• Applied Microscopy
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• 제26권1호
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• pp.79-93
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• 1996

The differentiation of nail matrix and fine structure of matrix cells were studied with light and electron microscope using specimens from nails of thumb finger in Korean fetuses 14 to 24 weeks old. Fetal nail matrix consisted of two horizontal layers, thicker ventral and thinner dorsal matrices, originating from invagination of epidermis in proximal nail field. Matrix being generally thicker in its distal region than the apex became gradually thickened with increase of the fetal age. Each matrix consisted of single layer of basal cells and multiple layers of squamous cells which are arranged close to and parallel to the central axis of the nail mairix. The process of keratinization of fetal nail matrix was noted to be occured concurrently in the ventral and dorsal matrices along the central axis of matrix toward distal and dorsal direction. Squamous cells became matured with accumulation of tonofilaments, increase of keratohyalin granules, discharge of membrane coating granules, and narrowing of intercellular spaces, thickening of plasma membrane and finally being transformed into horny cells of nail plate. Horny cells of nail plate filled with fibrous elements in the electron dense amorphous substance. These findings of keratinization process of fetal nail matrix appeared to be similar to those of keratinization in epidermis and inner root sheath of the hair. In the nail matrix, however, corresponding region to the keratogenous zone of growing hair follicle was not observed. Vacuolated squamous cells of nail matrix seen on light microscopy was considered to be artefactual product, but squamous cells with condensed small nuclei rarely found adjacent nail plate was considered to be one of the squamous cells with unknown function. Proximal end of nail plate was observed on dorsal surface of nail field distal to the proximal nail fold at 14 and 16 weeks old human embryos. Proximal prolongation of the proximal end of nail plate was occured with advancing fetal age and afterward 21 weeks nail plate invaded into nail matrix. Melanin granule containing cells and Merkel cells were present only on the basal layer of dorsal nail matirx.

• Archives of Plastic Surgery
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• 제46권4호
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• pp.344-349
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• 2019

Background Lymphaticovenous anastomosis is an important surgical treatment for lymphedema, with lymphaticovenous side-to-end anastomosis (LVSEA) and lymphaticovenous end-to-end anastomosis being the most frequently performed procedures. However, LVSEA can cause lymphatic flow obstruction because of regurgitation and tension in the anastomosis. In this study, we introduce a novel and simple procedure to overcome this problem. Methods Thirty-five female patients with lower extremity lymphedema who underwent lymphaticovenous anastomosis at our hospital were included in this study. Eighty-five LVSEA procedures were performed, of which 12 resulted in insufficient venous blood flow. For these 12 anastomoses, the proximal lymphatic vessel underwent clipping after the anastomotic procedure and the venous inflow was monitored. Subsequently, the proximal ligation after side-to-end anastomosis recovery (PLASTER) technique, which involves ligating the proximal side of the lymphatic vessel, was applied. A postoperative evaluation was performed using indocyanine green 6 months after surgery. Results Despite the clipping procedure, three of the 12 anastomoses still showed poor venous inflow. Therefore, it was not possible to apply the PLASTER technique in those cases. Among the nine remaining anastomoses in which the PLASTER technique was applied, three (33%) were patent. Conclusions Our findings show that achieving patent anastomosis is challenging when postoperative venous inflow is poor. We achieved good results by performing proximal ligation after LVSEA. Thus, the PLASTER technique is a particularly useful recovery technique when LVSEA does not result in good run-off.

• 대한심미치과학회지
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• 제31권2호
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• pp.47-55
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• 2022

임플란트 수복 후 발생하는 인접면 공간개방으로 인한 식편압입은 임플란트를 시술한 환자에게 매우 흔히 발생하는 현상이다. 이는 임플란트와 치아의 움직임 기전이 달라 발생하며 시간이 경과하면 30-60% 정도 발생하는데, 기여요인으로는 악골(하악), 부위(구치부), 인접치(실활치) 및 대합치(자연치 또는 임플란트) 등이 있다. 이런 현상을 방지할 수는 없으나 최소화하기 위한 노력을 기울여야 한다. 가급적 이상적인 인접접촉을 가지도록 상부 1/3에 협설로 인접치와 대칭적인 인접면 형태를 만들어 주기 위해 오목한 형태나 하방이 풍융한 인접치 형태를 수정하고 수복할 때는 다른 조건을 수정하여 변연융선의 높이를 맞추어 주어야 한다. 불규칙한 교합평면은 예후를 나쁘게 하는 원인이므로 정출된 대합치를 수정하고 기능이상을 유발하는 원심협측 교두를 수정함으로써 이상적인 교합평면을 회복함으로써 식편압입 현상을 최소화시켜야 한다.

• Geomechanics and Engineering
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• 제29권4호
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• pp.391-405
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• 2022

A newly proposed grouting simulation method, the sequential diffusion solidification method was introduced into the numerical simulation of combined bi-borehole grouting. The traditional, critical and difficult numerical problem for the temporal and spatial variation simulation of the slurry is solved. Thus, numerical simulation of grouting and blocking of flowing water in karst conduits is realized and the mechanism understanding of the combined bi-borehole technology is promoted. The sensitivity analysis of the influence factors of combined bi-borehole grouting was investigated. Through orthogonal experiment, the influences of proximal and distal slurry properties, the initial flow velocity of the conduit and the proximal and distal slurry injection rate on the blocking efficiency are compared. The velocity variation, pressure variation and slurry deposition phenomenon were monitored, and the flow field characteristics and slurry outflow behavior were analyzed. The interaction mechanism between the proximal and distal slurries in the combined bi-borehole grouting is revealed. The results show that, under the orthogonal experiment conditions, the slurry injection rate has the greatest impact on blocking. With a constant slurry injection rate, the blocking efficiency can be increased by more than 30% when using slurry with weak time-dependent viscosity behavior in the distal borehole and slurry with strong time-dependent viscosity behavior in the proximal borehole respectively. According to the results of numerical simulation, the grouting scheme of "intercept the flow from the proximal borehole by quick-setting slurry, and grout cement slurry from the distal borehole" is put forward and successfully applied to the water inflow treatment project of China Resources Cement (Pingnan) Limestone Mine.

