• Title/Summary/Keyword: 형태적 손상

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Practical Considerations of Arterial Spin Labeling MRI for Measuring the Multi-slice Perfusion in the Human Brain (스핀 라벨링 자기공명영상을 이용한 사람 뇌에서의 뇌 관류영상의 현실적 문제점을 향상 시키는 방법 연구)

  • Jahng, Geon-Ho
    • Progress in Medical Physics
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    • v.18 no.1
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    • pp.35-41
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    • 2007
  • In this work practical considerations of a pulsed arterial spin labeling MRI are presented to reliable multi-slice perfusion measurements In the human brain. Three parameters were considered in this study. First, In order to improve slice profile and Inversion efficiency of a labeling pulse a high power Inversion pulse of adiabatic hyperbolic secant was designed. A $900^{\circ}$ rotation of the flip angle was provided to make a good slice profile and excellent Inversion efficiency. Second, to minimize contributions of a residual magnetization be4ween Interleaved scans of control and labeling we tested three different conditions which were applied 1) only saturation pulses, 2) only spotter gradients, and 3) combinations of saturation pulses and spotter gradients Applications of bo4h saturation pulses and spoiler gradients minimized the residual magnetization. Finally, to find a minimum gap between a tagged plane and an imaging plane we tested signal changes of the subtracted image between control and labeled Images with varying the gap. The optimum gap was about 20mm. In conclusion, In order to obtain high quality of perfusion Images In human brain It Is Important to use optimum parameters. Before routinely using In clinical studios, we recommend to make optimizations of sequence parameters.

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Morphology and Mechanical Properties through Hydroxyapatite Powder Surface Composite (Hydroxyapatite의 파우더 표면 복합화를 통한 형태 및 기계적 성질에 관한 연구)

  • Kye, Sung Bong;Park, Soo Nam
    • Applied Chemistry for Engineering
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    • v.27 no.3
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    • pp.299-306
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    • 2016
  • In this study, new hydroxyapatite powder surface composites were investigated for protective effects against ultraviolet rays. Hydroxyapatite (HAp) is biocompatible and does not cause nebula phenomenon on skin. We investigated the surface modification of hydroxyapatite to improve UV block and skin usage. Dimethicone, lauroyl lysine, triethoxycaprylylsilane and silica were used as coating agents for the surface modification of HAp. To prepare the composite complex of the modified surface, the dimethicone, lauroyl lysine and triethoxycaprylylsilane were prepared by a dry process, and silica by a hydrothermal synthesis method. The HAp-silica was chosen as the best composite powder when measuring its sun protection levels. We investigated the characteristics of the surface of HAp-silica by SEM, particle size analyzer and energy dispersive spectrometry (EDS). Additionally, the stability in the formulation, UV block effect, and safety in BB creams were investigated. In conclusion, HAp-silica prepared by the modification of HAp complex surface improved the skin usage and UV block effect by enhancing the white cloudy phenomenon. These results indicate that HAp-silica may be used for UV block cosmetics.

The Study on Wound Healing in Rabbit Skins by Low-intensity Laser Irradiation (저강도 레이저 조사에 의한 가토 피부의 상처 치유에 관한 연구)

  • 김식현;전진석
    • Biomedical Science Letters
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    • v.6 no.2
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    • pp.119-129
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    • 2000
  • The skin is an organ that has many important roles, including protection against infection, regulation of temperature and fluid loss, and sensory function. Injury to the skin, wound repair normally involves: (1) balanced activity of inflammation, (2) the re-epithelial phase and (3) the matrix formation of remodeling phase. Thus, skin wound healing is a finely controlled biological process involving a series of complex cellular interactions. Laser therapy is being implemented with increasing frequency in medicine. Low intensity laser is one that is capable of producing an energy density so low that any biologic alterations are the result of direct irradiation effect, not thermal events. This study was designed to evaluate the efficacy of low intensity laser therapy on skin wound healing in rabbits. A total of 10 male rabbits (New Zealand White Rabbit), age 8 weeks were used. Skin wound were surgically created dorso-lateral on the flank of 10 rabbits (2$\times$2 cm/damage areas). The experimental animals were treated with 5Hz (830 nm wave length) low-intensity laser (MILTA-01 Model) daily for 10 min (1.6 J/$cm^2$) for 12 days. Control animals were sham treated with the laser head. Laser irradiation animals showed a complete remodeling of the epithelial layer, a positive repair of connective tissues, and enhanced the wound closure rate over time as compared to the control animals. Especially, laser irradiation groups improved fibroblast activity, cellular content, granulation tissue formation, and collagen deposition which is resulted in improving the tensile strength of the wound. These findings suggest that laser photostimulation could accelerate healing of open wound in rabbits, and may be benefit in the treatment of open wound, including decubitis ulcers.

