• Title/Summary/Keyword: suspension model

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Comparisons between the KKU-Model and Conventional Rectal Tubes as Markers for Checking Rectal Doses during Intracavitary Brachytherapy of Cervical Cancer

  • Padoongcharoen, Prawat;Krusun, Srichai;Palusuk, Voranipit;Pesee, Montien;Supaadirek, Chunsri;Thamronganantasakul, Komsan
    • Asian Pacific Journal of Cancer Prevention
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    • v.15 no.15
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    • pp.6115-6120
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    • 2014
  • Background: To compare the KKU-model rectal tube (KKU-tube) and the conventional rectal tube (CRT) for checking rectal doses during high-dose-rate intracavitary brachytherapy (HDR-ICBT) of cervical cancer. Materials and Methods: Between February 2010 and January 2011, thirty -two patients with cervical cancer were enrolled and treated with external beam radiotherapy (EBRT) and intracavitary brachytherapy (ICBT). The KKU-tube and CRT were applied intrarectally in the same patients at alternate sessions as references for calculation of rectal doses during ICBT. The gold standard references of rectum anatomical markers which are most proximal to radiation sources were anterior rectal walls (ARW) adjacent to the uterine cervix demonstrated by barium sulfate suspension enema. The calculated rectal doses derived from actual anterior rectal walls, CRT and the anterior surfaces of the KKU-tubes were compared by using the paired t-test. The pain caused by insertion of each type of rectal tube was assessed by the visual analogue scale (VAS). Results: The mean dose of CRT was lower than the mean dose of ARW ($Dmean_0-Dmean_1$) by $80.55{\pm}47.33cGy$ (p-value <0.05). The mean dose of the KKU-tube was lower than the mean dose of ARW ($Dmean_0-Dmean_2$) by $30.82{\pm}24.20cGy$ (p-value <0.05). The mean dose difference [($Dmean_0-Dmean_1$)-($Dmean_0-Dmean_2$)] was $49.72{\pm}51.60cGy$, which was statistically significant between 42.32 cGy -57.13 cGy with the t-value of 13.24 (p-value <0.05). The maximum rectal dose by using CRT was higher than the KKU-tube as much as 75.26 cGy and statistically significant with the t-score of 7.55 (p-value <0.05). The mean doses at the anterior rectal wall while using the CRTs and the KKU-tubes were not significantly different (p-value=0.09). The mean pain score during insertion of the CRT was significantly higher than the KKU-tube by a t-score of 6.15 (p-value <0.05) Conclusions: The KKU-model rectal tube was found to be an easily producible, applicable and reliable instrument as a reference for evaluating the rectal dose during ICBT of cervical cancer without negative effects on the patients.

A numerical study on pull-out behaviour of cavern-type rock anchorages (수치해석에 의한 암반상의 지중정착식 앵커리지 인발 거동 연구)

  • Hong, Eun-Soo;Cho, Gye-Chun;Baak, Seng Hyoung;Park, Jae-Hyun;Chung, Moonkyung;Lee, Seong-Won
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.16 no.6
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    • pp.521-531
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    • 2014
  • This paper is a study for behaviour of cavern type anchorage tunnels for suspension bridges with cable tension. Anchorage behaviour, design method for anchorage, and failure surface angle, ${\delta}$ are analyzed by comparing numerical analysis results and ultimate pullout capacities($P_u$) using bilinear corelation equation. Results show that design depths for cavern type anchorage tunnels are easily checked with linear relationships for $P/{\gamma}/H$ vs. displacement and $P_u/{\gamma}/H$ vs. H/b. The analysis results of maximum shear strain distribution and plastic status show that failure shapes are closer to circular arc model than soil cone model which frequently used. To an easy calculation of the ultimate pullout capacity, we propose a simple bilinear failure model in this study. The calculated ultimate pullout capacities from the proposed bilinear corelation equation using two failure angles results are similar to the ultimate pullout capacities from numerical analysis.

