• Proceedings of the KIEE Conference
• /
• 1999.07d
• /
• pp.1891-1894
• /
• 1999

We can classify the scratches after CMP process into micro-scratch and macro-scratches according to the scratch size, scratch intensity and defect map, etc. The micro-scratches on wafer after CMP process are discussed in this paper. From many causes, major factor that influences the formation of micro-scratch is known as particle size distribution of slurry.(1) It is indefinite what size or type of particle can cause micro-scratch on wafer surface, but there is possibility caused by large particle over 1um. The best way for controlling these large particle to inflow is to use the slurry filter on POU(Point of user). But the slurry filter(especially, depth-type filter) has sometimes the problem which makes more sever micro-scratches on wafer surface after CMP. We studied that depth-type slurry filter has what kind of week-points and the number of scratch could be reduced by lowering slurry flow rate and by using high spray bar which sprays DIW on polishing pad with high pressure.

• Asian-Australasian Journal of Animal Sciences
• /
• v.29 no.10
• /
• pp.1407-1415
• /
• 2016

Isolation and culture of spermatogonial stem cells (SSCs) are attractive for production of genetic modified offspring. In the present study, buffalo spermatogonial stem-like cells were isolated, cultured and expression pattern of different germ cell marker genes were determined. To recover spermatogonia, testes from age 3 to 7 months of buffalo were decapsulated, and seminiferous tubules were enzymatically dissociated. Two types of cells, immature sertoli cell and type A spermatogonia were observed in buffalo testes in this stage. Germ cell marker genes, OCT3/4 (Pou5f1), THY-1, c-kit, PGP9.5 (UCHL-1) and Dolichos biflorus agglutinin, were determined to be expressed both in mRNA and protein level by reverse transcription polymerase chain reaction and immunostaining in buffalo testes and buffalo spermatogonial stem-like cells, respectively. In the following, when the isolated buffalo buffalo spermatogonial stem-like cells were cultured in the medium supplemented 2.5% fetal bovine serum and 40 ng/mL glial cell-derived neurotrophic factor medium, SSCs proliferation efficiency and colony number were significantly improved than those of other groups (p<0.05). These findings may help in isolation and establishing long term in vitro culture system for buffalo spermatogonial stem-like cells, and accelerating the generation of genetic modified buffaloes.

• Journal of Microbiology and Biotechnology
• /
• v.15 no.6
• /
• pp.1330-1336
• /
• 2005

Polyhydroxyalkanoic acid (PHA) inclusion bodies were analyzed in situ by $^{13}C$-nuclear magnetic resonance ($^{13}C$-NMR) spectroscopy. The PHA inclusion bodies studied were composed of poly(3-hydroxybutyrate) or poly(3hydroxybutyrate-co-4-hydroxybutyrate), which was accumulated in Hydrogenophaga pseudoflava, and medium-chain-length PHA (MCL-PHA), which was accumulated in Pseudomonas fluorescens BM07 from octanoic acid or 11-phenoxyundecanoic acid (11-POU). The quantification of the $^{13}C$-NMR signals was conducted against a standard compound, sodium 2,2-dimethyl-2-silapentane-5-sulfonate (DSS). The chemical shift values for the in vivo NMR spectral peaks agreed well with those for the corresponding purified PHA polymers. The intracellular degradation of the PHA inclusions by intracellular PHA depolymerase(s) was monitored by in vivo NMR spectroscopy and analyzed in terms of first-order reaction kinetics. The H. pseudoflava cells were washed for the degradation experiment, transferred to a degradation medium without a carbon source, but containing 1.0 g/l ammonium sulfate, and cultivated at $35^{\circ}C$ for 72 h. The in vivo NMR spectra were obtained at $70^{\circ}C$ for the short-chain-length PHA cells whereas the spectra for the aliphatic and aromatic MCL-PHA cells were obtained at $50^{\circ}C\;and\;80^{\circ}C$, respectively. For the H. pseudoflava cells, the in vivo NMR kinetics analysis of the PHA degradation resulted in a first-order degradation rate constant of 0.075/h ($r^{2}$=0.94) for the initial 24 h of degradation, which was close to the 0.050/h determined when using a gas chromatographic analysis of chloroform extracts of sulfuric acid/methanol reaction mixtures of dried whole cells. Accordingly, it is suggested that in vivo $^{13}C$-NMR spectroscopy is an important tool for studying intracellular PHA degradation in terms of kinetics.

