Quantifying physiological stress in wild animals is essential for understanding their health, reproductive success, and survival in a variable environment. The yellow-bellied marmot (Marmota flaviventer) study at the Rocky Mountain Biological Laboratory near Crested Butte, Colorado, USA is the world\'s second longest study of free-living mammals. Historically, we used a validated corticosterone radioimmunoassay (RIA) to measure fecal glucocorticoid metabolites (FGMs) as a proxy for physiological stress. However, the costs and risks associated with working with radioisotopes drove us to consider a more sustainable method. Here we evaluate the suitability of two competitive corticosterone enzyme-linked assays (EIA), one from Cayman Chemical Company (CCC) and one from Arbor Assays (AA), to measure marmot FGMs via its cross-reaction. The findings revealed that the AA EIA better matched the RIA in terms of accuracy across high and low FGM concentrations, had superior assay parameters, showed the highest correlations with RIA results and effectively captured the annual variations in FGM concentrations, thus demonstrating its reliability for use in longitudinal studies. We further analytically validated the AA EIA for FGMs and confirmed its efficacy and lack of matrix effects, thus establishing its suitability for ongoing and future studies of FGMs in marmots. The transition to the AA EIA from the RIA ensures continued data integrity while enhancing safety and environmental sustainability.

During ex situ conservation, the adaptability of giant pandas to environmental changes is greatly challenged. The issue of natural reproduction in captive giant pandas remains unresolved both domestically and internationally. It hypothesized that the restricted natural reproductive capacity may be linked to abnormal mating behavior expression due to physiological stress resulting from incompatible pairings in confined environments. To test this hypothesis, we utilized ultra-high performance liquid chromatographytandem quadrupole-time-of-flight mass spectrometry (UPLC-Q-TOF/MS) to analyse urine metabolites in captive adult giant pandas during their breeding period. Simultaneously, enzyme-linked immunosorbent assay was employed to measure the levels of cortisol and epinephrine in urine, providing insight into the psychological state of captive giant pandas during mate selection by examining all metabolites and related biochemical pathways. This comprehensive approach aims to fully elucidate the physiological mechanisms underlying the decline in natural reproductive capacity. The metabolomics findings indicate that the aberrant expression of natural mating behaviour in captive adult male and female giant pandas may be associated with dysfunction in amino acid metabolic pathways. The activation of these metabolic pathways is linked to psychological stress, such as the tryptophan metabolic pathway and GABAergic synapse pathway. The results of physiological indicators indicate a significant correlation between the expression of natural mating behaviour in captive adult pandas and the hormone urine cortisol, which is associated with physiological stress. These findings indicate that the atypical manifestation of natural mating behaviour in captive adult giant pandas may be associated with physiological stress induced by incompatible pairings within confined environments.

OBJECTIVE: To analyze the impact of multiple protection model in the operating room on patients\' physiological stress and risk events after coronary artery stent implantation (CASI).
METHODS: During October 2021 to October 2022, 150 patients with coronary heart disease (CHD) were picked as the research subjects, all of whom underwent CASI. The clinical data were retrospectively analyzed, and the patients were divided into two groups according to different nursing methods, with 75 cases in each group. Patients in the intervention group received multiple protection model intervention in the operating room, and the patients in the control group adopted conventional care model. The patient satisfaction with nursing, postoperative recovery, psychological stress scores, physiological stress indicators, and adverse cardiac risk events were recorded.
RESULTS: Patients in the intervention group had much higher percentage of the patient satisfaction with nursing than those in the control group (P < 0.05). The time to get out of bed and hospital stay was significantly shorter and the 6-min walking distance was markedly longer in the intervention group than the control (P < 0.05). The Hamilton Anxiety (HAMA) scale and Hamilton Depression (HAMD) scale score of patients in two groups were sharply decreased after the intervention (P < 0.05), which were strongly lower in the intervention group than the control (P < 0.001). After the intervention, the heart rate, cortisol and epinephrine of patients were all sensibly elevated in two groups (P < 0.05), which were all memorably lower in the intervention group than the control (P < 0.001). The incidence of adverse cardiac risk events in the intervention group was 5.33%, which was dramatically lower than 16.00% in the control group (P < 0.05).
CONCLUSIONS: The application of multiple protection model in the operating room on patients undergoing coronary stent implantation promoted postoperative recovery, reduced patients\' psychological and physiological stress, maintained blood pressure and other vital signs, reduced the incidence of adverse cardiac risk events, and improved the patient satisfaction with nursing.

