초임계 용매를 포함한 Poly(propyl acrlate)와 Poly(Propyl methacrylate)의 이성분 및 삼성분계에 관한 상거동

변헌순,이하연 한국화학공학회 2002 Korean Chemical Engineering Research(HWAHAK KONGHA Vol.40 No.6

본 연구는 초임계 용매인 CO_2, 에틸렌, 프로판, 부탄, 프로필렌, 1-부텐, 디메틸에테르 및 CHCIF_2내에서 poly(propyl acrylate)와 poly(propyl methacrylate) 용액과의 고압 상거동을 측정하였다. 초임계 용매들과 poly(propyl acrylate) 및 poly(propyl methacrylate) 간의 상거동 측정 범위는 온도 23-186℃와 압력 2,400 bar까지 실험하여 나타내었다. poly(propyl acrylate)-CO_2혼합물은 약 2,070 bar 이내에서, poly(propyl acrylate)-에틸렌계는 1,400 bar 이하에서, poly(propyl acrylate)-프로판계는 1,880 bar 이하에서, poly(propyl acrylate)-프로필렌계는 450 bar 이하에서, poly(propyl acrylate)-부탄계는 2,200 bar이하에서, poly(propyl acrylate)-1-부텐계는 250 bar 이하에서, poly(propyl acrylate)-디메틸에테르계는 150 bar 이하에서 각각 용해되었으며, 이때 온도범위는 23-175℃이였다. poly(propyl methacrylate)-CO_2 혼합물은 2,900 bar 및 온도 240℃에서도 용해되지 않았다. poly(propyl methacrylate)-프로판계는 약 2,390 bar이하에서, poly(propyl methacrylate)-부탄계에 대해서는 2,100 bar이하에서, poly(propyl methacrylate)-프로필렌계에 대해서는 570 bar 이하에서 poly(propyl methacrylate)-1-부텐계는 310 bar 이하에서, poly(propyl methacrylate)-CHClF_2계에 대해서는 300 bar 이하에서, 그리고 poly(propyl methacrylate)-디메틸에테르계에 대해서는 170 bar이하에서 각각 용해되었으며, 이때 온도범위는 40-186℃사이였다. 또한 이성분 poly(propyl acrylate)-CO_2와 poly(propyl acrylate)-디메틸에테르계의 상거동 사이에 디메틸에테르를 공용매로 사용하여 5, 15 및 50wt% 첨가하여 구름점의 거동을 상임계용액온도 영역에서 하임계용액온도 영역까지 나타내었다. High pressure phase behavior data for poly(propyl acrylate) and poly(propyl methacrylate) with supercritical CO_2, ethylene, propane, butane, propylene, 1-butene, dimethyl ether, and CHICF_2 were measured in the temperature range from 23℃ to 186℃ and at pressures up to 2,400 bar. The cloud point were obtained at dissolved pressure below 2,070, 1,400, 1,880, 450, 2,200, 250, and 150 bar for poly(propyl acrylate) in supercritical CO_2, ethylene, propane, propylene, butane, 1-buthen, and dimethyl ether, respectively. The temperature range is 23-175℃. The poly(propyl methacrylate) does not dissolve in CO_2 at temperature of 240℃ and pressure 2,900 bar. The poly(propyl methacrylate)-propane, poly(propyl methacrylate)-butane, poly(propyl methacrylate)-propylene, poly(propyl methacrylate)-1-butene, and poly(propyl methacrylate)-CHClF_2 systems were dissolved at the pressures less than 2,390 bar, below 2,100 bar, below 570 bar, below 310 bar, below 300 bar, and below 170 bar, respectively. The temperature range shows from 40 to 186℃. The phase behavior of between binary poly(propyl acrylate)-CO_2 and poly(propyl acrylate)-dimethyl ether system were measured from upper critical solution temperature region to lower critical solution temperature region with added dimethyl ether concentrations of 5, 15 and 50 wt%.

