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A Case of IgG4-Related Lung Disease Presenting as Interstitial Lung Disease
Ahn, Jee Hwan,Hong, Sun In,Cho, Dong Hui,Chae, Eun Jin,Song, Joon Seon,Song, Jin Woo The Korean Academy of Tuberculosis and Respiratory 2014 Tuberculosis and Respiratory Diseases Vol.77 No.2
Intrathoracic involvement of immunoglobulin G4 (IgG4)-related disease has recently been reported. However, a subset of the disease presenting as interstitial lung disease is rare. Here, we report a case of a 35-year-old man with IgG4-related lung disease with manifestations similar to those of interstitial lung disease. Chest computed tomography showed diffuse ground glass opacities and rapidly progressive pleural and subpleural fibrosis in both upper lobes. Histological findings showed diffuse interstitial lymphoplasmacytic infiltration with an increased number of IgG4-positive plasma cells. Serum levels of IgG and IgG4 were also increased. The patient was diagnosed with IgG4-related lung disease, treated with anti-inflammatory agents, and showed improvement. Lung involvement of IgG4-related disease can present as interstitial lung disease and, therefore, should be differentiated when evaluating interstitial lung disease.
( Jee Hwan Ahn ),( Jin Won Huh ),( Sang-bum Hong ),( Chae-man Lim ),( Younsuck Koh ) 대한결핵 및 호흡기학회 2020 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.128 No.0
Background The high-flow nasal cannula (HFNC) therapy has been increasingly used in acute respiratory distress syndrome (ARDS). However, it is unclear whether the HFNC therapy benefits the prognosis of ARDS. We investigated the effects of the preceding HFNC therapy on the prognosis in mechanically ventilated patients with ARDS. Methods We retrospectively reviewed the medical charts of adult patients who were admitted to the ICU in Asan Medical Center due to de novo acute respiratory failure from 2013 to 2018. Patients meeting the Berlin definition of ARDS except the criterion of end-expiratory pressure ≥5 cm H2O until 24 hours from ICU admission were included. Study patients who received the HFNC therapy for ≥1 hour were classified to the HFNC group. Results A total of 92 patients (40 in the HFNC group, 52 in the non-HFNC group) were included. Two groups had no significant differences in the baseline characteristics. The median time from ARDS diagnosis to starting mechanical ventilation was significantly longer in the HFNC group (30.2 [17.1-65.6] vs. 3.8 [0.5-13.9] hours; P<0.001). Although the PaO2/FiO2 ratios of the two groups were similar at ARDS diagnosis (140±49 vs. 146±53 mm Hg; P=0.584), it became significantly lower in the HFNC group immediately before mechanical ventilation (91±33 vs. 128±55; P<0.001). This difference disappeared after starting mechanical ventilation (132±70 vs. 137±67; P=0.759). Two groups showed similar treatment outcomes in terms of ICU mortality (40% vs. 42%; P=0.824), hospital mortality (52% vs. 52%; P=0.956), and ventilator-free days up to the 28th day (a median of 16 [0-22] vs. 18 [7-21] days; P=0.484). Conclusions In our study, the preceding HFNC therapy delayed starting mechanical ventilation but did not affect treatment outcomes in mechanically ventilated patients with ARDS.
( Jee Hwan Ahn ),( Byung Ju Kang ),( Sun In Hong ),( Jung Su Lee ),( Jae Seung Lee ),( Yeon Mok Oh ),( Sang Do Lee ) 대한내과학회 2014 대한내과학회 추계학술대회 Vol.2014 No.1
Background: A vasoreactive subset of patients with idiopathic pulmonary arterial hypertension (IPAH) was noted in Western countries, which showed favorable prognosis with treatment with high-dose calcium channel blockers. We aimed to identify IPAH patients with vasoreactivity in Korea and to show their clinical characteristics and prognosis. Methods: Data on patients who were diagnosed with IPAH at Asan Medical Center between January 1994 and March 2013 were retrospectively collected. Acute vasodilator testing was performed with inhaled nitric oxide during diagnostic right heart catheterization. A positive acute response was defined as a reduction in mean pulmonary arterial pressure (PAP) =10 mm Hg to an absolute level of mean PAP <40 mm Hg without a decrease in cardiac output. Results: Among a total of 60 IPAH patients included for analysis, 9 (15%) showed a positive acute response to acute vasodilator testing. Acute responders showed signify-cantly lower peak velocity of a tricuspid regurgitation jet on echocardiography (4.1 ± 0.3 m/s versus 4.6 ± 0.6 m/s; P = 0.01) and significantly lower mean PAP hemodynamically (47 ± 10 mm Hg versus 63 ± 17 mm Hg; P = 0.003) than non-responders at baseline. The survival rate of acute responders was 88% at 1, 3, 5, and 10 years, respectively, which was significantly higher than that of non-responders (85%, 71%, 55%, and 40%, respectively; P = 0.029). Conclusions: Korean IPAH patients with vasoreactivity showed better baseline hemodynamic features and survival than those without vasoreactivity.
