이차원 LMS 알고리즘의 Systolic Array 구현

박완수,최훈,홍기섭,박봉수,배현덕 충북대학교 컴퓨터 정보통신 연구소 2000 컴퓨터정보통신연구 Vol.8 No.1

적응알고리듬의 VLSI 구현에 있어서 파이프라이닝이나 시스토릭과 같은 구조적 설계기법을 이용하여 알고리듬을 변환하는 것은 효과적이다. 알고리듬 변환은 z-변환 영역에서 연산의 규칙성과 반복성을 찾아 이루어 진다. 본 논문에서는 이차원 필터와 계수갱신 시스템을 시스토릭 구조로 설계하여 LMS의 확장 형태인 TDLMS을 STDLMS로 변환한다. 변화된 STDLMS를 이용 이차원 ALE를 Altera사의 Max-PlusII 상에서 구현하여 시뮬레이션을 통해 성능을 평가한다. 시뮬레이션 결과 salt-pepper 잡음과 가우시안 잡음에 오염된 화상을 ALE가 개선할 수 있음을 보였다. In VLSI realization of adaptive algorithm. it is necessary and efficient that the algorithm is transformed to structural one suitably using architectural design techniques such as pipelining or systolic array. These transform method use regular and recursive of operation of the algorithm on z-transform domain. In this paper, the TDLMS which is a extended version of LMS is transformed to STDLMS which has systolic array architecture in two dimensional filter and coefficients update system. The transformed STDLMS is applied for realization of two dimensional ALE. And the ALE performances are evaluated by Max-PlusII of Altera Co.. The simulation results show that the ALE enhances image data which were corrupted by salt-pepper noise and Gaussian noise.

호박(Cucurbita pepo L.) 종자의 자엽조직을 이용한 체세포배형성

홍남주,박현용 조선대학교 부설생명과학 연구소 1999 생명과학 연구 Vol.7 No.-

호박종자의 자엽절편체를 20μM 2,4-dichlorophenoxy acetic acid (2,4-D)가 첨가된 Murashige와 Skoog(MS) 배지에 치상한 후, 24시간 낮은 광조건(3000Lux)에서 배양하여 callus와 체세포배형성을 유도하였다. 2,4-D가 첨가된 MS배지에서 유도된 캘러스를 동일 배지에 계대배양하는 동안 치밀하게 생장하는 embryogenic callus는 계대배양 횟수의 증가와 함께 더 높은 빈도로 출현하였다. 이러한 callus로부터 somatic embryos의 생성은 3차 계대배양 후, 생장조절제가 첨가되지 않은 MS 배지에 2주 배양 후에 embryo의 형성이 관찰되었으며, 계속되는 배양에서 embryo 형성이 증가되었다. Somatic embryogensis was induced from seed cotyledons of pumpkin (Cucurbita pepo L.). Seed cotyledonary explants were cultured on MS medium supplemented with 20μM 2,4-dichlorophenoxey acetic acid(2,4-D) by incubating at 25 ± 2℃ under 24 hrs photoperiod (3000 Lux) for 4 weeks. The explants were transferred (subcultured) to same medium and to growth regulator-free MS medium for 4 weeks. Three times subculture on the same medium containing 20μM 2,4-D was required for somatic embryogenesis. Somatic embryos was only observed on growth regulator-free MS medium after 2 week cultures in the 4th subculture.

성견 절치에서 수직 골결손 형성후 함입이동시 치주조직의 반응

박양수,김영준,최홍란,황현식 전남대학교 치과대학 2000 전남치대논문집 Vol.12 No.1

The present study was performed to investigate the periodontal response following orthodontic intrusion of teeth with vertical bony defect produced by periodontal disease. Vertical bony defect and periodontal disease were produced adjacent to the both maxillary second lateral incisors in four adult dogs, weighing 20kg or more. Four weeks later, a flap operation was performed to eliminate inflammation and a reference notch was made on the root surface at the level of bottom of each defect. Two weeks after periodontal surgery, four weeks of intrusion and another four weeks of retention was executed on the right incisors while left incisors served as the control. Through the histologic analysis, following results were obtained. 1. The periodontal lesion which was produced by elastics and artificial bony defect was characterized by three walled infrabony pocket. 2. In the histologic section of control side, the base of the pocket was located below the level of the cemento-enamel junction. Connective tissue attachment was formed apically from the base of the pocket. 3. On the experimental side, the base of the pocket was localized close to the cemento-enamel junction. Connective tissue attachment was formed near to pocket base and extended apically. 4. New cementum was formed from the notch coronally toward the epithelial junction along the root surface in the both intruded incisors and control. 5. In the fluorescence microscopic observation, bone regeneration was began at the base of defect and the remodelling pattern characterized by a combination of coronal bone generation and resorption of the marginal crest could be detected. Although the remodelling pattern was the same in the both side, the bone remodelling in intruded incisors was continued during tooth movement. The results of the present study suggest that an orthodontic intrusion of extruded incisors with vertical bony defect can be carried out with a desirable periodontal response, provided that both the oral hygiene and the biomechanical force system are kept under control.

