73,128 research outputs found
Sorção/dessorção de cd(ii) na interface argilas - soluções aquosas
No full textTCC (graduação) - Universidade Federal de Santa Catarina. Centro de Ciências Físicas e Matemáticas. Curso de Química.O estudo da biodisponibilidade de metais-traço no meio aquático depende do comportamento desses metais frente a frações dos sedimentos como o caso das argilas caolinita, montimorillonita e de seus componentes alumina e sílica gel. As isotermas de adsorção de Cd (II) em argilas minerais podem ser tratadas adequadamente com o modelo de Langmuir para adsorção em monocamada. Os resultados mostram que a presença de complexantes dificulta a adsorção, possibilitando a retirada de Cd (II) adsorvido da superfície do sedimento. A precipitação do Cd (II) em pH = 7,0 é influenciada pelo tampão utilizado. Usando tampão ácido cítrico/citrato, ocorre complexação do metal o que evita sua precipitação. Na presença de Tris obteve-se uma constante de Langmuir KL = 14,78 L.mmol-1, e capacidade de adsorção máxima de 3,17 g/kg de montmorillonita. O tampão ácido cítrico/citrato inibe a adsorção, mantendo Cd (II) em solução e, apenas 2,7 % da capacidade de adsorção da montmorillonita é utilizada. Resultados semelhantes foram observados usando caolinita. O efeito complexante do citrato permite estudar a dessorção do Cd (II) de diferentes adsorventes como montmorillonita e caolinita. Os resultados mostram que o Cd (II) está solubilizado em sítios de troca iônica ou de adsorção química na superfície destas argilas, mas no caso da montmorillonita parte do cádmio está adsorvida em sítios de adsorção no interior da mesma, o que é consistente com os dados físicos, já que a montmorillonita tem uma estrutura altamente microporosa. Em pH 7,00 e na ausência de ligantes orgânicos, as capacidades de adsorção determinadas para alumina, montmorillonita, caolinita 1 e caolinita 2 tratada e sílica foram de 4,4 g/kg, 3,17 g/kg, 2,20 g/kg, 1,34 g/kg
Pearson correlation of [Cd]g and gene expression in Cd and Cd+N conditions.
No full textPearson correlation of [Cd]g and gene expression in Cd and Cd+N conditions.</p
Effect of different concentration of (A) CMC, (B) AA, (C) β-CD and (D) MBA on swelling index of ACV loaded β-CD/CMC-g-Poly(AA) hydrogel.
No full textEffect of different concentration of (A) CMC, (B) AA, (C) β-CD and (D) MBA on swelling index of ACV loaded β-CD/CMC-g-Poly(AA) hydrogel.</p
Measurement of isomeric-yield ratios of Pd-109m,Pd-g and Cd-115m,Cd-g with 50-, 60-, and 70-MeV bremsstrahlung
No full textThe isomeric-yield ratios of Pd-109m,Pd-g and Cd-115m,Cd-g were measured by the activation method with uncollimated bremsstrahlung beams of 50-, 60-, and 70-MeV generated from an electron linear accelerator at Pohang Accelerator Laboratory. The induced activities in the irradiated foils were measured by the high-resolution gamma-ray spectrometric system consisting of a high-purity germanium detector and a multichannel analyzer. The obtained isomeric-yield ratios in the formation of Pd-109m,Pd-g and Cd-115m,Cd-g are compared with the corresponding values found in the other experiments and the calculated values based on the statistical model code TALYS. The present results for Pd-109m,Pd-g and Cd-115m,Cd-g in this energy region are the first measurement. (C) 2012 Elsevier B.V. All rights reserved.X1133sciescopu
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Tandem quadruplication of HMA4 in the zinc (Zn) and cadmium (Cd) hyperaccumulator noccaea caerulescens
No full textZinc (Zn) and cadmium (Cd) hyperaccumulation may have evolved twice in the Brassicaceae, in Arabidopsis halleri and in the Noccaea genus. Tandem gene duplication and deregulated expression of the Zn transporter, HMA4, has previously been linked to Zn/Cd hyperaccumulation in A. halleri. Here, we tested the hypothesis that tandem duplication and deregulation of HMA4 expression also occurs in Noccaea. A Noccaea caerulescens genomic library was generated, containing 36,864 fosmid pCC1FOSTM clones with insert sizes ~20–40 kbp, and screened with a PCR-generated HMA4 genomic probe. Gene copy number within the genome was estimated through DNA fingerprinting and pooled fosmid pyrosequencing. Gene copy numbers within individual clones was determined by PCR analyses with novel locus specific primers. Entire fosmids were then sequenced individually and reads equivalent to 20-fold coverage were assembled to generate complete whole contigs. Four tandem HMA4 repeats were identified in a contiguous sequence of 101,480 bp based on sequence overlap identities. These were flanked by regions syntenous with up and downstream regions of AtHMA4 in Arabidopsis thaliana. Promoter-reporter b-glucuronidase (GUS) fusion analysis of a NcHMA4 in A. thaliana revealed deregulated expression in roots and shoots, analogous to AhHMA4 promoters, but distinct from AtHMA4 expression which localised to the root vascular tissue. This remarkable consistency in tandem duplication and deregulated expression of metal transport genes between N. caerulescens and A. halleri, which last shared a common ancestor >40 mya, provides intriguing evidence that parallel evolutionary pathways may underlie Zn/Cd hyperaccumulation in Brassicaceae
CSO-g-CM-β-CD synthesis and characterization.