Development of the Base Station Controller and Manager in the CDMA Mobile System
Ahn, Jee-Hwan,Shin, Dong-Jin,Cho, Cheol-Hye Electronics and Telecommunications Research Instit 1997 ETRI Journal Vol.19 No.3
The base station (BS) in the CDMA Mobile System (CMS) connects calls through the radio interface and is designed to provide mobile subscribers with high quality service in spite of mobile subscribers motions. The BS consists of multiple base station transceiver subsystems (BTSs), a base station controller (BSC) and a base station manager (BSM). This paper is concerned with the BSC and the BSM. The BSC is located between the BTSs and the mobile switching center (MSC) connected with the public network, and to mobile subscribers via the BTSs. The BSM provides operator-interfaces per the BS and takes responsibility of operation and maintenance (OAM) of the BS. Design of the BSC is based on two module types: functional module and unit module. The functional module is used to support new services easily and the unit module to increase the system capacity economically. Both modular types are easily achieved by inserting the corresponding modules to the system. Particularly, in order to efficiently support the soft handover which is one of CDMA superior advantages, the BSC adopts a large high-speed Packet switch connecting up to 512 BTSs, and thus mobile subscribers can be provided with soft handover in high probability. The BSM is based on a commercial workstation to support OAM functions efficiently and guarantee high reliability of the functions. The BSM uses graphical user interface (GUI) for efficient OAM functions of the BS.
( Jee Hwan Ahn ),( Byung Ju Kang ),( Sun In Hong ),( Jung Su Lee ),( Jae Seung Lee ),( Yeon Mok Oh ),( Sang Do Lee ) 대한결핵 및 호흡기학회 2014 대한결핵 및 호흡기학회 추계학술대회 초록집 Vol.118 No.-
Background: A vasoreactive subset of patients with idiopathic pulmonary arterial hypertension (IPAH) was noted in Western countries, which showed favorable prognosis with treatment with high-dose calcium channel blockers. We aimed to identify IPAH patients with vasoreactivity in Korea and to show their clinical characteristics and prognosis. Methods: Data on patients who were diagnosed with IPAH at Asan Medical Center between January 1994 and March 2013 were retrospectively collected. Acute vasodilator testing was performed with inhaled nitric oxide during diagnostic right heart catheterization. A positive acute response was defined as a reduction in mean pulmonary arterial pressure (PAP) =10 mm Hg to an absolute level of mean PAP <40 mm Hg without a decrease in cardiac output. Results: Among a total of 60 IPAH patients included for analysis, 9 (15%) showed a positive acute response to acute vasodilator testing. Acute responders showed significantly lower peak velocity of a tricuspid regurgitation jet on echocardiography (4.1 ± 0.3 m/s versus 4.6 ± 0.6 m/s; P = 0.01) and significantly lower mean PAP hemodynamically (47 ± 10 mm Hg versus 63 ± 17 mm Hg; P = 0.003) than non-responders at baseline. The survival rate of acute responders was 88% at 1, 3, 5, and 10 years, respectively, which was significantly higher than that of non-responders (85%, 71%, 55%, and 40%, respectively; P = 0.029). Conclusions: Korean IPAH patients with vasoreactivity showed better baseline hemodynamic features and survival than those without vasoreactivity.
