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  1 / 1029 MEDLINE  
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[PMID]:29031441
[Au] Autor:Xiao G; Zeng H; Xu S; Chen C; Zhao Q; Liu X
[Ad] Endereço:College of Chemical Engineering, Xiangtan University, Xiangtan 411105, Hunan, China. Electronic address: mgaofei@foxmail.com.
[Ti] Título:Preparation of Ti species coating hydrotalcite by chemical vapor deposition for photodegradation of azo dye.
[So] Source:J Environ Sci (China);60:14-23, 2017 Oct.
[Is] ISSN:1001-0742
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:TiO in anatase crystal phase is a very effective catalyst in the photocatalytic oxidation of organic compounds in water. To improve its photocatalytic activity, the Ti-coating MgAl hydrotalcite (Ti-MgAl-LDH) was prepared by chemical vapor deposition (CVD) method. Response surface method (RSM) was employed to evaluate the effect of Ti species coating parameters on the photocatalytic activity, which was found to be affected by the furnace temperature, N flow rate and influx time of precursor gas. Application of RSM successfully increased the photocatalytic efficiency of the Ti-MgAl-LDH in methylene blue photodegradation under UV irradiation, leading to improved economy of the process. According to the results from X-ray diffraction, scanning electron microscopy, Brunner-Emmet-Teller and Barrett-Joyner-Hallender, thermogravimetric and differential thermal analysis, UV-vis diffuse reflectance spectra analyses, the Ti species (TiO or/and Ti ) were successfully coated on the MgAl-LDH matrix. The Ti species on the surface of the Ti-MgAl-LDH lead to a higher photocatalytic performance than commercial TiO -P25. The results suggested that CVD method provided a new approach for the industrial preparation of Ti-coating MgAl-LDH material with good photocatalytic performances.
[Mh] Termos MeSH primário: Hidróxido de Alumínio/química
Compostos Azo/química
Hidróxido de Magnésio/química
Eliminação de Resíduos Líquidos/métodos
[Mh] Termos MeSH secundário: Corantes/química
Fotólise
Titânio
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Azo Compounds); 0 (Coloring Agents); 15FIX9V2JP (titanium dioxide); 17432CG1KU (hydrotalcite); 5QB0T2IUN0 (Aluminum Hydroxide); D1JT611TNE (Titanium); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171019
[Lr] Data última revisão:
171019
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171017
[St] Status:MEDLINE


  2 / 1029 MEDLINE  
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[PMID]:28498132
[Au] Autor:Tong X; Yang Z; Xu P; Li Y; Niu X
[Ad] Endereço:School of Environment and Energy, South China University of Technology, Guangzhou 510006, China E-mail: zqyang@scut.edu.cn.
[Ti] Título:Nitrate adsorption from aqueous solutions by calcined ternary Mg-Al-Fe hydrotalcite.
[So] Source:Water Sci Technol;75(9-10):2194-2203, 2017 May.
[Is] ISSN:0273-1223
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Calcined ternary hydrotalcite like compounds had been synthesized by co-precipitation and calcined at 450 °C for 6 h. It had been applied into the nitrate removal from aqueous solutions. Various factors during adsorption process, such as chemical composition of adsorbents, adsorbent dosage, initial concentration of nitrate, initial pH and co-existing anions on nitrate adsorption had been investigated. It was found that 1.5 g/L CHTlcs (Mg/Al/Fe molar ratio = 3:0.1:0.9) could achieve ideal adsorption efficiency at an initial nitrate concentration of 100 mg/L. The value of pH had little effect on nitrate adsorption. The co-existing anions had the inhibitory effect on nitrate adsorption, which was in the order of PO > SO > Cl > ClO . The batch adsorption studies showed that experimental data were well described by the pseudo-second-order kinetic model and Langmuir isotherm model, and the maximum isotherm adsorption capacity was 123.305 mg/g. The adsorption of nitrate was a spontaneous exothermic process with the reduction of entropy. The proposed adsorption mechanism obtained from characterization was that CHTlcs uptake nitrate through reconstruction effect and adsorption on external surface.
