• Journal of Gastric Cancer
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• 제15권1호
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• pp.64-67
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• 2015

Inflammatory myofibroblastic tumors (IMTs) of the stomach are extremely rare in adults, and their oncologic prognosis is not well understood. We present a 28-year-old man with a proximal gastric IMT. The patient visited the emergency department of Yeouido St. Mary's Hospital with syncope and hematemesis. Hemoglobin levels were <5.5 g/dl. Gastric fibroscopy showed a protruding mass $4{\times}4cm$ in size, with central ulceration on the posterior wall of the fundus and diffuse wall thickening throughout the cardia and anterior wall of the upper body. Endoscopic biopsy revealed indeterminate spindle cells, along with inflammation. Given the risk of rebleeding, an operation was performed despite the uncertain diagnosis. Because the mass was circumferential, laparoscopic proximal gastrectomy and double-tract anastomosis were performed to ensure a safe resection margin. The pathological diagnosis was consistent with an IMT originating from the stomach, although the tumor was negative for anaplastic lymphoma kinase gene mutation.

• Bulletin of the Korean Chemical Society
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• 제21권8호
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• pp.823-827
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• 2000

Gas-Phase reactions of methyl and ethyl nitrites with anionic nucleophiles of SH-, F- and OH- are investigated theoretically at the MP2/6-311+G* level. The SN2 processes are all highly exothermic and proceed with a typ-icaI double-weIl reaction coordinate profile. The elimination reactions of methyl nitrite with SH- and F- are double-well energy surface processes,with stabilizedproduct complexes of NO-...H2S and NO-...HF, pro-ceeding by an E1 cb-like E2 mechanism. The $\beta-elimination$ of ethyl nitrite is an E2 type process. The $\alpha-elimi-nation$ reactions of methyl and ethyl nitrites with OH- have triple-well energy profiles of Elcb pathway with an $\alpha-carbanion$ intermediate which is stabilized bythe vicinal $nc\alpha-{\sigma}*o-N$ charge transfer interactions. CompIex-ation ofmethyl carbanion with HF seems to provide a stable intermediate within a triple-well energy profile of El cb channel in the reaction of F- with methyl nitrite.

• 한국콘텐츠학회논문지
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• 제18권12호
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• pp.185-196
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• 2018

본 연구는 성인의 지각된 스트레스와 스마트폰 중독과의 관계에서 부적응적 인지적 정서조절전략과 부적 정서의 매개효과를 검증하고, 성인의 스마트폰 중독 상담을 위한 시사점을 찾아보기 위해 수행되었다. 성인 300명(남 146명, 여 154명)에게 지각된 스트레스척도, 부적응적 인지적 정서조절전략척도, 부적 정서척도, 스마트폰 중독진단척도를 실시하였다. 주요 결과를 정리하면 다음과 같다: 첫째, 지각된 스트레스는 스마트폰 중독에 정적인 영향을 미쳤다. 둘째, 지각된 스트레스와 스마트폰 중독과의 관계에서 부적 정서는 매개효과를 나타냈다. 셋째, 지각된 스트레스와 스마트폰 중독과의 관계에서 부적응적 인지적 정서조절 전략의 매개효과는 유의미하지 않았다. 넷째, 지각된 스트레스와 스마트폰 중독 간의 관계에서 부적응적 인지적 정서조절전략과 부적 정서의 이중매개효과는 유의미하였다. 연구결과를 기초로 성인의 스마트폰 중독 예방 및 상담과정에서 스트레스 관리 프로그램과 부적응적 인지적 정서조절전략의 수정을 통한 부적 정서의 완화 필요성이 논의되었다. 또한 후속 연구를 위한 제언을 논하였다.