Social bonds increase fitness in a range of mammals. One pathway by which social bonds may increase fitness is by reducing the exposure to physiological stress, i.e. glucocorticoid (GC) hormones, that can be detrimental to health and survival. This is achieved through downregulating hypothalamic-pituitary-adrenal (HPA)-axis activity. Indeed, long-term measures of social (grooming) bonds are often negatively correlated with HPA-axis activity. However, the proximate role of physical touch through allogrooming remains an open question in the sociality-health-fitness debate. Demonstrating the potential anxiolytic benefits of grooming in the wild is hindered by methodological limitations. Here, we match accelerometer-identified grooming in wild female chacma baboons (Papio ursinus) to non-invasive faecal GC metabolite concentrations (fGCs). Consistent with previous work, we found a negative (but statistically non-significant) overall relationship between individual averaged fGCs and grooming rates. However, when time-matching grooming to fGCs, we found that both more giving and receiving grooming were followed by higher fGCs. This upregulation of HPA-axis activity suggests that maintaining social bonds (and its ultimate fitness benefits) may come at a shorter-term physiological cost. This finding sheds new light on a ubiquitous social behaviour typically considered \'relaxing\' and suggests that sociopositive contact can trigger physiological stress.

This study examines how temperature influences the response of Japanese tree frogs (Dryophytes japonicus) to microplastic (MP) pollution, assessing whether temperature can regulate the harmful effects of MPs on their life history and the dispersal of MPs across habitats. This analysis aims to understand the ecological and physiological ramifications of MP pollution. Our results demonstrated an ontogenetic transfer of MP particles across amphibian metamorphosis, possibly allowing and facilitating the translocation of MPs across ecosystems. Temperature did not significantly affect the translocation of aquatic MPs to land. However, high temperatures significantly reduced mortality and hindlimb deformities caused by MPs, thereby mitigating their harmful impact on amphibian life histories. Importantly, our study found that MPs cause hindlimb deformities during amphibian metamorphosis, potentially linked to oxidative stress. Additionally, MP exposure and ingestion induced a plastic response in the morphology of the digestive tract and changes in the fecal microbiome, which were evident at high temperatures but not at low temperatures. The effects of MPs persisted even after the frogs transitioned to the terrestrial stage, suggesting that MPs may have complex, long-term impacts on amphibian population sustainability. Our results enhance the understanding of the intricate environmental challenges posed by MPs and underscore the significant role of temperature in ectotherms regarding ontogenetic impacts and pollutant interactions.

BACKGROUND: Health care workers (HCWs) frequently face multiple stressors at work, particularly those working night shifts. HCWs who have experienced distress may find it difficult to adopt stress management approaches, even if they are aware of the effects of stress and coping processes. Therefore, an individualized intervention may be required to assist distressed HCWs in bridging the \"knowledge-practice\" gap in stress management and effectively alleviating stress symptoms.
OBJECTIVE: The main objective of this research was to compare the effects of a complex interactive multimodal intervention (CIMI) to self-guided stress management interventions on stress symptoms of distressed HCWs, as measured by physiological (heart rate variability), psychological (perceived stress, mental distress, and subjective happiness), and sleep disorder (fatigue and sleepiness) indicators.
METHODS: We conducted a nonrandomized, controlled study in 2 Chinese general hospitals. The participants in this study were 245 HCWs who fulfilled at least 1 of the 3 dimensions on the Depression, Anxiety, and Stress Scale. All eligible individuals were required to complete a questionnaire and wear a 24-hour Holter device to determine the physiological signs of stress as indexed by heart rate variability at both baseline and after the intervention. The CIMI group received a 12-week online intervention with 4 components-mobile stress management instruction, a web-based WeChat social network, personalized feedback, and a nurse coach, whereas the control group simply received a self-guided intervention.
RESULTS: After a 12-week intervention, the Perceived Stress Scale (PSS) scores reduced significantly in the CIMI group (mean difference [MD] -5.31, 95% CI -6.26 to -4.37; P<.001) compared to the baseline levels. The changes in PSS scores before and after the intervention exhibited a significant difference between the CIMI and control groups (d=-0.64; MD -4.03, 95% CI -5.91 to -2.14; P<.001), and the effect was medium. In terms of physiological measures, both the control group (MD -9.56, 95% CI -16.9 to -2.2; P=.01) and the CIMI group (MD -8.45, 95% CI -12.68 to -4.22; P<.001) demonstrated a significant decrease in the standard deviation of normal-to-normal intervals (SDNN) within the normal clinical range; however, there were no significant differences between the 2 groups (d=0.03; MD 1.11, 95% CI -7.38 to 9.59; P=.80).
CONCLUSIONS: The CIMI was an effective intervention for improving sleep disorders, as well as parts of the psychological stress measures in distressed HCWs. The findings provide objective evidence for developing a mobile stress management intervention that is adaptable and accessible to distressed HCWs, but its long-term effects should be investigated in future research.
BACKGROUND: ClinicalTrials.gov NCT05239065; https://clinicaltrials.gov/ct2/show/NCT05239065.

