• Journal of Environmental Science International
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• v.20 no.5
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• pp.555-564
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• 2011

This study examines the potential restoration of abandoned channels of the Mangyeong River in South Korea. To analyze the morphological changes and equilibrium conditions, a flow duration analysis was performed to obtain the discharge of 255 m3/s with a recurrence interval of 1.5 year. It is a gravel-bed stream with a median bed diameter of 36 mm. The reach-averaged results using HEC-RAS showed that the top width is 244 m, the mean flow depth is 1.11 m, the width/depth ratio is very high at 277, the channel velocity is 1.18 m/s, and the Froude number is also high at 0.42. The hydraulic parameters vary in the vicinity of the three sills which control the bed elevation. The total sediment load is 6,500 tons per day and the equivalent sediment concentration is 240 mg/l. The Engelund-Hansen method was closer to the field measurements than any other method. The bed material coarser than 33 mm will not move. The methods of Julien-Wargadalam and Lacey gave an equilibrium channel width of 83 m and 77 m respectively, which demonstrates that the Mangyeong River is currently very wide and shallow. The planform geometry for the Mangyeong River is definitely straight with a sinuosity as low as 1.03. The thalweg and mean bed elevation profiles were analyzed using field measurements in 1976, 1993 and 2009. The measured profiles indicated that the channel has degraded about 2 m since 1976. The coarse gravel material and large width-depth ratio increase the stability of the bed material in this reach.

• Archives of Plastic Surgery
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• v.46 no.5
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• pp.449-454
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• 2019

Background Most patients with head and neck cancer successfully undergo oncologic resection followed by free or local flap reconstruction, depending on the tumor's size and location. Despite effective curative resection and reconstruction, head and neck cancer patients still face a high risk of recurrence and the possibility of a second primary cancer. Moreover, surgeons hesitate to perform sequential reconstruction following curative resection for several reasons. Few large-scale studies on this subject are available. Therefore, we retrospectively evaluated the outcome of sequential head and neck reconstruction to determine the possible risks. Methods In total, 467 patients underwent head and neck reconstruction following cancer resection at our center from 2008 to 2017. Of these cases, we retrospectively reviewed the demographic and clinical features of 58 who had sequential head and neck reconstruction following resection of recurrent cancer. Results Our study included 43 males (74.1%) and 15 females (25.9%). The mean age at the initial operation was $55.4{\pm}15.3years$, while the mean age at the most recent operation was $59.0{\pm}14.3years$. The interval between the first and second operations was $49.2{\pm}62.4months$. Twelve patients (20.7%) underwent surgery on the tongue, and 12 (20.7%) had procedures on the oropharynx. Thirty-four patients (58.6%) received a sequential free flap reconstruction, and 24 patients (41.4%) were treated using locoregional flaps. No cases of flap failure occurred. Conclusions Our findings suggest that patients who need additional operations with recurrent head and neck cancer could optimally benefit from sequential curative resections and reconstructions.

• Water for future
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• v.14 no.4
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• pp.53-72
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• 1981

In this study, South Korea is divided into 5 zones and is studied about the analysis of time-regional distribution of previpitation frequency and rainfall intensity in Korea. In the previpitation frequency analysis, the basic data groups of 39 stations were selected. The diagram of previpitation frequency was drawn, and the time-regional distribution of precipitation frequency was analized. In the rainfall intensity analysis, the basic data groups of 36 stations were selected. The probable rainfall, I-D-F curve, and regression equation between 24hr. and 10min.-18hr. areal depth were obtained. The results of this study are following; 1) The precipitation class of max. recurrence probability in every season except summer was commonly (1) 1-5mm, (2) 0.1-1mm, (3) 5-10mm in order. 2) The zone of max. recurrence frequency owing to the precipitation class was zone II in precipitation frequency of below 20mm, zone IV in precipitation frequency of 30-40mm, zone I in precipitation frequency of above 70mm for a year. 3) The recurrence probability of precipitation in Korea can be represented to the equation of exponential function; $$W(x)=e^{\alpha+\beta}$$ 4) The first and third zones were expected heavy rain for the short and long duration. 5) The I.D.F. curves were drawn, and established that the time interval for the least deviation of I.D.F curve is 10~40min., 40min. -4hr., 4~24hr. 6) The regression equations of areal mean depth between 24hr. and 10min.-18hr. for each zone were obtained. 7)The probable rainfall of 36 points were calculated.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.12 no.2
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• pp.163-170
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• 2009

