Base de dados : MEDLINE
Pesquisa : D01.837 [Categoria DeCS]
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  1 / 1902 MEDLINE  
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[PMID]:28466090
[Au] Autor:Ogawa A; Celikkol-Aydin S; Gaylarde C; Baptista-Neto JA; Beech I
[Ad] Endereço:Department Microbiology and Plant Biology, University of Oklahoma, Norman, USA.
[Ti] Título:Microbiomes of Biofilms on Decorative Siliceous Stone: Drawbacks and Advantages of Next Generation Sequencing.
[So] Source:Curr Microbiol;74(7):848-853, 2017 Jul.
[Is] ISSN:1432-0991
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Next Generation Sequencing (NGS), using the Illumina metabarcoding system, showed differences between biofilm communities on three degraded siliceous stone church façades in central Rio de Janeiro. Two church biofilms (on granite and augen gneiss) were dominated by Actinobacteria; the third (granite), surrounded by trees and further from intense vehicular traffic, by Gammaproteobacteria. Yeast-like forms of Basidiomycetes and Ascomycetes were major fungi on all facades, but 22.8% of Operational Taxonomic Units could not be assigned to any fungal taxon after DNA amplification with ITS primers and analysis with the UNITE database, indicating the need for more fungal NGS studies. The pipeline used in analysis of the V4 region of rRNA bacterial gene sequences influenced the taxa detected, with two major classes and many genera identified only by the pipeline using the Greengenes, and not the Silva, database. Principal Components Analysis separated façade biofilms into the appropriate three groups and indicated greater dissimilarity of the tree-surrounded church biofilm from the others, confirmed by Jaccard Similarity coefficients, suggesting that local environment influences community composition more than stone type. NGS allows rapid and detailed analysis of microbiomes, but results must be carefully assessed and must not be used as the sole indication of community composition.
[Mh] Termos MeSH primário: Bactérias/isolamento & purificação
Fungos/isolamento & purificação
Sedimentos Geológicos/microbiologia
Sequenciamento de Nucleotídeos em Larga Escala/métodos
Microbiota
[Mh] Termos MeSH secundário: Bactérias/classificação
Bactérias/genética
Fenômenos Fisiológicos Bacterianos
Biofilmes
Primers do DNA
Fungos/classificação
Fungos/genética
Fungos/fisiologia
Compostos de Silício/análise
[Pt] Tipo de publicação:EVALUATION STUDIES; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (DNA Primers); 0 (Silicon Compounds)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180212
[Lr] Data última revisão:
180212
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170504
[St] Status:MEDLINE
[do] DOI:10.1007/s00284-017-1257-3


  2 / 1902 MEDLINE  
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[PMID]:28966283
[Au] Autor:Alim NR; Miyazaki S; Shimoda Y; Sugiura M; Nakajima M; Kotani S
[Ad] Endereço:Graduate School of Pharmaceutical Sciences, Kumamoto University.
[Ti] Título:Asymmetric Aldol/Vinylogous Aldol/Cyclization Reaction Using Phosphine Oxide Catalysts.
[So] Source:Chem Pharm Bull (Tokyo);65(10):989-993, 2017.
[Is] ISSN:1347-5223
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Chiral phosphine oxide sequentially activates silicon tetrachloride and trichlorosilyl enol ethers to facilitate asymmetric aldol/vinylogous aldol reaction of 4-methoxy-3-penten-2-one and conjugated aldehydes in a highly enantioselective fashion, and the subsequent cyclization produced optically active 2,6-disubstituted 2,3-dihydro-4-pyranones bearing stereogenic centers at a remote position in a single operation.
[Mh] Termos MeSH primário: Aldeídos/química
Fosfinas/química
[Mh] Termos MeSH secundário: Catálise
Cloretos/química
Cristalografia por Raios X
Reação de Cicloadição
Conformação Molecular
Óxidos/química
Compostos de Silício/química
Estereoisomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Aldehydes); 0 (Chlorides); 0 (Oxides); 0 (Phosphines); 0 (Silicon Compounds); 8C6G962B53 (3-hydroxybutanal); 96L75U0BM3 (silicon tetrachloride); FW6947296I (phosphine)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171030
[Lr] Data última revisão:
171030
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171003
[St] Status:MEDLINE
[do] DOI:10.1248/cpb.c17-00540


  3 / 1902 MEDLINE  
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[PMID]:28609285
[Au] Autor:Minchenko DO; Tsymbal DO; Yavorovsky OP; Solokha NV; Minchenko OH
[Ad] Endereço:.
