Search Results (15,613)

2,3,5-triphenyl-2H-tetrazol-3-ium (TPT) chloride was studied through a combination of theoretical methods and experimental data, revealing structural and physical-chemical properties of the hydrate salt, [TPT]Cl^.H₂O. The previously reported crystal structure was confirmed, but our study at lower T (100 K vs. 220 K) showed different positions for the two H₂O molecules in the unit cell around the chlorides. One of them (Cl1) is found surrounded by the tetrazole units, which we call the “dry pocket”, in contrast to the other, Cl2, which is involved in a hydrogen bonding cluster that consists of chloride and two water molecules, referred to as the “wet pocket”. Hirshfeld surface analyses showed predominant H…H interactions, followed by C…H interactions (including C–H…Cl/O interactions), and H…Cl contacts, which represent the C–H…Cl2 hydrogen bonds. Density functional theory (DFT) and (time-dependent) TD-DFT calculations on a molecular model of the compound, benchmarking the three functionals B3LYP, CAM-B3LYP, and PBE1PBE, found excellent agreement with experimental solution data when using the CAM-B3LYP function. UV-Vis absorptions observed at 320 nm, 245 nm, and 204 nm (in MeOH solution) were quite accurately reproduced and assigned. The observed bands were assigned to mixed HOMO–n⟶LUMO+m transitions, involving in all cases the LUMO+1 for the most intense band at 245 nm. Solid-state calculations on the GGA (PBE) level of theory using the CASTEP code and including the Tkatchenko–Scheffler (TS) scheme for the description of long-range interactions gave a good match for the calculated electronic band gap in the solid-state of 3.54 eV compared with the experimental value of 3.12 eV obtained through the Tauc plot method. Full article

The objective of this study was to investigate the effects of replacing fishmeal with H. illucens larval meal on the colonic immune homeostasis in weaned piglets in enterotoxigenic Escherichia coli (ETEC)-challenged pig housing. Seventy-two weaned piglets, aged 28 days, were randomly divided into three groups for dietary treatment: the basal diet (negative control, NC), the positive control diet (PC) supplemented with 1445 mg zinc/kg zinc oxide in the basal diet, and the H. illucens larval meal complete replacement of fishmeal in the basal diet (HILM), for 28 days in ETEC-challenged pig housing. The results showed that the relative transcript abundances of ZO-1, pBD2, PR39, and PG1–5 were increased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. In addition, the HILM diet reduced (p < 0.05) the serum contents of IL-8 and increased (p < 0.05) the serum contents of IL-10 and IgG compared with the NC diet. In terms of the molecular mechanisms by which immune homeostasis is improved, the p-NF-κB/ NF-κB ratio and TLR2 protein expression in the colon were decreased (p < 0.05) in pigs fed the HILM diet compared with those fed the NC diet. Compared with the NC diet, the HILM diet reduced (p < 0.05) the protein expression of HDAC3 and HDAC7 in the colon of pigs. The SIRT1, acH3K9, and pH3S10 protein expressions in the colon were the greatest (p < 0.05) in pigs fed the HILM diet compared with the NC diet. HILM diets improved the colonic immune homeostasis in weaned piglets by enhancing the antimicrobial peptide expression, thereby mitigating ETEC challenges in pig housing. Mechanistically, HILM diets promote antimicrobial peptide expression through increased histone acetylation (acH3K9 and pH3S10). Full article

