• Asian Pacific Journal of Cancer Prevention
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• v.16 no.1
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• pp.271-274
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• 2015

Background: To explore vascular endothelial growth factor C (VEGF-C) and VEGF-D expression and its correlation with lymph node metastasis in esophageal squamous cell cancer (ESCC) tissue. Materials and Methods: Immunohistochemical methods were applied to detect the levels of VEGF-C and VEGF-D expression in 64 surgicall removal ESCC tissues, tissues adjacent to cancer and normal tissues, and the relationship between VEGF-C and VEGF-D expression and lymph node metastasis was analyzed. Results: Both VEGF-C and VEGF-D were expressed by varying degrees in esophageal cancer tissue, the tissue adjacent to cancer and normal tissue, and the positive expression rate went down successively. The positive expression rates of VEGF-C (59.4%) and VEGF-D (43.8%) in esophageal cancer tissue were significantly higher than in the tissue adjacent to cancer (34.4%, 15.6%) and normal tissue (20.3%, 12.5%), respectively, in which significant differences were manifested (p<0.01). Positive expression rates of VEGF-C and VEGF-D in esophageal cancers with lymph node metastasis were markedly higher than without such metastasis (p<0.01), while those in the tissue with TNM staging I~II were markedly lower than that with TNM staging III~IV (p<0.01). Conclusions: Both VEGF-C and VEGF-D are highly expressed in ESCC tissue, which may be related to the lymph node metastasis of cancer cells. Hence, VEGF-C and VEGF-D can be clinically considered as important reference indexes of lymph node metastasis in esophageal cancer.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.11 no.6
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• pp.846-854
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• 1999

Measurements of the local heat transfer coefficients were made on a hemispherically convex surface with a round oblique impinging jet. The liquid crystal transient method was used for these measurements. This method, which is a variation on the transient method, suddenly exposes a preheated wall to an impinging jet while video recording the response of liquid crystal for the surface temperature measurements. The Reynolds number used was 23000 and the nozzle-to-surface distance was L/d=2, 4, 6, 8, and 10 and the jet angle was $\alpha$=$0^{\circ}\; 15^{\circ}\;30^{\circ}C\; and \;40^{\circ}C$. In the experiment, the Nusselt number at the stagnation point decreases as the jet angle increases and has the maximum value for L/d=6. The X-axis Nusselt number distributions exhibit Secondary maxima at $0^{\circ}C\re $\alpha$\re 15^{\circ}C, L/d\le6$ for X/d＜0(upstream) and at $0^{\circ}C\re $\alpha$40^{\circ}C,\;L/d\le4\;and\; at\; 30^{\circ}C\re $\alpha$$\leq$40^{\circ}C,\;L/d\le 6 $for X/d＞0(downstream). The secondary maxima occurs at long distance from the stagnation point as the jet angle increases or the nozzle-to-surface distance decreases. The Y-axis Nusselt number distributions exhibit secondary maxima at Y/d=$\pm$2 for $0^{\circ}C\le a\le30^{\circ}C\; and\; L/d\le4, and \;for\;$\alpha$=40^{\circ}C$and L/d=2. The displacement of the maximum Nusselt number from the stagnation point increases as the jet angle increases or the nozzle-to-surface distance decreases and the maximum distance is about 0.67 times of the nozzle diameter. The ratio of the maximum Nusselt number to the stagnation Nusselt number increases as the jet angle increases.

• Bulletin of the Korean Chemical Society
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• v.23 no.12
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• pp.1790-1800
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• 2002

The DNA nucleosides(dA, dC, dG, dT)bound to gold nanoparticles (~13 nm) in aqueous solution has been studied as a probe by the SERS and their coordination structures have been proposed on the basis of them. According to UV-Visible absorption of gold nanoparticles after modifying with DNA nucleosides, the rates of absorption of dA, dC, and dG were much faster than that of dT as monitored by the aggregation kinetics at 700 nm. These data indicated that the nucleosides dA, dC, and dG had a higher affinity for the gold nanoparticles surface than nucleoside dT. As the result of SERS spectra, the binding modes of each of the nucleosides on gold nanoparticles have been assigned. A dA binds to gold nanoparticles via a N(7) nitrogen atom of the imidazole ring, which the C(6)-$NH_2$ group also participates in the coordination process. In the case of dC, it binds to the gold surface via a N(3) nitrogen atom of the pyrimidine ring with a partial contribution from the oxygen of C(2)=O group. A coordination of dG to the gold surfaces is also proposed. Although the dG has the two different nitrogens of a pyrimidine ring and the amino group, the N(1) nitrogen atom of a pyrimidine ring has a higher affinity after the hydrogen migrates to the amino group. Conversely, dT binds via the oxygen of the C(4)=O group of the pyrimidine ring. Accordingly, these data suggest that the nitrogen atom of the imidazole or the pyrimidine ring in the DNA nucleosides will bind more fast to the gold nanoparticles surfaces than the oxygen atom of the carbonyl group.

