Effect of Chemical Admixtures on Setting Time, Fluidity and Mechanical Properties of Phosphorus Gypsum Based Self-Leveling Mortar

Zhenzhen Zhi,Jian Huang,Yanfei Guo,Siwen Lu,Baoguo Ma 대한토목학회 2017 KSCE JOURNAL OF CIVIL ENGINEERING Vol.21 No.5

Phosphorus Gypsum (PG) based Self-Leveling mortar (GSL) is a green and efficient material for floor construction. Its hydration kinetics, rheology property and their effect on mechanical strength of hydrated GSL were crucial to its final application. This study analyzed the effect on setting time of three retarders, namely Protein Salt (PS), Citric Acid (CA), and Sodium Tripolyphosphate (STPP). The fluidity of GSL was investigated individually using three different types of superplasticizer, namely naphthalene (FDN), polycarboxylate (PCE) and melamine (MSF). Finally, the effect of these chemical admixtures on mechanical properties of GSL hardened was examined. Results showed that the optimal contents of PS were 0.1%-0.15% by weight. With 0.1% PS, setting time of GSL retarded to 80min. To reach a maximum fluidity of GSL to 350mm, the optimal contents of PCE, MSF and FDN were 0.2%, 0.6% and 1.0% respectively and corresponding compressive strength of GSL were 54.25MPa, 53MPa and 52.25MPa. Suggesting PCE is the most effective dispersant in PG based GSL system.

An advanced Parallel FPGA Architecture for Bi-directional Motion Estimation

Yangfan Huang,Minjun Deng,Donglian Li,Zhenzhen Li,Mingyan Yu,Cailan Zeng,Yu Zhang,Zhuo Chen,Pengcheng Cao,Ran Liu 보안공학연구지원센터 2015 International Journal of Hybrid Information Techno Vol.8 No.9

Motion estimation (ME) and motion compensation (MC) are the key elements for frame rate up-conversion (FRUC) system. Fast and accurate motion estimation is the premise of high quality motion compensation. Unlike conventional unidirectional motion estimation which brings holes, overlaps and blocking artifacts, the bi-directional motion estimation does not produce any overlapped pixel or hole in the interpolated frames. As a result, the bi-directional motion estimation has better performance than conventional unidirectional motion estimation. This paper presents an efficient FPGA architecture targeting bi-directional motion estimation hardware implementation. This proposed architecture can achieve real-time processing for 1280x720@60Hz under 200MHz operating frequency. The design is described in Verilog HDL, verified in Virtex5 FPGA platform. Experimental results show that the proposed architecture has high performance and low cost for bi-directional motion estimation algorithm. This architecture can be used for video post-processing system.

Effect of Wall Structures on Mechanical Properties of Small Caliber PHBHHx Vascular Grafts

Jing Gao,Zhenzhen Huang,Huiwen Guo,Shunzhu Tian,Lu Wang,Yuling Li 한국섬유공학회 2019 Fibers and polymers Vol.20 No.11

In order to analyze the effect of vascular wall structures on static and dynamic mechanical properties of vasculargrafts, small calibre PHBHHx (Poly(3-hydroxybutyrate-co-3-hydroxhexanoate)) vascular grafts (inner diameter 6 mm) withvarious wall shapes and thicknesses were fabricated by changing electrospinning time and receiving molds. As spinning timeincreased, wall thickness of the vascular grafts increased and both circumferential tensile strength and suture retentionstrength improved significantly. When the wall thicknesses of straight grafts were about 120 μm, the great radial dynamiccompliance was exhibited, however, the tensile strength and suture retention strength of the straight tubes can’t reach therequirements of normal blood vessel grafting. With the wall thicknesses increasing above 250 μm, although thecircumferential tensile strength and suture retention strength gradually achieved the transplanting requirements, the dynamiccompliance of the straight tubes declined too sharply to adapt the blood radial shock. For corrugated grafts, the effect of wallthickness on radial dynamic compliance was little, and the radial dynamic compliance was close to that of the commercialvascular grafts. The circumferential tensile strength and suture retention strength of the corrugated grafts were also improvedto approach the commercial vessels’ performances with the wall thickness improving to about 425 μm. Elastic recovery ratesof all the prepared vascular grafts were superior to that of the commercial sample. Along with the wall thickness exceeding250 μm, the water permeabilities of both the straight and the corrugated grafts were less than 300 ml/(cm2·min).

