Changes in the Angstrom Exponent during Aerosol Coagulation and Condensation

Chang H. Jung,Ji Yi Lee,Yong P. Kim,김용표 한국대기환경학회 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the Ångstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed,and a sensitivity analysis of the Ångstrom exponent with regards the coagulation and condensation process was performed. The Ångstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the Ångstrom exponent during coagulation and condensation,different real and imaginary parts of the refractive index were considered. The results show that the Ångstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the Ångstrom exponent. The degree of change in the Ångstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the Ångstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the Ångstrom exponent as well as the chemical composition. Subsequently, this study shows how the Ångstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Follow-Up Study on CDX1 and CDX2 mRNA Expression in Noncancerous Gastric Mucosae After Helicobacter pylori Eradication

Shin, C. M.,Kim, N.,Chang, H.,Kim, J. S.,Lee, D. H.,Jung, H. C. Plenum Pub. Corp 2016 Digestive diseases and sciences Vol.61 No.4

<P>Changes in CDX1/CDX2 in gastric mucosae following Helicobacter pylori eradication have not been clarified yet. To evaluate the changes in CDX1/CDX2 expression after H. pylori eradication, in relation to the reversibility of intestinal metaplasia (IM). Time course of CDX1/CDX2 expressions was investigated in 176 subjects with various gastroduodenal disorders. Among them, 132 patients were H. pylori positives; H. pylori were eradicated in 107 of them; 13 failed to eradicate; and 12 did not receive H. pylori eradication therapy. Forty-four subjects were H. pylori negatives. Expression levels in CDX1 and CDX2 from noncancerous gastric mucosae of the corpus, as well as the histologic findings of gastric mucosae, were evaluated during the follow-up. Average follow-up duration was 33.7 months (range 2-97 months). Expression levels in both CDX1 and CDX2 mRNAs were correlated with IM grade in the corpus (rho = 0.633 and 0.554, respectively, all P < 0.001). Changes in CDX1/CDX2 mRNA expressions following H. pylori eradication showed only insignificant results; IM grade at the antrum and corpus showed a tendency to decrease after H. pylori eradication without statistical significance (P > 0.05). However, histologic improvement of IM at the corpus was associated with a decrease in CDX2 mRNA expression during the follow-up (linear mixed model, P for slope = 0.015). In this study, eradication of H. pylori did not show any beneficial effects on aberrant CDX1/CDX2 expressions or IM. Reversibility of IM may be associated with a decrease in CDX2 mRNA expression.</P>

Changes in the Ångstrom Exponent during Aerosol Coagulation and Condensation

Jung, Chang H.,Lee, Ji Yi,Kim, Yong P. Korean Society for Atmospheric Environment 2012 Asian Journal of Atmospheric Environment (AJAE) Vol.6 No.4

In this study, the ${\AA}$ngstrom exponent for polydispersed aerosol during dynamic processes was investigated. Log-normal aerosol size distribution was assumed, and a sensitivity analysis of the ${\AA}$ngstrom exponent with regards the coagulation and condensation process was performed. The ${\AA}$ngstrom exponent is expected to decrease because of the particle growth due to coagulation and condensation. However, it is difficult to quantify the degree of change. In order to understand quantitatively the change in the ${\AA}$ngstrom exponent during coagulation and condensation, different real and imaginary parts of the refractive index were considered. The results show that the ${\AA}$ngstrom exponent is sensitive to changes in size distribution and refractive index. The total number concentration decreases and the geometric mean diameter of aerosols increase during coagulation. On the while, the geometric standard deviation approaches monodispersed size distribution during the condensation process, and this change in size distribution affects the ${\AA}$ngstrom exponent. The degree of change in the ${\AA}$ngstrom exponent depends on the refractive index and initial size distribution, and the size parameter changes with the ${\AA}$ngstrom exponent for a given refractive index or chemical composition; this indicates that the size distribution plays an important role in determining the ${\AA}$ngstrom exponent as well as the chemical composition. Subsequently, this study shows how the ${\AA}$ngstrom exponent changes quantitatively during the aerosol dynamics processes for a log-normal aerosol size distribution for different refractive indices; the results showed good agreement with the results for simple analytic size distribution solutions.

