• 한국노년학
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• 제30권4호
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• pp.1377-1392
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• 2010

본 연구는 농촌여성노인들이 체험하는 여가생활의 의미와 본질이 무엇인지 이해하고, 그들의 삶의 과정에 있어서 여가생활이 어떤 영향과 의미를 주는지 밝혀내어 건강과 관련된 간호중재 개발을 위한 기초자료를 제공하는데 목적을 두고 있다. 연구방법은 질적연구방법으로 van Manen의 해석학적 현상학적 분석방법을 사용하였다. 그 결과 농촌여성노인이 체험하는 여가생활은 '어울림을 통해 외로움 극복하기', '몸을 활용해 심신(心身)의 조화 이루기', '내 힘으로 자식(子息)의 짐 덜어주기', '무료한 세월보내기', '소소한 즐거움 찾기', '새로운 것을 익히며 뿌듯함 얻기', '세상과 소통하며 살아가기' 등의 7개의 본질적 주제를 도출하였다. 농촌여성노인이 체험하는 여가생활은 자연과 동화되면서, 건강과 사회관계를 유지하는 것으로 나타났다. 또한 농촌의 사회·경제적 특성으로 인한 외로움과 소외감 등을 연배노인들과 어울리며, 이를 극복하기 위한 시간임을 확인할 수 있었다.

• Educational Technology International
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• 제13권2호
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• pp.257-281
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• 2012

This study aims to examine individual perceptions and lived experiences of the Net generation of student teachers and the previous generation of teachers about their technology use in education. The participants of this study include 106 pre-service teachers and 50 in-service teachers from one teacher education university in Korea. Employing a mixed methodology, we first empirically examined the participants' perceptions toward multiple variables related to technology use in education, namely (a) past ICT experiences in schools, (b) personal computer use, (c) constructivist belief, (d) computer efficacy, (e) attitude toward computer in education, and (f) prospective computer use. In addition, we conducted face-to-face interviews with selected participants for the in-depth investigation of their lived experiences about technology use, beliefs, and attitude. Results indicate that there are significant differences between in-service and pre-service teachers in their prior experiences with technology in schools. However, the pre-service and in-service teachers did not differ significantly in their beliefs, attitude and other technology-related variables, which may indicate the danger of generational determinism in the Net Generation debate. The analysis of interview narratives revealed two major themes about the interplay of one's agency and structural changes in the participants' lived experiences with technology use in education: (a) transition from negative past experiences to opportunities for positive computer use, and (b) attitudes formation and change through apprenticeship experiences and structural influences. In conclusion, this study suggests that the Net Generation debate should move beyond dichotomous or techno-centric thinking. There is a critical need to pay more attention to develop deeper understandings of the fundamental diversity existing within the generation itself. Implications for teacher education are also discussed.

• Steel and Composite Structures
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• 제51권1호
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• pp.73-91
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• 2024

This paper has focused on presenting vibration analysis of trapezoidal sandwich plates with a damaged core and FG wavy CNT-reinforced face sheets. A damage model is introduced to provide an analytical description of an irreversible rheological process that causes the decay of the mechanical properties, in terms of engineering constants. An isotropic damage is considered for the core of the sandwich structure. The classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. The First-order shear deformation theory of plate is utilized to establish governing partial differential equations and boundary conditions for the trapezoidal plate. The governing equations together with related boundary conditions are discretized using a mapping-generalized differential quadrature (GDQ) method in spatial domain. Then natural frequencies of the trapezoidal sandwich plates are obtained using GDQ method. Validity of the current study is evaluated by comparing its numerical results with those available in the literature. After demonstrating the convergence and accuracy of the method, different parametric studies for laminated trapezoidal structure including carbon nanotubes waviness (0≤w≤1), CNT aspect ratio (0≤AR≤4000), face sheet to core thickness ratio (0.1 ≤ ${\frac{h_f}{h_c}}$ ≤ 0.5), trapezoidal side angles (30° ≤ α, β ≤ 90°) and damaged parameter (0 ≤ D < 1) are carried out. It is explicated that the damaged core and weight fraction, carbon nanotubes (CNTs) waviness and CNT aspect ratio can significantly affect the vibrational behavior of the sandwich structure. Results show that by increasing the values of waviness index (w), normalized natural frequency of the structure decreases, and the straight CNT (w=0) gives the highest frequency. For an overall comprehension on vibration of laminated trapezoidal plates, some selected vibration mode shapes were graphically represented in this study.