Water-insoluble, Whey Protein-based Microcapsules for Controlled Core Release Application (유청단백질을 이용한 미세캡슐의 응용)

  • Lee, Sung-Je
    • 한국유가공학회:학술대회논문집
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    • 2005.06a
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    • pp.37-61
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    • 2005
  • Microcapsules consisting of natural, biodegradable polymers for controlled and/or sustained core release applications are needed. Physicochemical properties of whey proteins suggest that they may be suitable wall materials in developing such microcapsules. The objectives of the research were to develop water-insoluble, whey protein-based microcapsules containing a model water-soluble drug using a chemical cross-linking agent, glutaraldehyde, and to investigate core release from these capsules at simulated physiological conditions. A model water soluble drug, theophylline, was suspended in whey protein isolate (WPI) solution. The suspension was dispersed in a mixture of dichloromethane and hexane containing 1% biomedical polyurethane. Protein matrices were cross-linked with 7.5-30 ml of glutaraldehyde-saturated toluene (GAST) for 1-3 hr. Microcapsules were harvested, washed, dried and analyzed for core retention, microstructure, and core release in enzyme-free simulated gastric fluid (SGF) and simulated intestinal fluid (SIF) at 37$^{\circ}C$, A method consisting of double emulsification and heat gelation was also developed to prepare water-insoluble, whey protein-based microcapsules containing anhydrous milkfat (AMF) as a model apolar core. AMF was emulsified into WPI solution (15-30%, pH 4.5-7.2) at a proportion of 25-50% (w/w, on dry basis). The oil-in-water emulsion was then added and dispersed into corn oil (50 $^{\circ}C$)to form an O/W/O double emulsion and then heated at 85$^{\circ}C$ for 20 min for gelation of whey protein wall matrix. Effects of emulsion composition and pH on core retention, microstructure, and water-solubility of microcapsules were determined. Overall results suggest that whey proteins can be used in developing microcapsules for controlled and sustained core release applications.

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A Study of Prediction of Daily Water Supply Usion ANFIS (ANFIS를 이용한 상수도 1일 급수량 예측에 관한 연구)

  • Rhee, Kyoung-Hoon;Moon, Byoung-Seok;Kang, Il-Hwan
    • Journal of Korea Water Resources Association
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    • v.31 no.6
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    • pp.821-832
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    • 1998
  • This study investigates the prediction of daily water supply, which is a necessary for the efficient management of water distribution system. Fuzzy neuron, namely artificial intelligence, is a neural network into which fuzzy information is inputted and then processed. In this study, daily water supply was predicted through an adaptive learning method by which a membership function and fuzzy rules were adapted for daily water supply prediction. This study was investigated methods for predicting water supply based on data about the amount of water supplied to the city of Kwangju. For variables choice, four analyses of input data were conducted: correlation analysis, autocorrelation analysis, partial autocorrelation analysis, and cross-correlation analysis. Input variables were (a) the amount of water supplied (b) the mean temperature, and (c)the population of the area supplied with water. Variables were combined in an integrated model. Data of the amount of daily water supply only was modelled and its validity was verified in the case that the meteorological office of weather forecast is not always reliable. Proposed models include accidental cases such as a suspension of water supply. The maximum error rate between the estimation of the model and the actual measurement was 18.35% and the average error was lower than 2.36%. The model is expected to be a real-time estimation of the operational control of water works and water/drain pipes.

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Histopathological and Neurobehavioral Characterization in Adult Mice Exposed to Traumatic Brain Injury (C57BL/6 쥐 외상성 뇌손상 모델에서 뇌 손상 정도에 따른 조직병리학적 변화 및 신경행동학적 특징)

  • Oh, Ki Young;Choi, Dong Won;Jang, Moon Soon;Lee, Ji Han;Kim, Sang Chul;Park, Jung Soo;Lee, Suk Woo;Kim, Hoon
    • Journal of The Korean Society of Emergency Medicine
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    • v.28 no.5
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    • pp.457-466
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    • 2017
  • Purpose: Traumatic brain injury (TBI) is a significant cause of morbidity and mortality worldwide. Severity of the initial insult is one of the most significant factors affecting outcome following TBI. In order to investigate the mechanisms of cellular injury and develop novel therapeutic strategies for TBI, we designed a standardized animal TBI model and evaluated histological and functional outcomes according to the degree of impact severity. Methods: Male adult C57Bl/6 mice underwent controlled cortical impact (CCI) at varying depths of deflection (1.0-2.0 mm). We performed hematoxylin and eosin staining at 7 days after recovery from TBI. Neurobehavioral characterization after TBI was analyzed by the Barnes maze test, passive avoidance test, open field test, rotarod test, tail suspension test, and light/dark test. Results: We observed a graded injury response according to the degree of deflection depths tested (diameter, 3 mm; velocity, 3 m/s; and duration, 500 ms) compared to sham controls. In the Barnes maze test, the severe TBI (2 mm depth) group showed reduced spatial memory as compared with the sham and mild TBI (1 mm depth) groups at 7 days after TBI. There was a significant difference in the results of the open field test and light/dark test among the three groups. Conclusion: Our findings demonstrate that the graded injury responses following TBI resulted in differential histopathological and behavioral outcomes in a mouse experimental CCI model. Thus, a model of CCI with histologic/behavioral outcome analysis may offer a reliable and convenient design for preclinical TBI research involving mice.