Analysis of Fifty Hotspot Mutations of Lung Squamous Cell Carcinoma in Never-smokers

이하연,이세훈,원재경,이동수,권낙중,최선미,이진우,이창훈,이상민,임재준,유철규,김영환,한성구,박영식 대한의학회 2017 Journal of Korean medical science Vol.32 No.3

Smoking is the major risk factor for lung squamous cell carcinoma (SCC), although a small number of lung SCCs occurs in never-smokers. The purpose of this study was to compare 50 hotspot mutations of lung SCCs between never-smokers and smokers. We retrospectively reviewed the medical records of patients newly diagnosed with lung SCC between January 1, 2011 and December 31, 2013 in the Seoul National University Hospital. Formalin-fixed, paraffin-embedded tumor samples were used for analysis of hotspot mutations. Fifty cancer-related genes in never-smokers were compared to those in ever-smokers. Of 379 lung SCC patients, 19 (5.0%) were never-smokers. The median age of these 19 patients was 67 years (interquartile range 57–73 years), and 10 of these patients were women (52.5%). The incidence rates of stage I, II, III, and IV disease in this group were 26.4%, 5.3%, 31.6%, and 36.8%, respectively, and sequencing was performed successfully in 14 cases. In the 26 lung SCC tumor samples (12 from never-smokers and 14 from ever-smokers) sequenced using personal genome machine, the most common mutations were in TP53 (75.0%), RAS (66.7%), and STK11 (33.3%), but mutations were also found in EGFR, KIT, and PTEN. The distribution of hotspot mutations in never-smokers was similar to that in ever-smokers. There was no significant difference in overall survival between the 2 groups. The 50 hotspot mutations of lung SCC in never-smokers were similar to those of ever-smokers.

Compression of the Main Pancreatic Duct by the Intrapancreatic-Replaced Common Hepatic Artery

이하연,하홍일,김민정,임현경 대한영상의학회 2013 Korean Journal of Radiology Vol.14 No.3

We describe a unique case of a patient who presented with a linear, transverse, and incidentally-detected main pancreatic duct dilatation that was caused by the intrapancreatic-replaced common hepatic artery, detected on the MDCT, MRCP and endoscopic retrograde cholangiopancreatography. We believe this case to be the first of its kind reported in the literature.

한국인의 이중 사회정체성과 내집단 투사, 남북한 통일태도 간 관계

이하연,권영미,서정길,박주화,최훈석 한국사회및성격심리학회 2022 한국심리학회지 사회 및 성격 Vol.36 No.4

The present study investigated the relationship between dual social identity, ingroup projection, and attitudes toward the unification of Korea. We hypothesized that South Koreans who are characterized as having dual social identity, namely, those who identify themselves strongly with both the superordinate category (i.e., ethnic identity) and the subordinate category (i.e., national identity), would show high levels of ingroup projection, which in turn would predict negatively their attitudes toward unification of North and South Korea. In addition, we examined the moderating effect of the centrality of the superordinate and the subgroup identity on the relationship between dual identity and ingroup projection. Data from a stratified sample of South Korean adults (N = 1,600) revealed that, as expected, ingroup projection negatively mediated the relationship between dual identity and attitudes toward the unification of Korea. Importantly, the relationship between dual identity and ingroup projection was attenuated among those who perceived their superordinate identity as a more central aspect of themselves than their subgroup identity. We discuss the implications of our findings for the role of social identity in social integration research in the context of the unification of Korea. 본 연구는 상위수준 한민족 범주와 하위수준 국가(남북한) 범주로 구분되는 층소된 사회정체성 구조에서 상위범주-하위범주 동일시 수준 간 상호작용과 내집단 투사, 남북한 통일에 대한 태도 간의 관계를 조사하였다. 한국인들이 남북한을 포섭하는 공동 상위범주인 한민족에 강하게 동일시하더라도 동시에 하위범주인 남한에 강하게 동일시할 경우, 남한이 북한보다 한민족의 전형적이고 필수적인 집단이라고 지각하는 내집단 투사가 발생하며, 내집단 투사는 통일태도를 부적으로 예측할 것으로 예상했다. 이에 더해 내집단 투사를 완화하는 기제로 상위범주와 하위범주 정체성 중심성의 역할을 검증했다. 인구비례할당표집으로 수집된 한국 거주 성인 1,600명의 자료를 분석한 결과, 가설과 일관되게 남한사람들이 한민족과 남한에 동시에 강하게 동일시할수록(즉, 이중 정체성이 우세할수록) 내집단 투사 수준이 높았으며, 이중 정체성은 내집단 투사를 매개로 통일태도를 부적으로 예측했다. 또한, 이중 정체성이 내집단 투사를 예측하는 효과는 구성원들이 하위범주 정체성을 상위범주 정체성보다 중시할 경우 유의했고, 하위범주 정체성을 상대적으로 덜 중시할 경우에는 유의하지 않았다. 이러한 결과는 남북한 관계에 관한 심리학 연구에서 층소된 사회정체성의 효과를 체계적으로 검증해야 하며 이를 반영하는 개입 전략이 필요함을 시사한다.

