일부 청소년들에서 흡연노출량에 따른 혈중 카드뮴 농도

장성실,권윤형,배진순,노영만,한진구 韓國學校保健學會 2001 韓國學校保健學會誌 Vol.14 No.2

Objectives: We surveyed the prevalence of smoking among the adolescent population and analysed the correlation of the two exposure biomarkers-concentration of blood cadmium and urinary cotinine-to the smoking status. Methods: Subjects were 193 middle and high school students in Chungnam province. Blood cadmium and urinary cotinine were compared by sex and smoking status. Smoking status were classified by either the concentration of urinary cotinine or subjective answering as a smoker in the questionnaire. Results: Smoking prevalence was 24.6%, 36.2% and 6.7% among all subjects, male and female subjects, respectively. Average smoking amount was 17.5 and 1.5 cigarettes per month among the male subjects and female subjects, respectively Mean concentration of urinary cotinine among the male subjects was 135.57 ㎍/ℓ, and that of female subjects was 116.59 ㎍/. Direct smokers showed higher concentration of urinary cotinine than those of indirect smokers, and subjects with higher urinary concentration showed higher prevalence of smoking, too. Mean concentration of blood cadmium was 0.0572 ㎍/㎗ among the male subjects, and 0.0693 ㎍/㎗ among the female subjects. Among the male subjects, both exposure biumarkers showed significant correlation to the smoking status, but among the female subjects urinary cotinine did not show significant correlation to the smoking status. Conclusion: Concentrations of these two biomarkers suggested that this population had significantly high evironmental tobacco smoking(ETS) and efficient stop-smoking programs to reduce ETS should be directed to this population. Key words : environmental tobacco smoking, urinary cotinine, blood cadmium

Novel pore generator, “Cyclodextrin” derivatives for the ultra low dielectric (k<2.2) meterials

( Jin-heong Yim ),( Jong-baek Seon ),( Hyeon-jin Shin ),( Kwang-hee Lee ),( Jae-Jun Lee ),( Sang-kook Mah ),( Hyun-dam Jeong ),( Lyong Sun Pu ) 한국공업화학회 2004 한국공업화학회 연구논문 초록집 Vol.2004 No.-

Glycidol을 개시제로 이용한 L-lactide 개환중합

임진형(Jin Heong Yim),김다희(Da Hee Kim),고영수(Young Soo Ko) 한국고분자학회 2013 폴리머 Vol.37 No.5

Al(O-i-Pr)3을 촉매로 이용하고 중합 개시제로 glycidol을 사용하여 L-lactide를 개환중합하여 glycidol-poly (lactide)(Gly-PLA)를 얻었다. 1H NMR 분석 결과 glycidol의 말단에 존재하는 수산기가 Gly-PLA에는 존재하지 않았고 이를 통해 glycidol의 말단에 존재하는 OH기가 개시제의 역할을 하여 중합이 진행되었음을 확인하였다. Llactide 용액중합과 벌크중합을 진행하였으며, L-lactide/glycidol 몰비, 중합 온도와 시간에 따라 생성된 Gly-PLA의분자특성을 관찰하였다. L-lactide/glycidol 몰비가 증가할수록 수율과 분자량은 증가하였다. 또한 L-lactide/glycidol 몰비가 증가할수록 저분자량에 해당하는 낮은 녹는점 피크는 줄어들고, 고분자량에 해당하는 높은 녹는점 피크가증가하였다. Glycidol-poly(lactide) (Gly-PLA) were synthesized via L-lactide ring opening polymerization with glycidol as an initiator and Al(O-i-Pr)3 catalyst. The structure of Gly-PLA was analyzed and successfully confirmed by 1H NMR. The OH group of glycidol in Gly-PLA was absent according to the 1H NMR analysis, indicating that the terminal OH group of glycidol successfully served as an initiator in the L-lactide polymerization. The solution and bulk polymerizations of L-lactide with glycidol were performed to examine the effect of L-lactide/glycidol molar ratio, polymerization temperature and time on the molecular characteristics of Gly-PLA. The conversion and molecular weight increased with an increase in L-lactide/glycidol molar ratio. Gly-PLA showed the bimodal type DSC curve. The low Tm peak of low molecular weight reduced but the high Tm peak of high molecular weight increased as L-lactide/glycidol molar ratio increased.

