Search Results (200)

Sulfur-containing amino acids (SCAA) and their metabolites constitute an integrated metabolic network essential for central nervous system (CNS) function. In mammals, sulfur metabolism links one-carbon metabolism, the methionine cycle and the transsulfuration pathway, thereby connecting nutrient availability with redox regulation, methylation reactions, neurotransmitter synthesis and cellular adaptation to stress. Among these metabolites, methionine, cysteine, glutathione, taurine, homocysteine and hydrogen sulfide play key roles in neuronal physiology, mitochondrial homeostasis, synaptic plasticity and antioxidant defense. Alterations in SCAA metabolism have been increasingly associated with neurological and neurodevelopment disorders, which share common features such as oxidative stress, mitochondrial dysfunction, altered glutamatergic signaling, impaired methylation capacity and neuroinflammation. These pathological mechanisms are also observed following exposure to toxic metals, suggesting the existence of convergent pathways between environmental neurotoxicity and neurological diseases. Several studies showed that chronic exposure to arsenic, mercury, cadmium, lead, and other toxic metals disrupts sulfur amino acid homeostasis by affecting methionine remethylation, transsulfuration activity, glutathione synthesis and reactive sulfur species production. Due to sulfur-containing metabolites possessing antioxidant and metal-binding properties, these pathways are also involved in adaptive detoxification response. However, sustained disruption of sulfur metabolism may compromise neuronal resilience and increase vulnerability to neurological dysfunction. This narrative review integrates current evidence on the physiological roles of SCAA in the CNS, and examines how toxic metals disrupt sulfur metabolic pathways. By combining findings from experimental studies, human data and exploratory transcriptomic analyses, we propose that disruption of SCAA homeostasis represents a mechanistic link between environmental metal exposure and increased vulnerability to neurological disease. Full article

The mechanism of cadmium (Cd) accumulation was analyzed in the marine alga Ulva compressa. The alga was cultivated with 10 µM Cd, with 10 µM of Cd and increasing concentrations of a sulfide donor (NaHS), or with a sulfide acceptor (hypotaurine), and intracellular Cd levels were monitored for 7 d. Glutathione (GSH) and phytochelatins (PCs) levels, and metallothioneins (MTs) transcript levels were also quantified, along with the extrusion of Cd, GSH, and PCs to the culture medium. The results showed that the sulfide donor increased intracellular Cd levels, whereas the sulfide acceptor decreased them. GSH, PCs, and MTs levels did not correlate with intracellular Cd contents. Both Cd and GSH were extruded to the culture medium, along with lower amounts of PCs. TEM-EDXS analysis revealed electron-dense nanoparticles containing Cd and O, likely CdO or Cd bound to fatty acids; in the presence of NaHS, nanoparticles containing Cd and S (likely CdS) or Cd, S, and N (likely Cd bound to GSH) were also observed. In conclusion, Cd accumulates as insoluble nanoparticles—probably not bound to GSH, PCs, or MTs—and is extruded to the culture medium together with GSH in the marine alga U. compressa. Full article

Thin-film solar cells (TFSCs) remain a cornerstone of the global transition toward renewable energy, characterized by consistent reductions in manufacturing costs and steady gains in power conversion efficiency. In addition to electricity generation, TFSCs play an important role in advanced solar thermal cooling, heating, and energy storage systems, where their tunable optical absorption, low thermal mass, and flexibility enable integration with photovoltaic–thermal (PV/T) collectors, thermally driven cooling cycles, and hybrid thermal–electrical storage architectures. This paper provides a comprehensive review of prominent TFSC technologies, including copper indium gallium selenide (CIGS), cadmium telluride (CdTe/CdS), amorphous silicon (a-Si), copper zinc tin sulfide (CZTS), organic photovoltaics (OPVs), and metal halide perovskite solar cells (PSCs), with a focus on their material structures, performance specifications, and current efficiency benchmarks. Compared to state-of-the-art reviews, this article distinguishes itself by addressing next-generation innovations, cross-domain solar thermal–photovoltaic applications, and economic analysis. Specifically, the integration of machine learning and simulation-based material dynamics is examined to accelerate material discovery, process optimization, and the characterization of novel TFPV components relevant to coupled thermal–electrical energy systems. Furthermore, the study explores how additive manufacturing is transforming the industry through the development of high-efficiency electrodes, electrohydrodynamic atomization for thin-film deposition, and the fabrication of flexible solar arrays suitable for thermally integrated and building-scale energy systems, including space applications. By integrating advancements in module efficiency, scalable manufacturing approaches, and techno-economic analysis, this paper positions TFSCs as sustainable, resource-abundant technologies essential for next-generation solar thermal cooling, heating, and energy storage infrastructures. Full article

