Search Results (1,192)

Background/Objectives: With the increasing incidence of drug counterfeiting and the emergence of personalized medicine, the need for unique marking of solid dosage forms, e.g., tablets, has attracted considerable interest in the current research and development landscape. Besides traditional printing methods, laser marking offers several advantages, as it eliminates the need for organic solvents and enables the generation of precise patterns. However, laser exposure may raise safety concerns regarding the stability of photosensitive drugs in the irradiated dosage forms. Therefore, the aim of the present study was to test the photoprotective effect of titanium dioxide (TiO₂) and its various alternatives, e.g., talc, calcium carbonate (CaCO₃), zinc oxide (ZnO), and black iron oxide (Fe₃O₄), alongside a ready-to-use reference formulation, Opadry^® Brown, which contains TiO₂ (titanium-containing, TC) on nifedipine, a light-sensitive model drug. Methods: Laser marking or short-term laser ablation at different wavelengths (193 nm, 248 nm, 532 nm, and 781 nm) was applied to different coating formulations. As a positive control, prolonged exposure to daylight was applied. The properties and photostability of these formulations were evaluated using several analytical methods (i.e., surface profilometry, Raman spectroscopy, and high-performance liquid chromatography (HPLC)). Results: The TiO₂, ZnO, Fe₃O₄, and Opadry^® TC Brown coatings maintained their color during the long-term study under all conditions. Furthermore, the prepared formulations exhibited different ablation depths and morphological changes depending on the coating and laser type. HPLC measurements confirmed significant differences in the protective ability of various pigments against sunlight and different types of lasers. Nevertheless, the obtained Raman spectra were not in complete agreement with HPLC results, which can be attributed to spectral overlap between key nifedipine degradation markers and excipient signals in the tablet core. Conclusions: Overall, laser treatment of tablets containing photosensitive drugs may induce API decomposition; however, this effect can be minimized or avoided by careful selection of the appropriate combination of laser type and photoprotective pigment. Under the applied experimental conditions, Ti:Sa laser treatment was associated with the lowest degree of nifedipine degradation among all formulations, while ZnO-containing coatings demonstrated the most consistent photoprotective performance against the majority of the tested laser types, while Fe₃O₄-containing coatings provided superior protection during prolonged sunlight exposure and Nd:YAG laser irradiation. Full article

Aqueous zinc–manganese dioxide (Zn–MnO₂) batteries are undergoing a paradigm shift from traditional ion-insertion mechanisms to a reversible deposition/dissolution process. By leveraging a two-electron transfer (Mn²⁺/MnO₂), this electrolytic system achieves a high theoretical capacity of 616 mAh g⁻¹ and a theoretical operating voltage of 1.99 V. However, the accumulation of dead Mn, electrically isolated inactive phases, and dynamic interfacial pH fluctuations remain critical barriers to cycle life and practical energy density. This review systematizes a trinitarian strategy to overcome these bottlenecks, focusing on interfacial engineering, redox mediator-assisted recovery, and advanced electrode architectures. We evaluate how anion engineering and pH-buffering stabilize reaction pathways, and how diverse mediators (e.g., halogens, metal ions, and organic molecules) chemically rescue inactive manganese. Furthermore, we examine the integration of 3D carbon networks and low-cost hybrid electrodes to sustain high-areal-capacity deposition. To elucidate these complex mechanisms, we highlight multiscale analytical approaches combining synchrotron X-ray techniques and density functional theory (DFT). Finally, we outline a roadmap for applications ranging from grid-scale flow batteries to flexible wearable electronics. This work provides a comprehensive perspective on realizing sustainable, safe, and high-performance zinc-based energy storage. Full article

