Search Results (163,753)

Unsymmetrical dimethylhydrazine (UDMH) was previously used as a rocket propellant in launch vehicles. During the operation and accidents of launch vehicles, hundreds of tons of UDMH were released. While these launch vehicles are gradually being phased out, UDMH continues to be used in space technology and other industries. When released into the environment, UDMH forms numerous transformation products. Several dozen have been reliably identified, and hundreds are believed to exist, many of which are highly toxic and quite persistent in the environment. Gas chromatography–mass spectrometry (GC-MS) is one of the primary methods for identifying these compounds. Library searches using mass spectra and retention indices are often used. However, UDMH transformation products are highly specific—they are organic compounds, typically aromatic heterocycles, with unusually high nitrogen content. Such compounds are poorly represented in GC-MS databases, while existing data are often of poor quality and were obtained back in the 1980s. A database of such compounds was presented, containing information on retention indices for non-polar (5%-phenylpolydimethylsiloxane) and polar (polyethylene glycol) stationary phases, as well as electron ionization mass spectra (70 eV) for 104 nitrogen-containing compounds: derivatives of triazoles, pyrazoles, imidazoles, pyridines, diazines, and triazines, as well as amides and other compounds. Many of the compounds presented in the database are proven UDMH transformation products, while many of the other compounds are probable. Derivatives of triazoles and triazines are also used as pesticides, and our database can be useful in detecting their derivatives. The database is free and available online. Full article

High-voltage overhead power lines consist of the non-insulated, densely packed round or trapezoidal aluminum strands supported by a reinforced core. This configuration may ensure the acceptable investment cost, mass per unit length, and aerodynamic effects caused by wind; however, the ampacity is lower than those of copper wires, which limits the power transmission. Today, it is especially important, since the peak power generation of, e.g., photovoltaics forces power lines to casually distribute high currents. To potentially improve long- and short-term capabilities of energy distribution, instead of a cylindrical wire, the helical structure was proposed. Preserving an identical core, the conductor was formed as many elongated helices wrapped around an aluminum tube. The design was meant to significantly enlarge the outer surface of the wire, improving the heat transfer of the line, which then allowed us to enhance its ampacity. The solution was investigated numerically utilizing a 3D model with the coupled electrical, heat transfer, and laminar flow analysis. Based on this, the parameters (unit weight, unit resistance, and aerodynamic drag) of such modified wires were identified. Then, at different current loadings and wind speeds, the conductors were studied and compared with the ACSS (aluminum conductor steel-supported). The optimal variants of helical wires were suggested and the results indicated that using the helical conductor makes it possible to increase the ampacity of power lines (with the same unit weight, resistance, and cross-section of the ACSS wire) by 44% at low wind speed, even up to 160% at higher temperatures. Full article

The purpose of this study was to examine the convergent validity and reliability of the session rating of perceived exertion (sRPE) in complete CrossFit^® sessions by comparing it with a weighted RPE measure (RPE_W) obtained from different session phases. Twenty-four recreational practitioners (13 men and 11 women; age 34.5 ± 8.3 years; height 172.9 ± 11.2 cm; body mass 76.2 ± 15.2 kg) completed 28 standardized sessions (~60 min) consisting of warm-up, strength/skill, Workout of the Day (WOD), and cooldown phases. Phase-specific RPE values were collected after each session component, and a global sRPE was recorded ~30 min post-session. Results showed that RPE_W (5.8 ± 1.5) was significantly lower than sRPE (6.8 ± 1.4; p < 0.001, d = 0.69), resulting in a higher training load estimated by sRPE (+15.5%). Bland–Altman analysis revealed a positive bias and wide limits of agreement, while relative reliability was moderate to good (ICC = 0.73–0.77). Multiple regression analysis indicated that WOD RPE explained 70% of the variance in sRPE (R² = 0.70, p < 0.001), confirming its role as the primary perceptual determinant. In conclusion, sRPE represents a valid, simple, and cost-effective tool for monitoring internal load in CrossFit^®. However, it tends to overestimate RPE_W and shows substantial interindividual variability, limiting its precision for individualized monitoring. Coaches and practitioners should therefore interpret sRPE values with caution, especially considering the strong influence of the final session phase. Full article