In flooded soils, the concentrations of exchangeable Mn²⁺ and, especially, Fe²⁺ can be high and must be considered when determining the cation exchange capacity (CEC) of the soil under flooded conditions. However, these reduced forms of Mn and Fe are oxidized and precipitated during the extraction process used in traditional CEC methods. This procedure underestimates the exchangeable portion of these cations and, consequently, the CEC value of the flooded soil. We introduce a pH-gradient-based model to predict ECEC and exchangeable Fe²⁺ in flooded soils, circumventing oxidation artifacts inherent in conventional methods. The objective of this study is to propose an alternative to estimate the exchangeable Fe²⁺ and the effective CEC (ECEC) of flooded soils. To achieve this goal, 21 surface samples (0–20 cm) of soil from rice fields were collected and distributed in the cultivation regions of southern Brazil. The soils were flooded for 50 days. The soil solution was collected on the first day and after 50 days of flooding and pH, Na, K, Ca, Mg, Fe and Mn were determined. In these samples, exchangeable cations (K, Na, Ca, Mg, Mn, Al and H + Al) were determined to calculate ECEC and CEC at pH 7 of unflooded soil and after 50 days of flooding. There was a wide range of variation in the exchangeable cation contents among the soil samples. The K contents ranged from 0.12 to 0.54 cmol_c kg⁻¹, the Na contents from 0.00 to 1.18 cmol_c kg⁻¹, the Ca contents from 0.48 to 37.31 cmol_c kg⁻¹, the Mg contents from 0.10 to 15.53 cmol_c kg⁻¹, the Mn contents from 0.01 to 0.36 cmol_c kg⁻¹, the Al contents from 0.10 to 1.74 cmol_c kg⁻¹ and the H + Al contents from 2.01 to 8.42 cmol_c kg⁻¹. The results were used to develop models to predict ECEC and exchangeable Fe content after 50 days of flooding. Estimating the ECEC after flooding using the pH gradient before and after flooding yielded values closer to CEC pH 7.0, correcting for the possible underestimation of the ECEC during flooding. The amount of exchangeable Fe estimated was higher than the exchangeable Fe determined, correcting the possible underestimation of these quantities determined during flooding. It is concluded that the estimations of ECEC after flooding through the equation ${ECEC}_{after}=ECEC+\left({pH}_{sol.after}-{pH}_{sol.before}\right)\times {\displaystyle \frac{({CEC}_{pH7}-ECEC)}{(7-{pH}_{sol.before})}}$, where pH_sol.before is pre-flooding soil pH, pH_sol.after is after flooding pH, ECEC_after is effective CEC after flooding and the exchangeable Fe²⁺ after flooding through the equation ${Fe}_{exc.after.estimated}={ECEC}_{after}-\left(Ca+Mg+K+Na+Mn\right)$ where Fe_{exc.after.estimated} is estimated exchangeable Fe²⁺ after flooding corrected the problem of underestimating the values of these variables by analytical methods, demonstrating its viability for use in flood-prone soils. Full article

CO₂ methanation offers a promising technology to convert CO₂ into methane, a valuable fuel that can be integrated into existing gas infrastructure. However, developing cost-effective, highly active, and stable catalysts remains a key challenge. In this paper, a series of La/NiAl-LDO catalysts were synthesized via a coprecipitation–impregnation method for catalytic CO₂ hydrogenation. Among the prepared catalysts, 6La/NiAl-LDO exhibited the highest CO₂ conversion (85.6%) with nearly 100% CH₄ selectivity at 300 °C and 2 MPa. The catalyst also demonstrated excellent stability over a 100 h durability test. Moreover, the kinetics of CO₂ hydrogenation over a 6La/NiAl-LDO catalyst were studied in a fixed-bed reactor at a catalyst particle size of 20–40 mesh, space velocity of 8000 mL/(g·h)), and temperatures ranging from 260 to 300 °C. The overall positive reaction followed approximately first-order kinetics, with an apparent activation energy of 89.4 kJ/mol. This work contributes to broader efforts in CO₂ capture and conversion to synthetic natural gas. Full article

