아파트 실내 환경에서 실시간 측정시스템을 활용한 HONO 농도 측정 및 생성기작 연구

박승식(Seung Shik Park),홍진의(Jin H. Hong),이재훈(Jai H. Lee),김영준(Young J. Kim),조성용(Sung Y. Cho),김승재(Seung J. Kim) 한국대기환경학회 2008 한국대기환경학회지 Vol.24 No.1

Nitrous acid (HONO) can be produced by heterogenous reactions of nitrogen dioxide on surface materials and direct emission from combustion sources. However, a little is known of indoor HONO levels or the relationship between residential HONO, NO, and NO₂ concentrations in occupied houses. Therefore, we measured simultaneously NO, NO2, and HONO concentrations in living room of an apartment using continuous analyzers to study the production of HONO (June 22~30, 2006). The 4-min average concentrations of indoor NO, NO₂, and HONO were 4.3 (range: 0.4~214.3), 10.3 (2.0~87.3), and 1.8 ppb (0.3~7.7), respectively. Peak levels of HONO up to 7.7 ppb and 24-hr averages as high as 1.7 ppb were measured. In agreement with previous studies, indoor HONO concentrations increased during operation of an unvented gas range. Examination of the observed kinetics suggests that the secondary production of indoor HONO, possibly as a result of heterogeneous reactions involving NO₂ and H₂O is associated with [NO₂]²[H₂O] (r²=0.88) rather than with [NO][NO₂][H₂O] (r²=0.75). Three combustion experiments at nighttime were also carried out to investigate the effects of vented combustion on the HONO, NO, and NO₂ concentrations. It was found to release HONO for 10~15 minutes after NO and NO₂ source was turned off, and peak values were finally attained. Compared to unvented combustion, peak NO₂ and HONO concentrations were 3.2 and 2.0 times lower at weak vented combustion (air flow: 340㎥/hr) and 4.9 and 2.4 times lower at strong vented combustion (air flow: 540 ㎥/hr), respectively, emphasizing importance of operating ventilation hood fan during combustion to improve indoor air quality.

Self-powered transparent flexible graphene microheaters

Khan, U.,Kim, T.H.,Lee, K.H.,Lee, J.H.,Yoon, H.J.,Bhatia, R.,Sameera, I.,Seung, W.,Ryu, H.,Falconi, C.,Kim, S.W. Elsevier 2015 Nano energy Vol.17 No.-

Transparent and flexible (TF) microheaters are required in wearable devices, labs-on-chip, and micro-reactors. Nevertheless, conventional microheaters are rigid or opaque or both. Moreover, the resistances of conventional metallic microheaters are too low to be effectively powered by wearable energy harvesters. Here, we demonstrate the first TF microheaters by taking advantage of chemical vapor deposition (CVD)-grown graphene heating tracks and of a hexagonal boron nitride (h-BN) sheet for passivation; the h-BN sheet increases the maximum temperature by ~80%. Our TF microheaters show excellent temperature uniformity and can reach temperatures above 200<SUP>o</SUP>C in just 4s, with power consumption as low as 39mW. Additionally, since the CVD-graphene sheet resistance is orders of magnitude higher than that of typical metallic heaters, our devices can be effectively powered by wearable energy harvesters. As a proof-of-concept, we demonstrate the first self-powered, wearable microheater which achieves a temperature increase of 8<SUP>o</SUP>C when operated by a sound driven textile-based triboelectric nanogenerator. This is a key milestone towards next generation microheaters with applications in portable/wearable personal electronics, wireless health, and remote and mobile environmental sensors.

