• 한국재료학회지
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• 제31권3호
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• pp.139-149
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• 2021

In this study, three kinds of bainitic steels are fabricated by controlling the contents of vanadium and boron. High vanadium steel has a lot of carbides and nitrides, and so, during the cooling process, acicular ferrite is well formed. Carbides and nitrides develop fine grains by inhibiting grain growth. As a result, the low temperature Charpy absorbed energy of high vanadium steel is higher than that of low vanadium steel. In boron added steel, boron segregates at the prior austenite grain boundary, so that acicular ferrite formation occurs well during the cooling process. However, the granular bainite packet size of the boron added steel is larger than that of high vanadium steel because boron cannot effectively suppress grain growth. Therefore, the low temperature Charpy absorbed energy of the boron added steel is lower than that of the low vanadium steel. HAZ (heat affected zone) microstructure formation affects not only vanadium and boron but also the prior austenite grain size. In the HAZ specimen having large prior austenite grain size, acicular ferrite is formed inside the austenite, and granular bainite, bainitic ferrite, and martensite are also formed in a complex, resulting in a mixed acicular ferrite region with a high volume fraction. On the other hand, in the HAZ specimen having small prior austenite grain size, the volume fraction of the mixed acicular ferrite region is low because granular bainite and bainitic ferrite are coarse due to the large number of prior austenite grain boundaries.

• 한국압력기기공학회 논문집
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• 제7권2호
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• pp.42-47
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• 2011

The purpose of this study is to investigate the effects of through thickness on the mechanical properties and microstructural features in Mod. 9Cr-1Mo steels for RPVs. The microstructures at all locations were typically tempered martensite, but small amount of delta ferrite was observed at the center region. The prior austenite grain size increased with the depth from the surface. The yield strengths of center and 1/4T location were higher than that of surface by 30MPa. The impact toughness of center was low compared to those of other specimens. Also, upper shelf energy was low at the center. The toughness deterioration in center might be caused by larger size of the prior austenite grains and existence of the delta ferrite.

• Journal of Chest Surgery
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• 제41권6호
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• pp.759-763
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• 2008

전폐절제술을 받았던 환자에서 시행하는 심장 수술은 수술 후 합병증과 사망의 위험이 높다. 내원 33년전 폐결핵으로 좌측 전폐절제술을 받았던 71세 남자환자에서 승모판막 치환술 및 삼첨판막륜 성형술을 성공적으로 시행하였기에 증례와 함께 수술 전 후 폐기능 저하의 예방, 수술 중 승모판막의 노출 및 수술 후 발생한 부정맥에 대한 내용을 문헌고찰과 함께 보고하는 바이다.

• 한국간호교육학회지
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• 제21권1호
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• pp.28-35
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• 2015

Purpose: The purpose of this study was to examine the effects of prior information about ICU environment on the anxiety and environmental stress of cardiac surgery ICU patients. Methods: A non-equivalent control group non-synchronized quasi-experimental research design was used. Participants were 60 (control 30, experimental 30) patients who had been admitted to ICU. Prior information about the ICU environment was provided to the experimental group. The anxiety level of subjects was measured by State-Trait Anxiety Inventory (STAI) and the stress level of subjects was measured by the Intensive Care Unit Environmental Stressor Scale (ICUESS). Data were analyzed using a Chi-square test or a Fisher's exact test, independent samples t-test, and paired samples t-test. Results: There was no difference in Anxiety (t=-0.58, p=.563), but there was a significant difference in environmental stress (t=10.46, p<.001). Conclusion: Providing prior information would be an effective nursing intervention to reduce environmental stress.