• Journal of Biosystems Engineering
• /
• v.41 no.2
• /
• pp.85-92
• /
• 2016

Background: The same plant, Camellia sinensis, is used to produce all types of tea, and the differences among the various types arise from the different processing steps that are used. Based on the degree of fermentation, tea can be classified as black, green, white, or oolong tea. Of these, black tea is the most or fully fermented tea. The oxidized polyphenolic compounds such as theaflavins (TF) and thearubigins (TR) formed during fermentation are responsible for the color, taste, flavor, and aroma of black tea. Results: Research indicates that an optimum ratio of TF and TR (1:10) is required to ensure a quality cup of tea. The concentrations of TF and TR as well as desirable quality characteristics increase as fermentation time increases, reaching optimum levels and then degrading if the fermentation time is prolonged. It is also necessary to control the environment for oxidation. There are no established environment conditions that must be maintained during the fermentation of the ruptured tea leaves. However, in most cases, the process is performed at a temperature of $24-29^{\circ}C$ for 2-4 h or 55-110 min for orthodox tea or crush, tear, and curl (CTC) black tea, respectively, under a high relative humidity of 95-98% with an adequate amount of oxygen. Conclusion: The polyphenolic compounds in black tea such as TF and TR as well as un-oxidized catechins are responsible for the health benefits of tea consumption. Tea is rich in natural antioxidant activities and is reported to have great potential for the management of various types of cancers, oral health problems, heart disease and stroke, and diabetes and to have other health benefits such as the ability to detoxify, improve urine and blood flow, stimulate, and improve the immune system.

• Journal of the Korean Academy of Child and Adolescent Psychiatry
• /
• v.29 no.2
• /
• pp.62-72
• /
• 2018

Objectives: The molecular mechanisms underlying attention-deficit hyperactivity disorder (ADHD) remain unclear. Therefore, this study aimed to identify the genetic susceptibility loci for ADHD in Korean children with ADHD. We performed a case-control and a family-based genome-wide association study (GWAS), as well as genome-wide quantitative trait locus (QTL) analyses, for two symptom traits. Methods: A total of 135 subjects (71 cases and 64 controls), for the case-control analysis, and 54 subjects (27 probands and 27 unaffected siblings), for the family-based analysis, were included. Results: The genome-wide QTL analysis identified four single nucleotide polymorphisms (SNPs) (rs7684645 near APELA, rs12538843 near YAE1D1 and POU6F2, rs11074258 near MCTP2, and rs34396552 near CIDEA) that were significantly associated with the number of inattention symptoms in ADHD. These SNPs showed possible association with ADHD in the family-based GWAS, and with hyperactivity-impulsivity in genome-wide QTL analyses. Moreover, association signals in the family-based QTL analysis for the number of inattention symptoms were clustered near genes IL10, IL19, SCL5A9, and SKINTL. Conclusion: We have identified four QTLs with genome-wide significance and several promising candidates that could potentially be associated with ADHD (CXCR4, UPF1, SETD5, NALCN-AS1, ERC1, SOX2-OT, FGFR2, ANO4, and TBL1XR1). Further replication studies with larger sample sizes are needed.

• Development and Reproduction
• /
• v.19 no.3
• /
• pp.119-126
• /
• 2015

The suitable feeder cell layer is important for culture of embryonic stem (ES) cells. In this study, we investigated the effect of two kinds of the feeder cell, MEF cells and STO cells, layer to mouse ES (mES) cell culture for maintenance of stemness. We compare the colony formations, alkaline phosphatase (AP) activities, expression of pluripotency marker genes and proteins of D3 cell colonies cultured on MEF feeder cell layer (D3/MEF) or STO cell layers (D3/STO) compared to feeder free condition (D3/-) as a control group. Although there were no differences to colony formations and AP activities, interestingly, the transcripts level of pluripotency marker genes, Pou5f1 and Nanog were highly expressed in D3/MEF (79 and 93) than D3/STO (61and 77) or D3/- (65 and 81). Also, pluripotency marker proteins, NANOG and SOX-2, were more synthesized in D3/MEF ($72.8{\pm}7.69$ and $81.2{\pm}3.56$) than D3/STO ($32.0{\pm}4.30$ and $56.0{\pm}4.90$) or D3/- ($55.0{\pm}4.64$ and $62.0{\pm}6.20$). These results suggest that MEF feeder cell layer is more suitable to mES cell culture.

