• Title/Summary/Keyword: Lead Accumulation

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Antimicrobial Property of $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-Glucopyranoside$ Isolated From the Root Bark of Lycium chinense Miller Against Human Pathogenic Microorganisms

  • Lee Dong Gun;Jung Hyun Jun;Woo Eun-Rhan
    • Archives of Pharmacal Research
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    • v.28 no.9
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    • pp.1031-1036
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    • 2005
  • [ $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ ] (1) was isolated from an ethyl acetate extract of the root bark from Lycium chinense Miller, and its structure was determined using 1D and 2D NMR spectroscopy including DEPT, HMQC, and HMBC. $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ exhibited potent antimicrobial activity against antibiotic-resistant bacterial strains, methicillin-resistant Staphylococcus aureus (MRSA) isolated from patients, and human pathogenic fungi without having any hemolytic effect on human erythrocytes. In particular, compound 1 induced the accumulation of intracellular trehalose on C. albicans as stress response to the drug, and disrupted the dimorphic transition that forms pseudo-hyphae caused by the pathogenesis. This indicates that $(+)-Lyoniresinol-3{\alpha}-O-\beta-D-glucopyranoside$ has excellent potential as a lead compound for the development of antibiotic agents.

Antiinflammatory Evaluation and Synthesis of Benzothiazine Derivatives as Cyclooxygenase-2 Inhibitor (Cyclooxygenase-2 저해제로서의 benzothiazine 유도체 합성과 항염작용 평가)

  • 신혜순;박명숙;권순경
    • YAKHAK HOEJI
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    • v.44 no.3
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    • pp.272-278
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    • 2000
  • The antiinflammatory mechanism of NSAIDs is attributed to the reduction of prostaglandin synthesis by the direct inhibition of cyclooxygenase. Inhibition of prostaglandin production in organs such as stomach and kidney can result in gastric lesions, nephrotoxicity and increased bleeding. In this study, newly designed COX-2 inhibitors, synthesized 1,2-benzothiazine derivatives, were screened in vitro for selectivity of COX-1 and COX-2 inhibition properties. Lead compounds in the structure-activity relationship were studied to synthesize new highly selective COX-2 inhibitors.13 determine inhibitory effect of COX-2, synthesized 1,2-benzothiazine derivatives were screened with accumulation of prostaglandin by lipopolysaccharide (LPS) in aspirin-treated macrophages and murine macropharge cell. Some of synthesized 1,2-benzothiazine derivatives were shown to be effective as selective COX-2 inhibitory activity. Others exhibited a preferential inhibition of COX-2, although some COX-1 inhibitory activity was still present. As a conclusion, simple monomer derivatives were more active than dimer derivatives. Substitution of halogen (Br, C1) on the benzothiazine nucleus slightly enhanced inhibition activity.

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산업부산물을 이용한 중금속 제거효율에 관한 연구

  • 권용삼;이기호;박준범;이상훈;박종범
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2003.09a
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    • pp.431-434
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    • 2003
  • Environmental pollution problems due to the wastes from various industrial facilities and activities have become a serious issue. The specific problem associated with heavy metals in the environment is their accumulation in the food chain and their persistence in nature. Present work investigates the possible uses of by-products for the removal of heavy metal ions. Heavy metals used in these studies were cadmium, lead and copper. Experiments were conducted with by-products such as oyster shell and fly ash to evaluate their sorption characteristics. The results of the study indicate that oyster shell can be properly used as an adsorbent for heavy metals because of its outstanding removal rate.

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Modeling of SO$_2$ Emissions from Yatagan Power Plant

  • Im, Ulas;Yenigun, Orhan
    • Proceedings of the Korean Environmental Sciences Society Conference
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    • 2003.11a
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    • pp.69-72
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    • 2003
  • The meteorological model, CALMET, and its plume dispersion model, CALPUFF, were used in order to simulate the dispersion of $SO_2$ emitted from Yatagan Power Plant and its effect on Yatagan district in the episodic event on December 2 and 3, 2000. It is found that south westerly and light winds and the nighttime surface inversion layers lead to accumulation of pollutants over Yatagan district. The results are compared with the measurements done by Local Environmental Authorities of Mu la. The simulation results indicate that the maximum ground level concentrations were found northeast from the source, which agrees with experimental measurement. On the other hand, the magnitude of results obtained with the model shows some differences compared with experimental measurements.

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Autophagy in Neurodegenerative Diseases: From Mechanism to Therapeutic Approach

  • Nah, Jihoon;Yuan, Junying;Jung, Yong-Keun
    • Molecules and Cells
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    • v.38 no.5
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    • pp.381-389
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    • 2015
  • Autophagy is a lysosome-dependent intracellular degradation process that allows recycling of cytoplasmic constituents into bioenergetic and biosynthetic materials for maintenance of homeostasis. Since the function of autophagy is particularly important in various stress conditions, perturbation of autophagy can lead to cellular dysfunction and diseases. Accumulation of abnormal protein aggregates, a common cause of neurodegenerative diseases, can be reduced through autophagic degradation. Recent studies have revealed defects in autophagy in most cases of neurodegenerative disorders. Moreover, deregulated excessive autophagy can also cause neurodegeneration. Thus, healthy activation of autophagy is essential for therapeutic approaches in neurodegenerative diseases and many autophagy-regulating compounds are under development for therapeutic purposes. This review describes the overall role of autophagy in neurodegeneration, focusing on various therapeutic strategies for modulating specific stages of autophagy and on the current status of drug development.

