Search Results (233)

Background and Objectives: Hyperthermia significantly limits endurance performance in hot environments. To enhance heat loss and optimize athletic performance, pre-cooling interventions can be employed to accelerate body cooling. Therefore, the aim of this study was to evaluate the effects of an internal pre-cooling intervention combined with external pre-cooling or hydrogen-rich water on endurance performance in the heat. Materials and Methods: In a double-blind crossover with counterbalanced trials, all participants underwent a shuttle run test after 30 min under the following conditions: (1) hydrogen-rich cold water ingestion (HRCW); (2) cold water ingestion and external pre-cooling (IEPC); and (3) cold-water ingestion (control). Maximal aerobic speed (MAS), number of shuttle run repetitions, dehydration, temperature, heart rate (HR), rate of perceived exertion (RPE), blood lactate, and feeling scale (FS) were measured during the 20 m shuttle run test. Results: Our results revealed a significant variation in dehydration, MAS, number of shuttle run repetitions, blood lactate, RPE, and FS (p = [0.001–0.036]); additionally, a significant group × time interaction was found for body temperature (p = 0.021). Post hoc tests revealed a significant change for MAS (HRCW: p < 0.001), number of shuttle run repetitions (HRCW: p < 0.001), dehydration (HRCW: p= 0.009; IEPC: p = 0.008), blood lactate (HRCW: p < 0.001; IEPC: p < 0.001), RPE (HRCW: p = 0.05; IEPC: p = 0.004), and FS (HRCW: p = 0.05; IEPC: p = 0.004), as well as a significant decrease in body temperature (IEPC: p < 0.001; HRCW: p = 0.028) compared to the control condition after the test. However, no significant differences were reported in HR among the different conditions. Conclusions: In conclusion, findings from this study suggest that ingesting hydrogen-rich cold water effectively mitigates the effects of heat stress, thereby improving endurance performance, enhancing mood, and reducing ratings of perceived exertion. Full article

Objectives: The ability to efficiently regulate body temperature is crucial during endurance activities such as trail running, especially during competitive events in hot conditions. Over the past decade, passive hyperthermia exposure has grown significantly in popularity as a means of improving acclimatization and performance in hot environments. The present study aims to compare the physiological changes that occur in a group of professional athletes due to passive sauna exposure (80–90 °C) and their own response to maximal aerobic performance. Methods: Twelve professional trail runners (eight men and four women) were tested in three conditions: (i) baseline; (ii) before; and (iii) after (a) passive dry sauna exposure and (b) a maximal endurance test. In both cases, physiological parameters such as heart rate, tympanic temperature, arterial and muscle oxygen saturation, and blood concentrations of glucose, total cholesterol, high-density lipoprotein (HDL) and hemoglobin were measured. Results: Sauna exposure produced similar trends in cardiovascular and metabolic responses to those occurring during exercise, but at a much lower physiological level. Glucose and HDL levels were both significantly elevated (or tended to be so) after sauna and exercise (p < 0.03 and p < 0.01, respectively). Athletes who mobilized the sum of substrates (glucose and HDL) performed the exercise test faster (r = −0.76; p < 0.004). The response of arterial oxygen saturation (decreased) was similar during sauna and exercise, but opposite at the muscular level (increased during sauna and decreased during exercise). Additionally, inter-individual variability in responses was noted for most of the other parameters, suggesting the existence of ‘responders’ and ‘non-responders’ to thermal stimuli. Conclusions: The physiological responses of trained endurance athletes are moderately impacted by passive sauna use. However, individual changes could be correlated with endurance performance and optimizing individualization. Heat stimuli promote different physiological responses in terms of cardiac function, oxygen kinetics and substrate mobilization, albeit to a lesser extent than exercise. Greater substrate mobilization during maximal endurance exercise was found to be correlated with better performance. Further studies are needed to explore the concepts of metabolic flexibility, as described here, and how heat exposure may improve systemic health and performance. Full article

