Search Results (248,830)

Background: Glioblastomas (GBMs) are the most aggressive and common neoplasms that affect glial cells, presenting rapid growth, invasion, and resistance to treatments. Studies have demonstrated the potentially inhibitory effect of flavonoids on glioblastoma cells’ stemness and viability. However, further research is needed to explore sensitivity and the mechanism of action in chemoresistant cells. Methods: In this study, we characterized the impact of apigenin treatment on the viability and differentiation of human GBM cells in vitro and its effects on tumorigenesis and regulation of the inflammatory response in vivo. Results: The flavonoid apigenin reduced the viability of U-251 cells, patient-derived cells TG-1 and OB-1 stem cells in a dose-dependent manner, associated with the induction of acidic vesicle organelles formation and apoptosis. Treatment with apigenin also inhibited migration and induced neural differentiation in the remaining viable cells, characterized by a decrease in the expression of the precursor marker nestin and an increase in the expression of astrocyte and neuron markers, GFAP and β-III tubulin, respectively. The xenotransplantation of apigenin-pretreated U251 cells into rat brains did not lead to tumor formation, unlike untreated cells. The surrounding area of transplanted untreated U251 cells exhibited reactive microglia and astrocytes, along with increased VEGF expression, which was absent in implant sites of apigenin-pretreated GBM cells. Moreover, in this implant area, we observed a significant decrease in the expression of mRNA for inflammatory factors IL-1β, TNF, and NOS2, and the downregulation of IL-10 and IL-4. Conclusions: These results demonstrate that apigenin inhibits the growth of tumoral cells, affecting the viability of tumor stem cells and impairing tumorigenicity, while altering the regulatory profile of immunomodulatory proteins. Therefore, this flavonoid can be considered for further studies to determine its use as an adjuvant to the treatment of human GBMs. Full article

Background/Objectives: Antibiotic resistance is a major public health concern, with considerable socio-economic consequences. Researchers are exploring alternative strategies, including nanotechnology, which has shown significance in targeted drug delivery. This study evaluates the synergistic antibacterial activity of azithromycin-loaded chitosan nanoparticles (AZM-CSNPs) against azithromycin-resistant clinical respiratory isolates of methicillin-resistant Staphylococcus aureus (MRSA) and Klebsiella pneumoniae (K. pneumoniae). Methods: A total of 87 sputum samples (n = 87) were collected and analyzed. The ermB gene for K. pneumoniae and the ermA gene for MRSA were used to confirm resistant isolates. Among 87 samples, 29 manifested K. pneumoniae, and 32 exhibited MRSA-positive cultures, confirmed through phenotypic and genotypic methods. The RT-PCR is performed by using a cDNA Kit to determine the gene expression. Results: The results elucidate resistance of K. pneumoniae against several antibiotics, including azithromycin (15 µg), chloramphenicol (30 µg), and amoxicillin (30 µg), while MRSA also showed resistance to cefoxitin (30 µg), azithromycin (15 µg), and gentamycin (10 µg). Reduction in the MIC value of the nanoparticle formulation showed their effectiveness. The AZM-CSNPs combined with cetirizine dihydrochloride helped to down-regulate the resistant genes. Conclusions: Notably, a strong synergistic effect was observed with AZM-CSNPs in combination with cetirizine, significantly enhancing antibacterial efficacy against resistant isolates. Full article

This study analyses the stratospheric concentrations of ozone (O₃) and nitrogen dioxide (NO₂) over a 16-year period (2005 to 2020) over central Brazil using satellite data with the aim of determining the influence of NO₂ on ozone distribution and the impact of fires and volcanic eruptions on these gases. The analysis shows that ozone and NO₂ follow seasonal patterns, with the highest concentrations occurring in September and October and the lowest from January to June. A positive correlation was found between the concentrations of ozone and NO₂, and the results of the Fourier analysis indicate semi-annual and annual cycles in the concentrations of these gases. Although there was an increase in the number of fires in the last 11 years of the study, this increase did not lead to significant changes in ozone or NO₂ concentrations, indicating the stability of these parameters in the observed area. It is presumed that the reason for the lack of changes is lower intensity of fires despite their increased number. Regarding wind patterns, it is observed that they do not differ much either which is in accordance with the fact that the monitored area is fairly close to the equator. Full article