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Performance Improvement of Word Clustering Using Ontology (온톨로지를 이용한 단어 군집화 성능 개선)

  • Park Eun-Jin;Kim Jae-Hoon;Ock Cheol-Young
    • The KIPS Transactions:PartB
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    • v.13B no.3 s.106
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    • pp.337-344
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    • 2006
  • In this paper, we describe the design and the implementation of word clustering system using a definition of an entry word in the dictionary, called a dictionary definition. Generally word clustering needs various features like words and the performance of a system for the word clustering depends on using some kinds of features. Dictionary definition describes the meaning of an entry in detail, but words in the dictionary definition are implicative or abstractive, and then its length is not long. The word clustering using only features extracted from the dictionary definition results in a lots of small-size clusters. In order to make large-size clusters and improve the performance, we need to transform the features into more general words with keeping the original meaning of the dictionary definition as intact as possible. In this paper, we propose two methods for extending the dictionary definition using ontology. One is to extend the dictionary definition to parent words on the ontology and the other is to extend the dictionary definition to some words in fixed depth from the root of the ontology. Through our experiments, we have observed that the proposed systems outperform that without extending features, and the latter's extending method overtakes the former's extending method in performance. We have also observed that verbs are very useful in extending features in the case of word clustering.

A Study on the Restoration Methods of the Excavated Costume: Focus on Excavated Costumes of Yeosan Song's Family at Mokdal-dong in Daejeon (출토복식의 보수방법에 관한 연구: 대전 목달동 출토 여산송씨 출토복식을 중심으로)

  • Ha, Shinhye;Kwon, Youngsuk
    • Journal of Conservation Science
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    • v.29 no.2
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    • pp.161-170
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    • 2013
  • The purpose of this study is to find the reasonable plan for the restoration method through the practical repair of excavated costume. The minimal repair only without adding the physical force as far as possible after investigating the state of excavated costume has been progressed in case of excavated costume since it is already degraded and weak due to the characteristics of organic matter at the moment when it is excavated. Moreover, it has been restored as the following course; The restoration has been applied according to the state of excavated costume with the maximum stability by classifying items capable of being restored considering the fabric state of excavated costume. The drawn thread from the weak in strength and the refined thread of the Juasa(simple gauze) or the light degraded silk thread has been used in case of thread for restoration. The cotton fabrics has been used in the fabric of cellulose system, the Juasa or the silk has been used in the silk depending on the kind of fabric in connection with the support fabric, some parts have been dyed with Alnus firma fruit and the persimmon, has been repaired by using the dyed fabric with the clove for the purpose of mothproof-antibacterial treatment. The method to repair has been carried out by classifying according to the state of damage and the way of formation of costume. The needlework method suitable for the part and state of damage by using the basting, the broad-stitching, backstitch, the blind stitch and the hemming stitch in connection with the needlework method for restoration.

Piping Analysis of Reservoir Embankment due to Leakage of Buried Box Culvert (저수지 제체 내 배수통관의 누수로 인한 파이핑 분석)

  • Kim, Han il;Yang, Hak Young;Kim, Young Muk
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.37 no.5
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    • pp.787-799
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    • 2017
  • Although the long-term leakage between the box culvert and the soil contact surface is one of the main causes of the failure in the embankment of the reservoir, there is a little studies on this matter. If a leakage occurs by the structure such as the buried box culvert of reservoir embankment is partially damaged, it is difficult to observe and there is a possibility of damage caused by piping. For these reasons, more research is necessary. In this study, the embankment type of the reservoir is divided into the core type and the homogeneous type when the damaged box culvert passing through the embankment of the reservoir is leaked due to the differential behavior of materials like differential settlement. In view of the condition, the seepage analysis of 2D was performed according to the water level change. The result of the study shows that the possibility of piping increases at the upper part rather than the bottom part of the box culvert when the leakage occurs to the box culvert passing through the embankment of the reservoir. Particularly, it is considered that the presence of the core helps to maintain the seepage stability of the embankment in case where the leakage occurs at the downstream side of the embankment. Also, if there is a drastic decrease on the internal pore water pressure in the embankment of reservoir, it is necessary to consider the possibility of piping.

Physicochemical Properties of Selected Cereals and Legumes for the Production of Extruded Multi-grain (압출성형 혼합쌀의 제조에 따른 곡종별 이화학적 특성)

  • Kim, Sung-Su;Chae, Eun-Mi;Lee, Young-Tack
    • Applied Biological Chemistry
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    • v.44 no.1
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    • pp.30-34
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    • 2001
  • Physicochemical properties of milled rice, brown rice, pearled barley, wheat, sorghum, foxtail millet, soybean, and adzuki bean were evaluated for the production of extrusion formed multi-grain. Grain flours showed large differences in chemical composition including starch, protein, fat, ash, and total dietary fiber contents. Grain flours were brighter in the following order of milled rice>pearled barley>soybean>brown rice>wheat>sorghum>adzuki bean>foxtail millet, and most of the grain flours showed red-yellowish color. Mean particle sizes of grain flours were different among various grains, and whole grain flours tended to have coarser particle size than milled grain flours. The amounts of damaged starch in cereal flours were varied from 5.4 to 10.9%, and limited amount of damaged starch was present in legume flours. Water absorption index of grain flours was, in decreasing order, adzuki>bean>milled rice>brown rice>sorghum>wheat>foxtail millet>pearled barley>soybean. Water solubility index was higher in legume flours containing high protein content.

