Search Results (320)

Transmetalation, the exchange of metal ions between coordination complexes and biomolecules, has emerged as a powerful design lever in cancer metallopharmacology. Using thiosemicarbazones (TSCs) as a unifying case study, we show how redox-inert carrier states such as zinc(II) or gallium(III) can convert in situ into redox-active copper(II) or iron(III/II) complexes within acidic, metal-rich lysosomes. This conditional activation localizes reactive oxygen species (ROS) generation and iron deprivation to tumor cells. We critically compare redox-active and redox-inert states, delineating how steric and electronic tuning, backbone rigidity, and sulfur-to-selenium substitution govern exchange hierarchies and kinetics. We further map downstream consequences for metal trafficking, lysosomal membrane permeabilization, apoptosis, and ferroptosis. Beyond TSCs, iron(III)-targeted transmetalation from titanium(IV)-chelator “chemical transferrin mimetics” illustrates a generalizable Trojan horse paradigm. We conclude with translational lessons, including mitigation of hemoprotein oxidation via steric shielding, stealth zinc(II) prodrugs, and dual-chelator architectures and outline biomarker, formulation, and imaging strategies that de-risk clinical development. Collectively, these insights establish transmetalation as a central therapeutic principle. We also highlight open challenges such as quantifying in-cell exchange kinetics, predicting speciation under non-equilibrium conditions, and rationally combining these agents with existing therapies. Full article

The high strength and light weight of aluminum matrix composites have made them the material of choice for many engineering applications. Snail shells and other bio-reinforcements offer a potential substitute for conventional ceramic reinforcements. However, the inherent difficulty in machining Aluminum Matrix Composites (AMCs) stems from the presence of reinforcing particles. This study investigates the machinability of aluminum matrix composites (AMCs) reinforced with Physella Acuta snail shell (PAS) particles using Wire Electrical Discharge Machining (WEDM) with a zinc-coated brass wire electrode. The primary objective is to determine how various input elements affect process conditions to achieve the desired surface quality. In order to do this, the Random Decision Forest approach was employed. Scanning Electron Microscopy (SEM) evaluation revealed the presence of microvoids, surface defects, deep craters, and crack propagation. It was found that the random forest method had an F1-score of 0.94, a recall of 0.96, and a precision of 0.97. The optimized parameters yielded an MRR of 0.5 mm³/min, SR of 2.14 µm, and EWR of 0.017. Full article

The increasing demand for sustainable construction materials has prompted the recycling of construction and demolition waste in concrete manufacturing. This study investigates the feasibility of utilizing porcelain and brick waste as partial substitutes for natural sand in concrete with the objective of improving sustainability and preserving mechanical and durability characteristics. The experimental program was conducted in three consecutive phases. During the initial phase, natural sand was partially substituted with porcelain waste powder (PWP) and brick waste powder (BWP) in proportions of 25%, 50%, and 75% of the weight of the fine aggregate. During the second phase, polypropylene fibers were mixed at a dosage of 0.5% by volume fraction to enhance tensile and flexural properties. During the third phase, zinc oxide nanoparticles (ZnO-NPs) were utilized as a partial substitute for cement at concentrations of 0.5% and 1% to improve microstructure and strength progression. Concrete samples were tested at curing durations of 7, 28, and 91 days. The assessed qualities encompassed workability, density, water absorption, porosity, compressive strength, flexural strength, and splitting tensile strength. Microstructural characterization was conducted utilizing X-ray diffraction (XRD), scanning electron microscopy (SEM), and energy-dispersive X-ray spectroscopy (EDS). The findings indicated that porcelain waste powder markedly surpassed brick waste powder in all mechanical and durability-related characteristics, particularly at 25% and 50% sand replacement ratios. The integration of polypropylene fibers enhanced fracture resistance and ductility. Moreover, the incorporation of zinc oxide nanoparticles improved hydration, optimized the pore structure, and resulted in significant enhancements in compressive and tensile strength throughout prolonged curing durations. The best results were obtained with a mix of 50% porcelain sand aggregate, 1% zinc oxide nanoparticles as cement replacement, and 0.5% polypropylene fibers, for which the improvements in compressive strength, flexural strength, and splitting tensile strength were 39.5%, 46.2%, and 60%, respectively, at 28 days. The results confirm the feasibility of using porcelain and brick waste as sand replacements in concrete, as well as polypropylene fiber-reinforced concrete and polypropylene fiber-reinforced concrete mixed with zinc oxide nanoparticles as a sustainable option for construction purposes. Full article