As artificial intelligence continues to push into real-time, edge-based and resource-constrained environments, there is an urgent need for novel, hardware-efficient computational models. In this study, we present and validate a neuromorphic computing architecture based on resonant-tunnelling diodes (RTDs), which exhibit the nonlinear characteristics ideal for physical reservoir computing (RC). We theoretically formulate and numerically implement an RTD-based RC system and demonstrate its effectiveness on two image recognition benchmarks: handwritten digit classification and object recognition using the Fruit-360 dataset. Our results show that this circuit-level architecture delivers promising performance while adhering to the principles of next-generation RC, eliminating random connectivity in favour of a deterministic nonlinear transformation of input signals. Full article

Although nanotechnology is increasingly applied in plant tissue culture in many parts of Europe, its use in the Balkans remains limited, revealing a regional gap with untapped potential for advancing in vitro propagation and preservation of woody plant species. Building upon a recently published regional review covering 2001–2024, which analyzed in vitro biotechnology progress in nine Balkan countries, this paper introduces the concept of a “nano gap”, referring to the limited connection between existing nanotechnology research potential and its use in in vitro woody plant biotechnology. In Serbia, Greece, Bulgaria, Croatia, and Albania, significant progress has been made in optimizing micropropagation and in vitro conservation strategies by introducing temporary immersion systems, synthetic seed technology, adapting genotype-specific sterilization and multiplication protocols, and modifying established cryopreservation methods for regional woody species. However, the integration of nanotechnology into these systems remains largely unexplored. To date, there are no published results or validated applications for nano-enhanced media or nanoscale delivery systems for micropropagation and in vitro conservation of woody species. The limited integration of nanotechnology may be due to insufficient funding, lack of specialized infrastructure, and limited interdisciplinary expertise. Nevertheless, many Balkan countries possess growing capacities in nano-applications within agriculture and environmental sciences and are ready to advance toward interdisciplinary research and innovation. By mapping both scientific readiness and structural barriers, this review provides a strategic framework for bridging the “nano gap” and offers a novel regional perspective with broader implications for European research policy, sustainable agriculture, biodiversity preservation, and green innovation. Full article

Dyslipidemia is a significant risk factor for atherosclerotic cardiovascular disease (ASCVD). Abnormal maternal lipid profiles in pregnancy are associated with pregnancy complications including preeclampsia, gestational diabetes, and pre-term delivery as well as increased ASCVD risk for both mother and child. Dyslipidemia management remains a central tenet for atherosclerotic cardiovascular disease prevention for women who are thinking about becoming pregnant or are already pregnant. Effective individualized guidance and multidisciplinary lifestyle/dietary strategies, along with targeted pharmacological interventions, are required for the successful management of lipid disorders in pregnancy in order to optimize outcomes. This review discusses the physiological changes occurring in lipid metabolism during pregnancy and provides an overview of the current strategies for managing dyslipidemia during pregnancy, with a special focus on consideration of pharmacological therapy. Full article

The Wadi Al-Baroud granite–pegmatite system in the Eastern Desert of Egypt displays a progressive rare-metal enrichment evident in the crystal chemistry of muscovite mica and associated Nb–Ta–Y–REE oxide minerals. EMP analyses demonstrate that pegmatite-hosted muscovite is systematically enriched in Si, Fe, Mg, and fluorine compared to its granitic counterpart, reflecting crystallization from volatile-rich, highly evolved melts. Columbite group minerals exhibit pronounced fractionation trends, with pegmatitic columbite showing Ta and Mn enrichment and a low Nb/Ta ratio, indicative of late-stage F- and H₂O-rich melt evolution and advanced magmatic differentiation. Y–Nb–Ti oxides, especially fergusonite-Y and euxenite-Y, record exceptional enrichment in high-field-strength elements (HFSEs) and heavy rare earth elements (HREEs), further driven by structural focusing and fluid-mediated alteration. These crystal-chemical trends record an extreme fractional crystallization and magmatic–hydrothermal transition, wherein F-rich fluids modified early magmatic minerals and promoted the incorporation of Y, REEs, Th, and U into late-stage oxides. The data indicate a two-stage evolutionary model, in which rare-metal mineralization first occurred through primary magmatic crystallization within the granite, followed by fluid-driven re-equilibration in the pegmatites. This integrated mineral-chemical approach provides a clearer understanding of rare-metal enrichment processes in granite–pegmatite systems and offers refined criteria for identifying exploration targets for Nb, Ta, Y, and HREEs. Full article

