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Characteristics of Squid Viscera Oil (오징어 내장의 지방질조성)

  • KIM Eun-Mi;JO Jin-Ho;OH Se-Wook;KIM Young-Myoung
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.30 no.4
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    • pp.595-600
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    • 1997
  • The oil content and composition of squid visera were determined to obtain data for utilization of this by-product. There was no significant difference in the glycolipid (GL) and phospholipid (PL) content in Illex argentinus and Todarodes pacificus, but neutral lipid (NL) was different (p<0.05). The viscera oil of I. argentinus contained $30.50\%$ total lipid which consisted of $96.24\%$ NL, $2.63\%$ GL, $2.37\%$ PL, and contained $644mg\%$ cholesterol. The viscera oil of T. pacificus contained $30.20\%$ total lipid which consisted of $94.82\%$ NL, $2.85\%$ GL, $2.34\%$ PL, and contained $1,224\;mg\%$ cholesterol. The NL, GL and PL of viscera oil in I. argentinus mainly consist of triglyceride $(44.01\%)$, esterified steryl glycosides $(58.95\%)$ and phosphatidyl cholines $(32.36\%)$, respertively. Those of viscera oil in T. pacificus mainly consist of triglyceride $(39.63\%)$, monogalactosyl diglycerides $(51.67\%)$ and phosphatidyl cholines $(31.98\%)$, respectively. The major fatty acids of the viscera oil of I. argentinus and T. pacificus were C16 : 0, $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$. In Illex argentinus, the fatty acids of NL mainly were $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$. PL were $C16\;:\;1\omega7,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$ and GL were $C18\;:\;1\omega9,\;C20\;:\;5\omega3,\;22\;:\;6\omega3$. The major fatty acids of NL in T. pacificus were $C16\;:\;0,\;C18\;:\;1\omega9,\;C20\;:\;4\omega6,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$, PL were $C16\;:\;1\omega7,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$, and GL were $C18\;:\;1\omega9,\;C20\;:\;5\omega3,\;C22\;:\;6\omega3$.

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Influence of Dietary Protein and Feeding Pattern on the Weight Gain, Metabolism and Body Composition of Rats (식이단백질과 급식형태가 흰쥐의 성장, 대사 및 체조성에 미치는 영향)

  • Park, Yaung-Ja;Han, In-Kyu
    • Journal of Nutrition and Health
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    • v.15 no.4
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    • pp.301-312
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    • 1982
  • A series of growing and digestion trials was conducted using Sprague- Dawley weanling male rats in order to determine the effects of two protein sources (casein and ISP (isolated soyprotein) ), three protein levels (10, 20 and 30%), and two feeding patterns (ad libitum and meal feeding) on the growth, protein and energy metabolism, and body composition of rats. The total energy level of experimental diets was kept constant in 3,600 kcal ME /kg diet. The results were as follows : 1) The amount of food intake and the weight gain of meal-fed group were lower than those of ad libitum group. Though the intake of meal-fed group on 20 and 30% casein diet was only 85% of ad libitum group, it was able to gain as much as ad libitum group. 2) There were no significant differences in the food efficiency ratio (FER) and the energy efficiency (weight gain per 100 kcal GE intake) between ad libitum and meal feeding group. The FER and the energy efficiency of 20 and 30% casein diets of meal-fed group were greater than those of ad libitum group. 3) Though the gross energy intake (GE ), the digestible energy (DE) and the metabolizable energy (ME) tended to be lower at meal-fed group, the DE/GE and the ME/GE ratios for meal-fed group were the same as those for ad libitum. 4) Though meal- fed group fed less amount of nitrogen than ad libitum group, there were no differences in nitrogen balance and the retention of rats among the treatments. Actually meal-fed group retained more nitrogen than ad libitum group at the levels of 20 and 30% dietary protein. 5) After growing and digestion trials, the body composition of rats was constant among all treatments. Significantly high negative correlation coefficient (r = -0.77) was found between the body fat content and the body moisture content. Consequently, this study suggests that meal- fed group on 20 and 30% casein diets has shown more effective utilization of the ingested food and energy than ad libitum group, and increasing tendency of weight gain and the body fat deposition. Those influences of meal feeding pattern in rats were more effective on the casein diet than on the ISP diet.

