Search Results (46)

Functional cure of chronic hepatitis B virus (HBV) infection remains a significant challenge, making viral-entry-blocking antibodies a promising antiviral strategy. Here, we developed a structure-guided computational workflow for affinity-enhancing candidate mutations at the interface between the humanized neutralizing antibody HzKR127 and the HBV preS1 peptide epitope. Based on the crystal structure of the HzKR127–preS1 complex, we performed single-site saturation mutagenesis across the paratope, evaluating variants with a consensus effect score integrated from seven computational models. Benchmarking against published alanine scanning data showed that our consensus score effectively identified major-affinity-loss residues, achieving ROC AUC values of 0.81 and 0.84 for residue-level and site-level predictions, respectively. Mutational profiling revealed distinct asymmetric mutational responses, with broad intolerance on the preS1 side and localized favorable substitutions within antibody CDRs. Multilevel prioritization identified 26 antibody-side candidates, 17 of which showed improved HADDOCK refinement scores compared to the wild type. In particular, the H:D97W/F/Y substitutions presented the strongest structural rationale for enhancing improved interfacial packing through aromatic hydrophobic contacts with preS1 Phe10. These findings provide a prioritized list of candidates for experimental validation and a practical framework for the rational optimization of antibodies targeting functionally constrained viral epitopes. Full article

This investigation primarily focuses on addressing the challenges posed by the traditional use of carbon steel, which, despite its strength and cost-effectiveness, is prone to rapid corrosion in harsh chemical environments within the petrochemical industry. This issue constitutes a chronic operational vulnerability, exacerbated by extreme environmental stressors. The combined effect of corrosive atmospheres and rigorous EHSS (Environment, Health, Safety, and Security) mandates creates a significant fiscal burden, primarily driven by escalated lifecycle maintenance and the necessity for specialized regulatory compliance. Integrating Inconel, known for its exceptional corrosion resistance and durability, particularly at high temperatures, will significantly enhance the lifespan, safety, and operational efficiency of these vessels. This investigation aims to study the corrosion resistance of carbon steel specimens and carbon steel specimens clad with Inconel at thicknesses of 2 mm and 4 mm in different environments: acidic pH = 2 (HCl), neutral pH = 7 (distilled water), and alkaline pH = 12 (NaClO). All specimens were tested at the same immersion intervals of 5 and 10 days. Corrosion resistance was measured for the immersion corrosion tests. Weight loss in the specimens was measured before and after immersion to calculate the corrosion rate, and surface analysis was conducted using a scanning electron microscope (SEM). It was observed that at pH = 12 (NaClO), carbon steel corrosion reached a rate of 6.96 mm/year, while Inconel showed very low corrosion, 0.05 mm/year, indicating a resistance 139 times greater than that of carbon steel. At pH = 2 (HCl), carbon steel corrosion reached a rate of 1.29 mm/year, while Inconel showed a very low corrosion rate of 0.015 mm/year, indicating a resistance 86 times greater than that of carbon steel. In a neutral environment, all materials exhibited approximately the same corrosion rate between 0.0017 and 0.12 mm/year. This indicates that Inconel is highly resistant to corrosion in both acidic and alkaline environments, making it suitable for petrochemical plants. Full article

Background/Objectives: Despite advances in preventive dental care, tooth enamel erosion remains a relevant concern, and very few comparisons of surface topography have been carried out under controlled conditions in the laboratory. This study primarily aimed to conduct a qualitative morphological evaluation, supported by semi-quantitative image analysis, of the effects of commonly consumed beverages on human enamel morphology and colour, and to explore their relationship with beverage acidity in an in vitro model. Methods: Forty-two human teeth were allocated at random into seven different groups, each containing six molars. These groups were Coca-Cola, orange juice, lemon juice, coffee, chlorhexidine, regular mouthwash without chlorhexidine, and one control group. Following a 24 h exposure to a simulated saliva environment at 37 °C, the test samples were then subjected to a five-day erosion cycle. SEM analysis was used to examine the enamel alterations after evaluating the morphology of the enamel surface and by digital image analysis. Results: Scanning electron microscopy, SEM, showed how erosion of the teeth’s surface increased with the acidity of the drink. The extensive exposure of the crystal prisms, along with the severe loss of intercrystalline material and honeycomb weathering patterns, was all brought about by Coca-Cola and lemon juice. The moderate erosion brought on by orange juice in tests resulted in partially exposed prisms. Both the mouthwashes and the coffee exhibited similar impacts on the tooth enamel in a microscopic view. Minimal enamel prism rods were exposed due to either the coffee or the mouthwash. The surface characteristics were found through a digital image analysis, which indicated alterations in surface texture. Conclusions: Under these immersion conditions, highly acidic beverages produced the most pronounced enamel surface changes, whereas coffee induced mainly staining and neutral mouthwashes caused minimal modification. These results reflect qualitative morphological trends and should not be interpreted as clinical outcomes. Full article

