• 제목/요약/키워드: phase-contrast

검색결과 840건 처리시간 0.032초

Efficient Macrocyclization for Cyclicpeptide Using Solid-Phase Reaction

  • Kim, Joong-Hup;Hong, Il-Khee;Kim, Hyo-Jeong;Jeong, Hyeh-Jean;Choi, Moon-Jeong;Yoon, Chang-No;Jeong, Jin-Hyun
    • Archives of Pharmacal Research
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    • 제25권6호
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    • pp.801-806
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    • 2002
  • Cyclicpeptides are important targets in peptide synthesis because of their interesting biological properties. Constraining highly flexible linear peptides by cyclization is one of the mostly widely used approaches to define the bioactive conformation of peptides. Cyclic peptides often have increased receptor affinity and metabolic stability over their linear counterparts. We carried out virtual screening experiment via docking in order to understand the interaction between HLE-Human Leukocyte Elastase and ligand peptide and to identify the sequence that can be a target in various ligand peptides. We made cyclic peptides as a target base on Metlle-Phe sequence having affinity for ligand and receptor active site docking. There are three ways to cyclize certain sequences of amino acids such as Met-lie-Phe-Gly-Ile. First is head-to-tail cyclization method, linking between N-terminal and C-terminal. Second method utilizes amino acid side chain such as thiol functional group in Cys, making a thioether bond. The last one includes an application of resin-substituted amino acids in solid phase reaction. Among the three methods, solid phase reaction showed the greatest yield. Macrocyclization of Fmoc-Met-Ile-Phe-Gly-Ile-OBn after cleavage of Fmoc protection in solution phase was carried out to give macrocyclic compound 5 in about 7% yield. In the contrast with solution phase reaction, solid phase reaction for macrocyclization of Met-Ile-Phe-Gly-Ile-Asp-Tentagel in normal concentrated condition gave macrocyclic compound 7 in more than 35% yield.

간 전이환자에서 최적의 펄스시퀀스에 따른 SPIO 특이성 조영제의 국소병변검출: Case review (Focal Lesion Detection of SPIO-specific agent Compared with Optimized Pulse Sequences in the Hepatic Metastases: Case Review)

  • 구은회
    • 대한디지털의료영상학회논문지
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    • 제14권2호
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    • pp.57-61
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    • 2012
  • To compare the accuracy of breath-hold magnetic resonance imaging sequences to establish the most effective superparamagnetic iron oxide-enhanced sequence for detection of hepatic metastases. A total of 100 patients(50men and 50women, mean age: 60years) with liver disease(including malignant and benign liver lesions) were investigated at 3.0T machine (GE, General Electric Medical System, Excite HD) with 8Ch body coil. Pulse sequence for MR imaging decided to the FS-T2-FSE-RT(TR/TE/Thick./Freq./Phase=12857ms/100ms/7mm/512/384), MGRE(TR/TE/Thick./Freq./Phase=100ms/9.7ms/7mm/384/288), in-out of phase echo(TR/$TE_1$, $TE_2$/Thick./Freq./Phase=140ms/2.4, 5.8ms/7mm/352/300), Images obtained before the injection of SPIO. Six sequences were optimized for lesion detection: FS-T2-FSE-RT, multigradient recalled echo data image(MGRE), T2-weighted MGRE with an 9.7msec echo time. Images were reviewed independently by five blinded observers. The accuracy of each sequence was measured by using picture archiving communication system analysis. All results were correlated with findings at multidectator computed tomography examination. Differences between the mean results of the six observers were measured by using paired student t-test analysis. Postcontrast T2-weighted MGRE sequences were the most accurate and were significantly superior to postcontrast FS-T2-FSE-RT, T2-weighted MGRE, in-out of phase MR sequences(p < .05). For all lesions that were malignant or smaller than 1 cm, respectively, contrast to noise ratio of pre and postcontrast sequences were -1and -0.3 for T2-weighted FSE, 0.53 and 4.5 in-out of phase, 7, 7.08, 5.08, 3.32, 1.7, 1.16, 0.79, 0.68 for GRE with 2.9, 7.5, 12.1, 16.6, 21.2, 25.8, 30.4, 35.0 TE values. Breath-hold various TE precontrast sequences offer improvement in sensitivity compared with fixed multigradient recalled echo sequences alone.

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Effects of protease enzyme supplementation in weanling pigs' diet with different crude protein levels on growth performance and nutrient digestibility

