Search Results (462)

Peptide mapping is a well-established method for confirming the identity of therapeutic proteins as part of batch release testing and product characterization for regulatory filings. Traditionally based on enzymatic digestion followed by reversed-phase liquid chromatography and UV detection, the method has evolved with technological advancements to incorporate mass spectrometry (MS), enabling more detailed structural insights. Residue-level confirmation of amino acid sequences requires MS/MS fragmentation, which produces large amounts of data that must be processed using specialized software. In regulated environments, the use of academic algorithms is often limited by validation requirements, making it necessary to rely on commercially approved tools, although their built-in scoring systems have limitations that can affect sequence assignment accuracy. Here, we present representative examples of incorrect peptide assignments generated by commercial software. In antibody sequence analysis, misidentifications resulted from isobaric and near-isobaric dipeptides (e.g., SA vs. GT). Additional examples from the analysis of SARS-CoV-2 spike protein variants revealed software-induced artifacts, including artificial succinylation of aspartic acid residues to compensate for sequence mismatches, and incorrect deamidation site assignments due to misinterpretation of isotopic peaks. These findings underscore the necessity for expert manual review of MS/MS data, even when using validated commercial platforms, and highlight the molecular challenges in distinguishing true sequence variants from software-driven artifacts. Full article

Metal–organic frameworks (MOFs) are a class of highly ordered nanoporous crystals that possess a designable framework and unique chemical versatility. MOF thin films are ideal for nanotechnology-enabling applications, such as optoelectronics, catalytic coatings, and sensing. Mg-MOF-74 has been drawing increasing attention due to its remarkable CO₂ uptake capacity among MOFs and other commonly used CO₂ absorbents. Mg-MOF-74 thin films are currently fabricated by immersing selected substrates in precursor solutions, followed by a traditional solvothermal synthesis process. Herein, we introduce a rapid, easy, and cost-effective synthesis protocol to fabricate MOF thin films in an additive manner. In this work, the controllable synthesis of Mg-MOF-74 thin films directly on optical supports is reported for the first time. Dense, continuous, and uniform Mg-MOF-74 thin films are successfully fabricated on bare glass slides, with an average growth rate of up to 85.3 nm min⁻¹. The structural and optical properties of the resulting Mg-MOF-74 thin films are characterized using X-ray diffraction, atomic force microscopy, scanning electron microscopy, UV-Vis-NIR spectroscopy, and Fourier Transform Infrared Spectroscopy (FTIR). The CO₂ adsorption performance of the resulting Mg-MOF-74 thin films is studied using FTIR for the first time, which demonstrates that, as per the length of the light path for gas absorption, 1 nm Mg-MOF-74 thin film could provide 400.9 ± 18.0 nm absorption length for CO₂, which is achieved via the extraordinary CO₂ adsorption by Mg-MOF-74. The synthesis protocol enables the rapid synthesis of MOF thin films, highlighting Mg-MOF-74 in more CO₂-related applications, such as enhanced CO₂ adsorption and MOF-enhanced infrared gas sensing. Full article

The utilization of carbon dioxide (CO₂) offers an effective approach for alleviating the carbon-reduction pressures associated with fossil energy consumption. However, studies on the use of CO₂ as an auxiliary agent in water treatment to enhance the removal of emerging contaminants are limited. In this study, the photodegradation of ciprofloxacin (CIP) was investigated using ultraviolet (UV) irradiation combined with CO₂ dosing (UV/CO₂). The results demonstrated that the UV/CO₂ system effectively degraded CIP, with CO₂ concentration and solution pH exerting a critical influence. Inorganic anions and metal cations had negligible effects on CIP degradation efficiency, whereas natural organic matter (NOM) had a pronounced inhibitory effect. Mechanistic analysis revealed that superoxide radicals ($·{\mathrm{O}}_2^{-}$) and carbonate radicals (${\mathrm{CO}}_3^{•-}$) were the primary oxidizing species, whereas the excited triplet state of CIP (³CIP*) and singlet oxygen played crucial roles in initiating radical generation. LC–MS analysis and density functional theory calculations indicated that the main degradation routes involved defluorination, decarboxylation, and epoxidation of the piperazine ring. Toxicity assessment indicated that the transformation products generated by UV/CO₂ were less toxic than the parent compound. Furthermore, the UV/CO₂ process demonstrated high energy efficiency, with a low electrical energy per order (EEO) value of 0.4193 kWh·m⁻³·order⁻¹. These findings suggest that the UV/CO₂ system is a promising alternative for the treatment of photosensitive organic pollutants and provides a beneficial pathway for CO₂ utilization. Full article