• Journal of Ginseng Research
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• 제35권4호
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• pp.413-420
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• 2011

We investigated whether Korean red ginseng (KRG) and highly active antiretroviral therapy (HAART) affect the frequency of gross deletion in 5'LTR/gag in 20 hemophiliacs. This study is a prospective study in 20 hemophiliacs who were infected with Korean subclade B of HIV-1 from two cash-paid plasma donors in 1990. Over a 13-year period, we obtained 436 amplicons of 5'LTR/gag genes by nested polymerase chain reaction using 147 peripheral blood mononuclear cells. Of the 436 amplicons, 92 (21.1%) showed gross deletion in 5'LTR/gag. Despite of a 2.3-fold higher monthly dose of KRG intake, the frequency of gross deletion in 5'LTR/gag (16.4%) was significantly decreased during HAART compared with 28.1% prior to HAART (p<0.01). Gross deletion in 5'LTR/gag was 10% more detected on KRG-therapy than prior to KRG-therapy (p<0.05). In addition, we also obtained 28 amplicons containing premature stop codon or isoleucine at initiation codon of 254 amplicons sequenced on KRG intake (7.5%) or HAART (13.6%) compared with 0% before KRG intake. These findings indicate that high frequency of gross deletion in 5'LTR/gag and genetic defects prior to HAART are significantly associated with KRG intake and the detection of gross deletion in 5'LTR/gag is decreased by HAART.

• Journal of Korean Neurosurgical Society
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• 제67권2호
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• pp.186-193
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• 2024

Objective : The treatment paradigm for acute ischemic stroke has undergone several major changes in the past decade, contributing to improved patient prognosis in clinical practice. However, the extent to which these changes have affected patient prognosis in the real-world is yet to be clarified. This study aimed to evaluate the real-world impact of modern reperfusion therapy for acute ischemic stroke using data from the National Health Insurance Service in Korea. Methods : This study included patients aged 18-80 years who were admitted via the emergency room with an I63 code between 2011 and 2020. The rates of intravenous thrombolysis use and endovascular treatment according to the year of admission were investigated. Furthermore, the rates of decompressive craniectomy and 3-month mortality were also analyzed. The 10-year observational period was divided into three periods based on the 2015 guideline change as follows : prior, 2011-2014; transitional, 2015-2016; and modern, 2017-2020. Results : A total of 307117 patients (mean age, 65.7±10.9 years) were included, and most patients were male (59.7%). The rate of endovascular treatment gradually increased during the study period from 0.71% in the prior period to 1.32% in the transitional period and finally to 1.85% in the modern period. Meanwhile, the 3-month mortality rate gradually decreased from 4.78% in the prior period to 4.03% in the transitional period and to 3.71% in the modern period. Conclusion : In Korea, the mortality rate decreased as the rate of modern reperfusion therapy increased in patients with acute ischemic stroke. Overall, technical and scientific advances in reperfusion therapy have improved the outcome of patients with acute ischemic stroke in Korea.

• Clinical and Experimental Reproductive Medicine
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• 제38권3호
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• pp.148-152
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• 2011

Objective: Laser-assisted intracytoplasmic sperm injection (LA-ICSI), also known as micro-opening or thinning of the zona pellucida (ZP) prior to ICSI, may help to reduce mechanical damage to the oocyte during the procedure. The aim of the present study was to evaluate and analyze the efficacy of our institutional LA-ICSI program, which features laser-assisted ZP thinning prior to ICSI, in comparison with conventional ICSI (C-ICSI), performed on patients with different clinical characteristics. Methods: Patients undergoing a total of 212 ICSI cycles were randomly divided into an LA-ICSI group (106 cycles) and a conventional ICSI group (106 cycles). To reduce tissue damage, we thinned the ZP by approximately 70%, using a laser, before ICSI. Patients thus treated formed the LAICSI group. Comparisons included the morphological quality of transferred embryos, blastocyst development of the remaining embryos, and clinical pregnancy, in terms of ICSI method and patient characteristics. Results: Fertilization, development of remaining embryos, and pregnancy rate were significantly higher in the LA-ICSI group compared with the C-ICSI group. Fertilization, embryonic development, and the pregnancy rate were all improved in younger patients (<38 years of age) and in those who underwent a low number of IVF-ET attempts (<3 trials). In addition, the pregnancy rate was increased in older patients. Conclusion: LA-ICSI may be useful in improving the chance of pregnancy in all ICSI patients.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• 제25권6호
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• pp.461-472
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• 2022

