Poly (dimethylsiloxane)-poly (tetrafluoroethylene)/poly (vinylidenefluoride) (PDMS-PTFE/PVDF) hollow fiber composite membrane for pervaporation of chloroform from aqueous solution

De Sun,Ping Yang,Lin Li,Hai-Hua Yang,Bing-Bing Li 한국화학공학회 2014 Korean Journal of Chemical Engineering Vol.31 No.10

A novel PDMS-PTFE/PVDF hollow fiber composite membrane using PTFE-PDMS as the top active layerand PVDF hollow fiber as the support layer was prepared for the pervaporation of chloroform from water. Sorptionand diffusion behaviors of chloroform and water in PDMS-PTFE membranes, which had different PTFE content, wereinvestigated. The results showed that with increasing PTFE content from 0 wt% to 40 wt%, chloroform/water idealseparation factor first increased and then decreased, and permeabilities of both chloroform and water increased. Forthe 30% PTFE-PDMS membrane, when feed temperature ranged from 40 oC to 60 oC, permeabilities of both chloroformand water increased, but ideal separation factor for chloroform/water first increased and then decreased. Effects of op-erating conditions, such as feed flow rate, active layer thickness, feed concentration and feed temperature, on PV per-formances of the 30% PDMS-PTFE/PVDF hollow fiber membrane for the pervaporation of chloroform-water mixtureswere studied. Examination showed that concentration polarization on the membrane surface occurred when feed flowrate was less than 3,000 mL/min. With the increase in active layer thickness from 13.8 to 78.0 µm, chloroform fluxand water flux dropped from 21 to 13 g·h−1·m−2and from 93 to 22 g·h−1·m−2, respectively, but the separation factorincreased from 1494 to 3949. With an increase of feed concentration from 55 to 850 ppm, chloroform flux increasedlinearly but water flux remained constant, and separation factor decreased. With an increase of the feed temperaturefrom 40 to 60 oC, both flux and separation factor increased, the variation of permeation flux followed the Arrheniusrelationship, and the activation energy values were 21.65 and 9.6 KJ/mol for water and chloroform, respectively.

NANOTOXICITY OF MULTIWALL CARBON NANOTUBES TO A549 CELLS IN VITRO

FU-DE WANG,Ying Tang,Yong Ji Yang,CHAN JIN,HUA ZHANG,HAO LIANG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2014 NANO Vol.9 No.2

Multiwall carbon nanotubes (MWCNTs) have been widely applied in many ¯elds due to theexcellent physical and chemical properties. As the production and applications of nanotubesexpand, public concern about their potential risks to human health has also raised. Cytotoxicityof MWCNTs was evaluated in this study using a cultured human epithelial cell line A549. Uptakeof MWCNTs by cultured A549 cells was observed by TEM imaging. Dose-dependent decrease ofcell viability showed the cytotoxicity of MWCNTs. Signi¯cant reactive oxygen species (ROS)generation and GSH depletion which reduced the cellular antioxidant level could be the majorfactor of cytotoxicity induced by MWCNTs. MWCNTs seemed to trigger the activation of cellautophagy with the intracellular ATG16L1 level increase as a defense mechanism.

Effects of roasting on composition of chili seed and storage stability of chili seed oil

Run-Yang Zhang,Hua-Min Liu,Yu-Xiang Ma,Xue-De Wang 한국식품과학회 2019 Food Science and Biotechnology Vol.28 No.5

This work focused on how roasting changed the chemical components of chili (Capsicum annuum L.) seeds and how it affected the stability of chili seed oils during storage. The oils from chili seeds before and after roasting treatments were stored at 63 °C for 30 days and then analyzed. Results showed that roasting changed the main sugars compositions and amino acid compositions (total content decreased from 15.9 to 7.4%), which confirmed that it could form brown pigments and volatile flavor compounds in pepper seeds after roasting. Compared with oil from unroasted seeds, oils from roasted seeds had greater oxidative stability and maintained greater antioxidant capacity during storage. These effects were possibly due to the synergistic of the neo-formed products by Maillard reaction, vitamin E, and other bioactive components. This investigation showed that roasting treatment could be considered as an appropriate method for extending the storage stability of chili seed oils.