The present study aimed to identify genes encoding enzymes involved in the biotransformation of monoterpenoid (–)-isopulegol by Rhodococcus rhodochrous IEGM 1362. This strain is able to transform (–)-isopulegol with formation of two novel metabolites with promising antitumor and analeptic activities. Cell fractions of rhodococci and specific inhibitor of cytochrome P450-dependent oxygenase activity were used to establish the localization and type of biotransformation enzymes. The expression of nine CYP450 genes selected by bioinformatics analysis was analyzed by quantitative real-time PCR (qRT-PCR). Selection of optimal reference genes for normalization of qRT-PCR results was performed using BestKeeper, Normfinder, geNorm, Delta CT, and RefFinder algorithms. As a result of these studies, the role of CYP450 enzyme complexes in the biotransformation of (–)-isopulegol was confirmed, and their cytoplasmic localization was established. The genes encoding DNA gyrase subunit B (gyrB) and protein translocase subunit A (secA) were selected as the most stable reference genes. The induced expression of the gene encoding CYP450 hydroxylase in the presence of (–)-isopulegol was determined. The obtained data allow us to identify the specific CYP450 enzyme involved in (–)-isopulegol biotransformation by R. rhodochrous IEGM 1362 and lay the foundation for further studies of molecular and genetic mechanisms of monoterpenoid biotransformation. Full article

The advancement of green energy is a crucial mechanism for balancing economic growth with environmental sustainability, helping to mitigate conflicts between development and ecological preservation. This paper assesses the policy effects of the Belt and Road Initiative (BRI) on China’s overseas green energy projects (including gas) using the difference-in-difference (DID) model from 2009 to 2022. The findings show that, overall, the BRI has notably augmented China’s green energy projects in the BRI countries. This result remains robust after excluding potential interference from Nationally Determined Contributions (NDCs). Specifically, its promotional effect shows heterogeneity. Firstly, the BRI has shown significant regional differences in promoting the development of China’s overseas green energy projects. Secondly, the BRI is more effective in promoting green energy projects in developing and low-risk countries compared to developed and high-risk countries. Additionally, it indicates that the BRI boosts green energy projects in BRI countries by enhancing their infrastructure quality, encompassing transportation, energy, communication, and financial infrastructure. Finally, based on the above findings, this paper provides context-specific recommendations aimed at enhancing the effectiveness of the BRI in promoting sustainable green energy cooperation. Full article

Background/Objectives: Acute-on-chronic liver failure (ACLF) is a life-threatening complication of cirrhosis, characterized by organ failures and high short-term mortality. Alcohol-related cirrhosis is one of the most frequent underlying etiologies of ACLF in Europe. Infections, particularly those leading to sepsis are recognized triggers; however, their relative contribution, clinical features, and prognostic impact in critically ill patients with alcohol-related cirrhosis remain incompletely defined. This study aimed to systematically identify and characterize precipitating events of ACLF in this population and to compare outcomes between sepsis- and non-sepsis-related cases. Methods: We conducted a retrospective cohort study including 188 ICU patients with alcohol-related cirrhosis who were treated for ACLF at a tertiary university medical center. ACLF was defined and graded according to the European Association for the Study of the Liver—Chronic Liver Failure Consortium (EASL-CLIF) criteria, and sepsis was diagnosed according to Sepsis-3 definitions. Clinical data, precipitating events, microbiological evidence, organ support requirements, and in-hospital outcomes were systematically analyzed. Results: Sepsis was the most frequent precipitating event, identified in 118 patients (62.8%), while 70 patients (37.2%) developed ACLF due to non-septic triggers such as gastrointestinal bleeding. Patients with sepsis-associated ACLF presented with more advanced disease (ACLF grade 2–3 in 80.5% vs. 57.1%, p = 0.004), higher Chronic Liver Failure Consortium—Acute-on-Chronic Liver Failure Score (CLIF-C ACLF) scores (median 55 vs. 50, p = 0.04), longer ICU stays (median 11 vs. 4.5 days, p < 0.001), and markedly higher in-hospital mortality (60.2% vs. 20.0%, p < 0.001) compared to patients without sepsis. Pneumonia (48.3%), urinary infections (17.8%) and spontaneous bacterial peritonitis (16.1%) were the leading infectious foci triggering sepsis. Microbiological evidence was obtained in 82.2% of sepsis cases, with frequent polymicrobial infections and opportunistic pathogens including Enterococcus faecium and Candida albicans. Conclusions: In critically ill patients with alcohol-related cirrhosis, infections leading to sepsis are the predominant precipitating event of ACLF and the strongest determinant of short-term prognosis. Compared with non-sepsis triggers, sepsis-associated ACLF is characterized by more severe disease, greater need for organ support, longer ICU stays, and substantially higher mortality. These findings highlight the urgent need for early recognition, rapid diagnostic strategies, and optimized infection management to improve outcomes in this high-risk population. Full article

