• 호남수학학술지
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• 제29권3호
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• pp.341-350
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• 2007

A dynamical system with a skew-commuting involution map is called a flip system. Every flip system on a subshift of finite type is represented by a pair of matrices, one of which is a permutation matrix. The transposition number of this permutation matrix is studied. We define an invariant, called the flip number, that measures the complexity of a flip system, and prove some results on it. More properties of flips on subshifts of finite type with symmetric adjacency matrices are investigated.

• 한국수학교육학회지시리즈C:초등수학교육
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• 제17권3호
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• pp.231-251
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• 2014

수치와 단위는 서로 동떨어진 것이 아니며, 단위는 수치의 의미를 명확히 하는 역할을 한다. 학생들이 해결해야하는 많은 문제에는 단위가 포함되는데, 문제해결 과정에서 관찰된 학생들은 연산 결과의 의미 이해에 어려움을 겪고 있었다. 이러한 현상의 현황을 확인하기 위해 초등학교 6학년 2개반 52명을 대상으로 검사지를 투입하여 그 실태를 파악하여 분석하였는데, 이들에게도 역시 단위는문제에 주어져 있는 것일 뿐, 단위를 연산의 의미 이해와 연결 짓지 못하였다. 이 연구에서는 이와 같은 결과를 토대로 기존의 교수학적 변환이 갖는 특징과 한계를 살펴보고, 연산 결과의 의미 이해 측면에서 단위가 갖는 이점을 고찰해 봄으로써 상황과 관련한 해석에 있어 단위가 갖는 효력을 구체화하였다. 특히 단위 연산 가능성을 허용한 교수학적 변환에 대한 구체적 논의와 시사점을 제안함으로써, 교수 학습에서 변화의 불가피성을 강조함과 동시에 실질적 도움을 제공하고자 하였다.

• 식물조직배양학회지
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• 제22권5호
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• pp.241-260
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• 1995

Transposons, present in the genomes of all living organisms, are genetic element that can change positions, or transpose, within the genome. Most genomes contain several kinds of transposable elements and the molecular details of the mechanisms by which these transposons move have recently been uncovered in many families of transposable elements. Transposition is brought about by an enzyme known as transposaese encoded by the autonomous transposon itself, but, in the unautonomous transposon lacking the gene encoding the transposase, movement occurs only at the presence of the enzyme encoded by the autonomous one. There are two types of transposition events, conservative and replicative transposition. In the former the transposon moves without replication, both strands of the DNA moving together from one place to the other while in the latter the transposition frequently involves DNA replication, so one copy of transposon remains at its original site as another copy insole to a new site. The insertion of transposon into a gene can prevent it expression whereas excision from the gene may restore the ability of the gene to be expressed. There are marked similarities between transposons and certain viruses having single stranded Plus (+) RNA genomes. Retrotransposons, which differ from the ordinary transposons in that they transpose via an RNA-intermediate, behave much like retroviruses and have a structure of integrated retrovial DNA when they are inserted to a new target site. An insertional mutagenesis called transposon-tagging is now being used in a number of plant species to isolate genes involved in developmental and metabolic processes which have been proven difficult to approach by the traditional methods. Attempts to device a transposon-tagging system based on the maize Ac for use in heterologous species have been made by many research workers.

• 한국식물학회:학술대회논문집
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• 한국식물학회 1999년도 제13회 식물생명공학심포지움 New Approaches to Understand Gene Function in Plants and Application to Plant Biotechnology
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• pp.11-15
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• 1999

