Causes and Predictive Factors Associated with "Diagnosis Changed" Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

Kang, Byung Ju,Jo, Kyung-Wook,Park, Tai Sun,Yoo, Jung-Wan,Lee, Sei Won,Choi, Chang-Min,Oh, Yeon-Mok,Lee, Sang-Do,Kim, Woo Sung,Kim, Dong Soon,Shim, Tae Sun The Korean Academy of Tuberculosis and Respiratory 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the "diagnosis changed" rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: "diagnosis maintained", "diagnosis changed" (initially notified as TB, but ultimately diagnosed as non-TB), and "administrative error" (notified as TB due to administrative errors). Results: Excluding 17 patients in the "administrative error" group, the "diagnosis maintained" and "diagnosis changed" groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of "diagnosis changed" were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn's disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a "diagnosis changed" result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high "diagnosis changed" rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the "diagnosis changed" rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of "diagnosis changed" cases is desirable.

전면문제중심학습이 치의학교육의 자기주도적 학습, 의사소통, 문제해결 능력에 미치는 영향

이강욱 ( Kang-wook Lee ),홍진실 ( Jin-sil Hong ),장기완 ( Kee-wan Chang ) 대한구강보건학회 2016 大韓口腔保健學會誌 Vol.40 No.4

Objectives: The purpose of this study was to examine the effect of problem-based learning (PBL) on dental education to dental students. The following were investigated in this study: 1. Does PBL improve the ability of self-directed learning? 2. Does PBL change communication ability? 3. Does PBL change the strategy of problem solving? Methods: The participants of this study were 39 students in the experimental group and 68 students in the control group. The measurement tools of this study were self-directed learning, communication, and problem solving abilities tests designed by the Korean Educational Development Institute. The data was analyzed by the two-way ANOVA and ANOVA with repeated measures. Results: In self-directed learning ability during 3 semesters, the experimental group showed a U-shape change but the control group showed a reverse U-shape change. In the experimental group, the selfdirected learning ability was decreased after one year (after the first and second semester). The level of communication ability decreased every day during the three semesters monitored in both the control and experimental groups. The level of communication ability in the experimental group continuously decreased during the three semesters, with the exception of one semester. Finally, for the problem solving ability during the three semesters, the experimental group showed a reverse U-shape change while the control group showed a U-shape change. In the experimental group, there was no change after two semesters. Conclusions: On the basis of the findings in this study, the following conclusions can be made. First, problem-based learning has a positive educational effect compared to didactic-based learning within one year. Second, the appropriate length of PBL is two semesters, or one year. It could be recommended that dental education in Korea should be combined or hybridized with PBL; for example, PBL could be used in combination with brief lectures or block lectures by teachers.

Causes and Predictive Factors Associated with “Diagnosis Changed” Outcomes in Patients Notified as Tuberculosis Cases in a Private Tertiary Hospital

( Byung Ju Kang ),( Kyung Wook Jo ),( Tai Sun Park ),( Jung Wan Yoo ),( Sei Won Lee ),( Chang Min Choi ),( Yeon Mok Oh ),( Sang Do Lee ),( Woo Sung Kim ),( Dong Soon Kim ),( Tae Sun Shim ) 대한결핵 및 호흡기학회 2013 Tuberculosis and Respiratory Diseases Vol.75 No.6

Background: The aim of our study was to evaluate the “diagnosis changed” rate in patients notified as tuberculosis (TB) on the Korean TB surveillance system (KTBS). Methods: A total of 1,273 patients notified as TB cases on the KTBS in one private tertiary hospital in 2011 were enrolled in the present study. Patients were classified into three groups: “diagnosis maintained”, “diagnosis changed” (initially notified as TB, but ultimately diagnosed as non-TB), and “administrative error” (notified as TB due to administrative errors). Results: Excluding 17 patients in the “administrative error” group, the “diagnosis maintained” and “diagnosis changed” groups included 1,097 (87.3%) and 159 patients (12.7%), respectively. Common causes of “diagnosis changed” were nontuberculous mycobacterial (NTM) disease (51.7%, 61/118), and pneumonia (17.8%) in cases notified as pulmonary TB, and meningitis (19.5%, 8/41) and Crohn`s disease (12.2%) in cases notified as extrapulmonary TB. Being older than 35 years of age (odds ratio [OR], 2.18) and a positive acid-fast bacilli stain (OR, 1.58) were positive predictors and a TB-related radiological finding (OR, 0.42) was a negative predictor for a “diagnosis changed” result via multivariate logistic regression analysis in pulmonary TB cases. Conclusion: Because of a high “diagnosis changed” rate in TB notifications to the KTBS, the TB incidence rate measured by the KTBS may be overestimated. Considering the worldwide trend toward increased NTM disease, the “diagnosis changed” rate may increase over time. Thus, when reporting the annual TB notification rate in Korea, the exclusion of “diagnosis changed” cases is desirable.