Background/Objectives: Alcohol and smoking during pregnancy may be associated with several complications, but the underlying mechanism is still unclear. The aim of this study was to evaluate the role of oxidative stress induced by smoking and alcohol during pregnancy and their effects on fetal and neonatal outcomes. Material and methods: We considered pregnant women at term. Validated questionnaires were used to investigate smoking and alcohol habits. Ultrasound was performed to evaluate fetal weight, amniotic fluid index, and maternal-fetal Doppler velocimetry. At the time of delivery, we collected a tuft of maternal hair, maternal venous blood, and cord blood. In these samplings we determined in phase I nicotine, cotinine, and ethyl glucuronide on the maternal keratin matrix with the gas chromatography-mass spectrometry technique. In phase II, the Free Oxygen Radicals Test (FORT) and Free Oxygen Radical Defense (FORD) test were used to assess circulating reactive oxygen species (ROS). Results: 119 pregnant patients were enrolled (n = 62 for smoking and n = 57 for alcohol). Twenty-six patients (42%) out of 62 were active smokers. Three patients (5%) out of 57 were alcoholic consumers. Mean neonatal weight and mean placental weight were significantly lower for active smokers (p = 0.0001). The neonatal weight was in the 1st–2nd percentile for all alcohol abusers. Considering two subgroups (n = 10 non-smokers and n = 10 smokers) for ROS determination, a statistically significant higher oxidative stress in the blood of smoking patients was evidenced (p < 0.0001). In cord blood the differences were not statistically significant (p = 0.2216). Conclusions: Fetal growth restriction was present in the group of active smokers and in patients with alcohol abuse. Oxidative stress was higher in smoking patients than in non-smokers. However, in cord blood, FORT was negative in all cases, suggesting a protective mechanism in utero. Given the limited sample size, the results obtained are preliminary and require future studies. Full article

This paper presents an analytical investigation of the free vibration behavior of fiber metal laminate (FML) beams with three types of boundary conditions, considering the temperature-dependent properties and the interfacial slip. In the proposed model, the non-uniform temperature field is derived based on one-dimensional heat conduction theory using a transfer formulation. Subsequently, based on the two-dimensional elasticity theory, the governing equations are established. Compared with shear deformation theories, the present solution does not rely on a shear deformation assumption, enabling more accurate capture of interlaminar shear effects and higher-order vibration modes. The relationship of stresses and displacements is determined by the differential quadrature method, the state-space method and the transfer matrix method. Since the corresponding matrix is singular due to the absence of external loads, the natural frequencies are determined using the bisection method. The comparison study indicates that the present solutions are consistent with experimental results, and the errors of finite element simulation and the solution based on the first-order shear deformation theory reach 3.81% and 3.96%, respectively. At last, the effects of temperature, the effects of temperature degree, interface bonding and boundary conditions on the vibration performance of the FML beams are investigated in detail. The research results provide support for the design and analysis of FML beams under high-temperature and vibration environments in practical engineering. Full article

Climate change continues to threaten global biodiversity, making it essential to assess how keystone species may shift their distributions and to use these findings to inform conservation planning. This study evaluated the current and future habitat suitability of D. macropodum, an important tree species within subtropical evergreen broad-leaved forests in China, using 354 occurrence records and a suite of environmental variables. A parameter-optimized MaxEnt model (calibrated with ENMeval; RM = 4, FC = QHPT) was applied to simulate the species’ present distribution and projected changes under three climate scenarios (SSP126, SSP245, SSP585). The main factors influencing distribution were determined to be moisture and temperature seasonality, with the precipitation of the coldest quarter (Bio19, 36.3%), the mean diurnal range (Bio2, 37.5%), and the precipitation of the warmest quarter (Bio18, 14.2%) jointly contributing 88.0% of the total influence. The model projections indicated a 40.1% reduction in the total number of suitable habitats under high-emission scenarios (SSP585) by the 2090s, including a loss of over 80% of highly suitable areas. Centroid movements also diverged across the scenarios: a southwestern shift under SSP126 and SSP245 contrasted with a southeastern shift under SSP585, with each accompanied by significant habitat fragmentation. Key climate refugia were identified primarily in central Taiwan Province and the mountainous zones of Zhejiang and Fujian Provinces, which should be prioritized for conservation activities. These insights offer a foundational understanding for the conservation of D. macropodum and other ecologically similar subtropical evergreen species. However, direct extrapolation to other taxa should be made cautiously, as specific responses may vary based on differing ecological tolerances and dispersal capacities. Further research is needed to test the generalizability of these patterns across diverse plant functional types. Full article