Efficacy and Safety of Intravenous Urapidil for Older Hypertensive Patients with Acute Heart Failure: A Multicenter Randomized Controlled Trial

Wei Yang,Qi Hua,Yu-Jie Zhou,Yan Fu,Jian Qin,Shu Qin,Xiao-Min Chen,Jin-Cheng Guo,De-Zhao Wang,Hong Zhan,Jing Li,Jing-Yu He 연세대학교의과대학 2017 Yonsei medical journal Vol.58 No.1

Purpose: Urapidil is putatively effective for patients with hypertension and acute heart failure, although randomized controlled trials thereon are lacking. We investigated the efficacy and safety of intravenous urapidil relative to that of nitroglycerin in older patients with hypertension and heart failure in a randomized controlled trial. Materials and Methods: Patients (>60 y) with hypertension and heart failure were randomly assigned to receive intravenous urapidil (n=89) or nitroglycerin (n=91) for 7 days. Hemodynamic parameters, cardiac function, and safety outcomes were compared. Results: Patients in the urapidil group had significantly lower mean systolic blood pressure (110.1±6.5 mm Hg) than those given nitroglycerin (126.4±8.1 mm Hg, p=0.022), without changes in heart rate. Urapidil was associated with improved cardiac function as reflected by lower N terminal-pro B type natriuretic peptide after 7 days (3311.4±546.1 ng/mL vs. 4879.1±325.7 ng/mL, p=0.027) and improved left ventricular ejection fraction (62.2±3.4% vs. 51.0±2.4%, p=0.032). Patients given urapidil had fewer associatedadverse events, specifically headache (p=0.025) and tachycardia (p=0.004). The one-month rehospitalization and all-cause mortality rates were similar. Conclusion: Intravenous administration of urapidil, compared with nitroglycerin, was associated with better control of blood pressure and preserved cardiac function, as well as fewer adverse events, for elderly patients with hypertension and acute heart failure.

Workspace analysis of 3-CPS parallel micro-manipulator for mirror active adjusting platform

Gang Cheng,Bing-jing Qiu,De-hua Yang,Hou-guang Liu 대한기계학회 2013 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.27 No.12

In order to adjust telescope mirrors with high precision, a 3 cylindrical-prismatic-spherical (CPS) parallel micro-manipulator with 6 degrees-of-freedom (DOF) and partial decoupling is proposed. Structure characteristics of the micro-manipulator were analyzed and the kinematic equations were derived based on Euler method. To avoid tedious derivation, Jacobian matrix with screw theory representing the input and output relation of micro-manipulator is established by using velocity influence coefficient method. Combining topological structure characteristics of the 3-CPS parallel micro-manipulator, the solving procedures of workspace are obtained. Moreover, the position workspace with a given orientation and the orientation workspace with a given translation position are constructed by numerical simulations. The workspace range is chosen as the optimization goal of structure parameters, and the circumcircle radius ratio of base and moving platform and the lengths of each sub-link are optimized. The maximum condition number and the minimum singular value are chosen as the precision indexes to analyze the precision performance of the workspace. Then, the properties of the position workspaces with various orientations and the orientation workspaces with various positions are simulated numerically, and the simulation results prove that the 3-CPS parallel micro-manipulator has an ability to achieve high precision operations. This research provides a workspace modeling and optimization method for the practical application in telescope mirror adjustment or other fields requiring high precision.

Antimicrobial glycoalkaloids from the tubers of Stephania succifera

Yan-Bo Zeng,Dai-Jing Wei,Wen-Hua Dong,Cai-Hong Cai,De-Lan Yang,Hui-Min Zhong,Wen-Li Mei,Hao Fu Dai 대한약학회 2017 Archives of Pharmacal Research Vol.40 No.4

Three new glycoalkaloids, N-formyl-asimilobine-2-O-b-D-glucoside (1), (-)-1-O-b-D-glucoside-8-oxotetrahydropalmatine(2), and 1-N-monomethylcarbamateargentinine-3-O-b-D-glucoside (3) were isolated fromtubers of Stephania succifera. The structures were establishedbased on spectroscopic analysis, and the antimicrobialactivities of the three glycoalkaloids are reported.

