GaAs 집적회로 제조를 위한 에피 성장 연구

김무성,엄경숙,박용주,김용,김성일,조훈영,민석기,Kim, Moo-Sung,Eom, Kyung-Sook,Park, Young-Joo,Kim, Yong,Kim, Seong-Il,Cho, Hoon-Young,Min, Suk-Ki 한국재료학회 1993 한국재료학회지 Vol.3 No.6

Bulk반절연 기판 웨이퍼에 이온 주입법에 의한 기존의 GaAs집적회로 제작시 발생하는 문제점을 보완하고자 반절연 기판 위에 반절연성의 고저항 GaAs 에피층을 성장하는 연구를 수행하였다. 먼저 반절연 기판의 EPD분포를 조사하고, MOCVD와 MBE법을 이용하여 undeped GaAs반절연성 에피층을 성장시켜 실제 집적회로의 제작에 적합한지를 평가하였다. 평가방법은 반절연성 에피\ulcorner을 buffer층으로 성장시킨 에피 기판에 ungated FET를 제작하여, 이 반절연성 에피\ulcorner을 통한 누설전류를 측정하고, 또한 반절연 기판의 EP분호의 영향을 조사하였다. 누설 전류의 측정결과 비교적 주설 전류가 큰 1$\mu\textrm{m}$ 두께의 MOCVD시료에서도 270nA/mm로 FET의 pinch-off에는 영향을 주지 못하는 매우 작은 누설 전류 값을 나타내었다. 또한 누설전류의 분포가 반절연 기판의 EPD분포와 일치하는 것을 발견하여, 에피층의 quality에 기판의 결함이 미치는 영향을 확인하였다. MBE법으로 성장한 2$\mu\textrm{m}$ 두께의 undoped burrer층 시료는 휠씬 좋은 특성을 나타내었으며, 매우 균일하고 낮은 누설전류(40nA/mm)가 측정되었다. The growth of semi-insulating(SI) high resistant undoped GaAs epilayer has been studied to solve the problems ocurring when GaAs IC is fabricated by the widely used ion implantation directly into the SI GaAs substrate. The EPD ditribution of the SI substrates has been examined, and the suitability of the buffer layers grown by MOCVD and MBE, respectively, has been tested for IC fabrication through leakage current measurement. IJngated FET has been fabricated on the SI epilayer and leakage current through the buffer layer has been measured. In the case of MOCVD grown 1$\mu\textrm{m}$-thick buffer layer, the leakage current is as small as about 270nA/mm, and this value does not affect the pinch-off of FET. In this case, the epilayer quality is affected by the substrate defects because the leakage current distribution is coincided with the EPD distribution of the SI substrate. The 2$\mu\textrm{m}$-thick buffer layer grown by MBE, however, has the better quality, and shows the lower leakage current(40nA/mrn) and higher uniformity.

당일 감마나이프수술 환자의 표준진료지침 개발을 통한 질 향상 효과 측정

김무성,하소영,배윤혁,정용태,김성태,이원희,고연주,Kim, Moo Seong,Ha, So Young,Bae, Yoon Hyuk,Jung, Yong Tae,Kim, Sung Tae,Lee, Won Hee,Go, Yeon Joo 한국의료질향상학회 2012 한국의료질향상학회지 Vol.18 No.1

Objectives : A protocol called "critical pathway" was developed to standardize the management of hospital patients the day after they underwent gamma knife radiosurgery. The quality of improvement in patient outcomes was evaluated. Methods : Critical pathway was developed, according to the regulations of the I hospital, by analyzing the medical records of 22 inpatients who underwent gamma knife surgery within the period from January to April 2011 on the day of the surgery. The study included a group of 22 patients admitted to the hospital the day after they underwent gamma knife radiosurgery, between July and September 2011. The control group included 22 patients who had surgery employing the same method within the period from May to June 2011. To measure the effects on quality improvement, the average length of stay, the execution rate of the hospital discharge notice system, daily hospital revenue, and the satisfaction of the patients and the medical team were assessed. The patient questionnaire employed a four-point Likert scale while the medical-staff questionnaire employed a five-point Likert scale. Result : The average length of stay was significantly shorter in the study group compared to the control group (2.3 days vs. 3.8 days, P<0.05). The execution rate of the hospital discharge notice system was higher in the study group (100% vs. 72%) than in the control group. Daily hospital revenues were higher by 264,178 Korean won in the study group when compared to the control group. The study group showed greater satisfaction of patients compared to the control group based on a four-point Likert scale (P<0.05). The study group showed greater satisfaction in medical team compared to the control group based on a five-point Likert scale (P<0.05). Conclusion : The development and implementation of a critical pathway protocol for hospital admission the day after gamma knife radiosurgery is an effective care process that improves the clinical quality.

