동물모델에서 PDE5 억제제의 투여경로에 따른 효과비교

김한석,정재민,최성 고신대학교의과대학 2006 고신대학교 의과대학 학술지 Vol.21 No.2

Background : Intracavernosal (IC) PDE5 (phosphodiesterase type 5) inhibitors, at tissue levels approaching millimolar concentrations, have been reported to cause penile erection in the absence of sexual stimulation. The objectives of this study were to confirm the effects of three PDE5 inhibitors on penile erection as IC agents, without PNS (pelvic nerve stimulation), and compare the efficacy of these agents on penile erection after intravenous (Ⅳ) administration with PNS to that of IC administration without PNS. Materials and Methods : Anesthetized male New Zealand White rabbits (3.5-4.0 kg) were divided into two groups, and the penile hemodynamics was assessed by mornitoring of the intracavernosal pressure (ICP) after penile erection induced by PNS (2.5 Hz, 10 V, 0.8 msec for 30 seconds) with IV administration of 3 PDE5 inhibitors or IC administration without PNS. ICP recordings were normalized to the systemic systolic arterial pressure (SAP). The intracavernosally or intravenously administered doses of zaprinast, sildenafil and vardenafil were 30-1,000 ㎍/kg, 1-30 ㎍/kg and 1-30 ㎍/kg, respectively. Results : PNS with Ⅳ administration of 3 PDE5 inhibitors caused significant frequency-dependent increase in the ICP. The IC administration of zaprinast, sildnafil and vardenafil produced significant increased in the ICP, in a dose dependent fashion. The ICP/SAPs with highest doses of zaprinast, sildenafil and vardenafil tested were 0.656, 0.550, 0.654 in group with Ⅳ administration and 0.625, 0.609, 0.666 in group with IC administration without PNS, respectively. Conclusion : All 3 PDE5 inhibitors showed increases in the ICP/SAP, in dose dependent manners, in response to IC administration in the absence of PNS as well as PNS with Ⅳ administration. IC administration was a much more effective route for penile erection than Ⅳ administration.

파티클보드의 박리 (剝離) 및 인장에 있어서의 파괴인성치(破壞靭性値)에 관한 연구

김한석,이필우 한국목재공학회 1990 목재공학 Vol.18 No.3

The objectives of this study were to investigate the relative effects of specific gravity and particle size on internal bond and tensile strengths and fracture toughness of particleboard and to compare mechanical strength with fracture toughness. The particleboard was manufactured with three different particle sizes at specific gravity levels of 0.6, U.7, and 0.8 with a resin content of 10% based on oven dry weight. The results were summarized as follows; 1. Internal bond strength, fracture toughness in internal bond test, maximum tensile strength, and fracture toughness in tension test increased with the increase of specific gravity of particleboard. 2. As partcle size increased, internal bond strength, fracture toughness, maximum tensile strength. and fracture toughness in tension test increased. 3. The maximum tensile strength and fracture toughness appeared to be in a direct relationship, and then maximum tensile strength could be used for predicition of fracture toughness for tension test. 4. The fracture toughness in internal bond test was somewhat independent on induced crack length.

CDMA방식 중계기용 전력증폭기의 설계에 관한 연구

김한석,김훈용,김대중,이종악,Kim, Han-Suk,Kim, Hoon-Yong,Kim, Dae-Jyung,Lee, Jong-Arc 한국전기전자학회 1999 전기전자학회논문지 Vol.3 No.2

본 논문에서는 CDMA 방식 중계기용 전력증폭기의 선형특성을 향상시키기 위해 기존의 전치왜곡 방식과 전방귀환 방식을 혼합한 전력증폭기를 설계 제작하였다. CDMA방식의 이동통신 시스템은 기존의 아날로그 셀룰라 방식과는 사용 스펙트럼 대역폭이 훨씬 크며 증폭기의 비선형성에 의한 채널사이의 혼변조 왜곡을 충분히 제거하여야만 통신이 가능하기에 선형성이 우수한 전력증특기가 필수적으로 요구된다. 본 논문에서 제작한 전력증폭기는 37dBm, 2-tone 인가시의 IMD 특성이 -50dBc로써 나타났으며, 불요방사 특성도 IS-95 기준을 만족하는 $fc{\pm}\;885kHz$에서 약 -46dBc, $fc{\pm}\;1.98MHz $ 에서는 약 -52dBc로 나타났다. In this paper, a new type of linearization technique proposed, in which the predistortor was added to the feedforward linearizer. As the input power level is applied to HPA, the gain and phase characteristics of the amplifier are also varied. By using of the predistorter the amplitude imbalance and phase imbalance is kept constant. Experimental results are present for Korea PCS frequency band. The center frequency of the feedforward amplifier is 1.843.75 MHz with 1.23 MHz bandwidth. The 2-tone intermodulation distortion at 37dBm output power is about -50dBc, and spurious emission are -46dBc at $fc{\pm}\;885KHz\;and\;-52dBc\;at\;fc\;{\pm}1.98MHz$, respectively.

