Long-duration human spaceflight exposes the organism to an environment characterized by microgravity, altered mechanical loading, cephalad fluid redistribution, radiation exposure, confinement, and other factors capable of modifying physiological homeostasis. This review aimed to analyze and integrate current evidence concerning cardiovascular, metabolic, and systemic adaptations associated with prolonged space missions, emphasizing their mechanisms, recovery patterns, and relevance to future human exploration. A structured narrative review based on the scientific method was conducted using international peer-reviewed literature, with priority given to studies indexed in PubMed/MEDLINE and Scopus and to evidence derived from human spaceflight, longitudinal observations, clinically relevant reports, and complementary physiological investigations. The reviewed evidence identified cardiovascular and hemodynamic responses as the predominant research domain, particularly fluid redistribution, plasma-volume regulation, cardiac and vascular remodeling, altered venous circulation, blood-pressure regulation, and postflight orthostatic intolerance. Metabolic and musculoskeletal findings included mechanical unloading, changes in bone remodeling and mineral regulation, physical deconditioning, and alterations that may persist after return to gravity. Renal, immune, molecular, neurovascular, and neuro-ocular responses further demonstrated the multisystem nature of human adaptation to prolonged spaceflight. Recovery was heterogeneous among physiological domains: fluid-volume regulation tended to readjust comparatively rapidly, whereas cardiovascular function, cardiac structure, and immune or molecular responses showed variable trajectories, and some skeletal and neuro-ocular alterations demonstrated slower or incomplete recovery. These findings indicate that long-duration spaceflight should be understood as an integrated physiological challenge requiring longitudinal and individualized monitoring. Future lunar, Martian, and deep-space missions will require combined cardiovascular, metabolic, musculoskeletal, and systemic countermeasures, together with autonomous medical assessment and broader international collaboration to preserve physiological reserve and operational capacity during sustained human exploration beyond Earth.
Jorge Angel Velasco Espinal, Alexa Fernanda Uriostegui Navarro, Anthony Jesús Pastrana Villares et al.· IECCMEXICO· 0 citations
Photon-Counting Computed Tomography (PCCT) has emerged as one of the most significant innovations in diagnostic imaging by introducing photon-counting detector technology capable of overcoming several intrinsic limitations of conventional energy-integrating detector computed tomography. This review analyzes the technological principles underlying PCCT, its integration with artificial intelligence, current clinical applications, implementation challenges, and future perspectives in precision medicine. A structured review of the contemporary scientific literature was conducted using internationally recognized biomedical databases and peer-reviewed publications focusing on detector technology, spectral imaging, quantitative imaging biomarkers, radiation dose optimization, and multidisciplinary clinical applications. The reviewed evidence consistently demonstrated that PCCT provides superior spatial resolution, improved contrast-to-noise ratio, enhanced spectral imaging, quantitative tissue characterization, and substantial reduction of electronic noise and beam-hardening artifacts while maintaining lower radiation exposure than conventional CT systems. The greatest clinical benefits were observed in cardiovascular imaging, oncology, neurology, pediatric radiology, pulmonary imaging, abdominal imaging, and musculoskeletal applications. The integration of artificial intelligence further enhances image reconstruction, automated segmentation, lesion detection, radiomics, workflow optimization, and quantitative image analysis, facilitating increasingly individualized diagnostic assessment. Despite important challenges related to acquisition costs, infrastructure requirements, protocol standardization, and broader clinical implementation, the available evidence supports Photon-Counting Computed Tomography as a transformative technology with the potential to redefine diagnostic imaging and strengthen the development of precision medicine across diverse healthcare systems.
A. F. Ortega, Eileen Julliette Orantes Zacaríaz, M. B. Apráez et al.· International science journa...· 0 citations
Immune senescence has emerged as one of the principal biological mechanisms linking aging with the development and progression of autoimmune rheumatic diseases. Rather than representing a simple decline in immune function, aging induces profound remodeling of both innate and adaptive immunity, characterized by chronic low-grade inflammation, loss of immune tolerance, impaired cellular regeneration, mitochondrial dysfunction, telomere shortening, epigenetic alterations, and expansion of senescent immune-cell populations. The objective of this review was to analyze current evidence regarding the mechanisms through which immune senescence reshapes autoimmune rheumatic diseases and to examine its clinical implications, biomarkers, and emerging therapeutic strategies. A narrative literature review was conducted using the scientific method and included publications retrieved from PubMed/MEDLINE, Scopus, Web of Science, ScienceDirect, SpringerLink, Nature, Frontiers, and Wiley. The evidence consistently demonstrated that inflammaging, adaptive immune remodeling, and cellular senescence contribute to disease progression, increased susceptibility to infections, reduced vaccine responsiveness, cardiovascular complications, frailty, osteoporosis, sarcopenia, and diminished functional capacity. Conventional inflammatory biomarkers remain widely used; however, increasing attention has been directed toward multi-omics technologies, epigenetic clocks, mitochondrial biomarkers, proteomics, metabolomics, and immune-cell phenotyping for more accurate assessment of biological immune aging. Current therapeutic approaches continue to rely on disease-modifying antirheumatic drugs and biologic agents, while emerging interventions—including JAK inhibitors, mTOR modulation, senolytic therapies, microbiome-targeted strategies, and precision medicine—offer promising opportunities for future individualized management. Overall, immune senescence should be recognized as a fundamental component of autoimmune rheumatic diseases, providing important opportunities for improving diagnosis, risk stratification, therapeutic decision-making, and long-term clinical outcomes in aging populations.
