Cr(VI) Resistance and Removal by Indigenous Bacteria Isolated from Chromium-Contaminated Soil

( Dong Yan Long ),( Xian Jin Tang ),( Kuan Cai ),( Guang Cun Chen ),( Chao Feng Shen ),( Ji Yan Shi ),( Ling Gui Chen ),( Ying Xu Chen ) 한국미생물 · 생명공학회 2013 Journal of microbiology and biotechnology Vol.23 No.8

The removal of toxic Cr(VI) by microorganisms is a promising approach for Cr(VI) pollution remediation. In the present study, four indigenous bacteria, named LY1, LY2, LY6, and LY7, were isolated from Cr(VI)-contaminated soil. Among the four Cr(VI)-resistant isolates, strain LY6 displayed the highest Cr(VI)-removing ability, with 100 mg/l Cr(VI) being completely removed within 144 h. It could effectively remove Cr(VI) over a wide pH range from 5.5 to 9.5, with the optimal pH of 8.5. The amount of Cr(VI) removed increased with initial Cr(VI) concentration. Data from the time-course analysis of Cr(VI) removal by strain LY6 followed first-order kinetics. Based on the 16S rRNA gene sequence, strain LY6 was identified as Pseudochrobactrum asaccharolyticum, a species that had never been reported for Cr(VI) removal before. Transmission electron microscopy and energy dispersive X-ray spectroscopy analysis further confirmed that strain LY6 could accumulate chromium within the cell while conducting Cr(VI) removal. The results suggested that the indigenous bacterial strain LY6 would be a new candidate for potential application in Cr(VI) pollution bioremediation.

Genome-Wide Association Study in East Asians Identifies Novel Susceptibility Loci for Breast Cancer

Long, Jirong,Cai, Qiuyin,Sung, Hyuna,Shi, Jiajun,Zhang, Ben,Choi, Ji-Yeob,Wen, Wanqing,Delahanty, Ryan J.,Lu, Wei,Gao, Yu-Tang,Shen, Hongbing,Park, Sue K.,Chen, Kexin,Shen, Chen-Yang,Ren, Zefang,Haima Public Library of Science 2012 PLoS genetics Vol.8 No.2

<P>Genetic factors play an important role in the etiology of both sporadic and familial breast cancer. We aimed to discover novel genetic susceptibility loci for breast cancer. We conducted a four-stage genome-wide association study (GWAS) in 19,091 cases and 20,606 controls of East-Asian descent including Chinese, Korean, and Japanese women. After analyzing 690,947 SNPs in 2,918 cases and 2,324 controls, we evaluated 5,365 SNPs for replication in 3,972 cases and 3,852 controls. Ninety-four SNPs were further evaluated in 5,203 cases and 5,138 controls, and finally the top 22 SNPs were investigated in up to 17,423 additional subjects (7,489 cases and 9,934 controls). SNP rs9485372, near the TGF-β activated kinase (<I>TAB2</I>) gene in chromosome 6q25.1, showed a consistent association with breast cancer risk across all four stages, with a <I>P</I>-value of 3.8×10<SUP>−12</SUP> in the combined analysis of all samples. Adjusted odds ratios (95% confidence intervals) were 0.89 (0.85–0.94) and 0.80 (0.75–0.86) for the A/G and A/A genotypes, respectively, compared with the genotype G/G. SNP rs9383951 (<I>P</I> = 1.9×10<SUP>−6</SUP> from the combined analysis of all samples), located in intron 5 of the <I>ESR1</I> gene, and SNP rs7107217 (<I>P</I> = 4.6×10<SUP>−7</SUP>), located at 11q24.3, also showed a consistent association in each of the four stages. This study provides strong evidence for a novel breast cancer susceptibility locus represented by rs9485372, near the <I>TAB2</I> gene (6q25.1), and identifies two possible susceptibility loci located in the <I>ESR1</I> gene and 11q24.3, respectively.</P><P><B>Author Summary</B></P> <P>Breast cancer is one of the most common malignancies among women worldwide. Genetic factors play an important role in the etiology of breast cancer. To identify common genetic susceptibility alleles for breast cancer, we performed a four-stage genome-wide association study in 19,091 cases and 20,606 controls among East-Asian women. Single nucleotide polymorphism (SNP) rs9485372, near the TGF-beta activated kinase 1 (<I>TAB2</I>) gene at chromosome 6q25.1, was associated with breast cancer risk (<I>P</I> = 3.8×10<SUP>−12</SUP>). SNPs rs9383951, located in intron 5 of the estrogen receptor 1 (<I>ESR1</I>) gene, and rs7107217, located at 11q24.3, were also consistently associated with breast cancer risk in all four stages with a combined <I>P</I> of 1.9×10<SUP>−6</SUP> and 4.6×10<SUP>−7</SUP>, respectively. This study provides strong evidence for a novel breast cancer susceptibility locus represented by rs9485372, near the <I>TAB2</I> gene (6q25.1), and identifies two possible susceptibility loci located in the <I>ESR1</I> gene and 11q24.3, respectively.</P>

