Chemical Papers最新文献

Traditional antifouling coatings for metal substrates typically involve three layers including an anticorrosion primer, a midcoat, and an antifouling paint. However, the limited bonding capacity between these layers restricts their effectiveness in industrial metal corrosion protection. In this work, we developed a single coating by dipping method on steel substrate that combines the anticorrosion properties of zinc and the antifouling properties of copper, using an ethyl silicate binder. This pigment mixture, containing flake ZnAl (5 wt%) and Cu₂O (10 wt%) with varying spherical Zn content (30, 40, and 50 wt%), was created and tested for its anticorrosion capabilities. Electrical properties were characterized using electrochemical impedance spectroscopy and the polarization curve method. Results showed that after 60 days of immersion in 3.5 wt% NaCl solution, the low-frequency impedance modulus of the coatings increased with higher Zn content, with the 40 wt% Zn content achieving the highest efficiency, showing an impedance modulus value of 56.43 kΩ cm². Stability evaluations revealed an increased release of Zn and Cu content in samples with higher Zn content. Antifouling assessments in natural seawater demonstrated that the Zn40 integrated coating had the lowest fouling density among the tested samples, with hard fouling surface coverage (FR ≥ 40) at 9.31% after three months. These findings highlight the effectiveness of the integrated coating utilizing Zn and Cu in providing robust corrosion protection, preventing settlement, and inhibiting fouling marine growth.

Salmonella is a common type of Gram-negative bacteria that is found in many food sources and can not only survive but also easily grow under unfavorable environmental conditions. Therefore, controlling Salmonella bacteria in agriculture, food, and processing industries is always a challenging issue, and the identification and detection of very small amounts of it are of great importance. Surface-enhanced Raman spectroscopy (SERS) has emerged as a reliable and accurate method for rapidly detecting small quantities of biological and chemical substances. In this study, a SERS biosensor was developed by utilizing a filter paper (FP) substrate that was coated with silver nanoparticles (AgNPs). The AgNPs were synthesized through a chemical reduction process and underwent characterization using DLS, UV–Vis, TEM, and FE-SEM. By coating the FP substrate with AgNPs, active plasmonic sites were created, enabling the detection of Salmonella molecular vibrations (MVs). When the FP substrate was exposed to Salmonella, an interaction occurred between the bacteria and the AgNPs, facilitating the identification of extremely low amounts of Salmonella. Additionally, the antibacterial properties of the AgNPs were observed. The SERS FP substrate exhibited the capability to detect Salmonella at concentrations as low as 10¹ CFU. Experimental measurements were conducted to obtain the Raman spectra and peak signals, and the reproducibility of the substrates was confirmed. The empirically calculated enhancement factor for identifying the Salmonella MVs was determined to be 1.448 × 10⁵; while, a numerical estimation yielded a value of 3.740 × 10⁵.

The process of adapting to changing environmental conditions plays a pivotal role in driving plant diversification. Elevational gradients provide a unique chance to explore adaptation to various climatic conditions. Aquilegia fragrans Benth. recognized as an important medicinal plant is distributed across various habitats with varying altitudes in the Kashmir Himalayan region. Nevertheless, a comprehensive examination of morphology and antioxidant phytochemicals concerning various environmental factors such as altitude and habitat conditions is currently lacking. The goal of this study is to understand the morphological and phytochemical variations, as well as antioxidant activity, in A. fragrans across diverse altitudes and habitats within the study area. The current investigation unveiled significant (p < 0.05) distinctions among populations of A. fragrans based on morphological, phytochemical, and antioxidant activity parameters. Across ten sampling sites phenolics (174 ± 2 mg GAE/g), flavonoids (109.14 ± 0.29 mg QE/g), BGFW (below ground fresh weight; 168.35 ± 4.3 g) and BGDW (below ground dry weight; 55.02 ± 1.42 g) were recorded maximum in Razdhan Pass followed by Mohand Marg population. Furthermore, the present investigation consistently validates the impact of altitude as a significant variable on the accumulation of phenolics and flavonoids in A. fragrans, and its antioxidant activity. Therefore, this research will be useful in identifying elite populations of target species and can aid in our knowledge of how plants modify the synthesis of secondary metabolites to adapt to harsh climatic conditions at higher altitudes. Moreover, HR-LCMS-QTOF was employed to identify bioactive compounds in the methanolic rhizome extract.

