Search Results (46,287)

A novel tera-dentate salen ligand and its Fe(III) complex was synthesized and characterized via several spectroscopic and physicochemical techniques. The corrosion rate inhibition of nickel and its alloys inspired the utilization of the L ligand and its FeL complex as vital and eco-friendly inhibitors. To assess their effectiveness, both Tafel plot analysis and electrochemical impedance spectroscopy were employed to examine the electrochemical properties of L and the FeL complex. The results show that corrosion current density (I_corr) steadily drops when the additive concentration is increased, but the inhibition efficiency increases. It has been observed that the efficiency of inhibition rises with temperature, particularly at high temperatures (55 °C) when 1 × 10⁻³ M of L and FeL are present as additives, with η = 90.5% and 92.7%, respectively. Additionally, the findings propose that the adsorption mechanism of both L and FeL additive reptiles follows the Langmuir design isotherm. Electrochemical impedance spectroscopy has also verified these findings. DFT calculations were employed to prove the structure of the investigated FeL complex and its activity as a corrosion inhibitor. Full article

ω-Transaminases are biocatalysts capable of asymmetrically synthesizing high-value chiral amines through the reductive amination of carbonyl compounds, and they are ubiquitously distributed across diverse microorganisms. Despite their broad natural occurrence, the industrial utility of naturally occurring ω-transaminases remains constrained by their limited catalytic efficiency toward sterically bulky substrates. Over recent decades, the use of structure-guided molecular modifications, leveraging three-dimensional structures, catalytic mechanisms, and machine learning-driven predictions, has emerged as a transformative strategy to address this limitation. Notably, these advancements have unlocked unprecedented progress in the asymmetric synthesis of bulky chiral amines, which is exemplified by the industrial-scale production of sitagliptin using engineered ω-transaminases. This review systematically explores the structural and mechanistic foundations of ω-transaminase engineering. We first delineate the substrate binding regions of these enzymes, focusing on their defining features such as substrate tunnels and dual pockets. These structural elements serve as critical targets for rational design to enhance substrate promiscuity. Next, we dissect the catalytic and substrate recognition mechanisms of (S)- and (R)-ω-transaminases. Drawing on these insights, we consolidate recent advances in engineering ω-transaminases to highlight their performance in synthesizing bulky chiral amines and aim to guide future research and the industrial implementation of tailored ω-transaminases. Full article

The inhibitory effects of two novel lophine derivatives were unexpectedly discovered during the development of a chemiluminescent monoacylglycerol lipase (MAGL) assay. The proposed lophine derivatives were found to exhibit concentration-dependent inhibitory effects on MAGL with the octanoic and palmitic acid esters of 2-(4-hydroxyphenyl)-4,5-diphenylimidazole showing the strongest activity. Reversibility assays using a fluorometric method confirmed that these compounds interact with MAGL in a stable, irreversible manner. To further investigate their mode of interaction, docking studies were performed, supporting the hypothesis that compounds 3 and 4 may act as competitive and irreversible inhibitors. Lophine derivatives were initially designed and synthesized as potential chemiluminescence pro-enhancers. However, assay optimization revealed no signal production upon MAGL hydrolysis, precluding their use as chemiluminescent probes. These findings suggest that lophine is a promising candidate for the development of MAGL inhibitors, although further optimization is needed to enhance binding affinity and selectivity. Full article

Chronic obstructive pulmonary disease (COPD) is a prevalent respiratory disorder characterized by persistent airway inflammation and progressive airflow limitation, resulting in a significant global health burden and high mortality. This narrative review synthesizes the current evidence on the roles of leukocyte subtypes—including neutrophils, monocytes, lymphocytes, eosinophils, and basophils—in the pathogenesis and clinical management of COPD. Relevant original studies and reviews are included, providing data on leukocyte functions, associated biomarkers, and therapeutic implications. Neutrophils contribute to airway damage and remodeling by releasing proteases and reactive oxygen species, particularly in response to environmental exposure such as cigarette smoke or air pollution. Lymphocytes, especially CD8⁺ T cells, drive chronic inflammation and immune dysregulation. Monocytes differentiate into macrophages that promote airway fibrosis and persistent inflammation, further impairing lung function. Eosinophils, though classically linked to asthma, are now recognized for their role in eosinophilic COPD, where they are associated with an increased exacerbation risk and corticosteroid responsiveness. Basophils, though less studied, may influence airway inflammation through interactions with eosinophils and cytokine release. Understanding these immune cell dynamics provides insights into the heterogeneity of COPD and highlights potential targets for precision therapy. Tailored interventions based on inflammatory phenotypes may improve clinical outcomes and advance personalized treatment strategies. Full article

