• The Bulletin of The Korean Astronomical Society
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• v.41 no.2
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• pp.57.1-57.1
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• 2016

Methanol ($CH_3OH$) is a key species in the formation of complex organic molecules. We report the first detection of solid $CH_3OH$ in a line of sight toward the Galactic center (GC) region, based on L-band spectra taken with the Subaru telescope, aided by L'-band imaging data and moderate-resolution spectra from NASA/IRTF. It is found toward a background star, ~8000 AU in projected distance from a newly discovered massive young stellar object (YSO). This YSO also exhibits a strong $CO_2$ ice absorption band at ${\sim}15{\mu}m$ in Spitzer/IRS data, which has a prominent long-wavelength wing. It confirms that a high $CH_3OH$ abundance is responsible for the broad $15{\mu}m$ $CO_2$ ice absorption towards massive YSOs in the GC. Clearly, $CH_3OH$ formation in ices is efficient in the GC region, as it is in star-forming regions in the Galactic disk. We discuss implications of our result on the astrochemical processes in the hostile GC molecular clouds.

• The Bulletin of The Korean Astronomical Society
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• v.44 no.2
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• pp.49.2-49.2
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• 2019

We present results from our long-term observing campaign, using the NASA IRTF at Maunakea, to obtain 2 - 4 ㎛ spectra of 118 red point sources in the line of sight to the Galactic Center (GC). Our sample is largely composed of point sources selected from near- and mid-infrared photometry, but also includes a number of massive young stellar objects. Many of these sources show high foreground extinction as shown by deep 3.4 ㎛ aliphatic hydrocarbon absorption feature, which is a characteristic of the diffuse ISM and comes from the long line of sight through the diffuse medium toward the Central Molecular Zone (CMZ), the central 300 pc region of the GC. The deep 3.1 ㎛ H₂O ice absorption band coming from the local, dense material in the GC CMZ suggests that most sources are likely located in the GC CMZ. A few of these sources show weak CCH₃OH ice absorption at 3.535 ㎛, which can provide a strong constraint on the CCH₃OH ice formation in the unique environment of the CMZ. From the best-fitting models, the optical depths of these features are determined and used to generate a well-rounded view of the ice composition across the GC CMZ and the spectral characteristics of massive YSOs in the GC.

• Progress in Medical Physics
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• v.28 no.1
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• pp.16-21
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• 2017

This study assessed the feasibility of a dual-channel (DC) compound method for film dosimetry. The red channel (RC) is usually used to ensure dosimetric quality using a conventional fraction dose because the RC is more accurate at low doses within 3 Gy than is the green channel (GC). However, the RC is prone to rapid degradation of sensitivity at high doses, while degradation of the GC is slow. In this study, the DC compound method combining the RC and GC was explored as a means of providing accurate film dosimetry for high doses. The DC compound method was evaluated at various dose distributions using EBT3 film inserted in a solid-water phantom. Measurements with $10{\times}20cm^2$ radiation field and $60^{\circ}$ dynamic-wedge were done. Dose distributions acquired using the RC and GC were analyzed with root-mean-squares-error (RMSE) and gamma analyses. The DC compound method was used based on the RC after correcting the GC for high doses in the gamma analysis. The RC and GC produced comparatively more accurate RMSE values for low and high doses, respectively. Gamma passing rates with an acceptance criterion of 3%/3 mm revealed that the RC provided rapid reduction in the high dose region, while the GC displayed a gradual decrease. In the whole dose range, the DC compound method had the highest agreement (93%) compared with single channel method using either the RC (80%) or GC (85%). The findings indicate that the use of DC compound method is more appropriate in dosimetric quality assurance for radiotherapy using high doses.

• Korean Journal of Microbiology
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• v.39 no.3
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• pp.128-134
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• 2003

Transformation-associated recombination (TAR) cloning is based on co-penetration into yeast spheroplasts of genomic DNA along with TAR vector DNA that contains 5'- and 3'-sequences (hooks) specific for a gene of interest, followed by recombination between the vector and the human genomic DNA to establish a circular YAC. Typically, the frequency of recombinant insert capture is 0.01-1% for single-copy genes by TAR cloning. To further refine the TAR cloning technology, we determined the effect of GC content on target hooks required for gene isolation utilizing the $Tg\cdot\AC$ mouse transgene as the targeted region. For this purpose, a set of vectors containing a B1 repeated hook and Tg AC-specific hooks of variable GC content (from 18 to 45%) was constructed and checked for efficiency of transgene isolation by radial TAR cloning. Efficiency of cloning decreased approximately 2-fold when the TAR vector contained a hook with a GC content ～${\leq}23$% versus ～40%. Thus, the optimal GC content of hook sequences required for gene isolation by TAR is approximately 40%. We also analyzed how the distribution of high GC content (65%) within the hook affects gene capture, but no dramatic differences for gene capturing were observed.

