• Korean Journal of Food Science and Technology
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• v.26 no.6
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• pp.665-669
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• 1994

A rapid gas chromatographic (GC) profiling method was applied to dairy products (milk and cheeses) for the simultaneous analysis of volatile and nonvolatile organic acids. Cheese samples were first made into aqueous samples by dissolving in water. The aqueous samples were then extracted with organic solvents after the acidification and NaCI saturation. The organic layers (diethyl ether : hexane= 1 : 1) were extracted with $NaHCO_3$ saturated solution with subsequent solid-phase extraction of the aqueous phases using Chromosorb P column/diethyl ether followed by triethylamine treatment. The resulting triethylammonium salts of acids were directly converted into volatile tert.-butyldimethylsilyl derivatives, which were analyzed by dual-capillary column GC, and GC-mass spectrometry. From milk and four cheese samples studied, 31 organic acids including 21 fatty acids and other hydroxy and dioic acids were tentatively identified. The amounts of the fatty acids were different among the kinds of cheese and thus the simplified retention index (RI) spectra of organic acids were useful for the visual pattern recognition of each sample, when the Direct Comparision method between cheese and a blind sample were attempted, it was quickly recognized to be a gouda cheese with the 999 ppt match quality value.

• The Korean Journal of Malacology
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• v.32 no.2
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• pp.127-131
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• 2016

The natives of the genus Corbicula have shown worldwide dispersion in recent times, which has caused great ecological and economic impacts on the introduced ecosystems. The species reported from the genus have been consumed as food and explored for medicine with pharmacological activity. Consequently, the demand of Corbicula sp. in the South Korean domestic market has increased and so also it's associated import to the country. However, due to the absence of identification keys of imported Corbicula, the market is facing confronting situations. We hypothesized that the mitochondrial Cytochrome Oxidase I gene (CO-I) based molecular profiling could be a necessary technique for identification of Corbicula sp. in the South Korea domestic market. The genetic analysis identified both Corbicula japonica and Corbicula fluminea from the market foods. C. japonica and C. fluminea are inhabitants in Korea, but C. fluminea production has decreased in Seomjingang river basin. Therefore, C. fluminea identified from this study, is expected to be imported from China and would have a mixed sales in Seomjingang river side basin.

• Asian-Australasian Journal of Animal Sciences
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• v.31 no.2
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• pp.189-197
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• 2018

Objective: Hemicastration is a unilateral orchiectomy to remove an injured testis, which can induce hormonal changes and compensatory hypertrophy of the remaining testis, and may influence spermatogenesis. However, the underlying molecular mechanisms are poorly understood. Here, we investigated the impact of hemicastration on remaining testicular function. Methods: Prepubertal mice (age 24 days) were hemicastrated, and their growth was monitored until they reached physical maturity (age 72 days). Subsequently, we determined testis DNA methylation patterns using reduced representation bisulfite sequencing of normal and hemicastrated mice. Moreover, we profiled the testicular gene expression patterns by RNA sequencing (RNA-seq) to examine whether methylation changes affected gene expression in hemicastrated mice. Results: Hemicastration did not significantly affect growth or testosterone (p>0.05) compared with control. The genome-wide DNA methylation pattern of remaining testis suggested that substantial genes harbored differentially methylated regions (1,139) in gene bodies, which were enriched in process of protein binding and cell adhesion. Moreover, RNA-seq results indicated that 46 differentially expressed genes (DEGs) involved in meiotic cell cycle, synaptonemal complex assembly and spermatogenesis were upregulated in the hemicastration group, while 197 DEGs were downregulated, which were related to arachidonic acid metabolism. Integrative analysis revealed that proteasome 26S subunit ATPase 3 interacting protein gene, which encodes a protein crucial for homologous recombination in spermatocytes, exhibited promoter hypomethylation and higher expression level in hemicastrated mice. Conclusion: Global profiling of DNA methylation and gene expression demonstrated that hemicastration-induced compensatory response maintained normal growth and testicular morphological structure in mice.

