothesis. The third hypothesis was corroborated for order Odonata, but partially for its suborders. Zygoptera thoracic temperature was only related to abdomen length, which was proportional to a temperature decrease. Anisoptera temperature showed a relationship only with thoracic metrics, especially thorax volume, which had a significant contribution to temperature increase. Despite the observed differences, which varied according to size, we noted exceptions in the thermal characteristics of some species that deviated from these predictions. Therefore, we emphasize the importance of considering the interaction of other eco-physiological aspects in dragonfly temperature regulation.

昆虫的生态生理特征对于了解其分布和生境选择非常重要，尤其是在土地利用发生变化的情况下。我们估算了20种蜻蜓（昆虫纲）胸腔表面的平均温度，并根据它们对阳光充足或荫蔽生境的偏好将它们划分为体温调节类别，以评估它们的温度变化。我们测试了气温以及与胸部和腹部大小相关的六个形态指标的影响。我们预计(i) 与变温物种相比，日温物种的胸腔温度较高；(ii) 与无翅类动物相比，颧翅类动物由于体型较小，维持相对于空气的恒定体温的效率较低；(iii) 胸部体积会导致蜻蜓胸腔温度升高，而腹部长度会导致胸腔温度降低。这项研究在东亚马孙流域的 18 条亚马孙溪流进行。正如第一个假设所预测的那样，我们观察到日温型和变温型物种的胸腔温度相差 2.5 °C。鞘翅目和蝶亚目都使用不同的形态和环境变量来控制温度。鞘翅目胸腔温度在气温附近和气温以下波动（-1.28 ± 0.62），而无翅目则保持在气温以上（1.81 ± 1.96）。气温只影响鞘翅目胸腔温度的升高，这支持了我们的第二个假设。第三个假设在鸟纲得到了证实，但在其亚纲中只得到了部分证实。鞘翅目胸腔温度只与腹部长度有关，腹部长度与温度下降成正比。鞘翅目的温度仅与胸部指标有关，尤其是胸部体积，它对温度升高有显著作用。尽管观察到的差异因体型大小而异，但我们注意到一些物种的热特征与上述预测存在偏差。因此，我们强调在蜻蜓温度调节过程中考虑其他生态生理方面的相互作用的重要性。

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引用次数: 0

Seasonal and depth-dependent thermoregulatory benefits of burrows for wombats – The largest burrowing marsupials 袋熊洞穴随季节和深度而变化的体温调节功能 - 最大的穴居有袋类动物

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103961

Shane D. Morris , Christopher N. Johnson , Barry W. Brook , Michael R. Kearney

Mammals use burrows to behaviourally thermoregulate, save water, and avoid predation. The advantages of burrows vary not only seasonally but also with burrow depth. To quantify these effects, we used biophysical ecological models, which predict an animal's energetic and hydric costs within a characterised microclimate. For Australia's three extant wombat species, we quantified variation in the energetic advantage of burrows spatially, temporally, and with burrow depth. We simulated resting wombats with different traits (e.g., body size, fur) in different microclimates (above ground and burrows of varying depth) at six sites across Australia, two for each wombat species, over five years (1980, 1990, 2000, 2010, 2020). We assessed time spent within their thermoneutral zone—heat production equals heat loss thus minimising energy and water expenditure —and frequency of extreme heat stress (i.e., no viable hydric solution for the conditions stipulated). Our findings show that burrows are essential for reducing energetic and hydric costs and for survival during the hottest season in areas with no shade, e.g., the semi-arid zone. We found no evidence that extreme heat stress has increased temporally i.e., due to climate change, but it was frequently predicted in shallow burrows in 2020, having rarely been previously forecast. For energy requirements, we found lower thermoregulatory costs for deeper burrows in the cold season and for shallow burrows in the hot season. This work underscores the critical balance between wombat survival, burrow utility, and environmental dynamics, offering new insights into mechanisms that dictate mammal behaviour from a thermoregulatory perspective.

