Search Results (170,776)

The impact of skin pigmentation on the accuracy of optical biomedical devices has gained increased attention since the COVID-19 pandemic, particularly following evidence of oximetry measurement bias in dark-skinned individuals. Meanwhile, many computational models utilising the Monte Carlo (MC) technique have been developed as a cost-effective and scalable method for investigating these effects. Hence, this review explores the application of the MC technique in modelling skin pigmentation, focusing specifically on how melanin in the epidermis is represented across different studies. First, the biological mechanisms of pigmentation and current stratification methods are outlined to contextualise the variability in skin tone, followed by the principles of MC modelling, including photon scattering, absorption, reflection, and detection. Following a screening and exclusion process, 50 studies were evaluated in terms of how melanin concentration and distribution are incorporated into MC models and their applications, revealing a range of approaches that include analytical equations, experimental optical property measurements, or hybrid methods. The benefits and limitations of each approach is discussed, in addition to emerging advancements such as heterogeneous melanin distribution and the relation between optical properties and skin colour classification scales. Overall, the review outlines the current methodological approaches utilised for skin pigmentation modelling and offers a reference framework for researchers seeking to improve the representation of skin pigmentation in MC-based optical simulations. Full article

Objectives: This overview of systematic reviews aimed to synthesize and critically evaluate the current evidence on the effects of exercise performed under hypoxic or altitude conditions in adults, with particular attention to studies reporting altitude-related clinical outcomes. Materials and Methods: Following PRIOR and PRISMA guidelines, and with the protocol registered in PROSPERO CRD420261325746, a comprehensive search was conducted on 22 February 2026 across Medline/PubMed, Scopus, Web of Science, Epistemonikos, and Preprints.org, using the query “Exercise AND Hypoxic AND Altitude Sickness.” Because the search included “Altitude Sickness,” this review may miss some studies on performance or physiological adaptations under hypoxia. Eligibility was defined according to the PICOS framework, including only systematic reviews with or without meta-analyses in adults exposed to normobaric or hypobaric hypoxia. Methodological quality was assessed using AMSTAR 2. Results: A total of 137 records were identified (114 from databases and 23 through citation tracking), of which 28 systematic reviews met inclusion criteria. Nineteen included quantitative meta-analyses. Structured altitude training strategies—live high–train low (LHTL), live low–train high (LLTH), and live high–train high (LHTH)—were generally associated with improvements in maximal oxygen uptake and hematological parameters, particularly in trained and athletic populations. In contrast, acute hypoxic exposure was consistently associated with reduced exercise performance and increased susceptibility to altitude-related symptoms in unacclimatized individuals. Evidence regarding effects on body composition and metabolic outcomes was heterogeneous and inconsistent. According to AMSTAR 2, most meta-analyses presented critically low or low methodological quality. Conclusions: Exercise under hypoxic conditions may enhances aerobic and hematological adaptations in trained populations, whereas acute exposure tends to impair performance and entails clinical risks. However, given the restricted search strategy, substantial heterogeneity, lack of formal overlap quantification, and the predominance of low methodological quality reviews, these findings should be interpreted with caution. Evidence on metabolic benefits remains limited, highlighting the need for further high-quality systematic reviews and meta-analyses to clarify optimal hypoxic training protocols and outcomes. Full article