Hericium erinaceus, a rare edible–medicinal fungus, has attracted great attention in food and pharmaceutical fields due to its rich nutritional and bioactive components. However, its traditional cultivation relies heavily on wood chip substrates, causing resource unsustainability. The “wood-replacing-with-grass” technology can address this issue, contributing to ecological conservation and alleviating resource conflicts between edible fungus cultivation and forestry development. This study focused on straw substitution for wood chips, initially screening suitable straw types and optimal addition ratios from 7 straw varieties, and systematically investigating the agronomic trait variations in H. erinaceus under different substrate formulations via cultivation experiments. Results showed the following: (1) Rapeseed straw, soybean straw, and corn straw substituting 20%, 30%, and 40% of wood chips, respectively, promoted better mycelial growth of H. erinaceus. (2) All screened straw formulations enabled fruiting. With increased straw addition, the mycelial full colonization time shortened (up to 5 days shorter in 40% corn/soybean straw treatments). The 20% corn straw treatment showed significantly higher biological efficiency and average fresh weight than the control (CK); the 20% soybean straw treatment had no significant difference in biological efficiency but significantly higher average fresh weight than CK; and the 20% rapeseed straw treatment showed no significant differences in both indexes from CK. However, when straw addition exceeded 20%, fruiting body firmness, yield, and biological efficiency decreased progressively. (3) The 40% soybean straw treatment yielded fruiting bodies with the highest crude protein, manganese, and iron contents, while the 40% rapeseed straw treatment had the highest crude fat, potassium, phosphorus, calcium, zinc, and selenium contents. These findings provide a theoretical basis and practical reference for optimizing H. erinaceus cultivation substrate formulations, improving product quality, and promoting sustainable industrial development. Full article

Aromatic ring systems appear ubiquitously in active pharmaceutical substances, such as FDA-approved histone deacetylase inhibitors. However, these rings reduce the water solubility of the molecules, which is a disadvantage during application. To address this problem, azaborine rings may be substituted for conventional aromatic ring systems. These are obtained by replacing two adjacent carbon atoms with boron and nitrogen. Incorporating B–N analogs in place of aromatic rings not only enhances structural diversity but also provides a strategy to navigate around patent-protected scaffolds. We synthesized azaborines, which are isosteric to naphthalene and indole, and utilized them as capping units for HDAC inhibitors. These molecules were attached to various aliphatic and aromatic linkers with different zinc-binding units, used in established active compounds. Nearly half of the twenty-four molecules tested exhibited inhibitory activity against at least one of the enzymes HDAC1, HDAC4, or HDAC8, with three compounds displaying IC₅₀ values in the nanomolar range. We have therefore demonstrated that azaborine building blocks can be successfully incorporated into HDACis, resulting in a highly active profile. Consequently, it should be feasible to develop active substances containing azaborine rings against other targets. Full article

Photodynamic inactivation and antimicrobial photodynamic therapy (PDI/APDT) based on the toxic properties of reactive oxygen species (ROS), which are generated by a number of photoexcited dyes, are promising for preventing and treating infections, especially those associated with drug-resistant pathogens. The negatively charged bacterial cell surface attracts polycationic photosensitizers, which contribute to the vulnerability of the bacterial plasma membrane to ROS. The integrity of the plasma membrane is critical for the viability of the bacterial cell. Polycationic phthalocyanines are regarded as promising photosensitizers due to their high quantum yields of ROS generation (mainly singlet oxygen), high extinction coefficients in the far-red spectral range, and low dark toxicity. For application in PDI/APDT, the wide range of possibilities of modifying the chemical structure of phthalocyanines is particularly valuable, especially by introducing various peripheral and non-peripheral substituents into the benzene rings. Depending on the type and location of such substituents, it is possible to obtain photosensitizers with different photophysical properties, photochemical activity, solubility in an aqueous medium, biocompatibility, and tropism for certain structures of photoinactivation targets. In this study, we tested novel water-soluble Zn (II) phthalocyanines bearing four 4-((diethylmethylammonium)methyl)phenoxy substituents with symmetric and asymmetric charge distributions for photodynamic antibacterial activity and compared them with those of water-soluble octacationic zinc octakis(cholinyl)phthalocyanine. The obtained results allow us to conclude that the studied tetracationic aryloxy-substituted Zn(II) phthalocyanines effectively bind to the oppositely charged cell wall of the Gram-negative bacteria E. coli. This finding is supported by data on bacteria’s zeta potential neutralization in the presence of phthalocyanine derivatives and fluorescence microscopy images of stained bacterial cells. Asymmetric substitution influences the aggregation and fluorescent characteristics but has little effect on the ability of the studied tetracationic phthalocyanines to sensitize the bioluminescent E. coli K12 TG1 strain. Both symmetric and asymmetric aryloxy-substituted phthalocyanines are no less effective in PDI than the water-soluble zinc octakis(cholinyl)phthalocyanine, a photosensitizer with proven antibacterial activity, and have significant potential for further studies as antibacterial photosensitizers. Full article

