• Bulletin of the Korean Chemical Society
• /
• v.31 no.2
• /
• pp.275-280
• /
• 2010

Actinobacillus actinomycetemcomitans is a gram-negative, nonmotile coccobacillus bacterium that is associated with several human diseases, including endocarditis, meningitis, osteomyelitis, subcutaneous abscesses and periodontal diseases. A full-length Omp1-like protein gene from A. actinomycetemcomitans was cloned into a pQE30 vector and overexpressed in Escherichia coli BL21(DE3) cells. The protein revealed sequence homologies to Seventeen kilodalton proteins (Skp) from Pasteurella multocida and E. coli that have been characterized as periplasmic chaperones. This soluble Omp1-like protein was successfully purified to homogeneity for further folding and functional studies. The purity, identity, and conformation of the protein were determined using sodium dodecyl sulfate polyacrylamide gel electrophoresis, matrix-assisted laser desorption ionization mass spectrometry, circular dichroism, fluorescence spectroscopic, and differential scanning calorimetric studies. We showed that the protein formed an oligomer larger than a tetramer. We found, further, that it is comprised of mostly $\alpha$-helices and boasts high thermal stability.

• Journal of the Korean Society of Propulsion Engineers
• /
• v.8 no.1
• /
• pp.27-37
• /
• 2004

The convergence characteristics of preconditioned Euler equations were studied. A perturbation analysis was conducted to understand the behavior of the preconditioned Euler equations. Various speed flows in a two-dimensional channel with a 10％ circular arc in the middle of the channel were calculated. Roe's FDS scheme was used for spatial discretization and the LU-SGS scheme was used for time integration. It is shown that the convergence characteristics of pressure and velocity were maintained regardless of the Mach numbers but that the convergence characteristics of temperature were strongly related to the Mach number and became worse as the Mach number decreased. The perturbation analysis well explained the trend of the convergence characteristics and showed that the convergence characteristics are strongly related with the behavior o( the Preconditioning matrix.

• Water for future
• /
• v.23 no.2
• /
• pp.251-263
• /
• 1990

For surcharge flow in a sewer, the slot technique simulates surcharge flow as open - channel flow using a hypothetical narrow open piezometric slot at the sewer crown. The flow in a sewer is described mathematically using the unsteady open - channel Saint-Venant equations. In this study, the computer simulation model(USS-slot) using slot techniques is develeped to simulate the inlet hydrographs to manholes and the flow under pressure as well as free - surface flow in tree - type sewer networks of circular conduits. The inlet hydrographs are simulated by using the rational method or the ILSD progrm. The Saint-Venant equations for unsteady open - channel flow in seweres are solved by using a four - point implicit difference scheme. The flow equations of the sewers and the junction flow equations are solved simulaneously using a sparse matrix solution technique.

• Archives of Plastic Surgery
• /
• v.35 no.6
• /
• pp.631-636
• /
• 2008

Purpose: Adipose tissue-derived stem cells(ADSC) has an osteoconductive potential and demineralized bone matrix(DBM) is an osteoinductive material. A combination of DBM and ADSC wound probably create osteoinductive properties. The purpose of this study is to determine the effect of the combination of DBM and ADSC mixture on healing of rat calvarial defect. Methods: Thirty adult male Sprague-Dawley rats were randomized into 3 groups(n=10) as 1) Control, 2) DBM alone, 3) DBM with ADSC mixture. DBM with ADSC mixture group has had a 3-day preculture of ADSC from groin fat pad. An 6 mm critical size circular calvarial defect was made in each rat. Defect was implanted with DBM alone or DBM with ADSC mixture. Control defect was left unfilled. 6 and 12 weeks after the implantation, the rats were sacrificed and the defects were evaluated by histomorphometric and radiographical studies. Results: Histomorphometric analysis revealed that DBM with ADSC mixture group showed significantly higher bone formation than DBM alone group(p<0.05). Although radiographs from DBM alone group and DBM with ADSC group revealed similar diffuse radiopaque spots dispersed throughout the defect. Densitometric analysis of calvarial defect revealed DBM with ADSC mixture group significantly higher bone formation than DBM alone(p<0.05). There was correlation of densitometry with new bone formation(Spearman's correlation of coefficient=0.804, 6 weeks, 0.802, 12 weeks). Conclusion: The DBM with ADSC mixture group showed the best healing response and the osteoinductive properties of DBM were accelerated with ADSC mixture. It will be clinically applicable that DBM and ADSC mixture in plastic and reconstructive surgery, such as alveolar cleft and congenital facial deformities that bone graft should be required.

