저신장 소아청소년의 임상적 접근

남효경 이화여자대학교 의과학연구소 2021 EMJ (Ewha medical journal) Vol.44 No.4

Growth represents a sentinel for general health state in children and adolescent. Linear growth in children and adolescent is a complex process influenced by numerous factors including genetic, prenatal, postnatal, and environmental factors. When children less than 2 standard deviation score below the average height for age and sex, they are considered as short stature. Accurate measurement of body profile and determination of height velocity over time are fundamental step. Whether the growth pattern is appropriate or deviated from standardized growth chart is a key point in approaching to short stature in children. Evaluation includes a detailed past medical and family history, physical examination, laboratory test and radiologic evaluation. Recent advances in genetic approaches are allowing for improved diagnosis for idiopathic short stature and various genetic syndromes. Growth hormone is the main treatment option for short stature. It is generally safe but has potential side effects. Individualized growth hormone treatment should be initiated under consideration of both efficacy and safety by pediatric endocrinologists. Early diagnosis and prompt initiation of treatment result in a good prognosis. This article reviews an overview of the diagnostic approach to children and adolescents with short stature, and summarizes etiologies and growth hormone treatment.

항공우주용 복합재튜브의 충격압궤특성에 관한 연구

김영남,최효석,기경서,김기형,양인영 朝鮮大學校 機械技術硏究所 2000 機械技術硏究 Vol.3 No.1

본 연구의 목적은 준정적 및 충격실험에 대한 CFRP 박육부재의 에너지흡수특성에 관하여 고찰하고자 한다. 준정적실험은 신강좌굴실험기를, 충격실험은 수직식 충격압궤실험장치를 사용하였으며, 총 178개의 CFRP 박육부재에 대하여 준정적 및 충격압궤실험을 수행하였다. CFRP 원형관의 압궤실험시 그 응답특성은 매우 복잡하며, 압궤과정중 상이한 역학적 상호관계에 의존하게 된다. 본 연구에서는 다양한 적층조건을 갖는 박육부재의 압궤특성과 흡수에너지에 관하여 실험후 고찰하였다. 그 결과 CFRP 박육부재의 에너지 흡수 특성은 초기결함(Trigger)과 계면수 등에 관한 다양한 함수로 나타났으며, 일반적으로 CT-타입의 CFRP 박육부재의 에너지 흡수특성이 다른 박육부재에 비해 가장 높음을 알수 있었다. The purpose of this study is to investigate on the energy absorption characteristics of CFRP (Carbon Fiber Reinforced Plastics) tubes on quasi-static and impact tests. Quasi-static and impact compression tests were performed on 178 tubes. Static compression tests have been carried out using the static testing machine(Shin-gang buckling testing machine) and impact compression tests have been carried out using the vertical crushing testing machine. When such tubes are subjected to crushing loads, the response is complex and depends on the interaction between the different mechanisms that control the crushing process. The collapse characteristics and energy absorption of a variety of tubes have been examined. The results varied significantly as a function of trigger and interlaminar number. In general, the CT-type tubes absorbed more energy than the others.

유치원, 초등, 중등 학생들의 고체, 액체, 기체의 압력개념 유형분석

김효남,조부경,백성혜 한국교원대학교 과학교육연구소 2003 청람과학교육연구논총 Vol.13 No.1

유치원에서 고등학생들 까지의 고체, 액체, 기체의 압력에 대한 개념 유형이 분석되었다. 28명의 학생들이 압력에 대한 활동을 하였고, 활동 전후에 압력에 대하여 면담하였다. 면담 내용이 비디오로 녹화되었고 전사되었다. 면담 내용은 지각적, 비과학적, 준과학적, 과학적 유형으로 나누어 보았다. 학생들이 학년이 올라갈수록 압력에 대한 과학적 유형의 응답이 많았는데, 이는 학생들의 인지수준의 발달과 학습의 결과로 보인다. 고체의 압력 크기는 대체로 초등학교 6학년에서, 고체의압력 방향에 대하여는 중학교 2학년에서 형성된 것으로 분석되었다. 액체의 압력 크기 개념은 고등학교 2학년에서, 액체의 압력 방향 개념은 초등학교 6학년에서 대체로 형성된 것으로 나타났다. 기체의 압력 크기와 기체의 압력 방향 개념은 고등학교 2학년에서 형성된 것으로 나타났다. 물질의 압력 개념은 대기압, 수압, 건물과 다리의 압력 등의 자연현상 이나 인공물에 나타나는 기본 개념이다. 이러한 압력 개념은 유치원에서 부터 고등학교 까지 체계적으로 나타나는 기본 개념이다.이러한 압력 개념은 유치원에서 부터 고등학교 까지 체계적으로 다루어져야 할 개념이다. 고체의 압력 크기와 방향, 액체의 압력 방향 개념은 초등학교 6학년에서 그리고 액체의 압력 크기와 기체의 압력크기와 방향 개념은 중학교 3학년에서 다루는 것이 학생들이 인지발달과 현재의 과학과 수학 교육과정을 고려할 때에 바람직하다고 본다. The K-12 students' conceptual patterns of the pressure of solid, liquid and gas are analyzed. Twenty eight students are interviewed after doing six activities about pressure. The interviews are video recorded and transcribed. The transcription is analyzed to find conceptual patterns about pressure. Students showed sensual, non-scientific, partial-scientific, and scientific patterns about pressure. The result showed that students understand pressure more scientifically according to increasing grades. The magnitude of pressure of solid is understood by the 6th grade; the direction of pressure of solid, by the 8th graders. The magnitude of pressure of liquid is understood by the 11th graders; the direction of pressure of liquid, by the 6th graders. The magnitude and the direction of pressure of gas is understood by the 11th graders. The pressure concept of matter is a basic concept about matter and natural phenomena such as atmosphere, water pressure, gas pressure and solid pressure in the buildings or bridges. The pressure concept should be taught in the K-12 science. It will be recomended that the pressure concept of solid is taught in the 6th grade, of liquid and gas, in the 9th grade.