No full textSynthetic route of CSO-g-CM-β-CD (A); FT-IR spectra of CSO-g-CM-β-CD and CSO (B) and 1H-NMR spectra of CSO and CSO-g-CM-β-CD in D2O (C).</p
Toxicity of Pb and of Pb/Cd combination on the springtail Folsomia candida in natural soils: Reproduction, growth and bioaccumulation as indicators
No full textThe toxicity of Pb and Cd+Pb was assessed on the Collembola F. candida in two cultivated soils (SV and AU) with low organic matter (OM) content and circumneutral to basic pH, and an acid forested soil (EPC) with high OM content. Collembola reproduction and growth as well as metal content in Collembola body, in soil, exchangeable fraction and soil solutions, pH and DOC were investigated. Pb and Cd+Pb were the highest in exchangeable fraction and soil solution of the acidic soils. Soil solution pH decreased after metal spiking in every soil due to metal adsorption, which was similar for Cd and the highest in AU for Pb. With increasing Pb and Cd+Pb, the most important reproduction decrease was in EPC soil. The LOEC for reproduction after metal addition was 2400 (Pb) and 200/2400 (Cd/Pb), 1200 and 100/1200, 300 and 100/1200 μg g−1 for AU, SV and EPC, respectively. The highest and the lowest Pb toxicity was observed for EPC and AU bulk soil, respectively. The metal in Collembola increased with increasing soil concentration, except in AU, but the decreasing BFsolution with increasing concentrations indicates a limited metal transfer to Collembola or an increased metal removal. Loading high Pb concentrations decreases Cd absorption by the Collembola, but the reverse was not true. The highest Pb toxicity in EPC can be explained by pH and OM content. Because of metal complexation, OM might have a protective role but its ingestion by Collembola lead to higher toxicity. Metal bioavailability in Collembola differs from soil solution indicating that soil solution is not sufficient to evaluate toxicity in soil organisms. The toxicity as a whole decreased when metals were combined, except for Pb in AU, due to adsorption competition between Cd and Pb on clay particles and OM sites in AU and EPC soils, respectively
02 Andante (Joseph Haydn: Sinfonie Nr. 8 G-Dur „Le Soir“) [7:05] (KD 23, 1 CD)
No full textStück: Andante
Werk: Sinfonie Nr. 8 G-Dur „Le Soir“
Komposition: Joseph Haydn (1732 - 1809)
Interpret*innen: Albana Laci, Andras Homoki (Violine), Martin Dimov (Violoncello) Andor M. Vinczi (Kontrabass), Georg Pammer (Cembalo); Ensemble KlangImPuls, Dirigent: Wolfgang Schmid
Album: Ensemble KlangImPuls Haydn & Gubaidulina, 2002 (KUG KD 23, 1 CD) © Kunstuniversität GrazStück: Andante
Werk: Sinfonie Nr. 8 G-Dur „Le Soir“
Komposition: Joseph Haydn (1732 - 1809)
Interpret*innen: Albana Laci, Andras Homoki (Violine), Martin Dimov (Violoncello) Andor M. Vinczi (Kontrabass), Georg Pammer (Cembalo); Ensemble KlangImPuls, Dirigent: Wolfgang Schmid
Album: Ensemble KlangImPuls Haydn & Gubaidulina, 2002 (KUG KD 23, 1 CD) © Kunstuniversität Gra
01 Allegro molto (Joseph Haydn: Sinfonie Nr. 8 G-Dur „Le Soir“) [4:22] (KD 23, 1 CD)
No full textStück: Allegro molto
Werk: Sinfonie Nr. 8 G-Dur „Le Soir“
Komposition: Joseph Haydn (1732 - 1809)
Interpret*innen: Albana Laci, Andras Homoki (Violine), Martin Dimov (Violoncello) Andor M. Vinczi (Kontrabass), Georg Pammer (Cembalo); Ensemble KlangImPuls, Dirigent: Wolfgang Schmid
Album: Ensemble KlangImPuls Haydn & Gubaidulina, 2002 (KUG KD 23, 1 CD) © Kunstuniversität GrazStück: Allegro molto
Werk: Sinfonie Nr. 8 G-Dur „Le Soir“
Komposition: Joseph Haydn (1732 - 1809)
Interpret*innen: Albana Laci, Andras Homoki (Violine), Martin Dimov (Violoncello) Andor M. Vinczi (Kontrabass), Georg Pammer (Cembalo); Ensemble KlangImPuls, Dirigent: Wolfgang Schmid
Album: Ensemble KlangImPuls Haydn & Gubaidulina, 2002 (KUG KD 23, 1 CD) © Kunstuniversität Gra
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