Search Results (709)

The nourishment of the human population depends on a handful of staple crops, such as maize, rice, wheat, soybeans, potatoes, tomatoes, and cassava. However, all crop plants are affected by at least one virus causing diseases that reduce yield, and in some parts of the world, this leads to food insecurity. Conventional management practices need to be improved to incorporate recent scientific and technological developments such as antiviral gene silencing, the use of double-stranded RNA (dsRNA) to activate an antiviral response, and nanobiotechnology. dsRNA with antiviral activity disrupt viral replication, limit infection, and its use represents a promising option for virus management. However, currently, the biggest limitation for viral diseases management is that dsRNA is unstable in the environment. This review is focused on the potential of nanoparticles and nanocarriers to deliver dsRNA, enhance stability, and activate antiviral gene silencing. Effective carriers include metal-based nanoparticles, including silver, zinc oxide, and copper oxide. The stability of dsRNA and the efficiency of gene-silencing activation are enhanced by nanocarriers, including layered double hydroxides, chitosan, and carbon nanotubes, which protect and transport dsRNA to plant cells. The integration of nanocarriers and gene silencing represents a sustainable, precise, and scalable option for the management of viral diseases in crops. It is essential to continue interdisciplinary research to optimize delivery systems and ensure biosafety in large-scale agricultural applications. Full article

This study presents a comprehensive morphological and structural analysis of carbon materials produced via simple thermal methane pyrolysis conducted under laboratory conditions in a quartz reactor without the use of catalysts. The process, carried out at 1000 °C, achieved moderate methane conversion (36.5%), process efficiency (36.1%), and very high selectivity (98.9%) towards hydrogen production, highlighting its potential as a CO₂-free hydrogen generation method. Distinct carbon morphologies were observed depending on the formation areas within the reactor: a predominant flake-like silver carbon formed on reactor walls at temperatures between 600 and 980 °C (accounting for 91% of the solid product) and a minor powdery carbon formed near 980–1000 °C (9% of the solids). The powdery carbon exhibited a high specific surface area (125.3 m²/g), substantial mesoporosity (60%), and porous spherical aggregates, indicating an amorphous structure. In contrast, flake-like carbon demonstrated a low surface area (1.99 m²/g), high structural order confirmed by Raman spectroscopy, and superior thermal stability, making it suitable for advanced applications requiring mechanical robustness. Additionally, polycyclic aromatic hydrocarbons were detected in cooler zones of the reactor, suggesting side reactions in low-temperature areas. The study underscores the impact of temperature zones on carbon structure and properties, emphasizing the importance of precise thermal control to tailor carbon materials for diverse industrial applications while producing clean hydrogen. Full article

Thallium is a soft metal with a grey or silvery hue. It commonly occurs in two oxidation states in chemical compounds: Tl⁺ and Tl³⁺. Thermodynamically, Tl⁺ is significantly more stable and typically represents the dominant form of thallium in environmental systems. However, in this chemical form, thallium remains highly toxic. This study focuses on the modification of a glassy carbon electrode (GCE) with silver nanostructures stabilised by potato starch derivatives. The modified electrode (GCE/AgNPs-E1451) was used for the determination of trace amounts of thallium ions using anodic stripping voltammetry. Emphasis was placed on assessing the effect of surface modification on key electrochemical performance parameters of the electrode. Measurements were carried out in a base electrolyte (EDTA) and in a real soil sample collected from Bali. The stripping peak current of thallium exhibited linearity over the concentration range from 19 to 410 ppb (9.31 × 10⁻⁸ to 2.009 × 10⁻⁶ mol/dm³). The calculated limit of detection (LOD) was 18.8 ppb (9.21 × 10⁻⁸ mol/dm³), while the limit of quantification (LOQ), corresponded to 56.4 ppb (2.76 × 10⁻⁷ mol/dm³). The GCE/AgNPs-E1451 electrode demonstrates several significant advantages, including a wide detection range, reduced analysis time due to the elimination of time-consuming pre-concentration steps, and non-toxic operation compared to mercury-based electrodes. Full article

