An Evolved Strain of the Oleaginous Yeast Rhodotorula toruloides, Multi-Tolerant to the Major Inhibitors Present in Lignocellulosic Hydrolysates, Exhibits an Altered Cell Envelope

The presence of toxic compounds in lignocellulosic hydrolysates (LCH) is among the main barriers affecting the efficiency of lignocellulose-based fermentation processes, in particular, to produce biofuels, hindering the production of intracellular lipids by oleaginous yeasts. These microbial oils are promising sustainable alternatives to vegetable oils for biodiesel production. In this study, we explored adaptive laboratory evolution (ALE), under methanol- and high glycerol concentration-induced selective pressures, to improve the robustness of a Rhodotorula toruloides strain, previously selected to produce lipids from sugar beet hydrolysates by completely using the major C (carbon) sources present. An evolved strain, multi-tolerant not only to methanol but to four major inhibitors present in LCH (acetic acid, formic acid, hydroxymethylfurfural, and furfural) was isolated and the mechanisms underlying such multi-tolerance were examined, at the cellular envelope level. Results indicate that the evolved multi-tolerant strain has a cell wall that is less susceptible to zymolyase and a decreased permeability, based on the propidium iodide fluorescent probe, in the absence or presence of those inhibitors. The improved performance of this multi-tolerant strain for lipid production from a synthetic lignocellulosic hydrolysate medium, supplemented with those inhibitors, was confirmed.

Suppression of Methanol and Formate Crossover through Sulfanilic-Functionalized Holey Graphene as Proton Exchange Membranes

Proton exchange membranes with high proton conductivity and low crossover of fuel molecules are required to realize advanced fuel-cell technology. The selective transportation of protons, which occurs by blocking the transportation of fuel molecules across a proton exchange membrane, is crucial to suppress crossover while maintaining a high proton conductivity. In this study, a simple yet powerful method is proposed for optimizing the crossover-conductivity relationship by pasting sulfanilic-functionalized holey graphenes onto a Nafion membrane. The results show that the sulfanilic-functionalized holey graphenes supported by the membrane suppresses the crossover by 89% in methanol and 80% in formate compared with that in the self-assembled Nafion membrane; an ≈60% reduction is observed in the proton conductivity. This method exhibits the potential for application in advanced fuel cells that use methanol and formic acid as chemical fuels to achieve high energy efficiency.

Evaluation and Improvement of Bio-Based Sustainable Resin Derived from Formic-Acid-Modified Epoxidized Soybean Oil for Packaging Applications

Bio-based epoxy resin materials have obtained significant attention in the packaging industry due to concerns about the environmental and economic impacts of traditional petroleum-based plastics. The aim of this research is to improve bio-based resins' properties by investigating varying formic acid contents in the presence of a green catalyst and characterizing their physical, chemical, and mechanical properties for further scaled-up bio-based resin production for industrial packaging applications. The crude soybean oil was epoxidized with formic acid as an oxidizing agent at varying equivalent weights of 10:1 to 10:10 of soybean oil: formic acid in the presence of hydrogen peroxide and choline chloride-oxalic acid as a bi-functional green catalyst. The effect of increasing the amount of formic acid used to epoxidize crude soybean oil was evaluated with infrared (IR) spectroscopy, rheological, and epoxy yield measurements. The results demonstrated that formic acid significantly influenced the epoxidation of soybean oil, leading to a higher conversion of carbon-carbon double bonds, with a selectivity of 98% when the ratio of soybean oil to formic acid was between 10:5 and 10:10. The bio-resin film was formulated using the improved epoxidized soybean oils-from ESO (10:2.5) to ESO (10:10)-and equal amounts of acrylic acid. The results showed that resin films led to an improvement in tensile strength (ca. 180 MPa) and thermal stability at 360 °C. Although further research is necessary, this study provides valuable insights for designing an effective epoxidation process for renewable sources and developing bio-resin materials for future packaging applications.