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A Development of Cholesterol Removed Cheese (콜레스테롤을 제거한 치즈의 개발에 관한 연구)

  • 정청송
    • Journal of Applied Tourism Food and Beverage Management and Research
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    • v.13 no.2
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    • pp.129-147
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    • 2002
  • 본 실험은 $\beta$-cyclodextrin을 사용하여 cholesterol을 제거한 균질우유로부터 cholesterol이 제거된 치즈 제조의 조건을 규명하고, 그 조건에 따라 제조된 cheese의 특성 및 관능 검사를 함으로써 cholesterol이 제거된 cheese의 개발 가능성을 조사하는데 그 목적을 두고 있다. 치즈 제조에 적합하다고 사료되는 낮은 균질압력에서 효과적인 cholesterol 제거율을 알아보기 위해 균질압력 0, 250, 500, 750, 1000psi(0-70kg/$cm^2$와 균질온도 40, 50, 60, $70^{\circ}$ 그리고 $\beta$-cyclodextrin 첨가량 1.0, 1.5 2.0% 등의 3가지 조건에 따라 우유를 처리하여 cholesterol이 제거된 cheese의 제조에 적합한 조건으로는 균질압력 1000psi(70kg/$cm^2$), 균질 온도 $70^{\circ}$$0^{\circ}C$, $\beta$-cyclodextrin 첨가량 2.0%로 관찰되었다. 따라서 균질온도는 $70^{\circ}$로 정하고, 균질압력을 400, 600, 900, 1200si(0,- 91kg/$cm^2$)로, $\beta$-cyclodextrin 첨가량을 1과 2%로 처리하여 제조한 cheese와 균질을 하지 않고 $\beta$-cyclodextrin의 처리를 하지 알은 control 치즈간의 수율, cholesterol 제거율, mettability, stretchability, oiling off, 조직검사, 관능검사 등의 실험을 실시하여 control 치즈와 가장 유사한 cholesterol이 제거된 cheese 개발의 가능성을 시도하였고, 그 결과는 다음과 같다. 1. Cholesterol을 제거한 cheese의 제조에서 최적조건은 균질압력 1200psi(70kg$cm^2$), 균질온도 $70^{\circ}$, $\beta$-cyclodextrin 첨가량 2%였으며, 이때 우유의 cholesterol의 제거율이 86.05%로 가장 높게 나타났다. 2. Cholesterol을 제거한 cheese들의 수율은 모두 12.53%(control 10.54%) 이상으로 균질 처리가 cheese의 수율을 18.88%이상 향상시키는 것으로 나타났다. 3. 유지방 함량 23.80%인 control 치즈의 cholesterol 함량은 81.47mg/100g이었고, 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2%를 첨가한 cheese에서는 cholesterol 함량이 20.15mg/100g으로 cholesterol 제거율이 75.27%로 가장 높게 나타났다. 4. Meltability는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 1과 2%로 처리한 치즈에서 2.25cm(control 3.34cm)로 가장 낮았으며, 균질압력이 증가할수록 meltability가 감소하여 치즈의 품질을 저하시켰다. 5. Control 치즈의 stretchability는 30cm 이상 늘어나 가장 양호한 수치인 5점을 나타낸 반면, cholesterol을 제거한 cheese에서는 5~10cm 사이를 나타내어 2점으로 stretchability가 저하된 것을 볼 수 있었다. 6. Oiling off는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 1과 2%로 처리한 치즈에서 0.03%(control 2.46%)로 가장 낮았으며, 균질압력이 증가할수록 oiling off는 감소하여 치즈의 외관상 품질을 향상시켰다. 7. Hardness, gumminess, chewiness는 균질압력 1200psi(91kg/$\textrm{cm}^2$)에 $\beta$-cyclodextrin 1%로 처리한 치즈에서 각각 나타내었으며, control과 cholesterol을 제거한 치즈들 사이에 유의적 (p<0.05) 차이를 보이며 큰 감소를 나타내었다. 8. Cholesterol을 제거한 cheese의 appearance와 flavor는 1200psi (91kg/$cm^2$)일 때 각각 가장 높은 5,56과 4.63(control 4.00)으로 균질압력이 증가하면서 향상되었으며, texture score는 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2%일때 1.22(control 4.00)로 가장 낮은 수치를 나타내었고, 균질이 cheese의 texture score를 상당히 저하시키는 것을 알 수 있었다. 9. 이 실험결과, 균질압력 1200psi(91kg/$cm^2$)에 $\beta$-cyclodextrin 2% 첨가한 cheese에서 cholesterol 제거율이 75.27%로 가장 높았으며, 균질처리가 cheese의 수율, oiling off, appearance score, flavor scope 등을 향상시켰고, meltability, stretchability, hardness, gumminess, chewiness, texture score를 저하시키는 것으로 나타나 cholesterol이 상당부분 제거된 cheese의 개발 가능성이 관찰되었다.

