Experimental study on the effect of hyperbaric oxygen therapy on the lschemic wound healing of rats

치의학과/박사[한글] 창상치유시 필수적으로 형성되는 육아조직은 그 생성과정에 많은 산소를 소비하게 되는데 산소는 조직의 혐기성 대사를 억제하고, 교원질 합성 동안Proline과 Lysine의 수산화(Hydroxylation)를 위해 필수적이며, 섬유아세포등의 세포증식에 지대한 영향을 미치는 것 으로 잘 알려져 있다. 특히 고압산소요법이 난치성창상의 치유에 유효하다는 것은 이미 여러 학자들에의해 입증된바 있으나 실제 임상적으로 적용되고 있는 시행방식은 기압과 시간등에 있어 특별히 정립된 기준이 없이 통상 2-3기압하에 1-2시간씩 하루에 1-2회 시행하고 있는 실정이다. 이에 저자는 구강영역의 난치성창상의 치유를 돕기위한 고압산소요법의 이상적 시행방식을 실험적으로 정립해 보고자 백서(Sprague-Dawley계) 238두를 1차 창상치유 실험군(실험 I 군)과 2차 창상치유 실험군(실험 ll군)으로 대별하고 실험 I 군은 대조군(20두)과 실험 A, B, C, D, E, F군(각 20두)으로, 실험 Ⅱ군은 대조군(14두)과 실혐 a, b, c, d, e, f군(각 14두)으로 분류하여 실험 I군은 안모양 미간에, 실험 Ⅱ군은 구개부에 각각 1차 및 2차 창상치유과정을 관찰하기 위한 허혈성 연조직 창상을 형성한후 창상 치유과정중에 기압과 시간을 달리하여 고압산소요법을 계속 시행하면서 광학현미경 표본을 제작하여 창상치유과정중의 염증세포 침윤정도, 주요 염증세포 출현, 모세혈관 증식, 교원질 형성 및 섬유아세포 증식등을 시기별로 비교 관찰한 바 다음과 같은 결론을 얻었다. 1. 염증세포 침윤은 모든 대조군 및 실험군 공히 창상치유 초기에 심하였으며 실험 I 군에서 대조군은 실험 8일째까지 중등도의 침윤이 지속된 반면 실험 D, E, F군은 실험 5일째부터 현저히 감소 되었고,실험 Ⅱ군에서도 대조군은 실험 12일째까지 증등도의 침윤이 지속된 반면 실험 d, f군은 실험8일째부터 현저히 감소 되었다. 2.주요 염증세포 출현에서 다형핵백혈구가 대식세포로 치환된 시기는 실험 I군에서 대조군은 실험6일째 부터였으나 실험 D군은 2일째, 실헐 E, F군은 3일째 부터로 대조군에 비해 빨랐으며, 실험 Ⅱ군에서도 대조군은 실험 10일째였던데 비해 실험 d, f 군은 6일째 로 대조군에 비해 빨랐다. 3. 모세혈관 증식은 실험 Ⅰ군의 경우 대조군은 실험 4일째부터 중등도로 증식해 8일째에 왕성해 진 반면 실험군들은 각군 공히 실험 1일째부터 중등도로 증식하면서 실험 D, F군은 3일째, 실험 A, B, E군은 4일째에 왕성해져 대조군보다 현저히 빠르고 왕성한 신생혈관 증식상을 보였다. 실험Ⅱ군 에서도 대조군에서는 실험 12일째에 왕성한 혈관증식을 보인 반면 실험 d, f군은 8일째부터 왕성하여 대조군보다 빨랐다. 4. 섬유아세포의 증식은 실험 Ⅰ군의 경우 대조군은 실험 7일째에 증등도, 8일째에 고도의 증식상을 보인 반면 실험 D, F군은 4일째에 중등도, 6일째에 고도의 증식상을 보여 대조군에 비해 빠르고 왕성하였다. 실험 Ⅱ군의 경우에도 대조군은 실험 8일째부터, 실험 d군은 4일째부터 중등도의 증식상을 보여 실험 d군이 대조군에 비해 빠르고 왕성하였다. 5.교원질 형성은 실험 Ⅰ군에서 대조군은 실험 8일째부터, 실험 D군은 4일째부터, 실험 Ⅱ군에서는 대조군의 경우 10일째부터, 실험 d, f군은 6일째부터 형성되기 시작하여 실험 D군 및 d, f군이 각각의 대조군보다 빠르고 왕성 하였다. 6. 고압산소요법 실험과정중 산소중독증상을 보인 경우는 실험 E군에서 5두(2.0%), 실험 f군에서 8두(3.4%)로서 모두 중추신경계의 산소중독증상(불안, 경련등)을 나타내었다. 이상을 종합하면 구강영역의 허혈성 연조직 창상의 치유에 고압산소요법은 확실한 효과가 있으며, 시행방식은 본 실험의 D, d군에 적용되었던 "2.5기압하 2시간"의 방식이 이상적으로 사료 된다. [영문] Recently, frequently using hyperbaric oxygen therapy is known for its effectiveness on the healing of problem wounds such as osteomyelitis, osteoradionecrosis and gas gangrenous wound etc. The main objectives of this study was to determine the best protocol of its application of hyperbaric oxygen therapy. Author used 238 rats (Sprague-Dawley strain) deviding into 2 Groups, experimental Ⅰ group for skin and experimental Ⅱ group for palatal mucosal ischemic wounds, and observed its effects by microscopically. The obtained results sumunarized as follows; 1. Severe infiltration of inflammatory cells was observed in initial stages of both control and experimental Ⅰ group. The infiltration showed decreasing tendency at 5th day of experimental D, E, F group while at 8th day in control group. In d, f of experimental Ⅱ group showed decreasing thendency at 8th experimental day while at 12th day in control group. 2. Macrophages appeared at 2nd day in D of experimental Ⅰ group while at 6th day in control group. In d, f of experimental Ⅱ group appeared at 6th day while at 10th day in control group. 3. As to the proliferation of capillary blood vessels showed at 3-4th day in most of experimental Ⅰ group severely while at 8th day in control group. In experimental Ⅱ group, it was at 8th day and 12th day respectively. 4. The proliferation of fibroblasts showed rather rapider in experimental Ⅰ group, at 4-6th day, while at 8th day in control group. In experimental Ⅱ group, it was at 8th day and 12th day respectively. 5. As to the collagen formations, it was at 4th day in experimental Ⅰ group while at 8th day in control group. In experimental Ⅱ group, it was at 6th day and 10th day respectively. 6. 5 rats (2.0%) in E group and 8 rats (3.4%) in f group showed oxygen toxic reaction, such as unstable attitude and tremor, during the experiments. This hyperbaric oxygen animal experiments disclosed excellent effects on the ischemic wound healing and it is thought to be the best protocol of its application was on D group (2.5 ATM. and 2 hrs, exposure).restrictio