哺乳动物利用洞穴进行行为体温调节、节约用水和避免捕食。洞穴的优势不仅随季节变化，而且随洞穴深度变化。为了量化这些影响，我们使用了生物物理生态模型，该模型可以预测动物在特定小气候条件下的能量和水分成本。对于澳大利亚现存的三种袋熊，我们对洞穴的能量优势在空间、时间和洞穴深度上的变化进行了量化。我们在澳大利亚的六个地点模拟了不同特征（如体型、皮毛）的袋熊在不同微气候（地面和不同深度的洞穴）下的休息情况，每个袋熊物种有两个地点，历时五年（1980、1990、2000、2010、2020）。我们评估了袋熊在热中性区（产热量等于散热量，从而最大限度地减少能量和水分消耗）内所花费的时间，以及极端热应激（即在规定条件下没有可行的水力解决方案）的频率。我们的研究结果表明，洞穴对于降低能量和水力成本以及在最炎热季节在无遮荫地区（如半干旱地区）生存至关重要。我们没有发现极端热应激在时间上增加的证据，即由于气候变化，但2020年在浅洞穴中经常出现极端热应激，而以前很少预测到。在能量需求方面，我们发现寒冷季节较深洞穴的体温调节成本较低，而炎热季节较浅洞穴的体温调节成本较高。这项研究强调了袋熊生存、洞穴效用和环境动态之间的关键平衡，从体温调节的角度为哺乳动物行为的决定机制提供了新的见解。

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引用次数: 0

Increased offspring size and reduced gestation length in an ectothermic vertebrate under a worst-case climate change scenario 在最坏的气候变化情况下，外温脊椎动物的后代体型增大，妊娠期缩短。

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103990

David L. Hubert , Ehren J. Bentz , Robert T. Mason

As global temperatures continue to rise, understanding the impacts of warming environments has become increasingly important. Temperature is especially relevant for ectothermic organisms which depend upon consistent and predictable annual temperature cycles for reproduction and development. However, additional research is required in this area to elucidate the potential impacts of climate change on future generations. To understand how projected increases in environmental temperatures may impact reproductive outcomes within natural populations of ectothermic vertebrates, we manipulated minimum ambient temperatures during gestation in Red-sided garter snakes (Thamnophis sirtalis parietalis). Wild snakes were collected in the Interlake region of Manitoba, Canada during their spring mating season and allowed to mate in controlled conditions. For the duration of gestation, mated females were placed into one of two ambient thermal conditions: temperatures emulating those found in the species’ natural habitat or temperatures with a consistent 5 °C increase to match end-of-century climate change projections. We recorded observations for each litter and all neonates resulting from controlled mating trials. We observed no difference in litter sizes or birth rates between thermal conditions. However, we observed a significant reduction in gestation length and significant increase to neonate body mass and body condition associated with increased ambient temperatures. These results suggest that increased minimum temperatures during gestation may confer reproductive benefits for the northern populations of this species even under the most extreme current modeled warming predictions. We discuss the broader implications of this effect, including possible negative ecological outcomes.

随着全球气温持续上升，了解环境变暖的影响变得越来越重要。温度对体外温度生物尤其重要，因为它们的繁殖和发育依赖于稳定和可预测的年度温度周期。然而，要阐明气候变化对后代的潜在影响，还需要在这一领域开展更多的研究。为了了解预计的环境温度升高会如何影响外温脊椎动物自然种群的繁殖结果，我们对红边吊带蛇（Thamnophis sirtalis parietalis）妊娠期间的最低环境温度进行了控制。在春季交配季节，我们在加拿大马尼托巴省的湖间地区采集了野生蛇，并让它们在受控条件下交配。在妊娠期间，交配后的雌蛇被置于两种环境温度条件中的一种：仿照该物种自然栖息地的温度或根据本世纪末气候变化预测持续升高5 °C的温度。我们对控制交配试验产生的每一窝雏鸟和所有新生儿进行了观察记录。我们观察到，不同温度条件下的产仔数和出生率没有差异。但是，我们观察到，随着环境温度的升高，妊娠期明显缩短，新生儿的体重和身体状况明显增加。这些结果表明，即使在目前最极端的气候变暖模型预测下，妊娠期最低气温的升高也可能会给该物种的北方种群带来繁殖益处。我们讨论了这种效应的广泛影响，包括可能的负面生态结果。

