Search Results (14,431)

Background: Obesity is commonly seen as a condition of overnutrition; however, it is paradoxically associated with micronutrient deficiencies. These deficiencies are clinically relevant and may contribute to the progression of obesity-related comorbidities through interconnected pathways, including chronic low-grade inflammation, oxidative stress, gut dysbiosis, and impaired nutrient absorption. Objectives: This narrative review aims to summarize current evidence regarding the prevalence, underlying mechanisms, and clinical consequences of micronutrient deficiencies in individuals with obesity, with particular emphasis on their metabolic implications and potential therapeutic strategies. Results: Among individuals with obesity, iron, zinc, magnesium, calcium, vitamin D, vitamin B12, and folate are the most frequently reported deficiencies. These deficiencies arise from multiple mechanisms, including poor diet quality, increased metabolic demands, and compromised gastrointestinal absorption. In addition, obesity-related alterations in pharmacokinetics may further interfere with micronutrient distribution and bioavailability. Together, these mechanisms may lead to various clinical outcomes, such as anemia, immune, metabolic, and cardiovascular dysfunctions, along with cognitive impairment. Although several studies suggest that correcting these deficiencies may improve clinical outcomes, findings remain inconsistent, highlighting the complex and multifactorial pathophysiology underlying micronutrient imbalance in obesity. Conclusions: Micronutrient deficiencies represent frequently overlooked contributors to metabolic dysregulation in obesity. Their identification and correction should be considered a central part of the obesity management strategy. A personalized supplementation approach, based on clinical, biological, and pathophysiological characteristics, may provide a complementary support for weight-management treatments. Full article

Background/Objectives: Benefiting from their outstanding tumor-penetrating ability and cytotoxic proteins and cytokines, natural-killer-cell-derived exosomes (NEX) show great potential for cell-free tumor immunotherapy. To meet the clinical tumor therapeutic need, engineered NEX are highly required to further enhance their tumor-tropism and antitumor abilities. Methods: We proposed a NEX engineering strategy, using a structure of AS1411-bivalent-cholesterol (B-Chol) anchor equipped with photosensitizer zinc phthalocyanine (ZnPc) attached on the membrane of NEX to form A-P-NEX. It not only preferably maintains the spatial structure of the AS1411 aptamer via a B-Chol anchor contributing to the tumor-tropism and stability of NEX but also significantly improves the photodynamic therapy (PDT) effect by firmly binding ZnPc in the unique G-quadruplex structure in the AS1411 aptamer. Results: The results showed that A-P-NEX could promote the precise uptake of NEX and ZnPc by tumor cells and produce obvious synergistic NEX-based immunotherapy and PDT upon laser irradiation, demonstrating excellent targeted antitumor effects both in vitro and in vivo. Conclusions: This study demonstrates a reliable NEX engineering strategy and paves the way for developing a useful tumor-tropism PDT method. Full article

Background/Objectives: The objective of the study was to assess the benefits on quality of life (QoL) of a natural-based dietary supplement in patients with tinnitus. Methods: An observational, prospective and exploratory study was conducted in 30 patients (mean age 50.7 years) diagnosed with tinnitus. The dietary supplement (Otocalm^®) contained L-theanine, Gingko biloba, melatonin, GABA, zinc, selenium and vitamins B3, B6 and B12, and was administered for 90 consecutive days. Clinical assessment included tone verbal audiometry, the Tinnitus Handicap Inventory (THI), the Goldberg anxiety and depression scale (GADS), and a 0–10 mm visual analogue scale (VAS) to score the intensity of tinnitus. Results: The mean THI score decreased from 40.8 at baseline to 30.9 at the end of the study (p = 0.012), and the percentage of patients with THI grade 1 (no handicap) increased from 3.3% to 20%. The mean anxiety score decreased from 4.7 to 3.0 (p = 0.006), and the percentage of patients scoring ≥ 4 in the GADS decreased from 63.3% to 33.3%. Changes in VAS scores and verbal tone audiometry were not observed. A decrease in the mean frequency of tinnitus from 2417.4 Hz to 1603.3 Hz (p = 0.519) was found. The product was safe and well-tolerated. Conclusions: The administration of a natural-based dietary supplement composed of L-theanine, Ginkgo biloba, melatonin, GABA, zinc, selenium, and group B vitamins during 90 days in patients with tinnitus was associated with a significant increase in QoL by reducing tinnitus-associated handicap and anxiety. Full article

