• Preventive Nutrition and Food Science
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• v.11 no.4
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• pp.261-267
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• 2006

This study investigated the physiological activities of different molecular weight (MW) fractions of crude polysaccharide from $D\check{o}d\check{o}k$ (Codonopsis lanceolata). The crude polysaccharide cut off for each fraction was: <1,000 MW (Fr I), 1,000 MW

• Journal of the Korean Graphic Arts Communication Society
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• v.19 no.1
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• pp.64-74
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• 2001

This study is to find the effect of the molecular weight distribution of components on the freeness and physical properties of paper by observing the change of properties according the modification of fibers by using production technology and process technology together to develop additives which can effectively control according to the purpose of paper-making process and by combining low molecular weight cellulase (below MW 20,000; CMC activity 400 unit) with different enzyme's molecular weight and activity and high molecular weight cellulase(MW 20,000∼80,000;CMC activity 90,000 unit) and then process them in Sw-BKP(Softwood Bleached Kraft Pulp) and Hw-BKP(Hardwood Bleached Kraft Pulp) and Cotton Linter Pulp and OCC(Old Corrugated Container) with different properties of pore of surface of fibers respectively, since it is judged that making the appropriate composition ratio of components is necessary in consideration of the properties of fibers and paper-making process.

• Journal of the Korean Wood Science and Technology
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• v.17 no.2
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• pp.20-25
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• 1989

This study was carried out in order to investigate the treatment effect of PEG soln which is a common dimensional stabilizer to green log. sawing panel etc, on bonding product including plywood widely-used in secondary processing unit. The 30% concentration of aqueous PEG soln. with molecular weight of 400, 1.000 and 4,000 were prepared respectively, and also dipping the veneer in the PEG soln. spreading the PEG soln. on veneer and mixing the PEG soln. in the adhesive were allowed. Then the ratio of PEG impregnation on veneer, the adhesive strength of plywood were epitomized as follows: The ratio of impregnation by PEG 4,000 at dipping condition was highest. while that by PEG 400 at same condition was lowest. However, the effect of PEG molecular weight on the ratio of impregnation at spreading condition did not occur. 2. The adhesive strength was great in the order of 4,000>400>1,000 in molecular weight of PEG at dipping and spreading conditions. In case of mixing the PEG soln. in the adhesive, the adhesive strength was great in the order of 400>1,000>4,000 in molecular weight of PEG. Throughout three treatment conditions, PEG 400 was relatively favourable with about 10kg/$cm^2$ dry strength. 3. The adhesive strength was great 10 the order of spreading >dipping >mixing condition. 4. Although adhesive strength with the 30% concentration of aqueous PEG soln. was decreased by 35% and over, compared to control (non-treatment) adhesive strength, all types of PEG treatment except mixing the PEG soln. in the adhesive exceeded the standard dry strength for common use panel. 7.5kg/$cm^2$. 5. In warm water-proof test, the adhesive strengths by all PEG treatment conditions were less than the standard wet strength, 7.5kg cot, and also delamination of glue line occured mostly in mixing in the PEG soln. in the adhesive condition.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.122-131
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• 2011

The object of this study was to evaluate the single dose toxicity of Yukmijihwangtanggamibang (YMJHTGMB), a polyherbal formula have been traditionally used as prevention or treatment agent for various lung diseases including chronic obstructive pulmonary disease (COPD), in male and female mice. Aqueous extracts of YMJHTGMB (Yield = 16.33%) wasadministered to female and male ICR mice as an oral dose of 2,000, 1,000 and 500 mg/kg (body weight) according to the recommendation of Korea Food and Drug Administration (KFDA) Guidelines. Animals were monitored for the mortality and changes in body weight, clinical signs and gross observation during 14 days after dosing, upon necropsy; organ weight and histopathology of 12 principle organs were examined. As results, we could not find any mortality, clinical signs, and changesin the body and organ weight except for soft feces restricted to YMJHTGMB 2,000 mg/kg treated two male mice (2/5; 40%) at 1 day after administration. In addition, no YMJHTGMB-treatment related abnormal gross findings and changes in histopathology of principle organs were detected except for some sporadic accidental findings. The results obtained in this study suggest that the 50% lethal dose and approximate lethal dose of YMJHTGMB aqueous extracts in both female and male mice were considered as over 2,000 mg/kg, the limited highest dosage recommended by KFDA Guidelines.

