발열을 동반한 호중구감소증에서 Cefepime 단독투여와 Ceftazidime 및 Tobramycin 병합투여의 효능비교

정현욱,채제욱,강미라,양정채,문치숙,기현균,장현하,오원섭,김기현,백경란,이남용,송재훈 대한감염학회 2004 감염과 화학요법 Vol.36 No.6

목적 : 국내에서 발열을 동반한 호중구감소증이 있는 악성 종양환자에게 경험적 항생제로 베타락탐계 항생제와 아미노배당체의 병합요법의 사용이 일반적이다. Cefepime은 광범위 항균 작용을 가지고 있어, 그람 음성균 뿐만 아니라 그람 양성균에 대해서도 우수한 효과를 나타낸다. 재료 및 방법: 발열을 동반한 호중구감소증이 있는 악성 종양환자를 대상으로 무작위, 공개, 비교 연구를 시행하였다. 대상 환자를 무작위로 cefepime 단독요법군과 ceftazidime 및 tobramycin 병합요법군으로 나누어 투여하고 각각의 임상적 효능과 안전성을 비교하였다. 구강및 인후 점막염이 있는 환자에서 분리된 녹색 연쇄알 구균에 대한 항생제 내성 정도를 조사하였다. 결과 : 대상환자 89명 중 CA 투여군이 48예(53.9%), CT 투여군이 41예(46.1%)이었다. 발열의 유형별로 MDI는 18예(20.2%), CDI는 9예(10.1%), UF는 62예(69.7%)로 두 군 간에 차이가 없었다. CA 투여군과 CT 투여군의 임상적 호전률은 시험약 투여 후 2-4일째 각각 91.7%, 85.4% (P=0.31), 치료 종료 시 각각 91.7%, 100% (P=0.15)로 두 군간에 유의한 차이가 없었다. 치료 종료 시 CA 투여군과 CT 투여군의 세균학적 소실률은 모두 100%로 두 군간의 유의한 차이가 없었다(P=0.78). 점막염이 있는 환자로부터 녹색 연쇄알 구균이 분리된 경우는 25예(28.1%)이었으며, 분리된 녹색 연쇄알 구균은 penicillin, ceftriaxone, cefepime, vancomycin에 모두 감수성을 보였다. 약제 관련 이상 반응의 발생 빈도도 두 군간에 유의한 차이가 없었다. 결론 : 발열을 동반한 호중구감소증이 있는 악성 종양환자의 경험적 항생제로서 cefepime 단독요법은 ceftazidime 및 아미노배당체의 병합요법만큼 효과적이고 안전하였다. Background : Broad-spectrum antibiotic therapy has been recommended as an empirical regimen in cancer patients with febrile neutropenia. Cefepime is a fourth generation cephalosporin with good activity against both gram-positive cocci and gram-negative bacilli. Materials and Methods : To compare the efficacy and safety of cefepime alone with ceftazidime plus tobramycin as empirical regimen for adult cancer patients with febrile neutropenia, a randomized, open label, comparative trial was performed. If the patient showed clinical improvent 72 hours, antibiotic could be changed to oral ciprofloxacin. Clinical and microbiological responses were determined at 72 hours and at the end of therapy. To investigate the antimicrobial resistance of viridans streptococci, swab cultures were obtained from throat in all enrolled patients and antimicrobial susceptibility tests were performed by using microdilution method according to the NCCLS. Results : A total of 89 patients were enrolled. Forty-eight patients received cefepime alone (CA), and 41 patients received ceftazidime plus tobramycin (CT). Demographic and baseline clinical characteristics were similar in both groups (P>0.05). The initial clinical success rate at day 2-4 in group CA (91.7%) was similar with that in CT group (85.4%) (P=0.31). At the end of therapy, the final clinical success rate in CA group (91.7%) was similar to that in CT group (100%) (P=0.15). In 18 patients, with microbiologically defined infections, the eradication rate was 100% in both groups. Adverse events including liver dysfunction (21.3%) and renal dysfunction (2.2%), were similar in both groups (P=0.87). Viridans streptococci were isolated from the throat cultures in 25 cases, and all of these strains were susceptible to penicillin (MIC_(90) 0.12 ㎍/mL), cefepime (1 ㎍/mL), and vancomycin (0.12 ㎍/mL). Conclusion : Efficacy and safety of cefepime monotherapy was comparable to the combination of ceftazidime and tobramycin. It could be used as an alternative empirical regimen for treating cancer patients with febrile neutropenia.

