신부전이 동반된 당뇨병 환자에서 발생된 침습성 모균증 : 수술과 Liposomal amphotericin B 및 GM-CSF 병합 요법에 의한 성공적인 치험 1예

이원영,오기원,임국희,장재혁,이동건,최정현,강무일,신완식,차봉연,이광우,손호영,강성구 대한화학요법학회 1999 대한화학요법학회지 Vol.17 No.4

저자들은 신부전이 동반된 당뇨병 환자에서 발생된 부비동형 모균증에 대하여 수술과 함께 liposomal amphotericin B 및 GM-CSF의 복합치료를 하여 성공적으로 치료한 1예를 경험하였기에 문헌 고찰과 함께 보고하는 바이다. Mucormycosis (zygomycosis) primarily affects diabetic or immunocompromised patients and typically progresses rapidly, necessitating surgical excision and antifungal therapy with amphotericin B. Large doses of amphotericin B are needed for cure, but it has the risk of causing significant renal toxicity. The recent development of liposomal amphotericin B allows antifungal therapy to be administered with potentially improved efficacy and reduced nephrotoxicity. We have experienced a case of paranasal mucormycosis successfully treated with surgery, liposomal amphotericin B and GM-CSF. A 59-year-old male suffering from diabetes mellitus for 6 years was admitted with pain at left maxillary area. He was diagnosed as mucormycosis after cytologic exam on the necrotic nasal mucosa, which showed typical hyphae. He have had diabetic nephropathy with macroproteinuria and had rapidly rising serum creatinine levels with the amphotericin B treatment: creatinine levels reverted to basal level with the use of liposomal amphotericin B. Despite surgical excision and continued antifungal therapy, his infection was not effectively controlled. Therefore, GM-CSF was administered additionally to improve phagocytic activity of leukocytes. He was finally cured after receiving a combination of aggressive surgery, liposomal amphotericin B and GM-CSF. To our knowledge, this is the first detailed clinical description of the treatment of mucormycosis with liposomal amphotericin B in Korea.

상부소환관협착에 대한 Savary-Gilliard Dilatation의 치료효과와 안전성에 관한 관찰

정현용,육은주,임의혁,김병호,성자원,이기천,허승식,이헌영,김영건 충남대학교 의과대학 지역사회의학연구소 1992 충남의대잡지 Vol.19 No.2

For the patient with stenosis of upper digestive tract caused by either benign or malignant process, esophageal dilatation is an important therapeutic modality. We reviewed retrospectively 39 cases treated by Savary-Gilliard dilatation for upper digestive tract stenosis, and results were follows : (1) Dysphagia was improved in 95% of the patients. (2) Eight patients(20%) sufferd perforation, five of them were managed with conservative medical measures, others were managed operatively. (3) In the cases with benign stenosis dysphagia was not noticed for 8.8 months, but with malignant stenosis dysphagia was reappeared after 2.8 months despite concomitant chemoradiotherapy. In conclusion, Savary-Gilliard dilatation was an effective measure for symptome due to upper digestive tract stenosis, but more careful attention for perforation should be necessitated. Also another therapeutic modality for treatment of malignant stenosis was inevitable.

내시경으로 진단된 소화성 궤양의 임상적 고찰

김영건,육은주,김성걸,임의혁,성자원,김병호,허승식,이기천,정현용,이헌영 충남대학교 의과대학 지역사회의학연구소 1993 충남의대잡지 Vol.20 No.2

A clinical analysis was performed of 3055 pateints with peptic ulcer who were diagnosed with gastroduodenoscopy, in Hospital of Chungnam National University College of Medicine from July 1988 to May 1993. 1) During the period 1988-1993, The proportion of gastric ulcer among peptic ulcer decreased from 47.8% to 42.8%, but that of duodenal ulcer increased from 36.8% to 39.6%. 2) Of the 3055 cases, the number of patients with esophageal ulcer was 98(3.2%), with gastric ulcer 1407(41.6%), with. duodenal ulcer 1104(36.1%), with channel ulcer 149(4.9%), and with combind ulcer 297(9.7%). 3) We observed a peak incidence of peptic ulcer in the 50-69age group, gastric ulcer in the 5069age, duodenal ulcer in the 40-59age group. The ratio of male to female was 3.6 : 1 in peptic ulcer, 4.4 : 1 in gastric ulcer, 3.0 : 1 in duodenal ulcer. 4) The common site was angle in gastric ulcer, and bulb in duodenal ulcer. 5) The active stage was 39.4% of gastric ulcer, and 37.4% of duodenal ulcer, the healing stage was 34.2% of gastric ulcer, and 17.9% of duodenal ulcer, and the scar stage of gastric ulcer was 26.4%, and duodenal ulcer was 44.7%. 6) The size of ulcer was less than 1Cm in 66.7% of gastric ulcer, and in 75.5% of duodenal ulcer, the size of ulcer was greater than 2Cm in 13.2% of gastric ulcer, and in 6.5% of duodenal ulcer. 7) The frequency of multiple ulcer was 29.9% in gastric ulcer, and 16.5% in duodenal ulcer.

