• 대한두개안면성형외과학회지
• /
• 제18권3호
• /
• pp.172-178
• /
• 2017

Background: The conventional cervicofacial flap may cause the aesthetic problem of sideburns with a mismatched shape and arrangement. We developed a modified method with the goals of minimizing the destruction of the shape and arrangement of the sideburns and minimizing complications in comparison with the conventional method. Methods: The incision line was designed to descend just in front of the sideburns, without passing through them, and then to ascend with the sideburns posteriorly when a cervicofacial flap is performed, unlike the conventional method. Patients in whom this method was applied (group B) and patients who underwent surgery using the conventional method (group A) were investigated in a retrospective study. The method was evaluated by assessing changes in the arrangement of the sideburns and patients' satisfaction, and differences in the complication rate. Results: In group A, 23 of the 31 patients experienced changes in the arrangement of their sideburns. Most patients who experienced a change in the arrangement of their sideburns were dissatisfied with the change. The patients in group B did not experience such changes, and the defects were well reconstructed. Most of them were satisfied with the final sideburn arrangement. Conclusion: A novel method was used to preserve the sideburns while performing a cervicofacial flap. As a result, the appearance of the sideburns was well preserved and the satisfaction of patients was also high. Moreover, this technique could also prove useful for reconstruction without any increase in complications compared to the conventional method.

• Archives of Plastic Surgery
• /
• 제45권1호
• /
• pp.62-68
• /
• 2018

Background Amputation is commonly performed for toe necrosis secondary to peripheral vascular diseases, such as diabetes mellitus. When amputating a necrotic toe, preservation of the bony structure is important for preventing the collapse of adjacent digits into the amputated space. However, in the popular terminal Syme's amputation technique, partial amputation of the distal phalanx could cause increased tension on the wound margin. Herein, we introduce a new way to resect sufficient bony structure while maintaining the normal length, based on a morphological analysis of the toes. Methods Unlike the pulp of the finger in the distal phalanx, the toe has abundant teardrop-shaped pulp tissue. The ratio of the vertical length to the longitudinal length in the distal phalanx was compared between the toes and fingers. Amputation was performed at the proximal interphalangeal joint level. Then, a mobilizable pulp flap was rotated $90^{\circ}$ cephalad to replace the distal soft tissue defect. This modified toe fillet flap was performed in 5 patients. Results The toe pulp was found to have a vertically oriented morphology compared to that of the fingers, enabling length preservation through cephalad rotation. All defects were successfully covered without marginal ischemia. Conclusions While conventional toe fillet flap coverage focuses on the principle of length preservation as the first priority, our modified method takes both wound healing and length into account. The fattiest part of the pulp is advanced to the toe tip, providing a cushioning effect and enough length to substitute for phalangeal bone loss. Our modified method led to satisfactory functional and aesthetic outcomes.

• 한국건축시공학회지
• /
• 제22권1호
• /
• pp.57-67
• /
• 2022

타워크레인은 기초 단면과 비교하여 상대적으로 불안정한 상부구조를 가지고 있어 사고위험성이 매우 크다. 현재 타워크레인 안전사고 저감을 위한 노력이 활발히 이루어지는 시점에 타워크레인의 안전성 확보를 위한 예방대책 수립이 필요하다. 따라서 본 연구의 목적은 타워크레인 안전성 확보를 위한 재해사례 분석 연구이다. 본 연구를 위해 2012년 7월부터 2020년 7월까지 한국산업안전보건공단에 접수된 타워 크레인 재해사례 260건을 대상으로 분석하였다. 그 결과, 작업 공종 중에서는 인양작업이 45.3%로 가장 높게 나타났으며, 재해 형태 중에서는 추락에 의한 사고가 35.8%로 가장 많이 발생하는 것으로 나타났다. 또한, 사고 발생원인은 작업방법 불량이 38.8%로 가장 높은 것으로 확인되었다. 향후 본 연구의 결과는 타워크레인 사고예방을 위한 정책수립에 기초자료로 활용될 것이다.