• Archives of Plastic Surgery
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• 제50권6호
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• pp.627-634
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• 2023

In recent decades, a number of simulation models for microsurgical training have been published. The human placenta has received extensive validation in microneurosurgery and is a useful instrument to facilitate learning in microvascular repair techniques as an alternative to using live animals. This study uses a straightforward, step-by-step procedure for instructing the creation of simulators with dynamic flow to characterize the placental vascular tree and assess its relevance for plastic surgery departments. Measurements of the placental vasculature and morphological characterization of 18 placentas were made. After the model was used in a basic microsurgery training laboratory session, a survey was given to nine plastic surgery residents, two microsurgeons, and one hand surgeon. In all divisions, venous diameters were larger than arterial diameters, with minimum diameters of 0.8 and 0.6 mm, respectively. The majority of the participants considered that the model faithfully reproduces a real microsurgical scenario; the consistency of the vessels and their dissection are similar in in vivo tissue. Furthermore, all the participants considered that this model could improve their surgical technique and would propose it for microsurgical training. As some of the model's disadvantages, an abundantly thick adventitia, a thin tunica media, and higher adherence to the underlying tissue were identified. The color-perfused placenta is an excellent tool for microsurgical training in plastic surgery. It can faithfully reproduce a microsurgical scenario, offering an abundance of vasculature with varying sizes similar to tissue in vivo, enhancing technical proficiency, and lowering patient error.

• 수산해양기술연구
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• 제60권3호
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• pp.217-227
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• 2024

To analyse and review the fishing performance and species composition according to the size of the entrance and mesh of the pot in the southern coastal waters (Tongyeong, Gyeongsangnam-do and Yeosu, Jeollanam-do), the experiment in this study caught one class, eight orders, 17 families, 23 species, 662 fishes, and 99,833 g. The largest number of fish species was Conger myriaster (301 fishes caught) accounting for 45.5%, followed by Octopus vulgaris (152) accounting for 23.0%, Charybdis japonica (45) accounting for 6.8%, Sebastiscus marmoratus (43) accounting for 6.5%, and Parapercis sexfasciata (42) accounting for 6.3%. Conger myriaster, Octopus vulgaris, Charybdis japonica, Sebastiscus marmoratus, and Parapercis sexfasciata accounted for 88.1% of the total catch. For other fish species, 68 fishes of 18 species were caught, accounting for 12.5% of the total. As a result of the total catch survey, the catch rate of Conger myriaster was the highest at 50.9% in B. 22 mm/280 mm. In addition, the average total length per fish increased as the entrance size increased. The weight ratios of Conger myriaster, Octopus vulgaris, and other fish species based on the total weight caught in each pots of the six species of test fishing gear are as follows. A pots 66.6%, 26.5%, 6.9%, B pots 57.2%, 24.5 %, 18.3%, C pots 43.2%, 31.5%, 25.3%, D pots 7.4%, 56.7%, 35.9%, E pots 43.6%, 0%, 56.4%, and F pots 5.0%, 79.6%, 15.4%.

• Journal of Veterinary Science
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• 제25권5호
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• pp.60.1-60.6
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• 2024

Importance: Alzheimer's disease (AD) is the most common cause of dementia in the elderly with the incidence rising exponentially after the age of 65 years. Unfortunately, effective treatments are extremely limited and definite diagnosis can only be made at autopsy. This is in part due to our limited understanding of the complex pathophysiology, including the various genetic, environmental, and metabolic contributing factors. In an effort to better understand this complex disease, researchers have employed nonhuman primates as translational models. Case Presentation: This report aims to describe the AD-like neuropathology in the brain of a 37-year-old female baboon (Papio hamadryas), which at the time of her death made her the oldest hamadryas baboon at any member institution of the Association of Zoos and Aquariums. A diagnostic necropsy was performed, and the brain was evaluated for neurodegenerative disease. Frequent amyloid-β deposits were identified, consistent with what has been described in other geriatric nonhuman primates. Phospho-tau pathology, including neurofibrillary tangles, a feature not well-described in other primate models, was also abundant. Conclusions and Relevance: Our results suggest that more detailed, prospective, longitudinal studies are warranted utilizing this particular species to see if they represent a viable model for human brain aging.