• BMB Reports
• /
• v.43 no.12
• /
• pp.830-835
• /
• 2010

Epigenetic modification of the genome through DNA methylation is the key to maintaining the differentiated state of human embryonic stem cells (hESCs), and it must be reset during differentiation by retinoic acid (RA) treatment. A genome-wide methylation/gene expression assay was performed in order to identify epigenetic modifications of RA-treated hESCs. Between undifferentiated and RA-treated hESCs, 166 differentially methylated CpG sites and 2,013 differentially expressed genes were discovered. Combined analysis of methylation and expression data revealed that 19 genes (STAP2, VAMP8, C10orf26, WFIKKN1, ELF3, C1QTNF6, C10orf10, MRGPRF, ARSE, LSAMP, CENTD3, LDB2, POU5F1, GSPT2, THY1, ZNF574, MSX1, SCMH1, and RARB) were highly correlated with each other. The results provided in this study will facilitate future investigations into the interplay between DNA methylation and gene expression through further functional and biological studies.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2001.11b
• /
• pp.185-188
• /
• 2001

Chemical mechanical polishing(CMP) process is widely used for global planarization of inter-metal dielectric (IMD) layer and inter-layer dielectric (ILD) for deep sub-micron technology. However, as the IMD and ILD layer gets thinner, defects such as micro-scratch lead to severe circuit failure, which affect yield. In this paper, for the improvement of CMP process, deionized water (DIW) pressure, purified $N_2 \; (PN_2)$ gas, slurry filter and high spray bar were installed. Our experimental results show that DIW pressure and $PN_2$ gas factors were not related with removal rate, but edge hot-spot of patterned wafer had a serious relation. Also, the filter installation in CMP polisher could reduce defects after CMP process, it is shown that slurry filter plays an important role in determining consumable pad lifetime. The filter lifetime is dominated by the defects. However, the slurry filter is impossible to prevent defect-causing particles perfectly. Thus, we suggest that it is necessary to install the high spray bar of de-ionized water (DIW) with high pressure, to overcome the weak-point of slurry filter. Finally, we could expect the improvements of throughput, yield and stability in the ULSI fabrication process.

• Nutrition Research and Practice
• /
• v.10 no.6
• /
• pp.616-622
• /
• 2016

BACKGROUND/OBJECTIVES: In Argentina, obesity prevalence rose from 14.6% in 2005 to 20.8% in 2013. Although the number of studies on noncommunicable diseases and dietary patterns as a unique dietary exposure measure has increased, information on this topic remains scarce in developing countries. This is the first population-based study investigating the association between diet and obesity using a dietary pattern approach in Argentina. We aimed (a) to identify current dietary patterns of the population of $C{\acute{o}}rdoba$ city, (b) to investigate its association with obesity prevalence, and (c) to identify and describe dietary patterns from the subgroup of people with obesity. SUBJECTS/METHODS: The $C{\acute{o}}rdoba$ Obesity and Diet Study (CODIES) was conducted in $C{\acute{o}}rdoba$ city by using a random sample of n = 4,327 subjects between 2005 and 2012. Empirically derived dietary patterns were identified through principal component factor analysis. A multiple logistic regression analysis was used to investigate the association of dietary patterns with obesity. RESULTS: Four dietary patterns were identified, called "Starchy-Sugar", "Prudent", "Western", and "Sugary drinks". High scores for the "Western" pattern (with strongest factor loading on meats/eggs, processed meats, and alcohol) showed a positive association with obesity (OR: 1.33, 95% CI: 1.06-1.67, for third versus first tertile of factor score). "Meats/Cheeses" and "Snacks/Alcohol" patterns emerged in people with obesity. CONCLUSIONS: The findings suggest that high adherence to the "Western" pattern promoted obesity in this urban population. In addition, people with obesity showed characteristic dietary patterns that differ from those identified in the overall population.

• Journal of the Economic Geographical Society of Korea
• /
• v.18 no.2
• /
• pp.206-223
• /
• 2015

Korea government has established 67 agri-food clusters for 10 years. In recent years, the criticism of this policy has significantly increased due to trials and errors. The purpose of this study is to suggest some policy implications for the focal firm and governance mechanism through the case study of Muan Loess Sweet Potato Cluster. The concept of netchain was used as an analysis framework. Muan Loess Sweet Potato Cluster doesn't operate an integrated production organization and focal firm doesn't exercise its influence as well. The cluster agency, focal firm of Cluster, is important for a Agri-food Cluster to grow continuously. it must have a great influence on organizing networks and an enough capacity for forming coordination mechanism. Also, Local governments must actively be involved in the network formation and coordination and inform the vision and plan for development.