Temperature and air pollution affected tree ring δ¹³C and water-use efficiency of pine and oak trees under rising CO₂ in a humid temperate forest

Kwak, J.H.,Lim, S.S.,Lee, K.S.,Viet, H.D.,Matsushima, M.,Lee, K.H.,Jung, K.,Kim, H.Y.,Lee, S.M.,Chang, S.X.,Choi, W.J. Elsevier 2016 Chemical geology Vol.420 No.-

<P>To better predict forest productivity under rising atmospheric CO2 concentration ([CO2]), it is critical to understand how intrinsic water-use efficiency (WUEi) and its relationship with tree growth are affected by the concomitant changes in environmental conditions such as precipitation, temperature, and air pollution that either enhance or undermine any potential CO2 fertilization effect. We investigated changes in delta C-13 and WUEi in annual rings and basal area increment (BAI) of Pinus densiflora (from 1968 to 2007) and Quercus variabilis (from 1970 to 2007) trees in relation to precipitation, temperature, and air pollution in a humid temperate forest. The WUEi of P. densiflora increased by 39.9%, whereas that of Q. variabilis did not change over time in the study period. The WUEi was not affected by precipitation for both species but increased (P < 0.001) with temperature for P. densiflora and with SO2 emissions for both species. Multiple regression models suggested that the effect of [CO2] on tree growth was much higher than temperature; however, for the period (1998 to 2007) when SO2 emissions data were available, SO2 emission was the driver of changes in BAI and WUEi, and temperature effects became stronger than [CO2]. Overall, BAI and WUEi were positively (P < 0.001) correlated for P. densiflora, but not for Q. variabilis. We conclude that temperature and air pollution rather than precipitation were key determinants of WUEi at the study site and that the two species had contrasting responses to environmental changes. (C) 2015 Elsevier B.V. All rights reserved.</P>

生藥 및 生藥製劑의 規格에 關한 硏究 (Ⅶ) : (1) 葛根 및 그 含有製劑의 分析法 (1) Studies on the Analysis of Puerariae Radix and its Crude Drug Preparations

元道喜,張承燁,趙貞姬,金惠洙,鄭基淑,金度勳,洪南斗 국립보건연구원 1989 국립보건원보 Vol.26 No.

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.

Safety assessment of trans-tympanic photobiomodulation

Moon, T. H.,Lee, M. Y.,Jung, J. Y.,Ahn, J. C.,Chang, S. Y.,Chung, P. S.,Rhee, C. K.,Kim, Y. H.,Suh, M. W. Springer Science + Business Media 2016 Lasers in medical science Vol.31 No.2

<P>We evaluated functional and morphological changes after trans-tympanic laser application using several different powers of photobiomodulation (PBM). The left (L) ears of 17 rats were irradiated for 30 min daily over 14 days using a power density of 909.1 (group A, 5040 J), 1136.4 (group B, 6300 J), and 1363.6 (group C, 7560 J) mW/cm(2). The right (N) ears served as controls. The safety of PBM was determined by endoscopic findings, auditory brainstem response (ABR) thresholds, and histological images of hair cells using confocal microscopy, and light microscopic images of the external auditory canal (EAC) and tympanic membrane (TM). Endoscopic findings revealed severe inflammation in the TM of C group; no other group showed damage in the TM. No significant difference in ABR threshold was found in the PBM-treated groups (excluding the group with TM damage). Confocal microscopy showed no histological difference between the AL and AN, or BL and BN groups. However, light microscopy showed more prominent edema, inflammation, and vascular congestion in the TM of BL ears. This study found a dose-response relationship between laser power parameters and TM changes. These results will be useful for defining future allowance criteria for trans-tympanic laser therapies.</P>

