Search Results (85)

Background/Objectives: The current need for new antibacterial compounds that target non-classical pathways is highlighted by the emergence of multidrug-resistant Klebsiella pneumoniae. In the development of antibiotics, DNA adenine methyltransferase (Dam), a key regulator of bacterial gene expression and pathogenicity, is still underutilized. Epoxy-functionalized analogues of isatin derivatives have not been adequately investigated for their antibacterial activity, particularly as Dam inhibitors. In the pursuit of antimicrobial agents, this study synthesized an epoxy-functionalized isatin derivative (L3) using a one-pot reaction. The compound was characterized using FT-IR, ¹H-NMR, ¹³C-NMR, HR-MS, and UV–Vis spectroscopy. Methods: In silico evaluation performed by using ADMETlab3 and SwissADME. While molecular docking studies were achieved by AutoDock and Vina to find L3’s interaction with potential antibacterial target (Dam protein in K. pneumoniae). In addition, the antibacterial potential of L3 was evaluated using minimum inhibitory concentration (MIC) assays against Bacillus cereus, Bacillus pumilus, Escherichia coli, and K. pneumoniae. Results: Among these, L3 exhibited potential inhibitory activity against K. pneumoniae, with a MIC value of 93.75 μg/mL. In silico evaluations confirmed L3’s favorable drug-like properties, including potential oral bioavailability, blood–brain barrier (BBB) permeability, and low plasma protein binding (PPB). The compound satisfied Lipinski’s and other drug-likeness rules as well as getting a quantitative estimate of drug-likeness (QED) score of 0.52. Here, a homology model of Dam protein in K. pneumoniae was generated using the SWISS-MODEL server and validated using computational tools. Targeted docking analysis revealed that L3 exhibited significant potential binding affinity against Dam protein, with binding energies of −6.4 kcal/mol and −4.85 kcal/mol, as determined by Vina and AutoDock, respectively. The associated inhibition constant was calculated as 280.35 µM. Further interaction analysis identified the formation of hydrogen bonds with TRP7 and PHE32, along with Van der Waals’ interactions involving GLY9, ASP51, and ASP179. Conclusions: These findings highlight L3 as a promising scaffold for antimicrobial drug development, particularly in targeting Dam protein in K. pneumoniae. Furthermore, the ADMET profiling and physicochemical properties of L3 support its potential as a drug-like candidate. Full article

NiFe (oxy)hydroxide has been widely used as a benchmark anodic catalyst for oxygen evolution reactions (OERs) in alkaline water electrolysis devices; however, the energy saving actually takes contributions from both the anodic OER and cathodic hydrogen evolution reaction (HER). In this work, we observe the catalytic promotion upon the in situ-derived NiFe (oxy)hydroxide from the NiFe alloy monolithic electrode and also point out that the coupled nickel cathode is contaminated, leading to the loss of HER activity and a reduction in overall efficiency. It is found that Ni²⁺ and Fe³⁺ cations are inevitably detached from the anode into the electrolyte and electrodeposited on the nickel cathode after the three-month industrial simulation. This research presents the significant enhancement of the oxygen evolution catalysis using an in situ aging process and emphasizes that the catalytic application should not only be isolated on the half reaction, but a reasonable coupled electrode match to get rid of the contamination from the electrolyte is also of great significance to sufficiently present the intrinsic catalytic yielding for the real application. Full article

Recently, major problems related to fuel consumption and greenhouse gas (GHG) emissions have arisen in the transportation sector. Therefore, developing transportation modes powered by alternative fuels has become one of the main targets for car manufacturers and governments around the world. This study aimed to investigate the economic prospects of using hydrogen fuel cell technology in taxi fleets in Westbank. For this purpose, a model that could predict the number of taxis was developed, and the expected economic implications of using hydrogen fuel cell technology in taxi fleets were determined based on the expected future fuel consumption and future fuel cost. After analysis of the results, it was concluded that a slight annual increase in the number of taxis in Palestine is expected in the future, due to the government restrictions on issuing new taxi permits in order to get this sector organized. Furthermore, using hydrogen fuel cells in taxi fleets is expected to become more and more feasible over time due to the expected future increase in oil price and the expected significant reduction in hydrogen cost as a result of the new technologies that are expected to be used in the production and handling of hydrogen. Full article