Design of a shape memory composite(SMC) using 4D printing technology

Kang, Minkyu,Pyo, Youngjun,Jang, Joon young,Park, Yunchan,Son, Yeon-Ho,Choi, MyungChan,Ha, Joo wan,Chang, Young-Wook,Lee, Caroline Sunyong Elsevier 2018 Sensors and actuators. A Physical Vol.283 No.-

<P><B>Abstract</B></P> <P>A fused deposition modeling (FDM) tool was used to fabricate a shape memory composite (SMC) that combined a shape memory alloy (SMA) with a shape memory polymer (SMP). The SMA caused a shape memory effect due to a phase change between martensite and austenite phases, in turn due to a temperature change. Also, the SMP had a shape memory effect caused by changes in the proportions of hard and soft segments near the glass transition temperature (T<SUB>g</SUB>). Usually, common SMAs and SMPs are not reversible, so these materials do not go back to their original shapes once they are deformed. In this study, we fabricated 4D printing actuator via reversible SMC actuations using 3D printing technology. Nylon 12 was used as the 3D printing material in filament form. Moreover, the volume fraction of SMA to SMP was varied to find the optimum ratio for good operation cycles. A volume fraction of SMA:SMP of 1:5 showed the largest length change, of 8 mm, and the most rapid response time, of 4 s in overall dimension of 140mm×10mm×1mm (length×width×thickness).Thus, the SMC showed promising results for the application of stents and valve controllers that could be manufactured by 3D printing technology.</P> <P><B>Highlights</B></P> <P> <UL> <LI> An 4D printed SMC actuator was fabricated using SMA and SMP with a FDM 3D printer. </LI> <LI> A volume fraction of SMA:SMP of 1:5 showed the largest length change of 8 mm, and the most rapid response time of 4 s. </LI> <LI> The reversible actuator mechanism explains the SMC actuation via each shape memory effect. </LI> <LI> SMC showed potential application for stents and valve controllers via 3D printing technology to achieve customized designs. </LI> </UL> </P>

내시경적 점막절제술로 치험한 식도 과립상 세포종 1례

강혁주,김성욱,최석진,이중현,장재식,서영범,윤병구,박건욱,김성자,김용섭,강승완,이구,양창헌,이창우,김욱년,이광헌,서정일 동국대학교 의학연구소 2000 東國醫學 Vol.7 No.-

과립상 세포종은 Schwann 세포 기원으로 생각되며 인체에 비교적 드물게 발생한다. 과립상 세포종은 전신 어느 곳에서나 발견될 수 있으나 주로 혀, 구강, 피부 혹은 유방 등에서 호발하며 드물게 위장관에서 발견된다. 위장관에서는 식도에서 가장 호발하며 다음으로 위, 대장 순이다. 과립상 세포종은 대부분, 특히 위장관에서는 양성이며 소수의 악성 병변이 보고되었다. 이러한 이유와 함께 수술 전의 진단이 어렵기 때문에 과립상 세포종에 대한 근본적인 치료는 현재까지 외과적 절제술이다. 최근에 시도되는 치료방법들로는 내시경적 레이저 치료, 용종절제술, 내시경적 점막 절제술 등이 있다. 저자들은 상부 소화관 내시경검사를 시행하여 식도 과립상 세포종을 진단하고 내시경적 점막 절제술을 시행하여 합병증 없이 퇴원하여 현재 재발없이 경과 관찰중인 1례를 경험하였기에 보고하는 바이다. Granular cell tumors, which occur infrequently, are probably of Schwann cell origin. They can occur almost anywhere in the body but usually affect the tongue, oral cavity, skin, or breasts and are rarely found in the gastrointestinal tracts. The esophagus is the most frequent gastrointestinal site, followed by the stomach and the colon. Granular cell tumors are generally benign, especially in the gastrointestinal tract, some malignant lesions have been reported. For this reason, and also because preoperative diagnosis is difficult, the standard treatment for granular cell tumor has until now been surgical excision. In recent years, other therapeutic methods is endoscopic laser therapy (ELT), polypectiomy, endoscopic mucosal resection (EMR). We report a case of esophageal granular cell tumor which was diagnosed by an endoscopy and managed using an endoscopic mucosal resection without complication.

