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      • KCI등재

        척수소뇌성 운동실조증 제7형

        정선용,장석훈,김현주,Seon-Yong, Jeong,Seok-Hun, Jang,Hyon-J., Kim 대한의학유전학회 2007 대한의학유전학회지 Vol.4 No.1

        The autosomal dominant spinocerebellar ataxias (SCAs) are a group of neurodegenerative diseases, clinically and genetically heterogeneous, characterized by degeneration of spinocerebellar pathways with variable involvement of other neural systems. At present, 27 distinct genetic forms of SCAs are known: SCA1-8, SCA10-21, SCA23, SCA25-28, DRPLA (dentatorubral-pallidoluysian atrophy), and 16q-liked ADCA (autosomal dominant cerebellar ataxia). Epidemiological data about the prevalence of SCAs are restricted to a few studies of isolated geographical regions, and most do not reflect the real occurrence of the disease. In general a prevalence of about 0.3-2 cases per 100,000 people is assumed. As SCA are highly heterogeneous, the prevalence of specific subtypes varies between different ethnic and continental populations. Most recent data suggest that SCA3 is the commonest subtype worldwide; SCA1, SCA2, SCA6, SCA7, and SCA8 have a prevalence of over 2%, and the remaining SCAs are thought to be rare (prevalence <1%). In this review, we highlight and discuss the SCA7. The hallmark of SCA7 is the association of hereditary ataxia and visual loss caused by pigmentary macular degeneration. Visual failure is progressive, bilateral and symmetrical, and leads irreversibly to blindness. This association represents a distinct disease entity classified as autosomal dominant cerebellar ataxia (ADCA) type II by Harding. The disease affectsprimarily the cerebellum and the retina by the moderate to severe neuronal loss and gliosis, but also many other central nervous system structures as the disease progresses. SCA7 is caused by expansion of an unstable trinucleotide CAG repeat in the ATXN7 gene encoding a polyglutamine (polyQ) tract in the corresponding protein, ataxin-7. Normal ATXN7 alleles contain 4-35 CAG repeats, whereas pathological alleles contain from 36->450 CAG repeats. Immunoblott analysis demonstrated that ataxin-7 is widely expressed but that expression levels vary among tissues. Instability of expanded repeats is more pronounced in SCA7 than in other SCA subtypes and can cause substantial lowering of age at onset in successive generations termed ‘anticipation’ so that children may become diseased even before their parents develop symptoms. The strong anticipation in SCA7 and the rarity of contractions should have led to its extinction within a few generations. There is no specific drug therapy for this neurodegenerative disorder. Currently, therapy remains purely symptomatic. Cellular models and SCA7 transgenic mice have been generated which constitute valuable resources for studying the disease mechanism. Understanding the pathogenetic mechanisms of neurodegeneration in SCAs should lead to the identification of potential therapeutic targets and ultimately facilitate drug discovery. Here we summarize the clinical, pathological, and genetic aspects of SCA7, and review the current understanding of the pathogenesis of this disorder. Further, we also review the potential therapeutic strategies that are currently being explored in polyglutamine diseases.

      • 다상유동 해석을 위한 전산수치해석 방법의 특성 및 연구사례

        정선용 ( Seon-yong Jeong ),이석호 ( Seok-ho Rhi ),이계복 ( Kye-bock Lee ) 충북대학교 산업과학기술연구소 2016 산업과학기술연구 논문집 Vol.30 No.1

        Multiphase flows with particles and droplets cover a wide range of applications. Because of the wide variety and importance of multiphase flows in industrial processes, the exact analysis of multiphase flow is required. Computational fluid dynamics is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. CFD technique is very powerful and spans a wide range of industrial areas. Application of CFD results in industrial research and design crucially hinges on confidence in its outcomes. There have been significant advances in the science and technology of multiphase flows because of enhanced computational capabilities. Computational fluid dynamics is the analysis of systems involving fluid flow, heat transfer and associated phenomena such as chemical reactions by means of computer-based simulation. The primary objective of this work is to review an characteristics of the CFD numerical methods suitable for the multiphase flows and to present the research cases for practical applications.