[Mh] Termos MeSH primário: Compostos de Alumínio
Hidróxido de Alumínio/química
Compostos de Ferro
Compostos de Magnésio
Hidróxido de Magnésio/química
Nitratos/química
Poluentes Químicos da Água/química
[Mh] Termos MeSH secundário: Adsorção
Ânions
Concentração de Íons de Hidrogênio
Cinética
Percloratos
Soluções/química
Purificação da Água/métodos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Aluminum Compounds); 0 (Anions); 0 (Iron Compounds); 0 (Magnesium Compounds); 0 (Nitrates); 0 (Perchlorates); 0 (Solutions); 0 (Water Pollutants, Chemical); 17432CG1KU (hydrotalcite); 5QB0T2IUN0 (Aluminum Hydroxide); NBZ3QY004S (Magnesium Hydroxide); VLA4NZX2P4 (perchlorate)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170914
[Lr] Data última revisão:
170914
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170513
[St] Status:MEDLINE
[do] DOI:10.2166/wst.2017.082


  3 / 1029 MEDLINE  
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[PMID]:28476002
[Au] Autor:Constantino LV; Quirino JN; Monteiro AM; Abrão T; Parreira PS; Urbano A; Santos MJ
[Ad] Endereço:Departamento de Química, Universidade Estadual de Londrina, Rod. Celso Garcia Cid-PR445, Londrina, Paraná, 86051-990, Brazil.
[Ti] Título:Sorption-desorption of selenite and selenate on Mg-Al layered double hydroxide in competition with nitrate, sulfate and phosphate.
[So] Source:Chemosphere;181:627-634, 2017 Aug.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Selenate and selenite are considered emerging contaminants and pose a risk to living organisms. Since selenium anion species are at low concentration in aquatic environments, materials for its retention are required to enable monitoring. Herein, hydrotalcite was calcined and characterised to investigate sorption and desorption of selenite and selenate in competition with nitrate, sulfate and phosphate. Sorption experiments were carried out in batch system and desorption by sequential dilution. Selenite and selenate concentration remaining after N desorption steps was determined by mass balance. The isotherms were adjusted to the dual-mode Langmuir-Freundlich model (R > 0.99). Maximum sorption capacity ranged from 494 to 563 meq kg for selenite and from 609 to 659 meq kg for selenate. Sulfate and phosphate ions showed greater competitive effect on the sorption of selenate and selenite, respectively. Low mobilization factors and high sorption efficiency (MF<3%; SE ≈ 100%) indicated that calcined hydrotalcite has the wanted characteristics for retention of relevant selenium anion species in aqueous media.
[Mh] Termos MeSH primário: Monitoramento Ambiental/métodos
Hidróxidos/química
Ácido Selênico/química
Ácido Selenioso/química
[Mh] Termos MeSH secundário: Absorção Fisico-Química
Hidróxido de Alumínio/química
Magnésio/química
Hidróxido de Magnésio/química
Modelos Teóricos
Nitratos/química
Fosfatos/química
Ácido Selênico/análise
Ácido Selênico/isolamento & purificação
Ácido Selenioso/análise
Ácido Selenioso/isolamento & purificação
Compostos de Selênio/química
Compostos de Selênio/isolamento & purificação
Sulfatos/química
Poluentes da Água/química
Poluentes da Água/isolamento & purificação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Hydroxides); 0 (Nitrates); 0 (Phosphates); 0 (Selenium Compounds); 0 (Sulfates); 0 (Water Pollutants); 17432CG1KU (hydrotalcite); 5QB0T2IUN0 (Aluminum Hydroxide); F6A27P4Q4R (Selenious Acid); HV0Y51NC4J (Selenic Acid); I38ZP9992A (Magnesium); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170922
[Lr] Data última revisão:
170922
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170506
[St] Status:MEDLINE


  4 / 1029 MEDLINE  
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[PMID]:28342548
[Au] Autor:Dong J; Li B; Bao Q
[Ad] Endereço:Key Lab of Groundwater Resources and Environment Ministry of Education, Jilin University, Changchun 130026, China.