Calcined Chitosan/Cellulous Aerogel Modified with Copper Oxide Nanoparticles as an Efficient Sorbent for the Optimized Removal of Formic Acid from Water

A porous aerogel sorbent was prepared by the carbonization of a biohydrogel consisting of cellulose and chitosan (CS/CE) biopolymers. The adsorbent was also modified with copper oxide nanoparticles to effectively remove formic acid from water in batch mode. Characterization techniques, including scanning electron microscopy, Fourier transform infrared, Brunauer-Emmett-Teller, and X-ray diffraction, were employed to study the prepared sorbents. The concentration of formic acid in the solution was exactly determined by using liquid chromatography. To achieve maximum removal efficiency, important process variables were optimized using a central composite design data-based algorithm. Under optimal conditions, i.e., the initial concentration of 167.98 mg/L, the amount of sorbent equal to 75.28 mg, the contact time of 10.41 min, and the sample volume of 22.56 mL, a maximum acid removal efficiency of 84% was obtained. The Langmuir isotherm model was appropriately fitted to the experimental data, which indicates the chemical interaction of the sorbent active sites with formic acid. An adsorption capacity of 116.28 mg/g was also attained. The adsorption followed a pseudo-second-order kinetic pattern. According to the thermodynamic criteria, the adsorption of formic acid on the copper oxide-modified aerogel was exothermic, entropy-reducing, and favorable at temperatures lower than 290 K. Based on the results, CS/CE hydrogels comprising CuO nanoparticles are promising precursors for synthesizing carbonized aerogel sorbents that are successful in removing formic acid from aqueous environments.

Pt-Coated Ni Layer Supported on Ni Foam for Enhanced Electro-Oxidation of Formic Acid

A Pt-coated Ni layer supported on a Ni foam catalyst (denoted PtNi/Nifoam) was investigated for the electro-oxidation of the formic acid (FAO) in acidic media. The prepared PtNi/Nifoam catalyst was studied as a function of the formic acid (FA) concentration at bare Pt and PtNi/Nifoam catalysts. The catalytic activity of the PtNi/Nifoam catalysts, studied on the basis of the ratio of the direct and indirect current peaks (jd)/(jnd) for the FAO reaction, showed values approximately 10 times higher compared to those on bare Pt, particularly at low FA concentrations, reflecting the superiority of the former catalysts for the electro-oxidation of FA to CO2. Ni foams provide a large surface area for the FAO, while synergistic effects between Pt nanoparticles and Ni-oxy species layer on Ni foams contribute significantly to the enhanced electro-oxidation of FA via the direct pathway, making it almost equal to the indirect pathway, particularly at low FA concentrations.

Salmonella Control in Fattening Pigs through the Use of Esterified Formic Acid in Drinking Water Shortly before Slaughter

The presence of Salmonella in pig feces is a major source of abattoir and carcass contamination, and one of the main sources of human salmonellosis. This study assessed whether using a form of esterified formic acid (30% formic acid) in drinking water (10 kg/1000 L) 5 days before slaughter could be a helpful strategy to mitigate this public health issue. Thus, 240 pigs from three Salmonella-positive commercial fattening farms were selected. From each farm, 40 pigs were allocated to a control group (CG) and 40 to a treatment group (TG). At the abattoir, fecal samples from both groups were collected for Salmonella detection (ISO 6579-1:2017) and quantification (ISO/TS 6579-2:2012). Salmonella was present in 35% (95% IC = 29.24-41.23) of the samples collected. The prevalence was significantly higher in the CG than in the TG (50% vs. 20%; p < 0.001). In all farms, the TG showed a lower percentage of shedders than the CG. A random-effects logistic model showed that the odds of shedding Salmonella were 5.63 times higher (95% CI = 2.92-10.8) for the CG than for the TG. Thus, the proportion of pigs shedding Salmonella that was prevented in the TG due to the use of this form of organic acid was 82.2%. In addition, a Chi-squared analysis for trends showed that the higher the Salmonella count, the higher the odds of the sample belonging to the CG. These results suggest that adding this type of acid to drinking water 5 days before slaughter could reduce the proportion of Salmonella-shedding pigs and the Salmonella loads in the guts of shedder pigs.