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引用次数: 0

Advances in understanding Lepidoptera cold tolerance 在了解鳞翅目昆虫耐寒性方面取得的进展

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103992

Hamzeh Izadi , Ross N. Cuthbert , Phillip J. Haubrock , David Renault

Ambient thermal conditions mediate insect growth, development, reproduction, survival, and distribution. With increasingly frequent and severe cold spells, it is critical to determine low-temperature performance and cold tolerances of ecologically and economically essential insect groups to predict their responses to global environmental change. This review covers the cold tolerance strategies of 49 species of Lepidoptera (moths and butterflies), focusing on species that are known as crop pests and crop storage facilities. We synthesize cold tolerance strategies of well-studied species within this order, finding that diapause is a distinctive mechanism that has independently evolved in different genera and families of Lepidoptera. However, the occurrence of diapause in each life stage is specific to the species, and in most studied lepidopteran species, the feeding stage (as larva) is the predominant overwintering stage. We also found that the onset of diapause and the improvement of cold tolerance are interdependent phenomena that typically occur together. Moreover, adopting a cold tolerance strategy is not an inherent, fixed trait and is greatly influenced by a species' geographic distribution and rearing conditions. This review further finds that freeze avoidance rather than freeze tolerance or chill susceptibility is the primary cold tolerance strategy among lepidopteran species. The cold hardiness of lepidopteran insects primarily depends on the accumulation of cryoprotectants and the depression of the supercooling point. We highlight variations in cold tolerance strategies and mechanisms among a subset of Lepidoptera, however, further work is needed to elucidate these strategies for the vast numbers of neglected species and populations to understand broad-scale responses to global change.

环境温度条件对昆虫的生长、发育、繁殖、存活和分布起着中介作用。随着寒流日益频繁和严重，确定生态和经济上重要的昆虫类群的低温性能和耐寒性以预测它们对全球环境变化的反应至关重要。本综述涵盖 49 种鳞翅目昆虫（飞蛾和蝴蝶）的耐寒策略，重点关注已知的作物害虫和作物储藏设施物种。我们综合了鳞翅目中已被充分研究的物种的耐寒策略，发现在鳞翅目的不同属和科中，停歇是一种独立进化的独特机制。然而，在每个生命阶段出现的停歇是因物种而异的，在大多数已研究的鳞翅目物种中，觅食阶段（幼虫）是主要的越冬阶段。我们还发现，开始停歇和提高耐寒性是相互依存的现象，通常同时发生。此外，采取耐寒策略并不是一种固有的、固定的性状，在很大程度上受到物种的地理分布和饲养条件的影响。本综述进一步发现，鳞翅目物种的主要耐寒策略是避冻，而不是耐冻或易受寒。鳞翅目昆虫的耐寒性主要取决于低温保护剂的积累和过冷点的降低。我们强调了一部分鳞翅目昆虫在耐寒策略和机制方面的差异，然而，要了解鳞翅目昆虫对全球变化的广泛响应，还需要进一步的工作来阐明大量被忽视的物种和种群的耐寒策略。

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引用次数: 0

Validity of the estimated core temperature algorithm during real-world prolonged walking exercise under warm ambient conditions 在温暖环境条件下进行真实世界长时间步行运动时估计核心温度算法的有效性。

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103982

Mandy A.G. Peggen , Coen C.W.G. Bongers , Johannus Q. de Korte , Bertil J. Veenstra , Koen Levels , Maria T.E. Hopman , Thijs M.H. Eijsvogels

Background

Non-invasive methods to estimate core body temperature (T_C) are increasingly available. We examined the group-level and individual participant-level validity of the Estimated Core Temperature (ECTemp™) algorithm to estimate T_C based on sequential heart rate (HR) measurements during real-world prolonged walking exercise in warm ambient conditions.

Methods

Participants walked 30 (n = 3), 40 (n = 13) or 50 (n = 2) km on a self-selected pace during which T_C was measured every minute using an ingestible temperature capsule. HR was measured every second and used to compute the estimated core temperature (T_C-est) using the ECTemp™ algorithm. Bland-Altman analyses were performed to assess agreement between T_C and T_C-est. A systematic bias <0.1 °C was considered acceptable.

Results

18 participants (56 ± 16 years, 11 males) walked for 549 min (range 418–645 min), while ambient temperature increased from 22 °C to 29 °C. Average HR was 108 ± 13 bpm and T_C ranged from 36.9 to 39.2 °C, whereas T_C-est ranged from 36.8 to 38.9 °C (n = 8572 observations). Group level data revealed a systematic bias of 0.09 °C (p < 0.001) with limits of agreements of ±0.44 °C. A weak correlation was found between T_C and T_C-est (r = 0.28; p < 0.001). Large inter-individual differences in bias (range −0.45 °C to 0.62 °C) and correlation coefficients (range −0.09 to 0.95) were found, while only 3 participants (17%) had an acceptable systemic bias of <0.1 °C.

