[ $Bi_2Sr_2CaCu_2O{8+\delta}$ ] Intrinsic Josephson Junctions in a Parallel Magnetic Field

Lee, J.H.,Chong, Yon-Uk,Lee, Su-Youn,Khim, Z.G. The Korean Superconductivity Society 2000 Progress in superconductivity Vol.1 No.2

We have investigated the Josephson vortex dynamics in $Bi_2Sr_2CaCu_2O{8+\delta}$ intrinsic Josephson junctions subjected to a magnetic field parallel to $CuO_2$ planes. We investigated mesas with $40\times40{\mu}m^2$ in size and containing 6 and 20. intrinsic junctions. The zero field I-V characteristics exhibited a typical hysteretic, multi-branched nature of the intrinsic Josephson effect. At high magnetic fields (H>1.5 T), I-V characteristics showed flux flow steps. The Swihart velocity obtained from this observation was about $4.2\times10^5$ m/s, which was the lowest mode electromagnetic wave velocity of N coupled stack. The experimental I-V curves fitted well into the simple model of Cherenkov radiation including Ohmic and non-linear dissipation terms. This suggests that the dissipation mechanism of Josephson vortex be due to both Cherenkov radiation and quasiparticle tunneling current.

Ferromagnetism in ZnCoO due to Hydrogen-Mediated Co–H–Co Complexes: How to Avoid the Formation of Co Metal Clusters?

Kim, Su Jae,Cha, Su Young,Kim, Ji Young,Shin, Jong Moon,Cho, Yong Chan,Lee, Seunghun,Kim, Won-Kyung,Jeong, Se-Young,Yang, Y. S.,Cho, Chae Ryong,Choi, H. W.,Jung, Myung-Hwa,Jun, Byeong-Eog,Kwon, Ki-Yon American Chemical Society 2012 The Journal of Physical Chemistry Part C Vol.116 No.22

<P>There have been many studies of ferromagnetism in ZnCoO, and the results have been controversial. Secondary phases, such as Co oxides and Co metal clusters, in ZnCoO are easily produced during treatment, but the formation conditions are not well understood. We fabricated samples under hydrogen-injection conditions at different heat-treatment temperatures and examined the conditions by using synchrotron X-ray analysis under which Co<SUB>3</SUB>O<SUB>4</SUB> appeared or was transformed into Co metal. We investigated the transforming process of the ferromagnetic origin from intrinsic to extrinsic nature via intermediate region competition by Co–H–Co and Co metal cluster and suggest conditions that induce ferromagnetic spin ordering in ZnCoO due to Co–H–Co complexes through hydrogen mediation.</P><P><B>Graphic Abstract</B> <IMG SRC='http://pubs.acs.org/appl/literatum/publisher/achs/journals/content/jpccck/2012/jpccck.2012.116.issue-22/jp300536w/production/images/medium/jp-2012-00536w_0010.gif'></P>

Genetically engineered fibroblasts with antigen-presenting capability:Efficient induction of an antigen-specific cytotoxic T-lymphocyte response and protection against tumor development in vivo

Kim, Tae S .,Chung, Su W .,Kim, Seung H .,Kang, Bok Y .,Hwang, Seung Y .,Lee, Jae W . 전남대학교 약품개발연구소 2000 약품개발연구지 Vol.9 No.1

BLK mouse fibroblasts (H-2^b) were genetically engineered to express costimulatory B7.1 and interleukin-2 (BLK/IL2/B7.1). The BLK/IL2/B7.1 cells were then pulsed with an ovalbumin (OVA) epitope as a model antigen (Ag) (BLK/IL2/B7.1/OVA), and tested for the induction of OVA-specific cytotoxic T lymphocytes (CTLs) in C57BL/6 mice (H-2^b). The genetically engineered fibroblasts lacking one or two of three factors (interleukin-2, B7.1, and OVA) were constructed and used as controls. Immunization with the BLK/IL2/B7.1/OVA cells induced strong cytotoxic activities against OVA-expressing EL4 (EG7) tumor cells, but not against other H-2^b tumor cells, such as EL4, C1498 and B16F1 cells. The magnitude of the cytotoxic response in mice with the BLK/IL2/B7.1/OVA cells was significantly higher than the response in mice immunized with any other cell constructs. CD8^+ T cells with OVA-specific cytotoxic activities were predominant in mice immunized with the BLK/IL2/B7.1/OVA cells. Furthermore, immunization with the BLK/IL2/B7.1/OVA cells significantly prolonged the survival of mice, compared with any other cell constructs, when the mice were challenged with EG7 tumor cells at 2 weeks postimmunization. Induction of antitumoral CTL immunity by the BLK/IL2/B7.1/OVA cells was independent of host Ag-presenting cells and of CD4^+ T-cell and natural killer 1.1^+ cell help. These results suggest that fibroblasts can be genetically modified to efficient Ag-presenting cells for the induction of an Ag-specific CTL response.

