• Title/Summary/Keyword: Bang-bang control

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Simultaneous HPLC Determination of Marker Compounds for the Standardization of Hedyotis diffusa (백운풀의 지표성분 설정 및 품질표준화를 위한 정량 분석법)

  • Bang, Han-Yeol;Yang, Eun-Ju;Kim, Jeong-Ah;Song, Kyung-Sik
    • Journal of Life Science
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    • v.23 no.8
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    • pp.1025-1031
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    • 2013
  • From a 95% ethanolic extract of H. diffusa, four marker compounds (HD1~HD4) were isolated, which were relatively unique and exist in comparably high contents. The structures of marker compounds were identified as digitolutein (1), 2-hydroxy-3-methylanthraquinone (2), (E/Z)-6-O-p-coumaroyl scandoside methyl ester (4:1 mixture) (3), and (E/Z)-6-O-p-methoxycinnamoyl scandoside methyl ester (4:1 mixture) (4), respectively, on the basis of $^{13}C$ and $^1H$-NMR analyses. The calibration curves of marker compounds showed high linearity, as their correlation coefficient ($R^2$) were in the range of 0.9991~0.9999. In addition, the limit of detection (LOD) and the limit of quantification (LOQ) were $0.03{\sim}0.07{\mu}g/ml$ and $0.099{\sim}0.231{\mu}g/ml$, respectively. The intra-day/inter-day precision and accuracy were 0.23~2.00%/0.25~1.16% and 94.60~108.44%/94.73-110.23%, respectively. The optimal HPLC conditions for the simultaneous quantification of HD1~HD4 were as follows: stationary phase; Merck Chromolith RP-18e ($100{\times}4.6mm$, $5{\mu}m$), column temp.; room temperature, UV detection at 280 nm, flow rate; 2.0 ml/min, injection volume; $10{\mu}l$, mobile phase; start with the mixture of 80% solvent A ($H_2O$ containing 0.5% acetic acid) and 20% solvent B (methanol containing 0.5% acetic acid) and gradually decrease solvent A to 40% in 9 min., then retain this condition to 18 min. Under the HPLC condition, the four marker compounds 1~4 were successfully separated without any interference of other constituents. The results obtained in this study are expected to be helpful for the development of nutraceutics and natural medicines and for the quality control of this plant.

Effect of Gas Mixture Ratio of Modified Atmosphere Packaging on Quality of Chicken Breast (CO2와 N2 혼합 비율에 따른 포장 닭고기 가슴육의 냉장 저장 중 품질 특성)

  • Chae, Hyun-Seok;Na, Jae-Cheon;Choi, Hee-Cheol;Kim, Min-Ji;Bang, Han-Tae;Kang, Hwan-Ku;Kim, Dong-Wook;Suh, Ok-Seok;Ham, Jun-Sang;Jang, Ae-Ra
    • Food Science of Animal Resources
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    • v.31 no.1
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    • pp.100-106
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    • 2011
  • The physicochemical characteristics of chicken breast were determined to identify the optimal ratio of $CO_2$ and $N_2$ to maintain chicken breast quality during cold storage for 6 d. The mixing ratios of $CO_2$ and $N_2$ were 20:80, 40:60, 60:40, and 80:20, respectively. The pH of the chicken breast packed with 80% $CO_2$ and 20% $N_2$ was lower than that of the control on day 1 (p<0.05). The lightness ($L^*$) of the breast increased with increasing $CO_2$ during storage (p<0.05), whereas no difference was found for redness ($a^*$) and yellowness ($b^*$). A lower volatile basic nitrogen level was found for chicken breasts exposed to higher $CO_2$ levels. Furthermore, lipid oxidation of the chicken breast packed with $CO_2$ decreased with increasing $CO_2$ level, and 40% $CO_2$ significantly reduced 2-thiobarbituric acid reactive substances (TBARS) values on days 1 and 6. The total number of microbes was reduced in chicken breast exposed to more than 40% $CO_2$ during storage days 3 and 6 (p<0.05); however, Escherichia coli was not affected by $CO_2$ level. Coliforms of chicken breast were reduced in the 40% $CO_2$ level on storage day 3. Moreover, tray-packed chicken breast exposed to 40% $CO_2$ did not collapse. These results suggest that 40% $CO_2$ and 60% $N_2$ were the optimal conditions for packaging chicken breasts during cold storage.

