• Title/Summary/Keyword: rate dependent

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Effect of Gamma Irradiation on Water Uptake Rate and Gelatinization of Brown Rice (감마선 조사가 현미의 수화속도 및 호화양상에 미치는 영향)

  • Lee, You-Seok;Shu, Chung-Sik;Lee, Ju-Woon;Byun, Myung-Woo
    • Korean Journal of Food Science and Technology
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    • v.36 no.6
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    • pp.900-904
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    • 2004
  • Effects of gamma irradiation on brown rice quality were evaluated. Brown rice was irradiated at absorbed dose of 1, 3 or 5 kGy, and ground. Water uptake, pasting properties, and physicochemical characteristics of flour samples were tested. Water uptake rates of irradiated samples were higher than that of control, and were dose-dependent. Hydration capacity decreased in sample irradiated at 5 kGy due to leaching out of soluble compounds, whereas no differences were observed among other irradiated samples and control. Irradiation significantly decreased pasting properties as determined by amylograph. Gamma irradiation accelerated water evaporation at high temperatures (over $300^{\circ}C$) in test of weight-loss profile with thermogravimetric analyzer.

Thermal Degradation Kinetics of Tocopherols during Heating without Oxygen (무산소 가열시 토코페롤의 열분해 키네틱스)

  • Chung, Hae-Young
    • The Korean Journal of Food And Nutrition
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    • v.20 no.2
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    • pp.120-124
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    • 2007
  • The thermal degradation kinetics of alpha-, gamma- and delta-tocopherols was studied during heating at 100, 150 200 and 250$^{\circ}C$ for 5, 15, 30 and 60 min in the absence of oxygen. The tocopherols were separated by HPLC using a reversed phase ${\mu}$-Bondapak C$_{18}$-column with two kinds of elution solvent system in a gradient mode. The kinetics for degradation of ${\alpha}$-, ${\gamma}$- and ${\delta}$-tocopherols was analyzed as a function of temperatures and times. The degradation of tocopherols was described by the first-order kinetics in the absence of oxygen. The rate of tocopherols degradation was dependent on heating temperatures. The degradation rate constants for ${\alpha}$-, ${\gamma}$ and ${\delta}$-tocopherols showed an increasing trend as the heating temperature increased. The magnitude order of the experimental activation energy was ${\delta}$->${\gamma}$->${\alpha}$-tocopherol.

Apoptosis-inducing Effect of Fructus Trichosanthis in HL-60 Leukemic Cells (백혈병 세포주 HL-60에서 과루실 세포고사 유도 효과)

  • Kwon Kang Beom;Kim Eun Kyung;Han Mi Jeong;Ryu Do Gon
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.19 no.4
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    • pp.903-907
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    • 2005
  • Many naturally occurring plant extracts are studied for their beneficial effects for health and particularly on cancer. Apoptosis, or programmed cell death, occurs in both normal and pathological conditions, including cancer Dysregulation of apoptosis allows transformed cells to continually and uninhibitedly enter the cell cycle, thus perpetuating the sequence of mutation, genomic instability and, finally, oncogenesis. To investigate the apoptosis-inducing effect of the extract of Fructus Trichosanthis (EFT) on leukemic HL-60 cells and its mechanism, HL-60 cells in vitro in culture medium were given different doses of the extract. The inhibitory rate of cells were measured by microculture tetrazolium assay, cell apoptotic rate was detected by flow cytometry, morphology of cell apoptosis was observed by DAPI fluorescence staining, and the activations of caspases and PARP were detected using Western blotting analysis. The extract could activate the caspase-3 and caspase-8, induce PARP cleavage, inhibit growth of HL-60 cells, and cause apoptosis significantly The suppression was in dose-dependent manner. Marked morphological changes of cell apoptosis including condensation of chromatin and nuclear fragmentation were observed clearly by DAPI fluorescence staining especially. These results will provide strong laboratory evidence of EFT for clinical treatment of acute leukemia.

Genotoxicity Study of GST Extract (GST 추출물의 유전독성평가)

  • Lee, Chul Wha;Han, Jong Min;Lee, Mi Young;Jung, In Chul;Jin, Mirim;Kim, Seung Hyung;Park, Yang Chun
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.28 no.6
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    • pp.621-629
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    • 2014
  • This study aimed to evaluate the genotoxicity of GST (Gamisasangja-tang). For examining genotoxicity, we carried out bacterial reverse mutation assay, chromosome aberration assay, micronucleus induction test according to OECD guidelines. Bacterial reverse mutation assay: In GST treating group, regardless of existence S9 mix, revertant colonies counts appeared to be less than twice of negative control group and dose dependent increase. In positive control group, revertant colonies counts were shown to be more than twice of negative control croup. Chromosome aberration assay: All cell line showed repetition rate of abnormal chromosome aberration less than 5%, regardless of treating time, existence of S9 mix, and no significant change ($p{\succeq}0.05$) compared with negative control group. Micronucleus induction test: Micronucleated polychromatic erythrocytes (MNPCE) repetition rate of Polychromatic erythrocytes (PCE) showed no significant changes compared with negative control group ($p{\succeq}0.05$). PCE portion of total erythrocytes also showed no significant changes ($p{\succeq}0.05$). Our results showed that GST didn't induce any genotoxicity.