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Biological characterization of Tenacibaculum maritimum isolated from cultured olive flounder in Korea and sensitivity against native plant extracts (한국의 양식넙치에서 분리한 Tenacibaculum maritimum의 특성과 자생식물 추출물에 대한 감수성)

  • Jang, Yeoung-Hwan;Jeong, Joon-Bum;Yeo, In-Kyu;Kim, Ki-Young;Harikrishnan, Ramasamy;Heo, Moon-Soo
    • Journal of fish pathology
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    • v.22 no.1
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    • pp.53-65
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    • 2009
  • Tenacibaculum maritimum (formerly Flexibacter maritimus) is the aetiological agent of an ulcerative and necrotic disease commonly called tenacibaculosis in marine fish. Tenacibaculosis is an economically important disease in a great variety species in Jeju Island cultured fish and leading to this pathogen initially affected by skin, mouth, fins, tail causing severe necrotic and ulcerative lesions on the body surface. In the present study, A-7 strain was isolated from Paralichthys olivaceus showing symptoms of tenacibaculosis and identified as T. maritimum by morphological, biochemical and molecular biological analysis. T. maritimum A-7 is experimentally infected through immersion route in Paralichthys olivaceus which the disease outbreaks in land-based fish tanks of Jeju Island. Up to data a number of treatments proposed for the tenacibaculosis outbreaks are based on the immersion administration of drugs in tank. Oxytetracycline is the most widely used disinfectants in fish farms. However, most of fish farms manager and consumers have expressed concern as bioaccumulation in tissue and its environmental. In addition, this antimicrobial compounds is expensive in fish farmers. The overcome of this problem is desired the application of natural plant derived products. To obtain as 70% EtOH extract antimicrobial compounds against tenacibaculosis from 35 species of Jeju Island native plants were screened for antimicrobial activity against T. maritimum. In the present study were identified most of the plant extracts were better antimicrobial activity against T. maritimum.

Physiological Properties of Microbial Cells Treated by Pulsed Electric Field(PEF) (고전압 펄스 전기장 처리된 미생물 세포의 생리특성)

  • Kim, Kyung-Tack;Kim, Sung-Soo;Choi, Hee-Don;Hong, Hee-Doo;Ha, Sang-Do;Lee, Young-Chun
    • Korean Journal of Food Science and Technology
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    • v.31 no.2
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    • pp.368-374
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    • 1999
  • This study was designed to investigate effects of pulsed electric field (PEF) treatment on physiological changes of microbial cells, using domestically fabricated pilot scale PEF device. The effect of non-thermal PEF treatment on physiological characteristics of microorganisms was determined by salt resistance, the amount of UV absorbents, cell staining, recovery rate of defected cells, and changes in structure of cell membrane. Salt resistance of Escherichia coli, Bacillus subtilis and Rhodotorula minuta was examined after PEF treatment at 40 kV/cm, 84 pulse, $10{\mu}s$ pulse duration. Approximately $1\;log_{10}$ cell number of viable microorganisms was decreased by addition of salt. PEF treatment significantly increased the amount of UV absorbents at 260 and 280 nm because of leakage from damaged cell membrane by PEF treatment. Although three kinds of microorganisms treated by PEF were difficult to be observed due to their cell membrane damage, untreated cells were clearly observed by a microscope. PEF-treated R. minuta was not stained by methylene blue due to cell membrane defect. When E. coli, B. subtilis and R. minuta were cultured after PEF treatment, they showed 5, 4, and 8 hr longer lag phase, respectively, compared to control, but growth rates were not affected.

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Protective Effect of Prunella spica Extracts against H2O2-Induced Cytotoxicity in PC12 Cells (Hydrogen peroxide가 유도하는 세포독성으로부터 PC12 세포를 보호하는 하고초(Prunella spica) 추출물의 영향)

  • Kim, Hyun-Jung;Lee, Jeung-Min;Moon, Seong-Hee;Park, Hae-Ryong
    • Journal of Life Science
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    • v.20 no.7
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    • pp.1121-1126
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    • 2010
  • The oxidative stress induced by reactive oxygen species (ROS) may play an important role in the pathogenesis of neurodegenerative diseases. In this study, we investigated the neuroprotective effects of methanolic extracts of Prunella Spica (PSE) against $H_2O_2$-induced oxidative stress in PC12 cells. The cells exposed to $H_2O_2$-induced oxidative stress were treated with various concentrations of PSE; this treatment resulted in the induction of a dose-dependent protective effect, which was evidenced by the results of MTT reduction assay, lactate dehydrogenase (LDH) release assay, morphological assay, and colony-formation assay. Interestingly, we also observed reduction of apoptotic bodies in the Hoechst staining and flow cytometric analysis. These data show that apoptosis was significantly suppressed in the PC12 cells that were exposed to $H_2O_2$-induced oxidative stress and treated with PSE. These results suggest that Prunella Spica could be a new potential protective agent against $H_2O_2$-induced oxidative stress.