Search

A nonenzymatic uric acid sensor is proposed based on an electrophoretically deposited Graphene/ITO electrode (EDG). The morphology and structure of the EDGs were characterized by scanning electron microscopy (SEM) and Raman spectroscopy. As a result, the EDGs electrode was successfully fabricated with a well‐adhered graphene film on the ITO substrate surface. The electrochemical properties of the EDG for uric acid were investigated in PBS buffer pH 7.4, using cyclic voltammetry (CV) studies. Quantification of uric acid using both cyclic scanning and differential addition polarization methods. As a result, the uric acid sensor has a linear range from 1 to 100 μM, sensitivity 318.4 (μAcm2mM‐1) from CV measurements. Moreover, by the differential pulse voltammetry (DPV), the sensor has a linear range from 1 to 50 μM, a sensitivity of 1242.7 (μAcm2mM‐1), and the detection limit (LOD) of 0.6 μM (S/N = 3). The oxidation peak potential separation of uric acid, ascorbic, and dopamine at the EDG electrode showed that the uric sensor could eliminate interferences (ascorbic acid, dopamine) and be used to simultaneously determine uric acid, ascorbic acid, and dopamine.

AbstractThree compounds were identified from the ethanolic extract of Anemarrhena asphodeloidesBunge (A. asphodeloides) plant using silica gel chromatography. Their structures were confirmed by NMR and MS data analysis. The inhibitory activities against the MCF7 cancer cell line were evaluated and study the caspase 3 activation activity. Compound 3 exhibited good inhibitory activity and caspase 3 activation activity on the MCF7 cell line.

In this study, the authors investigated the anti-icing performance of a hierarchical slippery polymer thin film that is inspired by structures of the lotus leaf and Nepenthespitcher plant. The polymer solution was mixed with the lubricant at the appropriate concentration to achieve slippery properties. The dry etching method followed by the spin-coating process was used to generate a uniform polymer microstructure on the thin film. The polymer nanostructure was then yielded by an additional plasma-etching method using carbon tetrafluoride (CF4) gas. The anti-icing efficiency was then compared with that of the non-functional samples to demonstrate the advantages of combination in all criteria. Moreover, a theoretical prediction based on the free-energy approach was used to measure the nucleation time at the interface and illustrated good agreement with real-time measurement. The results propose a new and facile approach for outdoor anti-icing applications.

Background: Reaction of α,β-unsaturated ketones with o-phenylenediamine afforded corresponding 2,3-dihydro-1H-1,5-benzodiazepines. Objective: α,β-Unsaturated ketones of 6-acetyl-5-hydroxy-4-methylcoumarin are precursors for synthesis of 2,3-dihydro-1H-1,5-benzodiazepines by a reaction with o-phenylenediamine. Methods: Enones of 6-acetyl-5-hydroxy-4-methylcoumarin were prepared from this ketone and (un)substituted benzaldehydes in the presence of piperidine, triethylamine, or pyridine as a catalyst in absolute ethanol with 1:1 molar ratios, respectively. 2',3'-Dihydro-1H-1',5'-benzodiazepines were synthesized by using the reaction of these enones with o-phenylenediamine in absolute ethanol in the presence of glacial acetic acid as a catalyst. Their biological activities were evaluated using the disk diffusion method. Results: Seven new 2',3'-dihydro-1H-1',5'-benzodiazepines were obtained and their structures were confirmed by thin-layer chromatography, IR, NMR and MS spectra. Some synthesized benzodiazepines showed antibacterial and antifungal activities against Escherichia coli (Gram-(−) bacterium), Staphylococus epidermidis (Gram-(+) bacterium). Candida albicans (fungus). Conclusion: The formation of enones from 6-acetyl-5-hydroxy-4-methylcoumarin and (un)substituted benzaldehydes could be catalyzed by piperidine, triethylamine, pyridine to afford similar yields. 2',3'-dihydro-1H- 1',5'-benzodiazepines have been synthesized from the aforementioned enones and o-phenylenediamine.

In this report, two new steroidal glycosides were isolated and determined from n-butanol fraction of A.asphodeloides. The structures were confirmed in comparison with the spectral data of known compounds by using different spectroscopic analysis approaches including 1D & 2D-NMR techniques and HRMS. The anti-proliferation screening against cancer cell lines A549 and HeLa indicated that compound 1 exhibited good inhibitory activities with IC50 values of 0.79 and 0.55 μg/mL, respectively.

AbstractThe flowers of Polianthesspecies were collected in the Thai Nguyen city, Viet Nam. Their volatile oil extracts were obtained via supercritical CO2extraction and chemical compositions of the volatile oil part were subsequently analysed by GC-FID and GC/MS systems. Some major chemical compositions of volatile oil were identified as methyl 2-amino benzoate, isoeugenol, 1-Eicosene, indole, 5-octadecene, benzylbenzoate, diisobutylphthalate, 1-nonadecene, trans-farnesol. The chemical compositions of volatile oil of Polianthes sessiliflora(P. sessiliflora) and Polianthes longiflora(P. longiflora) species were being reported for the first time.The activities of total volatile oil extract of the Polianthesgenus flowers against HeLa, A459, and Hep-2 cancer cell lines were evaluated.

In this study, the background subtraction of cyclic voltammetry of a low oxidation peak at NiO based electrode is employed for the determination of glucose in human serum in 0.1 M NaOH medium with 2 linear ranges of 10 to 100 μM and 100 to 2000 μM with a detection limit of 2 μM and the sensitivities of 2942.2 and 754.2 μAcm−2mM−1, respectively. As a result, determining the glucose concentration in the real sample shows that this type of NiO-based sensor can be used in practice and approach to accurately determining the glucose concentration in human serum.