Hexavalent chromium [Cr(VI)] is a lung carcinogen. Central to its carcinogenic mechanism are Cr(VI)-induced DNA double strand breaks and chromosome instability. While breaks are usually repaired in healthy cells, Cr(VI) inhibits homologous recombination repair by targeting RAD51. RAD51 paralogs (RAD51B, RAD51C, RAD51D, XRCC2, and XRCC3) are responsible for RAD51 loading and the stabilization of nucleoprotein filaments necessary for DNA strand exchange and repair. This study aimed to investigate the effects of Cr(VI) exposure on RAD51 paralogs. WTHBF-6 cells, a human lung cell line, were exposed to various environmentally and occupationally relevant concentrations of zinc chromate for acute (24 h) and prolonged (120 h) exposure times. After exposure to Cr(VI), we collected RNA for sequencing and assessed the ability of DNA repair proteins to form foci using immunofluorescence. Protein levels were measured with western blotting, RNA-Seq was validated with RT-qPCR, and protein–protein interactions were assessed with the Proximity Ligation Assay (PLA) assay. Cr(VI) transcriptionally repressed all RAD51 paralogs. Further functional analyses showed that Cr(VI) inhibited the foci formation of RAD51D after acute and prolonged exposures and of XRCC2 and XRCC3 after prolonged exposure. Cr(VI) also inhibited overall RAD51D protein expression, as well as its interaction with RAD51. These findings suggest that Cr(VI) inhibits all RAD51 paralogs, but RAD51D might be an early target of Cr(VI), leading to the loss of RAD51 filament formation and function and the overall inhibition of homologous recombination repair. Full article

Mining and metallurgical activities are among the main sources of heavy metal (HM) contamination of terrestrial ecosystems and the creation of persistent technogenic pollution hotspots. This study aimed to provide a comprehensive assessment of the accumulation of zinc (Zn), cooper (Cu), cadmium (Cd) and lead (Pb) in soils and vegetation under conditions of long-term industrial impact in Ridder, East Kazakhstan Region. A total of 52 soil samples were collected from 0–5 cm and 5–20 cm depths at 26 sites, and 44 species of natural vegetation, as well as three dominant agricultural crops, were examined. Soil concentrations of Zn (4415 mg·kg⁻¹), Cu (1177 mg·kg⁻¹), Cd (179 mg·kg⁻¹), and Pb (1996 mg·kg⁻¹) were classified as extremely high. Cadmium contributed most to the potential ecological risk (Cd > Pb > Zn > Cu). The industrial zone’s vegetation cover was predominantly formed by stress-tolerant and ruderal species, including Artemisia vulgaris, Calamagrostis epigeios, Bunias orientalis, Dactylis glomerata, Convolvulus arvensis, and Urtica dioica. The agricultural crops (Helianthus annuus, Avena sativa, and Triticum aestivum) mainly accumulated HMs in their root systems, with limited translocation to their aboveground organs (TF < 1). This indicates the predominance of phytostabilisation mechanisms, and highlights the potential of locally adapted plants for managing contaminated areas. Full article

