• Title/Summary/Keyword: magnification

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Two-Blade Guillotine Technique for Nipple Graft Harvest

  • Wong, Allen Wei-Jiat;Chew, Khong-Yik;Tan, Bien-Keem
    • Archives of Plastic Surgery
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    • v.44 no.5
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    • pp.449-452
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    • 2017
  • The nipple-sharing technique for nipple reconstruction offers excellent tissue matching. The method used for nipple graft harvesting determines the quality of the graft and hence, the success of nipple sharing. Here, we described a guillotine technique wherein the nipple is first transfixed with 2 straight needles to stabilise it. Two No. 11 blades are then inserted in the center and simultaneously swept outwards to amputate the distal portion of the nipple. This technique provides good control, resulting in a very evenly cut base. The recipient bed is deepithelialized thinly, and the nipple graft is inset with interrupted 8-0 nylon sutures under magnification. Being a composite graft, it is protected with splint dressings for 6 weeks, and the dressing is regularly changed by the surgeon. The height of the nipple grafts ranges from 4 to 8 mm. This technique was performed in 9 patients with an average follow-up of 2.9 years (range, 1-4.5 years). Apposition between the nipple graft and its bed is crucial for the success of this technique. When correctly applied, we observed rapid revascularization of the graft.

The effects of tetracycline gel with and without citric acid on periodontally diseased root surface - in vitro study (테트라싸이클린 젤 및 구연산함유 테트라싸이클린 젤의 도포가 치주염에 이환된 치근표면에 미치는 영향에 관한 실험 연구)

  • Choi, Kwang-Choon
    • Journal of Periodontal and Implant Science
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    • v.23 no.2
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    • pp.219-227
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    • 1993
  • The purpose of the present study was to evaluate the effects of 5% tetracycline(Tc) with or without citric acid on periodontally diseased root surfaces. Six single-rooted teeth extracted from one patient was selected and received thorough scaling and root planning, followed by saline irrigation. Each one tooth was divided into eight fragments with a thin separating disc. Total 48 fragments were prepared and setted into 4 groups for this study. Group I (control group)were treated with saline. Group II were treated with 5% Tc gel. Group III were treated with 33% citric acid-5% Tc gel. Group IV were treated with Tc solution. All the specimens are evaluated under Scanning Electron Microscope(SEM). Group I showed large amount of debris in spite of thorough scaling and root planing, but Group II, III & IV showed clean and soft root surface texture. In higher magnification(x3, 000), Group II, III & IV showed nunmerous dentinal tubules, especially Group IV showed collagen fibrils. In the present study, Tc gel and Tc gel with citric showed clinically successful result when treated on periodontally diseased root surface, in vitro.

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AN EXPERIMENTAL STUDY ON THE CERVICAL MARGIN FITNESS IN THE COLLARLESS METAL CERAMIC CROWNS FORMED BY DIFFERENT TECHNIQUES (Collarless도재소부전장금관의 제작방법에 따른 치경부 변연적합도에 관한 실험적 연구)

  • Lee, Jae-Hyeuk
    • The Journal of Korean Academy of Prosthodontics
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    • v.28 no.1
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    • pp.203-216
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    • 1990
  • The purpose of this study was to evaluate the cervical margin fitness in the collarless metal ceramic crowns formed by different techniques. Specimens were divided as follows : the metal ceramic crowns with metal butt margin as group I, the collarless metal ceramic crowns formed with resin binder technique as group II, and the collarless metal ceramic crowns formed with shoulder powder mixed with phosphate-bonded investment liquids on a refractory die as group III. Each group was made of five specimens, and their marginal fitness on each epoxy die was evaluated under scanning electron microscope of x200 magnification at three measuring points : mesial, central, distal. The following results were obtained. 1. The metal ceramic crowns with metal butt margin exhibited significantly better marginal fitness than the collarless metal ceramic crowns. The marginal fitness in descending order was group I, III, II. 2. The collarless metal ceramic crown formed with resin binder technique had the worst marginal fitness & showed cervical color variation and dermacation between the corrected porcelain & the dentin porcelain. 3. The collarless metal ceramic crowns formed with shoulder powder mixed with phosphate-bonded investment liquids on a refractory die exhibited significantly better marginal fitness & sharper marginal configuration than the other collarless group.

