• Title/Summary/Keyword: reverse tolerance

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Suitability of denervated muscle flaps as recipient sites for pancreatic islet cell transplantation

  • Park, Jong-Lim;Kim, Taewoon;Kim, Baek-Kyu
    • Archives of Plastic Surgery
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    • v.48 no.1
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    • pp.133-143
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    • 2021
  • Background Extensive research has been conducted on islet transplantation as a possible cure for diabetes. Islet transplantation in the liver via the portal vein has shown remarkable results, but numerous other recipient sites are currently being investigated. We aimed to show the effectiveness of using a muscle flap as a recipient site for islet transplantation. Methods Islet cells were harvested from 12 isogenic Lewis rats, and then diabetes was induced in another 12 isogenic Lewis rats by streptozotocin injection. In six rats, 3,000 islets were transplanted into gastrocnemius muscle flaps, and in the other six rats, the same number of islets were transplanted into the gastrocnemius muscle. The transplanted islet cell function between the two groups was compared by means of blood glucose tests, glucose tolerance tests, immunohistochemistry, and real-time reverse transcription polymerase chain reaction. Results In the muscle flap group, blood glucose levels significantly decreased after islet transplantation. Blood glucose levels were significantly different between the two groups at 3 weeks after transplantation. The muscle flap group showed nearly normoglycemic results upon the glucose tolerance test, whereas the muscle group was hyperglycemic. Immunohistochemical evaluation showed positive results against insulin and glucagon in biopsies of both groups, and the islet cell density was higher in the muscle flap group. There were no statistically significant differences between the two groups in real-time reverse transcription polymerase chain reaction results. Conclusions Our results suggest that muscle flaps are promising candidates for islet cell transplantation.

Point Data Reduction in Reverse Engineering by Delaunay Triangulation (역공학에서의 Delaunay 삼각형 분할에 의한 점 데이터 감소)

  • Lee, Seok-Hui;Heo, Seong-Min;Kim, Ho-Chan
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.25 no.8
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    • pp.1246-1252
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and the measurement of clay or wood models for the development of new products. To generate a surface from measured points by a laser scanner, typical steps include the scanning of a clay or wood model and the generation of manufacturing data like STL file. A laser scanner has a great potential to get geometrical data of a model for its fast measuring speed and higher precision. The data from a laser scanner are composed of many line stripes of points. A new approach to remove point data with Delaunay triangulation is introduced to deal with problems during reverse engineering process. This approach can be used to reduce a number of measuring data from laser scanner within tolerance, thus it can avoid the time for handling point data during modelling process and the time for verifying and slicing STL model during RP process.

A Study on the Ethanol Concentration by Osmotic Sink Reverse Osmosis Process (Osmotic Sink Reverse Osmosis Process를 이용한 에탄올의 농축특성에 관한 연구)

  • 이광현;민병렬
    • Membrane Journal
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    • v.2 no.1
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    • pp.33-48
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    • 1992
  • OSRO process was developed and it was confirmed more effective in ethanol concentrating process comparing to reverse osmosis process. It may be industrialized if more effective membrane for OSRO and reverse osmosis, which indicate the value greater than zero, it was shown that OSRO process was more effective than reverse osmosis for the ethanol concentration process. The decrease of feed concentration and flow rate and the increase of applied pressure made more effective operating conditions in OSRO process to concentrate ethanol. From the numerical esults for the multi-plates, theoretical DC values of reverse osmosis and OSRO process was increased as the umber of stages increased. DC values were increased with the increase of applied pressure in same number of stages. The theoretical values of DC by numerical calculation were corresponded to the experimental values within 15% tolerance. DC value was increased proportional to applied pressure and osmotic sink solution flow rate but it was decreased proportional to feed concentration and flow rate. The numerical calculation over the wide ranges inclading experimental condition was proposed in this study.

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Comparative Study of the Endotoxemia and Endotoxin Tolerance on the Production of Th Cytokines and Macrophage Interleukin-6: Differential Regulation of Indomethacin

