O-free polyacrylonitrile doping to improve the J_c(B) and H_c2 of MgB₂ wires

Hwang, S.M.,Sung, K.,Choi, J.H.,Kim, W.,Joo, J.,Lim, J.H.,Kim, C.J.,Park, Y.S.,Kim, D.H. North-Holland 2010 Physica. C, Superconductivity Vol.470 No.20

We selected polyacrylonitrile (PAN, -[C<SUB>3</SUB>H<SUB>3</SUB>N]-) as an O-free organic dopant and fabricated C-doped MgB<SUB>2</SUB> wires by in situ and powder-in-tube techniques. 0-5 wt.% PAN powders were uniformly mixed with B powder using a liquid mixing method. The precursor powders were mixed with Mg powder, filled into Fe tubes, and then drawn into wires. Sintering was performed at 900<SUP>o</SUP>C for 1h in a flowing Ar gas. The PAN doping decreased the critical temperature (T<SUB>c</SUB>) and a-axis lattice parameter, but significantly improved the critical current density (J<SUB>c</SUB>) in high fields, upper critical field (H<SUB>c2</SUB>), and irreversibility field (H<SUB>irr</SUB>) performances. These results are attributed to the replacement of B sites with C by the PAN doping. Furthermore, as expected, the MgO amount did not increase as the doping content increased. The J<SUB>c</SUB> of the PAN-doped MgB<SUB>2</SUB> wires was more than one order of magnitude higher than that of the undoped MgB<SUB>2</SUB> wire at 5K and 6.6T (1.46-3.82kA/cm<SUP>2</SUP> vs. 0.11kA/cm<SUP>2</SUP>).

Ligand release-independent transactivation of epidermal growth factor receptor by transforming growth factor-β involves multiple signaling pathways

Joo, C-K,Kim, H-S,Park, J-Y,Seomun, Y,Son, M-J,Kim, J-T Nature Publishing Group 2008 Oncogene Vol.27 No.5

Many of the signaling responses induced by transforming growth factor-β (TGF-β) are mediated by Smad proteins, but there is evidence that it can also signal independently of Smads. Here, we provide evidence that multiple signal pathways induced by TGF-β1—including Src family tyrosine kinases (SFKs), generation of reactive oxygen species (ROS), de novo protein synthesis and E-cadherin-dependent cell–cell interactions—transactivate the epidermal growth factor receptor (EGFR), which in turn regulates expression of c-Fos and c-Jun. Immunoprecipitation and immunofluorescence staining showed that EGFR was phosphorylated on tyrosine in response to TGF-β1. EGFR transactivation required the activation of SFKs and the production of ROS via NADPH oxidase, but was not dependent on metalloproteases or the release of EGF-like ligands. In addition, the production of ROS was dependent on signaling by specific SFKs as well as de novo protein synthesis. Stable transfection of E-cadherin into MDA-MB-231 cells as well as E-cadherin-blocking assays revealed that E-cadherin-mediated cell–cell interactions were also essential for EGFR transactivation. Finally, EGFR transactivation was involved in the expression of c-Fos and c-Jun via the extracellular signal-regulated kinase signaling cascade. Taken together our data suggest that ligand release-independent transactivation of EGFR may diversify early TGF-β signaling and represent a novel pathway leading to TGF-β-mediated gene expression.Oncogene (2008) 27, 614–628; doi:10.1038/sj.onc.1210649; published online 16 July 2007

Temperature-Dependent Terahertz Imaging of Excised Oral Malignant Melanoma

Sim, Y. C.,Kang-Min Ahn,Jae Yeon Park,Chan-Sik Park,Joo-Hiuk Son IEEE 2013 IEEE Journal of Biomedical and Health Informatics Vol.17 No.4

<P>We imaged a single case of oral malignant melanoma using terahertz (THz) reflection imaging at room temperature (20 °C) and below freezing (-20 °C). A malignant nodule beneath the oral tissue surface was visualized using 2-D and B-scan THz imaging techniques. The THz images were well correlated with the histological findings. The nodule was found to have lower water content than that of normal cells, and this water effect may have influenced the THz refractive index and absorption coefficient at 20 °C. The THz spectroscopic image of the frozen tissue at -20 °C showed better contrast because of the lack of liquid water; this implies that there are significant structural differences between malignant oral melanoma cells and normal mucosal cells. The better contrast in the frozen tissue images was due to the greater penetration of THz radiation into the sample. This temperature-dependent THz imaging approach demonstrated the feasibility of accurate imaging of the oral tumor tissue.</P>

