Search Results (234)

Background/Objectives: Following the recent publication of reassuring outcomes from the ARA MED 330 protocol regarding long-term insulin use in pilots, combined with continuous advancements in diabetes technology, European aeromedical examiners are increasingly optimistic about establishing more flexible medical requirements for insulin-treated aviation professionals. These professionals have historically been considered unfit for duty due to hypoglycemic risks. According to current research, hypoglycemia, the primary incapacitation risk for flight crew, is considered virtually non-existent among air traffic controllers (ATCOs). Additionally, stress-induced hyperglycemia also represents a low-frequency risk in these professionals, who are experienced in managing highly stressful operational environments. This study presents a narrative review examining stress and its metabolic effects in healthy individuals, ATCOs, and people with diabetes (PwD). Methods: This narrative review was conducted based on a comprehensive PubMed search performed by two independent reviewers (GAR and AM) spanning January 2023 to January 2025. The search strategy focused on English-language, peer-reviewed studies involving human participants and addressed stress, glucose regulation, and occupational factors in ATCOs and people with diabetes. Additional relevant articles were identified through reference screening. A total of 33 studies met the inclusion criteria. Studies focusing solely on oxidative or molecular mechanisms were excluded from the analysis. Results: Stressful events consistently triggered the expected hyperglycemic reaction in both healthy individuals and PwD. However, the literature indicates ATCOs demonstrate remarkable stress resilience and adaptation to the demanding conditions of their work environment, suggesting a unique occupational profile regarding metabolic stress responses. Conclusions: These findings contribute valuable insights to ongoing discussions regarding aeromedical fitness standards. The evidence suggests that ATCOs may not face the same metabolic risks as flight crews, indicating that current medical certification processes for insulin-treated aviation professionals warrant reconsideration in light of this emerging evidence. This research supports the potential for more individualized, occupation-specific aeromedical standards that better reflect the actual risk profiles of different aviation roles. Full article

Jet fuels are a complex mixture of hydrocarbons and performance additives, including some compounds with established human toxicity. They represent a significant occupational hazard for military personnel; however, little is known about possible long-term health effects, particularly following cessation of exposure. In response to United States (US) Veterans’ concerns, the US Department of Veterans Affairs (VA) and the Department of Defense (DoD) launched a large retrospective cohort study to assess the impact of military occupational jet fuel exposure on Veterans’ health. The Long-Term Impact of Fuel Exposure (LIFE) cohort consists of over 1.3 million Veterans who entered service on or after 1 January 1995, including both individuals with jet fuel-exposed occupations in their service history and a random sample of unexposed Veterans. Data from multiple VA and DoD administrative datasets were linked to evaluate morbidity, disability, and mortality endpoints. Analyses are underway to assess associations between jet fuel exposure and adverse health outcomes in multiple body systems. This study represents the largest effort to date to investigate these effects, with the intention of informing policies affecting Veterans for years to come. Full article

Background/Objectives: The advancing technological developments of recent decades have also changed the stress profile of pilots of high-performance aircraft (HPA) immensely. Pilots are exposed to different gravitational (G)-forces and are only able to fly with anti-G suits that compensate for the physiological loss of cerebral perfusion by applying external pressure to the body, and positive pressure breathing during G [PBG]. The present study therefore aims to investigate long-term effects of PBG on the lung capacity of fighter pilots. Methods: In a retrospective data analysis (1972–2024), the clinical findings of all German military pilots were analyzed. In total, 1838 subjects were included in the analysis, divided into three groups: HPA with PBG, HPA without PBG, and fixed-wing aircraft. Results: Lung function analysis showed that no significant decrease in FVC was found in the HPA group with PBG, but a decrease was found in the HPA group without PBG. FEV1 and FEV1/FVC decreased significantly in all groups. Multiple regression analyses indicated that the variables age and aircraft type were significant predictors of the changes in FVC and FEV1, but not for the Tiffeneau index. Conclusions: Our study showed that the lung function of HPA pilots who were exposed to both PBG and repeated increased G-forces did not deteriorate to a significantly greater extent compared with other pilots without these conditions; in some cases, it even deteriorated to a lesser extent. Overall, age has primarily been shown to be the predisposing factor for a deterioration in lung function parameters over time. Full article

