• Ocean and Polar Research
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• v.30 no.1
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• pp.79-87
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• 2008

Hydroacoustic technique was used to analyze spatiotemporal stability and distribution of demersal fish aggregations in the coastal region to overcome some limitations of the existing methods such as net and diving. The survey was carried out in the Baekeum Bay on the south coast of Korea in January 2007. The bottom depth in the study site ranges from 7 to 25 m. In order to outline aggregations of demersal fish initial scanning using 200 kHz split-beam transducer was randomly conducted over the large area. Having detected fish aggregation in the specific region, intensive acoustic survey of irregular star pattern was carried out along 14 transects across the area in question. The results of the acoustic survey show that all demersal fish aggregations are concentrated about 5 m from sea bottom having a slight slope and remain steady with no spatial or temporal variations during acoustic survey. The hydroacoustic method used in this study offers a new approach to understand vertical and horizontal distribution, spatiotemporal stability, and biomass estimate of demersal fish aggregations in coastal regions. Additionally, the number of individual fish estimated from in situ acoustic target strength data can be used to understand the standing stock of demersal fish aggregation.

• Korean Journal of Environmental Biology
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• v.32 no.4
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• pp.327-334
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• 2014

Emission reduction of $CH_4$ (methane gas) from rice paddy soil is a very important measure for climate change mitigation in agricultural sector. In this study, we investigated the changes in crop yield and $CH_4$ emissions in response to application of biochar and fertilizers. The experimental site is located in Hwasung, Kyunggido and experimental design is the split-plot method with three replicates. Treatments included rice straw (RS) and biochar (BC) amendments nested with the conventional NPK fertilizer (NPK) and slow release fertilizer (SRF). Control was also prepared with the soil with the conventional NPK fertilization with no amendment. Measurement of $CH_4$ emission was conducted during the growing season of 2014 using a dynamic chamber method. The results showed that application of rice straw increased daily $CH_4$ emission rate by 15%, while application of biochar reduced daily $CH_4$ emission rate by 38%. When we combined biochar application with slow release fertilizer, $CH_4$ emission was reduced by 45%. Further, the crop yield was also increased in all treatments compared with the control except for the treatment of rice straw application with slow release fertilizer. Overall results imply that biochar amendment to agricultural soil can be an effective strategy to decrease annual $CH_4$ emission with no reduction in crop yield.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.30 no.3
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• pp.228-233
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• 2004

Summary: The malignant peripheral nerve sheath tumor(MPNST) is an aggressive neoplasm and can either arise independently or result from malignant change in preexisting neurofibromatosis (von Recklinghausen's disease). Its histologic characteristics remain controversial, but currently it is believed that the schwann cell is the origin of the peripheral nerve sheath tumors. MPNST is an uncommon neoplasm of the head and neck region, and its presentation in the oral cavity is quite rare. In this study, we report a patient with a rare case of a MPNST involving the maxilla. A case report: A 29-year-old female presented with a chief complaint of painless swelling with bleeding tendency on the left maxillary tuberosity area 2 months ago. Clinical examination showed a $5.0{\times}3.0cm^2$ sized, indurative swelling on the site. Conventional radiographs showed a relatively well-defined soft tissue mass involving the left maxillary sinus, and destruction of the anterior, posterolateral walls of the left maxillary sinus. Subtotal maxillectomy and split-thickness skin graft from thigh were undertaken. In histochemical and immunohistochemical studies, the specimen revealed positive reactivities to Vimentin and S-100 protein. Final diagnosis was made as MPNST.

• Journal of Korean Orthopaedic Sports Medicine
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• v.3 no.1
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• pp.56-59
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• 2004

The hamstring tendons are popular for autografts in a variety of reconstructive procedures. The hamstring autografts are used widely for its potential advantages over the patella bone-tendon-bone(BTB) autograft, including lower graft site morbidity and easier harvesting technique. However, the use of hamstrings has potential disadvantages such as the damage of infrapatellar branches of the saphenous nerve, premature tendon amputation, and tendon split following inadequate hamstring identifications. In our studies, we used modified technique for harvesting the hamstring to decrease potential disadvantages. Reflected hamstring flap method seems to be easy and safe in avoiding nerve damage and tendon splitting. We recommend the reflected hamstring flap method for harvesting hamstring tendons.