군장병들의 요추체 윤상골기 골절의 분석

김무성 ( Moo Seong Kim ),김수천 ( Soo Chun Kim ),심재홍 ( Jae Hong Sim ) 국군의무사령부 1995 대한군진의학학술지 Vol.26 No.1

청신경초종에 대한 감마나이프 방사선 수술

팽성화,김무성,심홍보,정영균,이선일,정용태,김수천,심재홍,Paeng, Sung Hwa,Kim, Moo Seong,Sim, Hong Bo,Jeong, Yeong Gyun,Lee, Sun Il,Jung, Yong Tae,Kim, Soo Chun,Sim, Jae Hong 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.11

Object : The goals of radiosurgery include preservation of neurological function and prevention of tumor growth. We document the results of gamma-knife radio-surgery for vestibular schwannoma. Method & Object : Eighty-two patients underwent stereotactic radiosurgery for an vestibular schwannoma from October, 1994 to December, 2000. Sixty-five of these patients were followed up for radiological and clinical evaluation. As pregamma-knife modality, surgical resection were done in 23 patients,and V-P shunt in 2 patients. Initial symptoms were headache(n=45), dizziness(n=16), tinnitus(n=17). While normal facial function(House-Brackmann grade 1) was present in 48 patients(73.8%), other patients showed grade 2 function in 8, grade 3 function in 7,and grade 4 function in 2. The Gardner/Robertson scale was used to code hearing function. Male to female ratio was 1:3. Mean tumor volume was $7.98cm^3$. Mean dose delivered to the tumor margin was 14.2Gy,and mean maximal dose was 28.3Gy. Results : Mean follow-up duration of 19.9 months. Thirty-five showed decrease(53.8%) in size, 19 patients(29.2%) stationary, 3(4.6%) initial decrease follow up increase, 5(7.6%) initial increase follow up decrease,and 59 patients (90.8%) were well controlled. Two patients experienced transient facial neuropathy, one transient trigeminal neuropathy, and one transient hearing deterioration. After gamma-knife radiosurgery, ventriculoperitoneal shunt was done in 4 patients. Conclusions : Gamma-knife radiosurgery can be used to treat postoperative residual tumors as well as in patients with concomitant medical problems in patients with preserved hearing function. Gamma-knife radiosurgery is safe and effective method to treat small, medium sized(less than 3cm in extracanalicular diameter), intracanalicular vestibular schwannoma, associated with low rate of cranial neuropathy.

신경섬유종을 동반한 다발성 외경동맥 동맥류 - 증 례 보 고 -

표세영,김무성,심홍보,이선일,정용태,김수천,심재홍,Pyo, Sae Yeong,Kim, Moo Seong,Sim, Hong Bo,Lee, Sun Il,Jung, Yong Tae,Kim, Soo Chun,Sim, Jae Hong The Korean Neurosurgical Society 2000 Journal of Korean neurosurgical society Vol.29 No.9

신경섬유종을 동반한 다발성외경동맥 동맥류는 아주 드물며, 외경동맥동맥류의 원인으로 외상이 대부분을 차지한다. 39세 여자가 좌측 측두두정후두부의 거대한 종괴로 인한 두통을 주소로 내원하였다. 이학적 검사 소견상 좌측 측두두정후두부의 $5{\times}15{\times}18cm$ 거대한 종괴가 인지되었고, 아래로 처진 좌측 귀, 체간 및 사지에 다발성 담갈색 색소침착을 보였다. 뇌혈관조영술상 표재성 측두동맥과 후두동맥에 뇌동맥류가 인지되었으며 두부 자기공명영상에서 좌측 측두두정후두부에 거대한 혈종과 피하 종양이 관찰되었다. 수술전 다발성 외경동맥동맥류에 대해 색전술을 시행하고 혈종제거술, 피하 신경섬유종 절제술 및 뇌동맥류 절제술을 시행하였다. 수술후 증상은 호전되어 환자는 신경학적 장애 없이 퇴원하였다. Multiple external carotid artery aneurysms with neurofibromatosis are rare. Trauma is the primary cause in the development of aneurysms of the external carotid artery. A 39-year-old female patient was referred to the emergency room because of a headache and a huge lump over the left temporo-parieto-occipital region. The physical examination revealed a huge round mass, $5{\times}15{\times}18cm$, in the left temporo-parieto-occipital region and low set left ear and multiple caf au lait spots in trunk and extremities. The external carotid artery angiography demonstrated multiple aneurysms arising from the superficial temporal artery and occipital artery. A MRI showed a huge hematoma on temporo-parieto-occipital region and postauricular mass suggested of subcutaneous neurofibroma. Embolization followed by surgical resections of those aneurysms and neighboring mass were performed and good result was obtained. We report our case with review of literature.