This study reports the preparation of a nanocomposite using a black cumin surface as a carbon framework on which zinc oxide-doped manganese ferrite nanoparticles were deposited and grown. A simple precipitation method was used to prepare the nanocomposite. The resulting composite was characterized using various characterization analyses such as FTIR, XRD, EDX, SEM, TEM, and TGA. The composite surface was highly conformed with functional groups, and the nanocomposite was formed due to electrostatic and non-electrostatic interactions between the carbon framework and the nanoparticles. X-ray analysis revealed a crystalline structure with crystal sizes up to 45 nm. Microscopic images revealed the surface morphology, confirming the irregular distribution of particles within the composite. The resulting composite material was used for adsorption application. The composite material was tested for the removal of Congo red dye from water. It was found that under optimal conditions, a dose of 2 g per liter of absorbent removed nearly 100% of dye from a 10 mL volume of 10 mg per liter Congo red solution within 90 min and 7 pH. A monolayer adsorption was confirmed by the isotherm analysis. The monolayer adsorption capacity for the present study was ~13.0 mg per gram. The adsorption kinetics suggested the fitting of pseudo-second order. Based on the findings, it was concluded that the chemical mechanism was responsible for the present adsorption process. The regeneration study demonstrates the stability of current adsorbent up to two cycles only. This nanocomposite is the first of its kind which promotes the creation of nanocomposites in the future by using natural materials and reduces the dependency on activated carbon. Full article

Saltwater batteries can be made using brine from the desalination of seawater for low-cost energy storage. This study investigates the performance characteristics of saltwater batteries for potential off-grid energy applications. The systematic investigation of 15 electrode pairings from six electrodes (copper, iron, zinc, graphite, aluminium, and tin) across eleven concentration levels, combined with studies on electrode geometry, spacing, and volume, provides comprehensive insights into galvanic cell behaviour for saltwater batteries. Results indicate that the open-circuit voltage (OCV) is primarily determined by electrode potential differences rather than salt concentration, with zinc-carbon and aluminium-carbon pairings producing the highest voltages (1.1–1.2 V). Short circuit current increases with salt concentration up to approximately 30% (0.3 M), which is the saturation point, beyond which ion mobility decreases. This study demonstrates that electrode geometry and surface area significantly affect current density and internal resistance, while increased electrode spacing raises internal resistance and reduces maximum current output. These findings contribute to understanding the feasibility and performance characteristics of saltwater batteries as accessible energy sources using recyclable materials. Full article

The use of environmentally friendly corrosion inhibitors in corrosive solutions has attracted considerable attention over the past few decades. However, the uncontrolled use of such inhibitors in aggressive environments can lead to a reduction in the long-term corrosion protection performance of the system. Moreover, the need for frequent re-dosing of the inhibitor increases the overall cost. One of the effective approaches for controlled and smart release of inhibitors in corrosive media is the use of nanocarriers, in which the inhibitor molecules are adsorbed onto the surface of nanoparticles and subsequently desorbed into the corrosive electrolyte through a specific release mechanism. Among the commonly used methods to obtain such eco-friendly inhibitors is the extraction of plant-based compounds, which are abundant and cost-effective. In this study, zinc oxide (ZnO) nanoparticles were green-synthesised using a plant extract and employed as nanocarriers for the controlled release of phytochemicals in 1 M HCl solution. The corrosion behaviour of carbon steel (St37) was investigated using electrochemical polarisation techniques. Results revealed that the system acts as a mixed-type inhibitor, achieving an inhibition efficiency of approximately 85% at optimal concentration, demonstrating its potential as a sustainable and cost-effective alternative for corrosion protection. Full article