Conclusion

Group level data showed that the ECTemp™ algorithm had an acceptable systematic bias during prolonged walking exercise in warm ambient conditions, but only 3 out of 18 participants had an acceptable systemic bias. Future studies are needed to improve the accuracy of the algorithm before individual users can rely on their estimated T_C during real-world exercise.

背景：估计核心体温（TC）的无创方法越来越多。我们研究了在温暖环境条件下进行真实世界长时间步行运动时，根据连续心率（HR）测量结果估算核心体温（ECTemp™）算法在群体和个体参与者层面的有效性：方法：参与者以自选速度步行 30（n = 3）、40（n = 13）或 50（n = 2）公里，期间每分钟使用可摄入体温胶囊测量一次体温。每秒测量一次心率，并使用 ECTemp™ 算法计算估计核心温度（TC-est）。为评估 TC 和 TC-est 之间的一致性，进行了 Bland-Altman 分析。系统性偏差结果：18 名参与者（56 ± 16 岁，11 名男性）行走了 549 分钟（418-645 分钟不等），环境温度从 22 °C 升至 29 °C。平均心率为 108 ± 13 bpm，TC 范围为 36.9 至 39.2 °C，TC-est 范围为 36.8 至 38.9 °C（n = 8572 个观测值）。组级数据显示系统偏差为 0.09 °C（p C），TC-est（r = 0.28；p 结论：ECT 和 TC-est 的系统偏差为 0.09 °C（p C）：组级数据显示，在温暖环境条件下进行长时间步行运动时，ECTemp™ 算法具有可接受的系统偏差，但 18 名参与者中只有 3 人具有可接受的系统偏差。未来的研究需要提高该算法的准确性，才能让个人用户在实际运动中依赖其估计的血压。

{"title":"Validity of the estimated core temperature algorithm during real-world prolonged walking exercise under warm ambient conditions","authors":"Mandy A.G. Peggen , Coen C.W.G. Bongers , Johannus Q. de Korte , Bertil J. Veenstra , Koen Levels , Maria T.E. Hopman , Thijs M.H. Eijsvogels","doi":"10.1016/j.jtherbio.2024.103982","DOIUrl":"10.1016/j.jtherbio.2024.103982","url":null,"abstract":"<div><h3>Background</h3><div>Non-invasive methods to estimate core body temperature (T<sub>C</sub>) are increasingly available. We examined the group-level and individual participant-level validity of the Estimated Core Temperature (ECTemp™) algorithm to estimate T<sub>C</sub> based on sequential heart rate (HR) measurements during real-world prolonged walking exercise in warm ambient conditions.</div></div><div><h3>Methods</h3><div>Participants walked 30 (n = 3), 40 (n = 13) or 50 (n = 2) km on a self-selected pace during which T<sub>C</sub> was measured every minute using an ingestible temperature capsule. HR was measured every second and used to compute the estimated core temperature (T<sub>C-est</sub>) using the ECTemp™ algorithm. Bland-Altman analyses were performed to assess agreement between T<sub>C</sub> and T<sub>C-est</sub>. A systematic bias <0.1 °C was considered acceptable.</div></div><div><h3>Results</h3><div>18 participants (56 ± 16 years, 11 males) walked for 549 min (range 418–645 min), while ambient temperature increased from 22 °C to 29 °C. Average HR was 108 ± 13 bpm and T<sub>C</sub> ranged from 36.9 to 39.2 °C, whereas T<sub>C-est</sub> ranged from 36.8 to 38.9 °C (n = 8572 observations). Group level data revealed a systematic bias of 0.09 °C (p < 0.001) with limits of agreements of ±0.44 °C. A weak correlation was found between T<sub>C</sub> and T<sub>C-est</sub> (r = 0.28; p < 0.001). Large inter-individual differences in bias (range −0.45 °C to 0.62 °C) and correlation coefficients (range −0.09 to 0.95) were found, while only 3 participants (17%) had an acceptable systemic bias of <0.1 °C.</div></div><div><h3>Conclusion</h3><div>Group level data showed that the ECTemp™ algorithm had an acceptable systematic bias during prolonged walking exercise in warm ambient conditions, but only 3 out of 18 participants had an acceptable systemic bias. Future studies are needed to improve the accuracy of the algorithm before individual users can rely on their estimated T<sub>C</sub> during real-world exercise.</div></div>","PeriodicalId":17428,"journal":{"name":"Journal of thermal biology","volume":null,"pages":null},"PeriodicalIF":2.9,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142391518","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":2,"RegionCategory":"生物学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