Photocatalytic water splitting for hydrogen (H₂) evolution is a critical sustainable energy strategy, and cadmium sulfide (CdS) is a promising visible-light photocatalyst due to its suitable band gap. However, the practical application of pure CdS is severely hindered by rapid charge-carrier recombination and significant photocorrosion. In this work, we constructed a CdS/vanadium carbide (VC) photocatalyst via a simple ultrasonic method. The structural, morphological, optical, and photoelectrochemical properties of the composites were systematically investigated. Under visible light (λ ≥ 420 nm) and with 0.35 M Na₂S-0.25 M Na₂SO₃ as the sacrificial agent, the optimized composite featuring a CdS:VC mass ratio of 10:1 (denoted CV-10) achieved a remarkable hydrogen evolution rate of 3485.6 μmol g⁻¹ h⁻¹. This rate represents a 60-fold enhancement over pure-phase CdS and significantly surpasses that of a conventional Pt/CdS catalyst. Furthermore, the CV-10 composite demonstrated excellent stability, showing no activity decay after 16 h of cycling. Spectroscopic and electrochemical analyses revealed that the metallic VC can function as an efficient cocatalyst, accelerating charge separation and transfer while suppressing electron–hole recombination. This work demonstrates that noble-metal-free VC is a highly effective and low-cost cocatalyst, providing a new pathway for designing efficient and stable CdS-based photocatalysts in solar hydrogen production. Full article

With the rapid development of the edible fungus industry, the environmental pressure and resource waste caused by the massive generation of fungal residue have become increasingly prominent. Meanwhile, heavy metal wastewater pollution and the growing demand for clean energy pose dual challenges to sustainable development. This study focuses on Auricularia cornea var. Li. fungal residue, exploring the establishment of a multi-level resource utilization pathway integrating “porous carbon material preparation—heavy metal adsorption—photocatalytic hydrogen evolution.” Firstly, the Auricularia cornea var. Li. residue-based porous carbon material was examined by combining hydrothermal carbonization, activation and slow pyrolysis. In optimal conditions, the porous carbon obtained yielded a surface area of 675.56 m²/g and formed a composite pore structure consisting of micropores with coexisting micropore and mesopore. Secondly, we performed batch adsorption experiments to study the effects of solution pH, adsorbent dosage and contact time and the adsorption behavior via fitting adsorbing kinetic models. Under optimal conditions, Cd(II) removal efficiency reached 92.36% and an equilibrium adsorption capacity of 92.47 mg/g. We used Cd(II) adsorbed porous carbon as a cadmium source and converted into a CdS photocatalyst using a hydrothermal sulfidation process. The CdS prepared using sodium sulfide as a sulfur source gave an average hydrogen evolution rate of 668.01 μmol·g⁻¹·h⁻¹ and showed higher photocatalytic performance for water splitting to produce hydrogen. Full article

To improve the visible-light response and antibacterial performance of titanium dioxide, a TiO₂/GO/CdS mesoporous nanocomposite was prepared via an ultrasound-assisted sol–gel method in this study. Systematic characterizations including XRD, XPS, SEM, TEM, BET, UV-Vis DRS and FTIR were carried out to analyze the structure, morphology and optical properties of the material. The results show that the composite exhibits a typical mesoporous structure with a specific surface area of 197.0962 m²/g and a pore size distribution of 2–14 nm. CdS is successfully doped into the TiO₂ matrix and forms a heterostructure with GO. UV-Vis diffuse reflectance spectra indicate that the synergistic effect of CdS and GO significantly broadens the visible-light absorption range of TiO₂ and suppresses the recombination of photogenerated carriers. Antibacterial tests using Escherichia coli as the target strain demonstrate that the TiO₂/GO/CdS composite exhibits remarkably better visible-light photocatalytic bactericidal activity than pure TiO₂ and the TiO₂/GO composite. This work provides a new strategy for the modification of TiO₂-based photocatalytic antibacterial materials, and the as-prepared composite shows promising application prospects in the antibacterial field. Full article

