Effects of reactive oxidants generation and capacitance on photoelectrochemical water disinfection with self-doped titanium dioxide nanotube arrays

Cho, Kangwoo,Lee, Seonggeun,Kim, Hyeonjeong,Kim, Hyung-Eun,Son, Aseom,Kim, Eun-ju,Li, Mengkai,Qiang, Zhimin,Hong, Seok Won Elsevier BV 2019 Applied Catalysis B Vol.257 No.-

<P><B>Abstract</B></P> <P>We herein provide photoelectrochemical (PEC) disinfection activities of anodically prepared TiO<SUB>2</SUB> nanotube (TNT) arrays (diameter ˜ 100 nm, length ˜ 16 μm on average) that were electrochemically self-doped before (bk-TNT) and after (bl-TNT) an atmospheric annealing at 450 °C. The X-ray diffraction indicated predominating anatase TiO<SUB>2</SUB> signal on bl-TNT, while substantial lattice distortion was noticed for bk-TNT. Although the X-ray photoelectron spectra indicated negligible Ti<SUP>3+</SUP> on surface of both TNTs, linear sweep (cyclic) voltammetry and electrochemical impedance spectrometry confirmed the bk-TNT to show greater double layer capacitance and overall photocurrent, coupled with lower charge transfer resistance. Nevertheless, the PEC disinfection of <I>E. coli</I> was significantly invigorated on bl-TNT, while the bactericidal rates in tap water were comparable or even far greater than those in 0.1 M Na<SUB>2</SUB>SO<SUB>4</SUB> solutions, depending on [<I>E. coli</I>]<SUB>0</SUB> (10<SUP>5</SUP> or 10<SUP>7</SUP> CFU/mL). Under a presumed diffusion-controlled kinetic regime in this study, observed effects of capacitance and electrolyte could be interpreted in terms of electrostatic interaction between the electrical double layer of photoanodes and charged bio-solids, such as repulsion by co-ions (SO<SUB>4</SUB> <SUP>2−</SUP>) and adsorption/surface blocking. Analogous PEC experiments on model organic compounds degradation (4-chlorophenol and methylene blue) corroborated a long-term stability of the bl-TNT (up to 30 consecutive cycles) and the role of surface hydroxyl radical as the primary oxidant.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Self-doped anatase (bl-TNT) and amorphous TiO<SUB>2</SUB> nanotube (bk-TNT) were interrogated. </LI> <LI> Lower double layer capacitance of bl-TNT led to higher PEC disinfection of <I>E. coli</I>. </LI> <LI> PEC bactericidal rates in tap water were similar or greater than in Na<SUB>2</SUB>SO<SUB>4</SUB> solution. </LI> <LI> Electrostatic interaction between photoanode and bio-solids determined the kinetics. </LI> <LI> Commercial applicability for point-of-use disinfection was demonstrated. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

A 14 Bit Continuous-Time Delta-Sigma A/D Modulator With 2.5 MHz Signal Bandwidth

Li, Zhimin,Fiez, Terri S. IEEE 2007 IEEE journal of solid-state circuits Vol.42 No.9

<P> A continuous-time delta-sigma A/D modulator with 5 MS/s output rate in a 2.5 V 0.25 <TEX>$\mu$</TEX>m CMOS process is presented. The modulator has a fifth-order single-stage, dual-loop architecture allowing nearly one clock period quantizer delay. A multi-bit quantizer is used to increase resolution and multi-bit non-return-to-zero DACs are adopted to reduce clock jitter sensitivity. Capacitor tuning is utilized to overcome loop coefficient shifts due to process variations. Self-calibration is implemented to suppress current-steering DAC mismatch. Clocked at 60 MHz, the prototype chip achieves 81 dB peak SNR and 85 dB dynamic range with a 12X oversampling ratio. The power consumption is 50 mW. </P>

A Comparative Study on Physiological Activities of Lager and Ale Brewing Yeasts under Different Gravity Conditions

Zhimin Yu,Mou-Ming Zhao,Huiping Li,Hai-Feng Zhao,Qingli Zhang,Chunyan Wan,Huipin Li 한국생물공학회 2012 Biotechnology and Bioprocess Engineering Vol.17 No.4

