Raman lidar is an important technique for atmospheric temperature detection. However, under thick-cloud conditions, the accuracy of in-cloud temperature retrieval is severely compromised by leaked elastic signals beyond the system's conventional suppression capabilities. To address this problem, we propose a four-channel joint-retrieval cloud temperature correction method built on low- and high-quantum-number rotational Raman (RR), vibrational Raman (VR), and elastic scattering channels. Using the leakage-immune VR signal as a stable intermediate variable, the crosstalk coefficients for the two RR channels are calculated, thereby reducing biases in in-cloud temperature retrieval. The proposed method was validated through simulation experiments and further compared with other in-cloud temperature retrieval approaches using observational data. The results from multi-day observations indicate that, within cloudy regions, the mean absolute error (MAE) of Raman lidar temperature retrievals was reduced to within 1 K when compared with radiosonde data, and the root mean square error (RMSE) was lowered by over 86.34%. Compared with existing methods, it reduced RMSE by about 37.78% and provided more continuous spatiotemporal temperature evolution in 10 h of nighttime observations. The calibrated crosstalk coefficients can correct RR signals on different observation dates.
The Sumatran elephant (Elephas maximus sumatranus), a critically endangered subspecies endemic to Indonesia, is increasingly exposed to physiological stress associated with habitat disturbance and environmental conditions. Reliable assessment of stress physiology is therefore essential to support evidence-based welfare monitoring and conservation management, particularly for elephants maintained in conservation rescue units (CRUs). This study aimed to (1) validate a cortisol enzyme-linked immunosorbent assay (ELISA) kit for use in Sumatran elephants and (2) apply the validated assay to examine the effects of body condition score (BCS), ambient temperature, humidity, and temperature-humidity index (THI) on cortisol levels across CRUs in Aceh Province, Indonesia. Twenty elephants (8 males and 12 females; 10-49 years old) housed at six CRUs (CRU A-F) were included. Analytical validation assessed parallelism, accuracy, and assay precision, while biological validation compared cortisol levels during medical treatment and postrecovery. Factors influencing cortisol levels were evaluated using linear mixed-effects models incorporating BCS, location, ambient temperature, humidity, and THI as fixed effects, with elephant identity as random effects. The assay demonstrated acceptable analytical performance, with strong parallelism between serially diluted samples and the cortisol standard curve. Biological validation showed significantly higher cortisol levels during medical treatment than during recovery (p < 0.01). Mixed-effects analyses showed that BCS, location, ambient temperature, humidity, and THI were significantly associated with cortisol levels (p < 0.01). Elephants with BCS 7 (scale 1-9) tended to exhibit lower cortisol levels. Variation in cortisol levels was also observed among locations. Cortisol levels tended to increase with higher ambient temperature and THI, whereas higher humidity was associated with lower cortisol levels. In conclusion, the validated cortisol assay demonstrated suitability for use in Sumatran elephants under the conditions of this study. The findings suggest that body condition and environmental factors (e.g., ambient temperature, humidity, and THI) may be associated with variation in cortisol levels in elephants managed in CRUs, suggesting the importance of considering both physiological and environmental contexts in welfare monitoring.
An optical fiber sensing scheme for decoupled strain and temperature measurement is investigated based on a cascaded microfiber interferometer-fiber Bragg grating (MFI-FBG) configuration. MFI functions as the primary strain-sensitive element owing to its strong evanescent-field interaction, while FBG is designed to operate as an independent temperature reference. Experimental results indicate that the MFI exhibits a linear wavelength response to applied strain, with a sensitivity of 0.0226 nm/µɛ and a linearity coefficient (R2) of 0.9875. Temperature characterization experiments further demonstrate that both sensing units maintain stable and repeatable responses, with sensitivities of 0.0112 nm/°C for the MFI and 0.0075 nm/°C for FBG, respectively. By exploiting the distinct response characteristics of the two sensing components, a sensitivity matrix is established to effectively suppress strain-temperature cross-sensitivity, enabling accurate and independent demodulation.