In order to evlauate feasibility of the gene tagging by the maize transposable element Ac in heterologous plant systems, we have investigated physical distances and directions of transposition of the element in Arabidopsis thaliana and tobacco cultured cell line BY-2. We prepared a T-DNA construct that carried a non-autonomous derivative of Ac with a site for cleavage by endonuclease I-Scel (designated dAc-I-RS element). Another cleavage site was also introduced into the T-DNA region outside dAc-I-RS. A number of transgenic Arabidopsis plants were generated, each of which had a single copy of the T-DNA at a different chromosomal location. To examine the pattern of transposition, three out of these transgenic plants were crossed with the Arabidopsis plant that carried the gene for Ac transposase and progeny in which dAc-I-RS had been transposed were isolated. After digestion of the genomic DNA of these progeny with I-SceI, sizes of segment of DNA were determined byd pulse-field gel electrophoresis. We also performed linkage analysis for the transposed elements and sites of mutations near the elements. Our results with three transgenic lines showed that 50% of all transposition events had occurred within 1,700 kilo-base pairs (kb) on the same chromosome, with 35% within 200 kb, and that the elements transposed in both directions on the chromosome with roughly equal probability. The data thus indicate that the Ac-Ds system is most useful for tagging of genes that are present within 200 kb of the chromosomal site of Ac in Arabidopsis. In addition, determination of the precise localization of the transposed dAc-I-RS element should definitely assist in map-based cloning of genes around insertion sites. In the present paper, we report typical examples of such gene isolation studies.

• Journal of Chest Surgery
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• 제32권8호
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• pp.749-752
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• 1999

최근 여러 병원에서 선천성 수정대혈관전위의 해부학적 교정이 보고되고 있다. 해부학적 교정을 받은 수 정대혈관전위 환아의 단기 및 장기추적에서 문제가 되는 것은 주로 심방전환수술에 따르는 대정맥과 심방 문합 부\ulcorner의 협착과 상심실성 부정맥이며 이는 심방이 작은 경우에 위험도가 증가되고 특히 심첨과 대정맥 이 동측에 있는 경우에는 문제가 된다. 이런 경우 이중전환수술시 일부 선택된 환아에서 대정맥폐동맥단락 술을 추가함으로써 수술의 위험성과 심방의 잠재성 합병증을 피할 수 있다고 여겨진다. 본원에서는 수정대 혈관전위, 심실중격결손, 폐동맥폐쇄가 있으면서 심첨과 대정맥이 동측에 있는 환아의 해부학적 교정시에 대 정맥폐동맥단락술을 추가하여 좋은 결과를 얻었기에 보고하는 바이다.

• Journal of Chest Surgery
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• 제25권6호
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• pp.630-636
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• 1992

From August 1990 through December 1991, 14 patients[all males] underwent int-rathoracic muscle transposition of extrathoracic skeletal muscles to treat empyemas, 6 patients had tuberculous empyemas, 4 had chronic empyemas of unknown etiology, 3 had pos-tpneumonectomy empyemas, and 1 had postlobectomy empyema. 9 patients had associated bronchopleural fistulas, Their ages ranged from 22 to 67 years, with mean age of 45.1$\pm$17. 6[$\pm$S.D] years. The serratus anterior was transposed in 13 patients, the latissimus dorsi in 12. In 11 patients, both the serratus anterior and the latissimus dorsi were transposed. The omental flap also transposed in 3 patients. To reduce the dead space in the thoracic cavity, thr-oacoplasty was also carried out in 10 patients. The number of the partially resected ribs was 3.0$\pm$0.8[$\pm$S.D.]. All operations were single stage procedures, and all wounds were closed primarily, with no permanent tubes or chest wall openings. There was no hospital mortality, and so no subsequent operation has been required. Follow-up of the patients ranged from 5 to 16 months with a mean of 9.2$\pm$3.1[$\pm$S.D] months, All the patints had no further signs or symptoms of the original infection after discharge. We conclude that intrathoracic transposition of extrathoracic skeletal muscle is an excellent method of treatment for persistent, life-threatening intrathoracic infections.

• Journal of Plant Biotechnology
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• 제5권1호
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• pp.19-23
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• 2003

The Ac (activator) which is one of the well-characterized transposable elements from maize was examined for its transposition possibility to the heterologous plant (P.nigra x maximowiczii) genome via Agrobacterium tumefacience (LBA4404) mediated transformation system. A number of transgenic plants were successfully recovered after 30 weeks by amount reduction from 50 to 15 g/$m\ell$ kanamycin for in vitro selection to minimize phytotoxic effects and to increase callus growth and regeneration efficiency. Among transgenic plants, 62 out of 106 transgenic poplars (58.5%) showed abnormal phenotypes such as severe serrated leaves and light leaf coloration. Indigo staining with X-gluc proved indirectly the restoration of Gus enzyme function and the presence of Ac in poplar genome by PCR. Southern analysis indicated the transposition and existence of Ac element in poplar genomes. In this research, an Agrobacterium-mediated transformation system in poplar species was developed and identified that Ac derived from maize can be excised and trans posed into other poplar genomes.