引用次数: 0

Combined effects of thermal environment and gene regulation on metabolic enzyme activities of major metabolic tissues in a winter-breeding amphibian 热环境和基因调控对冬眠两栖动物主要代谢组织代谢酶活性的综合影响

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.104000

Chi-Ying Zhang , Hua-Li Hu , Yu Wang , Lin Zhang , Guo-Hua Ding

Variations in thermal environments can provoke diverse physiological responses in amphibians. Despite extensive studies on the thermal sensitivity of amphibian metabolic physiology, including enzyme activity at different temperatures, the rationale for selecting specific metabolic enzymes and their relationship with gene expression remains unclear. Cytochrome c oxidase (CCO), succinate dehydrogenase (SDH), and lactate dehydrogenase (LDH) are key metabolic enzymes within the primary metabolic regulatory tissues of animals. Through a comparative analysis of the effects of two different thermal conditions (12 and 18 °C) on the activities and mRNA expression levels of these enzymes within the kidney and liver tissues of a winter-breeding amphibian (Leptobrachium liui), with the field group during the breeding season as the control, we provide insights into the interplay between temperature and gene expression. The mRNA levels of CCO subunits 1 (cox1), 2 (cox2), and 3 (cox3), and LDH subunit A (ldha) were significantly higher in the kidney than in the liver of all individuals. High-temperature acclimation resulted in significantly decreased expression levels of cox1-3, ldha, and SDH complex flavoprotein subunit A (sdha) in the kidney. In the liver, the expression levels of sdha and ldha significantly reduced under high-temperature treatment, whereas cox3 expression increased. SDH and LDH activities displayed tissue-specific variations, while no significant differences in CCO activity were observed between tissues. CCO, SDH, and LDH activities in both liver and kidney tissues significantly declined after high-temperature acclimation, but simultaneously increased with up-regulated gene expression, indicating that the thermal environment and corresponding gene expression combined affect the activities of these metabolic enzymes. In conclusion, the thermal environment is a key factor affecting the physiological and biochemical responses of L. liui. Prolonged exposure to high temperatures during the breeding season could inhibit the activity of primary metabolic enzymes in the winter-breeding amphibian.

热环境的变化会引起两栖动物不同的生理反应。尽管对两栖动物代谢生理的热敏感性（包括不同温度下的酶活性）进行了大量研究，但选择特定代谢酶的理由及其与基因表达的关系仍不清楚。细胞色素 c 氧化酶（CCO）、琥珀酸脱氢酶（SDH）和乳酸脱氢酶（LDH）是动物主要代谢调节组织中的关键代谢酶。通过比较分析两种不同温度条件（12 °C和18 °C）对冬繁两栖动物（Leptobrachium liui）肾脏和肝脏组织中这些酶的活性和mRNA表达水平的影响，并以繁殖季节的野外组为对照，我们深入了解了温度与基因表达之间的相互作用。所有个体肾脏中CCO亚基1（cox1）、2（cox2）、3（cox3）和LDH亚基A（ldha）的mRNA水平均显著高于肝脏。高温驯化导致肾脏中 cox1-3、ldha 和 SDH 复合物黄蛋白亚基 A（sdha）的表达水平明显下降。在肝脏中，高温条件下 sdha 和 ldha 的表达水平明显降低，而 cox3 的表达水平则升高。SDH和LDH活性显示出组织特异性变化，而CCO活性在不同组织间无明显差异。高温驯化后，肝脏和肾脏组织中的 CCO、SDH 和 LDH 活性显著下降，但同时基因表达上调，CCO、SDH 和 LDH 活性上升，表明热环境和相应的基因表达共同影响了这些代谢酶的活性。总之，热环境是影响 L. liui 生理生化反应的关键因素。在繁殖季节长期暴露在高温环境中会抑制冬眠两栖动物体内主要代谢酶的活性。

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引用次数: 0

Role of metal oxide ferrites in the process of magnetic hyperthermia – A review 金属氧化物铁氧体在磁热效应过程中的作用 - 综述。