Microfibrillated cellulose (MFC) derived from wood sources is a biodegradable and eco-friendly reinforcing material for polymer composites. However, the high polarity of MFC is a challenge in homogeneous distribution into the hydrophobic PLA matrix, which limits its reinforcing efficiency. In this study, lignin-containing MFC (LMFC) with different residual lignin contents was prepared to investigate its dispersion behavior and reinforcing effect in polylactic acid (PLA). The aspect ratio and neutral sugar composition of LMFC remained similar regardless of lignin content, whereas the dispersion degree in PLA, quantified using a log-normal distribution model, increased from 24.2% to 35.1% with increasing lignin content. Mechanical testing showed that LMFC incorporation enhanced tensile strength and elastic modulus while reducing elongation at break. Higher residual lignin content in LMFC positively affected the tensile strength of the LMFC–PLA composites. Dynamic mechanical analysis revealed an increase in storage modulus and a decrease in loss factor with higher lignin content and LMFC loading (1–10 wt%), indicating enhanced interfacial interactions. Differential scanning calorimetry showed reductions in glass transition temperature (5–8 °C) and cold crystallization temperature (8–16 °C) compared to neat PLA. These findings indicate that residual lignin in LMFC enhances dispersion and interfacial interactions in PLA, leading to improved mechanical and thermal performance and highlighting its potential as an effective reinforcing component in sustainable biocomposites. Full article

High-energy Ni-rich layered cathodes are critical for next-generation lithium-ion batteries yet remain limited by severe interfacial degradation and thermal vulnerability under high-voltage operation. In this work, a robust spinel-layered heterostructure is constructed by encapsulating LiNi_0.8Co_0.1Mn_0.1O₂ (NCM811) with a LiNi_0.5Mn_1.5O₄ (LNMO) spinel shell via a scalable sol–gel route. Structural characterizations confirm that the coating maintains the secondary-particle architecture, while X-ray photoelectron spectroscopy reveals a chemically reconditioned interface, achieved by the scavenging residual lithium species and suppressing of rock-salt-like surface reconstruction. Consequently, the optimized 4 wt% LNMO@NCM811 electrode demonstrates significantly enhanced high-voltage (2.8–4.4 V) stability, maintaining 41.84% of its initial capacity after 200 cycles compared to only 15.75% for the pristine sample. Crucially, thermogravimetric-differential scanning calorimetry (TG-DSC) uncovers the kinetic origin of this safety improvement: the spinel shell alters the thermal decomposition pathway, delaying the 10% mass loss temperature (T_10%) from 515.2 °C to 716.6 °C and suppressing the total exothermic heat release from 208.3 J g⁻¹ to 81.5 J g⁻¹. Collectively, these results demonstrate that the co-free spinel encapsulation is a dual-functional strategy to simultaneously stabilize surficial chemistry and intrinsically enhance the thermal safety of Ni-rich cathodes for carbon-neutral energy storage applications. Full article