In the present study three composite materials based on iron in combination with bismuth, copper or lithium carbonates FeNO₃@Li₂CO₃ (SFL), FeNO₃@CuCO₃ (SFC), and FeNO₃@(BiO)₂CO₃ (SFB) were synthesized by coprecipitation. The purpose was to obtain materials that possess targeted adsorbent properties for the recovery of silver ions from aqueous solutions. After synthesis, to emphasize the adsorptive qualities of materials for the recovery of silver ions, the synthesized composite materials, as well as those doped with silver ions following the adsorption process (SFL-Ag, SFC-Ag, and SFB-Ag), were characterized and several adsorption-specific parameters were examined, including temperature, contact time, pH, adsorbent dose, and the initial concentration of silver ions in solution. Subsequently, the ideal adsorption conditions were determined to be as follows: pH > 4, contact time 60 min, temperature 298 K, and solid–liquid ratio (S–L) of 0.1 g of adsorbent to 25 mL of Ag (I) solution for all three materials. The Langmuir model properly fits the experimental equilibrium data of the adsorption process; however, the Ho–McKay model closely represents the adsorption kinetics. The maximum adsorption capacities of the materials, 19.7 mg Ag(I)/g for SFC, 19.3 mg Ag(I)/g for SFB, and 19.9 mg Ag(I)/g for SFL, are comparable. The adsorption mechanism is physical in nature, as evidenced by the activation energies of 1.6 kJ/mol for SFC, 4.15 kJ/mol for SFB, and 1.32 kJ/mol for SFL. The highest Ag(I) concentration used for doping all three materials in the study was 150 mg Ag(I)/L. The process is endothermic, spontaneous, and takes place at the interface between the adsorbent and the adsorbate, according to thermodynamic theory. Subsequently, the antimicrobial activity against Staphylococcus aureus, Escherichia coli, Pseudomonas aeruginosa, and Candida albicans microorganisms was evaluated by rate of inhibition assessment. The SFC-Ag material showed a percentage of 100% inhibition with respect to the positive control for each microorganism. All synthetized materials have better efficiency as antifungal agents. Full article

Alzheimer’s disease (AD) instantly requires affordable diagnostic tools for targeting the responsible molecular biomarkers. In this review, we briefly discussed the overview of the AD population, performance of different analytical techniques and nanoparticles/composites, molecular biomarkers, and the interest of countries towards the detection of AD biomarkers during 2012–2025. The desired result was attained by lateral flow assay, surface-enhanced Raman scattering, and colorimetric sensor techniques with nanoparticles of magnetic, gold, and carbon-containing silver, and iridium oxide nanoparticles, upon biomarkers of dopamine, amyloid beta41, and Apolipoprotein E, individually. Additionally, the outstanding performance of nanoparticles including gold nanoparticles, carbon-containing nanoparticles, and manganese dioxide with their particle size of 5.7 nm, 35 nm, 37.3 nm, 120 nm, and 220 nm, respectively, has been discussed. Moreover, the percentages of AD-related biomarkers including amyloid beta42 having research articles of 21.2%, amyloid beta1-42 12.1%, amyloid beta oligomer 12.1%, phosphorylated Tau detection 12.1%, amyloid beta1-40 9.09%, Dopamine 9.09%, amyloid beta40 9.17%, apolipoprotein 6.06%, etc., have also been included. Additionally, LOD comparison with respect to applied analytical techniques, investigated through a timeline and electrochemical sensor, was found most suitable. Finally, a portable molecular diagnostic device to combine amyloid beta1-42, amyloid beta1-40, and phosphorylated Tau detection in non-invasive bodily fluid was proposed for the future and clinical diagnosis. Full article

Corporate boards play a pivotal role in shaping firms’ environmental strategies, yet the influence of board demographics, particularly director age, on sustainability outcomes remains insufficiently understood. This study investigates how the age profile of board members affects corporate environmental performance, including greenhouse gas emissions. Analyzing a comprehensive panel of 1843US publicly listed firms (17,218 firm-year observations) from 1996 to 2018, primarily through panel regressions with firm and year fixed effects, we find consistent evidence that firms with older boards tend to exhibit poorer environmental performance and higher direct, indirect and value chain greenhouse gas emissions. We argue that this relationship is driven by age-related differences in risk tolerance, time horizons, and sensitivity to environmental concerns. Additionally, the study explores moderating factors such as poor governance oversight (board co-option), pressure for profitability from institutional ownership, CEO social and environmental consciousness (CEO gender), and managerial ability, revealing that these governance dynamics significantly influence the strength of the director age–environmental performance link. The results, robust to endogeneity concerns, underscore the importance of considering age diversity and board refreshment in corporate governance to foster more effective environmental stewardship. These insights offer valuable implications for board members, corporate leaders, and policymakers aiming to advance sustainable business practices, but also open up opportunities for further exploration in alternative institutional contexts. Full article