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A Study on the Analysis of Transient Overvoltages and Harmonics due to Utility STATCON Switching (전력회사의 스타콘 투입시 과도 전압 상승과 고조파 분석에 관한 연구)

  • 김경철;서범관;송영주;이일무
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.17 no.5
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    • pp.51-59
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    • 2003
  • The utility and many customers employ capacitor banks(STATCON so called at the utility) to help control the power factor(customers) or voltage(the utility) by supplying reactive power to inductive loads. This paper presents analysis of transient overvoltages and harmonics due to utility STATCON switching. One simple and inexpensive means of limiting the voltage magnification transient and reducing harmonics is to switch the capacitor banks on a few minutes after the STATCON has been switched. Simulation results used the EDSA software package show the effects of decreased the transient voltage and harmonic reduction at the customer. And also harmonic limits based on the well-known international harmonic standards IEEE 519 and IEC 1000 are evaluated for the customer.

Prestress force effect on fundamental frequency and deflection shape of PCI beams

  • Bonopera, Marco;Chang, Kuo-Chun;Chen, Chun-Chung;Sung, Yu-Chi;Tullini, Nerio
    • Structural Engineering and Mechanics
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    • v.67 no.3
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    • pp.255-265
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    • 2018
  • The prestress force effect on the fundamental frequency and deflection shape of Prestressed Concrete I (PCI) beams was studied in this paper. Currently, due to the conflicts among existing theories, the analytical solution for properly considering the structural behavior of these prestressed members is not clear. A series of experiments were conducted on a large-scale PCI beam of high strength concrete with an eccentric straight unbonded tendon. Specifically, the simply supported PCI beam was subjected to free vibration and three-point bending tests with different prestress forces. Subsequently, the experimental data were compared with analytical results based on the Euler-Bernoulli beam theory. It was proved that the fundamental frequency of PCI beams is unaffected by the increasing applied prestress force, if the variation of the initial elastic modulus of concrete with time is considered. Vice versa, the relationship between the deflection shape and prestress force is well described by the magnification factor formula of the compression-softening theory assuming the secant elastic modulus.

A Study on the Optimum Design of the Condenser Lens of a Compact Electrostatic-Type SEM (전기장형 소형 주사전자현미경의 집속렌즈의 최적 설계에 대한 연구)

  • Kim, Ki-Hwan;Jang, Dong-Young;Park, Man-Jin
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.24 no.3
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    • pp.270-277
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    • 2015
  • In this paper, we describe the production of a specific electrostatic-type scanning electron microscope based on miniaturization for application in other types of vacuum equipment. The initial configuration of the SEM starts with a minimal configuration that allows people to view sample images. After improving the stability of the SEM operation and resolution, we conducted experiments on identifying the characteristics and development of an einzel-type condenser lens with reference to the demagnification lens system of an SEM. The experiments were conducted at an acceleration voltage of 5 kV and we found the shape of the lens to be more reliable than a conventional lens. The lens was then added to improve the resolution in the nanometer region. The current measured on the sample was approximately 40 pA and its magnification was 4,000 times.

Self-Reference PCSR-G Method for Detecting Defect of Flat Panel Display (평판 디스플레이 결함 검출을 위한 자기 참조 PCSR-G 기법)

  • Kim, Jin-Hyung;Lee, Tae-Young;Ko, Yun-Ho
    • Journal of Korea Multimedia Society
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    • v.18 no.3
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    • pp.312-322
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    • 2015
  • In this paper a new defect detection method for flat panel display that does not require any separately prepared reference images and shows robustness against problems with regard to pixel tolerance and nonuniform illumination condition is proposed. In order to perform defect detection under any magnification value of camera, the proposed method automatically obtains the value of pattern interval through an image analysis. Using the information for pattern interval, an advanced PCSR-G method presented in this paper utilizes neighboring patterns as its reference images instead of utilizing any separately prepared reference images. Also this paper proposes a scheme to improve the performance of the conventional PCSR-G method by extracting and applying additional information for pixel tolerance and intensity distribution considering the value of pattern interval. Simulation results show that the performance of the proposed method utilizing pixel tolerance and intensity distribution is superior to that of the conventional method. Also, it is proved that the proposed method that is implemented using parallel technique based on GPGPU can be applied to real system.

