Measurement of $^{93}Nb(n,n{\alpha})^{89m}Y$, $^{93}Nb(n,{\alpha})^{90m}Y$ and $^{93}Nb(n,2n)^{92m}Nb$ Cross Sections for 14 MeV Neutrons

김영석,김낙배,정기형,박혜일,Kim, Y.S.,Kim, N.B.,Chung, K.H.,Bak, H.I. Korean Nuclear Society 1986 Nuclear Engineering and Technology Vol.18 No.2

The $^{93}Nb(n,n\alpha)^{89m}Y$, $^{93}Nb(n,{\alpha})^{90m}Y$ and $^{93}Nb(n,2n)^{92m}Nb$ cross sections at a neutron energy of 14.6 MeV have been measured relative to the $^{27}Al(n,p)^{27}Mg$ and $^{27}Al(n,{\alpha})^{24}Na$ cross sections. A small accelerator utilizing $T(D,n)^4He$ reaction was used as a neutron source and the neutron energy spread is about 0.4MeV at the sample. All induced activities were measured with a 70cc HPGe detector in the same geometry.

Haplotype and mutation analysis for newly suggested Y-STRs in Korean father-son pairs

Oh, Y.N.,Lee, H.Y.,Lee, E.Y.,Kim, E.H.,Yang, W.I.,Shin, K.J. Elsevier Science 2015 FORENSIC SCIENCE INTERNATIONAL GENETICS Vol.15 No.-

In this study, 363 Korean father-son haplotype transfers in 351 families were analyzed using an in-house multiplex PCR system for 14 Y-STRs (DYS385a/b, DYF387S1, DYS391, DYS449, DYS460, DYS481, DYS518, DYS533, DYS549, DYS570, DYS576, DYS627 and DYS643), that included 11 loci newly added to the PowerPlex Y23 system or the Yfiler Plus system. The Y-STRs showed gene diversity values ranging from 0.2499 to 0.9612; the multicopy Y-STR loci DYS385 and DYF387S1 had high gene diversity of 0.9612 and 0.9457, respectively. In addition, DYF387S1, which has two copies, showed three alleles in seven individuals, and micro-variant alleles were observed in 14 individuals at four loci (DYS448, DYS518, DYS570 and DYS627). Among 351 haplotypes for the 11 newly added Y-STRs, 350 different haplotypes were observed, with an overall haplotype diversity of 0.9999 and discrimination capacity of 99.72%. In 363 haplotype transfers from 351 pedigrees, 29 single-step mutations were observed at 11 Y-STRs. Locus-specific mutation rate estimates varied from 0.0 to 1.93x10<SUP>-2</SUP>, with an average estimated mutation rate of 6.66x10<SUP>-3</SUP>. Two father-son pairs had mutations at two different loci in 11 Y-STRs. The number of pairs with mutations at multiple loci increased to five when the mutation event was investigated for haplotype transfer at 28 Y-STRs including 17 Yfiler loci and 11 Y-STRs examined in this study: four father-son pairs had mutations at two loci, and one pair had mutations at three loci. Overall, mutations were frequently observed at DYS449, DYS576 and DYS627 loci, which are known to be rapidly mutating Y-STRs. Mutation rate estimates at most loci were not significantly different from rates in other populations, but estimates for DYF387S1, DYS518 and DYS570 were considerably lower in the Korean population than in other populations.

N₂/ CH₄가스비에 따른 Hydrogenated Amorphous Carbon Nitride 박막의 특성

장홍규(H. K. Jang),김근식(G. S. Kim),황보상우(S. W. Whangbo),이연승(Y. S. Lee),황정남(C. N. Whang),유영조(Y. Z. Yoo),김효근(H. G. Kim) 한국진공학회(ASCT) 1998 Applied Science and Convergence Technology Vol.7 No.3

