• The Journal of Korean Institute of Communications and Information Sciences
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• v.28 no.3A
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• pp.179-184
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• 2003

In this paper, an asymmetric topology of MMIC SPDT switch was proposed to increase the isolation in the receiving path and decrease the insertion loss with higher P1dB in the transmitting path for the ISM band. This SPDT switch was implemented with 0.5㎛ GaAs MESFETs processed by ETRI for the IDEC MPW project. For the receiving path the measured insertion losses were 1.518dB at 3GHz and 1.777dB at 5.75GHz and the isolations were 38.474dB at 3GHz and 29.125dB at 5.75GHz. For the transmitting path the insertion losses were 0.916dB at 3GHz and 1.162dB at 5.75GHz and the isolations were 23.259dB at 3GHz and 16.632dB at 5.75GHz. Compared to the symmetric topology the isolations of the receiving path for the asymmetric one were improved by 15.9dB at 3GHz and 11.9dB at 5.75GHz and its insertion loss was increased by about 0.6dB. In addition, P1dB of 21.5 dBm for the transmitting path was obtained, which is increased by 3.86dB compared to the symmetric one.

• ALGAE
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• v.18 no.1
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• pp.13-20
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• 2003

Two isolated Antarctic marine diatoms, Chaetoceros neogracile VanLandingham and Stellarima microtrias (Ehrenberg) Hasle and Sims were examined to show changes of growth and uptake rate of nitrate due to UV-B irradiance. Chlorophyll (chl) a concentration was regarded as the growth index of diatom. The diatoms were treated with UV-B radiation and cultured for 4 days under cool-white fluorescent light without UV-B radiation. Two levels of UV-B exposures were applies: 1 and 6 W $m^{-2}$. Durations of UV-B treatment were 20, 40 and 60 minutes under 6 W $m^{-2}$ and 1, 2, 3, 4 and 5 hrs under 1 W $m^{-2}$. The control groups were cultured at the same time without UV-B radiation. The growth rates of two diatoms decreased under 1 and 6 W $m^{-2}$ UV-B irradiances than that of control group. After 4 days, chl a concentrations of C. neogracile were increased more than 4 times from 133 μgo$l^{-1}$ to 632 μgo$l^{-1}$ in control group. However, the concentration of experimental groups under 1 W $m^{-2}$ UV-B were only increased from 139 μgo$l^{-1}$ to 421 μgo$l^{-1}$ during one hour and the chl a concentrations were decreased from 144 μgo$l^{-1}$ to 108 μgo$l^{-1}$ during five hour. Growth of diatom dramatically more decreased under 6 W $m^{-2}$ UV-B than 1 W $m^{-2}$ UV-B. The chl a concentration of experimental groups under 6 W $m^{-2}$ UV-B for one hour was only increased from 111 μgo$l^{-1}$ to 122 μgo$l^{-1}$. In the case of S. microtrias showed also similar pattern to C. neogracile by UV-B radiation. The uptake rates of nitrate by the two strains were decreased abruptly under 6 W $m^{-2}$ UV-B irradiances. When two strains were treated under 1 and 6 W $m^{-2}$ UV-B during one hour, the strains were only continued growth and uptake of nitrate under 1 W $m^{-2}$ UV-B. This experimental evidence shows that exposure to UV-B radiation especially to high irradiance of UV-B decreases diatom survival and causes lower decrease of nutrient concentrations by microalgae in Antarctic water. Furthermore, evidence suggests that microalgal communities confined to near-surface waters in Antarctica will be harmed by increased UV-B radiation, thereby altering the dynamics of Antarctic marine ecosystems.

