• Clinical and Experimental Reproductive Medicine
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• 제28권2호
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• pp.79-86
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• 2001

Objective: Mouse pre-antral follicles require the addition of gonadotropins (Gns) to complete maturation and ovulation of oocyte and antrum formation in vitro. However, we tried examination of in vitro growth of mouse pre-antral follicles in medium without Gns and/or phygiological factors. And also, pre-antral follicles were isolated from ovaries by mechanical method. Our present studies were conducted to evaluate on the growth of follicles and intra-follicular oocytes and antrum formation in vitro of mouse pre-antral follicles in two different media. Methods: Pre-antral follicles ($91{\sim}120{\mu}m$) were isolated mechanically by fine 30G needles not using enzymes from ovaries of 3-6 week-old female ICR mice. Isolated pre-antral follicles were cultured in $20{\mu}l$ droplets of TCM (n=17; follicles: $107.8{\pm}1.58{\mu}m$; oocytes: $57.9{\pm}1.2{\mu}m$) or MEM (n=12; follicles: $109.3{\pm}2.53{\mu}m$; oocytes: $55.4{\pm}1.6{\mu}m$) under mineral oil on the 60 mm culture dish. All experimental media was supplemented with 10% FBS without Gns and/or physiological factors. Pre antral follicles were individually cultured for 8 days. Antram formation and growth of pre-antral follicles and intra-follicular oocytes were evaluated using precalibrated ocular micrometer at X200 magnifications during in vitro culture. Results were analyzed using combination of Student's t-test and Chi-square, and considered statistically significant when p<0.05. Results: Antrum formation had started in two culture media on day 2. On day 8, antrum formation had occurred in 58.3% of pre-antral follicles cultured in DMEM, but only in 23.5% of those cultured in TCM (p=0.0364). Growth of pre-antral follicles and intra-follicular oocytes were observed on day 4 and 8. On day 4, follicular diameter was similar (p=0.1338) in TCM ($119.4{\pm}2.58{\mu}m$) and MEM ($125.4{\pm}4.52{\mu}m$). However, on day 8, diameters of pre-antral follicles cultured in MEM ($168.9{\pm}17.29{\mu}m$) were significantly bigger (p=0.0248) than that in TCM ($126.7{\pm}4.28{\mu}m$). On day 4 and 8, diameters of intra-follicular oocytes were similar in TCM ($67.1{\pm}1.3$ and $72.4{\pm}0.9{\mu}m$) and MEM ($65.2{\pm}1.7$ and $73.3{\pm}1.5{\mu}m$), respectively. Conclusion: We can conform that medium without Gns and/or physiological factors can be used for in vitro antrum formation and growth of pre-antral follicles and intra-follicular oocytes in mouse. In conclusion, MEM supplemented with FBS can be used for growth in vitro of mouse pre-antral follicles isolated mechanically.

• 대한의생명과학회지
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• 제23권2호
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• pp.73-79
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• 2017

Pulse pressure is an independent risk factor for cardiovascular disease. The aim of the present study was to assess the association between pulse pressure and metabolic syndrome in Korean men. The study subjects were 8,439 adults aged 40 to 64 years, who underwent health screening examination from January 2012 to December 2014 at the Health Promotion Center of one hospital in Gyeonggi-do for general health check-up. They include the metabolic syndrome absent group (Absent, n=3,078), the pre-metabolic syndrome group (Pre-MetS, n=4,242) and the metabolic syndrome group (MetS, n=1,119). Progressive increase in pulse pressure was demonstrated for increasing components of the metabolic syndrome (P<0.001). The pulse pressure according to the degree of the metabolic syndrome was higher in the pre-MetS and MetS groups compared to the Absent group (P<0.001). Systolic and diastolic blood pressure, total cholesterol, triglyceride, fasting glucose, and abdominal obesity positively correlated with pulse pressure (P<0.001).

• 한국과학교육학회지
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• 제31권2호
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• pp.164-180
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• 2011