• 동아시아식생활학회지
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• 제24권1호
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• pp.53-61
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• 2014

본 연구에서는 다양한 발효균 starter를 이용한 당화 혼합곡물 음료 개발의 가능성을 확인하고자 하였다. 혼합곡물의 수분 흡수 지수를 측정한 결과, 쌀 60분, 차조 120분, 기장 120분, 메밀 120분, 수수 180분으로 나타났다. 7종의 균주와 2가지의 혼합 균주를 이용하여 제조된 발효균 starter의 당화력은 0.13~3.58 units/g으로 형성되었다. Starter를 이용하여 제조한 당화 혼합곡물 음료의 가용성 고형분($^{\circ}Brix$)은 당화가 진행되는 동안 증가하는 것이 관찰되었고, 15시간 동안 당화를 진행하는 것이 효율적인 것으로 평가되었으며, C sample에서 $17.55{\pm}0.05$로 가장 높게 관찰되었다. 수분 함량은 77.9~80.7%로 높게 나타났으며, 조단백질, 조지방, 조회분 함량은 3.7~7.5%, 0.37~0.97%, 1.81~7.47%로 다양하게 나타났다. 음료의 점도를 측정한 결과, 60~528.3 CP로 다양하게 나타났다. 또한 음료의 유리아미노산을 측정한 결과, 아르기닌과 필수 아미노산이 다양하게 함유되어 있는 것으로 나타났다. 그 중 G sample에서 필수 아미노산으로 알려진 루신, 이소루신, 발린, 트레오닌과 단맛을 나타내는 알라닌, 라이신, 세린의 함량이 다른 당화 음료보다 높게 분석되었다. 이와 같은 결과는 발효균 starter가 가지는 고유의 효소 활성에 따라 나타난 것으로 예상된다. 이와 같이 Aspergillus oryzae CF1003, Asp. acidus KACC46420, Rhizopus delemar KACC-46149, Rhz. oryzae KACC45714, Rhz. oryzae KACC46148, Asp. oryzae CF1001, Asp. acidus CF1005의 7가지 균주 각각을 이용하여 제조한 starter와 이 균주들을 혼합한 starter를 이용한 당화물의 제조에 관한 기초 자료와 일반 성분을 검토함으로써 혼합곡물을 이용한 기능성 식품 개발을 위한 기초 자료를 제시하였다.

• Clinical and Experimental Reproductive Medicine
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• 제26권1호
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• pp.9-20
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• 1999

