• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.49 no.6
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• pp.324-331
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• 2023

Objectives: The purpose of this study was to evaluate the outcomes of implants placed in horizontally augmented alveolar ridges using porcine bone grafts and to investigate the long-term stability of the porcine bone grafts. Materials and Methods: A retrospective analysis was conducted on 49 sites that underwent horizontal ridge augmentation using porcine bone grafts and implant placement with a follow-up period longer than 5 years. Furthermore, additional analysis was conducted on 24 sites where porcine bone grafts were used exclusively for horizontal ridge augmentation and implant placement. Results: The mean follow-up period after prosthesis loading was 67.5 months, with a mean marginal bone loss of 0.23 mm at 1 year and a cumulative mean marginal bone loss of 0.40 mm over the entire follow-up period. Of the 49 implants, 2 were lost and 3 did not meet the success criteria, resulting in a survival rate of 95.9% and a success rate of 89.8%. In 24 sites, the mean marginal bone loss was 0.23 mm at 1 year and 0.41 mm at 65.8 months, with 100% survival and success rates. Conclusion: Porcine bone grafts can be successfully used in horizontal ridge augmentation for implant placement in cases of ridges with insufficient horizontal width.

• Archives of Craniofacial Surgery
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• v.24 no.6
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• pp.266-272
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• 2023

Background: In recent years, there has been an increase in reports of perioral vascular complications resulting from filler injections, such as necrosis of the lip or alar rim, occlusion, and in severe cases, blindness. Conversely, the use of perioral arterial flaps is becoming more prevalent in the treatment of cleft lips, cancer, and trauma. A thorough understanding of perioral arteries is essential to minimize complications and maximize the success of these flaps. However, the course of the facial artery (FA) in the perioral region remains incompletely understood. The aim of this study was to describe the variations of the FA in the perioral region. Methods: We dissected 52 embalmed and formaldehyde-fixed Vietnamese cadavers. We then studied the size and distribution of perioral arteries in 102 specimens. Results: The superior labial artery (SLA) was the most common branch, occurring in 87.25% of cadavers, followed by the inferior labial artery (ILA) at 78.43%. The SLA primarily originated above the mouth corner (cheilion), accounting for 91.01% of cases, and predominantly exhibited a tortuous course within the submucosa (78.65%). The ILA's branching pattern varied, but it was primarily located below the cheilion (91.25%). The ILA also followed a twisted path, generally within the submucosa. The ILA exhibited two patterns: the typical pattern, distributed at the vermilion border of the lower lip (8.82%), and the horizontal labiomental artery pattern, which ran horizontally in the middle of the lower lip area (69.61%). At their origin, the SLA and ILA had average external diameters of 1.29 mm and 1.28 mm, respectively. Conclusion: Numerous anatomical variations in the FA in the perioral region were found. A detailed anatomic description, suggested landmarks, and angiography before the procedure will be useful to help doctors avoid complications.

• Korean Journal of Veterinary Research
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• v.63 no.3
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• pp.24.1-24.6
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• 2023

This study compared the biomechanical properties of bone-stapling techniques with those of other fixation methods used for stabilizing tibial tuberosity fractures using 3-dimensionally (3D)-printed canine bone models. Twenty-eight 3D-printed bone models made from computed tomography scan files were used. Tibial tuberosity fractures were simulated using osteotomy. All samples were divided into 4 groups. Group 1 was stabilized with a pin and tension-band wire; group 2, with a pin and an 8 mm-wide bone staple; group 3, with 2 horizontally aligned pins and an 8 mm-wide bone staple; and group 4 with a 10 mm-wide bone staple. Tensile force was applied with vertical distraction until failure occurred. The load and displacement were recorded during the tests. The groups were compared based on the load required to cause displacements of 1, 2, and 3 mm. The maximum failure loads and modes were recorded. The loads at all displacements in group 4 were greater than those in groups 1, 2, and 3. The loads at 1, 2, and 3 mm displacements were similar in groups 1 and 3. There was no significant difference between groups 1 and 3. Groups 1 and 4 provided greater maximum failure loads than groups 2 and 3. Failure occurred because of tearing of the nylon rope, tibial fracture, wire breakage, pin bending, and fracture around the bone staple insertion. In conclusion, these results demonstrate that the bone-stapling technique is an acceptable alternative to tension-band wire fixation for the stabilization of tibial tuberosity fractures in canine bone models.

