축하중과 첨가질량이 작용하는 적층복합판의 진동해석

이봉학,김경진,원치문,성기태 江原大學校 産業技術硏究所 1995 産業技術硏究 Vol.15 No.-

A method of calculating the natural frequency corresponding to the first mode of vibration of beams and tower structures, with irregular cross-sections and with arbitrary boundary conditions was developed and reported by D. H. Kim in 1974. IN this paper, hte result of application of this method to the laminated plates with axial forces and with attached point mass/masses is presented. Both N? and N? forces are considered. The solution for the laminated plates with arbitrary boundary conditions and irregular section can be obtained by simply obtaining the deflection influence coefficients by any method. The effect of neglecting the mass of the plates on the natural frequency, as the ratio of the point mass/masses to the plate mass increases, is thoroughly studied. The influence of N? and N? is also carefully investigated.

신경회로망 제어기를 이용한 PID 파라미터 추정에 관한 연구

權重東,裵銀敬,金恩基,全基英,李承桓,吳鳳煥,李勳九,金容珠,韓慶熙 明知大學校 産業技術硏究所 2006 産業技術硏究所論文集 Vol.25 No.-

In this paper, supposed to solve these problem to PID parameters controller algorithm using ANN. In the proposed algorithm, the parameters of the controller were adjusted to reduce by on-line system the error of the speed of IM. In this process, EBPA NN was constituted to an output error value of an IM and conspired an input and output. The performance of the self-tuning controller is compared with that of the PH) controller tuned by conventional method (Ziehler-Nichols). The effectiveness of the proposed control method is verified thought the Matlab Simulink and experimental results.

백일해 백신이 Streptozotocin 유발성 당뇨백서의 당대사에 미치는 영향

박상기,문경래,박춘호,김갑승,박영봉,이병래,양남웅 朝鮮大學校 附設 醫學硏究所 1991 The Medical Journal of Chosun University Vol.16 No.1

Streptozotocin(STZ) may produce a permanent form of insulin-dependent diabetes (IDD) in experimental animals. This STZ-induced diabetes has become an useful model to study the pathogenesis of IDD in man primarily because it approximate clinical findings and also because it lends itself easily to controlled manipulation. The diabetogenic activity of STZ, however, is known to be modified by several agents such as nicotinamide, diazoxide, adrenergic blockers and pertussis vaccine (PV). The present study was undertaken to observe the protective effect of PV or boiled pertussis vaccine(bPV; incubating the PV at 80℃ for 30 minutes) against the development of IDD induced by STZ in young rats, and also the effect of PV on the activities of glycolytic & gluconeogeneic enzymes in both liver and muscle of rat. PV at a dose of 1.2×10^(10) microorganism was administrated intrapntoneally on 3days before & 7days after a single injection of STZ (GO㎎/㎏ body wt). The blood glucose and insulin levels were measured at 1st wk, 2nd wk, 4th wk, 6th wk and 8th wk after STZ injection, and the enzyme activities were exemined at 8th wk. The following results were obtained. 1. No significant difference was noted in blood glucose levels between STZ group and STZ+PV or STZ+bPV groups (P>0.05). 2. Blood insulin levels in STZ group decreased significantly from 2nd wk(P<0.05). Compared with STZ group, blood insulin levels in STZ+PV & STZ+bPV groups were higher, but not a significant value except at 2nd wk in STZ+PV grouP (P<0.05). 3. Compared with STZ group, hepatic glycolytic enzyme activities were significantly increased in STZ+PV or STZ+bPV groups, and muscular glycolytic enzyme activities were significantly increased in STZ+PV or STZ+bPV groups. 4. Compared with STZ group, hepatic gluconeogeneic enzyme activities were significantly increased in STZ+PV or STZ+bPV groups. These results suggest that the PV has somewhat protective effects on blood insulin levels and tissue glycolytic enzyme activities in rats, but it could not reduced blood glucose levels significantly, probably because of excessive increase of hepatic gluconeogeneic enzymes.