Comparative Study on the Supramolecular Nanocarriers Derived from the Assembly of Gemini and Conventional Surfactants onto Hyperbranched Polyethylenimine

Zhan-Long Yu,Fa Cheng,Shao-Jing Zhao,Jian-Wei Zhang,Zu-Cheng Cai,Yu Chen 한국고분자학회 2011 Macromolecular Research Vol.19 No.2

Conventional surfactant dodecylbenzenesulfonic acid (DBSA) and its corresponding Gemini surfactant acid (GSA) were simply mixed with a solution of hyperbranched polyethylenimine (HPEI) in chloroform. This resulted in the novel supramolecular complexes, HPEI-DBSA and HPEI-GSA, through a neutralization reaction between the amino groups of HPEI and the sulfonic-acid groups of DBSA and GSA. The formed supramolecular complexes and their precursors were characterized by FTIR, 1H NMR, and dynamic light scattering. HPEI-DBSA and HPEI-GSA exhibited inverted-micelle properties that could accommodate the water-soluble guest molecules in an apolar solvent. With the anionic dye methyl orange (MO) as the model guest, both HPEI-DBSA and HPEI-GSA showed superior guest-encapsulation performance than the supramolecular nanocarrier derived from the assembly of aliphatic acid onto HPEI. For example, HPEI-DBSA and HPEI-GSA nanocarriers could encapsulate more MO molecules, and a much smaller amount of the surfactant molecules was required to achieve the maximum MO encapsulation. These results highlight the importance of strong-acid groups of the surfactants in raising the guest-encapsulation efficiency of this type of supramolecular nanocarrier. HPEI-DBSA and HPEI-GSA had different guestencapsulation mechanisms. This indicates that HPEI-GSA can encapsulate basic guests more than HPEI-DBSA,such as MO and fluorescein sodium (FS), but fewer relatively acidic guests, such as Alizarin Yellow R sodium salt and bromophenol blue.

Electrochemical Performance of Lithium-Ion Capacitors Using Pre-Lithiated Multiwalled Carbon Nanotubes as Anode

Manyuan Cai,Xiaogang Sun,Yanyan Nie,Wei Chen,Zhiwen Qiu,Long Chen,Zhenhong Liu,Hao Tang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.4

Pre-lithiated multiwalled carbon nanotube anode was prepared by internal short circuit approach (ISC) for 5 min, 30 min, 60 min and 120 min respectively. Lithium ion capacitors (LICs) were assembled by using pre-lithiated multiwalled carbon nanotubes as anodes and activated carbon (AC) as cathodes. The structure of multiwalled carbon nanotubes and electrodes were investigated by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The electrochemical performance of pre-lithiated multiwalled carbon nanotube electrodes and pristine carbon nanotube electrodes were tested by galvanostatic charge/discharge and electrochemical impedance. The results indicated that pre-lithiation carbon nanotubes greatly improved the charge/discharge performance of LICs. The energy density was four times than conventional electric double-layer capacitors (EDLCs) at the current density of 100 mA/g. The LICs achieved a specific capacitance of 59.3 F/g at the current density of 100 mA/g with 60 min pre-lithiatiation process. The maximum energy density and power density was 96Wh/kg and 4035W/kg, respectively. The energy density still remained about 89.0% after 1000 cycles. The LIC showed excellent supercapacitor performance.

