• Publications of The Korean Astronomical Society
• /
• v.27 no.4
• /
• pp.321-324
• /
• 2012

Using extensive mid-IR datasets from AKARI, i.e. 9-band photometry covering the wavelength range from $2{\mu}m$ to $24{\mu}m$ and the unbiased spectroscopic survey for sources with $S_{\nu}$($9{\mu}m$)>0.3 mJy, we study starburst galaxies specifically at the redshift of z ~ 0.5, whose mid-IR spectra are clearly dominated by the PAH emission features. PAH-selected galaxies, selected with extremely red mid-IR colour due to PAHs, have high rest-frame PAH-to-stellar luminosity ratios, comparable to those in the most active regions in nearby starburst galaxies. Thus, they seem to have active starburst regions spreading over the whole body. Furthermore, some of PAH-selected galaxies are found to have peculiar rest-frame 11-to-$8{\mu}m$ flux ratios, which is systematically smaller than nearby starburst/AGN spectral templates. This may indicate a systematic difference in the physical condition of ISM between nearby and distant starburst galaxies.

• Journal of Environmental Health Sciences
• /
• v.40 no.1
• /
• pp.38-46
• /
• 2014

Objectives: This study was carried out in order to estimate atmospheric polycyclic aromatic hydrocarbon (PAH) concentrations and sources using pine needles as a passive air sampler (PAS) in urban (Pyeongtaek), semirural (Anseong) and rural (Jincheon) sites. Methods: One-year-old pine needles were collected for analysis of their PAH concentrations ($C_{p,n}g/g$ dry) at the end of December. PAHs concentrations in the ambient air ($C_a$, $ng/m^3$) were calculated with a $Log(C_p/C_a)-LogK_{oa}$ correlational equation. Results: PAHs concentrations in ambient air ($C_a$) were high, in the order of urban ($114.03ng/m^3$), semirural ($105.17ng/m^3$) and rural ($61.91ng/m^3$) sites. However, distributions of PAH isomer concentrations were very similar. PAHs of which molecular weight is smaller than 228.30 (AcPy, Acp, Flu, Phen, Ant, Flt, Pyr, BaA, Chry) made up most of the PAHs in the ambient air (96.6-98.5%). Conclusion: At urban, semirural and rural sites, it was concluded that the main source of PAHs in the ambient air ratio of each PAH isomer concentration was cars, especially diesel vehicles.

• BMB Reports
• /
• v.47 no.6
• /
• pp.311-317
• /
• 2014

microRNAs (miRNAs) are a class of small, non-coding RNAs that play critical posttranscriptional regulatory roles typically through targeting of the 3'-untranslated region of messenger RNA (mRNA). Mature miRNAs are known to be involved in global cellular processes, such as differentiation, proliferation, apoptosis, and organogenesis, due to their capacity to target multiple mRNAs. Thus, imbalances in the expression and/or activity of miRNAs are involved in the pathogenesis of numerous diseases, including pulmonary arterial hypertension (PAH). PAH is a progressive disease characterized by vascular remodeling due to excessive proliferation of pulmonary artery endothelial cells (PAECs) and pulmonary artery smooth muscle cells (PASMCs). Recently, studies have evaluated the roles of miRNAs involved in the pathogenesis of PAH in these pulmonary vascular cells. This review provides an overview of recent discoveries on the role of miRNAs in the pathogenesis of PAH and discusses the potential for miRNAs as therapeutic targets and biomarkers of PAH.

• Proceedings of the Korean Society of Soil and Groundwater Environment Conference
• /
• 2004.04a
• /
• pp.289-292
• /
• 2004

In order to identify the origin and nature of the spilled oil in the potential source, we analyzed the pattern of alkyi PAM(Polynuclear Aromatic Hydrocarbons) in fuel standard and environmental samples. Alkyl PAM patterns are used for fuel-type identification in weathered environmental samples. Detection of alkyl PAH was achieved by operation CC/MS in the SIM mode. We chose ions of naphthalene(m/z 128), C1-naphthalene(m/z 142), C2-naphthalene(m/z 156), C3-naphthalene(m/z 170), C4-naphthalene(m/z 184) for the comparison of this pattern according to the type of fuel. We analyzed tile pattern of alkyl PAH in neat gasoline, kerosene, diesel, and JP-8, and in groundwater samples which were collected in monitoring wells. The distribution map of alkyl-naphthalene shows different patterns among four different fuel types (gasoline, kerosene, diesel, and JP-8). Particularly, tile distribution map of kerosene and JP-8 is found to be of value in identifying fuel type in that the difference is clear. Therefore distribution patterns of alkyl-PAH compounds provide another useful tool for fuel-type identification of petroleum fuels.

• Journal of the Korean Society of Combustion
• /
• v.23 no.1
• /
• pp.1-7
• /
• 2018

The effect of LII interference on the measurement of LIF signals from PAH in a diffusion flame has been investigated. Argon-ion laser at 488 nm was vertically or horizontally polarized, and irradiated to the centerline of the flame at varying flame height. Signals from PAH-rich regions measured at 515 nm were mostly LIF signals, however, signals from soot-rich regions were determined to be mixed with Mie scattering signals and/or LII signals. Signals measured 1 mm above the excitation height were mostly LII signals from soot particles. The results show that a quantitative determination of the LIF's contribution to the measured signals would be difficult as long as the experimental setup described here is used for the regions where PAHs and soot particles exist together.