This investigation examines the Dead Hot Map (DHM) method and timing calibration for Run 14 Au+Au collisions in the PHENIX experiment. The DHM method guarantees data integrity by identifying and omitting defective detector towers (nonfunctional, hot, and very hot towers) via a set of criteria and statistical evaluations. This procedure entails hit distribution analysis, pseudorapidity adjustments, and normalization, resulting in an enhanced map of functional detector components. Timing calibration mitigates the issues associated with time-of-flight measurement inaccuracies, such as slewing effects and inter-sector timing differences. Numerous corrections are implemented, encompassing slewing, tower-specific offsets, and sector-by-sector adjustments, resulting in a final resolution of 500 picoseconds for the electromagnetic calorimeter. These calibrations improve the accuracy of photon and ${\pi }^0$ measurements, essential for investigating quark–gluon plasma in high-energy nuclear collisions. Full article

Background/Objectives: This study aimed to characterize the physicochemical properties and antioxidant activities of polysaccharides from Aconitum pendulum Bush processed through different methods (the polysaccharide from A. pendulum (DT), the polysaccharide from A. pendulum processed with zanba (Z-DT), the polysaccharide from A. pendulum processed with highland barley wine (Q-DT), and the polysaccharide from A. pendulum processed with hezi (H-DT)). Additionally, the research focused on optimizing the hot water extraction process for DT using response surface methodology (RSM) to enhance extraction efficiency and establish a scientific basis for pharmaceutical applications. Methods: The physicochemical properties and antioxidant activities of the four polysaccharides were systematically evaluated. RSM with a 17-run Box–Behnken design was employed to investigate the extraction process, examining three factors: extraction runs, liquid–solid ratio, and extraction time. Results: The physicochemical properties and antioxidant assays demonstrated that the DT exhibited significantly higher properties. The factors influencing the extraction process were ranked as extraction runs > liquid–solid ratio > extraction time. The optimal conditions for DT were a liquid–solid ratio of 25 mL/g, extraction time of 2.5 h, and four extraction runs, yielding a sugar content of 63.4%. Under these conditions, the extraction rate of DT was significantly higher than before optimization. Conclusions: The study demonstrated distinct structural features among the four polysaccharides, providing a scientific framework for their potential pharmaceutical applications. What’s more, the optimized hot water extraction protocol for DT was validated for high extraction rate and reproducibility. Full article

Objective: Current good manufacturing practice (cGMP) guidance for positron emission tomography (PET) drugs has been established in Europe and the United States. In Japan, the Pharmaceuticals and Medical Devices Agency (PMDA) approved the use of radiosynthesizers as medical devices for the in-house manufacturing of PET drugs in hospitals and clinics, regardless of the cGMP environment. Without adequate facilities, equipment, and personnel required by cGMP regulations, the quality assurance (QA) and clinical effectiveness of PET drugs largely depend on the radiosynthesizers themselves. To bridge the gap between radiochemistry standardization and site qualification, the Japanese Society of Nuclear Medicine (JSNM) has issued guidance for the in-house manufacturing of small-scale PET drugs under academic GMP (a-GMP) environments. The goals of cGMP and a-GMP are different: cGMP focuses on process optimization, certification, and commercialization, while a-GMP facilitates the small-scale, in-house production of PET drugs for clinical trials and patient-specific standard of care. Among PET isotopes, N-13 has a short half-life (10 min) and must be synthesized on site. [¹³N]Ammonia ([¹³N]NH₃) is used for myocardial perfusion imaging under the Japan Health Insurance System (JHIS) and was thus selected as a working example for the manufacturing of PET drugs in an a-GMP environment. Methods: A [¹³N]NH₃-radiosynthesizer was installed in a hot cell within an a-GMP-compliant radiopharmacy unit. To comply with a-GMP regulations, the air flow was adjusted through HEPA filters. All cabinets and cells were disinfected to ensure sterility once a month. Standard operating procedures (SOPs) were applied, including analytical methods. Batch records, QA data, and radiation exposure to staff in the synthesis of [¹³N]NH₃ were measured and documented. Results: 2.52 GBq of [¹³N]NH₃ end-of-synthesis (EOS) was obtained in an average of 13.5 min in 15 production runs. The radiochemical purity was more than 99%. Exposure doses were 11 µSv for one production run and 22 µSv for two production runs. The pre-irradiation background dose rate was 0.12 µSv/h. After irradiation, the exposed dosage in the front of the hot cell was 0.15 µSv/h. The leakage dosage measured at the bench was 0.16 µSv/h. The exposure and leakage dosages in the manufacturing of [¹³N]NH₃ were similar to the background level as measured by radiation monitoring systems in an a-GMP environments. All QAs, environmental data, bacteria assays, and particulates met a-GMP compliance standards. Conclusions: In-house a-GMP environments require dedicated radiosynthesizers, documentation for batch records, validation schedules, radiation protection monitoring, air and particulate systems, and accountable personnel. In this study, the in-house manufacturing of [¹³N]NH₃ under a-GMP conditions was successfully demonstrated. These findings support the international harmonization of small-scale PET drug manufacturing in hospitals and clinics for future multi-center clinical trials and the development of a standard of care. Full article