A Study on the effect of gelfoam preparation on the healing of experimental bone defect of rats

치의학과/석사[영문] [한글] 저자는 치과임상에서 발치와의 치유와 보철시술전 치조골 재생에 Gelfoam이 골손상 치 유 및 신생골 재생에 미치는 영향에 관하여 연구코저 백서 24마리를 이용하여 대조군과 실험군으로 구분하고 백서, 하악골 골체부에 손상을 낸후 실험군에는 Gelfoam편을 삽입하 여 실험후 1주, 2주, 3주, 4주후의 소견을 관찰한바 다음과 같은 유의한 결론을 얻었다. 1. 대조군은 염증세포 침윤이 1주만 현저 하였으며 2주 부터는 감소되는 경향을 보였다 . 2. 대조군에서 조골세포에 의한 새로운 골조직 형성은 2주부터 관찰 되었으며 4주에는 lamellation은 보이지 않지만 결손된 부위를 완전히 메우고 있었다. 3. Gelfoam을 사용한 실험군 에서는 염증세포 침윤이 2주까지 현저 하였으며 또한 괴사 된 골조직과 이물질에 의한 이물반응이 2주까지 관찰되었다. 4. Gelfoam을 사용한 실험군에서 새로운 골조직의 형성은 3주부터 관찰되기 시작하여 4 주에는 대조군과 유사한 소견을 보였다. 5. 골막골형성은 전군을 통하여 관찰되어 대조군과 실험군과의 차이를 볼수 없었다. 6. Gelfoam사용군은 대조군에 비하여 염증미 오래 지속되며 새로운 골조직의 형성도 지 연되는 경향을 보이나 4주부터는 대조군과 유사한 치유과정을 나타냈다. A STUDY ON THE EFFECT OF GELFOAM PREPARATION ON THE HEALING OF EXPERIMENTAL BONE DEFECT FO RATS. Chang Joon Park Dept. of Dental Science Graduate School, Yonsei University (Directed by Professor JUNG HO YOON, D.D.S.,Ph.D.) This study was undertaken to evaluate the effects of Gelfoam preparations on the healing process of rat's mandibular bony defects. 24 rats, sprague dawley strain, weighing about 400gm were used, devided into control group (4 rats) and experimental group (20 rats) Six rats were sacrificed every one week serially for four weeks and prepared microscopic slides with Hematoxylin-Eosin stain for pathological examination. The obtained results from this study were as follows. 1. Acute and chronic inflammatory cell infiltration was remarkable in first week control group and it showed decreasing tendency in second week control group. 2. New bone formation was found in second week control group and bony defect was filled with osseous tissue devoiding of lamella structure. 3. Inflammatory cell infiltration was obvious up to second week experimental group, foreign body reaction and necrotic bone were also observed. 4. New bone formation was noted in third week expeimental group and it showed very similar findings with control group in fourth experimental group. 5. There was no definit distinction both in control and experimental group as to periosteal bone formation. 6. There were persistant inflammatory reaction and delayed new bone formation in experimental groups compared with control groups by fourth weeks. Healing process was essentially the same in all groups.restrictio

