Search Results (3,507)

Reactions of benzoquinone with amines can potentially lead to the formation of coupled merocyanine or merocyanine/polymethine systems. In this study, several diamino-substituted 1,4-benzoquinones were synthesized. The crystal structures for three derivatives bearing 2-hydroxyethylamino or 2-(2-hydroxyethoxy)ethyl)amino substituents were determined using single-crystal X-ray crystallographic analysis. A characteristic feature of all molecular structures is the presence of an extensive network of intermolecular interactions, significantly stabilized by hydrogen bonding. Additionally, changes in the optical behavior of the synthesized compounds were monitored by UV-Vis spectroscopy in the presence of Cu²⁺ and Zn²⁺ ions, followed by the addition of primary, secondary or biogenic (butane-1,4-diamine) amines. Full article

Background/Objectives: Infective endocarditis (IE) remains a rare but increasingly complex condition, posing significant challenges for cardiologists and cardiac surgeons. Blood groups from the ABO/Rh system have been associated with susceptibility to various diseases, including infections and bacterial colonization tendencies. However, data on the distribution of ABO/Rh blood types among IE patients are lacking. We hypothesized that the prevalence of ABO/Rh blood types among IE patients differs from their frequency in the general population. This study aimed to assess the distribution of ABO/Rh blood types in the LODZ-ENDO database in comparison to general populations. Methods: LODZ-ENDO is a single-center retrospective study conducted in a tertiary cardiology and cardiac surgery facility serving 2.35 million residents. All consecutive patients with confirmed IE hospitalized between 1 January 2015 and 1 October 2025 were included. Clinical data and ABO/Rh blood types were collected and compared with national population data using Fisher’s exact and chi-square tests. Results: A total of 329 patients with IE were analyzed (median age 61 [41–68] years; 69% men), of whom 227 underwent cardiac surgery. Overall ABO/Rh distribution differed significantly from the general population (p = 0.033), driven by a tendency to an overrepresentation of B− (LODZ-ENDO 5.2% vs. Poland 2%; OR 2.88; 95% CI 1.17–7.29; p = 0.03; power 0.89; p(adj) = 0.23). Considering regional demographics and blood use (≈3 units per surgery), this represents an excess annual use of 1.9 B− units, equal to 0.23% of regional B− reserves, with additional indirect depletion of O− blood. Based on WHO data, if this overrepresentation exists elsewhere, IE-related surgeries could consume 0.2–1.3% of national B− stocks in smaller European countries such as Malta, Iceland, Luxembourg, Cyprus, Estonia, Lithuania, Latvia, and Slovenia. Conclusions: This, probably the first report of B− blood type overrepresentation in IE indicates disproportionate use of a rare blood group, highlighting the need for targeted blood management strategies, especially near specialized cardiac surgery centers. Full article

The determination of the elemental composition of minerals at mining enterprises is important at all stages of mineral processing. An evaluation of metrological characteristics achieved through the online analysis of lump, ore, charge feed, cake and slag materials on a conveyor belt is presented. Each implementation of the online XRF analysis at mining enterprises was preceded by laboratory studies, the development of measurement methods and the calibration of a specific XRF analyzer using standard reference samples for a specific concentration range of the monitored elements. In this work, typical application areas for monitoring the concentration of elements in rocks on conveyor belts are presented, as well as those solutions that made it possible to achieve the required measurement accuracy with an X-ray fluorescence analyzer in an online mode. Full article

As the volume of reinforced concrete structures continues to grow, it is important to determine the quality of concrete in the shortest time possible. Therefore, the development and validation of methods for non-destructive testing (NDT) of concrete structures are becoming increasingly important. However, some factors may affect the accuracy of the measurement results obtained as concrete is often exposed to a moist environment, e.g., in marine structures. Ignoring these factors may lead to an inaccurate interpretation of measurements. Therefore, in this research, the water saturation factor of concrete was investigated in response to various NDT methods. C25/30 and C40/50 MPa concrete were evaluated using ultrasonic pulse velocity and rebound hardness devices, and for the first time, a drilling resistance (DR) method was systematically adapted and validated for moisture-affected concrete testing. Unlike conventional approaches that only consider surface effects, the DR method introduced here provides in-depth profiling of concrete, revealing variations in resistance with depth and identifying zones influenced by internal moisture distribution. This study demonstrates that the DR method can complement traditional NDT techniques, providing a more reliable evaluation of moisture-induced variations in concrete properties. Moreover, with the novel DR method, changes in the mechanical response with depth have been quantified, offering new insight into internal moisture effects that are not accessible by conventional NDT methods. Full article