Background: Folic acid (FA), also known as vitamin B9, functions as a co-factor in many cellular processes. Ultraviolet radiation (UV) has been shown to cause the formation of free radicals, and chronic exposure of the skin to UV radiation has been demonstrated to result in many adverse effects. Skin protection against harmful environmental factors is one of the aims of cosmetic products. One such substance is folic acid. However, aqueous FA solutions decompose after exposure to UV radiation, and the decomposition products can exhibit variable pro/anti-oxidative roles depending on the cell type and its environment. Objectives: The objective of the present study was to demonstrate the effectiveness of folic acid as a UV-protective agent in vitro cell culture model. Methods: The experimental model comprised an in vitro culture of normal human fibroblasts derived from adult skin (NHDF-Ad). Paramagnetic electron resonance (EPR) was used to assess the interaction of folic acid with free radicals after exposure to UV radiation. RT-qPCR was utilized to evaluate the impact of ultraviolet (UV) radiation on the expression of selected cell cycle regulatory genes (CCND1, P53, BAX, and BCL-2) in vitro cultured fibroblasts that were protected by folic acid. Results: EPR studies revealed the antioxidant properties of folic acid. Free radical forms of folic acid are induced during UV irradiation. The strong effect of UV irradiation on interactions of folic acid with free radicals was observed. The interaction was found to be weaker for the irradiated samples. Molecular studies have demonstrated a decline in the BAX/BCL-2 ratio in cells that have been treated with folic acid and exposed to UV radiation in comparison to the BAX/BCL-2 ratio observed in cells that have been exposed exclusively to UV radiation and not treated with folic acid. Conclusions: Whilst molecular and EPR studies both confirm the effectiveness of folic acid as a UV-protective ingredient in cosmetics and pharmaceutical products, further research in this area is required. Full article

Perovskite-type CaBiO₂Cl with a unique layered Sillen X1 structure exhibits great potential as an efficient visible-light photocatalyst. In this study, CaBiO₂Cl was synthesized through calcination at 800 °C and subsequently composited with varying amounts of g-C₃N₄ to optimize photocatalytic performance. The prepared catalysts were characterized by multiple techniques to confirm their structural and compositional features. Under visible-light irradiation, the photocatalytic activities toward Rh6G degradation were systematically evaluated using UV–vis PDA and EPR analyses. To further elucidate the degradation mechanism, radical scavenger experiments were conducted to identify the reactive species generated during the photodegradation process. Kinetic analysis revealed that the reaction rate constant (k) of pure CaBiO₂Cl was 0.0525 h⁻¹, while that of pure g-C₃N₄ was 0.0423 h⁻¹. Notably, the CaBiO₂Cl/10 wt% g-C₃N₄ composite exhibited an enhanced k value of 0.0568 h⁻¹, which is 1.1 and 1.3 times higher than those of CaBiO₂Cl and g-C₃N₄, respectively. Furthermore, under ambient conditions (25 °C, 1 atm), the CO₂-to-CH₄ photocatalytic conversion efficiency of the CaBiO₂Cl/10 wt% g-C₃N₄ composite reached 0.5652 μmol g⁻¹ h⁻¹. These findings demonstrate that CaBiO₂Cl-based composite photocatalysts not only achieve superior visible-light photocatalytic activity but also exhibit excellent stability, highlighting their potential for environmental remediation and alignment with the principles of green chemistry. Full article

