• Computers and Concrete
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• v.15 no.4
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• pp.563-588
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• 2015

Piers are the most vulnerable part of a bridge structure during an earthquake event. During Kobe earthquake in 1995, several bridge piers of the Hanshin Expressway collapsed for more than 600m of the bridge length. In this paper, the most important results of an experimental and analytical investigation of ten reinforced concrete bridge piers specimens with the same cross section subjected to constant axial (or variable) load and reversed (or one direction) cycling loading are presented. The objective was to investigate the main parameters influencing the seismic performance of reinforced concrete bridge piers. It was found that loading history and axial load intensity had a great influence on the performance of piers, especially concerning strength and stiffness degradation as well as the energy dissipation. Controlling these parameters is one of the keys for an ideal seismic performance for a given structure during an eventual seismic event. Numerical models for the tested specimens were developed and analyzed using SeismoStruct software. The analytical results show reasonable agreement with the experimental ones. The analysis not only correctly predicted the stiffness, load, and deformation at the peak, but also captured the post-peak softening as well. The analytical results showed that, in all cases, the ratio, experimental peak strength to the analytical one, was greater than 0.95.

• Earthquakes and Structures
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• v.5 no.3
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• pp.261-276
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• 2013

Oil, hysteretic and inertial mass dampers are representatives of passive dampers used for smart enhancement of seismic performance of building structures. Since oil dampers have a nonlinear relief mechanism and hysteretic dampers possess nonlinear restoring-force characteristics, several difficulties arise in the evaluation of buildings including such dampers. The purpose of this paper is to propose a practical method for simultaneous optimal use of such dampers. The optimum design problem is formulated so as to minimize the maximum interstory drift under design earthquakes in terms of a set of damper quantities subject to an equality constraint on the total cost of dampers. The proposed method to solve the optimum design problem is a successive procedure which consists of two steps. The first step is a sensitivity analysis by using nonlinear time-history response analyses, and the second step is a modification of the set of damper quantities based upon the sensitivity analysis. Numerical examples are conducted to demonstrate the effectiveness and validity of the proposed design method.

• IMMUNE NETWORK
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• v.3 no.3
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• pp.242-247
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• 2003

Background: Psoriasis is an inflammatory skin disorder that is characterized by a marked proliferation of keratinocytes, vascular dilation and leukocyte infiltration. Cytokines play important roles in the pathogenesis of inflammatory disorders. An overexpression of proinflammatory cytokines was characterized in psoriasis plaque. Among these cytokines, IL-$1{\beta}$ is major pro-inflammatory cytokine synthesized during the infection and inflammatory process. The IL-1 receptor antagonist (IL-1Ra) competes for the same IL-1 receptor for $IL-1{\alpha}$ and $-1{\beta}$, which prevents activation of the target cells. Three single nucleotide polymorphisms (SNPs) in the IL-$1{\beta}$ gene have been reported at position -31, -511 and +3954. Within the IL-1Ra gene (IL-1RN), there is a variable number of tandem repeats (VNTR) of an 86 bp length in intron 2. These polymorphisms related to cytokine production and associated with various diseases. Methods: We investigated the polymorphisms of IL-1B (promoter -511 and +3954) and IL-1RN on 114 psoriasis patients and 311 healthy normal controls in Korean. We performed PCR-RFLP on single nucleotide polymorphisms (SNPs) of IL-1B (promoter -511 and +3954) and fragment analysis on IL-1RN 86 bp VNTR polymorphism. Results: The frequency of IL-1B $-511^*1$ allele (patients vs. controls; 50.0% vs. 42.3%, RR=1.4) was significantly increased and IL-1B $-511^*2$ allele (patients vs. controls; 50.0% vs. 57.7%, RR=0.7) decreased in psoriasis patients compared to normal controls. We also analyzed the IL-1B -511 polymorphism according to patients' characters (age of onset, sex and family history). The IL-1B -511 alleles were significantly associated in patients with male and family history than health normal controls. There were no significant associations of IL-1B +3954 and IL-1RN polymorphisms with psoriasis patients. Conclusion: These results suggest that the polymorphism of IL-1B -511 could be genetic susceptibility to psoriasis in Koreans.

• Journal of Gastric Cancer
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• v.2 no.3
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• pp.163-167
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• 2002

Purpose: Interleukin 1$\beta$ (IL-1$\beta$) polymorphisms are associated with hypochlorhydria, atrophic gastritis, and increased risk of gastric cancer in Caucasians. We tried to determine whether the IL-1.. and IL-1 receptor antagonist (IL-1 RN) genetic polymorphisms contribute to the development of gastric cancer and the specific type of gastritis in Korean. Materials and Methods: The study population was comprised of 128 gastric cancer patients with histologically proven carcinoma and 63 normal healthy individuals. Sixty-eight carcinomas were of intestinal-type and sixty tumors were of diffuse-type. No patient had a familial gastric cancer history. The 511 bp and 31 bp polymorphisms in the IL-1.. were genotyped by polymerase chain reaction (PCR)-restriction fragment length polymorphism. The polymorphism of the IL-1 RN was analyzed with variable number tandem repeat after PCR. Results: The genotype of 511C/-31T of IL-1$\beta$ and allele 1 of IL-1 RN was dominant in the present subjects. The allelic frequencies of the C allele IL-1$\beta$, which is a high risk genotype for gastric cancer, were 0.551 and 0.429 in gastric cancer and normal controls, respectively. Statistically, significant difference in allelic frequencies of three polymorphic sites between gastric cancer patients and normal controls, and between intestinal-type and diffuse-type was not observed. Conclusions: These results suggest that the polymorphisms of IL-1$\beta$ and IL-1 RN may not contribute to the development of Korean gastric caner and that other endogenous or exogenous factors will be important for gastric carcinogenesis.