The physical environment of inpatient wards plays a critical role in supporting rest and care delivery. In palliative care, environmental conditions such as sound, lighting, and temperature directly influence patient comfort, circadian rhythms, and staff performance. However, few studies have quantitatively assessed these factors in functioning palliative care units (PCUs).ObjectivesTo evaluate the spatial and environmental performance of an acute PCU through sensor-based monitoring of acoustic exposure, light levels, and temperature.MethodA postoccupancy evaluation approach was employed to assess conditions within inpatient rooms. Environmental loggers recorded data continuously at 1-min intervals across two 1-month periods. Parameters included sound levels (Lmax, Leq, Lmin in A-weighted decibels) to reflect perceived loudness, lighting (lux), and temperature (°C). Measurements were benchmarked against World Health Organization and Australian guidelines for sleep-supportive healthcare environments. Data were collected from both single- and multibed rooms in a metropolitan tertiary hospital PCU.ResultsSound levels frequently exceeded recommended thresholds. Nighttime averages reached 54 dB(A), while daytime LAeq exceeded 60 dB(A), with minimal day-night variation (<6 dB), indicating sustained exposure. Lighting data showed repeated nighttime spikes above 20 lux and insufficient daytime illumination for circadian regulation. Temperature exhibited minimal diurnal variation (<2°C), falling short of conditions known to support sleep.ConclusionEnvironmental monitoring revealed persistent deviations from sleep-supportive conditions. These stressors likely impact both patient well-being and staff performance. Findings underscore the need for evidence-based design strategies and translational research that position the built environment as an active contributor to holistic care. In palliative contexts, architectural design should enable rather than simply contain clinical practice.
Sepsis remains a major challenge in the ICU. Given the limitations of the one-size-fits-all strategy, precision medicine approaches are needed to identify distinct sepsis subtypes that may respond to different treatments. This study aimed to validate a temperature-trajectory model of sepsis developed in U.S. centers in a non-U.S. cohort from China, to characterize longitudinal immune and coagulation profiles, and to explore their potential value in guiding immunotherapy. This study validated a previously developed sepsis temperature-trajectory model, delineated longitudinal immune and coagulation dynamics across distinct subphenotypes, and, after propensity score matching, examined the heterogeneous effects of immunoglobulin treatment. Retrospective data from a tertiary-care hospital ICU in China. Adult ICU patients with suspected infection. None. Clinical and microbiological characteristics were compared across subphenotypes, and the interaction between subphenotype and immunoglobulin therapy on 30-day mortality was assessed. In total, 2478 patients were included and classified into four subphenotypes: hyperthermic slow resolvers (567; 23%), hyperthermic fast resolvers (397; 16%), normothermic (780; 31%), and hypothermic (HT, 734; 30%). The HT subphenotype exhibited the highest mortality rate (25%), consistent with previous findings. In longitudinal immune and coagulation profiling, the HT subphenotype exhibited the lowest inflammatory response (low and rapidly declining C-reactive protein and rapidly declining interleukin-6), suppressed immunity (persistently low lymphocyte counts and monocyte human leukocyte antigen-DR), and coagulation abnormalities (persistently prolonged prothrombin time and activated partial thromboplastin time; the lowest platelet counts, fibrinogen, and hemoglobin; and the highest rate and dose of RBC transfusion). Immunoglobulin therapy showed heterogeneous effects across different subphenotypes, with patients in the HT subphenotype showing a consistent direction of benefit (primary subtyping: hazard ratio, 0.47; p = 0.03). The temperature-trajectory subphenotypes were validated in an international cohort. Patients in the HT subphenotype exhibited the highest mortality and showed persistent immune dysfunction and coagulopathy. Furthermore, different subphenotypes demonstrated distinct responses to immunoglobulin therapy.
Accurate temperature assessment in complex combustion environments is crucial for the thermal diagnostics of aero-engines and gas turbines. To address the challenges posed by intense ambient radiation, a background-corrected multispectral light-field (MSLF) thermometry framework is developed. The system integrates single-snapshot 4D acquisition with an emissivity-adaptive model. A dual strategy is employed to mitigate radiative interference: a background-correction algorithm eliminates reflection artifacts, while discrete, narrowband wavelengths (specifically 700, 750, 800, and 850 nm) are selected to spectrally bypass gaseous radiation. Validation in a heating furnace demonstrates that reflection-induced errors can be reduced to within 6.5 K. Furthermore, jet-flame impingement tests confirm that absolute deviations were limited to within 20 K across varying emissivities (0.2-0.9), ensuring robust performance in high-temperature environments.