Active control of a nonlinear and hysteretic building structure with time delay

Liu, Kun,Chen, Long-Xiang,Cai, Guo-Ping Techno-Press 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.3

Time delay inevitably exists in active control systems, and it may cause the degradation of control efficiency or instability of the systems. So time delay needs to be compensated in control design in order to eliminate its negative effect on control efficiency. Today time delay in linear systems has been more studied and some treating methods had been worked out. However, there are few treating methods for time delay in nonlinear systems. In this paper, an active controller for a nonlinear and hysteretic building structure with time delay is studied. The nonlinear and hysteretic behavior of the system is illustrated by the Bouc-Wen model. By specific transformation and augmentation of state parameters, the motion equation of the system with explicit time delay is transformed into the standard state space representation without any explicit time delay. Then the fourth-order Runge-Kutta method and instantaneous optimal control method are applied to the controller design with time delay. Finally, numerical simulations and comparisons of an eight-story building using the proposed time-delay controller are carried out. Simulation results indicate that the control performance will deteriorate if time delay is not taken into account in the control design. The simulations also prove the proposed time delay controller in this paper can not only effectively compensate time delay to get better control effectiveness, but also work well with both small and large time delay problems.

Active control of a nonlinear and hysteretic building structure with time delay

Kun Liu,Long-Xiang Chen,Guo-Ping Cai 국제구조공학회 2011 Structural Engineering and Mechanics, An Int'l Jou Vol.40 No.3

Time delay inevitably exists in active control systems, and it may cause the degradation of control efficiency or instability of the systems. So time delay needs to be compensated in control design in order to eliminate its negative effect on control efficiency. Today time delay in linear systems has been more studied and some treating methods had been worked out. However, there are few treating methods for time delay in nonlinear systems. In this paper, an active controller for a nonlinear and hysteretic building structure with time delay is studied. The nonlinear and hysteretic behavior of the system is illustrated by the Bouc-Wen model. By specific transformation and augmentation of state parameters, the motion equation of the system with explicit time delay is transformed into the standard state space representation without any explicit time delay. Then the fourth-order Runge-Kutta method and instantaneous optimal control method are applied to the controller design with time delay. Finally, numerical simulations and comparisons of an eight-story building using the proposed time-delay controller are carried out. Simulation results indicate that the control performance will deteriorate if time delay is not taken into account in the control design. The simulations also prove the proposed time delay controller in this paper can not only effectively compensate time delay to get better control effectiveness, but also work well with both small and large time delay problems.

Association analyses of East Asian individuals and trans-ancestry analyses with European individuals reveal new loci associated with cholesterol and triglyceride levels

Spracklen, C. N.,Chen, P.,Kim, Y. J.,Wang, X.,Cai, H.,Li, S.,Long, J.,Wu, Y.,Wang, Y. X.,Takeuchi, F. IRL Press 2017 Human molecular genetics Vol.26 No.9

<P>Large-scale meta-analyses of genome-wide association studies (GWAS) have identified > 175 loci associated with fasting cholesterol levels, including total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol (LDL-C), and triglycerides (TG). With differences in linkage disequilibrium (LD) structure and allele frequencies between ancestry groups, studies in additional large samples may detect new associations. We conducted staged GWAS meta-analyses in up to 69,414 East Asian individuals from 24 studies with participants from Japan, the Philippines, Korea, China, Singapore, and Taiwan. These meta-analyses identified (P < 5 x 10(-8)) three novel loci associated with HDL-C near CD163-APOBEC1 (P = 7.4 x 10(-9)), NCOA2 (P = 1.6 x 10(-8)), and NID2-PTGDR (P = 4.2 x 10(-8)), and one novel locus associated with TG near WDR11-FGFR2 (P = 2.7 x 10(-10)). Conditional analyses identified a second signal near CD163-APOBEC1. We then combined results from the East Asian meta-analysis with association results from up to 187,365 European individuals from the Global Lipids Genetics Consortium in a trans-ancestry meta-analysis. This analysis identified (log(10)Bayes Factor a 6.1) eight additional novel lipid loci. Among the twelve total loci identified, the index variants at eight loci have demonstrated at least nominal significance with other metabolic traits in prior studies, and two loci exhibited coincident eQTLs (P < 1 x 10(-5)) in subcutaneous adipose tissue for BPTF and PDGFC. Taken together, these analyses identified multiple novel lipid loci, providing new potential therapeutic targets.</P>

