• Korean Journal of Radiology
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• v.24 no.5
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• pp.444-453
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• 2023

Objective: Meningeal lymphatic vessels are predominantly located in the parasagittal dural space (PSD); these vessels drain interstitial fluids out of the brain and contribute to the glymphatic system. We aimed to investigate the ability of dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) in assessing the dynamic changes in the meningeal lymphatic vessels in PSD. Materials and Methods: Eighteen participants (26-71 years; male:female, 10:8), without neurological or psychiatric diseases, were prospectively enrolled and underwent DCE-MRI. Three regions of interests (ROIs) were placed on the PSD, superior sagittal sinus (SSS), and cortical vein. Early and delayed enhancement patterns and six kinetic curve-derived parameters were obtained and compared between the three ROIs. Moreover, the participants were grouped into the young (< 65 years; n = 9) or older (≥ 65 years; n = 9) groups. Enhancement patterns and kinetic curve-derived parameters in the PSD were compared between the two groups. Results: The PSD showed different enhancement patterns than the SSS and cortical veins (P < 0.001 and P < 0.001, respectively) in the early and delayed phases. The PSD showed slow early enhancement and a delayed wash-out pattern. The six kinetic curve-derived parameters of PSD was significantly different than that of the SSS and cortical vein. The PSD washout rate of older participants was significantly lower (median, 0.09; interquartile range [IQR], 0.01-0.15) than that of younger participants (median, 0.32; IQR, 0.07-0.45) (P = 0.040). Conclusion: This study shows that the dynamic changes of meningeal lymphatic vessels in PSD can be assessed with DCE-MRI, and the results are different from those of the venous structures. Our finding that delayed wash-out was more pronounced in the PSD of older participants suggests that aging may disturb the meningeal lymphatic drainage.

• Journal of the Korean GEO-environmental Society
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• v.14 no.10
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• pp.49-57
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• 2013

Recently, recycling of the industrial by-products has been an important issue of the Yeosu bay, where large industrial complex is located. Major industrial by-products which are produced from Yeosu industrial complex area are phosphogypsum and flyash, which are about 82% and 10% of the 1.6 million tons industrial by-products. Moreover since the Yeosu industrial complex is located at seaside, phosphogypsum has been pointed as cause of serious environmental contaminant from the regional society. Therefore recycling study can't be delayed anymore. In this paper, artificial aggregate was manufactured by non-sintering process from industrial byproducts - e.g., phosphogypsum and slag - as a geotechnical drainage material. To show the feasibility of the artificial aggregate as a geotechnical drainage material, geotechnical experiments including particle size analysis, permeability test, and large scale direct shear test were carried out. Test results show that the permeability of the artificial aggregates range from $6.94{\times}10^{-1}cm/sec$ to $8.86{\times}10^{-1}cm/sec$, which is much larger value than those are required for the drainage material from the construction specification in Korea, and the friction angle of the artificial aggregate is as large as that of sand in water immersion conditions. From the test results, it was concluded that artificial aggregate made from industrial by-products can be used successfully as a geotechnical drainage material.

• Advances in pediatric surgery
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• v.17 no.1
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• pp.88-92
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• 2011

The onset of hypertrophic pyloric stenosis in the postoperative course of esophageal atresia with tracheoesophageal fistula is rarely reported. The diagnosis could be delayed due to its mimicking symptoms of other postoperative complications including gastroesophageal reflux or anastomotic stricture. We present an infant who had surgery for esophageal atresia with tracheoesophageal fistula. He had never fed since birth. The infant presented with an increased amount of orogastric tube drainage and consistently distended gastric air on simple abdominal X-ray. Abdominal ultrasonography showed hypertrophic thick pyloric muscle. The diagnosis of pyloric stenosis was confirmed d is rarely reported. The diagnosis could be delayed due to its mimicking symptoms of other postoperative complications including gastroesophageal reflux or anastomotic stricture. We present an infant who had surgery for esophageal atresia with tracheoesophageal fistula. He had never fed. The infant presented with uring surgery, After pyloromyotomy, the patient's condition improved.

• Archives of Craniofacial Surgery
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• v.24 no.2
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• pp.73-77
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• 2023

Hidradenitis suppurativa (HS) is a chronic inflammatory condition that is difficult to diagnose, with a period of 10.0±9.6 years from symptom onset to diagnosis. A 32-year-old Asian man presented with bilateral postauricular abscesses that first appeared 5 years previously. Despite several incisions and drainage, the symptoms only temporarily improved and continued to recur. On physical examination, chronic scars and sinus tracts were observed around the lesion. Postauricular HS was diagnosed, and surgical treatment was performed. We performed a wide excision and reconstructed the defect using a posterior auricular artery perforator-based keystone flap. Histological examination confirmed the diagnosis of HS. The reconstruction was successful, and there was no recurrence for 2 years after surgery. HS is difficult to diagnose without specific attention. Although the postauricular region is not a typical site of HS, it can occur in this area. Therefore, if a patient presents with recurrent abscesses in the postauricular region, HS should be considered. Additionally, if HS is diagnosed in the postauricular region, wide excision with reconstruction using a posterior auricular artery perforator-based keystone flap can lead to a favorable outcome.

