• 제목/요약/키워드: lead absorption

검색결과 374건 처리시간 0.022초

알코올의 투여가 흰쥐의 엽산대사에 미치는 영향 (Effect of Alcohol Adminstration on Folate Metabolism in Rats)

  • 장남수
    • Journal of Nutrition and Health
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    • 제31권4호
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    • pp.708-715
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    • 1998
  • Chronic abuse of alcohol can lead to the development of folate deficiency due to inadequate folate intaike, excessive urinary excretion and from effects of ethanol on folate absorption and metabolism . To investigate the effects of alcohol and folate intake on folate metabolism, the rates were raised for 4 and 10 weeks on experimental diets containing 0, 2 8mg folate/kg diet, and were administered 50% ethanol(1.8$m\ell$/kg body weight) three times a week intragastrically. Plasma and tissue folate concentrations were found to be significantly influenced by dietary folate level. In animals fed on folate-deficient diet, concentrations of folate in the plasma, liver and kidney were decreased by 60-89% compared to those on folate-adequate diet, and ther values were further decreased with experimental period. Folate supplementation increased plasma and tissue folate levels significantly by 16-78% compared to those on folate-adequate diet, and the folate levels in the plasma and liver were affected most by the supplementation. Alcohol administration did not seem to influence folate status in the body significantly when animals were raised on folate-deficient diet. However, when rats were fed folate-adequate or folate-supplemented diet, alcohol was shown to decrease plasma and tissue folate concentrations. Among the animals receiving alcohol, folate concentrations in the plasma and tissues were significantly higher when animals fed folate-supplemented diet compared to folate adequate diet. Alcohol seems to exert differential effects on urinary foalte excretion by experimental period it increased urinary folate in the 4-week period, but lowered foalte excretion in the urine when the experimental period was extended to 10 weeks. Alcohol did not seem to influence folate excretion in the feces. These results indicate that folate supplementation might be beneficial in ameliorating the inadequate folate status that might occur with chronic alcoholism.

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Glucose Oxidase 고정화에 대한 전기화학적/광학적 분석 (Spectro-electrochemical Analyses of Immobilization of Glucose Oxidase)

  • 김현철;조영재;구할본;사공건
    • 한국전기전자재료학회:학술대회논문집
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    • 한국전기전자재료학회 2000년도 영호남학술대회 논문집
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    • pp.316-319
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    • 2000
  • In the case of immobilizing of glucose oxidase into polypyrrole (PPy) using electrosynthesis, the glucose oxidase (GOx) forms a coordinate bond with the polymer's backbone. However, because of intrinsic insulation and net-chain of the enzyme, the charge transfer and mass transport are obstructed during the film growth. Therefore, the film growth is dull. We synthesized the enzyme electrode by electropolymerization added some organic solvent, A formative seeds of film growth is delayed by adding the solvent. The delay is induced by radical transfer between the solvent and pyrrole monomer. In the case of adding ethanol, the radical transfer shares the contribution of dopant between electrolyte anion and GOx polyanion. This may lead to increase amount of immobilized the enzyme in ppy. However, adding tetrahydrofuran (THF), the radical transfer is more brisk, resulting in short chained polymer. Therefore, the doping level is lowered and then amount of immobilized of enzyme is decreased. For the UV absorption spectra of synthetic solution before synthesis and after, in the case of ethanol added, the optical density was slightly decreased for the GOx peaks. It suggests amount of GOx in the solution was decreased and amount of GOx in the film was increased. We established qualitatively that amount of immobilization can be improved by adding a little ethanol in the synthetic solution. It is due to radical transfer reaction. The radical transfer shares the contribution of dopant between small and fast electrolyte anion and big and slow GOx polyanion.

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Environmental Genomics Related to Environmental Health Biomarker

  • Kim, Hyun-Mi;Kim, Dae-Seon;Chung, Young-Hee
    • Molecular & Cellular Toxicology
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    • 제2권2호
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    • pp.75-80
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    • 2006
  • Biomarkers identify various stages and interactions on the pathway from exposure to disease. The three categories of biomarkers are those measuring susceptibility, exposure and effect. Susceptibility biomarkers are identifiable genetic variations affecting absorption, metabolism or response to environmental agents. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. Biomarkers of exposure indicate the amount of a foreign compound that is absorbed into the body. Biological measurements performed on human tissues are vastly expanding the capabilities of classical epidemiology, which has relied primarily on estimates of human exposure derived form chemical levels in the air, water, and other exposure routes. The biomarker response is typical of chemical pollution by specific classes of compound, such as (i) heavy metals (mercury, cadmium, lead, zinc), responsible for the induction of metallothionein synthesis, and (ii) organochlorinated pollutants (PCBs, dioxins, DDT congeners) and polycyclic aromatic hydrocarbons (PAHs), which induce the mixed function oxygenase (MFO) involved in their bio transformations and elimination. Currently genomic researches are developed in human cDNA clone subarrays oriented toward the expression of genes involved in responses to xenobiotic metabolizing enzymes, cell cycle components, oncogenes, tumor suppressor genes, DNA repair genes, estrogen-responsive genes, oxidative stress genes, and genes known to be involved in apoptotic cell death. Several research laboratories in Korea for kicking off these Environmental Genomics were summarized.