Perturbative studies of toroidal momentum transport in KSTAR H-mode and the effect of ion temperature perturbation

Yang, S.M.,Na, Yong-Su,Na, D.H.,Park, J.-K.,Shi, Y.J.,Ko, W.H.,Lee, S.G.,Hahm, T.S. International Atomic Energy Agency 2018 Nuclear fusion Vol.58 No.6

<P>Perturbative experiments have been carried out using tangential neutral beam injection (NBI) and non-resonant magnetic perturbation (NRMP) to analyze the momentum transport properties in KSTAR H-modes. Diffusive and non-diffusive terms of momentum transport are evaluated from the transient analysis. Although the operating conditions and methodologies applied in the two cases are similar, the momentum transport properties obtained show clear differences. The estimated momentum diffusivity and pinch obtained in the NBI modulation experiments is larger than that in the NRMP modulation experiments. We found that this discrepancy could be a result of uncertainties in the assumption for the analysis. By introducing time varying momentum transport coefficients depending on the temperature gradient, the linearized equation shows that if the temperature perturbation exists, the evolution of toroidal rotation perturbation could be faster than the transport rate of mean quantity, since the evolution of toroidal rotation perturbation is related to <img ALIGN='MIDDLE' ALT='' SRC='http://ej.iop.org/images/0029-5515/58/6/066008/nfaab90eieqn001.gif'/>, a momentum diffusivity from perturbative analysis. This could explain the estimated higher momentum diffusivity using time independent transport coefficients in NBI experiments with higher ion temperature perturbation compared to that in NRMP modulation experiments. The differences in the momentum transport coefficient with NRMP and NBI are much reduced by considering time varying momentum transport coefficients in the time dependent transport simulation.</P>

Reversible and Irreversible Responses of Defect-Engineered Graphene-Based Electrolyte-Gated pH Sensors

Kwon, Sun Sang,Yi, Jaeseok,Lee, Won Woo,Shin, Jae Hyeok,Kim, Su Han,Cho, Seunghee H.,Nam, SungWoo,Park, Won Il American Chemical Society 2016 ACS APPLIED MATERIALS & INTERFACES Vol.8 No.1

<P>We have studied the role of defects in electrolyte-gated graphene mesh (GM) field-effect transistors (FETs) by introducing engineered edge defects in graphene (Gr) channels. Compared with Gr-FETs, GM-FETs were characterized as having large increments of Dirac point shift (similar to 30-100 mV/pH) that even sometimes exceeded the Nernst limit (59 mV/pH) by means of electrostatic gating of H+ ions. This feature was attributed to the defect-mediated chemisorptions of H+ ions to the graphene edge, as supported by Raman measurements and observed cycling characteristics of the GM FETs. Although the H+ ion binding to the defects increased the device response to pH change, this binding was found to be irreversible. However, the irreversible component showed relatively fast decay, almost disappearing after 5 cycles of exposure to solutions of decreasing pH value from 8.25 to 6.55. Similar behavior could be found in the Gr-FET, but the irreversible component of the response was much smaller. Finally, after complete passivation of the defects, both Gr-FETs and GM-FETs exhibited only reversible response to pH change, with similar magnitude in the range of 68 mV/pH.</P>

자율기능성 갑상선 결절

이문호,문대혁,이기업,김기수,송영기,이명혜,안세현,박건춘 대한내분비학회 1992 Endocrinology and metabolism Vol.7 No.2

To define the clinical characteristics and the course of the autonomously functioning thyroid nodule (AFTN) in Koreans, the authors reviewed case records of the patients with AFTN from May 1989 to December 1991. Among 1412 cases of thyroid nodule, 48 (3.4%) had AFTN, with 44 females and 4 males and mean age (±S.D.) of 45.2 (±15.0) years, ranging 17 to 79 years. The age and sex distribution of the patients with AFTN were not different with those in patients with cold thyroid nodules. Of the 48 patients with AFTN, 13 had hyperthyroidism (8 clinical and 5 subclinical). Hyperthyroid patients had larger nodule than euthyroid patients, however, their age was not different. Five patients with clinical hyperthyroidism were treated surgically and they maintained euthyroid until 5 to 27 months after operation. One patient had papillary carcinoma, and another four had adenomatous goiter. Five patients with subclinical hyperthyroidism and 25 patients with euthyroid AFTN were followed for 5 to 35 months without specificreatment, however, none of them showed significant changes in thyroid function. In summary, AFTN is not frequent in Koreans, some of AFTN is maligant, surgery is an effective therapeutic modality, and AFTN runs a chronic stable course without an abrupt change in function. (J Kor Soc Endocrinol 7:121~126, 1992)