The frictional resistance of impeller machinery blades such as aircraft engines, gas turbines, and wind turbines has a decisive impact on their efficiency and energy consumption. Inspired by the micro-tooth structure on the surface of shark skin, microstructural drag reduction technology has become a cutting-edge research direction for improving aerodynamic performance and a continuous focus of researchers over the past 20 years. However, the significant difficulty in fabricating microstructures on three-dimensional curved surfaces has led to the limited widespread application of this technology in engineering. Addressing the issue of drag reduction and efficiency improvement for small axial flow fans (local Reynolds number range: (36,327–40,330), this paper employs Design of Experiments (DOE) combined with high-precision numerical simulation to clarify the drag reduction law of bionic microgroove surfaces and determine the dimensions of bionic microstructures on fan blade surfaces. The steady-state calculation uses the standard k-ω model and simpleFoam solver, while the unsteady Large Eddy Simulation (LES) employs the pimpleFoam solver and WALE subgrid-scale model. The dimensionless height (h⁺) and width (s⁺) of microgrooves are in the range of 8.50–29.75, and the micro-grooved structure achieves effective drag reduction. The microstructured surface is fabricated on the suction surface of the blade via a spray coating process, and the dimensions of the microstructures are determined according to the drag reduction law of grooved flat plates. Aerodynamic performance tests indicate that the shaft power consumed by the bionic fan blades during the tests is significantly reduced. The maximum static pressure efficiency of the bionic fan with micro-dimples is increased by 2.33%, while that of the bionic fan with micro-grooves is increased by 3.46%. The fabrication method of the bionic microstructured surface proposed in this paper is expected to promote the engineering application of bionic drag reduction technology. Full article

The International Agreement on the Carriage of Perishable Foodstuffs and on the Special Equipment to Be Used for Such Carriage (usually known as ATP Treaty) defines a standardized isothermal test for qualifying refrigerated containers, but its current protocol is lengthy, costly and lacks scientific justification. This paper presents a combined theoretical and experimental study aimed at optimizing this procedure. First, a heat-transfer framework based on transient conduction and thermal diffusivity is developed to estimate stabilization times using dimensionless criteria. Then, extensive experimental tests on ATP containers validate these predictions and reveal additional phenomena such as air leakage and chimney effects. Based on these findings, a revised protocol is proposed that reduces the test duration from more than 18 h to approximately 2 h while preserving the thermal stabilization conditions required by ATP. Experimental results show that the uncertainty in the determination of the global heat-transfer coefficient K is reduced from about 2–$2.3\%$ in the classical ATP procedure to roughly $0.7$–$1.0\%$ with the new protocol. In addition, the method suppresses secondary physical effects—such as chimney-driven air leakage and latent-heat losses due to water evaporation—thus improving the physical representativeness of the measured K value. The proposed accelerated protocol offers a scientifically grounded, cost-effective alternative for future ATP standards. Full article

Biogas, a promising fuel for present and future generations, is produced from the anaerobic digestion of organic waste generated by the condominium itself. Therefore, this work aims to evaluate the exergoeconomic performance of a biogas cogeneration unit designed to meet the electrical and thermal energy demands of a residential condominium in the city of Teresina, Piauí, Northeast Brazil. The cogeneration unit consists of an internal combustion engine (ICE) coupled to an electric generator (genset) to produce electricity, and a heat exchanger that recovers part of the exhaust-gas heat to heat water. The analysis was conducted based on the concepts of Thermodynamics and Exergoeconomics, using the SPECO (Specific Exergy Costing) methodology to define the exergetic costs of the system. The novelty of the work lies in applying the SPECO exergoeconomic analysis to a small-scale biogas cogeneration unit fueled by residential organic waste. The achieved electricity production was 167.40 kW, and the heat transfer rate at the exchange rate was 51.55 kW. The results revealed that the exergy destroyed in the internal combustion chamber (ICE) was 223.65 kW, whereas that in the heat exchanger was significantly higher at 45.67 kW. The exergy efficiency of the ICE reached 39.19%, and the heat exchanger efficiency was around 9%. In financial terms, the cost of exergy destroyed in the ICEC was USD/h 135, but in the heat exchanger, it was dramatically higher at USD/h 158.40. The cost of producing hot water (product) was considered extremely high (USD/GJ 38.98). The relative difference parameter in the heat exchanger also has a value much higher than expected (10.240). This is because the product’s cost (USD/GJ 38.98) is well above the cost of fuel (USD/GJ 3.468). This study concludes that the cogeneration unit is more justifiable by the savings generated through thermal energy production than by electricity production alone, since the cogeneration system significantly enhances performance, raising both the energetic and exergetic efficiencies to 55% and 48%, respectively, thereby confirming the added value of the simultaneous utilization of heat and power. Full article