The dynamics of double-stranded DNA (dsDNA) are central to its biological role as a repository of genetic information. However, under physiological conditions DNA is subject to base mispairing and the formation of abasic sites through processes such as depurination. Such site-specific changes to the established Watson-Crick (WC) architecture would be expected to influence duplex dynamics and so affect key processes including protein binding. Here, we apply temperature-jump infrared spectroscopy to interrogate the relative impact of base pair mismatches and abasic sites on the structural dynamics of a 21-base pair (bp) dsDNA oligomer. The inclusion of an abasic site in the center of the strand leads to destabilization that is manifest as <1 μs time scale disruption of the nearby bases that is not present in fully WC-base paired sequences. Comparing this behavior with sequences featuring mismatches of different sizes shows that a single-bp mismatch causes minimal destabilization, whereas a triple base mismatch results in dynamics that closely mimic those resulting from the presence of an abasic site.
This study aimed to classify patients with bipolar disorder (BD) and normal controls (NCs) using machine-learning models that incorporate wearable-derived core body temperature (CBT) and actigraphy-derived sleep indices. We enrolled 23 euthymic patients with BD and 43 NCs. Sleep parameters were collected via wrist actigraphy for 14 days, and CBT was measured with a wearable device for 3 days to estimate the CBT nadir and its phase differences with sleep indices. Models were constructed with a base model using CBT- and sleep-derived features, and an extended model that included sociodemographic variables. Features were standardized (StandardScaler), and classifiers (random forest, LightGBM, and XGBoost) were evaluated. Hyperparameters were optimized using cross-validation within the training data. Performance was evaluated using repeated nested cross-validation. SHapley Additive exPlanations (SHAP) values were computed in the extended model to quantify relative feature contributions to the model output. In nested cross-validation at the MaxF1 operating point, the mean area under the receiver operating characteristic curve (ROC-AUC) was 0.771 ± 0.162 for the base model and 0.930 ± 0.050 for the extended model. In the extended model, SHAP suggested that total sleep time, wake time, and the wake time-CBT nadir phase difference were features potentially associated with the model output. In this small-sample study, a classification approach combining wearable-derived CBT indices and actigraphy-based sleep parameters suggested preliminary discrimination between BD and NC. Further validation is warranted in larger cohorts with balanced background characteristics, including disorders requiring differential diagnosis.
Swelling in polar solvents is a fundamental property of graphite oxide (GO). Using in situ synchrotron X-ray diffraction (XRD), Brodie graphite oxide (BGO) swelling was studied in a series of primary amides with the number of carbon atoms in the alkyl chain ranging from one (acetamide) to ten (decanamide) and compared to GO swelling in primary alcohols of equivalent chain lengths. The uptake of solvent due to swelling was determined via Differential Scanning Calorimetry (DSC). Swelling of BGO in acetamide, propionamide, and butyramide was found to expand the interlayer distance d(001) by ∼3.5-3.7 Å, consistent with the intercalation of a single molecular layer with an orientation parallel to the GO sheets. Swelling in longer molten amides produced larger c-lattice expansions correlating with the c-unit cell parameter of the pure amides, suggesting two-layer intercalation in a tilted "stand-up" orientation. Reversible swelling transition was found in the BGO-formamide system. This transition corresponds to the change between BGO structures with one-layer and two-layer formamide intercalation and has an enthalpy of 0.01 kJ g-1 (BGO). No temperature-driven swelling transitions were observed for the other studied amides, acetamide through decanamide, in contrast to previously reported transitions in BGO-alcohol systems. These results demonstrate the wide tunability of interlayer spacing in BGO-amide systems and highlight the potential of controlled intercalation for applications such as molecular separation and sorption.