우유 중 단백질과 요소태질소 분석에 의한 젖소의 에너지 및 단백질 균형 상태 평가에 관한 연구

박용호,문진산,주이석,장금찬,윤용덕,이보균,손창호 한국동물자원과학회 2000 한국축산학회지 Vol.42 No.4

Milk urea nitrogen (MUN) and milk protein (MP) are increasingly used as indicators of the protein-energy balance and the actual faun feeding practice, and also are related to nutritional and reproductive disorders. The purpose of this study was to investigate the MUN and MP concentrations by month and geographical distribution in individual and bulk milk, and to evaluate the protein-energy balance for feeding according to the level of MP and MUN by stage of lactation in Holstein cows. MP and MUN contents were determined using automated infrared procedures. Mean MUN and MP concentrations in the bulk milk samples obtained from Jan. 1999 until Dec. 1999 in the 26,467 cows of 1,077 herd were 16.9±4.2㎖/㎗ and 3.18±0.18%, respectively. The highest values were found during spring and lowest values during winter in MUN. But, the average contents of MP were the highest values during winter and the lowest ones during summer. Out of the total herd surveyed, 10.7% had MUN values lower than 12.0㎖/㎗ and 39.7% had values higher than 18.0㎖/㎗, and 53.0% had MP values outside the standard interval (3.0-3.2%). In order to evaluate protein-energy balance for feeding, we set the level of standard range of MP of 2.90-3.29% in early lactation considering dairy cows to experience a negative energy balance and the level of MP in mid-lactation and late lactation were 3.10-3.49%, and 3.30-3.69%, respectively. Standard MUN of 12-18㎖/㎗ was applied through the whole lactation because it is relatively constant without being affected by days in milk. Milk yield, body condition score, and milk composition were analyzed according to the 9 types based on the levels of MP and MUN. The lower body condition score than the recommended level by stage of lactation was associated with low MP, high MUN content and decreased milk yield. Out of a total, 26.8%, 25.8%, and 22.2% had protein-energy balance for feeding by stage of lactation, respectively. Therefore, when MUN and MP analysis is used for gross diagnosis of protein-energy balance and feeding management practice at the farm level.

한탄 바이러스 genome RNA의 packaging mechanism에 대한 연구

박근용,주명수,박찬,주영란,이호동,최규리,이점규,최우영,남재환,유정희 국립보건연구원 2000 국립보건원보 Vol.37 No.-

돼지의 도체등급 관한 연구 2 . 돼지도체의 거래정육율 추정에 관한 연구

김용곤,주선태,정숙근,김병철,강태홍 ( Y . K . Kim,S . T . Joo,S . K . Jong,B . C . Kim,T . H . Kang ) 한국축산학회 1990 한국축산학회지 Vol.32 No.12

This study was conducted to determine the estimating equations for retail cuts percentage of pork carcass by grading machines and manual measurement with 160 hogs. Carcass grading machines used were Destron Pork grader-100(PG) and Danish Fat-O-Meat`er(FOM), and the summarized results are as follows; l. The carcass weight and carcass length showed negative correlation(r=-0.23, -0.19, respectively) with retail cuts percentage. 2. Among average of two site measurements, the average of backfat thickness at 11-12th ribs and last ribs showed the highest correlation with retail cuts percentage. 3. Average of three site measurements showed lower correlation with retail cuts percentage than average of two site measurements. 4. Conclusively, the estimating equations for retail cuts percentage by measurement methods were Y=77.60-0.003(Hot carcass weight) -4.46(Backfat thickness) for Handling, Y=73.97+0.011(Hot carcass weight) -0.60(Backfat thickness) +0.09(Muscle depth) for PG and Y=74.58+0.022(Hot carcass weight)-0.69(Backfat thickness) +0.07(Muscle depth) for FOM, respectively.

Comparison of Live Performance and Meat Quality Parameter of Cross Bred (Korean Native Black Pig and Landrace) Pigs with Different Coat Colors

Hur, S.J.,Jeong, T.C.,Kim, G.D.,Jeong, J.Y.,Cho, I.C.,Lim, H.T.,Kim, B.W.,Joo, S.T. Asian Australasian Association of Animal Productio 2013 Animal Bioscience Vol.26 No.7

Five hundred and forty crossbred (Korean native black pig${\times}$Landrace) F2 were selected at a commercial pig farm and then divided into six different coat color groups: (A: Black, B: White, C: Red, D: White spot in black, E: Black spot in white, F: Black spot in red). Birth weight, 21st d weight, 140th d weight and carcass weight varied among the different coat color groups. D group (white spot in black coat) showed a significantly higher body weight at each weigh (birth weight, 140th d weight and carcass weight) than did the other groups, whereas the C group (red coat color) showed a significantly lower body weight at finishing stage (140th d weight and carcass weight) compared to other groups. Meat quality characteristics, shear force, cooking loss and meat color were not significantly different among the different coat color groups, whereas drip loss was significantly higher in F than in other groups. Most blood characteristics were not significantly different among the different groups, except for the red blood cells.