Methylaluminoxane을 이용한 L-lactide 중합

임진형(Jin-Heong Yim),김다희(Da Hee Kim),고영수(Young Soo Ko) 한국고분자학회 2015 폴리머 Vol.39 No.3

본 연구에서는 Al 화합물인 methylaluminoxane(MAO)를 이용하여 L-lactide의 벌크중합 및 용액중합을 실시하였다. 촉매 투입량에 따른 벌크중합 결과, 투입량이 증가할수록 전환율이 증가하였다. 분자량은 촉매 투입량이 0.15 mmol일 때 60800 g/mol로 가장 높은 분자량을 얻었으며 그 이상의 투입량에서는 분자량이 감소하였다. Turnover frequency(TOF)값의 경우 촉매 투입량이 0.15 mmol일 때 가장 크고 촉매 투입량이 증가할수록 감소하였다. 용액중합에서는 30분 가량 induction time이 존재하였다. 중합 시간에 따라 3시간까지 전환율이 선형적으로 증가하였으며 6시간일 때 54700 g/mol로 가장 높은 분자량을 얻었다. In this study, the bulk and solution polymerizations of L-lactide using an aluminium compound, methylaluminoxane (MAO), were performed. In the bulk polymerization, the conversion of polymerization was increased with increasing the amount of catalyst in feed. The largest molecular weight (Mw), 60800 g/mol, was shown at the MAO amount in feed of 0.15 mmol, and Mw was decreased above 0.15 mmol of MAO in feed. At the 0.15 mmol of MAO in feed, turn of frequency (TOF) was the highest, and it was decreased with increasing MAO amount in feed. In the solution polymerization, the induction time of 30 min was shown. The conversion of polymerization was linearly increased with the polymerization time, and the highest Mw, 54700 g/mol, was achieved at the polymerization time of 6 h.

The preparation and low-k application of asymmetric functionalized cyclodextrin templated nanoporous silsesquioxane films.

Yim, Jin-Heong,Park, Young-Kwon,Jeon, Jong-Ki,Ko, Young Soo American Scientific Publishers 2008 Journal of Nanoscience and Nanotechnology Vol.8 No.10

<P>Several kinds of Asymmetric Functionalized Cyclodextrin (AFCD), as a porogen, have been introduced for the first time to investigate their potential in the field of low-k applications. The novel AFCD templated films were compared in terms of their pore forming efficiency and the pore structure, such as pore size and pore size distribution. Of the AFCDs, btCD and tbsCD showed fairly good pore forming efficiencies. The pore diameter generating form of AFCD was larger than that of conventional CD (tCD) at a high porogen loading (> 30 wt%), which might have been due to the micelle-like assembled behavior of the AFCD porogen as a supramolecular surfactant. Ultra low-k films (k < 1.5) can be effectively made using the AFCD porogen. Mechanical properties, such as hardness and elastic modulus, decrease with increasing AFCD porogen loading.</P>