집단 창의성에서 집단주의 가치와 독립적 자기관의 상승효과: 현장 집단 연구

이하연,최훈석 한국사회및성격심리학회 2019 한국심리학회지 사회 및 성격 Vol.33 No.4

The present study reports data from a field experiment that tested a synergy model of collectivistic value orientation and independent self-representation on group creativity(Choi, Cho, Seo, & Bechtoldt, 2018). Participants were recruited from a university-wide learning camp on teamwork. We induced a collectivistic value orientation as part of a teamwork activity in all groups. With this, we primed either independent or interdependent self-representation in the two experimental conditions. We also included a control condition where there was no manipulation of self-representation. Using an interactive group brainstorming task, we found support for the hypothesized synergy effect in groups where participants were randomly assigned to the work unit. No significant effects were found in groups of friends. Results also suggest that the observed synergy effect is due in part to the creativity-enhancing nature of independent self-representation, rather than detrimental effects of interdependent self-representation on group creativity. We discuss implications of these findings vis-à-vis previous research on the link between individualism-collectivism and group creativity. We also discuss limitations and future directions of this research. 본 연구는 집단주의 가치지향성과 독립적 자기표상의 상승효과 모형(Choi, Cho, Seo, & Bechtoldt, 2018)을 바탕으로, 현장 집단에서 집단 창의성에 대한 모형의 개입효과성을 검증하였다. 대학 주관으로 진행된 학습캠프에 참여한 집단들에서 집단주의 가치지향성을 조작한 후, 독립적 또는 상호의존적 자기표상을 활성화하거나 활성화하지 않는(통제조건) 절차를 사용하여 총 세 개 조건에서 집단이 생산한 아이디어의 창의성을 비교하였다. 연구 결과, 구성원들에게 집단주의 가치지향성만 조작했거나 집단주의 가치지향성과 상호의존적 자기표상을 조합한 조건보다, 집단주의 가치지향성과 독립적 자기표상을 조합한 조건에서 집단 창의성이 높았다. 이 결과를 서구에서 보고된 관련 연구들과 비교하고, 개인주의-집단주의와 집단 창의성의 관계를 체계적으로 분석하기 위한 장래 연구 방향을 논의하였다.

