• Title/Summary/Keyword: Mean Residence Time

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Determinants of Health Service Utilization of Urban Health Center (도시 보건소 보건의료서비스 이용의 결정요인)

  • 강복수;이경수;김천태
    • Health Policy and Management
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    • v.5 no.2
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    • pp.104-126
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    • 1995
  • This study was carried out to assess the utilization of urban health center and its related factors among the urban residents. The survey was carried out for 2,394 households in Taegu and Kyongju by the structured questionnaire from 28 March to 4 April and from 2 July to 9 July, 1994. Well trained interviewers visited 2,630 households in Taegu and Kyongju, and interviewed with housewives. Of the target households, 91.0%(2,394 households) were responded through three-time visiting. The major results were summarized as follows : The fourth and fifth decad utilized the health center more frequently than any other age groups.. The lower income group showed higher rate of health center utilization than those in higher income group in Taegu City. The mean length of residence among residents of Kyongju City is longer than those of Taegu City, and the longer length of residence, the higher rate of the health center utilization. Those who are living together with neonate and infant or elderly people showed higher rate of health center utilization than those who are living without neonate and infant or elderly people in both Taegu and Kyongju. The most common reason for visiting the health center was 'low cost'. The major reasons for not visiting the health center were 'not regular customer', 'poor health center facility', and 'low quality of care'. Vaccination, communicable disease control, outpatient care, public hygiene, maternal and child health program were well recognized as health center activities. In logistic regression for the utilization of health center, the significant independent variables were length of residence and recognize the site of health center in both Taegu and Kyongju. The improvement of quality of health service, physical environment of health center and public relations on health center's activities shoulod be considered for reactivation and reingorcement of health center functions.

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Application of Cox and Parametric Survival Models to Assess Social Determinants of Health Affecting Three-Year Survival of Breast Cancer Patients

  • Mohseny, Maryam;Amanpour, Farzaneh;Mosavi-Jarrahi, Alireza;Jafari, Hossein;Moradi-Joo, Mohammad;Monfared, Esmat Davoudi
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.sup3
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    • pp.311-316
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    • 2016
  • Breast cancer is one of the most common causes of cancer mortality in Iran. Social determinants of health are among the key factors affecting the pathogenesis of diseases. This cross-sectional study aimed to determine the social determinants of breast cancer survival time with parametric and semi-parametric regression models. It was conducted on male and female patients diagnosed with breast cancer presenting to the Cancer Research Center of Shohada-E-Tajrish Hospital from 2006 to 2010. The Cox proportional hazard model and parametric models including the Weibull, log normal and log-logistic models were applied to determine the social determinants of survival time of breast cancer patients. The Akaike information criterion (AIC) was used to assess the best fit. Statistical analysis was performed with STATA (version 11) software. This study was performed on 797 breast cancer patients, aged 25-93 years with a mean age of 54.7 (${\pm}11.9$) years. In both semi-parametric and parametric models, the three-year survival was related to level of education and municipal district of residence (P<0.05). The AIC suggested that log normal distribution was the best fit for the three-year survival time of breast cancer patients. Social determinants of health such as level of education and municipal district of residence affect the survival of breast cancer cases. Future studies must focus on the effect of childhood social class on the survival times of cancers, which have hitherto only been paid limited attention.

Study on the Influence of Mixing Effect to the Measurement of Particle Size Distribution using DMA and CPC (혼합효과가 DMA와 CPC를 이용한 입자분포 측정에 미치는 영향에 관한 연구)

  • Lee, Youn-Soo;Ahn, Kang-Ho;Kim, Sang-Soo
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.3
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    • pp.326-333
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    • 2003
  • In the measurement using DMA and CPC in series, there is some time delay for particles classified in DMA to detect in CPC. During this time, the DMA time-response changes due to the velocity profile of sampling tube and the diffusion of particles in the volume that exists between the DMA exit and the detector of ultra-fine CPC. This is called mixing effect. In the accelerated measurement methods like the TSI -SMPS, the size distribution is obtained from the correlation between the time-varying electrical potential of the DMA and the corresponding particle concentrations sampled in DMA. If the DMA time -response changes during this delay time, this can cause the error of a size distribution measured by this accelerated technique. The kernel function considering this mixing effect using the residence time distribution is proposed by Russell et al. In this study, we obtained a size distribution using this kernel to compare to the result obtained by the commercial accelerated measurement system, TSI -SMPS for verification and considered the errors that result from the mixing effect with the geometric mean diameters of originally sampled particles, using virtually calculated responses obtained with this kernel as input data.