Background/Objectives: Type 2 Diabetes Mellitus (T2DM) is a prevalent metabolic disorder associated with major cardiovascular and metabolic complications. Regular physical activity is recommended for glycaemic management, but barriers such as obesity, joint pain, and impaired mobility may limit participation in land-based exercise. Aquatic exercise may provide a feasible alternative as water buoyancy reduces joint loading while allowing aerobic and resistance training. This systematic review and meta-analysis evaluated the effects of aquatic exercise interventions on glycaemic control in adults with T2DM. Methods: The review followed the PRISMA 2020 guidelines. MEDLINE, Cochrane CENTRAL, Scopus, Web of Science, and IEEE Xplore databases were searched. Randomised and non-randomised longitudinal studies involving adults aged ≥35 years with T2DM participating in structured aquatic exercise programmes were eligible. The primary outcome was glycated haemoglobin (HbA1c). Risk of bias was assessed using RoB 2 and RoBANS 2, and certainty of evidence was evaluated using GRADE. Random-effects meta-analysis calculated mean differences (MDs) with 95% confidence intervals. Results: Eleven randomised controlled trials involving 335 participants were included. Aquatic exercise significantly reduced HbA1c compared with passive control conditions (MD = −0.76%; 95% CI −1.21 to −0.32), although heterogeneity was high. No significant differences were observed between aquatic and land-based exercise interventions. Eight studies used wearable heart-rate monitors to regulate exercise intensity. Conclusions: Aquatic exercise may improve glycaemic control compared with sedentary conditions and yields effects comparable to those of land-based exercise in adults with T2DM. Further high-quality trials are needed to clarify optimal exercise dose–response and evaluate more advanced wearable technologies. Full article

This work deals with a practical method of using crumb rubber resulting from waste tires to produce modified bitumen via a wet mixing method for road construction in Iraq. Due to wide variation in temperatures and over-loading traffic in Iraq, rutting deformation is the most observed structural pavement problem. Also, tire wear and tear are higher in Iraq than in other countries due to high temperature and dry weather most of the year, which makes considerable amounts of waste tire piles easily accessible. Utilizing this waste material could be crucial to the environment and economy of the country, as well as to the sustainability of resources. Using waste tire materials as bitumen modifiers in the production of hot mix asphalt is a widely practiced experiment, although it is applied differently depending on the weather, type of bitumen used, and its availability. In the methodology of this research, it is suggested to modify asphalt grades 60/70 by a certain amount of crumb rubber (5–20%). The modified asphalt and asphalt grade 40/50 were used in preparing two types of asphalt concretes to examine their volumetric properties and evaluate their rutting behavior. The results for both mixtures were compared to the Iraqi General Specifications for Roads and Bridges (SORB/R9). The findings showed significant improvements in Marshall stability and flow, as well as in the percentages of voids satisfied in the modified mixture. After using rubberized asphalt in the mixture, the rutting depth was recorded below 20 mm and decreased by 30% and 26% at temperatures of 40 °C and 60 °C, respectively, compared to the controlled mixture. Full article

Background/Objectives: NF2-related schwannomatosis (NF2-SWN) is a genetic tumor predisposition syndrome of the nervous system caused by pathogenic variants in NF2 encoding the merlin tumor suppressor. Truncating variants in NF2 cause severe phenotypes with higher tumor burden, early mortality, and a lifetime need for multiple surgeries due to lack of medications that control schwannoma growth. Methods: We developed a functional precision medicine (FPM)-inspired workflow to identify drug sensitivities in cells isolated from a pediatric severe NF2-SWN patient’s spinal and peripheral schwannomas. Transcriptomic profiling, high-content drug sensitivity assays, tissue and isolated cell immunostaining, flow cytometry, and capillary-based immunoblotting were used to study the available tissues. Results: Aberrant merlin-dependent pathway expression was conserved between the spinal schwannoma and its cultured primary cells. Drug sensitivity screens in 2- and 3-dimensional formats revealed cytotoxic effects of fimepinostat in primary cells; dasatinib with brigatinib was the most effective cytostatic combination. Ineffective therapies attempted in the patient were also ineffective ex vivo. Conclusions: These data support the idea of using the FPM workflow to improve and individualize the standard of care for severe NF2-SWN patients using surgical samples. Full article