DC saddle-field-plasma-enhanced chemical-vapor deposition(PECVD) 장치를 이용하여 상온에서 p-type Si (100) 기판위에 hydrogenated amorphous carbon nitride [a-C:H(N)]박막을 증착하였다. 원료가스인 CH₄과 N₂의 전체압력은 90 mTorr로 고정하고 N₂/CH₄비를 0에서 4까지 변화하면서 제작한 a-C:H(N) 박막의 미세 구조의 변화를 연구하였다. 진공조의 도달 진공도는 1×10^(-6) Torr이고, 본 실험시 CH₄+N₂가스의 유량은 5 sc㎝으로 고정하고 배기량을 조절하여 진공조의 가스 압력을 90 mTorr로 고정하였으며 기판에 200 V의 직류 bias 전압을 인가하였다. α-step과 X-ray photoelectron spectroscopy(XPS)를 이용한 분석결과 N₂/CH₄비가 0에서 0.5로 증가함에 따라 박막 두께는 4840 Å에서 2600 Å으로 급격히 감소하였으며, 박막내의 탄소에 대한 질소함유량(N/C비)는 N₂/CH₄비가 4일때 최대 0.25로 증가하는 것을 확인하였다. 또한 XPS 스펙트럼의 fitting 결과 N₂/CH₄비가 증가할수록 CN결합이 증가하였다. Fourier Transformation Infrared (FT-IR) 분석결과 N₂/CH₄비가 증가함에 따라 박막내의 C-H 결합은 감소하고, N-H, C≡N 결합은 증가하였다. Optical bandgap 측정 결 과 N₂/CH₄비가 0에서 4로 증가함에 따라 a-C:H(N)박막의 bandgap 에너지는 2.53 eV에서 2.3 eV로 감소하는 것을 확인하였다. Hydrogenated amorphous carbon nitride[a-C:H(N)] films were deposited on p-type Si(100) at room temperature with substrate bias voltage of 200 V by DC saddle-field plasma-enhanced chemical vapor deposition. Effects of the ratio of N₂to CH₄(N₂/CH₄), in the range of 0 and 4 on such properties as optical properties, microstucture, relative fraction of nitrogen and carbon, etc. of the films have been investigated. The thickness of the a-C:H(N) film was abruptly decreased with the addition of nitrogen, but at N₂/CH₄> 0.5, the thickness of the film gradually decreased with the increase of the N₂/CH₄. The ratio of N to C(N/C) of the films was saturated at 0.25 with the increase of N₂/CH₄. N-H, C≡N bonds of the films increased but C-H bond decreased with the increase of N₂/CH₄. Optical band gap energy of the film decreased from 2.53 eV deposited with pure methane to 2.3 eV at the ratio of N₂/CH₄=4.

Identification and quantification of seven volatile n-nitrosamines in cosmetics using gas chromatography/chemical ionization-mass spectrometry coupled with head space-solid phase microextraction

Choi, N.R.,Kim, Y.P.,Ji, W.H.,Hwang, G.S.,Ahn, Y.G. Pergamon Press ; Elsevier Science Ltd 2016 Talanta Vol.148 No.-

<P>An analytical method was developed for the identification and quantification of seven volatile n-nitrosamines (n-nitrosodimethylamine [NDMA], n-nitrosoethylmethylamine [NMEA], n-nitrosodiethylamine [NDEA], n-nitrosodipropylamine [NDPA], n-nitrosodibutylamine [NDBA], n-nitrosopiperidine [NPIP], and n-nitrosopyrrolidine [NPYRD]) in water insoluble cream type cosmetics. It was found that the head space-solid phase microextraction (HS-SPME) was suitable for extraction, clean up, and pre-concentration of n-nitrosamines in the cream type samples so its optimal conditions were investigated. Identification and quantification of n-nitrosamines using single quadrupole gas chromatography/mass spectrometry (GC/MS) in chemical ionization (CI) mode were carried out with accurate mass measurements. Their accurate masses of protonated molecular ions were obtained within 10 mDa of the theoretical masses when sufficiently high signal was acquired from the unique calibration method using mass and isotope accuracy. For the method validation of quantification, spiking experiments were carried out to determine the linearity, recovery, and method detection limit (MDL) using three deuterated internal standards. The average recovery was 79% within 20% relative standard deviation (RSD) at the concentration of 50 ng/g. MDLs ranged from 0.46 ng/g to 36.54 ng/g, which was satisfactory for the directive limit of 50 ng/g proposed by the European Commission (EC). As a result, it was concluded that the method could be provided for the accurate mass screening, confirmation, and quantification of n-nitrosamines when applied to cosmetic inspection. (C) 2015 Elsevier B.V. All rights reserved.</P>

Diabetes augments cognitive dysfunction in chronic cerebral hypoperfusion by increasing neuronal cell death: Implication of cilostazol for diabetes mellitus-induced dementia