• Archives of Reconstructive Microsurgery
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• v.7 no.1
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• pp.1-9
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• 1998

From January 1985 to February 1997, 96 patients had undergone the free vascularized groin flap on the upper and lower extremities with microsurgical technique at the department of orthopaedic surgery, Yonsei University College of Medicine. The results were as follows: 1. Average age at the time of operation was 24.9 years. and there were 71 men and 25 women and mean follow up was 62.4 months. 2. The lesion site was 82 cases on the lower extremity: foot(40), leg(20), ankle(13), and 14 cases on the upper extremity: forearm(6), elbow(3), hand(3), wrist(2). 3. The anatomical classification of the superficial circumflex iliac artery was as follows: 1) 39.8% of common origin with superficial inferior epigastric artery, 2) 30.1% of isolated origin and absent superficial inferior epigastric artery, 3) 13.3% of separate origin, 4) 16.9% of origin from the deep femoral artery. 4. There was no statistical significance on arterial anastomosis between end to end and end to side, and on venous anastomosis(end to end) between one vein and two veins. 5. The success rate was average 84.4% in 81 of 96 cases. 6. In the 15 failed cases, the additional procedures were performed: 5 cases of free vascularized scapular flap, 6 cases of full thickness skin graft, 2 cases of cross leg flap, 1 case of latissimus dorsi flap, 1 case of split thickness skin graft. In conclusion, the free vascularized groin flap can be considered as the treatment of choice for the reconstruction of the extensive soft tissue injury on the extremities, and show the higher success rate with the experienced surgeon.

• Archives of Plastic Surgery
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• v.46 no.1
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• pp.57-62
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• 2019

Background Full-thickness nail bed defects with significant exposure of the distal phalanx are typically challenging to reconstruct. We describe a novel method of nail bed defect reconstruction using a thenar fascial flap combined with nail bed grafting. Methods Full-thickness nail bed defects were reconstructed in a 2-stage operation involving the placement of a thenar fascial flap and subsequent nail bed grafting. A proximally-based skin flap was designed on the thenar eminence. The flap was elevated distally to proximally, and the fascial layer covering the thenar muscle was dissected proximally to distally. The skin flap was then closed and the dissected fascial flap was turned over (proximal to distal) and inset onto the defect. The finger was immobilized for 2 weeks, and the flap was dressed with wet and ointment dressings. After 2 weeks, the flap was divided and covered with a split-thickness nail bed graft from the great toe. Subsequent nail growth was evaluated on follow-up. Results Nine patients (9 fingers) treated with the novel procedure were evaluated at follow-up examinations. Complete flap survival was noted in all cases, and all nail bed grafts took successfully. Five outcomes (55.6%) were graded as excellent, three (33.3%) as very good, and one (11.1%) as fair. No donor site morbidities of the thenar area or great toe were observed. Conclusions When used in combination with a nail bed graft, the thenar fascial flap provides an excellent means of nail bed reconstruction.

• Journal of Dental Anesthesia and Pain Medicine
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• v.20 no.6
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• pp.397-402
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• 2020

Background: Inferior alveolar nerve block (IANB) is the most common, painful, and anxiety-provoking procedure involving needle insertion for anesthetic solution deposition. DentalVibeⓇ (DV) delivers vibration at a sustained frequency as a counter-stimulation to the site of injection, thereby alleviating pain. The aim of this study was to evaluate and compare the effectiveness of DV and lignocaine hydrochloride 2% gel (Lox 2% jelly) in pain reduction during IANB in children. Methods: A split-mouth randomized clinical trial was designed with a sample of 60 children (age, 6 to 12 years) requiring bilateral IANB for various dental procedures; DV was used while administering IANB and Lox 2% jelly was used as the topical anesthetic before administering IANB at subsequent appointments. During both appointments, pain perception was measured using the sound, eye, motor (SEM) scale and Wong-Baker faces pain rating scale (WBFPRS); oxygen saturation (SpO2) and pulse rate were measured using a pulse oximeter before, during, and after the IANB procedure. The obtained values were tabulated and subjected to statistical analysis. Wilcoxon test was used for intergroup comparison, and Friedman test, for intragroup comparison of measured variables at different treatment phases. Results: The medians and interquartile ranges of the WBFPRS scores recorded during the IANB procedure for DV and Lox 2% jelly were 2 (2-4) and 2 (0-2), respectively (P < 0.05). The SEM scale scores, mean SpO2, and pulse rate did not show any significant differences during the IANB procedure between both treatments. Conclusion: Both DV and Lox 2% jelly were found to be effective in pain reduction during IANB in children.

