• Title/Summary/Keyword: stability period

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A Study on the Occurrence and A change in the times of the Nemok-dori (내목도리의 발생과 시대적 변화에 관한 연구)

  • Heo, Kyoung-Do;Chung, Myung-Sup
    • Journal of architectural history
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    • v.29 no.1
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    • pp.39-49
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    • 2020
  • A dapo type bracket system which consists of chuganpo(柱間包) and chusangpo(柱上包) with a fake-beam adopted a nemok-dori member to cope with oemok-dori member in order to obtain balance between the outer-side and the inner-side of the bracket system. The middle part of the longest rater in the dapo system is supported by three points made by oemok-dori, jusim-dori and nemok-dori members and the area between the rafer supporting points forms a supporting area. The increase of rafter supporting points and supporting area leads to heightening the structural stability and the efficiency of load delivery. In the eave of dapo system the portion where the three supporting points formed by oemok-dori, jusim-dori and nemok-dori members shows as 33% in the early period, 71% in the middle period and 78% in the later period. On the contrary the portion where more than one of the three dori members were omitted shows as 67% in the early period, 29% in the middle period and 22% in the later period. This is the result of the increase of the number and the distance of steps in the dapo bracket system as time goes on. This is because the structural role of three supporting points becomes important as the increase of distance between the dori members leads to the increase of load which burdens on each dori member.

Preparation and Evaluation of Mutivitamin Emulsion (복합비타민 유제의 제조와 평가)

  • Lee, Moon-Seok;Cho, Hea-Young;Lee, Yong-Bok
    • Journal of Pharmaceutical Investigation
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    • v.32 no.1
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    • pp.13-19
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    • 2002
  • Water-lipid soluble multivitamin formulations were widely used to reduce the disease and stress of animals as husbandry has made a remarkable progress in recent. But the efficiency of these formulations is far from satisfactory. So, this study was attempted to develop the physically and chemically stable and useful multivitamin o/w emulsion. Multivitamin o/w emulsion composed of water, soybean oil (10%, v/v), vitamin A, D, E, K, $B_2,\;B_6,\;B_{12}$ and panthenol. To make a stable o/w emulsion, the egg lecithin (2%, w/v) and glycerin (2.5%, w/v) were used for emulsifier and thickening agent, respectively. The oil in water emulsion system was manufactured by microfluidizer and the physicochemical stability of this emulsion was evaluated. The average particle size and interfacial tension were measured. From the result of interfacial tension tested, critical micelle concentration of the egg lecithin was 0.5% (w/v) and optimal concentration for the preparation of emulsion was 2% (w/v). The mean particle size was about $0.6\;{\mu}m$ which was suitable for injections. Short-term accelerated stability as physical stability study was tested by centrifuging and freeze-thawing the emulsion samples. The additions of vitamins resulted in the increment of particle size and reduction of physical stability of emulsion. But it is not an enormous problem for the stability of emulsion. Also, we have performed the long-period preservation stability test for the vitamins. All vitamins were analysed by HPLC. The result of storage under $4^{\circ}C$ and dark conditions demonstrated that all vitamins were maintained stable at least 16 weeks, except for vitamin $B_{12}$.

Algae-based antioxidant containing selenium yeast (Economase®) enhanced the growth performance, oxidative stability, and meat quality of broiler chickens

  • Nambapana, Maleeka N.;Wickramasuriya, Samiru S.;Macelline, Shemil Priyan;Samarasinghe, K.;Vidanarachchi, Janak K.
    • Animal Bioscience
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    • v.35 no.4
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    • pp.567-576
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    • 2022
  • Objective: An experiment was conducted to determine the effect of algae-based antioxidant containing Se yeast (EconomasE®) on the growth performance, visceral organ weight, meat quality, and oxidative stability of broiler chickens. Methods: Nine hundred sixty, day-old male broiler chickens (Cobb, 43.97±0.55 g) were divided into three dietary treatments and allocated into 12 deep litter pens in a completely randomized design giving 4 replicate cages for each treatment. Three dietary treatments were: i) control (CON, basal diet with sufficient nutrient), ii) vitamin E (VitE, basal diet supplemented with 100 IU VitE), and iii) Algae-based antioxidant containing Se yeast (EcoE, basal diet supplemented with 0.2% algae-based antioxidant containing Se yeast: EconomasE®). Maize soybean meal based basal diets were formulated to meet or exceed the nutrition requirement for broiler chickens. Chickens were fed ad-libitum experimental diets during the 42 days experiment period. On days 21 and 42, body weight and feed intake were measured to calculate the feed conversion ratio of the chickens. Intestine and visceral organs were measured together with meat quality and oxidative stability on days 14 and 42. Results: Chickens fed with EcoE showed improved (p<0.05) growth performance, meat quality, and higher (p<0.05) oxidative stability compared to the chicken fed on CON. Moreover, broiler chickens fed with EcoE showed similar (p<0.05) growth performance with better (p<0.05) meat quality and higher oxidative stability compared to the broiler chickens fed VitE (p<0.05). Conclusion: The algae-based antioxidant containing Se yeast can be supplemented into commercial broiler diets as a substitution of VitE while maintaining growth performance with enhancing meat quality and oxidative stability of the broiler chickens.