Controlled One-Step Synthesis of MOF-on-MOF Cocatalysts for Two-Channel Electrocatalytic Conversion of CO2 to Formic Acid

The synthesis of efficient and highly selective catalysts and rational reactor design play decisive roles in the industrial application of the electrocatalytic carbon dioxide reduction reaction (CO₂ RR). In this study, a dual-metal-organic framework (MOF) copper-based catalytic electrode is designed and prepared in one step by in situ synthesis on a foamed copper substrate. The MOF-on-MOF structure can effectively inhibit the generation of H₂ and CO, and further enhance the selectivity of HCOOH. Furthermore, by using cheap and durable poly(tetrafluoroethylene) (PTFE) instead of an expensive and fragile GDE, the optimized reactor design improves the stability and durability of the gas channel and the replaceability of the electrode. The structure-optimized reactor has a maximum Faradaic efficiency of 89.2% in neutral medium, and an average current density of 26.1 mA cm^-2 in the flow cell, which has comparable performance to a GDE and can continue to operate stably. The use of PTFE improves the service life of the gas mass transfer channel, and the independent catalytic electrode can provide good catalytic efficiency. These results provide new insights into the reaction mechanism of structurally recombined double MOFs and PTFE-optimized CO₂ RR reactor designs, providing technical support for the practical industrial application of the CO₂ RR.

Computational Studies on Microreactors for the Decomposition of Formic Acid for Hydrogen Production Using Heterogeneous Catalysts

Sustainable alternatives to conventional fuels have emerged recently, focusing on a hydrogen-based economy. The idea of using hydrogen (H₂) as an energy carrier is very promising due to its zero-emission properties. The present study investigates the formic acid (FA) decomposition for H₂ generation using a commercial 5 wt.% Pd/C catalyst. Three different 2D microreactor configurations (packed bed, single membrane, and double membrane) were studied using computational fluid dynamics (CFD). Parameters such as temperature, porosity, concentration, and flow rate of reactant were investigated. The packed bed configuration resulted in high conversions, but due to catalyst poisoning by carbon monoxide (CO), the catalytic activity decreased with time. For the single and double membrane microreactors, the same trends were observed, but the double membrane microreactor showed superior performance compared with the other configurations. Conversions higher than 80% were achieved, and even though deactivation decreased the conversion after 1 h of reaction, the selective removal of CO from the system with the use of membranes lead to an increase in the conversion afterwards. These results prove that the incorporation of membranes in the system for the separation of CO is improving the efficiency of the microreactor.

Effect of dual sintering with laser irradiation and thermal treatment on printed copper nanoparticle patterns

The dual sintering of copper (Cu) nanoparticles (NPs) was introduced to produce conductive patterns suitable for flexible electronics applications. In this method, laser irradiation using a Nd:YAG laser with a wavelength of 1064 nm was performed at laser powers of 400, 600, and 800 mJ. The laser irradiation time was 15 and 30 s for each laser power. After laser irradiation, all of the Cu NP patterns were thermally sintered under formic acid (FA) vapors. The temperature and time for thermal sintering were selected as 260 °C and 15 min, respectively. The resultant physical, chemical, electrical and mechanical properties were evaluated and compared considering the six different dual sintering conditions. The Cu NP patterns sintered using 800 mJ for 30 s showed increased necking and coalescence compared to the other patterns and featured a microstructure with increased density. Despite being oxidized, the Cu NP patterns sintered with 800 mJ for 30 s showed the lowest electrical resistivity of 11.25 μΩ·cm. The surface of every sintered Cu pattern was oxidized, and mechanical hardness increased with increasing laser power. The Cu NP pattern sintered with 800 mJ for 30 s demonstrated the highest hardness of 48.64 N/mm2. After sintering using the six different conditions, the Cu NP patterns exhibited a weight loss of 0.02-3.87 wt%, and their roughness varied in the range of 26.15-74.08 nm. This can be attributed to the effective removal of organic residues and the degree of particle agglomeration. After performing folding tests up to 50 cycles, Cu NP patterns showed an upward trend in resistance with increasing laser power and time. The highest and lowest resistance ratios were observed as 3.97 and 17.24 for the patterns sintered at 400 mJ for 15 s and 800 mJ for 30 s, respectively.

