Preparation and characterization of poly(dimethylsiloxane)-polytetrafluoroethylene (PDMS-PTFE) composite membrane for pervaporation of chloroform from aqueous solution

Zhen-Liang Xu,De Sun,Bing-Bing Li 한국화학공학회 2013 Korean Journal of Chemical Engineering Vol.30 No.11

Hydrophobic polydimethylsiloxane - polytetrafluoroethylene (PDMS-PTFE) flat-sheet membranes for pervaporation (PV) of chloroform from aqueous solution were successfully fabricated by solution casting method. The structures and the performance of the membranes was characterized by X-ray diffraction (XRD), scanning electron microscope combined with energy dispersive X-ray spectroscopy (SEM-EDXS), Fourier transform infrared spectroscopy (FT-IR), thermal gravimetric analysis (TGA) and the tests of contact angle and mechanical properties. The adding of PTFE particles (<4 μm) in the PDMS matrix enhanced the crystallinity, hydrophobicity, mechanical strength and thermal stability of the membranes. The examinations showed that the PTFE filled PDMS membranes exhibited striking advantages in flux and separation factor as compared with unfilled PDMS membranes. All the filled PDMS membranes with different PTFE content showed excellent PV properties for the separation of chloroform from water. When the content of the PTFE additive in PDMS composite membrane was 30 wt%, membrane performance was the best at feed temperature 50 oC and permeate-side vacuum 0.101MPa. For the 30% PTFE-PDMS membrane, with the increase of the feed temperature from 30 to 60 oC, the total, water and chloroform fluxes as well as the separation factor increased,the apparent activation energy (ΔEa) of total, chloroform and water were 21.08, 66.65 and 11.49 KJ/mol, respectively,with an increase of chloroform concentration in the feed from 50 to 950 ppm, total, water and chloroform fluxes increased but the separation factor decreased.

MicroRNA-576-3p Inhibits Proliferation in Bladder Cancer Cells by Targeting Cyclin D1

Liang, Zhen,Li, Shiqi,Xu, Xin,Xu, Xianglai,Wang, Xiao,Wu, Jian,Zhu, Yi,Hu, Zhenghui,Lin, Yiwei,Mao, Yeqing,Chen, Hong,Luo, Jindan,Liu, Ben,Zheng, Xiangyi,Xie, Liping Korean Society for Molecular and Cellular Biology 2015 Molecules and cells Vol.38 No.2

MicroRNAs (miRNAs) are small, endogenous RNAs that play important gene-regulatory roles by binding to the imperfectly complementary sequences at the 3'-UTR of mRNAs and directing their gene expression. Here, we first discovered that miR-576-3p was down-regulated in human bladder cancer cell lines compared with the non-malignant cell line. To better characterize the role of miR-576-3p in bladder cancer cells, we over-expressed or down-regulated miR-576-3p in bladder cancer cells by transfecting with chemically synthesized mimic or inhibitor. The overexpression of miR-576-3p remarkably inhibited cell proliferation via G1-phase arrest, and decreased both mRNA and protein levels of cyclin D1 which played a key role in G1/S phase transition. The knock-down of miR-576-3p significantly promoted the proliferation of bladder cancer cells by accelerating the progression of cell cycle and increased the expression of cyclin D1. Moreover, the dual-luciferase reporter assays indicated that miR-576-3p could directly target cyclin D1 through binding its 3'-UTR. All the results demonstrated that miR-576-3p might be a novel suppressor of bladder cancer cell proliferation through targeting cyclin D1.

A Review on DNA Methylation Occurring in Tissue Culture

Zhen Wang,Xin-Qiang Zheng,Yue-Rong Liang,Kwan-Jeong Song,Jian-Liang Lu 한국차학회 2015 한국차학회지 Vol.- No.S

Tissue culture is an important practice for industrial seedling production and germplasm conservation as well as transgenic operation. More and more evidences proved that DNA methylation change is usually involved in dedifferentiation, continuous cultivation and redifferentiation during tissue culture. DNA methylation variation increases with prolonging culture duration and increasing subculture times which might induce abnormal phenotype of propagules. The pattern and level of DNA methylation are significantly influenced by explants, growth regulators ents. DNA methylation change might reflect the growth and development processes and stress response of cells or tissues during tissue culture. Elucidation of epigenetic variation mechanism might help to improve tissue culture and transgene technology especially for the woody plant with high regeneration difficulty and low transformation frequency.