Aqueous zinc-ion batteries (AZIBs) are promising for large-scale grid storage due to inherent safety, low cost, environmental compatibility, high theoretical capacity (820 mAhg⁻¹), and suitable redox potential (−0.763 V vs. SHE). However, practical deployment is hindered by coupled challenges at the zinc anode–hydrogen evolution, dendrite growth, and corrosion/passivation, which severely limit cycle life and coulombic efficiency. This review systematically summarizes key advances in AZIB research. It first elucidates working principles and four cathode energy storage mechanisms: Zn²⁺ insertion/extraction, H⁺/Zn²⁺ co-insertion, chemical conversion, and dissolution/deposition. Second, it examines four mainstream cathodes (manganese-based, vanadium-based, Prussian blue analogs, and organic compounds), analyzing performance bottlenecks and corresponding optimization via structural modification. Third, it explores functional mechanisms of advanced separators (polymer, inorganic/ceramic composite, MOF-based, and cellulose-based) in regulating uniform Zn²⁺ deposition and suppressing dendrites. Fourth, it summarizes anode optimization strategies: artificial protective layers for interface stabilization, electrolyte additives to modulate Zn²⁺ solvation/deposition, and 3D porous structures to reduce local current density and provide nucleation sites. Finally, key scientific challenges and future directions are discussed—multi-strategy synergy, in situ characterization, practical battery construction, and sustainable technological development, offering theoretical guidance for advancing AZIBs toward large-scale applications. This review aims to provide a comprehensive perspective spanning from materials to systems, and from mechanisms to applications. Its core objective is not merely to list the types of cathode materials, but to establish a logical bridge directly connecting “key challenges” to “optimization strategies,” with a particular emphasis on the issues and solutions related to the cathode side. Full article

Organic field-effect transistors (OFETs) incorporating a triple insulating layer of polymethyl methacrylate (PMMA), silicon dioxide (SiO₂), and zinc oxide (ZnO) were successfully fabricated on glass and on flexible PET substrates. The insulating layers significantly enhanced device performance, with the OFETs achieving field-effect mobility (µ) values more than twice as high as those reported in the literature. Specifically, mobility values of ~6.75 cm²/V·s were recorded on glass, ~7.14 cm²/V·s on flexible substrates before bending, and ~6.88 cm²/V·s on flexible substrates after bending. Threshold voltages (V_th) of −7 V and −9 V were estimated for the flexible OFETs before and after bending, respectively, along with a high on/off current ratio, exceeding 10³ for all devices. Minimal hysteresis in the transfer and output characteristics indicated excellent, trap-free interaction between the insulating layers and the pentacene. The high dielectric constant of the PMMA/SiO₂/ZnO triple insulating layers was identified as a critical factor driving the exceptional performance, stability, and low hysteresis of the OFETs. These results underscore the pivotal role of advanced insulating layers in optimizing OFET performance and durability. Full article

Background/Objectives: Nanostructured biomaterials based on natural polymers have gained increasing attention in pharmaceutics due to their biocompatibility, multifunctionality, and diverse biomedical applications. This novel study aimed to biofabricate chitosan-doped zinc oxide nanocomposites (CS-ZnONCs) using Leucas aspera leaf extract and to evaluate their physicochemical properties and in vitro biomedical performance. Methods: CS-ZnONCs were synthesized using L. aspera leaf extract through a green precipitation approach, and the resulting nanocomposites were characterized by various spectroscopic techniques. The in vitro antioxidant, antibacterial, and anti-inflammatory activities were evaluated, while wound-healing potential was assessed using L929 fibroblast cell migration assays. Results: UV–visible analysis confirmed the formation of CS-ZnONCs, with a characteristic absorption peak at 362 nm, and FTIR spectra indicated the presence of various important functional groups. XRD results demonstrated the crystalline nature of ZnO within the chitosan matrix. Well-dispersed, quasi-spherical nanoparticles with an average size of 44 ± 3.1 nm were identified by HR-TEM, and a positive zeta potential (+9 mV) suggested considerable colloidal stability. CS-ZnONCs showed a high swelling capacity (88 ± 2.75% for 2%) and significant phytocompound release (65.38 ± 2.79% at pH 7.4). The CS-ZnONCs showed significant antioxidant activity (ABTS of 88.19 ± 1.59%), notable antibacterial efficacy against Staphylococcus aureus (18.78 ± 0.98 mm) and Escherichia coli (17.14 ± 0.96 mm), and significant anti-inflammatory activity (82.12 ± 1.47% membrane stabilization). In vitro biocompatibility and wound-healing assays revealed significant cytocompatibility in Vero cells, with 98.75 ± 1.17% cell viability observed, whereas the fibroblast migration assay demonstrated near-complete wound closure (96.55 ± 6.46%). Conclusions: The green-synthesized CS-ZnONCs exhibit favorable physicochemical properties, biocompatibility, and multifunctional biological activities, supporting their potential as a promising sustainable biomaterial nanomedicine for pharmaceutical formulations, wound healing, and regenerative medicine applications. Full article