Development of a Test Method for the Evaluation of DNA Damage in Mouse Spermatogonial Stem Cells

  • Jeon, Hye Lyun;Yi, Jung-Sun;Kim, Tae Sung;Oh, Youkyung;Lee, Hye Jeong;Lee, Minseong;Bang, Jin Seok;Ko, Kinarm;Ahn, Il Young;Ko, Kyungyuk;Kim, Joohwan;Park, Hye-Kyung;Lee, Jong Kwon;Sohn, Soo Jung
    • Toxicological Research
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    • v.33 no.2
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    • pp.107-118
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    • 2017
  • Although alternative test methods based on the 3Rs (Replacement, Reduction, Refinement) are being developed to replace animal testing in reproductive and developmental toxicology, they are still in an early stage. Consequently, we aimed to develop alternative test methods in male animals using mouse spermatogonial stem cells (mSSCs). Here, we modified the OECD TG 489 and optimized the in vitro comet assay in our previous study. This study aimed to verify the validity of in vitro tests involving mSSCs by comparing their results with those of in vivo tests using C57BL/6 mice by gavage. We selected hydroxyurea (HU), which is known to chemically induce male reproductive toxicity. The 50% inhibitory concentration ($IC_{50}$) value of HU was 0.9 mM, as determined by the MTT assay. In the in vitro comet assay, % tail DNA and Olive tail moment (OTM) after HU administration increased significantly, compared to the control. Annexin V, PI staining and TUNEL assays showed that HU caused apoptosis in mSSCs. In order to compare in vitro tests with in vivo tests, the same substances were administered to male C57BL/6 mice. Reproductive toxicity was observed at 25, 50, 100, and 200 mg/kg/day as measured by clinical measures of reduction in sperm motility and testicular weight. The comet assay, DCFH-DA assay, H&E staining, and TUNEL assay were also performed. The results of the test with C57BL/6 mice were similar to those with mSSCs for HU treatment. Finally, linear regression analysis showed a strong positive correlation between results of in vitro tests and those of in vivo. In conclusion, the present study is the first to demonstrate the effect of HU-induced DNA damage, ROS formation, and apoptosis in mSSCs. Further, the results of the current study suggest that mSSCs could be a useful model to predict male reproductive toxicity.

Evaluation on Cooling Effects of Geothermal Heat Pump System in Farrowing House (지열 냉방시스템을 이용한 분만돈사의 냉방효과 분석)

  • Choi, H.C.;Song, J.I.;Na, J.C.;Kim, M.J.;Bang, H.T.;Kang, H.G.;Park, S.B.;Chae, H.S.;Suh, O.S.;Yoo, Y.S.;Kim, T.W.;Park, J.H.
    • Journal of Animal Environmental Science
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    • v.16 no.2
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    • pp.99-108
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    • 2010
  • The principal objective of this study was to investigate the cooling effects of geothermal heat pump system (GHPS) in farrowing house. A total of 96 sows were allocated to 2 pig housings (GHPS and conventional housing) with 48 for four weeks in summer season. During the experimental period of four weeks, the highest outside temperature observed was approximately $34.1^{\circ}C$, GHPS decrease indoor temperature of pig housing up to $30.9^{\circ}C$, but conventional pig housing was similar to outside temperature. Dust concentrations (maximum 61.4%) of particulate matter less than $10{\mu}m$ (PM 10) in GHPS-housing were lower than the conventional housing. GHPS showed no signigicant difference in carbon dioxide emission, whereas the ammonia gas concentration was significantly decreased in GHPS-housing compared to that of conventional housing. Sows in GHPS-housing showed significantly lower respiratory rate than those of the control group. GHPS did not affect hormone level, litter size and birth weight, but weaning weight of piglets was influenced by GHPS. Feed consumption of sows was significantly increased in GHPS-housing compared to the conventional hosing. These results suggest that GHPS decrease dust concentration, ammonia gas emission and indoor temperature of pig housing and may affect performance in sows and weaned piglets.