[Ti] Título:In situ reactive zone with modified Mg(OH) for remediation of heavy metal polluted groundwater: Immobilization and interaction of Cr(III), Pb(II) and Cd(II).
[So] Source:J Contam Hydrol;199:50-57, 2017 Apr.
[Is] ISSN:1873-6009
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Mg(OH) dissolves slowly and can provide a long-term source of alkalinity, thus a promising alternative reagent for the in situ remediation of heavy metal polluted groundwater. However, the application of Mg(OH) on in situ reactive zone (IRZ) for heavy metal polluted groundwater has never been investigated. In this study, the behaviors of heavy metals in a Mg(OH) IRZ were monitored for 45d. The heavy metals show a sequential precipitation by modified Mg(OH) due to the difference of K . Column tests were conducted to investigate the temporal and spatial distribution of heavy metals in Mg(OH) IRZ and evaluate the stabilization effect for multi-heavy metal polluted groundwater. Experimental results indicate that there exist interactions between different heavy metals, and their zoning distribution is attributed either to the competitive adsorption onto porous media (control column) or to the sequential precipitation of heavy metal ions (IRZ column). In contrast with the control column, heavy metal contaminated area in Mg(OH) IRZ significantly shrinks. According to the chemical speciation analysis, when water containing Pb(II), Cd(II) and Cr(III) flows through Mg(OH) IRZ, exchangeable fraction of total concentration significantly reduce and the proportion of carbonate and Fe/Mn oxides fraction increase, indicating the decrease of their mobility and toxicity.
[Mh] Termos MeSH primário: Recuperação e Remediação Ambiental/métodos
Água Subterrânea/química
Hidróxido de Magnésio/química
Metais Pesados/análise
Poluentes Químicos da Água/análise
[Mh] Termos MeSH secundário: Cádmio/análise
Cádmio/química
Cromo/análise
Cromo/química
Chumbo/análise
Chumbo/química
Metais Pesados/química
Poluentes Químicos da Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Metals, Heavy); 0 (Water Pollutants, Chemical); 00BH33GNGH (Cadmium); 0R0008Q3JB (Chromium); 2P299V784P (Lead); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170608
[Lr] Data última revisão:
170608
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170327
[St] Status:MEDLINE


  5 / 1029 MEDLINE  
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[PMID]:28275307
[Au] Autor:Yang RQ; Mao H; Huang LY; Su PZ; Lu M
[Ad] Endereço:Rui-Qi Yang, Hua Mao, Li-Yun Huang, Pei-Zhu Su, Min Lu, Department of Digestive Diseases, Zhujiang Hospital of Southern Medical University, Guangzhou 510280, Guangdong Province, China.
[Ti] Título:Effects of hydrotalcite combined with esomeprazole on gastric ulcer healing quality: A clinical observation study.
[So] Source:World J Gastroenterol;23(7):1268-1277, 2017 Feb 21.
[Is] ISSN:2219-2840
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:AIM: To evaluate the effects of hydrotalcite combined with esomeprazole on gastric ulcer healing quality. METHODS: Forty-eight patients diagnosed with gastric ulcer between June 2014 and February 2016 were randomly allocated to the combination therapy group or monotherapy group. The former received hydrotalcite combined with esomeprazole, and the latter received esomeprazole alone, for 8 wk. Twenty-four healthy volunteers were recruited and acted as the healthy control group. Endoscopic ulcer healing was observed using white light endoscopy and narrow band imaging magnifying endoscopy. The composition of collagen fibers, amount of collagen deposition, expression of factor VIII and TGF-ß1, and hydroxyproline content were analyzed by Masson staining, immunohistochemistry, immunofluorescent imaging and ELISA. RESULTS: Following treatment, changes in the gastric microvascular network were statistically different between the combination therapy group and the monotherapy group ( < 0.05). There were significant differences ( < 0.05) in collagen deposition, expression level of Factor VIII and TGF-ß1, and hydroxyproline content in the two treatment groups compared with the healthy control group. These parameters in the combination therapy group were significantly higher than in the monotherapy group ( < 0.05). The ratio of collagen I to collagen III was statistically different among the three groups, and was significantly higher in the combination therapy group than in the monotherapy group ( < 0.05). CONCLUSION: Hydrotalcite combined with esomeprazole is superior to esomeprazole alone in improving gastric ulcer healing quality in terms of improving microvascular morphology, degree of structure maturity and function of regenerated mucosa.
