A Novel Approach to Controlling CaCO₃ Crystalline Assembly by Changing the Concentration of Poly(aspartic acid)

Zhou, Hongjian,Gao, Yanmin,Hwang, Sun-Gu,Lee, Dong-Yun,Park, Jung-Youn,Lee, Jae-Beom Korean Chemical Society 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

$CaCO_3$ crystalline structures having novel assemblies were in situ fabricated as analogs of naturally occurring proteins and polysaccharides for biomineralization. The calcite crystal was mineralized in a poly(vinyl alcohol)-$Ca^{2+}$ complex film immersed in a $Na_2CO_3$ solution containing poly(aspartic acid). The morphology and size of the $CaCO_3$ crystals were tuned by varying the concentration of poly(aspartic acid). The mechanisms of their nucleation orientation and formation were investigated experimentally and through molecular dynamics (MD) simulations in order to obtain a better understanding of the interactions between the polymers and the crystal at the molecular level. Both the MD results and experimental results indicate that the interaction between PVA and calcite mainly depends on the concentration of the polymer. The novel approach proposed herein for the fabrication of inorganic crystalline assembly structures can be used to fabricate precise crystalline structures.

A Novel Approach to Controlling CaCO_3 Crystalline Assembly by Changing the Concentration of Poly(aspartic acid)

Hongjian Zhou,Jung Youn Park,이동윤,황승구,Yanmin Gao,이재범 대한화학회 2011 Bulletin of the Korean Chemical Society Vol.32 No.11

CaCO_3 crystalline structures having novel assemblies were in situ fabricated as analogs of naturally occurring proteins and polysaccharides for biomineralization. The calcite crystal was mineralized in a poly(vinyl alcohol)-Ca^(2+) complex film immersed in a Na_2CO_3 solution containing poly(aspartic acid). The morphology and size of the CaCO_3 crystals were tuned by varying the concentration of poly(aspartic acid). The mechanisms of their nucleation orientation and formation were investigated experimentally and through molecular dynamics (MD) simulations in order to obtain a better understanding of the interactions between the polymers and the crystal at the molecular level. Both the MD results and experimental results indicate that the interaction between PVA and calcite mainly depends on the concentration of the polymer. The novel approach proposed herein for the fabrication of inorganic crystalline assembly structures can be used to fabricate precise crystalline structures.

Numerical investigation on the effect of baffles on liquid sloshing in 3D rectangular tanks based on nonlinear boundary element method

Guan, Yanmin,Yang, Caihong,Chen, Ping,Zhou, Li The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.1

The numerical simulation of liquid sloshing in the three-dimensional tanks under horizontal excitation and roll excitation was carried out, and the inhibition effect of different baffles on the sloshing phenomenon was investigated. The numerical calculations were carried out by the nonlinear Boundary Element Method (BEM) with Green's theorem based on the potential flow, which was conducted with the governing equation corresponding to the boundaries of each region. The validity of the method was verified by comparing with experimental values and published literatures. The horizontal baffle, the vertical baffle and the T-shaped baffle in the sloshing tanks were investigated respectively, and the baffles' position, dimension and the liquid depth were provided and discussed in detail. It is drawn that the baffle shape plays a non-negligible role in the tank sloshing. The vertical baffle is a more effective way to reduce the sloshing amplitude when the tank is under a horizontal harmonic excitation while the horizontal baffle is a more effective way when the tank is under a roll excitation. The amplitude of free surface elevation at right tank wall decreases with the increasing of the horizontal baffle length and the vertical baffle height. Although the T-shaped baffle has the best suppression effect on tank sloshing under horizontal excitation, it has limited suppression effect under roll excitation and will complicate the sloshing phenomenon when changing baffle height.

