Search Results (3,038)

A series of chlorinated chalcone derivatives containing oxazole and thiazole rings were synthesized via Claisen–Schmidt condensation of 6-acetyl-2(3H)-benzoxa(thia)zolone with substituted chlorobenzaldehydes. The synthesized compounds were evaluated for their antimicrobial activity against selected bacterial and fungal strains. Several compounds demonstrated moderate antimicrobial activity against the tested microorganisms. Full article

The vast majority of the ocean’s microbial natural product biosynthetic potential remains undescribed. To access this chemical diversity, we employed Small Molecule In Situ Resin Capture (SMIRC) across three ecologically distinct sites in San Diego, California. Using high-resolution LC-MS/MS, we detected spatial and temporal variability in the metabolomes captured. Low annotation rates and evidence of extensive halogenation supported the chemical novelty of the compounds captured. We detected rare chlorinated polyketides in the pinnaic acid class, previously known only from filter-feeding invertebrates. We also report the first detection of chlorosulfolipids in the Pacific Ocean including one that contained 11 chlorine atoms. We linked compound abundances to weekly phytoplankton counts to identify candidate producers and found evidence that different taxa produce chlorosulfolipids of different carbon chain lengths. This study provides evidence of the chemical novelty that can be captured directly from the environment and a framework for integrating environmental metabolomics with phytoplankton counts as a method to identify candidate compound producers. Full article

Lead-bearing dusts from metallurgical processes are hazardous secondary resources due to their complex composition and toxicity. At the same time, their high lead content makes them a promising feedstock for resource recovery. This study proposes an energy-efficient electrosmelting approach based on the partial substitution of sodium carbonate with calcium-rich industrial waste (sugar-industry defecate). Thermodynamic analysis and equilibrium modeling of the Pb–Sb–Fe–Na–Ca–Si–S–Cl–As system were performed in the temperature range of 200–1200 °C using Outotec HSC Chemistry. The results indicate that under equilibrium conditions approximately 90–95% of lead is concentrated in the metallic phase (~56 kg from ~60 kg in the feed), while antimony is co-recovered (~1.9–2.0 kg). The slag is dominated by calcium silicates, primarily Ca₂SiO₄, confirming the important role of CaO in slag formation and impurity fixation. Chlorine is predominantly bound as NaCl and partially as CaCl₂, while sulfur is distributed between Na₂S and Na₂SO₄. A significant portion of arsenic is predicted to be retained in the slag as calcium and sodium arsenates (Ca₃(AsO₄)₂ and Na₃AsO₄), whereas its volatilization is thermodynamically negligible under equilibrium conditions. Preliminary experimental results are generally consistent with the thermodynamic predictions and confirm the feasibility of partially replacing Na₂CO₃ with sugar-industry defecate. The proposed approach contributes to reducing the consumption of conventional fluxes and promotes the utilization of industrial waste within a circular-economy framework. Full article

High-temperature corrosion severely impairs the service life of boiler heating tubes and threatens the safe and economical operation of thermal power units. With diversified fuels (coal, biomass and refuse-derived fuels) and continuously elevated operating parameters (steam temperature exceeding 620 °C for ultra-supercritical units), boiler heating surfaces are exposed to increasingly complex corrosive environments. High-temperature oxidation, sulfidation, chlorination, molten salt hot corrosion and deposit-induced multi-factor coupled corrosion coexist and exacerbate each other. This paper adopts a four-dimensional analytical framework of “mechanisms–technologies–materials–evaluation” to systematically summarize relevant research progress. From the perspective of corrosion mechanisms, the evolution of understandings from single high-temperature oxidation to multi-factor coupled corrosion is reviewed. In terms of surface coating technologies, seven mainstream processes including HVOF/HVAF spraying, plasma spraying, cold spraying, laser cladding and weld overlay are compared in terms of preparation characteristics and engineering applicability. For coating materials, twelve material systems such as NiCr alloys, MCrAlY, cermets, Fe-based amorphous/nanocrystalline alloys and high-entropy alloys are evaluated for their corrosion resistance under diverse service conditions. As for monitoring and evaluation, this work introduces full-range corrosion management technologies covering electrochemical monitoring, non-destructive testing, numerical simulation and life assessment. Finally, the paper discusses the application prospects of gradient coating design, AI-assisted material screening and digital twin technology, and points out key research gaps including long-term service reliability verification of coatings and quantitative prediction models for multi-factor coupled corrosion. Full article