Phase 2 Study of an Intravenous Busulfan and Melphalan Conditioning Regimen for Autologous Stem Cell Transplantation in Patients with Multiple Myeloma (KMM150)

Jung, Sung-Hoon,Lee, Je-Jung,Kim, Jin Seok,Min, Chang-Ki,Kim, Kihyun,Choi, Yunsuk,Eom, Hyeon-Seok,Joo, Young Don,Kim, Sung-Hyun,Kwak, Jae-Yong,Kang, Hye Jin,Lee, Jae Hoon,Lee, Ho Sup,Mun, Yeung-Chul,M Elsevier 2018 Biology of blood and marrow transplantation Vol.24 No.5

<P><B>Abstract</B></P> <P>This prospective study evaluated the efficacy and toxicity of intravenous busulfan and melphalan as a conditioning regimen for autologous stem cell transplantation (ASCT) in patients with multiple myeloma (MM). A total of 99 patients with MM, enrolled between January 2013 and March 2016, received intravenous busulfan (9.6 mg/kg) and melphalan (140 mg/m<SUP>2</SUP>) before ASCT. The median time to transplant was 6.2 months, and 90 (90.9%) patients underwent ASCT within 12 months of the diagnosis. The overall response rate after ASCT was 94.0%, including 43.5% with a stringent complete response/complete response, 27.3% with very good partial response, and 23.2% with partial response. The most common severe nonhematologic toxicity (grade 3 to 4) was infection (26.3%) and stomatitis (15.2%). Three (3.2%) patients developed veno-occlusive disease. No treatment-related mortality was observed. After a median follow-up of 26.1 months, the median progression-free survival was 27.2 months (range, 13.0 to 41.4 months) and median overall survival was not reached. In conclusion, a conditioning regimen of intravenous busulfan and melphalan was effective and tolerable.</P> <P> ClinicalTrials.gov. number: NCT01923935</P> <P><B>Highlights</B></P> <P> <UL> <LI> Intravenous busulfex and melphalan conditioning regimen leads to high-quality response after autologous stem cell transplantation in patients with multiple myeloma. </LI> <LI> Intravenous busulfex and melphalan was a well-tolerated conditioning regimen with a low incidence of veno-occlusive disease and transplant-related mortality. </LI> </UL> </P>

<i>In vivo</i> tumor suppression activity by T cell‐specific T‐bet restoration

Lee, Kihyun,Min, Hyun Jung,Jang, Eun Jung,Hong, Jeong‐,Ho,Hwang, Eun Sook Wiley Subscription Services, Inc., A Wiley Company 2010 International journal of cancer: Journal internati Vol.127 No.9

<P><B>Abstract</B></P>10.1002/ijc.25238.abs<P>T‐box‐containing protein expressed in T cells (T‐bet) is a master transcription factor for the development of interferon (IFN) γ‐producing T helper 1 (Th1) cells and also functions in other immune cells including natural killer (NK), cytotoxic T lymphocytes and dendritic cells. T‐bet‐deficient mice increased susceptibility to viral infection and tumor development due to the defective functions of immune cells. T‐bet is known to play a key role in NK‐mediated antimetastatic response; however, it remains to be characterized whether T‐bet is essential for <I>in vivo</I> tumor suppression mediated by T cells. Here, we have investigated <I>in vivo</I> tumor suppression effect of T‐bet‐restored T cells using T cell‐specific and inducible T‐bet transgenic mice generated in a T‐bet‐deficient background. T‐bet‐null mice increased susceptibility to tumor development, whereas induction of T cell‐specific T‐bet expression upon melanoma cell injection substantially suppressed tumor development by inducing IFNγ production in T cells and tumor cell apoptosis. Late induction of T‐bet expression in tumor‐bearing mice produced comparable amounts of IFNγ with control and significantly decreased tumor volume. In addition, increased melanoma lung metastasis in T‐bet‐deficient mice was strikingly inhibited by T‐bet restoration in T cells. Intravenous injection of activated Th1 cells, not T‐bet‐null Th1 cells, attenuated metastatic melanoma progression, in addition, restoration of T‐bet in T‐bet‐null Th1 cells certainly retrieved antimetastatic activity. These results suggest that T‐bet expression in T cells is crucial for the control of tumor development and antimetastatic activity.</P>

