Search Results (16,094)

Given automotive PEMFCs’ susceptibility to thermal runaway and uneven temperature distribution under high-power-density operation, this study proposes a novel embedded pulsating heat pipe cooling system. The core innovations of this work are threefold, fundamentally distinguishing it from prior PHP cooling approaches: (1) an embedded PHP cooling plate design that integrates the heat pipe within a unified copper plate, eliminating the need for external attachment or complex bipolar plate channels and enhancing structural compactness; (2) a system-level modeling methodology that derives an effective thermal conductivity (k_eff ≈ 65,000 W·m⁻¹·K⁻¹) from a thermal resistance network for seamless integration into a full-stack CFD model, significantly simplifying the simulation of the passive PHP component; and (3) a parametric system-level optimization of the secondary active cooling loop. Numerical results demonstrate that the system achieves an exceptional maximum temperature difference (ΔT_max) of less than 1.7 K within the PEMFC stack at an optimal coolant flow rate of 0.11 m/s, far surpassing the performance of conventional liquid cooling baselines. This three-layer framework (PHP heat transfer, cooling plate conduction, liquid coolant convection) offers robust theoretical and design support for high-efficiency, passive-dominant thermal control of automotive fuel cells. Full article

Tyrosinase (EC 1.14.18.1) is a binuclear copper enzyme responsible for the rate-limiting steps of melanogenesis, catalyzing the hydroxylation of L-tyrosine and oxidation of L-DOPA into o-quinones that polymerize melanin. Beyond its physiological role in pigmentation, tyrosinase is also implicated in food browning and oxidative stress–related disorders, making it a key target in cosmetic, food, and biomedical industries. This systematic review, conducted following PRISMA guidelines, aimed to identify and analyze microbial metabolites with tyrosinase inhibitory potential as sustainable alternatives to conventional inhibitors such as hydroquinone and kojic acid. Literature searches in Scopus and Web of Science (March 2025) yielded 156 records; after screening and applying inclusion criteria, 11 studies were retained for analysis. The inhibitors identified include indole derivatives, phenolic acids, peptides, and triterpenoids, mainly produced by fungi (e.g., Ganoderma lucidum, Trichoderma sp.), actinobacteria (Streptomyces, Massilia), and microalgae (Spirulina, Synechococcus). Reported IC₅₀ values ranged from micromolar to milli-molar levels, with methyl lucidenate F (32.23 µM) and p-coumaric acid (52.71 mM). Mechanisms involved competitive and non-competitive inhibition, as well as gene-level regulation. However, methodological heterogeneity, the predominance of mushroom tyrosinase assays, and limited human enzyme validation constrain translational relevance. Computational modeling, site-directed mutagenesis, and molecular dynamics are proposed to overcome these limitations. Overall, microbial metabolites exhibit promising efficacy, stability, and biocompatibility, positioning them as emerging preclinical candidates for the development of safer and more sustainable tyrosinase inhibitors. Full article

Grapevine downy mildew is a major disease in vineyards all around the world, caused by the oomycete Plasmopara viticola (Berk. & M. A. Curtis) Berl. & De Toni. Normally, its control depends almost exclusively on chemical and copper-based fungicides, especially in high-incidence areas with high relative humidity and mild temperatures. However, the European Union is determined to reduce the application of these phytochemicals by at least 50% by 2030, forcing winegrowers to seek alternative low-input strategies for proper sanitary maintenance. Basic substances (BSs), described in European Regulation (EC) 1107/2009, stand out as promising alternatives, but their molecular mechanism of action remains mostly unknown. In this context, this study analyzed the genetic effect in grapevine plants of several commercial products composed of BSs (chitosan, soy lecithin, Equisetum arvense and Salix cortex). All products exhibited promising results, triggering the induction of similar defence mechanisms, which included pathogenesis-related proteins (PRs), involved in direct pathogen repression; stilbenes, capable of producing antimicrobial compounds such as resveratrol and pterostilbene; several hormones, including oxylipins, ethylene, salicylic acid and terpenes, mediating immune signalling; and genes related to structural features of the plant, such as lignin, callose, cellulose and cuticular wax, constituting a first physiological barrier against P. viticola. Disease severity reduction differed among treatments, with Salix cortex showing the highest efficacy (58%), followed by BABA (38%) and LESOY (35%), while LECI and CHIT had minor effects (<9%). Gene expression analyses revealed that Salix cortex modulated the highest percentage of genes (41%), followed by natural infection without treatment (32%), LESOY (27%), BABA (26%), LECI (23%) and CHIT (23%). In terms of defence mechanisms, Salix cortex promoted the most pathways, LESOY induced eight, BABA and LECI seven and CHIT five. Overall, these results indicate that BSs can modulate several defence pathways in grapevine, supporting their potential use as sustainable alternatives for controlling downy mildew. Full article

