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  • Author or Editor: Yang Deng x
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Abstract

Platinum nanoparticles, synthesized via ethanol reduction of hexachloroplatinic acid in the presence of poly-(N-vinyl-2-pyrrolidone), were anchored on magnesium aluminate spinel using a colloidal deposition method. The samples were characterized using the following methods: transmission electron microscopy, powder X-ray diffraction, scanning electron microscopy, and energy dispersive X-ray spectroscopy. The results revealed that platinum nanoparticles, with an average diameter of 2.8 nm, are homogenously dispersed on the surface of the carrier. Under very mild conditions, supported Pt/MgAl2O4 catalysts demonstrated excellent catalytic activity and high selectivity in the hydrogenation reaction of benzaldehydes to benzyl alcohols. The reaction kinetics for the catalytic hydrogenation of 3-phenoxybenzaldehyde to 3-phenoxybenzyl alcohol on a Pt/MgAl2O4 catalyst can be described by equation , and the apparent activation energy is 35.6 kJ mol−1.

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Summary

Rapid high-performance liquid chromatographic methods with evaporative light scattering detection (HPLC-ELSD) and electrospray ionization multistage mass spectrometry (HPLC-ESI-MSn) have been established and validated for simultaneous qualitative and quantitative analysis of eight steroidal saponins in ten batches of Gongxuening capsule (GXN), a widely commercially available traditional Chinese preparation. The optimum chromatographic conditions entailed use of a Kromasil C18 column with acetonitrile-water (30:70 to 62:38, υ/υ) as mobile phase at a flow rate of 1.0 mL min−1. The drift tube temperature of the ELSD was 102°C and the nebulizing gas flow rate was 2.8 L min−1. Separation was successfully achieved within 25 min. LC-ESI-MSn was used for unequivocal identification of the constituents of the samples by comparison with reference compounds. The assay was fully validated for precision, repeatability, accuracy, and stability, then successfully applied to quantification of the eight compounds in samples. The method could be effective for evaluation of the clinical safety and efficacy of GXN.

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Authors: Yuping Shen, Minhui Xu, Peipei Deng, Qinying Gu, Huawu Yin, Guohua Xia, Xiaobin Jia, Huan Yang and James Tam

Red Toon is a popular vegetable of favorable health benefits over Asia and Russia regions. In this study, isolation and identification of chemical constituents were performed to assess the quality of this functional food cultivated in various origins or harvested in different months. As a result, eight flavonol glycosides including rutin (I), myricitrin (II), quercetin-3-O-β-d-galactoranoside (III), quercetin-3-O-β-d-glucopyranose (IV), quercetin-3-O-α-l-arabinopyranoside (V), astragalin (VI), quercetin-3-O-α-l-rhamopyranoside (VII), and kaempferol-3-O-α-l-rhamopyranoside (VIII) were obtained. Among these, compounds III and V were isolated from Toona genus for the first time. Importantly, a rapid and convenient ultra-performance liquid chromatography (UPLC) method was developed to quantify the flavonol glycosides in Red Toon and validated for linearity, precision, stability, repeatability, and accuracy successively. In addition, it was found that total flavonoid glycosides (about 2.6%) in the food were kept at a higher level from April to June than other months of the year. Furthermore, their content in the Red Toon collected from ten different origins was also determined and compared, and the results suggested that the total flavonoid glycosides from Shandong Yantai were the highest, followed by Shandong Ximou, supporting a well-recognized viewpoint that Red Toon cultivated in Shandong Province, China, is considered genuine due to the best health benefits and flavor.

Open access
Authors: J. P. Zhou, Y. Cheng, L. L. Zang, E. N. Yang, C. Liu, X. L. Zheng, K. J. Deng, Y. Q. Zhu and Y. Zhang

In this study, a new substitution line, 12-5-1, with 42 chromosomes that was derived from BC3F2 descendants of the hybridization between Triticum aestivum cv. CN19 and Aegilops biuncialis was created and reported. The 12-5-1 was immune to both powdery mildew and stripe rust and has stable fertility. Multi-color fluorescence in situ hybridization indicated that 12-5-1 was a substitution line 1Mb(1B). The seed storage protein electrophoresis showed that 12-5-1 presented high molecular weight glutenin subunits (2 + 12) of CN19 and a new subunit designated as M which apparently originated from parent Ae. biuncialis, and absent 7 + 8 subunits. Additionally, the flour quality parameters showed that the protein content, Zeleny sedimentation value, wet gluten content, and grain hardness and mixing time of 12-5-1 were signifiantly higher than those of its parent CN19. Moreover, 5 pairs of the chromosome 1Mb-specifi polymerase chain reaction-based landmark unique gene markers, TNAC1021, TNAC1026, TNAC1041, TNAC1-02 and TNAC1-04, were also obtained. The new substitution line 1Mb(1B) 12-5-1 could be a valuable source for wheat improvement, especially for wheat end product quality and resistance to disease.

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Authors: Ji-Bin Li, Anise M.S. Wu, Li-Fen Feng, Yang Deng, Jing-Hua Li, Yu-Xia Chen, Jin-Chen Mai, Phoenix K.H. Mo and Joseph T.F. Lau

Abstract

Background and aims

Problematic online social networking use is prevalent among adolescents, but consensus about the instruments and their optimal cut-off points is lacking. This study derived an optimal cut-off point for the validated Online Social Networking Addiction (OSNA) scale to identify probable OSNA cases among Chinese adolescents.

Methods

A survey recruited 4,951 adolescent online social networking users. Latent profile analysis (LPA) and receiver operating characteristic curve (ROC) analyses were applied to the validated 8-item OSNA scale to determine its optimal cut-off point.

Results

The 3-class model was selected by multiple criteria, and validated in a randomly split-half subsample. Accordingly, participants were categorized into the low risk (36.4%), average risk (50.4%), and high risk (13.2%) groups. The highest risk group was regarded as “cases” and the rest as “non-cases”, serving as the reference standard in ROC analysis, which identified an optimal cut-off point of 23 (sensitivity: 97.2%, specificity: 95.2%). The cut-off point was used to classify participants into positive (probable case: 17:0%) and negative groups according to their OSNA scores. The positive group (probable cases) reported significantly longer duration and higher intensity of online social networking use, and higher prevalence of Internet addiction than the negative group.

Conclusions

The classification strategy and results are potentially useful for future research that measure problematic online social networking use and its impact on health among adolescents. The approach can facilitate research that requires cut-off points of screening tools but gold standards are unavailable.

Open access