Superhydrophobic nanocomposite fiber membranes were prepared by blend electrospinning of poly(vinylidene fluoride) (PVDF) mixed with silane coupling agent modified SiO 2 nanoparticles. The nanoparticles were prepared by the sol-gel method, and the average particle diameter was measured by dynamic light scattering (DLS) and transmission electron microscopy (TEM). The effects of the type of silane coupling agent, such as n-octyltriethoxysilane, vinyltrimethoxysilane (A-171), and vinyltriethoxysilane (A-151), and the mass ratio of the modified silica particles and PVDF on the surface wettability of the composite fiber membrane were investigated. The results indicated that the incorporation of silane coupling agent modified silica particles into the PVDF membrane increased the roughness of the surface and formed micro/nano dual-scale structure compared to the pristine PVDF membrane, which was responsible for the superhydrophobicity and self-cleaning property of the nanocomposite fiber membranes. The value of water contact angle (CA) increased with the increase of the content of modified SiO 2 nanoparticles in the nanocomposite membrane, ranging from 149.88 to 160.18 as the mass ratio of modified 170 nm SiO 2 with PVDF matrix increased from 0.5:1 to 5:1, indicating the membrane possesses a superhydrophobic surface. V C 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2017, 134, 44501.
A simple, rapid, reproducible, and universal non-aqueous capillary electrophoresis method has been developed for the separation and determination of three major active protoberberine alkaloids including berberine, palmatine, and jatrorrhizine within 7 min. The effects of the concentrations of acetic acid and electrolyte, the ratio of organic solvent, and the applied voltage on the separation were investigated. The optimum running buffer was composed of 50 mM ammonium acetate, 0.5% (v/v) acetic acid, and 10% (v/v) acetonitrile in methanol. The applied voltage was 18 kV. The analytes were detected by UV at 214 nm. The linearities between peak areas and the concentrations of the analytes were also investigated, and they exhibit excellent linear behavior over the concentration ranges (correlation coefficients: 0.9975-0.9986). The method was successfully applied to determine the three alkaloids in several families of herbal drugs (Rhizoma Coptidis, Cortex Berberidis, Cortex Phellodendri, Herba Chelidonii, Caulis Mahoniae) and their relevant medicinal preparations for the first time, and the recoveries of the three constituents ranged between 95.6-103.2% for berberine, 97.5-103.3% for palmatine, and 96.1 -103.6% for jatrorrhizine.
In our continuing search for camptothecin (CPT)-derived antitumor drugs, novel structurally diverse PEG-based 20(S)-CPT sulfonylamidine derivatives were designed, synthesized via a Cu-multicomponent reaction (MCR), and evaluated for cytotoxicity against four human tumor cell lines (A-549, MDA-MB-231, KB, and KBvin). All of the derivatives showed promising in vitro cytotoxic activity against the tested tumor cell lines, and were more potent than irinotecan. Significantly, these derivatives exhibited comparable cytotoxicity against KBvin, while irinotecan was less active against this cell line. With a concise efficient synthesis and potent cytotoxic profiles, especially significant activity towards KBvin, these compounds merit further development as a new generation of CPT-derived PEG-conjugated drug candidates.
Optimum animal production depends on the type of feedstuffs available for the whole year. Plants such as trees and shrubs have significance in the animal production due to high nutritious values of tannins which reduce the rumen protein degradability and improve the feed digestibility as well as amino acid absorption in the small intestine. But, some of these plant materials are usually rich in anti-nutritional factors, known as tannins. Tannins are a complex group of plant secondary compounds widely distributed in the plant kingdom. Tannins have both deleterious and advantageous effects depending on the types, doses, composition and concentration of tannins. Rural farmers face fodder scarcity during the winter season. Therefore, tannins containing browse species may help farmers to use tannins as supplementary feed for livestock. But higher concentrations of tannins cause metabolic disorder which in results reduces the animal productivity. Therefore, it is need to investigate the effects of tannin supplementation in animal feeding; mitigation strategies to overcome the toxic effects of tannins on animal health. In this review paper, we have discussed safety and hazard associated with tannins in animal feeding.
The aminated graphene oxide (GO) was prepared by the functionalization of pristine GO with ethylenediamine and then dispersed into the poly(amic acid) (the precursor of polyimide [PI]) solution followed by the chemical imidization to successfully fabricate the PI/amine‐functionalized GO mixed matrix membranes (MMMs) using in‐situ polymerization method. Chemical structure and morphology of the GO before and after amine modification were characterized by scanning electron microscopy, Raman spectrum, Fourier transform infrared, and X‐ray photoelectron spectroscopy. Scanning electron microscopy indicated that fine dispersion of GO throughout PI matrix was achieved, which indicates that the in‐situ polymerization approach can enhance the interfacial interaction between the GO and the PI matrix, and then improve the dispersion of carbon material in the polymer matrix. Compared with the conventional solution mixture method, the MMMs prepared with in‐situ polymerization method showed excellent CO2 permeability and CO2/N2 selectivity. The MMMs doped with 3 wt.% aminated GO exhibited maximum gas separation performance with a CO2 permeability of 12.34 Barrer and a CO2/N2 selectivity of 38.56. These results suggest that the amino groups on GO have strong interaction with the CO2 molecules, which can significantly increase the solubility of polar gas. Our results provide an easy and efficient way to prepare MMMs with good mechanical behavior and excellent gas separation performance.
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