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Ceria-supported copper catalysts exhibit high catalytic performance in the preferential oxidation of CO in excess H₂ (CO PROX). Highly dispersed copper oxide species have been experimentally identified as active centers. However, structural diagnostics of highly dispersed CuO_x species and CuO_x/CeO₂ interface areas remains a challenge. Here, we report a comprehensive structural study of a supported CuO/CeO₂ catalyst (5 wt% Cu) showing good activity in the CO PROX process. X-ray absorption spectroscopy (XAS) techniques and X-ray atomic pair distribution function (PDF) analysis were used as efficient methods for probing the atomic resolution structure. It was established that the catalyst contains Cu²⁺ species, mainly in the form of ultra-dispersed CuO-like particles and copper oxide clusters. Analysis of the local atomic arrangement revealed an interaction between copper ions and ceria surface. Oxygen-terminated {100} ceria facets can accommodate Cu²⁺ ions in square planar coordination. Moreover, some Cu ions are inserted into the CeO₂ crystal structure, forming a substitutional solid solution.

Graphical Abstract

Background

This study is aimed to develop a simple, effective and economic method for the UV spectrophotometric analysis of amoxicillin trihydrate in the presence of acetaminophen. The Beer–Lambert law was obeyed in the concentration range of 2–10 µg/ml for amoxicillin trihydrate, acetaminophen and combinations, in all the different pH media: pH 1.2, 6.8, 7.4 and neutral (double-distilled water). For the simultaneous equation method, the absorbance maxima of amoxicillin trihydrate was found at 228 nm, and for acetaminophen, it was found at 243 nm, after scanning the solutions in respective buffers.

Result

The standard curve of amoxicillin trihydrate and acetaminophen was plotted, and the correlation coefficient (R²) value was found to be in the range of 0.991–0.994 and 0.993–0.999, respectively. These two drugs were combined in a ratio of 5:3 (amoxicillin trihydrate: acetaminophen), and its absorbance maxima was discovered at 232 nm (isoabsorptive point), where its correlation coefficient was calculated from the standard curve which is in range of 0.993–0.996. The above-mentioned method was found to comply all the validation parameters as per the ICH guidelines such as accuracy, precision, linearity, LOD, LOQ, reproducibility and recovery. This method is successfully applied to estimate the combination of these two drugs in their pharmaceutical dosage forms without and interaction of their excipients. This method is based on to check the stability of amoxicillin trihydrate in different pH media in the presence of acetaminophen.

Conclusion

Hydrolysis of beta-lactam ring of amoxicillin trihydrate occurs in acidic pH (below 2) which causes the formation of amoxicilloic acid which may cause reduction in its microbial activity but neither shifting of wavelength nor appearance of extra peak occurred in UV spectroscopy. Although some changes of % area of amoxicillin trihydrate is observed in acidic media in HPLC method, there are no significant changes observed among the amoxicillin trihydrate solutions with acetaminophen prepared in different pH media, when using UV spectrophotometric method.

Non-Newtonian NEPCMs are utilized in a variety of fields, counting solar energy storage, electronics cooling, polymer processing, and industrial thermal management. Their advanced heat transfer capabilities and efficient energy storage properties make them particularly valuable for these applications. This study explores how magnetic fields affect mass and heat transfer in a non-Newtonian NEPCM within an A-shaped cavity. The investigation employs the ISPH technique and ANN model. Within the A-shaped cavity, a triangular region is kept at (left({T}_{c}, {C}_{c}right)). The top/center walls of the A-shaped cavity are maintained at (left({T}_{h}, {C}_{h}right)). The ANN model serves as a valuable complement to ISPH simulations, accurately predicting average Nusselt ((overline{Nu })) and Sherwood ((overline{Sh })) numbers. Results indicate a substantial increase in the Π strength by (138.46%) when the power-law index ((n)) rises from (1.025 text{to } 1.12). The current configuration of an A-shaped cavity with specific boundary conditions significantly influences the effectiveness of the relevant parameters.

The physics-informed neural network is a powerful tool for modeling complex biological systems. Computing with this network provide significant benefits for solving differential equations that describe biological processes, as well as for tackling inverse problems, where models are derived from data sets. In this study, we explore the potential application of physics-informed neural network approach embedded within the measles double-dose vaccination model to analyze its temporal dynamics. In particular, this study examines a compartmental model with double-dose vaccination to study the impact of vaccine controls on the measles transmission. Initially, a rigorous analysis of the proposed model including stability about the equilibria in terms of the basic reproduction number is presented. Both local and global stability are achieved depending on whether ({mathcal {R}}_0) is less than or greater than 1 using nonlinear Lyapunov functions. The findings demonstrate that a physics-informed neural network based approach can effectively handle complex dynamics and their potential to enhance our understanding of the disease dynamics treatment using vaccination. Furthermore, this research highlights the versatility and robustness of machine learning approaches to analyze and predict epidemiological dynamics in conjunction with transmission modeling.

Analysis of more than 300 M-class solar flares observed with the Atmospheric Imaging Assembly onboard the Solar Dynamics Observatory in the 131 Å channel, revealed 16 events of sloshing oscillations in hot solar coronal loops. Time–distance maps made along the loops demonstrated EUV emission intensity blobs bouncing between the footpoints, i.e., showing characteristic zigzagging patterns, of the size shorter than 25% of the loop length. The oscillation periods are found to range from about 150 s to 1325 s. The average phase speed, estimated as the ratio of the oscillation period and the loop length, is about 500 km s⁻¹. Parameters of the oscillations are consistent with the interpretation in terms of multi-harmonic slow magnetoacoustic oscillations.

