Bayberry Tannin as Stabilizer for the Synthesis of Highly Active and Reusable Heterogeneous Pd Catalysts and Their Application in the Catalytic Hydrogenation of Olefins

Chen, Chen,Lv, Guang,Huang, Xin,Liao, Xue Pin,Zhang, Wen Hua,Shi, Bi Korean Chemical Society 2012 Bulletin of the Korean Chemical Society Vol.33 No.2

In this study, the homogenous Pd nanoparticles (Pd NPs) were first prepared with bayberry tannin (BT) as the stabilizers. Subsequently, the obtained bayberry tannin-stabilized Pd nanoparticles (BT-Pd) were immobilized onto ${\gamma}-Al_2O_3$ to prepare heterogeneous ${\gamma}-Al_2O_3$-BT-Pd catalysts. Fourier Transformation Infrared Spectrum (FTIR) and X-ray Photoelectron Spectroscopy (XPS) analyses confirmed that the Pd NPs were well stabilized by the phenolic hydroxyl groups of BT. Transmission Electron Microscopy (TEM) observation indicated that the diameter of the Pd NPs can be effectively controlled in the range of 4.2-16.0 nm by varying the amount of BT. It is found that the ${\gamma}-Al_2O_3$-BT-Pd catalysts exhibit highly activity for various olefin hydrogenations. For example, the initial TOF (turnover frequency) of the ${\gamma}-Al_2O_3$-BT-Pd in the allyl alcohol hydrogenation is as high as $12804 mol{\cdot}mol^{-1}{\cdot}h^{-1}$. Furthermore, the ${\gamma}-Al_2O_3$-BT-Pd can be reused 5 times without significant loss of activity, exhibiting a superior reusability as compared with conventionally prepared ${\gamma}-Al_2O_3$-Pd catalysts.

SERS study of surface plasmon resonance induced carrier movement in Au@Cu₂O core-shell nanoparticles

Chen, Lei,Zhang, Fan,Deng, Xin-Yu,Xue, Xiangxin,Wang, Li,Sun, Yantao,Feng, Jing-Dong,Zhang, Yongjun,Wang, Yaxin,Jung, Young Mee Elsevier 2018 Spectrochimica acta. Part A, Molecular and biomole Vol.189 No.-

<P><B>Abstract</B></P> <P>A plasmon induced carrier movement enhanced mechanism of surface-enhanced Raman scattering (SERS) was investigated using a charge-transfer (CT) enhancement mechanism. Here, we designed a strategy to study SERS in Au@Cu<SUB>2</SUB>O nanoshell nanoparticles with different shell thicknesses. Among the plasmonically coupled nanostructures, Au spheres with Cu<SUB>2</SUB>O shells have been of special interest due to their ultrastrong electromagnetic fields and controllable carrier transfer properties, which are useful for SERS. Au@Cu<SUB>2</SUB>O nanoshell nanoparticles (NPs) with shell thicknesses of 48–56nm are synthesized that exhibit high SERS activity. This high activity originates from plasmonic-induced carrier transfer from Au@Cu<SUB>2</SUB>O to 4-mercaptobenzoic acid (MBA). The CT transition from the valence band (VB) of Cu<SUB>2</SUB>O to the second excited π-π* transition of MBA, and is of b<SUB>2</SUB> electronic symmetry, which was enhanced significantly. The Herzberg-Teller selection rules were employed to predict the observed enhanced b<SUB>2</SUB> symmetry modes. The system constructed in this study combines the long-range electromagnetic effect of Au NPs, localized surface plasmon resonance (LSPR) of the Au@Cu<SUB>2</SUB>O nanoshell, and the CT contribution to assist in understanding the SERS mechanism based on LSPR-induced carrier movement in metal/semiconductor nanocomposites.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We designed a shell-dependent Au@Cu<SUB>2</SUB>O nanoshell for SERS study. </LI> <LI> SERS contribution enables us to understand the possible enhancement of hybrid nanostructures. </LI> <LI> LSPR-induced carrier movement in Au@Cu<SUB>2</SUB>O nanocomposites. </LI> </UL> </P> <P><B>Graphical Abstract</B></P> <P>We designed the shell-dependent Au@Cu<SUB>2</SUB>O core-shell nanoparticles (NPs) for SERS study. For the electron-hole pairs in the Cu<SUB>2</SUB>O, the plasmon induced resonant energy transfer from Au to the Cu<SUB>2</SUB>O and the direct electron transfer simultaneously which can be observed from the SERS intensity.</P> <P>[DISPLAY OMISSION]</P>