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EFFECT OF ULTRASONIC VIBRATION ON ENAMEL AND DENTIN BOND STRENGTH AND RESIN INFILTRATION IN ALL-IN-ONE ADHESIVE SYSTEMS (All-in-one 접착제에서 초음파진동이 법랑질과 상아질의 결합강도와 레진침투에 미치는 영향)

  • Lee, Bum-Eui;Jang, Ki-Taeg;Lee, Sang-Hoon;Kim, Chong-Chul;Hahn, Se-Hyun
    • Journal of the korean academy of Pediatric Dentistry
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    • v.31 no.1
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    • pp.66-78
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    • 2004
  • The objective of this study was to apply the vibration technique to reduce the viscosity of bonding adhesives and thereby compare the bond strength and resin penetration in enamel and dentin achieved with those gained using the conventional technique and vibration technique. For enamel specimens, thirty teeth were sectioned mesio-distally. Sectioned two parts were assigned to same adhesive system but different treatment(vibration vs. non-vibration). Each specimen was embedded in 1-inch inner diameter PVC pipe with a acrylic resin. The buccal and lingual surfaces were placed so that the tooth and the embedding medium were at the same level. The samples were subsequently polished silicon carbide abrasive papers. Each adhesive system was applied according to its manufacture's instruction. Vibration groups were additionally vibrated for 15 seconds before curing. For dentin specimen, except removing the coronal part and placing occlusal surface at the mold level, the remaining procedures were same as enamel specimen. Resin composite(Z250. 3M. U.S.A.) was condensed on to the prepared surface in two increments using a mold kit(Ultradent Inc., U.S.A.). Each increments was light cured for 40 seconds. After 24 hours in tap water at room temperature, the specimens were thermocycled for 1000cycles. Shear bond strengths were measured with a universal testing machine(Instron 4465, England). To investigate infiltration patterns of adhesive materials, the surface of specimens was examined with scanning electron microscope. The results were as follows: 1. In enamel the mean values of shear bond strengths in vibration groups(group 2, 4, 6) were greater than those of non-vibration group(group 1, 3, 5). The differences were statistically significant except AQ bond group. 2. In dentin, the mean values of shear bond strengths in vibration groups(group 2, 4, 6) were greater than those of non-vibration groups(group 1, 3, 5). But the differences were not statistically significant except One-Up Bond F group. 3. The vibration group showed more mineral loss in enamel and longer resin tag and greater number of lateral branches in dentin under SEM examination.