1/<i>f</i> noise characteristics of AlGaN/GaN HEMTs with periodically carbon-doped GaN buffer layer

Im, Ki-Sik,Choi, Jinseok,Hwang, Youngmin,An, Sung Jin,Roh, Jea-Seung,Kang, Seung-Hyeon,Lee, Jun-Hyeok,Lee, Jung-Hee Elsevier 2019 MICROELECTRONIC ENGINEERING Vol.215 No.-

<P><B>Abstract</B></P> <P>We investigate the DC and 1/<I>f</I> noise properties in Al<SUB>0.25</SUB>Ga<SUB>0.75</SUB>N/GaN high-electron mobility transistors (HEMTs) with two types of 2 μm-thick periodically carbon-doped GaN buffer layer (PC-doped GaN buffer) with and without inserting the 30 nm-thick Al<SUB>0.05</SUB>Ga<SUB>0.95</SUB>N back barrier layer between the GaN channel layer and the PC-doped GaN buffer. The PC-doped GaN buffer layer consists of multiple layers of 12 nm-thick C-doped GaN layer with doping concentration of 1 × 10<SUP>18</SUP> cm<SUP>−3</SUP> and 50 nm-thick undoped GaN layer with unintentional n-typing concentration of 2 × 10<SUP>16</SUP> cm<SUP>−3</SUP>. A reference AlGaN/GaN HEMT with 2 μm-thick highly-resistive GaN buffer layer without C-doping is also fabricated for comparison. Similarly to the reference AlGaN/GaN HEMT, the AlGaN/GaN HEMTs with PC-doped GaN buffer show typical 1/<I>f</I> noise characteristics mainly due to the trapping effects at the AlGaN/GaN interface from subthreshold region to strong-accumulation region, which indicates that the deep trapping effects in the PC-doped GaN buffer layer is negligible, and experience the correlated mobility fluctuations (CMF), which is convinced from the drain current power spectral density (PSD) versus drain current. At off-state (deep-subthreshold region), on the other hand, the HEMTs with the PC-doped GaN buffer layer exhibit 1/<I>f</I> <SUP>2</SUP> noise characteristics, which are closely related to the generation-recombination (g-r) noise caused by the spatial trapping/detrapping process between the deep acceptor in the C-doped layer and the shallow donor in the undoped layer in the PC-doped GaN buffer, while the reference HEMT still shows typical 1/<I>f</I> noise characteristics.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Noise characteristics in AlGaN/GaN HEMTs with/without PC-doped buffer layer were investigated. </LI> <LI> PC-doped buffer layer consists of 12 nm-thick carbon-doped GaN and 50 nm-thick un-doped GaN. </LI> <LI> All devices exhibited 1/<I>f</I> noise properties and CMFs from subthreshold to strong-accumulation. </LI> <LI> At off-state, PC-doped buffer devices exhibited 1/<I>f</I> <SUP>2</SUP> noise properties at frequency > 40 Hz. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Heterojunction-Free GaN Nanochannel FinFETs With High Performance

Ki-Sik Im,Young-Woo Jo,Jae-Hoon Lee,Cristoloveanu, S.,Jung-Hee Lee IEEE 2013 IEEE electron device letters Vol.34 No.3

<P>Heavily doped GaN nanochannel fin-shaped field-effect transistors (FinFETs) without heterojunction have been fabricated and characterized for the first time. Simplified pragmatical technology for GaN epitaxial growth and FinFET process was used to achieve nanodevices with a channel width from 40 to 100 nm and a gate length of 1 μm. They exhibit excellent on-state performance, such as maximum drain current of 670 mA/mm and maximum transconductance of 168 mS/mm. Record off-state performance was measured: extremely low leakage current of ~ 10<SUP>-11</SUP> mA and source-drain breakdown voltage of ~280 V. The subthreshold slope of 68 mV/decade is close to the theoretical limit (60 mV/decade, so far achieved only in SOI MOSFETs) and leads to very high <I>I</I><SUB>on</SUB>/<I>I</I><SUB>off</SUB> ratio of 10<SUP>8</SUP> - 10<SUP>9</SUP>. The proposed heterojunction-free nanochannel GaN FinFET is a very promising candidate not only for high-performance and high-speed integrated circuits but also for high-power applications.</P>

Capacitance-voltage characterization of Al₂O₃/GaN-on-insulator (GaNOI) structures with TMAH surface treatment

Im, Ki-Sik,Kim, Jeong-Gil,Vodapally, Sindhuri,Caulmilone, Raphaë,l,Cristoloveanu, Sorin,Lee, Jung-Hee ELSEVIER 2017 MICROELECTRONIC ENGINEERING Vol.178 No.-

