Functional cortical neurons and astrocytes from human pluripotent stem cells in 3D culture

Paş,ca, Anca M,Sloan, Steven A,Clarke, Laura E,Tian, Yuan,Makinson, Christopher D,Huber, Nina,Kim, Chul Hoon,Park, Jin-Young,O'Rourke, Nancy A,Nguyen, Khoa D,Smith, Stephen J,Huguenard, John R,Ge Nature Publishing Group 2015 NATURE METHODS Vol. No.

The human cerebral cortex develops through an elaborate succession of cellular events that, when disrupted, can lead to neuropsychiatric disease. The ability to reprogram somatic cells into pluripotent cells that can be differentiated in vitro provides a unique opportunity to study normal and abnormal corticogenesis. Here, we present a simple and reproducible 3D culture approach for generating a laminated cerebral cortex–like structure, named human cortical spheroids (hCSs), from pluripotent stem cells. hCSs contain neurons from both deep and superficial cortical layers and map transcriptionally to in vivo fetal development. These neurons are electrophysiologically mature, display spontaneous activity, are surrounded by nonreactive astrocytes and form functional synapses. Experiments in acute hCS slices demonstrate that cortical neurons participate in network activity and produce complex synaptic events. These 3D cultures should allow a detailed interrogation of human cortical development, function and disease, and may prove a versatile platform for generating other neuronal and glial subtypes in vitro.

Effect of Strontium and Magnesium Additions on the Microstructure and Mechanical Properties of Al–12Si Alloys

Ali Paşa Hekimoğlu,Merve Çalış,Gizem Ayata 대한금속·재료학회 2019 METALS AND MATERIALS International Vol.25 No.6

In this study, a binary Al–12Si, eight ternary Al–12Si–Sr, and six quaternary Al–12Si–0.1Sr–(0.2–1)Mg alloys were producedby permanent mold casting. It was observed that microstructure of the binary alloy consisted of the phases of aluminum richα grains (dendrites), primary silicon, plate like β and eutectic Al–Si containing needle like silicon particles. The ternaryalloys have fine and globular (modified) eutectic silicon particles and higher volume fraction of α (Al) dendrites than binaryalloys. They also contained Al4Srphase after 0.02 wt% Sr, in addition to the phases in the binary alloy. This phase got coarsewhen the strontium ratio exceeded 0.1%. It was observed that the plate like β phase seen in the binary alloys transformed intothe fibrous form δ phase in the ternary alloys. Magnesium addition resulted in transformation of δ phase into script like πphase, and the formation of lamellar like Mg2Siphase when the ratio of it in the quaternary alloys reached the 0.6 wt%. Thelamellar like form of Mg2Siphase changed to Chinese-script type after the 0.6 wt% Mg. The results showed that hardness,yield and tensile strength of the Al–12Si–Sr alloys increased with increasing strontium content up to 0.1 wt%. The resultsalso showed that hardness of the quaternary alloys increased with increasing magnesium content, while yield and tensilestrength increased only up to 0.6 wt% Mg.

Some existence results on periodic solutions of ordinary (q,p)-Laplacian systems

Daniel Paşca,Chun-Lei Tang 한국전산응용수학회 2011 Journal of applied mathematics & informatics Vol.29 No.1

Some existence theorems are obtained for periodic solutions of nonautonomous second-order differential systems with (q,p)-Laplacian by the minimax methods in critical point theory.

SOLVING OF THERMOPLASTIC-CARBON BONDING ISSUE USING NUMERICAL SIMULATIONS

Paweł Paździor,Mirosław Szczepanik 한국자동차공학회 2021 International journal of automotive technology Vol.22 No.2

The aim of this study was to elaborate on the methods of constructing combined components of a car mirror. The components were made of materials with different thermal expansion coefficient. The basis for the research were numerical simulations prepared in Moldex 3D software. The external cover of a mirror would be made of carbon composite based on epoxy resin (hereafter referred to as carbon), and the internal insert would be made of ABS. The adhesive bonding applied did not provide appropriate properties and led to breaks during usage. After carrying out moldflows it was found that the areas of breaks were determined by the places where fronts of flowing material met during the injection. The cause of breaking was diametrically different thermal expansion of both materials. This induced significant stresses in the adhesive layer. Finally, the effective solution was to change the geometry of the mirror insert made of thermoplastic ABS.