운동성 장애에 대한 감마나이프 시술의 초기경험

홍준기,김무성,이선일,정용태,김수천,심재홍,Hong, Joon Ki,Kim, Moo Seong,Lee, Sun Il,Jung, Yong Tae,Kim, Soo Chun,Sim, Jae Hong 대한신경외과학회 2000 Journal of Korean neurosurgical society Vol.29 No.8

Objectives : With recent improvements in neuroimaging and the development of third and fourth-generation radiosurgical dose-planning soft ware, came a renewed interest in using radiosurgery for the treatment of movement disorders. Radiosurgery involves no opening of the cranium and no incisions, eliminating both the risk of hemorrhage from passing an electrode to the depths of meningitis from operative infection. It is for these reasons stereotactic radiosurgical treatment of movement disorders has value in a small subgroup of patients. The authors report four cases of Parkinson's disease and one case of dystonia that were treated by Gamma knife. Methods : Radiosurgical nucleus ventralis intermedius thalamotomy using the gamma knife unit was performed to make lesion in two Parkinson's disease patients. A radiation dose of 120Gy was delivered to nucleus using a single 4-mm collimator plug pattern following classic anatomical landmarks. Patients were followed for a median of 10.5 months(range 9-12 months). An independent neurological evaluation of tremor, based on the change in the United Parkinson's Disease Rating Scale tremor score(UPDRS), was correlated with a subjective evaluation. Gamma knife ventrolateral(V.O.P) thalamotomy was performed in one case of dystonia. A central dose of 150Gy was delivered and the patient was followed for 18 months. Gamma knife globus pallidus interna pallidotomy was performed in two Parkinson's disease patients. A radiation dose of 130Gy(range 120-140Gy) was delivered. Patients were followed for a median of 13 months(range 9-14 months). Result : Ventrolateral thalamotomy in dystonia produced regained left hand usage in order to be able to use the telephone. Ventralis intermedius thalamotomy produced an excellent improvement of the tremor in one case, mild improvement of the tremor in the other case of Parkinson's disease. A globus pallidus internalis(GPi) pallidotomy produced improvement of rigidity and dyskinesia : one other showed no change. There were no neurological complications. Conclusion : Gamma Knife thalamotomy considered a safe and effective technique for the treatment of tremor in Parkinson's disease. Although the results from Longer follow-up is not available yet, the short-term results seem to be encouraging.

포도막 흑색종에 대한 감마나이프 방사선수술 - 증례보고 -

김병욱,김무성,심홍보,정영균,이선일,정용태,김수천,심재홍,윤일한,김영일,백광욱,Kim, Byung Wook,Kim, Moo Seong,Sim, Hong Bo,Jeong, Yeong Gyun,Lee, Sun Il,Jung, Yong Tae,Kim, Soo Chun,Sim, Jae Hong,Youn, Il Han,Kim, Young Il,Paik, Koang 대한신경외과학회 2001 Journal of Korean neurosurgical society Vol.30 No.5

Uveal melanoma is uncommon but life-threatening intraocular malignancy and has been treated by irradiation, local excision and enucleation. Gamma-Knife radiosurgery allows a high dose of radiation to be delivered to an intracranial target with a very high spatial accuracy and has been used for the treatment of ocular melanomas. We have treated two cases of uveal melanoma between October 1994 and December 1999. They include one man and one woman(34, 62 years, respectively). They were followed up for 12 momths. Mean maximal dose was 65Gy. In one case, the tumor disappeared 7 months after gamma-knife radiosurgery. In another case, multiple tumors (uveal, suprasellar and cerebellar tumor) had decreased in size. These results show that single and high dose gamma-knife radiosurgery is may be an option in the local control of uveal melanoma which can spare the eyeball and vision.