FEM Analysis for Optimization of Hot Forging Process of Piston Crown (피스톤크라운의 열간단조공정 최적화를 위한 유한요소해석)

  • Min, K.Y.;Lim, S.J.;Choi, H.J.;Choi, S.O.;Park, Y.B.
    • Transactions of Materials Processing
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    • v.18 no.6
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    • pp.444-447
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    • 2009
  • Piston crown to the hot forge a unified nature of the product has a shape with multi-level step forging process, so if you are not a mechanical professional, this process could lead to a significant loss to the material. Therefore, material technology in minor terms; continue to improve the collection rate that undamaged the product material. The piston crown and the manufacturing products such as marine diesel engines are being forged to reduce costs and to improve mechanical properties. Piston crown molding is a hot forging process that works in large volume forging products. Because of the size of the hard plastic material flow process for improving the design and actual field experience through advanced plastic technology, it is important to interpret the results. Also for many experimental plastic procedures, the accumulation of results is very important.

Guanosine Regulates Germinal Vesicle Breakdown (GVBD) in Mouse Oocytes

  • Cheon Yong-Pil
    • Reproductive and Developmental Biology
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    • v.28 no.4
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    • pp.267-273
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    • 2004
  • Maturation of oocytes is maintained by complex procedures along with follicular genesis and is a critical step for embryonic development. Purine known as an oocyte maturation regulator is present in follicular fluid. In this study, the roles of guanosine as a strong inhibitor of GVBD and a modulator of cyclic GMP concentration in ooyctes were revealed. Denuded immature oocytes were treated with guanosine, and the maturation rates and cGMP concentration of oocytes were measured. GVBD was blocked in a concentration dependent manner by guanosine, but this effect was reversible. However, GVBD was lagged yet not significant by adenosine. Both guanosine and adenosine modified cGMP concentration in oocytes. The characteristic of the guanosine-treated oocyte was significantly higher cGMP compared with the adenosine-treated oocyes at initial time of the maturation. Based these results, guanosine may be a strong and reversible GVBD inhibitor. Although the precise mechanism of guanosine presently is unclear, the results suggest that guanosine may lead the accumulation of cGMP in oocyte cytoplasm, which in turn suppresses GVBD.

Roles of Endoplasmic Reticulum Stress in Immune Responses

  • So, Jae-Seon
    • Molecules and Cells
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    • v.41 no.8
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    • pp.705-716
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    • 2018
  • The endoplasmic reticulum (ER) is a critical organelle for protein synthesis, folding and modification, and lipid synthesis and calcium storage. Dysregulation of ER functions leads to the accumulation of misfolded- or unfolded-protein in the ER lumen, and this triggers the unfolded protein response (UPR), which restores ER homeostasis. The UPR is characterized by three distinct downstream signaling pathways that promote cell survival or apoptosis depending on the stressor, the intensity and duration of ER stress, and the cell type. Mammalian cells express the UPR transducers IRE1, PERK, and ATF6, which control transcriptional and translational responses to ER stress. Direct links between ER stress and immune responses are also evident, but the mechanisms by which UPR signaling cascades are coordinated with immunity remain unclear. This review discusses recent investigations of the roles of ER stress in immune responses that lead to differentiation, maturation, and cytokine expression in immune cells. Further understanding of how ER stress contributes to the pathogenesis of immune disorders will facilitate the development of novel therapies that target UPR pathways.

STUDY ON ALGORITHM FOR CALCULATION REMAINING CAPACITY OF INDUSTRIAL LEAD-ACID BATTERY (산업용 연축전지의 잔존용량 산출 알고리즘(Algorithm)에 관한 연구)

  • Lim, Gyu-Ryeong;Chun, Soon-Yong
    • Proceedings of the KIEE Conference
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    • 2001.07d
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    • pp.2187-2189
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    • 2001
  • The proposed algorithm has produced the rules of relationship between the load voltage, current, discharging electric power and ampere-hours, electric power capacity of battery on the basis of the data. Which were acquired through the battery discharging experiment that is defined by the battery's ambient temperature and various load conditions. Especially, by calculating the parameter of second order polynomial equation relation between the remaining capacity and the electric power, the algorithm is proposed adapting for the discharging pattern. And as the depth of discharging is increasing, the calculation-method of electric power is applied to decrease the accumulated error in the calculation method of capacity accumulation. Also, the proposed algorithm has compensated the temperature considering the capacity change of battery to the temperature.

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Beta-amyloid imaging in dementia

  • Chun, Kyung Ah
    • Journal of Yeungnam Medical Science
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    • v.35 no.1
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    • pp.1-6
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    • 2018
  • Alzheimer's disease (AD) is a neurodegenerative disorder associated with extracellular plaques, composed of amyloid-beta ($A{\beta}$), in the brain. Although the precise mechanism underlying the neurotoxicity of $A{\beta}$ has not been established, $A{\beta}$ accumulation is the primary event in a cascade of events that lead to neurofibrillary degeneration and dementia. In particular, the $A{\beta}$ burden, as assessed by neuroimaging, has proved to be an excellent predictive biomarker. Positron emission tomography, using ligands such as $^{11}C$-labeled Pittsburgh Compound B or $^{18}F$-labeled tracers, such as $^{18}F$-florbetaben, $^{18}F$-florbetapir, and $^{18}F$-flutemetamol, which bind to $A{\beta}$ deposits in the brain, has been a valuable technique for visualizing and quantifying the deposition of $A{\beta}$ throughout the brain in living subjects. $A{\beta}$ imaging has very high sensitivity for detecting AD pathology. In addition, it can predict the progression from mild cognitive impairment to AD, and contribute to the development of disease-specific therapies.