CPW 급전을 이용한 평면형 반원 UWB 안테나 설계

이효경,이정남,박종권 한밭대학교 정보통신전문대학원 2005 정보통신전문대학원 논문집 Vol.3 No.1

본 논문에서는 UWB 통신 시스템에 사용될 수 있는 CPW 급전 구조을 이용한 평면형 반원 UWB 안테나를 설계하였다. 제안된 안테나를 설계하기 위해 CST사의 MWS를 이용하였다. 유전율이 4.5이고, 두께가 0.762mm인 TMM4 기판을 사용하였다. 시뮬레이션 결과 VSWR≤2를 기준으로 2.6GHz에서 12.2GHz까지 UWB 전체 대역을 만족한다. 제안된 안테나의 group delay 변화량이 1ns 미만으로 UWB 통신 시스템 응용에 적합한 안테나이다. In this paper, a planar half-disk ultra-wideband (UWB) antenna fed by CPW is designed for UWB communications. We have used the Microwave Studio of CST to simulate the proposed antenna. It is designed to work an a substrate TMM4 of thickness 0.762mm and relative permittivity 4.5. The proposed antenna covers the entire UWB band (3.1 GHz ~ 10.6 GHz) from 2.6 GHz to 12.2 GHz for VSWR≤2. Group delay variation is less than 1 ns, thus indicating the proposed antenna a good candidate for UWB applications.

Clinical validation of a deep-learning-based bone age software in healthy Korean children

Nam Hyo-Kyoung,Lea Winnah Wu-In,Yang Zepa,Noh Eunjin,Rhie Young-Jun,Lee Kee-Hyoung,Hong Suk-Joo 대한소아내분비학회 2024 Annals of Pediatirc Endocrinology & Metabolism Vol.29 No.2

Purpose: Bone age (BA) is needed to assess developmental status and growth disorders. We evaluated the clinical performance of a deep-learning-based BA software to estimate the chronological age (CA) of healthy Korean children.Methods: This retrospective study included 371 healthy children (217 boys, 154 girls), aged between 4 and 17 years, who visited the Department of Pediatrics for health check-ups between January 2017 and December 2018. A total of 553 left-hand radiographs from 371 healthy Korean children were evaluated using a commercial deep-learning-based BA software (BoneAge, Vuno, Seoul, Korea). The clinical performance of the deep learning (DL) software was determined using the concordance rate and Bland-Altman analysis via comparison with the CA.Results: A 2-sample <i>t</i>-test (<i>P</i><0.001) and Fisher exact test (<i>P</i>=0.011) showed a significant difference between the normal CA and the BA estimated by the DL software. There was good correlation between the 2 variables (<i>r</i>=0.96, <i>P</i><0.001); however, the root mean square error was 15.4 months. With a 12-month cutoff, the concordance rate was 58.8%. The Bland-Altman plot showed that the DL software tended to underestimate the BA compared with the CA, especially in children under the age of 8.3 years.Conclusion: The DL-based BA software showed a low concordance rate and a tendency to underestimate the BA in healthy Korean children.

