A BIO-INSPIRED POLYDOPAMINE APPROACH TO PREPARATION OF GOLD-COATED Fe3O4 CORE-SHELL NANOPARTICLES: SYNTHESIS, CHARACTERIZATION AND MECHANISM

PENG AN,FANG ZUO,XINHUA LI,YUANPENG WU,JUNHUA ZHANG,ZHAOHUI ZHENG,XIAOBIN DING,YUXING PENG 성균관대학교(자연과학캠퍼스) 성균나노과학기술원 2013 NANO Vol.8 No.6

A biomimetic and facile approach for integrating Fe3O4 and Au with polydopamine (PDA) was proposed to construct gold-coated Fe3O4 nanoparticles (Fe3O4@Au–PDA) with a core–shell structure by coupling in situ reduction with a seed-mediated method in aqueous solution at room temperature. The morphology, structure and composition of the core–shell structured Fe3O4@Au–PDA nanoparticles were characterized by transmission electron microscopy (TEM), X-ray powder diffraction (XRD) and X-ray photoelectron spectrometry (XPS). The formation process of Au shell was assessed using a UV-Vis spectrophotometer. More importantly, according to investigating changes in PDA molecules by Fourier transform infrared spectroscopy (FTIR) and in preparation process of the zeta-potential data of nanoparticles, the mechanism of core–shell structure formation was proposed. Firstly, PDA-coated Fe3O4 are obtained using dopamine (DA) self-polymerization to form thin and surface-adherent PDA films onto the surface of a Fe3O4 "core". Then, Au seeds are attached on the surface of PDA-coated Fe3O4 via electrostatic interaction in order to serve as nucleation centers catalyzing the reduction of Au3+ to Au0 by the catechol groups in PDA. Accompanied by the deposition of Au, PDA films transfer from the surface of Fe3O4 to that of Au as stabilizing agent. In order to confirm the reasonableness of this mechanism, two verification experiments were conducted. The presence of PDA on the surface of Fe3O4@Au–PDA nanoparticles was confirmed by the finding that glycine or ethylenediamine could be grafted onto Fe3O4@Au–PDA nanoparticles through Schiff base reaction. In addition, Fe3O4@Au–DA nanoparticles, in which DA was substituted for PDA, were prepared using the same method as that for Fe3O4@Au–PDA nanoparticles and characterized by UV-Vis, TEM and FTIR. The results validated that DA possesses multiple functions of attaching Au seeds as well as acting as both reductant and stabilizing agent, the same functions as those of PDA.

SCALE-HEIGHTS OF GALACTIC DISKS AND THEIR CORRELATION WITH THE COLOUR INDEX OF THE GALAXIES

PENG QIUHE,JI ZHAOHUI,SHANG ZHAOHUI,SU HONGJUN The Korean Astronomical Society 1996 Journal of The Korean Astronomical Society Vol.29 No.suppl1

Yet another Hybrid Strategy for Auto-tuning SpMV on GPUs

Zhaohui Wang,Xiaojie Qiu,Aimin Zhang,Yichao Cheng,Yi Peng,Sun Sun 보안공학연구지원센터 2015 International Journal of Software Engineering and Vol.9 No.5

Sparse matrix-vector multiplication (SpMV) is a key linear algebra algorithm and is widely used in many application domains. Besides multi-core architecture, there is also extensive research focusing on accelerating SpMV on many-core Graphics Processing Units (GPUs). SpMV computations have many indirect and irregular memory accesses, and load imbalance could occur while mapping computations onto single-instruction, multiple-data (SIMD) GPUs. SpMV is highly memory bandwidth-bound, though GPUs have massive computational resources, the performance of SpMV on GPUs is still unsatisfying. In this paper, we present a new hybrid strategy for auto-tuning SpMV on GPUs. Our strategy combines the advantages of row-major storage and column-major storage. Like many other strategies, we reordered a given sparse matrix according to row lengths in decreasing order. In order to be more adaptive and efficient, we proposed a new hybrid Blocked CSR and JDS (BCJ) format based on original CSR and JDS. BCJ splits a sparse matrix into a denser part and a sparser part after reordering and uses different kernels to process the corresponding part. And we proposed corresponding auto-tuning framework to help transforming matrix and launching kernels according to the sparsity characteristics of the matrix. A CUDA implementation of BCJ outperforms the original formats significantly on a broad range of unstructured sparse matrices.