• Journal of Korean Neurosurgical Society
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• v.43 no.1
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• pp.11-15
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• 2008

Objective : Burr hole drainage has been widely used to treat chronic subdural hematoma (CSDH). However, the incidence of recurrent CSDH varies from 3.7 to 30% after surgery. The authors attempted to elucidate the risk factors associated with the recurrence of CSDH in one burr hole drainage technique. Methods : A total of 255 consecutive cases who underwent one burr hole drainage for CSDH were included in this study. Twenty-four patients (9.4%) underwent a repeated operation because of the recurrence of CSDH. We analyzed retrospectively the demographic, clinical and radiologic factors associated with the recurrence of CSDH. Results : In this study, two risk factors were found to be independently associated with the recurrence of CSDH. The incidence of CSDH recurrence in the high- and mixed-density groups was significantly higher than those in the low- and iso-density groups (p<0.001). Bleeding tendency such as in leukemia, liver disease and chronic renal failure was also significantly associated with recurrence of CSDH (p=0.037). Conclusion : These results suggest that high- and mixed- density shown on computed tomographic scan was closely relates with a high incidence of recurrence. Therefore, the operation could be delayed in those cases unless severe symptoms or signs are present. Reoperation using the previous burr hole site is a preferred modality to treat the recurrent CSDH.

• Journal of the Korean Association of Oral and Maxillofacial Surgeons
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• v.32 no.2
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• pp.168-173
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• 2006

The side effects of head and neck radiation therapy include mucositis, xerostomia, loss of taste, radiation caries, oral infection, osteoradionecrosis and trismus. When a patient is arranged to begin head & neck radiotherapy, oral pathologic lesions are examined and managed for the prevention of oral complications. The advanced odontogenic infection should be especially controlled before the radiotherapy and the patient must be instructed for proper oral prophylaxis. Generally the more conservative treatments, such as, scaling, restoration, endodontic treatment, are the care of choice and dental extraction is performed in advanced periapical and periodontal pathologic conditions. If the dental extraction should be done, the radiotherapy consequently will be delayed until there is epithelium covering the extraction socket, leaving no exposed bone. The cancer patient with severe emotional stress pray for the early radiation therapy, in spite of possibility of the recurrent odontogenic infectious lesions. So, the authors attempted to do the early radiation therapy by the conservative endodontic drainage and surgical incision & drainage without extraction of the infected teeth, and resulted in relatively good prognosis without the severe side effects of head and neck radiotherapy.

• Journal of The Korean Society of Agricultural Engineers
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• v.57 no.1
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• pp.69-78
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• 2015

The objective of this study was to investigate characteristics of irrigation return flow from paddy block in a reservoir irrigated district during growing seasons. The irrigation return flow was divided into three parts, quick return flow from irrigation canal (RFI), quick return flow from drainage canal (RFD), and delayed return flow (DRF). The RFI was calculated from water level and stage-discharge relationships at the ends of the irrigation canals. The DRF was estimated using measured infiltration amount from paddy fields of the irrigated district. A combined monitoring and modeling method was used to estimate the RFD by subtracting surface runoff from surface drainage. The paddy block irrigated from the Idong reservoir was selected to study the irrigation return flow components. The results showed that daily agricultural water supply (AWS), the RFI, and the RFD were $27.4mm\;day^{-1}$, $4.9mm\;day^{-1}$, and $19.8mm\;day^{-1}$, respectively in May, which were greater than other months (p<0.05). The return flow ratio of the RFI and the RFD were the greatest in July (34.6%) and May (72.3%), respectively. The daily AWS was closely correlated with the RFD (correlation coefficients of 0.76~0.86) in except for July with, while correlation coefficient with the RFI were 0.56 and 0.42 in June and July, respectively (p<0.01). The total irrigation return flow was 1,965 mm in 2011, and 1,588 mm in 2012, resulting in total return flow ratio of 84.6% and 79.1%, respectively. This results indicate that substantial amounts of agricultural water were returned to streams as irrigation return flow. Thus, irrigation return flow should be fully considered into the agricultural water resources planning in Korea.