Background/Objectives: Artificial intelligence-based software as a medical device (AI-SaMD) refers to AI-powered software used for medical purposes without being embedded in physical devices. Despite increasing approvals over the past decade, research in this domain—spanning technology, healthcare, and national security—remains limited. This research aims to bridge the existing research gap in AI-SaMD by systematically reviewing the literature from the past decade, with the aim of classifying key findings, identifying critical challenges, and synthesizing insights related to technological, clinical, and regulatory aspects of AI-SaMD. Methods: A systematic literature review based on the PRISMA framework was performed to select the relevant AI-SaMD studies published between 2015 and 2024 in order to uncover key themes such as publication venues, geographical trends, key challenges, and research gaps. Results: Most studies focus on specialized clinical settings like radiology and ophthalmology rather than general clinical practice. Key challenges to implement AI-SaMD include regulatory issues (e.g., regulatory frameworks), AI malpractice (e.g., explainability and expert oversight), and data governance (e.g., privacy and data sharing). Existing research emphasizes the importance of (1) addressing the regulatory problems through the specific duties of regulatory authorities, (2) interdisciplinary collaboration, (3) clinician training, (4) the seamless integration of AI-SaMD with healthcare software systems (e.g., electronic health records), and (5) the rigorous validation of AI-SaMD models to ensure effective implementation. Conclusions: This study offers valuable insights for diverse stakeholders, emphasizing the need to move beyond theoretical analyses and prioritize practical, experimental research to advance the real-world application of AI-SaMDs. This study concludes by outlining future research directions and emphasizing the limitations of the predominantly theoretical approaches currently available. Full article

Background: Radioresistance remains a significant obstacle in lung cancer radiotherapy, necessitating novel strategies to enhance therapeutic efficacy. This study investigated the radiosensitizing potential of a soybean lecithin–gallic acid complex (SL–GAC) in non-small cell lung cancer (NSCLC) cells and explored its underlying ferroptosis-related mechanisms. SL–GAC was synthesized to improve the bioavailability of gallic acid (GA), a polyphenol with anticancer properties. Methods: NSCLC cell lines (A549 and H1299) and normal bronchial epithelial cells (BEAS-2B) were treated with SL–GAC, ionizing radiation (IR), or their combination. Through a series of in vitro experiments, including cell viability assays, scratch healing assays, flow cytometry, and Western blot analysis, we comprehensively evaluated the effects of SL-GAC on NSCLC cell proliferation, migration, oxidative stress, and ferroptosis induction. Results: SL–GAC combined with IR synergistically suppressed NSCLC cell proliferation and migration, exacerbated oxidative stress via elevated ROS and malondialdehyde levels, and induced mitochondrial dysfunction marked by reduced membrane potential and structural damage, whereas no significant ROS elevation was observed in BEAS-2B cells. Mechanistically, the combination triggered ferroptosis in NSCLC cells, evidenced by iron accumulation and downregulation of Nrf2, SLC7A11, and GPX4, alongside upregulated ACSL4. Ferrostatin-1 (Fer-1), a ferroptosis inhibitor, reversed these effects and restored radiosensitivity. Conclusions: Our findings demonstrate that SL–GAC enhances NSCLC radiosensitivity by promoting ferroptosis via the Nrf2/SLC7A11/GPX4 axis, highlighting its potential as a natural radiosensitizer for clinical translation. Full article

In this study, we report a green, one-step synthesis of fluorescent carbon quantum dots (PET-FCQDs) derived from polyethylene terephthalate (PET) waste using an environmentally friendly pyrolytic method. The PET-FCQDs were systematically characterized using techniques such as UV-Vis spectroscopy, fluorescence spectroscopy, ATR-FTIR, TGA, and fluorescence microscope, confirming their nanoscale size (2–50 nm), rich functional groups and thermal stability. Thermal stability and dynamics evaluated by the Coats–Redfern method showed endothermic reactions with an activation energy of 88.84–125.05 kJ/mol. Density functional theory studies showed a binding energy, highest occupied molecular orbital, lowest unoccupied molecular orbital, and energy gap of −675.39, −5.23, −5.07, and 0.17 eV, respectively. The as-synthesized PET-FCQDs demonstrated excellent optical properties with quantum yield ($\mathsf{\Phi }$) of 49.6% and were applied as a dual-mode fluorescent sensing probe for the detection of Pd²⁺, ciprofloxacin (CIP), and fluoxetine (FLX) in aqueous systems via fluorescence quenching and enhancement mechanisms. For Pd²⁺, the fluorescence emission intensity at 470 nm was quenched proportionally to the increasing concentration, while CIP and FLX induced fluorescence enhancement. The Stern–Volmer analysis confirmed strong interaction between the analytes and PET-FCQDs, distinguishing dynamic quenching for Pd²⁺ and static interactions for CIP and FLX. The method exhibited linear detection ranges of 1–10 mg/L for Pd²⁺, 50–150 µg/L for CIP, and 100–400 ng/L for FLX, with corresponding limits of detection (LOD) of 1.26 mg/L, 3.3 µg/L, and 134 ng/L, respectively. Recovery studies in spiked tap water and river water samples demonstrated the practical applicability of PET-FCQDs, although matrix effects were observed, particularly for FLX. This work not only highlights a sustainable route for PET waste upcycling but also demonstrates the potential of PET-FCQDs as cost-effective, sensitive, and versatile fluorescent probes for environmental monitoring of heavy metal ions and pharmaceutical pollutants. Further optimization of the sensing platform could enhance its selectivity and performance in real-world applications. Full article