명승 내 사찰 경관 조성을 위한 산내암자 관리 방안

( Chong Chul Pa다 ),( Hak Beom Kim ),( Youn Soon Hong ) 한국전통조경학회(구 한국정원학회) 2014 Journal of Korean Institute of Traditional Landsca Vol.12 No.-

명승은 경치가 좋기로 이름난 경승지로서, 역사적?예술적?경관적 가치가 크며, 자연미가 빼어나게 아름다울 뿐만 아니라 그 형성과정에서 비롯된 고유성?희귀성?특수성이 큰 곳이다. 명승은 1970년부터 지정되기 시작하였고, 명승의 개념에 문화유산 개념이 포함되면서 문화유산 지정 속도가 가속화 되었다. 문화유산으로서 명승 지정이 급속히 이루어지면서, 지정 후 보존 및 관리에 관한 문제가 지속적으로 발생하였고, 명승의 개념과 기존 문화유산에 대한 정의가 제고되면서, 사찰을 포함한 사적 및 명승이 명승으로 지정종목이 재분류되었다. 사적 및 명승과 명승의 이원적으로 제시되었던 보전 방안들은 사찰경관 형성이라는 차원에서 제고되어야 하며, 이를 위해서는 사찰과 사찰 내 산내암자에 대한 연구가 이루어져야 할 것이다. 따라서 본 연구에서는, 2009년 12월 사적 및 명승에서 명승으로 지정종목이 재분류된 명승 5개소에 조성된 산내암자들을 대상으로, 첫째, 사찰과 산내암자의 정체성과 특이성을 규명하였고, 둘째, 각 대상지별 산내암자의 현황과 규모, 문제점등을 조사하였다. 이러한 산내암자의 현황을 파악하고 문제점을 분석하여, 사찰경관을 조성하기 위한 산내암자 관리방안을 제시하였다. Scenic sites refer to venues that are known to have beautiful landscapes as well as historic and artistic value. Not only do they stand out in terms of the natural landscape, but their unique characteristics that came into form during the site`s formation also give it special value. Scenic sites in Korea were first designated in the 1970s, and the pace picked up as the concept of scenic sites came to incorporate that of cultural heritage. With increased designation of scenic sites, issues of preservation and management of these sites, as well as the definition of existing cultural heritage sites became a constant issue. This led to a reclassification of the “historic site and scenic site” category into the “scenic site” category. Preservation measures that took different approaches to the category of “historic site and scenic site” and the “scenic site” category need to be revised within the larger framework of managing the landscape of temples. To that end, more research needs to be undertaken on temples and temples set against a natural landscape. As such, this study reviews the current status and issues of five scenic sites where Buddhist temples have been formed. These five scenic sites were reclassified from the category of “historic site and scenic site” to the category of “scenic site”. The results is follows: First, the identity and uniqueness of the main temple. Second, the mountain temple were identified. The review is used to suggest measures of managing the Buddhist temples within these scenic sites.

새론운 회전자검출 방법에 의한 8/6 스위치드 리럭턴스 모터 속도 제어

박영록(Y.R. Pa가),정도영(D.Y. Jung),이봉섭(B.S. Lee),이상호(S. H. Lee),천동진(D.J. Cheon) 전력전자학회 2002 전력전자학술대회 논문집 Vol.- No.-

This paper proposed new techniques of rotor position detection for Switched Reluctance Motor(SRM). This technique is very simple and easy to find out rotor position. The main idea uses the impulse responses which have different values between aligned and unaligned. in order to obtain the rotor position, the impulse applied to the unenergized phases and their responses are analized to control the speed of SRM without shaft sensor. experimental results verify the feasibility of the proposed method