• Archives of Reconstructive Microsurgery
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• v.20 no.1
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• pp.32-37
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• 2011

Purpose: Canalicular laceration is relatively common due to its exposed, vulnerable location in case of facial trauma. Conjunctivodacryocystorhinostomy has been the standard treatment for canalicular obstruction secondary to unrepaired canalicular laceration. In spite of a high rate of relieving tear-duct obstruction, this method is noted to be associated with low rate of patient satisfaction and a number of complications. The goal of this study is to report the good results of delayed lacrimal stent implantation with Mini Monoka$^{(R)}$ for patients whose canaliculi were not repaired by initial surgery. Methods: From May of 2005 to February of 2007, four patients who underwent delayed lacrimal stent implantation using Mini Monoka$^{(R)}$ in canalicular laceration were retrospectively reviewed. First, the previous scar incision was made over the lower lid and we identified the cut end of proximal lacerated canaliculus. The Mini Monoka$^{(R)}$ was passed through the punctum to the cut end of the proximal lacerated canaliculus. We identified the cut end of the distal lacerated canaliculus, whose cut end has rolled white edges after careful excision of the scarred lid tissue. We then passed Mini Monoka$^{(R)}$ through the lacerated inferior canaliculus. Using an operating microscope, we placed three interrupted sutures of 8-0 Ethilon to join the canalicular ends. Silicone stent was left in place for 6 months. The mean age of the patients was 48.5 years (range, 35 to 59 years). The time interval from initial trauma to delayed lacrimal stent implantation was between 3 and 31 days. Follow-up periods ranged from 12 and 20 months. Results: The results of reconstruction were classified into normal, fair and poor. Patent lacrimal drainage systems were achieved in three of the four cases. In one case, epiphora was encountered. No cases of stent displacement, conjunctivitis or granuloma formation were encountered. Conclusion: Even though canalicular reconstruction was delayed for a long time, attempting canalicular reconstruction would be acceptable before considering secondary operations like dacryocystorhinostomy and conjunctivodacryocystorhinostomy.

• Journal of The Korean Society of Agricultural Engineers
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• v.52 no.1
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• pp.41-49
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• 2010

Return flow rate of irrigation water was estimated by water balance method. Daepyeong pumping district to irrigate 75.8 ha of rice paddy in the Geum river basin was selected to install gauging instruments to collect data such as weather, water levels, infiltration rate and evapotranspiration during irrigation season (May 27 to Sept. 20) in 2003 and 2004. Irrigation and drainage discharge were calculated from the rating curve and evapotranspiration was estimated both by the modified Penman formula and by the lysimeter. The results were as followed : 1. Total amounts of pumping water during irrigation season were $1,076,000\;m^3$ in 2003 and $1,848,000\;m^3$ in 2004. Total amounts of rainfall were 1336.0mm and 1003.0mm respectively during the irrigation season in 2003 and 2004. 2. It was surveyed that the amount of infiltration was 196.5 mm (2.2 mm/day). The gauged evapotranspiration was 311.0 mm (3.5 mm/day) and the calculated evapotranspiration was 346.0 mm (3.9 mm/day) during irrigation period in 2003. It was surveyed that the amount of infiltration was 169.9 mm (2.4 mm/day). The amount of gauged evapotranspiration was 377.3 mm (5.3 mm/day) and the calculated evapotranspiration was 454.5 mm (6.6 mm/day) during irrigation period in 2004. 3. The rates of quick and delayed return flow were 52.4 % and 17.7 % respectively, and so return flow rate was 70.1 % in 2003. The rates of quick and delayed return flow were 45.4 % and 16.1 % respectively, and so return flow rate was 61.5 % in 2004. It means that average return flow rate in the Daepyeong pumping district was assumed to be 65 %.

• Journal of The Korean Society of Agricultural Engineers
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• v.65 no.6
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• pp.1-13
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• 2023

Irrigation return flow plays an important role in river flow forecasting, basin water supply planning, and determining irrigation water use. Therefore, accurate calculation of irrigation return flow rate is essential for the rational use and management of water resources. In this study, EPA-SWMM (Environmental Protection Agency-Storm Water Management Model) modeling was used to analyze the irrigation return flow and return flow rate of each intake work using irrigation canal network. As a result of the EPA-SWMM, we tried to estimate the quick return flow and delayed return flow using the water supply, paddy field, drainage, infiltration, precipitation, and evapotranspiration. We selected 9 districts, including pumping stations and weirs, to reflect various characteristics of irrigation water, focusing on the four major rivers (Hangang, Geumgang, Nakdonggang, Yeongsangang, and Seomjingang). We analyzed the irrigation period from May 1, 2021 to September 10, 2021. As a result of estimating the irrigation return flow rate, it varied from approximately 44 to 56%. In the case of the Gokseong Guseong area with the highest return flow rate, it was estimated that the quick return flow was 4,677 10³ m³ and the delayed return flow was 1,473 10³ m³ , with a quick return flow rate of 42.6% and a delayed return flow rate of 13.4%.