While existing studies on Guatemalan jadeite have predominantly focused on green varieties, the coloration mechanisms and origin of its blue counterparts remain poorly understood. Therefore, the present study provides the first comprehensive investigation of the Guatemalan blue jadeite using an integrated analytical approach, which combines Raman spectroscopy, micro X-ray fluorescence (µ-XRF), electron microprobe analysis (EMPA), X-ray diffraction (XRD), UV-Vis spectroscopy, and Cathodoluminescence (CL) imaging on seven representative samples. The results demonstrate that these jadeites consist of two distinct phases: a primary jadeite phase (NaAlSi₂O₆) and a secondary omphacite that form by metasomatic alteration by Mg-Ca-Fe-rich fluids. Spectroscopic analysis reveals that the blue coloration is primarily controlled by Fe³⁺ electronic transitions (with characteristic absorption at 381 nm and 437 nm) coupled with Fe²⁺-Ti⁴⁺ intervalence charge transfer, supported by μ-XRF mapping showing strong Fe-Ti spatial correlation with color intensity. CL imaging documents a multi-stage formation history involving initial high-pressure crystallization (Jd-I) followed by fluid-assisted recrystallization forming Jd-II and omphacite. The detection of CH₄, CO and H₂O in the fluid inclusions by Raman spectroscopy indicates formation in a serpentinization-related reducing environment, while distinct CL zoning patterns confirm a fluid-directed crystallization (P-type) origin. These findings not only clarify the chromogenic processes and petrogenesis of Guatemalan blue jadeite but also establish key diagnostic criteria for its identification, advancing our understanding of fluid-derived jadeite formation in subduction zone environments. Full article

Cnidium officinale (CO) and Angelica gigas (AG) are traditional herbal medicines known for their bioactive compound ferulic acid (FA), which exerts skin-whitening, anti-inflammatory, antioxidant, and UV-protective effects. However, conventional extraction yields are limited and often require solvent-intensive processes. In this study, an eco-friendly hot-melt extrusion (HME) process was applied to enhance the FA content and extractability from CO and AG. Process optimization significantly improved particle morphology and reduced size, as confirmed by Fourier transform-infrared spectroscopy (FT-IR) and field emission-scanning electron microscopy (FE-SEM) analysis. Quantitative High-performance liquid chromatography (HPLC) analysis showed increased FA content in HME-treated extracts, which corresponded to enhanced biological efficacy. The HME extracts exhibited no cytotoxicity up to 500 µg/mL in B16F10 melanocytes and significantly inhibited α-melanocyte stimulating hormone (α-MSH)-induced melanin synthesis. In HaCaT keratinocytes, the HME group promoted superior wound closure at 24 and 48 h, indicating accelerated skin regeneration. These findings support HME as a sustainable and effective strategy for developing natural ingredient-based cosmetic formulations targeting hyperpigmentation and skin repair. Full article

This work reports a low-cost, microwave-assisted wet chemistry synthesis of zinc antimonate (ZnSb₂O₆) powders with a trirutile structure, yielding highly homogeneous, nanometric particles. X-ray diffraction (XRD) confirmed the formation of the trirutile phase with lattice parameters of a = 4.664 Å and c = 9.263 Å, and an estimated crystallite size of 42 nm. UV–vis spectroscopy revealed a bandgap of 3.35 eV. Scanning electron microscopy (SEM) showed that ethylenediamine, as a chelating agent, formed porous microstructures of microrods and cuboids, ideal for enhanced gas adsorption. Brunauer–Emmett–Teller (BET) analysis revealed a specific surface area of 6 m²/g and a total pore volume of 0.0831 cm³/g, indicating a predominantly mesoporous structure. The gas sensing properties of ZnSb₂O₆ pellets were evaluated in CO and C₃H₈ atmospheres at 100, 200, and 300 °C. The material exhibited high sensitivity at 300 °C, where the maximum responses were 5.86 for CO at 300 ppm and 1.04 for C₃H₈ at 500 ppm. The enhanced sensitivity at elevated temperatures was corroborated by a corresponding decrease in electrical resistivity. Furthermore, the material demonstrated effective photocatalytic activity, achieving up to 60% degradation of methylene blue and 50% of malachite green after 300 min of UV irradiation, with the process following first-order reaction kinetics. These results highlight that ZnSb₂O₆ synthesized by this method is a promising bifunctional material for gas sensing and photocatalytic applications. Full article