A Study on Digital RF Receiver for Wideband Signal Processing

DoctorAs the multi-functional communication systems are developed, mobile terminals should be operated at multi-band multi-mode to handle the various systems.The software defined radio (SDR) system is introduced as an ultimate goal of multi-mode multi-band receiver systems. However, the technical limits in SDR system prevent the existence. A digital RF sampling receiver is suggested as a middle stage technique for the SDR. To satisfy the global communication market demands, highly integrated digital RF systems are being developed very rapidly. In this thesis, the simple architecture and concept of the digital RF receiver are introduced with comparison of the existing receiver systems. An approach to map the Bluetooth (BT) and mobile-WiMAX (WiBro) standards specifications into the architecture and specifications for the building blocks of a digital RF receiver are proposed. The design procedure focuses on optimization of the performance in each standard while attaining an efficient shared RF front-end solutions. Especially, analysis for two key building blocks for the digital RF receiver system is presented and applied in the designed building blocks. The proposed receiver design is verified through each circuit and a fully integrated implementation using IBM 130-nm and Samsung 65-nm CMOS technology. Firstly, architecture of the digital RF receiver systems are introduced and compared with other receiver systems. It is shown that the digital RF receiver architecture is suitable for the next generation system because of its reliability and digital tunability. Among various applications, we choose BT for narrowband characteristics and WiBro for its popularity and inherent wideband characteristics. Therefore architecture and system considerations of digital RF receiver are introduced. This thesis presents circuit designs, including RF front-end and baseband circuits, for BT and WiBro applications. The wideband low noise amplifier (LNA) is designed to cover poor linearity and noise figure and achieves 4 dBm IIP3 and under 3.8 dB noise figure in 0.7-3.5 GHz. The blocker filtering LNA is designed to remove the SAW filter in BT standard and achieves 1.46 dBm IIP3, 1.85 dB noise figure, -8.2 dBm P1dB and -13 dBc attenuation level at sideband. The charge-domain passive mixer (CDPM) with a trans-conductance amplifier (TA) block is designed to mitigate the critical flicker noise problem that is frequently encountered the direct conversion receivers and achieves a low flicker noise with corner frequency of under 100 kHz, 8.1 dB noise figure, 10.6 dB conversion gain, 2.5 dBm IIP3, and -5.7 dBm P1dB with 2.4 GHz LO driving at 5 dBm. In the baseband region, DC offset is resolved via feedback loop with resistors and capacitors at variable gain amplifier block and the filtering requirements for both applications are achieved by the proposed discrete-time (DT) filters with non-decimation filters and an anti-aliasing filter. This thesis also presents analysis of the performance of a charge-domain passive mixer with a capacitive load. We analyze performance of the mixer in terms of conversion gain and the 1 dB compression point and show the accuracy of our analysis by comparing with simulated results for a 130-nm technology based mixer design. The load capacitance influences the conversion gain of the mixer, and the bias voltage affects it linearly. The results provide a theoretical basis for CDPM in the digital RF receiver.Finally, a new FIR filter has been developed to realize a DT filter for wideband signal processing, and compared the conventional FIR filter and proposed FIR filter for filtering characteristic with numerical expressions. The filter maintains the moving average effect, but the decimation function is removed to realize a cascadable filter. The design is fabricated with a 65-nm CMOS process.By cascading the proposed FIR filter with a conventional FIR filter, about -60 dB attenuation across 50 MHz signal bandwidth is possible at the sampling rate of 600 Ms/s, and the noise generated by adding the proposed FIR filter is negligible. By the cascade more stages, the bandwidth can be even wider. This bandwidth is wide enough to process the signals of the next generation systems, opening up the possibility to realize a wide sampling receiver, whichwas not possible so for

A noise optimized FIR filter for digital RF receiver

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Digital RF Receiver Front-end With Wideband Operation Capability for m-WiMAX

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A 0.18-um CMOS switch with high isolation for 48 MHz ~ 860 MHz TV tuner application

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Noise improvement of active Gilert mixer with reduction current circuit

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A charge-domain passive mixer in 0.13-um CMOS

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A study on adaptive digital feedback predistortion technique combined with digital feedback technique

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