Integrated aquaculture, centered around polyculture involving multiple species, is a typical practice for the sustainable development of the aquaculture industry, capable of enhancing resource utilization efficiency, environmental stability, and overall productivity through establishing symbiotic interactions among species. This study employed multi-amplicon high-throughput sequencing to assess the ecological impacts of two polyculture methods involving river crabs on sediment bacteria, fungi, and protists. One method involved polyculturing river crabs with mandarin fish, silver carp, and the stone moroko (SPC), and the other involved polyculturing river crabs with only mandarin fish and silver carp (SMC). The results showed that, compared to the SMC group, the SPC group remarkably increased the Chao1 index of bacterial communities in pond sediment and decreased the Pielou_J index of protists. The relative abundances of all fungal phyla and most dominant bacterial and protistan phyla (top 10 in relative abundance) in the SPC group were considerably different from those in the SMC group. In the co-occurrence networks of bacterial, fungal, and protistan communities, the numbers of edges and nodes were higher in the SPC group than in the SMC group, and the habitat niche breadth of bacterial community was also notably increased in the SPC group. The levels of total carbon (TC), total nitrogen (TN), and phosphates within pond sediment in the SPC group were obviously lower than those in the SMC group, and were significantly correlated with the microbial communities, with TC being identified as the primary contributor driving changes in the microbial communities. All the findings collectively demonstrate that the polyculture of river crabs with mandarin fish, silver carp, and the stone moroko enhances the stability of bacterial, fungal, and protistan communities in sediment and enhances resource utilization efficiency in aquaculture, thereby preventing the environmental risks associated with excessive nutrient accumulation in sediment. Polyculture systems integrating river crabs with mandarin fish, silver carp, and the stone moroko represent a sustainable aquaculture model with significant ecological benefits. Full article

Sulfonamides represent a versatile class of biologically active compounds, best known for their antibacterial activity, but increasingly investigated for their potential in oncology. Free sulfonamides themselves display cytotoxic properties; however, coordination with metal ions often enhances both selectivity and potency, while also introducing new mechanisms of action. Although numerous studies have reported sulfonamide–metal complexes with anticancer activity, a systematic overview linking biological properties to the central metal atom has been lacking. This review summarizes current research on sulfonamide complexes with transition metals and selected main-group elements, focusing on their pharmacological potential as anticancer agents. The compounds discussed include complexes of titanium, chromium, manganese, rhenium, ruthenium, osmium, iridium, palladium, platinum, copper, silver, gold, iron, cobalt, nickel, uranium, calcium, magnesium and bismuth. For each group, representative structures are presented along with cytotoxicity data against cancer cell lines, comparisons with reference drugs such as for example cisplatin, and where relevant, studies on carbonic anhydrase inhibition. The survey of available data demonstrates that many sulfonamide–metal complexes show cytotoxic activity comparable to or greater than existing chemotherapeutic agents, while in some cases exhibiting reduced toxicity toward non-cancerous cells. These findings highlight the promise of sulfonamide–metal complexes as a fertile area for anticancer drug development and provide a framework for future design strategies. This review covers the research on anti-cancer activity of sulfonamide complexes during the years 2007–2025. Full article

This review summarizes recent advances in photoactive nanomaterials containing metals and their biomedical applications, particularly in cancer diagnosis and therapy. Conventional approaches such as chemotherapy and radiotherapy suffer from low specificity, systemic toxicity, and resistance, while light-based therapies, including photothermal therapy (PTT) and photodynamic therapy (PDT), offer minimally invasive and localized alternatives. Metal nanomaterials, especially gold and silver, exhibit unique localized surface plasmon resonance (LSPR) effects that enable efficient light-to-heat or light-to-reactive oxygen conversion, supporting precise tumor ablation, drug delivery, and imaging. We discuss strategies for structural design, surface functionalization, and encapsulation to enhance stability, targeting, and therapeutic efficiency. Emerging hybrid systems, such as carbon-based nanostructures and metal–organic frameworks, are also considered for their complementary properties. Computational modeling tools, including finite element and discrete dipole approximations, are highlighted for predicting nanomaterial performance and guiding rational design. Finally, we critically assess challenges such as toxicity, long-term biocompatibility, and clinical translation, and provide perspectives for future development. By integrating materials design, simulation, and preclinical findings, this review aims to inform the advancement of safer and more effective nanotechnology-based platforms for personalized cancer treatment and diagnosis. Full article