Novel Electrospun Composite Membranes Based on Polyhydroxybutyrate and Poly(vinyl formate) Loaded with Protonated Montmorillonite for Organic Dye Removal: Kinetic and Isotherm Studies

The use of biodegradable polyesters derived from green sources and their combination with natural abundantly layered aluminosilicate clay, e.g., natural montmorillonite, meets the requirements for the development of new sustainable, disposable, and biodegradable organic dye sorbent materials. In this regard, novel electrospun composite fibers, based on poly β-hydroxybutyrate (PHB) and in situ synthesized poly(vinyl formate) (PVF), loaded with protonated montmorillonite (MMT-H) were prepared via electrospinning in the presence of formic acid, a volatile solvent for polymers and a protonating agent for the pristine MMT-Na. The morphology and structure of electrospun composite fibers were investigated through SEM, TEM, AFM, FT-IR, and XRD analyses. The contact angle (CA) measurements showed increased hydrophilicity of the composite fibers incorporated with MMT-H. The electrospun fibrous mats were evaluated as membranes for removing cationic (methylene blue) and anionic (Congo red) dyes. PHB/MMT 20% and PVF/MMT 30% showed significant performance in dye removal compared with the other matrices. PHB/MMT 20% was the best electrospun mat for adsorbing Congo red. The PVF/MMT 30% fibrous membrane exhibited the optimum activity for the adsorption of methylene blue and Congo red dyes.

Phase-Inversion Induced 3D Electrode for Direct Acidic Electroreduction CO2 to Formic acid

Direct electrochemical CO₂ reduction to formic acid (FA) instead of formate is a challenging task due to the high acidity of FA and competitive hydrogen evolution reaction. Herein, 3D porous electrode (TDPE) is prepared by a simple phase inversion method, which can electrochemically reduce CO₂ to FA in acidic conditions. Owing to interconnected channels, high porosity, and appropriate wettability, TDPE not only improves mass transport, but also realizes pH gradient to build higher local pH micro-environment under acidic conditions for CO₂ reduction compared with planar electrode and gas diffusion electrode. Kinetic isotopic effect experiments demonstrate that the proton transfer becomes the rate-determining step at the pH of 1.8; however, not significant in neutral solution, suggesting that the proton is aiding the overall kinetics. Maximum FA Faradaic efficiency of 89.2% has been reached at pH 2.7 in a flow cell, generating FA concentration of 0.1 m. Integrating catalyst and gas-liquid partition layer into a single electrode structure by phase inversion method paves a facile avenue for direct production of FA by electrochemical CO₂ reduction.

Resource degradation of pharmacy sludge in sub-supercritical system with high degradation rate of 99% and formic acid yield of 32.44

In response to the social goal of 'carbon peak and carbon neutral' in the 14th Five-Year Plan of China, this article used Enrofloxacin (ENR), a common antibiotic, as a model compound to study the method of efficiently degrading pharmaceutical sludge and simultaneously producing Formic Acid (FA), hydrogen storage energy, in a sub-supercritical system. The Ni/SnO2 bimetallic catalyst, which was prepared by the equal volume impregnation method, was used for the liquid phase catalysis. As shown by the results, when the reaction temperature was 330°C, and the addition amount of H2O2 was 0.38 mL, the degradation rate of antibiotics could reach 99% after the reaction proceeded for 6 h. In terms of the resource utilization, the yield of FA could reach up to 32.44%. The resource utilization efficiency with Ni/SnO2 catalyst in sub-/supercritical reaction was about 2.5 times higher than that without catalyst. The kinetic reaction model was established to explore the reaction rate of the antibiotic degradation process. In addition, the Ea and the frequency factor of the reaction were 6455 J/mol and 5.78, respectively. As shown by characterization, the prepared Ni/SnO2 bimetallic catalyst had good activity and has already passed repeated stability experiments. In short, this method has broad application prospects in antibiotic catalysis and resource degradation.