The connectivity demands of high-performance computing (HPC), artificial intelligence (AI) and data centers are driving the development of a new generation of multimode optical components. This paper discusses the vertical cavity surface emitting laser (VCSEL) bandwidth and noise performance needed to support 106 Gbd line rates with PAM4 modulation for 200 Gbps per lane multimode optical links. A −3 dB bandwidth greater than 35 GHz and a RIN of less than −152 dB/Hz are demonstrated. No uncorrectable errors were observed over 50 m of OM4 fiber, demonstrating good link stability. VCSEL device performance and the associated wear-out life are presented. Leveraging good device reliability and low power consumption of VCSEL-based links, a novel VCSEL near-packaged optics (NPO) concept is proposed for optical interconnects in AI scale-up network applications. Optical interconnects allow for longer reaches, compared to copper interconnects, which facilitate larger AI clusters with network disaggregation. The proposed VCSEL NPO can achieve an energy efficiency of ~1 pJ/bit, which is the highest among optical interconnects. Full article

It is undeniable that rapid population increase coupled with growing resource constraints are making the demand for smart and sustainable solutions more urgent than ever to secure future resources for the transition to sustainable energy production. To address these issues, it is necessary to define innovative approaches that can exploit more efficiently and extensively the resources we have at our disposal. Consequently, this paper provides an overview of the potential benefits of processing waste-printed circuit boards (WPCBs) that are generated in large quantities and, due to their high metal content, can emerge as an adequate and profitable supply of critical metals, such as copper, aluminum, and nickel, which are essential for green energy transition. The review promotes the idea of industrial symbiosis as a concept that goes beyond circular economy and can integrate WPCB treatment and manufacturing processes related to sustainable energy transition, although they are different industrial sectors that can be even regionally separated. Major metal recovery processes from WPCBs are examined and discussed, with the primary focus on the performances of copper, aluminum, and nickel production, while additional metals relevant to the energy transition are also highlighted. Finally, the review paper argues and exemplifies that the recovered metals from WPCBs have the required properties to be supplied into the manufacturing processes of wind turbines, solar panels, and lithium-ion batteries. Full article

Background/Objectives: Trace metals, including copper (Cu) and zinc, are associated with the development and prognosis of hepatocellular carcinoma (HCC). However, their interference with magnetic resonance imaging (MRI) limits their use as potential biomarkers. This study investigated the usefulness of Synchrotron Radiation–excited X-ray Fluorescence (SR-XRF) imaging in studying the distribution of trace metals in HCC. Methods: This case–control study analyzed 33 specimens from 32 patients with HCC who underwent surgical resection (n = 29) or biopsy (n = 3) at Kobe University Hospital between December 1999 and November 2002. The findings of SR-XRF were compared with those of MRI and histopathology. Results: SR-XRF provided two-dimensional mapping of trace metal distribution with high spatial resolution (1.0 µm). The mean tumor-to-liver ratio (TLR) of Cu content was significantly higher in well-differentiated HCCs than in moderately and poorly differentiated HCCs (p < 0.05). Moreover, the mean TLRs of Cu content were significantly higher in high-intensity lesions than in iso- or low-intensity lesions on T1-weighted imaging (p < 0.05). Conclusions: This study supports previous evidence of the involvement of Cu in HCC development, suggesting its potential as a clinical biomarker for diagnosis and disease progression. Additionally, the results demonstrate that SR-XRF has potential for clinical application due to its ability to map trace metal distribution at high resolution. These findings suggest, rather than demonstrate, the association among Cu accumulation, tumor differentiation, and MRI signal characteristics. Full article

