Base de dados : MEDLINE
Pesquisa : D01.268.556.185 [Categoria DeCS]
Referências encontradas : 15881 [refinar]
Mostrando: 1 .. 10   no formato [Detalhado]

página 1 de 1589 ir para página                         

  1 / 15881 MEDLINE  
              next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29030319
[Au] Autor:Dutta S; Celestine MJ; Khanal S; Huddleston A; Simms C; Arca JF; Mitra A; Heller L; Kraj PJ; Ledizet M; Anderson JF; Neelakanta G; Holder AA; Sultana H
[Ad] Endereço:Department of Biological Sciences, Old Dominion University, Norfolk, VA, USA.
[Ti] Título:Coordination of different ligands to copper(II) and cobalt(III) metal centers enhances Zika virus and dengue virus loads in both arthropod cells and human keratinocytes.
[So] Source:Biochim Biophys Acta;1862(1):40-50, 2018 01.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:Trace elements such as copper and cobalt have been associated with virus-host interactions. However, studies to show the effect of conjugation of copper(II) or cobalt(III) metal centers to thiosemicarbazone ligand(s) derived from either food additives or mosquito repellent such as 2-acetylethiazole or citral, respectively, on Zika virus (ZIKV) or dengue virus (serotype 2; DENV2) infections have not been explored. In this study, we show that four compounds comprising of thiosemicarbazone ligand derived from 2-acetylethiazole viz., (E)-N-ethyl-2-[1-(thiazol-2-yl)ethylidene]hydrazinecarbothioamide (acetylethTSC) (compound 1), a copper(II) complex with acetylethTSC as a ligand (compound 2), a thiosemicarbazone ligand-derived from citral (compound 3) and a cobalt(III) complex with a citral-thiosemicarbazone ligand (compound 4) increased DENV2 and ZIKV replication in both mosquito C6/36 cells and human keratinocytes (HaCaT cells). Treatment of both cell lines with compounds 2 or 4 showed increased dengue viral titers at all three tested doses. Enhanced dengue viral plaque formation was also noted at the tested dose of 100µM, suggesting higher production of infectious viral particles. Treatment with the compounds 2 or 4 enhanced ZIKV and DENV2 RNA levels in HeLa cell line and primary cultures of mouse bone marrow derived dendritic cells. Also, pre- or post treatments with conjugated compounds 2 or 4 showed higher loads of ZIKV or DENV2 envelope (E) protein in HaCaT cells. No changes in loads of E-protein were found in ZIKV-infected C6/36 cells, when compounds were treated after infection. In addition, we tested bis(1,10-phenanthroline)copper(II) chloride ([Cu(phen) ]Cl , (compound 5) and tris(1,10-phenanthroline)cobalt(III) chloride ([Co(phen) ]Cl , (compound 6) that also showed enhanced DENV2 loads. Also, we found that copper(II) chloride dehydrate (CuCl ·2H O) or cobalt(II) chloride hexahydrate (CoCl ·6H O) alone had no effects as "free" cations. Taken together, these findings suggest that use of Cu(II) or Co(III) conjugation to organic compounds, in insect repellents and/or food additives could enhance DENV2/ZIKV loads in human cells and perhaps induce pathogenesis in infected individuals or individuals pre-exposed to such conjugated complexes. IMPORTANCE: Mosquito-borne diseases are of great concern to the mankind. Use of chemicals/repellents against mosquito bites and transmission of microbes has been the topic of interest for many years. Here, we show that thiosemicarbazone ligand(s) derived from 2-acetylethiazole or citral or 1,10-phenanthroline upon conjugation with copper(II) or cobalt(III) metal centers enhances dengue virus (serotype 2; DENV2) and/or Zika virus (ZIKV) infections in mosquito, mouse and human cells. Enhanced ZIKV/DENV2 capsid mRNA or envelope protein loads were evident in mosquito cells and human keratinocytes, when treated with compounds before/after infections. Also, treatment with copper(II) or cobalt(III) conjugated compounds increased viral titers and number of plaque formations. These studies suggest that conjugation of compounds in repellents/essential oils/natural products/food additives with copper(II) or cobalt(III) metal centers may not be safe, especially in tropical and subtropical places, where several dengue infection cases and deaths are reported annually or in places with increased ZIKV caused microcephaly.
[Mh] Termos MeSH primário: Cobalto
Complexos de Coordenação
Cobre
Vírus da Dengue/metabolismo
Queratinócitos/virologia
Carga Viral/efeitos dos fármacos
Zika virus/metabolismo
[Mh] Termos MeSH secundário: Animais
Cercopithecus aethiops
Cobalto/química
Cobalto/farmacologia
Complexos de Coordenação/química
Complexos de Coordenação/farmacologia
Cobre/química
Cobre/farmacologia
Culicidae
Células HeLa
Seres Humanos
Queratinócitos/metabolismo
Queratinócitos/patologia
Células Vero
Proteínas do Envelope Viral
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, N.I.H., EXTRAMURAL; RESEARCH SUPPORT, NON-U.S. GOV'T; RESEARCH SUPPORT, U.S. GOV'T, NON-P.H.S.
[Nm] Nome de substância:
0 (Coordination Complexes); 0 (Viral Envelope Proteins); 3G0H8C9362 (Cobalt); 789U1901C5 (Copper)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180309
[Lr] Data última revisão:
180309
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171015
[St] Status:MEDLINE