The genetic defects in human gametes and embryos can cause adverse effects on overall reproductive events. Biopsy of embryos for preimplantation genetic diagnosis (PGD) offers a new possibility of having children free of the genetic disease. In addition, advanced embryo culture method may enhance the effectiveness of embryo biopsy for the practical application of PGD. This experimental study was undertaken to evaluate the effects of coculture on the development in vitro of biopsied mouse embryos as a preclinical model for PGD of human embryos. Embryos were obtained after in vitro fertilization (IVF) from F1 hybrid mice (C57BLfemale/CBAmale). Using micromanipulation, 1, 2, 3 or 4 blastomeres of 8-cell stage embryos were aspirated through a hole made in the zona pellucida by zona drilling (ZD) with acidic Tyrode's solution (ATS). After biopsy of blastomeres, embryos were cultured in vitro for 110 hours in Ham's F-10 supplemented with 0.4% BSA or cocultured on the monolayer of Vero cells in the same medium. The frequence of blastocyst formation were recorded, and the embryos beyond blastocyst stage were stained with 10% Giemsa to count the total number of nuclei in each embryo. There was no significant difference in the blastocyst formation between the zona intact control group and the zona drilling (ZD) only, or biopsied groups. The hatching rate of all the treatment groups except 4/8 group was significantly higher than that of control group. In all the treatment groups, there was a significant reduction in the mean cell number of embryos beyond blastocyst stage ($50.2{\pm}14.0$ in control group vs. $41.2{\pm}7.9$ in ZD, $39.3{\pm}8.8$ in 7/8, $29.7{\pm}6.4$ in 6/8, $25.1{\pm}5.7$ in 5/8, and $22.1{\pm}4.3$ in 4/8 groups, p<0.05). When the same treatments were followed by coculture with Vero cells, a similar pattern was seen in the blastocyst formation and the hatching rate. However, in all the treatment groups, there was a significant increase in the mean cell number of embryos beyond blastocyst stage with coculture, compared with the parallel groups without coculture. In the cleavage rate of biopsied blastomeres cultured for 110 hours after IVF, there was no significant difference between coculture and non-coculture groups (87.2% vs. 78.7%). However, the mean cell number of embryos developed from the biopsied blastomeres was significantly higher in coculture group ($11.5{\pm}4.7\;vs.\;5.9{\pm}1.9$, p<0.05). In conclusion, biopsy of mouse embryos after ZD with ATS is a safe and highly efficient method for PGD, and coculture with Vero cells showed a positive effect on the development in vitro of biopsied mouse embryos and blastomeres as a preclinical model for PGD of human embryos.

• 생약학회지
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• 제3권3호
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• pp.151-160
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• 1972

Recent achievements of scientific research on the pharmacologic activities and the chemical problems of dammalene glycosides, which are considered to be effective principles of Korean ginseng, are reviewed and analyzed in view of structure-activity relationship. 1) S. Shibata and his co-workers detected 12 glycoside spots of dammalene series on the two dimensional T.L.C. of total glycoside fraction from Japanese ginseng, and designated them Ginsenoside Rx(x=a, b, c, g, h, etc.) in the order of increasing Rf-value. The aglycones of those glycosides were characterized to be protopanaxadiol for the Ginsenoside $Rx(x=a,\;b_{1},\;b_{2},\;c,\;d,\;e,\;f)$ and protopanaxatriol for the Ginsenoside $Rx(x=g_{1},\;g_{2},\;g_{3},\;h_{1}\;'h_{2})$. Using Korean ginseng as the material for our study, the author and his coworkers isolated a new dammalene glycoside(Panax Saponin C), which comes under the category of protopanaxadiol glycosides based on the classification of S. Shibata et al., and characterized this saponin to be the glycoside of protopanaxatriol series. Furthermore, Panax Saponin C dissociated into $two\;components(C_{1}\;and\;C_{2}-acetate)$ by acetylation, both of which returned to original Panax Saponin C by deacetylation. Based on this result, more than 13 glycoside components of dammalene series will be expected in the Korean ginseng. 2) The structures of protopanaxadiol and protopanaxatriol, the genuine aglycones of dammalene glycosides, are fully established to be structural analogues by S. Shibata and his co-workers, therefore antagonistic and/or analogical activities will be expected for the pharmacologic activities of these glycoside series of structural analogues. K. Takaki and his co-workers found central nervous system (CNS) stimmulant activity from the glycosides of protopanaxatriol series and CNS-depressant activity from the glycosides of protopanaxadiol series. On the other hand, the author and his co-workers found stimmulating activity on the protein synthesis from both the series of dammalene glycosides with delayed and long-lasting characteristics. This delayed and long-lasting characteristics were also observed in the anti-inflammatory activity of glycosides of protopanaxatriol series on their time course tendency. For the convenience's sake of argument, pluralistic pharmacologic activities of dammalene glycosides, which were observed by many workers at various pharmacologic site, may be classified into two main categories; one is pan-cellular activity and the other is organ specific activity to the certain tissue which is a mass of cells differentiated to a certain direction for their special functions in the body. Based on the data of K. Takaki and those of the authors, following assumption will be probable; Pharmacologic activities of both series of glycosides of protopanaxadiol and protopanaxatriol aglycones may be antagonistic on their tissue-specific activities and analogic on their pan-cellular activities. Therefore, the mixture of these two series of glycosides in an appropriate ratio, as the case of total extract of Korean ginseng, will be probably beneficial to the host by increasing the synthesis of some functional proteins, due to the additive action of pan-cellular activity, and with the disappearance of any significant behavioral symptoms due to the antagonism of tissue specific activity. This fact will probably be the main reason why classical trials of pharmacologists failed in re-discovering the efficacy of Korean ginseng with their behavioral test. 3) The author and his co-workers achieved the synthesis of $C^{14}-labelled\;Panax\;Saponin\;A\;on\;C_{25}-C_{27}\;position\;of\;aglycone$ in the interest of tracer studies in vivo. The method will be applicable to other dammalene glycosides regardless of their chemical structure. 4) The author and his co-workers converted chemically betulafolienetriol, a triterpene component of Betula platyphylla, to the protopanaxadiol, one of genuine aglycone of dammalene glycosides.