The global energy transition (ET) is widely portrayed as a technological shift toward low-carbon systems; however, it also entails profound geopolitical and socio-environmental transformations. While energy justice (EJ) has become a key framework for assessing fairness in energy systems, it seldom incorporates the geopolitical restructuring of material, energy, and economic flows that underpin contemporary transitions. This article develops a geopolitically informed approach to EJ, trying to capture how the new flows of energy, matter, and power shape—and are shaped by—enduring centre–periphery inequalities. Using a guided literature synthesis that combines EJ, political ecology, decolonial critiques, and green extractivism, the study enhances classical EJ tenets by incorporating transboundary flows, ecological unequal exchange, ontological plurality, and local self-determination. An illustrative application to copper extraction in Chile and Peru demonstrates how critical-mineral supply chains reproduce new sacrifice zones within emerging geopolitical configurations. By connecting local socio-environmental conflicts to global energy dynamics, the framework advances a more comprehensive, multidimensional approach to justice in the ET. The findings offer conceptual and practical insights for designing more equitable and geopolitically aware sustainability policies. Full article

Copper slag was introduced as a second phase into Cr₃C₂–NiCr coating to improve corrosion resistance and reduce material cost. Composite coatings with different copper slag/Cr₃C₂–NiCr ratios were prepared by high-velocity oxygen fuel (HVOF) spraying. The corrosion behavior was evaluated through electrochemical tests and immersion experiments, and the effect of coating composition on corrosion resistance was elucidated by microstructural and compositional analysis. To increase the addition of copper slag, the open-circuit potential of the coatings shifted positively, the corrosion current density decreased significantly, and both the polarization resistance and charge-transfer resistance increased markedly, leading to a notable reduction in corrosion rate. The coating with a copper slag-to-Cr₃C₂–NiCr mass ratio of 3:7 exhibited the best corrosion resistance. The improvement can be attributed to the reduced porosity and more compact structure resulting from the copper slag addition, as well as the homogeneous distribution of copper slag, which enhances the stability of the surface passivation layer. Full article

Immunogenic cell death (ICD) is a programmed pathway leading to cell death and promotion of immunological responses. Melanoma is resistant to chemotherapy and radiotherapy (RT). Disulfiram (DSF), which forms complexes with copper (Cu), has been shown to induce ICD of many tumor types. Here, we aim to investigate whether DSF/Cu combined with irradiation (IR) can induce ICD and exert anti-cancer effects in melanoma. In vitro experiments, treatment of MV3 and B16F10 melanoma cells with DSF/Cu + IR significantly increased the cellular apoptosis and increased ICD markers: damage-associated molecular pattern molecule (DAMP) exposure and release, including calreticulin cell surface expression, high-mobility group box 1 (HMGB1) release, and decreased intracellular ATP levels. In addition, DSF/Cu combined with IR treatment inhibited tumor growth and enhanced tumor-infiltrating immune cells in the B16F10-bearing C57BL/6 model. Our findings reveal that combining IR with DSF/Cu induces ICD and inhibits tumor growth in melanoma, providing a promising strategy to overcome the inherent resistance of RT in melanoma. Full article

Waste textiles may contain heavy metals, which can originate from dyes, mordants, or other chemical treatments used during manufacturing. To explore the impact of heavy metals on the adsorption properties of activated carbon derived from discarded textiles through pyrolysis and to mitigate heavy metal migration, this study investigated the adsorption behavior of copper-impregnated pyrolytic carbon toward typical pollutants—methylene blue and lead—in simulated dyeing wastewater. Aqueous copper nitrate was used to impregnate the waste pure cotton textiles (WPCTs) to introduce copper species as precursors for creating additional active sites. The study systematically examined adsorption mechanisms, single and binary adsorption systems, adsorption kinetics, adsorption isotherms, adsorption thermodynamics, and the influence of pH. Key findings and conclusions are as follows: Under optimal conditions, the copper-containing biochar (Cu-BC) demonstrated maximum adsorption capacities of 36.70 ± 1.54 mg/g for Pb(II) and 104.93 ± 8.71 mg/g for methylene blue. In a binary adsorption system, when the contaminant concentration reached 80 mg/L, the adsorption capacity of Cu-BC for Pb(II) was significantly enhanced, with the adsorption amount increasing by over 26%. However, when the Pb(II) concentration reached 40 mg/L, it inhibited the adsorption of contaminants, reducing the adsorption amount by 20%. SEM, XRD, Cu LMM, FTIR and XPS result analysis proves that the adsorption mechanism of methylene blue involves π–π interactions, hydrogen bonding, electrostatic interactions, and pore filling. For Pb(II) ions, the adsorption likely occurs via electrostatic interactions, complexation with functional groups, and pore filling. This study supplements the research content on the copper adsorption mechanism supported by biochar for heavy metal adsorption research and broadens the application scope of biochar in the field of heavy metal adsorption. Full article