Data-Based Identification of the Tire Cornering Properties Via Piecewise Affine Approximation

Sun Xiaoqiang,Hu Weiwei,Cai Yingfeng,Wong Pak Kin,Chen Long 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.3

The piecewise affine (PWA) model represents an attractive model structure for approximating nonlinear systems. In this paper, a procedure for obtaining the PWA model of the tire nonlinear cornering properties is introduced. In this approach, the highly nonlinear dynamic of the tire cornering properties is well approximated by a set of affine maps which relate inputs and outputs. These maps are defined in disjunctive regions in the regression space, itself composed of system inputs and outputs. The tire cornering properties tests are firstly carried out through a high-performance flat-plate test bench, thus the experimental data which can accurately reflect the tire cornering properties is obtained. On this basis, the PWA identification of the tire cornering properties is composed of the data clustering, the parameter estimation of the affine submodels and the calculation of the hyperplane coefficient matrices, which are respectively achieved by means of fuzzy c-means clustering, weighted least-squares and support vector machines. Finally, to verify the PWA model accuracy in approximating the tire nonlinear cornering properties, the comparison between the simulation results of the PWA identification model and the experimental data is conducted and the comparison results are analyzed.

Linear Distribution Principle for Sheet Forming Using Continuous Roll Forming Process

Mi Wang,Guo-long Lu,Zhong-Yi Cai,Shu-chen Yang,Ming-Zhe Li 한국정밀공학회 2020 International Journal of Precision Engineering and Vol.21 No.4

Continuous roll forming (CRF) process utilizes two reconfi gurable rollers as forming tools to manufacture 3D surface part. Inorder to investigate the longitudinal deformation of 3D curved surface part, the detailed mathematical methodology using ageometrical relationship is analyzed and described. The results show that the necessary condition for generating longitudinalbending deformation is the linear distribution of the longitudinal fi ber. The deformation characteristics of CRF studied bysimulation confi rm that the ideal longitudinal deformation is generated when the distribution of longitudinal fi bers satisfythe linear distribution principle, the maximum length diff erence of longitudinal fi bers is the major factor determining thelongitudinal curvature radius of formed part, and increasing maximum length diff erence of longitudinal fi bers incurs anincreasing longitudinal curvature. In addition, 3D surface parts with diff erent longitudinal curvature were prepared by CRFprocess, which had verifi ed the proposed linear distribution principle.

Three-Dimensional Porous Carbon Nanotube Papers as Current Collector and Buffer for SnO2 Anodes

Xiaogang Sun,Zhiwen Qiu,Long Chen,Manyuan Cai,Jie Wang,Xu Li,Wei Chen,Zhenhong Liu,Hao Tang 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2017 NANO Vol.12 No.11

A novel three-dimensional porous conductive papers have been successfully synthesized via a simple physical route. Multi-walled carbon nanotubes (MWCNTs)@SnO2 composite anode materials are embedded in porous conductive papers. The peculiar structure can accommodate the huge volume expansion of MWCNTs@SnO2 composite anode materials during charge–discharge process. The framework formed by MWCNTs and cellulose can greatly improve the strength, stability and flexibility of the electrode. In addition, the structure successfully prevent the aggregation of SnO2 nanoparticles and collapse of MWCNTs@SnO2 composite electrode, leading to the improvement in electrochemical utilization and stable cyclability. The samples were characterized by X-ray diffraction (XRD), field-emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM), respectively. The electrochemical properties and application were evaluated by galvanostatic discharge–charge testing and cycling voltammetry. As a result, the MWCNTs@SnO2 composite electrode showed excellent rate performance. The discharge capacity remains about 680mAh g -1 after 100 cycles at 200mA g -1, and even around 300mAh g -1 at 1000mA g -1.