Poly(ethylene glycol) (PEG) and poly(2-hydroxy ethyl methacrylate) are polymers used for many biomedical applications due to their biocompatibility, non-toxicity, and antibiofouling properties. In this work, a new comb-like hydrogel based on 2-hydroxyethyl methacrylate (HEMA) grafted onto a polyethylene glycol network (net-PEG) was synthesized by gamma radiation from Co⁶⁰ in two steps. First, PEG (Mw = 20,000) was crosslinked at 30 kGy, and then HEMA was grafted, varying the concentration (5–20% v/v) and irradiation dose (2.5–15 kGy). Results of infrared spectroscopy (FTIR) and thermogravimetric analysis (TGA) confirmed the incorporation of HEMA onto net-PEG. Moreover, the properties of comb-like hydrogel (net-PEG)-g-HEMA were studied through swelling kinetics, drug loading and release, antimicrobial activity, and biocompatibility assays. The findings showed a different behavior in swelling kinetics and drug delivery depending on HEMA grafting. Comb-like hydrogel with 30 and 66% grafting could load more ciprofloxacin (2 mg g⁻¹) than net-PEG (1.5 mg g⁻¹) but only release 38 and 48% at 24 h, respectively. In addition, all drug-loaded hydrogels displayed inhibition for Gram-negative bacteria (E. coli) and a cell viability superior of 95% using mouse embryonic fibroblasts (BALT/T3). Comb-like hydrogel has potential application in the biomedical field such as in wound dressings or controlled drug delivery systems. Full article

Avian influenza viruses (AIVs), including H5N1 and H7N9, from the Orthomyxoviridae family present substantial public health concerns. The predominant circulating clade 2.3.4.4b has demonstrated enhanced capacity for mammalian adaptation, raising concerns about potential reassortment with human seasonal influenza viruses. Unlike H7N9’s limited host range, H5N1 infects birds, various mammals, and humans. Recent concerns include widespread H5N1 infection of U.S. dairy cattle across 18 states, affecting over 1000 herds with 71 human infections (70 H5N1 and 1 H5N5). Key observations include cow-to-cow transmission, viral presence in milk, and transmission to humans, mainly through occupational exposure. Evidence of mammal-to-mammal transmission has been documented in European and Canadian foxes and South American marine mammals. Standard pasteurization effectively inactivates the virus in milk. The continuing mammalian adaptations, particularly mutations like PB2-E627K, PB2-D701N, and PB2-M535I, suggest potential for further evolution in new hosts, emphasizing the need for enhanced surveillance to mitigate pandemic risks. Full article

Pseudomonas extremorientalis PEY1, isolated from the intestinal contents of marine fish, was evaluated for the production and properties of antibacterial proteins active against Edwardsiella tarda, a major pathogen in aquaculture. Antibacterial production was maximized in a minimal medium supplemented with 1% yeast extract and 1% galactose under stationary cultivation at 25 °C and pH 7.0. Growth and bioactivity assays were conducted under varying carbon and nitrogen sources, temperatures, and pH levels. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis analysis revealed a distinct ~37 kDa protein band corresponding to antibacterial activity, exhibiting an inhibition zone of 2.4 ± 0.1 cm against E. tarda. The activity was completely abolished by papain digestion but remained detectable after exposure to 55 °C and pH 8, indicating that the active compound is a moderately heat-stable, proteinaceous antibacterial molecule. LC–MS/MS analysis identified the protein as a putative disulfide reductase with ~40% sequence coverage. The antibacterial factor exhibited strong physicochemical stability, retaining activity in the presence of surfactants and metal ions. Collectively, these findings demonstrate that P. extremorientalis PEY1 produces a thermostable, papain-sensitive antibacterial protein with selective activity against E. tarda, highlighting its potential as a promising natural biocontrol or postbiotic candidate for sustainable aquaculture. Full article