[Ti] Título:Expression of genes encoding IGFBPs, SNARK, CD36, and PECAM1 in the liver of mice treated with chromium disilicide and titanium nitride nanoparticles.
[So] Source:Endocr Regul;51(2):84-95, 2017 Apr 25.
[Is] ISSN:1210-0668
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:OBJECTIVE: The aim of the present study was to examine the effect of chromium disilicide and titanium nitride nanoparticles on the expression level of genes encoding important regulatory factors (IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK/NUAK2, CD36, and PECAM1/CD31) in mouse liver for evaluation of possible toxic effects of these nanoparticles. METHODS: Male mice received 20 mg chromium disilicide nanoparticles (45 nm) and titanium nitride nanoparticles (20 nm) with food every working day for 2 months. The expression of IGFBP1, IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK, CD36, and PECAM1 genes in mouse liver was studied by quantitative polymerase chain reaction. RESULTS: Treatment of mice with chromium disilicide nanoparticles led to down-regulation of the expression of IGFBP2, IGFBP5, PECAM1, and SNARK genes in the liver in comparison with control mice, with more prominent changes for SNARK gene. At the same time, the expression of IGFBP3 and CD36 genes was increased in mouse liver upon treatment with chromium disilicide nanoparticles. We have also shown that treatment with titanium nitride nanoparticles resulted in down-regulation of the expression of IGFBP2 and SNARK genes in the liver with more prominent changes for SNARK gene. At the same time, the expression of IGFBP3, IGFBP4, and CD36 genes was increased in the liver of mice treated with titanium nitride nanoparticles. Furthermore, the effect of chromium disilicide nanoparticles on IGFBP2 and CD36 genes expression was significantly stronger as compared to titanium nitride nanoparticles. CONCLUSIONS: The results of this study demonstrate that chromium disilicide and titanium nitride nanoparticles have variable effects on the expression of IGFBP2, IGFBP3, IGFBP4, IGFBP5, SNARK, CD36, and PECAM1 genes in mouse liver, which may reflect the genotoxic activities of the studied nanoparticles.
[Mh] Termos MeSH primário: Expressão Gênica/efeitos dos fármacos
Fígado/efeitos dos fármacos
Nanopartículas
RNA Mensageiro/efeitos dos fármacos
Titânio/farmacologia
[Mh] Termos MeSH secundário: Animais
Antígenos CD36/efeitos dos fármacos
Antígenos CD36/genética
Compostos de Cromo/farmacologia
Regulação para Baixo
Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos
Proteína 1 de Ligação a Fator de Crescimento Semelhante à Insulina/genética
Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos
Proteína 2 de Ligação a Fator de Crescimento Semelhante à Insulina/genética
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos
Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética
Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/efeitos dos fármacos
Proteína 4 de Ligação a Fator de Crescimento Semelhante à Insulina/genética
Fígado/metabolismo
Masculino
Camundongos
Molécula-1 de Adesão Celular Endotelial de Plaquetas/efeitos dos fármacos
Molécula-1 de Adesão Celular Endotelial de Plaquetas/genética
Reação em Cadeia da Polimerase
Proteínas Serina-Treonina Quinases/efeitos dos fármacos
Proteínas Serina-Treonina Quinases/genética
RNA Mensageiro/metabolismo
Reação em Cadeia da Polimerase Via Transcriptase Reversa
Compostos de Silício/farmacologia
Regulação para Cima
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (CD36 Antigens); 0 (Chromium Compounds); 0 (Insulin-Like Growth Factor Binding Protein 1); 0 (Insulin-Like Growth Factor Binding Protein 2); 0 (Insulin-Like Growth Factor Binding Protein 3); 0 (Insulin-Like Growth Factor Binding Protein 4); 0 (Platelet Endothelial Cell Adhesion Molecule-1); 0 (RNA, Messenger); 0 (Silicon Compounds); 6RW464FEFF (titanium nitride); D1JT611TNE (Titanium); EC 2.7.11.1 (Protein-Serine-Threonine Kinases); EC 2.7.11.1 (SNARK protein, mouse)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170614
[St] Status:MEDLINE


  4 / 1902 MEDLINE  
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[PMID]:28591607
[Au] Autor:Kuhlmann JW; Junius M; Diederichsen U; Steinem C
[Ad] Endereço:Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany.