Precision and real-time detection of hydrogen peroxide (H₂O₂) are essential in pharmaceutical, industrial, and defence sectors due to its strong oxidizing nature. In this study, silver (Ag)-doped CeO₂/Ag₂O-modified glassy carbon electrode (Ag-CeO₂/Ag₂O/GCE) has been developed as a non-enzymatic electrochemical sensor for the sensitive and selective detection of H₂O₂. The synthesized Ag-doped CeO₂/Ag₂O nanocomposite was characterized using various advanced techniques, including X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FT-IR), field-emission scanning electron microscopy (FE-SEM), and high-resolution transmission electron microscopy (HR-TEM). Their optical, magnetic, thermal, and chemical properties were further analyzed using UV–vis spectroscopy, electron paramagnetic resonance (EPR), thermogravimetric-differential thermal analysis (TG-DTA), and X-ray photoelectron spectroscopy (XPS). Electrochemical sensing performance was evaluated using cyclic voltammetry and amperometry. The Ag-CeO₂/Ag₂O/GCE exhibited superior electrocatalytic activity for H₂O₂, attributed to the increased number of active sites and enhanced electron transfer. The sensor displayed a high sensitivity of 2.728 µA cm⁻² µM⁻¹, significantly outperforming the undoped CeO₂/GCE (0.0404 µA cm⁻² µM⁻¹). The limit of detection (LOD) and limit of quantification (LOQ) were found to be 6.34 µM and 21.1 µM, respectively, within a broad linear detection range of 1 × 10⁻⁸ to 0.5 × 10⁻³ M. The sensor also demonstrated excellent selectivity with minimal interference from common analytes, along with outstanding storage stability, reproducibility, and repeatability. Owing to these attributes, the Ag-CeO₂/Ag₂O/GCE sensor proved effective for real sample analysis, showcasing its potential as a reliable, non-enzymatic platform for H₂O₂ detection. Full article

A large amount of CO₂ is released into the atmosphere by energy and industrial plants resulting in significant environment impacts. A considerable effort went into decreasing CO₂ emissions. The carboxylation reaction of converting CO₂ with aromatic alkynes to important chemicals such as carboxylic acids is one of the promising CO₂ utilization methods, and it can be performed in the catalytic or non-catalytic pathway. Our review article provides an overview of recent publications on the use of catalytic systems with different compositions and structures for the carboxylation of terminal alkynes by involving CO₂, and the effect of a solvent and base. Relying on the research results, the use of heterogeneous catalysts is the most effective. The advantage of catalytic systems is a lower reaction temperature and pressure. Heterogeneous silver-containing catalysts exhibit good yields of products and high selectivity. Moreover, the catalysts may lose their efficiency when interacting with moisture. It has been found that the most effective catalysts for the carboxylation of phenylacetylene with carbon dioxide as a carboxylating agent are copper-based catalysts. These catalysts are characterized by high activity and stability. We highlight the challenges of developing novel catalyst systems tuning catalytic properties. The future outlook and perspectives are also discussed. Full article

Environmental contamination is a critical global concern, primarily due to detrimental greenhouse gas (GHG) emissions, especially carbon dioxide (CO₂), which significantly contribute to climate change. Moreover, the presence of harmful heavy metals like Ni, Cd, Cu, Hg, and Pb in soil and water ecosystems has led to poor water quality. Noble metal nanoparticles (MNPs), for instance, Pd, Ag, Pt, and Au, have emerged as promising solutions for addressing environmental pollution. However, the practical utilization of MNPs faces challenges as they tend to aggregate and lose stability. To overcome this issue, the reverse double-solvent method (RDSM) was utilized to synthesis melamine-based porous polyaminals (POPs) as a supportive material for the in situ growing of silver nanoparticles (Ag NPs). The porous structure of melamine-based porous polyaminals, featuring aminal-linked (-HN-C-NH-) and triazine groups, provides excellent binding sites for capturing Ag⁺ ions, thereby improving the dispersion and stability of the nanoparticles. The resulting material exhibited ultrafine particle sizes for Ag NPs, and the incorporation of Ag NPs within the porous polyaminals demonstrated a high surface area (~279 m²/g) and total pore volume (1.21 cm³/g), encompassing micropores and mesopores. Additionally, the Ag NPs@POPs showcased significant capacity for CO₂ capture (2.99 mmol/g at 273 K and 1 bar) and effectively removed Cu (II), with a remarkable removal efficiency of 99.04%. The nitrogen-rich porous polyaminals offer promising prospects for immobilizing and encapsulating Ag nanoparticles, making them outstanding adsorbents for selectively capturing carbon dioxide and removing metal ions. Pursuing this approach holds immense potential for various environmental applications. Full article