The presence of various Ag species (Ag⁺ ions, Ag clusters, and Ag nanoparticles (NPs)) in Ag-zeolite nanocomposites strongly influences their catalytic, photocatalytic, and antibacterial properties. To tailor materials for specific applications, it is essential to employ strategies that control the redox processes between Ag⁺ and Ag⁰ and facilitate the formation of active Ag-containing composites. In this study, we present a comparative analysis of Ag-zeolite nanocomposites, focusing on their synthesis methods, structural characteristics, and antibacterial activity against Escherichia coli. Ag NPs were synthesized using three approaches: solid-state thermal reduction, chemical reduction in aqueous solutions with a mild reducing agent (sodium citrate, Na₃Cit), and chemical reduction with a strong reducing agent (sodium borohydride, NaBH₄). The resulting materials were characterized by X-ray diffraction (XRD), diffuse reflectance UV–Vis spectroscopy (DR UV–Vis), X-ray photoelectron spectroscopy (XPS), and transmission electron microscopy (TEM), while antibacterial activity was assessed using biological assays. Microscopic and spectroscopic analyses confirmed the formation of Ag NPs and the co-existence of immobilized Ag⁺ ions within the zeolite framework. The specific influence of the treatment method of Ag⁺-zeolite on the presence of silver species in the nanocomposites and their role in antibacterial properties were evaluated. The highest antibacterial efficiency was observed in the nanocomposite produced by thermal treatment of Ag-exchanged zeolite. Thus, the crucial function of Ag⁺ ions in the mechanism of bacteria cell death was suggested. Full article

Cost-effective procedures usually cannot achieve complete removal of priority contaminants present in water at very low concentrations (as pesticides or pharmaceuticals). Advanced oxidation processes (AOPs) represent promising technologies for removing priority contaminants from water at trace concentrations, yet practical implementation remains limited due to technical and economic constraints. This study presents an innovative flow-through photodegradation device designed to overcome current limitations while achieving efficient contaminant removal at industrial scale. The device integrates a UVC 254 nm lamp-equipped flow chamber with automated dosing pumps for hydrogen peroxide and/or solid catalyst suspensions, coupled with a 30 nm porous membrane filtration system for catalyst recirculation. This configuration optimizes light–catalyst–pollutant contact while enabling combined catalytic processes. Performance evaluation using acesulfame (ACE) and iohexol (IHX) as model contaminants demonstrated rapid and effective removal. IHX degradation with UVC and 75 μM H₂O₂ achieved complete removal with t₉₅% = 7.23 ± 1.21 min (pseudo-order 0.25, t₁/₂ = 3.27 ± 0.39 min), while ACE photolysis (with UVC only) required t₉₅% = 14.88 ± 2.02 min (pseudo-order 1.27, t₁/₂ = 2.35 ± 0.84 min). The introduction of t₉₅% as a performance metric provides practical insights for near-complete contaminant removal requirements. Real-world efficacy was confirmed using tertiary wastewater treatment plant effluents containing 14 μg/L IHX, achieving complete removal within 8 min. However, carbamazepine degradation proved slower (t₉₅% > 74 h), highlighting the need for combined catalytic approaches for recalcitrant compounds. Spiking experiments (1000 μg/L) revealed concentration-dependent kinetics and synergistic effects between co-present contaminants. Analysis identified degradation byproducts consistent with previous studies, including tri-deiodinated iohexol (474.17 Da) intermediates. This scalable system, constructed from commercially available components, demonstrates potential for cost-effective industrial implementation. The modular design allows adaptation to various contaminants through adjustable AOP combinations (UV/H₂O₂, photocatalysts, ozone), representing a practical advancement toward addressing the gap between laboratory-scale photocatalytic research and full-scale water treatment applications. Full article