• Steel and Composite Structures
• /
• v.44 no.1
• /
• pp.65-79
• /
• 2022

The main goal of this paper is to study the vibration of damaged core laminated annular plates with FG face sheets based on a three-dimensional theory of elasticity. The structures are made of a damaged isotropic core and two external face sheets. These skins are strengthened at the nanoscale level by randomly oriented Carbon nanotubes (CNTs) and are reinforced at the microscale stage by oriented straight fibers. These reinforcing phases are included in a polymer matrix and a three-phase approach based on the Eshelby-Mori-Tanaka scheme and on the Halpin-Tsai approach, which is developed to compute the overall mechanical properties of the composite material. In this study the effect of microcracks on the vibrational characteristic of the sandwich plate is considered. In particular, the structures are made by an isotropic core that undergoes a progressive uniform damage, which is modeled as a decay of the mechanical properties expressed in terms of engineering constants. These defects are uniformly distributed and affect the central layer of the plates independently from the direction, this phenomenon is known as "isotropic damage" and it is fully described by a scalar parameter. Three complicated equations of motion for the sectorial plates under consideration are semi-analytically solved by using 2-D differential quadrature method. Using the 2-D differential quadrature method in the r- and z-directions, allows one to deal with sandwich annular plate with arbitrary thickness distribution of material properties and also to implement the effects of different boundary conditions of the structure efficiently and in an exact manner. The fast rate of convergence and accuracy of the method are investigated through the different solved examples. The sandwich annular plate is assumed to have any arbitrary boundary conditions at the circular edges including simply supported, clamped and, free. Several parametric analyses are carried out to investigate the mechanical behavior of these multi-layered structures depending on the damage features, through-the-thickness distribution, and boundary conditions.

• Steel and Composite Structures
• /
• v.48 no.1
• /
• pp.1-17
• /
• 2023

The main goal of this paper is to study vibration of damaged core laminated sectorial plates with Functionally graded (FG) face sheets based on three-dimensional theory of elasticity. The structures are made of a damaged isotropic core and two external face sheets. These skins are strengthened at the nanoscale level by randomly oriented Carbon nanotubes (CNTs) and are reinforced at the microscale stage by oriented straight fibers. These reinforcing phases are included in a polymer matrix and a three-phase approach based on the Eshelby-Mori-Tanaka scheme and on the Halpin-Tsai approach, which is developed to compute the overall mechanical properties of the composite material. Three complicated equations of motion for the sectorial plates under consideration are semi-analytically solved by using 2-D differential quadrature method. Using the 2-D differential quadrature method in the r- and z-directions, allows one to deal with sandwich annular sector plate with arbitrary thickness distribution of material properties and also to implement the effects of different boundary conditions of the structure efficiently and in an exact manner. The fast rate of convergence and accuracy of the method are investigated through the different solved examples. The sandwich annular sector plate is assumed to be simply supported in the radial edges while any arbitrary boundary conditions are applied to the other two circular edges including simply supported, clamped and free. Several parametric analyses are carried out to investigate the mechanical behavior of these multi-layered structures depending on the damage features, through-the-thickness distribution and boundary conditions.

• Journal of Periodontal and Implant Science
• /
• v.40 no.1
• /
• pp.11-18
• /
• 2010

Purpose: Significant interest has emerged in the design of cell scaffolds that incorporate peptide sequences that correspond to known signaling domains in extracellular matrix and bone morphogenetic protein. The purpose of this study was to evaluate the bone regenerative effects of the synthetic peptide in a critical-size rat calvarial defect model. Methods: Eight millimeter diameter standardized, circular, transosseus defects created on the cranium of forty rats were implanted with synthetic peptide, collagen, or both synthetic peptide and collagen. No material was was implanted the control group. The healing of each group was evaluated histologically and histomorphometrically after 2- and 8-week healing intervals. Results: Surgical implantation of the synthetic peptide and collagen resulted in enhanced local bone formation at both 2 and 8 weeks compared to the control group. When the experimental groups were compared to each other, they showed a similar pattern of bone formation. The defect closure and new bone area were significantly different in synthetic peptide and collagen group at 8 weeks. Conclusions: Concerning the advantages of biomaterials, synthetic peptide can be an effective biomaterial for damaged periodontal regeneration.