Preparation and Photocatalytic Performance of MoS2/MoO2 Composite Catalyst

Solar energy is an inexhaustible clean energy providing a key solution to the dual challenges of energy and environmental crises. Graphite-like layered molybdenum disulfide (MoS₂) is a promising photocatalytic material with three different crystal structures, 1T, 2H and 3R, each with distinct photoelectric properties. In this paper, 1T-MoS₂ and 2H-MoS₂, which are widely used in photocatalytic hydrogen evolution, were combined with MoO₂ to form composite catalysts using a bottom-up one-step hydrothermal method. The microstructure and morphology of the composite catalysts were studied by XRD, SEM, BET, XPS and EIS. The prepared catalysts were used in the photocatalytic hydrogen evolution of formic acid. The results show that MoS₂/MoO₂ composite catalysts have an excellent catalytic effect on hydrogen evolution from formic acid. By analyzing the photocatalytic hydrogen production performance of composite catalysts, it suggests that the properties of MoS₂ composite catalysts with different polymorphs are distinct, and different content of MoO₂ also bring differences. Among the composite catalysts, 2H-MoS₂/MoO₂ composite catalysts with 48% MoO₂ content show the best performance. The hydrogen yield is 960 µmol/h, which is 1.2 times pure 2H-MoS₂ and two times pure MoO₂. The hydrogen selectivity reaches 75%, which is 22% times higher than that of pure 2H-MoS₂ and 30% higher than that of MoO₂. The excellent performance of the 2H-MoS₂/MoO₂ composite catalyst is mainly due to the formation of the heterogeneous structure between MoS₂ and MoO₂, which improves the migration of photogenerated carriers and reduces the possibilities of recombination through the internal electric field. MoS₂/MoO₂ composite catalyst provides a cheap and efficient solution for photocatalytic hydrogen production from formic acid.

Efficient Conversion of Biomass to Formic Acid Coupled with Low Energy Consumption Hydrogen Production from Water Electrolysis

The development of a new electrolytic water hydrogen production coupling system is the key to realize efficient and low-cost hydrogen production and promote its practical application. Herein, a green and efficient electrocatalytic biomass to formic acid (FA) coupled hydrogen production system has been developed. In such system, carbohydrates such as glucose are oxidized to FA using polyoxometalates (POMs) as the redox anolyte, while H2 is evolved continuously at the cathode. Among them, the yield of glucose to FA is as high as 62.5%, and FA is the only liquid-product. Furthermore, the system requires only 1.22 V to drive a current density of 50 mA·cm-2, and the Faraday efficiency of hydrogen production is close to 100%. Its electrical consumption is only 2.9 kWh·Nm-3(H2), which is only 69% of that of traditional electrolytic water. This work opens up a promising direction for the low-cost hydrogen production coupled with efficient biomass conversion.

Efficient [Fe-Imidazole@SiO2] Nanohybrids for Catalytic H2 Production from Formic Acid

Three imidazole-based hybrid materials, coded as IGOPS, IPS and impyridine@SiO₂ nanohybrids, were prepared via the covalent immobilization of N-ligands onto a mesoporous nano-SiO₂ matrix for H₂ generation from formic acid (FA). BET and HRTEM demonstrated that the immobilization of the imidazole derivative onto SiO₂ has a significant effect on the SSA, average pore volume, and particle size distribution. In the context of FA dehydrogenation, their catalytic activity (TONs, TOFs), stability, and reusability were assessed. Additionally, the homologous homogeneous counterparts were evaluated for comparison purposes. Mapping the redox potential of solution E_h vs. SHE revealed that poly-phosphine PP₃ plays an essential role in FA dehydrogenation. On the basis of performance and stability, [Fe²⁺/IGOPS/PP₃] demonstrated superior activity compared to other heterogeneous catalysts, producing 9.82 L of gases (VH₂ + CO₂) with TONs = 31,778, albeit with low recyclability. In contrast, [Fe²⁺/IPS/PP₃] showed the highest stability, retaining considerable performance after three consecutive uses. With VH₂ + CO₂ = 7.8 L, [Fe²⁺/impyridine@SiO₂/PP₃] activity decreased, and it was no longer recyclable. However, the homogeneous equivalent of [Fe²⁺/impyridine/PP₃] was completely inactive. Raman, FT/IR, and UV/Vis spectroscopy demonstrated that the reduced recyclability of [Fe²⁺/IGOPS/PP₃] and [Fe²⁺/impyridine@SiO₂/PP₃] nanohybrids is due to the reductive cleavage of their C-O-C bonds during catalysis. An alternative grafting procedure is proposed, applying here to the grafting of IPS, resulting in its higher stability. The accumulation of water derived from substrate's feeding causes the inhibition of catalysis. In the case of [Fe²⁺-imidazole@SiO₂] nanohybrids, simple washing and drying result in their re-activation, overcoming the water inhibition. Thus, the low-cost imidazole-based nanohybrids IGOPS and IPS are capable of forming [Fe²⁺/IGOPS/PP₃] and [Fe²⁺/IPS/PP₃] heterogeneous catalytic systems with high stability and performance for FA dehydrogenation.