In this study, hydrogen production by solar thermal energy has been studied in terms of economics, technology and hydrogen sources. Methane was captured and subjected to solar photovoltaic steam, solar methane cracking, high-temperature water electrolysis and thermochemical cycles. The price of hydrogen production was calculated compared to other methods, and means of using and exploiting hydrogen as an energy carrier were examined in addition to verifying the industrial need for hydrogen, especially in the presence of high solar energy, which improves hydrogen production. The study was carried out in order to generate hydrogen using a solar electrolyzer based on polymeric exchange membrane technology. The study was carried out using two methods. The first was involved the direct connection of the photovoltaic system to the hydrogen analyzer, and the second was a system for a solar electrolysis hydrogen analyzer consisting of a PV array and a maximum power tracker MPPT meant to operate the system at the maximum power of the photovoltaic system at all times uses a DC converter to supply the analyzer. With the necessary current and hydrogen tank, the results showed that the first method was less effective compared to the second method due to the instability of the intensity of solar radiation during the day, and the results show that adding potassium hydroxide, for example, enhances ionization and improves hydrogen supply. Full article

In this paper, we present concurrent atomistic-continuum (CAC) simulations of the hydrogen (H) diffusion along a grain boundary (GB), nearby which a large population of dislocations are piled up, in a plastically deformed bi-crystalline bcc iron sample. With the microscale dislocation slip and the atomic structure evolution at the GB being simultaneously retained, our main findings are: (i) the accumulation of tens of dislocations near the H-charged GB can induce a local internal stress as high as 3 GPa; (ii) the more dislocations piled up at the GB, the slower the H diffusion ahead of the slip–GB intersection; and (iii) H atoms diffuse fast behind the pileup tip, get trapped within the GB, and diffuse slowly ahead of the pileup tip. The CAC simulation-predicted local H diffusivity, $D_{\mathrm{pileup}-\mathrm{tip}}$, and local stresses, $\sigma$, are correlated with each other. We then consolidate such correlations into a mechanics model by considering the dislocation pileup as an Eshelby inclusion. These findings will provide researchers with opportunities to: (a) characterize the interplay between plasticity, H diffusion, and crack initiation underlying H-induced cracking (HIC); (b) develop mechanism-based constitutive rules to be used in diffusion–plasticity coupling models for understanding the interplay between mechanical and mass transport in materials at the continuum level; and (c) connect the atomistic deformation physics of polycrystalline materials with their performance in aqueous environments, which is currently difficult to achieve in experiments. Full article

Various methodologies, sensitivities, and types of interference affect the quantification of plant hydrogen peroxide (H₂O₂) concentration. Modified ferrous oxidation xylenol orange (eFOX) assay and titanium sulfate (Ti(SO₄)₂ assay are relatively accessible methods. However, their correlation is unknown, for example whether we can get the same results for different species in different environments. Leaf samples of Ambrosia trifida, Solidago altissima, Artemisia princeps, and Sicyos angulatus were collected from a riparian vegetation zone on sunny days. The H₂O₂ concentration in the plant leaves was evaluated in two groups. Nonfrozen leaf samples were prepared for analysis soon after arriving at the laboratory, and frozen leaf samples were stored at −80 °C for 25 days and prepared afterwards. The eFOX assay can measure even lower fluctuations in H₂O₂ concentration than the Ti(SO₄)₂ assay. A substantial correlation was observed between nonfrozen and frozen samples in the eFOX (r = 0.879, p < 0.001) and Ti(SO₄)₂ assays (r = 0.837, p < 0.001). Sample weight did not affect H₂O₂ quantification. Each species showed a substantial correlation between the eFOX and Ti(SO₄)₂ assays in nonfrozen conditions (Ambrosia trifida (r = 0.767, p < 0.001), Solidago altissima (r = 0.583, p < 0.001), Artemisia princeps (r = 0.672, p < 0.001), and Sicyos angulatus (r = 0.828, p < 0.001)). Therefore, both methods can be utilized easily and rapidly to quantify oxidative stress using H₂O₂. Full article