• JSTS:Journal of Semiconductor Technology and Science
• /
• v.16 no.6
• /
• pp.800-807
• /
• 2016

We propose a fast algorithm using Extreme Contour Point (ECP) to detect the angle of rotated images, is implemented by rotation feature of one covered frame image that can be applied to correct the rotated images like in image processing for real time applications, while CORDIC is inefficient to calculate various points like high definition image since it is only possible to detect rotated angle between one point and the other point. The two advantages of this algorithm, namely compatibility to images in preprocessing by using Sobel edge process for pattern recognition. While the other one is its simplicity for rotated angle detection with cyclic shift of two $1{\times}n$ matrix set without complexity in calculation compared with CORDIC algorithm. In ECP, the edge features of the sample image of gray scale were determined using the Sobel Edge Process. Then, it was subjected to binary code conversion of 0 or 1 with circular boundary to constitute the rotation in invariant conditions. The results were extracted to extreme points of the binary image. Its components expressed not just only the features of angle ${\theta}$ but also the square of radius $r^2$ from the origin of the image. The detected angle of this algorithm is limited only to an angle below 10 degrees but it is appropriate for real time application because it can process a 200 degree with an assumption 20 frames per second. ECP algorithm has an O ($n^2$) in Big O notation that improves the execution time about 7 times the performance if CORDIC algorithm is used.

• Clinical and Experimental Reproductive Medicine
• /
• v.47 no.2
• /
• pp.108-113
• /
• 2020

Objective: Endometrial fibrosis, the primary pathological feature of intrauterine adhesion, may lead to disruption of endometrial tissue structure, menstrual abnormalities, infertility, and recurrent pregnancy loss. At present, no ideal therapeutic strategy exists for this fibrotic disease. Eupatilin, a major pharmacologically active flavone from Artemisia, has been previously reported to act as a potent inducer of dedifferentiation of fibrotic tissue in the liver and lung. However, the effects of eupatilin on endometrial fibrosis have not yet been investigated. In this study, we present the first report on the impact of eupatilin treatment on transforming growth factor beta (TGF-β)-induced endometrial fibrosis. Methods: The efficacy of eupatilin on TGF-β-induced endometrial fibrosis was assessed by examining changes in morphology and the expression levels of fibrosis markers using immunofluorescence staining and quantitative real-time reverse-transcription polymerase chain reaction. Results: Eupatilin treatment significantly reduced the fibrotic activity of TGF-β-induced endometrial fibrosis in Ishikawa cells, which displayed more circular shapes and formed more colonies. Additionally, the effects of eupatilin on fibrotic markers including alpha-smooth muscle actin, hypoxia-inducible factor 1 alpha, collagen type I alpha 1 chain, and matrix metalloproteinase-2, were evaluated in TGF-β-induced endometrial fibrosis. The expression of these markers was highly upregulated by TGF-β pretreatment and recovered to the levels of control cells in response to eupatilin treatment. Conclusion: Our findings suggest that suppression of TGF-β-induced signaling by eupatilin might be an effective therapeutic strategy for the treatment of endometrial fibrosis.

• Korean Journal of Materials Research
• /
• v.3 no.2
• /
• pp.197-204
• /
• 1993

Abstract The effects of the hole size and the specimen width on the fracture behavior of several fabric composite plates are experimentally investigated in tension. Tests are performed on plain woven glass/ epoxy, plain woven carbon/epoxy and satin woven glass/polyester specimens with a circular hole. It is shown in this paper that the characteristic length according to the point stress criterion depends on the hole size and the specimen width. An excellent agreement is found between the experimental results and the analytical predictions of the modified failure criterion. The notched strength increase with an increase in the damage ratio, which is explained by a stress relaxation due to the formation of damage zone. When the unstable fracture occurred, the critical crack length equivalent for the damage zone is about twice the characteristic length. The critical energy release rate $G_c$ is independent of hole size for the same specimen width. The variation of $G_c$ according to the material system, fiber volume fraction and specimen width relates to the notch sensitivity factor. $G_c$ increases with a decrease in the notch sensitivity factor, which can be explained by a stress relaxation due to the increase of damage zone.