• 농업과학연구
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• 제13권2호
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• pp.243-254
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• 1986

무논에서 쇄토작업후(碎土作業後)에 토양경도(土壤硬度)를 측정(測定)할 수 있는 낙하식(落下式) 원추형(圓錐形) 토양경도기(土壤硬度器)를 설계(設計) 제작(製作)(6종(種))하여 이를 공시(供試)콘(cone)으로한 1, 2차(次)의 기초실험(基礎實驗)을 통(通)하여 1개(個)의 콘을 선정(選定)한 다음, 이로써 전국(全國) 5개지역(個地域), 56개(個) 측점(測點)에서 이앙당시(移秧當時)의 토양경도(土壤硬度)를 콘의 관입심(貫入深)으로 조사(調査)하여 다음과 같은 결과(結果)를 얻었다. 1. 1차(次) 실험(實驗)에서 4종(種)의 공시(供試)콘을 만들어 답토양(沓土壤)을 3유형(類型)의 토괴(土塊) 토양(土壤)으로 나누어 콘의 관입심(貫入深)을 비교(比較) 측정(測定)한 결과(結果) A, B, C 콘 사이에는 차이(差異)가 없었고, D콘만이 유의차(有意差)가 있었다. 2. 2차(次) 실험(實驗)에서 2종(種)의 공시(供試)콘을 추가제작(追加製作)하여 1차(次) 실험(實驗)에서 사용(使用)한 공시(供試)콘과 함께 쇄사(碎士) 정지(整地)한 상태(狀態)의 답토양(沓土壤)에서 콘의 관입심(貫入深)을 비교(比較) 분석(分析)한 결과(結果) D콘만 차이(差異)가 있었고 나머지 A, B, C, E, F 콘 사이에는 유의차(有意差)가 없었으나, 이 중에서 반복간(反覆間)에 변화(變化)가 적은 F콘을 선정(選定)하였다. 3. 전국(全國) 5개지역(個地域) 56개(個) 포장(圃場)의 로우터리에 의(依)한 써래질 작업(作業) 직후(直後)의 토양경도(土壤硬度)는 공시(供試) cone의 관입심(貫入深)으로 11.0~14.4cm이며 평균(平均) 13.0cm로 나타났으며, 한편 이앙당시(移秧當時)는 9.2~13.7cm로 평균(平均) 11.2cm로 나타났다. 4. 이상(以上)의 결과(結果)와 같이 이앙(移秧) 준비(準備)를 위(爲)한 써래질 작업(作業) 직후(直後)의 과다(過多)한 쇄토작업(碎土作業)은 토성(土性)에 따라 차이(差異)는 있으나 1~3일간(日間) 침지(沈地)시켜야만 동력(動力) 이앙기(移秧機)의 사용(使用)이 가능(可能)한 점을 본(本) 연구(硏究)에서 개발(開發)한 토양경도계(土壤硬度計)에 의(依)해 충분히 계측수량화(計測數量化) 할 수 있을 것으로 판단(判斷)된다.