This study investigated the efficacy of sodium fumarate combined with the commercial organic acid disinfectant NatureSeal FS (FS) against the prominent foodborne pathogens Listeria monocytogenes, Escherichia coli and Salmonella Typhimurium. Sodium fumarate at 10 mM enhanced the antimicrobial activity of FS against overnight cultures of all three pathogens in growth media within 1–5 min. Subsequently, FS supplemented with 25 mM sodium fumarate (pH 2.4) showed enhanced antimicrobial activity by 1–2 log cycles, reaching a total of 2.14–3.22 log cycles within 5 min against the three pathogens inoculated each one individually, on the surface of strawberries, pears and apples compared to a <1.1 log reduction for all control treatments (no treatment, water, 100 ppm chlorine and FS) at pH 2.4. Then, six different organic acid mixes containing key components of FS, two of which were supplemented with 50 and 25 mM sodium fumarate, were tested against the three pathogens, which also performed significantly better than the rest. Sodium fumarate enhanced the efficacy of a commercial acidic disinfectant on fresh produce significantly. The results of this study are highly important for the food industry and consumer protection, as the use of sodium fumarate could significantly enhance the food safety of fresh produce, which is the main contributor to foodborne illness nowadays. Full article

Packing density regulates the microenvironment of tobacco (Nicotiana tabacum L.) fermentation and may thereby influence microbial activity and product quality. However, its effects on microbial community assembly and quality formation remain poorly understood. This study aimed to clarify how packing density affects flue-cured tobacco quality by shaping microbial communities, functional potential, and ecological interactions. Here, we investigated the effects of three packing densities (60%, 70%, and 80%) on chemical components, aroma compounds, microbial community structure, functional potential, co-occurrence networks, and assembly mechanisms of flue-cured tobacco (cv. Piaohe No. 2) after 10 days of fermentation. Moderate density (70%) achieved the most balanced chemical profile, with appropriate nicotine retention, potassium/chlorine ratio, and sugar/nicotine balance. T70 also exhibited the highest levels of total esters, total ketones, and β-ionone, key contributors to fruity, floral, and woody aromas. Microbial analysis revealed that T70 supported the highest diversity and was characterized by the enrichment of aroma-related bacterial taxa, including Bacillus and lactic acid bacteria, as well as the fungal genus Pichia. In contrast, T60 favored aerobic nicotine degraders, whereas T80 selected for obligate anaerobes associated with off-odor production. Functional predictions and network analysis showed that T70 upregulated fatty acid and carotenoid biosynthesis pathways and exhibited the highest modularity, indicating a compartmentalized, functionally complementary community. Neutral model fitting revealed increasing stochasticity with density, with T70 displaying a mixed assembly regime. Collectively, our findings show that packing density influences tobacco quality by regulating microbial community composition, functional potential, network interactions, and assembly processes. These results provide a scientific basis for optimizing packing density in tobacco processing. Full article

The long-term stability of biodegradable polymer coatings deposited by matrix-assisted pulsed laser evaporation (MAPLE) remains insufficiently understood, particularly under ultraviolet irradiation conditions where photochemical effects may accompany material transfer. In this work, thin films of poly(lactide-co-caprolactone)-block-poly(ethyleneglycol)-block-poly(lactide-co-caprolactone), also known as PLCL-PEG-PLCL, are deposited from chloroform solutions by UV-MAPLE using a nanosecond Nd:YAG laser operating at 266 nm over a wide laser fluence range (0.25–0.9 J/cm²). The effect of laser fluence on the morphological, structural, and chemical evolution of the coatings is investigated by atomic force microscopy (AFM), scanning electron microscopy (SEM), Fourier-transform infrared spectroscopy (FTIR), energy-dispersive X-ray spectroscopy (EDS), focused ion beam scanning electron microscopy (FIB-SEM), and X-ray diffraction (XRD). At low laser fluence, relatively homogeneous coatings are obtained while largely preserving the characteristic functional groups of the triblock copolymer. Increasing the laser fluence progressively induces surface restructuring phenomena, including droplets, wrinkles, and the appearance of highly symmetric faceted structures. These entities develop preferentially in samples deposited at elevated fluence and frequently appear only after prolonged aging under ambient conditions, revealing delayed recrystallization behaviour associated with metastable species generated during the deposition process. EDS analyses reveal localized chlorine enrichment within the faceted structures, while FIB-SEM investigations show porous internal morphologies. XRD confirms that the polymer matrix remains predominantly amorphous. The combined observations suggest that UV-MAPLE deposition from chloroform involves not only physical material transfer but also photochemical processes that promote decomposition, recombination, and delayed crystallization phenomena. A phenomenological model describing the successive stages of surface evolution, aging, and recrystallization is proposed. These results provide new insight into the long-term evolution of laser-deposited biodegradable polymer coatings and highlight the importance of solvent selection and processing conditions in determining their stability. Full article

