• Journal of the Korean Orthopaedic Association
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• v.56 no.5
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• pp.404-412
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• 2021

Purpose: This study examined the degree of cartilage regeneration by performing second-look arthroscopy in a group of patients who underwent high tibial osteotomy and microfractures for unicompartmental osteoarthritis of the medial knee joint and to determine the factors affecting cartilage regeneration. In addition, this study analyzed whether there is a relationship between the degree of cartilage regeneration and functional results. Materials and Methods: From 2007 to 2015, this study evaluated 81 cases who underwent second-look arthroscopy at the time of plate removal after a microfracture and high tibial osteotomy with a minimum two-year follow-up. The degree of femoral cartilage injury before surgery was classified by ICRS (International Cartilage Research Society), and all were grade III and IV. After second-look arthroscopy, cartilage regeneration was classified into a well-regenerated group (grade I, II) and a poorly regenerated group (grade III, IV). The independent factors influencing cartilage regeneration were identified through multivariate logistic regression analysis. In addition, the functional results were compared before and after surgery between the two groups using the Knee Society score (KSS) and the Western Ontario and McMaster Universities Osteoarthritis Index score (WOMAC). Results: Age, sex, body mass index, postoperative radiologic factors, and preoperative joint condition did not affect the degree of cartilage regeneration significantly. The large cartilage defect (≥2.0 cm²) (p=0.011) and the presence of kissing lesions (p=0.027) were associated with poor cartilage regeneration. No significant difference in the KSS and WOMAC scores was observed between the group with good and poor cartilage regeneration. Conclusion: The presence of a large cartilage defect and kissing lesions is associated with poor cartilage regeneration after high tibial osteotomy and microfracture. On the other hand, the degree of the regenerated cartilage did not show any correlation with the functional outcome.

• Journal of the Korean Orthopaedic Association
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• v.56 no.1
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• pp.61-67
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• 2021

Purpose: To evaluate the prognostic factors affecting poor functional outcomes in patients with retear after rotator cuff repair. Materials and Methods: From January 2013 to December 2018, among 631 patients who underwent arthroscopic repair of a rotator cuff tear, 42 patients, who could be followed-up for more than one year and showed a retear of the repaired cuff on magnetic resonance imaging (MRI), were collected retrospectively. The preoperative demographic data, range of motion, American Shoulder and Elbow Surgeons (ASES) score, fatty degeneration, and tear progression on postoperative MRI, as well as other factors that could affect the clinical outcomes, were analyzed. Patients who scored <80 points on the ASES score were allocated to the poor function group. The risk factors for poor clinical outcomes were compared with the group with ASES scores of 80 or above. Results: The postoperative functional results in the group with retear (n=42) after arthroscopic rotator cuff repair showed significant improvement. Univariate analysis revealed the preoperative visual analogue scale (VAS) score and tear progression to have associations with a poor shoulder function. In addition, subscapularis repair was found to be associated with a good shoulder function. The preoperative VAS score and tear progression except for subscapularis repair were independent factors associated with poor clinical outcomes according to multivariate logistic regression analysis. Conclusion: In patients with retear after rotator cuff repair, the preoperative VAS and tear progression in postoperative MRI are factors predicting a poor functional outcome.

• Journal of the Korean Orthopaedic Association
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• v.56 no.3
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• pp.245-252
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• 2021