독성물질의 세포사 기전 및 세포사 유발물질의 검색법 개발에 관한 연구(Ⅰ) : 독성물질로 인한 파킨슨병 모델에서의 세포사 기전 연구 Study on the cell-death mechanisms of toxin-induced parkinsonism

강태석,김종민,서경원,김영옥,김준규,오재호,이윤동,김규봉,오정자,송연정,임종준,전범석,문전옥,최광식 식품의약품안전청 2000 식품의약품안전청 연보 Vol.4 No.-

MPTP 독성물질이 도파민성 신경세포에 선택적으로 작용하여 산화성 손상에 의한 신경세포사를 일으키는 것을 이용하여 파킨슨병의 동물모델을 만들고, 이를 통해서 아폼토시스를 비롯한 포사의 기전에 대한 연구 및 너코틴의 신경세포 보호효과 여부를 판정하는 실험을 병행하고자 하였다. 파킨슨꾐의 동물모델을 MPTf 독성 물질을 이용하여 확립하였으며, MPTP(30mgag, i.p.)를 투여한 후 1, 2,3, 4, 5일째 흑질 조직을 채춰하여 tarm로 박걸하여 tyrosine hydroxylase 면역조직화학염색을 수행하여 cell countif우한 결과, control은 57.635ce11s, 1일째 친.OfDells,2일째 57.9±6cells,3일릴 없.3±죠ells, 4일째 49.0츠3cells, 5일째 39.4±Scells료 4, 3일째 뚜렷한 신경세포 수의 감소를 보였다. 신경세포사 기전 규명을 위한 아폼토시스 분걱에서는 벼PTP 투여 후 1, 2, 3, 4, 5일째 조직을 채취하여 Hoechst staining, TUNEL staining을 수곡하였는데 양성 반응을 보인 신경세포는 관찰되지 않아. 아폼토시스로 인한 세포사가 관찰되지 않았다. bIPTP 파킨슨병 동물모델에서 nicotine 보호효과 탐색에 관한 실험은 nicat푸e 0.2mgAg을 5일 퐁안 투여 후 리『fP(30mgag)를 CS7Bt/6 마은스에 복강 내주사로 nicotine과 병용 투여한 후 1, 2, 3, 4, 5일째 뇌를 적출하땄다. 신경세포사가 뚜렷이 관찰되기 시작하는 4, 5일째의 신경세포 수의 감소 정도를 20. 30% 정도 약화시키는 경향을 보였으나, nicotine 보호효과에 대한 추가 실헝이 현재 수행 중에 있다. The cause of Parkinson's disease (PD) is largely unknown. However, free radical toxicit? may plaf a role ip. the degeneration of substantia nigra, which is the Hajorfocus of pathological damages in PD. Recently, a neuroprotective effect of nicotine in PD has been suggested. Therefore, the mechanism of neurodegenerafion and protective potential o( nicotine in PD were investigated in the experimental modeB of Pll using a neurotoxin, C57BL/6mice were administered with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP, 30 mg/kg,j.p.). The degree of neurodegenerafion was determined by immunohistochemical stainiHB oftyrosine hydroxylase (TH). TH-positive cells on nigral sections were found 56.0 ±4, 57.9 ±6,52.315ce11s, 49.0±3cells, and 39,4±Scells at days 1, 2, 3, 4, 5, respectively (controls : 57.6±Scells). Hoechst and TUNEL staining showed no evidence of apoptosis. The exandnation on themice co-adrunistered with nicotine(0.2mgAg) and MPTP(30mgag) revealed a tendency ofnicotine protective effects. At days 4 and 5, the degree of TH-positive cells was decreased by20-30%, In corclusiffn, the role of apoptosis was not evidenced in this MPTP modeB of PB.The possible proteccon by nicotine should be elucidated with further studies.

Palmes Tube를 이용한 지역별 NO₂농도와 직종별 NO₂개인 폭로량에 관한 연구

김준연,박순우,김동일,장봉기,정경동,김두희,홍대용,정갑열,김용규,이종섭,유일수,김정만 동아대학교 의과대학 부설 산업의학연구소 1992 산업의학연구소 논총 Vol.- No.1