Numerical investigation on the effect of baffles on liquid sloshing in 3D rectangular tanks based on nonlinear boundary element method

Guan, Yanmin,Yang, Caihong,Chen, Ping,Zhou, Li The Society of Naval Architects of Korea 2020 International Journal of Naval Architecture and Oc Vol.12 No.-

The numerical simulation of liquid sloshing in the three-dimensional tanks under horizontal excitation and roll excitation was carried out, and the inhibition effect of different baffles on the sloshing phenomenon was investigated. The numerical calculations were carried out by the nonlinear Boundary Element Method (BEM) with Green's theorem based on the potential flow, which was conducted with the governing equation corresponding to the boundaries of each region. The validity of the method was verified by comparing with experimental values and published literatures. The horizontal baffle, the vertical baffle and the T-shaped baffle in the sloshing tanks were investigated respectively, and the baffles' position, dimension and the liquid depth were provided and discussed in detail. It is drawn that the baffle shape plays a non-negligible role in the tank sloshing. The vertical baffle is a more effective way to reduce the sloshing amplitude when the tank is under a horizontal harmonic excitation while the horizontal baffle is a more effective way when the tank is under a roll excitation. The amplitude of free surface elevation at right tank wall decreases with the increasing of the horizontal baffle length and the vertical baffle height. Although the T-shaped baffle has the best suppression effect on tank sloshing under horizontal excitation, it has limited suppression effect under roll excitation and will complicate the sloshing phenomenon when changing baffle height.

Experimental Study on Fracture Resistant Design Method for Steel Structural Components at Low Temperature

Hui Zhou,Yuanqing Wang,Yongjiu Shi,Yanmin Wu 한국강구조학회 2015 International Journal of Steel Structures Vol.15 No.2

Three-point bending tests were conducted at various low temperatures to obtain the crack-tip opening displacement (CTOD) values of three varieties of structural steels with several plate thicknesses. Parameters of the crack growth resistance curve (Rcurve) of each specimen were calibrated by regression of the test data points (CTOD versus crack extension). The temperature and the plate thickness had great effects on the R-curve shape (flat or rising) and the fracture mode (brittle or ductile). In a design process of a steel component, an initial crack is assumed according to its fatigue category. Through the analyses of the crack driving force and the resistance, a practical method is proposed for fracture resistant design and evaluation of flawless or flawed steel components at low temperature.

Effects of Different Levels of Supplementary Alpha-amylase on Digestive Enzyme Activities and Pancreatic Amylase mRNA Expression of Young Broilers

Jiang, Zhengyu,Zhou, Yanmin,Lu, Fuzeng,Han, Zhaoyu,Wang, Tian Asian Australasian Association of Animal Productio 2008 Animal Bioscience Vol.21 No.1

Four hundred and forty 1-day-old Arbor Acre broilers were fed commercial starter diets with 0, 250, 750 and 2,250 mg/kg of an alpha-amylase preparation from 1 to 21 days of age to investigate the effects of an exogenous enzyme on growth performance, activities of digestive enzymes in the pancreas and anterior intestinal contents and pancreatic amylase mRNA expression. Body weight gain (BWG) and average daily gain (ADG) increased linearly (p<0.01) with increasing levels of supplementary amylase but feed conversion ratio (FCR) was not affected. There was a negative quadratic change of protease and amylase in the small intestinal contents with the increase of supplementary amylase level. The activity of intestinal trypsin was also increased (p<0.05). Lipase was unaffected by amylase supplementation (p>0.05). The pancreatic protease, trypsin, and lipase were not affected by exogenous amylase levels. Consistent with the tendency for a linear depression of amylase activity, pancreatic ${\alpha}$-amylase mRNA was down-regulated by dietary amylase supplementation. The present study suggested that oral administration of exogenous amylase affected activities of intestinal enzymes and the production of pancreatic digestive enzymes in a dose-dependent manner.

Mobility properties analyses of a wall climbing hexapod robot

Bin He,Shoulin Xu,Yanmin Zhou,Zhipeng Wang 대한기계학회 2018 JOURNAL OF MECHANICAL SCIENCE AND TECHNOLOGY Vol.32 No.3

In this paper, we investigate the Degree of freedom (DOF), workspace and singularity of a wall climbing hexapod robot. The robot has two typical working modes, which are the six or three legs attaching on the wall, so robot can be regarded as 6SRRR or 3SRRR parallel mechanism, respectively. First, the DOF of the robot is analyzed by the screw theory. The result indicates that two configurations of the robot possess 6-DOF, and the screw theory makes the calculation of the DOF become extremely simple. Moreover, the workspace of the robot body is studied with constraint equations, which obtains the influence of structural parameters on workspace. After that, a new simple Jacobian matrix is proposed to analyze the singularity, and obtain the singular configurations of the robot, which greatly simplifies the calculation of Jacobian matrix of the robot. Finally, by experiments to verify that the singularity analysis method is correct. The singularity analysis of this paper could be applied for effective control of the robot to avoid singular configurations.

