• Journal of the Korean Orthopaedic Association
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• v.55 no.5
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• pp.405-410
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• 2020

Purpose: Pedicle screw insertion has been traditionally used as a surgical treatment for degenerative lumbar spine disease. As an alternative, the cortical-bone trajectory screw allows less invasive posterior lumbar fixation and excellent mechanical stability, as reported in several biomechanical studies. This study evaluated the clinical and radiological results of a case of early failure of cortical-bone screw fixation in posterior fixation and union after posterior decompression. Materials and Methods: This study examined 311 patients who underwent surgical treatment from 2013 to 2018 using cortical orbital screws as an alternative to traditional pedicle screw fixation for degenerative spinal stenosis and anterior spine dislocation of the lumbar spine. Early fixation failure after surgery was defined as fixation failure, such as loosening, pull-out, and breakage of the screw on computed tomography (CT) and radiographs at a follow-up of six months. Results: Early fixation failure occurred in 46 out of 311 cases (14.8%), screw loosening in 46 cases (14.8%), pull-out in 12 cases (3.9%), and breakage in four cases (1.3%). An analysis of the site where the fixation failure occurred revealed the following, L1 in seven cases (15.2%), L2 in three cases (6.5%), L3 in four cases (8.7%), L4 in four cases (8.7%), L5 in four cases (8.7%), and S1 in 24 cases (52.2%). Among the distal cortical bone screws, fixation failures such as loosening, pull-out, and breakage occurred mainly in the S1 screws. Conclusion: Cortical-bone trajectory screw fixation may be an alternative with comparable clinical outcomes or fewer complications compared to conventional pedicle screw fixation. On the other hand, in case with osteoporosis and no anterior support structure particularly at L5-S1 fusion sites were observed to have result of premature fixation failures such as relaxation, pull-out, and breakage.

• Journal of the Korean Orthopaedic Association
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• v.56 no.6
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• pp.504-511
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• 2021

Purpose: This study examined the difference between the drainage volume, blood loss, transfusion rate, volume, and complications with or without an intra-articular (IA) tranexamic acid (TXA) injection among patients who underwent simultaneous bilateral total knee arthroplasty (SBTKA) with bilateral knee joint osteoarthritis, including patients who have contraindications of intravenous administration. Materials and Methods: Among patients who underwent SBTKA from April 2016 to December 2018, 139 patients injected with 3 g of TXA in each side through a drainage tube after joint capsule repair (group T), and 57 patients (group A) who underwent the procedure without TXA between October 2007 and August 2010 were tested. No significant difference in age and sex was observed between the two groups (p=0.572, 0.474). TXA was injected in patients with contraindications of intravenous administrations. Patients who underwent SBTKA with inflammatory arthritis were excluded from this study. The average amount of drainage, blood loss, transfusion rate, volume and daily average transfusion rate, and hemoglobin (Hb) change by the postoperative day were compared. Complications, such as deep vein thrombosis, pulmonary thromboembolism, myocardial infarction, cerebral infarction, and infection, were investigated. Results: The average total blood losses in groups A and T were 2195.32±1175.63 ml and 1145.09±382.95 ml, respectively, and the average total drain volume was 1,178.30±48.59 ml and 774.19±310.06 ml, respectively; both were significantly lower in group T (p=0.002, <0.001). The transfusion rates were 77.2% (44/57) and 0.7% (1/139), which were significantly lower in group T (p<0.001). The total average transfusion volume in groups A and T were 735.44±550.83 ml and 4.60±54.28 ml, respectively, which were significantly lower in group T (p<0.001). Hb tended to increase for three or four days after surgery in group A and group T. Regarding complications, deep vein thrombosis was encountered in two cases (1.4%), and pulmonary thromboembolism was noted in three cases (2.2%) in group T, but there were no cases in group A. No infections, cerebral infarction, or myocardial infarction occurred. Conclusion: In SBTKA, IA injections of TXA reduced the average drain volume, blood loss, transfusion rate, and volume significantly and did not increase the incidence of complications, even in patients with contraindications of intravenous administration.