• Elastomers and Composites
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• v.48 no.4
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• pp.263-268
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• 2013

In this study, we prepared poly(ethylene-ter-1-hexene-ter-divinylbenzene) using bridged rac-$Et[Ind]_2ZrCl_2$ metallocene catalysts. The effect of 1-hexene on the terpolymerization rate was evaluated. When cocatalyst/catalyst molar ratio was 3,000, catalytic activity indicated more than 8,000 which was very remarkable value. As polymerization time increased, the weight-average molecular weight of the terpolymer gradually increased to some degree. In case of a polymerization time of 50 minutes, the terpolymer became amorphous state. The molecular weight distribution and densities of the terpolymer were 110,000-200,000 and $0.85-0.89g/cm^3$, respectively. Thermal properties and structure of the terpolymer were also identified.

• The Journal of Korean Society of Virology
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• v.28 no.1
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• pp.63-69
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• 1998

To establish in vivo antiviral evaluation system by using murine herpesvirus intracerebral infection model, 5-6 female BALB/c mice per group aged 5 weeks were inoculated i.c. into cerebrum with different inocular HSV-1 F. Signs of clinical disease noted everyday for one month. Observed were body weight decrease, neurological signs and death caused by encephalitis. Mice discontinued body weight decrease were recovered from the disease, and keratitis was often observed during recovery. The groups inoculated with higher than 1,000 PFU showed 100% mortaltiy and $LD_{50}$ was <100 PFU/mouse. To study the effect of virus inoculum sizes on antiviral effect of acyclovir (ACV), mice inoculated with different inocula were administered i.p. with different doses of ACV immediately after infection, and twice a day for 5 days. The higher inculum size, the less protective. $ED_{50}$ of ACV was >25, >25, 18.4 and 8.0 mg/kg b.i.d. in the group infected with 1,000,000, 100,000, 10,000 and 1,000 PFU/mouse, respectively. $LD_{50}$ of ACV was 62.5 mg/kg b.i.d. Therapeutic index of ACV was <2.5, <2.5, 3.0 and 7.0 in the groups with inocula 1,000,000, 100,000, 10,000 and 1,000 PFU/mouse, respectively. Inoculum size 1,000 PFU/mouse showing 100% mortaltiy and 5-6 days mean time to death, 5 days drug administration and 14 days observation will be future experimental conditions.

• Toxicological Research
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• v.34 no.1
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• pp.55-63
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• 2018

As a part of general toxicity studies of Enterococcus Faecalis 2001 (EF 2001) prepared using heat-treatment bacillus mort body EF 2001 in mice, this study examined the toxicity of EF 2001 in single and repeated administrations following the previous report in order to apply this product to preventive medicine. The safety of oral ingestion of EF 2001 was examined in 6-week-old male and female ICR mice with 1,000 mg/kg, 3,000 mg/kg and 5,000 mg/kg body weight/day administrated by gavage of the maximum acceptable dose of EF 2001. The study was conducted using distilled water as a control following the methods for general toxicity studies described in the "Guidelines for Non-clinical Studies of Pharmaceutical Products 2002". As a control, 1) observation of general conditions, 2) measurement of body weight, 3) determination of food consumption, 4) determination of water consumption, 5) blood test and urinalysis and 6) pathological examination were performed for the administration of EF 2001. Mice received EF 2001 for 13 weeks and results were compared with those of the control group that received distilled water. The results of the above examinations revealed no significant differences between control and EF 2001 groups for both males and females. Thus, no notable toxicity was confirmed with single and repeated oral administrations of EF 2001. Oral administration in the above doses did not result in abnormal symptoms or death during the observation period. No abnormalities in blood cell count or organ weights were seen. Without any evidence of toxicity to cells and organs, EF 2001 is speculated to not adversely affect living organisms. The 50% lethal dose of EF 2001 with oral administration in mice is estimated to be greater than 5,000 mg/kg body weight/day for both male and female mice. Therefore, $LD_{50}$ value for animals was 5,000 mg/kg or more.