Role of oxygen in the growth of carbon nanotubes on metal alloy fibers by plasma-enhanced chemical vapor deposition

Moon, Young Kyun,Jung, Chang Goo,Park, Seok Joo,Kim, Tae Gyu,Kim, Soo H. Cambridge University Press (Materials Research Soc 2009 Journal of materials research Vol.24 No.4

<P>A method allowing for the stable growth of carbon nanotubes (CNTs) on the surface of a fibrous metal mesh substrate (SUS304) was developed with the assistance of the microwave plasma-enhanced chemical vapor deposition process. The controlled addition of up to ∼13% of O2 to the CH4 plasma reacting gas flow was found to promote the growth of the CNTs by oxidizing the amorphous carbon and removing the active H2 radicals. However, excessive amounts of O2 (i.e., fraction of O2 > ∼13%) and H2 were found to play a negative role in the growth of the CNTs. The control of the density and length of the CNTs was also achieved by varying the H2 plasma reduction time and CH4 plasma reacting time, respectively. Longer H2 reduction pretreatment of the catalytic metal islands resulted in the formation of a less dense CNT forest with craters. When the growth time of the CNTs was increased to ∼20 min, their length was increased to ∼10 μm. However, when the growth time of the CNTs exceeded 20 min, their length was significantly decreased, indicating that the continuous presence of O2 in the CH4 plasma destroys the preformed CNTs due to the oxidation reaction.</P>

Intranasal Adenovirus-Vectored Vaccine for Induction of Long-Lasting Humoral Immunity-Mediated Broad Protection against Influenza in Mice

Kim, Eun Hye,Park, Hae-Jung,Han, Gye-Yeong,Song, Man-Ki,Pereboev, Alexander,Hong, Jeong S.,Chang, Jun,Byun, Young-Ho,Seong, Baik Lin,Nguyen, Huan H. American Society for Microbiology 2014 Journal of virology Vol.88 No.17

<P>Influenza vaccines aimed at inducing antibody (Ab) responses against viral surface hemagglutinin (HA) and neuraminidase (NA) provide sterile immunity to infection with the same subtypes. Vaccines targeting viral conserved determinants shared by the influenza A viruses (IAV) offer heterosubtypic immunity (HSI), a broad protection against different subtypes. We proposed that vaccines targeting both HA and the conserved ectodomain of matrix protein 2 (M2e) would provide protection against infection with the same subtype and also HSI against other subtypes. We report here that single intranasal immunization with a recombinant adenovirus (rAd) vector encoding both HA of H5 virus and M2e (rAdH5/M2e) induced significant HA- and M2e-specific Ab responses, along with protection against heterosubtypic challenge in mice. The protection is superior compared to that induced by rAd vector encoding either HA (rAdH5), or M2e (rAdM2e). While protection against homotypic H5 virus is primarily mediated by virus-neutralizing Abs, the cross-protection is associated with Abs directed to conserved stalk HA and M2e that seem to have an additive effect. Consistently, adoptive transfer of antisera induced by rAdH5/M2e provided the best protection against heterosubtypic challenge compared to that provided by antisera derived from mice immunized with rAdH5 or rAdM2e. These results support the development of rAd-vectored vaccines encoding both H5 and M2e as universal vaccines against different IAV subtypes.</P><P><B>IMPORTANCE</B> Current licensed influenza vaccines provide protection limited to the infection with same virus strains; therefore, the composition of influenza vaccines has to be revised every year. We have developed a new universal influenza vaccine that is highly efficient in induction of long-lasting cross-protection against different influenza virus strains. The cross-protection is associated with a high level of vaccine-induced antibodies against the conserved stalk domain of influenza virus hemagglutinin and the ectodomain of matrix protein. The vaccine could be used to stimulate cross-protective antibodies for the prevention and treatment of influenza with immediate effect for individuals who fail to respond to or receive the vaccine in due time. The vaccine offers a new tool to control influenza outbreaks, including pandemics.</P>

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>