      • CFD 해석을 이용한 막여과 공정 밸브의 개폐시간에 따른 유동 특성

        정선용 ( Seon-yong Jeong ),이계복 ( Kye-bock Lee ) 충북대학교 산업과학기술연구소 2018 산업과학기술연구 논문집 Vol.32 No.2

        A device that opens or closes the passage of a fluid for the purpose of controlling the flow, pressure and temperature of the fluid in a pipe is called a valve. Hydraulic actuator is a primary component of the hydraulic valve systems. Actuators are installed on these valves to convert power into mechanical outputs such as force or torque to allow the loads of valves to be operated remotely or automatically controlled. As the opening and closing time of the valve varies depending on the type of actuator used, the characteristics of the pressure and velocity distribution depending on the valve opening and closing time are compared using computational fluid dynamics analysis. The flow characteristics of around the valve in the pipe and at the pipe exit were analyzed for the valves with opening times of the valves of 3 seconds and 7 seconds. The velocity and pressure distribution at the exit of the tube are almost the same regardless of the opening time of the valve.

      • KCI등재

        여아 환자에서의 취약 X 증후군의 분자유전학적 진단

        정선용(Seon-Yong Jeong),양정아(Jeong-A Yang),김현주(Hyon J. Kim) 대한의학유전학회 2008 대한의학유전학회지 Vol.5 No.1

        목적 : 취약 X 증후군(fragile X syndrome)은 FMR1 유전자의 5' 비해독부위에 있는 CGG 3염기 반복의 확장에 의해 발생되는 유전성 질환이다. 방법 : 본 연구에서는 임상 소견과 핵형분석에서 취약 X 증후군으로 진단 받은 여아 환자와 그 부모를 대상으로 Abbott Molecular Fragile X PCR Kit를 이용하여 CGG 3염기 영역을 PCR로 증폭하여 normal, premutation, full mutation의 CGG 반복의 유형을 확인하였으며, premutation과 normal allele의 경우에는 정확한 CGG 반복수를 분석하였다. 결과 : 환자는 30회와 >200회의 CGG 3염기가 반복된 FMR1 대립유전자를 갖고 있는 것으로 확인되어 취약 X 증후군으로 진단되었다. 또한 환자의 어머니에서 30과 98회의 반복 allele을 확인함으로써, 이 환자의 full mutation allele은 모계의 premutation allele로부터 유래한 것임을 알 수 있었다. 결론 : Abbott Molecular Fragile X PCR Kit를 사용한 진단방법은, 취약 X 증후군환자의 경우에서 통상적으로 시행되고 있는 PCR, MS-PCR, Southern blotting을 병행하는 방법에 비해 신속하고 정확한 분자유전학적 진단이 가능한 유용한 방법이라 생각된다. Purpose : Fragile X syndrome (FXS) is the most common heritable cause of cognitive impairment. FXS is caused by hyperexpansion and hypermethylation of a polymorphic CGG trinucleotide repeat in the 5' untranslated region of the fragile X mental retadation-1(FMR1) gene. Combination of Southern blotting and simple polymerase chain reaction(PCR) amplification of the FMR1 repeat region is commonly used for diagnosis in females. To give a definite diagnosis in a female child suspected of having FXS, we carried out the molecular diagnostic test for FXS using the recently developed Abbott Molecular Fragile X PCR Kit. Methods : The PCR amplification of the FMR1 repeat region was performed using the Abbott Mdecular Fragile X PCR Kit. The amplified products were analyzed by size-separate analysis on 1.5% agarose gels and by DNA fragment analysis using Gene scan. Results : Agarose gel and Gene scan analyses of PCR products of the FMR1 repeat region showed that the patient had two heterozygous alleles with a normal 30 repeats and full mutation of >200 repeats whereas her mother had two heterozygous alleles with the normal 30 repeats and premutation of 108 repeats, suggesting that the premutation of 108 repeats in her mother may have led to the full mutation of >200 repeats in the patient. Conclusion : We diagnosed FXS in a female patient using a simplified molecular diagnostic test. This commercially available diagnostic test for FXS, based on PCR, may be a suitable alternative or complement method to Southern blot analysis and PCR analysis and/or methylation specific(MS)-PCR analysis for the molecular diagnosis of FXS in both males and females.