• Journal of Microbiology and Biotechnology
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• v.28 no.4
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• pp.645-651
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• 2018

The carcinogenicity of chemicals in the environment is a major concern. Recently, numerous studies have attempted to develop methods for predicting carcinogenicity, including rodent and cell-based approaches. However, rodent carcinogenicity tests for evaluating the carcinogenic potential of a chemical to humans are time-consuming and costly. This study focused on the development of an alternative method for predicting carcinogenicity using quantitative PCR (qPCR) and colon cancer stem cells. A toxicogenomic method, mRNA profiling, is useful for predicting carcinogenicity. Using microarray analysis, we optimized 16 predictive gene sets from five carcinogens (azoxymethane, 3,2'-dimethyl-4-aminobiphenyl, N-ethyl-n-nitrosourea, metronidazole, 4-(n-methyl-n-nitrosamino)-1-(3-pyridyl)-1-butanone) used to treat colon cancer stem cell samples. The 16 genes were evaluated by qPCR using 23 positive and negative carcinogens in colon cancer stem cells. Among them, six genes could differentiate between positive and negative carcinogens with a p-value of ${\leq}0.05$. Our qPCR-based prediction system for colon carcinogenesis using colon cancer stem cells is cost- and time-efficient. Thus, this qPCR-based prediction system is an alternative to in vivo carcinogenicity screening assays.

• Journal of Microbiology and Biotechnology
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• v.30 no.10
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• pp.1467-1479
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• 2020

Profiling the transcriptome changes involved in xylose metabolism by the fungus Trichoderma reesei allows for the identification of potential targets for ethanol production processing. In the present study, the transcriptome of T. reesei HJ-48 grown on xylose versus glucose was analyzed using next-generation sequencing technology. During xylose fermentation, numerous genes related to central metabolic pathways, including xylose reductase (XR) and xylitol dehydrogenase (XDH), were expressed at higher levels in T. reesei HJ-48. Notably, growth on xylose did not fully repress the genes encoding enzymes of the tricarboxylic acid and respiratory pathways. In addition, increased expression of several sugar transporters was observed during xylose fermentation. This study provides a valuable dataset for further investigation of xylose fermentation and provides a deeper insight into the various genes involved in this process.

• Korean Journal of Food Science and Technology
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• v.25 no.4
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• pp.373-378
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• 1993

A rapid gas chromatographic profiling method for the simultaneous analysis of free fatty and other acids was applied to vegetable oils. Oil samples were dissolved in dichloromethane and the free acids were extracted with saturated $NaHCO_3$ solution. The aqueous extract was acidified and then loaded onto the Chromosorb P column for the extraction. The acids were eluted with diethyl ether selectively from Chromosorb P column and were treated with triethylamine to prevent the losses of volatile acids. Several long chain fatty acids were detected from soybean oil, rice-bran oil, sesame oil and perilla oil. Various organic acids including odd number fatty acids were detected in crude oil, especially sesame oil. Arachidic acid from perilla oil and vanillic acid from sesame oil, which were not reported before were detected. The content ratio of free linoleic acid to oleic acid was $1.02{\sim}1.18$, which was similar to the reported data. When the GC profile of organic acids were simplified to their corresponding retention index spectra of bar graphical forms, they presented characteristic pattern of each vegetable oil that can be quickly recognized.

• Journal of the Korean BIBLIA Society for library and Information Science
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• v.31 no.3
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• pp.5-27
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• 2020

This study aimed at analyzing the keywords and authors of the KCI listed theological journals and finding the official research performance of Korean theology. This study divided the periods in two according to how duplicate the authors are and found hierarchical clusters by analyzing 92 keywords using the McQuitty method. In analyzing them, the Ward linkage method was selected to prevent the authors from gathering into a small number of clusters. Also, to find how influential the journals were to the keywords, the keywords and the percentage of the journals in them were presented together. The authors were analyzed in terms of deciding the positions of them using normalized performance index representing the number of journals and growth index as a growth tendency. Especially, significant researchers were all reformed theologians in a growth index. In the analysis of the keywords of the KCI journals and the authors, the main subject terms of the Korean theology were related to systematic theology and the New Testament. By analyzing the KCI listed journals as the Korean official citation index, this study has made a difference to the advanced articles analyzing the non-KCI listed theological journals.