Purpose: Golimumab (GLM) is an anti-tumor necrosis factor (TNF)-α antibody preparation known to be less immunogenic than infliximab (IFX) or adalimumab. Few reports on GLM in pediatric patients with ulcerative colitis (UC) are available. This study aimed to review the long-term durability and safety of GLM in a pediatric center. Methods: The medical records of 17 pediatric patients (eight boys and nine girls) who received GLM at the National Center for Child Health and Development were retrospectively reviewed. Results: The median age at GLM initiation was 13.9 (interquartile range 12.0-16.3) years. Fourteen patients had pancolitis, and 11 had severe disease (pediatric ulcerative colitis activity index ≥65). Ten patients were biologic-naive, and 50% achieved corticosteroid-free remission at week 54. Two patients discontinued prior anti-TNF-α agents because of adverse events during remission. Both showed responses to GLM without unfavorable events through week 54. However, the efficacy of GLM in patients who showed primary nonresponse or loss of response to IFX was limited. Four of the five patients showed non-response at week 54. Patients with severe disease had significantly lower corticosteroid-free remission rate at week 54 than those without severe disease. No severe adverse events were observed during the study period. Conclusion: GLM appears to be safe and useful for pediatric patients with UC. Patients with mild to moderate disease who responded to but had some adverse events with prior biologics may be good candidates for GLM. Its safety and low immunogenicity profile serve as favorable options for selected children with UC.

• 과학교육연구지
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• 제34권1호
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• pp.105-112
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• 2010

본 연구의 목적은 탐구 과제에 대한 사전지식이 초등 과학 영재의 관찰방법과 의문에 미치는 영향을 알아보기 위한 것이다. 이를 위해 '거미와 거미줄' 이라는 과제를 해결하는 과정에서의 학생들의 관찰방법과 의문이 사전지식에 의해 어떻게 영향을 받는지 연구하였다. 사전지식이 상대적으로 높은 집단의 학생들은 사전지식이 낮은 집단에 비해서 관찰의 방법과 양이 높게 나타났다. 그러나 사전지식이 양이 높은 집단이나 낮은 집단 모두 관찰 방법에서는 오감을 이용한 단순 관찰을 주로 하였다. 이는 사전지식의 양이 관찰의 양에는 영향을 미치나 관찰 방법에는 영향을 주지 못하는 것으로 볼 수 있다. 사전지식이 높은 집단에서는 보다 높은 수준의 관찰이 나타났다. 이는 관찰의 수준이 높아지기 위해서는 사전에 충분한 교육이 필요함을 의미한다. 따라서 교사들이 관찰을 이용한 수업을 수행할 경우에 사전에 관련된 지식에 대하여 충분한 수업이 이루어져야 보다 효율적인 관찰이 일어난다고 볼 수 있다.

• 여성건강간호학회지
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• 제22권2호
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• pp.78-85
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• 2016

Purpose: The purpose of this study was to evaluate the effect of abdominal massage on alleviating pain caused by the injection of recombinant gonadotropin for In Vitro Fertilization (IVF) among infertile women. Methods: This study employed a nonequivalent control group non-synchronized design. A total sample of 149 infertile women who never experienced in vitro fertilization was recruited at C fertility center. Seventy women were assigned into experimental group and 79 into controls. The experimental group had been informed to do abdominal massage prior to the injection and to record their subjective pain using visual analogue scale. The control group had been informed to record their subjective pain in the same way just after the injection. Results: Compared to the pre-tested pain scores, the pain scores in experimental group were significantly reduced by 0.7 points, whereas the control group increased by 0.9 points (t=-4.55, p=.001). Conclusion: This study confirms that the use of abdominal massage prior to the injection is an effective way to alleviate pain on injection site. This massage may be a useful intervention for infertile women about pain alleviation.