• Steel and Composite Structures
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• v.1 no.3
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• pp.295-312
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• 2001

The purpose of this paper is to propose a new type of steel reinforced concrete (SRC) beam-column joints and to examine the structural performance of the proposed joints, which simplify the construction procedure of steel fabrication, welding works, concrete casting and joint strengthening. In the proposed beam-column joints, the steel element of columns forms continuously built-in crossing of H-sections (${\Box}$), with adjacent flanges of column being connected by horizontal stiffeners in a joint at the level of the beam flanges. In addition, simplified lateral reinforcement (${\Box}$) is adopted in a joint to confine the longitudinal reinforcing bars in columns. Experimental and analytical studies have been carried out to estimate the structural performance of the proposed joints. Twelve cruciform specimens and seven SRC beam-column subassemblage specimens were prepared and tested. The following can be concluded from this study: (1) SRC subassemblages with the proposed beam-column joints show adequate seismic performances which are superior to the demand of the current code; (2) The yield and ultimate strength capacities of the beam-to-column connections can be estimated by analysis based on the yield line theory; (3) The skeleton curves and the ultimate shear capacities of the beam-column joint panel are predicted with a fair degree of accuracy by considering a simple stress transfer mechanism.

• Parasites, Hosts and Diseases
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• v.48 no.4
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• pp.285-290
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• 2010

Tyrosine kinases are one of the most important regulators for intracellular signal transduction related to inflammatory responses. However, there are no reports describing the effects of tyrosine kinases on neutrophil apoptosis induced by Entamoeba histolytica, In this study, isolated human neutrophils from peripheral blood were incubated with live trophozoites in the presence or absence of tyrosine kinase inhibitors. Entamoeba-induced receptor shedding of CD16 and PS externalization in neutrophils were inhibited by pre-incubation of neutrophils with the broad-spectrum tyrosine kinase inhibitor genistein or the Src family kinase inhibitor PP2. Entamoeba-induced ROS production was also inhibited by genistein or PP2, Moreover, genistein and PP2 blocked the phosphorylation of ERK and p38 MAPK in neutrophils induced by E. histolytica. These results suggest that Src tyrosine kinases may participate in the signaling event for ROS-dependent activation of MAPKs during neutrophil apoptosis induced by E. histolytica.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.16 no.5
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• pp.413-423
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• 1991

Some digital partical response continuous phase modulation signals such as 3RC, 3SRC, 4SRC, and TFM have cconstant envelope characteristics and compact power spectra. However, their bit error rates in fast fading environments are too high when a simple frequency detection is used. This is due to high inter symbol interference resulting from adjacent bits. The improvement of BER performance by using DFE(Decision Feedback Equalization) to cancel the ISI of one adjacent bit is theoretically investigated in this paper. Numerical resuls are presentes to compare the BER performance of frequency detection with and without decision feedback equalization.

• BMB Reports
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• v.52 no.12
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• pp.718-727
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• 2019

Severe combined immunodeficiency (SCID) is a group of inherited disorders characterized by compromised T lymphocyte differentiation related to abnormal development of other lymphocytes [i.e., B and/or natural killer (NK) cells], leading to death early in life unless treated immediately with hematopoietic stem cell transplant. Functional NK cells may impact engraftment success of life-saving procedures such as bone marrow transplantation in human SCID patients. Therefore, in animal models, a T cell-/B cell-/NK cell+ environment provides a valuable tool for understanding the function of the innate immune system and for developing targeted NK therapies against human immune diseases. In this review, we focus on underlying mechanisms of human SCID, recent progress in the development of SCID animal models, and utilization of SCID pig model in biomedical sciences. Numerous physiologies in pig are comparable to those in human such as immune system, X-linked heritability, typical T-B+NK- cellular phenotype, and anatomy. Due to analogous features of pig to those of human, studies have found that immunodeficient pig is the most appropriate model for human SCID.

• Steel and Composite Structures
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• v.24 no.4
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• pp.409-423
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• 2017

This paper presents an experimental study on damage evolution laws of solid-web steel reinforced concrete (SRC) T-shaped columns along the direction of the web under various loadings. Ten specimens with a scale ratio of 1/2 and a shear span ratio of 2.5 were designed and fabricated. The influences of various parameters, including the axial compression ratio, steel ratio, and loading mode, were examined. The mechanical performances including load-displacement curve and energy dissipation capacity under the monotonic and low cyclic loadings were analyzed. Compared with the monotonic loading, bearing capacity, ultimate deformation capacity, and energy dissipation capacity of the specimens decrease to some extent with the increase of the displacement amplitude and the number of loading cycle. The results show that the damage process of the SRC T-shaped column can be divided into five stages, namely non-damage, slight-damage, steadily-developing-damage, severe-damage and complete-damage. Finally, based on the Park-Ang model, a modified nonlinear damage model which combines the maximum deformation with hysteretic energy dissipation is proposed by taking into account the dynamic influence of the aforementioned parameters. The results show that the modified model in this paper is more accurate than Park-Ang model and can better describe the damage evolution of SRC T-shaped columns.