Minimum presurgical orthodontic treatment: The influence of the postsurgial occlusal stability on postsurgical mandibular changes in class III malocclusion (임상가를 위한 특집 2 - 최소술전교정: 수술교합의 안정성이 술후 하악골 위치변화에 미치는 영향)

  • Kim, Byoung-Ho
    • The Journal of the Korean dental association
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    • v.50 no.2
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    • pp.64-71
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    • 2012
  • Recently, the presurgical orthodontic duration tends to be shortened by virtue of the advancement of surgical and orthodontic techniques in class III orthognathic surgery cases. But the predictability of the surgical results should be secured by removing several uncertain factors in presurgical orthodontic treatment. The purpose of this study is to investigate the influence of immediate postsurgical occlusal stability on postsurgical mandibular change. The study includes 40 patients who underwent orthognathic surgery to correct skeletal class III malocclusion. The patients were divided into two groups based on the numbers of occlusal contact in surgical setup occlusion: group 1 (stable surgical occlusion, n=24) and group 2(unstable surgical occlusion, n=16). Changes of horizontal and vertical mandibular measurements during postsurgical follow up period(from 1 week postsurgery to 12month after debonding) were compared to examine the differences between two groups. The stability of surgical occlusion is one of the factors influencing postsurgical mandibular changes in class III malocclusion. The various class III malocclusion cases have specific prerequisites for the orthognathic surgery according to the skeletal patterns. The prerequisites should be obtained by minimum presurgical orthodontics to increase the predictability of the surgical results.

Stability Study for Herbal Drug According to Storage Conditions and Periods (탕약의 실온과 냉장보관 및 기간별 안정성에 대한 실험적 연구)

  • Son, Jin-Young;Shin, Jang-Woo;Son, Chang-Gue
    • The Journal of Korean Medicine
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    • v.30 no.2
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    • pp.127-132
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    • 2009
  • Objectives: This study aimed to investigate the stability of a decoction using three herbal plants and their major components according to the storage conditions and periods. Materials and Methods: A three-herb mixture (1:1:1) of Glycyrrhiza uralensis Fischer, Artemisia capillaris Thunberg, and Poncirus trifoliata Rafinesqui was decocted and kept at room temperature ($25{\pm}2^{\circ}C$) or cold temperature ($4^{\circ}C$) for 0, 2, 4 or 8 weeks in liquid form in a plastic pack under dark conditions. At time points given, they were lyophilized. 200 mg of powdered samples were dissolved in 1 mL of 90% methanol and then applied to a high performance thin layer chromatography (HPTLC) with glycyrrhizin, 6,7-dimethoxycoumarin or poncirin for quantitative or qualitative analysis. Results: There were no gross changes in HPTLC-based compositional band-patterns of the three herbal mixture according to the storage conditions and period. The major components of each herb, glycyrrhizin, 6,7-dimethoxycoumarin and poncirin, showed slight time-dependent reduction in their contents both at room and cold temperature for 8 weeks. Conclusion: We could conclude that the current herbal decoction is generally safe for the stability at both RT or CT for at least 8 weeks. Nevertheless, we proposed that further advanced studies are required for more multiple herbal mixtures and longer storage periods.

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Temperature and pH Stability Profiles of ortho and para DEET

  • Choi, Mi-Rine;Kim, Seok-Yong;Choi, Joon-Ho;Park, Sang-Hee;Yong, Chul-Soon;Kim, Jung-Sun
    • Journal of Pharmaceutical Investigation
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    • v.41 no.4
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    • pp.233-238
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    • 2011
  • DEET, N,N'-diethyl-m-toluamide, is the most commonly used mosquito repellent. However, it can easily permeate through skin leading to toxic effects. A recent study showed that the ortho analogue of DEET showed enhanced repellency with reduced permeation compared to the commercially used meta analogue. Thus, in order to understand the differences in properties and effectiveness among the m-, o- and p-analogues of DEET, an HPLC-UV method was developed for separately analyzing the three analogues. Moreover, stability profiles at temperatures ranging from $30^{\circ}C$ to $70^{\circ}C$ as well as pH ranging from pH 3 to pH 9 have been determined. All three analogues were stable with no degradation observed during the 5 day period. o-DEET therefore could be further developed into a safer and more effective mosquito repellent.