Purpose: Intussusception is the most common cause of intestinal obstruction in young children. Although intussusceptions are easily treated, some intussusceptions with or without a pathologic lead point (PLP) often recur. In this study, we analyzed the clinical characteristics and prognosis of recurrent intussusceptions (RI), the frequency of the PLP, and correlation between RI with PLP. Methods: The medical records of 144 patients, among 590 patients with intussusceptions who had been admitted to the Department of Pediatrics and Pediatric Surgery of Dankook University Hospital between May 1994 and June 2009 were reviewed retrospectively. Results: The overall recurrence rate of intussusceptions in this study was 9.2%. The mean interval between the initial occurrence and the first recurrent attack was 130${\pm}$175 days (range, 12 hours to 3 years). There was no statistically significant difference in the recurrence rate among patients who underwent air, barium, and manual reduction (p=0.131). Eighty-seven cases (92.6%) of RI had a successful reduction by the use of non-operative techniques. A PLP was present in 18 patients (3.0%). The most common PLP was intestinal lymphoid hyperplasia, followed by Meckel's diverticulum, duplication cyst, intestinal polyp, and adenomyoma. The mean number of intussusceptions was 4.7${\pm}$1.9 in 7 patients with PLP, which was significantly higher than (2.4${\pm}$0.9) patients without a PLP (p=0.023). The mean duration of recurrences was 17.4${\pm}$19.8 months (range, 2 days to 72 months). Conclusion: A careful search for a PLP should be performed to prevent recurrence of intussusception, especially when intussusception has recurred more than three times.

• Journal of Chest Surgery
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• v.42 no.2
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• pp.206-213
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• 2009

Background: Previous series have suggested that younger patients with primary lung cancer exhibit a more aggressive disease course with a worse prognosis, as compared to older patients, although this issue is still debatable. Material and Method: We reviewed the medical records of 79 patients (32 patients 50 years and younger (Group I) and 47 patients 70 years and older (Group II)) who underwent curative resection for primary lung cancer between July 2000 and June 2008. Result: The median age of the patients was 46.5 years in Group I and this was 73 years in Group II. The older patients were more likely to have major comorbidities (44% versus 77%, respectively; p=0.003). Histological examinations identified that the minor histological types (excluding non-small cell lung cancer (NSCLC)) were predominantly found in the Group I patients (16% versus 2%, respectively; p=0.037). For the TNM staging of the NSCLC, with excluding the minor histologic types, a higher proportion of patients had stage III disease in Group I (33% versus 13%, respectively; p=0.038). There was no significant difference in major morbidity (16% versus 30%, respectively; p=0.148) and operative mortality (0% versus 4.3%; p=0.512) between the groups. The mean follow-up interval was 33 months (range: $1{\sim}98$ months) for patients in both groups. For the patients with NSCLC, the five-year overall survival rate was 52.3% for Group I and 53.7% for Group II (p=0.955). The rate of freedom from recurrence at five years was significantly lower for the Group I patients than for the Group II patients (39.4% versus 70.4%, respectively; p=0.027), and only being a member of Group I impacted recurrence, based on the Cox proportional hazard analysis (p=0.034). Of the patients who had recurrence, four patients in Group I underwent aggressive surgical treatment. All of these patients exhibited long-term survival (range: $46{\sim}87$ months). Conclusion: In our study, the early outcome and long-term survival were similar for the younger and older patients after curative resection of primary lung cancer. However, we think that younger patients require meticulous follow-up as they had a tendency to proceed to surgery with advanced stage disease, a higher recurrence rate than did the older patients and the survival rates were improved, even for the recurred cases, with early aggressive treatment.