Fundamental Studies on the Net-Shape of the Drag Net-II On the Section Shape of the Simplified Model of the Bag Net in Four-Point Suspension (저예망의 어구형상에 관한 기초적 연구-II 단순화모형에 의한 4폭짜리 자루그물의 단면형상)

  • Lee, Ju-Hee
    • Journal of the Korean Society of Fisheries and Ocean Technology
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    • v.20 no.2
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    • pp.65-71
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    • 1984
  • As a primary step in studying the relationship between the arrangement of netting and the section shape of the bag net in the four-seam trawling net, a series of experiments were performed with the simplified model of the bag net made of vinyl film. This model was suspended horizontally in circularly flowing water, with two pairs of suspending threads to four points of symetry at the border of the bag mouth in place of both wing nets. And then, the area distribution of each panel in the bag net was arranged by the portion of the length of the side panel, q to that of the lower or upper panel, p at the border of bag mouth. In the experiments, the section shape of the bag mouth photographed and the tensions on both pairs of suspending threads were measured with two loadcells in circularly flowing water. From the results that the section shape of the bag mouth in circularly flowing water is controlled by the area distribution of panels in the bag net, the author estimated an experimental equation. h/w=k sub(1) e super(k) 2 super(q/p)+C, where h is the central height of the bag mouth, and w is the lateral width of that.

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Application of Buoyant Density Centrifugation Method for the Rapid Detection of Feline Calicivirus in Oyster and Lettuce as Norovirus Surrogate

  • Cho, Yun-Sik;Lee, Kang-Whie;Jang, Keum-Il;Ahn, Jun-Bae;Kim, Kwang-Yup
    • Food Science and Biotechnology
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    • v.17 no.5
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    • pp.925-930
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    • 2008
  • Norovirus has become the most common cause of human gastroenteritis in developed countries. Detection procedures of foodborne viruses from foods require several steps. The concentration step using polyethylene glycol (PEG) is time-consuming and the detection efficiency of reverse transcription-polymerase chain reaction (RT-PCR) is affected by inhibitors from food components. In this study, a rapid detection method based on buoyant density centrifugation was developed to replace the time-consuming chloroform-polyethylene glycol-Tris Tween method. Feline calicivirus that belongs to the family Caliciviridae was used as a surrogate model for norovirus. After artificial inoculation of feline calcivirus (FCV) to oyster and lettuce, 830 ${\mu}L$ of homogenized sample suspension was layered on the top of 670 ${\mu}L$ 20% percoll and centrifuged. Then RNA extraction step was proceeded with the supernatant. By varying several physical conditions, the detection limits were lowered to $2.4{\times}10^2$ PFU per 1 g in oyster and $2.4{\times}10^0$ PFU per 1 g in lettuce. The protocol obtained in this study could be used to develop new detection method for norovirus in foods.

Removal of Fluoride Ions from Electronic Industrial Wastewater Using Lime Stone Slurry (초미분말 석회석 현탁액을 이용한 전자산업 폐수 불소이온 제거연구)

  • Park, Hyeon Soo;Park, Yeon Soo;Jung, Goo Ill;Kim, Jae Woo;Jo, Young Min
    • Applied Chemistry for Engineering
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    • v.29 no.3
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    • pp.258-263
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    • 2018
  • This study attempted to utilize ultrafine precipitated calcium carbonate for fluoride removal from the wastewater of electronics industries. An average particle size of the calcium carbonate was $0.96{\mu}m$, and pH of the aqueous slurry was 10 with 70% in mass. The suspension solution showed approximately 2 mL/hr of the sedimentation rate. The present calcium carbonate solution could be comparable to the conventional aqueous calcium source, $Ca(OH)_2$, for the neutralization and removal of fluoride ions. Depending on the amount of an additional alkali source, less amounts of test Ca-source slurries were required to reach the solution pH of 7.0 than that of using the aqueous calcium hydroxide. It was also found from XRD analysis that more calcium fluoride precipitates were formed by the addition of calcium carbonate solution rather than that of calcium hydroxide. In addition, Minteq equilibrium modelling estimated various ion complexes of fluoride and calcium in this process.