An evaluation of heat on protein oxidation of soy protein isolate or soy protein isolate mixed with soybean oil in vitro and its consequences on redox status of broilers at early age

Xianglun Zhang,Peng Lu,Wenyue Xue,Dawei wu,Chao Wen,Yanmin Zhou 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.8

Objective: The objective of this study was to evaluate effects of heat treatment and soybean oil inclusion on protein oxidation of soy protein isolate (SPI) and of oxidized protein on redox status of broilers at an early age. Methods: SPI mixed with soybean oil (SPIO) heated at 100°C for 8 h was used to evaluate protein oxidation of SPI. A total of two hundred and sixteen 1-day-old Arbor Acres chicks were divided into 3 groups with 6 replicates of 12 birds, receiving basal diet (CON), heat-oxidized SPI diet (HSPI) or mixture of SPI and 2% soybean oil diet (HSPIO) for 21 d, respectively. Results: Increased protein carbonyl, decreased protein sulfhydryl of SPI were observed as heating time increased in all treatments (p<0.05). Addition of 2% soybean oil increased protein carbonyl of SPI at 8 h heating (p<0.05). Dietary HSPI and HSPIO decreased the average daily gain of broilers as compared with the CON (p<0.05). Broilers fed HSPI and HSPIO exhibited decreased glutathione (GSH) in serum, catalase activity and total sulfhydryl in liver and increased malondialdehyde (MDA) and protein carbonyl in serum, advanced oxidation protein products (AOPPs) in liver and protein carbonyl in jejunal mucosa as compared with that of the CON (p<0.05). Additionally, broilers receiving HSPIO showed decreased glutathione peroxidase activity (GSH-Px) in serum, GSH and hydroxyl radical scavenging capacity in liver, GSH-Px activity in duodenal mucosa, GSH-Px activity and superoxide anion radical scavenging capacity in jejunal mucosa and increased AOPPs in serum, MDA and protein carbonyl in liver, MDA and AOPPs in jejunal mucosa (p<0.05). Conclusion: Protein oxidation of SPI can be induced by heat and soybean oil and oxidized protein resulted in redox imbalance in broilers at an early age.

Effects of zinc bearing palygorskite supplementation on the growth performance, hepatic mineral content, and antioxidant status of broilers at early age

Weili Yang,Yueping Chen,Yefei Cheng,Chao Wen,Yanmin Zhou 아세아·태평양축산학회 2017 Animal Bioscience Vol.30 No.7

Objective: This study was conducted to investigate effects of zinc (Zn) bearing palygorskite (ZnPal) supplementation on growth performance, hepatic mineral content, and antioxidant status of broilers at early age. Methods: A total of 240 1-day-old Arbor Acres broiler chicks were allocated into 5 treatments with 6 replicates of 8 chicks each. Birds in 5 treatments were fed a basal diet supplemented with 0 (Control group; Analyzed Zn content: 81 mg/kg), 20, 40, 60, and 80 mg/kg Zn as ZnPal for 21 days, respectively. Blood, liver and intestinal mucosa were collected at 21 days of age. Results: Treatments did not affect growth performance of broilers during the 21-day study (p> 0.05). The contents of hepatic Zn and magnesium (Mg) were linearly increased (p<0.001) by ZnPal supplementation. ZnPal inclusion linearly (p = 0.007) reduced malondialdehyde (MDA) concentration in serum. The activity of total superoxide dismutase (T-SOD) in liver increased linearly (p = 0.001) with concentration of ZnPal in diet. ZnPal inclusion linearly (p = 0.036) and quadratically (p = 0.005) increased T-SOD activity, and linearly (p = 0.012) increased copper/zinc superoxide dismutase (Cu/Zn SOD) activity in jejunal mucosa. The maximum responses of hepatic and jejunal antioxidant enzymes activities (T-SOD and Cu/Zn SOD) were found when supplementing the basal diet with 60 mg/kg Zn as ZnPal. Furthermore, ZnPal supplementation quadratically (p = 0.001) increased Cu/Zn SOD activity in ileal mucosa, and its maximum activity was observed in the diet supplemented with 20 mg/kg Zn as ZnPal. Conclusion: ZnPal supplementation did not alter growth performance of broilers. Dietary ZnPal inclusion could increase concentrations of hepatic trace minerals (Zn and Mg) and inhibit lipid peroxidation by reducing serum MDA accumulation, with the optimal dosage of Zn from ZnPal being 80 mg/kg diet (analyzed Zn content in the diet: 165 mg/kg), and 60 mg/kg Zn as ZnPal (analyzed Zn content in the diet: 148 mg/kg) was the optimum dosage for broilers to achieve maximum antioxidant enzyme activities.