• Korean Journal of Optics and Photonics
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• v.35 no.1
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• pp.24-29
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• 2024

We propose a hyperbolic metastructure based on a nanopatterned metal (Ag)-dielectric (PDMS) multilayer and report on its performance in an infrared (IR) cut-off filter for imaging devices. By optimizing the size of the square-shaped Ag nanopattern and the thickness of PDMS surrounding the Ag nanopattern, the proposed IR cut-off filter blocks 99% of light in the 0.70-1.01 ㎛ wavelength band while maintaining a high transmittance of over 94% in the visible region. Here, the cut-off wavelength band starts at a region above the epsilon-near-zero wavelength of the hyperbolic metastructure and ends at the point where plasmonic absorption appears strongly. It is observed that transmittance in the wavelength region longer than the IR cut-off band increases again due to plasmonic coupling among horizontally adjacent Ag nanopatterns. This metastructure can improve the performance of IR-blocking filters as well as allow it to be manufactured ultra-thin, which is applicable to various planar optical elements and integrated optical components.

• Tunnel and Underground Space
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• v.33 no.6
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• pp.472-482
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• 2023

The grid-type or room-and-pillar method is applied for the purpose of mining horizontally buried minerals. In this study, design and pilot test were performed to apply the room-and-pillar method which uses natural rock as a rock pillar to the construction of underground space. The area where the pilot test was conducted was in stone mine and had good rock conditions with an appropriate depth (about 30 m) to apply the pilot test. The pilot test site was selected by reviewing accessibility and ground conditions and then site construction was performed through detailed ground investigation and design. The pilot test was designed with a column shape of 8×8 m and a cross-section of 8×12 m. The blasting pattern was determined through test blasting at the site, and blasting of 3 m excavation with 89 holes was performed. Through field observations, the average width of 12.5 m and the average height of 8.3 m were measured. Therefore, it is possible to proceed similar to the cross-sectional shape considered in the design.

• Korean Journal of Environmental Agriculture
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• v.42 no.4
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• pp.269-278
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• 2023

Antibiotics either kill or inhibit the growth of bacteria. However, antibiotic-resistant bacteria are difficult to treat with antibiotics. Infections caused by such bacteria often lead to severe diseases. Antibiotic resistance genes (ARG) can be horizontally transmitted across different bacterial species, necessitating a comprehensive understanding of how ARGs spread across various environments. In this study, we analyzed the plasmid sequences of 33 extended-spectrum beta-lactamases (ESBL) producing Escherichia coli isolated from pigs, farms, and their owners. We conducted an antibiotic susceptibility test (AST) with aztreonam and seven other antibiotics, as well as whole genome sequencing (WGS) of the strains using MinION. Our results demonstrated that the plasmids that did not harbor ARGs were mostly non-conjugative, whereas the plasmids that harbored ARGs were conjugative. The arrangement of these ARGs exhibited a pattern of organization featuring a series of ARG cassettes, some of which were identical across the isolates collected from different sources. Therefore, this study suggests that the sets of ARG cassettes on plasmids were mostly shared between pigs and their owners. Hence, enhanced surveillance of ARG should be implemented in farm environments to proactively mitigate the risk of antibiotic-resistant bacterial infections.

• Journal of the Economic Geographical Society of Korea
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• v.26 no.3
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• pp.274-288
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• 2023

While the integration into global value chains has garnered attention as a rural development strategy, less is known about why some integrations are successful while others are not. This study draws on rent theory and on empirical examples from Jinju and Nonsan, the two biggest strawberry production regions in South Korea, to explore the mechanisms of Jinju creating and exclusively retaining monopoly rents from the exports. Based on five months of fieldwork and in-depth interviews with stakeholders, the findings show that a producer-driven chain integration into the overseas markets was possible in Jinju due to the natural barriers to entry based on an exportable variety, as well as the region's climate conditions being suitable to the variety. Moreover, the farmers have attempted to retain the monopoly rents and extra profits from public supports by associating producers. The horizontally associated farmers stabilized their positions by enhancing their bargaining power against exporters, as well as by managing access to the public supports by controlling memberships.