[Ti] Título:SNARE-Mediated Single-Vesicle Fusion Events with Supported and Freestanding Lipid Membranes.
[So] Source:Biophys J;112(11):2348-2356, 2017 Jun 06.
[Is] ISSN:1542-0086
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In vitro single-vesicle fusion assays are important tools to analyze the details of SNARE-mediated fusion processes. In this study, we employed planar pore-spanning membranes (PSMs) prepared on porous silicon substrates with large pore diameters of 5 µm, allowing us to compare the process of vesicle docking and fusion on the supported parts of the PSMs (s-PSMs) with that on the freestanding membrane parts (f-PSM) under the exact same experimental conditions. The PSMs harbor the t-SNARE ΔN49-complex to investigate the dynamics and fusogenicity of single large unilamellar vesicles doped with the v-SNARE synaptobrevin 2 by means of spinning-disc confocal microscopy with a time resolution of 10 ms. Our results demonstrate that vesicles docked to the s-PSM were fully immobile, whereas those docked to the f-PSM were mobile with a mean diffusion coefficient of 0.42 µm /s. Despite the different dynamics of the vesicles on the two membrane types, similar fusion kinetics were observed, giving rise to a common fusion mechanism. Further investigations of individual lipid mixing events on the s-PSMs revealed semi-stable post-fusion structures.
[Mh] Termos MeSH primário: Fusão de Membrana/fisiologia
Proteínas SNARE/metabolismo
Lipossomas Unilamelares/metabolismo
[Mh] Termos MeSH secundário: Animais
Difusão
Escherichia coli
Cinética
Bicamadas Lipídicas/química
Microscopia Confocal
Microscopia de Fluorescência
Porosidade
Ratos
Proteínas SNARE/química
Compostos de Silício
Dióxido de Silício
Lipossomas Unilamelares/química
Proteína 2 Associada à Membrana da Vesícula/química
Proteína 2 Associada à Membrana da Vesícula/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Lipid Bilayers); 0 (SNARE Proteins); 0 (Silicon Compounds); 0 (Unilamellar Liposomes); 0 (Vesicle-Associated Membrane Protein 2); 12033-89-5 (silicon nitride); 7631-86-9 (Silicon Dioxide)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170814
[Lr] Data última revisão:
170814
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170608
[St] Status:MEDLINE


  5 / 1902 MEDLINE  
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[PMID]:28477004
[Au] Autor:Zhu D; Zhu W; Wang W; Liu X
[Ad] Endereço:Key Laboratory for Soft Chemistry and Functional Materials of Ministry of Education, Nanjing University of Science and Technology, 200 Xiaolingwei Street, Nanjing 210094, People's Republic of China.
[Ti] Título:Gold functionalised attapulgite for discrimination of hydrogen peroxide and oxidising ions.
[So] Source:IET Nanobiotechnol;11(2):200-204, 2017 Mar.
[Is] ISSN:1751-8741
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Aiming to monitor hydrogen peroxide and oxidizing ions in aqueous circumstance, functionalized attapulgite [i.e. gold-modified attapulgite nanocomposites (Au/ATP NCs)] as peroxidase mimics were prepared by loading ß-cysteamine-capped gold nanoparticles onto attapulgite with the use of electrostatic interactions. As-prepared Au/ATP NCs were used for the detection of H O . The linear range and detection limit for H O were determined by quantitative experiments emerging excellent stability and recyclability. The peroxidase-like activity of Au/ATP NCs could be expanded for the detection of some oxidative ions (Fe and Ag ) was also been discovered. Based on the absorption spectrum and steady-state kinetics, the mechanism for peroxidase mimic reaction is investigated. This work represents the first example of multitarget detection for molecule and cations (H O , Fe and Ag ) using Au/ATP NCs as peroxidase enzyme mimics and holds a promise for future biomedical and analytical applications.