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Maternal and Child Factors Associated with Early Detection of Cerebral Palsy (뇌성마비아 조기발견과 관련된 모자인자)

  • Bae, Sung-Soo;Park, Jung-Han
    • Journal of Preventive Medicine and Public Health
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    • v.20 no.2 s.22
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    • pp.312-321
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    • 1987
  • To investigate the maternal and child factors associated with early detection of cerebral palsy, 74 mothers of cerebral palsy children who were born since January 1, 1980 and being treated at Taegu Rehabilitation Center for the Handicapped, Rehabilitiation Center of Taegu University, St. Paul Children's House and Pusan Welfare Association of Cerebral Palsy Children were interviewed from February to April 1987. There is no association between age of child when parents noticed the child's abnormality and educational level of father but it tend to be detected earlier when education level of mother is college or above compared with high school or under. There is a trend of earlier detection of child's abnormality although statistically not significant in case father is professional or managerial worker, monthly income of father is over \610,000, child is first-born, age of the parents is 34 years or under, child is a boy, and child has periodic well-baby check-up. The child's abnormality is detected earlier when mothers had 7 prenatal visits or more compared with those who had 6 visits or less (p<0.05). Parents noticed the child's abnormality first in 85.1% of the cases whereas doctors detected it first in 2.7% and this percentage was not different whether the child had periodic well-baby check-up or not. The first physician's diagnosis of the children was cerebral palsy in 36.5% and the rest was normal, need for observation, uncertain, etc. Parents took the child to doctor for diagnosis 2-3 months after they noticed the child's abnormality and after the child was diagnosed as cerebral palsy parents either took no therapeutic measure or brought the child to physiotherapy or acupuncture or gave herb medicine before they started specific rehabilitative therapy. For early detection of the cerebral palsy children, teaching of evaluation method for child development should be reinforced both in medical school and clinical training course and should train the specialist for diagnosis and treatment of crippling conditions. Also, public education is needed for the importance of early detection of crippling conditions and currently available methods for diagnosis and treatment.

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Study on Temporal Decay Characteristics of Naturally Occurring Radionuclides in Groudwater in Two Mica Granite Area (복운모화강암지역 지하수 중 자연방사성 물질의 경시적 붕괴특성 연구)

  • Kim, Moon Su;Kim, Tae Seung;Kim, Hyun Koo;Kim, Dong Su;Jeong, Do Hwan;Ju, Byoung Kyu;Hong, Jung Ki;Kim, Hye Jin;Park, Sun Hwa;Jeong, Chan Ho;Cho, Byong Wook;Han, Jin Seok
    • Journal of Soil and Groundwater Environment
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    • v.18 no.4
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    • pp.19-31
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    • 2013
  • To figure out the decay characteristics of naturally occurring radionuclides, eight sampled groundwaters from a monitoring borehole having high levels of uranium and radon concentrations in a two mica granitic area have analyzed by liquid scintillation counters (LSC) for over 1 year. In December 2011, three groundwater samples (DJ1, DJ2, DJ3) were obtained from each aquifer system located at -20 m, -40 m, -60 m of the monitoring borehole below the ground surface, respectively. Five samples (DJ4, DJ5, DJ6, DJ7, DJ8) were additionally gained from each aquifer positioned -20 m, -40 m, -60 m, -100 m, -105 m of the borehole in February 2012, respectively. Temporal variation characteristics of uranium and radon concentrations have showed over maximum 2.1 times and 1.4 times fluctuations of the values in the same sampling intervals over time, respectively. The intervals of -40 m and -105 m in the borehole have the highest values of uranium and radon concentrations, respectively. This may imply that the concentrations of naturally occurring radionuclides such as uranium and radon in groundwater have been changed over time and indicate that the qualities of groundwaters from the aquifers developed at each interval in the borehole are different each other. This discrepancy, moreover, could be caused by behaviour differences between uranium which is in ionic status having a half life of 4.6 billion years and is transported along with the flowing groundwater, and radon which is in gaseous status having a 3.82 day's half life in the aquifer systems. Physicochemical characteristics of groundwaters from the aquifer systems could be identified by the results of the on-situ measuring items such as pH and Eh, and the major ionic contents. The CPM values of eight groundwater samples analysed by LSC over one year have shown not to follow the theoretical decay curve of the radon. The CPM values of the samples have ranged from 2 to 7.5 after it had passed two months when the theoretical CPM values of the radon started zero since the initial analysis. Alpha and beta particle spectrums have shown the peaks of radium-226, however they have not revealed any peaks of radon and it's daughter products such as polonium-218 and 214, bismuth-214 for the late stage of the analysis. This implies that the groundwater from the borehole may contain radium-226 having a half life of 1,600 years which decays continuously.