Hepatic Resection Provides Survival Benefit for Selected Intermediate-Stage (BCLC-B) Hepatocellular Carcinoma Patients

Zhang Zhaohui,Shen Shunli,Chen Bin,Li Shaoqiang,Hua Yunpeng,Kuang Ming,Liang Lijian,Peng Bao Gang 대한암학회 2019 Cancer Research and Treatment Vol.51 No.1

Purpose The intermediate stage of hepatocellular carcinoma (HCC) (Barcelona Clinic Liver Cancer [BCLC] B) comprises a highly heterogeneous population, and the treatment strategy is still controversial. Because of the heterogeneity, a subclassification of intermediate-stage HCCs was put forward by Bolondi according to the ‘beyond Milan and within up-to-7’ criteria and Child-Pugh score. In this study, we aim to analyze the prognosis of BCLC-B stage HCC patients who received hepatic resection according to the Bolondi’s subclassification. Materials and Methods One thousand and one hundred three patients diagnosed with HCC and treated with hepatic resection were enrolled in our hospital between 2006 and 2012. According to Bolondi’s subclassification, the BCLC-B patients were divided into four groups. Recurrence-free survival (RFS) and overall survival (OS) were analyzed. Results According to Bolondi’s subclassification, the BCLC-B patients were divided into four groups: B1 (n=41, 18.7%), B2 (n=160, 73.1%), B3 (n=11, 5.0%), and B4 (n=7, 3.2%). Significant difference was observed between B1 and other groups (B1 vs. B2, p=0.022; B1 vs. B3, p < 0.001; B1 vs. B4, p < 0.001), but no difference for B2 vs. B4 (p=0.542) and B3 vs. B4 (p=0.542). In addition, no significant differences were observed between BCLC-A and BCLCB1 group for both RFS (p=0.087) and OS (p=0.643). In multivariate analysis, BCLC-B subclassification was not a risk factor for both OS (p=0.263) and RFS (p=0.892). Conclusion In our study, HCC patients at B1 stage were benefited from hepatic resection and had similar survival to BCLC-A stage patients. Our study provided rationality of hepatic resection for selected BCLC-B stage HCC patients instead of routine transarterial chemoembolization.

Seismic vibration control of an innovative self-centering damper using confined SMA core

Canxing Qiu,Zhaohui Gong,Changle Peng,Han Li 국제구조공학회 2020 Smart Structures and Systems, An International Jou Vol.25 No.2

Using confined shape memory alloy (SMA) bar or plate, this study proposes an innovative self-centering damper. The damper is essentially properly machined SMA core, i.e., bar or plate, that encased in buckling-restrained device. To prove the design concept, cyclic loading tests were carried out. According to the test results, the damper exhibited desired flag-shape hysteretic behaviors upon both tension and compression actions, although asymmetric behavior is noted. Based on the experimental data, the hysteretic parameters that interested by seismic applications, such as the strength, stiffness, equivalent damping ratio and recentering capacity, are quantified. Processed in the Matlab/Simulink environment, a preliminary evaluation of the seismic control effect for this damper was conducted. The proposed damper was placed at the first story of a multi-story frame and then the original and controlled structures were subjected to earthquake excitations. The numerical outcome indicated the damper is effective in controlling seismic deformation demands. Besides, a companion SMA damper which represents a popular type in previous studies is also introduced in the analysis to further reveal the seismic control characteristics of the newly proposed damper. In current case, it was found that although the current SMA damper shows asymmetric tension-compression behavior, it successfully contributes comparable seismic control effect as those having symmetrical cyclic behavior. Additionally, the proposed damper even shows better global performance in controlling acceleration demands. Thus, this paper reduces the concern of using SMA dampers with asymmetric cyclic behavior to a certain degree.

Constructing all-in-one graphene-based supercapacitors for electrochemical energy storage via interface integration strategy

Zhu Yucan,Peng Long,Chen Song,Feng Yuchao,Xia Jianxing,Wang Wei,Chen Liang,Yin Hong,Zhou Minjie,Hou Zhaohui 한국탄소학회 2023 Carbon Letters Vol.33 No.3

With the rapid development of flexible wearable electronic products, flexible all graphene-based supercapacitors (FGSCs) with reduced graphene oxide rGO//graphene oxide (GO)//rGO structure have attracted substantial attention due to their unique structures and energy storage mechanism. However, restricted by design idea and preparation technology, improvement of capacitance performance for the FGSCs is not obvious recently. Herein, we demonstrate that an interface integration strategy of constructing the high-performance FGSCs with compact structure. Hydroquinone (HQ)-modified rGO (HQ-rGO) films (electrode materials) and sulfuric acid-intercalated GO films (electrolyte/separator) are assembled into the FGSCs utilizing hydrogen bonding and capillary contractility. The HQ further improves the electrochemical capacitance of electrode materials. The synergistic effect of the hydrogen bonding and capillary contractility guarantees compact and stable structure of the device. The resulting FGSCs exhibit an excellent areal capacitance of 804.6 mF cm−2 (@2 mA cm−2) and 441 mF cm−2 (@30 mA cm−2), and their highest energy and power densities can achieve 109.5 μWh cm−2 and 21,060 μW cm−2, respectively. These performances are superior to other all-in-one graphene-based SCs reported. Therefore, the construction technology of the FGSCs is a promising for developing all graphene-based SCs with high-performance.