Determining the Decision Limit of CUSUM Chart for A Fixed Sample Size

Kang, Chang Wook,Hawkins, Donglas M. The Korean Society for Quality Management 1992 품질경영학회지 Vol.20 No.1

When we compare different control charting schemes, the average run length of each control chart is usually used. The use of the average run length implies that there is unbounded number of samples or observations. The regression recursive residuals, however, have been applied to the cumulative sum chart to detect whether the mean or variance changes. To implement choice of decision interval, we calculate the probability that certain fixed number of control statistics stay in the in-control state. This probability can be used as the significance level of a test for detecting the change in the residual mean or variance of the data with a finite number of observations.

N Use Efficiency and Nitrate Leaching by Fertilization Level and Film Mulching in Sesame Cultivated Upland

Dong-Wook Lee,Ki-Do Park,Chang-Young Park,Il-Soo Son,Ui-Gum Kang,Jee-Yeon Ko,Kang-Bo Shim,Young-Son Cho,Sung-Tae Park 韓國作物學會 2007 Korean journal of crop science Vol.52 No.3

This study was conducted to evaluate the effect of slow release fertilizers (SRF), crotonylidene diurea (CDU) and latex coated urea (LCU), on nitrogen (N) use efficiency (NUE) and nitrate-N leaching in a silty clay loam soil under polyethylene film mulching (PFM) for sesame cultivation. In PFM plot, concentrations of NO3-N and NH4-N in SRF applied soils were less than that in the urea plot during the whole growing period. However, NO3-N and NH4-N in all the non-mulched plots (NM) were not significantly different. Urea-N in soil treated with SRF was higher than urea plot until 50 days after application and was comparable in all the treatments after 50 days. NO3-N concentrations in leached solution in 21 days after urea fertilization in PFM and NM were 26 mg L-1 and 83 mg L-1 , respectively. However, NO3-N in leached solution at applied CDU and LCU was less than that of urea similar to nitrate concentration in soil. NO3-N in leached solution in applied CDU and LCU in 44 days after application was about 25% lower than that urea plot and PFM, while the NO3-N concentration of CDU and LCU treatment in NM did not changed. Application of SRF increased the yield of sesame and N recovery compared to urea and there was a little difference between SRF and N levels. In conclusion, application of 80% N level with SRF increased N recovery and reduced nitrate leaching without reduction of yields compared with urea application.

N Use Efficiency and Nitrate Leaching by Fertilization Level and Film Mulching in Sesame Cultivated Upland

Lee, Dong-Wook,Park, Ki-Do,Park, Chang-Young,Son, Il-Soo,Kang, Ui-Gum,Ko, Jee-Yeon,Shim, Kang-Bo,Cho, Young-Son,Park, Sung-Tae The Korean Society of Crop Science 2007 Korean journal of crop science Vol.52 No.3