Purpose: This study examined the radiological and clinical outcomes of internal fixation using a reconstruction plate and 21G circumferential wire in comminuted midshaft clavicular fractures. Materials and Methods: A retrospective cohort study was performed on 51 patients between 2005 and 2019. Thirty-two patients underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and 19 patients underwent surgery without a wire. The patients were assessed with the radiographic parameters, the University of California at Los Angeles (UCLA) score, and the visual analogue scale (VAS) pain score. Based on this, patients who operated without a circumferential wire were set as the control group, and the differences in bone union between the two groups were compared. Results: Thirty-two patients were followed-up for an average of 65 weeks, and 19 patients in the control group were followed-up for an average of 56 weeks. The radiological evaluation confirmed the anatomical reduction and bone union in all 32 patients. No case of nonunion was present. The UCLA score was 32.38 on average and 33.11 in the control group (p=0.395). The VAS score was 1.00 on average and 0.84 in the control group (p=0.668). A significant difference in the bony union time was observed between the group who underwent internal fixation with a reconstruction plate and a 21G circumferential wire with minimal soft tissue detachment, and the control group (p=0.015). On the other hand, there was no statistical significance when other variables were controlled (p=0.107). Conclusion: For displaced midshaft clavicular fractures, internal fixation using a reconstruction plate and 21G circumferential wire maintained accurate anatomical reduction. The satisfactory clinical and radiological results mean that internal fixation using a reconstruction plate and 21G circumferential wire may be a good option for surgical treatment.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.38-45
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• 2020

Purpose: To examine the clinical and structural outcomes of an at least two-year follow-up of arthroscopic full-thickness rotator cuff repairs with a single-row or suture-bridge technique in patients more than 65 years of age. Materials and Methods: Patients diagnosed with a full-thickness rotator cuff tear who were more than 65 years of age, underwent arthroscopic rotator cuff repair after at least six months of conservative treatment, agreed to take a follow-up magnetic resonance imaging (MRI) six months postoperatively, and visited outpatient for at least two years were enrolled in this study. Clinical evaluations were done using The University of California Los Angeles score, Constant Shoulder Score, and visual analogue scale evaluated two years after the surgery. The structural integrity was analyzed using follow-up MRI. During surgery, a suture-bridge technique was used if the rotator cuff tendon could cover half of the footprint under constant tension. Otherwise, single-row repair was performed. Results: The samples were 158 cases, consisting of 93 single-repairs and 65 suture-bridge repairs. A preoperative comparison of the age distribution, fatty degeneration of supraspinatus and infraspinatus muscle, medial retraction of torn cuff tendon, and tear size between the two groups were not significant. The clinical scores were improved significantly in all cases. The distribution of the structural integrity by Sugaya classification were 49 cases in type 1 (31.0%), 62 cases in type 2 (39.2%), 30 cases in type 3 (19.0%), 11 cases in type 4 (7.0%), and six cases in type 5 (3.8%). The re-tear rate of the single-row group was 9.7% (nine out of 93 cases) and 12.3% (eight out of 65 cases) for the suture-bridge group. Conclusion: Satisfactory clinical and radiological outcomes were achieved after arthroscopic full-thickness rotator cuff repair in patients more than 65 years of age. Both single-row and suture-bridge techniques would be beneficial for the elderly.

• Journal of the Korean Orthopaedic Association
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• v.56 no.2
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• pp.157-163
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• 2021

Purpose: Xanthomatosis of the Achilles tendons is rare. In some patients, however, the lesions in the Achilles tendon need to be removed, which may be painful and disfiguring. While studies of successful surgical outcomes for the total resection and reconstruction of the Achilles tendon have been reported, reconstruction surgery has a technical challenge, and extended surgical exposures are required. This study analyzed five cases of bilateral xanthoma of the Achilles tendon, which was treated surgically using a wedge-shaped tendon-sparing approach to eliminate the need for tendon reconstruction. Materials and Methods: From July 2010 to May 2018, five patients with xanthomatosis in both Achilles tendons underwent wedge-shaped tendon preserving surgery. The average age was 49 years (range, 40-55 years), and the follow-up period was 21.4 months (range, 12-31 months). The patients consisted of three males and two females. Complications related to surgery were recorded. The outcome measures included the range of motion of the ankle joint, American Orthopaedic Foot and ankle Society (AOFAS) ankle/hindfoot score, and visual analogue scale (VAS) for overall satisfaction at the last follow-up. The availability of a single-limb heel raise and returning time to work were also measured. Results: Wound dehiscence that did not require secondary surgery was noted in one patient. At the last follow-up, the range of motion of the ankle joint was normal in all patients. The mean AOFAS ankle/hindfoot score was 91 (range, 85-96) and the VAS for the overall satisfaction ranged from 8 to 10. The average time between surgery and return to work was 27.6 days (range, 17-58 days) and all patients could perform a single-limb heel raise test. Conclusion: The tendon-sparing technique, which can preserve the anatomical functioning of the Achilles tendon, could be an excellent surgical approach because it has very promising functional and cosmetic surgical outcomes in patients with Achilles tendon xanthomatosis.