Beneficial interactions between nitrogen-fixing soil bacteria and legumes offer a solution to increase crop yield on Earth and potentially in future Martian colonies. Paraburkholderia phymatum is a nitrogen-fixing beta-rhizobium, which enters symbiosis with more than 50 legumes and can survive in acidic or aluminium-rich soils. In a previous RNA-sequencing study, we showed that the beta-rhizobium P. phymatum grows well in simulated microgravity and identified phymabactin as the only siderophore produced by this strain. Here, the growth of the beta-rhizobium P. phymatum was assessed in Martian simulant soil using Enhanced Mojave Mars Simulant 2 (MMS-2), which contains a high amount of iron (18.4 percent by weight) and aluminium (13.1 percent by weight). While P. phymatum wild-type’s growth was not affected by exposure to MMS-2, a mutant strain impaired in siderophore biosynthesis (ΔphmJK) grew less than P. phymatum wild-type on gradient plates in the presence of a high concentration of MMS-2 or aluminium. This result suggests that the P. phymatum siderophore phymabactin alleviates aluminium-induced heavy metal stress. Ultra-high performance liquid chromatography–mass spectrometry (UHPLC-MS) showed that phymabactin can bind to aluminium more efficiently than iron. These results not only deepen our understanding of the behaviour of rhizobia in simulated extraterrestrial environments but also provide new insights into the potential use of P. phymatum for bioremediation of aluminium-rich soils and the multiple roles of the siderophore phymabactin. Full article

A dual-parameter optical fiber sensor for measuring the magnetic field and temperature based on the Fabry–Perot interferometer (FPI) and magnetic polymer film was proposed and designed, realizing dual-parameter measurement of temperature and the magnetic field. The sensor uses the excellent elasticity and thermal expansion coefficient of PDMS and the magnetostrictive effect of Fe₃O₄ magnetic polymer film to provide magnetic field and temperature detection while maintaining good reusability, achieving a magnetic field sensitivity and temperature sensitivity of 69 pm/mT and 390 pm/K, respectively. The sensor has the advantages of a low cost, a simple manufacturing process, good linearity, and a sensitive temperature response. It has broad application prospects in medicine, geography, aerospace, and other fields. Full article

Objectives: Assessing balance in highly trained individuals, such as military pilots, poses challenges, as deficits may be underestimated when compared to general population norms. To address this, several studies have proposed tailored databases providing reference values for specific populations. This study retrospectively analyzed balance characteristics in active-duty military pilots of the Italian Air Force. Methods: We enrolled 106 subjects split into two groups: 53 military pilots from the Italian Air Force and 53 civilians without flight experience or exposure to specific vestibular stimuli. All participants underwent ENT examinations with audiometric testing to exclude related pathologies, followed by a personal history collection. Subsequently, they completed the EquiTest protocol across six standard conditions. Results: Significant differences were observed between Army Aviators and Non-Aviators. The PREF variable showed the most consistent distinction, with military pilots demonstrating a superior performance (p < 0.01). Additionally, borderline differences were noted in Condition 6 of the equilibrium scores (p = 0.056), and in the Centre of Gravity (COG) analysis along the X-axis for Conditions 1 and 5 (p = 0.090), and for Condition 2 (p = 0.050). These findings suggest enhanced postural control strategies among Army Aviators under conditions of sensory conflict. Conclusions: These findings suggest that normative balance values specific to military pilots should be used when evaluating aviators recovering from balance deficits. Such tailored benchmarks can help determine the need for rehabilitation before returning to duty, ensuring optimal performance under demanding conditions. Further research is necessary to explore the underlying mechanisms responsible for these adaptations and to identify the specific stimuli that contribute to the enhanced balance capabilities observed in this highly trained population. Full article

