• Title/Summary/Keyword: Complex exposure

검색결과 455건 처리시간 0.024초

신부전 요인에 의해 유발된 닭 신장변화의 병리학적 관찰 I. 병리조직학적 및 전자현미경적 관찰 (Pathological evaluation of renal changes induced by multiple nephropathogenic factors in SPF chickens I. Histopathological and electron microscopical observation)

  • 강경일;모인필;권용국;강민수;한태욱;한정희
    • 대한수의학회지
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    • 제39권6호
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    • pp.1126-1140
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    • 1999
  • Renal failure is one of the main causes of economic impacts in the poultry industry and complex syndrome with different severity of clinical signs caused by multiple nephropathogenic factors such as infectious bronchitis viral infection and excess salt and calcium in diet. To evaluate the correlation between severity of renal failure and the causative nephropathogenic factors, one-day-old specific pathogen free chicks were treated with either single causative factor or multiple causative factors described as above. Each group was designed as control for non-treated control, IB for infectious bronchitis virus (IB virus) infection, IBHNa for IB virus infection with high diet salt, IBHCa for IB virus infection with high diet calcium, IBHNC for IB virus infection with high diet salt and calcium, HNa for high diet salt, HCa for high diet calcium and HNC for high diet salt and calcium. Chickens were inoculated with IB virus at 1-day-old and remained on their respective diets until 21 day of age. The high dietary salt feeding groups such as IBHNa, IBHNC, HNa, HNC increased water intake, watery diarrhea, general subcutaneous edema and the high dietary calcium feeding groups such as IBHCa and IBHNC showed severe visceral gout. Two more than treated groups caused high mortality in comparison with the single treated groups. IB virus exposure significantly increased urate deposition and lymphocytic interstitial nephritis. Especially urate deposition dramatically increased when excess diet calcium was combined together. In excess diet salt treated groups enlarged edematous kidneys were observed and hypertrophy of glomeruli were showed. These results suggest that IB virus enhanced the incidence and severity on chicken renal failure clearly related to the quantity of salt and calcium.

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Biochemical Analysis of a Cytosolic Small Heat Shock Protein, NtHSP18.3, from Nicotiana tabacum

  • Yu, Ji Hee;Kim, Keun Pill;Park, Soo Min;Hong, Choo Bong
    • Molecules and Cells
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    • 제19권3호
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    • pp.328-333
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    • 2005
  • Small heat shock proteins (sHSPs) are widely distributed, and their function and diversity of structure have been much studied in the field of molecular chaperones. In plants, which frequently have to cope with hostile environments, sHSPs are much more abundant and diverse than in other forms of life. In response to high temperature stress, sHSPs of more than twenty kinds can make up more than 1% of soluble plant proteins. We isolated a genomic clone, NtHSP18.3, from Nicotiana tabacum that encodes the complete open reading frame of a cytosolic class I small heat shock protein. To investigate the function of NtHSP18.3 in vitro, it was overproduced in Escherichia coli and purified. The purified NtHSP18.3 had typical molecular chaperone activity as it protected citrate synthase and luciferase from high temperature-induced aggregation. When E. coli celluar proteins were incubated with NtHSP18.3, a large proportion of the proteins remained soluble at temperatures as high as $70^{\circ}C$. Native gel analysis suggested that NtHSP18.3 is a dodecameric oligomer as the form present and showing molecular chaperone activity at the condition tested. Binding of bis-ANS to the oligomers of NtHSP18.3 indicated that exposure of their hydrophobic surfaces increased as the temperature was raised. Taken together, our data suggested that NtHSP18.3 is a molecular chaperone that functions as a dodecameric complex and possibly in a temperature-induced manner.