  • Chae, Byeong-Suk
    • Archives of Pharmacal Research
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    • v.25 no.6
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    • pp.910-916
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    • 2002
  • Endotoxin tolerance reduces the capacity of monocytes to produce proinflammatory cytokines, results in cellular immune paralysis, and down-regulates the production of helper T (Th)1 type cytokines with a shift toward a Th2 cytokine response. Prostaglandin (PG)E$_2$ in the immune system also results in macrophage inactivation and the suppression of Th1 activation and the enhancement of Th2 activation. However, the inhibitory effects of PGE$_2$ on the altered polarization of the Th cell and macrophage interleukin (IL)-6 production characterized in part by cellular immune paralysis in a state of endotoxin tolerance is unclear. This study was undertaken, using indomethacin, to investigate the role of endogenous PGE$_2$ on the Th cytokines and macrophage IL-6 production in a state of endotoxin tolerance compared to those with endotoxemia mice, wherein, in this latter case, the increased production of proinflammatory cytokines and PGE$_2$ is exhibited. Endotoxemia was induced by injection of lipopolysaccharide (LPS; 10 mg/kg in saline) i.p. once in BALB/c mice, and endotoxin tolerance was induced by pretreatment with LPS (1 mg/kg in saline) injected i.p. daily for two consecutive days and then with LPS 10 mg/kg on day 4. Splenocytes or macrophages were obtained from endotoxemia and endotoxin tolerance models pretreated with indomethacin, and then cytokine production was induced by Con A-stimulated splenocytes for the Th cytokine assays and LPS-stimulated macrophages for the IL-6 assay. Our results showed that endotoxemia led to significantly reduced IL-2 and IL-4 production, to significantly increased IL-6 production, whereas interferon $(IFN)-{\gamma}$ production was not affected. Indomethacin in the case of endotoxemia markedly attenuated $IFN-{\gamma}$ and IL-6 production and didnt reverse IL-2 and IL-4 production. Endotoxin tolerance resulted in the significantly reduced production of IL-2 and $IFN-{\gamma}$ and the significantly increased production of IL-4 and IL-6. Indomethacin in endotoxin tolerance greatly augmented IL-2 production, significantly decreased IL-4 production, and slightly attenuated IL-6 production. These findings indicate that endogenous PGE$_2$ may mediate the suppressed Th1 type immune response, with a shift toward a Th2 cytokine response in a state of endotoxin tolerance, whereas endotoxemia may be regulated differentially. Also, endogenous PGE$_2$ may mediate macrophage IL-6 production in the case of endotoxemia to a greater extent than in the case of endotoxin tolerance.

The development of the machine vision system to inspect the front-chassis module of an automobile (자동차 프런트 샤시 모듈 측정을 위한 머신 비전 시스템 개발)

  • 이동목;이광일;양승한
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2003.04a
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    • pp.245-250
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    • 2003
  • Today, automobile world market is highly competitive. In order to strengthen the competitiveness, quality of automobile is recognized as important and efforts are being made to improve the quality of manufactured components. The directional ability of automobile has influenced on driver directly and hence it must be solved on the preferential basis. In the present research an automated vision system has been developed th inspect the front chassis module. To interpret the inspection data obtained for front chassis module, new interpreting algorithm have been developed. Previously the control of tolerance front chassis module was done manually. With the help of the new algorithm developed, the dimension is calculated automatically to check whether the front chassis module is within the tolerance limit or not.

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내성 및 의존성 형성 약물의 약효 검색

  • 김학성;오기완
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1993.04a
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    • pp.77-77
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    • 1993
  • 약물 내성 (tolerance) 및 의존성 (dependence)은 그 약물이 지니고 있는 여러 가지 약리작용과 관련되어 형성된다. 약물의 반복투여 후, 나타나는 작용이 처음의 반응 (response) 보다 감소되어 나타나는 현상 즉, 내성과, 이와는 반대로 약물반복 투여 후 나타나는 작용이 처음의 반응보다 점점 증가하는 역내성 (reverse tolerance 또는 sensitization) 측정에 있어서 약물에 따라 적절한 검색 방법을 설명한다. 의존성에 있어서 약물 섭취 결과 mood가 변하거나 도취감 또는 만족감을 일으키게 되면 그 감각을 재 경험하고 싶다는 욕구가 일어나게 되는 정신적 의존성(psychic dependence)과, 약물을 반복 투여하다가 갑자기 투여를 중단 했을때 여러가지 생리학적인 또는 행동적인 변화가 급격히 증가하여 금단증상을 나타내는 신체적 의존성 (physical dependence) 측정 방법을 제시한다. 내성과 의존성은 근본적으로 다르지만 대부분의 경우 내성이 형성되면 의존성이 형성된다. 여기서는 주로 morphine과 psychostimulants를 투여한 후 나타나는 약리작용에 대한 내성과 opioids (마약성 진통제)의 의존성 평가 방법에 대한 model을 설명하고자 한다 진통성 내성(analgesic tolerance)에 있어서 진통제의 진통력은 진통력 측정 방법(tail pinch, paw-withdrawal, tail flick, tail-withdrawal, hot plate, writhing, etc)에 따라 차이가 있기 때문에 각각의 진통제의 정합한 내성 측정 방법을 결정할 필요가 있다. 역내성 (roversetolerance)은 cocaine, amphetamine, opioids둥의 만성투여에서 일어난다. 이들 역내성을 측정하는 한 방법으로 자발운동을 측정하는데 locomotor activity cage나 tilting cage를 이용한다. 정신적 의존성(psychic dependence)은 약물 섭취 욕구를 이용한 CPP (conditioned place preference)법을 소개한다. 신체적 의존성 (physical dependence)은 opioids를 만성적으로 투여한 후 naloxone으로 precipitation하여 나타난 여러 가지 금단증상을 측정하고 몇몇 평가 model을 제시한다.