버섯류의 미양금속, 중금속 및 유기산 함양에 관한 연구 (Studies on the Trace Elements, Heavy Metals and Organic acids Content of Edible Mushrooms)

  • 허선행
    • 환경위생공학
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    • 제7권1호
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    • pp.57-66
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    • 1992
  • To investigate on the element content of twelve edible mushrooms and Aloe arborescent, i.e., Lentinus edodes, Ganoderma lucidum (culturing in wood and soil), Tricholoma matsutake, Agaricus auricula-Jude (produced in Korea and China), sarcodon asparatus, Pleurotus ostreatus, Coriolus bisporus, Cyrophora esculenta, Auricularia auricula-Jude (produced in Korea and China), Sarcodon asparatus, Pleurotus ostreatus, Coriolus rersicolor, Smilax rotundifolia and Aloe arborescenstyl were analyzed by Atomic absorption spectrometer. The obtained results were summarized as follows : 1. Potassium, sodium, magnesium and iron content for the most part samples were in large quantities, especi phosphorus content of those was highest ammount for the all samples. 2. Sodium content f·as much ammount in the Lentinus edodes(39 mg, and Ganoderma lucidum(20 mg) , Culturing in wood and soil, while potassium was very high ammount in the Aloe arborescens and other samples. Mush ammount of magnesium as compared with others was Lentinus edodes(144 mg) , Ganoderma lucidum(128 mg), Aloe arborescens(50 mg) and Pleurotus ostreatus (60 mg) . 3, Phosphorus content of Lentinus edodes, Gyrophora esculenta, Auricularia polytricha and Agaricus bisporus was much ammount while iron content of all samples equality higher ammount. Sodium content of Aloe arborescens was not analyzed out for almost all, its potassium(82 mg), magnesium(50 mg) and iron(18 mg) content comparatively higher quentity than others nllnerals and phosphorus volume (4.9 mg) as compared with others, was conspicuously lower detect. 4. Cadimium and lead content of harmful metal element were detected on trace quantity for the most part samples. 5. Organic acids of samples i.e., Lentinus edodes, Agaricus bisporus, Pleuritus ostreatus and Ganoderma lucidum were Citrate, Malate, Fumalate, Succinate, Oxalate, Acetate, Lactate, and Tartarate and Citrate, Malate and Fumarate contents were higher amount remarkbly than other organic acids. Tartarate content was trace amount.

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Performance of Fixing Agents in Controlling Micro-Stickies in Recycled Newsprint Pulp

  • Wang, Li-Jun;Chen, Fu-Shan;Zhou, Lin-Jie
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.1
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    • pp.111-116
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    • 2006
  • The microstickes control effects of some fixing agents, including an inorganic PAC, an organic polyamine (PA) and polydiallydimethyl ammonium chloride (Pdadmac), and a high cationic starch (HCS), were investigated, together with their effects on wet end performances and physical properties of handsheets. Despite that the HCS and Pdadmac had lower cationic charge densities than the PA and PAC (the HCS being even lower), they gave higher zeta potentials to fibers, and lower turbidities, cationic demands and residual COD contents to the pulp liquid phases than the PA and PAC did. In all cases, the HCS showed even better effects than the Pdadmac. In addition, drainage speed was also much higher by the HCS treatments although paper formation was worsened. All the phenomena showed that the HCS can fix more dissolved and colloidal substances to cellulose fibers, indicating that the HCS functioned mainly with flocculation and even hydrogen bonding mechanisms. Data on optical properties further indicated that the HCS interacted preferentially with colloidal substances, since it fixed more 'dirty' microstickes to fibers which decreased more sheet brightness while increasing more sheet opacity (with both higher light absorption and scattering coefficients). Interestingly, the organic fixing agents did not decrease tensile, tearing, and folding strengths of paper sheets made from 100% recycled newsprint pulp, except when they were dosed in high amounts. On the contrary, the inorganic PAC had more serious negative effects on the strength properties, especially on folding endurance. The study suggested that proper use of the HCS can lead to better microstickies control effects than traditional agents and methods.