• 서비스연구
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• 제13권2호
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• pp.161-180
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• 2023

본 연구에서는 코로나19로 인한 비대면 소비 증가로 크게 성장한 온라인 음식 배달 서비스(Online food delivery service, OFDS)기업에서 제시하는 서비스 회복 방안에 대한 불공정 인식이 소비자의 실망감에 미치는 영향을 실증적으로 분석하였다. 본 연구는 공정성 이론(Justice theory)을 기반으로 하여, 공정성 인식의 하위요인으로 절차의 공정성, 상호작용의 공정성, 정보의 공정성, 분배의 공정성을 채택하였다. 더불어, 서비스 회복 실패에 따른 실망감으로 인한 부정적 구전행동 및 전환의도 간의 관계에서 세대별(MZ세대와 그 외 세대) 차이점을 살펴보았다. 본 연구모델의 실증분석을 위하여 미국 내 성인 소비자 250명을 대상으로 온라인 설문조사를 실시하였고, 분석 결과 서비스 회복 방안 중 절차의 공정성과 분배의 공정성에 대한 부정적 인식이 소비자 실망감에 정(+)의 영향을 미치는 것으로 나타났다. 또한, 서비스 회복 전략에 대한 불공정성 인식으로 인한 소비자의 실망감은 소비자의 부정적 구전행동과 전환 의도에 정(+)의 영향을 미치는 것으로 확인되었다. 본 연구는 서비스 회복 전략의 실패로 인한 소비자의 역기능적 행동(Dysfunctional behavior)을 검증함으로써 서비스 회복과정의 공정성 인식에 관한 새로운 관점을 제시하며 관련 연구의 범위를 확장하였다. 본 연구의 결과는 소비자의 이중 이탈을 방지하기 위한 온라인 음식 배달 서비스 기업의 실무 전략 수립의 기초자료로 활용될 것으로 기대된다.

• Journal of Microbiology and Biotechnology
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• 제30권10호
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• pp.1583-1591
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• 2020

CRISPR/Cpf1 has emerged as a new CRISPR-based genome editing tool because, in comparison with CRIPSR/Cas9, it has a different T-rich PAM sequence to expand the target DNA sequence. Single-base editing in the microbial genome can be facilitated by oligonucleotide-directed mutagenesis (ODM) followed by negative selection with the CRISPR/Cpf1 system. However, single point mutations aided by Cpf1 negative selection have been rarely reported in Corynebacterium glutamicum. This study aimed to introduce an amber stop codon in crtEb encoding lycopene hydratase, through ODM and Cpf1-mediated negative selection; deficiency of this enzyme causes pink coloration due to lycopene accumulation in C. glutamicum. Consequently, on using double-, triple-, and quadruple-base-mutagenic oligonucleotides, 91.5-95.3% pink cells were obtained among the total live C. glutamicum cells. However, among the negatively selected live cells, 0.6% pink cells were obtained using single-base-mutagenic oligonucleotides, indicating that very few single-base mutations were introduced, possibly owing to mismatch tolerance. This led to the consideration of various target-mismatched crRNAs to prevent the death of single-base-edited cells. Consequently, we obtained 99.7% pink colonies after CRISPR/Cpf1-mediated negative selection using an appropriate single-mismatched crRNA. Furthermore, Sanger sequencing revealed that single-base mutations were successfully edited in the 99.7% of pink cells, while only two of nine among 0.6% of pink cells were correctly edited. The results indicate that the target-mismatched Cpf1 negative selection can assist in efficient and accurate single-base genome editing methods in C. glutamicum.