• Steel and Composite Structures
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• v.18 no.3
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• pp.623-639
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• 2015

Self-compacting Concrete (SCC) Filled Square steel Tubes (SCFST) was used to strengthen square RC columns. To establish the efficiency of this strengthening method, 17 columns were tested under axial compression loading including 3 RC columns without any strengthening (WRC), 1 RC column strengthened with concrete jacket (CRC), 13 RC columns strengthened with self-compacting concrete filled square steel tubes (SRC). The experimental results showed that the use of SCFST is interesting since the ductility and the bearing capacity of the RC columns are greatly improved. The improvement ratio is significantly affected by the nominal wall thickness of steel tubes (t), the strength grade of strengthening concrete (C), and the length-to-width ratio (L / B) of the specimens. In order to quantitatively analyze the effect of these test parameters on axial loading behavior of the SRC columns, three performance indices, enhancement ratio (ER), ductility index (DI), and confinement ratio (CR), were used. The strength of the SRC columns obtained from the experiments was then employed to verify the proposed mode referring to the relevant codes. It was found that codes DBJ13-51 could relatively predict the strength of the SRC columns accurately, and codes AIJ and BS5400 were relatively conservative.

• BMB Reports
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• v.52 no.11
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• pp.625-634
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• 2019

Severe combined immunodeficiency (SCID) is a group of inherited disorders characterized by compromised T lymphocyte differentiation related to abnormal development of other lymphocytes [i.e., B and/or natural killer (NK) cells], leading to death early in life unless treated immediately with hematopoietic stem cell transplant. Functional NK cells may impact engraftment success of life-saving procedures such as bone marrow transplantation in human SCID patients. Therefore, in animal models, a T cell-/B cell-/NK cell＋ environment provides a valuable tool for understanding the function of the innate immune system and for developing targeted NK therapies against human immune diseases. In this review, we focus on underlying mechanisms of human SCID, recent progress in the development of SCID animal models, and utilization of SCID pig model in biomedical sciences. Numerous physiologies in pig are comparable to those in human such as immune system, X-linked heritability, typical T-B＋NK- cellular phenotype, and anatomy. Due to analogous features of pig to those of human, studies have found that immunodeficient pig is the most appropriate model for human SCID.

• Steel and Composite Structures
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• v.44 no.6
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• pp.789-801
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• 2022

In order to study the influence of loading angles on seismic performance of steel reinforced concrete (SRC) special-shaped columns, cyclic loading tests and finite element analysis (FEA) were both carried out. Seven SRC special-shaped columns, including two L-shaped columns, three T-shaped columns and two cross-shaped columns, were tested, and the failure patterns of the columns with different loading angles were obtained. Based on the tests, the FEA models of SRC special-shaped columns with different loading angles were established. According to the simulation results, hysteretic curves and seismic performance indexes, including bearing capacity, ductility, stiffness and energy dissipation capacity, were analyzed in detail. The results showed that the failure patterns were different for the columns with the same section and different loading angles. With the increasing of loading angles, the hysteretic curves became fuller and the bearing capacity and initial stiffness appeared increasing tendency, but the energy dissipation capacity changed insignificantly. When the loading angle changed, the ductility got better with the larger area of steel at the failure side for the unsymmetrical section and near the neutral axis for the symmetrical section, respectively.

• Composites Research
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• v.26 no.4
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• pp.218-222
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• 2013

This study demonstrated that a slag, an industrial solid waste, can be used as a structural reinforcement. The mechanical properties(tensile strength and Elastic modulus) of slag reinforced composite(SRC) was investigated as functions of slag particle size (8~12 ${\mu}m$ and 12~16 ${\mu}m$) and volume fraction (0-40 vol.%). In order to investigate the interface and a degree of particle dispersion which have an effect on mechanical properties, optical microscopic images were taken. The results of tensile tests showed that the tensile strength decreased with an increase in slag volume fraction and particle size. The elastic modulus increased with an increase in slag volume fraction and particle size except for 30 vol.% SRC. The tensile strength decreased with an increase in slag particle size. The microscopic picture showed SRC has fine degree of particle dispersion at low slag volume fraction. SRC has a good interface at every volume fraction. However particle cluster was incorporated with an increase in slag volume fraction.

• Journal of Korean Society of Steel Construction
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• v.24 no.4
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• pp.361-369
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• 2012

In this study, prefabricated composite columns using high-strength angles (PSRC composite column) was studied. Concentric axial loading tests were performed for 2/3 scale PSRC specimens and an conventional SRC specimen with H-steel at the center of the cross-section. The test parameters were the steel ratio of angles and the spacing of lateral re-bars. The test results showed that by placing the angles at the corners of the cross-section for confinement with provided for the core concrete, the PSRC column specimens exhibited greater load-carrying capacity and deformation capacity than those of the conventional SRC column. The axial load-carrying capacity of the PSRC columns was greater than the prediction by KBC 2009. Using existing stress-strain relationship of confined concrete, the axial load-deformation relationship of the specimens were predicted. The numerical predictions correlated well with the test results in terms of initial stiffness, load-carrying capacity, and post-peak strength- and stiffness-degradations.