Inhibition of oxidative stress induced‑cytotoxicity by coptisine in V79‑4 Chinese hamster lung fibroblasts through the induction of Nrf‑2 mediated HO‑1 expression

Hyeon‑Gyun Jo,Cheol Park,이혜숙,Gi‑Young Kim,Young‑Sam Keum,Jin Won Hyun,Taeg Kyu Kwon,Yung Hyun Choi,Su Hyun Hong 한국유전학회 2021 Genes & Genomics Vol.43 No.1

Background Coptisine is a natural alkaloid compound and is known to have multiple benefcial efects including antioxidant activity. However, whether it can protect lung fbroblasts from oxidative damage has not been studied yet. Objectives To investigate the potential inhibitory efect of coptisine against oxidative stress in V79-4 lung fbroblast cells. Methods V79-4 cells were treated with H2O2 (1 mM) in the presence or absence of coptisine (50 µg/ml), N-acetyl cysteine (NAC, 10 mM) or zinc protoporphyrin IX (ZnPP, 10 µM) for the indicated times. The alleviating efects of coptisine on cytotoxicity, cell cycle arrest, apoptosis, reactive oxygen species (ROS) production, DNA damage, mitochondrial dynamics, and inhibition of ATP production against H2O2 were investigated. Western blot analysis was used to analyze the expression levels of specifc proteins. Results Coptisine inhibited H2O2-induced cytotoxicity and DNA damage by blocking abnormal ROS generation. H2O2 treatment caused cell cycle arrest at the G2/M phase accompanied by increased expression of cyclin-dependent kinase (Cdk) inhibitor p21WAF1/CIP1 and decreased expression of cyclin B1 and cyclin A. However, these efects were attenuated in the presence of coptisine or NAC. Coptisine also prevented apoptosis by decreasing the rate of Bax/Bcl-2 expression in H2O2-stimulated cells and suppressing the loss of mitochondrial membrane potential and the cytosolic release of cytochrome c. In addition, the activation of nuclear factor-erythroid-2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) was markedly promoted by coptisine in the presence of H2O2. However, zinc protoporphyrin IX, a potent inhibitor of HO-1, attenuated the ROS scavenging and anti-apoptotic efects of coptisine. Conclusions Based on current data, we suggest that coptisine can be used as a potential treatment for oxidative stress-related lung disease.

외과적 보조의 급속상악확장술 : 치험 5예 REPORT OF 5 CASES

박충열,이용욱,송종운,김영운,박홍주,오희균,유선열,이기현,황현식 대한악안면성형재건외과학회 2002 Maxillofacial Plastic Reconstructive Surgery Vol.24 No.1

Five adults (3 cases of bilateral posterior crossbite, 2 cases of unilateral posterior crossbite) with intermaxillary discrepancy of over 5㎜ due to maxillary transverse deficiency were treated by surgically assisted rapid maxillary expansion (SARME). Bilateral maxillary horizontal osteotomies, osteotomies of pterygomaxillary junction and anterior lateral nasal wall, ans anterior palatal osteotomy were performed in 4 cases, and unilateral osteotomies in 1case, followed by palatal expansion with tooth-borne orthopedic applicance. No significant complication was observed. The mean palatal expansion was 7.2㎜ (5.8∼10.0㎜) in the maxillary first molar region. During the mean follow-up period of 4 years (5 months∼8 years 7 months), no recurrence of crossbite was observed in all cases. The SARME seemed to be a simple, stable, and reliable procedure for achieving a permanent increase of over 5㎜ in skeletal maxillary transverse width of adults.