CASE REPORT : A Case of IgG4-Related Lung Disease Presenting as Interstitial Lung Disease
( Jee Hwan Ahn ),( Sun In Hong ),( Dong Hui Cho ),( Eun Jin Chae ),( Joon Seon Song ),( Jin Woo Song ) 대한결핵 및 호흡기학회 2014 Tuberculosis and Respiratory Diseases Vol.77 No.2
Intrathoracic involvement of immunoglobulin G4 (IgG4)-related disease has recently been reported. However, a subset of the disease presenting as interstitial lung disease is rare. Here, we report a case of a 35-year-old man with IgG4-related lung disease with manifestations similar to those of interstitial lung disease. Chest computed tomography showed diffuse ground glass opacities and rapidly progressive pleural and subpleural fibrosis in both upper lobes. Histological findings showed diffuse interstitial lymphoplasmacytic infiltration with an increased number of IgG4-positive plasma cells. Serum levels of IgG and IgG4 were also increased. The patient was diagnosed with IgG4-related lung disease, treated with anti-inflammatory agents, and showed improvement. Lung involvement of IgG4-related disease can present as interstitial lung disease and, therefore, should be differentiated when evaluating interstitial lung disease.
Unsteady streaming flow based TENG using hydrophobic film tube with different charge affinity
Ahn, Jee Hwan,Hwang, Jeong Yun,Kim, Chang Gon,Nam, Gyu Hyeon,Ahn, Kyoung Kwan Elsevier 2020 Nano energy Vol.67 No.-
<P><B>Abstract</B></P> <P>This paper proposes a simple, eco-friendly and economical fluid-based triboelectric nanogenerator (Flu-TENG), which is based on polyvinylidene fluoride (PVDF) between elastomeric tubes (P-TENG) and biaxially oriented polypropylene (BOPP) between elastomeric tubes (B-TENG). We examined the interactions based on the relation between the hydrodynamics of pipe flow and electrostatic induction at the electrical double layer (EDL). This is the first study to focus on the hydrodynamics of the unsteady pipe flow. From the experimental results, it was verified that the peak to peak current from unsteady flow is 70 times higher than that of steady flow. We also investigated the effect of triboelectric series to generate higher output. When the PVDF and Ground/PVDF/BOPP are connected respectively, it is called as P-TENG/PP-TENG/PB-TENG. The measured short circuit current at 15.9 Hz for P-TENG/PP-TENG/PB-TENG are 0.29 μA, 1.59 μA and 2.40 μA, respectively. And the measured open circuit voltage of P-TENG/PP-TENG/PB-TENG are 3.71 V, 14.6 V and 29.7 V, respectively. Finally, we verified the maximum power reaches 11.5 μW in the case of PB-TENG. This provides a new approach for improving the output power of the FluTENG for special applications.</P> <P><B>Highlights</B></P> <P> <UL> <LI> A novel <B>PB-TENG</B> utilizing unsteady fluctuating flow has been proposed. </LI> <LI> The mechanism of energy harvesting in <B>unsteady streaming flow</B> is investigated. </LI> <LI> It was verified that current output of unsteady flow is 70 times larger than that of steady. </LI> <LI> Maximum RMS power has been achieved up to 11.5 μW for PB-TENG and 8.1 μW for PG-TENG. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>
오작동 방지를 위한 화재위험 감지기 및 수신기 시스템 기술
안지환(Jee-Hwan Ahn),안재우(Jae-Woo Ahn),김경수(Kyung-Soo Kim),이재각(Jae-Gak Lee),구경완(Kyung-Wan Koo) 대한전기학회 2021 대한전기학회 학술대회 논문집 Vol.2021 No.10
주택, 사무실, 다중이용시설, 산업현장, 물류창고, 등에서 각종 화재에 따른 인명 및 재산 피해가 빈번히 발생하고 있으며, 이를 감지하는 센서의 잦은 오작동으로 소방차의 오인출동으로 인한 비용과 실재해 발생 시에 긴급대응 지연에 따른 피해가 발생할 수 있다. 화재 감지기는 화재 발생 시에 피해를 최소화하기 위하여 화재 발생을 초기에 감지하여 화재 경보하는 것이중요하다. 감지기 설치현장 상황을 반영하지 않은 경우에는 감지기의 잦은 오작동·미작동으로 인하여 잦은 비화재보와 화재실보가 야기된다. 본 논문에서는 비화재보 방지를 위하여 감지기 설치 현장의 특성을 고려한 복합센서의 다신호 파라메터 분석을 통하여 화재경보의 오작동과 미작동을 방지할 수 있는 화재 감지기와 수신기 시스템 기술을 소개한다.