The development of highly efficient, stable, and cost-effective non-precious metal electrocatalysts to replace conventional platinum-based materials holds profound significance for accelerating the commercialization of advanced energy conversion devices, such as zinc–air batteries (ZABs). Herein, we propose a facile and highly efficient strategy to prepare a defect-rich, highly active nitrogen-doped porous carbon-based electrocatalyst (denoted U-Fe-N-C, urea-assisted iron–nitrogen–carbon material), via high-temperature co-pyrolysis of heme with urea. Our results demonstrate that urea not only serves as an excellent nitrogen source during pyrolysis, introducing abundant topological defects and heteroatom doping sites, but also induces the carbon substrate to form a hierarchical sponge-like porous structure with a high specific surface area. This unique microenvironment effectively prevents the agglomeration of iron species at high temperatures, achieving enhanced dispersion of iron species stabilized within the nitrogen-rich carbon matrix. Electrochemical evaluations reveal that under the optimal synthesis conditions (a precursor mass ratio of 1:3, calcination at 900 °C), U-Fe-N-C exhibits excellent oxygen reduction reaction (ORR) catalytic performance, delivering a half-wave potential of 0.731 V vs. RHE, and shows long-term operational durability that significantly surpasses that of commercial Pt/C. Furthermore, liquid rechargeable zinc–air batteries assembled with U-Fe-N-C as the air cathode deliver remarkable cycling stability, operating for up to 270 h of charge–discharge cycling without noticeable performance degradation. This study not only provides useful insights into the mechanisms of pore formation and assistance but also offers a practical perspective for the rational design and scalable synthesis of high-performance metal–nitrogen–carbon (M-N-C) electrocatalysts. Full article

Gao-shan-hong-jing-tian (GSHJT) Oral Liquid is a phytochemical-rich preparation derived from Rhodiola, yet its anti-hypoxic active constituents and molecular mechanisms remain poorly understood. This study aimed to identify the key anti-hypoxic phytochemicals in GSHJT Oral Liquid and clarify their mechanisms of action to support its potential use in managing acute mountain sickness (AMS). We first established and validated an HPLC method for quality control, then comprehensively profiled the chemical composition using LC-MS. Network pharmacology and molecular docking were applied to predict the core anti-hypoxic components, candidate targets and signaling pathways. The primary bioactivity was further verified through an in vitro carbonic anhydrase (CA) inhibition assay. A total of 71 constituents were identified, with kaempferol and ellagic acid emerging as the primary anti-hypoxic phytochemicals. These compounds target seven core proteins (SRC, PIK3R1, ESR1, EGFR, PTK2, IGF1R, and LYN) to regulate vascular tone, inflammation, oxidative stress, blood–brain barrier integrity, and cell survival under hypoxic conditions. By modulating pathways such as HIF-1α, PI3K/AKT, FAK/PTK2, SRC, and IGF1R, these phytochemicals ultimately influence the onset and alleviation of AMS. Enzyme inhibition assays demonstrated that kaempferol and ellagic acid inhibited CA with IC₅₀ values of 34.05 μM and 119.1 μM, respectively. Molecular docking further revealed that both compounds suppressed CA activity through a combination of hydrogen bonding and hydrophobic interactions, consistent with a zinc-bound water-anchoring mechanism. This study elucidates the phytochemical basis and molecular mechanism responsible for the anti-hypoxic effects of GSHJT Oral Liquid, providing scientific support for its potential application as a natural, plant-derived intervention for preventing and alleviating acute mountain sickness, providing scientific support for its potential application and offering a reproducible paradigm for the rational development of other Rhodiola-based phytomedicines, though further in vivo validation is required to confirm the anti-hypoxic efficacy. Full article

Hierarchical ZnO–SiO₂/carbon composites (C-Zn1, C-Zn2, C-Zn3) were synthesised via the carbonisation of resorcinol–formaldehyde gels in the presence of ZnO-modified fumed silica, and characterised by N₂ adsorption–desorption, FTIR, XRD, SEM, and zeta potential analysis. The composites exhibited hierarchical micro–mesoporous structures with BET surface areas of 467–499 m² g⁻¹; the non-microporous volume fraction increased from 0.09 (reference carbon RFC, 545 m² g⁻¹) to 0.54–0.63 upon ZnO–SiO₂ incorporation. Adsorption of methylene blue (MB), crystal violet (CV), and rhodamine 6G (R6G) followed the Marczewski–Jaroniec isotherm model. Maximum adsorption capacities for the best-performing composite (C-Zn1) reached 1.22 mmol g⁻¹ for MB, 1.04 mmol g⁻¹ for CV, and 0.63 mmol g⁻¹ for R6G, compared to 1.32, 1.17, and 0.67 mmol g⁻¹ for unmodified RFC. Kinetic analysis revealed up to 3.5-fold faster adsorption rates for C-Zn1 relative to RFC (for CV and R6G), attributed to enhanced diffusion through mesoporous channels while preserving the micropore-driven capacity. Agar well-diffusion assays against four bacterial strains showed no inhibition zones for any composite, indicating that no biologically active concentration of zinc species was released under the assay conditions. The proposed approach yields composites with enhanced adsorption kinetics, preserved capacity, and confirmed non-leaching character, positioning them as effective candidates for water purification. Full article