[Mh] Termos MeSH primário: Hidróxido de Alumínio/administração & dosagem
Esomeprazol/administração & dosagem
Mucosa Gástrica/efeitos dos fármacos
Hidróxido de Magnésio/administração & dosagem
Úlcera Gástrica/tratamento farmacológico
[Mh] Termos MeSH secundário: Administração Oral
Adulto
Idoso
Antiulcerosos/uso terapêutico
Colágeno/metabolismo
Endoscopia
Fator VIII/metabolismo
Feminino
Mucosa Gástrica/microbiologia
Infecções por Helicobacter/diagnóstico
Infecções por Helicobacter/microbiologia
Seres Humanos
Hidroxiprolina/metabolismo
Imuno-Histoquímica
Masculino
Meia-Idade
Inibidores da Bomba de Prótons/uso terapêutico
Úlcera Gástrica/microbiologia
Fator de Crescimento Transformador beta1/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RANDOMIZED CONTROLLED TRIAL
[Nm] Nome de substância:
0 (Anti-Ulcer Agents); 0 (Proton Pump Inhibitors); 0 (Transforming Growth Factor beta1); 17432CG1KU (hydrotalcite); 5QB0T2IUN0 (Aluminum Hydroxide); 9001-27-8 (Factor VIII); 9007-34-5 (Collagen); N3PA6559FT (Esomeprazole); NBZ3QY004S (Magnesium Hydroxide); RMB44WO89X (Hydroxyproline)
[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:170310
[St] Status:MEDLINE
[do] DOI:10.3748/wjg.v23.i7.1268


  6 / 1029 MEDLINE  
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[PMID]:28192355
[Au] Autor:Crutchik D; Morales N; Vázquez-Padín JR; Garrido JM
[Ad] Endereço:Department of Chemical Engineering, Institute of Technology, University of Santiago de Compostela, Santiago de Compostela 15782, Spain E-mail: dafne.crutchik@gmail.com; Faculty of Engineering and Sciences, Universidad Adolfo Ibáñez, Diagonal Las Torres 2640, Santiago, Chile.
[Ti] Título:Enhancement of struvite pellets crystallization in a full-scale plant using an industrial grade magnesium product.
[So] Source:Water Sci Technol;75(3-4):609-618, 2017 02.
[Is] ISSN:0273-1223
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:A full-scale struvite crystallization system was operated for the treatment of the centrate obtained from the sludge anaerobic digester in a municipal wastewater treatment plant. Additionally, the feasibility of an industrial grade Mg(OH) as a cheap magnesium and alkali source was also investigated. The struvite crystallization plant was operated for two different periods: period I, in which an influent with low phosphate concentration (34.0 mg P·L ) was fed to the crystallization plant; and period II, in which an influent with higher phosphate concentration (68.0 mg P·L ) was used. A high efficiency of phosphorus recovery by struvite crystallization was obtained, even when the effluent treated had a high level of alkalinity. Phosphorus recovery percentage was around 77%, with a phosphate concentration in the effluent between 10.0 and 30.0 mg P·L . The experiments gained struvite pellets of 0.5-5.0 mm size. Moreover, the consumption of Mg(OH) was estimated at 1.5 mol Mg added·mol P recovered . Thus, industrial grade Mg(OH) can be an economical alternative as magnesium and alkali sources for struvite crystallization at industrial scale.