A Comparison of Nicotine Diffusive Sampler and XAD-4 Tube for Determination of Nicotine in ETS

Hyo Cherl Klm,Nam Won Paik,Kyoung Ran Kim,Kyoung Su Kim,Kyoung Suk Lee,Kyung Ah Cho 한국환경보건학회 2005 한국환경보건학회 학술대회 자료집 Vol.2005 No.-

반복적인 천음과 호흡곤란을 보인 영아에서 진단된 선천성 심, 폐기형 3례

남효경 ( Hyo Kyoung Nam ),라경숙 ( Kyong Suk La ),변정혜 ( Jung Hye Byeon ),최익선 ( Ic Sun Choi ),장기영 ( Gi Young Jang ),유영 ( Young Yoo ),정지태 ( Ji Tae Choung ),손창성 ( Chang Sung Son ),함수연 ( Soo Youn Ham ) 대한소아알레르기호흡기학회 2009 소아알레르기 및 호흡기학회지 Vol.19 No.2

Although laryngomalacia is the most common cause of congenital stridor in infancy, it is a benign, self-limited disease which usually resolves by the age of 18 months with no long-term sequelae. Nevertheless, infants who suffered from recurrent stridor and respiratory distress should be evaluated for other causes of stridor such as cardiopulmonary anomalies. We report 3 cases of infants who had recurrent stridor and respiratory distress from their early infancy. Case 1 had a double aortic arch and a tracheomalacia, case 2 had a hypoplasia of the right lung, and case 3 had a horseshoe lung as well as scimitar syndrome. Physicians should be alert for the possibility of the congenital cardiopulmonary abnormalities in infants with recurrent stridor and/or respiratory distress. [Pediatr Allergy Respir Dis(Korea) 2009; 19:183-190]

In-situ rf plasma treatment of multiwall carbon nanotubes with Various Reactive Gases for Enhanced Field Emission

Kyoung Soo Ahn,Ji Hoon Kim,Kyoung Nam Lee,Chang Hyo Lee,Chae Ok Kim,Jin Pyo Hong,정현식,Yu Jin Jeon 한국물리학회 2004 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.45 No.1

Well-aligned multi-wall carbon nanotubes (MWNTs) were fabricated at a low temperature of 400 C by utilizing a radio-frequency plasma-enhanced chemical vapor deposition (rf-PECVD) system. The MWNTs were in-situ treated with external rf plasma sources, such as hydrogen (H2) and ammonia (NH3), in order to enhance the structural and electrical properties of the MWNTs. Structural properties of carbon nanotubes were investigated by using scanning electron microscopy, Fourier transform infrared spectroscopy, energy-dispersive spectrometry and transmission electron microscopy. Finally, the emission properties of the MWNTs treated with various gases were also measured, for application in eld emission displays in the near future.

One Stage Posterior Minimal Laminectomy and Video-Assisted Thoracoscopic Surgery (VATS) for Removal of Thoracic Dumbbell Tumor

Nam, Kyoung Hyup,Ahn, Hyo Yeoung,Cho, Jeong Su,Kim, Yeoung Dae,Choi, Byung Kwan,Han, In Ho The Korean Neurosurgical Society 2017 Journal of Korean neurosurgical society Vol.60 No.2

Objective : This study was conducted to assess the surgical results of one-stage posterior minimal laminectomy and video-assisted thoracoscopic surgery (VATS) for the treatment of thoracic dumbbell tumor and to describe its precise technique. In addition, we investigated the technique's usefulness and limitations. Methods : Seven cases of thoracic dumbbell tumor (two men and five women, mean age, 43 years) were analyzed retrospectively. Pathological findings included schwannoma in four patients, neurofibroma in two patients, and hemangioma in one patient. The location of tumors varied from T2/3 to T12/L1. Dumbbell tumors were resected by one-stage operation using posterior laminectomy followed by VATS without instrumentation. Clinical data were reviewed. Results : The mean follow-up period was 25 months (range, 3-58 months), and the operative time ranged from 255 to 385 min (mean, 331 min), with estimated blood loss ranging from 110 to 930 mL (mean, 348 mL). The tumor was completely resected without instrumentation and postoperative instability in all cases. Postoperative complications included atelectasis and facial anhydrosis in one case each. Conclusion : One-stage posterior minimal laminectomy and VATS may be a safe and less invasive technique for removal of thoracic dumbbell tumor without instability. This method has the advantage of early ambulation and rapid recovery because it reduces blood loss and postoperative pain.

Bulky solitary plasmacytoma in retroperitoneal space (초)

( Hyo Shik Kim ),( Young Woo Jeon ),( Ji Na Yoon ),( Han Jo Kim ),( Kyoung Ha Kim ),( Se Hyoung Kim ),( Hyun Jung Kim ),( Sang Cheol Lee ),( Sang Byung Bae ),( Chan Kyu Kim ),( Nam Su Lee ),( Kyu Taeg 대한내과학회 2012 대한내과학회 추계학술대회 Vol.2012 No.1