Paint Removal of Airplane & Water Jet Application

Xue, Sheng-Xiong,Chen, Zheng-Wen,Ren, Qi-Le,Su, Ji-Xin,Han, Cai-Hong,Pang, lei Korean Society for Fluid machinery 2014 International journal of fluid machinery and syste Vol.7 No.3

The paint removal and recoating are the very important process in airplane maintenance. The traditional technology is to use the chemical way corroding the paint with paint remover. For changing the defects, corrosion & pollution & manual working, of the traditional technology, the physical process which removes the paint of airplane with 250MPa/250kW ultra-high pressure rotary water jetting though the surface cleaner installed on the six axes robot is studied. The paint layer of airplane is very thin and close. The contradiction of water jetting paint removal is to remove the paint layer wholly and not damage the surface of airplane. In order to solve the contradiction, the best working condition must be reached through tests. The paint removal efficiency with ultra-high pressure and move speed of not damaged to the surface. The move speed of this test is about 2m/min, and the paint removal efficiency is about $30{\sim}40m^2/h$, and the paint removal active area is 85-90%. No-repeat and no-omit are the base requests of the robot program. The physical paint removal technology will be applied in airplane maintenance, and will face the safety detection of application permission.

Colorectal Cancer Screening in High-risk Populations: a Survey of Cognition among Medical Professionals in Jiangsu, China

Chen, Yao-Sheng,Xu, Song-Xin,Ding, Yan-Bing,Huang, Xin-En,Deng, Bin,Gao, Xue-Feng,Wu, Da-Cheng Asian Pacific Journal of Cancer Prevention 2013 Asian Pacific journal of cancer prevention Vol.14 No.11

To investigate the cognition of medical professionals when following screening guidelines for colorectal cancer (CRC) and barriers to CRC screening. Between February 2012 and December 2012, an anonymous survey with 19-questions based on several CRC screening guidelines was randomly administered to gastroenterologists, oncologists, general surgeons, and general practitioners in Jiangsu, a developed area in China where the incidence of CRC is relatively high. The average cognitive score was 26.4% among 924 respondents. Gastroenterologists and oncologists had higher scores compared with others (p<0.01 and p<0.01, respectively); doctor of medicine (M.D.) with or without doctor of philosophy (Ph.D.) or holders with bachelor of medical science (BMS) achieved higher scores than other lower degree holders (P<0.05). More importantly, doctors who finished CRC related education in the past year achieved higher scores than the others (p<0.001). The most commonly listed barriers to referring high-risk patients for CRC screening were "anxiety about colonoscopy without anesthesia", "lack of awareness of the current guidelines" and "lack of insurance reimbursement". Lack of cognition was detected among doctors when following CRC screening guidelines for high-risk populations. Educational programs should be recommended to improve their cognition and reduce barriers to CRC screening.

Performance-based Analysis of Elastoplastic Rotational Behavior of Multi-cell Shaped Concrete-filled Steel Tubular Connection

Xi Chen,Jian-yang Xue,Hechao Li,Guangxu Tu,Xin Lu 대한토목학회 2023 KSCE Journal of Civil Engineering Vol.27 No.10

Experimental and theoretical research on the rotational behavior of Multi-cell shaped concrete-filled steel tubular (MCFST) connection under low-period cyclic load is performed. The experimental results showed that the design parameters had significant effects on the elastic rotational stiffness of the connection, and affected the sequence and position of the plastic hinges appearance at the column and beam ends. Furthermore, the damage mechanism of the plastic hinge lines is obtained, and the simultaneous yielding for the plastic hinges results in the rapid increase of the beam end rotation. In order to handle the problem with irregular geometry boundary and uneven distribution of tightening-ring stresses a differential element of an unified material is proposed considering the effective tightening-ring stresses of special-shaped steel tube on confined concrete, which can be used to analyse the whole mechanical and damage performance of the connection. Combining unified design theory and experimental results, the calculation for the elastic bending rigidity of the connection is obtained. Finally, the moment-rotation relation model of the connection is proposed by regression analysis on experimental results, and the theoretical results are observed to agree well with the experimental results.

