Authors:Peng Yuan, Zhongyi Liu, Tianjun Hu, Haijie Sun, and Shouchang Liu
A Cu–Zn–Al catalyst was prepared by the co-precipitation method and was applied for the hydrogenation of dimethyl adipate.
Selectivity to 1,6-hexanediol exceeding 99% was obtained at 99% conversion of dimethyl adipate. The catalyst was highly efficient
and stable. The influences of the calcination temperature of the catalyst were studied.
Authors:Qingrong Peng, Chunrong Zhang, Youzhu Yuan, and Shicong Hou
A series of (o-alkylaminophenyl)diphenylphosphine ligands (P–N ligands) containing different alkyl carbon numbers or amino groups have been
synthesized and characterized by IR and NMR (1H, 13C, 31P). The rhodium complexes ligated with P–N ligands in the hydroformylation of 1-hexene showed a considerable enhancement with
the addition of water. NMR characterization studies suggested that the addition of water would engage in hydrogen bonding
to the nitrogen atom of the coordinated P–N ligand, inhibiting the internal Rh–N interaction and generating more of the active
unsaturated Rh-species that could react with 1-hexene to start the hydroformylation.
Authors:Qi Tao, Hongping He, Ray Frost, Peng Yuan, and Jianxi Zhu
Anionic surfactant and silane modified layered double hydroxides (LDHs) were synthesized through an in situ coprecipitation
method. The structure and morphology were characterized by XRD and TEM techniques, and their thermal decomposition processes
were investigated using infrared emission spectroscopy (IES) combined with thermogravimetry (TG). The surfactant modified
LDHs (H-DS) shows three diffractions located at 1–7° (2θ), while there is only one broad reflection for silane grafted LDHs
(H–Si) in this region. The morphologies of the H-DS and H–Si show fibrous exfoliated layers and curved sheets, respectively.
The IES spectra and TG curves indicate that alkyl chain combustion and dehydroxylation are overlapped with each other during
heating from 373 to 723 K in H-DS and to 873 K in H–Si. Sulfate anion transformation process occurs at 473 K in H-DS and 523 K
in H–Si. The derivant of sulfate can exist even above 1073 K. After further decomposition, the metal oxides and the new type
of Si–O compounds are formed beginning at around 923 K in silane modified sample.
Authors:Jianxi Zhu, Wei Shen, Yuehong Ma, Lingya Ma, Qing Zhou, Peng Yuan, Dong Liu, and Hongping He
Organically modified clay minerals with high thermal stability are critical for synthesis and processing of clay-based nanocomposites. Two series of organo-montmorillonites have been synthesized using surfactants with different alkyl chain length. The organo-montmorillonites were characterized by X-ray diffraction and differential thermogravimetry, combining with molecule modelling. For surfactant with relatively short alkyl chain, the resultant organo-montmorillonite displays a small maximum basal spacing (ca. 1.5 nm) and most surfactants intercalate into montmorillonite interlayer spaces as cations with a small amount of surfactant molecules loaded in the interparticle pores with “house-of-cards” structure. However, for surfactant with relatively long alkyl chain, the resultant organo-montmorillonite displays a large maximum basal spacing (ca. 4.1 nm) and the loaded surfactants exist in three formats: intercalated surfactant cations, intercalated surfactant molecules (ionic pairs), and surfactant molecules in interparticle pores. The surfactant molecules (ionic pairs) in interparticle pores and interlayer spaces will be evaporated around the evaporation temperature of the neat surfactant while the intercalated surfactant cations will be evaporated/decomposed at higher temperature.
Authors:Y. Feng, S. Zhang, X. Peng, J. Yuan, Y. Yang, H. Zhan, and Y. Gong
In mammals, testis development is initiated by the expression of the sex-determining gene,
, where-as the genetic trigger for sex determination in birds remains unknown. In the present study, the expression of seven genes implicated in vertebrate sex determination and differentiation were studied in chicken embryonic gonads from day 4 to day 12 of incubation using reverse transcription and the polymerase chain reaction (RT-PCR). Results showed transcription of c
were sexually dimorphic during chicken gonadal development, whereas c
were expressed at similar levels in both sexes. Results of comparative studies between mammals and chickens show that vertebrate sex-determining pathways comprise both conserved and divergent elements: expression profiles of c
are similar to those in mammals, while others appear some differences. Possible functions of these genes on chicken gonadal development were analyzed based on their expression profiles.