Iris Recognition based on Block Theory and Self-adaptive Feature Selection

Jia Zhen Liang 보안공학연구지원센터 2015 International Journal of Signal Processing, Image Vol.8 No.2

目連戲中的特殊民俗演出形式

楊振良(Yang Zhen-Liang) 중국문화연구학회 2004 중국문화연구 Vol.0 No.5

目連?는 현재 中國에 남아있는 地方戱의 活化石이라고 할 수 있다. 목련희의 演出 속에는 일종의 宗敎禮式 적인 要素가 내포되어 있다. 오늘날 절이나 사당에서 民間의 평안을 기원하는 平安戱的인 성격을 지니고 있다. 이러한 종교적인 요소는 멀리 楚나라의 屈原의 《九歌》의 제천의식에서 그 영향을 받았다고 볼 수 있다. 목련희 속의 鬼神世界는 일종의 空間構成을 형성하고 있다. 필자는 이러한 공간구성을 목련희의 연출양식과 관련하여 규명해 보았다. 일반적으로 神戱는 天上을 표현하구, 鬼?는 地獄을 표현한다. 그러나 이러한 세계와 인간세계와는 아무런 空間距離가 혀다. 또한 西洋의 극장형태와도 비교하여 목련희의 특수한 民俗演出 형태를 비교해 보았다.

중국어 회화교과서에 대한 역사적 고찰

량오진 ( Wu-zhen Liang ) 덕성여자대학교 인문과학연구소 2000 인문과학연구 Vol.5 No.-

韓國爲事大交隣的外交目的, 歷來重視外語敎學, 由於中韓兩國的特殊關係, 尤其重視漢語敎育. 本論文以歷史文獻爲依據, 着重考察韓國歷代使用的漢語會話敎材, 幷分析其特點. 據本文分析, 韓國歷代使用的漢語敎材, 主要有兩種. 一種爲用口語直譯中國經典的直解體敎材, ?一種爲兩人對話形式的會話敎材. 這些敎材, 有的直接由中國引進, 有的則由韓國自行編纂. 經本文考察不難發現, 當時的譯學者們爲掌握實用而準確的漢語, 在選用和編纂會話敎材方面所付出的巨大努力. 如爲了適應語言的發展變化, 就同樣的一種會話敎材, 在元, 明, 淸不同的歷史時期, 進行了多次修改. 幷且爲了學習方便, 用韓文諺解原文內容幷逐字注音. 特別引人注目的是用韓文注音時, 除了注下傳統的漢語語音外, 還特意注下了當時中國北方地區實際使用的漢語口音. 此外, 譯學者們還編纂了實用而方便的辭典和韻書等參考書. 據本文考察, 韓國在歷史上選用和編纂漢語敎材方面, 爲今人留下了?多値得借鑑的寶貴經驗。

Post-fire Bond Behaviors Between Grout and Steel Rebar

Liang-Lin Liu,Chun-Yong Luo,Lu-Xia Ouyang,Zhen-Hua Xia,Wei-Hua Li 한국콘크리트학회 2022 International Journal of Concrete Structures and M Vol.16 No.5

Firstly, according to the theoretical analysis, the force mechanism and failure modes were assured for the bond behavior between grout and steel rebar. Then, a pull-out experiment was exerted to probe the bond behavior developments of specimens after exposed to 500 °C. It is found that the mixed measures of pre-drying and slow elevating rate, i.e., 5 °C/min, inhibits the explosive spalling in grout with compressive strength of 76.7 MPa. In addition, there are two failure modes including the steel rebar fracture and the bond slip failure in the test. Based on the elevated temperature, compressive strength of post-fire grout, diameter of steel rebar and its embedment length, a new expression has been built to calculate the bond strength between grout and steel rebar of post-fire specimens. Furthermore, the finite element simulation is employed to investigate the bond behaviors of pull-out specimens after exposed to elevated temperatures up to 500 °C. The steel rebar fracture is captured firstly in the pull-out test simulation. Moreover, it is found that the peak slips increase and peak loads decrease along with the temperature elevating. Finally, it is proposed that the crucial elevated temperatures of the failure mode change should be 300, 300 and 400 °C for the specimens with embedment lengths of 6, 7 and 8 times diameter of steel rebar with diameter of 16 mm, respectively, which is beneficial for evaluating the fire safety of the existing structure elements.

