• Title/Summary/Keyword: High-loading

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Surface Chemistry in Biocompatible Nanocolloidal Particles (생체 적합한 나노입자와 계면화학)

  • Kim Jong-Duk;Jung Jae Hyun
    • Journal of the Society of Cosmetic Scientists of Korea
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    • v.30 no.3 s.47
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    • pp.295-305
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    • 2004
  • Colloid and surface chemistry have been focused on surface area and surface energy. Local surface properties such as surface density, interaction, molecular orientation and reactivity have been one of interesting subjects. Systems of such surface energy being important would be listed as association colloid, emulsion, particle dispersion, foam, and 2-D surface and film. Such nanoparticle systems would be applied to drug delivery systems and functional cosmetics with biocompatible and degradable materials, while nanoparticles having its size of several nm to micron, and wide surface area, have been accepted as a possible drug carrier because their preparation, characteristics and drug loading have been inves-tigated. The biocompatible carriers were also used for the solubilization of insoluble drugs, the enhancement of skin absorption, the block out of UV radiation, the chemical stabilization and controlled release. Nano/micro emulstion system is classified into nano/microsphere, nano/microcapsule, nano/microemulsion, polymeric micelle, liposome according to its prep-aration method and size. Specially, the preparation method and industrial applications have been introduced for polymeric micelles self-assembled in aqueous solution, nano/microapsules controlling the concentration and activity of high concen-tration and activity materials, and monolayer or multilayer liposomes carrying bioactive ingredients.

THERAPEUTIC APPROACHES FOR TREATMENT RESISTANT OBSESSIVE-COMPULSIVE DISORDER IN CHILDREN AND ADOLESCENTS (소아청소년기 치료저항성 강박장애의 치료적 접근)

  • Suh, Hyun-Ju;Kim, Boong-Nyun
    • Journal of the Korean Academy of Child and Adolescent Psychiatry
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    • v.14 no.1
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    • pp.64-80
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    • 2003
  • Although obsessive-compulsive disorder(OCD) affects children, adolescents, and adults whether its juvenile(dhild and adolescent) and adult forms are different subtype of a disorder remains unknown. But there are increasing findings that suggest that juvenile OCD may be unique subtype of the disorder. One proposed subtype is the childhood OCD associated with high comorbidity of tic disorder and increased familial loading for OCD or tic disorder. The other proposed subtype is the childhood OCD and/or tic disorder occuring in association with streptococcal infection(PANDAS). These two subtypes of OCD are unlikely to respond to SSRI due to possible different pathphysiological mechanism. So this paper reviews the characteristics of OCD and therapeutic approaches for treatment resistant OCD in childhood and adolescence. Considering the likely heterogeneity of OCD, the possibility that juvenild OCD may be a variant of the disorder can have important clinical and scientific implications because it may further our understanding of this disorder, its etiology, and perhaps its treatment.

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Study on the stress distribution depending on the bone type and implant abutment connection by finite element analysis (지대주 연결 형태와 골질에 따른 저작압이 임프란트 주위골내 응력분포에 미치는 영향)

  • Park, Hyun-Soo;Lim, Sung-Bin;Chung, Chin-Hyung;Hong, Ki-Seok
    • Journal of Periodontal and Implant Science
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    • v.36 no.2
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    • pp.531-554
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    • 2006
  • Oral implants must fulfill certain criteria arising from special demands of function, which include biocompatibility, adequate mechanical strength, optimum soft and hard tissue integration, and transmission of functional forces to bone within physiological limits. And one of the critical elements influencing the long-term uncompromise functioning of oral implants is load distribution at the implant- bone interface, Factors that affect the load transfer at the bone-implant interface include the type of loading, material properties of the implant and prosthesis, implant geometry, surface structure, quality and quantity of the surrounding bone, and nature of the bone-implant interface. To understand the biomechanical behavior of dental implants, validation of stress and strain measurements is required. The finite element analysis (FEA) has been applied to the dental implant field to predict stress distribution patterns in the implant-bone interface by comparison of various implant designs. This method offers the advantage of solving complex structural problems by dividing them into smaller and simpler interrelated sections by using mathematical techniques. The purpose of this study was to evaluate the stresses induced around the implants in bone using FEA, A 3D FEA computer software (SOLIDWORKS 2004, DASSO SYSTEM, France) was used for the analysis of clinical simulations. Two types (external and internal) of implants of 4.1 mm diameter, 12.0 mm length were buried in 4 types of bone modeled. Vertical and oblique forces of lOON were applied on the center of the abutment, and the values of von Mises equivalent stress at the implant-bone interface were computed. The results showed that von Mises stresses at the marginal. bone were higher under oblique load than under vertical load, and the stresses were higher at the lingual marginal bone than at the buccal marginal bone under oblique load. Under vertical and oblique load, the stress in type I, II, III bone was found to be the highest at the marginal bone and the lowest at the bone around apical portions of implant. Higher stresses occurred at the top of the crestal region and lower stresses occurred near the tip of the implant with greater thickness of the cortical shell while high stresses surrounded the fixture apex for type N. The stresses in the crestal region were higher in Model 2 than in Model 1, the stresses near the tip of the implant were higher in Model 1 than Model 2, and Model 2 showed more effective stress distribution than Model.