TNF계 CD137L 및 RANKL의 파골세포와 T 세포에 대한 활성조절

홍성준,박재홍,이현우,이긍호 大韓小兒齒科學會 2008 大韓小兒齒科學會誌 Vol.35 No.4

본 연구는 TNFR family인 CD137 및 RANK. 파골세포의 CD137L와 T 세포의 RANKL 간의 역신호에 의한 이들 세포의 역할을 알아보고자 하였다. 이에 RANKL 및 CD137L 자극으로 유도되는 역신호 전달에 의한 T 세포 활성과 파골세포분화에 미치는 영향을 규명하고자 웅성 생쥐의 골수세포와 T 세포를 공동배양하여 다음과 같은 결과를 얻었다. 1. 생쥐 단핵세포주 및 골수유도 단핵전구세포에서 CD137L이 발현되며, CD137L 단클론 항체로 자극을 주었을 경우 파 골세포 표지단백절인 TRAP 양성 파골세포의 형성이 억제되었다. 2. 활성화된 CD4^(+) 및 CD8^(+) T 세포에서 RANKL을 발현하였으며 RANKL의 유사 수용체인 OPG 재조합 단백질을 처리하여 CD4^(+) 및 CD8^(+) T 세포의 세포증식이 억제되었다. 이 연구의 결과는 CD137자극에 의한T세포활성 및 RANK 자극에 의한파골세포분화및 활성이 각각수용체에 결합하는 라이겐드의 역신호에 의해 억제되었는데, 이는 파골세포와 T 세포의 과도한 활성을 제어하는 생체의 항상성조절에 관여하는 기전으로 생각된다. Resorption of alveolar bone in periodontitis is due to excessive differentiation and activation of osteoclasts. Bacterial antigens causing periodontitis activates CD4 T cells, which leads to expressing RANK ligand (RANKL) on CD4 T cells. RANKL binds RANK on preosteoclasts or osteoclasts, and enhances the differentiation preosteoclasts into osteoclasts and the activation of mature osteoclasts. CD137, one of TNF receptor (TNFR) family, expressed on activated T cells binds with CD137 ligand (CD137L) on antigen presenting cells. Cross-linking of CD137 by CD137L acts as T cell co-stimulatory signals and, therefore, enhances the activation of T cell. In this study, I elucidated the biological responses of CD137L on (pre)osteoclasts and RANKL on T cells in the context of in vivo interaction between T cells and osteoclasts. RAW264.7. murine monocytic cells, constitutively express CD137L. Ligation of CD137L with anti-CD137L mAb inhibited RANKL-induced osteoclast formation in a dose-dependent manner. Bone marrow cells are expressed CD137L by the treatment with M-CSF. Cross-linking of CD137L abolished M-CSF/RANKL-evoked the formation of multi-nucleated osteoclasts. Both mouse CD4 and CD8 T cells are expressed RANKL following their activation. Ligation of RANKL with OPG, the decoy receptor for RANKL, inhibited both CD4 and CD8 T cell proliferation. These effects were attributed to RANKL-induced apoptosis. These data indicate that CD137L and RANKL on osteoclasts and T cells, respectively provide them with inhibitory signal.

인터넷 캐쉬를 위한 멀티미디어 데이터의 재배치 정책

홍현옥,임은지,박성호 동의공업대학 2000 論文集 Vol.26 No.1

Through the dramatic growth of Internet, it becomes easy for people to access geographically distributed vast amounts of information. But, currently Internet is suffering from problems such as server overload, network congestion and client response time. In addition, currently the number of continuous media data such as audio and video is growing rapidly. In this paper, we propose SCU(Smallest Caching Utility) proxy caching scheme that stores a portion of continuous media stream or entire stream on the Internet. The proposed scheme reduces client latency and maximizes the amount of data served directly from cache without accessing the central server. By caching the initial fraction of stream data, service startup latency can be reduced. And, by varying the size of the fraction of stream to be cached according to variation of stream popularity, we can utilize the cache space efficiently and maximize the amounts of data served directly from cache. We use the caching utility formula of each stream for the measurement of cache replacement. The way to measure popularity of continuous media stream should be different from that of traditional data such as text and image. We propose the method of measuring popularity of stream using the amounts of data played by clients. We have performed simulations to evaluate our caching policy, Simulation results show that our caching policy outperforms other caching algorithms such as LRU, LFU and SIZE in aspects of BHR(byte hit ratio), initial latency and replacement overhead.

