• Title/Summary/Keyword: Half Life Time

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Establishment of Pre-Harvest Residue Limits (PHRLs) of Insecticide Clothianidin and Fungicide Fluquinconazole on Peaches during Cultivation Period (복숭아의 재배기간 중 살충제 Clothianidin 및 살균제 Fluquinconazole의 생산단계 농약잔류허용기준의 설정)

  • Park, Jae-Hun;Lim, Jong-Sung;Yoon, Ji-Yeong;Moon, Hye-Ree;Han, Ye-Hoon;Lee, Yong-Jae;Lee, Kyu-Seung
    • Korean Journal of Environmental Agriculture
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    • v.31 no.3
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    • pp.271-276
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    • 2012
  • BACKGROUND: It is hard to control the agricultural products exceeding MRL (maximum residue limit) before forwarding. Therefore, NAQS (National Agricultural Products Quality Management Service, South Korea) established PHRL (pre-harvest residue limit) on agricultural products during their cultivation periods. This study was performed to set the PHRLs of peach during cultivation period, and also to estimate biological half-lives for residues of clothianidin and fluquinconazole. METHODS AND RESULTS: Two groups of peach were treated under Korean GAP (Good Agricultural Practices) with application time, single and triple treatments. Sample was collected over 14days (each after 0, 2, 4, 6, 8, 10, 12, 14 days. 8times), and clothianidin and fluquinconazole were analyzed by HPLC/DAD and GC/ECD, respectively. CONCLUSION: The biological half-life of clothianidin in single treatment and triple treatment was 5.2days and 7.0days. That of fluquinconazole was also 3.9days and 4.1days, respectively. The PHRL of peach on 10days before harvest was 1.4 mg/kg in clothianidin and 1.8 mg/kg in fluquinconazole.

Glial Fibrillary Acidic Protein Splice Variants in Hepatic Stellate Cells - Expression and Regulation

  • Lim, Michelle Chin Chia;Maubach, Gunter;Zhuo, Lang
    • Molecules and Cells
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    • v.25 no.3
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    • pp.376-384
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    • 2008
  • The glial fibrillary acidic protein (GFAP) is traditionally used as a marker for astrocytes of the brain, and more recently for the hepatic stellate cells (HSCs) of the liver. Several GFAP splice variants have been previously reported in the astrocytes of the CNS and in the non-myelinating Schwann cells of the PNS. In this study, we investigate whether GFAP splice variants are present in the HSCs and their expression as a function of HSCs activation. Furthermore, the regulation of these transcripts upon treatment with interferon gamma ($IFN-{\gamma}$) will be explored. Using semi-quan-titative RT-PCR and real-time PCR, we examine the expression and regulation of GFAP splice variants in HSCs as well as their respective half-life. We discover that most of the GFAP splice variants ($GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$) found in the neural system are also expressed in quiescent and culture-activated primary HSCs. Interestingly, $GFAP{\alpha}$ is the predominant form in quiescent and culture-activated primary HSCs, while $GFAP{\beta}$, predominates in the SV40-immortalized activated HSC-T6. $GFAP{\delta}$, ${\varepsilon}$ and ${\kappa}$ have similar half-lives of 10 hours, while $GFAP{\beta}$ has a half-life of 17 hours. Treatment of HSC-T6 with $IFN-{\gamma}$ results in a significant 1.29-fold up-regulation of $GFAP{\alpha}$ whereas the level of the other transcripts remains unchanged. In summary, $GFAP{\alpha}$, ${\beta}$, ${\delta}$, ${\varepsilon}$ and $\kappa$ are present in HSCs. They are differentially regulated on the transcription level, implying a role of the 5' and 3' untranslated regions.

CAN WE MEASURE A REMOTE SENSING SCIENCE? BIBLIOMETRIC ANALYSIS OF THE LITERATURE, 1975-2005

  • Nabiullin, Ahat A.;Shoom, Mariya Yu.
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.340-343
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    • 2006
  • Remote sensing science is a rapidly growing field of Earth sciences. Since emergence and to present day, an extensive literature has evolved which traces the wide application of remote sensing in human activities. According to the ISI Web of Science in the 1975-2005 time span more then 20,000 papers were published on remote sensing. The number of papers grew exponentially with doubling period of about 6 years. Notwithstanding all specialized proceedings, there is a lot more remote sensing papers published in a vast list of source titles (up to 350 proceedings). Only 25% of retrieved papers are published in 10 proceedings which ISI assigns to subject category of remote sensing. In 2005 all these proceedings published 1291 articles and received cca 24,000 citations. Average impact factor of the proceedings is equal to 1.181 and average cited half-life is 7.1. It means that an average paper in remote sensing proceedings is cited more then once per year and half of citations the paper receive within the next 7 years after publication. The time line of remote sensing periodicals issued in 1927-1995 shows an exponential growth with doubling period about 15 years. After 1995 there is a prominent deviation from the exponential curve which shows the demand saturation for specialized proceedings. The features revealed are discussed in terms of dynamics and impact of remote sensing in current Earth sciences development.