Investigation of nitrous acid concentration in an indoor environment using an in-situ monitoring system

Park, Seung Shik,Hong, Jin H.,Lee, Jai H.,Kim, Young J.,Cho, Sung Y.,Kim, Seung J. Elsevier 2008 Atmospheric environment Vol.42 No.27

<P><B>Abstract</B></P><P>An in-situ measurement system for the determination of nitrous acid (HONO) was developed and used at an indoor residential environment. The system uses a diffusion scrubber to sample gaseous HONO and the peroxynitrite-induced luminol chemiluminescent method to quantify the amount of HONO. In this system, the detection limit of HONO, estimated as three times the noise level of the scrubbing solution blank, was 120pptv for a 2-min integrated sample. Indoor HONO and NO<I><SUB>x</SUB></I> concentrations were determined for 7 days in the living room of an apartment with a gas range for cooking in the kitchen. Close examination of the relationships among HONO, NO, and NO<SUB>2</SUB> concentrations during both the background and combustion periods confirm that the observed HONO was formed not only by direct emission from gas combustion, but also from heterogeneous reactions of NO<SUB>2</SUB> with H<SUB>2</SUB>O on indoor surfaces. The average ratio of HONO to NO<SUB>2</SUB> over the study period was 0.12±0.05. The HONO/NO<SUB>2</SUB> concentration ratio was 0.04–0.08 during the combustion period, whereas it was 0.10–0.25 after combustion had stopped. This suggests that HONO was generated through different production processes, both during combustion and after the completion of combustion. The controlled combustion experiments indicate that the burning rate is an important factor to determine the peak HONO concentration. In darkness, HONO had a nearly constant removal rate for all of the combustion experiments, whereas the removal rates of NO and NO<SUB>2</SUB> depended on the burning rates of the gas range. Combustion experiments conducted at the fixed burning rate setting show also that ventilation decreased HONO concentration. This indicates that the airflow rate of the range hood fan is an important factor to control the concentration of indoor air pollutants.</P>

Genetically engineered fibroblasts with antigen-presenting capability:Efficient induction of an antigen-specific cytotoxic T-lymphocyte response and protection against tumor development in vivo

Kim, Tae S .,Chung, Su W .,Kim, Seung H .,Kang, Bok Y .,Hwang, Seung Y .,Lee, Jae W . 전남대학교 약품개발연구소 2000 약품개발연구지 Vol.9 No.1

BLK mouse fibroblasts (H-2^b) were genetically engineered to express costimulatory B7.1 and interleukin-2 (BLK/IL2/B7.1). The BLK/IL2/B7.1 cells were then pulsed with an ovalbumin (OVA) epitope as a model antigen (Ag) (BLK/IL2/B7.1/OVA), and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2^b). The genetically engineered fibroblasts lacking one or two of three factors (interleukin-2, B7.1, and OVA) were constructed and used as controls. Immunization with the BLK/IL2/B7.1/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells, but not against other H-2^b tumor cells, such as EL4, C1498 and B16F1 cells. The magnitude of the cytotoxic response in mice with the BLK/IL2/B7.1/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8^+ T cells with OVA-specific cytotoxic activities were predominant in mice immunized with the BLK/IL2/B7.1/OVA cells. Furthermore, immunization with the BLK/IL2/B7.1/OVA cells significantly prolonged the survival of mice, compared with any other cell constructs, when the mice were challenged with EG7 tumor cells at 2 weeks postimmunization. Induction of antitumoral CTL immunity by the BLK/IL2/B7.1/OVA cells was independent of host Ag-presenting cells and of CD4^+ T-cell and natural killer 1.1^+ cell help. These results suggest that fibroblasts can be genetically modified to efficient Ag-presenting cells for the induction of an Ag-specific CTL response.

