• 한국진공학회:학술대회논문집
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• 한국진공학회 1998년도 제14회 학술발표회 논문개요집
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• pp.17-17
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• 1998

Synchrotron radiation is produced when charged particles moving with relativistic velocities a are accelerated - for example, deflected by the bending magnets which guide the electron or p positrons in circular accelerators or storage rings. By using special focusing magnetic lattices i in the particle accelerators it is possible to make the dimensions of the particle beam very small with a hi맹 charge density which results in a light source with high b디lIiance. Synchrotron light h has important properties which make it ideal for a wide range of investigations in surface s science. The fact that the spectrum of electromagnetic radiation emitted in a bending magnet e extends in a continuum from the 얹r infra red region to hard x-rays means that it is id않I for a v variety of spectroscopic studies. Since there are no convenient lasers, or other really bright l light sources, in the vacuum ultraviolet and soft x-ray re.밍ons the development of synchrotron r radiation has enabled enormous advances to be made in this di펌C비t spectr따 re밍on. P Polarization-dependent measurements, for ex없nple ellipsometry or circular dichroism studies a are possible because the radiation has a well-defined polarization - linear in the plane of orbit w with additional right-circular, or left-circular, components for emission an생es above, or below, t the horizontal, respectively. Since the synchrotron light is emitted from a bunch of charge c circulating in a ring the light is emitted with a well-defined time structure with a short flash of l light every time a bunch passes an exit port. The time structure depends on the size of the ring a and the number and sequence of filling of the bunches. A pulsed light source enables time¬r resolved studies to be performed which provide direct information on the lifetimes and decay m modes of excited states and in addition opens up the possibility of using time of flight t techniques for spectroscopic studies. The fact that synchrotron radiation is produced in a clean u ultrahi야 vacuum environment is of gr않t importance for surce science studies. The current t비rd generation synchrotron light sources provide exceptionally high baliance and stability a and open up possibilities for experiments which would have been inconceivable only a short time ago.

• 한국식품영양과학회지
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• 제41권12호
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• pp.1716-1726
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• 2012

더위지기 추출물이 STZ으로 유발된 당뇨쥐에서 혈당, 지질 및 항산화효소에 미치는 영향을 알아보고자 용량(1 g, 2 g 및 3 g/kg b.w.)을 달리하여 14일간 경구투여한 실험에서 다음과 같은 결과를 얻었다. 정상군을 비롯한 당뇨유발군, 당뇨유발에 더위지기를 투여시킨 군을 14일간 실험한 결과 STZ 투여로 식이섭취량은 증가된 반면 체중은 감소되었는데, 더위지기 추출물을 2 g 투여 시 체중증가량의 변화는 관찰되지 않은 반면 식이섭취량은 억제되었다. 장기의 상대적인 중량비교에서 신장의 경우 당뇨대조군에 비해 더위지기 추출물을 1 g 투여 시 비대가 유의적으로 억제되었다. 당뇨로 인하여 증가된 ALT 활성도는 더위지기 추출물을 2 g과 3 g 투여 시, AST 활성도는 1 g과 3 g 투여 시 당뇨대조군에 비해 유의적으로 감소되었다. 혈장 포도당 함량은 실험 4일째부터 실험 14일째까지 당뇨대조군에 비해 더위지기 추출물을 2 g 투여함으로써 혈당치가 저하됨을 관찰할 수가 있었으며, 간의 글리코겐 함량도 더위지기 추출물을 2 g 투여 시 유의적으로 증가하였다. 혈장의 중성지방과 유리지방산 함량은 더위지기 추출물 2 g 투여 시 당뇨대조군에 비해 유의적으로 감소하였다. 동맥경화지수는 더위지기 추출물을 투여한 모든 당뇨실험군에서 유의적으로 저하되는 것으로 나타났다. 간의 MDA 함량이 모든 Ai투여군에서 당뇨대조군보다 유의적으로 감소하였다. 간에서의 항산화 효소 중 SOD 활성도는 당뇨대조군에 비해 더위지기 추출물을 3 g 투여 시 유의적으로 증가하였다. CAT와 GSH-px 활성도는 당뇨대조군에 비해 더위지기 추출물을 1 g과 3 g 투여 시 유의적으로 증가하였다. GST 활성도는 당뇨대조군에 비해 모든 Ai투여군이 유의적으로 높았으며 용량의존적으로 차이를 보였다. 이상의 실험결과를 통해 더위지기 추출물은 당뇨로 인한 체중저하를 방지하고, STZ로 유도한 고혈당을 완화시키는 항당뇨작용과 더불어 항산화효소의 활성도를 증가시켜 산화스트레스 감소를 유도하여 고혈당에 의한 조직손상을 감소시켜 주는 것으로 사료된다.