Heart rate variability (HRV) has been established as a measure for the variation in time intervals between successive cardiac actions as a marker of the autonomic nervous system. However, despite many efforts in this field, there are no reference values that are generally accepted. The objective of this systematic review is, therefore, to present an overview of the studies on HRV normal values published to date, with due consideration of any influencing factors. A systematic database query was carried out in PubMed, Scopus, Ovid Medline, and PsychInfo using the search string “((hrv) or (heart rate variability)) and ((reference values) or (reference range) or (normal values))”. Of the 6640 studies yielded by the query, 58 were used for this systematic review. The STARD-HRV procedure was used to assess the quality of the studies. The studies considered date from 1989 to 2022. The number of subjects examined was between 20 and 84,772. The age of the subjects was between 1 day and 99 years. A total of 51 of the studies examined both male and female subjects. In total, 19 studies used long-term measurements, 22 studies used short-term measurements, and 17 studies used intermediate measuring periods. Many different HRV parameters were analyzed, most often traditional time-domain and frequency-domain ones. Nine studies described the subjects as “healthy” without giving more detailed explanations. There are no generally accepted HRV normal values (yet). Some large studies provide values that may be used for orientation purposes. However, further studies are required to collect HRV normal values. It was not possible to merge the results of the studies in terms of a meta-analysis; this would also not be practical since, among other reasons, the consideration of confounders as well as recording and measuring modalities sometimes vary to a large extent and impede the comparability of the studies. Generally, HRV seems to be influenced by various mechanisms and external factors that are still not fully understood. An exploration of these factors will ultimately allow HRV normal values to be obtained in a manner that is generally accepted. Full article

Swimming goggles still face numerous challenges in practical use, including deterioration and failure of anti-fog coatings, residual water marks on lens surfaces, and relatively short service life in complex environments. When swimming outdoors during winter, goggles also present an icing problem. To address these problems and enhance the performance of swimming goggles, this study employs a combination of plasma cleaning and mechanical spraying methods, utilizing HB-139 SiO₂ to modify the surface of goggle lenses, thereby fabricating lenses with superhydrophobic properties. The changes in lens surfaces before and after friction and immersion treatments were characterized using three-dimensional profilometry and scanning electron microscopy, further investigating the hydrophobic, drag-reducing, wear-resistant, and anti-icing properties of the lenses. Experimental results demonstrate that SiO₂ can enhance the hydrophobic, drag-reducing, durability, and anti-icing performance of the lenses. Under standard conditions, the contact angle of modified samples reached 162.33 ± 3.15°, representing a 48.77 ± 2.15% improvement over original samples. Under friction conditions, modified samples exhibited a 45.86 ± 2.53% increase in contact angle compared to original samples, with Sa values decreasing by 58.64 ± 3.21%. Under immersion conditions, modified samples showed a 54.37 ± 2.44% increase in contact angle relative to original samples. The modified samples demonstrated excellent droplet bouncing performance at temperatures of −10 °C, 10 °C, and 30 °C. De-icing efficiency improved by 14.94 ± 2.37%. Throughout the experimental process, SiO₂ demonstrated exceptional hydrophobic, drag-reducing, durability, and anti-icing capabilities. This establishes a robust foundation for the exemplary performance of swimming goggles in both training and competitive contexts. Full article

Objective: The air content within the lungs directly influences the dielectric properties of lung tissue; however, previous studies were conducted under ex vivo conditions and without quantitatively controlling air volume. This study aims to develop an improved model using in vivo measurements to accurately characterize the dielectric properties of rabbit lung tissue across various tidal volumes. Methods: In this study, six sets of different tidal volumes (30, 40, 50, 60, 70, 80 mL) were set in the frequency band of 100 MHz~1 GHz to analyze the trend of the dielectric properties, and the dielectric parameters were systematically constructed under the conditions of different tidal volumes. Results: It was found that the conductivity and permittivity of rabbit lung tissue showed a decreasing trend with increasing tidal volume in the measuring frequency band. The traditional Cole–Cole model has limitations in simulating the dielectric properties of in vivo lung tissues. Therefore, by refining and optimizing the model, this study successfully reduced the average error between the measured data and the model fitting to less than 5%. Conclusions: This study lays the groundwork for investigating the relationship between total air volume within the lungs and their dielectric properties in vivo. Full article