• Restorative Dentistry and Endodontics
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• 제47권2호
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• pp.15.1-15.18
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• 2022

This review aimed to characterize the effect of direct restorative material types and adhesive protocols on marginal adaptation and the bond strength of the interface between the material and the proximal dentin/cementum. An electronic search of 3 databases (the National Library of Medicine [MEDLINE/PubMed], Scopus, and ScienceDirect) was conducted. Studies were included if they evaluated marginal adaptation or bond strength tests for proximal restorations under the cementoenamel junction. Only 16 studies met the inclusion criteria and were included in this review. These studies presented a high degree of heterogeneity in terms of the materials used and the methodologies and evaluation criteria of each test; therefore, only a descriptive analysis could be conducted. The included studies were individually evaluated for the risk of bias following predetermined criteria. To summarize the results of the included studies, the type of restorative material affected the test results, whereas the use of different adhesive protocols had an insignificant effect on the results. It could be concluded that various categories of resin-based composites could be a suitable choice for clinicians to elevate proximal dentin/cementum margins, rather than the open sandwich technique with resin-modified glass ionomers. Despite challenges in bonding to proximal dentin/cementum margins, different adhesive protocols provided comparable outcomes.

• The Korean Journal of Physiology
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• 제30권2호
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• pp.249-256
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• 1996

The effect of probenecid on the transport of tetraethylammonium (TEA) was studied in renal cortical slices and isolated membrane vesicles to investigate the interaction of organic anion with the organic cation transport system in proximal tubule. Probenecid reversibly inhibited TEA uptake by renal cortical slices in a dose-dependent manner over the concentration range of 1 and 5 mM. The efflux of TEA was not affected by the presence of 3 mM probenecid. Kinetic analysis indicated that probenecid decreased Vmax without significant change in Km. Probenecid inhibited significantly tissue oxygen consumption at concentrations of 3 and 5 mM. However, probenecid did not significantly reduce TEA uptake in brush border and basolateral membrane vesicles prepared from renal cortex even at a concentration as high as 10 mM. These results indicate that probenecid reduces TEA uptake in cortical slices by inhibiting tissue metabolism rather than by an interaction with the organic ration transporter.

• 한국수학교육학회지시리즈A:수학교육
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• 제44권1호
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• pp.41-65
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• 2005

In this paper we make an experiment in order to test whether the teaching method with the Zone of Proximal Development (ZPD) developed by Vygotsky can be more effective and well applied in the middle school pratces. Based on this investigation, we conclude that ZPD help to efficiently enhance the study of students, in particular, the inferior student group. Moreover, if we divide the student by more precise stoups, the ZPD will be more effective on teaching and learning in middle school. Lastly, we arrive at the conclusion that a continuous teaching with ZPD will improve the student attitude positively in solving mathematical problem even it does not appeared apparently on this test.

• Clinics in Shoulder and Elbow
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• 제17권4호
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• pp.197-200
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• 2014

Reports of osteomyelitis in the proximal humerus with pyogenic glenohumeral arthritis of adjacent joints mostly involve pediatric patients. Nowadays, osteomyelitis that is secondary to adjacent pyogenic glenohumeral arthritis is extremely rare, even more so in adults than in pediatrics. We report a rare case of the pyogenic glenohumeral arthritis followed by osteomyelitis of the proximal humerus in an elderly patient. Initially, we diagnosed a case of pyogenic glenohumeral arthritis only, which, despite arthroscopic synovectomy, did not resolve and severe pain continued. Subsequent radiological imaging, performed after our suspicion of a secondary involvement, allowed us to diagnose osteomyelitis combined with the pyogenic glenohumeral arthritis, which we had overlooked because of the extreme rarity of the condition in adults since the antibiotic era began.

• Journal of Korean Neurosurgical Society
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• 제30권1호
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• pp.66-72
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• 2001

Apatient with multiple dissecting aneurysms of a posterior inferior cerebellar artery trunk who presented with SAH is reported. A 58-year-old woman presented with sudden occipital headache, dizziness and vomiting. The intial vertebral angiography revealed a suspicious pearl and string sign at the proximal posterior inferior cerebellar artery(PICA) segment. After 2 weeks, follow up angiography showed a progression of the proximal PICA dissection and newly developed dissecting aneurysm of the distal PICA segment. A far lateral suboccipital transcondylar appoach confirmed two dissecting aneurysms at distant sites of the PICA trunk. The dissection segments were wrapped with muslin wrap, which preserved the flow through the PICA and brain stem perforators. The angiographys at 3 weeks and 6 months after operation revealed serial disappearance of the dissecting aneurysms which is distal to proximal. The diagnosis, course and treatment of the dissecting aneurysms of the PICA are discussed with literature review.

• 대한약학회:학술대회논문집
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• 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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• pp.236.2-237
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• 2002

Proximal femur fracture is known as one of the major medical problems in terms of mortality. disability and economic costs. To assess the association between the use of corticosteroids and proximal femur fracture. a cohort study was conducted upon Korean elderly women. (omitted)