• Design & Manufacturing
• /
• 제16권3호
• /
• pp.9-15
• /
• 2022

In order to reduce the manufacturing costs of the glass lens, it is necessary to manufacture a lens using a UV curable resin or a thermosetting resin, which is a curable material, in order to replace a glass lens. In the case of forming a lens using a thermosetting material, it is necessary to form several lenses at once using the wafer-level lens manufacturing technologies due to the long curing time of the material. When a lens is manufactured using a curable material, an error in the shape of the lens due to the shrinkage of the material during the curing process is an important cause of defects. The major factors for these shape errors and deformations are the shrinkage and the change of mechanical properties in the process of changing from a liquid material during curing to a solid state after complete curing. Therefore, it is necessary to understand the curing process of the material and to examine the shrinkage rate and change of physical properties according to the degree cure. In addition, it is necessary to proceed with CAE for lens molding using these and to review problems in lens manufacturing in advance. In this study, the viscoelastic properties of the material were measured during the curing process using a rheometer. Using the results, Rheological investigation of cure kinetics was performed. At the same time, The shrinkage of the material was measured and simple mathematical models were created. And using the results, the molding process of a single lens was analyzed using Comsol, a commercial S/W. In addition, the experiment was conducted to compare and verify the CAE results. As a result, it was confirmed that the shrinkage rate of the material had a great influence on the shape precision of the final product.

• Journal of Korean Neurosurgical Society
• /
• 제66권4호
• /
• pp.393-399
• /
• 2023

Objective : Chiari II malformation (CM II) is still the main cause of severe morbidity and mortality in children with open neural tube defects (ONTDs). The goal of this study was to validate a CM II model in late-stage chick embryos with surgically induced ONTDs. Methods : To make the chick embryo model of ONTD, their neural tubes were opened for a length of 5-6 somites at the thoracic level in Hamburger and Hamilton stage 18 chick embryos (n=150). They were reincubated in ovo up to a total age of 17-21 days. A total of 19 embryos survived and were assigned to either the postoperative day (POD) 14-15 group (n=6) or the POD 17-18 group (n=13). Magnetic resonance imaging (MRI) and histopathologic findings of embryo heads with spinal ONTDs were compared with age-matched normal chick embryos. Results : The chick embryos with ONTDs demonstrated definite and constant structural changes, such as downward displacement of the cerebellum to just above the foramen magnum and narrow and small cerebrospinal fluid spaces in the crowded small posterior fossa. These morphologic features were more prominent in the POD 17-18 group than in the POD 14-15 group. Conclusion : This is the first description of CM II with spinal ONTD in a late-stage chick embryo model with MRI and histopathological analysis. The morphological changes of the posterior fossa in this study mimic those of CM II associated with spinal ONTD in humans. This model will facilitate investigation of the pathogenesis of CM II.

• Archives of Plastic Surgery
• /
• 제43권2호
• /
• pp.204-209
• /
• 2016

Temporal hollowing occurs to varying degrees after pterional craniotomy. The most common cause of temporal hollowing is a bony defect of the pterional and temporal regions due to the resection of the sphenoid ridge and temporal squama for adequate exposure without overhang. The augmentation of such bony defects is important in preventing craniofacial deformities and postoperative hollowness. Temporal cranioplasty has been performed using a range of materials, such as acrylics, porous polyethylene, bone cement, titanium, muscle flaps, and prosthetic dermis. These methods are limited by the risk of damage to adjacent tissue and infection, a prolonged preparation phase, the possibility of reabsorption, and cost inefficiency. We have developed a method of temporal augmentation using a calvarial onlay graft as a single-stage neurosurgical reconstructive operation in patients requiring craniotomy. In this report, we describe the surgical details and review our institutional outcomes. The patients were divided into pterional craniotomy and onlay graft groups. Clinical temporal hollowing was assessed using a visual analog scale (VAS). Temporal soft tissue thickness was measured on preoperative and postoperative computed tomography (CT) studies. Both the VAS and CT-based assessments were compared between the groups. Our review indicated that the use of an onlay graft was associated with a lower VAS score and left-right discrepancy in the temporal contour than were observed in patients undergoing pterional craniotomy without an onlay graft.