Inhibition of glutathione metabolism attenuates esophageal cancer progression

Liang Peng,Ruixia Linghu,Demeng Chen,Jing Yang,Xiaoxue Kou,Xiang-Zhen Wang,Yi Hu,Yi-Zhou Jiang,Junlan Yang 생화학분자생물학회 2017 Experimental and molecular medicine Vol.49 No.-

Esophageal squamous cell carcinoma (ESCC) is a deadly malignancy with regard to mortality and prognosis, and the 5-year survival rate for all patients diagnosed with ESCC remains poor. A better understanding of the biological mechanisms of ESCC tumorigenesis and progression is of great importance to improve treatment of this disease. In this study, we demonstrated that the glutathione metabolism pathway is highly enriched in ESCC cells compared with normal esophageal epithelial cells in an in vivo mouse model. In addition, treatment with L-buthionine-sulfoximine (BSO) to deplete glutathione decreased the ESCC tumor burden in mice, thus demonstrating the critical role of glutathione metabolism in ESCC progression. BSO treatment also led to decreased cell proliferation and activation of cell apoptosis in ESCC. Finally, BSO treatment blocked NF-kB pathway activation in ESCC. Our study reveals a new pathway that regulates ESCC progression and suggests that inhibition of glutathione metabolism may be a potential strategy for ESCC treatment

吏文과 吏文諸書輯覽의 言語

梁伍鎭 한국중국언어학회 2002 중국언어연구 Vol.14 No.-

學界一般認爲吏文是自高麗朝以來和中國來往的外交文書, 但對吏文的性質及語言特點等, 至今還沒有系統而詳細的硏究. 本論文首先以歷史文獻爲依據, 明確吏文所包括的文體範圍, 分析韓吏文和漢吏文的不同特點. 然後, 以吏文諸書輯覽爲根據, 着重考察漢吏文的語言特點. 韓國現存的漢吏文資料基本上屬於明代文獻, 這些資料除了和中國來往的外交文書以外, 還包括國內使用的行政, 法律等各種公文文體. 據本文考察, 吏文除了與傳統的漢語書面語基本相似之外, 還具有反映時代特徵的獨特的語言特點. 如吏文首先具有當時使用的特殊的公文格式, 其次, 吏文大量使用反映近代漢語特點的詞彙和語法形式, 再次, 吏文還留有不少受蒙古語影響的元代漢語成分. 此外, 吏文諸書輯覽裏還發現不少諺解資料, 저사자료부진위근대한어적연구, 而且還爲國語史的硏究, 將提供豊富而珍貴的資料.

Geolocation Spectrum Database Assisted Optimal Power Allocation: Device-to-Device Communications in TV White Space

( Zhen Xue ),( Liang Shen ),( Guoru Ding ),( Qihui Wu ) 한국인터넷정보학회 2015 KSII Transactions on Internet and Information Syst Vol.9 No.12

TV white space (TVWS) is showing promise to become the first widespread practical application of cognitive technology. In fact, regulators worldwide are beginning to allow access to the TV band for secondary users, on the provision that they access the geolocation database. Device-to-device (D2D) can improve the spectrum efficiency, but large-scale D2D communications that underlie TVWS may generate undesirable interference to TV receivers and cause severe mutual interference. In this paper, we use an established geolocation database to investigate the power allocation problem, in order to maximize the total sum throughput of D2D links in TVWS while guaranteeing the quality-of-service (QoS) requirement for both D2D links and TV receivers. Firstly, we formulate an optimization problem based on the system model, which is nonconvex and intractable. Secondly, we use an effective approach to convert the original problem into a series of convex problems and we solve these problems using interior point methods that have polynomial computational complexity. Additionally, we propose an iterative algorithm based on the barrier method to locate the optimal solution. Simulation results show that the proposed algorithm has strong performance with high approximation accuracy for both small and large dimensional problems, and it is superior to both the active set algorithm and genetic algorithm.