Renewable hydrogen production has an opportunity to reduce carbon emissions in the transportation and industrial sectors. This method generates hydrogen utilizing renewable energy sources, such as the sun, wind, and hydropower, lowering the number of greenhouse gases released into the environment. In recent years, considerable progress has been made in the production of sustainable hydrogen, particularly in the disciplines of electrolysis, biomass gasification, and photoelectrochemical water splitting. This review article figures out the capacity, efficiency, and cost-effectiveness of hydrogen production from renewable sources effectively comparing the conventionally used technologies with the latest techniques, which are getting better day by day with the implementation of the technological advancements. Governments, investors, and industry players are increasingly interested in manufacturing renewable hydrogen, and the global need for clean energy is expanding. It is projected that facilities for manufacturing renewable hydrogen, as well as infrastructure to support this development, would expand, hastening the transition to an environment-friendly and low-carbon economy. Full article

Cellular interactions within the bone marrow microenvironment modulate the properties of subsets of leukemic cells leading to the development of drug-resistant phenotypes. The intercellular transfer of proteins and organelles contributes to this process but the set of transferred proteins and their effects in the receiving cells remain unclear. This study aimed to detect the intercellular protein transfer from mouse bone marrow stromal cells (OP9 cell line) to human T-lymphoblasts (CCRF-CEM cell line) using nanoLC-MS/MS-based shotgun proteomics in a 3D co-culture system. After 24 h of co-culture, 1513 and 67 proteins from human and mouse origin, respectively, were identified in CCRF-CEM cells. The presence of mouse proteins in the human cell line, detected by analyzing the differences in amino acid sequences of orthologous peptides, was interpreted as the result of intercellular transfer. The transferred proteins might have contributed to the observed resistance to vincristine, methotrexate, and hydrogen peroxide in the co-cultured leukemic cells. Our results suggest that shotgun proteomic analyses of co-cultured cells from different species could be a simple option to get a preliminary survey of the proteins exchanged among interacting cells. Full article

Carbon capture and use may provide motivation for the global problem of mitigating global warming from substantial industrial emitters. Captured CO₂ may be transformed into a range of products such as methanol as renewable energy sources. Polymers, cement, and heterogeneous catalysts for varying chemical synthesis are examples of commercial goods. Because some of these components may be converted into power, CO₂ is a feedstock and excellent energy transporter. By employing collected CO₂ from the atmosphere as the primary hydrocarbon source, a carbon-neutral fuel may be created. The fuel is subsequently burned, and CO₂ is released into the atmosphere like a byproduct of the combustion process. There is no net carbon dioxide emitted or withdrawn from the environment during this process, hence the name carbon-neutral fuel. In a world with net-zero CO₂ emissions, the anthroposphere will have attained its carbon hold-up capacity in response to a particular global average temperature increase, such as 1.5 °C. As a result, each carbon atom removed from the subsurface (lithosphere) must be returned to it, or it will be expelled into the atmosphere. CO₂ removal technologies, such as biofuels with carbon sequestration and direct air capture, will be required to lower the high CO₂ concentration in the atmosphere if the Paris Agreement’s ambitious climate targets are to be realized. In a carbon-neutral scenario, CO₂ consumption with renewable energy is expected to contribute to the displacement of fossil fuels. This article includes a conceptual study and an evaluation of fuel technology that enables a carbon-neutral chemical industry in a net-zero-CO₂-emissions environment. These are based on the use of collected CO₂ as a feedstock in novel chemical processes, along with “green” hydrogen, or on the use of biomass. It will also shed light on innovative methods of green transformation and getting sustainable, environmentally friendly energy. Full article