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RNA-Seq transcriptome 분석을 통한 갈치 광수용체 유전자 탐색 및 mRNA 조직발현 (RNA-Seq Transcriptome Analysis of the Cutlass Fish Reveals Photoreceptors Gene Expression in Peripheral Tissues)

  • 현지연;김문관;임봉수;변준환;문지성;강형철;허성표;오성립
    • Ocean and Polar Research
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    • 제39권2호
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    • pp.149-158
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    • 2017
  • The opsin family of light sensitive proteins family makes up are the universal photoreceptor molecules of all visual systems in the vertebrates including teleosts. They can change their conformation from a resting state to a signaling state upon light absorption, which activates the G-protein coupled receptor, thereby resulting in a signaling cascade that produces physiological responses. However, this species is poorly characterized at molecular level due to little sequence information available in public databases. We have investigated the opsin family of nocturnal cutlass fish using the whole transcriptome sequencing method. The opsin genes were cloned and its expression in the tissues and organs were examined by qPCR. We cloned 6 opsin genes (RRH, Opn4, Rh1, Rh2, VA-opsin, and Opn3) in retina and brain tissue. It contained the seven presumed transmembrane domains that are characteristic of the G-protein-coupled receptor family. However, short wavelength sensitive pigment (SWS) and long wavelength sensitive pigment (LWS) were not detected in this study. The mRNA expression of the 6 photoreceptor genes were detected in retina and peripheral tissue. Our studies will lead to further investigation of the photic entrainment mechanism at molecular and cellular levels in cutlass fish and can be used in comparative studies of other fishes.

Optimising Ink Setting Properties on Double Coated Wood-free Papers

  • Bluvol, Guillermo;Carlsson, Roger
    • 한국펄프종이공학회:학술대회논문집
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    • 한국펄프종이공학회 2006년도 PAN PACIFIC CONFERENCE vol.2
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    • pp.215-225
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    • 2006
  • Today's requirements for print-press runnability and print quality demand an optimised absorption and adhesion of printing ink on the paper surface. Modern coating concepts for high glossing offset grades use ultra fine pigments, whereas binder level has continuously been decreased to a minimum in recent years to achieve the highest possible sheet gloss development and for economical reasons. Both the ultra fine pigments and the reduced binder levels lead in many cases to a faster ink setting rate. On the other hand, matt paper grades use relatively coarse pigments leading to a slow ink setting compared to the high glossing papers. Both too fast and too slow ink setting properties implicate drawbacks in print quality and print press runnability. The mechanisms behind the interactions between ink and coating have been presented in many previous publications. The purpose of this study was to determine and quantify how the ink setting rate is influenced by pigment system (GCC and GCC/clay blends), latex level and latex properties in the topcoat of double coated sheet fed offset paper. The roles of binder level and type in the precoat were also assessed. The effect of calendering (temperature and pressure) was studied with one formulation. The resulting ink setting characteristics were tested using three different laboratory testing instruments. The correlation amongst the different laboratory testing methods is discussed. The results show that by varying the latex properties, the pigment system and/or latex addition level, the ink tack development of ink applied to a topcoat pigment system can be significantly influenced. It can be slowed down as often desired with ultra fine pigments or speeded up in the case of coarse pigments. There was no visible effect on the ink setting rate by using different binder systems in the precoat..

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국내에서 시판 중인 몇몇 채소류의 중금속에 관한 조사 연구 (Studies on the Heavy Metal Content in Some Vegetables Sales on Market in Korea)

  • 유춘철;김덕웅
    • 한국식품영양학회지
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    • 제18권3호
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    • pp.254-264
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    • 2005
  • This study was conducted to estimate the contents of heavy metals 'Hg, Cd, Pb, As, Zn, Cu, Cr, Mn' in some vegetables which were produced in Korea. The levels of heavy metals were determined using a mercury analyzer, an ICP(inductively coupled plasma spectrometer) and an AAS(atomic absorption spectrophotometer) after wet digestion. The values of heavy metals "mean(mini.~maxi.)" ppm(mg/kg) in some vegetables(raw of perilla leaf, chard, small water dropwort, water dropwort, kale, bud of aralia, pumpkin(round type) and pumpkin(long type) were as follows : Hg : 0.0021(0.0006~0.0054)mg/kg, Cd : 0.0035(ND*~0.0377)mg/kg, Pb : 0.0191(0.0023~0.0928)mg/kg, As : 0.0757(ND~0.5294)mg/kg, Zn : 2.6299(0.4478~6.8567)mg/kg, Cu : 1.0261(0.2046~8.9417)mg/kg, Cr : 0.1535 (0.0240~0.4982)mg/kg, Mn : 3.2476(0.3283~9.8280)mg/kg. This results showed that Mn was generally simillar to previous reports and Cd, Hg, Pb were lower than other reseaches, but As was little higher or Zn, Cu, Cr were higher than the levels of those reported contents in some vegetables on domestic supermarkets in Korea, Although tolerable limit of Hg and Cd is not in a regulation of WHO/FAO, these mean levels(Pb, As, Zn, Cu) are lower than recommended levels of WHO/FAO, Pb "0.1~2.0" mg/kg, As "1.0" mg/kg, Zn "5.0" mg/kg and Cu "0.1~50"mg/kg from vegetables in 'the tolerable contents of food' by the FAO/WHO, therefor some vegetables has set to evaluate their safeties.