• Korean Journal of Remote Sensing
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• v.38 no.6_2
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• pp.1677-1689
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• 2022

Air pollution is social issue that has long-term and short-term harmful effect on the health of animals, plants, and environments. Chimneys are the primary source of air pollutants that pollute the atmosphere, so their location and type must be detected and monitored. Power plants and industrial complexes where chimneys emit air pollutants, are much less accessible and have a large site, making direct monitoring cost-inefficient and time-inefficient. As a result, research on detecting chimneys using remote sensing data has recently been conducted. In this study, YOLOv5-based chimney detection model was generated using BUAA-FFPP60 open dataset create for power plants in Hebei Province, Tianjin, and Beijing, China. To improve the detection model's performance, data split and data augmentation techniques were used, and a training strategy was developed for optimal model generation. The model's performance was confirmed using various indicators such as precision and recall, and the model's performance was finally evaluated by comparing it to existing studies using the same dataset.

• Geomechanics and Engineering
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• v.29 no.2
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• pp.99-111
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• 2022

Instability of bolted rock mass has been a major hazard in the underground coal mining industry for decades. Developing effective support guidelines requires understanding of complex bolted rock mass failure mechanisms. In this study, the dynamic failure behavior, mechanical behavior, and energy evolution of a laboratory-scale bolted specimens is studied by conducting laboratory static-dynamic coupled loading tests. The results showed that: (1) Under static-dynamic coupled loading, the stress-strain curve of the bolted rock mass has a significant impact velocity (strain rate) correlation, and the stress-strain curve shows rebound characteristics after the peak; (2) There is a critical strain rate in a rock mass under static-dynamic coupled loading, and it decreases exponentially with increasing pre-static load level. Bolting can significantly improve the critical strain rate of a rock mass; (3) Compared with a no-bolt rock mass, the dissipation energy ratio of the bolted rock mass decreases exponentially with increasing pre-static load level, the ultimate dynamic impact energy and dissipation energy of the bolted rock mass increase significantly, and the increasing index of the ratio of dissipation energy increases linearly with the pre-static load; (4) Based on laboratory testing and on-site microseismic and stress monitoring, a design method is proposed for a roadway bolt support against dynamic load disturbance, which provides guidance for the design of deep underground roadway anchorage supports. The research results provide new ideas for explaining the failure behavior of anchorage supports and adopting reasonable design and construction practices.

• Journal of Periodontal and Implant Science
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• v.52 no.6
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• pp.466-478
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• 2022

Purpose: Coronally advanced split-or full-thickness (CAST or CAFT) flaps in combination with subepithelial connective tissue grafts (SCTGs) are commonly used in root-coverage procedures despite postoperative pain and bleeding from the graft donor site. Therefore, the modified vestibular incision subperiosteal tunnel access procedure (VISTAX) uses a novel collagen matrix (VCMX) instead of autogenous tissue to address the limitations associated with autogenous tissue grafting. This retrospective study compared the clinical outcomes of VISTAX to the results obtained after using a CAST or CAFT flap in combination with SCTG for root coverage. Methods: Patients with single or multiple adjacent recession I/II defects were included, with 10 subjects each in the VISTAX, CAFT, and CAST groups. Defect coverage, keratinized tissue width, esthetic scores, and patients' perceived pain and dentinal hypersensitivity (visual analogue scale [VAS]) were assessed at baseline, 3 months, and 6 months. Results: All surgical techniques significantly reduced gingival recession (P<0.0001). Defect coverage, esthetic appearance, and the reduction in dentinal hypersensitivity were comparable. However, the VAS scores for pain were significantly lower in the VISTAX group than in the CAFT and CAST groups, which had similar scores (P<0.05). Furthermore, the clinical results of VISTAX and CAFT/CAST generally remained stable at 6 months. Conclusions: The clinical outcomes of VISTAX, CAFT, and CAST were comparable. However, patients perceived significantly less pain after VISTAX, indicating a potentially higher patient acceptance of the procedure. A prospective trial with a longer follow-up period and a larger sample size should therefore evaluate VISTAX further.