This study explores the electrochemical reduction in CO₂ using room temperature ionic liquids as solvents or electrolytes, which can minimize the environmental impact of CO₂ emissions. To design effective CO₂ electrochemical systems, it is crucial to identify intermediate surface species and reaction products in situ. The study investigates the electrochemical reduction in CO₂ using a cobalt porphyrin molecular immobilized electrode in 1-n-butyl-3-methyl imidazolium tetrafluoroborate (BMI.BF4) room temperature ionic liquids, through in-situ surface-enhanced Raman spectroscopy (SERS) and electrochemical technique. The results show that the highest faradaic efficiency of CO produced from the electrochemical reduction in CO₂ can reach 98%. With the potential getting more negative, the faradaic efficiency of CO decreases while H₂ is produced as a competitive product. Besides, water protonates porphyrin macrocycle, producing pholorin as the key intermediate for the hydrogen evolution reaction, leading to the out-of-plane mode of the porphyrin molecule. Absorption of CO₂ by the ionic liquids leads to the formation of BMI·CO₂ adduct in BMI·BF₄ solution, causing vibration modes at 1100, 1457, and 1509 cm⁻¹. However, the key intermediate of ${\mathrm{CO}}_2^{-}·$ radical is not observed. The υ(CO) stretching mode of absorbed CO is affected by the electrochemical Stark effect, typical of CO chemisorbed on a top site. Full article

Alkane functionalization using safe and low-energy processes is of great interest to industry and academia. Aiming to contribute to the process of saturated hydrocarbon functionalization, we have studied a set of three manganese(III) complexes as catalysts for promoting the oxidation of saturated hydrocarbons (cyclohexane and methylcyclohexane) in the presence of hydrogen peroxide or trichloroisocyanuric acid (TCCA). The mononuclear manganese(III) compounds were prepared using the ligands H₂L^Met4 (6,6’-((1,4-diazepane-1,4-diyl)bis(methylene))bis(2,4-dimethylphenol), H₂salen (2,2’-((1E,1’E)-(ethane-1,2-diylbis(azaneylylidene))bis(methaneylylidene))diphenol) and H₂salan (2,2’-((ethane-1,2-diylbis(azanediyl))bis(methylene))diphenol). The catalytic processes were carried out in acetonitrile at 25 and 50 °C for 24 h. The increase in the temperature was important to get a better conversion. The compounds did not promote cyclohexane oxidation in the presence of H₂O₂. However, they were active in the presence of TCCA, employing a ratio of 1000:333:1 equivalents of the substrate:TCCA:catalyst. The best catalytic activity was shown by the compound [Mn(salen)Cl], reaching conversions of 14.5 ± 0.3% (25 °C) and 26.3 ± 1.1% (50 °C) (yield for chlorocyclohexane) and up to 12.1 ± 0.5% (25 °C) and 29.8 ± 2.2% (50 °C) (total yield for the mixture of the products 1-chloro-4-methylcyclohexane, 3-methylcyclohexene and 1-methylcyclohexene). The interaction of the catalysts with TCCA was studied using electron paramagnetic resonance (EPR), suggesting that the catalysts [Mn(L^Met4)Cl] and [Mn(salan)Cl] act via a different mechanism from that observed for [Mn(salen)Cl]. Full article