The efficient photocatalytic generation of hydrogen peroxide (H₂O₂) from pure water remains a formidable challenge, primarily due to the rapid recombination of photogenerated electron–hole pairs and insufficient redox potentials inherent in single-component photocatalysts. To address these issues, we designed and synthesized a heterojunction material comprising cadmium sulfide nanoparticles loaded on carbon spheres (CS@CdS). Under conditions utilizing pure water and ambient air, the CS@CdS composite achieves an H₂O₂ production rate of 1305 μmol·g⁻¹·h⁻¹, which is 3.1 and 3.6 times higher than that of pure CdS and CS, respectively, without the need for any sacrificial agents or external oxygen supply. Systematic characterization reveals that CS and CdS form a tightly coupled electronic interface, which significantly accelerates charge carrier separation and effectively prolongs the lifetime of photogenerated carriers, thereby boosting photocatalytic performance. Furthermore, the CS component extends the visible-light absorption range of the composite and functions as an electron acceptor to suppress charge recombination, collectively endowing CS@CdS with enhanced photocatalytic activity. Mechanistic studies indicate that H₂O₂ production over CS@CdS proceeds predominantly via a two-step single-electron oxygen reduction reaction (ORR) pathway. This work offers a viable strategy for constructing CS-based heterojunction photocatalysts for efficient H₂O₂ synthesis. Full article

Thallium (Tl) and cadmium (Cd) are highly toxic heavy metals that frequently co-occur in sulfide ores, posing a serious food safety risk through accumulation in rice. Although calcium-based (Ca-based) amendments have been widely applied to remediate heavy metal-contaminated soils, their effectiveness in Tl–Cd co-contaminated paddy soils remains unclear. A pot experiment was conducted to evaluate four Ca-based amendments—limestone powder, dolomite powder, hydrated lime, and oyster shell powder—on Tl and Cd bioavailability and uptake in paddy soil near a mining area. Ca-based amendments effectively reduced Tl and Cd bioavailability, with DTPA-Tl reducing by 11.2–17.2% and DTPA-Cd by 8.9–21.3%. These reductions were attributed to increased soil pH and decreased DOC, Fe, and Mn in the pore water. Additionally, Ca-based amendments shifted Tl and Cd from acid-extractable to residual fractions, reducing mobility. Additionally, Ca-based amendments promoted Fe/Mn plaque formation on rice roots, reducing Tl and Cd uptake. Consequently, Tl and Cd concentrations in brown rice decreased by over 14%, with the lowest levels observed under oyster shell powder. However, Cd concentrations still exceeded the maximum permissible limit, indicating that, although Ca-based amendments show considerable potential for in situ remediation of Tl–Cd co-contaminated paddy soils, further optimization and additional measures are required to achieve safe production. Full article

Polyaniline-cadmium sulfide-gold (PANI-CdS-Au) nanocomposites were synthesized with varying Au loadings (0.023, 0.046, 0.092 wt%) to enhance antibacterial performance. Structural (FTIR, XRD) and morphological (FESEM) analyses confirmed successful formation, with nearly homogeneous nanoparticle distribution (27–53 nm) and slight XRD peak shifts indicating interfacial interactions between PANI, CdS, and Au. UV–Vis spectra revealed gold surface plasmon resonance and polaronic transitions consistent with PANI emeraldine base. XRD results showed the expected wurtzite CdS and fcc Au phases. Agar well diffusion tests against Escherichia coli (Gram-negative) and Staphylococcus aureus (Gram-positive) demonstrated that the 0.092 wt% of Au composite produced the largest inhibition zones at 100 µg mL⁻¹ (E. coli: 36 mm; S. aureus: 24 mm), with the same trend at 25 µg mL⁻¹. The results indicate that PANI–CdS/Au nanocomposites are promising antibacterial materials; however, the presence of CdS necessitates additional cytotoxicity assays to confirm their suitability for medical applications. Full article