Mycobacterium bovis와 M. tuberculosis 감별을 위한 등온증폭법 (Loop-mediated isothermal amplification assay for differentiation of Mycobacterium bovis and M. tuberculosis)

  • 고바라다;김재명;성창민;지태경;나호명;박성도;김용환;김은선
    • 한국동물위생학회지
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    • 제36권2호
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    • pp.79-86
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    • 2013
  • Mycobacterium (M.) bovis, a member of the M. tuberculosis complex (MTC), is a re-emerging, zoonotic agent of bovine tuberculosis whose prevalence probably depends on variations in direct exposure to cattle and ingestion of raw milk. Accurate species differentiation of M. bovis and M. tuberculosis is needed to distinguish between human and zoonotic tuberculosis. This study successfully developed a loop-mediated isothermal amplification (LAMP) assay for rapid detection and differentiation of M. bovis and M. tuberculosis, however showed negative reactions in eight non-tuberculous mycobacteria (NTM) samples and ten other bacterial species. Sensitivity of this assay for detection of genomic M. bovis DNA was 10 $fg/{\mu}l$. And this assay successfully detected M. bovis in bovine clinical specimens. In conclusion, the LAMP assay is a simple and powerful tool for rapid detection of M. bovis in both pure bacterial culture and in clinical samples.

충주지역 주민 피부 알레르기 반응율에 관한 연구 (A Study on Allergen Skin Test Prevalence Among the Residents of Chungju City as a Non-industrial Area)

  • 김대선;이보은;남상훈;안승철
    • 한국환경보건학회지
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    • 제40권5호
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    • pp.367-375
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    • 2014
  • Objectives: The main purpose of this study is to produce background data which can be compared with several large-scale industrial complex regions. Methods: The framework of this study was designed to evaluate and monitor health effects associated with low-level and long-term exposure to environmental pollutants. In this study, 1,009 local residents were recruited in the city of Chungju using personal questionnaires, medical check-ups, and allergen skin-prick tests for 12 common allergens. The prevalence rate of skin allergens was reviewed together with that from large-scale industrial areas. Results: The diagnosis prevalence and medical treatment prevalence of asthma was 5.6% and 1.7%, respectively. Allergic rhinitis was 25.4% and 16.7%, allergic dermatitis was 16.6% and 9.9% and allergic conjunctivitis was 18.7% and 7.9%, respectively. These results were similar with those of industrial complexes. The prevalence of allergen skin-prick test was 16.4% and the most common allergen was dust mites (27.9-31.6%). This result was lower than those of the industrial complexes (22.5-39.9%) and Gangneung (18.2-24.7%). Conclusion: Further study is required to find the cause of the regional differences in skin prick prevalence.

중국 유학생의 의복 구매 및 착용 실태에 관한 연구 (A Study on Chinese Students' Clothing Purchase and Wearing Condition)

  • 남영란;김지영;최혜선
    • 복식
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    • 제63권6호
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    • pp.40-55
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    • 2013
  • The purpose of this study was to find ways to increase sales and enhance of the competitiveness of the Korean fashion brands expanding into the Chinese market by conducting a survey of the Chinese female students in order to gather data regarding their preferences and features so that clothes that are more suitable for Chinese women can be designed. For this study, a survey was conducted to 305 students attending universities or language schools located in the metropolitan areas near Seoul who had exposure to Korean clothes. The study results can be summed up as follows: According to the analysis, the Chinese students preferred comfortable, practical, and casual styles. And the analysis shows that they prefer achromatic monotonous colors rather than vivid colors or splendid and complex patterns. The students felt that Korean clothes reflected the trends very well, and they also showed very high satisfaction with the design. The most common way of gathering information for their clothing purchase was through Internet search and magazine advertisements. The survey showed that the biggest strength of the Korean fashion brands was their ability to reflect the fast changing fashion trends in their designs, and they were very much satisfied with their diverse designs and colors. Among the domestic fashion brands, they prefer domestic SPA brands such as MIXXO, SPAO, and 8IGHT SECONDS.