Cement clinker production is a thermal- and emissions-intensive process requiring high-temperature heat for drying, calcination, and sintering. This review provides a process-based assessment of refuse-derived fuel (RDF), solid recovered fuel (SRF), tire-derived fuel (TDF), and biomass as partial substitutes for coal and petcoke in modern dry-process cement kilns. The study synthesized the evidence from plant-scale trials, pilot and laboratory experiments, process modeling, computational fluid dynamics, emissions studies, life-cycle assessment (LCA), techno-economic analysis (TEA), and regional case studies to evaluate alternative fuels across fuel properties, kiln-zone suitability, process stability, clinker quality, emissions performance, and environmental outcomes. The review shows that stable co-processing generally requires fuels with net calorific values above 14 MJ kg⁻¹ and moisture contents below 15%, although TDF can provide 26–33 MJ kg⁻¹ and sustain high-energy kiln duty when sulfur, zinc, and steel residues are controlled. RDF, SRF, and biomass require pre-processing, homogenization, calibrated dosing, and continuous fuel-quality monitoring to limit incomplete burnout, deposit formation, volatile circulation, and clinker-quality variation. LCA studies show that 20% RDF thermal substitution can reduce global warming potential by about 3.3–4.2%, increasing to approximately 6.7% when avoided landfill methane credits are included. Modern abatement systems can maintain particulate matter at about 10–30 mg Nm⁻³ and PCDD/F below 0.1 ng TEQ Nm⁻³ under stable operation. The review concludes that alternative fuels are quality-dependent co-processing options whose mitigation role is complementary to clinker-factor reduction, energy-efficiency improvement, low-clinker binders, electrified heating, oxy-fuel calcination, and carbon capture. Full article

Seawater zinc–air batteries (SZABs) stand out as promising candidates for marine and offshore energy supply. However, their practical implementation is greatly restricted by tardy oxygen reduction reaction (ORR) and oxygen evolution reaction (OER) kinetics at the air cathode, severe chloride ion-induced catalyst corrosion, and structural deterioration of traditional binder-containing electrodes in seawater media. Herein, we design and fabricate a binder-free integrated electrode consisting of carbon-supported iron phthalocyanine- modified star-like cobalt sulfide arrays directly grown on nickel foam. The optimal catalyst (0.3FePc-C/CoS) integrates the respective advantages of Fe single atoms and cobalt sulfide, exhibiting excellent ORR and OER activity, delivering a prominent half-wave potential of 0.89 V versus RHE, and exhibiting a low OER overpotential of 160 mV at 50 mA cm⁻² and robust stability in seawater. As a self-supported air cathode, the 0.3FePc-C/CoS-based battery attains a favorable open-circuit voltage reaching 1.48 V, prominent peak power density (126.4 mW cm⁻²), small charge–discharge potential polarization (0.52 V), excellent energy efficiency (68.8%) and extraordinary long-term cycling durability (>360 h). This work not only discloses a feasible synergistic modulation strategy for constructing high-performance bifunctional electrocatalysts but also provides a valuable reference for developing corrosion-resistant integrated air electrodes toward practical marine energy storage applications. Full article