• Toxicological Research
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• v.25 no.3
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• pp.140-146
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• 2009

This study was performed to evaluate the toxicity of cadmium selenide for a period of 28 days in Sprague-Dawley rats. Each of 10 healthy male and females rats per group received daily oral administration for 28-day period at dosage levels 30, 300 and 1,000 mg/kg of body weight. Mortality and clinical signs were checked, and body weight, water intake and food consumption were also recorded weekly. There were no dose-related changes in food consumption or urine volume. All animals survived to the end of study with no clinical signs or differences in body weight gain observed when compared with the control group. At the end of study, all animals including control group, were subjected to necropsy. Blood samples were collected for hematology tests including coagulation time and biochemistry analysis. Blood coagulation time and relative organ weight were unaffected by all received doses. White Blood Cell (WBC) counts significantly increased in the 300 mg/kg administered male animal group when compared to the control. Monocyte (MO) value were also increased significantly in both 300 and 1,000 mg/kg male animal group. However, Mean Corpuscular Volume (MCV) were significantly decreased compared with the control in the 1,000 mg/kg dose groups for male and female animals. Mean Corpuscular Hemoglobin (MCH) decreased significantly for female in the 300 and 1,000 mg/kg group compared to the control. Blood biochemical values of Inorganic phosphorus (IP) were significantly increased in both the 300 and 1,000 mg/kg dose groups in male animals when compared to the control. Creatinine (CRE) levels indicated significant increase in kidney function for the female, 30 mg/kg dose group when compared with control. There was a significant decrease in thymus absolute organ weight in the female, 1,000 mg/kg dose group when compared with control. Histopathological findings revealed no evidence of injury related to cadmium selenide except for one case of focal hepatic inflammation in the high dose (1,000 mg/kg) group. One case of lung inflammation was also seen in the control group. Basis on these result, the No Observable Adverse Effect Level (NOAEL) of cadmium selenide was determined to be more than 1,000 mg/kg/day for male and female rats under conditions in this study.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.35 no.3
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• pp.211-217
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• 1990

This study was carried out to elucidate the effect of different time and severity of defoliation on the dry matter accumulation in grain of rye (cv, Paldanghomil) and triticale (cv, Sinkihomil). The weight of the 2nd leaf blade was the greatest and this was followed by the 3rd and flag leaf in that order. The chlorophyll content in leaf blade and sheath were decreased at lower leaf position (flag > 2nd > 3rd). The average chlorophyll content of rye was higher than that of triticale. The earlier and severer defoliation was made, the more grain weight was its was decreased. As the time of defoliation was made later and the degree of its was small, 1,000 grain weight was increased. The results showed that the effect of defoliation on 1,000 grain weight followed the order of the flag, the 2nd and the 3rd leaf. The greatest 1,000 grain weight was observed at the middle part of panicle, which followed by the top and bottom part in that order.

• Journal of Environmental Science International
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• v.7 no.1
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• pp.104-111
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• 1998

The Dongbok lake water before and after alum coagulation and activated carbon adsorption were analyzed in terms of organic contents, molecular weight distributuin (MWD), and UV-absorbance. Dissolved organic compounds in the Dongbok lake were fractionated into three molecular size classes by gel permeation chromatography. The fractionation was reasonably successful in isolating compounds with The bulk of the dissolved carbon was present in compounds of molecular weight in the range of 3,000~10,000. Alum coagulation preferentially treated molecules of high molecular weight, which has molecules larger than 10,000. The dissolved organic carbon (DOC) removal after activated carbon adsorption was high in the Fraction B , IR . The $A_{260}$/DOC ratio after alum and activated carbon treatment the Fraction II, III. This results suggest that the organics remaining after each treatment has a trihalomethane formation potential