Orthophoto and DEM Generation Using Low Specification UAV Images from Different Altitudes (고도가 다른 저사양 UAV 영상을 이용한 정사영상 및 DEM 제작)

  • Lee, Ki Rim;Lee, Won Hee
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.34 no.5
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    • pp.535-544
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    • 2016
  • Even though existing methods for orthophoto production using expensive aircraft are effective in large areas, they are drawbacks when dealing with renew quickly according to geographic features. But, as UAV(Unmanned Aerial Vehicle) technology has advanced rapidly, and also by loading sensors such as GPS and IMU, they are evaluates that these UAV and sensor technology can substitute expensive traditional aerial photogrammetry. Orthophoto production by using UAV has advantages that spatial information of small area can be updated quickly. But in the case of existing researches, images of same altitude are used in orthophoto generation, they are drawbacks about repetition of data and renewal of data. In this study, we targeted about small slope area, and by using low-end UAV, generated orthophoto and DEM(Digital Elevation Model) through different altitudinal images. The RMSE of the check points is σh = 0.023m on a horizontal plane and σv = 0.049m on a vertical plane. This maximum value and mean RMSE are in accordance with the working rule agreement for the aerial photogrammetry of the National Geographic Information Institute(NGII) on a 1/500 scale digital map. This paper suggests that generate orthophoto of high accuracy using a different altitude images. Reducing the repetition of data through images of different altitude and provide the informations about the spatial information quickly.

A Study of Musculotendinous Problems of Students Majoring in Musical Instruments in Korea (기악과 학생들의 근육과 건 증상에 대한 조사연구)

  • Lee, Eun-Nam;Lee, Eun-Ok;Lee, In-Sook;Park, In-Hyae;Park, Jeong-Sook;Bae, Sung-Cheol;So, Hee-Young
    • Journal of muscle and joint health
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    • v.4 no.1
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    • pp.48-60
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    • 1997
  • This study was undertaken to identify the musculotendinous problems and contributing factors to those problems In students majoring in musical instruments in Korea. The data were collected from March 2, 1996 to March 31, 1996 from 261 music students in various geographical areas. The data were analyzed for descriptive statistics, t-test, chi-square using SPSS $PC^+$ program. The results of this study were as follows : 1. In a questionnaire survey of 261 music students, one hundred twenty five(47.9%) reported having had various musculotendinous symptoms. Twenty seven students among the those who had previous symptoms(21.9%) reported the present symptoms. 2. The experience rates of musculotendinous problems in keyboard players, string players and woodwind players were 50.3%, 48.2%, 33.3% respectively. 3. Most of the students practiced most intensively during their high school years and the musculotendinous symptoms began at the same period. 4. Pain, tenderness and stiffness were the most common symptoms, while paresthesia and motor dysfunction were rare. This indicates that most players had muscle tendinous overuse, while small number had nerve entrapment and motor dysfunction. 5. In past and present symptoms, string players experienced musculotendinous symptoms mainly in both sides of shoulders, lumbar area, left finger, and left wrist, while keyboard players experienced more symptoms in the right wrist, shoulder, fingers than left side. 6. The major contributing factors to the symptoms were weight of instrument, types of instruments, types of daily activities, duration of practice, and playing technique. 7 The most frequent treatment modalities for the symptoms were acupuncture or moxibustion, other alternative therapy such as heat compress and massage. Through this study it was found that the musculotendinous problems might be increased along with their career, due to lack of knowledge about preventive measures and patterns of health behavior seeking alternative modalities rather than professional consultation. Therefore, preventive measures that focus on playing habits such as duration of practice, frequency of rest and position while playing should be developed and taught to the students, their parents, and music educators. Doctors who are interested in this area should attempt to correct the position and posture while playing of the posture. And measures for reduction of loading of instrument weight should also be developed.