Penaeus monodon is widely cultured in Asia; however, intensive farming practices often result in water-quality deterioration and compromised production performance. Copper-loaded montmorillonite (Cu-MMT) is a functional additive with adsorption and antimicrobial properties, yet the relative effectiveness of different application strategies remains insufficiently evaluated. In this study, 270 shrimp were assigned to three treatments: a control group (KZ), water application of Cu-MMT (PZ), and dietary inclusion of Cu-MMT (BZ). Juvenile Penaeus monodon with an initial body weight of 3.25 ± 0.15 g were used in the trial. Growth performance, intestinal histology, and rearing-water quality were assessed over a 56-day culture period. Shrimp in the BZ group exhibited a significantly higher weight gain rate (311.88 ± 38.17%) and survival rate (88.04%) than those in the KZ (247.45 ± 32.82%; 76.67%) and PZ (286.49 ± 29.78%; 83.33%) groups (p < 0.05). Intestinal histological observations revealed treatment-associated differences in morphology, with more pronounced intestinal enlargement observed in the PZ group, whereas the BZ group exhibited a more moderate intestinal architecture. Water-quality analyses showed that dietary Cu-MMT supplementation was associated with higher dissolved oxygen levels and lower concentrations of total ammonia nitrogen, sulfide, and dissolved iron, particularly during the later stages of the experiment. Overall, these results indicate that dietary inclusion of Cu-MMT provides more favorable outcomes than water application in improving growth performance and rearing-water quality in P. monodon culture under the experimental conditions tested. These findings highlight the importance of application strategy when evaluating functional additives in shrimp aquaculture. Full article

Metabolic bariatric surgery (MBS) induces substantial metabolic, inflammatory, and nutritional changes that can alter hemostatic balance through redox-dependent mechanisms. This systematic review evaluated coagulation disturbances after MBS with emphasis on oxidative stress and micronutrient deficiencies. A structured search of PubMed, Scopus, and Web of Science (2000–2025) identified 1707 records; 21 studies met inclusion criteria. Available evidence suggests that although MBS reduces obesity-related inflammation and oxidative burden in many patients, a proportion of individuals may present with persistent redox imbalance, elevated D-dimer or vWF (von Willebrand Factor), and delayed normalization of fibrinolysis. Micronutrient deficiencies—particularly vitamins K, B12, folate, selenium, zinc, and copper—are common after malabsorptive procedures and contribute to both thrombotic and hemorrhagic complications by impairing antioxidant defenses, endothelial function, and vitamin K-dependent coagulation pathways. Postoperative venous thromboembolism (VTE) incidence ranges from 0.3 to 0.5%, with higher risk after Roux-en-Y gastric bypass than sleeve gastrectomy, while bleeding is primarily associated with vitamin K deficiency, marginal ulcers, and anticoagulant exposure. The findings underscore the interdependence of oxidative stress, nutritional status, and hemostasis after MBS. Individualized thromboprophylaxis, routine detection of micronutrient deficiencies, and long-term biochemical monitoring are essential to maintain hemostatic stability. Standardized redox–hemostasis biomarker panels are needed to clarify mechanistic pathways and improve postoperative preventive strategies. Full article