Aqueous Spray-dried Green Tea Extract Regulates Body Weight and Epididymal Fat Accumulation in Mice (열수 녹차추출물이 생쥐의 체중 및 부고환 지방축적 조절에 미치는 영향)

  • Park, Pil-Joon;Kim, Chae-Wook;Cho, Si-Young;Rha, Chan-Su;Seo, Dae-Bang;Lee, Sang-Jun
    • Korean Journal of Food Science and Technology
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    • v.42 no.1
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    • pp.103-108
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    • 2010
  • To obtain the best yield of the beneficial ingredients in green tea, such as catechins, green tea powder is most often prepared by ethyl alcohol extraction. However, the taste, cost and composition of ethyl alcohol extract is different from aqueous spray-dried green tea extract (aq-GTE). Specifically, aq-GTE has a better flavor, lower production costs and higher purity when compared to ethyl alcohol extract. In this study, we elucidated the effect of aq-GTE on diet-induced obesity in male C57BL/6J mice following dose-dependent oral administration of aq-GTE. After eight weeks, the body weight was reduced by 13-17% in mice fed 200 mg/kg bw aq-GTE ($12.468{\pm}0.45\;g$; p<0.05) and 20-25% in mice fed 400 mg/kg bw aq-GTE ($11.259{\pm}0.61\;g$; p<0.05) when compared with the high-fat diet (HFD) control group mice ($14.714{\pm}0.95\;g$; p<0.05). The correlation between epididymal fat accumulation and body weight also decreased by approximately 26.6% (p<0.05) in mice fed a HFD with aq-GTE 400 mg/kg bw. Finally, serum parameters such as the triglyceride, glucose and cholesterol levels in the HFD groups were reduced by the aq-GTE 400 mg/kg bw diet. Analysis on glutamic-pyruvic transaminase, blood urea nitrogen and development of hepatic steatosis revealed no histologic evidence of hepatotoxicity in HFD mice fed aq-GTE. Overall, our results imply that aq-GTE is able to regulate body weight and fat accumulation in mice.

The Comparison between High Dose and Low Dose Morphine in Terminal Cancer Patients During the Last 1 Week to Death (고용량과 저용량의 몰핀을 쓰는 말기 암 환자에서 임종 1주일동안 비교)

  • Cho, Doo-Yeoun;Cha, Kyu-Jin;Yoon, Bang-Boo;Yeom, Chang-Hwan
    • Journal of Hospice and Palliative Care
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    • v.5 no.1
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    • pp.24-30
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    • 2002
  • Background : Pain is one of the most feared consequences of cancer. $65{\sim}85%$ of cancer patients experienced severe pain, and sometimes high dose morphine is used to these patients. But many doctors still have 'opioid-phobia' and hesitate to use high dose morphine. We investigated the morphine therapy in terminal cancer patients during the last 1 week to death, and found any differences according to the morphine dosage. Methods : 93 patients admitted to National Health Insurance Corporation Ilsan Hospital, department of family medicine for hospice care between September 2000 and the end of October 2001 and lived more than 1 week entered in the study. We investigated the demographic data, laboratory tests and sufficient dosage of morphine for pain control. According to the calculated dosage by OME(oral morphine equivalent), patients were divided into low dosage group (${\leq}150mg/day$) and high dosage group (>150 mg/day). The chi-squared test were used to evaluate the influence of age, gender, tumor sites, metastasis and adverse effects of morphine. Results : Mean age was $65.0{\pm}13.1year$ in low dosage group and $59.9{\pm}11.6year$ in high dosage group. 32 men (50.0%) and 32 women (50.0%) were included in low dosage group and 15 men (51.7%) and 14 women (48.3%) in high dosage group. Stomach was the most frequent tumor site and lung was the next. Metastasis were found 58 (90.6%) in low dosage group and 28 (96.6%) in high dosage group. In other palliative radiotherapy and adverse effects, there were no differences in both group. Conclusion : During the last 1 week to death in cancer patients, there were no difference according to the morphine dosage. So we don't have to have 'opioid-phobia' in treating the terminal cancer patients.