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103936

Santhiya R, A. Ruban Kumar

Extensive research has been conducted on the manufacturing of nano ferrites, and their use in magnetic hyperthermia therapy has shown promising results in cancer treatment. This study aims primarily to provide an overview of the latest developments in the synthesis of magnetic nanoparticles (MNPs) for the treatment of hyperthermia. Magnetic nanoparticles are biocompatible and have a stable magnetic state, nano ferrites have become recognized as apex thermoseeds in biomedical applications, specifically for the treatment of magnetic hyperthermia. Employing dopant materials, biocompatible overlay, and preparation techniques, one may study the effectiveness of nano ferrites. Furthermore, specific requirements need to be met for using nano ferrites in cancer treatments like magnetic hyperthermia. These include low toxicity, biocompatibility, a higher specific absorption rate, a shorter time to reach the targeted hyperthermia temperature, crystalline size within the biological radius, and a lower dose of the nano ferrite. A potential resolution involves identifying the limitations and proposing enhanced nanocomposite materials that amplify their magnetic characteristics via a biocompatible overlay, all while optimizing the effectiveness and functioning of magnetic nanoferrites. To increase the effectiveness of ferrite nanoparticles in treating hyperthermia, this study will figure out their constraints and offer solutions for more effective ferrite-based nanocomposites that may prove to be a viable therapy option for cancer in the future.

人们对纳米铁氧体的制造进行了广泛的研究，其在磁热疗中的应用已在癌症治疗中显示出良好的效果。本研究的主要目的是概述合成磁性纳米粒子（MNPs）用于热疗的最新进展。磁性纳米粒子具有生物相容性和稳定的磁性状态，纳米铁氧体已被公认为生物医学应用中的顶级热源，特别是用于治疗磁性热疗。利用掺杂剂材料、生物相容性覆盖层和制备技术，可以研究纳米铁氧体的有效性。此外，将纳米铁氧体用于癌症治疗（如磁热疗法）需要满足特定的要求。这些要求包括低毒性、生物相容性、更高的特定吸收率、更短的达到目标热疗温度的时间、生物半径内的结晶尺寸以及更低的纳米铁氧体剂量。潜在的解决方案包括找出限制因素，并提出增强型纳米复合材料，通过生物相容性覆盖层放大其磁性特征，同时优化磁性纳米铁氧体的功效和功能。为了提高铁氧体纳米粒子在治疗热疗中的有效性，本研究将找出它们的局限性，并为更有效的基于铁氧体的纳米复合材料提供解决方案，这可能被证明是未来治疗癌症的一种可行选择。

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引用次数: 0

Profiling the dynamic variations in body and scrotal surface temperatures of goats reared under stressful conditions using infrared thermography: Analytical perspectives 利用红外热成像技术分析应激条件下饲养的山羊体温和阴囊表面温度的动态变化：分析视角

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-10-01 DOI: 10.1016/j.jtherbio.2024.103960

Emad M. Samara

Infrared thermography (IRT) is an essential non-invasive method for analyzing surface temperature variations in animals, offering valuable insights into livestock stress responses. Despite their resilience, goats can face significant challenges under extreme conditions like heat-stress and water deprivation. This experiment aimed to delineate the dynamic variations in whole-body and scrotal surface temperatures in goats subjected to the combined impact of both conditions using IRT. Eight healthy Aardi bucks were exposed to three 72-h treatments: euhydration, dehydration, and rehydration. Continuous meteorological monitoring provided ambient-temperature, relative-humidity, and temperature-humidity index (THI) values. Surface temperatures were measured twice daily at 08:00 and 15:00, and thermal gradients between ambient and body or scrotal surface temperatures were computed. Based on the obtained mean THI values, the bucks experienced heat-stress throughout the experiment. Additionally, results revealed noticeable variations in both surface temperatures across treatments and time points, indicated by measures of central tendency, variability, shape descriptors, and frequency distribution of temperature. Morning measurements indicated lower temperatures and gradients under euhydration, while water deprivation led to higher temperatures and compromised thermal regulation. Conversely, afternoon data showed higher variability in temperature responses, highlighting the compounded effect of diurnal heat-stress and water deprivation. Although water-restoration mitigated some effects of deprivation, it did not fully restore thermal homeostasis to euhydrated levels. Thermal gradients further emphasized the goats' dynamic thermoregulatory mechanisms, which were compromised under water deprivation, particularly in the scrotal region, but were partially restored upon restoration. These findings demonstrate the effectiveness of IRT in assessing thermal responses in goats and underscore the importance of adequate hydration for maintaining thermal balance under heat-stress. The herein performed profiling provides valuable insights with implications for overall health, reproductive efficiency, productivity, and welfare in heat-stressed and water-deprived goats, which might offer a framework for future research on livestock adaptation to such challenging environmental conditions.