Long-Duration Three-Dimensional Spheroid Culture Promotes Angiogenic Activities of Adipose-Derived Mesenchymal Stem Cells

  • Lee, Jun Hee;Han, Yong-Seok;Lee, Sang Hun
    • Biomolecules & Therapeutics
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    • v.24 no.3
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    • pp.260-267
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    • 2016
  • Mesenchymal stem cells (MSCs) offer significant therapeutic promise for various regenerative therapies. However, MSC-based therapy for injury exhibits low efficacy due to the pathological environment in target tissues and the differences between in vitro and in vivo conditions. To address this issue, we developed adipose-derived MSC spheroids as a novel delivery method to preserve the stem cell microenvironment. MSC spheroids were generated by suspension culture for 3 days, and their sizes increased in a time-dependent manner. After re-attachment of MSC spheroids to the plastic dish, their adhesion capacity and morphology were not altered. MSC spheroids showed enhanced production of hypoxia-induced angiogenic cytokines such as vascular endothelial growth factor (VEGF), stromal cell derived factor (SDF), and hepatocyte growth factor (HGF). In addition, spheroid culture promoted the preservation of extracellular matrix (ECM) components, such as laminin and fibronectin, in a culture time- and spheroid size-dependent manner. Furthermore, phosphorylation of AKT, a cell survival signal, was significantly higher and the expression of pro-apoptotic molecules, poly (ADP ribose) polymerase-1 (PARP-1) and cleaved caspase-3, was markedly lower in the spheroids than in MSCs in monolayers. In the murine hindlimb ischemia model, transplanted MSC spheroids showed better proliferation than MSCs in monolayer. These findings suggest that MSC spheroids promote MSC bioactivities via secretion of angiogenic cytokines, preservation of ECM components, and regulation of apoptotic signals. Therefore, MSC spheroid-based cell therapy may serve as a simple and effective strategy for regenerative medicine.

Development of Target-Specific Drug Delivery Systems Using Glycosylated Proliposome I-Binding of Asialofetuin-Labeled Liposomes to Lectin RCA- (표면수식된 프로리포솜에 의한 표적부위 지향성 약물수송체의 개발 I-갈락토스 당쇄로 표면수식된 리포솜의 간세포 렉틴 결합성-)

  • Shim, Chang-Koo;Lee, Chang-Yong;Kim, Chong-Kook
    • Journal of Pharmaceutical Investigation
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    • v.22 no.2
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    • pp.155-161
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    • 1992
  • Although glycosylated liposomes have attracted much attention as targeting delivery systems (DDS) of drugs to specific organs which have glycoside receptors, physical instability of liposomes greatly limits their practical application. In this case, proliposomes might be a potential answer to solve this problem. Utilizing the proliposomes as tageting DDS has been a goal of our series of works; we have tried to develop DDS which form liposomes uppon adding water and can deliver drugs to specific target organs/cells such as hepatocytes. In this paper, preparation of glycosylated liposomes and binding of the liposomes with lectin (agglutinin RCA 120) was studied. Asialoletuin (AF) was selected as a model compound which has galactose terminal and is favorable for binding with galactose receptor on the surface of hepatocytes. AF was obtained by splitting the terminal N-acetylneuraminic acid (NANA) of fetuin. Small unilamellar AF-liposomes were prepared by mixing aqueous solution of AF-palmitate with thin film of phosphatidyl choline and cholesterol (30:10 w/w) formed on the innersurface of the round bottomed flask. They were successively extruded through polycarbonate membranes (0.45 mm). Palmitoyl-AF not incorporated into the liposomal bilayer was separated from liposomes by a Sepharose 4B column equilibrated with 10 mM Tris-HCI buffered saline. Lectin (agglutinin RCA 120) was added to the suspension of AF-liposomes and incubated at $37^{\circ}C$ for 2 hr. After centrifugation, the unbound lectin in the supernatant was assayed for protein. The binding of the lectin to AF-liposomes (AF content 2.8 nmole) at $37^{\circ}C$ was linear at least upto 35 mg of lectin indicating high affinity association of the lectin to AF molecules of the liposomes.

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