본 연구에서는 초등 예비교사들에게 아동의 과학 개념을 직접 조사하고 분석하는 활동을 안내하고 수행하도록 하면서 과학 교수 학습의 원리에 대해 예비 교사들이 탐구적으로 접근할 수 있는 기회를 제공하였다. 예비교사들의 탐구 과정을 자세히 살펴보고 이 과정에서 어떠한 긍정적 학습 경험이 있었는지 알아보고자 하는 것이 이 연구의 목적이다. 연구 대상은 C 교육대학교 2개 분반 68명이며 매주 90분씩 15주간 진행되는 '초등과학교육2' 강좌에서 실시되었다. 총 20모둠으로 구성하여 모둠별 프로젝트 형식으로 탐구 활동이 진행되었으며 설문, 수업 녹화 비디오, 수업일지, 모둠의 최종 보고서, 심층 면담자료 등이 분석되었다. 데이터 분석은 다중 사례 분석 방법을 통하여 사례 내 자료 분석과 사례 간 자료 분석과정을 거쳤다. 연구 결과 예비교사의 탐구 과정에서 다음과 같은 주요한 긍정적 학습 경험이 관찰되었다. 첫 번째로 예비교사가 아동의 과학 개념 조사를 준비하는 과정은 자신의 과학 개념을 점검하고 수정, 보완하는 계기가 되었다. 두 번째로 면담 질문을 구체화하면서 예비교사의 질문 구성 능력이 향상되었다. 세 번째로 예비교사들은 아동의 과학 개념이 다양하고, 상황에 따라 불안정하다는 것을 인식하였다. 네 번째로, 예비교사들은 아동의 과학 개념에 대한 조사를 바탕으로, 구체적인 지도 방안을 도출할 수 있었다.

• BMB Reports
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• 제29권2호
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• pp.180-182
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• 1996

One of the essential functions of virus surface proteins is the recognition of specific receptors on target cell membranes, and cellular receptors play an important role in viral pathogenesis. But the earliest steps of hepatitis B virus (HBV) infection, such as hepatocyte receptor interaction with the virus, are poorly understood. Previous work has suggested an important role of the preS1 region of HBV envelope protein in mediating viral binding to hepatocytes. Although hepatitis B virus (HBV) infection appears to be initiated by specific binding of virions to cell membrane structures via one or potentially several viral surface proteins, data showing the identification or isolation of the HBV receptor (s) are not yet available. The receptor-like proteins on the plasma membrane surface of HepG2 cells that bind to PreS1 were separated and identified using affinity chromatography, and the amino-terminal amino acid sequences of the receptor-like proteins were determined.

• 한국우주과학회:학술대회논문집(한국우주과학회보)
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• 한국우주과학회 2009년도 한국우주과학회보 제18권2호
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• pp.38.3-39
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• 2009

Equatorial Plasma Bubble (herafter, EPB) is a common feature in low-latitude F-region during the night time. Since EPB causes significant impacts on the satellite communication and navigation systems, its accurate forecast is highly demanded by the GNSS users. Thus, further understanding of these features and their configuration is a challenging issue in space weather studies. The day-to-day variability of the plasma bubble activity was investigated by analyzing the TIMED/GUVI, ROCSAT-1, DMSP, and CHAMP satellite data. The pre-reversal enhancement (PRE) is known as the most important single parameter for the onset of plasma bubbles but we do not know yet to what extent the day-to-day variability of the bubble activity can be attributed to the PRE. We obtained the magnitude of the PRE from ROCSAT-1 and the occurrence of bubbles in relation to the PRE was investigated by using the coincident observations of EPBs from TIMED/GUVI, DMSP, and CHAMP. By conducting one-to-one comparison of the PRE characteristics with the EPB occurrence we examined the role of the PRE in the onset of EPBs.

• 대한정형도수물리치료학회지
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• 제8권2호
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• pp.5-17
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• 2002

The aim of study carried out to determine the effects of myofascial release on the cranial arteries velocity from November 11, 2001 to March 29, 2002 the objects were 10 patients who having the tension-type headache at H-hospital This research compared with measure the mean flow velocity middle cerebral artery, posterior cerebral artery, vertebral cerebral artery. Result obtain were as follows; 1. Middle cerebral artery blood velocity between pre treatment and after treatment for 10days experiment was significantly increased 9.76cm/s(p<0.05)in right, 4.88cm/s(p<0.05)in left. 2. Posterior cerebral artery blood velocity between pre treatment and after treatment experiment was difference 6.35cm/s(p<0.01)in right, 5.14cm/s(p<0.01)in left, between pre treatment and after treatment for 5days experiment was 11.48cm/s(p<0.01)in right, 10.74cm/s(p<0.01)in left, between pre treatment and treatment for 10days experiment was 12.92cm/s(p<0.001) in right, 12.68cm/s(p<0.001) in left. 3. Vertebral artery blood velocity between pre treatment and post treatment experiment was difference 4.48cm/s(p<0.05)in right, 6.10cm/s(p<0.05) in left, between pre treatment and after treatment for 5days experiment was 12.50cm/s(p<0.001)in right, 14.40cm/s(p<0.001)in left, between pre treatment and after treatment for 10days experiment was 14.70cm/s(p<0.001)in right, 13.90cm/s(p<0.001)in left.

