Base de dados : MEDLINE
Pesquisa : B01.650.940.800.150.990 [Categoria DeCS]
Referências encontradas : 5 [refinar]
Mostrando: 1 .. 5   no formato [Detalhado]

página 1 de 1

  1 / 5 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:26701777
[Au] Autor:Lingott J; Lindner U; Telgmann L; Esteban-Fernández D; Jakubowski N; Panne U
[Ad] Endereço:BAM Federal Institute for Materials Research and Testing, Richard-Willstaetter-Str. 11, 12489 Berlin, Germany. norbert.jakubowski@bam.de.
[Ti] Título:Gadolinium-uptake by aquatic and terrestrial organisms-distribution determined by laser ablation inductively coupled plasma mass spectrometry.
[So] Source:Environ Sci Process Impacts;18(2):200-7, 2016 Feb.
[Is] ISSN:2050-7895
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Gadolinium (Gd) based contrast agents (CA) are used to enhance magnetic resonance imaging. As a consequence of excretion by patients and insufficient elimination in wastewater treatment plants they are detected in high concentrations in surface water. At present, little is known about the uptake of these species by living organisms in aquatic systems. Therefore the uptake of gadolinium containing chelates by plants and animals grown in exposed water or on soil irrigated with exposed water was investigated. For this purpose two types of plants were treated with two different contrast agents. The uptake of the Gd contrast agents was studied by monitoring the elemental distribution with laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the multi-elemental analysis of solid samples with high resolution and little sample preparation. The analysis of L. minor showed that the uptake of Gd correlated with the concentration of gadodiamide in the water. The higher the concentration in the exposed water, the larger the Gd signal in the LA-ICP-MS acquired image. Exposure time experiments showed saturation within one day. The L. minor had contact with the CAs through roots and fronds, whereas the L. sativum only showed uptake through the roots. These results show that an external absorption of the CA through the leaves of L. sativum was impossible. All the analyzed parts of the plant showed Gd signal from the CA; the highest being at the main vein of the leaf. It is shown that the CAs can be taken up from plants. Furthermore, the uptake and distribution of Gd in Daphnia magna were shown. The exposure via cultivation medium is followed by Gd signals on the skin and in the area of the intestine, while the uptake via exposed nutrition algae causes the significantly highest Gd intensities in the area of the intestine. Because there are hints of negative effects for human organism these findings are important as they show that Gd based CAs may reach the human food chain via plants and animals growing in contaminated water or plants growing in fields which are irrigated with surface water.
[Mh] Termos MeSH primário: Meios de Contraste/isolamento & purificação
Daphnia/química
Gadolínio/isolamento & purificação
Lepidium sativum/química
Águas Residuais/química
Poluentes Químicos da Água/isolamento & purificação
Zygnematales/química
[Mh] Termos MeSH secundário: Animais
Quelantes
Daphnia/crescimento & desenvolvimento
Feminino
Seres Humanos
Lasers
Lepidium sativum/crescimento & desenvolvimento
Espectrometria de Massas
Plantas/química
Zygnematales/crescimento & desenvolvimento
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Chelating Agents); 0 (Contrast Media); 0 (Waste Water); 0 (Water Pollutants, Chemical); AU0V1LM3JT (Gadolinium)
[Em] Mês de entrada:1610
[Cu] Atualização por classe:161230
[Lr] Data última revisão:
161230
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:151225
[St] Status:MEDLINE
[do] DOI:10.1039/c5em00533g


  2 / 5 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:25607667
[Au] Autor:Shamshad I; Khan S; Waqas M; Ahmad N; Khushnood-Ur-Rehman; Khan K
[Ad] Endereço:Department of Environmental Science, University of Peshawar, Peshawar, Pakistan E-mail: sardar.khan2008@yahoo.com.
[Ti] Título:Removal and bioaccumulation of heavy metals from aqueous solutions using freshwater algae.
[So] Source:Water Sci Technol;71(1):38-44, 2015.
[Is] ISSN:0273-1223
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Four freshwater algae, including Cladophora glomerata, Oedogonium westii, Vaucheria debaryana and Zygnema insigne, were tested for their bioaccumulation capacity for cadmium (Cd), chromium (Cr) and lead (Pb) in a controlled environment with an average temperature of 18 °C, and light/dark duration of 12:12 h. Experiments were performed in aqueous solutions containing selected heavy metals (HM) (ranging from 0.05 to 1.5 mg L(-1)) with 0.5 g of living algae at 18 °C and pH 6.8. The results indicated that C. glomerata was observed to be the most competent species for the removal of Cr, Cd and Pb from aqueous solutions. HM removal trends were in the order of Cd>Cr>Pb while the removal efficiency of selected algae species was in the order of C. glomerata, O. westii, V. debaryana and Z. insigne. The bioaccumulation capacity of C. glomerata, V. debaryana and Z. insigne was observed for different HM. Removal of HM was higher with low levels of HM in aqueous solutions. The results indicated that C. glomerata, O. westii, V. debaryana and Z. insigne had significant (P≤0.01) diverse bioaccumulation capacity for Cr, Cd and Pb.
[Mh] Termos MeSH primário: Clorófitas/metabolismo
Metais Pesados/metabolismo
Estramenópilas/metabolismo
Eliminação de Resíduos Líquidos/métodos
Zygnematales/metabolismo
[Mh] Termos MeSH secundário: Cádmio/metabolismo
Cromo/metabolismo
Água Doce
Chumbo/metabolismo
Especificidade da Espécie
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Metals, Heavy); 00BH33GNGH (Cadmium); 0R0008Q3JB (Chromium); 2P299V784P (Lead)
[Em] Mês de entrada:1510
[Cu] Atualização por classe:150122
[Lr] Data última revisão:
150122
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:150122
[St] Status:MEDLINE
[do] DOI:10.2166/wst.2014.458