Undergraduate students are frequently afflicted by major depressive disorder (MDD). Oxidative and nitrosative stress (O&NS) has been implicated in the pathophysiology of MDD. There is no information regarding whether mild outpatient MDD (SDMD) and first episode SDMD (FE-SDMD) are accompanied by O&NS. The current study compared lipid hydroperoxides (LOOH), malondialdehyde (MDA), advanced protein oxidation products, nitric oxide metabolites (NOx), thiol groups, plasma total antioxidant potential (TRAP), and paraoxonase 1 activities among SDMD and FE-SDMD patients versus healthy controls. We found that SDMD and FE-SDMD exhibit elevated MDA and NOx, and decreased TRAP and LOOH as compared with controls. There was a significant and positive correlation between O&NS biomarkers and adverse childhood experiences (ACEs), and negative life events (NLEs). O&NS pathways, NLEs and ACEs accounted for 51.7 % of the variance in the phenome of depression, and O&NS and NLS explained 42.9 % of the variance in brooding. Overall, these results indicate that SDMD and FE-SDMD are characterized by reduced total antioxidant defenses and increased aldehyde and NOx production. The combined effects of oxidative and psychological stressors are substantially associated with the manifestation of SDMD.

Athletes are at high risk of dehydration, fatigue, and cardiac disorders due to extreme performance in often harsh environments. Despite advancements in sports training protocols, there is an urgent need for a non-invasive system capable of comprehensive health monitoring. Although a few existing wearables measure athlete\'s performance, they are limited by a single function, rigidity, bulkiness, and required straps and adhesives. Here, an all-in-one, multi-sensor integrated wearable system utilizing a set of nanomembrane soft sensors and electronics, enabling wireless, real-time, continuous monitoring of saliva osmolality, skin temperature, and heart functions is introduced. This system, using a soft patch and a sensor-integrated mouthguard, provides comprehensive monitoring of an athlete\'s hydration and physiological stress levels. A validation study in detecting real-time physiological levels shows the device\'s performance in capturing moments (400-500 s) of synchronized acute elevation in dehydration (350%) and physiological strain (175%) during field training sessions. Demonstration with a few human subjects highlights the system\'s capability to detect early signs of health abnormality, thus improving the healthcare of sports athletes.

Understanding the critical thresholds of dissolved oxygen (O2) that trigger adaptive physiological responses in aquatic organisms is long hampered by a lack of robust, non-lethal or non-invasive methodologies. The isotope fractionation of triple O2 isotopes (18O/17O/16O) during respiration is linked to the amount of oxygen utilised, offering a potential avenue for new insights. Our experimental research involved measuring the oxygen isotope fractionation of dissolved O2 in closed-system aquatic respirometry experiments with wild sticklebacks (Gasterosteus aculeatus). These fish were either naturally adapted or experimentally acclimated to hypoxic and normoxic conditions. The aim was to observe their oxygen usage and isotope fractionation in response to increasingly severe hypoxia. Initial observations revealed a progressive 18O enrichment from the preferential uptake of 16O to a dissolved oxygen threshold of 3-5 mg O2 L-1, followed by an apparent reversal in oxygen isotope fractionation, which is mixing of 16O and 17O with the remaining O2 pool across all populations and indicative of a systematic change in oxygen metabolism among the fish. Unexpectedly, sticklebacks adapted to hypoxia but acclimated to normoxia exhibited stronger oxygen isotope fractionation compared to those adapted to normoxia and acclimated to hypoxia, contradicting the hypothesis that hypoxia adaptation would lead to reduced isotope discrimination due to more efficient oxygen uptake. These preliminary experimental results highlight the novel potential of using dissolved O2 isotopes as a non-invasive, non-lethal method to quantitatively assess metabolic thresholds in aquatic organisms. This approach could significantly improve our understanding of the critical oxygen responses and adaptation mechanisms in fish and other aquatic organisms across different oxygen environments, marking a significant step forward in aquatic ecological and physiological research.

Epidemiological results on the link between chronic stress and cancer initiation have been inconsistent. This study examined the relation between chronic biological stress, indicated as hair cortisol (HairF) and hair cortisone (HairE), and cancer incidence, adjusting for metabolic syndrome (MetS) components. We analyzed HairF and HairE samples from 6341 participants from the population-based cohort Lifelines in 2014. A linkage with the Dutch Nationwide Pathology Databank (Palga) provided the cancer incidence from 2015 to 2021. The association between dichotomized HairF and log-transformed HairE (LogHairE) and cancer incidence was estimated using Cox regression. MetS components were evaluated as confounders or moderators. Of the 2776 participants with known HairF levels and no cancer history, 238 developed cancer. The HairF level did not predict cancer incidence (HR: 0.993, 95%CI: 0.740-1.333). No confounders or moderators were identified. Among the 4699 participants with known HairE levels and no cancer history, 408 developed cancer. There was no association between LogHairE and cancer incidence (HR: 1.113, 95%CI: 0.738-1.678). When including age as a confounder and gender as a moderator, LogHairE was statistically significantly associated with cancer incidence (HR: 6.403, 95%CI: 1.110-36.92). In a population-based cohort, chronic biological stress, measured by HairE, was associated with cancer incidence, after controlling for age and gender.