[Mh] Termos MeSH primário: Ouro/química
Peróxido de Hidrogênio/análise
Peróxido de Hidrogênio/química
Compostos de Magnésio/química
Nanopartículas Metálicas/química
Oxidantes/química
Compostos de Silício/química
[Mh] Termos MeSH secundário: Íons/análise
Íons/química
Nanopartículas Metálicas/ultraestrutura
Oxidantes/isolamento & purificação
Tamanho da Partícula
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ions); 0 (Magnesium Compounds); 0 (Oxidants); 0 (Silicon Compounds); 7440-57-5 (Gold); BBX060AN9V (Hydrogen Peroxide); U6V729APAM (attapulgite)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170817
[Lr] Data última revisão:
170817
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170507
[St] Status:MEDLINE
[do] DOI:10.1049/iet-nbt.2016.0006


  6 / 1902 MEDLINE  
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[PMID]:28415441
[Au] Autor:Chen J; Liu G; Ma C; Zhao G; Du W; Zhu W; Chu J
[Ad] Endereço:Dept. of Precision Machinery and Precision Instrumentation, University of Science and Technology of China, Hefei, Anhui Province, China.
[Ti] Título:Stress stiffened silicon nitride micro bridges array as substrate with tunable stiffness for cell culture.
[So] Source:Mater Sci Eng C Mater Biol Appl;75:1489-1495, 2017 Jun 01.
[Is] ISSN:1873-0191
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Recently, interactions between one-dimensional structural stiffness of physical micro environments and cell biological process have been widely studied. However in previous studies, the influence of structural stiffness on biological process was coupled with the influence of micro fiber curvature. Therefore decoupling the influences of fiber curvature and structural stiffness on cell biological process is of prime importance. In this study, we proposed a novel cell culture substrate comprised of silicon nitride bridges whose structure stiffness can be regulated by altering the axial residual stress without changing material and geometry properties. Both theoretical calculations and finite element simulations were performed to study the influence of residual stress on structure stiffness of bridges. Then multi-positions AFM bending tests were implemented to measure local stiffness of a single micro bridge so as to verify our predictions. NIH/3T3 mouse fibroblast cells were cultured on our substrates to examine the feasibility of the substrate application for investigating cellular response to microenvironment with variable stiffness. The results showed that cells on the edge region near bridge ends were more spread, elongated and better aligned along the bridge axial direction than those on the bridge center region. The results suggest that cells can sense and respond to the differences of stiffness and stiffness gradient between the edge and the center region of the bridges, which makes this kind of substrates can be applied in some biomedical fields, such as cell migration and wound healing.
[Mh] Termos MeSH primário: Técnicas de Cultura de Células/métodos
Fibroblastos/citologia
Compostos de Silício/química
[Mh] Termos MeSH secundário: Células 3T3
Animais
Fibroblastos/metabolismo
Camundongos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Silicon Compounds); 12033-89-5 (silicon nitride)
[Em] Mês de entrada:1707
[Cu] Atualização por classe:170724
[Lr] Data última revisão:
170724
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170419
[St] Status:MEDLINE


  7 / 1902 MEDLINE  
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[PMID]:28343056
[Au] Autor:Ma R; Yuan N; Sun S; Zhang P; Fang L; Zhang X; Zhao X
[Ad] Endereço:College of Chemistry and Environmental Engineering, Shenzhen University, Shenzhen 518060, China.
[Ti] Título:Preliminary investigation of the microwave pyrolysis mechanism of sludge based on high frequency structure simulator simulation of the electromagnetic field distribution.
[So] Source:Bioresour Technol;234:370-379, 2017 Jun.
[Is] ISSN:1873-2976
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Under microwave irradiation, raw sludge was pyrolyzed mainly by evaporation of water, with a weight loss ratio of 84.8% and a maximum temperature not exceeding 200°C. High-temperature pyrolysis of SiC sludge could be realized, with a weight loss ratio of 93.4% and a final pyrolysis temperature of 1131.7°C. Variations between the electric field intensity distribution are the main reason for the differences of pyrolysis efficiencies. HFSS simulation showed that the electric field intensity of the raw sludge gradually decreased from 2.94×10 V/m to 0.88×10 V/m when pyrolysis ends, while that of SiC sludge decreased from 3.73×10 V/m at the beginning to 1.28×10 V/m, then increased to 4.03×10 V/m. The electromagnetic effect is the main factor (r≥0.91) influencing the temperature increase and weight loss of raw sludge. Both the electromagnetic effect and heat conduction effect influenced temperature rise and weight loss of SiC sludge, but the former's influence was comparatively larger.