Association between the TP53BP1 rs2602141 A/C Polymorphism and Cancer Risk: A Systematic Review and Meta-Analysis

Liu, Lei,Zhang, Dong,Jiao, Jing-Hua,Wang, Yu,Wu, Jing-Yang,Huang, De-Sheng Asian Pacific Journal of Cancer Prevention 2014 Asian Pacific journal of cancer prevention Vol.15 No.6

Background: The p53-binding protein 1 (TP53BP1) gene may be involved in the development of cancer through disrupting DNA repair. However, investigation of associations between TP53BP1 rs2602141 A/C polymorphism and cancer have yielded contradictory and inconclusive outcomes. We therefore performed a meta-analysis to evaluate the association between the TP53BP1 rs2602141 A/C polymorphism and cancer susceptibility. Materials and Methods: Published literature from PubMed, Medline, the Cochrane Library, EMbase, Web of Science, Google (scholar), CBMDisc, Chongqing VIP database, and CNKI database were retrieved. Pooled odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using fixed or random-effects models. Publication bias was estimated using funnel plots, Begg's and Egger's test. Results: A total of seven studies (3,018 cases and 5,548 controls) were included in the meta-analysis. Our results showed that the genotype distribution of TP53BP1 rs2602141 A/C was not associated with cancer risk overall. However, on subgroup analysis, we found that TP53BP1 rs2602141 A/C was associated with cancer risk within an allele model (A vs C, OR=1.14, 95%CI: 1.01-1.29) and a codominant model (AA vs CC, OR=1.36, 95%CI: 1.06-1.74) in Asians rather than in Caucasians. Subgroup analysis by cancer type, genotype, and with or without adjustment for controls showed no significant association. Conclusions: The findings suggested an association between rs2602141 A/C polymorphism in TP53BP1 gene and increased risk of cancer in Asians.

First-principles study of transport properties of endohedral Li@C20 metallofullerene

Yi-Peng An,Chuan-Lu Yang,Mei-Shan Wang,Xiao-Guang Ma,De-Hua Wang 한국물리학회 2010 Current Applied Physics Vol.10 No.1

The transport properties of the endohedral Li@C20 metallofullerene are studied using density functional non-equilibrium Green’s function method. The equilibrium conductance of Li@C20 metallofullerene becomes larger than that of the empty C20 fullerene molecule. The I.V curve under low-bias voltage shows the characteristic of metallic behavior; another, the novel negative differential resistance behavior is also observed. It is found that the doping effect of Li atom significantly changes the transport properties of C20 fullerene.

Luminescence and photoconductivity properties of porous polycrystalline silicon

Yue Zhao,Dong-sheng Li,Jie Zhao,Wen-bin Sang,De-ren Yang,Min-hua Jiang 한국물리학회 2008 Current Applied Physics Vol.8 No.2

In recent years, the photoluminescence and the photoconductivity of porous silicon were comprehensively studied. But the photoluminescence and the photoconductivity of porous polycrystalline silicon have not been wholely studied. In this paper, the results showed that luminescent property of the samples prepared by poly-crystal silicon wafers may be related to the defects on Si complexes surface, which can be proved by microwave-detected photoconductivity decay measurements. Furthermore, the luminescence of samples was disappeared under the external illumination, which may be related to the elimination of luminescent-centers. In addition, the conductivities of the samples were dependent on etched time and current density, and the large porosity of samples led to isotropic photoconductivity, which may be related to the change of energy band structure of the devices. In recent years, the photoluminescence and the photoconductivity of porous silicon were comprehensively studied. But the photoluminescence and the photoconductivity of porous polycrystalline silicon have not been wholely studied. In this paper, the results showed that luminescent property of the samples prepared by poly-crystal silicon wafers may be related to the defects on Si complexes surface, which can be proved by microwave-detected photoconductivity decay measurements. Furthermore, the luminescence of samples was disappeared under the external illumination, which may be related to the elimination of luminescent-centers. In addition, the conductivities of the samples were dependent on etched time and current density, and the large porosity of samples led to isotropic photoconductivity, which may be related to the change of energy band structure of the devices.