고정식 교정 환자에서 전동치솔 효과에 관한 연구

박창헌,황현식,이기헌,홍석진 대한치과교정학회 2004 대한치과교정학회지 Vol.34 No.4

고정식 교정장치를 부착한 경우 장치주위의 치태 축적 가능성이 증가되고 이로 인해 치은염, 법랑질 탈회 등의 부작용이 초래 될 수 있는 바 치태 제거를 위한 효과적인 치솔질이 필요하다. 본 연구는 교정환자에서 일반적으로 사용되고 있는 치솔에 비하여 전동치솔이 구강위생에 도움이 되는지 알아보기 위하여 시행되었다. 고정식 장치에 의한 교정치료 예정인 환자 34명을 본 연구의 대상으로 하여 고정식 교정장치 부착 전에 치태지수, 치은염지수, 치은출혈지수를 측정하였다. 장치 부착 4주 후에 각 지수를 측정한 다음, 연구대상을 치솔의 종류에 따라 전동치솔군과 수동치솔군으로 임의 구분하여 수동치솔 또는 전동치솔을 사용하도록 구강위생교육을 각각 시행하였다. 이때 전동치솔의 경우 본체는 Braun Oral-B D9511을 브러쉬 헤드는 Braun Oral-B Ortho OD 15-1을 사용하게 하였으며, 수동치솔의 경우는 Butler G.U.M 124를 사용하게 하였다. 구강위생교육 4주 및 8주 후에 각 지수를 측정한 다음 시간 경과에 따른 전동치솔군과 수동치솔군의 구강위생 상태를 비교 분석하여 다음과 같은 결과를 얻었다. 1. 고정식 교정장치 부착 4주 후 치태지수, 치은염지수, 치은출혈지수 모두 증가 양상을 나타내었다. 2. 구강위생교육 후 치태지수, 치은염지수, 치은출혈지수 모두 감소 양상을 나타내었다. 3. 치은염지수, 치은출혈지수의 경우 감소양상이 수동치솔과 전동치솔군 간의 유의한 차이를 보이지 않았다. 4. 치태지수의 경우 수동치솔에 비해 전동치솔군에서 감소효과가 유의하게 크게 나타났다. 이상의 연구 결과는 고정식 교정장치로 치료받는 환자에서 전동치솔이 구강위생에 도움이 됨을 시사하였다. Patients with fixed orthodontic appliances frequently have increased levels of plaque accumulation leading to the possibility of gingivitis or enamel decalcification. Although many methods may be helpful in reducing dental plaque formation, the optimal mechanical removal of plaque is the most important factor during orthodontic treatment. The purpose of this study was to evaluate the efficacy of an electric toothbrush (with a specially designed orthodontic brush head) compared to a manual toothbrush in controlling plaque and gingivitis for patients with fixed orthodontic appliances. Oral hygiene status was measured in thirty-four patients using a plaque index, a gingival index and a bleeding index, before and four weeks after the attachment of fixed orthodontic appliances. Patients were randomly divided into two groups: electric and manual toothbrush groups. Oral hygiene instruction was given according to the type of toothbrush used. The Braun Oral-B D9511 with Braun Oral-B Ortho OD 15-1 brush head was used as the electric toothbrush while the Butler G.U.M. 124 was given as the manual toothbrush. After four and eight weeks, oral hygiene status was measured again. Through a comparison between the electric and the manual toothbrush groups, the following results were obtained. 1. All oral hygiene indices showed an increasing tendency after four weeks of fixed orthodontic appliance. 2. All indices presented a decreasing tendency four and eight weeks after oral hygiene instruction. 3. In case of the gingival index and bleeding index, the decreasing tendency did not show a statistically significant difference between the electric and the manual toothbrush groups. 4. The decreasing tendency of plaque index presented a statistically significant difference between the two groups, showing that the electric toothbrush was more effective in terms of oral hygiene. These findings suggest that an electric toothbrush is useful to orthodontic patients with fixed appliances.