• Journal of Korea Water Resources Association
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• v.55 no.11
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• pp.923-929
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• 2022

The Chuncheon Mullori area is an underprivileged area of water welfare where local water supply is not supplied, and it is supplying water to the villages with small water supply facilities using lateral flow and groundwater as water sources. This is an area with poor water supply conditions, such as relying on water trucks due to water shortages during the recent severe drought. Therefore, in order to solve the problem of water shortage during drought and to prepare for the increasing water demand, a sand dam was installed along the valley, and this facility has been operating since May 2022. In this study, repeated simulations were performed according to the hydraulic conductivity of the filler material and the storage coefficient value for the inflow condition for about two years from mid-March 2020 to mid-March 2022. For each case, the amount of discharge through the perforated drain pipe was calculated. Overall, as the hydraulic conductivity increased, the amount of discharge and its ratio increased. However, when the hydraulic conductivity of the second floor was relatively low, the amount of discharge increased and then decreased as the hydraulic conductivity of the third floor increased. This is considered to be due to the fact that the water level was kept low due to the rapid drainage compared to the net inflow into the third floor because the water permeability of the third floor and the drainage coefficient of the drain pipe were large. As a result of simulating the flow of the open channel in the upper part of the sand dam as a hypothetical groundwater layer with very high hydraulic conductivity, the decrease in discharge rate was slower than the increase in the hydraulic conductivity of the hypothetical layer, but it was clearly shown that the discharge volume decreased relatively as the hydraulic conductivity of the virtual layer increased.

• Clean Technology
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• v.28 no.3
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• pp.218-226
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• 2022

As a result of the recent social transformation towards a hydrogen economy and carbon-neutrality, the demands for hydrogen energy have been increasing rapidly worldwide. As such, eco-friendly hydrogen production technologies that do not produce carbon dioxide (CO₂) emissions are being focused on. Among them, ammonia (NH₃) is an economical hydrogen carrier that can easily produce hydrogen (H₂). In this study, Ru/Al₂O₃ catalyst coated onmetallic monolith for hydrogen production from ammonia was prepared by a dip-coating method using a catalyst slurry mixture composed of Ru/Al₂O₃ catalyst, inorganic binder (alumina sol) and organic binder (methyl cellulose). At the optimized 1:1:0.1 weight ratio of catalyst/inorganic binder/organic binder, the amount of catalyst coated on the metallic monolith after one cycle coating was about 61.6 g L^-1. The uniform thickness (about 42 ㎛) and crystal structure of the catalyst coated on the metallic monolith surface were confirmed through scanning electron microscopy (SEM) and X-ray diffraction (XRD) analysis. Also, a numerical optimization regression equation for NH3 conversion according to the independent variables of reaction temperature (400-600 ℃) and gas hourly space velocity (1,000-5,000 h^-1) was calculated by response surface methodology (RSM). This model indicated a determination coefficient (R²) of 0.991 and had statistically significant predictors. This regression model could contribute to the commercial process design of hydrogen production by ammonia decomposition.