Hydrogen Production from Formic Acid by In Situ Generated Ni/CdS Photocatalytic System under Visible Light Irradiation

Simple and practical noble-metal-free catalyzed hydrogen production from sustainable resources, such as renewable formic acid, is highly desirable. Herein, the development of an efficient photocatalytic hydrogen production from aqueous solution of formic acid using in situ generated Ni/CdS photocatalytic system was described. CdS-Cys (Cys=l-cysteine) quantum dots (QDs) acting as photocatalyst with Ni(OAc)₂ as H₂ production catalyst precursor, a 94 % yield was obtained within 5 h under visible light irradiation at 50 °C. The average rate of H₂ production reached up to 282 μmol mg^-1  h^-1 with 99.8 % H₂ selectivity. Mechanistic studies indicate cooperation of dynamic quenching and static quenching of CdS-Cys QDs by Ni(OAc)₂ . Especially, Ni⁰ , generated in the dynamic quenching, accelerated the electron transfer by acting as an electron outlet and enhancing the stability of CdS to slow down the photocorrosion distinctly, delivering efficient H₂ production with high selectivity. Our study will inspire exploration of various efficient non-noble-metal catalysts for practical H₂ production from bio-based formic acid.

Nanophase-Separated Copper-Zirconia Composites for Bifunctional Electrochemical CO2 Conversion to Formic Acid

A copper-zirconia composite having an evenly distributed lamellar texture, Cu#ZrO₂, was synthesized by promoting nanophase separation of the Cu₅₁Zr₁₄ alloy precursor in a mixture of carbon monoxide (CO) and oxygen (O₂). High-resolution electron microscopy revealed that the material consists of interchangeable Cu and t-ZrO₂ phases with an average thickness of 5 nm. Cu#ZrO₂ exhibited enhanced selectivity toward the generation of formic acid (HCOOH) by electrochemical reduction of carbon dioxide (CO₂) in aqueous media at a Faradaic efficiency of 83.5% at -0.9 V versus the reversible hydrogen electrode. In situ Raman spectroscopy has revealed that a bifunctional interplay between the Zr⁴⁺ sites and the Cu boundary leads to amended reaction selectivity along with a large number of catalytic sites.

Highly Efficient Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol over CoRe/TiO2 Catalyst

Allylic alcohols typically produced through selective hydrogenation of α,β-unsaturated aldehydes are important intermediates in fine chemical industry, but it is still a challenge to achieve its high selectivity transformation. Herein, we report a series of TiO₂-supported CoRe bimetallic catalysts for the selective hydrogenation of cinnamaldehyde (CAL) to cinnamyl alcohol (COL) using formic acid (FA) as a hydrogen donor. The resultant catalyst with the optimized Co/Re ratio of 1:1 can achieve an exceptional COL selectivity of 89% with a CAL conversion of 99% under mild conditions of 140 °C for 4 h, and the catalyst can be reused four times without loss of activity. Meanwhile, the Co₁Re₁/TiO₂/FA system was efficient for the selective hydrogenation of various α,β-unsaturated aldehydes to the corresponding α,β-unsaturated alcohols. The presence of ReO_x on the Co₁Re₁/TiO₂ catalyst surface was advantageous to the adsorption of C=O, and the ultrafine Co nanoparticles provided abundant hydrogenation active sites for the selective hydrogenation. Moreover, FA as a hydrogen donor improved the selectivity to α,β-unsaturated alcohols.

Study of the mechanism underlying the role of PINK1/Parkin in the formic acid-induced autophagy of PC12 cells

This study aimed to explore PINK1/Parkin's role in methanol metabolite formic acid-induced autophagy in PC12 cells and provide a theoretical basis for elucidating methanol-induced neurotoxicity. After treatment with different formic acid concentrations, we observed the morphology and mitochondria of PC12 cells. We used an ultra-micro enzyme kit to detect the mitochondrial Na⁺ -K⁺ -ATPase and Ca²⁺ -Mg²⁺ -ATPase activities; a JC-1 kit to detect changes in the mitochondrial membrane potential (MMP); MDC staining to detect the autophagy levels; and western blotting to measure the expression levels of the mitochondrial marker protein COX IV and the autophagy-related proteins Beclin1, P62 and LC3II/LC3I, and the mitochondrial and cytoplasmic levels of PINK1, Parkin and P-Parkin. Compared with the control group, the mitochondrial diameters, the mitochondrial Na⁺ -K⁺ -ATP and Ca²⁺ -Mg²⁺ -ATPase activities, the MMP, and the COX IV expression levels decreased significantly (P < 0.05). The fluorescence signal intensity (indicating autophagy); relative Beclin1 and LC3II/LC3I protein expression levels; and relative mitochondrial PINK1, Parkin and P-Parkin levels increased significantly, and the relative P62 protein expression levels and relative cytoplasmic PINK1, Parkin and P-Parkin levels decreased significantly (P < 0.05) compared with the control group. Thus, formic acid alters mitochondrial morphology, causes mitochondrial dysfunction, affects the PINK/Parkin pathway and, thus, activates the process of mitochondrial autophagy.