고순도 SiC 미분말을 적용한 4H-SiC 단결정 성장에 관한 연구

신동근,김병숙,손해록,김무성,Shin, Dong-Geun,Kim, Byung-Sook,Son, Hae-Rok,Kim, Moo-Seong 한국결정성장학회 2019 한국결정성장학회지 Vol.29 No.6

개선된 열탄소환원법으로 합성된 금속불순물함량 1 ppm 이하의 고순도 SiC 미립 분말을 이용하여 2,100℃ 이상고온의 RF 가열 PVT 장치에서 SiC 단결정을 성장시켰으며, In-situ x-ray 이미지 분석을 통해 성장과정 중 분말의 승화거동 및 단결정 성장거동을 관찰하였다. SiC 분말은 단결정 성장의 공급원으로 온도가 높은 외곽 부분부터 소진되고 graphite 잔여물이 남았다. 성장 중 원료의 흐름은 가운데 부분으로 집중되었으며 SiC 단결정의 성장거동에도 영향을 미쳤는데, 이는 미립분말로 인한 도가니 내부 온도분포 차이가 원인으로 예상되었다. 단결정 성장이 완료된 후, 단결정 잉곳을 1 mm 두께의 단결정 기판으로 절단하고 또한, 잉곳에서 얻어진 단결정 기판은 전반적으로 짙은 황색의 4H -SiC가 관찰되었으며, 외곽에 일부 발생한 다결정은 시드결정을 시드홀더에 부착하는 과정에서 혼입된 기포층과 같은 불순물 혼입이 원인으로 사료된다. High purity SiC fine powder with metal impurity contents of less than 1 ppm was synthesized by improved carbothermal reduction process, and the synthesized powder was used for SiC single crystal growth in RF heating PVT device at temperature above 2,100℃. In-situ x-ray image analyzer was used to observe the sublimation of the powder and single crystal growth behavior during the growth process. SiC powder was used as a source of single crystal growth, exhausted from the outside of the graphite crucible at the growth temperature and left graphite residues. During the growth, the flow of raw materials was concentrated in the middle and influenced the growth behavior of SiC single crystals. This is due to the difference in temperature distribution inside the crucible due to the fine powder. After the single crystal growth was completed, the single crystal ingot was cut into a 1 mm thick single crystal substrate and finely polished using a diamond abrasive slurry. A dark yellow 4H-SiC was observed overall of single crystal substrate, and the polycrystals generated in the outer part may be caused by the incorporation of impurities such as the bubble layer mixed in the process of attaching the seed crystal to the seed holder.

Pcp-2 Interacts Directly with Kinesin Superfamily KIF21A Protein

Hye-Young Park(박혜영),Sang-Jin Kim(김상진),Sung Su Ye(예성수),Won Hee Jang(장원희),Sang Kyeong Lee(이상경),Yeong-Hong Park(박영홍),Yong Wook Jung(정용욱),Il Soo Moon(문일수),Moo Seong Kim(김무성),Dae-Hyun Seog(석대현) 한국생명과학회 2008 생명과학회지 Vol.18 No.8