Background: The global rise in antimicrobial resistance (AMR) has created an urgent need for innovative antibacterial strategies and localized delivery systems. This study aimed to develop and characterize electrospun poly (vinyl alcohol) (PVA) nanofibers co-loaded with atorvastatin (ATR) and zinc oxide (ZnO) nanoparticles for use as a multifunctional topical platform for wound healing and infection control. Methods: ZnO nanoparticles were prepared via ball milling and characterized for size and zeta potential. Four PVA-based nanofiber formulations were fabricated using electrospinning: blank (F1), ZnO-loaded (F2), ATR-loaded (F3), and ATR/ZnO co-loaded (F4). The nanofibers were evaluated for morphology, thermal properties, crystallinity, and drug release. Antibacterial efficacy was tested against S. aureus, S. epidermidis, MRSA, and P. aeruginosa using broth microdilution and checkerboard assays. Biocompatibility and wound healing potential were assessed via MTT and fibroblast scratch assays on human foreskin fibroblasts (hFFs). Results: SEM imaging confirmed the production of uniform, bead-free nanofibers. ATR and ZnO nanoparticles were successfully incorporated in the nanofiber. The co-loaded formulation (F4) demonstrated a sustained release profile, releasing approximately 78.7% of ATR over 24 h. While all treatments showed limited activity against P. aeruginosa, the ATR/ZnO co-loaded nanofibers exhibited significantly enhanced antibacterial activity against Gram-positive strains, achieving the lowest MIC values (1.5–2.0 mg/mL). Synergy analysis confirmed an enhanced effect with ATR and ZnO against MRSA. Furthermore, F4 achieved the highest wound closure rate of 92.41% in 24 h while maintaining acceptable cytocompatibility. Conclusions: The integration of ATR and ZnO into PVA nanofibers provides an enhanced antibacterial effect consistent with the synergistic potential observed between free agents targeting Gram-positive wound pathogens. The platform’s ability to simultaneously inhibit bacterial growth and promote rapid fibroblast migration positions it as a promising localized therapeutic for managing infected wounds. Full article

The concentration of heavy metals in the environment has been steadily increasing, raising concerns about their adverse effects on ecosystems and human health. Fine-grained particulate matter is of particular concern due to its enhanced mobility, bioavailability, and potential for inhalation exposure. Facilities involved in the mechanical processing of electronic waste (e-waste) represent a significant potential source of metal-containing fine particles. In this study, crushed e-waste components containing precious metals were separated into particle-size fractions ranging from 3.0 to 0.15 mm using a vibratory sieving system. The elemental composition of the individual fractions was determined by energy-dispersive X-ray fluorescence spectrometry (ED-XRF), while the spatial distribution of selected metals in fine fractions was further investigated using scanning electron microscopy combined with energy-dispersive X-ray spectroscopy (SEM–EDS). The results demonstrate that e-waste contains a wide range of heavy non-ferrous metals whose distribution is strongly dependent on particle size. A pronounced enrichment of metals was observed in the finest fractions, particularly below 0.25 mm. Compared to the coarse fraction (>3 mm), the zinc concentration increased by approximately one order of magnitude, while chromium, nickel, and cadmium exhibited increases of up to approximately 20-fold. Lead showed particularly high enrichment, reaching approximately 2 wt.% in the finest fraction (<0.15 mm), corresponding to nearly fiftyfold enrichment relative to the coarse fraction. Tin concentrations also increased markedly, in some cases by up to two orders of magnitude. Trace amounts of arsenic and selenium were detected in the finest fractions, whereas mercury was not detected. The combined ED-XRF and SEM–EDS results confirm that fine-grained e-waste fractions are the dominant carriers of hazardous metals and respirable particles generated during mechanical processing. These findings highlight the dual character of fine fractions as both a critical environmental and occupational risk and a potentially valuable secondary resource. The study emphasizes the importance of controlled handling, effective dust management, and targeted processing strategies to minimize human exposure while enabling efficient recovery of valuable metals from e-waste. Full article