[Mh] Termos MeSH primário: Hidróxido de Magnésio/química
Fosfatos/análise
Estruvita/química
Águas Residuais/química
Poluentes da Água/análise
Purificação da Água/métodos
[Mh] Termos MeSH secundário: Cristalização
Estudos de Viabilidade
Fosfatos/química
Esgotos/química
Poluentes da Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Phosphates); 0 (Sewage); 0 (Waste Water); 0 (Water Pollutants); AW3EJL1462 (Struvite); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170626
[Lr] Data última revisão:
170626
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170214
[St] Status:MEDLINE
[do] DOI:10.2166/wst.2016.527


  7 / 1029 MEDLINE  
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[PMID]:28164737
[Au] Autor:Kouitcheu Mabeku LB; Nanfack Nana B; Eyoum Bille B; Tchuenteu Tchuenguem R; Nguepi E
[Ad] Endereço:a Microbiology and Pharmacology Laboratory, Department of Biochemistry, Faculty of Science , University of Dschang , Dschang , Cameroon.
[Ti] Título:Anti-Helicobacter pylori and antiulcerogenic activity of Aframomum pruinosum seeds on indomethacin-induced gastric ulcer in rats.
[So] Source:Pharm Biol;55(1):929-936, 2017 Dec.
[Is] ISSN:1744-5116
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:CONTEXT: Peptic ulcer is one of the most common diseases affecting mankind. Although there are many products used for its treatment, most of these products produce severe adverse reactions requiring the search for novel compounds. Some Afromomum species are used traditionally to cure acute gastritis. OBJECTIVE: To evaluate the antiulcer activity of the methanol extract of Aframomum pruinosum Gagnepain (Zingiberaceae) seeds against two major etiologic agents of peptic ulcer disease; Helicobacter pylori and non-steroidal anti-inflammatory drugs. MATERIALS AND METHODS: The anti-Helicobacter activity of A. pruinosum was evaluated using the broth microdilution method. After oral administration of indomethacin (5 mg/kg) for 5 consecutive days, gastric ulcerated animals were divided into control group and five other groups: three groups that recieved respectively 125, 250 and 500 mg/kg of plant extract, the fourth group received Maalox (50 mg/kg) and the fifth group, Misoprostol (100 µg/kg), respectively, for 5 days. Ulcer areas, gastric mucus content and nitric oxide gastric levels of animals were assessed 24 h after this treatment. RESULTS: A. pruinosum extract shows a moderate anti-Helicobacter activity with an MIC value of 128 µg/mL. A. pruinosum extract, like Misoprostol and Maalox, markedly reduces the % of ulcerated area from 8.15 ± 0.33 to 1.71 ± 0.44% (500 mg/kg). It also increased significantly mucus and NO gastric production with respective values of 4.44 ± 1.35 and 965.81 ± 106.74 µmol/g (500 mg/kg). DISCUSSION AND CONCLUSION: These findings suggest that A. pruinosum methanol extract possesses antiulcer properties as ascertained by the comparative decreases in ulcer areas, increase of mucus and NO gastric production.
[Mh] Termos MeSH primário: Antibacterianos/farmacologia
Antiulcerosos/farmacologia
Mucosa Gástrica/efeitos dos fármacos
Helicobacter pylori/efeitos dos fármacos
Indometacina
Sementes/química
Úlcera Gástrica/prevenção & controle
Zingiberaceae/química
[Mh] Termos MeSH secundário: Hidróxido de Alumínio/farmacologia
Animais
Antibacterianos/isolamento & purificação
Modelos Animais de Doenças
Relação Dose-Resposta a Droga
Combinação de Medicamentos
Mucosa Gástrica/metabolismo
Mucosa Gástrica/patologia
Helicobacter pylori/crescimento & desenvolvimento
Hidróxido de Magnésio/farmacologia
Masculino
Metanol/química
Testes de Sensibilidade Microbiana
Misoprostol/farmacologia
Muco/metabolismo
Óxido Nítrico/metabolismo
Fitoterapia
Plantas Medicinais
Ratos Sprague-Dawley
Solventes/química
Úlcera Gástrica/induzido quimicamente
Úlcera Gástrica/metabolismo
Úlcera Gástrica/patologia
Fatores de Tempo
[Pt] Tipo de publicação:COMPARATIVE STUDY; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Anti-Bacterial Agents); 0 (Anti-Ulcer Agents); 0 (Drug Combinations); 0 (Solvents); 0E43V0BB57 (Misoprostol); 31C4KY9ESH (Nitric Oxide); 37317-08-1 (aluminum hydroxide, magnesium hydroxide, drug combination); 5QB0T2IUN0 (Aluminum Hydroxide); NBZ3QY004S (Magnesium Hydroxide); XXE1CET956 (Indomethacin); Y4S76JWI15 (Methanol)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170309
[Lr] Data última revisão:
170309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170207
[St] Status:MEDLINE
[do] DOI:10.1080/13880209.2017.1285326


  8 / 1029 MEDLINE  
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[PMID]:28140521
[Au] Autor:Cattelan L; Perosa A; Riello P; Maschmeyer T; Selva M
[Ad] Endereço:Department of Molecular Sciences and Nanosystems, Università Ca' Foscari Venezia, Via Torino, 155, Venezia Mestre, Italy.