Mixed metallic oxides are getting increasing attention as novel electrode materials for energy conversion devices. However, low mixed ionic-electronic conductivity and high operating temperature hamper the practical applications of these devices. This study reports an effective strategy to improve the conductivity and performance of the fuel cell at low temperature by partially incorporating graphene in the Li_0.1Cu_0.2Zn_0.7-oxide (LCZ) composite. The proposed cathode material is synthesized via the cost effective conventional solid-state route. Graphene incorporated LCZ shows excellent performance, which is attributed to the favorable charge transport paths offering low area-specific resistance. An X-ray diffractometer (XRD) and scanning electron microscope (SEM) are employed for microstructural and surface morphological analyses, respectively. Electrical conductivities of all the materials are determined by the DC four probe method, and interestingly, LCZ-1.5% graphene exhibits an excellent conductivity of 3.5 S/cm in air atmosphere at a temperature of 450 °C with a minimum value of 0.057 Ωcm² area-specific resistance (ASR) that demonstrates significantly good performance. Moreover, the three-layer fuel cell device is fabricated using sodium carbonated Sm_0.2Ce_0.8O (NSDC) as an electrolyte, which can operate at low temperatures exhibiting open circuit voltage 0.95 V and shows a peak power density, i.e., 267.5 mW/cm² with hydrogen as the fuel. Full article

The main aim of the present paper is to characterize the hydration properties of glucose and the hydrogen bond network in glucose–water mixtures. For these purposes, temperature scans on ten concentration values of glucose–water mixtures were performed by means of Fourier Transform InfraRed (FTIR) spectroscopy. More specifically, in order to get this information an analysis of the intramolecular OH stretching mode, investigating the 3000–3700 cm⁻¹ spectral range, was performed by means of an innovative approach based on the evaluation of the Spectral Distance (SD). The adopted procedure allows evaluating the glucose hydration number as well as characterizing the temperature behavior of the hydrogen bond network in the glucose–water mixtures. The obtained results for the hydration number are in excellent agreement with literature data and suggest the existence of a particular concentration value for which the hydrogen bond network shows a maximum strength. Full article

The two-center wave-packet convergent close-coupling method has been applied to model the processes of electron capture and ionisation in collisions of fully stripped neon and lithium ions with atomic hydrogen at projectile energies from 1 keV/u to 1 MeV/u. For the Ne${}^{10+}$ projectile, the resulting total electron-capture cross section lies between the two sets of experimental results available for system, which differ from each other significantly. For Li${}^{3+}$, our total electron-capture cross section agrees with the available experimental measurements by Shah et al. [J. Phys. B: At. Mol. Opt. Phys 11, L233 (1978)] and Seim et al. [J. Phys. B: At. Mol. Opt. Phys 14, 3475 (1981)], particularly at low and high energies. We also get good agreement with the existing theoretical works, particularly the atomic- and molecular-orbital close-coupling calculations. Our total ionisation cross section overestimates the experimental data by Shah et al. [J. Phys. B: At. Mol. Opt. Phys 15, 413 (1982)] at the peak, however we get good agreement with the other existing theoretical calculations at low and high energies. Full article

Natural resources, particularly plants and microbes, are an excellent source of bioactive molecules. Bromelain, a complex enzyme mixture found in pineapples, has numerous pharmacological applications. In a search for therapeutic molecules, we conducted an in silico study on natural phyto-constituent bromelain, targeting pathogenic bacteria and viral proteases. Docking studies revealed that bromelain strongly bound to food-borne bacterial pathogens and SARS-CoV-2 virus targets, with a high binding energy of −9.37 kcal/mol. The binding interaction was mediated by the involvement of hydrogen bonds, and some hydrophobic interactions stabilized the complex and molecular dynamics. Simulation studies also indicated the stable binding between bromelain and SARS-CoV-2 protease as well as with bacterial targets which are essential for DNA and protein synthesis and are required to maintain the integrity of membranous proteins. From this in silico study, it is also concluded that bromelain could be an effective molecule to control foodborne pathogen toxicity and COVID-19. So, eating pineapple during an infection could help to interfere with the pathogen attaching and help prevent the virus from getting into the host cell. Further, research on the bromelain molecule could be helpful for the management of COVID-19 disease as well as other bacterial-mediated diseases. Thus, the antibacterial and anti-SARS-CoV-2 virus inhibitory potentials of bromelain could be helpful in the management of viral infections and subsequent bacterial infections in COVID-19 patients. Full article