Floating marine plastics undergo weathering and fragmentation, generating abundant small microplastics (MPs) (≤10 μm) that can be released into the atmosphere by sea spray aerosol (SSA), enabling long-range atmospheric transport. However, despite being increasingly recognized as emerging pollutants, the cross-boundary transport and cycling of MPs remain poorly constrained, and the response of their sea-to-air transfer mechanisms and fluxes to environmental drivers remains highly uncertain. Here, we combine controlled laboratory simulations with model estimation to quantify how sea surface temperature (SST) regulates the SSA-mediated emission of size-resolved MPs (0.5-10 μm). We find that warming SST significantly suppresses MPs enrichment in SSA, with stronger effects observed for smaller MPs. Compared to 0 °C seawater, size-resolved MPs enrichment factors decreased by factors of 1.5 to 4.2 at 30 °C, and this trend was coupled with the decrease in particle size of MPs. Mechanistic analyses indicate that warming SST reduces the submerged bubble scavenging and interfacial enrichment during bubble bursting, thereby impeding the transfer of MPs from the ocean to the atmosphere. By incorporating SST-driven changes in SSA production, surface-ocean MPs concentrations, and size-dependent enrichment of MPs, we developed a high-resolution global emission inventory, yielding total SSA-mediated MPs emissions in the range 3.85-23.32 tons yr-1. These findings identify SST as a key parameter regulating the release of marine MPs, which has significant implications for improving global emission inventories and atmospheric transport modeling.
Extreme heat is a significant and growing health hazard in urban locations around the world, particularly in the Southeastern United States (U.S.). While most extreme heat research and interventions are focused on ambient outdoor conditions and the neighborhood environment, the indoor residential environment is where the most severe heat-health consequences occur. The aim of this study was to characterize the indoor thermal environments and identify predictors of high indoor temperatures for residents of heat-vulnerable neighborhoods within New Orleans, Louisiana, within the context of current heat adaptation measures and issues of energy insecurity. We conducted surveys with both open- and closed-ended questions and measured indoor temperature over 2-week sampling periods in 114 households across two heat vulnerable New Orleans wards during the warm seasons of 2023 and 2024. Our study found that a combination of AC type and use, along with outdoor daily maximum temperature, were significant predictors of indoor maximum overnight temperature. Our results indicate that households without AC, using window AC units, or those not running central AC all or most of the time struggled to maintain 80 degrees Fahrenheit overnight (a threshold deemed appropriate by a recent healthy homes ordinance) once outdoor daily maximum temperatures exceeded 90 degrees Fahrenheit. Homeownership, compared to renting, was associated with higher overnight indoor temperatures, greater variability in typical AC use patterns, and greater sensitivity of summer monthly energy expenditures to differences in AC use patterns, potentially indicating that this group is practicing energy limiting behavior. This paper contributes to limited literature on indoor thermal environments, particularly in the Southeastern U.S., and underscores the importance of housing and energy burden in heat adaptation.
Rising environmental temperatures may differentially affect physiological processes in ectotherms, with sperm function representing a potentially critical but understudied vulnerability. We experimentally evaluated post-ejaculatory thermal sensitivity of sperm kinematics in the high-altitude viviparous lizard Phymaturus extrilidus. Ejaculated sperm from adult males were exposed to three ecologically relevant temperatures (28°C, 35°C, and 38°C), and motility and swimming parameters were quantified over a 2-hour incubation period using computer-assisted sperm analysis. Sperm performance was strongly affected by temperature, incubation time, and their interaction, indicating progressive thermal damage. Contrary to our prediction, peak sperm motility and swimming performance occurred at 28 °C rather than at the preferred body temperature (35 °C). Incubation at 35 °C and especially 38 °C caused marked, declines in motility, curvilinear velocity (VCL), and average path velocity (VAP), while straight-line velocity (VSL) remained comparatively stable. Increased linearity and straightness at elevated temperatures suggest reduced trajectory complexity and flagellar oscillation amplitude. These results reveal a mismatch between the thermal optimum for sperm function and locomotor performance, highlighting a physiological trade-off between somatic and reproductive traits. Under climate-warming scenarios, reduced access to cooler microhabitats may accelerate sperm senescence and compromise reproductive success in high-mountain ectotherms.