컨테이너 내륙운송에 있어서 운전기사에 대한 컨테이너 관리의 전가문제에 대한 고찰

이하연,조찬혁 한국항만경제학회 2022 韓國港灣經濟學會誌 Vol.38 No.2

우리나라에서 화물 수송분담율을 가장 많이 차지하는 것이 도로운송이다. 도로 컨테이너 운송은 컨테이너 운송의 출발점이자 완결점일 뿐만 아니라 매우 복잡하고 종사자 또한 많다. 육상물류에서 핵심역할을 하고 있는 컨테이너 운전기사의 본업은 컨테이너를 항만 및 터미널에서부터 목적지까지 운송해주는 것이다. 그러나 운송과정에서 컨테이너의 청소 및 데미지 컨테이너의 관리 등 본업외에도 여러 가지 컨테이너 관리의무를 묵시적으로 전가받고 있는 실정이다. 그러나 동 사안에 대해서는 그동안 거의연구가 되고 있지 않은 상황이다. 본 연구는 컨테이너 운전기사의 근로환경에 대해 파악하고, 컨테이너관리 작업에 대한 실태와 현황을 실증적으로 분석했다. 나아가 선사, 터미널, 화주별로 컨테이너 관리요구 정도의 차이가 있는지 분석하는 한편 조사지역별 요구사항의 차이를 분석하고, 컨테이너 관리 전가문제에 대한 개선방안을 제시하였다.

The Situation of Life-Sustaining Treatment One Year After Enforcement of the Act on Decisions on Life-Sustaining Treatment for Patients at the End-of-Life in Korea: Data of National Agency for Management of Life-Sustaining Treatment

이하연,김화정,권정혜,백선경,원영웅,김유정,백수진,류혜원 대한암학회 2021 Cancer Research and Treatment Vol.53 No.4

Purpose The “Act on Hospice and Palliative Care and Decisions on Life-Sustaining Treatment for Patients at the End-of-Life” was enacted on February 3, 2016 and went into effect on February 4, 2018 in Korea. This study reviewed the first year of determination to life-sustaining treatment (LST) through data analysis of the National Agency for Management of Life-Sustaining Treatment. Materials and Methods The National Agency for Management of LST provided data between February 4, 2018 and January 31, 2019 anonymously from 33,549 patients. According to the forms patients were defined as either elf-determinants or family-determinants. Results The median age of the patient was 73 and the majority was male (59.9%). Cancer patients were 59% and self-determinants were 32.1%. Cancer patients had a higher rate of self-determinants than non-cancer (47.3% vs. 10.1%). Plan for hospice service was high in cancer patients among self-determinants (81.0% vs. 37.5%, p < 0.001). In comparison to family-determinants, self-determinants were younger (median age, 67 years vs. 75 years; p < 0.001) and had more cancer diagnosis (87.1% vs. 45.9%, p < 0.001). Decision of withholding or withdrawing of LSTs in cancer patients was higher than non-cancer patients in four items. Conclusion Cancer patients had a higher rate in self-determination and withholding or withdrawing of LSTs than non-cancer patients. Continued revision of the law and education of the public will be able to promote withdrawing or withholding the futile LSTs in patients at end-of-life. Further study following the revision of the law should be evaluated to change of end-of-life care.

아임계수 추출 기술을 이용한 흑후추 추출물의 유효성분 및 산화방지 평가

이하연,고민정 한국식품과학회 2023 한국식품과학회지 Vol.55 No.2

Subcritical water extraction (SWE) is an eco-friendly extraction technique using only water as the solvent. The extraction of less-polar compounds is possible by altering the temperature-dependent dielectric constant of water. This study analyzed the concentration of piperine, total phenolics, total flavonoids, and antioxidant activities in black pepper extracts obtained via subcritical water extraction. The piperine concentration (6.63±0.65 mg/g) was maximized with extraction at 200oC for 20 min. The black pepper extraction via the SWE method demonstrated a higher piperine yield than that using extraction solvents (such as ethanol) and hot water. The total phenolics (85.39±2.16 mg gallic acid equivalent/ g), total flavonoids (18.27±0.18 mg quercetin equivalent/g), and 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) free radical scavenging activity (97.38±0.52%) were maximal at extraction conditions of 200oC and 20 min. In conclusion, the SWE technique could be an alternative to the method using organic solvents for extracting bioactive compounds.