      • 액체상 이젝터의 노즐직경 변화에 따른 2차측 액체 유동 특성

        정선용 ( Seon Yong Jeong ),이계복 ( Kye Bock Lee ),이석호 ( Seok Ho Rhi ) 충북대학교 산업과학기술연구소 2015 산업과학기술연구 논문집 Vol.29 No.2

        An ejector is used to supply a secondary flow via the ejection of a primary flow. It is utilized in many industrial fields, and is used for mixing the fluids because of less failures and simple structure. The liquid ejector is also applied in many industry but few study has been performed. In this study, numerical simulation and experiment of a liquid-liquid ejector were carried out to analyze the influence of nozzle diameter on the performance of ejector using the commercial code FLUENT. The simulation results showed that the mass flow rates of the secondary flow were influenced by the nozzle diameter of the liquid ejector. From the experimental results, the validity of CFD results was confirmed.

      • 로타리 댐퍼의 주요 설계인자 영향

        정선용 ( Seon-yong Jeong ),이계복 ( Kye-bock Lee ) 충북대학교 산업과학기술연구소 2018 산업과학기술연구 논문집 Vol.32 No.1

        Rotary damper utilizes the braking force generated by the oil's viscosity resistance. The braking force generated by oil viscosity, clearance between the rotor and the main body and the oil’s contact area varies based on the structure. The torque of a rotary damper varies according to the ambient temperature. This is because the viscosity of the oil inside the damper changes according to the temperature. The braking torque of a rotary damper varies according to the cycle rate. In general, the torque increases when the cycle rate increases, and the torque decreases when the cycle rate decreases. In this study, the effects of each design variables such as gap clearance, rotation speed, viscosity and the amount of oil for generating the torques were investigated by numerical simulation analysis.

      • KCI등재

        관내 혼화장치의 오리피스 형상과 개수에 따른 혼화 및 유동특성

        정선용(Jeong, Seon Yong),정원식(Chung, Won Sik),이석호(Rhi, Seok Ho),이계복(Lee, Kye Bock),이대규(Lee, Dae Gyu) 한국산학기술학회 2017 한국산학기술학회논문지 Vol.18 No.2

        본 연구에서는 혼화기의 혼화성능과 압력손실을 개선하기 위해 오리피스의 형상과 개수에 따른 영향을 해석하였다. 물의 정수에서 중요한 과정은 물속의 이물질을 포집하는 응집 과정이고 응집제가 얼마나 물속에 고른 분포를 가지고 물속에 혼화되어 있는 지가 정수에 큰 영향을 미친다. 기계식 혼화방식이 갖는 정수과정에서의 긴 체류시간, 기계 소음, 과다한 에너지의 소비 및 높은 유지관리 비용 등의 단점을 보완하기 위해서 최근에는 응집제가 원수에 주입됨과 동시에 가능한 한 빠르게 수중에 확산시킬 수 있는 장치로서 관내혼화장치의 도입이 증가추세에 있다. 본 연구에서는 관내 혼화기의 혼화성능과 압력손실을 개선하기 위해 오리피스의 유무, 형상과 개수에 따른 약품의 체적분률, 관내 압력손실 등 유동특성과 체적분률이 수치해석에 의해 계산된다. 관내 혼화장치에 장착된 오리피스는 혼화정도를 향상시키나 압력손실이 증가되므로 오리피스의 개수를 제한하여야 한다. 주요 인자에 대한 민감도 분석을 통해 가이드 베인을 장착한 오리피스 1개를 사용하여 약품의 체적분률과 압력손실이 개선된 관내 혼화장치를 제안하였다. This study examines the effect of the type and number of orifices in an in-line mixer to improve the mixing performance and pressure loss. Recently, in-line non-power-consuming mixers have been increasingly used to complement mechanical mixers, which have a long dwell time, noise, excessive energy consumption, and high maintenance costs. An in-line mixer with an orifice for efficient mixing in water treatment was examined by numerical analysis using the commercial code FLUENT. The flow characteristics of pressure loss and velocity distribution within the mixer and the mixing efficiency were compared with and without the orifices. The CFD results show that the mixing efficiency was improved, but the pressure loss was increased by the in-line mixer with an orifice. A sensitivity study was also done on the principal parameters.

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