폐광산지역 농산물, 토양 및 농경수의 중금속오염에 관한 연구 (Studies on Heavy Metal Contamination of Agricultural Products, Soils and Irrigation Waters in Abandoned Mines)

  • 김미혜;소유섭;김은정;정소영;홍무기
    • 한국식품위생안전성학회지
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    • 제17권4호
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    • pp.178-182
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    • 2002
  • 전국 폐광지역(48곳) 평야지역(8곳) 농산물(280건), 토양(280건), 농경수(48건)를 채취하여 수은 함량은 Mercury analyzer로, 납, 카드뮴, 비소 등 중금속은 습식분해후 ICP, AAS등으로 분석하였다. 본 연구결과, 평야지역에 비해 폐광산지역의 토양에 있어 크롬을 제외한 수은, 납 등 중금속 함량이 더 높았으며 농경수에 있어서는 수은을 제외한 다른 중금속함량이 더 높았다. 폐광산지역의 농산물중 납, 카드뮴 등 중금속 함량은 평야지역에 비해 대체로 높은 편이었으나 구리 함량은 평야지역의 농산물이 다소 높았다. 토양과 농산물중 납 등 중금속함량간의 유의적인 상관관계는 관찰되지 않았다(p>0.05). 앞으로도 식품의 안전성 확보 및 국민건강증진차원에서 폐광산지역의 토양, 농산물중 중금속 함량에 대한 모니터링 사업이 지속적으로 수행되어야 할 것으로 사료된다.

In2S3 Co-Sensitized PbS Quantum Dot Solar Cells

  • Basit, Muhammad Abdul;Park, Tae Joo
    • 한국표면공학회:학술대회논문집
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    • 한국표면공학회 2014년도 추계학술대회 논문집
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    • pp.273-273
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    • 2014
  • Quantum-dot sensitized solar cells (QDSCs) are an emerging class of solar cells owing to their easy fabrication, low cost and material diversity. Despite of the fact that the maximum conversion efficiency of QDSCs is still far less than that of Dye-Sensitized Solar Cells (>12 %), their unique characteristics like Multiple Exciton Generation (MEG), energy band tune-ability and tendency to incorporate multiple co-sensitizers concurrently has made QDs a suitable alternative to expensive dyes for solar cell application. Lead Sulfide (PbS) Quantum dot sensitized solar cells are theoretically proficient enough to have a photo-current density ($J_{sc}$) of $36mA/cm^2$, but practically there are very few reports on photocurrent enhancement in PbS QDSCs. Recently, $Hg^{2+}$ incorporated PbS quantumdots and Cadmium Sulfide (CdS) co-sensitized PbS solarcells are reported to show an improvement in photo-current density ($J_{sc}$). In this study, we explored the efficacy of $In_2S_3$ as an interfacial layer deposited through SILAR process for PbS QDSCs. $In_2S_3$ was chosen as the interfacial layer in order to avoid the usage of hazardous CdS or Mercury (Hg). Herein, the deposition of $In_2S_3$ interfacial layer on $TiO_2$ prior to PbS QDs exhibited a direct enhancement in the photo-current (Isc). Improved photo-absorption as well as interfacial recombination barrier caused by $In_2S_3$ deposition increased the photo-current density ($J_{sc}$) from $13mA/cm^2$ to $15.5mA/cm^2$ for single cycle of $In_2S_3$ deposition. Increase in the number of cycles of $In_2S_3$ deposition was found to deteriorate the photocurrent, however it increased $V_{oc}$ of the device which reached to an optimum value of 2.25% Photo-conversion Efficiency (PCE) for 2 cycles of $In_2S_3$ deposition. Effect of Heat Treatment, Normalized Current Stability, Open Circuit Voltage Decay and Dark IV Characteristics were further measured to reveal the characteristics of device.

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