Background: Anxiety disorders, including panic disorder, agoraphobia, specific phobias, and generalized anxiety disorder, are among the most frequent psychiatric conditions in primary care. They often present with somatic symptoms such as dyspnea, palpitations, chest or gastrointestinal discomfort, sweating, or flushing. Adaptol^® is a non-benzodiazepine anxiolytic with nootropic properties that modulates the limbic-reticular system, hypothalamic emotional centers, and multiple neurotransmitter systems. This study aimed to assess the association between Adaptol^® use and changes in anxiety symptoms, including somatic manifestations, in routine practice. Methods: A noninterventional observational study was conducted in 100 adults diagnosed with anxiety disorders in primary care. All received Adaptol^® 500 mg as prescribed. Patients had to have mild-to-moderate anxiety (5–14 points according GAD-7) to be enrolled. Exclusion criteria ruled out individuals with concomitant psychiatric or severe somatic conditions and those with use of other medications or any interventions that could affect the symptoms. Anxiety severity and somatic symptom burden were assessed at baseline and after treatment. Results: Adaptol^® treatment was associated with reduction in anxiety and somatic complaints. Improvements were reported in palpitations, chest discomfort, gastrointestinal disturbances, and autonomic symptoms. Greater benefit was observed in male patients, though without significance testing, and in those with severe baseline anxiety, as demonstrated by correlation between GAD-7 scores at baseline and changes after the treatment (r = 0.5). No unexpected adverse events occurred. Conclusions: In this real-world study, Adaptol^® showed anxiolytic efficacy and good tolerability, improving both psychological and somatic manifestations of anxiety disorders. These findings support its use in primary care, especially in severe cases of anxiety. Controlled trials are needed to support these results. Full article

Modern agricultural production faces challenges, caused by soil degradation, declining natural fertility, and a lack of organic matter and productive moisture in the arable layer, which is especially relevant in the context of global climate change and rising prices for fuel and lubricants, mineral fertilizers, and plant protection products. Five tillage systems (moldboard, flat-cut, adaptive, shallow and surface) and three fertilization options (no fertilization, by-product, by product + N₆₅P₆₀K₇₀) were tested. The combination of adaptive cultivation and organic-mineral fertilization resulted in the highest input of crop by-products (up to 1.26 g cm⁻³), elevated humus reserves (69.2 t ha⁻¹ in the 0–40 cm layer), reduced bulk density in the root zone (down to 1.26 g cm⁻³), improved soil moisture conditions, and, consequently, the highest grain yield—4.34 t ha⁻¹, which is 7.4–21.4% higher than in other treatments. The use of adaptive cultivation with differentiation of the depth and type of loosening allowed the humus reserve to be increased to 66.4 t ha⁻¹, the productive moisture in the 0–40 cm layer to reach 86 mm, and ensured an increase in the yield of the grain units to 4.34 t ha⁻¹. The obtained results prove the validity of the efficient integration of the plant biomass on light-textured soils with low physicochemical parameters and humus content as a renewable resource in sustainable agriculture technologies, especially in conditions of climate instability and the rising costs of the resources. Full article

Previous research shows that better socio-emotional skills are associated with students’ behavioral adjustment and positive learning outcomes; however, the protective role of socio-emotional skills regarding academic learning during global crises has not been studied sufficiently. This research aims to evaluate longitudinal changes in students’ socio-emotional skills and learning outcomes during the implementation of a universal prevention program Promoting Mental Health at Schools (PROMEHS). The research coincided with lockdown due to the COVID-19 pandemic, therefore allowing an assessment of the protective role of socio-emotional learning even in the face of adverse circumstances. In total, 3166 students (aged 7–17 years) from Latvia and Portugal participated in the research, and a survey of their respective teachers was used to collect data. The SSIS-SEL teacher form and a three-item learning outcomes measure addressing academic motivation, engagement, and performance were applied in the study. It was found that growth in socio-emotional skills has a positive effect on academic outcomes, while a decline in socio-emotional learning has a detrimental effect on academic outcomes. This applies to both experimental and control groups, both genders, all educational levels, and both countries. Additionally, the increase in socio-emotional skills predicted better academic outcomes in upper secondary schools than in primary and lower secondary schools. Full article