Background/Objectives: The exposome includes all environmental exposures throughout a lifetime and profoundly influences health and disease, reflecting the totality of environmental chemical exposures throughout an individual’s life, encompassing both natural and anthropogenic chemicals from external sources. Conventional methods for environmental chemical analysis have generally concentrated on individual representatives or substance classes; however, single analyte/class techniques are impractical for extensive epidemiological studies that require the analysis of thousands of samples, as anticipated for forthcoming exposome-wide association studies. This narrative review analyzes the evolution and implementation of multiclass assays for measuring ambient chemical exposure, emphasizing analytical techniques that provide the concurrent quantification of various chemical classes. Methods: This narrative review consolidates existing literature on multiclass analytical methodologies for measuring exposure to environmental chemical mixtures, encompassing mass spectrometry platforms, sample preparation techniques, chromatographic separation methods, and validation strategies for thorough exposure assessment in human biomonitoring research. The review includes liquid chromatography–mass spectrometry techniques, solid-phase extraction methods, and data analysis strategies for both targeted and non-targeted study. Results: Multi-class methodologies provide the concurrent quantification of compounds from many classes without the necessity for distinct conventional procedures, thus minimizing time, expense, and sample volume. The robustness of the method indicates appropriate extraction recovery and matrix effects between 60 and 130%, inter-/intra-day precision under 30%, and remarkable sensitivity with detection limits from 0.015 to 50 pg/mL for 60–80% of analytes in the examined human matrices. The methodology facilitates the concurrent identification of the endogenous metabolome, food-associated metabolites, medicines, home chemicals, environmental contaminants, and microbiota derivatives, including over 1000 chemicals and metabolites in total. Conclusions: These thorough analytical methods deliver the requisite performance for extensive exposome-wide association studies, yielding quantitative results and uncovering unforeseen exposures, thereby augmenting our comprehension of the chemical exposome, which is essential for advancing disease prevention in public health and personalized medicine. Full article

Background: Healthcare systems face significant challenges due to waiting times, resource shortages, and increasing demand for services. The combination of Artificial Intelligence (AI) and simulation is emerging as a promising solution to optimise healthcare processes, although their joint application remains limited. This systematic review analyses current methodological approaches that integrate both technologies to enhance healthcare management. Methods: A systematic search was conducted in PubMed and IEEE Xplore for articles published between 2014 and 2025, following PRISMA guidelines. The search strategy included terms related to AI, simulation, and healthcare management, and was supplemented by a “snowball” search. Original studies describing combined applications of AI and simulation in healthcare processes were included. Results: Out of 2506 records identified, 22 studies were selected for final analysis, most of which were published between 2021 and 2025, indicating growing interest in the field. The studies show that integrating AI and simulation has the potential to improve the efficiency of healthcare management, optimise resource allocation, and reduce waiting times, particularly in areas such as emergency departments and clinical pathways. Supervised learning algorithms, discrete event simulation (DES), and agent-based systems (ABS) were the most commonly used approaches. Conclusions: The combination of AI and simulation is an emerging field with great potential to revolutionise the management of healthcare processes. However, effective implementation requires overcoming technological, standardisation, and data integration barriers, as well as expanding its application to more hospital departments to maximise its impact. Full article