• The Korean Journal of Physiology
• /
• v.21 no.2
• /
• pp.283-289
• /
• 1987

Uric acid transport across the basolateral membrane of renal proximal tubules was studied in rabbit kidney cortical slices. Uric acid uptake was greater under $O_2$ atmosphere compared to under $N_2$ atmosphere, and was increased with $Na^{2+}$ concentration in incubation medium. Uric acid inhibited PAH uptake but not TEA uptake and did trans-stimulated PAH efflux. PAH also inhibited uric acid uptake. Uric acid uptake was inhibited by harmaline, ouabin, SITS, DIDS and pyrazinoic acid. The inhibition of PAH uptake by these inhibitors also was reasonably comparable to that of uric acid uptake. These results suggest that uric acid was transported across the basolateral membrane of renal tubule by a carrier-mediated process which was by a common transport system with PAH in rabbit.

• Journal of Environmental Science International
• /
• v.12 no.8
• /
• pp.871-879
• /
• 2003

The complexation of co-contaminant mixtures between Ag(I) and polycyclic aromatic hydrocarbon (PAH) molecules (naphthalene, pyrene, and perylene) were investigated to quantify the equilibrium constants of their complexes and elucidate the interactions between Ag(I) and PAH molecules. The apparent solubilities of PAHs in aqueous solutions increased with increasing Ag(I) ion concentration. The values, K$_1$ and K$_2$ of equilibrium constants of complexes of Ag(I)-PAHs, were 2.990 and 0.378, 3.615 and 1.261, and 4.034 and 1.255, for naphthalene, pyrene, and perylene, respectively, The K$_1$and K$_2$ values of PAHs for Ag(I) increased in the order of naphthalene ＜ pyrene ＜ perylene and naphthalene ＜ pyrene ≒ perylene, respectively, indicating that a larger size of PAH molecule is likely to have more a richer concentration of electrons on the plane surfaces which can lead to stronger complexes with the Ag(I) ion. For the species of Ag(I)-PAH complexes, a 1:1 Ag(I) : the aromatic complex, AgAr$\^$＋/, was found to be a predominant species over a 2:1 Ag(I) : aromatic complex, Ag$_2$Ar$\^$＋＋/. The PAH molecules with four or more aromatic rings and/or bay regions were observed to have slightly less affinity with the Ag(I) ion than expected, which might result from inhibiting forces such as the spread of aromatic $\pi$ electrons over o wide molecular surface area and the intermolecular electronic repulsion in bay regions.

• The Korean Journal of Zoology
• /
• v.31 no.2
• /
• pp.142-146
• /
• 1988

Metabolism of benzo(a)pyrene, the most thoroughly studied PAH, was studied in mouse placental microsomes incubated with $^3$H-labeled B(a)P. B(a)P metabolites were separated using HPLC fitted with a C18- $\mu$ Bondapak column. The single major metabolite by mouse placental microsomes induced by B(a)P was 7, 8-diol B(a)P, while 4, 5-diol B(a)P, 3-OH and quinones constituted minor metabolites. Treatment with 3-methyl-cholanthrene to mice resulted in indudion of hydroxy B(a)P and quinone compounds. Phenobarbital treated mouse placental microsomes also showed elevated level of B(a)P metabolism with 7, 8-diol B(a)P as a major metabolite.

• Health Policy and Management
• /
• v.29 no.2
• /
• pp.220-227
• /
• 2019

Background: Potentially avoidable hospitalizations (PAH) contribute to an increased post-discharge mortality. Methods: To investigate the between-hospital variation and the relationship between all predictors and mortality after discharge among older adults with PAH, we studied 15,186 older patients with PAH in 2,200 hospitals included in the National Health Insurance Service-Senior claims database from 2002 to 2013. Multivariable multilevel logistic regression analyses were performed to analyze the variance at between-hospital for mortality after accounting for differences in patient characteristics. Results: The between-hospital variation in mortality that could be attributed to hospital practice variations were 37.6% at 1-week to 13.9% at 12-month post-discharge, after adjustment for individual patient characteristics and hospital-level factors. Hospital-level factors significantly explained mortality at 3 weeks after discharge. Clinics, compared with general hospitals, demonstrated a 2.75 times higher likelihood of deaths at 3-week post-discharge (p<0.001). Compared with private hospitals, public hospitals exhibited 1.61 times higher odds of 3-week mortality (p=0.01). Conclusion: This study demonstrates considerable between-hospital variations in PAH-related mortality that could be attributed to hospital practices. Monitoring of hospitals to identify practice variations would be warranted to improve the survival of older patients with PAH.

• 한국연소학회:학술대회논문집
• /
• 2000.12a
• /
• pp.229-235
• /
• 2000

Soot formation characteristics in counterflow diffusion flames of ethylene/propane/nitrogen mixtures have been studied experimentally to investigate the soot formation mechanism. The effect of HACA reaction on PAH and soot growth has been experimentally investigated by using 2-D planar LII and PAH LIF techniques.