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Characterization of transcription factor genes related to cold tolerance in Brassica napus

  • Sharma, Mayur Mukut Murlidhar;Ramekar, Rahul Vasudeo;Park, Nam-Il;Choi, Ik-Young;Choi, Seon-Kang;Park, Kyong-Cheul
    • Genomics & Informatics
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    • v.19 no.4
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    • pp.45.1-45.8
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    • 2021
  • Brassica napus is the third most important oilseed crop in the world; however, in Korea, it is greatly affected by cold stress, limiting seed growth and production. Plants have developed specific stress responses that are generally divided into three categories: cold-stress signaling, transcriptional/post-transcriptional regulation, and stress-response mechanisms. Large numbers of functional and regulatory proteins are involved in these processes when triggered by cold stress. Here, our objective was to investigate the different genetic factors involved in the cold-stress responses of B. napus. Consequently, we treated the Korean B. napus cultivar Naehan at the 4-week stage in cold chambers under different conditions, and RNA and cDNA were obtained. An in silico analysis included 80 cold-responsive genes downloaded from the National Center for Biotechnology Information (NCBI) database. Expression levels were assessed by reverse transcription polymerase chain reaction, and 14 cold-triggered genes were identified under cold-stress conditions. The most significant genes encoded zinc-finger proteins (33.7%), followed by MYB transcription factors (7.5%). In the future, we will select genes appropriate for improving the cold tolerance of B. napus.

Delaunay triangulation for efficient reduction of measured point data (측정데이터의 효율적 감소를 위한 De Iaunay 삼각형 분할의 적용)

  • 허성민;김호찬;이석희
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.53-56
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    • 2001
  • Reverse engineering has been widely used for the shape reconstruction of an object without CAD data and it includes some steps such as scanning of a clay or wood model, and generating some manufacturing data in an STL file. A new approach to remove point data with Delaunay triangulation is introduced to deal with the size problems of STL file and the difficulties in the operation of RP process. This approach can be used to reduce a number of measuring data from laser scanner within a specified tolerance, thus it can avoid the time for handing point data during modeling process and the time for verifying and slicing STL model during RP process. Developed software enables the user to specify the criteria for the selection of group of triangles either by the angle between triangles or the percentage of triangles reduced, and thus RP models with accuracy will be helpful to automated process.

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Simulation of Sintering for the Complex Ceramic Bodies by NASTRAN

  • Lee, Sang-Ki;Kim, Hyung-Jong;Lee, June-Gunn
    • The Korean Journal of Ceramics
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    • v.5 no.3
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    • pp.235-238
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    • 1999
  • In a ceramic green body, some degree of nonuniformity in density always presents. These differences in green density will appear as nonuniform shrinkage after sintering takes place. For the complex ceramic bodies with various curves and angles, therefore, it is quite difficult to foresee the final dimensions precisely after sintering. This simulation study shows that, considering the sintering process as a thermal shrinkage phenomenon, the use of NASTRAN enables to predict the precise shape of a sintered body. Based on this result, 'the reverse engineering technique' has been developed that can unfold the exact dimensions of a green body to have the desired shape after sintering. This approach will provide a simple and useful tool for ceramic engineers to fabricate complicate bodies with tight dimensional tolerances.

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Determination of Methamphetamine and its Metabolite Amphetamine in Biological Fluids from 11 Fatal Gases

  • Yoo, Young-Chan;Chung, Hee-Sun;Choi, Hwa-Kyung
    • Archives of Pharmacal Research
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    • v.16 no.3
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    • pp.175-179
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    • 1993
  • Gas chromoatography with flame ionization detector (FID) along with mass spectrometry (GC/MS) were used for the screening and quantification of methamphetamine (MA) and its major metabolite, amphetamine (AM0, in blood and urine in eleven fatal cases in which MA abuse was suspected. Postmortem blood MA varied from $0.5-30.2\;\mu{g/ml}$, while Am levels ranged from none detected (6 of 11 cases) to 4.8 .mu.g/ml. Additionally, distribution studies were performed in three of these cases in which tissue smaples were available for evaluation. Liver contained the highest ocncentration of MA among the tissu samples. In eight of the eleven cases, when no other direct cause of death was evident (i.e. 3 cases of traumatic dath0, either no blood AM was found or the ratio of MA/AM was 3.4 or greater. These data are consistent with acute MA use followed by death due to acute drug intoxication or by the occurrence of hypersensitivity and reverse seen in cases of chronic drug abuse.

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