Application of a New Portable Microscopic Somatic Cell Counter with Disposable Plastic Chip for Milk Analysis

Moon, J.S.,Koo, H.C.,Joo, Y.S.,Jeon, S.H.,Hur, D.S.,Chung, C.I.,Jo, H.S.,Park, Y.H. American Dairy Science Association 2007 Journal of dairy science Vol.90 No.5

The somatic cell count (SCC) is one of the international standards for monitoring milk quality, and it is a useful indicator of mastitis. The current reference method for determining the SCC in raw milk is direct microscopic analysis, but this method requires well-trained staff to maintain its accuracy and reproducibility. To overcome these inconveniences, we developed a portable system (the C-reader system) that utilizes the capillary flow of a microfluidic chamber by surface modification of the hydrophilicity. The microfluidic technology of disposable microchips allows for low consumption of reagents, and a combination of ready-to-use reagents makes the daily work easier. The repeatability test of the C-reader using 10 composite bovine milk samples satisfied the recommended values for SCC equipment. In addition, an acceptable accuracy level of the natural logarithmic-transformed SCC [ln(SCC/1,000):+/-0.059 to 0.112] was achieved using composite raw milk samples and various somatic cell standard solutions from the American Eastern Laboratory and the Korean National Veterinary Research and Quarantine Service. After testing 875 composite milk samples, the C-reader showed a high correlation coefficient (R<SUP>2</SUP>0.935 to 0.964) and a low mean difference value in log-transformed SCC (-0.088 to 0.004) compared with 3 automatic commercialized somatic cell counters (Fossomatic 4000, Somacount 150, and Somascope). In conclusion, the C-reader system is a new, easy-to-use automatic on-farm method with acceptable repeatability and accuracy for measuring SCC in large dairies and smaller laboratories.

Fabrication of superconducting MgB₂ thin films on textured Cu(100) tape by hybrid physical–chemical vapor deposition

Lee, Tae Gyoung,Ranot, Mahipal,Seong, Won Kyung,Jung, Soon-Gil,Kang, W N,Joo, J H,Kim, C-J,Jun, B-H,Kim, Youngha,Zhao, Y,Dou, S X IOP Publishing Ltd 2009 Superconductor science & technology Vol.22 No.4

<P>We report on the fabrication of superconducting MgB<SUB>2</SUB> thin films on textured Cu(100) tape under low pressure and temperature by using a hybrid physical–chemical vapor deposition (HPCVD) technique to explore the possible broad range of deposition. Thermodynamic calculations for the Mg–B system have been carried out and the pressure–temperature phase diagram was obtained. Our results demonstrate that the deposition of superconducting MgB<SUB>2</SUB> films is possible beyond the theoretically calculated growth window, where the sublimation of Mg is taking place. The structural and microstructural investigations reveal that MgB<SUB>2</SUB> films are <I>c</I>-axis-oriented normal to the substrate. The highest <I>J</I><SUB>c</SUB> of ∼1.34 × 10<SUP>5</SUP> A cm<SUP>−2</SUP> at 5 K under 3 T is obtained for the film grown at 460 °C. The critical current density (<I>J</I><SUB>c</SUB>) and flux pinning force density (<I>F</I><SUB>p</SUB>) of MgB<SUB>2</SUB> films are enhanced with decreasing growth temperature. This could be attributed to the high density of grain boundaries which may act as effective flux pinning centers. These findings suggest an alternative route to fabricate MgB<SUB>2</SUB> tapes at low temperature for large scale applications.</P>

초음파검사시 ASME와 RCC-M CODE에 따른 결함 크기측정 및 허용기준 비교평가

주영상,김병철,임형택,이종포 韓國非破壞檢査學會 1988 한국비파괴검사학회지 Vol.7 No.2

The comparison and analysis of flaw detectability, flaw sizing methods and allowable criteria in accordance with the applicable codes, ASME and RCC-M Code, in ultrasonic examination of pressure vessel in nuclear power plants were studied. According to the codes, calibration blocks were made. The artificial flaws such as disc and band types in test specimens were machined. They were detected and evaluated with each code requirements and measured values were compared with the actual flaws.