Background and Objectives: Chairside bleaching can alter enamel morphology and mineral content. This in vitro study compared surface changes and elemental shifts after three in-office protocols using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). Materials and Methods: Forty-two human premolars/molars were sectioned; matched halves served as control or received Opalescence Quick 45% carbamide peroxide (CP), Opalescence Boost 40% hydrogen peroxide (HP), or BlancOne Ultra+ 35% HP with light activation. Gels were applied per manufacturers’ instructions. SEM assessed topography (×500–×1100); EDS quantified atomic percent of O, Ca, P, C and trace elements. One-way ANOVA compared Ca and P between bleached groups (α = 0.05). Results: Controls showed compact surfaces with preserved Ca and P. After Quick, SEM revealed roughness, fissures and microcracks; Ca fell from 11.5 to 12.5 to 9.53–11.73 at% and P from 7.5 to 8.9 to 7.41–8.59 at%. Boost produced mild superficial restructuring and granular deposits with variable Ca 13.80–27.94 at% and P 7.32–14.65 at%. BlancOne Ultra+ caused diffuse erosion and loss of prismatic clarity with marked demineralization (Ca 1.42–7.85 at%, P 1.22–6.71 at%); C rose locally to 46.61 at%. Across bleached groups, Ca and P differed significantly (both p < 0.001). Oxygen remained dominant (~39–50 at%) in all spectra; occasional Al/Si/Cl/K likely reflected residues or preparation artifacts. Conclusions: All protocols produced surface and compositional alterations, with a severity gradient: BlancOne Ultra+ > Boost > Quick. High-concentration, light-activated HP yielded the largest Ca/P losses. Clinically, neutral-pH, non-activated or chemically activated regimens and immediate post-bleach remineralization should ideally be used when feasible, particularly before adhesive procedures. Full article

Background: In childhood acute lymphoblastic leukemia (ALL), in addition to classical chromosomal abnormalities, loss of heterozygosity (LOH), including copy-neutral LOH, is also observed. While LOH has been described in the literature, its clinical relevance in pediatric ALL remains unclear. The aim of this study is to identify and analyze patterns of LOH, assess their frequency, and evaluate their association with clinical characteristics and early treatment response during the induction phase of the ALL protocol. Methods: The study included 853 pediatric ALL patients, of whom 120 had B-ALL LOH+ and 58 had T-ALL LOH+. LOH was analyzed using CytoScan HD SNP microarrays. Patients were stratified using multiple correspondence analysis (MCA) and hierarchical clustering on principal components (HCPC), which identified three genetically and clinically distinct clusters. Results: In B-ALL, two clusters with extensive LOH—particularly involving chromosome 9—were associated with poor prognosis and suboptimal response to therapy. In contrast, Cluster 2, characterized by CDKN2A duplication and rare LOH, showed a favorable clinical course. In T-ALL, Cluster 1 had LOH in CDKN2A but favorable outcomes; Cluster 2 exhibited biallelic CDKN2A deletion and aggressive disease; Cluster 3 lacked CDKN2A alterations and showed a genetically stable profile. LOH was common on chromosomes not typically affected by trisomy and rare on those gained. Conclusions: Our study indicates that LOH profiling can positively influence patient stratification by identifying high-risk subgroups, inform prognosis by highlighting unfavorable genetic alterations, and help predict poor treatment response in specific clinical profiles. Full article

In this study, Cu-doped TiO₂ combined with natural zeolite (ZT) was synthesized and applied as a fixed powder layer on poly(methyl methacrylate) (PMMA) tablets. The material’s morphology, structural, and chemical properties were characterized using high-resolution scanning electron microscopy, Raman spectroscopy, and Brunauer–Emmett–Teller analysis. The antioxidant capacity was evaluated by assessing the neutralization of hydroxyl radicals and iron (III) ions. For the first time, tablets with Cu-TiO₂ and ZT deposited on PMMA as the carrier were investigated for removing two dyes, methyl orange (MO) and methylene blue (MB), from water under simulated solar (SS) and UVC irradiation. Under SS irradiation, the Cu-TiO₂/PMMA and Cu-TiO₂/ZT/PMMA tablets achieved about 21% degradation of MB after 240 min. This result is particularly noteworthy because SS radiation provides lower energy compared with UVC, making the process more economically efficient. Furthermore, the photocatalysts are immobilized on a stable carrier, which enhances the method’s cost-effectiveness by reducing material loss and simplifying recovery. In the presence of ZT/PMMA tablets, 69% of MB was removed by adsorption after 240 min. Additionally, we explored the mechanism of degradation, revealing that the enhanced generation of hydroxyl radicals plays a pivotal role in the effective degradation of MB. At the same time, photogenerated holes contribute to the removal of MO. The overall results suggest that the tablets obtained are a promising solution for water purification due to their effectiveness, simplicity, and low processing cost. Full article