• Journal of the Korean Orthopaedic Association
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• v.55 no.6
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• pp.495-502
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• 2020

Purpose: The aim of this study was to assess the effectiveness of domestically developed volar locking plate which has the concept of double-tiered subchondral support (DSS) in maintaining the reduction after distal radial fracture surgery. Materials and Methods: From July 2017 to December 2018, 54 patients were assessed. Plain radiographs were obtained immediately after surgery and at the last follow-up, and the radiographic parameters were measured in those images: radial length, radial inclination, volar tilt, ulnar variance, and distal dorsal cortical distance. The patients were subdivided into their age, type of fracture, and the position of the plate to evaluate the influence of each factors on the reduction maintenance. Results: Distal dorsal cortical distance in radiographs after the surgery was 5.91 mm (standard deviation, ±1.95 mm) on average. Significant differences in the radial length (p=0.038) and ulnar variance (p=0.001) were observed between immediately after surgery and at the last follow-up. When the parameters were evaluated by dividing the patients into subgroups according to the three specific factors, the ulnar variance showed a significant increase at the last follow-up when the patients were included 65-years-old or older. AO/OTA type C3 fracture, and Soong classification grade 0 plate position (p=0.007, p=0.012, p=0.046, respectively). Conclusion: Using the domestically developed DSS-type volar locking plate, significant reduction after distal radial fracture surgery could be maintained successfully. On the other hand, further study will be needed to determine about the reduction loss of the lunate facet identified in special cases that deal with fractures in elderly patients, unstable AO/OTA type C3 distal radial fractures, and Soong classification grade 0 plate position.

• Journal of the Korean Orthopaedic Association
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• v.55 no.1
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• pp.78-84
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• 2020

Purpose: This paper compares the clinical outcomes of patients who were treated with a cervical nerve block by ultrasound and C-arm and reports the complication. Materials and Methods: A total of 97 patients were treated with an ultrasound-guided nerve root block from May 1, 2015 to February 8, 2018. On the other hand, 94 patients were treated with a C-arm guided nerve root block. The consequences of the cervical pain and the radiating pain before and after the procedures were reviewed using the verbal numeric rating scale (VNRS). In addition, the complications related to the procedures from the daily notes from the chart were inspected. Results: Sixty-six cases out of 97 cases of ultrasound-guided nerve root block were enrolled in the study. The average age of the patients was 57 years, including 41 males and 25 females. Seventy seven out of 94 cases by a C-arm guided root block were included in the study. The average age of the patients was 55 years, including 40 males and 37 females. Before the nerve root block, the mean numeric rating pain scale (NRS) of the cervical pain in ultrasound-guided block decreased from 5.4 points to 2.7 points at three weeks and 1.4 points at six weeks (p=0.0023, p<0.001), and 3.1 points in the C-arm (p<0.001, p<0.001) at three weeks and 1.5 points at six weeks (p<0.001, p<0.001). In the case of radiating pain, the mean NRS in the ultrasound-guided nerve root block group improved from 6.3 points after the procedure to 2.8 points at three weeks and 1.5 points at six weeks (p<0.001, p<0.001). In the C-arm guided nerve root block group, the NRS improved from 7.4 points after the procedure to 3.3 points at three weeks and 1.9 points at six weeks. In the case of complications, Horner's syndrome and propriospinal myoclonus were observed in one case of C-arm guided block group. Conclusion: The clinical results of the patients who underwent ultrasound-guided cervical nerve root block were not significantly different from those who underwent a C-arm guided cervical nerve root block.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.312-323
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• 2022

This study began with the hypothesis of whether "solar radiation" and "terrestrial radiation" can be replaced by "visible radiation" and "infrared radiation", respectively. To this end, we investigated the perceptions of high school students who completed the Earth Science I course through a questionnaire to reveal how they perceived each concept. We also analyzed the descriptions and illustrations of textbooks that may have affected their perceptions. All of the students who participated in the questionnaire recognized solar radiation as radiation emitted only in the visible light region. About 35% of the students recognized convection, conduction, and latent heat as energy transfer by radiation in the Earth's heat budget. By analyzing six types of Earth Science I textbooks in the 2015 revised curriculum, we observed that two types introduced the terms "shortwave radiation" and "longwave radiation" but had no explanation for them, while the other two described solar radiation as "radiation mainly in the visible light region" or "radiation in short wavelengths". Regarding solar and terrestrial radiation in the last two types, there was no explanation for the wavelength regions, or ambiguous terms such as "short wavelength" and "long wavelength" were used. In addition, the two textbooks contained some errors in the illustration of the energy budget. Considering that textbooks described solar and terrestrial radiation without defining the exact terms for shortwave and longwave radiation, learners are likely to recognize solar and terrestrial radiation as visible and infrared radiation, respectively. This finding implies that vague statements or errors in textbooks can cause or reproduce students' misconceptions. The discussion in this study is expected to be used as a helpful reference material for teaching and learning processes regarding the Earth's radiation equilibrium and heat budget, and thereby contribute to proposing reasonable description plans for future textbook writing.