We investigate primordial gravitational waves produced in the early universe within the Running Vacuum Model, which ensures a smooth transition from a primeval inflationary epoch to a radiation-dominant era, ultimately following the standard Hot Big Bang trajectory. In contrast to traditional methods, we approach the gravitational wave equation by reformulating it as an inhomogeneous equation and addressing it as a back-reaction problem. The effective potential, known as the Grishchuk potential, which drives cosmic expansion, is crucial in damping the amplitude of gravitational waves. Our findings indicate that this potential is contingent upon the maximum value of the reduced Hubble parameter, ${\mathcal{H}}_{\max }$, which is sensitive to the time at which there is a transition from vacuum energy dominance to radiation dominance. By varying ${\mathcal{H}}_{\max }$, we explore its influence on the scale factor and effective potential, revealing its connection to the spectrum of gravitational wave amplitudes that can be constrained by observational data. Full article

Hunan Province, located in Central-South China, has a hot and humid climate, which has shaped the unique characteristics of its cattle. In this study, we analyzed the genomic diversity of 110 indigenous Hunan cattle using whole-genome sequencing and found that they have a mixed ancestry of indicine and taurine. By grouping the cattle based on their collection regions (western, central, southeastern, and southern Hunan), we used an unsupervised three-component Gaussian model to classify the runs of homozygosity (ROH) and calculated the genomic inbreeding coefficient based on runs of homozygosity (FROH) to assess inbreeding levels. The results showed that western Hunan cattle had the highest level of hybridization, while southern Hunan cattle had the lowest. Through selective sweep analysis, we identified candidate genes and pathways related to environmental adaptation and homeostasis. Notably, the SLC5A2 gene showed strong selection signals across all four regions and exhibited a distinct haplotype compared to other referenced cattle breeds. Additionally, we detected introgression from wild species into Hunan domestic cattle and analyzed their Y-chromosome haplotypes. Full article

The steel industry, as a large-scale equipment-intensive sector, emphasizes the importance of maintaining and managing equipment without failure. In line with the recent Fourth Industrial Revolution, there is a growing shift from preventive to predictive maintenance (PdM) strategies for cost-effective equipment management. This study aims to develop a PdM model for the Run-Out Table (ROT) equipment in hot rolling mills of steel plants, utilizing artificial intelligence (AI) technology, and to propose methods for contributing to energy efficiency through this model. Considering the operational data characteristics of the ROT equipment, an autoencoder (AE), capable of detecting anomalies using only normal data, was selected as the base model. Furthermore, Long Short-Term Memory (LSTM) networks were chosen to address the time-series nature of the data. By integrating the technical advantages of these two algorithms, a predictive maintenance model based on the LSTM-AE algorithm, named the Run-Out Table Predictive Maintenance Model (ROT-PMM), was developed. Additionally, the concept of an anomaly ratio was applied to identify equipment anomalies for each coil production. The performance evaluation of the ROT-PMM demonstrated an F1-score of 91%. This study differentiates itself by developing an optimized model that considers the specific environment and large-scale equipment operation of steel plants, and by enhancing its applicability through performance verification using actual failure data. Furthermore, it emphasizes the importance of PdM strategies in contributing to energy efficiency. It is expected that this research will contribute to increased energy efficiency and productivity in industrial settings, including the steel industry. Full article