<P><B>Abstract</B></P> <P>The capacitance-voltage (<I>C-V</I>) characterizations of Al<SUB>2</SUB>O<SUB>3</SUB>/GaN-on-insulator (GaNOI) structure, prepared with the Smart Cut™ technology, with and without tetramethylammonium hydroxide (TMAH) surface treatment have been investigated. The GaNOI structure consists of a 150nm-thick GaN layer and a 800μm-thick Si<SUB>3</SUB>N<SUB>4</SUB>/SiO<SUB>2</SUB> buried insulating layer deposited on sapphire substrate. For fabrication of the MIS capacitor, an Al<SUB>2</SUB>O<SUB>3</SUB> layer with thickness of 28nm as a gate dielectric was deposited on the GaNOI wafer by atomic layer deposition (ALD). The calculated carrier concentration of the GaN layer on the buried insulator was increased to 2.8×10<SUP>17</SUP> cm<SUP>−3</SUP> from the value of ~5×10<SUP>16</SUP> cm<SUP>−3</SUP> for the as-grown undoped GaN layer prior to the wafer transfer. The MIS capacitor with TMAH surface treatment showed a positive threshold voltage shift with negligible hysteresis and low interface trap density compared to the capacitor without TMAH surface treatment. Severe frequency dispersion was observed regardless of the TMAH treatment due to the crystal defects generated during the complicated wafer transfer process.</P> <P><B>Highlights</B></P> <P> <UL> <LI> The Al<SUB>2</SUB>O<SUB>3</SUB>/GaN-on-insulator (GaNOI) capacitors were fabricated using TMAH surface treatment. </LI> <LI> The calculated doping density of GaN layer was obtained to 2.8×10<SUP>17</SUP> cm<SUP>−3</SUP>. </LI> <LI> This capacitors exhibited the severe frequency dispersion due to the crystal damaged GaN layer. </LI> <LI> The TMAH surface-treated MIS capacitor showed better performances compared to the TMAH-free device. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

GaN junctionless trigate field-effect transistor with deep-submicron gate length: Characterization and modeling in RF regime

Im, Ki-Sik,Seo, Jae Hwa,Yoon, Young Jun,Jang, Young In,Kim, Jin Su,Cho, Seongjae,Lee, Jae-Hoon,Cristoloveanu, Sorin,Lee, Jung-Hee,Kang, In Man Institute of Pure and Applied Physics 2014 Japanese Journal of Applied Physics Vol. No.

Fabrication of AlGaN/GaN Ω-shaped nanowire fin-shaped FETs by a top-down approach

Im, Ki-Sik,Sindhuri, Vodapally,Jo, Young-Woo,Son, Dong-Hyeok,Lee, Jae-Hoon,Cristoloveanu, Sorin,Lee, Jung-Hee JAPAN SOCIETY OF APPLIED PHYSICS 2015 Applied physics express Vol.8 No.6

<P>An AlGaN/GaN-based Omega-shaped nanowire fin-shaped FET (FinFET) with a fin width of 50 nm was fabricated using tetramethylammonium hydroxide (TMAH)-based lateral wet etching. An atomic layer deposited (ALD) HfO2 side-wall layer served as the etching mask. ALD Al2O3 and TiN layers were used as the gate dielectric and gate metal, respectively. The Omega-shaped gate structure fully depletes the active fin body and almost completely separates the depleted fin from the underlying thick GaN buffer layer, resulting in superior device performance. The top-down processing proposed in this work provides a viable pathway towards gate-all-around devices for III-nitride semiconductors. (C) 2015 The Japan Society of Applied Physics</P>

High-Performance GaN-Based Nanochannel FinFETs With/Without AlGaN/GaN Heterostructure

Ki-Sik Im,Chul-Ho Won,Young-Woo Jo,Jae-Hoon Lee,Bawedin, Maryline,Cristoloveanu, Sorin,Jung-Hee Lee IEEE 2013 IEEE transactions on electron devices Vol.60 No.10

<P>Two types of fin-shaped field-effect transistors (FinFETs), one with AlGaN/GaN heterojunction and the other with heavily doped heterojunction-free GaN layer operating in junctionless mode, have been fabricated and characterized. The threshold voltages of both devices shift toward positive direction from large negative value as the fin width decreases. Both devices exhibit high ON-state performance. The heterojunction-free GaN FinFETs show superior OFF-state performance because the current flows through the volume of the GaN channel layer, which can be fully depleted. The proposed GaN nanochannel FinFETs are very promising candidates not only for high performance, but also for high power applications.</P>

Normally Off GaN MOSFET Based on AlGaN/GaN Heterostructure With Extremely High 2DEG Density Grown on Silicon Substrate

Ki-Sik Im,Jong-Bong Ha,Ki-Won Kim,Jong-Sub Lee,Dong-Seok Kim,Sung-Ho Hahm,Jung-Hee Lee IEEE 2010 IEEE electron device letters Vol.31 No.3

<P>A normally off GaN MOSFET was proposed by utilizing an extremely high 2-D electron-gas density (> 10<SUP>14</SUP> / cm<SUP>2</SUP>) at an AlGaN/GaN heterostructure as source and drain, which can be obtained by controlling the tensile stress accompanied with the growth of GaN on silicon substrate. The fabricated MOSFET with an Al<SUB>2</SUB>O<SUB>3</SUB> gate insulator exhibited excellent device performance, such as a threshold voltage of 2 V, drain current of 353 mA/mm, extrinsic transconductance of 98 mS/mm, and field-effect mobility of 225 cm<SUP>2</SUP>/V·s.</P>