Increased cell-free DNA concentrations in patients with obstructive sleep apnea

Shin, Chol,Kim, Jin K.,Kim, Je H.,Jung, Ki H.,Cho, Kyung J.,Lee, Chang K.,Lee, Seung G. Blackwell Publishing Asia 2008 PSYCHIATRY AND CLINICAL NEUROSCIENCES Vol.62 No.6

<P>Aim: </P><P>Blood concentrations of cell-free DNA, which is considered to be released during apoptosis, are elevated under some pathological conditions such as cardiovascular disease and cancer. The association between obstructive sleep apnea (OSA) and cell-free DNA concentrations has not been reported so far. The purpose of the present study was to examine the association between OSA and plasma DNA concentrations.</P><P>Methods: </P><P>A case–control study was conducted using a total of 164 men aged 39–67 years, who were free of coronary heart disease and cancer. Laboratory-based overnight polysomnography was performed for all participants.</P><P>Results: </P><P>On the basis of polysomnography, patients with an apnea–hypopnea index (AHI) = 5–30 events/h were defined as having mild–moderate OSA (<I>n</I> = 33) and those with >30 events/h were defined as having severe OSA (<I>n</I> = 49). All 82 controls had AHI < 5 events/h. Plasma DNA concentrations from all participants were analyzed for the &bgr;-globin gene using fluorescence-based real-time polymerase chain reaction. Patients with severe OSA had significantly higher plasma DNA concentrations than persons with mild–moderate OSA and those without OSA (<I>P</I> < 0.05). AHI was significantly associated with body mass index (<I>P</I> < 0.001), hypertension (<I>P</I> < 0.001), and plasma DNA concentration (<I>P</I> < 0.05).</P><P>Conclusion: </P><P>After taking into account hypertension and other potential risk factors, persons with high plasma DNA concentrations (>8 µg/L) had approximately fourfold higher odds of OSA than those with low DNA levels. Further data are warranted to confirm the association for men and to evaluate the association for women.</P>

Formation of Ag Nanostrings Induced by Lyotropic Liquid–Crystalline Phospholipid Multilayer

Kim, Suk J.,An, Hyeun H.,Lee, Seung J.,Lee, Jong H.,Kim, Young H.,Yoon, Chong S.,Suh, Sang H. American Chemical Society 2012 Langmuir Vol.28 No.1

<P>Morphological variation of the Ag nanoparticles embedded in a lyotropic phospholipid (1,2-dioleoyl-<I>sn</I>-glycero-3-phosphoethanolamine, DOPE) membrane during hydration was investigated. Hydration at 5 °C resulted in transformation of the Ag nanoparticles into a bundle of Ag nanostrings as the Ag nanoparticles conformed to the H<SUB>II</SUB> phase of the DOPE molecules. Above 30 °C, the nanoparticles quickly coarsened into large polygonal-shaped particles since high mobility of the lipid molecules overwhelmed the tendency for the Ag nanoparticles to order. The result provided an insight into the long-term stability of nanoparticles trapped in different lipid membranes depending on the structural ordering of the molecules.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/langd5/2012/langd5.2012.28.issue-1/la203721c/production/images/medium/la-2011-03721c_0008.gif'></P><P><A href='http://pubs.acs.org/doi/suppl/10.1021/la203721c'>ACS Electronic Supporting Info</A></P>

암환자에서 단구매개 세포파괴능과 혈청내 Sialic acid농도

승기배,이흥현,서재열,문한림,진종률,박종원,김춘추,김동집 大韓血液學會 1984 大韓血液學會誌 Vol.19 No.1

레지오넬라 폐렴의 진단용 바이오마커의 발굴 : A/J 마우스 감염 모델에서 Legionella pneumophila의 독력 유전자들의 발현양상 분석

