• Journal of KIISE:Information Networking
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• v.29 no.4
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• pp.386-396
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• 2002

This paper presents a neural network-based near-optimal routing algorithm. It employs a modified Hopfield Neural Network (MHNN) as a means to solve the shortest path problem. It uses every piece of information that is available at the peripheral neurons in addition to the highly correlated information that is available at the local neuron. Consequently, every neuron converges speedily and optimally to a stable state. The convergence is faster than what is usually found in algorithms that employ conventional Hopfield neural networks. Computer simulations support the indicated claims. The results are relatively independent of network topology for almost all source-destination pairs, which nay be useful for implementing the routing algorithms appropriate to multi -hop packet radio networks with time-varying network topology.

• Clinical and Experimental Pediatrics
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• v.51 no.4
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• pp.367-371
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• 2008

Purpose : The surfactant dysfunction may play an important role in meconium aspiration syndrome (MAS). We aim to evaluate the effect of surfactant lavage in the treatment of term infants with MAS. Methods : The medical records of 15 neonates with severe MAS admitted at Yongdong Severance Hospital from 2005 to 2007 were reviewed and analyzed. Seven infants with severe MAS necessitating mechanical ventilation underwent tracheobronchial lavage with 20 mL/kg of diluted (5.3 mg phospholipid/mL) surfactant saline suspension ($Newfactan^{(R)}$). Data regarding clinical outcomes was assessed by comparison with 8 control infants with equally severe MAS retrospectively. Results : In the lavage group, radiological improvement was evident after 6 hours of treatment. The duration of artificial ventilation and duration of hospital day were also significantly shorten in the lavage group compared with the control group. The mean oxygen index, mean ventilation index improved significantly within the first 6 hours after treatment. No differences were found in the incidence of major complications and mortality between the two groups. Conclusion : The surfactant lavage seems to be an effective and safe method for treatment of severe MAS. A multicenter, large scaled randomized controlled trial is needed for further study.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.11 no.2
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• pp.116-121
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• 2008

Purpose: Cricopharyngeal incoordination is a rare cause of swallowing difficulties in newborns and infants; it is characterized by delayed pharyngeal contractions related to cricopharyngeal relaxation. Dysphagia and repeated aspiration are common findings despite normal sucking. We conducted this study to assess the clinical features of cricopharyngeal incoordination in newborns and infants. Methods: An analysis of the clinical data from 17 patients with cricopharyngeal incoordination who were admitted to the Department of Pediatrics, Pusan National University Hospital, between 2000 and 2006 was conducted retrospectively. The diagnosis of cricopharyngeal incoordination was established by the clinical characteristics and the videofluoroscopic swallowing studies. Results: The male to female ratio was 1:1.1 (males 8, females 9) the age range 1 to 60 days. The body weight of 11 patients (64.7%) was less than the $10^{th}$ percentile at diagnosis. Six patients (35.3%) were born prematurely. The associated anomalies or diseases were chromosomal anomaly (2 cases), congenital heart disease (3 cases), and laryngomalacia, hypoxic brain damage or neonatal seizures (1 case each). The chief complaints of patients were recurrent aspiration pneumonia (10 cases), feeding difficulty (9 cases), dyspnea (4 cases), and chocking (4 cases). The severity of aspiration on the videoesophagogram or esophagogram was mild in 12 cases. The correlation between the severity of aspiration and the duration of tube feeding after the diagnosis was significant (p<0.05). Conclusion: Cricopharyngeal incoordination should be considered in the differential diagnosis of newborns and infants, without known risk factors associated with swallowing dysfunction, when they present with unexplained respiratory problems. Although the prognosis of cricopharyngeal incoordination is good, early diagnosis and tube feeding are recommended to prevent the complications associated with this disorder.