Alveolar ridge preservation (ARP) is crucial for maintaining bone and soft-tissue integrity after tooth extraction, thereby facilitating future implant placement. Among various biomaterials, platelet-rich fibrin (PRF) and freeze-dried bone allograft (FDBA) are commonly used; however, their comparative effectiveness remains unclear. This systematic review and meta-analysis aimed to evaluate and compare the outcomes of PRF, FDBA, and spontaneous healing with blood clot in ARP, incorporating recent randomized controlled trials and comparative studies published up to June 2025. Electronic searches were conducted across multiple databases following the PRISMA 2020 guidelines, and the risk of bias was assessed using RoB-2 and ROBINS-I tools. Primary outcomes included changes in alveolar ridge height and width, while secondary outcomes encompassed histological, radiographic, implant-related, and patient-centered measures. Twenty studies were included for qualitative synthesis and sixteen for quantitative analysis. Meta-analyses showed no significant difference between PRF and FDBA in ridge height (SMD = −0.24; 95% CI: −0.56 to 0.08; p = 0.145) or width preservation (SMD = −0.16; 95% CI: −0.73 to 0.42; p = 0.597). PRF significantly reduced ridge height loss compared to spontaneous healing (SMD = −0.79; 95% CI: −1.33 to −0.25; p = 0.004) and enhanced histologic new bone formation (SMD = 1.43; 95% CI: 0.39 to 2.47; p = 0.007), while FDBA showed a non-significant trend toward benefit (SMD = −0.37; 95% CI: −0.86 to 0.11; p = 0.129). Moderate risk-of-bias and heterogeneity were observed among included studies. In conclusion, PRF and FDBA are both effective for alveolar ridge preservation, outperforming spontaneous healing. PRF offers biologically driven benefits in bone quality and soft-tissue healing, whereas FDBA provides greater structural stability. These findings suggest a promising clinical potential for PRF in improving bone quality at the implant site. Moreover, considering cost, preparation complexity, and site-specific needs, PRF may serve as a cost-effective, clinically favorable option for ARP. Future multi-center randomized trials with standardized PRF protocols and long-term follow-up are recommended. Full article

Functional bread development with clean-label ingredients remains a technological challenge due to the negative effects of certain functional additives on dough rheology and bread quality. The aim of this study was to evaluate the effectiveness of dried sourdough as a natural improver in carob-enriched bread. Dough formulations included 10–20% carob flour as a partial replacement of wheat flour, with dried sourdough added as a dough improver at 5–10%. The results demonstrated that the addition of 10% dried sourdough increased maximum creep compliance of dough with 10% and 15% carob flour by 26% and 56%, respectively. The addition of 5% and 10% dried sourdough to dough with 10% carob flour decreased its Newtonian viscosity by 24% and 36%, resulting in improved dough handling. Crumb pore structure was enhanced by the addition of 5% dried sourdough, with average pore surface area increasing around 2.5 times in breads with 15% and 20% carob flour. Incorporation of dried sourdough reduced bread hardness and chewiness by up to 40% in samples with 15% carob flour and by 20–30% in samples with 20% carob flour. Sensory properties of crumb structure (crumb development, pore fineness, elasticity and crumbliness), which were adversely affected by carob flour addition, showed varying levels of improvement by the addition of dried sourdough. These results demonstrate the feasibility of using dried sourdough as a natural improver in functional bakery formulations, supporting the development of clean-label products without synthetic additives. Full article

Altered mitochondrial function is implicated in disorders characterized by prefrontal cortex activation deficits, including attention deficit hyperactivity disorder (ADHD). The expression of mitochondrial DNA-coded respiratory chain complex I genes (ND1–ND6) in the prefrontal cortex of ADHD animal models was estimated in the present study. ND gene expression was assessed in two publicly available datasets: GSE117357 (Adgrl3 knockout mice) and GSE173926 (MYT1L heterozygous knockout mice). Additionally, we measured NDs gene expression via qPCR in dopamine transporter knockout (DAT-KO) rats and their heterozygous (DAT-Het) littermates. Transcriptomic analysis revealed consistent ND1–ND6 expression profiles across both datasets, and co-expression among ND genes was significantly enhanced in ADHD models compared to wild-type controls. Whole-transcriptome analysis identified associations between ND3 and ND4L expression and genes involved in neural tissue-specific processes, exclusively in ADHD models. In DAT-KO and DAT-Het rats, NDs gene co-expression increased. Furthermore, in DAT-Het rats, which do not exhibit hyperactivity, the upregulation of ND4L expression relative to wild-type littermates was demonstrated. The observed changes in mitochondrial complex I gene co-expression in ADHD models suggest mitochondria may serve as a prospective target for adjuvant therapy. These findings highlight the need for further investigation into mitochondrial contributions to ADHD pathophysiology. Full article