• The Sea:JOURNAL OF THE KOREAN SOCIETY OF OCEANOGRAPHY
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• v.27 no.2
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• pp.87-102
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• 2022

To clarify the spatial distribution pattern of macrozoobenthos in Korean coastal waters in the summer season and investigate the relationship between community structure and benthic environmental factors, field surveys on community structure and benthic environmental factors were conducted at 117 stations in August 2017. A total of 613 macrobenthic species were identified, with the mean density of 1,228 ind./m² and the mean biomass (wet weight) of 110.9 g WW/m². Rich biodiversity was found at stations near Wando and along the coast of the East Sea, and there is a trend that stations with greater biodiversity also showed higher mean density as well. The dominant species in all the coastal areas in Korea was Heteromastus filiformis, which were found at most of the stations during the survey. The relatively deep areas in the East Sea were dominated by Magelona johnsoni and Maldane cristata, which were the third and ninth dominant species in the study areas, respectively. Pseudopolydora kempi and Rhynchospio sp. were observed only at the station located in the Nakdong River estuary. From the cluster analysis the stations could be clustered into three station groups with more similar faunal composition. Group A was located in the eastern coast, characterized with deep water depth and low levels of sand contents, while Group B was located in the southern coast, characterized by shallow depth of water and high content of mud and organic matter. Lastly, Group C was in the western coast, demonstrating low levels of mud content and organic matters. The biodiversity of macrobenthic species in the study area showed high positive correlation coefficients with benthic environmental factors such as sorting, clay, silt, and contents of organic matter in sediments, but negatively correlated with the sand contents. Major dominant species, Theora lata and Eriopisella sechellensis, both showed negative correlation coefficients with the sand contents, but a relatively high positive correlation with the levels of organic contents.It can be concluded that the spatial distribution patterns of macrobenthic organisms in Korean coastal waters are affected by depth, sediment type, and contents of organic matters.

• Journal of Applied Biological Chemistry
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• v.64 no.4
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• pp.453-463
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• 2021

This study investigated that comparison of the nutrients (including fatty acids, amino acids, and minerals) and ginsenoside, total phenolic (TP) and total flavonoid (TF) contents and antioxidant activities in 5-year-old cultivated ginseng (CG), mountain-cultivated ginseng (MCG), and whole plant parts of MCG (WPMCG). The contents of total fatty acids and unsaturated fatty acids were determined highest in MCG (1215.9 and 751.2 mg/100 g), and saturated fatty acid was determined highest in WPMCG (486.4 mg/100 g) respectively. Characteristically, the α-linolenic acid content was detected up to 10 times higher in MCG (139.3 mg/100 g) and WPMCG (194.4 mg/100 g) compared to CG (18.1 mg/100 g). Total free and essential amino acid contents were high with CG < MCG < WPMCG (1006.35 mg/100 g and 839.46 mg/100 g). Notably, γ-aminobutyric acid and arginine were detected as the main non-essential amino acids with highest levels detected in WPMCG (163.10 mg/100 g) and MCG (305.23 mg/100 g), respectively. Total mineral content was high in CG (30.36 mg/100 g) and WPMCG (29.82 mg/100 g). Particularly, Calcium (Ca) was detected more than twice as high in WPMCG (6.68 mg/100 g) as compared to CG and MCG. TP and TF contents were 5.12 gallic acid mg/g and 3.04 RE mg/g respectively. Ginsenoside content was the highest in WPMCG (42.44 mg/g) in general and the highest antioxidant activity was also observed in WPMCG.

• Journal of Bio-Environment Control
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• v.31 no.1
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• pp.43-51
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• 2022