• Tuberculosis and Respiratory Diseases
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• v.56 no.1
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• pp.18-28
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• 2004

Background : Many diseases like lung cancer and tuberculosis can involve cervical lymph node. Fine needle aspiration cytology(FNAC) was known as a useful screening test for the evaluation of enlarged lymph node. But the usefulness and limitations of FNAC according to disease category or physical characteristics of lymph node were not yet fully established. Methods : Retrospective analysis of three hundred forty two adult patients who performed FNAC due to enlarged cervical lymph nodes at the Seoul Municipal Boramae Hospital during the period from January 1999 to December 2002 and final diagnosis could be made by surgical biopsy, microbiology or clinical observation. Results : Among the 342 cases, 176(51.5 %) were finally diagnosed as benign nature ncluding reactive hyperplasia, Kikuchi's disease and acute suppuration. Eighty eight(25.7 %) were diagnosed as tuberculous lymphadenitis, 66(19.3 %) as metastasis, and 12(3.5 %) as lymphoma. Tuberculosis, metastasis, and lymphoma all showed significantly larger diameter, longer duration of lymph node enlargement. There were higher frequency of supraclavicular involvement in the cases of tuberculosis and metastasis. The overall diagnostic sensitivity of FNAC was 88.0 %, and 88.6 % in benign nature lesion, 77.3 % in tuberculosis, 90.1% in metastasis and 58.3 % in lymphoma. The diagnosis of tuberculosis was made by FNAC in 68 cases (77.3 %) among 88 cases. Lung cancer(43.9 percent) was most frequent cause of cervical lymph node metastasis. Diagnostic sensitivity of FNAC was significantly lower in the supraclavicular than other cervical lymph node(80 % vs. 91.3 %) and not correlated with disease nature, node size or number. Conclusion : Though FNAC was a reliable screening test for enlarged cervical lymph node enlargement, the diagnostic sensitivity was low in the case of lymphoma or when the enlarged lymph node was located at the supraclavicular area.

• Journal of Korean Orthopaedic Sports Medicine
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• v.4 no.1
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• pp.55-59
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• 2005

Purpose: To evaluate the drainage effect of silk suture material following aspiration of the bursa as an early treatment of chronic prepatellar bursitis. Materials and Methods: Twelve cases, which have over two weeks of history and over one year of follow-up, were investigated. The average duration of follow-up was 18.3 months. The average symptom duration before introduction into this study was 2.2 months. With an aseptic technique, the aspiration of the bursa was done with spinal needle or injection needle and syringe and then the insertion of silk suture material through the aspiration needle was performed. Over one year follow-up, recurrence, infection, pain, and limitation of range of motion were investigated by telephone interview. Results: Redness around the insertion site of silk suture material was found in all cases, but there was no development of active infection in eleven cases. At five days after procedure, a supprative infection was developed in one case. The results were considered satisfactory in 92% of cases and the average duration of treatment is 14.5 days. Conclusion: The drainage with silk suture material following aspiration of the bursa is effective and less invasive method in the early treatment of chronic prepatellar bursitis.

• Journal of the Korean Society of Radiology
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• v.4 no.3
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• pp.19-25
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• 2010

Dysphagia is common and serious problems in post-stroke patients. The post-stroke dysphagia with aspiration is associated with dehydration, malnutrition, pneumonia, sepsis and death. Up to date, gag reflex and choking history used to decide the aspiration in clinical. The purpose of this study was to evaluate the aspiration and to choice the proper meal formation using by video fluoroscpic swallowing study(VFSS) with post-stroke dysphagia patients. 58 post-stroke patients and ten normal person participated to perform the VFSS with liquid type, puding, yoplait, rice mixed with barium(Ba). Two rehabilitation medicine doctors and a radiological technologist analysed the phase(oral, pharyngeal, esophageal phase)with video film, and checked the pharyngeal transition time(PTT). 38 patients showed abnormality in pharyngeal phase, 13 patients in oral and pharyngeal phase, 3 patients in oral phase, and 2 patients in pharyngeal and esophageal phase. 43 patients(65.2%) occured the aspiration, but 23 of 43 patients improved by the chin tuck position. Aspiration occured 34 patients in liquid type, 2patients in rice gruel and nothing in boiled rice. After VFSS, 13 of 23 patients change the intaking pathway from nasogastric tube(NGT) to oral, On the contrary with 3 of 42 patients from oral to NGT. Consequently VFSS is clearly effective to evaluate the aspiration with post-stroke dysphagia patients.