Indoor air quality is important to human wellbeing because people their spend much of time indoors. Current efforts to reduce ventilation rates in building may conserve energy but may also passibly empair human health and welfare through increased levels of indoor contaminants. Nitrogn dioxide( NO₂)has been regarded as one of the important indoor air pollutants. This report updates the assessment of NO₂concentrations at indoor & vehicle road and personal NO₂exposure levels by job groups in four urban cities. NO₂concentrations were measured using the diffusion tube method on 671 subjects in four cities(Pusan, Taegu, Chinju. Iri) from Dec. 1988 to Feb, 1989 and from Dec. 1989 to Feb. 1990. The results of the study obtained were as follows. Ⅰ. Indoor & vehicle road NO₂levels 1. The mean NO₂level was 37.8±19.6(8∼189)ppb and the highest with 42.2±20.5ppb at Bus & Taxi. 2. The NO₂levels by area were as follows: Pusan city, 38.3±20.3ppb: Taegu city, 41.1±17.6ppb: Chinju city, 33.0±19.4ppb: Iri city, 35.8±20.6ppb. 3. The site of the highest NO₂level in Pusan, Taegu, Chinju and Iri city were as follows: Bus & Taxi, 45.4ppb: Vehicle road, 50.8ppb: Bus & Taxi, 37.5ppb: Bus & Taxi. 45.0ppb. Ⅱ. Personal NO₂exposure level 1. The mean level of personal NO₂exposure was 42.7 ±23.1(6∼145)ppb and the highest with 54.0±25.5ppb at office workers. 2. Personal NO₂exposure levels by area were as follows: Pusan city 44.8±20.2ppb: Taegu city, 50.6±24.3ppb: Chinju city, 47.1±23.2ppb: Iri city, 48.0±27.0ppb. 3. The job group of the highest personal NO₂exposure level in Pusan, Taegu, Chinju and Iri city were as follows: Office workers, 50.3ppb: Bus & Taxi drivers, 63.8ppb: Office workers, 59.8ppb: Office workers, 60.0ppb.

Structures of <i>Staphylococcus aureus</i> peptide deformylase in complex with two classes of new inhibitors

Lee, Sang Jae,Lee, Seung‐,Jae,Lee, Seung Kyu,Yoon, Hye‐,Jin,Lee, Hyung Ho,Kim, Kyeong Kyu,Lee, Bong Jin,Lee, Byung Il,Suh, Se Won International Union of Crystallography 2012 Acta crystallographica. Section D, Biological crys Vol.68 No.7

<P>Peptide deformylase (PDF) catalyzes the removal of the formyl group from the N‐terminal methionine residue in newly synthesized polypeptides, which is an essential process in bacteria. Four new inhibitors of PDF that belong to two different classes, hydroxamate/pseudopeptide compounds [PMT387 (7a) and PMT497] and reverse‐hydroxamate/nonpeptide compounds [PMT1039 (15e) and PMT1067], have been developed. These compounds inhibited the growth of several pathogens involved in respiratory‐tract infections, such as <I>Streptococcus pneumoniae</I>, <I>Moraxella catarrhalis</I> and <I>Haemophilus influenzae</I>, and leading nosocomial pathogens such as <I>Staphylococcus aureus</I> and <I>Klebsiella pneumoniae</I> with a minimum inhibitory concentration (MIC) in the range 0.1–0.8 mg ml<SUP>−1</SUP>. Interestingly, the reverse‐hydroxamate/nonpeptide compounds showed a 250‐fold higher antimicrobial activity towards <I>S.?aureus</I>, although the four compounds showed similar <I>K</I><SUB>i</SUB> values against <I>S.?aureus</I> PDF enzymes, with <I>K</I><SUB>i</SUB> values in the 11–85 n<I>M</I> range. To provide a structural basis for the discovery of additional PDF inhibitors, the crystal structures of <I>S. aureus</I> PDF in complex with the four inhibitors were determined at resolutions of 1.90–2.30 Å. The inhibitor‐bound structures displayed distinct deviations depending on the inhibitor class. The distance between the Zn<SUP>2+</SUP> ion and the carbonyl O atom of the hydroxamate inhibitors (or the hydroxyl O atom of the reverse‐hydroxamate inhibitors) appears to be correlated to <I>S.?aureus</I> inhibition activity. The structural information reported in this study should aid in the discovery of new PDF inhibitors that can be used as novel antibacterial drugs.</P>

Electrical manipulation of nanofilaments in transition-metal oxides for resistance-based memory.

Lee, Myoung-Jae,Han, Seungwu,Jeon, Sang Ho,Park, Bae Ho,Kang, Bo Soo,Ahn, Seung-Eon,Kim, Ki Hwan,Lee, Chang Bum,Kim, Chang Jung,Yoo, In-Kyeong,Seo, David H,Li, Xiang-Shu,Park, Jong-Bong,Lee, Jung-Hyun American Chemical Society 2009 Nano letters Vol.9 No.4