• The Bulletin of The Korean Astronomical Society
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• v.36 no.1
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• pp.83.2-83.2
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• 2011

I present results from the Spitzer/IRS study to identify massive young stellar objects (YSOs) in the Galactic Center (GC). Our sample of 107 YSO candidates was selected based on Spitzer/IRAC colors in the central 300 pc region of the Milky Way Galaxy. We obtained IRS spectra over $5{\mu}m$ to $35{\mu}m$, and identified massive YSOs by the presence of a $15.4{\mu}m$ shoulder on the absorption profile of $15{\mu}m$ $CO_2$ ice, suggestive of high $CH_3OH$ abundance on $CO_2$ ice grains. This $15.4{\mu}m$ shoulder is clearly observed in 16 sources and possibly observed in an additional 19 sources. We further show that 9 massive YSOs reveal molecular gas-phase absorption from $CO_2$, $C_2H_2$, and/or HCN, which traces warm and dense gas in YSOs. Our results provide the first spectroscopic census of the massive YSO population in the GC.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.4
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• pp.1407-1412
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• 2012

Background & Objectives: Gastric cancer is a leading cause of cancer-related deaths in both sexes in Iran. This study was designed to assess upper GI endoscopic findings among people > 50 years targeted in a mass screening program in a hot-point region. Methods: Based on the pilot results in Guilan Cancer Registry study (GCRS), one of the high point regions for GC-Lashtenesha- was selected. The target population was called mainly using two methods: in rural regions, by house-house direct referral and in urban areas using public media. Upper GI endoscopy was performed by trained endoscopists. All participants underwent biopsies for rapid urea test (RUT) from the antrum and also further biopsies from five defined points of stomach for detection of precancerous lesions. In cases of visible gross lesions, more diagnostic biopsies were taken and submitted for histopathologic evaluation. Results: Of 1,394 initial participants, finally 1,382 persons (702 women, 680 men) with a mean age of $61.7{\pm}9.0$ years (range: 50-87 years) underwent upper GI endoscopy. H. pylori infection based on the RUT was positive in 66.6%. Gastric adenocarcinoma and squamous cell carcinoma of esophagus were detected in seven (0.5%) and one (0.07%) persons, respectively. A remarkable proportion of studied participants were found to have esophageal hiatal hernia (38.4%). Asymptomatic gastric masses found in 1.1% (15) of cases which were mostly located in antrum (33.3%), cardia (20.0%) and prepyloric area (20.0%). Gastric and duodenal ulcers were found in 5.9% (82) and 6.9% (96) of the screened population. Conclusion: Upper endoscopy screening is an effective technique for early detection of GC especially in high risk populations. Further studies are required to evaluate cost effectiveness, cost benefit and mortality and morbidity of this method among high and moderate risk population before recommending this method for the GC surveillance program at the national level.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.227-233
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• 2010

This study examined microbial community structures (MCSs) according to environmental factors through DGGE analysis and comparison in various soils collected from near army bases and gas stations. As a result, the similarities based on DGGE band profiles showed the closer relationship in regional properties than in pollution characteristics, probably due to the degree of weak contamination. The highly contaminated samples with oil revealed low MCS similarities with others in the same region and very low with all the other samples in the other regions. Thus the microbial community structure would more be affected by region-based natural factors than by contamination factors in case of minor pollution. All the dominant culturable bacterial species were involved in firmicutes or high GC Gram+ in a major portion of soil samples and the highly oil-contaminated samples contained Arthrobacter, Bacillus, Methylobacterium, Clavibacter, Streptomyces and Nocardia as reported genera, and Leifsonia as a unreported genus.