Carbon capture and sequestration (CCS) is an essential strategy for mitigating greenhouse gas emissions and addressing climate change. In this study, the biochar of bamboo and orange peel (BB and OPB) are synthesized and appraised as potential CO₂ adsorbents. Comprehensive characterizations viz. sorption isotherm, FTIR spectroscopy, and SEM-EDS reveal substantial differences in their structural and functional properties. OPB exhibits a significantly higher BET surface area (40.13 m²/g) compared to BBs (7.38 m²/g). FTIR and EDS analyses further demonstrate more amine, carboxylic, ester, and ether functional groups in OPB, indicating its affinity for CO₂ molecules. The CO₂ adsorption isotherm shows a higher adsorption capacity (22.83 cm³/g) in OPB than BB (14.12 cm³/g) at 273 K and 1 bar. The adsorption process is augmented by mesoporous structures and interactions between surface functional groups and CO₂ molecules. The thermogravimetric analysis further reveals the higher CO₂ uptake capability of OPB than BB. This result also shows that the CO₂ uptake stabilizes after 48 h for both the biochars. These results highlight the potential of OPB as an efficient CCS material, demonstrating the importance of specific biochar properties in the development of CO₂ capture. Full article

Two modifications of ZnMoO₄ were successfully obtained by mechanochemical treatment with two milling speeds applied at 500 and 850 rpm. The phase formation was monitored by XRD analysis. The metastable monoclinic ß-ZnMoO₄ was directly synthesized at room temperature using the higher milling speed of 850 rpm. The thermodynamically stable triclinic α-ZnMoO₄ was obtained by combining heat treatment t 600 °C and ball milling at the lower milling speed of 500 rpm. The IR spectra contain typical vibration bands and confirm the formation of both ZnMoO₄ polymorphs. UV-Vis absorption and photoluminescence (PL) spectroscopy are used to study the optical properties of the as-prepared samples. The calculated optical band gaps for α- and ß-ZnMoO₄ are 4.09 and 3.02 eV. The photoluminescence emission spectrum of both samples shows peaks with different maximum intensity at 615 and 403 nm for α and ß phase, respectively. CIE co-ordinates are located in the orange and blue range of the color diagram. Full article

This study investigates the development and performance of a novel GE-EP@OIM solid corrosion inhibitor for enhancing long-term corrosion protection in the oil-and-gas industry’s corrosive environment. The inhibitor was synthesized by incorporating organic imidazole molecules (OIMs) into a Gel-Epoxy (GE-EP) matrix, achieving an OIM-loading capacity of approximately 34.75% (generally reported capacity is up to 20%). The solid inhibitor was designed as a smart material, which exhibits temperature-responsive release behavior in a chlorine-corrosive environment. A combination of electrochemical measurements, weight loss testing, and scanning electron microscopy (SEM) was employed to assess the inhibitor’s performance. The results demonstrate that GE-EP@OIMs significantly improve corrosion resistance, particularly at elevated temperatures (50 °C), with the long-term protection effect serving as a key highlight, maintaining efficacy for up to 60 days, and it shows enhanced stability compared to conventional inhibitors. While the mechanical properties of GE-EP@OIMs are slightly diminished due to the incorporation of OIMs, the inhibitor still meets the necessary fluidity and performance criteria for medium- to long-term applications. This material shows considerable promise for mitigating corrosion in oilfield operations, especially for downhole tubing, and presents a cost-effective solution to the widespread corrosion challenges in the industry. Full article