Current Status of Gene Therapy in Asia

Kim, Sunyoung,Peng, Zhaohui,Kaneda, Yasufumi Elsevier 2008 MOLECULAR THERAPY Vol.16 No.2

<P>Asian countries, in particular China, Japan, and Korea, have been aggressively researching and developing gene medicines over the last 15 years or so. In China, an adenovirus expressing p53 was approved for commercial use in the year 2003, and has been on the actual market since then, becoming the world's first commercial gene-based drug. In Japan and Korea, many interesting scientific discoveries have been made, and industrially valuable technologies have been developed. It is particularly noteworthy to see that in these countries, gene therapy has been very keenly nurtured in relation with industrial and financial sectors. Despite remarkable progresses made in Asia, however, their activities have not been visibly noticed by many scientists in the US and European countries. This article briefly reviews key features of the past achievements and recent progresses made in three Asian countries.</P>

Exploiting User Behavior Changes in Privacy Disclosure by Modified Clustering Technique

Hongchen Wu,Xinjun Wang,Zhaohui Peng,Qingzhong Li 보안공학연구지원센터 2015 International Journal of Security and Its Applicat Vol.9 No.5

The analysis of user behaviors has been an important subject in recommending research recently. This paper proposes a modified clustering technique, showing that users privacy disclosure may change when they are answering the information requests, and we argues that their attitudes, including risk, useful, appropriate, played an important role behind those changes. We presented the new data structure in our dataset that would be loaded to experiment, e.g. personal information requests, users’ answers to those requests, and most importantly, users cluster and attitude for later analysis. Our modified clustering technique would not only locate users privacy disclosure change by comparing the results from learning their past disclosure behaviors and from learning their current disclosures, but also exploit the relationship between the inconsistence in those two results and their attitudes. The data containing users’ answers to a questionnaire with personal information requests was integrated to analyze their disclosure behaviors and attitude with the proposed clustering technique. We indeed find some interesting connections between their privacy disclosure change and attitudes, and the exploration of this paper could benefit to any researchers and online community owners who focusing on user-centered strategies and personal-information-requesting issues.

Thermal characteristics analysis and error prediction for lubricated multi-link high-speed precision presses

Enlai Zheng,Yuanzhao Yang,Zhaohui Peng,Yue Zhu,Xiao Zhao,Xiangze Lin,Min Kang 대한기계학회 2019 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.33 No.6

Thermal models are important in the process of predicting the thermal characteristics and corresponding thermal error of multi-link high-speed precision presses (MLHSPPs) with an oil-lubrication system. Previous models only involved the effects of bearing stiffness, temperature change of bearings, flexibility of crank shaft on the heat generation power, while the influences of revolute clearance joint and flexibility of linkage are seldom considered, which inevitably reduces the accuracy of thermal analysis. To overcome this problem, dynamic models of flexible multi-link mechanisms (MLM) with clearance, lubrication, crankshaft-bearing system are constructed, the interaction forces between pin and bushing are obtained to calculate its heat generation power. Then, an improved model of MLHSPP with lubrication is proposed to analyze the temperature evolution and the thermal error between slider and work table at the position of LDP, by considering bearing stiffness, temperature change of bearings, flexibility of crank shaft, linkage, clearance, lubrication and thermal contact resistance all together. Compared with results from traditional models, the simulation data from this improved thermal model agree well with experiment, which proves the validity of the proposed model. Furthermore, the temperature rise and the thermal error of MLHSPP between slider and work table at the position of LDP under different input speeds, lubricating oil flux and contact angles of ball bearing were also studied.

Systematic identification and characterization of miRNAs and piRNAs from porcine testes

Bo Weng,Maoliang Ran,Maisheng Wu,Fuzhi Peng,Lianhua Dong,Changqing He,Shanwen Zhang,Zhaohui Li,Bin Chen 한국유전학회 2017 Genes & Genomics Vol.39 No.10

microRNAs (miRNAs) and PIWI-interacting RNAs (piRNAs) execute important regulatory roles in testis development and spermatogenesis, while previous studies mainly focus on the expression profiles in immature and mature porcine testes, which may cause a bottleneck for further understanding their complex physiological processes in porcine testes development and spermatogenesis. Thus, we presented the expression and characterization of miRNAs and piRNAs in DS (60-day-old), DN (90-dayold), DT (120-day-old) and DF (150-day-old) pig testes. In total, 12,834,628, 13,359,726, 12,851,249 and 12,938,601 clean reads were generated from these libraries, respectively. 293 mature and 36 novel miRNAs as well as 4923 piRNA clusters were identified from pig testes, and they showed an age-dependent manner. GO enrichment analysis of miRNA target genes and piRNA generated genes showed that they participated widely in regulating the pig spermatogenesis process. In addition, 12 differentially expressed miRNAs were randomly selected to validate using qRT-PCR. Our results provided novel comprehensive expression profiles of miRNAs and piRNAs in pig testes at different stages of sexual maturity, which will promote our knowledge of them in regulating the pig testes development and spermatogenesis process.