  3 / 5 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:24476153
[Au] Autor:Pichrtová M; Hájek T; Elster J
[Ad] Endereço:Institute of Botany, Academy of Sciences of the Czech Republic, Trebon, Czech Republic; Department of Botany, Faculty of Science, Charles University in Prague, Prague, Czech Republic.
[Ti] Título:Osmotic stress and recovery in field populations of Zygnema sp. (Zygnematophyceae, Streptophyta) on Svalbard (High Arctic) subjected to natural desiccation.
[So] Source:FEMS Microbiol Ecol;89(2):270-80, 2014 Aug.
[Is] ISSN:1574-6941
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Zygnema is a genus of filamentous green algae belonging to the class of Zygnematophyceae (Streptophyta). In the Arctic, it typically forms extensive mats in habitats that regularly dry out during summer, and therefore, mechanisms of stress resistance are expected. We investigated its natural populations with respect to production of specialized desiccation-resistant cells and osmotic acclimation. Six populations in various stages of natural desiccation were selected, from wet biomass floating in water to dried paper-like crusts. After rewetting, plasmolysis and osmotic stress effects were studied using hypertonic sorbitol solutions, and the physiological state was estimated using chlorophyll a fluorescence parameters. All populations of Zygnema sp. formed stationary-phase cells filled with storage products. In green algal research, such cells are traditionally called akinetes. However, the populations differed in their reaction to osmotic stress. Whereas the wet-collected samples were strongly impaired, the osmotic stress resistance of the naturally dried samples was comparable to that of true aeroterrestrial algae. We showed that arctic populations of Zygnema acclimate well to natural desiccation via hardening that is mediated by slow desiccation. As no other types of specialized cells were observed, we assume that the naturally hardened akinetes also play a key role in winter survival.
[Mh] Termos MeSH primário: Clorofila/metabolismo
Estresse Fisiológico
Zygnematales/fisiologia
[Mh] Termos MeSH secundário: Adaptação Fisiológica
Regiões Árticas
Dessecação
Ecossistema
Microscopia de Fluorescência
Pressão Osmótica
Svalbard
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
1406-65-1 (Chlorophyll); YF5Q9EJC8Y (chlorophyll a)
[Em] Mês de entrada:1411
[Cu] Atualização por classe:140805
[Lr] Data última revisão:
140805
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:140131
[St] Status:MEDLINE
[do] DOI:10.1111/1574-6941.12288