For the study, we used four kerosene-based ferrofluid samples containing magnetite nanoparticles stabilized with oleic acid. Starting from the initial sample (A0), the other three samples were obtained by dilution with kerosene. The complex magnetic permeability measurements were performed in the microwave region (0.5–6) GHz, for different H values of the polarizing magnetic field, between (0–115) kA/m. These measurements revealed the ferromagnetic resonance phenomenon for each sample, allowing the determination of the anisotropy field (H_A) and the effective anisotropy constant (K_eff) of nanoparticles, depending on the volume fraction of particles (φ). At the same time, the measurements allowed the determination of the specific magnetic loss power (p_m), effective heating rate (HR_eff), intrinsic loss power (ILP), and specific absorption rate (SAR) as functions of the frequency (f) and magnetic field (H), of all investigated samples, using newly proposed equations for their calculation. For the first time, this study evaluates the maximum limit of the applied polarizing magnetic field (H_max ≈ 80 kA/m) and the minimum limit volume fraction of nanoparticles (φ_min ≈ 3.5%) at which microwave heating of the ferrofluid remains efficient. At the same time, the results obtained show that the temperature increase of the ferrofluid samples, upon interaction with a microwave field, can be controlled by varying both H and φ, pointing to possible applications in magnetic hyperthermia. Full article

Highly pathogenic avian influenza (HPAI) A(H5N1) clade 2.3.4.4b has recently emerged as a major threat to wildlife, agriculture, and public health due to its expanding host range and the increasing frequency of spillover into mammals. In July–August 2023, the mass death of over 3500 northern fur seals (Callorhinus ursinus) and at least one Steller sea lion (Eumetopias jubatus) was recorded on Tyuleniy Island in the Sea of Okhotsk, Russia. Two HPAI A(H5N1) viruses were isolated from fur seal carcasses and designated A/Northern_fur_seal/Russia_Tyuleniy/74/2023 and A/Northern_fur_seal/Russia_Tyuleniy/75/2023. Both viruses exhibited high pathogenicity in chickens (IVPI 2.7–3.0) and mice (MLD₅₀ 1.9–2.5 log₁₀EID₅₀/mL), with distinct differences in disease progression, histopathology, and organ tropism. Experimental infection of mice revealed that strain A/74/2023 induced more severe pulmonary and neurological lesions than A/75/2023. Whole-genome sequencing and phylogenetic analysis demonstrated close relatedness to HPAI H5N1 strains circulating in the Russian Far East and Japan from 2022 to 2023, with several mutations associated with mammalian adaptation, including NP-N319K and, in one isolate, PB2-E627K. According to our findings, northern fur seals (Callorhinus ursinus) on Tyuleniy Island acted as spillover hosts for the highly pathogenic avian influenza (HPAI) H5N1 virus of clade 2.3.4.4b. Furthermore, the high population density of fur seals and the extensive mortality observed during the outbreak highlight these animals’ potential role as another vessel for the evolution of avian influenza viruses. This study represents the first documented case of HPAI H5N1 in pinnipeds in the North Pacific region and supports previous reports indicating that pinnipeds, including northern fur seals, are highly susceptible to HPAI H5N1 clade 2.3.4.4b viruses. Full article