• The Plant Pathology Journal
• /
• 제36권4호
• /
• pp.314-322
• /
• 2020

Interplay between histone acetylation and deacetylation is one of the key components in epigenetic regulation of transcription. Here we report the requirement of MoHDA1-mediated histone deacetylation during asexual development and pathogenesis for the rice blast fungus, Magnaporthe oryzae. Structural similarity and phylogenetic analysis suggested that MoHDA1 is an ortholog of Saccharomyces cerevisiae Hda1, which is a representative member of class II histone deacetylases. Targeted deletion of MoHDA1 caused a little decrease in radial growth and large reduction in asexual sporulation. Comparison of acetylation levels for H3K9 and H3K14 showed that lack of MoHDA1 gene led to significant increase in H3K9 and H3K14 acetylation level, compared to the wild-type and complementation strain, confirming that it is a bona fide histone deacetylase. Expression analysis on some of the key genes involved in asexual reproduction under sporulation-promoting condition showed almost no differences among strains, except for MoCON6 gene, which was up-regulated more than 6-fold in the mutant than wild-type. Although the deletion mutant displayed little defects in germination and subsequent appressorium formation, the mutant was compromised in its ability to cause disease. Wound-inoculation showed that the mutant is impaired in invasive growth as well. We found that the mutant was defective in appressorium-mediated penetration of host, but did not lose the ability to grow on the media containing H₂O₂. Taken together, our data suggest that MoHDA1-dependent histone deacetylation is important for efficient asexual development and infection of host plants in M. oryzae.

• 대한기계학회논문집A
• /
• 제25권5호
• /
• pp.805-815
• /
• 2001

Glaucoma is an eye disease which is caused by abnormal high IOP (Intra Ocular Pressure). High IOP is caused by the aqueous humor which is produced consistently but not drained due to malfunction of the trabecular system which has a role of draining the aqueous humor into the venous system. Currently, there are three methods to treat glaucoma-using medicines, surgical operation, and using implant device. The first and second methods are not long acting, so the use of implants is increasing in these days in order to drain out the aqueous humor compulsory. However, though conventional implants have a capability of pressure regulation, they cannot maintain IOPs desired for different patients, and too much aqueous humor are usually drained, to cause hypotony. To solve these problems, it is needed to develop a new implant which is capable of controling the IOP actively and copes with personal difference of patients. An active glaucoma implant consists of the valve actuator, pressure sensor, controller, and power supply. In this paper, firstly, we make an analysis of the operation of a conventional implant using a bond graph and show defects and limitations of the conventional valve analytically. Secondly, we design and analyze a valve actuator considering actuation principles, resistance elements, control methods, and energy sources focused on power saving problem. Finally, using simulations the possibility of the proposed valve actuator is investigated.

• 한국건축시공학회:학술대회논문집
• /
• 한국건축시공학회 2006년도 추계 학술논문 발표대회 논문집
• /
• pp.147-150
• /
• 2006

Of the total defects that have occurred recently in the Korean construction market, over 30% are caused by the construction of defective waterproofing, and the phenomenon of air pockets in the waterproofing layer, which is caused by the concrete vapor pressure, is known to be the primary cause of defective waterproofing. Accordingly, in this study the theory about the relationship between water pressure and temperature as well as the damp-proofing volume of concrete and, then, the change of vapor pressure volume was measured and analyzed by making a test sample after spraying a dampness remover and a waterproofing material to a prepared test body. As a result of measuring the water vapor pressure for the surface temperature of the waterproofing layer with the fluid-applied membrane temperature based on about $10^{\circ}C$, which is the average temperature of Seoul, it was found that first, the fluid-applied membrane elevated up to about $40^{\circ}C$, and the water vapor pressure generated from the fluid-applied membrane was about $0.3kgf/cm^2$ when the surface temperature of the waterproofing layer was raised up to about $80^{\circ}C$. Second, when the fluid-applied membrane temperature of the waterproofing layer was raised from $30^{\circ}C\;to\;35^{\circ}C,\;about\;0.1kgf/cm^2$ of water vapor pressure was generated, and when supplying a thermal source to raise the fluid-applied membrane temperature of the waterproofing layer from $35^{\circ}C\;to\;40^{\circ}C$, approximately $0.05kgf/cm^2$ of water vapor pressure was generated.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
• /
• 제49권3호
• /
• pp.163-168
• /
• 2023

An oroantral fistula (OAF) or oroantral communication (OAC) is an opening between the oral cavity and the maxillary sinus. If left untreated, these openings may cause chronic maxillary sinusitis. Although small defects (diameter <5 mm) may close spontaneously, larger communications require surgical intervention. Various studies have been conducted on OAC closure using a platelet-rich fibrin (PRF) membrane; most of these prior studies have involved simple direct application of PRF clots. This study introduces a new "double-barrier technique" using PRF for closure of an OAF involving sinus mucosal lifting and closure. The PRF material is inserted into the prepared maxillary sinus space, and the buccal advancement flap covers the oral side. This technique was successfully used to treat two patients with chronic OAF in the posterior maxillary region after implant removal or tooth extraction. The use of a PRF membrane in a double-barrier technique may have advantages in soft-tissue healing and could enable easy closure of chronic OAF with minimal trauma.