A STUDY OF THE MECHANISM OF IMPROVING ACID RESISTANCE OF BOVINE TOOTH ENAMEL AFTER PULSED Nd-YAG LASER IRRADIATION (펄스형 Nd-YAG 레이저 조사에 의한 법랑질 내산성 증가 기전에 관한 연구)

  • Lee, Young-Soon;Shon, Heung-Kyu
    • Journal of the korean academy of Pediatric Dentistry
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    • v.23 no.3
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    • pp.640-658
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    • 1996
  • The purpose of this study was to examine the mechanism of improving acid resistance of Nd-YAG laser irradiated tooth enamel and determine the most effective energy density for improving acid resistance. The bovine tooth enamel were lased with a pulsed Nd-YAG laser. The energy densities of exposed laser beam were varied from 10 to $70\;J/cm^2$. To investigate the degree of improving acid resistance by irradiation, all the samples were submerged to demineralize in 0.5 N $HClO_4$ solution for 1 minute. After 1 minute, 0.05 % $LaCl_3$ was added to the solution for interrupting the demineralization reaction. The amounts of dissolved calcium and phosphate in the solution were measured by using an atomic absorption spectrophotometer and the UV/VIS spectrophotometer, respectively. To examine the mechanism of improving acid resistance, X-ray diffraction analysis, infrared spectroscopy, and scanning electron microscopy were taken. The X-ray diffraction pattern of the samples were obtained in the $10^{\circ}{\sim}80^{\circ}2{\theta}$ range with $Cu-K{\alpha}$ radiation using M18HF(Mac Science Co.) with X-ray diffractometer operating at 40 KV and 300 mA. The infra-red spectra of the ground samples in 300 mg KBr pellets 10 mm diameter were obtained in the $4000cm^{-1}\;to\;400cm^{-1}$ range using JASCO 300E spectrophotometer. The scanning electron microscopy was carried out using JSM6400(JEOL Co.) with $500{\sim}2000$ times magnification. The results were as follow 1. The concentration of calcium dissolved from laser irradiated enamel with $50J/cm^2$ was significantly lesser than that of unlased control group (p<0.05) 2. From the result of the X-ray diffraction analysis, $\beta$-TCP, which increases acid solubility, was identified in lased enamel but the diffraction peaks of (002) and (004) became sharp with increasing energy density of laser irradiation. This means that the crystals in lased samples were grown through the c-axis and subsequently, the acid solubility of enamel decreased. 3. The a-axis parameter was slightly increased by laser irradiation, whereas the c-axis parameter was almost constant except for a little decrease at $50J/cm^2$. 4. In the infra-red spectra of lased enamels, phosphate bands ($600{\sim}500cm^{-1}$), B-carbonate bands (870, $1415{\sim}1455cm^{-1}$), and A-carbonate band ($1545cm^{-1}$) were observed. The amounts of phosphate bands and the B-carbonate bands were reduced, on the other hand, the amount of the A-carbonate band was increased by increase the energy density. 5. The SEM experiments reveal that the surface melting and recrystallization were appeared at $30J/cm^2$ and the cracks were observed at $70J/cm^2$. From above results, It may be suggested that the most effective energy density for improving acid resistance of tooth enamel with the irradiation of Nd-YAG laser was $50J/cm^2$. The mechanism of improving acid resistance were reduction of permeability due to surface melting and recrystallization of lased enamel and reduction of acid solubility of enamel due to decrease of carbonate content and growth of crystal.