• 의료ㆍ복지 건축 : 한국의료복지건축학회 논문집
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• 제28권4호
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• pp.61-69
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• 2022

Purpose: In response to the rapid spread of COVID-19 in 2020, the government supported facilities and equipment through the 'Urgent Isolation Ward Expansion Project'. Design and remodeling of efficient negative pressure isolation facilities had to be done in a short period of time, and the performance gap between facilities was very large because the types of hospitals and wards of existing medical facilities were diverse. In order to secure the stability of isolation wards between medical facilities and reduce the facility gap, guidelines for planning isolation wards considering the diversity of each hospital should be appropriately presented. In consideration of these points, this study aims to provide basic data for future remodeling guidelines for each plan type of the negative pressure isolation ward first. Methods: We analyzed the plans before and after the change of 13 case hospitals that performed the urgent care bed expansion project for COVID-19 confirmed patients. Before the remodeling, the current status of the facility was analyzed according to the type of corridor, the location of the nursing station, and the location of the elevator. After remodeling, the flow of medical staff and patients, the flow of entry and exit of clean and contaminated items, and the space of negative pressure and non-negative pressure areas. Results: The ward type was divided into three types according to the corridor type and room arrangement: double loaded corridor type with two side wards, race track type with one side ward, and race track type with two side wards. Based on these three types, the standard floor plan type of the isolation ward was proposed in terms of the location of the elevator bank and Nurse station. Implications: When the existing general ward is converted into a negative pressure isolation ward, this study can be a basic data to present customized guidelines for each ward type.

• Environmental Engineering Research
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• 제16권1호
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• pp.29-34
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• 2011

The electric charge on a membrane was investigated by analyzing the experimental rejection of various monovalent and divalent ionic solutes. The characteristics of the separation of ionic solutes using various nanofiltration membranes were obtained from an experimental nanofiltration set-up, with a surface area of $40cm^2$ under the operational pressures between 0.25-0.3 MPa. The state of the membrane electric charge was observed using separation coefficients, i.e., the permeation ratio of monovalent to divalent ions. To confirm the state of the membrane charge observed via the separation coefficient, a calculation using the extended Nernst-Planck equation, coupled with the Donnan equilibrium, assuming different electric charge states of the membrane, was compared with the experimental rejection of ionic solutes. The examination of the characteristics of separation using three types of nanofiltration membranes showed that one of the membranes carried a negative/positive double charge density inside, while other two membranes carried either a positive or negative charge density.

• Journal of Electrical Engineering and Technology
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• 제6권4호
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• pp.505-512
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• 2011

A novel passive boost power converter forsingle-phaseswitched reluctance motor is presented. A simple passive circuit is proposed comprisingthree diodes and one capacitor. The passive circuitis added in the front-end of a conventional asymmetric converter to obtain high negative bias. Based on this passive network, the terminal voltage of the converter side is a general DC-link voltage level in parallel mode up to a double DC-link voltage level in series mode. Thus,it can suppress the negative torque generation from the tail current and improve the output power. The results of the comparative simulation and experiments forthe conventional and proposed converter verify the performance of the proposed converter.

• Journal of electromagnetic engineering and science
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• 제13권3호
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• pp.189-191
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• 2013

This letter presents a compact metamaterial-based tunable zeroth-order resonant antenna. It is based on the double-negative unit cell with a function of tunable inductance realized by a varactor and impedance convertor in the shunt branch. The resonant frequency of the designed antenna ranges from 2.31 to 3.08 GHz, depending on the capacitance of the used varactor. Its size is very compact ($0.05{\lambda}_0{\times}0.2{\lambda}_0$) with a relatively wide tunable range of 29.1%. The impedance bandwidth of the antenna is from 20 to 50 MHz for the resonant center frequency. The measured maximum total realized gain is from -0.68 dBi (2.43 GHz) to 1.69 dBi (2.97 GHz). The EM-simulated and measured results are in good agreement.

• Journal of Magnetics
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• 제13권4호
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• pp.153-156
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• 2008

We conducted a micromagnetic modeling study to investigate the spin torque oscillator (STO) using a perpendicular polarizer. We used an additional layer of negative anisotropy constant materials (NAM) on a conventional STO. For the NAM layer, the magnetic easy plane is parallel to the in-plane easy axis of the free layer, and inhibits the development of the out-of-plane component of the magnetization in the free layer. As a result, this new type of STO provides a high frequency limit up to 50 GHz.