• 대한수의학회지
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• 제29권1호
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• pp.37-44
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• 1989

This paper dealt with the distribution of Shigella spp. on 5 piggeries in Taegu and Kyungpook during the period from August to October 1987. Isolated Shigella were examined for serogrouping, antimicrobial drug resistance and detection of R plasmid. Genetic properties of R plasmid in Shigella have examined to fertility inhibition (Fi) and gel electrophoresis was performed for the isolation of plasmid DNA. The results obtained were summarised as followings; 1. Of total 2,978 samples from 5 piggeries, 82 strains (2.8%) of Shigella spp. were isolated from 82 samples. The isolated strains were identified as S dysenteriae (60 strains), S flexneri (20 strains) and S sonnei (2 strains). 2. Of the 82 strains examined 67 (95.1%) were resistant to one or more antibiotics, such as ampicillin (Am), chloramphenicol (Cm), kanamycin (Km), nalidixic acid (Na), rifampicin (Rf), streptomycin (Sm), sulfademethoxine (Su), and tetracycline (Tc) and higher resistant to Su (90.2%), Sm (63.4%) and Tc (63.4%). 3. Of the 78 resistant Shigella strains 26 (33.3%) harbored conjugative R plasmids and the transfer frequency of Sm (50.0%), Cm(33.3%) resistance was much higher than that of the other drug resistance. 4. The most common resistant patterns were SmSuTc, Su and AmSmSuTc. 5. Out of the 26 Shigella R plasm ids examined for Fi, 14(53.8%) were $Fi^+$ and the remainder were $Fi^-$. 6. The plasmid DNA profiles in Shigella spp. (9 strains) isolated from pigs were confirmed as being 2 to 9 fragments by the gel electrophoresis. Their molecular size ranged 2.17 to 87.62 kilobase (Kb). All strains of Shigella spp. consisted in 15.4 Kb plasmids.

• Molecules and Cells
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• 제40권10호
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• pp.714-730
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• 2017

Pre-mRNA splicing further increases protein diversity acquired through evolution. The underlying driving forces for this phenomenon are unknown, especially in terms of gene expression. A rice alternatively spliced transcript detection microarray (ASDM) and RNA sequencing (RNA-Seq) were applied to differentiate the transcriptome of 4 representative organs of Oryza sativa L. cv. Ilmi: leaves, roots, 1-cm-stage panicles and young seeds at 21 days after pollination. Comparison of data obtained by microarray and RNA-Seq showed a bell-shaped distribution and a co-lineation for highly expressed genes. Transcripts were classified according to the degree of organ enrichment using a coefficient value (CV, the ratio of the standard deviation to the mean values): highly variable (CVI), variable (CVII), and constitutive (CVIII) groups. A higher index of the portion of loci with alternatively spliced transcripts in a group (IAST) value was observed for the constitutive group. Genes of the highly variable group showed the characteristics of the examined organs, and alternatively spliced transcripts tended to exhibit the same organ specificity or less organ preferences, with avoidance of 'organ distinctness'. In addition, within a locus, a tendency of higher expression was found for transcripts with a longer coding sequence (CDS), and a spliced intron was the most commonly found type of alternative splicing for an extended CDS. Thus, pre-mRNA splicing might have evolved to retain maximum functionality in terms of organ preference and multiplicity.

• 한국농공학회논문집
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• 제52권3호
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• pp.39-45
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• 2010

Quantification of carbon absorption and understanding the human induced land use changes (LUC) forms one of the major study with respect to global climatic changes. An attempt study has been made to quantify the carbon absorption by LUC through remote sensing technology. The Landsat imagery four time periods was classified with the hybrid classification method in order to quantify carbon absorption by LUC. Thereafter, for estimating the amount of carbon absorption, the stand biomass of forest was estimated with the total weight, which was the sum of individual tree weight. Individual tree volumes could be estimated with the crown width extracted from digital forest cover type map. In particular, the carbon conversion index and the ratio of the $CO_2$ molecular weight to the C atomic weight, reported in the IPCC guideline, was used to convert the stand biomass into the amount of carbon absorption. Total carbon absorption has been modeled by taking areal estimates of LUC of four time periods and carbon factors for land use type and standing biomass. Results of this study, through LUC suggests that over a period of construction, 7.10 % of forest and 9.43 % of barren were converted into urban. In the conversion process, there has been a loss of 6.66 t/ha/y (7.94 %) of carbon absorption from the study area.