• Korean Journal of Radiology
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• 제22권3호
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• pp.308-323
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• 2021

An increasing number of adult congenital heart disease (ACHD) patients continue to require life-long diagnostic imaging surveillance using cardiac CT and MRI. These patients typically exhibit a large spectrum of unique anatomical and functional changes resulting from either single- or multi-stage palliation and surgical correction. Radiologists involved in the diagnostic task of monitoring treatment effects and detecting potential complications should be familiar with common cardiac CT and MRI findings observed in patients with repaired complex ACHD. This review article highlights the contemporary role of CT and MRI in three commonly encountered repaired ACHD: repaired tetralogy of Fallot, transposition of the great arteries after arterial switch operation, and functional single ventricle after Fontan operation.

• Journal of Korean Neurosurgical Society
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• 제66권1호
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• pp.90-94
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• 2023

Objective : Cubital tunnel syndrome, the most common ulnar nerve entrapment neuropathy, is usually managed by simple decompression or anterior transposition. One of the concerns in transposition is damage to the nerve branches around the elbow. In this study, the location of ulnar nerve branches to the flexor carpi ulnaris (FCU) was assessed during operations for cubital tunnel syndrome to provide information to reduce operation-related complications. Methods : A personal series (HJY) of cases operated for cubital tunnel syndrome was reviewed. Cases managed by transposition and location of branches to the FCU were selected for analysis. The function of the branches was confirmed by intraoperative nerve stimulation and the location of the branches was assessed by the distance from the center of medial epicondyle. Results : There was a total of 61 cases of cubital tunnel syndrome, among which 31 were treated by transposition. Twenty-one cases with information on the location of branches were analyzed. The average number of ulnar nerve branches around the elbow was 1.8 (0 to 3), only one case showed no branches. Most of the cases had one branch to the medial head, and one other to the lateral head of the FCU. There were two cases having branches without FCU responses (one branch in one case, three branches in another). The location of the branches to the medial head was 16.3±8.6 mm distal to the medial epicondyle (16 branches; range, 0 to 35 mm), to the lateral head was 19.5±9.5 mm distal to the medial epicondyle (19 branches; range, -5 to 30 mm). Branches without FCU responses were found from 20 mm proximal to the medial condyle to 15 mm distal to the medial epicondyle (five branches). Most of the branches to the medial head were 15 to 20 mm (50% of cases), and most to the lateral head were 15 to 25 mm (58% of cases). There were no cases of discernable weakness of the FCU after operation. Conclusion : In most cases of cubital tunnel syndrome, there are ulnar nerve branches around the elbow. Although there might be some cases with branches without FCU responses, most branches are to the FCU, and are to be saved. The operator should be watchful for branches about 15 to 25 mm distal to the medial epicondyle, where most branches come out.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제16권1호
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• pp.12-20
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• 1994

Generally, the totally paralyzed face can never be made normal by any of the current methods of reconstruction. Careful selection of patients based on sound judgment of what can and cannot be achieved by the proposed surgical technique is paramount to a successful operation and a satisfied patient. The results are related to time of delayed between injury and repair ; the shorter the delay the better are the results. The objectives in correcting facial paralysis are to achieve normal appearance at rest ; symmetry with voluntary motion ; control of the ocular, oral, and nasal sphincter ; symmetry with involuntary emotion and controlled balance when expressing when expressing emotion ; and no significant functional deficit secondary to the reconstructive surgery. It must be employed a number of concepts, for treatment of the paralyzed face by surgeon, depending on the cause, time interval, and wound characteristics, as well as the availability of and necessity for neuromuscular substitution. Nerve grafts, crossovers, muscle transfers, free muscle and nerve-muscle grafts, micronuerovascular muscle transfers, and regional muscle transposition are the principal methods being developed. We applied the temporal musle transposition for reanimation of unilatrally paralyzed faces for long times on two patients. The results of muscle transposition can be enhanced by the patient's learning to activate the transposed muscle by voluntary effort, and are best in patients who are motivated to learn the necessary motor-sensory coordination techniques.