• Korean Journal of Veterinary Service
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• v.47 no.1
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• pp.41-48
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• 2024

Feline bocavirus (FBoV) is considered an emerging pathogen recently identified in domestic cats worldwide. To date, three species of FBoVs (FBoV-1, FBoV-2, and FBoV-3) have been reported, but there are no reports identifying FBoVs in Korea. In this study, we detected novel FBoVs for the first time in Korea in captive wild felids (four European lynx and a lion) kept at Seoul Zoo. In FBoV-positive fecal samples, not only singular infections but also dual or triple infections with three different species of FBoVs were confirmed, suggesting that three species of FBoVs are already introduced and co-circulated in susceptible host animals in Korea. These results will help expand our understanding of the geographical distribution and host susceptibility of novel FBoVs. Further studies are necessary to determine the infection status of FBoVs in domestic cats and the genetic characteristics of the viruses circulating in Korea.

• Investigative Magnetic Resonance Imaging
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• v.6 no.1
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• pp.35-40
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• 2002

Purpose : To evaluate the NMR relaxation properties and imaging characteristics of tissue-specificity for a newly developed macromolecular MR agent. Materials and methods : Phthalocyanine (PC) was chelated with paramagnetic ion, Mn.2.01g (5.2 mmol) of Phthalocyanine was mixed with 0.37g (1.4 mmol) of Mn chloride at $310^{\circ}C$ for 36 hours and then purified by chromatography (CHC13/CH3OH 98/2 v/v, Rf, 0.76) to obtain 1.04g (46%) of MnPC (molecular weight= 2000d). The $T1}T2$ relaxivity of MnPC was measured in 1.5T(64 MHz) MR using 0.1 mM MnPC. The MR image characteristics of MnPC was evaluated using spin-echo (TR/TE=500/14 msec) and gradient-echo (FLASH) (TR/TE=80/4 msec, flip angle=60) techniques in 1.57 MR scanner. The images of rabbit liver were obtained every 10 minutes up to 4 hours. To study the effect of concentration on image, 20 mM, 50 mM, 100 mM of MnPC were tested. Results : The relaxivities of MnPC at 1.5T(64MHz) were Rl=7.28 $mM^{-1}S^{-1},{\;}R2=55.56mM^{-1}S^{-1}$. Compared to the values of Gd-DTPA (Rl[=4.8 $mM^{-1}S^{-1})$], R2[=5.2 $mM^{-1}S^{-1}])$]), both T1/T2 relaxivities of MnPC were higher than those of Gd-DTPA. For both of SE and FLASH techniques, the contrast enhancement reached maximum at 10 minutes after bolus injection and the enhancement continued for more than 2 hours. When compared with small molecular weight liver agents such as Gd-EOB-DTPA, Gd-BOPTA and MnDPDP, MnPC was characterized by more prolonged enhancement time. The time course of MR images also revealed biliary excretion of MnPC. Conclusion : We developed a new macromolecular MR agent, MnPC. The relaxivities of MnPC were higher than those of small molecular weight Gd-chelate. Hepatic uptake and biliary excretion of MnPC suggests that this agent is a new liver-specific MR agent.

• Journal of The Korean Association For Science Education
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• v.25 no.7
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• pp.728-735
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• 2005

In this study, relationships between student the cognitive affective characteristics and conceptual understanding from individual computer-assisted instruction were investigated. Tests regarding field dependence-independence, learning strategy, self-regulated ability, visual learning preference, goal orientation, self-efficacy on ability, and computer attitude were administered. After having been taught by means of a CAl program, a conception test on molecular motion was administered. It was found that student conceptual understanding was significantly related to field independence, learning strategy, self-regulated ability among the cognitive characteristics and visual learning preference, goal orientation, self-efficacy on ability among the affective characteristics. Multiple regression analysis of the cognitive characteristics on conceptual understanding found that field dependence-independence was the most significant predictor. Self-regulated ability and a deep learning strategy were also found to have predictive power. Lastly, analysis of the affective characteristics, visual learning preference and self-efficacy on ability exposed them to be significant predictors of student conceptual understanding.