교사의 셀프 리더십과 조직 건강 및 교사 효능감 간의 관계

구자원(Koo, Ja-weon) 경인교육대학교 교육연구원 2020 교육논총 Vol.40 No.2

본 연구는 교사의 셀프 리더십, 조직 건강 및 교사 효능감 간의 관계를 알아보는데 목적을 두었으며 서울특별시, 인천광역시 소재 초등 교사 211명을 대상으로 하였다. 이에 따라 본 연구는 교사의 셀프 리더십과 조직 건강 및 교사 효능감 간의 상관관계를 알아보기 위하여 Pearson의 상관계수를 구했으며, 교사의 셀프 리더십이 조직 건강과 교사 효능감에 미치는 영향을 살펴보기 위하여 중다회귀분석을 실시하였으며, 변인 간의 가설적 경로모형의 적합도와 인과 관계는 구조방정식 분석 방법을 통해 살펴보았고, SPSS 21.0과 AMOS 21.0 프로그램을 사용하여 자료를 분석하였다. 연구 결과 첫째, 교사의 셀프 리더십과 조직 건강 및 교사 효능감 간에는 통계적으로 유의미한 높은 상관관계를 보였다. 둘째, 중다회귀분석의 결과로 교사의 셀프 리더십은 조직 건강(R²=.266) 및 교사 효능감(R²=.412)에 모두 영향을 미치는 것으로 나타났다. 셋째, 가설적 경로모형의 적합도는 적합한 편이었으며, 교사의 셀프 리더십은 교사 효능감에 직접적인 영향을 미치며, 조직 건강을 통한 간접적인 영향도 미치는 것으로 나타났다. This study is to examine the relationship among Teacher s Self-Leadership, Organizational Health and Teacher’s Efficacy. This study is based on the survey 211 elementary school teachers, who have been working in Seoul and Incheon. Accordingly, this study sought Pearson s correlation to identify the correlation between Teacher’s Self-Leadership and Organizational Health and Teacher’s Efficacy. In order to examine the effects of Teacher’s Self-Leadership on Organizational Health and Teacher’s Efficacy multiple regression analysis was conducted. The suitability and causal relationship of the hypothetical path model between the variables were examined through the structural equation analysis method. All the analyses were processed by SPSS 21.0 and AMOS 21.0. The result of this study were as in the following. First, there were significant correlations among the three variables. Second, the multiple regression analysis, resulted that Teacher’s Self-Leadership provides effects on both Organizational Health and Teacher’s Efficacy. Third, fit of the research model used in this study was confirmed as good. Fourth, Teacher’s Self-Leadership affected directly Teacher’s Efficacy and indirectly Teacher’s Efficacy through Organizational Health.

실리카 나노기공내 담지된 알루미늄계 유기금속화합물을 이용한 L-lactide 중합

임진형(Jin Heong Yim),고영수(Young Soo Ko) 한국고분자학회 2013 폴리머 Vol.37 No.5

본 연구에서는 polylactide(PLA) 중합 촉매로 알루미늄계 유기금속화합물인 triethylaluminium(TEAL)을 이용하여 실리카에 담지하고 이를 이용하여 L-lactide 벌크중합을 진행하였다. TEAL을 실리카에 담지하기 위해 촉매 투입량, 담지시간, 담지온도를 변화시켜 촉매를 합성하고 이를 이용하여 생성된 PLA의 중합특성을 확인하였다. 담지된 촉매 투입량이 증가할수록 전환율이 높고 촉매 투입량이 8 mmol/g-silica일 경우에 가장 높은 분자량을 보였다. 담지시간을 변화시켜 합성된 담지촉매를 이용하여 중합한 결과 담지시간이 증가할수록 전환율 및 분자량이 증가하였다. 담지온도를 변화시켜 촉매를 합성하기 위해 용매로 hexane과 toluene을 사용하였다. 담지온도를 변화시켜 합성된 촉매로 L-lactide 중합한 결과, hexane을 용매로 사용하고 담지온도가 50 oC일 경우에 전환율 및 분자량이 높았다. In this study, the bulk polymerizations of L-lactide were carried out with triethylaluminium (TEAL), which was supported inside of the nanopore of silica. The feed amount of TEAL in the feed, the immobilization time and temperature were changed to observe the effect of immobilization condition on the polymerization performance with the silica-supported TEAL. As the feed amount of TEAL increased, the conversion of polymerization increased. The highest molecular weight (MW) was achieved at 8 mmol/g-silica of TEAL. Hexane and toluene as solvents were employed to investigate the effect of temperature on the immobilization. Hexane showed better efficiency of immobilization TEAL and the immobilization temperature at 50 oC showed the highest conversion and MW.