Low-Temperature Transient Liquid Phase Bonding Technology via Cu Porous-Sn58Bi Solid-Liquid System under Formic Acid Atmosphere

This study proposes a low-temperature transient liquid phase bonding (TLPB) method using Sn58Bi/porous Cu/Sn58Bi to enable efficient power-device packaging at high temperatures. The bonding mechanism is attributed to the rapid reaction between porous Cu and Sn58Bi solder, leading to the formation of intermetallic compounds with high melting point at low temperatures. The present paper investigates the effects of bonding atmosphere, bonding time, and external pressure on the shear strength of metal joints. Under formic acid (FA) atmosphere, Cu₆Sn₅ forms at the porous Cu foil/Sn58Bi interface, and some of it transforms into Cu₃Sn. External pressure significantly reduces the micropores and thickness of the joint interconnection layer, resulting in a ductile fracture failure mode. The metal joint obtained under a pressure of 10 MPa at 250 °C for 5 min exhibits outstanding bonding mechanical performance with a shear strength of 62.2 MPa.

Selective Valorization of Glycerol to Formic Acid on a BiVO4 Photoanode through NiFe Phenolic Networks

The integration of the glycerol oxidation reaction (GOR) with the hydrogen evolution reaction in photoelectrochemical (PEC) cells is a desirable alternative to PEC water splitting since a large quantity of glycerol is easily accessible as the byproduct from the biodiesel industry. However, the PEC valorization of glycerol to the value-added products suffers from low Faradaic efficiency and selectivity, especially in acidic conditions, which is beneficial for hydrogen production. Herein, by loading bismuth vanadate (BVO) with a robust catalyst composed of phenolic ligands (tannic acid) coordinated with Ni and Fe ions (TANF), we demonstrate a modified BVO/TANF photoanode for the GOR with a remarkable Faradaic efficiency of over 94% to value-added molecules in a 0.1 M Na₂SO₄/H₂SO₄ (pH = 2) electrolyte. The BVO/TANF photoanode achieved a high photocurrent of 5.26 mA·cm^-2 at 1.23 V versus reversible hydrogen electrode under 100 mW/cm² white light irradiation for formic acid production with 85% selectivity, equivalent to 573 mmol/(m²·h). Transient photocurrent and transient photovoltage techniques and electrochemical impedance spectroscopy along with intensity-modulated photocurrent spectroscopy indicated that the TANF catalyst could accelerate hole transfer kinetics and suppress charge recombination. Comprehensive mechanistic investigations reveal that the GOR is initiated by the photogenerated holes of BVO, while the high selectivity to formic acid is attributed to the selective adsorption of primary hydroxyl groups in glycerol on TANF. This study provides a promising avenue for highly efficient and selective formic acid generation from biomass in acid media via PEC cells.

Renewing Lost Genetic Variability with a Classical Yeast Genetics Approach

Due to their long domestication time course, many industrial Saccharomyces cerevisiae strains are adopted in numerous processes mostly for historical reasons instead of scientific and technological needs. As such, there is still significant room for improvement for industrial yeast strains relying on yeast biodiversity. This paper strives to regenerate biodiversity with the innovative application of classic genetic methods to already available yeast strains. Extensive sporulation was indeed applied to three different yeast strains, specifically selected for their different origins as well as backgrounds, with the aim of clarifying how new variability was generated. A novel and easy method to obtain mono-spore colonies was specifically developed, and, to reveal the extent of the generated variability, no selection after sporulation was introduced. The obtained progenies were then tested for their growth in defined mediums with high stressor levels. A considerable and strain-specific increase in both phenotypic and metabolomic variability was assessed, and a few mono-spore colonies were found to be of great interest for their future exploitation in selected industrial processes.