The fortification of bakery products with alternative protein sources, including edible insects, offers a promising approach to improving nutritional quality while addressing sustainability challenges. This study evaluated graded replacement of type 750 wheat flour with Acheta domesticus (house cricket) powder—together with an extreme 100% cricket-powder formulation—on the nutritional composition, color, particle size distribution, fermentative properties, baking loss, crumb hardness, and sensory quality of bread. Fifteen baked variants were prepared: a 100% wheat flour control; thirteen wheat–cricket blends containing 5–90% cricket powder; and an extreme formulation with 100% cricket powder. Increasing cricket-powder levels significantly increased protein, fat, fiber, zinc, and riboflavin contents while decreasing carbohydrate and starch levels. Technologically, higher substitution levels resulted in darker crumb color, a shift toward coarser particle size distribution, reduced gas retention during proofing, and increased baking loss. Sensory analysis indicated that up to 15% inclusion maintained full consumer acceptability, while 20–25% was at the acceptance threshold. Above 35%, acceptability declined sharply due to intensified earthy flavors and textural changes. The findings highlight 15% inclusion as the optimal balance between enhanced nutritional value and sensory quality, with potential for higher incorporation if appropriate technological modifications are applied. Full article

This study aims to investigate the vibrational, structural, morphological, optical, and magnetic properties of Zn_1−xCo_xO with 0.00 ≤ x ≤ 0.05 prepared by the sol–gel method via an amorphous citrate precursor. FTIR spectroscopy was used to follow the thermal decomposition process of the ZnO precursor, identifying acetate zinc as the intermediate main component. XRD and FTIR-ATR techniques showed only the single wurtzite crystalline phase with the presence of oxygen deficiency and/or vacancies, and secondary phases were not detected. SEM micrographs showed agglomerated particles of irregular shape and size with a high distribution and evidenced particles of nanometric size with a morphology change for x = 0.05. We detected high–spin Co²⁺ ions located in the tetrahedral core and pseudo–octahedral surface sites, substituting Zn²⁺ ions. The energy band gap of the ZnO semiconductor decreased gradually when the Co doping concentration was increased. M vs. H for undoped ZnO nanoparticles exhibited a diamagnetic signal overlapped with a weak ferromagnetic signal at room temperature. Interestingly, temperature-dependent magnetization showed superparamagnetic behavior with a blocked state in the low temperature range. The Co–doped ZnO samples evidenced a weak ferromagnetic signal and a paramagnetic component, which increased with x. The saturation magnetization increased until x = 0.03 and then decreased for x = 0.05, while the coercive field gradually decreased. Full article

Currently, electrochemical devices and portable electronic equipment play a significant role in people’s daily lives. Zinc-ion batteries (ZIBs) are growing rapidly due to their excellent safety, eco-friendliness, abundance of resources, and cost-effectiveness. The application of biomass as a polymer separator is gradually expanding in order to promote a circular economy and sustainable materials. This research focuses on the usage of cellulose fibers obtained from coffee parchment (CP) waste. The extracted cellulose fibers are produced via both mechanical and chemical methods. The sustainable separators are fabricated through vacuum filtration using a polymer filter membrane. The impact of incorporating silica particles and varying silica content on the physical and electrochemical properties of a cellulose-based separator is examined. The optimum amount of silica integrated into the cellulose separator is determined to be 5 wt%. This content led to an effective distribution of the silica particles, enhanced wettability, and improved fire resistance. The ZIBs incorporating cellulose/recycled silica at 5 wt% demonstrate exceptional cycle stability and the highest capacity retention (190% after 400 cycles). This study emphasizes the promise of sustainable polymers as a clean energy resource, owing to their adaptability and simplicity of processing, serving as a substitute for synthetic polymers sourced from fossil fuels. Full article