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GET Imaging Evaluation of Patients with Esophageal Cancer (식도암 환자의 GET 영상 평가)

  • Moon, Jong Wun;Lee, Chung Wun;Seo, Young Deok;Yun, Sang Hyeok;Kim, Yong Keun;Won, Woo Jae
    • The Korean Journal of Nuclear Medicine Technology
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    • v.17 no.2
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    • pp.31-36
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    • 2013
  • Purpose: Measure gastric emptying time (GET: Gastric Emptying Time) is a non-invasive and quantitative evaluation methods, mainly by endoscopic or radiological examination confirmed no mechanical obstruction in patients with symptoms of congestion is checked. Such tests are not common gastric emptying time measured esophageal cancer patients (who underwent esophagectomy) patients after surgery for gastric emptying time was measured test. And the period of time for more than one year after the gastric emptying time measurement was performed. By comparing the two kinds of tests in the chest cavity after surgery as the evaluation of gastrointestinal function tests evaluate the usefulness of GET, and will evaluate the characteristics of the image. Materials and Methods: 93 patients who underwent esophagectomy with gastric emptying time measurement of subject tests immediately after surgery and after 1 year or longer were twice. Preparation of the patient before the test is more than 12 hours of overnight fasting is important, in addition to the medicine or to stop smoking, and diabetes insulin injections should be early in the morning is ideal to test. Generally labeled with $^{99m}Tc-DTPA$ resin which is used to make steamed egg, seaweed and fermented milk with a high viscosity after eating, three hours in the standing position was measured. Evaluation of gastric emptying curves on the way intragastric radioactivity level by 50% the time (half-time [T1/2]) was calculated, based on the half-life was divided into three steps: over 180 minutes was defined as delayed gastric emptying, within 180minutes was defined as intermediate gastric emptying and when all the radioisotopes were dumped into the jejunum as soon as swallowed, was defined as rapid gastric emptying. Results: Gastric emptying time of a typical images stomach of antrum and fundus additional images appear stronger over time move on to the small intestine. but esophageal cancer who underwent esophagectomy side of the thoracic cavity showed a strong image. Immediately after surgery, the half-time (T1/2) of rapid gastric emptying appeared to 12.9%, intermediate gastric emptying appeared to 52.7%, delay gastric emptying appeared to 34.4%. After more than a year the results of the half-life after surgery, 67% of rapid gastric emptying to intermediate gastric emptying was changed, 69% of delay gastric emptying to intermediate gastric emptying changed. Intermediate gastric emptying worse in patients rapid gastric emptying and the delay gastric emptying is 24% in the case. Conclusion: Esophagectomy for esophageal cancer who underwent half-time measurement test (T1/2) rapid gastric emptying and delay gastric emptying are the result of the comparison over time, changes were observed intermediate gastric emptying. Mainly seeing of gastric emptying time measurement in the esophagus instead of thoracic cavity to check the evaluation of gastrointestinal function can be useful even means. And segmentation criteria and narrow time interval of checking if more accurate information and analysis of the clinical diagnosis and evaluation seems to be done.

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A Study of Citing Patterns of Korean Scientists on Korean Journals (국내 과학기술 연구자의 한국 학술지 인용패턴 연구)

  • Choi, Seon-Heui;Kim, Byung-Kyu;Kang, Mu-Yeong;You, Beom-Jong;Lee, Jong-Wook;Park, Jae-Won
    • Journal of the Korean Society for information Management
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    • v.28 no.2
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    • pp.97-115
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    • 2011
  • A large and reliable citation database is necessary to identify and analyze citation behavior of Korean researchers in science and technology. Korea Institute of Science and Technology Information (KISTI) built the Korea Science Citation Database (KSCD), and have provided Korea Science Citation Index (KSCI) and Korea Journal Citation Reports (KJCR) services. In this article, citing behavior of Korean scientists on Korean journals was examined by using the KSCD that covers 459 Korean core journals. This research dealt with (1) statistical numeric information of journals in KSCD, (2) analysis of document types cited, (3) ratio of domestic to international documents cited and ratio of citing different disciplines, (4) analysis on immediacy index, peak time, and half-life of cited documents, and (5) analysis on impact of journals based on KJCR citation indicators. From this research, we could find the immediacy citation rate (average 2.36%), peak-time (average 1.7 years) and half-life (average 5.2 years) of cited journals in Korea. We also found that the average journal self-citation rate is more than 50% in every field. In sum, citing behavior of Korean scientists on Korean journals was comprehensively identified from this research.