• Journal of the Korean Society of Clothing and Textiles
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• v.30 no.3 s.151
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• pp.386-395
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• 2006

Chitosan, a natural polymer has been used to nonwoven fabrics based polypropylene for sanitary top sheets. The changes in mechanical properties relating to the surface structure of functionally improved nonwoven fabrics were investigated with respect to the molecular weight and concentration of chitosan that was used. Low molecular weight(LMW) chitosan treated fabric was found to be evenly coated on the fabrics. It was shown that the bending and shearing characteristics of chitosan treated fabrics increased, which helped to make it stronger and harder, while shape stability improved following treatment using high molecular weight(HMW) chitosan. And the surface structure of treated fabrics was smooth and the sensitivity of its bulk improved somewhat. The treated fabrics were not overly stiff because the increase in Koshi value was not considerable compared to that of the bending characteristics. In the change of hand value relating to chitosan treated fabrics, THV generally improved. In the case of a 0.5$\%$ chitosan, HMW chitosan treated fabrics produced better THV than LMW chitosan treated fabrics. However, in the case of a 1.0$\%$ chitosan, THV of LMW chitosan treated fabrics produced outstanding results.

• Journal of Radiation Protection and Research
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• v.28 no.3
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• pp.165-172
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• 2003

Humic acids present in the soils at the vicinity of domestic atomic power plants(NPPs), located in Yeongkwang(YK), Uljin(UJ), Kori(KR), Koseong(KS), Wolseong(WS) area were isolated, and characterized using elemental analysis and UV/Vis, IR, CPMAS $^{13}C$ NMR spectroscopic methods. The characteristics were compared with one another and with commercial humic acid (Aldrich Co.). Molecular size distributions of the humic acids were determined using a stirred cell ultrafiltration technique. The results of elemental analysis showed that soil humic acid from UJ contains higher oxygen content than humic acids from KR and KS (O/C ratios: 0.51 (UJHA) us. 0.45(KRHA), 0.43(KSHA)). The molecular size distribution revealed that the soil humic acids of UJ and YK contained a higher percentage of larger molecules of > 30,000 daltons, compared to those of KR and KS. The spectral features obtained from UV/vis., IR and CPMAS $^{13}C$ NMR showed that the aromatic character and oxygen containing functional groups in the humic acids from UJ and YK were relatively higher than those of KR and KS. These results indicate that the soil humic acids from UJ and YK were in a higher degree of humification, which may suggest higher affinity of the humic acids with radionuclides released in the soil environments.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.15-22
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• 2008

This study was carried out to investigate physical and chemical characteristics of the distillates and residue of Athabasca oilsand bitumen obtained from Canada, using a vacuum distillation unit. The distillates and residue produced from the vacuum distillation were characterized through atomic analysis, SARA analysis, and measurement of boiling point distribution, molecular weight, and API gravity. The vacuum distillation equipment consisted of a 6-litter volume vessel, a glass-packed column, a condenser, a reflux device, a flask fer collecting distillates, and a temperature controller. The cutting of distillates was performed with four steps under the condition of full vacuum and maximum temperature of $320^{\circ}C$. The results showed that the sulfur amount and average molecular weight of the distillates were significantly reduced compared to those of oilsand bitumen. As the cutting temperature increased, the hydrogen amount decreased but the sulfur amount and average molecular weight increased in the distillates.