The sustainable management of balneological resources is vital for the development of eco-friendly health tourism and regional economic stability. This study presents a comprehensive physicochemical and eco-toxicological characterization of the therapeutic peloids (mud) from Lake Maly Akkol, which is located in the Zhambyl region of Kazakhstan. Utilizing an integrated approach of laboratory analysis and Python-based statistical modeling, we evaluated the resource’s clinical potential and environmental safety. The results identify the deposit as a high-quality sulfide–silt peloid with a mean humidity of 66.91% (95% CI: [65.21, 68.60]) and a mineralization level of 11.21 g/dm³ (95% CI: [10.84, 11.57]). Statistical validation using one-sample t-tests confirmed that critical therapeutic indicators, including shear strength ($\mu$ = 2593.72 dyne/cm²) and total sulfide content ($\mu$ = 0.079%), are significantly aligned with international balneological standards (p < 0.05). Eco-toxicological screening for heavy metals revealed that Lead (37.03 mg/kg) and Cadmium (0.06 mg/kg) remain well below safety thresholds, ensuring the resource’s “clean” environmental profile. These findings establish a statistically robust “Digital Quality Passport” for the Lake Maly Akkol deposit, providing the scientific foundation necessary for its sustainable industrial utilization and long-term ecological preservation. Full article

A new fluorescence detection method for PO₄³⁻ was developed through the in situ synthesis of cadmium sulfide quantum dots (CdS QDs). Without PO₄³⁻, the CdS QDs could not be effectively formed by only the S²⁻ and Cd²⁺ in the solution. As a stabilizer, PO₄³⁻ is an essential component to regulate the in situ synthesis of CdS QDs. The fluorescence intensity following the addition of different concentrations of PO₄³⁻ was monitored for quantification. Under optimum conditions, the fluorescence intensity shows a linear relationship with concentrations ranging from 3.0 to 300 µM, and a detection limit of 2.9 µM. This assay was successfully employed to assess PO₄³⁻ in tap water and wastewater. Compared with traditional methods, which require pre-synthesizing QDs and tethering them with recognition elements to achieve sample detection, the proposed method is simpler and quicker. It takes less than 5 min to complete PO₄³⁻ detection. Full article

Rice (Oryza sativa L.) readily accumulates cadmium (Cd), posing dietary exposure risks in populations dependent on rice-based diets. This study investigated how sulfur (S) redox processes regulate Cd mobility in S-deficient, Cd-contaminated paddy soil under waterlogged conditions. A pot experiment was conducted with two S treatments (−S and +S, 30 mg kg⁻¹) throughout the rice growing season. S addition markedly increased pore water S²⁻ concentrations during early growth (tillering) and mid-season (booting) and suppressed the diffusion of SO₄²⁻ from non-rhizosphere to rhizosphere at later stages (filling–maturity). Consequently, Cd in soil pore water was significantly lower in +S than −S treatments at all stages. Sulfur-amended soil showed a redistribution of Cd from labile fractions (exchangeable and carbonate-bound) to more stable fractions (Fe/Mn oxide-bound). Sulfur application also altered the rhizosphere microbiome: the relative abundance of sulfate-reducing bacteria (SRB) increased at the booting and filling stages, while sulfur-oxidizing bacteria (SOB) became more dominant at maturity. Additionally, +S enhanced Cd sequestration on rice root iron plaque by 32–67% during the grain-filling and maturity stages compared to −S. Throughout the rice growing period, redox-driven shifts in the S²⁻/SO₄²⁻ ratio emerged as a key control on Cd behavior, with low pe + pH (strongly reducing conditions) promoting Cd sulfide precipitation and high pe + pH (more oxidizing conditions) causing Cd remobilization. Full article