The market for plant-based alternatives to animal foods has increased rapidly in the past decade, mainly due to consumer demand. Little evidence is available regarding nutritional impacts, drivers, and barriers to using these products as substitutes for animal foods in real-life conditions. This pilot study followed 16 Danish adults (30 ± 11 years old; 11 females) for 4 weeks with substituting milk, cheese, and yogurt with plant-based analogues to dairy (PBADs) and assessed their drivers and barriers to applying the intervention with a mixed-method approach. PBADs are constantly compared to their animal counterparts, both regarding product characteristics, such as price and sensory properties, as well as cultural roles and subjective memories. The mixed methods showed dairy attachment, price, and taste were the main barriers to consuming PBAD, while changes in life and social circles were drivers (qualitative data). As for the liking of PBADs, plant-based yoghurt was the preferred intervention product (73.5/100, p < 0.05), followed by plant-based drinks (65.9/100), while plant-based cheese was the lowest rated (47.9/100, p < 0.05). As for dietary changes, a lower average intake of sugars, saturated fatty acids, cholesterol, calcium, phosphorus, and zinc was observed after the intervention. Additionally, this study describes the attachment of the study population to milk and dairy products. It shows that choosing dairy is beyond nourishment but is connected to tradition, culture, pleasure, memories, and a sense of belonging. In contrast, there is no history or attachment to PBADs. Full article

Molasses, a by-product of raw sugar production, is widely used as a cost-effective carbon and nutrient source for industrial fermentations, including the production of baker’s yeast (Saccharomyces cerevisiae). Due to the cost and limited availability of molasses, efforts have been made to replace molasses with cheaper and more readily available substrates such as corn syrup. However, the quality of dry yeast drops following the replacement of molasses with corn syrup, despite the same amount of total sugar being provided. Our understanding of how molasses replacement affects yeast physiology, especially during the dehydration step, is limited. Here, we examined changes in gene expression of a strain of baker’s yeast during fermentation with increasing corn syrup to molasses ratios at the transcriptomic level. Our findings revealed that the limited availability of the key metal ions copper, iron, and zinc, as well as sulfur from corn syrup (i) reduced their intracellular storage, (ii) impaired the synthesis of unsaturated fatty acids and ergosterol, as evidenced by the decreasing proportions of these important membrane components with higher proportions of corn syrup, and (iii) inactivated oxidative stress response enzymes. Taken together, the molecular and metabolic changes observed suggest a potential reduction in nutrient reserves for fermentation and a possible compromise in cell viability during the drying process, which may ultimately impact the quality of the final dry yeast product. These findings emphasize the importance of precise nutrient supplementation when substituting molasses with cheaper substrates. Full article

Zinc oxide nanoparticles (ZnO NPs) have attracted significant attention due to their wide-ranging applications in animal production, largely because of their notable biocompatibility, low toxicity, and strong antimicrobial activity. These properties make ZnO NPs a promising substitute for traditional antibiotics. Their application could address the growing concern of antibiotic resistance in livestock industries. This review examines the unique physicochemical characteristics of ZnO NPs, including their nanoscale size and high surface area, which contribute to their biological functionality. Emphasis is placed on green synthesis methods that minimize environmental impact while producing high-quality ZnO NPs. In animal farming, ZnO NPs play a crucial role not only in promoting growth and improving immune responses, but also in enhancing meat and egg quality. Additionally, this review discusses the environmental and safety implications of ZnO NPs, considering their sustainable application potential in future animal production practices, aimed at fostering a more eco-friendly and efficient livestock sector. Full article

The ReAV enzyme from Rhizobium etli, a representative of Class 3 L-asparaginases, is sequentially and structurally different from other known L-asparaginases. This distinctiveness makes ReAV a candidate for novel antileukemic therapies. ReAV is a homodimeric protein, with each subunit containing a highly specific zinc-binding site created by two cysteines, a lysine, and a water molecule. Two Ser-Lys tandems (Ser48-Lys51, Ser80-Lys263) are located in the close proximity of the metal binding site, with Ser48 hypothesized to be the catalytic nucleophile. To further investigate the catalytic process of ReAV, site-directed mutagenesis was employed to introduce alanine substitutions at residues from the Ser-Lys tandems and at Arg47, located near the Ser48-Lys51 tandem. These mutational studies, along with enzymatic assays and X-ray structure determinations, demonstrated that substitution of each of these highly conserved residues abolished the catalytic activity, confirming their essential role in enzyme mechanism. Full article