• BMB Reports
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• v.37 no.6
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• pp.700-708
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• 2004

The genes located within the p74 gene region of the Choristoneura fumiferana granulovirus (ChfuGV) were identified by sequencing an 8.9 kb BamHI restriction fragment on the ChfuGV genome. The global guanine-cytosine (GC) content of this region of the genome was 33.02%. This paper presents the ORFs within the p74 gene region along with their transcriptional orientations. This region contains a total of 15 open reading frames (ORFs). Among those, 8 ORFs were found to be homologues to the baculoviral ORFs: Cf-i-p , Cf-vi, Cf-vii, Cf-viii (ubiquitin), Cf-xi (pp31), Cf-xii (lef-11), Cf-xiii (sod) and Cf-xv-p (p74). To date, no specific function has been assigned to the ORFs: Cf-i, Cf-ii, Cf-iii, Cf-iv, Cf-v, Cf-vi, Cf-vii, Cf-ix and Cf-x. The most noticeable ORFs located in this region of the ChfuGV genome were ubiquitin, lef-11, sod, fibrillin and p74. The phylogenetic trees (constructed using conceptual products of major conserved ORFs) and gene arrangement in this region were used to further examine the classification of the members of the granulovirus genus. Comparative studies demonstrated that ChfuGV along with the Cydia pomonella granulovirus (CpGV), Phthorimaea operculella granulovirus (PhopGV), Adoxophyes orana granulovirus (AoGV) and Cryptophlebia leucotreta granulovirus (ClGV) share a high degree of amino acids sequence and gene arrangement preservation within the studied region. These results support a previous report, which classified a granuloviruses into 2 distinct groups: Group I: ChfuGV, CpGV, PhopGV and AoGV and Group II: Xestia c-nigrum granulovirus (XcGV) and Plutella xylostella granulovirus (PxGV). The phylogenetic and gene arrangement studies also placed ClGV as a novel member of the Group I granuloviruses.

• The Bulletin of The Korean Astronomical Society
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• v.39 no.1
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• pp.45.2-45.2
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• 2014

We carry out the first survey for globular clusters (GCs) of three galaxies in cosmic voids using Hubble Space Telescope (HST) Advanced Camera for Survey archival F606W and F814W images. While all sample galaxies are classified as early-type galaxies based on ground-based imaging, the high resolution HST images reveal that they are actually spiral galaxies. We identify the point sources with red colors typical for GCs as GC candidates in the color-magnitude diagrams. As a result, we find a significant number of GC candidates. The spatial and radial distribution of GCs show central concentration on each galaxy region. Their mean colors are similar to that of the Milky Way and M31 GCs. The void GCs are somewhat bluer by, and than cluster and field GCs in early-type galaxies with similar luminosity to our samples, but the discrepancy is not significant. We also estimate the specific frequencies of GCs in these galaxies and the values are consistent with those in field and cluster galaxies with similar luminosity. From these results, we suggest that the formation process of void GCs is similar to that of GCs in other environments. The further implications will be discussed.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2018.04a
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• pp.40-40
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• 2018

Pseudostellaria Pax (Caryophyllaceae) is a small genus distributed in temperate region. It consists of 25 species presenting high diversity in Asia. Pseudostellaria longipedicellata S. Lee, K. Heo & S. C. Kim was first announced as new species in 2012. Morphological characters of P. longipedicellata are closely related to those of Psedusotellaria palibiniana and Psedusotellaria okmotoi. These are distinguished from P. longipedicellata by shorter pedicel and puberulent pedicels, respectively and by being distributed allopatically between P. longipedicellata and rest of species. The complete chloroplast genome of P. longipedicellata was successfully rescued from raw reads generated by HiSeq2000. Its total length is 149,626 bp consisting of four regions: large single copy (LSC) region (81,292 bp), small single copy (SSC) region (16,984bp), and inverted repeats (IRs; 25,765 bp per each). It contained 126 genes (81 coding DNA sequence (CDS), eight rRNAs, and 37 tRNAs); 18 genes (seven CDS, four rRNAs, and seven tRNAs) are duplicated in inverted repeat regions. The overall GC content of P. longipedicellata is 36.5% and in the LSC, SSC, and IR regions were 34.3%, 29.3%, and 42.4%, respectively. Based on phylogenetic analysis of chloroplast genomes of P. longipedicellata and relatives species presents clear phylogenetic positions of Pseudostellaria genus. This chloroplast genome will be an important sequence resources for further researches of Pseudostellaria genus.