Developing a water-soluble and chlorine-free palladium compound to replace conventional PdCl₂ or Pd(NO₃)₂ as the precursor for Pd-based catalysts remains both challenging and of considerable significance for highly efficient degradation of volatile organic compounds (VOCs). Herein, we report a facile synthetic route to such a Pd compound, (NH₄)₂[Pd(C₂O₄)₂]·2H₂O (denoted as Pd-X5), via a three-step reaction starting from PdCl₂, under mild and readily controllable conditions, rendering the process amenable to industrial manufacture. The molecular structure of Pd-X5 was confirmed mainly by elemental analysis, FT-IR, and ¹³C NMR. The overall yield was greater than 95% and the content of residual chloride was reduced to below 100 ppm. Pd-X5 exhibited high water solubility of 350 g L⁻¹. Subsequently, Pd-X5 was used as a catalytic precursor, and a Pd/Al₂O₃ catalyst was prepared by an impregnation technique and evaluated for its catalytic performance in the degradation of VOCs. Compared with Pd(NO₃)₂-derived Pd/Al₂O₃, the Pd-X5-based catalyst exhibited markedly enhanced activity for the oxidation of CH₄ and C₃H₈ at different temperatures and under different contents of water vapor, indicating that Pd-X5 is superior to Pd(NO₃)₂ as a catalytic precursor and has potential application in the production of Pd-based catalysts. Full article

In medicinal chemistry, halogen substitution is often used to enhance the biological activity of anticancer compounds. Phenethyl isothiocyanate (PEITC), a natural compound found in cruciferous vegetables, exhibits anti-cancer activity by modulating oxidative stress and apoptosis-related pathways. This study compared the effects of PEITC and its chlorinated derivative, Cl-PEITC, on human leukemia cell lines, including multidrug-resistant (MDR) variants that overexpress P-glycoprotein (P-gp). We evaluated cell viability, apoptosis, reactive oxygen species (ROS) production, the modulation of the NRF2/KEAP1 signaling pathway, NF-κB p65 protein expression, DNA fragmentation, and autophagy in SKM-1, MOLM-13 and their MDR variants SKM/VCR and MOLM/VCR cells. Cl-PEITC exhibited stronger antiproliferative and cytotoxic effects than PEITC in all tested cell lines and maintained similar activity in P-gp-positive resistant cells. In contrast, resistant sublines showed reduced sensitivity to PEITC. Cl-PEITC induced higher ROS production and enhanced apoptosis, accompanied by the activation of caspases-3, -8, and -9 and PARP1 cleavage. It also caused more pronounced DNA fragmentation. Both PEITC and Cl-PEITC modulated autophagy-related markers, as demonstrated by increased LC3-II/LC3-I conversion and decreased p62 protein levels. In addition, these compounds modulated NRF2/KEAP1 and reduced NF-κB p65 expression in a concentration-dependent manner. These findings suggest that the chlorination of PEITC enhances its antileukemic activity and could retain its efficacy against P-gp-associated MDR. Full article