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A Study on The Content of Liver Protein, Nucleic Acids, and Guanine Deaminase Activity of Mouse During Acute Starvation (급성(急性) 기아(饑餓)마우스의 간단백질(肝蛋白質), 핵산(核酸) 및 Guanine Deaminase 활성(活性)에 관(關)한 연구(硏究))

  • Park, Seung-Hee;Kim, Seung-Won
    • Journal of Nutrition and Health
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    • v.1 no.2
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    • pp.107-115
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    • 1968
  • Number of aspects, not only nutritional but social as well as political involved in human starvation pose nowadays global problems. In order to help establish the minimum nutritional requirements in the daily life of a man and to free people as well from either undernourishment, malnutrition or even starvation many workers have devoted themselves so far on the research programs to know what and how number of metabolic events take place in animals in vivo. It is the purpose of the present paper to examine in effect to what extent both of the protein and nucleic acids (DNA & RNA) together with an enzyme, guanine deaminase, which converts guanine into xanthine and in turn ends up to uric acid as an end product, undergo changes, quantitatively during acute starvation, using the mouse as an experimental animal. The mouse was strictly inhibited from taking foods except drinking water ad libitum and was sacriflced 24, 48, and 72 hours following starvation thus acutely induced. The animals consisted of two experimental groups, one control and another starvation groups, each being consisted of 6-24 mice of whose body weights ranged in the vicinity of 10 g. The animals were sacriflced by a blow on the head, followed by immediate excision of their livers into ice-cold distilled water, washing adherent blood and other contaminant tissues. The liver was minced foramin, by an all-glass homogenizer immersing it in an ice-bath, followed by subsequent fractionatin of the homogenate (10% W/V in 0.25M sucrose solution made up with 0.05M phosphate buffer of pH 7.4). For the liver protein and guanine deaminase assay, the 10% homogenate was centrifuged at 600 x g for 10 minutes to eliminate the nuclear fraction; and for the estimation of DNA and RNA, the homogenate was prepared by the addition of 10% trichloroacetic acid in order to free the homogenate from the acid-soluble fraction, the remaining residue being delipidate by the addition of alcohol and dried in vacuo for later KOH (IN) hydrolysis. The changes in body and liver wegihts during acute starvation were checked gravimetrically. Protein contents in the liver were monitored by the method of Lowry et al; and guanine deaminase activities were followed by the assay of liberated ammonia from the substrate utilizing the Caraway's colorimetry. The extraction of both DNA and RNA was performed by the Schmidt-Thannhauser's method, which was followed by Marmur's method of purification for DNA and by Chargaff's method of purification for RNA. The determinations of both DNA and RNA were carried out by the diphenylamine reaction for the former and by the orcinol reaction for the latter. The following resume was the results of the present work. 1. It was observed that the body as well as liver weights fall abruptly during starvation, and that the loss of body weight showed no statistical correlation with the decreases in the content of liver protein. 2. The content of liver protein and activity of liver guanine deaminase activity as well decline dramatically, and the specific activities of the enzyme (activity/protein), however, decreased gradually as starvation proceeded. 3. Both of the nucleic acids, DNA and RNA, showed decrements in the liver of mouse during acute starvation; the latter, however, being more striking in the decline as compared to the former. 4. The decreases in the liver protein content as resulted from the acute starvation had no statistically significant correlation with the decrements of DNA in the same tissue, but had regressed with a significant statistical correlation with the fall of RNA in the tissue. 5. The decrease in the activity of guanine deaminase in the liver of mouse during acute starvation was functionally more proportional to the decrease in RNA than DNA, and moreover correlated with the changes in the content of the liver protein. 6. The possible mechanisms involved during in this acute starvation as bring the decreases in the contents of DNA, protein, and guanine deaminase were discussed briefly.