남북한 관계에서 한민족 범주복잡성과 한민족동일시가 외집단 관용 및 집단 간 통합지향 행동의도에 미치는 효과

이하연,최훈석,노중현,도은별,한지민 한국사회및성격심리학회 2023 한국심리학회지 사회 및 성격 Vol.37 No.2

The current study examined the interplay between superordinate category (i. e., ‘Ethnic Han’) complexity and superordinate ingroup identification on outgroup (North Koreans) tolerance and support for intergroup integration amongst South Koreans. Category complexity reflects the extent to which the category contains distinctive and equally representative subgroups. We hypothesized that individuals’ superordinate ingroup identification positively predicts outgroup tolerance when the superordinate category is perceived as complex rather than simple in its representational structure. In addition, we expected that this effect would positively predict outgroup tolerance, which in turn, positively predicts behavioral intentions for intergroup integration. In a laboratory experiment involving South Korean undergraduates (N = 124), we measured participants’ level of identification with the superordinate category and manipulated the superordinate category complexity (high vs. low). Results indicated, as expected, that in the high superordinate category complexity condition, superordinate ingroup identification positively predicted outgroup tolerance. When category complexity was low, there was no significant relationship between superordinate ingroup identification and outgroup tolerance. Further, outgroup tolerance mediated the interaction effect between the superordinate category complexity and the ingroup identification on behavioral intentions for intergroup integration. We discussed the role of superordinate category complexity and superordinate ingroup identification in establishing harmonious and integrative subgroup relationships between the two Koreas. 본 연구는 남북한 관계에서 공동 상위범주인 한민족의 범주복잡성이 낮거나 높다고 지각할 때 한민족동일시가 북한에 대한 관용과 남북한 통합지향 행동의도에 미치는 효과를 검증하였다. 높은 한민족 범주복잡성은 한민족이 다양한 속성을 지닌 하위집단들로 구성되었다는 지각을 의미한다. 본 연구에서는 남한 사람들이 한민족을 남북한뿐만 아니라 여러 하위집단(예: 한국계 외국인, 재외국민 등)으로 구성된다고 지각할 때 한민족동일시가 외집단인 북한에 대한 관용을 매개로 남북한 통합지향 행동의도를 정적으로 예측한다는 가설을 실험을 통해 검증하였다. 실험에서는 남한 대학생(N = 124)을 대상으로 한민족동일시 수준을 측정하고 한민족의 범주복잡성(높음 vs. 낮음)을 조작하였다. 실험 결과, 한민족 범주복잡성이 높은 조건에서 참가자들의 한민족동일시 수준이 높을수록 북한에 대한 관용 수준이 높았다. 반면 한민족 범주복잡성이 낮은 조건에서는 한민족동일시가 북한에 대한 관용을 예측하지 못했다. 그리고 한민족 범주복잡성과 한민족동일시의 상호작용이 북한에 대한 관용을 매개로 남북한 통합지향 행동의도를 정적으로 예측하였다. 본 연구가 남북관계에 관한 심리학 연구에 시사하는 바와 장래 연구과제를 논의하였다.

Cloning of Orotidine-5'-phosphate Decarboxylase (URA3) Gene from Sourdough Yeast Candida milleri CBS 8195

이하연,박은희,김명동 한국식품과학회 2012 Food Science and Biotechnology Vol.21 No.5

The nucleotide sequence of the URA3 gene encoding orotidine-5'-phosphate decarboxylase (OMPDCase)in sourdough yeast Candida milleri CBS 8195 was determined by degenerate PCR and genome walking. Sequence analysis revealed the presence of an openreading frame of 810 bp, encoding 269 amino acid residue protein with the highest identity to the OMPDCase of the yeast Saccharomyces cerevisiae. Phylogenetic analysis of deduced amino acid sequence revealed that it shares a high degree of identity with other yeast OMPDCases. The cloned URA3 gene successfully complemented the ura3mutation in S. cerevisiae, indicating that it encodes a functional OMPDCase in C. millieri CBS 8195.