• 한국초등과학교육학회지:초등과학교육
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• 제31권1호
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• pp.109-124
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• 2012

Developing pedagogical content knowledge (PCK) has been emphasized for teacher's professionalism and it should be done from systematic teacher training courses. In this study, we investigated changes of elementary pre-service teachers' PCK of science teaching and motivational strategies before and after a training course. For the analysis of pre-service teachers' PCK, their lesson plans, surveys, and interviews were collected. According to the results, in the beginning of the semester, pre-service teachers in the experimental group usually used didactic or combination of didactic and inquiry teaching strategies and a few pre-service teachers used inquiry or discovery teaching strategies when making lesson plans. However, at the end of the semester many pre-service teachers used inquiry teaching strategies in their lessons which included activities of asking students' prior knowledge, conducing experiments, finding conclusion, and comparing teachers' explanations with students' explanations. Regarding motivational strategies, in the beginning of the semester they focused using activities to create student's emotional interest in science lesson but at the end they used other strategies to create positive atmosphere for learning, capture intellectual interest in science, and connect science to students' everyday lives. The changes in pre-service teachers' PCK in the experimental group was meaningful because there was less change in pre-service teachers' PCK in the control group. This study implies the need for effective professional development programs for developing pre-service teachers' PCK.

• East Asian mathematical journal
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• 제33권2호
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• pp.177-197
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• 2017

The purpose of this study is to investigate and analyze the understandings of elementary pre-service teachers about 'estimation' in the elementary mathematics. Together with this analysis, we identify elementary pre-service teacher's Mathematical Pedagogical Contents Knowledge(MPCK), especially focusing to Subject Matter Knowledge(SMK). In order to this goals, we investigate contents relating to 'estimation' from $1^{st}$ curriculum to 2009 revised curriculum and compare 'rounding up', 'rounding off', 'rounding' in the elementary mathematics textbooks. As results of investigations, 'estimation' has been teaching at the 'Measurement' domain from $3^{rd}$ curriculum, but contexts of measuring weaken from $7^{th}$ curriculum. 'Rounding up(off)' is defined three types in the textbooks from $1^{st}$ to 2009 revised curriculum. And we examine elementary pre-service teachers through the questions on these 'estimation' contents. On the analysis of pre-service teacher's understanding relating MPCK, four themes is summarized as followings; the understanding of '0' in the 'rounding up', the cognitive gap between 'rounding up' and 'rounding off', the difference of percentage of correct answers according to types of question in the 'rounding up', and the difference between the definition of 'rounding up' and the definition of 'rounding'.

• 한국의상디자인학회지
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• 제17권2호
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• pp.45-61
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• 2015

In order to analysis on color difference of natural dyes, I have dyed Hanji, cotton, silk fabric and exposed them to carbon arc light. The results of experiment have been analysed by wavelength of maximum absorption, amounts of dye uptake, color difference, Hunter's value and Munsell's value. Gardenia Jasminoides is monogenetic dye, but it gained darker color by pre-mordanting method used Al mordant agent and greenish yellow color by Fe mordant agent. whereas Curcuma, an Amur cork, and bud of pagoda tree are shown as greenish yellow color, and A barberry root, Betel nut, and Rhubarb are shown as reddish yellow color. these gained khaki colored dyed fabric by Fe mordanting. In addition, Sappan wood showed great result in pre-mordanting. Especially, it gained dark red color by Al pre-mordanting. The pink color was shown by post-mordanting. and Logwood showed great dyeing result in Hanji and cotton better than silk. Specially pre-mordanting was effective. Hanji and cotton showed greenish blue color by Al pre-mordanting, and silk showed brown color.

• 한국초등과학교육학회지:초등과학교육
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• 제34권1호
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• pp.58-71
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• 2015

Ability of understanding students' ideas and thinking is critical to teachers' professional growth. In this study, 'pedagogical reasoning' was conceptualized as teachers' reasoning ability of students' misconceptions and possible causes of misconceptions when they hear and observe students' science discourses. To investigate elementary pre-service teachers' pedagogical reasoning levels, children's science discourses on light reflection and electric circuit were video recorded and 43 pre-service elementary teachers were asked to identify children's misconceptions and possible causes of misconceptions after watching the video clips. In conclusion, pedagogical reasoning levels of pre-service elementary teachers were not high enough, showing significant difference in light reflection and electric circuit. Possible explanations of this difference and educational implications were discussed.