This study was conducted to investigate the effect of ventilation at high temperature on the control of powdery mildew, silverleaf whitefly two-spotted spider mite occurred at Korean melon cultivation greenhouse, and on leaf rolling and flowering of the plant in summer season. 'Alchanggul' grafted onto 'Hidden Power' rootstock was planted on soil bed with the distance of 40 cm. Three ventilation temperatures of 45℃, 40℃, and 35℃ as set points were compared. Ventilation treatment was done by control of side window operation from 18th June to 13th July when silverleaf whitefly, mite, and powdery mildew were occurred in all greenhouses. The temperature inside greenhouse was increased up to the set temperature point on sunny days and maintained for about 9 hours with high relative humidity at 45℃ condition. The differences of day maximum air temperature and day minimum RH were the highest at 45℃ treatment. After 11 days of treatments, the damage by powdery mildew and two-spotted spider mite was almost recovered at 45℃ treatment but not at 40 and 35℃. The population of silverleaf whitefly and two-spotted spider mite were significantly decreased at 45℃ treatment at 14 days after treatment, while powdery mildew symptom was not significantly decreased. Leaf rolling was observed at high temperature but not severe at 45℃ treatment. After 26 days of treatments, female flowers did not bloom at all at 45℃ treatment, and the number of male flowers was 1.2 among 15 nodes of newly grown shoots. As the result, it indicates that ventilation at the high temperature of 45℃ for about 2 to 3 weeks can be an applicable method to control above mentioned pests and disease, and to recover the vegetative growth of Korean melon by reducing flowering of the plant.

• Journal of Environmental Impact Assessment
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• v.31 no.2
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• pp.117-127
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• 2022

The survey of bird community characteristics was carried out four times on 2016 and 2017, respectively May and October to figure out effects of the manmade small ecosystem, Anseong. Twenty five species and 94 individuals were observed in the study area. The dominant species were Passer montanus 19.1%, Pica pica 12.8%, Cyanopica cyana 8.51%, Sinosuthora webbiana and Carduelis sinica ussuriensis respectively 7.45%, the diversity of the species was 2.787. With migration, the highest number and percentage to the lowest was residents 72.0%, summer visitors 20.0% and winter visitors 8.00%. Among 22 species which bred (check or possibility) in the manmade small ecology, Anseong, canopy (C) was 54.5%, hole (H) was 31.8%, bush (B) was 9.09% and ground (G) was 4.55% in their nesting guilds. In foraging guilds in breeding season was canopy (C) was 69.6%, bush (C) was 21.7%, water (W) and ground (G) was respectively 4.35%, and in non-breeding season, canopy was 64.0%, bush 24.0%, ground was 8.00% and water 4.00%. In the study site, the manmade habitats for birds were nest box and wetland (rain garden). In 7 nest box, Parus major was uesd 1 nest box as their breeding on 2016 and 2017, and Passer montanus was used 1 nest box on 2017. We assumed that sustainable rainwater supply may be important to attract many birds in rain garden, the manmade habitat for birds.Unfortunately, however, no birds used rain garden (wetland) as their habitats due to water shortage.

• Journal of Korea Water Resources Association
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• v.54 no.spc1
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• pp.1107-1118
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• 2021

Climate change brought on by global warming increased the frequency of flood and drought on the Korean Peninsula, along with the casualties and physical damage resulting therefrom. Preparation and response to these water disasters requires national-level planning for water resource management. In addition, watershed-level management of water resources requires flow duration curves (FDC) derived from continuous data based on long-term observations. Traditionally, in water resource studies, physical rainfall-runoff models are widely used to generate duration curves. However, a number of recent studies explored the use of data-based deep learning techniques for runoff prediction. Physical models produce hydraulically and hydrologically reliable results. However, these models require a high level of understanding and may also take longer to operate. On the other hand, data-based deep-learning techniques offer the benefit if less input data requirement and shorter operation time. However, the relationship between input and output data is processed in a black box, making it impossible to consider hydraulic and hydrological characteristics. This study chose one from each category. For the physical model, this study calculated long-term data without missing data using parameter calibration of the Soil Water Assessment Tool (SWAT), a physical model tested for its applicability in Korea and other countries. The data was used as training data for the Long Short-Term Memory (LSTM) data-based deep learning technique. An anlysis of the time-series data fond that, during the calibration period (2017-18), the Nash-Sutcliffe Efficiency (NSE) and the determinanation coefficient for fit comparison were high at 0.04 and 0.03, respectively, indicating that the SWAT results are superior to the LSTM results. In addition, the annual time-series data from the models were sorted in the descending order, and the resulting flow duration curves were compared with the duration curves based on the observed flow, and the NSE for the SWAT and the LSTM models were 0.95 and 0.91, respectively, and the determination coefficients were 0.96 and 0.92, respectively. The findings indicate that both models yield good performance. Even though the LSTM requires improved simulation accuracy in the low flow sections, the LSTM appears to be widely applicable to calculating flow duration curves for large basins that require longer time for model development and operation due to vast data input, and non-measured basins with insufficient input data.