• Anatomy and Cell Biology
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• v.56 no.4
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• pp.435-440
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• 2023

Few studies have examined the basilar venous plexus (BVP) and to our knowledge, no previous study has described its histology. The present anatomical study was performed to better elucidate these structures. In ten cadavers, the BVP was dissected. The anatomical and histological evaluation of the intraluminal trabeculae within this sinus were evaluated. Once all gross measurements were made, the clivus and overlying BVP were harvested and submitted for histological analysis. A BVP was identified in all specimens and in each of these, intraluminal trabeculae were identified. The mean number of trabeculae per plexus was five. These were most concentrated in the upper half of the clivus and were more often centrally located. These septations traveled in a posterior to anterior direction and usually, from inferiorly to superiorly however some were noted to travel horizontally. In a few specimens the trabeculae had wider bases, especially on the posterior attachment to the meningeal layer of dura mater. More commonly, the trabeculae ended in a denticulate form at their two terminal ends. The trabeculae were on average were 0.85 mm in length. The mean width of the trabeculae was 0.35 mm. These septations were consistent with the cords of Willis as are found in the lumen of some of the other intradural venous sinuses. An understanding of the internal anatomy of the BVP can aid in our understanding of venous pathology. Furthermore, this knowledge will benefit patients undergoing interventional treatments that involve the BVP.

• The Journal of the Acoustical Society of Korea
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• v.25 no.6
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• pp.305-311
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• 2006

In this paper the performance of a array invariant method is evaluated for source-range estimation in horizontally stratified shallow water ocean waveguide. The method has advantage of little computationally effort over existing source-localization methods. such as matched field processing or the waveguide invariant and array gain is fully exploited. And. no knowledge of the environment is required except that the received field should not be dominated by purely interference This simple and instantaneous method is applied to simulated acoustic propagation filed for testing range estimation performance. The result of range estimation according to the SNR for the underwater impulsive source with broadband spectrum is demonstrated. The spatial smoothing method is applied to suppress the effect of mutipath propagation by high frequency signal. The result of performance test for range estimation shows that the error rate is within 20% at the SNR above 10dB.

• Journal of Dental Rehabilitation and Applied Science
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• v.17 no.4
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• pp.283-305
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• 2001

The purpose of this study was to analyze the stress distribution of condylar regions and edentulous mandible with implant-supported cantilever prostheses on the certain conditions, such as amount of load, location of load, direction of load, fixation or non-fixation on the condylar regions. Three dimensional finite element analysis was used for this study. FEM model was created by using commercial software, ANSYS(Swanson, Inc., U.S.A.). Fixed model which was fixed on the condylar regions was modeled with 74323 elements and 15387 nodes and spring model which was sprung on the condylar regions was modeled with 75020 elements and 15887 nodes. Six Br${\aa}$nemark implants with 3.75 mm diameter and 13 mm length were incorporated in the models. The placement was 4.4 mm from the midline for the first implant; the other two in each quardrant were 6.5 mm apart. The stress distribution on each model through the designed mandible was evaluated under 500N vertical load, 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. The load points were at 0 mm, 10 mm, 20 mm along the cantilever prostheses from the center of the distal fixture. The results were as follows; 1. The stress distribution of condylar regions between two models showed conspicuous differences. Fixed model showed conspicuous stress concentration on the condylar regions than spring model under vertical load only. On the other hand, spring model showed conspicuous stress concentration on the condylar regions than fixed model under 250N horizontal load linguobuccally, buccal 20 degree 250N oblique load and buccal 45 degree 250N oblique load. 2. Fixed model showed stress concentration on the posterior and mesial side of working and balancing condylar necks but spring model showed stress concentration on the posterior and mesial side of working condylar neck and the posterior and lateral side of balancing condylar neck under vertical load. 3. Fixed model showed stress concentration on the posterior and lateral side of working condylar neck and the anterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior sides of working and balancing condylar necks under horizontal load linguobuccally. 4. Fixed model showed stress concentration on the posterior side of working condylar neck and the posterior and lateral side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 20 degree oblique load. 5. Fixed model showed stress concentration on the anterior and lateral side of working condylar neck and the posterior and mesial side of balancing condylar neck but spring model showed stress concentration on the anterior side of working condylar neck and the anterior and lateral side of balancing condylar neck under buccal 45 degree oblique load.. 6. The stress distribution of bone around implants between two models revealed difference slightly. In general, magnitude of Von Mises stress was the greatest at the bone around the most distal implant and the progressive decrease more and more mesially. Under vertical load, the stress values were similar between implant neck and superstructure vertically, besides the greatest on the distal side horizontally. 7. Under horizontal load linguobuccally, buccal 20 degree oblique load and buccal 45 degree oblique load, the stress values were the greatest on the implant neck vertically, and great on the labial and lingual sides horizontally. After all, it was considered that spring model was an indispensable condition for the comprehension of the stress distributions of condylar regions.