Active antimicrobial films based on polyethylene terephthalate (PET) were developed through atomic layer deposition (ALD) and plasma sputtering to obtain ZnO (≈15 nm) and ZnO/Cu (≈18 nm) coatings. Surface characterization by X-ray photoelectron spectroscopy confirmed zinc in ZnO form and copper as Cu₂O/CuO, while mass spectrometry quantified approximately 10 µg/cm² of Zn in both samples and about 130 ng/cm² of Cu in the ZnO/Cu films. The antimicrobial performance of the coatings was evaluated on burrata cheese and turkey fillets stored under refrigeration, assessing microbial growth and sensory quality over time. The films exhibited different effects depending on food type and the initial contamination levels. On burrata cheese, PET-ZnO moderately extended the shelf life by inhibiting Pseudomonas spp., while PET-ZnO/Cu further enhanced preservation. Cheese packaged with PET-ZnO/Cu remained acceptable for over 21 days compared to 19–20 days for the controls. More pronounced effects were observed in turkey fillets, characterized by a higher initial contamination. In control samples, Staphylococcus spp. rapidly proliferated, leading to spoilage within one day. Both active films significantly delayed microbial growth and sensory decay, with PET-ZnO/Cu providing the best performance, extending acceptability beyond two days compared to less than one day for the controls. Full article

As a ternary metal oxide, indium gallium zinc oxide (IGZO) has gathered much attention for various applications, including gas sensors, due to its remarkable semiconducting properties, even in amorphous phases and at a low process temperature. For gas sensing applications, as surface area is an important factor affecting the response and performance of a gas sensor, nanofibers (NFs) with 1D morphology are expected to have good sensing performance. In this research, IGZO NFs were synthesized using an electrospinning process, which is a suitable technique for the large-scale and low-cost fabrication of NFs. Various characterizations were performed on the synthesized IGZO NFs, and the desired NF morphology and chemical composition were confirmed. Gas sensing experiments showed that the sensor was sensitive and selective to H₂S gas at 250 °C with a response of 40.5 to 100 ppm gas. This study demonstrates the strong potential of IGZO for use in sensitive and selective H₂S gas sensors. Full article

Copper-based hybrid metal matrix composites reinforced with graphene and zinc were developed to achieve a balanced combination of mechanical strength, corrosion resistance, wear performance, and electrical conductivity. In this study, Cu matrix composites containing a constant graphene content of 1 wt.% and varying Zn contents (0, 5, 10, and 15 wt.%) were fabricated through mechanical alloying followed by Spark Plasma Sintering (SPS). The effects of zinc content on microstructure, densification, hardness, corrosion behavior, tribological performance, and electrical conductivity were systematically investigated. Microstructural analyses revealed that the combined use of graphene and Zn significantly influenced grain refinement, interfacial stability, and densification behavior. The composite containing 10 wt.% Zn exhibited the highest relative density (~90.5%) and maximum hardness (62 HB), indicating an optimal reinforcement level. Corrosion tests conducted in 3.5 wt.% NaCl solution demonstrated that the 10 wt.% Zn composite showed the most noble corrosion potential and the lowest corrosion current density, which was attributed to reduced porosity and improved microstructural homogeneity. Tribological results confirmed that graphene contributed to a self-lubricating effect, while Zn enhanced load-bearing capacity, leading to improved wear resistance under increasing normal loads. Electrical conductivity measurements showed a gradual decrease with increasing Zn content, mainly due to solid-solution-induced electron scattering in the Cu matrix; however, the fixed graphene addition and effective SPS consolidation helped preserve conductive pathways, allowing all composites to retain acceptable conductivity levels. The results indicate that the hybrid Cu–graphene–Zn composites exhibit a balanced combination of mechanical, corrosion, tribological, and electrical properties, with 10 wt.% Zn emerging as the optimal composition. Full article