A Dual-scale Network with Spatial-temporal Attention for 12-lead ECG Classification

Shuo Xiao,Yiting Xu,Chaogang Tang,Zhenzhen Huang 한국인터넷정보학회 2023 KSII Transactions on Internet and Information Syst Vol.17 No.9

The electrocardiogram (ECG) signal is commonly used to screen and diagnose cardiovascular diseases. In recent years, deep neural networks have been regarded as an effective way for automatic ECG disease diagnosis. The convolutional neural network is widely used for ECG signal extraction because it can obtain different levels of information. However, most previous studies adopt single scale convolution filters to extract ECG signal features, ignoring the complementarity between ECG signal features of different scales. In the paper, we propose a dual-scale network with convolution filters of different sizes for 12-lead ECG classification. Our model can extract and fuse ECG signal features of different scales. In addition, different spatial and time periods of the feature map obtained from the 12-lead ECG may have different contributions to ECG classification. Therefore, we add a spatial-temporal attention to each scale sub-network to emphasize the representative local spatial and temporal features. Our approach is evaluated on PTB-XL dataset and achieves 0.9307, 0.8152, and 89.11 on macro-averaged ROC-AUC score, a maximum F1 score, and mean accuracy, respectively. The experiment results have proven that our approach outperforms the baselines.

Production of a Thermostable Metal-tolerant Laccase from Trametes versicolor and its Application in Dye Decolorization

Zhu Youshuang,Zhang Haibo,Cao Mingle,Wei Zhenzhen,Huang Feng,Gao Peiji 한국생물공학회 2011 Biotechnology and Bioprocess Engineering Vol.16 No.5

Production of laccase using a submerged culture of Trametes versicolor sdu-4 was optimized using a central composite design of the Response Surface Methodology. Optimized conditions gave a laccase yield of 4,213 U/L which was approximately three times of that in basal medium. The laccase was purified to homogeneity using a three-step process. The overall yield of the purification was 58%, with a purification fold of 11.4 and a specific activity of 1320.7 U/mg protein. The molecular mass of the laccase was 60 kDa. The optimum pH values of the enzyme were 2.2, 3.7, and 7 for the oxidations of ABTS, DMP, and syringaldazine, respectively. The enzyme had adaptability to a broad pH range and high temperature and wsa stable at pH 3.0 ~ 10.0. The half-life of this laccase at 70°C was 2.2 h. Methyl red, 2-bromophenol, and 4-bromophenol were oxidized by the purified laccase in the absence of mediators. Purified laccase was effective in the decolorization of several dyes and was not inhibited by Cu^(2+), Mn^(2+), Zn^(2+), Na^+, K^+, Mg^(2+), Ba^(2+), and Ca^(2+) at 5 mM. These excellent characteristics made it a highly attractive candidate for industrial use.

A Novel Acid-Stable Endo-Polygalacturonase from Penicillium oxalicum CZ1028: Purification, Characterization, and Application in the Beverage Industry

( Zhong Cheng ),( Dong Chen ),( Bo Lu ),( Yutuo Wei ),( Liang Xian ),( Yi Li ),( Zhenzhen Luo ),( Ribo Huang ) 한국미생물 · 생명공학회 2016 Journal of microbiology and biotechnology Vol.26 No.6

Acidic endo-polygalacturonases are the major part of pectinase preparations and extensively applied in the clarification of fruits juice, vegetables extracts, and wines. However, most of the reported fungal endo-polygalacturonases are active and stable under narrow pH range and low temperatures. In this study, an acidic endo-polygalacturonase (EPG4) was purified and characterized from a mutant strain of Penicillium oxalicum. The N-terminal amino acid sequence of EPG4 (ATTCTFSGSNGAASASKSQT) was different from those of reported endopolygalacturonases. EPG4 displayed optimal pH and temperature at 5.0 and 60-70°C towards polygalacturonic acid (PGA), respectively, and was notably stable at pH 2.2-7.0. When tested against pectins, EPG4 showed enzyme activity over a broad acidic pH range (>15.0% activity at pH 2.2-6.0 towards citrus pectin; and >26.6% activity at pH 2.2-7.0 towards apple pectin). The Km and Vmax values were determined as 1.27 mg/ml and 5,504.6 U/mg, respectively. The enzyme hydrolyzed PGA in endo-manner, releasing oligo-galacturonates from PGA, as determined by TLC. Addition of EPG4 (3.6 U/ml) significantly reduced the viscosity (by 42.4%) and increased the light transmittance (by 29.5%) of the papaya pulp, and increased the recovery (by 24.4%) of the papaya extraction. All of these properties make the enzyme a potential application in the beverage industry.