This article explores the foundational principles of ionizing radiation and provides a comprehensive overview of its impact on thermoplastic polymers. Ionizing radiation, encompassing gamma rays, X-rays, and electron beams, has been extensively studied due to its capacity to alter the molecular structure of polymers. These changes enable advancements in various applications by promoting molecular crosslinking, controlled degradation, molecular grafting, and crystallinity adjustments. The article delves into the fundamental mechanisms of radiation thermoplastic polymer interactions, including ionization, electronic excitation, and free radical formation. It highlights how these processes lead to structural transformations that enhance the physical, thermal, and mechanical properties of thermoplastic polymers. Factors such as radiation type, absorbed doses, temperature, and environmental conditions are discussed in the context of their role in controlling these modifications. Key practical applications are identified across fields such as medicine, food packaging, aerospace, and industry. Examples include the production of sterilizable medical devices, enhanced food packaging for longer shelf life, and radiation-resistant materials for the aerospace and nuclear sectors. Despite its many advantages, the article also emphasizes challenges such as process variability, polymer sensitivity to radiation, and standardization difficulties. The review underscores emerging research directions, including optimizing irradiation parameters and integrating advanced characterization techniques like Fourier Transform Infrared Spectroscopy (FT-IR) and X-ray diffraction (XRD). The development of new polymer blends and composites, designed for irradiation-induced property enhancement, represents a promising area of innovation. Full article

Background/Objectives: Metabolite risk score (MRS), which considers the collective effects of metabolites closely reflecting a phenotype, is a new approach for disease assessment, moving away from focusing solely on individual biomarkers. This study aimed to investigate a metabolite panel for dyslipidemia and verify the diagnostic efficacy of MRS on dyslipidemia. Methods: Key metabolite identification and MRS establishment were conducted in the discovery set, and MRS validation was performed in the replication set, with 50 healthy individuals and 50 dyslipidemia patients in each set. The MRS was constructed using key metabolites, identified via UPLC-MS/MS analysis, employing a weighted approach based on linear regression analysis. Results: N-acetylisoputreanine-γ-lactam and eicosapentaenoic acid were identified as key metabolites for dyslipidemia and were utilized for establishing the MRS. In addition to the MRS model, a conventional dyslipidemia diagnostic model based on lipid profiles, as well as a combined model (MRS + lipid profiles), were also established. In the discovery set, the MRS model diagnosed dyslipidemia with 85.4% accuracy. When combined with lipid profiles, accuracy improved to 91.8%. In the replication set, the MRS demonstrated diagnostic power with 76.1% accuracy, while the combined model achieved 86.0% accuracy for dyslipidemia assessment. Conclusions: The MRS alone indicated sufficient assessment power in a real-world setting, despite a slight reduction in assessment ability when validated in the replication set. At this stage, therefore, the MRS serves as an auxiliary tool for disease diagnosis. This first attempt to apply MRS for dyslipidemia may offer a foundational concept for MRS in this disease. Full article

Thoracic electrical impedance tomography (EIT) provides real-time, bedside imaging of pulmonary function and has demonstrated significant clinical value in guiding treatment strategies for critically ill patients. However, the practical application of EIT remains challenging due to its susceptibility to measurement disturbances, such as electrode contact problems and patient movement. These disturbances often manifest as spike-like noise that can severely degrade EIT image quality. To address this issue, we propose a robust Principal Component Analysis (RPCA)-based approach that models EIT data as the sum of a low-rank matrix and a sparse matrix. The low-rank matrix captures the underlying physiological signals, while the sparse matrix contains spike-like noise components. In simulation studies considering different spike magnitudes, widths and channels, all the image correlation coefficients between RPCA-processed images and the ground truth exceeded 0.99, and the image error of the original fEIT image with spike-like noise was much larger than that after RPCA processing. In eight patient cases, RPCA significantly improved the image quality (image error: p < 0.001; image correlation coefficient: p < 0.001) and enhanced the clinical EIT-based indexes accuracy (p < 0.001). Therefore, we conclude that RPCA is a promising technique for reducing spike-like noise in clinical EIT data, thereby improving data quality and potentially facilitating broader clinical application of EIT. Full article