• BMB Reports
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• v.52 no.6
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• pp.391-396
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• 2019

Receptor activator of nuclear factor kappa B ligand (RANKL) expression in osteoblasts is regulated by 1,25-dihydroxyvitamin D3 (1,25D3). CCAAT/enhancer-binding protein beta ($C/EBP{\beta}$) has been proposed to function as a transcription factor and upregulate RANKL expression, but it is still uncertain how $C/EBP{\beta}$ is involved in 1,25D3-induced RANKL expression of osteoblasts. 1,25D3 stimulation increased the expression of RANKL and $C/EBP{\beta}$ genes in osteoblasts and enhanced phosphorylation and stability of these proteins. Moreover, induction of RANKL expression by 1,25D3 in osteoblasts was downregulated upon knockdown of $C/EBP{\beta}$. In contrast, $C/EBP{\beta}$ overexpression directly upregulated RANKL promoter activity and exhibited a synergistic effect on 1,25D3-induced RANKL expression. In particular, 1,25D3 treatment of osteoblasts increased $C/EBP{\beta}$ protein binding to the RANKL promoter. In conclusion, $C/EBP{\beta}$ is required for induction of RANKL by 1,25D3.

• Wind and Structures
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• v.23 no.2
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• pp.109-125
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• 2016

Flow interference is investigated between two tripped cylinders of identical diameter D at stagger angle ${\alpha}=0^{\circ}{\sim}180^{\circ}$ and gap spacing ratio $P^*$ (= P/D) = 0.1 ~ 5, where ${\alpha}$ is the angle between the freestream velocity and the line connecting the cylinder centers, and P is the gap width between the cylinders. Two tripwires, each of diameter 0.1D, were attached on each cylinder at azimuthal angle ${\beta}={\pm}30^{\circ}$, respectively. Time-mean drag coefficient ($C_D$) and fluctuating drag ($C_{Df}$) and lift ($C_{Lf}$) coefficients on the two tripped cylinders were measured and compared with those on plain cylinders. We also conducted surface pressure measurements to assimilate the fluid dynamics around the cylinders. $C_D$, $C_{Df}$ and $C_{Lf}$ all for the plain cylinders are strong function of ${\alpha}$ and $P^*$ due to strong mutual interference between the cylinders, connected to six interactions (Alam and Meyer 2011), namely boundary layer and cylinder, shear-layer/wake and cylinder, shear layer and shear layer, vortex and cylinder, vortex and shear layer, and vortex and vortex interactions. $C_D$, $C_{Df}$ and $C_{Lf}$ are very large for vortex and cylinder, vortex and shear layer, and vortex and vortex interactions, i.e., the interactions where vortex is involved. On the other hand, the interference as well as the strong interactions involving vortices is suppressed for the tripped cylinders, resulting in insignificant variations in $C_D$, $C_{Df}$ and $C_{Lf}$ with ${\alpha}$ and $P^*$. In most of the (${\alpha}$, $P^*$ ) region, the suppressions in $C_D$, $C_{Df}$ and $C_{Lf}$ are about 58%, 65% and 85%, respectively, with maximum suppressions 60%, 80% and 90%.

• Reproductive and Developmental Biology
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• v.37 no.4
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• pp.269-279
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• 2013

Low efficiency of somatic cell nuclear transfer (SCNT) is attributed to incomplete reprogramming of transfered nuclei into oocytes. Trichostatin A (TSA), histone deacetylase inhibitor and 5-aza-2'deoxycytidine (5-aza-dC), DNA methylation inhibitor has been used to enhance nuclear reprogramming following SCNT. However, it was not known molecular mechanism by which TSA and 5-aza-dC improve preimplantation embryo and fetal development following SCNT. The present study investigates embryo viability and gene expression of cloned porcine preimplantation embryos in the presence and absence of TSA and 5-aza-dC as compared to embryos produced by parthenogenetic activation. Our results indicated that TSA treatment significantly improved development. However 5-aza-dC did not improve development. Presence of TSA and 5-aza-dC significantly improved total cell number, and also decreased the apoptotic and autophagic index. Three apoptotic-related genes, Bak, Bcl-xL, and Caspase 3 (Casp3), and three autophagic-related genes, ATG6, ATG8, and lysosomal-associated membrane protein 2 (LAMP2), were measured by real time RT-PCR. TSA and 5-aza-dC treatment resulted in high expression of anti-apoptotic gene Bcl-xL and low pro-apoptotic gene Bak expression compared to untreated NT embryos or parthenotes. Furthermore, LC3 protein expression was lower in NT-TSA and NT-5-aza-dC embryos than those of NT and parthenotes. In addition, TSA and 5-aza-dC treated embryos displayed a global acetylated histone H3 at lysine 9 and methylated DNA H3 at lysine 9 profile similar to the parthenogenetic blastocysts. Finally, we determined that several DNA methyltransferase genes Dnmt1, Dnmt3a and Dnmt3b. NT blastocysts showed higher levels Dnmt1 than those of the TSA and 5-aza-dC blastocysts. Dnmt3a is lower in 5-aza-dC than NT, NTTSA and parthenotes. However, Dnmt3b is higher in 5-aza-dC than NT and NTTSA. These results suggest that TSA and 5-aza-dC positively regulates nuclear reprogramming which result in modulation of apoptosis and autophagy related gene expression and then reduce apoptosis and autophagy. In addition, TSA and 5-aza-dC affects the acetylated and methylated status of the H3K9.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.16 no.8
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• pp.5492-5500
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• 2015