• Korean Journal of Head & Neck Oncology
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• v.18 no.2
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• pp.192-196
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• 2002

Objectives: Tuberculous cervical lymphadenitis is a frequently recurring disease when treated with chemotherapy alone without enough surgical removal of the tuberculous lesions. Authors reviewed retrospectively the treatment result of antituberculous chemotherapy following almost complete surgical removal of tuberculous foci in the neck. Materials and Methods: A retrospective clinical review and analysis was made in 127 cases of tuberculous cervical lymphadenitis patients treated during the past 10 years from 1989 to 1998 at the Department of General Surgery, Inje University Paik Hospital, Pusan. Results: 1) The peak age incidence was the 2nd decade(37.8%), and female was predominated over male by 2.3:1. 2) The time interval from the onset of symptoms to the first visit was less than 3 months in 60.6% of the patient. 3) The location of lymphadenitis was the right neck in 60%, the left neck 34%, and bilateral in 6% of the patient. 4) Signs on the first visit showed solitary masses(60%), abscess(25%) and both mixed(15%). 5) 25 patients(19%) had present or past history of tuberculosis; pulmonary tuberculosis 12 patients, tuberculous lymphadenitis 10 patients, and others 3 patients. 6) Locations of tuberculous lymphadenitis were posterior cervical triangle 70, supraclavicular 51, submandibular 19, anterior triangle 16 and others 4 cases. 7) The principle of treatment of cervical lymphadenitis was surgical management followed by chemotherapy. Surgical procedures were excision(s), curettage and drainage of abscess, combination of both, and biopsy in 60%, 22%, 12% and 6% respectively. Mean duration of antituberculous medication was 9 months after surgery. 8) The rate of recurrent and persistent tuberculous lymphadenitis was 9% in 4 years follow up. Conclusion: Tuberculous cervical lymphadenitis is a frequently recurring disease in young adult when only antituberculous chemotherapy was employed without almost complete removal of the lesions. It is considered that antituberculous medications for 6-9 months after removing the foci at a maximal extent by surgical excision and curettage will reduce the recurrence rate or persistence of tuberculous lymphadenitis.

• Journal of Korean Neurosurgical Society
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• v.29 no.7
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• pp.929-934
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• 2000

Objective : The results of secondary transsphenoidal surgery(TSS) for either residual or recurring pituitary adenomas have been reported to be unfavorable. To evaluate the effectiveness of secondary TSS, we analyzed the surgical results of residual or recurred pituitary adenomas in patients who underwent secondary TSS from 1992 to 1998. Material and Methods : Among the 95 patients who underwent TSS during this period, 14(15%) received repeated TSS. Two of the 14 patients underwent three TSS. Among the 11 patients with pituitary adenomas, three had nonfunctioning tumors ; six prolachnomas ; two GH-secreting adenomas. The remaining three patieats had craniopharyngioma, pituitary abscess and hemangioendothelioma respectively. The interval between the two surgical procedures ranged from one week to 33 months(mean ; 12 months). Causes of the secondary TSS were tumor recurrence in 11 patients, intentional staged operation in three, persistent disease despite medical therapy and CSF leak after initial operation in one respectively. Treatments prior to secondary TSS were medical treatment only in eight patients. Results : During the repeated operationtss some adhesion was noted in septal mucous membrane. The sphenoid cavity was filled with fibrous tissue which correlated with the methods of reconstruction of the sellar floor at the previous operation. There was no statistically significant difference in success rate of surgery between the initial and the second TSS(86% vs 81%). The complication rate was similar between the two procedures. There was no statistically significant factors affecting the results of second TSS. Conclusion : Transsphenoidal reoperation was regarded as a suitable approach for treating recurrent pituitary adenomas in spite of some degree of operative difficulties. In patients with transsphenoidally resectable tumor residuals or recurrences confirmed by magnetic resonance imaging, remissions can be obtained with high probability, especially in secondary surgery after an staged decompression.

• Asian Pacific Journal of Cancer Prevention
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• v.13 no.3
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• pp.937-940
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• 2012