miRNA-103a-3p Promotes Human Gastric Cancer Cell Proliferation by Targeting and Suppressing ATF7 in vitro

Hu, Xiaoyi,Miao, Jiyu,Zhang, Min,Wang, Xiaofei,Wang, Zhenzhen,Han, Jia,Tong, Dongdong,Huang, Chen Korean Society for Molecular and Cellular Biology 2018 Molecules and cells Vol.41 No.5

Studies have revealed that miR-103a-3p contributes to tumor growth in several human cancers, and high miR-103a-3p expression is associated with poor prognosis in advanced gastric cancer (GC) patients. Moreover, bioinformatics analysis has shown that miR-103a-3p is upregulated in The Cancer Genome Atlas (TCGA) stomach cancer cohort. These results suggest that miR-103a-3p may function as an oncogene in GC. The present study aimed to investigate the role of miR-103a-3p in human GC. miR-103a-3p expression levels were increased in 33 clinical GC specimens compared with adjacent nontumor stomach tissues. Gain- and loss-of-function studies were performed to identify the correlation between miR-103a-3p and tumorigenesis in human GC. Inhibiting miR-103a-3p suppressed GC cell proliferation and blocked the S-G2/M transition in MKN-45/SGC-7901 cells, whereas miR-103a-3p overexpression improved GC cell proliferation and promoted the S-G2/M transition in vitro. Bioinformatics and dual-luciferase reporter assays confirmed that ATF7 is a direct target of miR-103a-3p. Analysis of the TCGA stomach cancer cohort further revealed that miR-103a-3p expression was inversely correlated with ATF7 expression. Notably, silencing ATF7 showed similar cellular and molecular effects as miR-103a-3p overexpression, namely, increased GC cell proliferation, improved CDK2 expression and decreased P27 expression. ATF7 overexpression eliminated the effects of miR-103a-3p expression. These findings indicate that miR-103a-3p promotes the proliferation of GC cell by targeting and suppressing ATF7 in vitro.

miRNA-103a-3p Promotes Human Gastric Cancer Cell Proliferation by Targeting and Suppressing ATF7 in vitro

Xiaoyi Hu,Jiyu Miao,Min Zhang,Xiaofei Wang,Zhenzhen Wang,Jia Han,Dongdong Tong,Chen Huang 한국분자세포생물학회 2018 Molecules and cells Vol.41 No.5

Studies have revealed that miR-103a-3p contributes to tumor growth in several human cancers, and high miR-103a-3p expression is associated with poor prognosis in advanced gastric cancer (GC) patients. Moreover, bioinformatics analysis has shown that miR-103a-3p is upregulated in The Cancer Genome Atlas (TCGA) stomach cancer cohort. These results suggest that miR-103a-3p may function as an oncogene in GC. The present study aimed to investigate the role of miR-103a-3p in human GC. miR-103a-3p expression levels were increased in 33 clinical GC specimens compared with adjacent nontumor stomach tissues. Gain- and loss-of-function studies were performed to identify the correlation between miR-103a-3p and tumorigenesis in human GC. Inhibiting miR-103a-3p suppressed GC cell proliferation and blocked the S-G2/M transition in MKN-45/SGC-7901 cells, whereas miR-103a-3p overexpression improved GC cell proliferation and promoted the S-G2/M transition in vitro. Bioin-formatics and dual-luciferase reporter assays confirmed that ATF7 is a direct target of miR-103a-3p. Analysis of the TCGA stomach cancer cohort further revealed that miR-103a-3p expression was inversely correlated with ATF7 expression. Notably, silencing ATF7 showed similar cellular and molecular effects as miR-103a-3p overexpression, namely, increased GC cell proliferation, improved CDK2 expression and decreased P27 expression. ATF7 overexpression eliminated the effects of miR-103a-3p expression. These findings indicate that miR-103a-3p promotes the proliferation of GC cell by targeting and suppressing ATF7 in vitro.