• Korea-Australia Rheology Journal
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• 제13권4호
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• pp.205-217
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• 2001

This review article summarizes results of recent viscoelastic and dielectric studies for entangled cis-polyisoprene (PI) chains. The PI chains have the so-called type-A dipoles parallel along the chain backbone, and their slow viscoelastic and dielectric relaxation processes reflect the same global chain motion. However, this motion is differently averaged in the viscoelastic and dielectric properties, the former representing the isochronal orientational anisotropy of individual entanglement segments while the latter detecting the orientational correlation of the segments at two separate times (0 and t). On the basis of this difference, the viscoelastic and dielectric data of the entangled PI chains were compared to elucidate detailed features of the chain dynamics. Specifically, the molecular picture of dynamic tube dilation (DTD) incorporated in recent models was tested for linear and star PI chain. The comparison revealed that the DTD picture was valid for linear PI chains but failed for the star PI chains in the dominant part of the terminal relaxation. The failure for the star chains was related to the pre-requisite for the DTD process, rapid equilibration of successive entanglement segments through their constraint release (CR) motion: For the star chains, the dilated tube diameter expected in the terminal regime was considerably large because of a broad distribution of motional modes of the chains, so that the CR-equilibration required for DTD could not occur in time. The terminal relaxation of the star chain appeared to occur through the CR process before the expected DTD process was completed. The situation was different for the linear chain exhibiting narrowly distributed motional modes. The dilated tube expected for the linear chain was rather thin and the required CR-equilibration occurred in time, resulting in the success of the DTD picture. These detailed features of the chain dynamics was revealed only when the viscoelastic and dielectric properties were compared, demonstrating the importance of this comparison.

• Food Science and Biotechnology
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• 제16권6호
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• pp.928-934
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• 2007

Physiochemical properties, such as yield and molecular weight distribution of polysaccharide fractions, of polysaccharides in the enzymatic hydrolysates of purslane were investigated and characterized. A higher amount of micro nutrients, such as potassium (9,413 mg/100 g), phosphorus acid (539 mg/100 g), leucine, alanine, lysine, valine, glycine, and isoleucine, was present in whole purslane. The yield of water soluble polysaccharides (WSP) was 0.29, 7.01, and 7.94% when extracted using room temperature water (RTW), hot-water (HW), and hot temperature/high pressure-water (HTPW), respectively, indicating that HW or HTPW extraction may be effective to obtain WSP from purslane. The average ratio of L-arabinose:D-galactose in the WSP was 37:49, 34:37, and 27:29, when extracted using RTW, HW, and HTPW, respectively. These results indicate that water was a suitable extraction solvent for preparation of the arabinogalactan component of whole purslane. A higher yield and total carbohydrate content was obtained by using Viscozyme L instead of Pectinex 5XL during extraction of the WSP, which indicates that enzymatic treatment of purslane may be an effective method to control the Mw of polysaccharides. Finally, it was confirmed that Viscozyme L is a suitable enzyme for the hydrolysis and separation of polysaccharides obtained from purslane.

• 공업화학
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• 제17권1호
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• pp.12-15
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• 2006

본 연구의 목적은 물유리에 의해 제조된 실리카 미립자의 평균입도와 입도분포에 미치는 반응조건, 용매 및 계면활성제의 영향을 조사하는 것이다. 실리카 미립자는 다양한 종류의 계면활성제와 분산용매를 사용하는 에멀젼법에 의해 제조하였다. 계면활성제로는 비이온성인 Span 20, Span 40, Span 60 및 Span 80을 사용하였으며, 분산용매로는 알킬그룹인 n-Hexane, n-Heptane, iso-Octane 및 n-Decane을 사용하였다. 실험결과에 의하면 유화교반속도에 따른 실리카 미립자의 평균 입경은 교반속도가 증가함에 따라 감소하였으며, 일정한 입경의 에멀젼을 형성하기 위한 최적의 유화교반시간은 약 6 min임을 알 수 있었다. 생성된 실리카 미립자의 평균입경은 사용된 용매의 분자량이 증가함에 따라 감소하며, 사용한 계면활성제의 hydrophobic lipophilic balance(HLB) 값이 감소함에 따라 증가하였다.

• 한국어병학회지
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• 제29권1호
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• pp.13-23
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• 2016

Lectins play significant roles in the innate immune responses through binding to pathogen-associated molecular patterns (PAMPs) on the surfaces of microorganisms. In the present study, tissue distribution and expression analysis of olive flounder lectins were performed after viral hemorrhagic septicemia virus (VHSV) challenge. Fish egg lectin and serum lectin were found to be predominantly expressed in the gills and liver, these results indicate that the transcript expression of olive flounder lectins is concentrated in immune-related tissues. Following a VHSV challenge, an overall increase in the transcript levels of the genes was observed and the expression patterns were distinctly divided into early and later responses during VHSV infection. In conclusion, olive flounder lectins are specifically expressed in immune-related organs and induced in both the immediate and long-lasting immune responses to VHSV in the olive flounder. These results indicate that lectins may be play important roles in the host defense mechanism and involved in the innate and adaptive immune response to viruses in fish.