Centrifuge Model Experiments and Numerical Analyses of the Behavior of Excavated Marine Clay Slope (해성점토 굴착사면의 거동에 관한 원심모형실험 및 수치해석)

  • Park, Byung-Soo
    • Journal of Ocean Engineering and Technology
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    • v.20 no.5 s.72
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    • pp.49-56
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    • 2006
  • In this thesis, centrifuge model experiments and numerical analyses were carried out to investigate the behavior of an excavated slope in soft clay ground. Centrifuge model tests were performed with various slopes for the excavated ground, such as 1:1.5 and 1:2. Pore pressuresthe model ground were measured to find their effects on the stability of the excavated slope. These experiments showed that the model with 1:2.5 maintained its stability within a short period of time and failed gradually. Therefore, anexcavated slope of soft soil with this slope might maintain stable conditions within a certain time. The mode1 with a 1:3 slope was observed to maintain a very stable condition, showing insignificant deformation in the ground after being excavated. Numerical analyses with PLAXIS, a commerciallyavailable software implemented with the finite element numerical technique, were performed to find the pore pressure distribution within the ground mass and the deformation of the soil. From the results of numerical analysis, a negative pore pressure was developed after the excavation and thus the stability of the slope was maintained. The safety factor for slope failure was found to decrease with time because of the dissipation of negative pore pressure with time.

Effect of Taurine Supplementation on Lipid Peroxidation, Activities of Defense Enzymes and Membrane Stability During Rat Hepatocarcinogenesis (쥐의 간암화 과정에서 타우린의 공급이 지질과산화물 함량, 생체방어 효소 및 세포막 안정도에 미치는 영향)

  • 유정순
    • Journal of Nutrition and Health
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    • v.29 no.10
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    • pp.1080-1086
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    • 1996
  • The purpose of this study was to determine the effects of taurine supplementation on the hepatic lipid peroxidation, activiteis of defense enzymes and membrane stability during rat hepatocarcinogenesis. Hepatocarcinogenesis was induced by Solt & Farber modification. Lipid peroxide contents of carcinogen treated group which was not supplemented with taurine were lower than those of control group. This might be that peroxide is decreased because of the activation of detoxifing enzyme. Glutathione S-transferase(GST) activites of carcinogen treated groups were significantly (p<0.05) increased compared to those of control groups. The GST activities of group supplemented with taurine before treatment of carcinogen and during the all period of experiment were only less increased. In carcinogen treated groups, glutathione peroxidase(GPx) activites of groups supplemented with taurine were higher than those of non supplemented group. By carcinogen treatemtn, glucose 6-phosphatase(G6Pase) activites, index of membrane stability were decreased, but in carcinogen treated groups supplemented with taurine, they were less decreased. These results suggest that taurine supplementation seems to inhibit lipid peroxidation, to change the activities of defense enzymes and to prevent to membrane disintegration during chemically induced hepatocarcinogenesis.

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Effects of Addition of Sugars on the Stability of Hepatitis B Virus Vaccine (당첨가가 B형 간염 바이러스 백신의 안정성에 미치는 영향)

  • Seong, In-Wha
    • The Journal of Korean Society of Virology
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    • v.27 no.2
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    • pp.143-149
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    • 1997
  • Most of the current licenced hepatitis B vaccines are being produced by recombinant DNA technology in large fermentation cultures of Saccharomyces cerevisiae of yeast cells which carry the gene coded for hepatitis B virus surface antigen. These vaccines are proved very effective clinically and the immunogenicity of vaccines could be maintained for a long time under refrigeration. To develope the stabilizer that could increase the stability of hepatitis B virus vaccine which could be stored for a long period at room temperature or higher conditions, glucose, lactose and sucrose solutions in phosphate buffered saline were added into hepatitis B vaccine respectively to make 2.5%, 5%, 7.5% and 10% final concentration in vaccines. These sugar-vaccine mixtures were stored at room temperature for one month, two months and three months respectively and then inoculated into ICR mice intramuscularly. On the fourteenth day after inoculation, mice were bled and sera were tested for the evaluation of efficacies of vaccines. The results showed that 5% glucose, 7.5% lactose and sucrose increased the stability of vaccines in some degree and this method could be applied for the production of other viral vaccines and bacterial vaccines.

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The Effect of Bridging Exercise on Dysmenorrhea Back Pain of Women University Students (교각운동이 월경곤란증으로 인한 허리통증을 가진 여대생에게 미치는 영향)

  • Jeong, Yeonwoo;Hong, Sanghyeon;Lee, Seunghyub
    • Journal of The Korean Society of Integrative Medicine
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    • v.4 no.4
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    • pp.1-6
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    • 2016
  • Purpose : This study determines the effect and sustainability of the trunk stability exercise program, specifically using the bridge exercise, by measuring Visual Analogue Scale(VAS), Menstrual Distress Questionaire(MDQ) and muscle strength in women university students complaining of low back pain. Methods : The trunk stability exercise program was progressed by 22 women university students, for 4 weeks, (3 times a week, 1 hour per session). At this time, low back pain happened at the period of menstruation and was measured using VAS, Dysmenorrhea using the MDQ tool and abdominal and back muscle strength using HUR. This study was evaluated 4 times (before and after the exercise program, after 4 weeks and 8 weeks) to investigate the effect of time variation after the exercise program. Results : The trends showed a decrease in VAS and MDQ and an increase in abdominal and back muscle strength. Therefore, these results were evaluated positively from a statistical perspective(p<.05). Conclusions : The trunk stability exercise results in a decreased VAS and MDQ, and increases the muscle strength in women university students who complained of low back pain form dysmenorrhea. Therefore, the low back pain from dysmenorrhea could have been avoided and quality of everyday life improved.