[Mh] Termos MeSH primário: Esgotos/química
[Mh] Termos MeSH secundário: Compostos Inorgânicos de Carbono/química
Dessecação
Campos Eletromagnéticos
Temperatura Alta
Micro-Ondas
Compostos de Silício/química
Gerenciamento de Resíduos/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carbon Compounds, Inorganic); 0 (Sewage); 0 (Silicon Compounds); WXQ6E537EW (silicon carbide)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170515
[Lr] Data última revisão:
170515
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170327
[St] Status:MEDLINE


  8 / 1902 MEDLINE  
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[PMID]:28337857
[Au] Autor:Wang XL; Tang YJ; Huang W; Liu CH; Dong LZ; Li SL; Lan YQ
[Ad] Endereço:Jiangsu Key Laboratory of Biofunctional Materials, School of Chemistry and Materials Science, Nanjing Normal University, Nanjing, 210023, P. R. China.
[Ti] Título:Efficient Electrocatalyst for the Hydrogen Evolution Reaction Derived from Polyoxotungstate/Polypyrrole/Graphene.
[So] Source:ChemSusChem;10(11):2402-2407, 2017 Jun 09.
[Is] ISSN:1864-564X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Efficient hydrogen evolution reaction (HER) from water by electrocatalysis using cost-effective materials is critical to realize the clean hydrogen production. Herein, with controlling the structure and composition of polyoxotungstate/conductive polypyrrole/graphene (PCG) precursor precisely and followed by a temperature-programmed reaction, we developed a highly active and stable catalyst: NC@W C/NRGO (NC: nitrogen-doped porous carbon, NRGO: nitrogen-doped reduced graphene oxide). The composite presents splendid performance towards HER in acidic media, with a small onset overpotential of 24 mV versus RHE (reversible hydrogen electrode), a low Tafel slope of 58.4 mV dec , a low overpotential of 100 mV at 10 mA cm , and remarkable long-term cycle stability. This is one of the highest HER catalysts among the tungsten carbide-based materials ever reported.
[Mh] Termos MeSH primário: Grafite/química
Hidrogênio/química
Polímeros/química
Pirróis/química
Compostos de Silício/química
Compostos de Tungstênio/química
[Mh] Termos MeSH secundário: Catálise
Eletroquímica/métodos
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Polymers); 0 (Pyrroles); 0 (Silicon Compounds); 0 (Tungsten Compounds); 0 (polyoxotungstate PM 48); 059QF0KO0R (Water); 11130-73-7 (tungsten carbide); 30604-81-0 (polypyrrole); 7782-42-5 (Graphite); 7YNJ3PO35Z (Hydrogen)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170816
[Lr] Data última revisão:
170816
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170325
[St] Status:MEDLINE
[do] DOI:10.1002/cssc.201700276


  9 / 1902 MEDLINE  
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[PMID]:28327464
[Au] Autor:Derenzo SE
[Ad] Endereço:Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, Berkeley, CA, United States of America.
[Ti] Título:Monte Carlo simulations of time-of-flight PET with double-ended readout: calibration, coincidence resolving times and statistical lower bounds.
[So] Source:Phys Med Biol;62(9):3828-3858, 2017 May 07.
[Is] ISSN:1361-6560
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:This paper demonstrates through Monte Carlo simulations that a practical positron emission tomograph with (1) deep scintillators for efficient detection, (2) double-ended readout for depth-of-interaction information, (3) fixed-level analog triggering, and (4) accurate calibration and timing data corrections can achieve a coincidence resolving time (CRT) that is not far above the statistical lower bound. One Monte Carlo algorithm simulates a calibration procedure that uses data from a positron point source. Annihilation events with an interaction near the entrance surface of one scintillator are selected, and data from the two photodetectors on the other scintillator provide depth-dependent timing corrections. Another Monte Carlo algorithm simulates normal operation using these corrections and determines the CRT. A third Monte Carlo algorithm determines the CRT statistical lower bound by generating a series of random interaction depths, and for each interaction a set of random photoelectron times for each of the two photodetectors. The most likely interaction times are determined by shifting the depth-dependent probability density function to maximize the joint likelihood for all the photoelectron times in each set. Example calculations are tabulated for different numbers of photoelectrons and photodetector time jitters for three 3 × 3 × 30 mm scintillators: Lu SiO :Ce,Ca (LSO), LaBr :Ce, and a hypothetical ultra-fast scintillator. To isolate the factors that depend on the scintillator length and the ability to estimate the DOI, CRT values are tabulated for perfect scintillator-photodetectors. For LSO with 4000 photoelectrons and single photoelectron time jitter of the photodetector J = 0.2 ns (FWHM), the CRT value using the statistically weighted average of corrected trigger times is 0.098 ns FWHM and the statistical lower bound is 0.091 ns FWHM. For LaBr :Ce with 8000 photoelectrons and J = 0.2 ns FWHM, the CRT values are 0.070 and 0.063 ns FWHM, respectively. For the ultra-fast scintillator with 1 ns decay time, 4000 photoelectrons, and J = 0.2 ns FWHM, the CRT values are 0.021 and 0.017 ns FWHM, respectively. The examples also show that calibration and correction for depth-dependent variations in pulse height and in annihilation and optical photon transit times are necessary to achieve these CRT values.