경로생성 및 지형차폐를 고려한 통신영역 생성 방법 (Research of Communication Coverage and Terrain Masking for Path Planning)

  • 우상효;김재민;백인혜;김기범
    • 한국군사과학기술학회지
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    • 제23권4호
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    • pp.407-416
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    • 2020
  • Recent complex battle field demands Network Centric Warfare(NCW) ability to control various parts into a cohesive unit. In path planning filed, the NCW ability increases complexity of path planning algorithm, and it has to consider a communication coverage map as well as traditional parameters such as minimum radar exposure and survivability. In this paper, pros and cons of various propagation models are summarized, and we suggest a coverage map generation method using a Longley-Rice propagation model. Previous coverage map based on line of sight has significant discontinuities that limits selection of path planning algorithms such as Dijkstra and fast marching only. If there is method to remove discontinuities in the coverage map, optimization based path planning algorithms such as trajectory optimization and Particle Swarm Optimization(PSO) can also be used. In this paper, the Longley-Rice propagation model is used to calculate continuous RF strengths, and convert the strength data using smoothed leaky BER for the coverage map. In addition, we also suggest other types of rough coverage map generation using a lookup table method with simple inputs such as terrain type and antenna heights only. The implemented communication coverage map can be used various path planning algorithms, especially in the optimization based algorithms.

Integrating GPS/INS/PL for Robust Positioning: The Challenging Issues

  • Wang, Jinling;Babu, Ravindra;Li, Di;Chan, Franics;Choi, Jin-Ho
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 2006년도 International Symposium on GPS/GNSS Vol.1
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    • pp.127-132
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    • 2006
  • The Global Positioning System (GPS), Inertial Navigation System (INS) and Pseudolite (PL) technologies all play very important roles in navigation systems. As an independent navigation system, GPS can provide high precision positioning results which are independent of time. However, the performance will become unreliable when the system experiences high dynamics, or when the receiver is exposed to jamming or RF interference. In comparison to GPS, though INS is autonomous and provides good short-term accuracy, its use as a standalone navigation system is limited due to the time-dependent growth of the inertial sensor errors. PLs are ground-based transmitters that can transmit GPS-like signals. They have some advantages in that their positions can be determined precisely, and the Signal-to-Noise Ratios (SNR) are relatively high. Because their combined performance, in principle, overcomes the shortcomings of the individual systems, the integration of GPS, INS and PL is increasingly receiving attention from researchers. Depending on the desired performance vs complexity, system integration can be carried out at different levels, namely loose, tight and ultra-tight coupling. Compared with loose and tight integration, although it is more complex in terms of system design, ultra-tight integration will be the basis of the next generation of reliable and robust navigation systems. Its main advantages include improved performance under exposure to high dynamics, and jamming and RF interference mitigation. This paper presents an overview of the ultra-tight integration developments and discusses some of the challenging issues.

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Cadmium Inhibition of Renal Endosomal Acidification

  • Kim, Moo-Seong;Kim, Kyoung-Ryong;Ahn, Do-Whan;Park, Yang-Saeng
    • The Korean Journal of Physiology and Pharmacology
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    • 제4권1호
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    • pp.63-72
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    • 2000
  • Chronic exposure to cadmium (Cd) results in an inhibition of protein endocytosis in the renal proximal tubule, leading to proteinuria. In order to gain insight into the mechanism by which Cd impairs the protein endocytosis, we investigated the effect of Cd on the acidification of renal cortical endocytotic vesicles (endosomes). The endosomal acidification was assessed by measuring the pH gradient-dependent fluorescence change, using acridine orange or FITC-dextran as a probe. In renal endosomes isolated from Cd-intoxicated rats, the $V_{max}$ of ATP-driven fluorescence quenching ($H^+-ATPase$ dependent intravesicular acidification) was significantly attenuated with no substantial changes in the apparent $K_m,$ indicating that the capacity of acidification was reduced. When endosomes from normal animals were directly exposed to free Cd in vitro, the $V_{max}$ was slightly reduced, whereas the $K_m$ was markedly increased, implying that the biochemical property of the $H^+-ATPase$ was altered by Cd. In endosomes exposed to free Cd in vitro, the rate of dissipation of the transmembrane pH gradient after $H^+-ATPase$ inhibition appeared to be significantly faster compared to that in normal endosomes, indicating that the $H^+-conductance$ of the membrane was increased by Cd. These results suggest that in long-term Cd-exposed animals, free Cd ions liberated in the proximal tubular cytoplasm by lysosomal degradation of cadmium-metallothionein complex (CdMT) may impair endosomal acidification 1) by reducing the $H^+-ATPase$ density in the endosomal membrane, 2) by suppressing the intrinsic $H^+-ATPase$ activity, and 3) possibly by increasing the membrane conductance to $H^+$ ion. Such effects of Cd could be responsible for the alterations of proximal tubular endocytotic activities, protein reabsorption and various transporter distributions observed in Cd-exposed cells and animals.