연구논문 : 피히테와 Aufforderung: 『학문론의 원리들에 의한 자연권의 기초(1796/97)』를 중심으로

백훈승 ( Hun Seung Pa다 ) 한국동서철학회 2014 동서철학연구 Vol.72 No.-

이 글은 피히테(J.G. Fichte)의 실천철학의 핵심개념들 가운데 하나인 촉구(促求, Aufforderung)문제를 그의 『학문론의 원리에 의한 자연권의 기초』(Grundlage des Naturrechts nach den Principien der Wissenschaftslehre, 1796/97)를 중심으로 다룬다. 특히, 이 개념이 그의 이론철학의 대표작인 『전 학문론의 기초』(Grundlage der gesamten Wissenschaftslehre, 1794/95)에서 등장하는 ‘추구(追求, Streben)’ 및 ‘저지(沮止, Anstoß)’ 개념과 갖는 연관성 및 그것이 그의 공동체 이론, 승인이론, 자유개념, 그리고 교육과 맺고 있는 연관성을 해명한다. This essay treats Aufforderung (Summon), which is one of the central concepts in Fichte`s practical philosophy, focused on Foundations of Natural Right according to the Principles of the Wissenschaftslehre (Grundlage des Naturrechts nach den Principien der Wissenschaftslehre, 1796/97). This concept is discussed especially in relation to the concepts: Strife (Streben), Check (Anstoss) in Foundations of the Science of Knowledge (Grundlage der gesamten Wissenschaftslehre, 1794/95). Moreover the relation between ``Aufforderung`` and his theories of Community (Gemeinschaft), Recognition (Anerkennung), Freedom (Freiheit) and Education (Erziehung) ist elucidated.

보문 : 홍삼 섭취량에 따른 피부상태 변화에 관한 연구 -30대 여성의 목피부를 중심으로-

백혜연 ( Hye Yeon Pa다 ) 대한미용학회(구 대한미용과학회) 2014 대한미용학회지 Vol.10 No.3

This study is a comparative research of women`s neck skin condition in 30`s aaccording to the intake dose of red ginseng which is famous for the enhancement of immunity level, high anti-oxidative activity, and promotion of blood circulation. The experimental groups are total 21 women in 30`s which were divided into 7 persons each group; intake group of 3 g red ginseng, intake group of 6 g red ginseng, and control group. The subjects took the daily amount of red ginseng in the morning before having breakfast once a day. The changes of moisture capacity, melanin index, and erythema index of central parts of front and rear neck, left neck, and right neck were observed for 12 weeks. The average moisture capacity in G3 and G6 groups increased 10% and 14%, respectively, compared to the control group. The average melanin index in G3 and G6 groups decreased 10% and 11%, respectively, compared to the control group. The average erythema index in G3 and G6 groups decreased 10% and 11%, respectively, compared to the control group. As a result of observation the skin condition in each neck area, 3 g intake of red ginseng was enough to represent sufficient effect on reduction of melanin index and erythema index and on increase in moisture capacity. It could be confirmed that 3 g intake of red ginseng was more efficient in terms of economic aspects than 6 g intake of red ginseng in women in thirties.

학교자치의 활성화 방안

백종섭 한국지방행정연구원 1999 地方行政硏究 Vol.13 No.1

The school autonomy is an important factor in the education autonomy. Education autonomy has been in force from 1991 in Korea, but many people say that there are several controversial problems. Therefore Kim DaeJung government endeavors to reform the controversial issues. This article makes an attempt to suggest alternatives for improving the school autonomy. It is important that the school committee which consists of the teachers, pupils, parents and community should be operated in a democratic way. It is necessary to improve and activate the school autonomy by means of the decentralization of the educational administration, the chief teacher system, an institution that a principal is elected by the school committee. Likewise the principle that a principal is the chairman of the committee and the establishment of the teacher council, pupil council and parents council should be prescribed by the statute. It is very important for all of us to realize that participation and autonomy are valuable for the development of the school autonomy.

진리의 의미와 소재

백종현 서울대학교철학과 1992 哲學論究 Vol.20 No.-