Achieving the co-combustion of biomass and coal in utility boilers while reducing carbon dioxide emissions poses significant challenges owing to the divergent physicochemical properties of the fuels. These differences can induce high-temperature corrosion and erosion of heating surfaces, threatening boiler safety. Despite this, integrated CFD-based assessments of sulfidic corrosion and particle erosion risks remain insufficiently addressed under realistic biomass–coal cofiring conditions. In this study, an integrated CFD-based risk assessment framework was established for biomass–coal cofiring boilers. The main novelty lies in the combined evaluation of high-temperature sulfidic corrosion and particle erosion risks under different biomass injection strategies. Specifically, user-defined functions were developed to classify high-temperature sulfidic corrosion risks based on local O₂, CO, and H₂S concentrations; the effects of biomass injection layers were quantitatively compared; the Oka erosion model was coupled with CFD particle tracking to predict wall wear; and an entropy-weighted multi-indicator method was used to rank the overall safety of different cofiring strategies. This study found that sufficiently high near-wall H₂S concentrations in the main combustion zone indicate an increased risk of sulfidic corrosion under reducing-atmosphere conditions. Compared with pure coal combustion, biomass injection through layer A exacerbates wall corrosion, whereas biomass injection through layer AB mitigates it. Erosion is primarily localized near burner nozzles. Notably, biomass cofiring reduces the average erosion rate by 7.9–30.2% but increases the local maximum erosion rate by 7.1–25.1%. The comprehensive evaluation indicates that the condition with 30% RS injected from layer AB, mixed with coal, yields the best overall performance. The corrosion assessment is limited to sulfidic corrosion risks associated with reducing atmospheres and does not explicitly model alkali- or chlorine-induced corrosion. This study provides a theoretical foundation for biomass cofiring optimization and offers practical guidance for boiler operational safety and maintenance. Full article

Commonly occurring polychlorinated biphenyls (PCBs) in the environment have been linked to a broad range of adverse toxicological effects in both animals and humans. In this study, in vitro, in silico, and in vivo models were used to investigate the surface interactions of PCBs with green-engineered clays (GECs). Earlier studies showed that these GECs significantly reduced the toxicities of important planar aromatic chemicals such as benzene and aflatoxin B₁ along with ochratoxin A, a chlorinated aromatic chemical. The overall objective for this study was to show that GECs could tightly adsorb PCBs, resulting in a decrease in toxicity of a commercial PCB mixture (Aroclor 1260). Gastrointestinal pH and temperature were simulated in vitro, and the clay surface binding interactions of six PCBs were characterized using isothermal analyses. Molecular dynamics (MD) simulations were employed to provide atomistic understanding into PCB congener interactions with parent and chlorophyll-amended clays. To confirm the ability of GECs to protect a living organism, Aroclor 1260 was investigated using a well-established hydra bioassay. According to simulations, coplanar PCBs had an increased probability of binding to parent clay compared to non-coplanar ones, in line with experiments, due to their ability to lay flat on the clay surface. Chlorophyll amendments enhanced binding of all PCBs according to both experiments and computations. Within the simulations, chlorophyll amendments facilitated both coplanar as well as non-coplanar PCBs to directly bind to the clay and additionally interact with chlorophyll amendments, as well as to bind to chlorophyll amendments without necessarily interacting with the clay. Aroclor 1260 caused irreversible damage to hydra. At 0.05% inclusion, parent clay offered limited protection (20%) while GECs offered 55% to 65% protection, showing the advantage of GECs over parent clays. The findings of this study indicate that edible GECs adsorb PCBs, with the highest sorption associated with the coplanar congeners. Further studies are warranted to determine the application of GECs as potential disaster-response supplements in the diet to reduce the bioavailability of PCBs from contaminated food and water, especially following floods and other emergencies. Full article

A chlorinated water station in Delfino, Greece, was studied from the control and fault diagnosis point of view, using the interaction of the devices installed to the station as well as rules resulting from the physical characteristics of the station. The DES models of the station’s devices (pumps, level sensors, flow sensors, and pressure sensors) are presented. The models of the pumps include both the activation/deactivation functionality and the regulation of the output flow of the pump. The models of the devices were validated using field data extracted from the monitoring system of the station. Towards protecting the pump from dry running and the tanks from overflow, a set of safety requirements were realized in the form of supervisor automata. Using field data, the effect of the supervisors in the activation/deactivation of the pumps was tested. A modular fault diagnosis system, where the number of fault diagnosers is equal to the number of pumps, was implemented to diagnose the faulty case of pump having stuck open despite deactivation command. A fault diagnosis system for a flow sensor of the station was developed and tested using the field data of the sensors and the pumping system. Supervisors and diagnosers were tested using one-week field data. The structured language code for PLC implementation of the diagnosers is presented. Full article