The contrast between a target and its background is particularly pronounced in the infrared spectral region, which has led modern surveillance systems to widely adopt thermal imaging technology for detection and identification purposes. To mitigate detectability under thermal infrared observation, thermal infrared camouflage has emerged as an active research field with broad practical applications. Two principal approaches are commonly employed: enhancing the thermal insulation and heat-shielding performance of camouflage materials and tailoring their surface emissivity to achieve radiative compatibility with the surrounding environment. This study elucidates the fundamental mechanism of thermal infrared camouflage by analyzing the relationship between the actual surface temperature of an object and its apparent temperature measured by a thermal imaging system. On this basis, a computational framework is developed to determine the appropriate surface emissivity of camouflage coatings for ground vehicles. The suitable surface emissivity is theoretically derived as a function of background temperature, atmospheric temperature, and target temperature. The results indicate that an emissivity range of 0.66-0.70 is suitable for effective thermal infrared camouflage. The proposed approach is experimentally validated through field observations using a thermal imaging system and spectral emission data acquired by a spectroradiometer (SR-5000N) in both the mid-wave infrared (MWIR) and long-wave infrared (LWIR) bands. Experimental results show that when the average surface emissivity of the coating over the 3-14 µm spectral range is approximately 0.7, the spectral radiance contrast of the non-camouflaged target is nearly three times greater than that of the camouflaged target relative to the background across both spectral regions. These findings demonstrate that an appropriate design of surface emissivity significantly enhances thermal infrared camouflage performance. Furthermore, the evaluation method based on spectral radiance analysis provides a reliable and meaningful framework for the design and assessment of thermal infrared camouflage systems.
Building-integrated photovoltaics (BIPVs) are promising for sustainable urban energy systems but remain constrained by coupled trade-offs among aesthetics, power output, thermal management, and cost. Conventional pigment- or dye-based coloring often reduces power conversion efficiency (PCE) and durability, whereas many structurally colored photovoltaic strategies rely on complex, difficult-to-scale nanostructures. Here, we report a scalable colored photovoltaic strategy based on color-selective polymer multilayer films (PMF-C) derived from a PEN/PMMA platform compatible with continuous coextrusion and layer multiplication. PMF-C generates vivid structural coloration through a selective high-reflection stopband in the visible range while maintaining high transmission over the remaining photovoltaic-relevant spectrum. This spectral selectivity enables color generation and passive thermal regulation by reducing solar heat gain. Integrated with an infrared-emissive EVA encapsulation architecture, PMF-GPV achieves an operating-temperature reduction of up to ∼8.65 °C while retaining ∼74% of the baseline PCE. Beyond experimental demonstration, we establish a data-driven opto-thermo-electrical framework that predicts color, efficiency, and operating temperature prior to fabrication across a broad PMF-C material and structural design space. Parametric sweeps and Pareto analysis identify refractive-index combinations for efficiency-priority, temperature-priority, and balanced designs; notably, under an idealized uniform-thickness design, the PEN/PMMA pair is predicted to retain 86.9% of the reference-cell PCE while reducing the operating temperature by 5.17 K. A machine-learning-assisted inverse-design workflow rapidly maps target colors to feasible PMF-C structural parameters. This work provides both a scalable material platform and a predictive design framework for colored BIPVs with jointly engineered appearance, efficiency, and passive thermal-management performance.
The thermal environment can profoundly modify the damage that pathogens cause to hosts. Yet while the interacting impacts of infection and temperature on individual life-history traits are well documented, how these effects scale to demographic consequences across thermal gradients remains poorly understood. Using the Daphnia magna-Pasteuria ramosa system across a 10-30°C gradient, we tested whether virulence in individual-level life history metrics reliably reflects the consequences for predicted population growth rates. Our results reveal a stark mismatch between scales: the cost of infection on individual life-history traits (fecundity, body size, and lifespan) was maximised at low temperatures, whereas the impact on population growth rate was maximised at high temperatures and at the thermal optima of healthy hosts. These findings demonstrate that standard virulence metrics at the scale of individual life-history traits may underestimate demographic risk in warming environments. To reliably predict population persistence in the face of disease under a changing climate, it is important to account for the temperature-dependent scaling of pathogen virulence and host life-history to population growth rates.