Novel three-dimensional porous composites of alginate–pectin (A/P) with zinc- or manganese-substituted hydroxyapatites (A/P-ZnHA and A/P-MnHA) were synthesized via lyophilization and calcium cross-linking. Powder X-ray diffraction and infrared spectroscopy analyses confirmed single-phase apatite formation (crystallite sizes < 1 µm), with ZnHA exhibiting lattice contraction (*c*-axis: 6.881 Å vs. 6.893 Å for HA). Mechanical testing revealed tunable properties: pristine A/P sponges exhibited an elastic modulus of 4.7 MPa and a tensile strength of 0.10 MPa, reduced by 30–70% by HA incorporation due to increased porosity (pore sizes: 112 ± 18 µm in the case of MnHA vs. 148 ± 23 µm-ZnHA). Swelling capacity increased 2.3–2.8-fold (125–155% vs. 55% for A/P), governed by polysaccharide interactions. Scanning electron microscopy investigation showed microstructural evolution from layered A/P (<100 µm) to tridimensional architectures with embedded mineral particles. The A/P-MnHA composites demonstrated minimal cytotoxicity for the NCTC cells and good viability of dental pulp stem cells, while A/P-ZnHA caused ≈20% metabolic suppression, attributed to hydrolysis-induced acidification. Antibacterial assays highlighted A/P-MnHA′s broad-spectrum efficacy against Gram-positive (Bacillus atrophaeus) and Gram-negative (Pseudomonas protegens) strains, whereas A/P-ZnHA targeted only the Gram-positive strain. The developed composite sponges combine cytocompatibility and antimicrobial activity, potentially advancing osteoplastic materials for bone regeneration and infection control in orthopedic/dental applications. Full article

The Dulong deposit in Wenshan, southeastern Yunnan Province, is rich in zinc, tin, and copper resources, accompanied by rare metals such as indium and silver. It is a particularly important indium production base, with reserves of approximately 7000 tons, ranking first globally. Enrichment and recovery of indium-bearing minerals are mainly achieved through mineral processing technology. However, the recovery rate of indium in the Dulong concentrator remains relatively low, and there is an insufficient understanding of its occurrence state and distribution characteristics, resulting in marked indium resource wastage. Here, we conducted a systematic process mineralogy study on indium-bearing polymetallic ore in the Dulong concentrator. The average grade of indium in the ore is 43.87 g/t, mainly occurring in marmatite (63.63%), supplemented by that in silicate minerals (23.31%), chalcopyrite (7.84%), and pyrrhotite (4.22%). The indium has a relatively dispersed distribution, which is inconducive to enrichment and recovery. The substitution mechanism of indium in marmatite was investigated using laser ablation inductively coupled plasma mass spectrometry. This revealed a positive correlation between indium and copper, allowing us to revise the substitution relationship to: ${\mathrm{Zn}}_x\mathrm{S}+{\mathrm{Cu}}^{+}+{\mathrm{In}}^{3+}\to {\mathrm{Zn}}_{\mathrm{x}-2}\mathrm{CuInS}+2{\mathrm{Zn}}^{2+}$ or ${\mathrm{Zn}}_{\mathrm{x}-1}\mathrm{FeS}+{\mathrm{Cu}}^{+}+{\mathrm{In}}^{3+}\to {\mathrm{Zn}}_{\mathrm{x}-2}\mathrm{CuInS}+{\mathrm{Zn}}^{2+}+{\mathrm{Fe}}^{2+}$. Electron probe microanalysis revealed the presence of roquesite (CuInS₂), an independent indium mineral not previously reported from this deposit. Our detailed investigation of the Dulong concentrator mineral processing technology showed that the recovery rate of indium from marmatite is currently poor, at only 48.01%. To improve the comprehensive utilization rate of indium resources, it will be necessary to further increase the recovery rate from marmatite and explore the flotation recovery of indium from chalcopyrite and pyrrhotite. Full article