Nitrous oxide is a highly suitable oxidizer for hybrid rockets due to its self-pressurizing properties, moderate cost, and high accessibility. However, its vapor pressure and density are highly dependent on ambient temperature, requiring careful consideration of temperature variations in real applications. To mitigate this issue, an oxidizer called Nytrox was produced by adding a small fraction of oxygen to bulk nitrous oxide. This modification enables the hybrid rocket propulsion system to maintain a nearly constant average thrust and total impulse across a wide range of ambient temperatures. A series of 7 s hot-fire tests of a small Nytrox/polypropylene hybrid rocket engine operating at ~60 barA of running tank pressure demonstrated a consistent average thrust of 45.3 ± 0.7 kgf and a total impulse of 307.6 ± 3.9 kgf·s within a N₂O temperature range of 5.9–22.6 °C, compared to highly varying values of the N₂O/polypropylene one within a N₂O temperature range of 10.8–29.8 °C. Furthermore, the specific impulse of the Nytrox hybrid rocket engine increases mildly with decreasing temperature because of the increasing amount of added oxygen that benefits the combustion for generating the thrust. Full article

Environmental and social governance targets, as well as the global transition to cleaner renewable energy sources, push for advancements in hydrogen-based solutions for energy generators due to their high energy per unit mass (energy density) and lightweight nature. Hydrogen’s energy density and lightweight nature allow it to provide an extended range of uses without adding significant weight, potentially revolutionizing many applications. Moreover, a variety of sources, including renewable energy, can produce hydrogen, making it a potentially more sustainable option for energy storage despite its main limitations in production and transportation costs. In this framework we are proposing an innovative energy generator that might merge the benefits of batteries and hydrogen. The energy generator is based on a worldwide patented solution introduced by MIEEG s.r.l. regarding the shape of the chambers. This innovative solution can be used to design a 100% H2-fed microturbine with a high power/weight/volume ratio that works as a range extender of battery packs for a comprehensive, high-efficiency hybrid powertrain. In fact, it runs at 100,000 rpm and is designed to deliver about 100 kW in about 15 L of volume and 15 kg of weight (alternator excluded). The system is highly complex due to high firing temperatures, long life requirements, corrosion protection, mechanical and vibrational stresses, sealing, couplings, bearings, and the realization of tiny blades. This paper analyzes the main design challenges to face in the development of such complex generators, focusing on the hot gas path components, which are the most critical part of gas turbines. The contribution of additive manufacturing techniques, the adoption of special materials, and coatings have been evaluated for system improvement. Full article

In hot-forming, integrating in situ quality monitoring is essential for the early detection of thermally induced geometric deviations, especially in the production of hybrid bulk metal parts. Although hybrid components are key to meeting modern technical requirements and saving resources, they exhibit complex shrinkage behavior due to differing thermal expansion coefficients. During forming, these components are exposed to considerable temperature gradients, which result in density fluctuations in the ambient air. These fluctuations create an inhomogeneous refractive index field (IRIF), which significantly affects the accuracy of optical geometry reconstruction systems due to light deflection. This study utilizes existing simulation IRIF data to predict the magnitude and orientation of refractive index fluctuations. A light deflection simulation run on a GPU-accelerated ray tracing framework is used to assess the impact of IRIFs on optical measurements. The results of this simulation are used as a basis for selecting optimized measurement positions, reducing and quantifying uncertainties in surface reconstruction, and, therefore, improving the reliability of quality control in hot-forming applications. Full article

Legionella colonization of water systems represents a potential hazard for humans within healthcare facilities. It is possible to contain its spread through continuous disinfection systems and the correct management and maintenance of the systems. The hygienic and sanitary quality of the water cannot be ignored in an evaluation of the management and energy costs. The Fondazione Policlinico Universitario A. Gemelli IRCCS in Rome has installed the “ME.SI. MR ACS” (MEthod of SavIngs Maximum eneRgy for hot water) device, which allows the system to activate, when necessary, avoiding continuous water recirculation. The objectives of this study are to evaluate the health and hygiene quality of the hospital water network and to evaluate the thermal and electrical energy savings and chlorine dioxide consumption, with and without this device in operation. This study involved three phases of microbiological sampling in the facility under study: ME.SI. MR ACS device installed but not running, with the boilers’ setpoint temperature at 60 °C; device running with the boilers’ setpoint temperature at 60 °C; and device in operation with the boilers’ setpoint temperature at 45 °C. The microbiological analyses were carried out in accordance with the ISO standard. The data show a constant absence of Legionella spp. in all samples. The application of ME.SI. MR ACS on the hot water recirculation circuit leads to a reduction in the daily consumption of electrical and thermal energy of 68.6% and 48.6%, respectively, for a savings of approximately EUR 23,000/year per circuit. Furthermore, with the device in operation, there is a 50% reduction in the chlorine dioxide consumption with a savings of EUR 11,500/year. ME.SI. MR ACS guarantees thermal and electrical energy savings associated with a reduction in chlorine dioxide consumption, maintaining the hygienic and sanitary quality of the water network. Full article