Fabrication of an electroconductive, flexible, and soft poly(3,4-ethylenedioxythiophene)-thermoplastic polyurethane hybrid scaffold by <i>in situ</i> vapor phase polymerization

Park, Jin Seul,Kim, Boram,Lee, Byong-Taek,Choi, Jong Seob,Yim, Jin-Heong The Royal Society of Chemistry 2018 Journal of materials chemistry. B, Materials for b Vol.6 No.24

<P>The inherent insolubility and brittleness of poly(3,4-ethylenedioxythiophene) (PEDOT) reduce its processability and practical applicability. Herein, we use <I>in situ</I> vapor phase polymerization (VPP) of 3,4-ethylenedioxythiophene (EDOT) on an oxidant-impregnated thermoplastic polyurethane (TPU) matrix comprising a three-dimensional silica particle assembly to produce a soft, flexible, and conductive TPU-PEDOT hybrid scaffold. The selective removal of silica yielded a highly porous (∼95%) skeletal structure, with the effective penetration, diffusion, and polymerization of EDOT resulting in uniform PEDOT formation both on the surface and the inner side of the TPU matrix. The mechanical and electrical properties of the obtained scaffold were investigated by bending, compression testing, and stress-strain and electrical measurements. The electrical resistance of the scaffold equaled 17 kΩ and did not change after ∼500-fold bending, whereas the observed elastic modulus was much lower (300 kPa) than that of TPU (3.3 MPa). <I>In vitro</I> biocompatibility was investigated by MC3T3-E1 cell culturing with cell viability evaluated using the WST assay and cell morphology examined by confocal microscopy. Thus, the soft and flexible TPU-PEDOT hybrid scaffold produced by VPP might be practically useful, implying that this preliminary investigation needs to be extended to study the behavior of muscle and nerve cells under electrical stimulation.</P>

Effects of Engineered Saccharomyces cerevisiae Fermenting Cellobiose through Low-Energy-Consuming Phosphorolytic Pathway in Simultaneous Saccharification and Fermentation

( Hyo-jin Choi ),( Yong-su Jin ),( Won-heong Lee ) 한국미생물 · 생명공학회 2022 Journal of microbiology and biotechnology Vol.32 No.1

Until recently, four types of cellobiose-fermenting Saccharomyces cerevisiae strains have been developed by introduction of a cellobiose metabolic pathway based on either intracellular β-glucosidase (GH1-1) or cellobiose phosphorylase (CBP), along with either an energy-consuming active cellodextrin transporter (CDT-1) or a non-energy-consuming passive cellodextrin facilitator (CDT-2). In this study, the ethanol production performance of two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-2 (N306I) with GH1-1 or CBP were compared with two cellobiose-fermenting S. cerevisiae strains expressing mutant CDT-1 (F213L) with GH1-1 or CBP in the simultaneous saccharification and fermentation (SSF) of cellulose under various conditions. It was found that, regardless of the SSF conditions, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the best ethanol production among the four strains. In addition, during SSF contaminated by lactic acid bacteria, the phosphorolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-2 with CBP showed the highest ethanol production and the lowest lactate formation compared with those of other strains, such as the hydrolytic cellobiose-fermenting S. cerevisiae expressing mutant CDT-1 with GH1-1, and the glucose-fermenting S. cerevisiae with extracellular β-glucosidase. These results suggest that the cellobiose-fermenting yeast strain exhibiting low energy consumption can enhance the efficiency of the SSF of cellulosic biomass.

실리카 담지 메탈로센 촉매를 이용한 Syndiotactic Polystyrene 합성에 관한 연구

임진형(Jin Heong Yim),추경준(Kyung Jun Chu),최경우(Kyung Woo Choi),임선기,Son Ki Ihm 한국고분자학회 1994 한국고분자학회 학술대회 연구논문 초록집 Vol.1994 No.10