Swine wastewater, composed of farm effluents, is frequently applied as fertilizer, but repeated use can lead to eutrophication and contamination. This study investigated the improvement of swine wastewater quality by means of the electroflocculation technique using various alternative electrodes (aluminum, stainless steel, carbon, copper, and zinc) under very short exposure durations (3, 6, and 9 min) and low voltage conditions (12 V), aiming to optimize the process. After the treatments, both treated and control samples were analyzed in the laboratory for pollutants including turbidity, organic matter, phosphorus and other minerals. The results showed that zinc and stainless steel electrodes were particularly effective in reducing turbidity (47–67%), organic matter (23%), phosphorus (36–62%), calcium (24–54%), magnesium (34–52%) and sodium (19–38%) respectively in the effluent after only 6 or 9 min of current exposure. However, these electrodes released some heavy metals into the solution, which should be further reduced through a complementary treatment. Overall, electroflocculation using alternative electrode materials with short treatment times appears to be a suitable pre-treatment strategy for swine wastewater, reducing pollutant loads while maintaining low energy consumption and preserving nutrients for subsequent use as fertilizer. Full article

Moisture-induced damage is one of the primary causes of premature distress in asphalt pavements, leading to reduced service life and increased maintenance costs. Although nanomaterials have shown potential in enhancing asphalt performance, the underlying composite interaction mechanisms among nanomaterials, asphalt binder, and aggregate phases under moisture exposure are still not fully understood. In addition, comparative evaluations under consistent experimental conditions remain limited. This study investigates the influence of five nanomaterials: nano-silica (NS), nano-alumina (NA), nano-titanium dioxide (NT), nano-zinc oxide (NZ), and carbon nanotubes (CNT) on the physical and mechanical properties of asphalt binders and mixtures, with particular emphasis on moisture damage resistance. The nanomaterials were incorporated at dosages of 1.5%, 3.0%, 4.5%, and 6.0% by binder weight. Binder performance was evaluated using conventional and performance grading (PG) tests, while mixture performance was assessed through Marshall properties and moisture susceptibility indicators, including the tensile strength ratio (TSR) and the index of retained strength (IRS). Fluorescence microscopy (FM), scanning electron microscopy (SEM), and Fourier transform infrared spectroscopy (FTIR) were employed to investigate nanomaterial dispersion characteristics, microstructural morphology, and physicochemical interactions within the asphalt composite system. The results indicate that nanomaterial modification reduced penetration and increased softening point and Marshall stability, reflecting enhanced stiffness and thermal resistance, although ductility decreased at higher dosages. Significant improvements in moisture resistance were observed, particularly under conditioned states. The TSR increased from 81.2% for the control mixture to 92.4% for NS and 91.7% for NA, while the IRS improved from 72.7% to 88.5% for NS. Statistical analysis indicated that both nanomaterial type and dosage significantly affected TSR and IRS performance, with dosage exhibiting comparatively greater influence on moisture resistance improvement. FM and SEM analyses revealed comparatively better dispersion and lower agglomeration tendency for NS and NA, which corresponded to their superior moisture resistance performance. FTIR analysis indicated that the modification process was predominantly physical, with no major formation of new chemical functional groups. Among the investigated nano materials, NS at 6% dosage exhibited the most pronounced improvement, followed by NA at similar dosage levels. Overall, the findings suggest that nanomaterial modification can considerably improve the moisture resistance and mechanical performance of asphalt mixtures under laboratory conditions. However, higher nanomaterial dosages may adversely affect binder workability due to increased viscosity, particularly in CNT-modified binders. Full article