The increasing antibiotic resistance necessitates sustainable methods for synthesizing antibacterial nanoparticles. This study focuses on the bio-assisted synthesis of silver/silver chloride nanoparticles (Ag/AgCl-NPs) using aqueous extracts of Acalypha arvensis, Hampea rovirosae, and Inga jinicuil. Polyphenols and flavonoids were quantified, and functional groups were analyzed via Fourier-transform infrared to assess their influence on the properties of Ag/AgCl-NPs. The effects of thermal treatment at 60 and 500 °C on the NPs’ size, morphology, and antibacterial efficacy were assessed. UV–Vis spectroscopy indicated absorption peaks between 430 and 449 nm, while X-ray diffraction analysis confirmed the presence of metallic Ag and a cubic AgCl structure, with crystallite sizes ranging from 11–51 and 28–60 nm, respectively. Dynamic light scattering showed hydrodynamic sizes of up to 127.2 ± 0.9 nm at 60 °C and up to 348.9 ± 10.7 nm at 500 °C. Field emission scanning electron microscopy micrographs exhibited a quasi-spherical morphology with significant agglomeration; showing particle sizes between 55 ± 11 and 81 ± 28 nm at 60 °C, and up to 135 ± 65 nm at 500 °C. X-ray photoelectron spectroscopy confirmed the metallic silver (Ag⁰), organic molecules, and absorbed chlorides on the NP surface. Pearson correlation analysis indicated a strong positive correlation between polyphenol content and NPs yield (r = 0.922), while it indicated a strong negative correlation with flavonoid content (r = −0.996). Additionally, a negative correlation was found between hydrodynamic size and antibacterial activity against Staphylococcus aureus (r = −0.854). The Ag/AgCl-NPs, after drying at 60 and 500 °C, were tested against Escherichia coli and S. aureus with minimum bactericidal concentrations below 19 µg/mL against E. coli. Minimum inhibitory concentration (MIC) for Ag/AgCl-NPs synthesized with A. arvensis and H. rovirosae extracts were above 312 µg/mL for S. aureus, while those synthesized with I. jinicuil showed MIC as low as 156 µg/mL. These results highlight the potential of medicinal plant extracts in the synthesis of Ag/AgCl with enhanced antibacterial properties.

Background

Among 2,3-butanediol (2,3-BDO) stereoisomers, (R,R)-2,3-BDO is particularly noteworthy for its application in the agricultural industry. It is an eco-friendly plant immune system stimulant, promoting plant growth and enhancing resistance to biotic and abiotic stresses.

Results

This study aimed to address the limitations of a previous study, which produced (R,R)-2,3-BDO with only 98% purity despite Kp-dhaD overexpression. First, BLi-gldA demonstrated significantly higher activity and selectivity in converting racemic acetoin to (R,R)-2,3-BDO compared to others among 2,3-BDO dehydrogenases (Kp-dhaD and Kp-gldA from Klebsiella pneumoniae, and BLi-gldA from Bacillus licheniformis). The K. pneumoniae GEM167 ΔadhEΔldhAΔbudC-BLi-gldA/pETM6 strain produced the highest (R,R)-2,3-BDO amount, with 99% purity (73.51 ± 1.69 g/L at 48 h), by isopropyl β-D-1-thiogalactopyranoside addition at the early exponential growth phase (6 h) compared to other cell growth phases. The availability of crude glycerol was investigated, and crude glycerol promoted cell growth resulting in efficient (R,R)-2,3-BDO in the early stage of culture [90.32 ± 1.12 g/L (R,R)-2,3-BDO with 99.0% purity after 60 h]. The productivity and yield remained comparable for crude glycerol (1.51 g/L/h, 0.41 g/g) and pure glycerol (1.53 g/L/h, 0.43 g/g).

Conclusions

This study successfully produced 99% enantiopure (R,R)-2,3-BDO from crude glycerol for the first time using the K. pneumoniae GEM167 ΔadhEΔldhAΔbudC-BLi-gldA/pETM6 strain. (R,R)-2,3-BDO production from crude glycerol, a biodiesel process byproduct, is expected to contribute to a sustainable and circular biomass supply chain and biodiesel production system by positively influencing the stable cultivation of biodiesel crops even under unpredictable climate conditions.

Graphical abstract

Boron toxicity is an increasingly serious problem leading to soil degradation and vegetation loss in arid and semi-arid environments worldwide. The soils of solonetzic complexes often display this characteristic. This study aimed to investigate the vertical distribution of hot water soluble-boron (hws-B) in the sodic and agricultural soils of Israna block in Haryana, India. The study also examined the influence of various soil variables on hws-B. The samples were collected at six depths to assess the availability of B. Additionally, an assessment was conducted to ascertain the appropriateness of the water sources for irrigation. The findings of our study revealed a notable disparity in the hws-B content between sodic soils and control agricultural soils, with the former exceeding the toxic thresholds. The levels of B available to plants were highest in the upper layers of soil and reduced as the depth increased. A number of variables influenced the water-soluble B content in sodic soils, particularly pH, calcite content, electrical conductivity (EC), organic matter (OM), and calcium-boron ratio (Ca/B). The results indicated that the boron levels in both surface and groundwater were within acceptable limits for irrigation purposes, suggesting that boron toxicity may not be directly attributed to these sources. Our study suggests that sodic soils contain high levels of boron, which can be toxic, and consequently, proper management of these soils is recommended. It is essential to have a comprehensive understanding of boron levels in surface and sub-surface soils, as well as in irrigation water, in order to effectively manage soil and improve crop productivity.