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Characteristic Evaluation of Optically Stimulated Luminescent Dosimeter (OSLD) for Dosimetry (광유도발광선량계(Optically Stimulated Luminescent Dosimeter)의 선량 특성에 관한 고찰)

  • Kim, Jeong-Mi;Jeon, Su-Dong;Back, Geum-Mun;Jo, Young-Pil;Yun, Hwa-Ryong;Kwon, Kyung-Tae
    • The Journal of Korean Society for Radiation Therapy
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    • v.22 no.2
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    • pp.123-129
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    • 2010
  • Purpose: The purpose of this study was to evaluate dosimetric characteristics of Optically stimulated luminescent dosimeters (OSLD) for dosimetry Materials and Methods: InLight/OSL $NanoDot^{TM}$ dosimeters was used including $Inlight^{TM}MicroStar$ Reader, Solid Water Phantom, and Linear accelerator ($TRYLOGY^{(R)}$) OSLDs were placed at a Dmax in a solid water phantom and were irradiated with 100 cGy of 6 MV X-rays. Most irradiations were carried out using an SSD set up 100 cm, $10{\times}10\;cm^2$ field and 300 MU/min. The time dependence were measured at 10 minute intervals. The dose dependence were measured from 50 cGy to 600 cGy. The energy dependence was measured for nominal photon beam energies of 6, 15 MV and electron beam energies of 4-20 MeV. The dose rate dependence were also measured for dose rates of 100-1,000 MU/min. Finally, the PDD was measured by OSLDs and Ion-chamber. Results: The reproducibility of OSLD according to the Time flow was evaluated within ${\pm}2.5%$. The result of Linearity of OSLD, the dose was increased linearly up to about the 300 cGy and increased supralinearly above the 300 cGy. Energy and dose rate dependence of the response of OSL detectors were evaluated within ${\pm}2%$ and ${\pm}3%$. $PDD_{10}$ and PDD20 which were measured by OSLD was 66.7%, 38.4% and $PDD_{10}$ and $PDD_{20}$ which were measured by Ion-chamber was 66.6%, 38.3% Conclusion: As a result of analyzing characteration of OSLD, OSLD was evaluated within ${\pm}3%$ according to the change of the time, enregy and dose rate. The $PDD_{10}$ and $PDD_{20}$ are measured by OSLD and ion-chamber were evaluated within 0.3%. The OSL response is linear with a dose in the range 50~300 cGy. It was possible to repeat measurement many times and progress of the measurement of reading is easy. So the stability of the system and linear dose response relationship make it a good for dosimetry.

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Change of Nutrients and Behaviour of Total Coliforms in the Natural Treatment of Wastewater by Subsurface Flow Wetland System (인공습지를 이용한 자연정화 오수처리시설에서 영양물질의 변화와 대장균군의 행동)

  • Yoon, Chun-Gyeong;Kwun, Soon-Kuk;Kim, Hyung-Joong
    • Korean Journal of Environmental Agriculture
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    • v.16 no.3
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    • pp.249-254
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    • 1997
  • The constructed wetland system which is applicable to rural wastewater treatment was examined by pilot plant experiment. Removal rates of nutrients including nitrogen and phosphorus and total coliform were evaluated. The $NH_4\;^+$ concentration of the influent was in the range of 91.57 to 275.88mg/l and the effluent concentration was about 40% lower than the influent. The decreasing of the $NH_4\;^+$ concentration might be due to volatilization, plant uptake, adsorption onto soil particles, and mainly nitrification. However, generally concentrations of $NO_2\;^-$ and $NO_3\;^-$ were increased in the effluents compared to the influent concentrations, which implies that nitrogen components in the system were nitrified. Overall, the average removal rate of the nitrogen was about 5% which seems inadequate as a wastewater treatment system, and this system needs improvement on nitrogen removal mechamism. The removal rate of the phosphorus was quite high and effluent concentration was very low. Reason for high removal rate of the phosphorus might be mainly strong adsorption characteristic onto soil particles. The average removal rate of the total coliforms was about 83%, and main removal mechanisms are thought to be adsorption onto soil and inability to compete against the established soil microflora. From the results of the study, the constructed wetland system needs to be improved in nitrogen removal mechanism for field application.

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