Effects of operative conditions on membrane fouling of jet loop membrane bioreactor     

徐高田  孙佳琳  秦哲  阮慧娟 《上海大学学报(英文版)》2010,14(4):251-254

The orthogonal experiments, which involves three factors： aeration intensity, suction time and suction suspended time, were designed to research membrane fouling of jet loop membrane bioreactor （JLMBR）. Experimental results indicate that increasing aeration intensity, reducing suction time and increasing suction suspended time all could mitigate membrane fouling effectively. However excessive aeration intensity, too short suction time and excessive suction suspended time were bad for bioreactor running. The optimal aeration intensity, suction time and suction suspended time were 0.75 1.00 m3/（m2.h）, 8 -10 min and 4 -5 min, respectively. The three factors all had effect on membrane pollution rate, while the suction time was the most important one and followed by aeration intensity and suction suspended time. It also indicates that, comparing with traditional submerged membrane bioreactors, JLMBR had lower membrane pollution rate.  相似文献   

Toxic effects of Litsea elliptica Blume essential oil on red blood cells of Sprague-Dawley rats     

Izatus Shima Taib  Siti Balkis Budin  Seri Maseran Siti Nor Ain  Jamaludin Mohamed  Santhana Raj Louis  Srijit Das  Sulaiman Sallehudin  Nor Fadilah Rajab  Othman Hidayatulfathi 《Journal of Zhejiang University. Science. B》2009,10(11):813-819

Litsea elliptica Blume leaves have been traditionally used as medicinal herbs because of its antimutagenicity, che-mopreventative and insecticidal properties. In this study, the toxic effects of L. elliptica essential oil against Sprague-Dawley rat's red blood cells (RBCs) were evaluated. L. elliptica essential oil was given by oral gavage 5 times per week for 3 treated groups in the doses of 125, 250, and 500 mg/(kg body weight), respectively, and the control group received distilled water. Full blood count, RBC osmotic fragility, RBC morphological changes, and RBC membrane lipid were analyzed 28 d after the treatment. Although L. elliptica essential oil administration had significantly different effects on hemoglobin (Hb), mean cell hemoglobin concentration (MCHC), mean cell volume (MCV), and mean cell hemoglobin (MCH) in the experimental groups as compared to the control group (P<0.05), the values were still within the normal range. L. elliptica induced morphological changes of RBC into the form of echinoeyte. The percentage of echinocyte increased significantly among the treated groups in a dose-response manner (P<0.001). The concentrations of RBC membrane phospholipids and cholesterol of all treated groups were significantly lower than those of control group (P<0.001). However, the RBC membrane osmotic fragility and total proteins of RBC membrane findings did not differ significantly between control and treated groups (P>0.05). It is concluded that structural changes in the RBC membrane due to L. elliptica essential oil administration did not cause severe membrane damage.  相似文献   

Detection of plasmid-mediated IMP-1 metallo-β-lactamase and quinolone resistance determinants in an ertapenem-resistant Enterobacter cloacae isolate     

Li-rong CHEN  Hong-wei ZHOU  Jia-chang CAI  Rong ZHANG  Gong-xiang CHEN 《Journal of Zhejiang University. Science. B》2009,10(5)

Objective: To investigate the mechanism of carbapenem resistance and the occurrence of plasmid-mediated quinolone resistance determinants qnr and aac(6')-Ib-cr in a clinical isolate of Enterobacter cloacae. Methods: An ertapenem-resistant E. cloacae ZY106, which was isolated from liquor puris of a female gastric cancer patient in a Chinese hospital, was investigated. Antibiotic susceptibilities were determined by agar dilution method. Conjugation experiments, isoelectric focusing, polymerase chain reaction (PCR), and DNA sequence analyses of plasmid-mediated carbapenemases and quinolone resistance determinants were preformed to confirm the genotype. Outer membrane proteins (OMPs) were examined by urea-sodium dodecyl sulfate-polyacrylamide gel electrophoresis (Urea-SDS-PAGE). Results: Minimum inhibitory concentrations (MCs) of imipenem, mer-openem, and ertapenem for ZY106 were 2,4, and 16 ug/ml, respectively. Conjugation studies with Escherichia coli resulted in the transfer of significantly reduced carbapenem susceptibility. ZY106 produced IMP-1 metallo-p-lactamase and CTX-M-3 extended-spectrum P-lactamase, and E. coli transconjugant produced IMP-1. Plasmid-mediated quinolone resistance determinant qnrSI was detected in ZY106. Transfer of the qnrSI-encoding-plasmid into E. coli by conjugation resulted in intermediate resistance to ciprofloxacin in E. coli transconjugant. Urea-SDS-PAGE analysis of OMPs showed that ZY106 lacked an OMP of approximately 38 KDa. Conclusion: It is the first IMP-1-producing Enterobacteriaceae in China and the first report of a clinical isolate that harbors both blaIMP and qnrS genes as well. The blaIMP-1, blaCTX-M-3, and qnrSl are encoded at three different plasmids. IMP-1 combined with the loss of an OMP possibly resulted in ertapenem resistance and reduced imipenem and mero-penem susceptibility in E. cloacae.  相似文献   

On the vein-stiffening membrane structure of a dragonfly hind wing     

Zhong-xue Li  Wei Shen  Gen-shu Tong  Jia-meng Tian  Loc Vu-Quoc 《浙江大学学报(A卷英文版)》2009,10(1):72-81