红外热成像（IRT）是一种分析动物体表温度变化的重要非侵入性方法，可为了解家畜的应激反应提供宝贵的信息。尽管山羊具有顽强的生命力，但在热应激和缺水等极端条件下仍会面临巨大挑战。本实验旨在利用 IRT 分析山羊在这两种情况下全身和阴囊表面温度的动态变化。八只健康的阿尔迪公羊接受了三种 72 小时的处理：缺水、脱水和补水。连续气象监测提供了环境温度、相对湿度和温湿度指数（THI）值。每天 8:00 和 15:00 测量两次体表温度，并计算环境温度与体表或阴囊表面温度之间的热梯度。根据获得的平均 THI 值，雄鹿在整个实验期间都经历了热应激。此外，结果表明，不同处理和不同时间点的体表温度存在明显差异，这体现在温度的中心倾向、变异性、形状描述符和频率分布上。上午的测量结果表明，缺水时的温度和温度梯度较低，而缺水时的温度较高，热调节功能受到影响。相反，下午的数据显示温度反应的变异性更大，突出了昼夜热应激和缺水的复合效应。虽然补水减轻了缺水的一些影响，但并不能完全将热平衡恢复到缺水水平。热梯度进一步强调了山羊的动态体温调节机制，这种机制在缺水情况下受到损害，尤其是在阴囊区域，但在恢复后又得到了部分恢复。这些研究结果证明了 IRT 在评估山羊热反应方面的有效性，并强调了充足的水合对在热应激下保持热平衡的重要性。本文所做的分析提供了宝贵的见解，对热应激和缺水山羊的整体健康、繁殖效率、生产率和福利都有影响，可为今后研究牲畜对此类挑战性环境条件的适应性提供一个框架。

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引用次数: 0

Upper thermal limits are ‘hard-wired’ across body mass but not populations of an estuarine fish 热上限在不同体质的河口鱼类中是 "硬连接 "的，但在不同种群中并非如此。

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-09-19 DOI: 10.1016/j.jtherbio.2024.103970

Daniel F. Gomez Isaza , Essie M. Rodgers

Climate warming is seeing temperatures breach exceptional thresholds as the frequency and intensity of heat waves increase. Efforts to forecast species vulnerability to climate warming often focus on upper thermal limits threatening survival, overlooking the role of intraspecific variation in determining vulnerability. Using an estuarine fish (black bream, Acanthopagrus butcheri) as a model, we explore how intraspecific variation in body mass and among populations affects upper thermal tolerance. Upper thermal limits were quantified using critical thermal maxima (CTmax) of wild fish. We used a ∼500 g (mean = 52.4 g, range = 0.57–541 g) mass range to test the relationship between body mass and thermal tolerance. Four distinct black bream populations were chosen along a 5° latitudinal cline to explore population differences in thermal limits. Contrary to expectations, there was no effect of body mass on upper thermal limits. However, significant population differences in thermal tolerance were observed that correlate with mean habitat temperatures. Specifically, the southern population had a significantly lower CTmax (35.57 ± 0.43 °C) compared to northern (36.32 ± 0.70 °C) and mid-latitude (36.36 ± 1.15 °C) populations. These data underscore the importance of observing intraspecific variation in thermal limits to reveal the capabilities of individuals within a species to cope with climate warming and improve the management of at-risk life stages and populations.

随着气候变暖，热浪的频率和强度不断增加，气温也突破了特殊阈值。预测物种对气候变暖的脆弱性的工作往往侧重于威胁生存的热上限，而忽视了种内变异在决定脆弱性方面的作用。我们以河口鱼类（黑鲷鱼）为模型，探讨了种内体重差异和种群间差异如何影响热耐受上限。我们使用野生鱼类的临界最大热量（CTmax）来量化热上限。我们使用体重范围为 500 克（平均值 = 52.4 克，范围 = 0.57-541 克）来检验体重与热耐受性之间的关系。沿 5° 纬度线选择了四个不同的团头鲂种群，以探索种群在热极限方面的差异。与预期相反，体质量对热上限没有影响。不过，观察到种群在耐热性方面存在明显差异，这与平均栖息地温度有关。具体地说，与北部（36.32 ± 0.70 °C）和中纬度（36.36 ± 1.15 °C）种群相比，南部种群的 CTmax（35.57 ± 0.43 °C）明显较低。这些数据强调了观察种内热极限变化的重要性，以揭示物种内个体应对气候变暖的能力，并改善对濒危生命阶段和种群的管理。