The removal of methylene blue (MB) cationic dye from aqueous solutions was investigated by applying magnesium molybdate (β-MgMoO₄) as a nanosorbent. The β-MgMoO₄ was synthesized through a simple, rapid, and efficient method. The MB dye removal process was optimized by evaluating various parameters such as temperature, contact time, nanosorbent dosage, pH, and initial cationic dye concentration. The optimal conditions for MB removal were found to be pH 3, with a 99% removal efficiency achieved in just 10 min of contact time, when using an MB cationic dye concentration of 160 ppm. Magnesium molybdate (β-MgMoO₄) showed a maximum adsorption capacity of 356 mg/g, according to Langmuir model-based calculations. The MB dye removal process occurred spontaneously while being favorable and endothermic. The kinetic investigation showed that the pseudo-second-order model accurately represented the reaction kinetics. The thermal regeneration test results indicated that the removal efficiency remained stable even after three consecutive rounds of reuse. A Fourier Transform Infrared (FTIR) spectroscopic analysis confirmed the adsorption and desorption of MB on β-MgMoO₄ and its regeneration. Overall, these results indicate that a β-MgMoO₄ nanosorbent is a favorable and robust adsorbent for the removal of MB cationic dye from wastewater at its maximum capacity. Full article

Melatonin is found in all classes of living organisms. In particular, in plants melatonin acts as an antioxidant that helps plants deal with both biotic and abiotic stress. In plants, melatonin improves seed germination, fruit ripening, photosynthesis, biomass production, circadian rhythm, membrane integrity, root development, leaf senescence, osmoregulation, and stress modulation. Melatonin concentrations vary enormously in different plants, different plant growth stages, different plant organs, and both the season and time of day that a plant is harvested. In addition, melatonin promotes root growth and development, prevents leaf senescence, promotes flowering and fruit ripening, promotes lateral root formation, stimulates gene expression of enzymes involved in photosynthesis, and protects plants from phytopathogen attack. Moreover, melatonin produced by soil bacteria can affect plant tolerance and health; in turn, melatonin synthesized by plants can influence the soil and rhizosphere microbiome. Finally, very recent literature indicates that melatonin can directly and positively affect the functioning of other soil bacteria. Full article

Background/Objectives: Flatfoot is a common pediatric foot deformity characterized by a reduced or absent medial longitudinal arch (MLA). The condition can lead to altered gait, pain, and potential long-term morbidity if untreated. Identifying potential risk factors—such as body mass index (BMI), ligamentous or joint instability, shoe choices, and physical activity—is crucial for prevention and management. The objectives are to systematically review and synthesize current evidence on how flatfoot severity correlates with BMI and other risk factors in children and adolescents, and to highlight methodological considerations essential for future research. Methods: Following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, we searched five electronic databases from inception to February 2024. Flatfoot severity was measured by various clinical or radiographic indices. Two reviewers independently screened and assessed the risk of bias. Results: Thirty-seven studies met the inclusion criteria. Children with high BMI had increased odds of flatfoot (pooled Odds Ratio = 2.3, 95% Confidence Interval: 1.6–3.1), with one outlier reporting an OR of 9.08. Heterogeneity (I² up to 70%) stemmed from varied diagnostic methods. Other factors, including joint instability, shoe choices, and physical activity, showed mixed associations. Conclusions: Elevated BMI strongly correlates with pediatric flatfoot severity, highlighting the importance of proactive weight management and foot assessments. Future standardized, longitudinal studies are needed to clarify causality and refine interventions. Full article

The FeZn-MOFs@Al₂O₃ catalyst was synthesized under solvothermal conditions. Fourier transform infrared (FT-IR) spectroscopy, X-ray diffraction (XRD), scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), temperature-programmed desorption of ammonia (NH₃-TPD), and specific Brunauer–Emmett–Teller (BET) surface area and pore volume were used to systematically investigate the effects of different parameters such as molar ratio of iron to zinc, synthesis temperature, and synthesis time on the properties of the materials. The results showed that the optimum synthesis conditions of FeZn-MOFs@Al₂O₃ composites were 140 °C for 1 h, and the optimum molar ratio of Fe³⁺ and Zn²⁺ was 1.3:0.7. Under the aforesaid conditions, FeZn-MOFs@Al₂O₃ had the deacidification rate of vacuum gas oil (VGO) up to 96.3%. The optimum esterification parameters were as follows: the amounts of catalyst and ethylene glycol were, respectively, 2.5 wt% and 4.0 wt% of the sample oil, the reaction temperature was 250 °C, and the reaction time was 1 h. Full article

The use of dyes as sensitizing agents to increase semiconductor activity is a strategy already adopted in the field of heterogeneous photocatalysis, but the compounds applied are noble metal-based and sometimes difficult to synthesize, which make it more expensive. In this work, it was discovered that methylene blue can perform such an effect on an iron molybdate functionalized with peroxo groups on the surface. This material, called MoOxoFe, was tested together with its analogue MoFe (produced without H₂O₂ in the synthesis) in the degradation of methylene blue. The rapid degradation of the dye led to the hypothesis of sensitization, which was investigated and proven by additional photocatalytic tests with sensitized material, MoOxoFe-MB, and spectroscopies, such as EPR and XPS. Full article