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161.
《Comptes Rendus Chimie》2014,17(2):135-140
The synthesis, IR, 31P NMR and cyclic voltammetry characterizations of new Wells–Dawson-type heteropolyanions that contain iron, HFe2.5P2W18O62, 23H2O and HFe2.5P2W12Mo6O62, 22 H2O, are reported. The catalytic activity of these compounds was evaluated through the oxidation of methyl violet dye, by hydrogen peroxide. The influence of different parameters such as the initial pH, the initial H2O2 concentration, the catalyst mass, and the initial dye concentration have been studied. 相似文献
162.
《Arabian Journal of Chemistry》2014,7(5):747-751
The copolymer carbazole–phenol formaldehyde doped with 4 (4-hydroxy-phenyl azo)-benzene sulfonic acid (PABS), 2,5-dimethyl benzene sulfonic acid (PXSA) and 4-hydroxy-m-benzene disulfonic acid (PDSA) were prepared. These compounds are identified by FT-IR spectroscopy.The conductivity of copolymer carbazole–phenol formaldehyde doped with 4 (4-hydroxy-phenyl azo)-benzene sulfonic acid (PABS), 2,5-dimethyl benzene sulfonic acid (PXSA) and 4-hydroxy-m-benzene disulfonic acid (PDSA) was studied as a function of weight of the dopant compounds; an increase of conductance of the copolymer by doping with PABS is noted; the conductance became equal to 0.000595 ohm−1 for 0.1 g higher conductance for the copolymer when it is doping with PABS. 相似文献
163.
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165.
Tomohiro Sakata Shingo Ogawa Keiko Inoue Yumiko Shimizu Yusaku Tanahashi 《Surface and interface analysis : SIA》2022,54(6):661-666
To systematically evaluate the quality of SiNx films in multi-stacked structures, we investigated the effects of post-deposition annealing (PDA) on the film properties of SiNx within the SiO2/SiNx/SiO2/Si stacked structure by performing X-ray photoelectron spectroscopy (XPS), X-ray reflectivity (XRR), Fourier transform infrared (FT-IR) spectroscopy, and scanning transmission electron microscope–electron energy loss spectroscopy (STEM-EELS) analyses. The XPS results showed that PDA induces the oxidation of the SiNx layer. In particular, new finding is that Si-rich SiNx in the SiNx layer is preferentially oxidized by PDA even in multi-stacked structure. The XRR results showed that the SiNx layer becomes thinner, whereas the interface layer between the SiNx layer and Si becomes thicker. It is concluded by STEM-EELS and XPS that this interface layer is SiON layer. The density of N–H and Si–H bonding within the stacked structure strongly depends on the PDA temperature. Our study helps elucidate the properties of SiNx films in stacked structures from various perspectives. 相似文献
166.
Bin Ran Chaozhan Chen Bo Liu Minbo Lan Huaying Chen Yonggang Zhu 《Electrophoresis》2022,43(20):2033-2043
The detection of cancer biomarkers is of great significance for the early screening of cancer. Detecting the content of sarcosine in blood or urine has been considered to provide a basis for the diagnosis of prostate cancer. However, it still lacks simple, high-precision and wide-ranging sarcosine detection methods. In this work, a Ti3C2TX/Pt–Pd nanocomposite with high stability and excellent electrochemical performance has been synthesized by a facile one-step alcohol reduction and then used on a glassy carbon electrode (GCE) with sarcosine oxidase (SOx) to form a sarcosine biosensor (GCE/Ti3C2TX/Pt–Pd/SOx). The prominent electrocatalytic activity and biocompatibility of Ti3C2TX/Pt–Pd enable the SOx to be highly active and sensitive to sarcosine. Under the optimized conditions, the prepared biosensor has a wide linear detection range to sarcosine from 1 to 1000 µM with a low limit of detection of 0.16 µM (S/N = 3) and a sensitivity of 84.1 µA/mM cm2. Besides, the reliable response in serum samples shows its potential in the early diagnosis of prostate cancer. More importantly, the successful construction and application of the amperometric biosensor based on Ti3C2TX/Pt–Pd will provide a meaningful reference for detecting other cancer biomarkers. 相似文献
167.
Vijay Narayan Anoop Kumar Pandey Apoorva Dwivedi Benard Samwel Mwankemwa Avantika Maurya Ankit Kumar Sharma Vijay Singh 《印度化学会志》2022,99(8):100580
Uracil mustard belongs to the nitrogen mustard family and is primarily used in anticancer drugs. The research that follows, investigates many quantum chemical features such as the computation of global minimum energies with no negative wavenumber values using the Density Functional Theory (DFT) with Becke three functional and 6-311G (d, p)/6–311++G (d, p) basis sets. All the vibrational modes have been calibrated and justified in comparison to their experimental counterparts. Mustard's polarizability and hyperpolarizability components, Natural Bond Analysis (NBO), electronic properties, Fukui function analysis, various global parameters, Quantum Theory of Atoms In Molecule (QTAIM) analysis, ADMET analysis, and docking analysis have all been investigated using the same theory and basis sets, indicating its biochemical significance. The biological activity of the molecule is reported by using PASS software. The Full fitness score and binding affinity parameters are utilized to determine the binding strength with 6cq3 protein. The acidity of the title molecule is calculated in water solvent by polarizable continuum model (PCM) solvent effects (estimated in water). The HOMO, LUMO, and MESP plots are used to explore the nature of binding and surfaces. The Fukui functions are computed using Mulliken atomic charges for neutral atoms, cations, and anions. The Ultraviolet–visible (UV–vis) of the molecule is computed employing the TD-DFT method. 相似文献
168.