Statistical Back Trajectory Analysis for Estimation of CO2 Emission Source Regions (공기괴 역궤적 모델의 통계 분석을 통한 이산화탄소 배출 지역 추정)

  • Li, Shanlan;Park, Sunyoung;Park, Mi-Kyung;Jo, Chun Ok;Kim, Jae-Yeon;Kim, Ji-Yoon;Kim, Kyung-Ryul
    • Atmosphere
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    • v.24 no.2
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    • pp.245-251
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    • 2014
  • Statistical trajectory analysis has been widely used to identify potential source regions for chemically and radiatively important chemical species in the atmosphere. The most widely used method is a statistical source-receptor model developed by Stohl (1996), of which the underlying principle is that elevated concentrations at an observation site are proportionally related to both the average concentrations on a specific grid cell where the observed air mass has been passing over and the residence time staying over that grid cell. Thus, the method can compute a residence-time-weighted mean concentration for each grid cell by superimposing the back trajectory domain on the grid matrix. The concentration on a grid cell could be used as a proxy for potential source strength of corresponding species. This technical note describes the statistical trajectory approach and introduces its application to estimate potential source regions of $CO_2$ enhancements observed at Korean Global Atmosphere Watch Observatory in Anmyeon-do. Back trajectories are calculated using HYSPLIT 4 model based on wind fields provided by NCEP GDAS. The identified $CO_2$ potential source regions responsible for the pollution events observed at Anmyeon-do in 2010 were mainly Beijing area and the Northern China where Haerbin, Shenyang and Changchun mega cities are located. This is consistent with bottom-up emission information. In spite of inherent uncertainties of this method in estimating sharp spatial gradients within the vicinity of the emission hot spots, this study suggests that the statistical trajectory analysis can be a useful tool for identifying anthropogenic potential source regions for major GHGs.

Lymphatic Delivery of Oral Anticancer Tegafur by Emulsion Formulations

  • Lee, Yong-Bok;Koh, Ik-Bae
    • Journal of Pharmaceutical Investigation
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    • v.23 no.3
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    • pp.19-30
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    • 1993
  • The influence of emulsion type of tegafur, an oral anticancer agent, on lymphatic transport was studied in rats. The water-in-oil-type of emulsion and the oil-in-water-type emulsion of tegafur each in 50 mg, calculated in terms of tegafur, were prepared by adding tegafur aqueous solution to sesame oil containing hydrogenated castor oil following ultrasonic treatment, and then the prepared emulsions and aqueous solution as a comparative formulation were administered orally to rats (50 mg/5 ml/kg). The concentration levels of tegafur in plasma of femoral artery and lymph from thoracic duct cannula were measured simultaneously along a time course after administration and the pharmacokinetic parameters were investigated. At the same time, we examined the above described factors of 5-FU which is known as an active metabolite of tegafur. In comparison with tegafur solution, AUC and mean residence time of plasma tegafur were significantly increased in w/o-emulsion but significantly decreased in o/w-emulsion. Lymph flow rates were similar in both solution and w/o-emulsion but half in o/w-emulsion. Ratios between area under the lymph and plasma concentration time curves were always less than 1 reflecting the passive lymphatic delivery after oral administration of the prepared tegafur emulsions, but those to the 5-FU in the case of w/o-emulsion were more than 1. These results suggested that lymphatic delivery of tegafur by w/o-emulsion was more effective than that by o/w-emulsion due to its differences of formation ability of chylomicrons.