김승민,심희선,김희남,심호기,윤영경,김정연,박윤선,박대원,손장욱,김민자 대한감염학회 2010 감염과 화학요법 Vol.42 No.1

Background: Legionella pneumophila is the causative agent of Legionnaires’ disease, a severe form of pneumonia. After L. pneumophila is inhaled through contaminated aerosols, it is phagocytized by alveolar macrophages, multiplies in a specialized phagosome approximately 10 h postinfection, and eventually leads to the death of host cells. Currently available diagnostic tests for Legionella pneumonia have some limitations. This study was conducted to find diagnostic biomarkers for Legionella pneumonia using virulence gene expression profiling in a murine experimental model. Materials and Methods: A/J mice were intranasally inoculated with L. pneumophila serogroup 1, and lungs were harvested 4, 8, 24, and 48 h postinfection. The strain grown in buffered yeast extract broth was used as reference samples. Cy-dye labeled cDNA samples were prepared with total RNA from lungs or broth culture, and hybridized on the oligo-microarray slide containing 2,895 genes of L. pneumophila serogroup 1. Virulence gene expression patterns were analyzed using a MIDAS software from TIGR (www.tigr.org). Results: Among a total of 332 virulence genes examined, 17 genes including sidA, lepB, the genes related to flagella assembly (fliR and fliP), LPS lipid A biosynthesis, and the enhanced entry protein EnhA were up-regulated at all four time points. We further confirmed by quantitative real-time reverse transcription PCR that the expression of fliP gene was highly expressed in lung tissue as well as in bronchoalveolar lavage fluids from the mouse infected with L. pneumophila serogroup 1. Conclusions: Through gene expression analysis of L. pneumophila in a mouse model, several candidate biomarkers for diagnosing Legionnaires’ disease could be identified.

Boron-nitrogen functional groups on porous nanocarbon fibers for electrochemical supercapacitors

Kim, B.H.,Seung Yang, K.,Woo, H.G. North-Holland 2013 Materials letters Vol.93 No.-

Boron- and nitrogen-containing porous carbon nanofibers (BN-CNFs) were prepared through one-step electrospinning using boric acid (H<SUB>3</SUB>BO<SUB>3</SUB>) and urea as boron and nitrogen precursors and a subsequent thermal treatment. The BN-CNFs showed higher capacitance and energy/power density values than the control sample of CNFs in aqueous electrolyte; the large surface area of 559m<SUP>2</SUP>g<SUP>-1</SUP> and the NH, COOH, and [O]BN functional groups facilitated these improvements. The specific capacitance of the supercapacitor was 180Fg<SUP>-1</SUP> at 1mAcm<SUP>-2</SUP>, and the energy density was 17.2-23.5Whkg<SUP>-1</SUP> in the power density range of 400-10,000Wkg<SUP>-1</SUP> in an aqueous electrolyte.