Background: Cu/Zn Superoxide Dismutase 1 (SOD1) is a 32 kDa cytosolic dimeric metalloenzyme that neutralizes superoxide anions into oxygen and hydrogen peroxide. Mutations in SOD1 are associated with ALS, a disease causing motor neuron atrophy and subsequent mortality. These mutations exert their harmful effects through a gain of function mechanism, rather than a loss of function. Despite extensive research, the mechanism causing selective motor neuron death still remains unclear. A defining feature of ALS pathogenesis is protein misfolding and aggregation, evidenced by ubiquitinated protein inclusions containing SOD1 in affected motor neurons. This work aims to identify compounds countering SOD1(A4V) misfolding and aggregation, which could potentially aid in ALS treatment. Methods: The approach employed was in vitro screening of a library comprising 1280 pharmacologically active compounds (LOPAC^®) in the context of drug repurposing. Using differential scanning fluorimetry (DSF), these compounds were tested for their impact on SOD1(A4V) thermal stability. Results and Conclusions: Dimer stability was the parameter chosen as the criterion for screening, since the dissociation of the native SOD1 dimer is the step prior to its in vitro aggregation. The screening revealed one compound raising protein-ligand T_m by 6 °C, eleven inducing a higher second T_m, suggesting a stabilization effect, and fourteen reducing T_m from 10 up to 26 °C, suggesting possible interactions or non-specific binding. Full article

The amino acid L-histidine, which has an imidazole ring, was investigated as a corrosion inhibitor for AISI 1018 carbon steel in chloride solution based on the effectiveness of inhibitors containing imidazole in their composition. A neutral environment was chosen for this study due to the scarcity of research on this amino acid in this environment type. Concentrations of 250, 500, and 1000 ppm were evaluated. Various methods were used to determine inhibition effectiveness, including mass loss, open circuit potential, linear potentiodynamic polarization, and electrochemical impedance spectroscopy. For mass loss, the inhibition efficiency varied from 83 to 88% according to the increase in concentration. For the electrochemical tests, the efficiency variation ranged from 62 to 90% with increasing amino acid concentration. Furthermore, a simulation analysis using quantum chemical calculations within the scope of Density Functional Theory (DFT) revealed that histidine’s nucleophilic character is crucial for its corrosion inhibitory capacity in an aqueous medium at pH 7. The inhibition efficiency increased with increasing concentration in a neutral medium, following the Langmuir isotherm for the adsorption of L-histidine. Additional studies were carried out using Fourier transform infrared spectroscopy (FTIR) and thermogravimetry (TGA). Analysis of the substrate surface by scanning electron microscopy (SEM) showed greater preservation with the addition of L-histidine, confirming its adsorption on the steel. Atomic Force Microscopy (AFM) also demonstrated an improvement in surface roughness in the presence of amino acids compared to the medium without an inhibitor. Full article

Mealworms (Tenebrio molitor) have been used as an alternative source of proteins and lipids. Triacylglycerols (TAGs) are major sources of energy and have been used to provide essential fatty acids. They are also the main components of mealworm oil, and their composition and content are extensively linked to its physical and chemical properties. However, because of the complexity of TAG molecules, their identification and quantitation are challenging. This study employed electrospray ionization tandem mass spectrometry (ESI-MS/MS) with multiple neutral loss scans (NLS) to analyze the TAG composition and content in mealworm oil. Identifying and quantifying TAGs using ESI-MS/MS in combination with multiple NLS was an efficient way to improve accuracy and timeliness. For the accurate quantification of TAGs, isotopic deconvolution and correlation factors were applied. A total of 57 TAGs were identified and quantified: C52:2 (16:0/18:1/18:1) (1549.4 nmol/g, 18.20%), C52:3 (16:0/18:1/18:2) (1488.1 nmol/g, 17.48%), C54:4 (18:1/18:1/18:2) (870.1 nmol/g, 10.23%), C54:6 (18:1/18:2/18:2) (659.8 nmol/g, 7.76%) and C52:4 (16:0/18:2/18:2) (600.5 nmol/g, 7.06%), which were the most abundant TAGs present in the mealworm oil. The fundamental properties of mealworm oil, including its degree of oxidation, nutritional effect and physical properties, were elucidated. Full article