  • Olivier, Munezero;In Ho, Kim
    • Journal of Animal Science and Technology
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    • 제64권5호
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    • pp.854-862
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    • 2022
  • The purpose of this study is to determine the impact of different levels of crude protein (CP) diets supplemented with dietary protease on the growth performance and nutrient digestibility of the weanling pigs. In a 5-week study, 100 crossbred ([Landrace × Yorkshire] × Duroc) of weaner pigs that have an average initial body weight (BW) of 7.17±1.06 kg were assigned to one of four dietary treatments with 5 replications and 5 pigs (3 gilts and 2 castrated male pigs) per pen in a randomized complete block design. The dietary treatments were as follows: Phase 1: CON: basal diets (20.60% CP); low protein (LP): CON - 0.30% CP; PLP1: (CON - 0.30% CP) + 0.05% protease; PLP2: (CON - 0.50% CP) + 0.05% protease. Phase 2: CON: basal diets (18.88% CP); LP: CON - 0.30% CP; PLP1: (CON - 0.30% CP) + 0.05% protease; PLP2: (CON - 0.50% CP) + 0.05% protease. The addition of protease to low CP diets significantly increased the feed conversion ratio (FCR) (p = 0.039), BW (p = 0.046), average daily gain (ADG) (p = 0.049), and average daily feed intake (ADFI) tended to increase (p = 0.053) in the young pigs during phase 1. However, FCR tended to increase throughout the experiment but did not change during phase 2, whereas BW, ADG, and ADFI stayed unchanged throughout phase 2 and overall. There was no significant difference in dry matter, nitrogen (N), and gross energy of nutrient digestibility in all phases and overall in weaned pigs with low CP when protease was fed. In contrast, adding protease to the low CP diets increased the tendency of N digestibility (p = 0.059) during phase 1. It is concluded that dietary protease supplementation tended to increase N retention during the first phase of the weaning period, hence increasing piglet performance.

지진동을 받는 중력식 안벽에 작용하는 하중산정 및 Newmark 변위해석 (Evaluation of Force Components and Newmark Sliding Block Analysis of Quay Walls during Earthquake)

  • 김성렬;하익수;권오순;김명모
    • 한국지진공학회:학술대회논문집
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    • 한국지진공학회 2002년도 춘계 학술발표회 논문집
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    • pp.93-100
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    • 2002
  • In this paper, new simple model is developed to evaluate the variation of the magnitude and the phase contrast of force components with the development of excess pore pressure in backfill soil. Also, Newmark sliding block analysis is performed inputting the calculated total force from new model. The applicability of new simple model and Newmark sliding block model is verified from the analyses of 1g shaking table test results.

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서울지역의 Asbestos 環境濃度分布 (Airborne Asbestos Concentrations of Various Locations in Seoul)

  • 兪榮植;金鍾奎
    • 한국대기환경학회지
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    • 제5권2호
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    • pp.36-41
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    • 1989
  • Concentrations of atmospheric asbestos at 5 sites in the central Seoul area, were determined by phase contrast microscopy. The observed numbers of asbestos per liter of air were: maximum 4.51, minimum 0.72 and average 2.20. The direct relationship between asbestos concentration at each sampling site and automobile traffics was not demonstrated. But the more there are automobile traffics, the higher asbestos concentratiof of total fibers is.

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정자형태 및 정자농도의 검사를 위한 Unopette의 사용 (Use of Unopette for the Observation of Sperm Morphology and Sperm Concentration)

  • 김명철
    • 한국임상수의학회지
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    • 제7권2호
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    • pp.497-500
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    • 1990
  • This study was carried out determine whether Unopette can be used for the observation of sperm morphology and sperm Concentration. Rabbit sperm and frozen-thawed bovine sperm were observed with phase contrast microscope after dilution with Unopette acooriding to duration of preservation at 3~5$^{\circ}C$. Sperm using Unopette showed high normal sperm(%) than sperm using hematoxylin-eosin until 48 hours. Sperm using Unopette revealed no difference in sperm concentration until 24 hours, as compared with control sperm. As a result, Unopette was assessed as appropriate solution for preservation in terms of morphological observation and sperm concentration.

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불확실한 시스템의 가변구조 모델 추종 제어기 설계에 관한 연구 (A study on the variable structure model following controller design of uncertain system)

  • 박재홍;이형찬;양해원
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.155-160
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    • 1990
  • This paper presents the new VSMFC (variable structure model following control) algorithm of a system with parameter uncertainty. In contrast to the conventional approach, continuous control inputs am used instead of discontinous ones and modified reachability condition for sliding mode reduces a reaching phase and a newly proposed sliding surfaces are used for the robust control of uncertain system.

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Diffractive Liquid Crystal Displays

  • Tsvetkov, V.A.
    • Journal of Information Display
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    • 제4권1호
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    • pp.9-13
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    • 2003
  • An overview of author activity in the area diffractive LCDs are given. The formation of colour spectrum DL CDs is made by switchable phase diffraction gratings created in a LC layer due to using of comb-like electrodes. The offered DLCDs functionate without polarizes, have high contrast and spectral of pure colours, broad viewing ngles. The existing production equipment can be adapted to manufacturing of DLCD without considerable alterations.

복부 외상 후 발생한 동맥-집뇨계 간 연결 (Artery to Collecting System Communication after Abdominal Trauma)

  • 이창욱;권오정;방성학;최낙영;이창섭;안승현
    • Journal of Trauma and Injury
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    • 제19권2호
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    • pp.192-195
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    • 2006
  • Degenerative vascular disease, previous arterial surgery, long-term ureteral stenting, pelvis surgery, and radiotheraphy are reported as causes of artery-to-collecting-system communication.. Artery-to-collecting-system- communication associated with blunt trauma is rare, but potentially fatal. The diagnosis is very difficult and requires a high degree of suspicion. We were able to make the diagnosis based on the characteristic finding of contrast-enhanced computed tomography (CT) obtained in the early phase, equivalent to the finding obtained in the corticomedullary phase of the kidney. We report a case of artery to collecting system communication due to blunt abdominal trauma following a fall, which was treated by embolization.