구내 골신장술 후 식립된 전치부 임플란트보철 치험보고

김한석,김명래,이성근,강상원,김기환,김형섭 大韓顎顔面成形再建外科學會 2003 Maxillofacial Plastic Reconstructive Surgery Vol.25 No.1

Objective : This is to report the effectiveness of intraoral distraction osteogenesis for alveolar augmentation in the extremely atrophied alveolar defects and to review the clinical results of the 2 cases. Subjects and Methods : Anterior segmental osteotomy was performed and the trans-oral alveolar distractors(Martin, Germany) were applied in 2 patients with the severe acquired anterior maxillary and mandibular defect. After latent period for 1 week, the osteomized alveolar segments were distracted by 1 ㎜ a day (0.5 ㎜/l turn) for 8 days in case Ⅰ and 0.6 ㎜ a day(0.3 ㎜/l turn) for 10 days in case Ⅱ. The consolidation period was about 8 weeks in each case. Thereafter, 6 titanium threaded implants(Branemark, Restore) were simultaneously installed with removal of distractor. The implants were tested clinically and radiographically. Results : Amounts of acquired alveolar bone were 8 ㎜ in case Ⅰ and 6 ㎜ in case Ⅱ respectively, with the increased width of the ridge crests and soft tissue expansion. Dental implants installated on the augmented alveolar ridges in 8 weeks after distrction were confirmed as in good osseointegration and in good function without any complications. Conclusion : Intraoral distraction osteogenesis can be a good option for alveolar ridge augmentation of the severely atrophied ridges and soft-tissue defects. However, for the better vector control of distracting segments and for anterior esthetics, customized distraction devices could be considered later.

골반골절 후 발기부전의 유발원인 : 역동적음경해면체내압측정술 및 음경해면체조영술의 중요성

김한석,문일,최성 KOSIN UNIVERSITY COLLEGE OF MEDICINE 2006 高神大學校 醫學部 論文集 Vol.21 No.1

Background: Erectile dysfunction (ED) develops as common complication of the pelvic fractures, in particular those involving the pubic arch and associated with the posterior urethral injury. ED in these patients can be neurogenic or vasculogenic in origin due to damage to cavernous nerves or the internal iliac vascular system and their branches. We evaluated the causes of ED following pelvic trauma. Materials and Methods: Patients referred to our department for evaluation of ED due to pelvic fractures were reviewed retrospectively. Patients underwent nocturnal penile tumescence test (stamp test, Rigiscan), audiovisual sexual stimulation test, endocrinologic laboratory test, neurologic test, and either penile color duplex ultrasonography (CDU) or dynamic infusion cavernosometry and cavernosography (DICC). Arterial insufficiency was diagnosed when peak systolic velocity (PSV) was less than 30 cm/sec in CDU, or cavernosal artery systolic occlusion pressure (CASOP) was less than 100 mmHg or more than 30 mmHg below brachial arterial pressure in DICC. Venous leakage was diagnosed when end diastolic velocity (EDV) was more than 5 cm/sec in CDU, or flow-to-maintain (FTM) value was greater than 3 ml/min or the pressure decay (PD) was greater than 45 mmHg/30 sec in DICC. Results: 20 patients with ED due to pelvic fractures whose mean age was 36.7 (range 20-60) were studied. 8 patients underwent CDU only, 8 patients underwent DICC only, and 4 patients underwent both studies. 9 (45%) patients were presumed to have neurogenic ED, 6 (30%) patients had mixed arteriogenic and cavernous ED, and 5 (25%) patients had cavernous ED. Conclusion: According to this study, the causes of ED after pelvic fractures were turned out to be neurogenic (45%), arterio-venogenic (30%) and venogenic (25%), orderly.