This study presents the production of polypropylene (PP) biocomposites utilizing different biomasses such as apricot kernel shell (AKS, 48% lignin), hazelnut shell (HS, 40%), walnut shell (WS, 35% lignin), and corn cob (CC, 15% lignin, 40% cellulose). The biocomposites were manufactured using a twin-screw extruder by varying the type and amount (5% to 20%) of biomass used as filler. The characterizations are done using spectral, thermal, and mechanical methods. In addition, using two different brands of PP samples the effects of crystallinity on thermal and mechanical properties of the biocomposites were examined. The composition of the biomass was important; higher lignin content (as in AKS) resulted in better compounding due to its hydrophobic behavior. Another important factor affecting the performance of the biocomposites was filler content. The optimum performance was obtained 10% content. In general, addition of the filler caused an increase in crystallinity which was detected by spectral and thermal methods.

The dust accumulation on the surfaces of photovoltaic (PV) modules greatly limits the development and promotion of solar PV power generation. In this study, extensive research is conducted on the characteristics of dust accumulation on the surface of PV modules from Wuhan and Dengkou, China, and their power generation performance. In addition, the influence of dust accumulation on PV system efficiency is investigated. The results indicate that the primary phase compositions of dust in Dengkou and Wuhan are SiO₂, Al₂O₃, CaAl₂Si₂O₄·4H₂O, CaCO₃ and CaO. The PV characteristics and degree of particle agglomeration of roof PV modules in urban cities are weaker and greater, respectively, than those of desert PV modules in arid and semiarid areas. The PV system efficiency in Wuhan and Dengkou reaches a minimum value in October and August, decreasing by 40.8% and 32.8%, respectively, in comparison with those without dust accumulation. Throughout the year, the PV system efficiency in Wuhan and Dengkou is greatest in February. The power generation decreases by 74.8% and the dust accumulation coefficient increases by 61.2%, as the density of dust accumulation varies from 4.92 to 8.51 g/m². The optical performance and PV module temperature reach their maximum values in July. Dust accumulation on the surface of PV modules can reduce their optical performance by 3.2–42.2%. The PV module temperature can be increased by a maximum of 1.1% with dust accumulation in September. PV system efficiency is greater in winter than in other seasons. These findings provide significant theoretical guidance related to solar PV module cleaning methods and power generation.

A low-cost adsorbent for Ni(II) uptake was developed using orange peel waste after pretreatment with ethanol/water at 40 °C for 6 h. Various experimental factors such as pH, adsorbent dosage, and contact time were investigated, with optimal conditions determined to be pH 5, an orange peel dose of 2.5 g/L, and a contact time of 90 min. The characterization of the adsorbent was analyzed. The linear and nonlinear isotherm and kinetic models were investigated. The Langmuir model suggested chemisorption with a 19.42 mg/g capacity, following pseudo-second-order kinetics. The thermodynamic analysis revealed that the uptake was exothermic (ΔH° < 0), feasible, and spontaneous (ΔG° < 0). Regeneration studies (NaCl, NaOH, HCl, HNO₃), interference studies (Al³⁺, Cd²⁺, Ca²⁺, Na⁺, mixed solution), and application studies with real water samples (wastewater, drainage water, tap water, bottled water) were also conducted. A possible uptake mechanism was suggested. Utilizing ethanol/water-pretreated orange peels (EOP) addresses organic biomass waste disposal and offers a cost-effective, readily available solution for heavy metal removal.