Role of Spinal Adenosine $A_2$ Receptor in the cardiovascular Regulation in Rats (흰쥐에서 실혈관 조절기전에 대한 척수의 Adenosine $A_2$수용체의 역할)

  • 문삼영;신현진;신인철;고현철;엄애선;박정로;김범수;강주섭
    • Biomolecules & Therapeutics
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    • v.8 no.4
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    • pp.325-331
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    • 2000
  • The present study was designed to assess the role of spinal adenosine $A_2$ receptor in the regulation of cardiovascular functions such as mean arterial pressure (MAP) and heart rate (HR) in male Sprague-Dawley rats. Rats (250~300 g) were anesthetized with urethane and paralyzed with d-tubocurarine and artificially ventilated. blood pressure and HR were continuously monitored via a femoral catheter connected to a pressure transducer and a polygraph. Drugs were administered intrathecally using injection cannula through guide cannula which was inserted inthrathecally at lower thoracic level through a puncture of an atlantooccipital mombrane. Intrathecal injection of an adenosine $A_2$ receptor agonist, 5'-(N-cyclopropyl)-carboxamaidoadenosine (CPCA; 1, 2 and 3 nmol, respectively), produced a dose-dependent decrease in MAP and HR. Pretreatment with $N^{G}$-nitro-L-arginine methyl ester (L-NAME), a nitric oxide synthase inhibitor or 10 nmol of MDL-12,330, an adenylate cyclase inhibitor blocked significantly the depressor and bradycardic effect of 2 nmol of CPCA. But, Pretreatment with 3 nmol of bicuculline, gamma-aminobutyric acid A (GAB $A_{A}$) receptor antagonist, or 50 nmol of 5-aminovaleric acid, GAB $A_{B}$ receptor antagonist did not inhibit the depressor and bradycardic effect of 2 nmol of CPCA. These results indicate that adenosine $A_2$ receptor in the spinal cord plays an inhibitory role in the regulation of cardiovascular function and that the depressor and bradycardic action of adonosine $A_2$ receptor are mediated via the synthesis of nitric oxide and the activation of adenylate cyclase in the spinal cord of rats.s.s.s.

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Ultrastructural characteristics of the pancreatic acinar cells in the diabetes-prone BB rat (BB랫드의 췌장 샘포세포의 미세구조적 특징)

  • Jeong, Young-gil;Kim, Kil-soo;Lee, Chul-ho;Won, Moo-ho;Cho, Sung-whan;Kim, Moo-kang
    • Korean Journal of Veterinary Research
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    • v.36 no.1
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    • pp.1-9
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    • 1996
  • Functional and morphological characteristics of the exocrine pancreas in genetic model BB rat of insulin dependent diabetes medllitus(IDDM) were carried out. Wistar rat was used as control animal. Flow rate of pancreatic juice, output of amylase and protein, and plasma glucose and insulin levess were examined. Also light and ultrastructural characteristics of the exocrine pancreas were observed. Pancreatic flow rate, output of amylase and protein, and insulin level were lower;glucose level was higher comparing with those of the control Wistar rat. In Wistar rat, exocrine pancreas was typical light microscopically. Zymogen granules and cell organelles were well developed in fine structure. Cell size of the periinsular acini was larger, and number of zymogen granules were more than those of the teleinsular acini. Most acinar cells were dark cells which containe well-developed RER in their cytoplasm. On the other hand, some light cells which have the dilated RER cisterns were found. In BB rat exocrine pancreas, cell size of per-and tele-insular acini similar to that of Wistar rat. The number of light cells occupied 40-50% compairing with that of Wistar rat. Zymogen granules were lower in number than that of Wistar rat and divied into three types in morphological characteristics ; type I showing normal structure, type II showing the wide hallo and small electron dense core in center of the zymogen granule and type III not having the electron dense core in the zymogen granule. The present ratio of type I, type II and type III are less than 5%, 30-40% and more than 50%, respectively.