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Study on the fabrication of Ceramic Core using a Gel-casting Process in Aqueous Medium(II) : Physical Properties of Sintered Ceramic Core Body (수용액 매체에서 젤-케스팅 공정을 이용한 세라믹 코어 제조에 관한 연구(II) : 세라믹 코어 소결체의 물성)

  • Kim, Jae-Won;Kim, Du-Hyeon;Kim, In-Su;Yu, Yeong-Su;Choe, Baek-Gyu;Kim, Ui-Hwan;Jo, Chang-Yong
    • Korean Journal of Materials Research
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    • v.11 no.6
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    • pp.465-471
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    • 2001
  • The effect of sintering condition on the mechanical properties and leachability of polydispersed ceramic core body made by gel-casting process in aqueous medium have been investigated. The polydispersed ceramic slip that has low viscosity($\leq$1000cP, at 1000cP (at $50sec^{-1}$ ) and high solid loading(50vo1%) was obtained. The green bodies were fabricated through casting and gelation at room temperature followed by drying at $25^{\circ}C$for 48hrs under relative humidity of 80%. Crack-free green body was successfully fabricated through the above process. The strength at room temperature, apparent bulk density, and shrinkage of the ceramic core body increased propotionally with increasing sintering temperature(1100~150$0^{\circ}C$). However, porosity of the ceramic core body showed relatively low vague. Leaching rate of sintered core body increased with increasing porosity of the sintered body, and was significantly dependent upon the concentration of alkali caustic solution at the same leaching temperature.

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Immobilization of Cyclodextrin Glucanotransferase for Production of 2-O-\alpha-D-Glucopyranosyl L-Ascorbic Acid. (2-O-\alpha-D-Glucopyranosyl L-Ascorbic acid 생산을 위한 Cyclodextrin glucanotransferase의 고정화)

  • 성경혜;김성구;장경립;전홍기
    • Microbiology and Biotechnology Letters
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    • v.31 no.4
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    • pp.368-376
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    • 2003
  • Cyclodextrin glucanotransferase (CGTase) from Paenibacillus sp. JB-13 was immobilized on various carriers by several immobilization methods such as ionic binding, covalent linkage and ultrafiltration to improve the process performance. The ultrafiltration and covalent linkage with CNBr-activated sepharose 4B were found as the best method for immobilization of CGTase. The ability of CGTase immobilization onto CNBr-activated sepharose 4B was as high as 18,000 units/g resin when the conditions was as follows: contact time 9 hrs at $37^{\circ}C$, pH 6.0, 100 nm and enzyme loading 24,000 units/g resin. The optimum conditions for production of 2-O-$\alpha$-D-Glucopyranosyl L-Ascorbic acid by immobilized CGTase turned out to be: pH 5.0, temperature $37^{\circ}C$, 20% substrate solution containing 8% (w/v) of soluble starch and 12% (w/v) of L-ascorbic acid sodium salt, 100 rpm, far 25 hrs and with 800 units of immobilized CGTase/ml substrate solution. Moreover the CGTase activity could be stably maintained for 8 times of repetitive reactions after removing products by ultrafiltration through YM 10 membrane.

THREE-DIMENSIONAL PHOTOELATIC STRESS ANALYSIS OF CLASP RETAINERS INFLUENCED BY VARIOUS DESIGNS ON UNILATERAL FREE-END REMOVABLE PARTIAL DENTURES (하악 편측 유리단 국소의치의 직접유지장치 형태에 따른 3차원적 광탄성 응력분석 연구)

  • Kim Byeong-Moo;Yoo Kwang-Hee
    • The Journal of Korean Academy of Prosthodontics
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    • v.32 no.4
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    • pp.526-552
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    • 1994
  • The extent and direction of movement of removable partial dentures during function are influenced by the nature of the supporting structures and and the design of the prosthesis. Since forces are transmitted to the abutment teeth through occlusal rests, guide planes and direct retainers during functional movements, proper design based on the avaialble research data will maintain the health of abutment teeth and their supporting structures. The purpose of this in vitro study is evaluating stress distribution clinically around the abutment teeth prepared following 4-type clasping systems for unilateral free-end removable partial dentures. Three-Dimensional Photoelastic Stress Analysis method was used because it shows a visual display of stresses of the simulated abutment teeth and residual ridges and reveals stress concentration that can be read at any given points in terms of direction and magnitude. For this study, the author fabricated 4 mandibular photoelastic epoxy models missing left 1st and End molar. Epoxy models were duplicated and 4 unilateral removable partial dentures were construe- ted in accordance with 4-type direct retainers. Unilateral free-end removable partial dentures were positioned on their own models. 6kg force was loaded on the every removable partial dentures of the epoxy model on the central fossa of mandibular left 1st molar vertically by the loading device. After the stress was frozen in a stress freezing furnace, 6 specimens of 6-mm thickness were made from every epoxy model and examined with the circular polariscope. The results were as follows : 1. Generally I-bar clasp revealed the most favorable stress distribution around the abutment teeth. 2. At the end portion of the free-end ridge, Back action clasp showed the highest stress concentration at the bucco-lingual and top portions of the residual alveolar ridge. 3. At the distal area of the abutment teeth, Akers clasp and Roach clasp showed higher stress concentration bucco-lingually and apically than the others. 4. To the abutment tooth, I-bar clasp showed the least stress distribution bucco-lingually but the others showed irregular stress distribution. 5. At the mesial area of the abutment teeth, the order of effective stress distribution was I-bar clasp, Back-action clasp, Akers clasp and Roach clasp. There was big difference of stress distribution between them. 6. At the right 2nd premolar and 1st molar, the stress concentration of Akers clasp was a little high but that of I-bar clasp was low.