Streptococcus sanguinis (S. sanguinis) is an oral commensal and early colonizer of the tooth surface that contributes to dental biofilm homeostasis. Zinc oxide nanoparticles (ZnO NPs) are often incorporated into dental restorative materials to enhance mechanical performance and confer antibacterial properties; however, their effects on S. sanguinis have not been thoroughly studied. Here, we investigated the antimicrobial and antibiofilm efficacy of ZnO NPs against this bacterial species. ZnO NPs exhibited a minimal inhibitory concentration (MIC) of 100 µg/mL and caused rapid, dose-dependent suppression of intracellular ATP levels and overall metabolic activity within 2–4 h of exposure. ZnO NPs induced reactive oxygen species (ROS) production in a dose-dependent manner. The free radical scavenger α-tocopherol partly prevented the antibacterial effect of ZnO NPs, suggesting that lipid peroxidation contributes to ZnO NP-mediated toxicity, although it is not the sole mechanism involved. Short-term exposure (2 h) to ZnO NPs did not significantly affect membrane integrity or cellular morphology, whereas prolonged treatment (24 h) resulted in pronounced membrane permeabilization, membrane hyperpolarization, and cellular swelling. Computational morphometric analyses of high-resolution scanning electron microscopy (HR-SEM) images of planktonic growing bacteria after a 24 h treatment confirmed a significant, dose-dependent increase in cell surface area and surface roughness. Importantly, ZnO NPs also reduced the metabolic activity and compromised the structural integrity of mature, preformed biofilms. Collectively, these findings demonstrate that ZnO NPs exert antimicrobial and antibiofilm effects against S. sanguinis through early metabolic inhibition associated with oxidative stress followed by progressive membrane dysfunction. Full article

The rapid detection of zinc in different aqueous matrices is very relevant. For example, a Zn²⁺ level above ca. 50 µM affects drinking water quality, while levels below ca. 25 µM in urine are related to higher probability of prostate cancer. Herein, a simple and rapid qualitative colorimetric sensor for the detection of zinc ions in aqueous samples is developed. The sensor exploits the reaction between 1,5-diphenylthiocarbazone and Zn²⁺ to form colored chelates whose color changes with increasing Zn²⁺ concentration. The chelating agent has been immobilized in a dried form on various cellulose- and synthetic-based materials to obtain a sensor that can be used for in situ analysis. The procedure to obtain the colorimetric device is easy and straightforward. Moreover, it requires neither specialized personnel to perform the analysis nor specialized personnel for the interpretation of the analytical results. The analysis requires only 20 µL of sample, and a reliable colorimetric output is obtained within 10 min and is stable up to 30 min. The sensor allows Zn²⁺ visual detection in drinking water and urine without any sample pre-treatment with excellent efficiency and repeatability. Considering the ability to distinguish between Zn²⁺ concentrations equal to 0.5 and 2× the cut-off level, the sensor showed sensitivity and specificity of 100% for fortified tap water analysis and 100% sensitivity and 88.9% specificity for urine samples. The almost-perfect concordance with the reference atomic absorption spectrometer and the 94.1% accuracy demonstrated the sensor’s excellent potential to be applied for selective qualitative Zn²⁺ detection in real-life situations. Full article