• Bulletin of the Korean Mathematical Society
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• v.35 no.1
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• pp.99-117
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• 1998

Let $(B, H, p_1)$ be an abstract Wiener space and $F(B)$ the Fresnel class on $(B, H, p_1)$ which consists of functionals F of the form : $$ F(x) = \int_{H} exp{i(h,x)^\sim} df(h), x \in B, $$ where $(\cdot, \cdot)^\sim$ is a stochastic inner product between H and B, and f is in $M(H)$, the space of complex Borel measures on H. We introduce an $L_1$ analytic Fourier-Feynman transforms for functionls in $F(B)$. Furthermore, we introduce a convolution on $F(B)$, and then verify the existence of the $L_1$ analytic Fourier-Feynman transform for the convolution product of two functionals in $F(B)$, and we establish the relationships between the $L_1$ analytic Fourier-Feynman tranform of the convolution product for two functionals in $F(B)$ and the $L_1$ analytic Fourier-Feynman transforms for each functional. Finally, we show that most results in [7] follows from our results in Section 3.

• Korean Journal of Pharmacognosy
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• v.41 no.3
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• pp.227-231
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• 2010

Protein tyrosine phosphatase 1B (PTP1B) is predicted to be therapeutic target in treatment of type 2 diabetes and obesity. Thus, in order to search for PTP1B inhibitors, we screened the inhibitory activity of PTP1B in the water extracts of 84 medicinal herbs. Among them, the extracts of Pini Folium, Magnoliae Cortex, Artemisiae asiaticae Herba, Schizonepetae Herba, Menthae Herba, Mume Fructus, Cimicifugae Rhizoma, and Amomi Cardamomi Fructus showed relatively significant (58-68%) inhibitory activity against PTP1B. Especially, the methylene chloride fraction of the methanol extract of Menthae Herba (81% inhibition at 30 ${\mu}g$/ml) showed more potent inhibitory activity against PTP1B than others.

• Journal of Veterinary Clinics
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• v.29 no.5
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• pp.395-399
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• 2012

In 2011, several herds in Youngju city in Gyeongbuk province underwent an outbreak of bovine viral diarrhea virus (BVDV) causing high morbidity and mortality. Genetic analysis revealed that two subgenotypes of BVDV-1b (n = 21) and BVDV-2a (n = 7) were identified. The BVDV-1b subgenotype was most frequently detected from our field cases and BVDV-2a subgenotype was also identified in this outbreak. These BVDV-1b infections showed severe acute clinical manifestations similar to BVDV-2 infection. This result reports the detection of BVDV-1b associated with an acute and fatal outbreak of BVDV in Korean indigenous calves.

• Journal of Microbiology and Biotechnology
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• v.17 no.5
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• pp.774-783
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• 2007

In the present study, acidocin 1B, a bacteriocin produced by Lactobacillus acidophilus GP 1B, exhibited profound inhibitory activity against a variety of LAB and pathogens, including Gram-negative bacteria, and its mode of action was to destabilize the cell wall, thereby resulting in bactericidal lysis. Acidocin 1B was found to be heat stable, because it lost no activity when it was heated up to $95^{\circ}C$ for 60 min. It retained approximately 67% of the initial activity after storage for 30 days at $4^{\circ}C$, and 50% of its initial activity after 30 days at $25^{\circ}C$ and $37^{\circ}C$. The molecular mass of acidocin 1B was estimated to be 4,214.65 Da by mass spectrometry. Plasmid curing results indicated that a plasmid, designated as pLA1B, seemed to be responsible for both acidocin 1B production and host immunity, and that the pLA1B could be transformed into competent cells of L. acidophilus ATCC 43121 by electroporation. Our findings indicate that the acidocin 1B and its producer strain may have potential value as a biopreservative in food systems.

• Journal of Korean Neurosurgical Society
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• v.29 no.6
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• pp.725-730
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• 2000

Purpose : The subcellular localization of E1B-19k has been known cytosol or nuclear membrane by immunohistochemical staining and could dimerize with Bax to regulate cell death also known by the in-vitro immunoprecipitation. We planed to confirm this dimerization of E1B-19k with Bax in vivo in Cos-7 cells by using green fluorescent protein. Material and Method : We cloned E1B-19k and Bax into C3-EGFP. C3-EGFP-E1B-19k, C3-EGFP-Bax, and C3-EGFP-E1B-19k and pcDNA3-Bax were transfected into Cos-7 cells. We explored location of E1B-19k and Bax, and confirmed its dimerization with Bax in transfected living healthy Cos-7 cells by following green fluorescent protein of E1B-19k on the confocal microscope. Results : E1B-19k was located diffusely in cytoplasm and in nucleus but not in mitochondria. It prevented cell death from the apoptosis by staurosporine but its location was not changed. GFP-E1B-19k is not changed its intracellular location with Bax even with staurosporine. Conclusion : These results support that E1B-19k does not localize in mitochondria nor dimerize with Bax even with staurosporine. We could anticipate E1B-19k prevent cell death via the other dimerizing partner or pathways.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.50 no.6
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• pp.442-446
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• 2005