In this study, copper–carbon material composites, Cu/CM (where CM is reduced graphene oxide (rGO), graphitic carbon nitride (g-C₃N₄), their mixture, and N-doped reduced graphene oxide (N-rGO)), were prepared using a simple method of chemical reduction of copper cations in the presence of CM related to molecular-level mixing methods. Additionally, copper cations from its oxides present in the composites were reduced in an electrochemical cell by depositing them on the surface of a horizontally positioned cathode. The structure and morphology of the Cu/CM composites were studied using electron microscopy and X-ray diffraction analysis. The thermal stability and elemental analysis were determined for the carbon materials. The resulting Cu/CM composites were used as electrocatalysts in the electrohydrogenation of the aromatic ketone, acetophenone. Cu/rGO and Cu/N-rGO composites with a 1:1 ratio exhibited catalytic activity in this process, increasing the rate of APh hydrogenation and its degree of conversion with the selective formation of a single product, methyl phenyl carbinol (or 1-phenylethanol), compared to the electrochemical reduction of APh on a cathode without a catalyst. The Cu/N-rGO composite demonstrated the highest electrocatalytic activity. Full article

The properties of chemically bonded core sands strongly depend on the reactivity of phenol-formaldehyde resole binders and on the granulometry of the sand matrix. This study presents an evaluation of the mechanical, technological, thermomechanical, and thermophysical properties of core sands prepared using two resole binders with different reactivity levels (Resin 1—lower reactivity; Resin 2—higher reactivity) and two fractions of quartz sand (BK 40 and BK 45). The investigations included the kinetics of strength development (1–48 h), friability, permeability, thermal deformation (DMA), and the determination of thermophysical coefficients (λ₂, a₂, b₂) based on temperature field registration during the solidification of a copper plate. The results indicate that sands containing the higher-reactivity binder exhibit a faster early strength increase (≈0.42–0.45 MPa after 1–3 h), whereas sands bonded with the lower-reactivity resin reach higher tensile strength after 24–48 h (≈0.58–0.62 MPa). Specimens based on BK 45 quartz sand achieved higher tensile strength; however, the finer grain fraction resulted in increased friability (up to ≈3.97%) and a reduction in permeability by 30–40%. DMA analysis confirmed that sands based on BK 40 exhibit delayed and more stable thermal deformation. Thermophysical parameters revealed that BK 45 provides significantly higher thermal insulation, extending the solidification time of the Cu plate from 71–73 s to 89–92 s compared with BK 40. Overall, the results indicate that the combination of BK 40 quartz sand and a lower-reactivity resin offers an optimal balance between thermal conductivity and thermal stability, promoting improved technological performance in casting processes. The determined thermophysical coefficients can be directly applied as input data for foundry process simulations. Full article

Developing sustainable and molecularly selective adsorbents for heavy-metal removal remains a critical challenge in water purification. Herein, we report a green molecular-engineering approach for fabricating aza-crown ether functionalized sodium alginate aerogels (ACSA) capable of highly selective Cu²⁺ capture. The aerogels were synthesized via saccharide-ring oxidation, Cu²⁺-templated self-assembly, and reductive amination, enabling the covalent integration of aza-crown ether motifs within a hierarchically porous biopolymer matrix. Structural analyses (FTIR, ¹³C NMR, XPS, SEM, TGA) confirmed the in situ formation of macrocyclic N/O coordination sites. Owing to their interconnected porosity and chemically stable framework, ACSA exhibited rapid sorption kinetics following a pseudo-second-order model (R² = 0.999) and a Langmuir maximum adsorption capacity of 150.82 mg·g⁻¹. The material displayed remarkable Cu²⁺ selectivity over Zn²⁺, Cd²⁺, and Ni²⁺, arising from the precise alignment between Cu²⁺ ionic radius (0.73 Å) and crown-cavity dimensions, synergistic N/O chelation, and Jahn-Teller stabilization. Over four regeneration cycles, ACSA retained more than 80% of its original adsorption capacity, confirming excellent durability and reusability. This saccharide-ring modification strategy eliminates crown-ether leaching and weak anchoring, offering a scalable and environmentally benign route to bio-based adsorbents that combine molecular recognition with structural stability for efficient Cu²⁺ remediation and beyond. Full article