Kwon, K.J.,Lee, E.J.,Kim, M.K.,Kim, S.Y.,Kim, J.N.,Kim, J.O.,Kim, H.J.,Kim, H.Y.,Han, J.S.,Shin, C.Y.,Han, S.H. Blackwell Science ; Academic Press 2015 Neurobiology of disease Vol.73 No.-

Many patients with diabetes are at increased risk of cognitive dysfunction and dementia. Diabetes mellitus is a vascular risk factor that may increase the risk of dementia through its associations with vascular dementia. We tested whether cognitive impairment could be exacerbated in combined injury using a rat model of chronic cerebral hypoperfusion with diabetes. We also determined whether a potent inhibitor of type III phosphodiesterase could prevent the cognitive decline caused by this combined injury. We used Otsuka Long-Evans Tokushima Fatty (OLETF) rats as a model of type II diabetes (T2DM) and Long-Evans Tokushima Otsuka (LETO) rats as a control. Chronic cerebral hypoperfusion was modeled by permanent bilateral common carotid artery occlusion (BCCAO). At 24weeks, the non-diabetic and T2DM rats were randomly assigned into groups for the following experiments: analysis I (1) sham non-diabetic rats (n=8); (2) hypoperfused non-diabetic rats (n=9); (3) sham T2DM rats (n=8); (4) hypoperfused T2DM rats (n=9); analysis II- (1) sham T2DM rats without treatment (n=8); (2) cilostazol-treated T2DM rats (n=8); (3) hypoperfused T2DM rats (n=9); and (4) hypoperfused T2DM rats and cilostazol treatment (n=9). The rats were orally administered cilostazol (50mg/kg) or vehicle once a day for 2weeks after 24weeks. Rats performed Morris water maze tasks, and neuronal cell death and neuroinflammation were investigated via Western blots and histological investigation. Spatial memory impairment was exacerbated synergistically in the hypoperfused T2DM group compared with the hypoperfused non-diabetic group and sham T2DBM group (P<0.05). Compared with the control group, neuronal cell death was increased in the hippocampus of the hypoperfused T2DM group. Cilostazol, a PDE-3 inhibitor, improved the memory impairments through inhibition of neuronal cell death, activation of CREB phosphorylation and BDNF expression in the hypoperfused T2DM group. Our experimental results support the hypothesis that there are deleterious interactions between chronic cerebral hypoperfusion and T2DM. That is, metabolic diseases such as diabetes may exacerbate cognitive impairment in a rat model of vascular dementia. We also suggest that surprisingly, the phosphodiesterase III inhibitor, cilostazol may be useful for the treatment of cognitive impairment in diabetes mellitus-induced dementia. In conclusion, diabetes can aggravate cognitive dysfunction in vascular dementia, and PDE-3 inhibitors, such as cilostazol, may form the basis of a novel therapeutic strategy for diabetes-associated cognitive impairment or vascular dementia.

Complete degradation of perchlorate using Pd/N-doped activated carbon with adsorption/catalysis bifunctional roles

Kim, Y.N.,Lee, Y.C.,Choi, M. Pergamon Press ; Elsevier Science Ltd 2013 Carbon Vol.65 No.-

Although perchlorate (ClO<SUB>4</SUB><SUP>-</SUP>) has a detrimental effect on human health, there have been only limited solutions for its complete degradation due to its extraordinary chemical stability. Physical adsorption using activated carbons and ion-exchange resins can provide fast, economic methods for perchlorate removal, but energy-efficient and environmentally benign ways for the disposal and regeneration of perchlorate-saturated adsorbents should be developed. Here we demonstrated an integrated process synergistically combining the strengths of physical adsorption and catalytic degradation by using 0.1wt.% Pd on N-doped activated carbon (Pd/N-AC) as an adsorption/catalysis bifunctional material. During the perchlorate adsorption from polluted water, the N-doped carbon surface provides increased number of adsorption sites for perchlorate compared to pristine carbon surface. After the carbon is saturated with perchlorate, the perchlorate concentrated on the carbon surface can be fully decomposed into non-toxic chloride (Cl<SUP>-</SUP>) by the catalytic function of supported Pd in H<SUB>2</SUB> atmosphere. Notably, the N-doped carbon surface and adsorbed water synergistically enhance the catalytic decomposition rate of perchlorate. As a result, Pd/N-AC showed complete perchlorate decomposition even at very mild condition (333K). The perchlorate adsorption/catalytic decomposition cycle could be repeated up to five times without loss of perchlorate adsorption capacity.