This study was conducted to obtain basic information on the utilization of wheat flour for good organoleptic evaluation score. Wheat seed was milled by Buhler test mill. Volatile flavor compounds of five milling fractions such as Break $I{\cdot}II (B_1+B_2)$, Reduction I ($R_1$), Reduction II ($R_2$), Bran and Short were determined and their differences were discussed. There was significant difference in quantity of flavor compounds but no difference in qualitative composition among milling fractions. The outer layer of wheat endosperm ($R_2$ layer) showed higher amount of m-xylene and n-butanol in volatile flavor com­pounds compared with inner endosperm layer ($B_1,\;B_2,\;R_1$). The $R_2$ layer showed quantitatively higher composition of major flavor compounds than inner endosperm layer ($B_1,\;B_2,\;R_1$). This result points out that the $R_2$ layer exhibited stronger flavor than $B_1,\;B_2$, and Rl layers.

• IMMUNE NETWORK
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• v.6 no.3
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• pp.138-144
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• 2006

Background: There are at least two different subsets of B cells, B-1 and B-2. The characteristic features and function of B-2 cells in addition to the effect of steroids on B-2 cells are well-known. Although B-1 cells have different features and functions from B-2 cells, the effect of steroids on B-1 cells is not completely understood. Therefore, this study examined the effects of dexamethasone on peritoneal (or B-1 cells) and splenic B cells (or B-2 cells). Methods: Purified B cells were obtained from the peritoneal fluid and the spleens of mice. The isolated B cells were cultured in a medium and after adding different concentrations of dexamaethasone. The cell survival rate was measured by flow cytometry using propidium iodide. The expression level of the B cell surface marker was analyzed by flow cytometry. During the culture of these cells, immunoglobulin secreted into the culture supernatants was evaluated by an enzyme-linked immunosorbent assay. Results: The survival rate of peritoneal and splenic B cells decreased with increasing dexamethasone concentration. However, the rate of peritofieal B cell apoptosis was lower than that of splenic B cells. CDS and B7.1 expression in peritoneal B cells and CD23 and sIgM expression in splenic B cells after the dexamethasone treatment were reduced. When B cells were treated with dexamethasone, the spontaneous IgM secretion decreased with increasing dexamethasone concentration. Conclusion: Dexamethasone induces apoptosis in peritoneal and splenic B cells. However, peritoneal B cells are less sensitive to dexamethasone. The dexamethasone suppressed expression of the surface markers in peritoneal B cells is different from those in splenic B cells.

• Investigative Magnetic Resonance Imaging
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• v.7 no.2
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• pp.137-143
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• 2003

Purpose : B1 field of birdcage RF (radiofrequency) coil that is used most for brain imaging in magnetic resonance imaging (MRI) decreases toward endring from the coil center. We investigated how much RE B1 homogeneity effect the endcap shield brings form the coil center as it towards to endcap region. Materials and Methods : We compared RF B1 field distribution by each finite difference time domain (EDTD) simulations for lowpass, highpass and hybrid birdcage RF coils. We selected the highpass birdcage RF coil that was the highest RF B1 field condition as simulation result, and studied how much RF B1 homogeneity effect was occurred when endcap shield was applied to endring area. Results : B1 field of the highpass birdcage RF coil was higher than other birdcage RF coil types as simulation result. However, the RF B1 homogeneity was lower than other coil types. RE B1 field of highpass birdcage RF coil with endcap shield is similar with RF B1 field of hybrid birdcage RF coil and the overall RE B1 homogeneity in sagittal direction was better. Conclusion In this paper, proposed method can apply improving RF B1 homogeneity of RF coil in clinical examination.