Pharmacokinetic profile and tissue distribution of sulfamethazine in pigs and rats (돼지와 랫트에서 sulfamethazine의 약물동태학 및 조직분포)

  • Yun, Hyo-in;Park, Seung-chun;Oh, Tae-kwang;Cho, Joon-hyoung;Park, Jong-myeong
    • Korean Journal of Veterinary Research
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    • v.37 no.2
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    • pp.291-299
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    • 1997
  • In order to establish optimal dosage schedules and withdrawal times for sulfamethazine(SMZ) in pigs, pharmacokinetic and tissue distribution experiments were conducted in pigs. For comparative purposes, tissue depletion kinetics are also studied in rats. From three pigs administered with SMZ i.v., the pharmacokinetic profile of SMZ in two pigs was adequately described by a one-compartment open model whereas that in one pig was patterned after a two-compartment open model. Volume of distribution(Vd) was 0.48~0.57 L/kg and biological half-life($t_{1/2}$) was 11.8-16.8 h. From three pigs dosed with SMZ p.o., pharmacokinetic profile was explainable with a one-compartment open model. Time to reach maximum SMZ concentration in serum (Tmax) was 2.8 h, 3.2 h and 7.5 h. Elimination half-life was 2.8-7.5 h. The descending order in concentration of SMZ was plsama > kidney > liver > lung > heart > pancreas > spleen > duodenum > ileum > brain > adipsoe tissue from three pigs sacrificed at 5h, 29h and 54h after the administration of SMZ, p.o.. The protein binding of SMZ in pigs was 55.2%($2.5{\mu}g/ml$), 71.5% ($5{\mu}g/kg$) and 71.5%($10{\mu}g/ml$). The mean systemic bioavailability (F) of SMZ p.o. was 49.1 %. Meanwhile the pharmacokinetic profile of SMZ in rats was adequately described by a one-compartment open model. Absorption of SMZ p.o. in the rat was very rapid. In conclusion, the oral optimal dosage regimen of SMZ for pigs was the initial dose of 45.7 mg/kg followed by the maintenance dose of 30.2 mg/kg for high specific pathogens to SMZ. The time to reach below the stipulated residual allowable concentration (0.1 ppm) was calculated 93 h after oral administration of 200 mg/kg recommended by manufactureres.

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Radiolabeling of nanoparticle for enhanced molecular imaging

  • Kim, Ho Young;Lee, Yun-Sang;Jeong, Jae Min
    • Journal of Radiopharmaceuticals and Molecular Probes
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    • v.3 no.2
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    • pp.103-112
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    • 2017
  • The combination of nanoparticle with radioisotope could give the in vivo information with high sensitivity and specificity. However, radioisotope labeling of nanoparticle is very difficult and radioisotopes have different physicochemical properties, so the radioisotope selection of nanoparticle should be carefully considered. $^{18}F$ was first option to be considered for labeling of nanoparticle. For the labeling of $^{18}F$ with nanoparticle, Prosthetic group is widely used. Iodine, another radioactive halogen, is often used. Since radioiodine isotopes are various, they can be used for different imaging technique or therapy in the same labeling procedures. $^{99m}Tc$ can easily be obtained as pertechnatate ($^{99m}{TcO_4}^-$) by commercial generator. Ionic $^{68}Ga$ (III) in dilute HCl solution is also obtained by generator system, but $^{68}Ga$ can be substituted for $^{67}Ga$ because of the short half-life (67.8 min). $^{64}Cu$ emits not only positron but also ${\beta}-particle$. Therefore $^{64}Cu$ can be used for imaging and therapy at the same time. These radioactive metals can be labeled with nanoparticle using the bifunctional chelator. $^{89}Zr$ has longer half-life (78.4 h) and is used for the longer imaging time. Unlike different metals, $^{89}Zr$ should use the other chelate such as DFO, 3,4,3-(LI-1,2-HOPO) or DFOB.