비육돈 생산단계에 따른 도체 및 부분육 생산 특성

김진형,박범영,유영모,조수현,김용곤,이종문,윤희진,김경남 한국동물자원과학회 2002 한국축산학회지 Vol.44 No.6

본 연구는 수출규격돈 생산과 고품질 돈육 생산에 필요한 기초자료를 제시하고자 도체 및 부분육 생산 특성을 조사한 것으로 도체중량에서는 듀록종이 원종, F_1종 및 비육돈에 비하여 적었다(p<0.05). 거래정육중량은 요그셔종과 F_1종이 다른 원종과 비육돈에 비하여 높은 반면 듀록종이 가장 낮았다(p<0.05). 도체길이는 랜드레이스와 F_1종이 다른 원종 및 비육돈에 비하여 길게 나타났고(p<0.05), 도체폭은 F_1종이 다른 순종 및 비육돈 보다 넓었다. 도체후도는 F_1종과 비육돈이 원종에 비하여 유의적으로 두꺼운 것으로 나타났다(p<0.05). 안심과 등심의 생산량은 랜드레이스와 요그셔 및 F_1종이 듀록 및 비육돈에 비하여 높게 나타났고 듀록이 가장 적었다(p<0.05). 목심 생산량은 요크셔와 F_1종이 다른 순종 및 비육돈에 비하여 높게 생산되었고(p<0.05), 듀록과 랜드레이스종이 가장 낮았다. 삼겹살 생산량은 듀록종이 낮았으며, 뒷다리는 요크셔와 F_1종이 다른 순종과 비육돈에 비하여 높게 생산되었고, 앞다리는 요크셔종이 생산량이 많았다(p<0.05). 일본 수출 기준에 따른 등심 합격률은 전체적으로 대단히 낮았고, 안심 합격률은 랜드레이스종이 100%로 가장 높았다. 앞다리와 뒷다리 합격률은 요크셔종이 각각 90.91%, 87.88%로 가장 높았다. 이상의 결과를 종합하면 비육돈의 부분육 및 수출급격육 생산이 미흡하므로 이를 만족시킬 수 있는 순종의 도입과 교배체계의 확립이 필요할 것으로 사료된다. The characteristics of carcass and meat yields of fattening pigs by production steps were investigated with Landrace (LL, n=41), Yorkshire (YY, n=33), and Duroc (DD, n=30), F_1 (LY, n=25), the Crossbred of LYD (n=48). Duroc had more weight loss in carcasses weight than that of the other breed(p<0.05). Yorkshire and F_1 had higher production weight in retail cut than that of the other pure or crossbred. Carcass from Landrace and F_1 were significantly longer in length than the other breed(p<0.05). F_1 produced wider carcass than the other breed. Carcass thickness at aitch bone was higher for F_1 and Crossbred than the other breed(p<0.05). Landrace, Yorkshire and F_1 produced more loin and tenderloin in weight than the other breed(p<0.05). Yorkshire and F_1 produced more picnic shoulder when compared to the other breed. The hind legs produced from Yorkshire and F_1 were higher in weight and the fore legs produced from the Crossbred were higher in weight. Duroc produced the lowest weight of belly among the breeds. The acceptance level of loin were extremely low for all breed. Landrace had the highest acceptance level for tenderloin. Yorkshire had the highest acceptance level for picnic shoulder and ham when evaluated by export standard of Japan. In conclusion, The introduction of pure breed and establishment of mating steps are necessary to produce highly accepted pork with high acceptance in carcass and meat yields.

Effect of annealing of graphene layer on electrical transport and degradation of Au/graphene/n-type silicon Schottky diodes

Kim, D.J.,Kim, G.S.,Park, N.W.,Lee, W.Y.,Sim, Y.,Kim, K.S.,Seong, M.J.,Koh, J.H.,Hong, C.H.,Lee, S.K. Elsevier Sequoia 2014 JOURNAL OF ALLOYS AND COMPOUNDS Vol.612 No.-