• Journal of Energy Engineering
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• v.17 no.1
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• pp.38-45
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• 2008

In this work, we investigated the variation of physical and chemical characteristics of solvent-insolubles and solvent-solubles in Canada's Athabasca oil sands by solvent-insolubles experiments. N-Heptane, n-Hexane, and n-Pentane were tested for solvents and asphaltenes were separated from maltenes by using a modified ASTM D 3279 method. Elemental analysis, boiling point distribution (SIMDIS), molecular weight distribution, heavy metal contents, API gravity, viscosity and SARA fractions were measured for thorough samples. The asphaltenes-removed maltenes contained less sulfur and heavy metal amounts and had lower molecular weight than the original bitumen. N-Pentane solvent could lower sulfur and heavy metal amounts, molecular weight, and viscosity of maltenes compared to the other solvents. Eventually, we confirmed that the obtained experimental data could be used as basic informations of bitumen upgrading processes for the production of SCO (synthetic crude oil).

• Journal of Plant Biotechnology
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• v.42 no.4
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• pp.312-325
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• 2015

In this review, we summarized the trends of genomics and transcriptomics research on peach, a model species of Rosaceae. Peach genome maps have been developed from various progeny groups with many next-generation sequencing (NGS) based single nucleotide polymorphism markers. Molecular markers of qualitative traits and quantitative trait loci (QTL) such as fruit characteristics, blooming date, and disease resistance have been analyzed. Among many characteristics, markers related to flesh softening and flesh adhesion are useful for marker assisted selection. Through comparative genomics, peach genome has been compared to the genome of Arabidopsis, Populus, Malus, and Fragaria species. Through transcriptomics and proteomics, fruit growth and development, and flavonoid synthesis, postharvest related transcriptomes and disease resistance related proteins have been reported. Recently, development of NGS based markers, construction of core collection of germplasm, and genotyping of various progenies have been preceded. In the near future, accurate QTL analysis and identification of useful genes are expected to establish a foundation for effective molecular breeding.

• Journal of Chest Surgery
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• v.30 no.7
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• pp.701-707
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• 1997

Although many reseraches have been persued to detect the molecular tumor marker to define the cancer, ideal tumor marker which speak for the characteristics of malignancy and has high sensitivity and specificity is not known. One of the characteristics of the malignant cells is indefinite proliferative potential, in other word, immortality. The expression of telomerase and stabilization of te10meres are con omitant with the attaiunent of immortality in tumor cells; thus the measurement of telomerase activity in clinically obtained tumor samples may provide important information which would be useful as a diagnostic marker to detect immortal cancer cells. Telomerase activity was analyzed in 12 non-small cell . lung cancer cell lines and 41 primary non-small cell lung cancers with the use of a PCR-based assay. All the cell lines and the majority of tumors displayed telomerase activity, but telomerase was not detectable in most of the corresponding pathologically-normal tissues. Telomere length was not correlated with telomerase activity. The present study indicate that measurement of telomerase activity may be useful as a molecular tumor marker in non-small cell lung cancer.

• Tuberculosis and Respiratory Diseases
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• v.60 no.2
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• pp.187-193
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• 2006

Background : Normal cell proliferation and viability is strongly depends on the availability of metabolic energy and the maintenance of the appropriate adenylate-nucleotide pools. Hypothetically, changes in adenylate kinase (AK) expression could therefore be associated with adaptation to altered growth characteristics or inversely altered growth characteristics of proliferating cells could drive the changes in the metabolic profile. This study investigated whether the expression of either AK1 or a Mycobacterium tuberculosis adenylate kinase mutant which has the same catalytic activity of AK1 could affect the growth rate of slow-growing BCG. Method : Recombinant BCGs, which were cloned the human muscle-type adenylate kinase synthetic gene (AK1) and adenylate kinase mutation gene (AKmtDM) of Mycobacterium tuberculosis into the Mycobacterium/E.coli expression vectors, were constructed. Recombinant BCGs and wild-type BCG were cultured in 7H9 media and the optical density at 600nm was measured at intervals of 2-3 days. Result : There wasn't the growth rate change induced by AK1 or AKmtDM expression in recombinant BCGs. Conclusion : The expression of AK1 or Mycobacterium tuberculosis adenylate kinase mutant in BCG does not affect the growth rate of BCG.