The adverse effects of weightlessness on the human cardiovascular system greatly hinder the process of long-term and long-distance space exploration. Succinylation is an important type of protein post-translational modification. However, whether succinylation modification is able to play a role in altered vascular endothelial cell function under microgravity or simulated microgravity has not been reported. This study aims to investigate the quantitative global proteome and the changes in lysine succinylation in related proteins, seeking to facilitate a better understanding of the protein post-translational modification in cardiovascular deconditioning under microgravity. LC-MS/MS combined with bioinformatics analysis were used to quantitatively detect the perspectives at the global protein level. Immunoprecipitation and Western blot analysis were conducted to further verify the alterations of related proteins and lysine succinylation. A total of 132 differentially expressed proteins and 164 differentially expressed lysine succinylation sites were identified in human umbilical vein endothelial cells (HUVECs). Bioinformatics analysis indicates that lysine succinylation may play a potential role in energy metabolism. In addition, desuccinylase SIRT5 was downregulated and regulated succinylation modification levels of HUVECs under simulated microgravity. Notably, the overexpression of SIRT5 effectively protected HUVECs from apoptosis induced by simulated microgravity. And the succinylation of Lys396 in ERO1A was significantly increased in HUVECs under simulated microgravity. Mechanistically, the knockdown of SIRT5 was found to induce the apoptosis of HUVECs through the succinylation of Lys396 in ERO1A. These results can provide new ideas for elucidating the molecular mechanism of cardiovascular dysfunction in microgravity environments, and provide key molecular targets for scientific protective measures against microgravity in space. Full article

Additive manufacturing (AM), commonly known as 3D printing, is revolutionizing manufacturing, medicine, and engineering. This perspective explores recent breakthroughs that position AM as a disruptive technology. Innovations like volumetric additive manufacturing (VAM) enable rapid, high-resolution, layer-free fabrication, overcoming limitations of traditional methods. Multi-material printing allows the integration of diverse functionalities—fluid channels, structural elements, and possibly functional electronic circuits—within a single device. Advances in material science, such as biocompatible polymers, ceramics, and transparent silica glass, expand the applicability of AM across healthcare, aerospace, and environmental sectors. Emerging applications include custom implants, microfluidic devices, various sensors, and optoelectronics. Despite its potential, challenges such as scalability, material diversity, and process optimization remain active and critical research areas. Addressing these gaps through interdisciplinary collaboration over the coming decade will solidify AM’s transformative role in reshaping production and fostering innovation across many industries. Full article

Background and Objectives: Hyperbaric oxygen therapy (HBOT) has shown promise in managing complications due to cancer treatments, particularly those related to radiotherapy and surgery. Despite its clinical benefits, concerns persist regarding its potential to influence cancer progression. This study aimed to evaluate the safety and clinical outcomes of HBOT in patients with active or previously treated solid tumors. Methods: A retrospective analysis was conducted on patients with solid tumors who underwent at least five HBOT sessions. Comprehensive data, including patient demographics, cancer type, total number of HBOT sessions, imaging findings, and clinical outcomes (recurrence, metastasis, and mortality), were collected. Descriptive statistics and the relationship between the number of HBOT sessions and long-term cancer outcomes were analyzed. Results: This study included 45 patients (median age: 64 years; 60% male) who received a median of 27 HBOT sessions. At initiation, 27.9% of the patients were classified as cured, 53.5% were in remission, and 18.6% had active cancer. Over a median follow-up period of 783 days, 8.7% experienced recurrence, 2.7% had persistent active cancer, and 59.5% had no recurrence. No HBOT-related complications were observed during the course of HBOT. Statistical analyses revealed no significant correlations between the number of HBOT sessions and metastasis (p = 0.213) or mortality (p = 0.881). Conclusions: HBOT appears to be a safe and effective adjunctive therapy for managing complications in patients with solid tumors. No evidence was found to suggest HBOT contributes to tumor progression, recurrence, or metastasis. Future prospective studies with larger cohorts are needed to confirm these results and further evaluate the therapeutic role of HBOT in oncology. Full article