  4 / 5 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:22959821
[Au] Autor:Kaplan F; Lewis LA; Herburger K; Holzinger A
[Ad] Endereço:University of Innsbruck, Institute of Botany, Functional Plant Biology, Sternwartestrasse 15, 6020 Innsbruck, Austria.
[Ti] Título:Osmotic stress in Arctic and Antarctic strains of the green alga Zygnema (Zygnematales, Streptophyta): effects on photosynthesis and ultrastructure.
[So] Source:Micron;44:317-30, 2013 Jan.
[Is] ISSN:1878-4291
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The osmotic potential and effects of plasmolysis on photosynthetic oxygen evolution and chlorophyll fluorescence were studied in two Arctic Zygnema sp. (strain B, strain G) and two Antarctic Zygnema sp. (strain E, strain D). Antarctic strain D was newly characterized by rbcL sequence analysis in the present study. The two Antarctic strains, D and E, are most closely related and may represent different isolates of the same species, in contrast, strain B and G are separate lineages. Incipient plasmolysis in the cells was determined by light microscopy after incubating cells in sorbitol solutions ranging between 200 mM and 1000 mM sorbitol for 3, 6 and 24h. In Zygnema strain B and G incipient plasmolysis occurred at ~600 mM sorbitol solution (720 mOsmol kg(-1), ψ=-1.67 MPa) and in strains D and E at ~300 mM (318 mOsmol kg(-1), ψ=-0.8 MPa) sorbitol solution. Hechtian strands were visualized in all plasmolysed cells, which is particularly interesting, as these cells lack pores or plasmodesmata. Ultrastructural changes upon osmotic stress were a retraction of the condensed cytoplasm from the cell walls, damages to chloroplast and mitochondrial membranes, increasing numbers of plastoglobules in the chloroplasts and membrane enclosed particles in the extraplasmatic space. Maximum photosynthetic rates (P(max)) in light saturated range were between 145.5 µmol O(2) h(-1)mg(-1)Chl a in Zygnema G and 752.9 µmol O(2) h(-1)mg(-1)Chl a in Zygnema E. After incubation in 800 mM sorbitol for 3h P(max) decreased to the following percentage of the initial values: B: 16.3%, D: 16.8%, E: 26.1% and G: 35.0%. Osmotic stress (800 mM sorbitol) decreased maximum photochemical quantum yield of photosystem II (F(v)/F(m)) when compared to controls. Maximum values of relative electron transport rates of photosystem II (rETR(max)) decreased after incubation in 400 mM sorbitol in Zygnema D and E, while they decreased in Zygnema B and G only after incubation in 800 mM sorbitol. The kinetics of the rETR curves were similar for the Arctic strains Zygnema B and G, but distinct from the Antarctic strains Zygnema D and E, which were similar when compared with each other. This suggests that the investigated Arctic Zygnema sp. strains might be better adapted to tolerate osmotic water stress than the investigated strains from the Antarctic.
[Mh] Termos MeSH primário: Pressão Osmótica/fisiologia
Fotossíntese/fisiologia
Zygnematales/metabolismo
[Mh] Termos MeSH secundário: Regiões Antárticas
Regiões Árticas
Carbonatos/farmacologia
Clorofila/metabolismo
Cloroplastos/metabolismo
Transporte de Elétrons
Microscopia Eletrônica de Transmissão
Osmose
Oxigênio/metabolismo
Complexo de Proteína do Fotossistema II/metabolismo
Ribulose-Bifosfato Carboxilase/genética
Sorbitol/farmacologia
Zygnematales/classificação
Zygnematales/ultraestrutura
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Carbonates); 0 (Photosystem II Protein Complex); 1406-65-1 (Chlorophyll); 45P3261C7T (sodium carbonate); 506T60A25R (Sorbitol); EC 4.1.1.39 (RbcL protein, plastid); EC 4.1.1.39 (Ribulose-Bisphosphate Carboxylase); S88TT14065 (Oxygen)
[Em] Mês de entrada:1306
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120911
[St] Status:MEDLINE


  5 / 5 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
PubMed Central Texto completo
Texto completo
[PMID]:22253761
[Au] Autor:Timme RE; Bachvaroff TR; Delwiche CF
[Ad] Endereço:Cell Biology and Molecular Genetics, University of Maryland, College Park, Maryland, United States of America. retimme@gmail.com
[Ti] Título:Broad phylogenomic sampling and the sister lineage of land plants.
[So] Source:PLoS One;7(1):e29696, 2012.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The tremendous diversity of land plants all descended from a single charophyte green alga that colonized the land somewhere between 430 and 470 million years ago. Six orders of charophyte green algae, in addition to embryophytes, comprise the Streptophyta s.l. Previous studies have focused on reconstructing the phylogeny of organisms tied to this key colonization event, but wildly conflicting results have sparked a contentious debate over which lineage gave rise to land plants. The dominant view has been that 'stoneworts,' or Charales, are the sister lineage, but an alternative hypothesis supports the Zygnematales (often referred to as "pond scum") as the sister lineage. In this paper, we provide a well-supported, 160-nuclear-gene phylogenomic analysis supporting the Zygnematales as the closest living relative to land plants. Our study makes two key contributions to the field: 1) the use of an unbiased method to collect a large set of orthologs from deeply diverging species and 2) the use of these data in determining the sister lineage to land plants. We anticipate this updated phylogeny not only will hugely impact lesson plans in introductory biology courses, but also will provide a solid phylogenetic tree for future green-lineage research, whether it be related to plants or green algae.
[Mh] Termos MeSH primário: Genoma de Planta/genética
Filogenia
Zygnematales/classificação
Zygnematales/genética
[Mh] Termos MeSH secundário: Análise por Conglomerados
Evolução Molecular
Proteínas de Plantas/genética
Análise de Sequência de DNA
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Plant Proteins)
[Em] Mês de entrada:1205
[Cu] Atualização por classe:170220
[Lr] Data última revisão:
170220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:120119
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0029696



página 1 de 1
   


Refinar a pesquisa
  Base de dados : MEDLINE Formulário avançado   

    Pesquisar no campo  
1  
2
3
 
           



Search engine: iAH v2.6 powered by WWWISIS

BIREME/OPAS/OMS - Centro Latino-Americano e do Caribe de Informação em Ciências da Saúde