High gravity (HG) or very high gravity (VHG)brewing has become popular in modern breweries due to its economic and product quality advantages. However,there are the negative impacts such as the fermentation performance of brewer’s yeast in HG or VHG wort, which are closely related to changes in cell physiological activity. In the present study, 3 kinds of worts, with different gravities, were used to examine the systematic effects on fermentation performance and physiological activity of lager yeast FBY009505 (Saccharomyces pastorianus) and ale yeast FBY0099 (Saccharomyces cerevisiae), as well as the resulting beer flavor. Results showed that the responses of FBY009505 and FBY0099 to the HG or VHG worts were similar. The specific fermentation rate and viability of cropped yeast of FBY009505 and FBY0099 were decreased with increasing wort gravity. The increased wort gravity resulted in the increase of energy charge and the decrease of α-glucosides transport rate and glycolytic enzyme activities. Moreover, the environmental stresses in the HG or VHG wort showed a higher inhibitory activity against α-glucoside transport than glycolytic enzymes. The content of intracellular trehalose and glycerol of FBY009505 and FBY0099 increased with the increase in wort gravity. The results from this study provided a potential means to systematically understand the physiology of brewer’s yeast under HG or VHG conditions. High gravity (HG) or very high gravity (VHG)brewing has become popular in modern breweries due to its economic and product quality advantages. However,there are the negative impacts such as the fermentation performance of brewer’s yeast in HG or VHG wort, which are closely related to changes in cell physiological activity. In the present study, 3 kinds of worts, with different gravities, were used to examine the systematic effects on fermentation performance and physiological activity of lager yeast FBY009505 (Saccharomyces pastorianus) and ale yeast FBY0099 (Saccharomyces cerevisiae), as well as the resulting beer flavor. Results showed that the responses of FBY009505 and FBY0099 to the HG or VHG worts were similar. The specific fermentation rate and viability of cropped yeast of FBY009505 and FBY0099 were decreased with increasing wort gravity. The increased wort gravity resulted in the increase of energy charge and the decrease of α-glucosides transport rate and glycolytic enzyme activities. Moreover, the environmental stresses in the HG or VHG wort showed a higher inhibitory activity against α-glucoside transport than glycolytic enzymes. The content of intracellular trehalose and glycerol of FBY009505 and FBY0099 increased with the increase in wort gravity. The results from this study provided a potential means to systematically understand the physiology of brewer’s yeast under HG or VHG conditions.

Characterization of Rosa chinensis CBF Genes and the Function of RcCBF6 in Cold Tolerance

Jianbo Li,Guangshun Zheng,Shaofeng Li,Zhimin Tang,Jingshuang Sun,Xuebing Xin 한국식물학회 2020 Journal of Plant Biology Vol.63 No.4

As a class of AP2 family transcription factors, C-repeat binding factor (CBF) gene family plays an important role in resisting low-temperature stress and improving cold tolerance of plants. Rosa chinensis is an important horticultural and ornamental plant, but little is known about the molecular characteristics of CBF genes in R. chinensis. In our study, six RcCBFs members were identified at R. chinensis whole genome, including one member RcCBF1 on Chromosome 1 and other five members RcCBF2-6 on Chromosome 7. The analysis of cis-acting elements indicated that there were various cis-acting elements related to stress, development, hormone, and light. The expression profiles showed that most of RcCBFs were mainly expressed in root, and the expression levels of RcCBFs were significantly induced by low-temperature stress, especially RcCBF6. To verify the function of RcCBF6, we generated its overexpressing transgenic lines in Arabidopsis thaliana. The RcCBF6-overexpressing plants exhibited higher tolerance to cold stress as evidenced by a better growth and higher antioxidative enzyme activities than the wild-type plants. Furthermore, the expression levels of some cold-response genes were up-regulated in the transgenic plants, such as KIN1, RD29A, LTP3, and GOLS3. Our study contributes to a better understanding of RcCBF gene family and provides a foundation for the further functional research of RcCBFs.

Asymmetric reduction of 3-oxo-3-phenylpropionic acid ethyl ester by undifferentiated cells of white turnip in phosphate buffer/organic solvent

Zhimin Ou,Qingmei Chen,Gensheng Yang,Li Xu 한국화학공학회 2011 Korean Journal of Chemical Engineering Vol.28 No.2

Ethyl (S)-3-hydroxy-3-phenylpropionate was synthesized by asymmetric reduction of 3-oxo-3-phenylpropionic acid ethyl ester with undifferentiated cells of white turnip in phosphate buffer/organic solvent. The conversion increased with the LogP_oct of organic solvent increase. The phosphate buffer (0.2 mol/L, pH 7.0)/dodecane was selected as optimum medium for reduction. The optimal content of dodecane in medium is 10% (v). The conversion decreased with initial substrate concentration increase. Addition of more biomass of plant cells and 10% ethanol as co-substrate can improve conversion. The plant cells can be reused well for three times. The enantiomeric excess of ethyl (S)-3-hydroxy-3-phenylpropionate reached 100% with 1% allyl bromide as inhibitor.