피부감작성에 있어 Local lymph node의 반응성 연구

이종권,박재현,김형수,정승태,엄준호,황인창,장은정,윤소미,남기택,허용,오혜영 식품의약품안전청 2001 식품의약품안전청 연보 Vol.5 No.-

알레르기설 접촉 괴부염은 다양한 화학물질에 의해 유포될 수 있다. 화학물질이 피부 감작성을 알 킬 수 있는지 여부는 전통적으로 기니픽을 사용한 등물모겔이 이용되어 쏜으나, 최근에는 마우스를 이용한 local Iymph node assily tLLNA) 발법 개발이 요구되고 있떠 본 연구는 focal Iymph not assa)·의 시험방법을 개발하고, 감작을 일으키는 기전을 파악하고자 하였다. 콕헝물질로는 패표적 접촉 알러전인 DffCB(2,4-dinitrochlorobenzone), 호홉 알러젠인 fDl(toluene diisocyanate), 약한 알러젠인Cf.(o-kerplcinamaldehl,do:4, 강한 자극물질인 SLS(sodum lauryl sulfate)를 사용하였다. 각 시험물질 2sr4를 적절한 농도로 6-8주령의 암컷 Balb/c 마우스의 귀의 배측에 3일간 도포한 후 5일째에 부검하여 이개림프절, 귀의 변화 등을 관찰하였다. DNCB, TDI를 도포한 마우스의 이개 림프절의 중량은 대조군에 비해 증가하였으며, 고농도의 HCA를 투여한 마우스에서의 림프절 중량도 증가하였다. SLS를 투여한 군의 림프걸치 중량은 저농도에서는 변화가 없었으나, 고농도에서는 중량이 증가하였다. 꼬리정맥에 3H-thymidine을 투여하여 림프절의 증식정도를 파악한 결과, BNCB를 도포한 군에서는 프절의 증식지수(Stimulation 1.Idex, Sl)가 용량별로 20.3, 24.6, 27.5로 관찰되었으며, TDI군에서는 각 19.0, 29.T, 42.3으로 관찰되첬고 HCA군에서는 각각 3.8, 9.7, 19.8로 관찰되었다. sLs군에서는 0.8 3.7, 6.6으로 관찰되었다. 이잖끈 결과 fH-thynudine을 이용한 피부 감작성 평가는 기니픽을 대체할수 있는 방법으로 _평가되었다. 그러나 방사선이용이라는 단점과 강한 자극성물질에서의 위양성 반응이 관찰되어 BrdU(Eromodeoklpuddine) 면역조직차학기법으로 시험한 결과 비방사선법도 이용 가능함을 알 수 있었다. 또는 TDI를 처리한 마우스의 림프절에서 cytoklne의 발현을 RT-PCR로 측정한 결과 IL-2 IL-4, U-10과 INf-r의 mRNA발현이 증가하였으며, HCA를 처리한 경우에는 토-4, IL-10. INf-γ mRNA의 발현이 증가 하였다. 또한 B리CB의 경우에는 U-4의 발현이 증가하였다. 그러나, sLs의 경우에는 IL-?, IL-4, 0--10 과 rNF-r꼭 발현이 증가되지 않았다. 이러한 결과는 LLNA를 이용한 c번okine의 n)교NA발현이 유용싼 측정 지포중 하나가 될 수 있을 것으로 생각되며. 특히 IL-4의 발현정도의 증가는 알레르기 유발성을 평가할 유용한 생체지표의 하나가 될 수 있을 것으로 생각되어진다. Allergic contact dermatitis (skin sensitization) may be caused by a wide variety of chemicals. A murine local lymph node assay(LLNA) has been developed as an alternative to guinea pig models for assessing the contact sensitization potential of chemical. First, the objective of this study was to evaluate allergenecity of chemicals by LLNA. Secondly, we aimed to investigate the possibility of development of non-radio isotopic endpoint for LLNA using immunohistochemistry. Thirdly, we aimed to analyze cytokine mRNA expression of draining lymph node cell in mice exposed to chemical allergen and irritant. In this study, contact allergen, dinitrochlorobenzone (DNCB), respiratory allergen toluene diisocyanate (TDI) and moderate allergen, α-hexylcinnamaldehyde (HCA) were used as positive chemicals and the irritant, sodium lauryl sulfate(SLS) also used as reference chemical. The stimulation index (SI) of lymph node cell in the mice treated with allergens. DNCB, TDI, and HCA were more increased dose-dependently compared to vehicle control by ^(3)H-thymidine uptake. And SI of lymph node cell in strong irritant, SLS were also increased dose-dependently compared to control. The BrdU(Bromodeoxyuridine) LI of lymph node in DNCB and TDI were dramatically increased campared to that of control. However, the LI of lymph node in SLS were not significantly increased compared to vehicle control. This data represents that BrdU LI of lymph node could be one of useful method for screening for irritant and allergen. The expression of IL-2, IL-4, IL-10 and IFN-γ mRNA was increased in draining auricular lymph node cell of the mice treated with TDI by RT-PCR. The level of IL-4, IL-10 and IFN-γmRNA was increased in mice treated with HCA. The expression of IL-4 was increased in lymph node cell of mice treated with DNCB. However, the level of IL-2, IL-4, IL-10 and IFN-γ in lymph node cell of mice treated with SLS was not increased. These results suggest the measurement for increase in level of IL-4 mRNA expression could by one of the method for screening the allergenic potential.