Finite Element Analysis on the Mechanical Properties of Self-lubricating Fabric Liners Based on Periodic Boundary Conditions

Yahong Xue,Jigang Chen,Xin Shi,Jichuan Yao,Junting Luo 한국섬유공학회 2018 Fibers and polymers Vol.19 No.3

A new parameterized finite element model was established for self-lubricating fabric liners in different weaving patterns. This model precisely simulated the spatial configuration of woven yarns with consideration of the cross-section deformation as well as the anisotropic material characteristics of yarns by converting the principal material direction along the yarn-path. Moreover, a set of simple and universal periodic boundary equations was proposed to solve the problem of the overabundance restriction in the boundary surfaces. To verify the validation of the finite element method proposed in this paper, an experimental prediction on elastic constants of self-lubricating fabric liners was carried out. The results indicate that the finite element model can successfully predict the macro mechanical properties of self-lubricating fabric liners with periodical structures. Based on the finite element model, the distributions of stress and strain, as well as the effects of weaving type and weaving density on the elastic modulus of fabric liners were investigated in details.

Involvement of Lysosome Membrane Permeabilization and Reactive Oxygen Species Production in the Necrosis Induced by Chlamydia muridarum Infection in L929 Cells

( Lixiang Chen ),( Cong Wang ),( Shun Li ),( Xin Yu ),( Xue Liu ),( Rongrong Ren ),( Wenwen Liu ),( Xiaojing Zhou ),( Xiaonan Zhang ),( Xiaohui Zhou ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.4

Chlamydiae, obligate intracellular bacteria, are associated with a variety of human diseases. The chlamydial life cycle undergoes a biphasic development: replicative reticulate bodies (RBs) phase and infectious elementary bodies (EBs) phase. At the end of the chlamydial intracellular life cycle, EBs have to be released to the surrounded cells. Therefore, the interactions between Chlamydiae and cell death pathways could greatly influence the outcomes of Chlamydia infection. However, the underlying molecular mechanisms remain elusive. Here, we investigated host cell death after Chlamydia infection in vitro, in L929 cells, and showed that Chlamydia infection induces cell necrosis, as detected by the propidium iodide (PI)-Annexin V double-staining flow-cytometric assay and Lactate dehydrogenase (LDH) release assay. The production of reactive oxygen species (ROS), an important factor in induction of necrosis, was increased after Chlamydia infection, and inhibition of ROS with specific pharmacological inhibitors, diphenylene iodonium (DPI) or butylated hydroxyanisole (BHA), led to significant suppression of necrosis. Interestingly, live-cell imaging revealed that Chlamydia infection induced lysosome membrane permeabilization (LMP). When an inhibitor upstream of LMP, CA-074-Me, was added to cells, the production of ROS was reduced with concomitant inhibition of necrosis. Taken together, our results indicate that Chlamydia infection elicits the production of ROS, which is dependent on LMP at least partially, followed by induction of host-cell necrosis. To our best knowledge, this is the first live-cell-imaging observation of LMP post Chlamydia infection and report on the link of LMP to ROS to necrosis during Chlamydia infection.