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Symptom Prevalence During Terminal Cancer Patients' Last 48 Hours of Life (말기 암 환자에서 임종 전 48시간 동안 나타나는 신체적 증상 빈도)

  • Jung, Soo-Jin;Lee, Bok-Ki;Choi, Kyung-Hi;Youn, Bang-Bu;Yeom, Chang-Hwan
    • Journal of Hospice and Palliative Care
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    • v.5 no.1
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    • pp.17-23
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    • 2002
  • Purpose : The prevalence of symptoms in patients with terminal cancer varies considerably and these symptoms are very difficult to control. However, patients can spend their last days or hours of life without suffering pain with appropriate care. One of the major concerns during last days of life is to predict the time of death. We would like to investigate symptom prevalence during terminal cancer patients' last 48 hours in Korea, and therefore contribute to predict the time of death and to help to determine appropriate treatments. Methods : The data for this study was recorded from 92 of 132 patients who died with terminal cancer at the hospital between February 1 and October 31, 2000. We investigated the symptom prevalence during the last 48 hours through medical obligation record and analyzed the changes of symptom prevalence at the admission, $48{\sim}24$ hours and $24{\sim}0$ hours before death. Results : The predominant symptom prevalence was pain (57.6%), followed by confusion (55.4%), dyspnea (48.9%), voiding difficulty (42.4%) in the last 48 hours before death. From the statistical analysis for the changes of symptom prevalence in time, pain, nausea and vomiting were decreased but noisy and moist breathing, sweating, groan, restlessness and agitation, and loss of consciousness were increased (P<0.05). Conclusion : The results from this study show the tendency to increase of prevalence of noisy and moist breathing, sweating, groan, restlessness and agitation as well as loss of consciousness in 48 hours before death. Therefore the symptoms above can be used for the important indicators to predict the imminent death.

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Analysis of Adolescent Awareness of Radiation: Marking the First Anniversary of the Fukushima Nuclear Accident (청소년의 방사선 인식도 분석: 일본 후쿠시마 원전사고 1주년 계기)

  • Park, Bang-Ju
    • Journal of Radiation Protection and Research
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    • v.37 no.2
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    • pp.75-83
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    • 2012
  • Marking the first anniversary of the Fukushima nuclear accident, which took place on March 11th, 2011, the level of adolescent awareness and understanding of radiation was surveyed, and the results were then compared with those for adults with the same questionnaires conducted at similar times. A qualitative survey and frequency analysis were made for the design of the study methodology. Those surveyed were limited to 3rd grade middle school students, 15 years of age, who are the future generation. The questionnaire, which is a survey tool, was directly distributed to the students and 2,217 answers were analysed. The questionnaires were composed of 40 questions, and it was found that Cronbach's coefficient was high with 'self awareness of radiation' at 0.494, 'risk of radiation' at 0.843, 'benefit of radiation' at 0.748, 'radiological safety control' at 0.692, 'information sources of radiation' at 0.819, and 'impacts of Fukushima accident'. The results of the survey analysis showed that the students' knowledge of radiation was not very high with 67.4 points (69.5 points for adults) calculated on a maximum scale of 100 points (converted points). The impacts of the Fukushima nuclear accident were found to be less significant to adolescents than adults, and the rate of answer of "so" or " very so" in the following questions demonstrates this well. It was also shown that the impacts of the Fukushima accident to adolescents were comparatively low with 27.0% (38.9% for adults) on the question of "attitude changed against nuclear power due to the Fukushima accident," 65.7%(86.6% for adults) on the question of "the damages from the Fukushima accident was immeasurably huge," and 65.0% (86.3% for adults) on "the Fukushima accident contributed to raising awareness on the safety of nuclear power plants". The adolescents had a high rate of "average" answers on most of the questions compared with adults, and it can be construed that this resulted from adolescent awareness of radiation not being firmly rooted on themselves. This study was the first of its kind for surveying adolescents regarding the level of awareness of radiation after the Fukushima accident, and the results were compared with the survey results of adults, and they are expected to greatly contribute toward establishing a radiation policy by the government in the future.