Background: An effective healthcare system relies on sufficient and competent human resources. However, many countries face staff shortages, burnout, and turnover, which threaten the quality and safety of care. To address the absence of validated tools assessing healthcare professionals’ perceptions of staff resource adequacy in Latvia, the Staff Resource Adequacy Questionnaire for Healthcare Professionals (SRAQ-HP) was developed. Methods: This study examined its construct validity through exploratory factor analysis (EFA) and confirmatory factor analysis (CFA) using a nationwide sample of 1369 healthcare professionals. EFA supported a three-factor structure comprising (1) adequacy of workload and staff resources, (2) quality of care, and (3) working conditions and support. Results: The instrument demonstrated high internal reliability (Cronbach’s α > 0.94) and moderate model fit indices (CFI/TLI > 0.90; RMSEA = 0.145; SRMR = 0.100). Although RMSEA values (0.145) were above conventional cutoffs, this was expected given the large sample and model complexity. Convergent validity was supported by correlations with established measures—the Measure of Moral Distress for Healthcare Professionals (MMD-HP), the Copenhagen Burnout Inventory (CBI), and the Anticipated Turnover Scale (ACT)—while criterion validity showed significant predictive value only for moral distress. Conclusions: Overall, the SRAQ-HP demonstrates promising psychometric properties and practical applicability for assessing staff resource adequacy in healthcare settings, although further refinement and re-validation (particularly of one reverse-worded item) are recommended before broader implementation. Full article

Metal-coated mesoporous PSi (mesoPSi) opens up disruptive perspectives for biosensing, which is primarily enabled by surface-enhanced Raman scattering (SERS). Although the unique performance of SERS-active substrates based on metal-coated mesoPSi has already been praised, influence of defects in silicon wafer on its morphology has not been revealed. Defects lead to formation of spiral regions in mesoPSi with varying porosity, which affects SERS activity of the overlying metallic nanostructures. It limits the reliability of SERS analysis. Here, we investigate repeatability of morphology and SERS activity of silver particles on mesoPSi as a function of defects in parent silicon, which are induced by irregular dopant levels. We propose an original corrosion approach that has not yet been applied to control the morphology of silicon nanostructures in general and mesoPSi in particular. By replacing silicon nanocrystallites with sacrificial copper nanoparticles, we were able to eliminate the surface irreproducibility of mesoPSi. The copper-corrosion-modified porous silicon surface was shown to be a suitable substrate for reliable SERS-active substrates. In more detail, SERS-active substrate based on mesoPSi without a defective surface layer allowed for a more than 40% increase in the SERS-active surface area with a signal deviation of only 10 % compared to that with a defective layer. Full article

Transcription factors orthodenticle homeobox 2 gene (OTX2), paired box 6 gene (PAX6), and SRY-box transcription factor 2 gene (SOX2) are key regulators of ocular morphogenesis; however, their comparative embryonic localization across species—and the correspondence between transcript and protein distributions—remain incompletely defined. Chromogenic in situ hybridization (CISH) was employed to detect OTX2, PAX6, and SOX2 transcripts, while biotin–streptavidin immunohistochemistry (IHC) was used to assess Otx2, Pax6, and Sox2 protein expression. A semi-quantitative scoring system was applied to evaluate positive structures across ocular compartments. Transcripts were predominantly localized to the retina in both species, with occasional low-level expression in the optic nerve, sclera, and eyelid. Proteins displayed broader distributions: Otx2 was abundant in the retina and eyelid, while Pax6 and Sox2 were detected in multiple tissues, including cornea and extraocular muscles. OTX2, PAX6, and SOX2 show retina-predominant transcription and wider protein expression across ocular tissues. These findings highlight spatial differences between transcript and protein localization, supporting a complex regulatory framework underlying vertebrate eye development. Full article

Background and Objectives: Preoperative cefazolin is the standard of care for intervertebral disc surgery as it reduces the incidence of iatrogenic spondylodiscitis. The aim of this study was to determine the impact of intervertebral disc degeneration and endplate changes on the penetration of prophylactic cefazolin into the intervertebral disc during spinal surgery. Materials and Methods: Adult patients undergoing single-level microdiscectomy for lumbar disc herniation received prophylaxis with 2 g of cefazolin. Venous blood and intervertebral disc samples were collected and analyzed using high-performance liquid chromatography to determine cefazolin concentrations. The severity of intervertebral disc and endplate changes was assessed on magnetic resonance images using the Pfirrmann and Modic grading systems. Results: Cefazolin concentrations were significantly higher in cases with Modic type II changes compared to type 0/I (14.6 ± 9.2 µg g⁻¹ vs. 10.2 ± 4.5 µg g⁻¹ and 9.2 ± 4.1 µg g⁻¹; p = 0.01). 35.4% of patients with Modic type II changes had concentrations > 16 µg g⁻¹, compared to 10% and 25% for patients with Modic type 0/I (p = 0.008). For Pfirrmann grading, 34.6% of grade V discs reached >16 µg g⁻¹ versus 16.7% and 20.3% for grades III and IV (p = 0.26). Patient age, weight, and timing showed no significant correlations with intradisc concentrations. Conclusions: Ninety-four percent of disc samples exceeded the minimum inhibitory concentration for Staphylococcus aureus (>4 µg/g), but considerable variability in cefazolin levels was observed, with higher concentrations in discs showing Modic type II changes. Full article