Heptamethine cyanine fluorophores are widely used in NIR imaging, due to their excellent photophysical properties. In the present work, new meso-ethoxy substituted heptamethine carbocyanine fluorophores 6a–c were prepared by replacing the meso-chlorine atom on a cyclohexenyl-bridged scaffold through a base-driven S_RN1 substitution reaction with an ethoxy group. Once isolated, the compounds were examined in several solvents to study how strongly the medium influenced their absorption, emission, and brightness. The fluorophores absorbed in the 755–770 nm range and showed their strongest fluorescence in ethanol, whereas their emissions were heavily quenched in buffer solutions. Calculations of the HOMO and LUMO energies supported the observed data. A comparison with indocyanine green (ICG) under continuous light exposure showed that fluorophores 6a–c degraded more slowly and maintained their absorbance for a considerably longer period. Having long hydrophobic alkyl chains raised the hypothesis that they could act as sensors for bovine serum albumin (BSA), which is known for its hydrophobic pockets. Therefore, they were tested for BSA binding both in silico and in cuvette. Fluorophore 6b produced a clear optical response when BSA was added, giving both a red shift and an increase in absorbance and fluorescence. Quantitative analysis of the fluorophore 6b–BSA interaction revealed a dissociation constant (K_d) of 0.75 μM and an apparent binding stoichiometry of approximately 1:1 (Hill coefficient n = 1.25), confirming high-affinity, single-site binding. Using the linear range of the fluorescence titration, the limit of detection (LOD) and limit of quantitation (LOQ) for BSA were determined to be 1.9 and 6.0 μM, respectively. Selectivity experiments demonstrated that fluorophore 6b does not exhibit fluorescence enhancement in the presence of collagen or human parvalbumin, confirming its selectivity toward BSA. These observations suggest that introducing an alkoxy group at the meso-position can improve carbocyanine fluorophores properties and achieve high photostability, with significant potential for various biomedical applications. Full article

Secondary aluminum dross (SAD) from the aluminum industry is a hazardous residue that restricts sustainable aluminum production. Residual aluminum nitride (AlN) and insoluble fluorides after conventional pretreatment are major barriers to the safe utilization of SAD. In this study, a low-temperature intensified roasting–alkaline leaching process was developed to remove harmful elements by using reaction heat and waste heat to expose enveloped AlN and fluoride phases, form soluble sodium-bearing compounds, and intensify AlN oxidation. Without additives, roasting at 750 °C for 3 h converted 91.65% of AlN, leaving 1.37% AlN in the roasted SAD. With Na₂O₂ as an oxygen donor in situ, NaF as a mineralizer to reduce roasting temperature, and sodium-bearing species as reactants for soluble NaAlO₂/Na₂SiO₃ formation, the AlN conversion increased up to 97.01% under 5% NaF and 2.5% Na₂O₂ at 750 °C for 3 h. Afterwards, higher temperature, longer duration, lower roasted SAD dosage, and higher caustic soda concentration all improved fluorine removal in the subsequent alkaline leaching. Under 100 g/L Na₂O, 20 g/L roasted SAD, and 100 °C, fluorine and chlorine removal efficiencies reached 92.52% and 99.47%, respectively. The final high-alumina residue contained 74% Al₂O₃, mainly in the forms of α-Al₂O₃, NaAl₁₁O₁₇, and MgAl₂O₄, with only 0.19% F and 0.03% Cl, making it suitable for the preparation of various alumina-bearing materials and alumina production. Full article

Chlorinated paraffins (CPs) are recognized as a novel class of persistent organic pollutants (POPs) and are categorized into short- (SCCPs, C_10–13), medium- (MCCPs, C1_4–17), and long- (LCCPs, C_≥18) chain CPs considering the carbon-chain length. Among them, SCCPs possess lower molecular weights, higher vapor pressures, and greater water solubilities compared to their longer-chain counterparts (MCCPs and LCCPs), which promote their environmental release. Consequently, SCCPs were designated as POPs of concern under the Stockholm Convention in 2017. This review concludes the recent research progress of SCCPs in China from 2015 to present, and we present a comprehensive overview of SCCP concentrations, encompassing diverse environmental matrices and human tissues, for example, air, water, soil, sediments, biota, food, human placenta, breast milk, blood, and organs (fat, kidney, liver, brain, bone, etc.). Whereafter, we summarize the development of SCCPs determination methods, benefiting from quantifying relative carbon-chain length and chlorine content of SCCPs correctly. Moreover, toxicity, toxicokinetics, and adverse health effects of SCCPs in humans from China are concluded and discussed. Meanwhile, we review the existing control and treatment technologies for SCCPs. Lastly, we describe some noteworthy and prospective issues that are worthy of further study. In the future, the relevant studies are still necessary to keep up with consecutive monitoring and evaluation of SCCP levels and relative potential health impacts in China. Full article