The Sichuan–Yunnan–Guizhou Pb-Zn metallogenic belt (SYG metallogenic belt), a crucial metallogenic unit on the southwestern margin of the Yangtze Block, is a key part of the South China low-temperature metallogenic domain. The incorporation mechanisms and distribution of trace elements (e.g., Ge, Ga, Cd) widely enriched in Pb-Zn sulfides throughout this region remain poorly understood. This study investigates main-ore-stage sulfides (sphalerite and pyrite) from the Maoping Pb-Zn deposit using in situ laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) analyses and mapping to systematically elucidate the partitioning and occurrence of these trace elements. The key findings are as follows: (1) Sulfides show distinct elemental partitioning: sphalerite preferentially concentrates Cd, Ag, Ge, Ga, and Se, whereas pyrite is significantly enriched in Mn, Ni, As, and Co. (2) Sphalerite is the primary host for many trace elements. Cadmium, Ge, Mn, Cu, and Ag mainly enter the sphalerite lattice by substituting for Zn²⁺. Coupled substitution mechanisms, such as Zn²⁺ ↔ Cd²⁺, 2Zn²⁺ ↔ Ge²⁺ + Cu²⁺, and 2Zn²⁺ ↔ Ga³⁺ + Cu⁺, facilitate the incorporation of Ge and Ga. (3) The sphalerite exhibits a trace element assemblage of high Cd-Ge and low Fe-Mn, which is geochemically similar to typical Mississippi Valley-type (MVT) deposits and differs significantly from sedimentary exhalative (SEDEX) and magmatic–hydrothermal deposits, indicating a medium- to low-temperature metallogenic environment. Based on these geochemical signatures and epigenetic textures, we confirm that the Maoping Pb-Zn deposit exhibits similarities with MVT deposits. Nevertheless, distinct differences in the tectonic setting and metal grades suggest it is a unique SYG-type Pb-Zn deposit. Full article

Cadmium sulfide is an important II-VI semiconductor known for its valuable photocatalytic properties ascribable to its band gap energy, which allows light absorption in the visible domain. Nonetheless, the application of cadmium sulfide in wastewater organic pollutant degradation is restricted due to its high toxicity to humans, soil, and marine life. To address this issue, we developed new composite materials by depositing CdS on a bentonite support in a 1:9 mass ratio to develop a photocatalyst with lower toxicity. In the first step, bentonite was activated using an aqueous HCl solution; for the deposition of CdS powder, we proposed the trituration method and compared it with chemical precipitation and hydrothermal synthesis, using thioacetamide as a sulfide ion source. The modified bentonite underwent characterization using X-ray diffraction, scanning electron microscopy, X-ray fluorescence, UV-Vis, and FTIR spectroscopy. The photocatalytic activity was tested in the degradation of Congo red (CR), a persistent diazo dye. The efficiency of removing CR with CdS–bentonite composites depended on the deposition method of CdS, and it was higher than that of pristine CdS and of only adsorption onto acid-activated bentonite. The photocatalytic degradation mechanism was estimated by the scavenger test using ethylenediaminetetraacetic acid disodium salt, ascorbic acid, ethanol, and silver nitrate as radical scavengers. Full article

Resistance to conventional antibiotics remains a global health challenge. The search for more effective antimicrobial agents has led to the consideration of nanoparticles due to their potential biocidal activities. This study synthesized, characterized, and evaluated the antimicrobial behavior of cadmium sulfide nanoparticles (CdS NPs) during incubations at 37 °C and at room temperature (rt; 23 to 27 °C). XRD results showed that the synthesized nanoparticles had a cubic zinc blende structure, while microscopic investigations confirmed the particle size to be 7.236 nm on average. UV-Vis spectroscopy showed that the nanoparticles are active in the visible light region. Raman spectroscopy results showed peaks at 302.3 cm⁻¹ and 601 cm⁻¹, which represent the first- and second-order longitudinal optical phonon. Agar well diffusion, minimum inhibitory concentration (MIC), and minimum bactericidal concentration (MBC) assays were conducted to investigate the antimicrobial activity of CdS NPs (50 mg/mL, 25 mg/mL, and 10 mg/mL) against Escherichia coli and Staphylococcus aureus. CdS NPs were effective against both test organisms. However, they were more effective against Gram-negative E. coli. The higher the concentration of CdS NPs, the more effective they were against the test organisms. Furthermore, MBC results showed greater bactericidal activity of CdS NPs at 37 °C. With increasing incidences of antimicrobial resistance against conventional antimicrobial agents, especially in wastewater treatment, nanoparticles are considered promising alternatives and the next generation of antimicrobial agents. Full article