乳牛의 繁殖障碍에 關한 硏究

韓壽南,李文漢,韓弘粟 서울대학교 1975 서울대학교 論文集 Vol.25 No.-

In order to investigate the status of reproductive disturbances, 523 Holstein dairy cows in Chung Nam and Kyengki areas were examined, and 26 heads of normal pregnant cows and 77 heads of sterile cows among these were chosen to determine urinary physicochemical values. For estrogen determination, 2 heads of normal vacant cows in the period of estrus were chosen. These values were statistically and etiologically analysed. The results obtained in this work are summarised as follows: 1. Among 523 heads, 103 (19.4%) were sterile dairy cows and were classified as 19 (18.4%) of follicular cyst, 7 (6.8%) of luteal cyst, 16(15.5%) of endometritis, of unknown etiology, 4 (3.9%) of ovarian hypoplasia, 5(4.85%) of ovarian atrophy, 2(1.94%) of mesosalpingitis, 3(2.9%) of lutein cyst. 2(1.94%) of granulomatic change in ovary, 1(0.97%) of uterine atrophy and 2(1.94%) of pyometra. 2. Significantly hither values of urinary glucose, protein and inorganic phosphorus, and a wide calcium­phosphorus ratio of the sterile dairy cow group (77 heads) were observed compare to the normal group. 3. In the follicular cyst group (16 heads), The values of urinary glucose, inorganic phos­phorus and urobilinogen were significantly higher than those of normal groups. 4. In the luteal cyst group (6 heads), the urinary values of specific gravity, urobilinogen, total nitrogen and nonprotein nitrogen were significantly lower than those of normal groups. 5. In the endometritis group (10 heads), the urinary values of pH, Specific gravity, nonprotein nitrogen, magnesium, protein and glucose were significantly higher, however, inorganic phos­phorus and albumin­globulin ratio of the group were significantly lower than those of normal groups. 6. In the unknown etiology group (40 heads), the values of urinary glucose, ketone bodies and protein were significantly higher than those normal groups. 7. In the other diseases group (5 heads included 2 heads of ovarian hypoplasia and 1 head of ovarian atrophy, mesosalpingitis and granulomatic change of ovary, respectively.), only the specific gravity was lower than that of normal group. 8. The result of determination for three original estrogens; estrone, estradiol and estriol, only estrone content of sterile dairy cow group (5 heads included 4 heads of follicular cyst, 2 heads of luteal cyst and 1 heads of ovarian atrophy) was lower than that of normal vacant cow group.

Anti-Helicobacter pylori activities of FEMY-R7 composed of fucoidan and evening primrose extract in mice and humans

Tae-Su Kim,Ehn-Kyoung Choi,Jihyun Kim,Kyungha Shin,Sung-Pyo Lee,Youngjin Choi,Joseph H. Jeon,Yun-Bae Kim 한국실험동물학회 2014 Laboratory Animal Research Vol.30 No.3

Helicobacter pylori-eliminating effects of FEMY-R7, composed of fucoidan and evening primrose extract, were investigated in mice and humans. Male C57BL/6 mice were infected with the bacteria by intragastric inoculation (1×10<SUP>9</SUP> CFU/mouse) 3 times at 2-day intervals, and simultaneously, orally treated twice a day with 10 or 100 mg/kg FEMY-R7 for 2 weeks. In Campylobcter-like organism-detection test, FEMY-R7 markedly reduced the urease-positive reactivity. In a clinical sudy, human subjects, confirmed to be infected with Helicobacter pylori, were orally administered twice a day with a capsule containing 150 mg FEMY-R7 for 8 weeks. FEMY-R7 significantly decreased both the Delta over baseline-value in urea breath test and the serum pepsinogens I and II levels. The results indicate that FEMY-R7 not only eliminates H. pylori from gastric mucosa of animals and humans, but also improves gastric function.