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A Study on Numerical Calculations of Hybrid Air Pollution Control System Coupled with SDR and Bag Filter (반건식 반응기와 백필터를 결합한 하이브리드 대기오염제어 시스템의 수치해석적 연구(I))

  • Kwon, Young-Hyun;Kim, Jin-Uk;Jung, Yu-Jin;Kim, Min-Choul;Lee, Jae-Jeong;Lee, Gang-Woo;Shon, Byung-Hyun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.11 no.11
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    • pp.4656-4663
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    • 2010
  • In this study, the 3D computational fluid dynamics (CFD) was performed in relation to the internal fluid characteristics, flow distribution, air mean ages, and residence time for the development of the most optimal model in the complex post-disposal device. As it is expected that a channeling (drift) would be made by the semi-dry reactor due to the large difference in the flow distribution by the compartment in the bag filter, a structural improvement should be urgently made for more uniformed flow distribution in the bag filter. In addition, it showed the possibility that the velocity field and distribution characteristics of the residence time could be improved through a modification to inlet structure of the spray dryer reactor. The complex post-disposal device, modified and supplemented with this analysis, integrated the semi-dry reactor and the bag filter in a single body, so it follows that the improvement can make the device compact, the installation area, the operation fee, and management more convenient.

Bioequivalence of Cyclosporin A Hard Capsules (사이클로스포린 A 경질캅셀제에 대한 생물학적 동등성 평가)

  • 김종국;이은진;이미경;박준규;신희종;김인숙
    • Biomolecules & Therapeutics
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    • v.6 no.3
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    • pp.296-302
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    • 1998
  • The bioequivalence of two cyclosporin A products was evaluated in 26 normal male volunteers (age 25 ~33 yr, body weight 56~84 kg) following single oral administration. Test product was a hard capsule containing the granule of cyclosporin A (Chong Kun Dang Corp., Korea) and reference product, Sandimmun", was a soft capsule containing surfactant, oil, alcohol and cyclosporin A (Sandoz, Swiss). Both products contain 100 mg of cyclosporin A. Four capsules of the test and the reference product were administered to the volunteers, respectively, by randomized two period cross-over study (2$\times$2 Latin square method). Average drug concentrations at each sampling time and pharmacokinetic parameters were not significantly different between two products (p>0.05); the area under the concentration-time curve to last sampling time (24 hr) (AU $Co_{24}$) (5034.8$\pm$ 1760.6 vs 4635.4$\pm$ 1158.9 ng . h/ml), maximum plasma concentration ( $C_{max}$) (1002.7$\pm$353.1 vs 980. 4$\pm$ 171.7 ng/71), and mean residence time (MRT) (6.16$\pm$0.81 vs 5.64$\pm$0.50 h). The differences of mean AUC 7-,4,7~, T_ and MRT between the two products (7.93,2.22,16 and 8.39%, respectively) were less than 20% given as a guideline. The power (1-$\beta$) and treatment difference ($\Delta$) for AU $Co_{24}$, $C_{max}$ and MRT were more than 0.8 and less than 0.2, respectively. Although $T_{max}$ of the two products was significantly different each other (p<0.05), $T_{max}$ might be an insignificant parameter because cyclosporin A generally requires long-term administration. From these results, the two products are bioequivalent.alent.t.

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Rectal Absorption of Omeprazole from Syppositories in Rabbits