The persistent occurrence of antibiotics like chloramphenicol (CAP) in aquatic systems poses serious environmental and public health risks. This study investigates the photocatalytic degradation of CAP using cerium oxide (CeO₂), lanthanum oxide (La₂O₃), and lanthanum-doped cerium oxide (Ce_xLa_yO_2−δ), synthesized via co-precipitation. The catalysts were tested under a solar simulator, UV-A, and UV-C radiation, both with and without hydrogen peroxide (H₂O₂). Structural characterization confirmed successful synthesis of nanometric catalysts, with La doping causing lattice expansion in CeO₂ and a reduction in crystallite size (from 27 nm in CeO₂ to ~20 nm in doped samples). Photolysis alone achieved limited CAP removal (~34–35%), while photocatalysis with La₂O₃ under UV-A and UV-C improved removal up to 58% and 55%, respectively. Complete degradation was obtained with La₂O₃ under UV-C in the presence of H₂O₂ within 15 min. Pareto analysis highlighted the dominant effect of the interaction between radiation and H₂O₂ (43%), while the catalyst type contributed minimally (0.23%). These findings confirm the potential of REE oxides, especially La₂O₃, in advanced oxidation processes and underscore the importance of light source and radical generation over catalyst selection alone. Full article

This study reports the synthesis and evaluation of iron molybdate (Fe₂(MoO₄)₃) and iron tungstate (FeWO₄) as photocatalysts for the degradation of a real industrial effluent from aluminum anodizing processes under visible light irradiation. The oxides were synthesized via a co-precipitation method in an aqueous medium, followed by microwave-assisted hydrothermal treatment. Structural and morphological characterizations were performed using X-ray diffraction, field-emission scanning electron microscopy, Raman spectroscopy, ultraviolet–visible (UV–vis), and photoluminescence (PL) spectroscopies. The effluent was characterized by means of ionic chromatography, total organic carbon (TOC) analysis, physicochemical parameters (pH and conductivity), and UV–vis spectroscopy. Both materials exhibited well-crystallized structures with distinct morphologies: Fe₂(MoO₄)₃ presented well-defined exposed (001) and (110) surfaces, while FeWO₄ showed a highly porous, fluffy texture with irregularly shaped particles. In addition to morphology, both materials exhibited narrow bandgaps—2.11 eV for Fe₂(MoO₄)₃ and 2.03 eV for FeWO₄. PL analysis revealed deep defects in Fe₂(MoO₄)₃ and shallow defects in FeWO₄, which can influence the generation and lifetime of reactive oxygen species. These combined structural, electronic, and morphological features significantly affected their photocatalytic performance. TOC measurements revealed degradation efficiencies of 32.2% for Fe₂(MoO₄)₃ and 45.3% for FeWO₄ after 120 min of irradiation. The results highlight the critical role of morphology, optical properties, and defect structures in governing photocatalytic activity and reinforce the potential of these simple iron-based oxides for real wastewater treatment applications. Full article