<P>The fabrication of controlled nanostructures such as quantum dots, nanotubes, nanowires, and nanopillars has progressed rapidly over the past 10 years. However, both bottom-up and top-down methods to integrate the nanostructures are met with several challenges. For practical applications with the high level of the integration, an approach that can fabricate the required structures locally is desirable. In addition, the electrical signal to construct and control the nanostructures can provide significant advantages toward the stability and ordering. Through experiments on the negative resistance switching phenomenon in Pt-NiO-Pt structures, we have fabricated nanofilament channels that can be electrically connected or disconnected. Various analyses indicate that the nanofilaments are made of nickel and are formed at the grain boundaries. The scaling behaviors of the nickel nanofilaments were closely examined, with respect to the switching time, power, and resistance. In particular, the 100 nm x 100 nm cell was switchable on the nanosecond scale, making them ideal for the basis for high-speed, high-density, nonvolatile memory applications.</P>

Acquisition of Tomato yellow leaf curl virus (TYLCV) change the pesticide susceptibility on the vector Bemisia tabaci

Bong-Gi Choi,Jae-Kyoung Shim,Kyeong-Yeoll Lee 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.04

The sweetpotato whitefly Bemisia tabaci (Hemiptera: Aleyrodidae) is a disastrous pest in horticultural plants worldwide. B. tabaci is a species complex including at least 24 biotypes in the world. In Korea, B-biotype has been invaded in 1998, Q-biotype in 2005 and widely spread into the country. B. tabaci is also a vector of more than 100 plant viruses, especially begomoviruses. Since 2008, Tomato yellow leaf curl virus (TYLCV) has been invaded into Korea and severely damaged tomato cultivar in all over of the country. B. tabaci is the only vector insect of TYLCV. Here we demonstrated whether TYLCV influence on the vector physiology during virus transmission. Pesticide susceptibility of whiteflies on TYLCV acquisition was determined in B. tabaci using the two-layered parafilm feeding chamber which containing 20% sugar solution including different doses of imidacloprid. Our result showed that TYLCV-viruliferous whiteflies were more susceptible to imidacloprid ingestion than non-viruliferous whiteflies. This study suggests that plant virus can manipulate the physiological conditions of vector insects.

Molecular cloning of the glucose regulated protein 78 (Grp78) gene of Bemisia tabaci, and its expression in response to thermal and nutrient stress

Bong-Gi Choi,Jae-Kyoung Shim,Kyeong-Yeoll Lee 한국응용곤충학회 2015 한국응용곤충학회 학술대회논문집 Vol.2015 No.10

The sweetpotato whitelfy Bemisia tabaci distribute worldwide and infests more than 500 species of plants. To determine nutritional stress of whiteflies at molecular level, we identified a full cDNA of glucose regulated protein 78 (grp78) which is known to be respond to nutritional restriction in vertebrate species. GRP78 of B. tabaci was highly conserved motifs of the HSP70 family and the C-terminal motif of KDEL characteristic of endoplasmic reticulum-specific HSPs. Real-time RT-PCR analysis showed that the grp78 level was not changed by thermal stress treatment from 4°C to 40°C for 1 h. However, the grp78 level was proportionally increased to the ingestion of a sucrose solution ranging in concentrations from 0% to 30% in a Parafilm feeding chamber. In addition, the grp78 levels were various by the ingestion of leaves of 10 different plants for 24 h; its level was higher with eggplant and pepper but lower with rice and apple. Our study suggests that the grp78 may have a role for cellular chaperones in relation to nutritional uptake of B. tabaci.

Cystic Lesions of the Gastrointestinal Tract: Multimodality Imaging with Pathologic Correlations

Lee, Jongmee,Park, Cheol Min,Kim, Kyeong Ah,Lee, Chang Hee,Choi, Jae Woong,Shin, Bong Kyung,Lee, Soon Jin,Choi, Dongil,Jang, Kee-Taek The Korean Society of Radiology 2010 KOREAN JOURNAL OF RADIOLOGY Vol.11 No.4

<P>The cystic lesions of the gastrointestinal (GI) tract demonstrate the various pathologic findings. Some lesions may present a diagnostic challenge because of non-specific imaging features; however, other lesions are easily diagnosed using characteristic radiologic features and anatomic locations. Cystic masses from the GI tract can be divided into several categories: congenital lesions, neoplastic lesions (cystic neoplasms, cystic degeneration of solid neoplasms), and other miscellaneous lesions. In this pictorial review, we describe the pathologic findings of various cystic lesions of the GI tract as well as the radiologic features of GI cystic lesions from several imaging modalities including a barium study, transabdominal ultrasound (US), computed tomography (CT), and magnetic resonance (MR) imaging.</P>