• Journal of Plant Biotechnology
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• 제1권2호
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• pp.91-95
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• 1999

Genetic engineering of stone fruit species like apricot, plum, peach and cherry are hampered by the inefficient and low-level regeneration processes in tissue culture. The first transgenic stone fruit species have emerged from transformed hypocotyls. These great achievements were applauded by the scientific community contrary the fact that hypocotyl derived transgenic plants have no real brooding value. Tissue culture of different organs of valuable cultivars are recorded with an extremely low-level of regeneration in the literature. To improve the tissue culture basis of stone fruit plants an extensive tissue culture programme were launched and dozens of different media were compared including a series of hormone concentration in the tissue culture systems. Our continuous efforts were crowned by a very efficient method for achieving up to 30-40% regenerable petioles. Usually on a single petiole several well-separated meristems were induced. After 3-4 weeks of cultivation shoots were developed. The basic media $K_2$ were supplemented with 10g/L saccharose, 10g/L glucose and 10g/L maltose. The following plant hormones were used BAP 1mg/L, TDZ 1mg/L, 2-iP 1mg/L and IAA 0,1 mg/L concentrations. The Petri dishes were kept for 3 weeks in dark at a temperature 22$^{\circ}C$ for 8 hours and 22-24$^{\circ}C$ for 16 hours. The Petri dishes were sealed with Parafilm. The regeneration of the petioles were genotype independent and we were able to regenerate different plum cultivars with almost the same efficiency.

• 한국수학교육학회지시리즈A:수학교육
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• 제26권1호
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• pp.41-45
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• 1987

In this paper, we give several fixed point theorems in a complete metric space for two multi-valued mappings commuting with two single-valued mappings. In fact, our main theorems show the existence of solutions of functional equations f($\chi$)=g($\chi$)$\in$S$\chi$∩T$\chi$ and $\chi$=f($\chi$)=g($\chi$)$\in$S$\chi$∩T$\chi$ under certain conditions. We also answer an open question proposed by Rhoades-Singh-Kulsherestha. Throughout this paper, let (X, d) be a complete metric space. We shall follow the following notations : CL(X) = {A; A is a nonempty closed subset of X}, CB(X)={A; A is a nonempty closed and founded subset of X}, C(X)={A; A is a nonempty compact subset of X}, For each A, B$\in$CL(X) and $\varepsilon$>0, N($\varepsilon$, A) = {$\chi$$\in$X; d($\chi$, ${\alpha}$) < $\varepsilon$ for some ${\alpha}$$\in$A}, E$\sub$A, B/={$\varepsilon$ > 0; A⊂N($\varepsilon$ B) and B⊂N($\varepsilon$, A)}, and (equation omitted). Then H is called the generalized Hausdorff distance function fot CL(X) induced by a metric d and H defined CB(X) is said to be the Hausdorff metric induced by d. D($\chi$, A) will denote the ordinary distance between $\chi$$\in$X and a nonempty subset A of X. Let R$\^$+/ and II$\^$+/ denote the sets of nonnegative real numbers and positive integers, respectively, and G the family of functions ${\Phi}$ from (R$\^$+/)$\^$s/ into R$\^$+/ satisfying the following conditions: (1) ${\Phi}$ is nondecreasing and upper semicontinuous in each coordinate variable, and (2) for each t>0, $\psi$(t)=max{$\psi$(t, 0, 0, t, t), ${\Phi}$(t, t, t, 2t, 0), ${\Phi}$(0, t, 0, 0, t)} $\psi$: R$\^$+/ \longrightarrow R$\^$+/ is a nondecreasing upper semicontinuous function from the right. Before sating and proving our main theorems, we give the following lemmas:

• 한국축산식품학회지
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• 제35권2호
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• pp.211-215
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• 2015