Background: Patients with type 2 diabetes mellitus (T2DM) undergoing cardiac surgery represent a high-risk population characterized by substantial cardiometabolic stress and increased susceptibility to postoperative heart failure, renal dysfunction, and unplanned rehospitalization. Although sodium-glucose cotransporter 2 (SGLT2) inhibitors provide established cardiorenal protection in ambulatory populations, their perioperative impact in cardiac surgery cohorts remains insufficiently defined. Methods: In a single-center retrospective cohort of 620 T2DM patients, inverse probability of treatment weighting and time-dependent Cox regression were applied to account for perioperative treatment interruption and delayed postoperative reinitiation when evaluating the association between chronic SGLT2 inhibitor therapy and 12-month rehospitalization risk. To provide biological context for the observed clinical associations, target-driven systems pharmacology, molecular docking against SGLT2, NHE1, AMPK, and NLRP3, and protein–protein interaction (PPI) network analysis were performed. Hub proteins were identified using Maximal Clique Centrality, followed by functional enrichment (GO/KEGG) analysis. Results: Chronic SGLT2 inhibitor therapy was associated with reduced first rehospitalization (HR 0.64; 95% CI 0.48–0.85; p = 0.002) and a lower cumulative rehospitalization burden (IRR 0.61; 95% CI 0.46–0.82; p = 0.001), primarily driven by heart failure-related and metabolic phenotypes. Molecular docking analyses identified favorable binding with SGLT2 and additional cardiometabolic and inflammatory targets, including NHE1, AMPK, NLRP3, IKKβ, IL-6Rα, and PPAR isoforms, suggesting modulation of myocardial ion homeostasis, metabolic resilience, and inflammatory signaling. PPI analysis identified eight hub proteins (AKT1, MTOR, STAT3, EGFR, PIK3CA, SRC, MAPK1, and MAPK3) significantly enriched in PI3K/AKT, MAPK/ERK, and ErbB signaling pathways. Conclusions: Chronic SGLT2 inhibitor therapy was independently associated with reduced postoperative rehospitalization and cumulative event burden in T2DM patients undergoing cardiac surgery. Integrated in silico analyses offer mechanistic hypotheses consistent with the observed clinical associations. These findings suggest that structured perioperative SGLT2 inhibitor management may contribute to improved postoperative outcomes, while prospective validation in future studies would strengthen these findings. However, given the retrospective observational design, these findings should be interpreted as associative rather than causal. Full article

Gypsum-based materials are widely used in construction but suffer from poor water resistance and durability, limiting their application in moisture-prone environments. While fiber-reinforced modified gypsum (FRMG) improves mechanical performance, the lack of systematic research on waterproofing strategies and their influence on both durability and strength remains a key challenge. This study investigated three waterproofing methods: surface coating with paraffin emulsion, internal incorporation of paraffin emulsion, and internal incorporation of vinyl acetate ethylene (VAE) emulsion. The workability, water absorption, mechanical properties, contact angle, and microstructure of the FRMG matrix were analyzed. The results showed that surface coating provided only short-term waterproofing. Internal incorporation of paraffin emulsion reduced water absorption but weakened mechanical performance. In contrast, VAE emulsion formed continuous polymer films that filled pores, significantly reducing water absorption while improving flexural and compressive strength, with optimal performance observed at a 6% dosage. In addition, increasing emulsion content enhanced hydrophobicity. These results indicate that VAE-based internal modification is an effective approach to improving the durability and performance of gypsum-based materials, providing guidance for their application in interior wall systems and prefabricated building components. Full article

Coal is the primary energy source in China and has long dominated energy consumption, serving as both the cornerstone for safeguarding national energy security and the backbone of stable energy supply. Despite the gradual improvement in the level of fully mechanized and intelligent mining in recent years, as well as the remarkable progress achieved in safe and efficient mining technologies, significant challenges are still encountered in the horizontal slicing mining of steeply inclined coal seams. This study was conducted against the engineering backdrop of the steeply inclined extra-thick coal seam in the Yimen Coal Mine, Sichuan Province. A combination of theoretical analysis, FLAC3D numerical simulation, and on-site monitoring was employed to investigate the support technology for mining roadways. Considering the geological occurrence conditions, roadway dimensions, and service life, the bolt (cable) + steel strip + metal mesh system was selected as the basic support method, with shed supports supplemented for reinforcement in areas with special geological structures or fractured surrounding rock. A non-uniform roadway support technology for horizontal slicing mining of steeply inclined extra-thick coal seams was proposed. The optimal support parameters of the roadways were determined through numerical simulation, and favorable support effects were verified by field measurements. Full article