Effect of the Different pH Levels of Nutrient Solution on the Growth and Color of Echeveria ‘Perle von Nurnberg’

Pil Man Park,Su Young Lee,Pue Hee Park,Hye Ryun An,J. Ryan Stewart,Héctor Genaro Ortiz Cano 한국화훼학회 2021 화훼연구 Vol.29 No.3

양액 pH가 에케베리아 생육과 색상에 미치는 영향을 알아 보기 위해 본 연구를 수행하였다. 에케베리아 ‘Perle von Nurnberg’ 품종을 선택하여 미국 유타주 프로보(Provo)시 소재 브리검영대학교 Plant and Wildlife 학과의 연구온실에서 수행되었다. 이 품종에 pH 4, pH 7 및 pH 10 3종류의 양액을 공급하여 연구를 수행하였다. 양액 pH 4 처리구에서는 초폭이 120.6mm로 pH 10 처리구의 105.3mm 보다 크게 자랐으며 유의성도 있었다. 하지만 엽장, 엽폭, 엽수에 있어서는 처리간 유의성은 없었다. pH meter를 통해서 식물체 즙액의 pH 를 측정하였는데 4.5에서 4.7 범위의 값을 보였으며 처리간 유의성은 없었다. 위의 결과로 양액의 pH는 식물체의 pH에 영향을 미치지 않는 것으로 판단되었다. 색차계를 이용하여 CIELAB 값을 측정하였을 때 pH 4 처리구에서의 적색도(a)는 -4.0이었으며 pH 10 처리구보다 더 녹색을 띠었다. 명도(L)과 황색도(b) 값은 처리간에 유의적인 차이가 없었다. HPLC를 통한 안토시아니딘 분석에서는 주로 cyanidin, delphinidin 및 pelargonidin의 함량이 모든 처리구에서 상대적으로 높게 나타났다. 공급양액의 pH가 상승함 따라 그 함량도 높아지는 경향을 보였다. Petunidin, malvidin 함량은 미량으로 존재하였으며, peonidin은 분석되지 않았다. 이상의 결과로부터 양액을 pH 10으로 처리하였을 때 에케베리아의 생육억제와 잎 착색에 가장 효과적임을 알 수 있었다. This experiment investigated the growth and leaf color of Echeveria ‘Perle von Nnurnberg’ in the experimental greenhouse of Plant and Wildlife Sciences, Brigham Young University, Provo, Utah. For one month, this cultivar was grown with three pH levels in nutrient solutions of pH 4, 7, and 10. The plant diameter of pH 4 nutrient solution was 120.6 mm and significantly bigger than that of pH 10 (105.3 mm). However, there were no significant differences in leaf length, leaf width, and number of leaves. The plant pH was measured by leaf extraction using a pH meter. The pH values were 4.5–4.7, but not significantly different among the treatments. Our result showed that the pH of the nutrient solution did not affect the plant pH. Additionally, the CIELAB values of leaves were measured using a colorimeter. The redness (a) of leaves in pH 4 treatment was -4.0, and the leaf was more greenish than that of pH 10 treatment. The degrees of lightness (L) and yellowness (b) were not significantly different among the treatments. From high-performance liquid chromatography analysis (HPLC), cyanidin, delphinidin, and pelargonidin were mainly detected in the treatments. As the pH level of the nutrient solutions increased, these anthocyanidins contents trended to be high. The contents of petunidin and malvidin were relatively small, and peonidin was not detected in all treatments. we conclude that pH10 treatment of the nutrient solution was most effective for the growth retardation and coloration of leaf in Echeveria.

Momilactone B, an Allelochemical of Rice Hulls, Induces Apoptosis on Human Lymphoma Cells (Jurkat) in a Micromolar Concentration

Lee, Seung C.,Chung, Ill-Min,Jin, Yeong J.,Song, Yeon S.,Seo, Su Y.,Park, Bong S.,Cho, Kwang H.,Yoo, Ki S.,Kim, Tae-Hyun,Yee, Su-Bog,Bae, Yoe-Sik,Yoo, Young H. Routledge 2008 Nutrition and cancer Vol.60 No.4

<P> Although momilactone B has been studied as an allelochemical of rice (Oryza sativa L.), to date we have no report showing the effect of momilactone B on mammalian cells. This study was undertaken to examine whether this allelochemical has anticancer activity on cancer cells. We show here that momilactone B at micromolar doses has antitumor efficacy by inducing apoptosis in several blood cancer cells including human leukemic T cells. In addition, our study elucidated that anticancer activity of momilactone B on human leukemic T cells resulted from the induction of apoptosis via caspase and mitochondria. From these results, momilactone B can be considered as a novel therapeutic strategy for human leukemic T cells from its direct apoptosis-inducing activity.</P>