From the previous study, Enterococcus faecium SH01 was isolated from mukeunji, an over-ripened kimchi, and it produced bacteriocin SH01. Bacteriocin SH01 showed an inhibitory effect against Listeria monocytogenes ATCC 19111, a bacterial strain causing human listeriosis. Crude bacteriocin SH01 was purified by ammonium sulfate precipitation and its inhibitory activity at two concentrations (500 and 1,000 AU/g) against Listeria monocytogenes ATCC 19111 was investigated in ground beef at increasing temperatures (5, 10, 15, and 20℃) for 8 d. The number of Listeria monocytogenes ATCC 19111 significantly decreased (p<0.05) as the concentration of bacteriocin increased from 500 to 1,000 AU/g. Intrinsic crude protease activities in ground beef were examined and increased as the temperature increased. Experiments varying both the concentrations of added bacteriocin SH01 and temperature demonstrated a maximum inhibition (2.33 log reduction of bacteria) in samples containing 1,000 AU/g of bacteriocin SH01 incubated at 20℃. When the crude bacteriocin SH01 solution (1,280 AU/mL) was incubated with crude protease solutions at different temperatures, its activity decreased by only half (640 AU/mL), as assessed in an agar well diffusion assay. The finding that the antilisterial activity of bacteriocin SH01 increased with temperature can be explained by the fact that higher temperatures increase bacterial membrane fluidity, thereby promoting the cellular penetration of bacteriocin SH01 into L. monocytogenes. Bacteriocin SH01 may be an excellent candidate as a biopreservative for controlling L. monocytogenes growth in ground beef.

• 대한약리학회지
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• 제12권2호
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• pp.43-49
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• 1976

The facts that $PGE_2$ produced diuresis in the rabbit when given into a lateral ventricle of the brain and that $PGF_{2{\alpha}}$ is abundantly found in the brain prompted us to investigate the effects of $PGF_{2{\alpha}}$ introduced directly into the ventricle on the renal function. $PGF_{2{\alpha}}$ given intraventriculary in doses of $10{\mu}g\;and\;100{\mu}g$ elicited prompt diuresis, 10-fold increase of sodium excretion and two-fold increment of potassium excretion. Free water reabsorption also increased along with the increased osmolar clearance. Neither renal plasma flow nor glomerular filtration rate did change significantly. This, along with the fact that the percentage of reabsorbed sodium filtered decreased from 99.5 to 93.9, indicates the tubular site of the diuretic and natriuretic action. Atropine pretreatment did not influence the renal effects of intraventricular $PGF_{2{\alpha}}$. Intravenously administered $PGF_{2{\alpha}}$ in doses of 30 to $100{\mu}g$ did not produce any significant change in renal function. Intraventricular $PGF_{2{\alpha}}$ had no effect on the systemic blood pressure, whereas intravenous administration brought about a transient hypotension. These observations suggest that $PGF_{2{\alpha}}$ induces diuresis and natriuresis via central mechanism, that the site of the action resides in renal tubules, and that the reabsorption of sodium is inhibited in the proximal tubule, possibly through mediation of certain humoral agent. Overall, it is suggested that $PGF_{2{\alpha}}$ might play a roll in regulating renal function through the center.

• Earthquakes and Structures
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• 제18권2호
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• pp.223-231
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• 2020

Due to the fact that Bingöl province is at the intersection of the North Anatolian Fault and the Eastern Anatolian Fault, the seismicity of the region is important. In this study, probabilistic seismic hazard analyzes (PSHA) were conducted to cover the boundaries of Bingöl province. It occurred since 1900, the seismicity of the region was obtained statistically by considering the earthquake records with a magnitude greater than 4 and the Gutenberg-Richter correlation. In the study, magnitude-frequency relationship, seismic hazard and repetition periods were obtained for certain time periods (10, 20, 30, 40, 50, 75 and 100 years). Once a project area determined in this study, which may affect the peak ground acceleration according to various attenuation relationships are calculated and using the Turkey Earthquake Hazard Map, average acceleration value for Bingöl province were determined. As a result of the probabilistic seismic hazard analysis, the project earthquakes with a probability of exceeding 50 years indicate that the magnitude of the project earthquake is 7.4 and that the province is in a risky area in terms of seismicity. The repetition periods of earthquakes of 6.0, 6.5, 7.0 and 7.5 are 42, 105, 266 and 670 years respectively. Within the province of Bingöl; the probability of exceeding 50 years is 2%, 10% and 50%, while the peak ground acceleration values are 1.03 g, 0.58 g and 0.24 g. As a result, probabilistic seismic hazard analysis shows that the seismicity of the region is high and the importance of considering the earthquake effect during construction is emphasized for this region.