[Ti] Título:Continuous-Flow O-Alkylation of Biobased Derivatives with Dialkyl Carbonates in the Presence of Magnesium-Aluminium Hydrotalcites as Catalyst Precursors.
[So] Source:ChemSusChem;10(7):1571-1583, 2017 Apr 10.
[Is] ISSN:1864-564X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The base-catalysed reactions of OH-bearing biobased derivatives (BBDs) including glycerol formal, solketal, glycerol carbonate, furfuryl alcohol and tetrahydrofurfuryl alcohol with non-toxic dialkyl carbonates (dimethyl and diethyl carbonate) were explored under continuous-flow (CF) conditions in the presence of three Na-exchanged Y- and X-faujasites (FAUs) and four Mg-Al hydrotalcites (HTs). Compared to previous etherification protocols mediated by dialkyl carbonates, the reported procedure offers substantial improvements not only in terms of (chemo)selectivity but also for the recyclability of the catalysts, workup, ease of product purification and, importantly, process intensification. Characterisation studies proved that both HT30 and KW2000 hydrotalcites acted as catalyst precursors: during the thermal activation pre-treatments, the typical lamellar structure of the hydrotalcite was broken down gradually into a MgO-like phase (periclase) or rather a magnesia-alumina solid solution, which was the genuine catalytic phase.
[Mh] Termos MeSH primário: Hidróxido de Alumínio/química
Alumínio/química
Carbonatos/química
Hidróxido de Magnésio/química
Magnésio/química
[Mh] Termos MeSH secundário: Alquilação
Catálise
Furanos/química
Glicerol/química
Peso Molecular
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Carbonates); 0 (Furans); 17432CG1KU (hydrotalcite); 5QB0T2IUN0 (Aluminum Hydroxide); CPD4NFA903 (Aluminum); D582054MUH (furfuryl alcohol); I38ZP9992A (Magnesium); NBZ3QY004S (Magnesium Hydroxide); PDC6A3C0OX (Glycerol); XD95821VF9 (tetrahydrofurfuryl alcohol)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170606
[Lr] Data última revisão:
170606
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170201
[St] Status:MEDLINE
[do] DOI:10.1002/cssc.201601765


  9 / 1029 MEDLINE  
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[PMID]:27983815
[Au] Autor:Wang L; Putnis CV; King HE; Hövelmann J; Ruiz-Agudo E; Putnis A
[Ad] Endereço:College of Resources and Environment, Huazhong Agricultural University , Wuhan 430070, China.
[Ti] Título:Imaging Organophosphate and Pyrophosphate Sequestration on Brucite by in Situ Atomic Force Microscopy.
[So] Source:Environ Sci Technol;51(1):328-336, 2017 Jan 03.