Laser annealing of oxide functional thin films makes them compatible with substrates of various types, especially flexible materials. The effects of optical annealing on Ni-doped ZnO thin films were the subject of investigation and analysis in this study. Using pulsed laser deposition, we deposited polycrystalline ZnNiO films on sapphire and silicon substrates. The deposited film was annealed by laser heating. A continuous CO₂ laser was used for this purpose. The uniformly distributed long-wavelength radiation of the CO₂ laser can penetrate deeper from the surface of the thin film compared to short-wavelength lasers such as UV and IR lasers. After growth, optical post-annealing processes were applied to improve the conductive properties of the films. The crystallinity and surface morphology of the grown films and annealed films were analyzed using SEM, and their electrical parameters were evaluated using van der Pauw effect measurements. We used electrical conductivity measurements and investigated the photovoltaic properties of the ZnNiO film. After CO₂ laser annealing, changes in both the crystalline structure and surface appearance of ZnO were evident. Subsequent to laser annealing, the crystallinity of ZnO showed both change and degradation. High-power CO₂ laser annealing changed the structure to a mixed grain size. Surface nanostructuring occurred. This was confirmed by SEM morphological studies. After irradiation, the electrical conductivity of the films increased from 0.06 Sm/cm to 0.31 Sm/cm. The lifetime of non-equilibrium charge carriers decreased from 2.0·10⁻⁹ s to 1.2·10⁻⁹ s. Full article

Micro/nanoplastics (MNP) and endotoxin, typical emerging contaminants, can be found in marine aqueous systems due to various natural and anthropogenic activities, and their co-occurrence may influence the biophysicochemical characteristics of seawater. Moreover, endotoxins may be transported by the micro/nanoplastics or increase the deformation of these substances, comprising other risks to the ecosystem. However, the impacts of the co-occurrence of micro/nanoplastics and endotoxins in seawater remain unknown. We studied the effects of endotoxin at three concentration levels in seawater and its combined impact with micro/nanoplastics at three doses on biophysicochemical processes in seawater through spectroscopic analysis, leaching indicators (turbidity and humidification index), oxidative potential, antioxidant activity, and biofilm production. The results showed that the UV–VIS spectra of seawater changed with their co-occurrence. The co-presence of MNPs and endotoxins increased the turbidity in seawater, indicating the leaching of micro/nanoplastic in the presence of endotoxins. A higher humification index in seawater showed the formation of dissolved organic substances in micro/nanoplastic and endotoxin seawater compared to the results for untreated seawater. Dithioerythritol assay revealed the differences in oxidative potentials of plain seawater and seawater in the co-presence of micro/nanoplastics and endotoxins. An important biochemical reaction in seawater was tested using biofilm formation. The results showed higher biofilm formation in their co-presence. This study provides new insights into the effects of micro/nanoplastics and their composite pollution with endotoxins on biophysiochemical indicators in seawater. Full article

Calcipotriol, a synthetic vitamin D₃ analogue widely used in psoriasis treatment, requires a detailed stability assessment due to its topical application and potential exposure to UV radiation. As a drug applied directly to the skin, calcipotriol is particularly susceptible to photodegradation, which may affect its therapeutic efficacy and safety profile. The present study focuses on the analysis of calcipotriol photostability. An advanced UHPLC/MS^E method was employed for the precise determination of calcipotriol and its degradation products. Particular attention was given to the effects of commonly used organic UV filters—approved for use in cosmetic products in both Europe and the USA (benzophenone-3, dioxybenzone, meradimate, sulisobenzone, homosalate, and avobenzone)—on the stability of calcipotriol. Unexpected degradation of calcipotriol was observed in the presence of sulisobenzone. Importantly, this effect was consistently detected in methanolic solution and in the pharmaceutical formulation containing calcipotriol and betamethasone, which is particularly significant from a practical perspective. This finding underscores the necessity of evaluating photostability under real-life conditions, as cosmetic ingredients, when co-applied with topical drugs on the skin, may substantially influence the stability profile of the pharmaceutical active ingredient. The research resulted in the first-time characterization of four degradation products of calcipotriol. The degradation process was found to primarily affect the E-4-cyclopropyl-4-hydroxy-1-methylbut-2-en-1-yl moiety, causing its isomerization to the Z isomer and the formation of diastereomers with either the R or S configuration. Computational analyses using the OSIRIS Property Explorer indicated that none of the five degradation products exhibit a toxicity effect, whereas molecular docking studies suggested possible binding of two of the five degradation products of calcipotriol with the VDR. Full article