Aiming at exploring the excellent structural performance of the vein-stiffening membrane structure of dragonfly hind wings, we analyzed two planar computational models and three 3D computational models with cambered corrugation based on the finite element method. It is shown that the vein size in different zones is proportional to the magnitude of the vein internal force when the wing structure is subjected to uniform out-of-plane transverse loading. The membrane contributes little to the flexural stiffness of the planar wing models, while exerting an immense impact upon the stiffness of the 3D wing models with cambered corrugation. If a lumped mass of 10% of the wing is fixed on the leading edge close to the wing tip, the wing fundamental fre- quency decreases by 10.7%-13.2%; if a lumped mass is connected to the wing via multiple springs, the wing fundamental frequency decreases by 16.0%-18.0%. Such decrease in fundamental frequency explains the special function of the wing pterostigma in alleviating the wing quivering effect. These particular features of dragonfly wings can be mimicked in the design of new-style reticulately stiffening thin-walled roof systems and flapping wings in novel intelligent aerial vehicles.  相似文献   

Numerical Simulation of a Mathematical Model for Dry/Wet-Spun Nascent Hollow Fiber Membrane     

法德勒  许振良 《上海大学学报(英文版)》2004,(2)

NomenclatureCsh—solventconcentrationinanascenthollowfiber ( g·cm-3 )fo—dragcoefficientattheexternalsurfaceofanascenthollowfiberF( γE)—materialfunctiondefined (Eq .( 2 ) )g—gravitationalfunction ( 980cm·s-2 )G(Csh)—materialfunctiondefined (Eq .( 2 ) )Ho—thecombinedreciprocalradiiofthecurvaturesattheouterskinofthenascenthollowfiber (cm-1)L—air gapdistance (cm )Ri—innerradiusofanascenthollowfiber (cm)Ro—outerradiusofanascenthollowfiber (cm)R′o,R″o—thefirstandsecondorderderivat…  相似文献   

Removal of aqueous phenol compound by vacuum membrane distillation   总被引：4，自引：0，他引：4  

LIU Zuohu  LIU Renlong  DU Jun  TAO Changyuan  LI Xiaohong College of Chemistry & Chemical Engineering  Chongqing University  Chongqing  P. R. China College of Resources & Environmental Science  Chongqing University  Chongqing  P. R. Chin 《重庆大学学报(英文版)》2004,3(1):61-64

1.IntroductionPhenolisanimportantchemicalindustrymaterial,butitalsoaboundswithserioushazardtoenvironmentandthreatstohumanhealth.Rigidruleshavebeenmadeoutonthephenoldischargeconcentration.Researchesonthetreatmentofphenolwastewaterwerecarriedoutinvariouscountries[1-5].Membraneseparationmethodsincludingreverseosmosis,ultrafiltrationandpervaporationhaveattractedmuchattentionforphenolwastewatertreatment,withcelluloseacetate(CA)membraneemployedmostly[6].Membranedistillationisanewmembraneseparation…  相似文献   

膜分离技术及其在染料生产中的应用     

刘卫斌  易长海  严钦华  王华权  熊建平 《桂林师范高等专科学校学报》2003,17(3):121-124

简述了膜分离技术的原理、装置和应用现状，介绍了反渗透、纳滤、超滤和徽滤技术的研究进展极其在染料生产中的应用。  相似文献   

反渗透系统的效能影响因素分析     

王鹏  李松良  华常春 《扬州职业大学学报》2012,16(2):38-42

从膜自身的结构特性、膜系统运行的条件以及进水水质等方面,对反渗透效能具有影响作用的因素进行分析,找出具体的解决办法和适当的操作条件,使其在使用过程中增强反渗透膜的抗污染性、延长使用寿命、降低清洗的次数。  相似文献   

Transportation of AIE-visualized nanoliposomes is dominated by the protein corona     

Yi-Feng Wang  Chunqiu Zhang  Keni Yang  Yufei Wang  Shaobo Shan  Yan Yan  Kenneth A Dawson  Chen Wang  Xing-Jie Liang 《国家科学评论(英文版)》2021,8(6)

Liposomes, especially cationic liposomes, are the most common and well-investigated nanocarriers for biomedical applications, such as drug and gene delivery. Like other types of nanomaterials, once liposomes are incubated in a biological milieu, their surface can be immediately cloaked by biological components to form a protein corona, which confers a new ‘biological identity’ and modulates downstream interactions with cells. However, it remains unclear how the protein corona affects the transportation mechanism after liposomes interact with cells. Here, we employed home-made aggregation-induced-emission-visualized nanoliposomes TR4@Lipo as a model to investigate transportation with or without the protein corona by optical imaging techniques. The results show that the protein corona can change the cellular transportation mechanism of TR4@Lipo from energy-independent membrane fusion to energy-dependent endocytosis. The protein corona also modulates the intracellular distribution of loaded cargoes. This knowledge furthers our understanding of bio-nano interactions and is important for the efficient use of cationic liposomes.  相似文献   

微孔防虫膜在防治天麻跳虫为害的试验研究     

LIANG YU-yong  LI Jian-dong  TIAN Zhan-qiang 《铜仁职业技术学院学报》2008,(6)

防虫膜防治跳虫至今未见报道,跳虫在印江土家族自治县及周边县天麻产区发生普遍而为害日益加重,对天麻的产量与品质影响很大,用显微镜观察鉴定为刺跳虫,经室内微孔防虫膜覆盖河沙厢式栽培天麻,对防虫膜防治跳虫技术进行了研究。  相似文献