THE CLINICAL RELIABILITY AND EFFECTIVENESS OF THE POSTERO-ANTERIOR CEPHALOMETRIC VIEW, SUBMENTOVERTEX VIEW & PANORAMIC VIEW IN THE DIAGNOSIS OF THE FACIAL ASYMMETRY (안면 비대칭 환자 진단에 있어서 후전방두부 방사선사진과 이하두정 방사선사진 및 파노라마 방사선사진의 임상적 효용성)

  • Choi Eun-Young;Park Tae-Won
    • Journal of Korean Academy of Oral and Maxillofacial Radiology
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    • v.24 no.2
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    • pp.427-437
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    • 1994
  • Clinical examination, photometric evaluation, & radiographic analysis have been used to evaluate the asymmetry of the face. Commonly used skull radiographs to assess skeletal asymmetry include poatero-anterior cephalometries, submentovertex view, & panoramic view. The purpose of this study is the comparison of the reliance of the postero-anterior cephalometric view, submentovertex view, & panoramic view in the asymmetry evaluation. All measurements were performed on the each radiographs of 31 control group & 30 asymmetric group. The measurements are MSL(midsagittal plane)-Co, MSL-Go, MSL-Me, MSL-Al, MSL-Bl, Mn. Ramus Height(Co-Go), Mn. Body Length(Go-Me), and Total Mn. Length(Co-Me). The results were as follows: 1. The lack of either a right-sided or left-sided asymmetric dominant was found. 2. The postero-anterior cephalometric view & submentovertex view relatively agreed with each other in the result. The postero-anterior cephalometric view & submentovertex view had the clinical reliability & effectiveness in the diagnosis of the skeletal asymmetry(p<0.05). 3. The panoramic view showed more magnification compared to the other radiographs. In the vertical measurements the panoramic view had clinical reliability relatively(p<0.05). But we cannot rely on the horizontal measurements in the panoramic view(p>0.05).

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High Quality Volume Rendering Using the Empty Space Jittering and the Sampling Alignment Method (빈공간 교란과 샘플링 위치 정렬을 이용한 고화질 볼륨 가시화)

  • Kye, Heewon
    • Journal of Korea Multimedia Society
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    • v.16 no.7
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    • pp.852-861
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    • 2013
  • When users use medical volume rendering applications, selecting specific region of volume data and observing the region by magnification is a common process.As the wood-grain artifact is arise from the magnified image, the jittered sampling technique has been used to remove the problem. However, the jittered sampling leads to some noise along the volume edge. In this research, we reveal the reason of the noise, and present a solution. To remove the wood-grain artifact without the noise, we propose the empty space jittering and the sampling alignment method. Using these methods, we can produce high quality volume rendering images without noticeable time consuming.

Improvement of Histopathological Sample Preparation by Employing Microwave Heating Method on Frozen Section Specimens

  • Ahn, Seung-Ju
    • Biomedical Science Letters
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    • v.13 no.4
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    • pp.361-368
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    • 2007
  • Biological samples can be fixed either by chemical method by using chemical solution or physical methods by using heat treatment. The problem in traditional heat fixation is unsatisfactory quality due to uneven heat conduction in specimen and loss of inner cell contents. Chemical fixation method also bears several intrinsic problems like the limit in specimen size, time consumption in fixative impregnation, and loss of low molecular weight cell components. These factors deteriorate the quality of fixed specimen, thus limit the magnification and contrast of tissue pictures. Microwave heat has been reported to be a good alternative to current chemical methods to overcome these problem. In this study, we tried to introduce the microwave energy method to routine fixation work in hospital. We replaced chemical fixative with saline to provide moderate reaction condition, and used frozen section to reduce time for sample preparation. Temperature was measured at each experiment. The fixation of rat kidney tissue with 2.45 GHz electromagnetic wave and saline showed similar result to the control group fixed with traditional chemical method. Human tumor tissue fixed with 2.45 GHz electromagnetic in frozen section was improved in terms of histochemistry of PAS and immunohistochemistry of tumor marker like cytokeratin. Total turnaround time was reduced from $24\sim38$ h to to $2\sim4$ h. In conclusion, the quality of samples prepared by microwave heating method was at least as good as that of traditional method. If the condition for the fixation of different specimens is standardized, this new method could be applied to routine work in hospital, and could save working time as well.

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