Low-density lipoprotein cholesterol (LDL-C) is a major modifiable risk factor for cardio- cerebrovascular disease. In clinical practice, however, it is primarily calculated using the Friedewald formula as a cost-effective method. The aim of this study was to compare Friedewald-estimated and directly measured LDL-C values and assess the concordance in guideline LDL-C risk classification between the two methods. The data were derived from the 2009 and 2010 Korea National Health and Nutrition Survey (KNHANES). Analysis was done for 4,319 subjects with lipid panels-total cholesterol (TC), high-density lipoprotein cholesterol (HDL-C), directly measured LDL-C using an enzymatic homogeneous assay, and triglycerides (TG). For subjects with TG lower than 400 mg/dL, Friedewald-estimated and directly measured LDL-C were highly correlated (r = 0.958, p < 0.001) and overall concordance was 82.7%. As TG increased, overall concordance decreased. Overall concordance was 85.4% at TG lower than 150 mg/dL; 78.2% at TG of 150-199 mg/dL; and 71.4% at TG of 200-399 mg/dL. The Friedewld equation tended to overestimate LDL-C when TG are of < 150 mg/dL; however, underestimate LDL-C when TG are of ${\geq}150mg/dL$. As a result, Friedewald estimation misclassified 382 subjects (9.1%) in a higher category versus 348 subjects (8.3%) in a lower category. Our findings suggest that overestimation of LDL-C by the Friedewald formula can be a great problem as well as underestimation.

• The Korean Journal of Ecology
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• v.21 no.3
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• pp.269-276
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• 1998

The study of the Rana plancyi, was done during the calling period at a pond in Osong, Chungbuk, Korea from May to the middle of August of 1996 and 1997. Five basic types of call-A, B, C, D, E, - were identified in Rana plancyi according to the structure of call types. The structure of A type call has only one pulse, B type call has two pulses and C, D type call has one separated pulse which is called introductory call and pulse group as follow it. On the other hand, E type call has 3-6 separate pulses. The interval between introductory call and pulse group is $0.73{\pm}0.29$ s(n=159) in C type call and $0.60{\pm}0.21$ s (n=48) in D type call. The number of pulses in the pulse group is $30.08{\pm}8.69$ in C type call and $15.78{\pm}2.40$ in D type call. An increase in water temperature induces a decrease in C and D type call duration (C type call r= -0.4153, p<0.001, D type call r=-0.7064, p<0.001). In case of C and D type call, the interval between introductory call and pulse group influenced more call duration than pulse group duration. We regarded A, B type call as a territorial call and C, D type call as a mating call and we recognized that E type call has the function of threat or alarm.

• Journal of Microbiology and Biotechnology
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• v.29 no.3
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• pp.401-409
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• 2019

Heat-resistant microbial hosts are required for bioprocess development using high cell density cultivations at the industrial scale. We report that the thermotolerance of Escherichia coli can be enhanced by overexpressing ybeD, which was known to encode a hypothetical protein of unknown function. In the wild-type E. coli BL21(DE3), ybeD transcription level increased over five-fold when temperature was increased from $37^{\circ}C$ to either $42^{\circ}C$ or $46^{\circ}C$. To study the function of ybeD, a deletion strain and an overexpression strain were constructed. At $46^{\circ}C$, in comparison to the wild type, the ybeD-deletion reduced cell growth half-fold, and the ybeD-overexpression promoted cell growth over two-fold. The growth enhancement by ybeD-overexpression was much more pronounced at $46^{\circ}C$ than $37^{\circ}C$. The ybeD-overexpression was also effective in other E. coli strains of MG1655, W3110, DH10B, and BW25113. These findings reveal that ybeD gene plays an important role in enduring high-temperature stress, and that ybeD-overexpression can be a prospective strategy to develop thermotolerant microbial hosts.

• 전기의세계
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• v.28 no.9
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• pp.51-59
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• 1979

The forming and design method of D.C thyristor chopper circuit for DC Series motor control is suggested, ard the computation method of thyristor commutaing element's, value which makes it all the more important, is possible. Also the trigger circuit was dealt with. In this paper, in order to control the duty cycle, the duty time is kept on constancy and variable chopping frequency was adopted. By above mentioned circuit design method, the D.C thyristor chopper circuit was implemented and tested. In this circuit, the result of D.C motor control was good and reliable. The relation between the $K_{d}$ and the ratio of input-output current, or the characteristic of speed was varied lineary at the range 0.1 ~ 0.9 of duty cycle. This confirms the fact that D.C to D.C power conversion which is the merit of chopper control is operated most likely a transformer.ormer.