  • Eun, Kyong-Hoon;Lee, Yong-Hee;Shim, Chang-Koo
    • Archives of Pharmacal Research
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    • v.18 no.4
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    • pp.219-223
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    • 1995
  • Rectal absorption of opeprazole, a proton pump inhibitor, from suppositories was studied in rabbits. The suppositories were prepared by the conventional melting method with two types of bases, water-soluble polyethylene glycol (PEG) 4000 and oil-soluble Witepsol H15 bases, and administered intractally (ir) to rabbits at a dose of 10 mg omeprazole/kg. The plasma omeprazole concentration-time profiles of the two suppositories were compared with those following intravenous 9iv) administration of the same dose. There were no significant differences between the two suppositories in bioabailabilities and peak plasma concentrations $(C_{max})$. Bioavaiabilities and $C_{max}$ of PEG- and Witpsol suppositories were 30.3 and 33.9%, and 7.0 and $5.6\mug/ml$, resepectively. However, PEG suppository showed significantly (p<0.05) shorter time to reach peak plasma concentration $(T_{max})$ mean absorption time (MAT) and mean residence time in the plasma (MRT) than Witepsol suppository. The $T_{max}$ MRT nad MAT were 25.0, 83.0 and 38.5 min for PEG syppository, but were 90.0, 122.5 and 78.0 min for Wiepsol supposiotory, respectively. These differences between thw two suppositories could be explanined by the difference in the in vitro dissolution rates between the suppositories. The dissolution of omeprazole form PEG suppository was reportedly much faster than that from Witepsol suppository. It suggests that plasma profiles of omeprazole, especially $C_{max}$ MAT and MRT, could be controlled by modifying the in vitro dissolution rate of the drug from the suppositories. Above results suggest that rectal suppository is worth developing as an alternative dosage form of omeprazole to the conventional oral preparations which need sophisticated treatments, such as enterix coating, to prevent acid degradation of the drug in the stomach fluid.

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Analysis of SEER Adenosquamous Carcinoma Data to Identify Cause Specific Survival Predictors and Socioeconomic Disparities

  • Cheung, Rex
    • Asian Pacific Journal of Cancer Prevention
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    • v.17 no.1
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    • pp.347-352
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    • 2016
  • Background: This study used receiver operating characteristic curve to analyze Surveillance, Epidemiology and End Results (SEER) adenosquamous carcinoma data to identify predictive models and potential disparities in outcome. Materials and Methods: This study analyzed socio-economic, staging and treatment factors available in the SEER database for adenosquamous carcinoma. For the risk modeling, each factor was fitted by a generalized linear model to predict the cause specific survival. An area under the receiver operating characteristic curve (ROC) was computed. Similar strata were combined to construct the most parsimonious models. Results: A total of 20,712 patients diagnosed from 1973 to 2009 were included in this study. The mean follow up time (S.D.) was 54.2 (78.4) months. Some 2/3 of the patients were female. The mean (S.D.) age was 63 (13.8) years. SEER stage was the most predictive factor of outcome (ROC area of 0.71). 13.9% of the patients were un-staged and had risk of cause specific death of 61.3% that was higher than the 45.3% risk for the regional disease and lower than the 70.3% for metastatic disease. Sex, site, radiotherapy, and surgery had ROC areas of about 0.55-0.65. Rural residence and race contributed to socioeconomic disparity for treatment outcome. Radiotherapy was underused even with localized and regional stages when the intent was curative. This under use was most pronounced in older patients. Conclusions: Anatomic stage was predictive and useful in treatment selection. Under-staging may have contributed to poor outcome.

The Importance of Nitrogen Release and Denitrification in Sediment to the Nitrogen Budget in Hiroshima Bay

  • KIM Do-Hee;MATSUDA Osamu
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.29 no.6
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    • pp.779-786
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    • 1996
  • The main purpose of this study was to estimate the role of dissolved inorganic nitrogen (DIN) released from sediment and denitrification process in sediment on the nitrogen budget of Hiroshima Bay by means of collecting data on distributions and budgets of nitrogen and phosphorus in the bay, DIN fluxes across sediment-water interface and denitrification rates in the sediments of the same area. The TN : TP and DIN:DIP atomic ratios of the discharged freshwater were about 26 and 21, respectively. The standing stocks in the seawater of the TN : TP atomic ratio varied from 8 to 14 with an annual mean value of 11, while the DIN : DIP atomic ratio varied from 10 to 15 with an annual mean value of 12 in the bay. The residence time of nitrogen and phosphorus were estimated to be about 109 days and 200 days in the bay, respectively. The proportion of DIN released from sediment and denitrification rate to the loading of total nitrogen into Hiroshima Bay were $45\%\;(37\~82\%)\;and\;13\%(0.0\~37\%)$, respectively, and the amount of nitrogen through denitrification process was 6.5 times larger than the outflow of nitrogen from the bay. The results show that DIN released from sediment and denitrification process in sediment play important roles on the nitrogen budget in Hiroshima Bay.

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