Background: Rowing is a highly demanding endurance sport, requiring simultaneous work of approximately 70% of the body’s muscle mass and the combined contribution of aerobic and anaerobic energy systems. Objective: This study aimed to analyze the cardiorespiratory responses and performance characteristics of elite junior male and female rowers during maximal effort over 2000 m on a rowing ergometer. Methods: Fifteen junior rowers (six males aged 15–17 and nine females aged 15–18) participated in the study. Anthropometric data (body height, weight, and body surface area) were recorded. All participants performed a maximal 2000 m test on a Concept2 D-model ergometer. Throughout the test, oxygen uptake (VO₂), carbon dioxide production (VCO₂), heart rate, and ventilation parameters were continuously measured. Performance and physiological data were analyzed in three intensity zones, defined by ventilatory thresholds (VT1–VT3), as well as at peak exercise. Results: Significant anthropometric differences were observed between genders. In terms of performance, males completed the 2000 m test significantly faster than females (208.83 ± 87.66 s vs. 333.78 ± 97.51 s, p = 0.0253). Relative VO₂ at peak exercise was higher in males (58.73 ± 5.25 mL·kg⁻¹·min⁻¹) than females (48.32 ± 6.09 mL·kg⁻¹·min⁻¹, p = 0.0046). In most cardiorespiratory parameters, males outperformed females significantly, except for heart rate and ventilatory equivalents. Ranking analysis revealed that higher VO₂max values were generally associated with a better placement in both genders, though this relationship was not perfectly linear. Performance time was negatively correlated with VO₂Peak (r = −0.8286; p < 0.001), rVO₂Peak (r = −0.6781; p < 0.01), and O₂P_Peak (r = −0.7729; p < 0.01). Conclusions: The findings confirm significant gender differences in anthropometric and cardiorespiratory characteristics of elite junior rowers and reinforce VO₂max as a key determinant of performance. Yet, deviations from a direct VO₂max–rank correlation highlight the influence of tactical, psychological, and biomechanical factors. Future research should provide practical recommendations for monitoring performance and tailoring training to optimize adaptation and long-term athlete development. Full article

Due to the rising atmospheric carbon dioxide levels driven by human activity, extensive scientific efforts have been dedicated to developing methods aimed at reducing its concentration in the atmosphere. A novel approach involves using hydrates as a long-lasting reservoir of CO₂ sequestration. This review provides an initial overview of hydrate characteristics, their formation mechanisms, and the experimental techniques commonly employed for their characterization, including X-ray, Raman spectroscopy, cryoSEM, DSC, and molecular dynamic simulation. One of the main challenges in CO₂ sequestration via hydrates is the requirement of high pressures and low temperatures to stabilize CO₂ molecules within the hydrate crystalline cavities. However, deviations from classical temperature-pressure phase diagrams observed in natural and engineered environments can be explained by considering that hydrate stability and formation are primarily governed by chemical potentials, not just temperature and pressure. Activity, which reflects concentration and non-ideal interactions, greatly influences chemical potentials, emphasizing the importance of solution composition, salinity, and additives. In this context the role of promoters and inhibitors in facilitating or hindering hydrate formation is discussed. Furthermore, the review presents an overview of the impact of marine sediments and naturally occurring compounds on CO₂ hydrate formation, along with the sampling methodologies used in sediments to determine the composition of these natural compounds. Special attention is given to the effect and chemical characterization of dissolved organic matter (DOM) in marine aquatic environments. The focus is placed on the key roles of various natural occurring molecules, such as amino acids, protein derivatives, and humic substances, along with the analytical techniques employed for their chemical characterization, highlighting their central importance in the CO₂ gas hydrates formation. Full article