KIF21A는 kinesin superfamily에 속하는 분자 motor로서 미세소관을 따라서 분비소포를 운반한다. 최근의 연구결과 KIF21A 유전자 일부의 missense 돌연변이에 의하여 congenital fibrosis of the extraocular muscles (CFEOM)1의 유발됨이 밝혀졌다. CFEOM1은 KIF21A의 돌연변이로 인하여 분화 발생과정에 occulo-motor신경과 neuromuscular junction 형성에 필요한 단백질을 이동시키지 못함으로써 유발된다. 본 연구에서는 효모 two-hybrid system을 사용하여 KIF21A의 WD-40 repeat domain과 결합하는 분자량이 작은 Purkinje cell protein-1 (Pcp-2), 또는 L7으로도 알려진 단백질을 분리하였다. Pcp-2는 효모 two-hybrid assay에서 KIF21A와 KIF21B의 WD-40 영역과는 결합하지만 다른 종류의 KIFs와는 결합하지 않았다. 또한 단백질간의 특이적 결합을 pull-down assay로 확인 하였으며, 생쥐의 뇌 파쇄액에 Pcp-2 항체로 면역침강을 행하여 KIF21A를 확인한 결과 Pcp-2와 같이 침강하였다. 이러한 결과들은 KIF21A는 Pcp-2와 결합하며, 또한 Pcp-2는 KIF21A의 adaptor 단백질로서 세포 내 KIF21A의 수송에서 매개 단백질로 작용함을 시사한다. KIF21A is a member of the Kinesin superfamily proteins (KIFs), which are microtubule-dependent molecular motors, anterograde axonal transporters of cargoes. Recently, congenital fibrosis of the extraocular muscles 1 (CFEOM1) has been shown to result from a small number of recurrent heterozygous missense mutations of KIF21A. CFEOM1 results from the inability of mutated KIF21A to successfully deliver cargoes to the development of the occulo-motor neuron or neuromuscular junction. Here, we used an yeast two-hybrid system to identify a protein that interacts with the WD-40 repeat domain of KIF21A and found a specific interaction with Purkinje cell protein-2 (Pcp-2), a small protein also known as L7. Pcp-2 protein bound to the WD-40 domain of KIF21A and KIF21B but not to other KIFs in yeast two-hybrid assays. In addition, this specific interaction was also observed in the glutathione S-transferase pull-down assay. An antibody to Pcp-2 specifically co-immunoprecipitated KIF21A associated with Pcp-2 from mouse brain extracts. These results suggest that Pcp-2 may be involved in the KIF21A-mediated transport as a KIF21A adaptor protein.

Interaction of GAT1 with Ubiquitin-Specific Protease Usp14 in Synaptic Terminal

Dae-Hyun Seog(석대현),Sang-Jin Kim(김상진),Young-Ju Joung(정영주),Sung Su Yea(예성수),Yeong-Hong Park(박영홍),Moo Seong Kim(김무성),Il Soo Moon(문일수),Won Hee Jang(장원희) 한국생명과학회 2010 생명과학회지 Vol.20 No.7

γ-aminobutyric acid (GABA)는 중추신경계에서 억제성으로 작용하는 주요한 신경전달물질이다. GABA 수송체(GAT)는 연접간격에 존재하는 GABA를 세포 내로 재 흡수하여 GABA의 농도를 조절한다. 그런데 GABA 수송체가 어떻게 조절되는지는 아직 밝혀지지 않았다. 본 연구에서는 효모 two-hybrid system을 사용하여 뇌의 주요 GABA 수송체인 GAT1의 C-말단과 특이적으로 결합하는 ubiquitin-specific protease 14 (Usp14)를 분리하였다. Usp14는 GABA 수송체 GAT1및 GAT2와는 결합하지만, 다른 GAT isoform과는 결합하지 않았다. GAT1과의 결합에는 Usp14의 C-말단부위가 필수적으로 관여함을 확인하였다. 또한 이 단백질간의 결합을 GST pull-down assay로 확인하였으며, 생쥐 뇌 균질액의 co-immunoprecipitation을 통하여 in vivo에서도 GAT1과 Usp14가 결합함을 확인하였다. 이러한 결과들은 Usp14가 GAT1과 결합하여 세포막에 존재하는 GAT1의 수를 조절하는 역할을 할 가능성을 시사한다. γ-aminobutyric acid (GABA) is the major inhibitory neurotransmitter in the central nervous system. GABA transporters (GATs) control extracellular GABA levels by reuptake of released GABA from the synaptic cleft. However, how GATs are regulated has not yet been elucidated. Here, we used the yeast two-hybrid system to identify the specific binding protein(s) that interacts with the carboxyl (C)-terminal region of GAT1, the major isoform in the brain and find a specific interaction with the ubiquitin-specific protease 14 (Usp14), a deubiquitinating enzyme. Usp14 protein bound to the tail region of GAT1 and GAT2 but not to other GAT members in the yeast two-hybrid assay. The C-terminal region of Usp14 is essential for interaction with GAT1. In addition, these proteins showed specific interactions in the glutathione S-transferase (GST) pull-down assay. An antibody to GAT1 specifically co-immunoprecipitated Usp14 from mouse brain extracts. These results suggest that Usp14 may regulate the number of GAT1 at the cell surface.