Public health concerns related to food contaminants, including biotoxins, pesticide and veterinary drug residues, illegal additives, foodborne pathogens, and heavy metals, have garnered significant public attention in recent years. Consequently, there is an urgent need to develop rapid and accurate technologies to detect these harmful substances. Surface-enhanced Raman spectroscopy (SERS), due to its characteristics of high sensitivity and specificity enabling the detection of food contaminants within complex matrices, has attracted widespread interest. This review focuses on the application of noble metal-based nanocomposites as SERS-active substrates for food contaminant detection. It particularly highlights the structure–performance relationships of metallic nanomaterials, including gold and silver nanoparticles (e.g., nanospheres, nanostars, nanorods), bimetallic structures (e.g., Au@Ag core–shell), as well as metal–nonmetal composite nanomaterials such as semiconductor-based, carbon-based, and porous framework-based materials. All of which play a crucial role in achieving effective Raman signal enhancement. Furthermore, the significant applications in detecting various contaminants and distinct advantages in terms of the sensitivity and selectivity of noble metal-based nanomaterials are also discussed. Finally, this review addresses current challenges associated with SERS technology based on noble metal-based nanomaterials and proposes corresponding strategies alongside future perspectives. Full article

During the roasting, leaching, and electrodeposition of zinc ores, lead–silver residues are produced. These residues contain valuable metals (Pb, Zn, and Ag) and toxic metals (Cd and As). In this study, a pyrometallurgical process is proposed for treating Pb-Ag residues, consisting of drying, roasting, and reduction steps to recover valuable metals, such as silver in a metallic Pb phase, while converting the waste into an environmentally friendly slag. First, the Pb-Ag residue is dried at 100 °C, then roasted at 700 °C, and finally reduced at a high temperature, with Na₂CO₃ as a flux and CaSi as a reducing agent, rather than carbon-based reducing agents (carbon or carbon monoxide), to minimize greenhouse gas production. The effects of the reduction temperature and the mass of the reducing agent were investigated on a laboratory scale. The metallic phase and slag obtained in the reduction step were characterized by their chemical composition and mineralogy via chemical analysis, X-ray diffraction, and SEM-EDS. The results showed that silver and lead formed a metallic phase, and that silver content decreased from 1700 ppm in the Pb-Ag residue to 32 ppm in the final slag at 1300 °C. The Pb-Ag residue and final slag were leached with an aqueous acetic acid solution to evaluate their chemical stability. Full article

Silver is a promising electrocatalyst for electrochemical CO₂ reduction reaction owing to its high selectivity and efficiency for CO production. However, it still faces a fundamental trade-off between reaction activity and stability. Here, we developed a three-dimensional coral-like porous silver (CP-Ag) catalyst through seed-assisted nanoparticle attachment synthesis, which creates a unique architecture featuring interconnected pores and stable grain boundaries (GBs) between constituent Ag nanoparticles (Ag NPs). Compared to normal Ag NPs, CP-Ag demonstrates superior catalytic performance, maintaining >90% Faradaic efficiency (FE) for CO across a wide potential range (−0.6 to −1.0 V vs. RHE) while achieving 2-times higher current density. Importantly, CP-Ag demonstrated an impressive long-term stability by sustaining nearly 90% FE for CO approximately 40 h at a current density of −50 mA cm⁻² in a flow cell. The enhanced catalytic performance arises from three factors: (1) the three-dimensional coral-like morphology increases accessible active sites and promotes charge transfer efficiency; (2) stable GBs between interconnected nanoparticles increase reaction activity; (3) more moderate binding on Ag (100) preferentially promotes *CO intermediate formation. Our findings highlight the importance of simultaneously engineering both morphological and crystallographic features to optimize silver catalysts for CO₂ conversion. Full article