A Study on Needs of Teachers in Community Children's Centers for Oral Health Education in Incheon (인천광역시 지역아동센터 교사의 구강보건교육 요구도 조사)

  • Kim, Jin-Hee;Kim, Hyun-Jin;Kim, Hye-Jin;Park, Ji-Hye;Bang, Woo-Ri;Shin, Hye-Ju;Han, Su-Jin
    • Journal of dental hygiene science
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    • v.11 no.6
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    • pp.505-512
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    • 2011
  • The purpose of this study was to examine the oral health behavior and awareness of teachers in community children's centers, the state of oral health care among children in the centers and the opinions of the teachers on child oral health education in a bid to gather information required for the development of oral health education programs geared toward community children's center teachers. The subjects in this study were 178 teachers who worked in 98 community children's centers in the city of Incheon. After a survey was conducted from April 28 to June 4, 2010, the collected data were analyzed. The findings of the study were as follows: The 57.3% of the teachers investigated provided toothbrushing guidance from time to time or couldn't do it at all. As for the reason why toothbrushing guidance was scarcely conducted, the largest group cited shortage of sinks(27.5%) as the reason, and the second biggest group replied they couldn't afford to pay attention to that due to heavy workload(20.6%). The third greatest group was pressed for time(16.7%). The teachers got a mean of 3.27 in oral health behavior, and 87.7% were concerned about children's oral health. The group of teachers who ever received oral health education was significantly better at oral health behavior and showed significant more interest in oral health(p<0.01). The 97.2% of the respondents considered oral health important. Concerning the reason, they replied it was crucial for systemic health (74.2%). The 89.4% of the teachers viewed child oral health education as necessary, and 86.5% had an intention to provide oral health education for children. They hoped to receive education on the oral health control act(4.52) and the prevention of dental caries(4.40). The above-mentioned findings confirmed that in order to step up the oral health promotion of child users of local children's centers, it's necessary to provide secondhand education for them through their teachers who have a great impact on them. Therefore the development of oral health education programs that cater to local children's center teachers is required.

Development and Application of Web-based Instruction Program for the Enriched Course of School Biology (중등 생물교과 심화과정 학습용 웹 기반 학습 프로그램 개발 및 적용)

  • Ye, Jin-Hee;Park, Chang-Bo;Seo, Hae-Ae;Song, Bang-Ho
    • Journal of The Korean Association For Science Education
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    • v.22 no.2
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    • pp.299-313
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    • 2002
  • A web-based instruction program for the enriched course under the 7th Revised National Curriculum of Biology in Korea was developed and the application effects to learners were analyzed. For the development of the web-based instruction program, five topics of biology from the enriched courses through 7th to 10th grades in the middle and high school science textbooks were selected and modulated with interrogative sentences. Each topic of programs was divided into four activity sections according to the learners' activity procedures supplemented with explanations and evaluations. Each activity was hyper-linked to multi-layers and animations. Further, a virtual experiment was also developed and an evaluation section designed by Java Script was attached. Among five topics, one topic of 'Reproduction and development' at 9th grade level was selected to examine the effects on students' learning. Among 247 9th grade students in the research subject school, only 67 students were able to accessible to ultra-thin Internet cables with their computers at home and they became an experimental group. A control group was assigned to those who are similar level of school science achievement to the experiment group and did not use the web-based program. It was found that most of 9th grade students are able to use Internet at home, however, they do not prefer to use Internet for homework or task project. Rather, most of students used Internet for e-mail or information navigation. Students used internet to solve problems of science and perceived the benefits of Internet for science learning. However, there are not many students to utilize Internet for science homework or task project. Students expressed that they do not prefer to use a web-based learning program for science learning due to lack of interests in science. The effects on students who studied with this program appeared to be significantly high compared to those who did not study with this program. Students who studied with this program positively evaluated this program, in particular, they enjoyed animation effect and virtual experiments. It was concluded that a web-based program for science learning should be developed and distributed through Internet in an attractive and interesting format for students. It was also concluded that various web-based programs for science learning with animation effect and virtual experiments should be developed to increase students' interests in science as well as to improve students' science achievements.