Effect of Leukocyte-Platelet Rich Fibrin (L-PRF) on Tissue Regeneration and Proliferation of Human Gingival Fibroblast Cells Cultured Using a Modified Method

Mudalal Mahmoud,Wang Zhanqi,Mustafa Shockry,Liu Yiping,Wang Yao,Yu Jize,Wang Shengnan,Sun Xiaolin,Zhou Yanmin 한국조직공학과 재생의학회 2021 조직공학과 재생의학 Vol.18 No.5

Background: An in vitro study on rapid culturing method of human gingival fibroblast cells (HGFCs) was established to investigate the potential use of the leukocyte-platelet rich fibrin (L-PRF) in tissue engineering technology, different medical fields, including periodontology and implantology. Methods: Eight biopsies were obtained from eight different donors and a modified culturing technique was developed to obtain HGFCs. The modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT assay was used to compare the cell viability when the modified culturing method was used in comparison to the standard method. Blood samples were collected from the same patients and L-PRF was isolated using a standard protocol. The releases of platelet-derived growth factor-AA and transforming growth factor-beta1 at various time intervals were observed using enzyme-linked immunosorbent assay (ELISA) kit. The proliferative effect of L-PRF on HGFCs was assessed by the cell counting kit—8 assay. Results: A simple and rapid modified method for in vitro HGFC culture yielded a cellular monolayer within three to nine days after cell culture. L-PRF with three-dimensional polymer fibers released growth factors that peaked during the first three hours and continued to produce up to 10 days. The L-PRF presented a dose-dependent effect on HGFCs proliferation where HGFCs proliferation increased with an increase in L-PRF concentration. Conclusion: The modified technique for the culture of HGFCs might be useful for the development of future experimental and clinical studies, besides L-PRF has great therapeutic potential in oral surgery fields. Background: An in vitro study on rapid culturing method of human gingival fibroblast cells (HGFCs) was established to investigate the potential use of the leukocyte-platelet rich fibrin (L-PRF) in tissue engineering technology, different medical fields, including periodontology and implantology. Methods: Eight biopsies were obtained from eight different donors and a modified culturing technique was developed to obtain HGFCs. The modified 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide MTT assay was used to compare the cell viability when the modified culturing method was used in comparison to the standard method. Blood samples were collected from the same patients and L-PRF was isolated using a standard protocol. The releases of platelet-derived growth factor-AA and transforming growth factor-beta1 at various time intervals were observed using enzyme-linked immunosorbent assay (ELISA) kit. The proliferative effect of L-PRF on HGFCs was assessed by the cell counting kit—8 assay. Results: A simple and rapid modified method for in vitro HGFC culture yielded a cellular monolayer within three to nine days after cell culture. L-PRF with three-dimensional polymer fibers released growth factors that peaked during the first three hours and continued to produce up to 10 days. The L-PRF presented a dose-dependent effect on HGFCs proliferation where HGFCs proliferation increased with an increase in L-PRF concentration. Conclusion: The modified technique for the culture of HGFCs might be useful for the development of future experimental and clinical studies, besides L-PRF has great therapeutic potential in oral surgery fields.