The progress in the development of gas sensors has considerably grown using some novel nanomaterials of metal, metal oxide and composite. In the current study, we intended and evaluated the properties of nanomaterials like CeO2, NiO, and CeO2–NiO composite and its application as NO2 gas sensor. Sensing of low concentration of NO2 gas at optimum functional temperature was succeeded using CeO2–NiO nanocomposites (NCs) film. The working temperature ranges in between 100 and 225 ?°C. Highly crystalline nanomaterials (CeO2, NiO and CeO2–NiO) have been prepared by applying microwave-assisted sol-gel route. The as-prepared nanomaterials are characterized for their structure, size, morphology and constitution by X-ray diffraction (XRD), scanning electron microscopy (SEM) and energy dispersive X-ray analysis. XRD studies of nanoparticles reveal the formation of nanoscale CeO2 and NiO with crystallite size 26, 23 ?nm, respectively. Both are having a face centered cubic structure. The nanocomposite (NC) Ce:Ni ?= ?60:40 has crystallite size of 13 ?nm. XRD study of NCs shows assimilation of Ni metal into the ceria and proves physical similarities of two phases. It can be observed from SEM that prepared NC has a porous surface which enables more surface active sites for adsorbing oxygen. The optical properties are measured with the help of UV–Vis. Spectroscopy. Optical band gaps of 3.19, 3.41 and 2.9 ?eV were observed for CeO2, NiO nanoparticles (NPs) and CeO2–NiO NC, respectively. Gas sensing properties state that the NC material shows a higher gas response % of 67.34% for NO2 gas (25 ?ppm) at comparatively low operating temperature (125 ?°C). It gives response time as (~28 ?s) and the recovery (~54 ?s). NiO incorporation in CeO2 results in a decline of operating temperature of NC and improves the sensing features. 相似文献
169.
Divya Kumar Vemuri Rambabu Gundla Naresh Konduru Ravindra Mallavarapu Naresh Kumar Katari 《Biomedical chromatography : BMC》2022,36(6):e5363
Favipiravir finished dosage was approved for emergency use in many countries to treat SARS-CoV-2 patients. A specific, accurate, linear, robust, simple, and stability-indicating HPLC method was developed and validated for the determination of degradation impurities present in favipiravir film-coated tablets. The separation of all impurities was achieved from the stationary phase (Inert sustain AQ-C18, 250 × 4.6 mm, 5-μm particle) and mobile phase. Mobile phase A contained KH2PO4 buffer (pH 2.5 ± 0.05) and acetonitrile in the ratio of 98:2 (v/v), and mobile phase B contained water and acetonitrile in the ratio of 50:50 (v/v). The chromatographic conditions were optimized as follows: flow rate, 0.7 mL/min; UV detection, 210 nm; injection volume, 20 μL; and column temperature, 33°C. The proposed method was validated per the current International Conference on Harmonization Q2 (R1) guidelines. The recovery study and linearity ranges were established from the limit of quantification to 150% optimal concentrations. The method validation results were found to be between 98.6 and 106.2% for recovery and r2 = 0.9995–0.9999 for linearity of all identified impurities. The method precision results were achieved below 5% of relative standard deviation. Forced degradation studies were performed in chemical and physical stress conditions. The compound was sensitive to chemical stress conditions. During the study, the analyte degraded and converted to unknown degradation impurities, and its molecular mass was found using the LC–MS technique and established degradation pathways supported by reaction of mechanism. The developed method was found to be suitable for routine analysis of research and development and quality control. 相似文献
170.
Eva Greibe Magnus Leth-Møller Sofie Stampe Per Ovesen Michael Pedersen Elke Hoffmann-Lücke 《Biomedical chromatography : BMC》2022,36(6):e5350
Artificial sweeteners are widely used as substitutes for sugar. The sweeteners are generally considered safe, however their whereabouts during pregnancy and lactation and the effect on child development are poorly explored. There is a need for new tools to measure these substances during pregnancy and lactation. Here, we describe the development and validation of a sensitive liquid chromatography–tandem mass spectrometry method for the simultaneous quantification of acesulfame, cyclamate, saccharin and sucralose in human plasma, umbilical cord blood, amniotic fluid and breast milk. The samples were prepared by protein precipitation and separated on a Luna Omega Polar C18 column (2.1 × 50 mm, 1.6 μm). Electrospray ionization in negative mode and multiple reaction monitoring were used to monitor the ion transitions. The validated concentration ranges were from 1 to 500 ng/ml (10–500 ng/ml for sucralose). Interassay precisions were all ≤15% and the accuracies were within ±15%. Stability, linearity, dilution integrity, carryover and recovery were also examined and satisfied the validation criteria. Finally, this analytical method was successfully applied on spiked samples of plasma, umbilical cord blood, amniotic fluid and breast milk, proving its suitability for use in clinical studies on artificial sweeteners, including during pregnancy and lactation. 相似文献