The large-scale integration of renewable energy systems requires hydrogen storage technologies that can decouple energy production from energy utilization and allow for seasonal storage. Metal hydrides can offer higher volumetric energy density and operational safety than compressed H₂ but are limited by heat-transfer constraints that slow hydrogen absorption and desorption. This work investigates the performance of metal hydride–phase-change material hydrogen storage systems through advanced numerical modeling. Five reactor geometries are evaluated to quantify how longitudinal fins, transversal fins, helical fin structures, and graphite-enhanced composites influence heat removal, charge/discharge rates, and overall power density. Results show that longitudinal and transversal fins accelerate hydrogen absorption and desorption, reducing cycle times by up to 80.6%. The optimized finned helix configuration achieves the highest performance, with a power density of 2.55 kW/kg and charge/discharge powers of 6.75 kW and 13.25 kW, respectively. Expanded graphite further enhances kinetics in low-Biot-number designs, reducing cycle times by more than 30%. These findings provide design guidelines to maximize performance and efficiency of solid-state hydrogen storage for medium- and high-power applications. Full article

Noise pollution represents a significant environmental stressor that compromises the health and welfare of farm animals. While music enrichment has been suggested to mitigate stress, the specific mechanisms by which it protects against noise-induced immune damage remain poorly understood. This study investigated whether music can mitigate acute noise-induced injury to the bursa of Fabricius in broilers. A total of 175 male Arbor Acres broilers were randomly allocated into four groups: Control (C), Noise (N), Noise plus Music (NM), and Music (M). Starting on day 14, groups N and NM were exposed to daily acute noise exposure (115–120 dB for10 min), while groups NM and M received daily 6-h Mozart’s K.448 music enrichment. We evaluated the effects of short-term (by day 21) and long-term (by day 42) music intervention. Results showed that acute noise induced significant histopathological damage, oxidative stress, and apoptosis in the bursa. While short-term music intervention showed limited efficacy, prolonged music exposure significantly attenuated these injuries. Mechanistically, music suppressed the noise-activated NF-κB signaling pathway and reduced inflammatory cytokines (IL-1β, IL-6, and TNF-α). Concurrently, it inhibited mitochondrial-dependent apoptosis by modulating Bcl-2, Bax, Cyt-C, and Caspase-3. These findings provide experimental evidence that long-term music enrichment effectively alleviates noise-induced immune injury, suggesting a practical strategy for improving poultry welfare. Full article

This paper is dedicated to the investigation of new generalizations of the classical Gronwall–Bellman–Bihari integral inequalities, which are fundamental tools in the qualitative and quantitative analysis of differential, integral, and integro-differential equations. We establish two primary, novel theorems. The first theorem presents a significant generalization for inequalities involving composite nonlinear functions and iterated integrals. This result provides an explicit bound for an unknown function $u\left(t\right)$ satisfying an inequality of the form $\mathsf{\Phi }\left(u\right(t\left)\right)\le a\left(t\right)+{\int }_{t_0}^t f\left(s\right)\mathsf{\Psi }\left(u\right(s\left)\right)ds+{\int }_{t_0}^t g\left(s\right)\mathsf{\Omega }({\int }_{t_0}^s h(\tau \left)K\right(u\left(\tau \right)\left)d\tau \right)ds$. The proof is achieved by defining a novel auxiliary function and applying a rigorous comparison principle. The second main theorem establishes a new bound for a class of fractional integral inequalities involving the Riemann–Liouville fractional integral operator ${\mathcal{I}}^{\alpha }$ and a non-constant coefficient function $b\left(t\right)$ in the form $u\left(t\right)\le a\left(t\right)+b\left(t\right){\mathcal{I}}^{\alpha }\left[\omega \right(u\left(s\right)\left)\right]$. This result extends several recent findings in the field of fractional calculus. The mathematical derivations are detailed, and the assumptions on the involved functions are made explicit. To illustrate the utility and potency of our main results, we present two applications. The first application demonstrates how our first theorem can be used to establish uniqueness and boundedness for solutions to a complex class of nonlinear integro-differential equations. The second application utilizes our fractional inequality theorem to analyze the qualitative behavior (specifically, the boundedness of solutions) for a generalized class of fractional integral equations. These new inequalities provide a powerful analytical framework for studying complex dynamical systems that were not adequately covered by existing results. Full article