Background: The edible gonads of the sea urchin Paracentrotus lividus are highly valued, yet sex cannot be determined externally, limiting selective harvest and quality control. Objective: We aimed to test whether headspace solid-phase microextraction gas chromatography–mass spectrometry combined with chemometrics can discriminate sex from gonadal volatilomes. Methods: Gonads from 29 individuals (21 females, 8 males) were profiled by this technique. Spectral data were modeled with Partial Least Squares–Linear Discriminant Analysis (PLS–LDA), Variable Importance in Projection scores highlighted key features, and Mann–Whitney tests assessed univariate differences. Tentative identifications were assigned by library match and curated for potential environmental artifacts. Results: Chemometric modeling yielded a clear female–male separation. Female gonads were enriched in low-odor-threshold oxygenates—aldehydes (hexanal, heptanal) and alcohols (1-penten-3-ol, 1-octen-3-ol)—together with diet-linked monoterpenes (e.g., D-limonene), consistent with PUFA LOX/HPL pathways and macroalgal inputs. Male gonads were dominated by saturated/branched hydrocarbons and long-chain alcohols with limited direct odor impact. Minor aromatic hydrocarbons (e.g., styrene; 1,3-bis(1,1-dimethylethyl)-benzene) were retained as environmental/artifact markers and excluded from biological interpretation. Conclusions: HS-SPME gas chromatography–mass spectrometry volatilomics coupled with PLS–LDA effectively distinguishes the sex of P. lividus gonads and rationalizes reported sensory differences. The marker set offers a basis for future non-destructive sexing workflows, pending confirmation with retention indices, authentic standards, and GC-olfactometry. Full article

Social media has become a central element in the daily lives of adolescents, shaping not only their communication patterns but also their self-perception, identity construction, and relationships with others. While these platforms provide opportunities for connection and self-expression, they also entail significant risks. This paper presents a scoping review of the literature, following principles of transparency and rigor inspired by the PRISMA framework, on the impact of social media on adolescent identity, with particular attention to self-concept, self-esteem, and body image. It also examines cyberbullying as a prevalent form of digital violence during adolescence, analyzing its causes, consequences, and variations according to gender, age, and social context. The findings indicate that adolescents build their identities both offline and online, where constant comparison, the use of filters, and the pursuit of social validation can generate emotional distress, insecurity, humiliation, and even social exclusion. Gender differences are also observed: girls are more exposed to aesthetic pressure, whereas boys tend to reproduce ideals of strength and leadership. Finally, the review highlights the importance of social work interventions focused on prevention, digital education, and emotional support in order to foster safe online environments and promote the development of authentic, stereotype-free identities. Full article

Background/Objectives: Heterofunctional cationic polyester dendrimers derived from a 2-(bromomethyl)-2-(hydroxymethyl)propane-1,3-diol (BHP-diol) based AB₂C monomer were evaluated as efficient and biodegradable nonviral carriers for siRNA delivery. Methods: These dendrimers feature dual internal and external charge architectures, enabling precise control of charge distribution and siRNA interaction strength. Results: They achieved complete siRNA complexation at nitrogen-to-phosphate (N/P) ratios of 0.50–2.14 and provided up to 93% RNase protection, outperforming amino-functional scaffolds based on 2,2-bis(methylol)propionic acid (bis-MPA). In human (T98G) and murine (GL261) glioblastoma cells, the dendrimers exhibited minimal cytotoxicity while achieving 52–61% target protein knockdown, a two- to three-fold improvement over conventional polyester dendrimers, and approaching the silencing efficiency of the commercial Interferin^® reagent. Conclusions: The combination of high complexation efficiency, strong nuclease resistance, and excellent biocompatibility establishes these heterofunctional dendrimers as a new generation of precisely tunable, biodegradable vectors for therapeutic siRNA delivery. Full article