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引用次数: 0

Embryonic thermal manipulation and post-hatch dietary guanidinoacetic acid supplementation alleviated chronic heat stress impact on broiler chickens 胚胎热控制和孵化后日粮中的鸟苷酸补充可减轻慢性热应激对肉鸡的影响

IF 2.9 2区生物学 Q2 BIOLOGY

Journal of thermal biology

Pub Date : 2024-09-18 DOI: 10.1016/j.jtherbio.2024.103976

Gholamreza Zaboli , Enayat Rahmatnejad

The study investigated the effects of embryonic thermal manipulation (TM) and post-hatch guanidinoacetic acid (GAA) supplementation on male broiler chickens exposed to chronic heat stress (HS). Ross 308 eggs (n = 710) were randomly assigned to control (37.8 °C, 56% RH) or TM (39.5 °C, 65% RH for 12 h/day from embryonic day 7–16) treatments. After hatching, chicks were further assigned to four dietary treatments (n = 12 birds/pen, 5 replicates/treatment): control, control with 1.2 g/kg GAA supplementation (CS), TM, and TM with 1.2 g/kg GAA supplementation (TMS). All birds were subjected to chronic HS (32–36 °C and 55% RH for 6 h/day) from day 28–42. Embryonic TM treatment decreased hatchability, hatching weight (HW), and facial temperature (FT). During the pre-HS period (days 1–28), no significant differences in feed conversion ratio (FCR) and mortality were observed, although the TM group exhibited the lowest body weight gain (BWG). Following HS exposure (days 29–42), the TMS group displayed significantly higher BWG than the control and CS groups. The TM and TMS groups also demonstrated significantly lower FCR and mortality rates during this period. Across the entire period (days 1–42), BWG was significantly higher in the TMS group compared to other groups. Furthermore, TM and TMS treatments were associated with lower mortality rates, improved FCR, better European Performance Efficiency Index (EPEI), and reduced abdominal fat deposition. The experimental treatments did not significantly affect intestinal morphology or most blood parameters, except triiodothyronine (T3), thyroxine (T4), and uric acid. Plasma concentrations of T3, T4, and uric acid were significantly lower in the TM and TMS groups compared to the control and CS treatments. The findings suggest that a combined strategy of embryonic TM and post-hatch dietary GAA supplementation may not only alleviate the detrimental effects of HS but also promote beneficial physiological responses in broiler chickens.

该研究调查了胚胎热处理（TM）和孵化后补充鸟苷酸（GAA）对暴露于慢性热应激（HS）的雄性肉鸡的影响。Ross 308鸡蛋（n = 710）被随机分配到对照组（37.8 °C，56%相对湿度）或TM组（39.5 °C，65%相对湿度，从胚胎第7-16天，每天12小时）。孵化后，雏鸡被分配到四种饮食处理（n = 12 只/笔，5 个重复/处理）：对照组、对照组加 1.2 克/千克 GAA 补充剂（CS）、TM 组和 TM 组加 1.2 克/千克 GAA 补充剂（TMS）。从第 28-42 天开始，所有鸟类均接受慢性 HS（32-36 °C，55% 相对湿度，每天 6 小时）。胚胎 TM 处理降低了孵化率、孵化体重（HW）和面部温度（FT）。在 HS 暴露前（第 1-28 天），虽然 TM 组的体重增加（BWG）最低，但饲料转化率（FCR）和死亡率没有明显差异。暴露于 HS 后（第 29-42 天），TMS 组的体重增长显著高于对照组和 CS 组。在此期间，TM 组和 TMS 组的 FCR 和死亡率也明显较低。在整个期间（第 1-42 天），TMS 组的体重总和明显高于其他组。此外，TM 和 TMS 治疗与死亡率降低、FCR 提高、欧洲性能效率指数（EPEI）提高和腹部脂肪沉积减少有关。除了三碘甲状腺原氨酸（T3）、甲状腺素（T4）和尿酸外，实验处理对肠道形态和大多数血液参数没有明显影响。与对照组和 CS 组相比，TM 组和 TMS 组血浆中的 T3、T4 和尿酸浓度明显较低。研究结果表明，胚胎 TM 和孵化后日粮 GAA 补充相结合的策略不仅能减轻 HS 的有害影响，还能促进肉鸡的有益生理反应。

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引用次数: 0