2,031 research outputs found
Seismic response of beam-column joints rehabilitated with FRP sheets and buckling restrained braces
An experimental test was performed to evaluate the seismic resistance of reinforced concrete beam-column joints rehabilitated with FRP sheets and Buckling Restrained Braces (BRBs). Six beam-column joints were rehabilitated and tested. The test results were compared in terms of hysteresis loops, stiffness degradation, energy dissipation and ductility. The comparison result showed that wrapping FRP sheets can contribute to increase the effect of confinement and to delay crack development in the joints. Also retrofitting buckling restrained braces (BRBs) can improve the stiffness and energy dissipation capacity. Both FRP sheets and BRBs can effectively improve the strength, stiffness and ductility
Structural behavior of concrete filled carbon fiber reinforced polymer sheet tube column
In order to examine both static and dynamic behaviors of Concrete Filled Carbon Fiber Reinforced Polymer Sheet Tube (CFCST) columns, experimental tests have been performed. The main variables of this experimental program included the number and wrapping angles of CFRP sheets. Stress versus strain relation of CFCST specimens was investigated by uni-axial tests. And, six full-scaled CFCST columns subjected to quasi-static lateral loading, as well as constant axial compression, were tested. Finally, an analytical procedure to predict the response of CFCST columns subjected to both axial and lateral loadings has been suggested in conjunction with the findings from the experimental tests
Autoimmune hemolytic anemia predominantly associated with IgA anti-E and anti-c.
A patient with warm autoimmune hemolytic anemia (AIHA) due to predominance of immunoglobulin A (IgA) with an Rh specificity, considered to be the first case in Korea, is described. A 13-year-old male patient with severe hemolytic anemia showed a weak reactivity (1+) in the direct antiglobulin test (DAT) by using anti-IgG antiglobulin reagent. This finding, however, could not fully explain the patient's severe AIHA. When anti-IgA reagent was used for the DAT, strong reactivity (4+) was observed and free anti-E and anti-c autoantibodies were also detected by anti-IgA and anti-IgG reagents. The patient's hemoglobin began to rise with the administration of steroids. Because RBCs coated with multiple types of immunoglobulins are associated with more severe hemolysis than those only with IgG, the DATs using anti-IgA and other reagents are needed for the correct diagnosis when the result of DAT is not compatible with patient's clinical manifestations
Should Epidermal Growth Factor Receptor-Tyrosine Kinase Inhibitor Be Continued beyond Progressive Disease?
Epidermal growth factor receptor-tyrosine kinase inhibitor (EGFR-TKI) is almost exclusively effective in patients with activating EGFR mutations, and median time to progression in such patients is generally up to 12 months. Usually, treatment with EGFR-TKI is terminated when disease progression is confirmed; however, acute exacerbation after the withdrawal of EGFR-TKI has been reported. In this paper, we report a case of a 35-year-old patient whose disease rapidly progressed after discontinuation of gefitinib and then rapidly regressed after reintroduction of gefitinib. In addition, we summarize the cases of 3 other patients who could be safely treated with continued erlotinib in combination with pemetrexed after disease progression. Currently, the mechanism of acquired resistance is intensively investigated and a number of new agents, such as irreversible EGFR inhibitors or MET inhibitors, are under development; however, they are still unavailable in clinical setting. We believe that continuing EGFR-TKI treatment after disease progression should be an option in patients who previously responded to EGFR-TKI under the present circumstances
The Relationship between Aldosterone to Renin Ratio and RI Value of the Uterine Artery in the Preeclamptic Patient vs. Normal Pregnancy
aldosterone are increased during normal pregnancy. However, these values in preeclampsia are decreased to nearly that of a nonpregnant subject, and vascular sensitivity to angiotensin II is increased. In preeclampsia, aldosterone is decreased less than rennin. Therefore current studies were undertaken to determine the relationship between aldosterone to renin ratio (ARR) and uterine artery perfusion via RI value. Materials and Methods: In this study, the relationship between plasma aldosterone and renin concentration was determined in 27 preeclamptic women and 50 normal pregnant women, whose gestational weeks were matched. The aldosterone to renin ratio was calculated and compared between the two groups. Doppler velocimetry of the uterine artery, which was used to calculate resistance index (RI), was performed on all subjects. The relationship between ARR and RI value was reviewed
Performance of a lead rubber damper under cyclic shear loading and its applicability to a full-scale structure
In this paper, we investigate the performance of a new lead rubber damper (LRD) and its applicability to a full-scale structure. This device is more advanced than existing lead-rubber based isolation devices. In contrast to the existing devices, multiple lead cores are installed in the LRD in order to enhance the performance of the laminated rubber and lead. It is able to perform effectively under the application of shear force. An experiment was performed to investigate its dependency on the level of shear strain and frequency. The applicability of this new device to a full-scale structure is also examined by performing a vibration test on a five floor modal-test tower
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