Due to lack of sufficient data on characteristics of breast cancer patients and risk factors for developing metastasis in Iran this study was designed to understand clinical aspects impacting on survival. A cross-sectional study on breast cancer patients was conducted in an oncology clinic of the university hospital between 1995 and 2010. Data were retrieved from medical records and included age, menopausal status, tumor diameter, number of involved nodes, histopathological type, estrogen and progesterone receptor expression, c-erbB-2, primary and secondary metastasis sites, overall survival, disease free interval and type of chemotherapy protocol. The results were analyzed with SPSS 13 software. The mean age of the patients was 49.2 (27-89) years. The primary tumors were mainly ER positive (48%) and PR negative (49.3%). The status of lymph nodes dissected and examined in these patients was unknown in 19 patients (25.3%) while 18 patients (24%) had positive lymph nodes with no report on the number of involved nodes. All of the patients had received antracyclin based chemotherapy in an adjuvant or metastatic setting. Adjuvant hormonal therapy was administered to receptor positive patients. In average, overall survival after recurrence was 30 months (95%CI 24.605-35.325) for non-skeletal versus 42 months (95%CI 31.211-52.789) for skeletal metastasis (P= 0.002). The median survival was also greater for receptor positive patients; 39 months (95%CI 33.716-44.284) for PR+ versus 26 months (95%CI 19.210-32.790) for PR- (P=0.047) and 38 months (95%CI 32.908-43.092) for ER+ versus 27 months (95%CI 18.780-35.220) for ER- patients (P=0.016). No relation was found between site of first metastasis and hormone receptor, age, tumor diameter, DFI and menopausal status. Sites of metastasis were independent of age, size of the tumor, menopausal and hormone receptor status in this study. Overall survival provided significant relations with respect to receptor status and bone metastasis.

• Journal of Yeungnam Medical Science
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• v.40 no.4
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• pp.412-418
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• 2023

Background: The aim of this study was to evaluate the risk factors for prostate-specific antigen (PSA) persistence in pathological stage T3aN0 prostate cancer (PCa) after robot-assisted laparoscopic radical prostatectomy (RALP). Methods: A retrospective study was performed on 326 patients with pT3aN0 PCa who underwent RALP between March 2020 and February 2022. PSA persistence was defined as nadir PSA of >0.1 ng/mL after RALP, and the risk factors for PSA persistence were evaluated using logistic regression analysis. Results: Among 326 patients, 61 (18.71%) had PSA persistence and 265 (81.29%) had PSA of <0.1 ng/mL after RALP (successful radical prostatectomy [RP] group). In the PSA persistence group, 51 patients (83.61%) received adjuvant treatment. Biochemical recurrence occurred in 27 patients (10.19%) in the successful RP group during the mean follow-up period of 15.22 months. Multivariate analysis showed that the risk factors for PSA persistence were large prostate volume (hazard ratio [HR], 1.017; 95% confidence interval [CI], 1.002-1.036; p=0.046), lymphovascular invasion (LVI) (HR, 2.605; 95% CI, 1.022-6.643; p=0.045), and surgical margin involvement (HR, 2.220; 95% CI, 1.110-4.438; p=0.024). Conclusion: Adjuvant treatment may be needed for improved prognosis in patients with pT3aN0 PCa after RALP with a large prostate size, LVI, or surgical margin involvement.

• Geophysics and Geophysical Exploration
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• v.20 no.3
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• pp.185-192
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• 2017

A sequence of earthquakes with the main shock $M_L$ 5.8 occurred on September 12 2016 in the Gyeongju area. The main shock was the largest earthquakes in the southern part of the Korean peninsula since the instrumental seismic observation began in the peninsula in 1905 and clearly demonstrated that the Yangsan fault is seismically active. The mean focal depth of the foreshock, main shock, and aftershock of the Gyeongju earthquakes estimated by the crustal model of single layer of the Korean peninsula without the Conrad discontinuity turns out to be 12.9 km, which is 2.8 km lower than that estimated based on the IASP91 reference model with the Conrad discontinuity. The distribution of the historical and instrumental earthquakes in the Gyeongju area indicates that the Yangsan fault system comprising the main Yangsan fault and its subsidiary faults is a large fracture zone. The epicenters of the Gyeongju earthquakes show that a few faults of the Yangsan fault system are involved in the release of the strain energy accumulated in the area. That the major earthquakes of Gyeongju earthquakes occurred not on the surface but below 10 km depth suggests the necessity of the study of the distribution of deep active faults of the Yangsan fault system. The magnitude of maximum earthquake of the Gyeongju area estimated based on the earthquake data of the area turns out to be 7.3. The recurrence intervals of the earthquakes over magnitudes 5.0, 6.0 and 7.0 based on the earthquake data since 1978, which is the most complete data in the peninsula, are estimated as 80, 670, and 5,900 years, respectively. The September 2016 Gyeongju earthquakes are basically intraplate earthquakes not related to the Great East Japan earthquake of March 11 2011 which is interplate earthquake.