Environmental sustainability reporting is increasingly adopted by firms, yet its actual impact on economic performance remains unclear, raising the question of whether such disclosures represent genuine strategic resources or merely symbolic practices. This study examines the relationship between environmental disclosure and economic performance, in the Italian chemical and pharmaceutical industries. Adopting the Resource-Based View (RBV), we evaluate the effectiveness of certified environmental practices as strategic assets that can enhance firm performance. We utilized an AI-based content analysis of financial reports from non-listed, non-SME Italian chemical and pharmaceutical companies between 2012 and 2020 to determine the level of firms’ generic environmental disclosures (without third-party verification) and on specific environmental certifications. We then examine the relationship between economic performance and the type of environmental disclosure observed. Using financial data at the firm level as moderators, we found that generic environmental disclosures have no significant impact on economic performance. In contrast, disclosures on environmental certifications are positively associated with higher economic performance in the chemical sector. Certifications may provide a competitive advantage in environmentally intensive sectors but appear to be less relevant in innovation-driven sectors such as the pharmaceutical industry. Our findings emphasize the strategic value of reliable, externally validated environmental practices, and highlight the limitations of symbolic disclosure. Full article

This paper proposes a novel method for locating single-phase grounding faults in generator stator windings with high resistance, which are typically challenging to locate due to weak fault characteristics. The method utilizes an active voltage injection technique combined with traveling wave reflection analysis, singular value decomposition (SVD) denoising, and discrete wavelet transform (DWT). A DC voltage signal is then injected into the stator winding, and the voltage and current signals at both terminals are collected. These signals undergo denoising using SVD, followed by DWT, to identify the arrival time of the traveling waves. Fault location is determined based on the reflection and refraction of these waves within the winding. Simulation results demonstrate that this method achieves high accuracy in fault location, even with fault resistances up to 5000 Ω. The method offers a reliable and effective solution for locating high-resistance faults in generator stator windings without requiring winding parameters, demonstrating strong potential for practical applications. Full article

Gasoline is the most common ignitable liquid used to initiate fires, making its detection and identification in fire debris crucial for determining incendiary origins. Fire debris is typically collected after extinguishment and safety clearance, often resulting in gasoline weathering, especially when delayed. Most research on gasoline weathering has been conducted in controlled laboratory settings in temperate climates. However, the effects of tropical conditions on the rate of gasoline weathering and the resulting chemical composition of volatiles remain largely unexplored. Understanding how tropical environmental factors alter gasoline weathering is essential for accurate fire debris interpretation in such regions. This study investigates how tropical climates impact gasoline weathering indoors and outdoors. Weathered samples were prepared by volume reduction method, gradually evaporating gasoline from 10% to 95%. Indoor samples were exposed to room temperature, while outdoor samples were left in open space under natural tropical conditions. Gas Chromatography/Mass Spectrometry (GC-MS) analysis revealed chromatographic shifts in heavier compounds (C₃–C₄ alkylbenzenes) compared to lighter ones like toluene as weathering progressed. Correlation between indoor and outdoor samples was high (>0.970) at 10–50% weathering but declined (<0.600) at 90–95%, indicating differing patterns. All target compounds remained detectable across all samples. Full article

The result of accelerated development and technological progress is manifested through numerous changes in the labor market, primarily concerning the competencies of future employees. Many of those competencies have symmetrical character. The determinants that may influence the development of specific competencies are variable and dynamic, yet they share the characteristic of transcending temporal and spatial boundaries. In this paper we propose the use of a combination of Principal Component Analysis (PCA) and Fuzzy Analytic Hierarchy Process (FAHP) to rank 21st-century competencies that are developed independently of the formal educational process. Ability to organize and plan, appreciation of diversity and multiculturalism, and ability to solve problems appeared to be the highest-ranked competencies. The development of key competencies is symmetrical to the skills for the labor market. Also, the development of key competencies is symmetrical to the right selection of the quality of media content. The paper proves that the development of key competencies is symmetrical to the level of education of both parents. One of the key findings is that participants with higher levels of media literacy express more readiness for the contemporary labor market. Moreover, the family, particularly parents, exerts a highly significant positive influence on the development of 21st-century competencies. Parents with higher levels of education, in particular, provide a stimulating environment for learning, foster critical thinking, and encourage the exploration of diverse domains of knowledge. Full article