PIN 다이오드를 이용한 C-Band 위상 변위기의 설계에 관한 연구

김한석,김훈영,이창식,이종악,Kim, Han-Suk,Kim, Hoon-Yong,Lee, Chang-Sik,Lee, Jong-Arc 한국전기전자학회 1999 전기전자학회논문지 Vol.3 No.2

본 논문에서 C-밴드 6-비트 변위기의 설계와 제작을 하였고 각 비트에 대한 설계 기술을 기술하였다. $5.625^{\circ},\;11.25^{\circ},\;22.5^{\circ}$ 그리고 $45^{\circ}$ 위상 비트는 부하선로 방식, $90^{\circ}$ 위상 비트는 하이브리드 결합 방식 그리고 $180^{\circ}$ 위상 비트는 가변선로 방식을 각각 마이크로스트립 구리 기판 위에 적용하였다. In this paper, a C-band 6-bit phase shifter is designed and fabricated and design techniques for each phase bit are represented. We applied the loaded line type to $5.625^{\circ},\;11.25^{\circ},\;22.5^{\circ}\;and\;45^{\circ}$ phase bits and the hybrid coupled type to $90^{\circ}$ phase bit and the switched line type to $180^{\circ}$ phase bit, respectively on a microstrip copper substrate.

액체연료표면에서의 화염 확장에 관한 연구

김한석,백승욱,문정기 대한기계학회 1989 대한기계학회논문집 Vol.13 No.2

본 실험에서는 액체연료인 석유와 등유을 사용하여 전도, 복사, 대류, 연료의 표면유동 등이 각각 어느 정도 화염확장에 영향을 주는 가를 예측하기 위하여 위의 각각을 제어할 수 있는 장애물을 설치하였으며, 연료의 깊이에 의한 화염확장의 영향을 알아보기 위하여 3가지 종류의 깊이에 대하여 실험을 수행하였다. Flame spreading over a hydrocarbon fuel surface has been investigated for liquid fuels such as kerosene and diesel, using thermocouple. Without forced convection, it was clearly found that the flame spreading was mainly controlled by the liquid fuel surface flow. Furthermore, the radiative heat transfer was dominant over a conductive heat transfer in kerosene. But in diesel the latter was found to be more influential than the former, when the direction of windflow was the same as that of flame spreading. The oscillation period and amplitude of the flame spreading velocity increase if the windflow is blowing in the direction of the flame spreading velocity, and decrease if the direction of windflow is blowing against the flame spreading direction.

공기 다단 분무연소기의 NOx 발생특성에 관한 실험적 연구

김한석,안국영,김호근,백승옥,Kim, Han-Seok,An, Guk-Yeong,Kim, Ho-Geun,Baek, Seung-Ok 한국기계연구원 2001 硏究論文集 Vol.31 No.-

An experimental investigation on the reduction of nitrogen oxide emission from swirling, turbulent diffusion flames was conducted using multi air staged combustor, The combustor utilizes swirler to dampen fuel/air mixing, allowing an extended residence time for fuel pyrolysis and fuel-N conversion chemistry in an locally fuel-rich environment prior to burnout. This process also allow to reduce thermal NOx formation to lessen the temperature of reaction zone. The aerodynamic process therefore emulates the conventional staged combustion process, but without the need for the physically separate fuel-rich and -lean stages. Parametric studies on the ratios of each staged air and droplet size were carried out the feasibility of fuel/air mixing for low NOx combustion with diesel and pyridine mixed diesel fuel oil.

파티클보오드의 휨에 있어서 破壤靭性値에 關한 硏究

李弼宇,吳世昌,金漢錫 서울대학교농과대학농업개발연구소 1990 서울대농학연구지 Vol.15 No.1

The objectives of this study were to investigate the relative effects of specific gravity and particle size on bending strength and fracture toughness of particleboard and to compare mechanical strength with fracture toughness. The test particleboards were manufactured with three different particle sizes at specific gravity levels of 0.6, 0.7, and 0.8 with a resin content of 10% based on oven dry weight. The results were summarized as follows: 1. As specific gravity of particleboard increased, MOR, and fracture toughness in bending test increased. 2. Modulus of rupture and fracture toughness in bending test increased with the increase of particle size. 3. The bending strength and fracture toughness appeared to be in a direct relationship, and then bending strength could be used for predicition of fracture toughness for bending test.

영상신호전송을 위한 BISDN SAR 부계층의 구조 ( SAR Sublayer Structure of BISDN for Image Signal Transmission )

김한석,이병기 한국통신학회 1992 한국통신학회 학술대회논문집 Vol.- No.-