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Design and Development of Multiple Input Device and Multiscale Interaction for GOCI Observation Satellite Imagery on the Tiled Display (타일드 디스플레이에서의 천리안 해양관측 위성영상을 위한 다중 입력 장치 및 멀티 스케일 인터랙션 설계 및 구현)

  • Park, Chan-Sol;Lee, Kwan-Ju;Kim, Nak-Hoon;Lee, Sang-Ho;Seo, Ki-Young;Park, Kyoung Shin
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.18 no.3
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    • pp.541-550
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    • 2014
  • This paper describes a multi-scale user interaction based tiled display visualization system using multiple input devices for monitoring and analyzing Geostationary Ocean Color Imager (GOCI) observation satellite imagery. This system provides multi-touch screen, Kinect motion sensing, and moblie interface for multiple users to control the satellite imagery either in front of the tiled display screen or far away from a distance to view marine environmental or climate changes around Korean peninsular more effectively. Due to a large amount of memory required for loading high-resolution GOCI satellite images, we employed the multi-level image load technique where the image was divided into small tiled images in order to reduce the load on the system and to be operated smoothly by user manipulation. This system performs the abstraction of common input information from multi-user Kinect motion and gestures, multi-touch points and mobile interaction information to enable a variety of user interactions for any tiled display application. In addition, the unit of time corresponding to the selected date of the satellite images are sequentially displayed on the screen and multiple users can zoom-in/out, move the imagery and select buttons to trigger functions.

Pharmacokinetic Evaluation of Ketorolac Tromethamine Sustained-Release Pellets after Oral Administration in Rabbits (케토롤락트로메타민 서방성 펠렛의 약물속도론적 평가)

  • Kwak, Son-Hyok;Hwang, Sung-Joo;Jiang, Ge;Nam, Kyung-Wan;Moon, Young-Girl;Lee, Hai-Bang;Cho, Sun-Hang;Yuk, Soon-Hong;Lee, Han-Koo;Jeong, Sang-Young;Lee, Young-Won
    • Journal of Pharmaceutical Investigation
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    • v.30 no.4
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    • pp.241-246
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    • 2000
  • To develop a sustained-release preparation containing ketorolac tromethamine, two sustained-release pellet formulations were evaluated with a pharmacokinetic study as compared with a conventional commercial tablets (10 mg $Tarasyn^{TM}$, Roche Korea Ltd.). Two sustained-release formulations were as follows; formulation A was composed of an inner layer containing 75% of drug coated with $Eudragit^{TM}$ RS 100 membrane and an outer layer containing 25% of drug mixed with $Eudragit^{TM}$ NE30D, and formulation B was composed of only an inner layer containing 100% of drug coated with $Eudragit^{TM}$ RS 100 membrane. The dissolution test was performed for two formulations. In case of conventional tablets, 2.5 mg of drug per a dose was administered orally into male Albino rabbit (2.0-2.3 kg of body weight) 3 times at intervals of 4 hours. In case of two sustained formulations, 7.5 mg of drug was administered once orally. Blood samples were withdrawn periodically after the administration, and the blood concentration was determined by HPLC. The conventional tablets showed very high peak-trough fluctuation between administered doses, but two sustained formulations showed less fluctuation. Formulation A with the loading dose showed the time to reach minimum effective concentration (MEC) i.e. the onset time was less than 20 min, while Formulation B had more than 1 hr of the onset time. Formulation A had the more constant plasma level than formulation B. However, formulation B had a time lag, so the plasma level was less than MEC for an initial period of 1 hr. In formulation A, the plasma level was maintained within the therapeutic window $(0.3-5\;{\mu}g/ml)$ for a long period. Formulation A was thought to be an ideal sustained-release formulation for ketorolac tromethamine oral delivery system.

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