The wear surface morphology of AlSi10Mg specimens, originally manufactured using selective laser melting (SLM), has been analyzed in the context of exposure to heat from gas flames. The first stage of the experimental work included the performance of surface heat-exposure on SLM-prepared specimens through oxyacetylene gas welding. Gas welding was utilized with three different flames, namely; reducing, neutral, and oxidizing on the as-built specimens of SLM. The post-surface-treated specimens were subjected to pin-on-disk wear testing against fixed parameters. After the performance of wear testing at two different radii, the mass loss of each of the four types of specimens was calculated including the three specimens exposed to heat along with the as-built specimens. The results showed that the maximum amount of mass losses at 24 mm and 30 mm radii belongs to the neutral flame specimens and the least was for the as-built condition specimens. Upon analysis, the heat-exposure specimens through all three types of gas flames resulted in an increase in the amount of mass in contrast to the as-built specimens. Moreover, the morphologies of the developed wear tracks at surfaces were examined using the scanning electron microscope (SEM) for the understating of the mechanism. Full article

Ophiopogonis Radix (OR) is a traditional Chinese medicine. In recent years, in order to achieve the purpose of drying, bleaching, sterilizing and being antiseptic, improving appearance, and easy storage, people often use sulfur fumigation for its processing. However, changes in the chemical composition of medicinal herbs caused by sulfur fumigation can lead to the transformation and loss of potent substances. Therefore, the development of methods to rapidly reveal the chemical transformation of medicinal herbs induced by sulfur fumigation can guarantee the safe clinical use of medicines. In this study, a combined full scan-parent ions list-dynamic exclusion acquisition-diagnostic product ions analysis strategy based on UHPLC-LTQ-Orbitrap MS was proposed for the analysis of steroidal saponins and their transformed components in sulfur-fumigated Ophiopogonis Radix (SF-OR). Based on precise mass measurements, chromatographic behavior, neutral loss ions, and diagnostic product ions, 286 constituents were screened and identified from SF-OR, including 191 steroidal saponins and 95 sulfur-containing derivatives (sulfates or sulfites). The results indicated that the established strategy was a valuable and effective analytical tool for comprehensively characterizing the material basis of SF-OR, and also provided a basis for potential chemical changes in other sulfur-fumigated herbs. Full article

This study focuses on the thermal properties and structural features of blends consisting of thermoplastic starch (TPS) and poly(ethylene-co-methacrylic acid) copolymer (EMAA) or its ionomer form (EMAA-54Na). The aim is to investigate how carboxylate functional groups of the ionomer form intervene in blends compatibility at the interface of the two materials and how this impacts their properties. Two series of blends (TPS/EMAA and TPS/EMAA-54Na) were produced with an internal mixer, with TPS compositions between 5 and 90 wt%. Thermogravimetry shows two main weight losses, indicating that TPS and the two copolymers are primarily immiscible. However, a small weight loss existing at intermediate degradation temperature between those of the two pristine components reveals specific interactions at the interface. At a mesoscale level, scanning electron microscopy confirmed thermogravimetry results and showed a two-phase domain morphology, with a phase inversion at around 80 wt% TPS, but also revealed a different surface appearance evolution between the two series. Fourier-transformed infrared spectroscopy analysis also revealed discrepancies in fingerprint between the two series of blends, analysed in terms of additional interactions in TPS/EMAA-54Na coming from the supplementary sodium neutralized carboxylate functions of the ionomer. Full article

In this study, glutaraldehyde cross-linked chitosan support, as well as the catalysts obtained after loading Ag metal (Ag/Chitosan), were synthesised and applied for adsorption and reduction of phenol red dye in an aqueous solution. The Ag/chitosan catalysts were characterised by X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FT-IR) and inductively coupled plasma-optical emission spectrometry (ICP-OES) analysis techniques. The catalytic reduction and adsorption performance of phenol red dye with Ag/chitosan and cross-linked chitosan, respectively, was performed at ambient reaction conditions. The reduction of dye was carried out using sodium borohydride (NaBH₄) as the reducing agent, while the progress of adsorption and reduction study was monitored with ultraviolet-visible (UV-vis) spectrophotometry technique. The reduction of the phenol red dye varied with the amount of catalyst, the concentration of NaBH₄, Ag metal loading, reaction temperature, phenol red dye concentration and initial pH of the dye solution. The dye solution with a nearly-neutral pH (6.4) allowed efficient adsorption of the dye, while acidic (pH = 4) and alkaline (pH = 8, 11, 13.8) solutions showed incomplete or no adsorption of dye. The reusability of the Ag/chitosan catalyst was applied for the complete reduction of the dye, where no significant loss of catalytic activity was observed. Hence, the applicability of cross-linked chitosan and Ag/catalyst was thus proven for both adsorption and reduction of phenol red dye in an aqueous solution and can be applied for industrial wastewater treatment. Full article