Effects of Parenteral Lipid Formulas on Seurm Lipids Clearance in Normal Volunteers (지질 수액체 투여가 정상인의 혈장 지질변화에 미치는 영향)

  • Choe Myeon·Kim
    • Journal of Nutrition and Health
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    • v.25 no.6
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    • pp.461-467
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    • 1992
  • Although intravenous fat emulsions are well accepted as a consituent of a total parenteral nutrition regimen it is still controversial how much it can be used and who to use it in consideration of physical situation of useres. In this study the effect of two marketed lipid formulas on serum lipids change was investigated. Each lipid formula was injected to twelve normal adult volunteers and a set of blood samples was drawn at 5 minute interval during the experiment. Changes of triglycerides. free fatty acids free glycerol total cholesterol and phospolipids in the serum wre determined. To calculate serum lipids clearance the phar-macokinetics of serum triglyceride fractional removal rate(k) and half-life time(t/2) were calculated using intravenous fat tolerance-test(IVFTT) None of the parameters determined in this experiment was statistically different between two marketed formulas. In summary the bolus injection of the lipid formulas did not produce any adverse effects and their elimination kinetics from the blood stream were similar.

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Correlation Analysis between Gastric Emptying Measurement by Ultrasonography and Korean Medical Questionnaires (초음파 위배출 측정과 한의설문 간의 상관성 분석)

  • Cho, Soo-ho;Lee, Jae-hong;Ko, Seok-jae;Kim, Jin-sung;Park, Jae-woo
    • The Journal of Internal Korean Medicine
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    • v.39 no.4
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    • pp.570-591
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    • 2018
  • Objective: This study was designed to investigate the correlation between gastric emptying measurement by ultrasonography and the findings of various questionnaires of functional dyspepsia (FD) or in Korean medicine to explore the possibility of quantification of questionnaires. Methods: Eighty-eight patients (44 patients with FD and 44 healthy controls) were recruited from October 2016 to November 2017. Gastric emptying half-time (T1/2) was measured by ultrasonography at fasting, and at 0, 15, 30, 45, 60, 90, and 120 min after meals (apple juice, 500 ml, 224 kcal). The average half-time (average T1/2) was calculated by averaging all measured half-times. A visual analogue scale (VAS), food retention questionnaire (FRQ), damum questionnaire (DQ), cold and heat questionnaire (CHQ), deficiency and excess questionnaire (DEQ), spleen-qi deficiency questionnaire (SQDQ), Nepean dyspepsia index-Korean version (NDI-K), and quality of life of NDI (NDI-QoL) were filled out by all participants. Correlation between the average T1/2 and questionnaires were analyzed for 79 patients (37 patients with FD and 42 healthy controls) after excluding missing and erroneous data. Results: The FRQ, DEQ, SQDQ, NDI-K, and NDI-QoL scores, especially for some gastrointestinal symptoms and general weakness-related symptoms, showed statistically significant correlations with average T1/2. Conclusions: Our results suggest that gastric emptying measurement by ultrasonography may be a quantitative substitute method for some Korean medical questionnaires or for some dyspepsia-related and deficiency-related items among them. However, further studies using various measurements of gastric emptying will be needed.

A Study of Food Habit and Food Purchase Behavior on Healthy Dietary Life by Housewives in Daejeon (대전지역 주부의 건강식생활과 관련된 식습관과 식품구매행동 조사)

  • Yu, Ji Hyun;Koo, Nan Sook
    • Korean Journal of Human Ecology
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    • v.22 no.2
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    • pp.375-389
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    • 2013
  • This survey was conducted to compare the housewife's food habit and food purchase behavior on healthy dietary life. The questionnaires were collected from 151 working housewives and 159 housewives in Daejeon. The average meal time was 20~30 min., 67.6% of respondents ate breakfast and bap with guk(72.9%) was the most favourite foods. Almost half of them ate egg, fruit, vegetable everyday. They concerned highly about less intake of frozen foods(64.2%) and food additives(61.6%) for wellbeing dietary life. Because of close distance and various foods items, big discount store was chosen as food purchase place. The most considering purchase factor was food additives in working housewife and nutrition in housewife(p<0.05). In grocery shopping, working housewife considered children and their husbands(p<0.05). The most important purchase factor was the freshness in vegetables fishes fruits seaweeds eggs. TV or Radio was utilized the most frequently to obtain the useful knowledge on healthy foods. It is suggested that practical information should be offered housewives to purchase proper foods within their income and to manage dietary life according to their family's health condition.