• Journal of Microbiology and Biotechnology
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• 제17권7호
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• pp.1221-1225
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• 2007

A ${\beta}$-ionone-resistant mutant strain isolated from the red yeast Xanthophyllomyces dendrorhous KCTC 7704 was used for batch and continuous fermentation kinetic studies with glucose media in a 2.5-1 jar fermentor at $22^{\circ}C$ and pH 4.5. The kinetic pattern of growth and carotenoid concentration in the batch fermentations exhibited a so-called mixed-growth-associated product formation, possibly due to the fact that the content of intracellular carotenoids depends on the degree of physical maturation toward adulthood. To determine the maximum specific growth rate constant (${\mu}_m$) and Monod constant ($K_s$) for the mutant, glucose-limited continuous culture studies were performed at different dilution rates within a range of $0.02-0.10\;h^{-1}$. A reciprocal plot of the steady-state data (viz., reciprocal of glucose concentration versus residence time) obtained from continuous culture experiments was used to estimate a ${\mu}_m$ of $0.15\;h^{-1}$ and $k_s$ of 1.19 g/l. The carotenoid content related to the residence time appeared to assume a typical form of saturation kinetics. The maximum carotenoid content ($X_m$) for the mutant was estimated to be $1.04\;{\mu}g/mg$ dry cell weight, and the Lee constant ($k_m$), which was tentatively defined in this work, was found to be 3.0 h.

• The Korean Journal of Ecology
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• 제19권6호
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• pp.529-541
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• 1996

During the period of December 1992 (winter-spring) and from February 1995 (winter-spring), the leaf processing rates of oak (Quercus serrata) and tulip (Liriodendron tulipifera) tree was investigated in the headwater streams in southeastern part of Korea in conjunction with the distribution pattern of macroinvertebrate fauna. Using two types of bags ($10\times30cm$ with 5 g of dry leaves; open bag with holes, closed bag without holes), decomposition rates of oak and tulip tree by shredder and/or microbiota at a reatively undisturbed 2nd-order stream were compared, Regardless of leaf type, leaves in the open bage decomposed slightly faster than those in the closed bags. In the 1992 experiment, osk leaves decomposed much slower than tulip leaves (after 138 degree days, osk : closed, 0.006% loss/day ; open, 0.008 ; tulip: closed, 0.021 ; open, 0.023; n=2). The of the first experiment using oak leaves in 1995 were similar to those of the first experiment (after 151 degree days, oak: closed, 0.005% loss / day; open, 0.006; n=6). Over 50% of invertebrates from 122 leaf pack samples collected from 12 streams during the winter period of 1994 were identified as shredders (shredder, 56.2; collector, 32.7; scraper, 8.65; predator, 2.45%). Among shredders, Gammarus sp. and Tipula sp. were dominant species in terms of number and biomass (8.2 ind./g, 1.0 ind./g AFDW of leaves). Among many physico-chemical parameters, the width of stream channel was found to be the most influential factor in the distribution of Gammarus and Tipula (Gammarus: r=-0.34, P<0.001;Tipula:r=0.40, P<0.001). Considering the fact that oak is one the dominant riparian vegetation in the southeastern part of korea, the patterns of oak processing and shredder distribution shown in theis study may well represent some of the important characteristics of headwater steams in southeastern Korea.

• Asian Pacific Journal of Cancer Prevention
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• 제13권8호
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• pp.3863-3868
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• 2012

In this study mitochondrial D-Loop variations in Iranian prostate cancer and benign prostatic hyperplasia (BPH) patients were investigated. Tumour samples and corresponding non-cancerous prostate tissue from 40 prostate cancer patients and 40 age-matched BPH patients were collected. The entire mtD-loop region (16024-576) was amplified using the PCR method and products were gel-purified and subjected to direct nucleotide sequencing. A total of 129 variations were found, the most frequent being 263A${\rightarrow}$G and 310T${\rightarrow}$C among both BPH and prostate cancer patients. Variation of 309 C${\rightarrow}$T was significantly more frequent in prostate cancer patients (P value<0.05). Four novel variations were observed on comparison with the MITOMAP database. Novel variations were np16154delT, np366G${\rightarrow}$A, np389G${\rightarrow}$A and 56insT. There was no correspondence between the different variations and the age of subjects. Considering that D-loop variations were frequent in both BPH and prostate cancer patients in our study, the fact that both groups had high average age can be a possible contributing factor. D-loop polymorphisms and microsatellite instability can influence cell physiology and result in a benign or malignant phenotype. Significantly higher frequency of 309 C${\rightarrow}$T variation in cancer patients is a notable finding and must be a focus of attention in future studies.