Phase Transformation during the Selective Dissolution of a Cu85Pd15 Alloy: Nucleation Kinetics and Contribution to Electrocatalytic Activity

This study determined the critical parameters for the morphological development of the electrode surface (the critical potential and the critical charge) during anodic selective dissolution of a Cu-Pd alloy with a volume concentration of 15 at.% palladium. When the critical values were exceeded, a phase transition occurred with the formation of palladium's own phase. Chronoamperometry aided in the determination of the partial rates of copper ionization and phase transformation of palladium under overcritical selective dissolution conditions. The study determined that the formation of a new palladium phase is controlled by a surface diffusion of the ad-atom to the growing three-dimensional nucleus under instantaneous activation of the nucleation centres. We also identified the role of this process in the formation of the electrocatalytic activity of the anodically modified alloy during electro-oxidation of formic acid. This study demonstrated that HCOOH is only oxidated at a relatively high rate on the surface of the Cu₈₅Pd₁₅ alloy, which is subjected to selective dissolution under overcritical conditions. This can be explained by the fact that during selective dissolution of the alloy, a pure palladium phase is formed on its highly developed surface which has prominent catalytic activity towards the electro-oxidation of formic acid. The rate of electro-oxidation of HCOOH on the surface of the anodically modified alloy increased with the growth of the potential and the charge of selective dissolution, which can be used to obtain an electrode palladium electrocatalyst with a set level of electrocatalytic activity towards the anodic oxidation of formic acid.

Ru Catalysts Supported on Bamboo-like N-Doped Carbon Nanotubes: Activity and Stability in Oxidizing and Reducing Environment

The catalysts with platinum-group metals on nanostructured carbons have been a very active field of research, but the studies were mainly limited to Pt and Pd. Here, Ru catalysts based on nitrogen-doped carbon nanotubes (N-CNTs) have been prepared and thoroughly characterized; Ru loading was kept constant (3 wt.%), while the degree of N-doping was varied (from 0 to 4.8 at.%) to evaluate its influence on the state of supported metal. Using the N-CNTs afforded ultrafine Ru particles (<2 nm) and allowed a portion of Ru to be stabilized in an atomic state. The presence of Ru single atoms in Ru/N-CNTs expectedly increased catalytic activity and selectivity in the formic acid decomposition (FAD) but had no effect in catalytic wet air oxidation (CWAO) of phenol, thus arguing against a key role of single-atom catalysis in the latter case. A remarkable difference between these two reactions was also found in regard to catalyst stability. In the course of FAD, no changes in the support or supported species or reaction rate were observed even at a high temperature (150 °C). In CWAO, although 100% conversions were still achievable in repeated runs, the oxidizing environment caused partial destruction of N-CNTs and progressive deactivation of the Ru surface by carbonaceous deposits. These findings add important new knowledge about the properties and applicability of Ru@C nanosystems.

Epiglottis Cartilage, Costal Cartilage, and Intervertebral Disc Cartilage as Alternative Materials in the Postmortem Diagnosis of Methanol Poisoning

Alternative materials for postmortem diagnosis in the case of fatal poisonings are much needed when standard materials, such as blood and urine, are unavailable. The study presents a case of fatal mass methanol intoxication resulting from industrial alcohol consumption. The study aimed to determine methanol and formic acid concentrations in epiglottis cartilage, costal cartilage, and intervertebral disc cartilage and to analyze the correlation between their concentrations in cartilage tissues and the femoral blood. Methanol and formic acid concentrations in samples collected from 17 individuals (n = 17) were estimated using gas chromatography with flame ionization detection (GC-FID). Methanol concentration in the costal cartilage correlated with its concentration in the femoral blood (r = 0.871). Similar correlations were found for epiglottis cartilage (r = 0.822) and intervertebral disc cartilage (r = 0.892). Formic acid concentration in the blood correlated only with its concentration in urine (r = 0.784) and the epiglottis (r = 0.538). Cartilage tissue could serve as an alternative material for methanol analyses in postmortem studies. Formic acid, a methanol metabolite, does not meet the requirements for its presence determination in cartilage tissues.