We have investigated the effect of annealing of graphene sheets on the electrical properties of Au/graphene/n-type silicon Schottky diode. Large scale graphene sheets were grown by chemical vapor deposition and then annealed at 300, 400, and 500<SUP>o</SUP>C; one sheet was left un-annealed as the control. The diodes were fabricated by transferring the graphene sheets directly onto n-type Si substrates and the current-voltage (I-V) and capacitance-voltage (C-V) characteristics were evaluated. The average values of the Schottky barrier height (SBH) and ideality factor (η) for the as-fabricated Au/graphene/n-type silicon Schottky diode from I-V measurements were determined to be ~0.8+/-0.01eV and ~1.79+/-0.05, respectively, whereas the SBH from C-V measurements was ~0.89+/-0.01eV. The electrical transport characteristics measured at room temperature indicated that annealing of graphene sheet prior to the transfer of the graphene onto the n-Si substrates significantly reduces the electric degradation of the Schottky diodes, even though no distinct differences in other electric properties, including ideality factors and SBHs, before or after annealing of the graphene sheets were observed. Thus, by simply annealing the graphene sheets at 500<SUP>o</SUP>C, we found that the Au/graphene/n-type silicon Schottky diode showed an approximately 3.3-fold lower series resistance as compared with the un-annealed Schottky diode under air exposure of up to 7days. These annealed diodes showed significantly reduced electrical degradation by removing the potentially trapped H<SUB>2</SUB>O and/or O<SUB>2</SUB> at the interface between the graphene layer and the n-Si substrate.

Lasalocid induces cytotoxic apoptosis and cytoprotective autophagy through reactive oxygen species in human prostate cancer PC-3 cells

Kim, K.Y.,Kim, S.H.,Yu, S.N.,Park, S.G.,Kim, Y.W.,Nam, H.W.,An, H.H.,Yu, H.S.,Kim, Y.W.,Ji, J.H.,Seo, Y.K.,Ahn, S.C. Masson Pub. USA, Inc 2017 BIOMEDICINE AND PHARMACOTHERAPY Vol.88 No.-

<P>Lasalocid is an antibiotic from the group of carboxylic ionophores, produced by Streptomyces lasaliensis. But there was limited information of lasalocid on human prostate cancer cells. In the present studies, to better understand its effect in human prostate cancer cells, apoptosis and autophagy associated with possible signal pathways in vitro was examined. Our study showed that lasalocid mediated cell cycle arrest in G(0)/G(1) phase by reducing G(1) phase dependent proteins, indicating entering into apoptotic cell death pathway. Lasalocid-induced apoptosis was involved with reactive oxygen species (ROS) production, and mitochondrial hyperpolarization. In addition, lasalocid induced autophagy through microtubule-associated protein 1 light chain 3 (LC-3)-II conversion, acidic vesicular organelles formation and GFP-LC-3 punctuate, which was inhibited by 3-methyladenine (3-MA), a widely used pharmacological inhibitor of autophagy. Furthermore, the autophagic phenomena were mediated by production of ROS, confirming that inhibition of ROS with N-acetyl-L-cysteine, a ROS inhibitor, attenuated lasalocid-triggered autophagy. Inhibition of autophagy with 3-MA enhanced the lasalocid-induced apoptosis through enhanced ROS generation. Taken together, lasalocid should be useful in the search for new potential chemotherapeutic agents for understanding the molecular mechanisms of anticancer in prostate cancer cells. (C) 2017 Elsevier Masson SAS. All rights reserved.</P>

간호대학생의 팀 프로젝트 경험

김명선,김주리,김휘주,손유진,신하늘,이나영,정다영,채유미,최지연,김미영,김태연 이화여자대학교간호학회 2020 이화간호학회지 Vol.- No.54

Purpose: The purpose of this study was to explore what nursing students have experienced in carrying out team projects and what factors should be considered in the following team projects. Methods: The data were collected from June 2019 to January 2020 by nine researchers conducting a semi-structured and face-to-face interview with 10 participants. A total of three interviews per participant were conducted respectively, and additional datas were supplemented by In-person or telephone interview. This study was applied qualitative content analysis method by Elo and Kyngas in data analysis process. Results: Participants' team project experience were emerged into six categories. These were ‘method of team organization’, ‘the number of team members’, ‘team leader’, ‘method of communication’, ‘free rider’, and ‘peer evaluation’. Conclusion: This study is meaningful in that it focused on nursing students and explored their team project experience. It is also important that this study suggested that the number of team members, which has not been noted before in other studies, affects the quality of team projects.