[Is] ISSN:1520-5851
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:In order to evaluate the organic phosphorus (OP) and pyrophosphate (PyroP) cycle and their fate in the environment, it is critical to understand the effects of mineral interfaces on the reactivity of adsorption and precipitation of OP and PyroP. Here, in situ atomic force microscopy (AFM) is used to directly observe the kinetics of coupled dissolution-precipitation on cleaved (001) surfaces of brucite [Mg(OH) ] in the presence of phytate, glucose-6-phosphate (G6P) and pyrophosphate, respectively. AFM results show that the relative order of contribution to mineral surface adsorption and precipitation is phytate > pyrophosphate > G6P under the same solution conditions and can be quantified by the induction time of OP/PyroP-Mg nucleation in a boundary layer at the brucite-water interface. Calculations of solution speciation during brucite dissolution in the presence of phytate or pyrophosphate at acidic pH conditions show that the solutions may reach supersaturation with respect to Mg H Phytate.6H O as a Mg-phytate phase or Mg P O as a Mg-pyrophosphate phase that becomes thermodynamically stable before equilibrium with brucite is reached. This is consistent with AFM dynamic observations for the new phase formations on brucite. Direct nanoscale observations of the transformation of adsorption/complexation-surface precipitation, combined with spectroscopic characterizations and species simulations may improve the mechanistic understanding of organophosphate and pyrophosphate sequestration by mineral replacement reactions through a mechanism of coupled dissolution-precipitation occurring at mineral-solution interfaces in the environment.
[Mh] Termos MeSH primário: Difosfatos
Hidróxido de Magnésio
[Mh] Termos MeSH secundário: Adsorção
Microscopia de Força Atômica
Organofosfatos
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Diphosphates); 0 (Organophosphates); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1706
[Cu] Atualização por classe:170609
[Lr] Data última revisão:
170609
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161217
[St] Status:MEDLINE
[do] DOI:10.1021/acs.est.6b05456


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[PMID]:27839879
[Au] Autor:Hudcová B; Veselská V; Filip J; Cíhalová S; Komárek M
[Ad] Endereço:Department of Environmental Geosciences, Faculty of Environmental Sciences, Czech University of Life Sciences Prague, Kamýcká 129, Prague 6 - Suchdol, 165 21, Czech Republic.
[Ti] Título:Sorption mechanisms of arsenate on Mg-Fe layered double hydroxides: A combination of adsorption modeling and solid state analysis.
[So] Source:Chemosphere;168:539-548, 2017 Feb.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Layered double hydroxides have been proposed as effective sorbents for As(V), but studies investigating adsorption mechanisms usually lack a comprehensive mechanistic/modeling approach. In this work, we propose coupling surface complexation modeling with various spectroscopic techniques. To this end, a series of batch experiments at different pH values were performed. Kinetic data were well fitted by a pseudo-second order kinetic model, and the equilibrium data were fitted by the Freundlich model. Moreover, the pH-dependent As(V) sorption data were satisfactorily fitted by a diffuse layer model, which described the formation of >SOAsO H monodentate and >(SO) AsO bidentate inner-sphere complexes (">S" represents a crystallographically-bound group on the surface). Additionally, XPS analyses confirmed the adsorption mechanisms. The sorption mechanisms were affected by anion exchange, which was responsible for the formation of outer sphere complexes, as identified by XRD and FTIR analyses. Furthermore, a homogenous distribution of As(V) was determined by HR-TEM with elemental mapping. Using low-temperature Mössbauer spectroscopy on isotope Fe, a slight shift of the hyperfine parameters towards higher values following As(V) sorption was measured, indicating a higher degree of structural disorder. In general, mechanistic adsorption modeling coupled with solid state analyses presents a powerful approach for investigating the adsorption mechanism of As(V) on Mg-Fe LDH or other sorbents.
[Mh] Termos MeSH primário: Arseniatos/química
Compostos Férricos/química
Hidróxido de Magnésio/química
Modelos Teóricos
[Mh] Termos MeSH secundário: Adsorção
Arseniatos/isolamento & purificação
Concentração de Íons de Hidrogênio
Cinética
Soluções
Espectroscopia de Infravermelho com Transformada de Fourier
Propriedades de Superfície
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Arsenates); 0 (Ferric Compounds); 0 (Solutions); 2UA751211N (ferric hydroxide); NBZ3QY004S (Magnesium Hydroxide)
[Em] Mês de entrada:1701
[Cu] Atualização por classe:170119
[Lr] Data última revisão:
170119
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161115
[St] Status:MEDLINE



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