• Journal of the Korean Applied Science and Technology
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• v.39 no.3
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• pp.397-406
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• 2022

This study is an experimental study on the single group pre-post test design for the effects of the exercise program combined with telephone coaching on postural balance, grip strength and depression of the elderly living alone. The subjects of this study were 20 elderly living alone who registered at a senior welfare center located in S City, Gyeonggi-do. A total of 12 session programs were applied from July 3 to October 14, 2021. Before and after the program, the participant's home was visited and 4 stage standing balance test(4 SBT), grip strength and depression were measured. The contents of the intervention consisted of elastic bands and grip balls, and weekly telephone coaching interventions were provided. In the result of this study, the exercise program combined with telephone coaching were statistically significant differences in 4 SBT(3stage)(t=-2.37, p=.029), 4 SBT(4stage)(t=-2.46, p=.024), right grip strength(t=-2.18. p=.042) and depression(t=2.82, p<.001). Therefore, it is expected that the exercise program combined with telephone coaching can be applied as a nursing intervention to improve postural balance, grip strength and reduce depression in the elderly living alone in the community.

• Korean Journal of Food Science and Technology
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• v.54 no.4
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• pp.455-461
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• 2022

In this study, kombucha was prepared using saccharified rice solution to assess this possible means of increasing rice consumption. Chucheong rice yielded the highest starch content (80.40±1.33%) when used to produce saccharified rice solution. The resultant saccharified rice solution showed the highest 10.42 °Brix at 90 min of saccharification. Chamdream rice yielded the highest acidity at 0.38%, and Kawaji No.1 yielded the lowest at 0.24%. Organic acid analysis on the 15th day of fermenting kombucha made with different rice varieties indicated an acetic acid content of 111.70±1.09 ppm in Chamdream, and 46.86±1.00 ppm in Dongjinchal. Comparison of enzymes used in saccharified rice kombucha fermentation revealed that α-amylase resulted in the highest acidity (1.06%), and β-amylase yielded the lowest acidity (0.58%). Kombucha with green tea yielded the highest acidity (1.09%), and kombucha with rooibos tea yielded the lowest (0.37%). Polyphenol analysis indicated that the amount of polyphenol increased the most (1,623.75 ppm to 3,989.00 ppm) on day 0 of fermentation with green tea. Organic acid analysis revealed that the acetic acid content of kombucha supplemented with green tea increased from 172.89 ppm on day 0 of fermentation to 2,649.11 ppm on day 15. Kombucha with 2.0% added alcohol had the highest acidity (1.32%), and kombucha with 0.5% alcohol had the lowest (0.97%). Taken together, these results confirm that it is possible to make kombucha using saccharified rice solutions.

• Journal of the Society of Disaster Information
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• v.17 no.4
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• pp.864-881
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• 2021

Purpose: This study aims is to provide a total care solution preventing disaster based on Big Data and AI technology and to service safety considered by individual situations and various risk characteristics. The purpose is to suggest a method that customized comprehensive index services to prevent and respond to safety accidents for calculating the living safety index that quantitatively represent individual safety levels in relation to daily life safety. Method: In this study, we use method of mixing AHP(Analysis Hierarchy Process) and Likert Scale that extracted from consensus formation model of the expert group. We organize evaluation items that can evaluate life safety prevention services into risk indicators, vulnerability indicators, and prevention indicators. And We made up AHP hierarchical structure according to the AHP decision methodology and proposed a method to calculate relative weights between evaluation criteria through pairwise comparison of each level item. In addition, in consideration of the expansion of life safety prevention services in the future, the Likert scale is used instead of the AHP pair comparison and the weights between individual services are calculated. Result: We obtain result that is weights for life safety prevention services and reflected them in the individual risk index calculated through the artificial intelligence prediction model of life safety prevention services, so the comprehensive index was calculated. Conclusion: In order to apply the implemented model, a test environment consisting of a life safety prevention service app and platform was built, and the efficacy of the function was evaluated based on the user scenario. Through this, the life safety index presented in this study was confirmed to support the golden time for diagnosis, response and prevention of safety risks by comprehensively indication the user's current safety level.