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A Study on the Degradation Properties of MTBE in Solution using Ultrasound (초음파를 이용한 수용액 속의 MTBE 분해 특성 연구)

  • Kim, Heeseok;Yang, Inho;Oh, Jeill;Her, Nam Guk;Jeong, Sangjo
    • Journal of Korean Society on Water Environment
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    • v.25 no.4
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    • pp.522-529
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    • 2009
  • To supply safe drinking water to areas lacking in water supply and drainage system, such as rural area and military bases in proximity to Demilitarized Zone, effective method for treating organic contaminants such as MTBE is required. This study focuses on seeking optimal conditions for effective degradation of MTBE using a bath type ultrasound reactor. Effectiveness of MTBE degradation by ultrasound is dependent on the frequency, power, temperature, treatment volume, initial concentration, catalyst, etc. In this study the degradation rate of MTBE by ultrasound was proportional to power/unit volume ratio and removal is relatively more efficient for 0.1 mM than for 1 mM of MTBE solution. Efficiency of ultrasound treatment for 1 mM MTBE solution was enhanced under bath temperature of $30^{\circ}C$ compared to $4^{\circ}C$, but the temperature effect was negligible for 0.1 mM MTBE solution. Also for 0.1 mM MTBE solution, effect of catalyst such as $TiO_2$ and $Fe^0$ on treatment speed was negligible, and zeolite even increases the time taken for the degradation. Under these specific experimental conditions of this study, the most determinant factor for degradation rate of MTBE in solution was frequency and power of ultrasound. The results have shown that a continuous ultrasound reactor system can be used for small scale remediation of organically polluted groundwater, under optimal conditions.

Effect of substrate temperature and hydrogen dilution on solid-phase crystallization of plasma-enhanced chemical vapor deposited amorphous silicon films (PECVD로 증착된 a-Si박막의 고상결정화에 있어서 기판 온도 및 수소희석의 효과)

  • 이정근
    • Journal of the Korean Vacuum Society
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    • v.7 no.1
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    • pp.29-34
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    • 1998
  • The solid-phase crystallization (SPC) of plasma-enhanced chemical vapor depsoited (PECVD) amorphous silicon (a-Si) films ha s been investigated by x-ray diffraction (XRD). The a-Si films were prepared on Si (100) wafers using $SiH_4$ gas and without $H_2$ dilution at the substrate temperatures between $120^{\circ}C$ and $380^{\circ}C$, and than annealed at $600^{\circ}C$ for crystallization. The annealed samples exhibited (111), (220), and (311) XRD peaks with preferential orientation of (111). The XRD peak intensities increased as the substrate temperature decreased, and the $H_2$dilution suppressed the solid-phase crystallization. The average grain size estimated by XRD analysis for the (111) texture has increased from about 10 nm to about 30 nm, as the substrate temperature decreased. The deposition rate also increased with the decreasing substrate temperature and the grain size was closely dependent on the deposition rate of the films. The grain size enhancement was attributed to an increase of the structural disorder of the Si network.

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Kinetic Study on the Gelatinization of Barley Starch (보리전분의 호화에 관한 속도론적 연구)

  • Mok, Chul-Kyoon;Lee, Sang-Hyo;Nam, Young-Jung;Min, Byong-Yong
    • Korean Journal of Food Science and Technology
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    • v.17 no.6
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    • pp.409-414
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    • 1985
  • The gelatinization kinetics of barley starch in dilute system (1% w/v concn.) at the temperature range of $60{\sim}95^{\circ}C$ was investigated. The gelatinization rate was extremely temperature dependent. The gelatinization at the temperature above $90^{\circ}C$ was an one step 1st order reaction throughout the gelatinization time, but that below $85^{\circ}C$ consisted of two stages which showed different reaction rates. The reaction rate of the 1 st stage was greater than that of the 2nd stage. The activation energy of the 1 st stage was 31.93 Kcal/g mole and those of the 2nd stage were 78.49 and 23.41 Kcal/g mole above and below $75^{\circ}C$, respectively.

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Influencing factors to dental caries and periodontal diseases in Korean adults (성인의 치아우식증 및 치주질환에 영향을 미치는 요인)

  • Jung, Yu-Jin;Cho, Mi-Hyang;Moon, Deog-Hwan
    • Journal of Korean society of Dental Hygiene
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    • v.15 no.1
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    • pp.47-54
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    • 2015
  • Objectives: The aim of this study was to investigate the factors related to dental caries and periodontal disease in Korean adults. Methods: The subjects were 5,149 adults over 19 years old who participated in the 5th Korea National Health and Nutrition Examination Survey 2012. Data were analyzed by chi-square test and logistic regression analysis using SPSS 18.0 statistical package program. The questionnaire consisted of 17 questions of independent variables and 2 kinds of dependent variables including dental caries and periodontal diseases by direct interview. The independent variables included 5 questions of general characteristics, 3 questions of health behavior, 5 questions of oral health behavior, and 4 questions of chronic diseases diagnosed by the doctors. Results: The prevalence rate of dental caries was higher in those who did not regularly work out and did not receive regular checkups including dental floss and dental brush use. The prevalence rate of periodontal diseases was higher in male adults, smokers, and those who were obese and had diabetes mellitus, poor oral health care habit without using dental floss and inter-dental brush. Conclusions: In order to prevent the dental caries in the adults, it is very important to do regular exercise and regular dental checkup. The best ways of dental caries prevention include tooth brushing after meal with use of dental floss and inter-dental brush. This study suggests that dental health promotion can be enhanced by smoking cessation, ideal body weight maintenance, timely tooth brushing after meal, and use of dental floss and inter-dental brush.