Metalloporphyrins play an important role in biomedicine, catalysis, and energy, among other fields, due to their structural complexity and functional diversity. In this study, GO was used as the precursor support and chitosan was employed to reduce and functionalize GO into chitosan-functionalized rGO. Furthermore, metalloporphyrins were covalently linked to the amino side chains of chitosan via an amide crosslinking method, and a series of metalloporphyrin–chitosan-functionalized rGO nanocomposites were designed and synthesized. A set of poly(metalloporphyrin–chitosan)-functionalized rGO working electrodes was constructed by drop-coating onto glassy carbon electrodes, and their electrocatalytic performance toward dopamine was investigated in PBS solution. Finally, zinc(II) porphyrin, with the best performance, was selected as the core catalytic unit to fabricate an enzyme-free dopamine sensor. Under optimal working conditions, the sensor exhibited a sensitivity of 0.30 mA mM⁻¹cm⁻², a linear detection range of 0.001~1.0 mM, and a low detection limit of 0.05 μM (S/N = 3). The sensor showed anti-interference ability against various interfering ions and electroactive substances, as well as good stability and repeatability. Full article

Metal–organic frameworks (MOFs) exhibit high specific surface area and porosity, which may facilitate electron transfer during electrochemical reactions. Therefore, it is clear that MOFs are promising materials for the development of electrochemical sensors. In particular, zinc (Zn) based MOFs offer several advantages such as high specific surface area, porosity, environmental friendliness and low cost. Thus, Zn-based MOF materials and their composites have been extensively utilized in the detection of various pollutants, biomolecules and food additives. The Zn-MOF-based materials have been extensively utilized in electrochemical and fluorescence sensing applications. Previously, various Zn-MOF-based sensing systems such as pristine Zn-MOF, carbon-supported Zn-MOF composites, MXene hybrids with Zn-MOF, and bimetallic/trimetallic Zn-based MOFs were explored to enhance sensing performance. Such materials exhibit remarkable analytical performance, such as a low limit of detection (LOD) (nM to pM range), wide linear response range (LR), fast response times, and high selectivity in the presence of interfering species. In electrochemical sensing, Zn-MOF-modified electrodes demonstrated improved charge-transfer kinetics and sensitivity, enabling accurate determination of the biomolecules, drugs and heavy metal ions in real samples. Similarly, Zn-MOF-based fluorescence sensors showed high luminescent properties and displayed sensitive detection of pollutants and biomolecules. Despite such promising sensing performances, some challenges, such as low stability, reproducibility and selectivity in real-time monitoring, etc., remain that need to be overcome. This review article summarizes the previously reported literature on the fabrication of Zn-MOFs, their composites and Zn-MOF-derived materials for the development of electrochemical and fluorescence sensors. We have also discussed the future directions for the rational design of the high-performance Zn-MOF-based sensing systems for environmental and biomedical applications. We believe that the present review article would be useful for the scientific community working on the fabrication of Zn-MOF-based sensors. Full article

Fundamental understanding of the biomass pyrolysis process on a molecular level provides important guidelines for designing advanced porous carbon materials. In this study, the effects of KOH and K₂CO₃ activators on the thermal decomposition of agarose were elucidated using TG-FTIR-GCMS coupling techniques. The results demonstrate that the presence of KOH/K₂CO₃ shifts the pyrolysis gaseous products from organic fragments to CO₂ and H₂O, thereby preserving more C-C bonds in the solid phase and facilitating the subsequent aromatization process. Furthermore, compared to using KOH as the sole activator, the K₂CO₃/KOH co-activation strategy suppresses the violent evolution of CO₂ within the 300–400 °C range, thereby alleviating the structural shock to the material skeleton and ensuring its integrity. Therefore, the HPC-KCO prepared via a synergistic KOH/K₂CO₃ co-activation and one-step carbonization process exhibits a high specific surface area of 1670 m² g⁻¹ and successfully retains its interconnected hierarchical porous framework. Benefiting from its well-developed porous structure, HPC-KCO exhibits an impressive specific capacitance of 370 F g⁻¹ when employed in zinc-ion capacitors. Furthermore, the assembled symmetric supercapacitor demonstrates robust stability over a wide temperature range from −60 to 100 °C, delivering a remarkable capacitance of 121 F g⁻¹ even at −60 °C. This work offers a new insight for synthesizing porous structures of biomass-derived carbon. Full article