Authors:Peng Sun, Cunquan Yuan, Li Dai, Yang Xi, Yunfei Li, Ruiyang Hu, Yuhan Sun, Zhaohe Xu, and Yun Li
Emasculation and bagging of flowers, which are widely used in the controlled pollination of monoclinous plants, may induce premature senescence, flower abscission and low fruit set. To determine the mechanism responsible for these phenomena, levels of abscisic acid (ABA), jasmonic acid (JA), indole-3-acetic acid (IAA), ethylene, soluble sugars, reducing sugars and free amino acids in black locust (Robinia pseudoacacia) flowers subjected to different treatments were quantified at different developmental stages. The phytohormones and assimilates were also quantified in untreated flowers to investigate the presence of discernible patterns. The levels of ethylene and ABA in emasculated and bagged (EB) flowers increased prematurely compared with those of untreated flowers, whereas the content of reducing sugars in EB flowers decreased compared with that of untreated flowers. These results indicated that the premature increase in ethylene and ABA synthesis, and the decrease in reducing sugars content, in EB flowers may cause flower abscission and result in low fruit set, which may be relevant for assimilate applications and future research on the regulation of controlled pollinations with exogenous phytohormones.
Authors:Jin-Peng Yuan, Zhao-Jie Cui, Chuan-Ge Cheng, Xiao-Li Wang, Shan-Shan Wang, Xin-Li Song, and Fu-Wei Li
A rapid and simple analytical method based on matrix solid-phase dispersion combined with liquid chromatography coupled with tandem mass spectrometry has been developed by using bamboo charcoal as a dispersive adsorbent to simultaneously determine tetrabromobisphenol A (TBBPA) and hexabromocyclododecane diastereoisomers (HBCDs) in soil. The factors influencing the performance of the proposed method were investigated and optimized in detail, and the matrix effects were evaluated. Under optimum conditions, the proposed method showed good linearity within the range of 0.8–80 ng g−1 and limits of detection of 4–75 pg g−1 (S/N = 3). The satisfactory recoveries of TBBPA ranging from 72.8% to 92.5% and HBCDs ranging from 76.8% to 102.2% were obtained with relatively standard deviation (RSD) ranging from 3.4% to 9.8%. The proposed method has been successfully applied to analyze TBBPA and HBCDs in actual soil samples from the Yellow River Delta in China.
The aim of this study was to investigate the mechanisms of Internet gaming disorder (IGD) and the associated interaction effects of childhood trauma, depression and anxiety in college students.
Participants were enrolled full-time as freshmen at a University in the Hunan province, China. All participants reported their socio-demographic characteristics and undertook a standardized assessment on childhood trauma, anxiety, depression and IGD. The effect of childhood trauma on university students' internet gaming behaviour mediated by anxiety and depression was analysed using structural equation modelling (SEM) using R 3.6.1.
In total, 922 freshmen participated in the study, with an approximately even male-to-female ratio. A mediation model with anxiety and depression as the mediators between childhood trauma and internet gaming behaviour allowing anxiety and depression to be correlated was tested using SEM. The SEM analysis revealed that a standardised total effect of childhood trauma on Internet gaming was 0.18, (Z = 5.60, 95% CI [0.02, 0.05], P < 0.001), with the direct effects of childhood trauma on Internet gaming being 0.11 (Z = 3.41, 95% CI [0.01, 0.03], P = 0.001), and the indirect effects being 0.02 (Z = 2.32, 95% CI [0.00, 0.01], P = 0.020) in the pathway of childhood trauma-depression-internet gaming; and 0.05 (Z = 3.67, 95% CI [0.00, 0.02], P < 0.001) in the pathway of childhood trauma-anxiety-Internet gaming. In addition, the two mediators anxiety and depression were significantly correlated (r = 0.50, Z = 13.54, 95% CI [3.50, 5.05], P < 0.001).
The study revealed that childhood trauma had a significant impact on adolescents' Internet gaming behaviours among college students. Anxiety and depression both significantly mediated the relationship between childhood trauma and internet gaming and augmented its negative influence. Discussion of the need to understand the subtypes of childhood traumatic experience in relationship to addictive behaviours is included.