• Journal of the Korean Vacuum Society
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• v.7 no.1
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• pp.51-58
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• 1998

ZnS and TB-doped ZnS (ZnS:Tb) thin films were grown by traveling wave reactor atomic layer epitaxy (AKE) and characterized using materials and surface analysis techniques. $ZnCl_2$, $H_2$S,and tris(2,26,6-tetramethyl-3,5-heptandionato) terbium ($Tb(TMHD)_3$) were used as the precursors in the growth of ZnS:Tb films. The dependence of Cl content in ZnS films on growth temperature was investigated using Rutherford backscattering spectrometry. The Cl content decreased from approximately 9 at.% to 1 at. % as increasing the growth temperature from 400 to $500^{\circ}C$. The segregation of Cl in near surface region was also observed by depth profiling using Auger electron spectroscopy. Scanning electron microscopic studies showed that the ALE-grown ZnS and ZnS:Tb film during ALE process using $Tb(TMHD)_3$was also investigated. Approximately 1 at.% of O in ZnS:Tb(0.5 at.%) film which showed a good crystallinity of hexagonal 2H structure.

• Journal of Microbiology
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• v.45 no.1
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• pp.21-28
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• 2007

In order to search for specific genotypes related to this unique phenotype, we used whole genomic DNA microarray to characterize the genomic diversity of Helicobacter pylori (H. pylori) strains isolated from clinical patients in China. The open reading frame (ORF) fragments on our microarray were generated by PCR using gene-specific primers. Genomic DNA of H. pylori 26695 and J99 were used as templates. Thirty-four H. pylori isolates were obtained from patients in Shanghai. Results were judged based on In(x) transformed and normalized Cy3/Cy5 ratios. Our microarray included 1882 DNA fragments corresponding to 1636 ORFs of both sequenced H. pylori strains. Cluster analysis, revealed two diverse regions in the H. pylori genome that were not present in other isolates. Among the 1636 genes, 1091 (66.7%) were common to all H. pylori strains, representing the functional core of the genome. Most of the genes found in the H. pylori functional core were responsible for metabolism, cellular processes, transcription and biosynthesis of amino acids, functions that are essential to H. pylori's growth and colonization in its host. In contrast, 522 (31.9%) genes were strain-specific genes that were missing from at least one strain of H. pylori. Strain-specific genes primarily included restriction modification system components, transposase genes, hypothetical proteins and outer membrane proteins. These strain-specific genes may aid the bacteria under specific circumstances during their long-term infection in genetically diverse hosts. Our results suggest 34 H. pylori clinical strains have extensive genomic diversity. Core genes and strain-specific genes both play essential roles in H. pylori propagation and pathogenesis. Our microarray experiment may help select relatively significant genes for further research on the pathogenicity of H. pylori and development of a vaccine for H. pylori.

• Asian-Australasian Journal of Animal Sciences
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• v.30 no.7
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• pp.1037-1047
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• 2017

Objective: Despite an increasing number of investigations into the pathophysiology of necrotic enteritis (NE) disease, etiology of NE-associated diseases, and gene expression profiling of NE-affected tissues, the microRNA (miRNA) profiles of NE-affected poultry have been poorly studied. The aim of this study was to induce NE disease in the genetically disparate Fayoumi chicken lines, and to perform non-coding RNA sequencing in the intestinal mucosal layer. Methods: NE disease was induced in the Fayoumi chicken lines (M5.1 and M15.2), and non-coding RNA sequencing was performed in the intestinal mucosal layer of both NE-affected and uninfected chickens to examine the differential expression of miRNAs. Next, quantitative real-time polymerase chain reaction (real-time qPCR) was performed to further examine four miRNAs that showed the highest fold differences. Finally, bioinformatics analyses were performed to examine the four miRNAs target genes involvement in the signaling pathways, and to examine their interaction. Results: According to non-coding RNA sequencing, total 50 upregulated miRNAs and 26 downregulated miRNAs were detected in the NE-induced M5.1 chickens. While 32 upregulated miRNAs and 11 downregulated miRNAs were detected in the NE-induced M15.2 chickens. Results of real-time qPCR analysis on the four miRNAs (gga-miR-9-5p, gga-miR-20b-5p, ggamiR-196-5p, and gga-let-7d) were mostly correlated with the results of RNAseq. Overall, ggamiR-20b-5p was significantly downregulated in the NE-induced M5.1 chickens and this was associated with the upregulation of its top-ranking target gene, mitogen-activated protein kinase, kinase 2. Further bioinformatics analyses revealed that 45 of the gene targets of gga-miR-20b-5p were involved in signal transduction and immune system-related pathways, and 35 of these targets were predicted to interact with each other. Conclusion: Our study is a novel report of miRNA expression in Fayoumi chickens, and could be very useful in understanding the role of differentially expressed miRNAs in a NE disease model.