[Mh] Termos MeSH primário: Tomografia por Emissão de Pósitrons/métodos
Dosímetros de Radiação/normas
Contagem de Cintilação/instrumentação
[Mh] Termos MeSH secundário: Calibragem
Elétrons
Funções Verossimilhança
Lutécio/efeitos da radiação
Método de Monte Carlo
Fótons
Distribuição Aleatória
Contagem de Cintilação/métodos
Contagem de Cintilação/normas
Compostos de Silício/efeitos da radiação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Silicon Compounds); 0 (dilutetium silicon pentaoxide); 5H0DOZ21UJ (Lutetium)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170323
[St] Status:MEDLINE
[do] DOI:10.1088/1361-6560/aa6862


  10 / 1902 MEDLINE  
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[PMID]:28319743
[Au] Autor:Ugochukwu UC; Fialips CI
[Ad] Endereço:SHELL Centre for Environmental Management & Control, University of Nigeria, Enugu Campus, Enugu State, Nigeria. Electronic address: uzochukwu.ugochukwu@unn.edu.ng.
[Ti] Título:Crude oil polycyclic aromatic hydrocarbons removal via clay-microbe-oil interactions: Effect of acid activated clay minerals.
[So] Source:Chemosphere;178:65-72, 2017 Jul.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Acid treatment of clay minerals is known to modify their properties such as increase their surface area and surface acidity, making them suitable as catalysts in many chemical processes. However, the role of these surface properties during biodegradation processes of polycyclic aromatic hydrocarbons (PAHs) is only known for mild acid (0.5 M Hydrochloric acid) treated clays. Four different clay minerals were used for this study: a montmorillonite, a saponite, a palygorskite and a kaolinite. They were treated with 3 M hydrochloric acid to produce acid activated clay minerals. The role of the acid activated montmorillonite, saponite, palygorskite and kaolinite in comparison with the unmodified clay minerals in the removal of PAHs during biodegradation was investigated in microcosm experiments. The microcosm experiments contained micro-organisms, oil, and clays in aqueous medium with a hydrocarbon degrading microorganism community predominantly composed of Alcanivorax spp. Obtained results indicated that acid activated clays and unmodified kaolinite did not enhance the biodegradation of the PAHs whereas unmodified montmorillonite, palygorskite and saponite enhanced their biodegradation. In addition, unmodified palygorskite adsorbed the PAHs significantly due to its unique channel structure.
[Mh] Termos MeSH primário: Silicatos de Alumínio/química
Biodegradação Ambiental
Petróleo
Hidrocarbonetos Aromáticos Policíclicos/isolamento & purificação
[Mh] Termos MeSH secundário: Ácidos/química
Bactérias/metabolismo
Bentonita
Caulim
Compostos de Magnésio
Compostos de Silício
Propriedades de Superfície
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acids); 0 (Aluminum Silicates); 0 (Magnesium Compounds); 0 (Petroleum); 0 (Polycyclic Aromatic Hydrocarbons); 0 (Silicon Compounds); 1302-78-9 (Bentonite); 1302-87-0 (clay); 24H4NWX5CO (Kaolin); 66732-77-2 (saponite); U6V729APAM (attapulgite)
[Em] Mês de entrada:1705
[Cu] Atualização por classe:170524
[Lr] Data última revisão:
170524
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170321
[St] Status:MEDLINE



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