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Janus Kinase 2 Inhibitor AG490 Inhibits the STAT3 Signaling Pathway by Suppressing Protein Translation of gp130

  • Seo, In-Ae;Lee, Hyun-Kyoung;Shin, Yoon-Kyung;Lee, Sang-Hwa;Seo, Su-Yeong;Park, Ji-Wook;Park, Hwan-Tae
    • The Korean Journal of Physiology and Pharmacology
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    • 제13권2호
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    • pp.131-138
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    • 2009
  • The binding of interleukin-6 (IL-6) cytokine family ligands to the gp130 receptor complex activates the Janus kinase (JAK)/ signal transducer and activator of transcription 3 (STAT3) signal transduction pathway, where STA T3 plays an important role in cell survival and tumorigenesis. Constitutive activation of STAT3 has been frequently observed in many cancer tissues, and thus, blocking of the gp130 signaling pathway, at the JAK level, might be a useful therapeutic approach for the suppression of STAT3 activity, as anticancer therapy. AG490 is a tyrphostin tyrosine kinase inhibitor that has been extensively used for inhibiting JAK2 in vitro and in vivo. In this study, we demonstrate a novel mechanism associated with AG490 that inhibits the JAK/STAT3 pathway. AG490 induced downregulation of gp130, a common receptor for the IL-6 cytokine family compounds, but not JAK2 or STAT3, within three hours of exposure. The downregulation of gp130 was not caused by enhanced degradation of gp130 or by inhibition of mRNA transcription. It most likely occurred by translation inhibition of gp130 in association with phosphorylation of the eukaryotic initiation factor-2 a. The inhibition of protein synthesis of gp130 by AG490 led to immediate loss of mature gp130 in cell membranes, due to its short half-life, thereby resulting in reduction in the STAT3 response to IL-6. Taken together, these results suggest that AG490 blocks the STAT3 activation pathway via a novel pathway.

Evolution the surface morphology and mechanical properties of Polyimide induced by Ion Beam Irradiation

  • Ahmed, Sk. Faruque;Nho, Gun-Ho;Moon, Myoung-Woon;Han, Jun-Hyun;Lee, Kwang-Ryeol
    • 한국진공학회:학술대회논문집
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    • 한국진공학회 2009년도 제38회 동계학술대회 초록집
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    • pp.98-98
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    • 2010
  • Ion beam irradiation has been extensively used for surface modification of polymers, glassy metals and amorphous and crystalline materials at micron and submicron scales. The surface structures created by exposure to an ion beam range from dots, steps and one-dimensional straight wrinkles to highly complex hierarchical undulations and ripples. In general, the morphology of these nanoscale features can be selected by controlling the ion beam parameters (e.g. fluence and acceleration voltage), making ion beam irradiation a promising method for the surface engineering of materials. In the work, we presented that ion beam irradiation results in creation of a peculiar nanoscale dimple-like structure on the surface of polyimide - a common polymer in electronics, large scale structures, automobile industry, and biomedical applications. The role of broad Ar ion beam on the morphology of the structural features was investigated and insights into the mechanisms of formation of these nanoscale features were provided. Moreover, a systematic experimental study was performed to quantify the role of ion beam treatment time, and thus the morphology, on the coefficient of friction of polyimide surfaces covered by nanostructure using a tribo-experiment. Nano-indentation experiment were performed on the ion beam treated surfaces which shows that the hardness as well as the elastic modulus of the polyimide surface increased with increase of Ar ion beam treatment time. The increased of hardness of polyimide have been explained in terms of surface structure as well as morphology changes induced by Ar ion beam treatment.

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