This study was conducted to evaluate the effect of slow release fertilizers (SRF), crotonylidene diurea (CDU) and latex coated urea (LCU), on nitrogen (N) use efficiency (NUE) and nitrate-N leaching in a silty clay loam soil under polyethylene film mulching (PFM) for sesame cultivation. In PFM plot, concentrations of $NO_3-N$ and $NH_4-N$ in SRF applied soils were less than that in the urea plot during the whole growing period. However, $NO_3-N$ and $NH_4-N$ in all the non-mulched plots (NM) were not significantly different. Urea-N in soil treated with SRF was higher than urea plot until 50 days after application and was comparable in all the treatments after 50 days. $NO_3-N$ concentrations in leached solution in 21 days after urea fertilization in PFM and NM were 26 mg $L^{-1}$ and 83 mg $L^{-1}$, respectively. However, $NO_3-N$ in leached solution at applied CDU and LCU was less than that of urea similar to nitrate concentration in soil. $NO_3-N$ in leached solution in applied CDU and LCU in 44 days after application was about 25% lower than that urea plot and PFM, while the $NO_3-N$ concentration of CDU and LCU treatment in NM did not changed. Application of SRF increased the yield of sesame and N recovery compared to urea and there was a little difference between SRF and N levels. In conclusion, application of 80% N level with SRF increased N recovery and reduced nitrate leaching without reduction of yields compared with urea application.

축소형 틸트로터 무인기의 안전줄 호버 시험

강영신 ( Young Shin Kang ),박범진 ( Bum Jin Park ),유창선 ( Chang Sun Yoo ),장성호 ( Sung Ho Chang ),최성욱 ( Seong Wook Choi ),구삼옥 ( Sam Ok Koo ) 한국항공운항학회 2007 한국항공운항학회지 Vol.15 No.4

Tilt rotor aircraft can take off and land vertically and cruise faster than any other helicopter. A scaled flight demonstration model of a tilt rotor aircraft has been developed by KARI. Because the flight characteristics of tilt rotor are not well known, the developed scaled model would be helpful to evaluate flight control algorithm of a full scale aircraft. The tethered hover test has been performed in order to improve hover flight characteristics of tilt rotor aircraft prior to flight test of the small scaled model. During the tethered hover test, the performance of rotor speed governor, rate SAS (Stability Augmentation System) and control surface mixers have been evaluated. We expect that the results of real flight hover test would be quite same as tethered hover test. Therefore the tethered hover test results will reduce the risk of flight test properly by fixing some of hidden problems which might occur during the flight test. This paper presents the results of tethered hover test in detail and shows how it could be final ground test before flight test. The control mixer gain and rate SAS feedback gains were modified in order to get higher controllability and stability during the tethered hover flight. The rotor governor showed that it could keep rotor RPM constant with very small deviation even during severe pilot collective input change. The tethered hover test results gave pilot and engineers confirmation and experience about the scheduled flight test.

Effect of epidural corticosteroid injection on magnetic resonance imaging findings

( Min Soo Kim ),( Tae Yoon Jeong ),( Yu Seon Cheong ),( Young Wook Jeon ),( So Young Lim ),( Seong Sik Kang ),( In Nam Kim ),( Tsong Bin Chang ),( Hyun Ho Seong ),( Byeong Mun Hwang ) 대한통증학회 2017 The Korean Journal of Pain Vol.30 No.4

Background: Magnetic resonance imaging (MRI) of the spine is the preferred diagnostic tool for pathologic conditions affecting the spine. However, in patients receiving epidural corticosteroid injection (ESI) for treatment of spinal diseases, there is a possibility of misreading of MR images because of air or fluid in the epidural space after the injection. Therefore, we defined the characteristics of abnormal changes in MRI findings following an ESI in patients with low back pain. Methods: We reviewed the medical records of 133 patients who underwent MRI of the lumbar spine within 7 days after ESI between 2006 and 2015.All patients were administered an ESI using a 22-gauge Tuohy needle at the lumbar spine through the interlaminar approach. The epidural space was identified by the loss of resistance technique with air. Results: The incidences of abnormal changes in MRI findings because of ESI were 54%, 31%, and 25% in patients who underwent MRI at approximately 24 h, and 2 and 3 days after ESI, respectively. Abnormal MRI findings included epidural air or fluid, needle tracks, and soft tissue changes. Epidural air, the most frequent abnormal finding (82%), was observed in 41% of patients who underwent MRI within 3 days after injection. Abnormal findings due to an ESI were not observed in MR images acquired 4 days after ESI or later. Conclusions: Pain physicians should consider the possibility of abnormal findings in MR images acquired after epidural injection using the interlaminar approach and the loss of resistance technique with air at the lumbar spine. (Korean J Pain 2017; 30: 281-6)