• Tuberculosis and Respiratory Diseases
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• v.46 no.1
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• pp.75-81
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• 1999

Background : Recently, there are many patients with lipoid pneumonia by ingestion of shark liver oil in Korea, but only a few animal experimentations have been carried out. The purpose of this study is to evaluate sequential change of the lung after aspiration of shark liver oil and to provide the radiologic-pathologic correlation. Methods: A single intratracheal administration of shark liver oil was given to 14 white rabbits. They were then sacrificed sequentially from 1 week to 6 weeks after injection. We investigated the HRCT and pathologic findings Results: One was sudden death immediately after injection. Six of the 13 rabbits showed pneumonic infiltrations on the HRCT. There were air space consolidation with air-bronchogram on the HRCT of the first week. They were associated with the volume loss in the 4th week, and the traction bronchiectasis in the 6th week. The important pathologic findings were peribronchial alveolar inflammation with septal widening and cuboidal metaplasia of the alveolar wall. The number of macrophages in an alveoli was peaked in the second week and then gradually decreased. On the 6th week, we could find the proliferation of fibroblasts. Conclusion: We can prove the development of lipoid pneumonia after aspiration of squalene by animal experimentation, and the understanding of HRCT and pathologic findings may be helpful in proper evaluation of pneumonia due to aspiration of fish-extracted lipid.

• Journal of the Korean Society of Radiology
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• v.81 no.2
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• pp.409-417
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• 2020

Purpose To evaluate the safety and efficacy of the percutaneous manual aspiration thrombectomy technique to treat thrombotic occlusion of native arteriovenous fistulas. Materials and Methods A retrospective review of 20 patients who underwent percutaneous manual aspiration thrombectomy for native thrombotic arteriovenous fistula occlusion from March 2012 to December 2017 was performed. We evaluated technical and clinical success rates and complications. The primary and secondary patency rates were calculated using the Kaplan-Meier analysis. Results Percutaneous manual aspiration thrombectomy was performed in 20 patients (n = 20) with concomitant balloon angioplasty. The overall technical and clinical success rates were both 85% (n = 17). The native arteriovenous fistulas, based on their site, were the left radiocephalic (n = 13), left brachiocephalic (n = 4), and right radiocephalic (n = 3) fistulas. An underlying stenosis was detected in the juxta-anastomotic venous site (n = 16), outflow draining vein (n = 12), and central vein (n = 4). The primary and secondary patency rates at 1, 3, 6, and 12 months were 100%, 70.6%, 70.6%, and 56.5% and 100%, 94.1%, 94.1%, and 86.9%, respectively. There were no complications associated with procedure. Conclusion Percutaneous manual aspiration thrombectomy is a safe and effective method to treat thrombotic native arteriovenous fistula occlusion.

• Clinical and Experimental Pediatrics
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• v.45 no.9
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• pp.1134-1140
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• 2002

Purpose : Childhood accidents have been increasing recently. Accidents rank as the leading cause of childhood mortality and morbidity. We performed this study to evaluate the causes of childhood accidents. Methods : The authors analysed retrospectively the medical records of 6,410 cases of childhood accidental injuries who visited the emergency room of Asan Medical Center from January 1990 to December 1999. Results : The most common type of accidents was trauma which accounted for 5,038 cases of the total accidents, followed by falls, burns, foreign body aspiration, and poisoning. The most common age of foreign body aspiration was under two years old and the male to female ratio was 2 to 1. The most common site of foreign body aspiration was the esophagus and the stomach, followed by the respiratory tract. In airways, the right and left main bronchus were the most common site for foreign body aspiration and were accompanied by the highest mortality. The most common foreign body in the gastrointestinal tract and respiratory tract were coins and peanuts, respectively. Conclusion : The most common cause of accidents was trauma, followed by falls, burns, foreign body aspiration, and poisoning. The incidence of foreign body aspiration and poisoning is increasing in infants. In cases of foreign bodies in airways, proper management is needed because of the high mortality rate.

• Journal of Chest Surgery
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• v.21 no.6
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• pp.1078-1083
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• 1988