This work presents a preliminary “Strengths, Weaknesses, Opportunities, and Threats” (SWOT) analysis followed by a “Correct, Adapt, Maintain, and Explore” (CAME) analysis on wood sawdust biofuel. New designs of sawdust biofuels boilers and reactors require gathering relevant information on the main characteristics of sawdust biofuels. Optimisation algorithms require not only the numerical parameters needed to find optimal solutions but also the consideration of scenarios related to the use of this type of biofuel. This work provides complementary information to create a comprehensive framework for assessing the viability and sustainability of integrating wood sawdust into diverse energy production systems. This includes an examination of the current state of sawdust utilisation, its environmental implications, and the potential of valorising this abundant biomass resource. This review further delves into the technical aspects of converting sawdust into biofuel pellets, examining various technical processes involved in its physical analysis. The intended audience of this review encompasses researchers, mechanical designers, policymakers, and industry strategists and stakeholders interested in sustainable energy solutions and waste management strategies, providing a holistic perspective on the opportunities presented by wood sawdust as a renewable energy source. Full article

The problem of obtaining new examples of fuzzy metrics is of interest, as this type of fuzzy measurement has been proven to be useful in engineering applications. In this context, different works have addressed the problem of deriving fuzzy metrics from classical ones. This paper is devoted to generalizing a construction of non-strong fuzzy metrics from metrics already provided in the literature, both for continuous Archimedean t-norms and for the minimum t-norm. Moreover, we explore the conditions under which one adapts this generalized method to obtain fuzzy metrics in the sense of George and Veeramani. In addition, we investigate the connection between the topology associated with the fuzzy metric constructed via these procedures and that determined by the metric. Several examples are provided to support and illustrate our findings. Full article

This pilot study examined the effects of a 12-week reaction training program on physical and cognitive performance (choice reaction) in U20 Latvian fencers. Five qualified right-handed male fencers (aged 14.8–18.6 years) completed the Vienna Test System choice reaction task at baseline and after 12 weeks while cycling through five heart rate zones (1–5). Reaction speed (RS), motor speed (MS), choice reaction time (CR), and heart rate (HR) were recorded. Paired-sample t-tests indicated no significant group-level changes: RS (t = 1.46, p = 0.21, d = 0.65, 95% CI [−36.92, 118.92]), MS (t = 2.37, p = 0.07, d = 1.06, 95% CI [−3.14, 40.34]), CR (t = 1.70, p = 0.16, d = 0.76, 95% CI [−37.30, 156.26]), and HR (t = −2.69, p = 0.054, d = −1.20, 95% CI [−12.53, 0.17]). Individual responses revealed that three athletes improved CR in low- to moderate-intensity zones (−12.66% to −27.18%), whereas heart rate increased modestly (1.35% to 9.60%). Given the critical age for developing choice reaction, these findings should be considered as preliminary and exploratory, offering initial insights into how training might influence cognitive performance in young fencers and demonstrating that responses can differ across heart rate zones and among individuals. Full article

This conceptual article introduces Perceived Cognitive Assistance (PCA)—a novel psychological construct capturing how interactive support from Large Language Models (LLMs) alters investors’ perception of their cognitive capacity to execute complex trading strategies. PCA formalizes a behavioral shift: LLM-empowered retail investors may transition from intuitive heuristics to institutional-grade strategies—sometimes without adequate comprehension. This empowerment–distortion duality forms the theoretical contribution’s core. To empirically validate this model, this article outlines a five-step research agenda including psychological diagnostics, trading behavior analysis, market efficiency tests, and a Behavioral Shift Index (BSI). One agenda component—a dual-agent simulation framework—enables causal benchmarking in post-LLM environments. This simulation includes two contributions: (1) the Virtual Trader, a cognitively degraded benchmark approximating bounded human reasoning, and (2) the Digital Persona, a psychologically emulated agent grounded in behaviorally plausible logic. These components offer methods for isolating LLM assistance’s cognitive uplift and evaluating behavioral implications under controlled conditions. This article contributes by specifying a testable link from established decision frameworks (Theory of Planned Behavior, Technology Acceptance Model, and Risk-as-Feelings) to two estimators: a moderated regression for individual decisions (Equation (1)) and a composite Behavioral Shift Index derived from trading logs (Equation (2)). We state directional, falsifiable predictions for the regression coefficients and for index dynamics, and we outline an identification and robustness plan—versioned, time-locked, and auditable—to be executed in the subsequent empirical phase. The result is a clear operational pathway from theory to measurement and testing, prior to empirical implementation. No empirical results are reported here; the contribution is the operational, falsifiable architecture and its implementation plan, to be executed in a separate preregistered study. Full article