• Molecules and Cells
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• 제22권1호
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• pp.97-103
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• 2006

Phosphoinositides are critical regulators of ion channel and transporter activity. There are multiple isomers of biologically active phosphoinositides in the plasma membrane and the different lipid species are non-randomly distributed. However, the mechanism by which cells impose selectivity and directionality on lipid movements and so generate a non-random lipid distribution remains unclear. In the present study we investigated which structural elements of phosphoinositides are responsible for their subcellular location and movement. We incubated phosphatidylinositol (PI), phosphatidylinositol 4-monophosphate (PI(4)P) and phosphatidylinositol 4,5-bisphosphate ($PI(4,5)P_2$) with short or long acyl chains in CHO and HEK cells. We show that phosphate number and acyl chain length determine cellular location and translocation movement. In CHO cells, $PI(4,5)P_2$ with a long acyl chain was released into the cytosol easily because of a low partition coefficient whereas long chain PI was released more slowly because of a high partition coefficient. In HEK cells, the cellular location and translocation movement of PI were similar to those of PI in CHO cells, whereas those of $PI(4,5)P_2$ were different; some mechanism restricted the translocation movement of $PI(4,5)P_2$, and this is in good agreement with the extremely low lateral diffusion of $PI(4,5)P_2$. In contrast to the dependence on the number of phosphates of the phospholipid head group of long acyl chain analogs, short acyl chain phospholipids easily undergo translocation movement regardless of cell type and number of phosphates in the lipid headgroup.

• 한국수산과학회지
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• 제43권5호
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• pp.540-546
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• 2010

We investigated variations in alkaline phosphatase (APase) activity and alkaline phosphatase hydrolyzable phosphorus (APHP) in northern Gamak Bay from September to December 2009. Dissolved inorganic nitrogen (DIN) and dissolved inorganic phosphorus (DIP) decreased gradually, and the DIN/DIP ratio was higher than the Redfield ratio (16) based on molecular concentrations during most of the observation period. The total APase (T-APase) activity increased with decreasing DIP concentration; i.e., the Relationship between T-APase and DIP showed a high negative correlation (r=-0.80, P<0.001), with APase activity being a good indicator of DIP limiting the Redfield ratio. The T-APase was positively correlated with the concentration of chlorophyll a (r=0.73, P<0.001). This suggests that a major portion of APase activity in northen Gamak Bay seawater is attributed to phytoplankton. The proportion of APHP among dissolved organic phosphorus (DOP) was low in September and high in November. Thus, APase-producing phytoplankton may be able to grow by utilizing APHP as a phosphorus source in autumn when DIP is limiting. Thus, APase activity and the use of DOP by phytoplankton may play an important role in the growth of phytoplankton under DIP limiting conditions such as those of northern Gamak Bay.

• Advances in pediatric surgery
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• 제8권1호
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• pp.41-47
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• 2002

장 운동은 장근 및 점막하 신경총으로 구성된 내인성 신경계와 외인성 신경계가 합세하여 균형을 이루면서 장관이 팽창하면 상부는 수축하고 하부는 이완되어 장 내용물이 하방으로 이 동하는 운동이 연속적으로 이어지는 것이다. 신경절 세포가 없으면 내인성 신경계 억제작용 매체인 NO의 결손으로 평활근이 이완되지 않을 뿐더러 외인성 신경계 작용이 장벽에 현저히 증가되어 평소의 2-3배가 되는데 특히 adrenergic 계가 더 작용이 강하여 장벽 긴장도가 증가된 것이 무신경절 장관에서 나타나는 장 운동장애 현상의 병태생리로 설명되고 있다. 이러한 신경총의 부재는 NCC의 이동, 정착 및 성숙에 관여하는 여러 인자들의 복합적인 병적 작용 발현으로 일어나는 발생학적인 현상이며, 이러한 각종 인자들의 결함은 이와 관련된 염색체 혹은 유전자들의 변이 현상에 의한 것으로 밝혀짐에 따라 유전적인 요인들이 깊이 내재되어 있는 것이 하나씩 증명되어가고 있는 단계라고 말 할 수 있다. 지금까지는 HD와 동반되어 나타나는 이러한 현상들을 밝혀 나가고 있는 단계에 불과하며, 이러한 분자생물학적인 지식을 기초로 한다고 하여도 아직은 발병 예방이나 유전적인 치료를 고려할 수 있는 수준에는 미치지 못하는 실정이다.