Association between Dietary Factors and Breast Cancer Risk among Chinese Females: Systematic Review and Meta-analysis

Liu, Xue-Ou,Huang, Yu-Bei,Gao, Ying,Chen, Chuan,Yan, Ye,Dai, Hong-Ji,Song, Feng-Ju,Wang, Yao-Gang,Wang, Pei-Shan,Chen, Ke-Xin Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.3

Background: Evidence for associations between dietary factors and breast cancer risk is inconclusive among Chinese females. To evaluate this question, we conducted a systematic review of relevant case-control and cohort studies. Methods: Studies were systematically searched among 5 English databases (PudMed, ScienceDirect, Wiley, Clinicaltrials.gov, and Cochrane) and 3 Chinese databases (CNKI, WanFang, and VIP) until November 2012. Random effects models were used to estimate summary odds ratios (ORs) and the corresponding 95% confidence intervals (CIs). Results: Thirty one case-control studies and two cohort studies involving 9,299 cases and 11,413 controls were included. Consumption of both soy and fruit was significantly associated with decreased risk of breast cancer, with summary ORs of 0.65 (95% CIs: 0.43-0.99; I2=88.9%, P<0.001; N=13) and 0.66 (95% CIs: 0.47-0.91; $I^2$=76.7%, P<0.001; N=7), respectively. Consumption of fat was significantly associated with increased risk of breast cancer (OR=1.36; 95% CIs: 1.13-1.63; $I^2$=47.9%, P=0.088; N=6). There was nonsignificant association between consumption of vegetables and breast cancer risk (OR=0.72; 95% CIs: 0.51-1.02; $I^2$= 74.4%, P<0.001; N=9). However, sensitivity analysis based on adjusted ORs showed decreased risk of breast cancer was also associated with consumption of vegetables (OR=0.49; 95% CIs: 0.30-0.67). Conclusion: Both soy food and fruit are significantly associated with decreased risk of breast cancer among Chinese females, and vegetables also seems to be protective while dietary fatexerts a promoting influence.

Highly efficient catalytic valorization of biomass-derived furfural in methanol and ethanol

Haigang Zhang,Xinli Tong,Yiqi Gao,Hui Chen,Pengfei Guo,Song Xue 한국공업화학회 2019 Journal of Industrial and Engineering Chemistry Vol.70 No.-

Catalytic valorization of furfural (FUR) using a simple and low-cost metal catalyst has been considered asa hot topic in sustainable chemistry. In this work, a new Ni@R-Ca catalyst is prepared via the autocombustionand in situ reduction method. When it is employed to promote the catalytic valorization ofFUR in aliphatic alcohol, a nearly complete FUR conversion with excellent product selectivity is obtainedunder mild reaction conditions. Using methanol as reaction medium, the sole product is furfuryl alcohol(FA) in which ca. 99% yield of FA was attained. While, in ethanol, the obtained products mainly contain FAand furan-2-acrolein (FUA) in which a 94% conversion of FUR with a 91% total selectivity of FA and FUAwas acquired. Based on the characterization of catalyst including XRD, SEM, XPS and H2-TPR techniques,it is concluded that the synergy effect of metal Ni and R-Ca crystal lattice plays a crucial role in theefficient conversion of FUR in aliphatic alcohol.

Shear behavior of concrete-encased square concrete-filled steel tube members: Experiments and strength prediction

Yong Yang,Xin Chen,Yicong Xue,Yunlong Yu,Chaorui Zhang 국제구조공학회 2021 Steel and Composite Structures, An International J Vol.38 No.4

This paper presents experiments and theoretical analysis on shear behavior of eight concrete-encased square concrete-filled steel tube (CECFST) specimens and three traditional reinforced concrete (RC) specimens. A total of 11 specimens with the test parameters including the shear span-to-depth ratio, steel tube size and studs arrangement were tested to explore the shear performance of CECFST specimens. The failure mode, shear capacity and displacement ductility were thoroughly evaluated. The test results indicated that all the test specimens failed in shear, and the CECFST specimens enhanced by the interior CFST core exhibited higher shear capacity and better ductility performance than that of the RC specimens. When the other parameters were the same, the larger steel tube size, the smaller shear span-to-depth ratio and the existence of studs could lead to the more satisfactory shear behavior. Then, based on the compatible truss-arch model, a set of formulas were developed to analytically predict the shear strength of the CECFST members by considering the compatibility of deformation between the truss part, arch part and the steel tube. Compared with the calculated results based on several current design specifications, the proposed formulas could get more accurate prediction.