Opposing Effects of ERK and p38 MAP Kinases on HeLa Cell Apoptosis Induced by Dipyrithione

Zhimin Yin,Yumei Fan,Hui Chen,Bo Qiao,Lan Luo,Hsiaoyen Ma,Heng Li,Jihong Jiang,Dezhong Niu 한국분자세포생물학회 2007 Molecules and cells Vol.23 No.1

Cluster-Based Polarized Spectrum Sharing in Channels with Polarization Mode Dispersion

Dongming Li,Zhimin Zeng,Caili Guo,Xiaolin Lin 한국전자통신연구원 2014 ETRI Journal Vol.36 No.3

Polarized spectrum sharing (PSS) exploits the spectrumopportunities in a polarized domain. However, when it comesto wideband environments PSS is impaired by the frequencydependentpolarization mode dispersion (PMD); thus, theeffective throughput of PSS drops. To combat the PMD effect,this work proposes a cluster-based PSS approach to enablePSS on a narrower frequency span. Simulation results showthat the effective throughput of PSS on cluster basisoutperforms that of PSS on bandwidth and subcarrier basis.

Selection of candidate genes affecting meat quality and preliminary exploration of related molecular mechanisms in the Mashen pig

Pengfei Gao,Zhimin Cheng,Meng Li,Ningfang Zhang,Baoyu Le,Wanfeng Zhang,Pengkang Song,Xiaohong Guo,Bugao Li,Guoqing Cao 아세아·태평양축산학회 2019 Animal Bioscience Vol.32 No.8

Objective: The aim of this study was to select the candidate genes affecting meat quality and preliminarily explore the related molecular mechanisms in the Mashen pig. Methods: The present study explored genetic factors affecting meat quality in the Mashen pig using RNA sequencing (RNA-Seq). We sequenced the transcriptomes of 180-day-old Mashen and Large White pigs using longissimus dorsi to select differentially expressed genes (DEGs). Results: The results indicated that a total of 425 genes were differentially expressed between Mashen and Large White pigs. A gene ontology enrichment analysis revealed that DEGs were mainly enriched for biological processes associated with metabolism and muscle development, while a Kyoto encyclopedia of genes and genomes analysis showed that DEGs mainly participated in signaling pathways associated with amino acid metabolism, fatty acid metabolism, and skeletal muscle differentiation. A MCODE analysis of the protein-protein interaction network indicated that the four identified subsets of genes were mainly associated with translational initiation, skeletal muscle differentiation, amino acid metabolism, and oxidative phosphorylation pathways. Conclusion: Based on the analysis results, we selected glutamic-oxaloacetic transaminase 1, malate dehydrogenase 1, pyruvate dehydrogenase 1, pyruvate dehydrogenase kinase 4, and activator protein-1 as candidate genes affecting meat quality in pigs. A discussion of the related molecular mechanisms is provided to offer a theoretical basis for future studies on the improvement of meat quality in pigs.

A Variation Analysis Method for Linkage Mechanism with Consideration of Joint Clearance and Deformation

Tao Liu,Zhimin Li,Sun Jin,Wei Chen 한국정밀공학회 2018 International Journal of Precision Engineering and Vol.19 No.10

As typical transmission mechanisms, linkage mechanisms are widely applied in mechanical engineering field, and accuracy prediction of them has received much more attentions especially from some high-precision application fields. For a certain linkage mechanism system, external forces will also cause linkage deformations and deterministic oriented-drift of joint clearances, which become additional variation sources besides component tolerances. In order to perform a more accurate prediction of linkage mechanism, a variation analysis method is proposed in this study, in which component tolerances, joint clearances and deformations are considered. With an equivalent method, positional tolerance and joint clearances are taken into the present variation analysis model, and serve as circular tolerances. Based on classical Euler-Bernoulli beam theory, linkage deformations are disposed as equivalent deviations and contribute to assembly deviations. A decomposing method of percentage contribution, which contains different variation sources, is presented as well. A case study of four-bar linkage mechanism is illustrated to validate the accuracy of the present method by corresponding FEA simulation and experimental test. Moreover, a case study of a three-loop mechanism is also analyzed for the accuracy and percentage contribution of different variation sources with the present method.

On Privacy and Anonymity in Freenet System

Tianbo Lu,Zhimin Lin,Lingling Zhao,Yang Li 보안공학연구지원센터 2016 International Journal of Security and Its Applicat Vol.10 No.5

As a typical representative of anonymous network applications, Freenet system has so many advantages in sharing, privacy, anonymity as well as uploading and downloading convenience that it adequately realizes expression freedom. So it’s widely used in different fields. For Freenet system, academia and system designers have been conducting research and improvement which mainly on following points: structure, topology, routing algorithm and the Darknet mechanism which proposed by new version. The purpose of these efforts is to increase the system network utilization, enhance the reliability of transmission and improve the safety and robustness of the system. This paper reviews and summarizes the research progress of Freenet system by collating and analyzing relevant articles. We also analyze and compare the main ideas, the algorithm application as well as pros and cons of different articles surrounding different topics. In addition, we also tease out the development and the evolution trends of Freenet system in time order, and combined with current network situation, we made reasonable proposals and prospects and draw scientific conclusions.