Cytochrome c is a critical protein in energy metabolism, and its structural adaptations to different temperatures play a key role in enabling species like the wild Bactrian camel (Camelus ferus) and the Arabian camel (Camelus dromedarius) to thrive in their respective cold and hot environments. This study investigates the structural, thermodynamic, and dynamic properties of cytochrome c at different temperatures. Thermal Titration Molecular Dynamics (TTMD) simulations, which involve analyzing protein behaviour across a range of temperatures, were carried out using GROMACS, with each simulation running for 100 nanoseconds, at 245 K, 280 K, 303 K, 308 K, and 320 K, to evaluate stability and flexibility. Structural alterations were indicated by an increase in root mean square deviations (RMSDs) to 0.4 nm at 320 K, as opposed to lower RMSD values (0.1–0.2 nm) at 245 K and 280 K. Root mean square fluctuation (RMSF) analyses revealed modest flexibility at 245 K and 280 K (0.1–0.2 nm) but considerable flexibility (0.3–0.4 nm) at 303 K and 320 K. Principal component analysis (PCA) found that the formational space was constrained at lower temperatures but expanded at higher temperatures. Entropy peaked at 280 K (13,816 J/mol) and then fell substantially at 320 K (451.765 J/mol), indicating diminished stability. These findings highlight cytochrome c adaptations for cold stability in Camelus ferus and thermal resilience in Camelus dromedarius, showing evolutionary strategies for harsh conditions. Full article

Good sleep is essential for a healthy life. While airflow improves sleep in a hot environment, it may cause an excessive drop in body temperature because thermal-adaptive behavior is inactive during sleep. This study aims to propose an airflow control theory that prevents the excessive drop in body temperature while maintaining good sleep. The theory changes the heat transfer coefficient between the skin and the environment by the intensity of the fan operation to maintain a heat loss of 30 W/m² from a body with a skin temperature of 34.5 °C in a temperature-changing environment. We fabricated a ventilated sleep capsule in which this theory was embedded. Thermal manikin experiments were conducted to obtain the relationship between sensible heat transfer coefficients and the fan operating signal to establish control equations. We conducted a case study to evaluate whether the theory provided better sleep than sleeping with a regular fan running freely in homes in Ueda City, Japan, in one summer. Although the data used in the analysis were from only three subjects, the statistical analysis showed that sleeping in the ventilated sleep capsule provided better sleep, with a mean of 6% better sleep efficiency. Full article

Background: Runs of homozygosity (ROHs) and heterozygosity (ROHets) serve for the identification of genomic regions as candidates of selection, local adaptation, and population history. Methods: The present study aimed to comprehensively explore the ROH and ROHet patterns and hotspots in Greek native dairy goats, Eghoria and Skopelos, genotyped with the Illumina Goat SNP50 BeadChip. SNP and functional enrichment analyses were conducted to further characterize hotspots and the candidate genes located within these genomic regions. Genetic relationships between and within breeds and inbreeding coefficients were also evaluated. Results: Clear genetic differentiation and diversified management practices were depicted between the two native populations. The ROH and ROHet average genome coverage for Skopelos (65.35 and 35 Mb) and Eghoria (47.64 and 43 Mb) indicated differences in mainland and insular goats, with Skopelos showing more long ROH fragments, reflecting its geographic isolation and small population size. An ROH hotspot (CHR12: 43.59–44.61 Mb) detected in the Skopelos population has been also reported across European goats and co-localizes with a selection signal detected in the Egyptian Barki goats and sheep adapted to hot–arid conditions. A novel ROH hotspot (CHR18: 60.12–61.81 Mb), shared among the Greek breeds, harbors candidate genes enriched in biosynthesis, metabolism, and immune response. Two well-conserved ROHet islands were detected in Greek goats on chromosomes 1 and 18, with genes participating in development and embryogenesis. The Eghoria population showed the highest number of ROHet islands, potentially reflecting its adaptability to diverse environments. Conclusions: These findings offer new insights into the environmental adaptation and artificial selection in Greek goats and could be utilized in future breeding strategies for sustainable goat farming. Full article