주행 안정성을 고려한 최악 상황 시나리오 도출 및 적용

정대이(Daeyi Jung),정도현(Dohyun Jung),문기현(Kihyun Moon),정창현(Changhyun Jeong),노기한(Kihan Noh),최형진(Hyungjeen Choi) 한국자동차공학회 2008 한국 자동차공학회논문집 Vol.19 No.6

The current test methods are insufficient to evaluate and ensure the safety and reliability of vehicle system for all possible dynamic situation including the worst case such as rollover, spin-out and so on. Although the known NHTSA J-turn and Fish-hook steering maneuvers are applied for the vehicle performance assessment, they aren't enough to estimate other possible worst case scenarios. Therefore, it is crucial for us to verify the various worst cases including the existing severe steering maneuvers. This paper includes the procedure to search for other useful worst case based upon the existing worst case scenarios mentioned above and its application in simulation basis. The only human steering angle is selected as a design parameter here and optimized to maximize the index function to be expressed in terms of either roll angle or yaw rate. The obtained scenarios were enough to generate the worst case to meet NHTSA worst case definition (ex.2-inch wheel lift). Additionally, as an application, the worst case steering maneuver is acquired for the vehicle to operate with a simple ESP system. It has been concluded that the new procedure in this paper is adequate to create other feasible worst case scenarios for a vehicle system both with an intelligent safety control system and without it.

Proton conductive cross-linked benzoxazine-benzimidazole copolymers as novel porous substrates for reinforced pore-filling membranes in fuel cells operating at high temperatures

Kihyun Kim,Choi, Seong-Woo,Park, Jung Ock,Kim, Sung-Kon,Lim, Min-Young,Kim, Ki-Hyun,Ko, Taeyun,Lee, Jong-Chan Elsevier 2017 Journal of membrane science Vol.536 No.-

<P><B>Abstract</B></P> <P>Proton conductive porous substrates consisting of cross-linked benzoxazine-benzimidazole copolymers are developed for practical application of reinforced pore-filling membranes in polymer electrolyte membrane fuel cells operating at high-temperatures (>100°C) and low relative humidity (<50% RH) conditions. The porous proton conductive substrates are prepared by casting solution mixtures of sodium 3-(4-sulfonatophenyl-3,4-dihydro-2<I>H</I>-1,3 benzoxazine-6-sulfonate (<I>p</I>S) and poly[2,2′-(<I>m</I>-<I>p</I>henylene-5,5′-bibenzimidazole] (PBI) with dibutyl phthalate (DBP) as a porogen, followed by subsequent stepwise heating to 220°C and extraction of DBP from the P(<I>p</I>S-<I>co</I>-BI) films. The resulting porous substrates are found to have mechanically robust cross-linked structures, tunable hydrophilicity, and proton conductivity. A pore-filling membrane is prepared by impregnating the porous substrate with sulfonated poly(arylene ether sulfone) having the degree of sulfonation of 70mol%. The pore-filling membrane exhibits much improved dimensional stability and mechanical strength compared to the linear sulfonated poly(arylene ether sulfone) membrane and its proton conductivity and cell performance are found to be superior to the pore-filling membrane prepared using the porous substrate based on cross-linked benzoxazine-benzimidazole copolymers without any proton conductive acid groups.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Proton conductive benzoxazine having sulfonic acid groups was synthesized. </LI> <LI> Porous cross-linked benzoxazine-benzimidazole copolymer substrates were prepared. </LI> <LI> Tunable hydrophilicity, porosity and proton conductivity of porous substrates. </LI> <LI> Excellent physical stability and mechanical strength of pore-filling membrane. </LI> <LI> Outstanding cell performance of MEA prepared with the pore-filling membrane. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Comparison of High Power Semiconductor Devices in 5MW PMSG MV Wind Turbines

Kihyun Lee,Kyungsub Jung,Yongsug Suh,Changwoo Kim,Taemin Cha,Hyoyol Yoo,Sunsoon Park 전력전자학회 2013 전력전자학술대회 논문집 Vol.2013 No.7

Comb-shaped polysulfones containing sulfonated polytriazole side chains for proton exchange membranes

Kim, Kihyun,Jung, Bo-Kyung,Ko, Taeyun,Kim, Tae-Ho,Lee, Jong-Chan Elsevier 2018 Journal of membrane science Vol.554 No.-