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The steroidal tetracyclic skeleton and the chalcones are considered as privileged structures in medicinal chemistry. In this endeavour, pregnenolone, which is considered as the main precursor of the all steroid hormones, was subjected to Claisen-Schmidt condensation with differently substituted benzaldehydes to synthesise 12 steroidal chalconoids or chalconoyl pregnenolones (PC-1 to PC-12) including 7 new chalconoids. The structural confirmation of the synthesised compounds was based on their IR, ¹H- and ¹³C-NMR, as well as the HRMS data. Three different in vitro antioxidant assays such as DPPH^• (2,2-diphenyl-1-picrylhydrazyl), ABTS^•+ (2,2́-azino-bis(3-ethylbenzothiazoline-6-sulphonic acid)), and FRAP (ferric reducing antioxidant power) assays were performed to evaluate the antioxidant properties of the synthesised compounds. Compound PC-3, with hydroxy substituents in the 3- and 4- positions of the benzaldehyde moiety, exhibited the highest antioxidant properties, with comparable FRAP value and radical inhibitory capability to the standards employed. The antidiabetic potential of the compounds was evaluated through the α-glucosidase inhibitory assay; in which significant α-glucosidase inhibitory potential (with over 50% inhibition of the enzyme) was demonstrated by the majority of the synthesised compounds. The compounds were tested against six different bacterial strains to ascertain their antibacterial properties. The results of the antibacterial studies, such as zone of inhibition against the selected Gram-positive and Gram-negative bacteria and their minimum inhibitory concentration values suggest that the synthesised compounds possess promising antimicrobial properties against the bacterial strains.

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This paper described the development of a practical, improved and efficient method for the multigram-scale synthesis of volasertib, an injectable bioavailable potent and selective inhibitor of PLK1. The key to this optimization was the design and development of a novel synthetic strategy, which involved the preparation of key intermediate 4-amino-N-{4-[4-(cyclopropylmethyl)piperazin-1-yl]cyclohexyl}-3-methoxybenzamide (W-5) through nitro reduction sequence and (7R)-2-chloro-7-ethyl-7,8-dihydro-8-(1-methylethyl)-6(5H)-pteridinone (W-11) through reductive cyclization and N-methylation reaction. The developed process provided 46% overall yield, which enabled us to rapidly synthesize multi-gram quantities of volasertib in 99.42% purity.

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A series of (2E)-3-[2,4-bis(2-propen-1-yloxy)phenyl]-1-phenyl]-2-propen-1-ones—chalcone derivatives with O-allyloxy groups—were synthesized in good yields and characterized by different analytical techniques. Their anticancer activity was evaluated against the A549 (lung cancer) cell line. The most active compounds of this series were the 1-(4-fluorophenyl derivative 9c (IC₅₀ = 0.48 ± 0.07 µM) and the 1-(4-octyloxy)phenyl derivative 9f (IC₅₀ = 0.04 ± 0.01 µM). Network pharmacology analysis using the SwissTarget and DisGeNet databases identified potential targets for 9c in the Non-Small Cell Lung Carcinoma (NSCLC) cell line. Protein–Protein Interaction (PPI) network analysis revealed seven hub genes: MAPK14, PTGS2, HSP90AA1, MAPK8, NOS2, SYK, and NR3C1. Gene ontology analysis highlighted diverse biological functions. KEGG pathway analysis implicated pathways in cancer and immunoregulation. Molecular docking analysis suggested a strong interaction between 9c with MAPK14 (calculated docking score of  –8.4 kcal mol^–1). Compound 9c's potent activity warrants further preclinical and clinical evaluation as a potential NSCLC therapy Based on this results, study of heterocyclic compounds with O-allyloxy groups will help to explore their impact on anticancer activity and mechanistic pathway.

A sustainable, eco-friendly, and effective adsorbent has been employed for the removal of eriochrome black T (EBT) toxic dye from the effluent. This adsorbent, derived from natural chalky limestone, underwent thorough characterization using various investigative tools, including X-ray diffraction, energy-dispersive X-ray spectroscopy, Brunauer–Emmett–Teller, field emission scanning electron microscopy, transmission electron microscopy, dynamic light scattering, zeta potential, thermogravimetric analysis (TGA), and ultraviolet–visible technique. The chalky limestone exhibited distinctive properties, achieving an efficient removal percentage and high capacity within a short timeframe. Kinetic studies were conducted to assess the reaction speed, employing both pseudo-first-order and pseudo-second-order models, yielding R² values of 0.67 and 0.62, respectively. Furthermore, thermal studies were carried out using Langmuir and Freundlich models to elucidate the interaction nature between the active sites of chalky limestone and EBT dye molecules, resulting in R² values of 0.75 and 0.91, respectively. The research findings indicated that the adsorption process achieved equilibrium in just five minutes with adsorption capacity (q_t) about 1.99 mg g⁻¹, and the chalky limestone showed the ability to be reused for up to five cycles without any decrease in removal efficiency or requiring a desorption step.