Climate change, characterized by long-term shifts in temperatures and weather patterns including extreme weather events, primarily caused by the combustion of fossil fuels, has increasingly been linked to adverse health outcomes caused by infectious diseases. In this manuscript we review available data from the last 10 years assessing the influence of climate change and its proximate causes on enteric (diarrheal) diseases worldwide. A scoping review following PRISMA guidelines was conducted using search strategies encompassing climate change, extreme weather events exacerbated by climate change, proximate causes of climate change, and the relationship of these factors to incidence and outcomes of enteric diseases. The review included articles published in English that utilized clinical data. Overarching themes were extracted from these studies. The review identified 122 manuscripts with common themes including the effects of climatic variables such as temperature, precipitation, and extreme weather events on diarrheal disease incidence, the interplay between these factors and social determinants of health such as access to Water, Sanitation, and Hygiene (WASH) services, and expected exacerbations with long-term climatic trends. Climate change-associated increases in temperatures and extreme weather events was generally associated with increased incidence of diarrheal diseases in most locations studied. There was a particularly strong intersection of these effects with social determinants of health and WASH. These data will be useful for setting research agendas, planning appropriate adaptation measures, and for reinforcing the urgent need for climate change mitigation globally.
Malnutrition is a common problem during the treatment of pediatric cancer. Therapy-induced taste alterations (dysgeusia) can further exacerbate this and may reduce the acceptance of oral nutritional supplements (ONS). There are no available data on the acceptability of commercially available ONS among children and adolescents in Germany. In a prospective, double-blind tasting trial, 36 pediatric oncology patients (6-20 years) evaluated commercially available ONS and a cocoa-based reference beverage. The primary outcome was overall liking (taste rating) on a 1-6 ordinal scale (1 = excellent; 6 = unacceptable). Additional assessments included ratings of appearance and temperature, perceived basic taste qualities, and free-text flavour descriptions. Using linear mixed models, beverage taste ratings were compared globally and pairwise (adjusted for multiple comparisons), and sensory characteristics associated with higher acceptance were explored. Cocoa was rated best overall (mean taste rating 1.42 ± 0.7) and significantly outperformed all tested ONS in taste (Bonferroni-corrected p = 0.025 compared to next-best), appearance, and temperature. The best-rated supplements were predominantly sweet or sweet-sour (red fruits: 2.42 ± 1.3; summer fruit smoothie: 2.64 ± 1.5); the other products were rated rather poorly (all ≥3.47) and most were not accepted (4.0). For salty/savoury beverages, patients' qualitative taste descriptions frequently diverged from manufacturer-declared flavours. Ratings of appearance and temperature, along with perceived sweetness, and in many cases sourness, emerged as the most robust predictors of overall taste evaluations. However, a model comparison indicated that these characteristics did not fully explain between-beverage differences (likelihood-ratio test p < 0.001), suggesting additional unmeasured determinants of acceptance. Among patients in pediatric oncology, receiving chemotherapy, cocoa was consistently preferred over commercially available high-energy ONS. While cocoa served as a highly accepted reference beverage, the findings highlight the importance of flavour characteristics for acceptance. Strategies focusing on flavour optimization of nutritionally complete supplements may help improve oral intake during therapy. In addition to fruit-based beverages, cocoa-based formulations - particularly when combined with energy enrichment approaches - may represent a practical and cost-efficient strategy to support oral nutritional intake when acceptance of standard ONS is limited.
One focal challenge in engineering low-power oxide spintronic devices lies in seeking room-temperature ferromagnetic insulators capable of generating pure spin currents free from Joule heating. Nevertheless, a robust ferromagnetic-insulating state in oxide materials is fundamentally restricted by a long-standing trade-off between ferromagnetic ordering and itinerant electrons in magnetic exchange interactions. Here, hydrogenation establishes a versatile paradigm for accessing exotic magnetoelectric states by precisely adjusting coupled ion-electron-lattice interplay, through which emergent room-temperature ferromagnetic insulators are stabilized in the LaCoO3 system. The incorporation of hydrogen drives sequential LaCoO3-HLaCoO2.67-HLaCoO2.5 topotactic phase transformations through oxygen vacancy ordering, progressively enhancing electron localization and ferromagnetic ordering. Benefiting from the double exchange interactions between high-spin Co3+ and high-spin Co2+, hydrogen-driven spin-state crossover results in the emergence of robust ferromagnetic ordering in LaCoO3 above room temperature, beyond the traditional magnetoelectric phase diagram. Of particular note is the reversible but robust ferromagnetic-insulating state realized in LaCoO3 through hydrogenation, which is attractive for low-power spintronic devices. Our present work demonstrates hydrogen-driven multistate magnetoelectric evolutions in LaCoO3 through adjusting ion-electron-lattice interplay, fostering a ferromagnetic insulator above room temperature with great potential for low-power spintronics.