<P><B>Abstract</B></P> <P>Comb-shaped polysulfone copolymers were synthesized by the click reaction, copper(I) catalyzed azide-alkyne 1,3-dipolar cycloaddition, using polysulfone having azidomethyl side group (PSf-N<SUB>3</SUB>) and sulfonated polytriazole having one ethynyl chain-end group. PSf-N<SUB>3</SUB> was prepared by the substitution reaction of polysulfone through chloromethylation followed by azidation, and sulfonated polytriazoles having one ethynyl chain-end group was synthesized <I>via</I> the click reaction using 1,4-diethynylbenzene and 4,4′-diazido-2,2′-stilbenedisulfonic acid disodium salt tetrahydrate with CuI followed by end-capping process. Tough, flexible, and transparent membranes could be prepared by solution casting from the comb-shaped polysulfone copolymers and ion exchange capacity (IEC) of the resulting membranes could be controlled by changing the chain length of the sulfonated polytriazoles. The comb-shaped polysulfone membranes showed enhanced physicochemical stability and significantly higher proton conductivity when compared with a sulfonated poly(arylene ether sulfone) (SPAES) membrane having a similar IEC due to the distinct hydrophilic-hydrophobic phase separated morphology. The fuel cell performance of membrane electrode assembly with the comb-shaped polysulfone membrane is superior to those with the SPAES and Nafion-212 membranes at the various operating conditions.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Sulfonated polytriazoles having one ethynyl chain-end group were synthesized. </LI> <LI> Comb-shaped polysulfone copolymers were synthesized by click reaction. </LI> <LI> Excellent physicochemical stability of comb-shaped polysulfone membranes. </LI> <LI> Distinct phase-separated structure of comb-shaped polysulfone membranes. </LI> <LI> Outstanding cell performance of MEA prepared with comb-shaped polysulfone membrane. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

가솔린과 디젤을 연료로 적용한 대형 디젤 엔진에서 분사기 형상이 연소 및 배기 배출물에 미치는 영향

김기현(Kihyun Kim),김동훈(Donghoon Kim),정용진(Yongjin Jung),배충식(Choongsik Bae) 한국자동차공학회 2011 한국자동차공학회 학술대회 및 전시회 Vol.2011 No.11

Experimental study was performed to investigate effects of various injector configurations on combustion and exhaust emissions in a heavy duty diesel engine fueled with gasoline and diesel. Including baseline injector which has 8 holes and 146° injection angle, five kinds of injector with different injection angle and number of nozzle hole were used for the study. Engine was operated at low speed and load conditions. Stable engine operation for gasoline was not achieved with baseline injector under naturally aspirated condition. Engine operation was become stable only when high boosting pressure was applied. However, it was possible to achieve more stable engine operation with injectors of narrow injection angle compared to baseline injector at same intake pressure. Over the whole injection timing range, gasoline combustion shows longer ignition delay and retarded combustion phase than those of diesel. This trend enables to obtain higher power output at early injection timing for gasoline compared to diesel. However, high HC and CO were emitted under these early injection timing range so narrow injection angle injector was used to reduce these emissions by spray targeting technology. Consequently, low load operation using gasoline was realized with lower emission and comparable power output compared to diesel combustion.

Differentiated Services를 위한 CBQ 기반의 버퍼 관리 방안

권기현(Kihyun Kwon),정석종(Suk-Jong Jung),홍진표(Jin-Pyo Hong),이명문(Myungmoon Lee),박진우(Jinwoo Park) 한국통신학회 2002 한국통신학회 학술대회논문집 Vol.2002 No.7

패드 그루브의 밀도변화가 연마특성에 미치는 영향

박기현(Kihyun Park),정재우(Jaewoo Jung),이현섭(Hyunseop Lee),서헌덕(Heondeok Seo),정석훈(Seokhun Jeong),이상직(Sangjik Lee),정해도(Haedo Jeong) Korean Society for Precision Engineering 2005 한국정밀공학회지 Vol.22 No.8

Polishing pads play an important role in chemical mechanical polishing(CMP) which has recently been recognized at the most effective method to achieve global planarization. In this paper, we have investigated CMP characteristics as a change of groove density of polishing pads. The parameter(K<SUB>n</SUB>) is proposed to estimate groove density of pad. The K<SUB>n</SUB> is defined as groove area divided by pitch area. As the groove density value increased, removal rate increased to some point and then gradually saturated in case of increasing the groove density excessively. In addition Within wafer non-uniformity(WIWNU) worse as groove density increased excessively, although WIWNU improved as groove density increased. Also the uniformity of temperature of pad surface decreased as the groove density increased. It was because that the cooling effect increased as groove density increased. In other words, increasing the groove density which means the apparent contact area of pad has influence on amount of discharge of slurry during polishing process.