고정식 교정 환자에서 전동치솔 효과에 관한 연구

박창헌,이기헌,황현식,홍석진 전남대학교 치의학연구소 2002 구강과학 Vol.14 No.4

Patients with fixed orthodontic appliances frequently have increased levels of plaque accumulation leading to the possibility of gingivitis or enamel decalcification. Although many methods may be helpful in reducing dental plaque formation, optimal mechanical removal of plaque is tile most important factor during orthodontic treatment. The porpose of this study was to evaluate the efficacy of'an electric toothbrush, with a specially designed orthodontic brush head. compared with a manual toothbrush in controlling plaque and gingivitis for patients with fixed orthodontic appliances. Oral hygiene status was measured in thirty four patients, using a plaquc index, a gingival index and a bleeding index. before and four weeks after attachment of fixed orthodontic appliances. Patients were randomly divided into two groups, the electric and the manual toothbrush groups. Oral hygiene instruction was given according to the type of toothbrush used. The Braun Oral-B D9511 with Braun Oral-B Ortho OD 15-1 brush head was used as the electric toothbrush while the Butler G.U. M 124 was given as the manual toothbrush. After 4 weeks and 8 weeks, oral hygiene status was measured again. Through the comparison berween the electric and the manual toothbrush grpups. following results were obtained. 1. All oral hygiene indices showed increasing tendency after 4weeks of fixed orthodontic appliances. 2. All indices presented decreasing tendency four and eight weeks after oral hygiene instruction. 3. In case of gingival index and bleeding index. decreasing tendency did not show a statistically significant difference between the electric and the manual toothbrush groups. 4. The decreasing tendency of plaque index presented statistically significant difference between the two groups. showing that the electric toothbrush was more effective in terms of oral hygiene. These findings suggest that an electric toothbrush is useful to the orthodontic patients with fixed appliances.

에이즈 환자의 거대세포바이러스 감염증

김홍빈,박상원,김남중,최희정,신동현,오명돈,김우호,정흠,최강원 대한감염학회 1998 감염 Vol.30 No.4

배 경 : 거대세포바이러스 감염은 인간면역부전바이러스 (Human Immunodeficiency Virus, HIV) 감염자에서 발생하는 가장 중요한 기회감염증의 하나이다. 특히, 국내에서는 95%이상의 국민이 거대세포바이러스의 1차감염을 경험한 상태이므로 에이즈 환자에서 거대세포바이러스 질환의 빈도가 높을 것으로 예상된다. 대상 및 방법 : 1987년 10월부터 1996년 9월까지 서울대학교 병원에서 추적 관찰하였던 128명의 HIV 감염자를 대상으로 하였다. 이들 환자의 의무 기록에서 임상 자료를 얻었다. 거대세포바이러스 망막염은 안과 전문의의 임상적인 소견으로 진단하였으며, 위장관 등 망막이외 부위의 거대세포마이러스 질환은 조직학적으로 확인된 경우에 한하였다. 결 과 : 대상환자 128명의 추적관찰기간은 중앙값이 6(0∼59)개월 이었으며 7명 (5.4%)에서 거대세포바이러스 질환이 발생하였다. 거대세포바이러스 질환은 망막염이 6예, 식도염이 2예, 대장염이 1예, 폐렴 및 부신감염이 1예, 범발성 감염이 1예였다. 거대세포바이러스 질환의 발생빈도는 CD4+ 림프구 수가 적을수록 높았으며, CD4+ 수가 200/㎣미만인 환자 중 15% (6/33)에서 거대세포바이러스 질환이 확인되었다. 11예 중 9예를 ganciclovir로 치료하였으며 이중 7예에서 호전 또는 진행의 억제가 확인되었다. 추적관찰이 가능한 6예 중 3예 (50%)에서 재발하였다. 결 론 : 국내 에이즈 환자에서 거대세포바이러스 질환은 비교적 흔한 기회감염증이다. Background : Cytomegalovirus (CMV) infection is one of the important opportunistic infections in immunocompromised patients. In Korea, seroprevalence of IgG against CMV is over 95%. Therefore, CMV diseases are expected to be a prevalent opportunistic infection in AIDS patients. in Korea. Methods : We reviewed the medical records of 128 patients with HIV infection who visited the Seoul National University Hospital during the period from Nov. 1987 TO Sep. 1996. All the patients were examined by one ophthalmologist and the diagnosis of CMV retinitis were made by funduscopic findings. Other CMV diseases were diagnosed when histopathologic examinations showed the characteristic cytomegalic cells. Results : Median duratior, of follow-up was 8 months. Eleven CMV diseases were found in 7 patients (5.4%): 6 patients ahd retinitis, 2 esophagitis, 1 colitis, 1 pneumonitis, and one patient developed disseminated infection. Fifteen percent (6/33) of the patients whose CD4+ lymphocyte counts were less than 200/㎣ at baseline developed CMV diseases. Out of the 9 cases treated with ganciclovir, 7 improved or were stabilized. No patient received maintenance treatment and 3 had relapsed. Conclusion : CMV diseases are common opportunistic infections in AIDS patients in Korea.