Heat stroke is a life-threatening emergency characterized by severe hyperthermia and acute central nervous system (CNS) dysfunction. We describe a 72-year-old man who was found unresponsive in his vehicle on a day with ambient temperatures exceeding 90°F. On arrival, his core temperature was 105.8°F, and Glasgow Coma Scale (GCS) score was 5. Despite prompt initiation of active cooling and supportive care with normalization of body temperature, the patient developed persistent and fluctuating encephalopathy. Extensive metabolic, infectious, and toxicologic evaluations were unrevealing. Thyroid-stimulating hormone was normal, arterial blood gases showed no acid-base derangements, ammonia and liver function tests were within normal limits, and urine toxicology was negative. Electroencephalography demonstrated diffuse cerebral slowing without epileptiform activity. Brain MRI performed approximately 1 week after admission under anesthesia, including diffusion-weighted imaging, showed no acute abnormalities, revealing only mild age-related atrophy and chronic small-vessel ischemic changes. The patient's neurologic function failed to recover over a prolonged hospitalization, and he ultimately died following transition to comfort-focused care on hospital Day 27. This case highlights that severe and persistent encephalopathy may occur in the setting of probable heat stroke despite unrevealing conventional neuroimaging and underscores the diagnostic uncertainty and limitations of MRI in evaluating heat-related neurologic injury.
Klebsiella pneumoniae (K. pneumoniae) is recognized as a significant opportunistic pathogen capable of infecting both humans and animals. The emergence of multidrug-resistant strains presents a severe challenge to current antimicrobial therapies, necessitating the development of alternative treatments such as bacteriophages and their encoded enzymes. In this study, a polysaccharide depolymerase, designated DepZ57, was identified, expressed, and characterized from the K57-specific lytic phage vB_Kp_Z57. Bioinformatic analysis indicated that DepZ57 is a hydrophilic protein with a theoretical isoelectric point of 6.27 and adopts a typical β-helix structure. The purified depolymerase exhibited high physicochemical stability across a broad pH range (2.0-11.0) and temperature range (4°C-70°C). In vitro, the K57 capsule was degraded by DepZ57 at a minimum effective concentration ranging from 0.04 to 0.4 μg/mL, which subsequently sensitized the bacteria to macrophage phagocytosis and complement-mediated serum killing. In a lethal systemic mouse infection model induced by intraperitoneal injection, a 100% survival rate was achieved following the administration of 50 μg of DepZ57, compared with a 60% survival rate observed with the phage treatment. Bacterial burdens were effectively reduced by both treatments. Notably, the bacterial loads in the blood, lungs, and liver were significantly decreased in the DepZ57 treatment group. Specifically, the bacterial load in the blood was completely eliminated, and the bacterial loads in the liver and lungs were reduced by more than 99%. Histopathological analysis confirmed that DepZ57 treatment effectively prevented hepatic necrosis and pulmonary inflammatory infiltration. Collectively, these findings demonstrate the in vivo efficacy and stability of DepZ57, suggesting it may represent a viable candidate for the control of K. pneumoniae infections. The emergence of multidrug-resistant and hypervirulent Klebsiella pneumoniae represents a severe threat to human health and the dairy industry. Capsular polysaccharide (CPS) is the primary virulence factor that shields K. pneumoniae from host immune clearance, and the hypervirulent K57 serotype is frequently linked to severe invasive infections. Phage-derived depolymerases have emerged as promising antivirulence agents capable of specifically dismantling bacterial capsules without inducing bacterial resistance. Here, we characterized a novel, highly stable phage depolymerase, DepZ57, which exhibits robust tolerance to extreme pH and temperature conditions and specifically targets K57-type CPS. Distinct from the parental phage, DepZ57 provides full protection against lethal K57 K. pneumoniae infection in vivo and effectively alleviates infection-induced tissue damage. This work highlights the potential of phage depolymerases as stable, safe, and efficient nonantibiotic therapeutics for the prevention and control of hypervirulent K. pneumoniae infections.