  2 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29339722
[Au] Autor:Sousa DZ; Visser M; van Gelder AH; Boeren S; Pieterse MM; Pinkse MWH; Verhaert PDEM; Vogt C; Franke S; Kümmel S; Stams AJM
[Ad] Endereço:Laboratory of Microbiology, Wageningen University & Research, Stippeneng 4, 6708 WE, Wageningen, The Netherlands.
[Ti] Título:The deep-subsurface sulfate reducer Desulfotomaculum kuznetsovii employs two methanol-degrading pathways.
[So] Source:Nat Commun;9(1):239, 2018 01 16.
[Is] ISSN:2041-1723
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Methanol is generally metabolized through a pathway initiated by a cobalamine-containing methanol methyltransferase by anaerobic methylotrophs (such as methanogens and acetogens), or through oxidation to formaldehyde using a methanol dehydrogenase by aerobes. Methanol is an important substrate in deep-subsurface environments, where thermophilic sulfate-reducing bacteria of the genus Desulfotomaculum have key roles. Here, we study the methanol metabolism of Desulfotomaculum kuznetsovii strain 17 , isolated from a 3000-m deep geothermal water reservoir. We use proteomics to analyze cells grown with methanol and sulfate in the presence and absence of cobalt and vitamin B12. The results indicate the presence of two methanol-degrading pathways in D. kuznetsovii, a cobalt-dependent methanol methyltransferase and a cobalt-independent methanol dehydrogenase, which is further confirmed by stable isotope fractionation. This is the first report of a microorganism utilizing two distinct methanol conversion pathways. We hypothesize that this gives D. kuznetsovii a competitive advantage in its natural environment.
[Mh] Termos MeSH primário: Álcool Desidrogenase/metabolismo
Proteínas de Bactérias/metabolismo
Desulfotomaculum/enzimologia
Redes e Vias Metabólicas/genética
Metanol/metabolismo
Metiltransferases/metabolismo
[Mh] Termos MeSH secundário: Álcool Desidrogenase/genética
Proteínas de Bactérias/genética
Cobalto/metabolismo
Cobalto/farmacologia
Meios de Cultura/química
Desulfotomaculum/genética
Expressão Gênica
Perfilação da Expressão Gênica
Hidrólise
Metiltransferases/genética
Oxirredução
Filogenia
Proteômica/métodos
Vitamina B 12/metabolismo
Vitamina B 12/farmacologia
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Proteins); 0 (Culture Media); 3G0H8C9362 (Cobalt); EC 1.1.1.1 (Alcohol Dehydrogenase); EC 2.1.1.- (Methyltransferases); EVS87XF13W (cobaltous chloride); P6YC3EG204 (Vitamin B 12); Y4S76JWI15 (Methanol)
[Em] Mês de entrada:1803
[Cu] Atualização por classe:180307
[Lr] Data última revisão:
180307
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180118
[St] Status:MEDLINE
[do] DOI:10.1038/s41467-017-02518-9


  3 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29390311
[Au] Autor:Suwarsa O; Rahardjo RM; Sutedja E; Dharmadji HP; Hindritiani R; Gunawan H
[Ad] Endereço:Division of Allergy and Immunology, Department of Dermatology and Venereology, Faculty of Medicine, Universitas Padjadjaran-Dr. Hasan Sadikin Hospital, Bandung, Indonesia.
[Ti] Título:Systemic contact dermatitis due to corrosion of titanium-coated nickel and cobalt bone plate fixation: A case report.
[So] Source:Medicine (Baltimore);96(50):e9120, 2017 Dec.
[Is] ISSN:1536-5964
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:RATIONALE: Corrosion refers to the degradation of a material that occurs following its interaction with other substances in the environment. Corrosion of metallic substances into tissues may lead to inflammatory responses such as systemic contact dermatitis (SCD), a skin condition where an individual who has previously been sensitized to a particular allergen via the cutaneous route will subsequently react to same allergen via the systemic route. This condition occurs following exposure to allergens such as metals, medications, and certain food substances. In recent years, the use of metal plates for internal fixation has become increasingly common in bone fracture repairs. PATIENT CONCERNS: A 34-year-old Indonesian male presented with systemic erythema with itching 7 days following a bone plate fixation as a management for mandibular fracture. DIAGNOSES: Physical examination showed pruritic red macules, papules, and scales on almost his entire body, along with facial swelling. The patch test results revealed a positive reaction to nickel and cobalt. Therefore, the patient was diagnosed with SCD. INTERVENTIONS: The patient was treated with topical and systemic corticosteroids as well as bone plate removal. OUTCOME: After treatment, the eruption turned brown, the itching was resolved, and there were no facial swelling as well. LESSONS: This case report highlights the need to consider the occurrence of SCD in patients following bone plate fixation.
[Mh] Termos MeSH primário: Placas Ósseas
Dermatite de Contato/etiologia
Dermatite de Contato/terapia
Fixação Interna de Fraturas/instrumentação
Fraturas Mandibulares/cirurgia
[Mh] Termos MeSH secundário: Corticosteroides/uso terapêutico
Adulto
Cobalto
Corrosão
Remoção de Dispositivo
Seres Humanos
Masculino
Níquel
Testes do Emplastro
Titânio
[Pt] Tipo de publicação:CASE REPORTS; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Adrenal Cortex Hormones); 3G0H8C9362 (Cobalt); 7OV03QG267 (Nickel); D1JT611TNE (Titanium)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180301
[Lr] Data última revisão:
180301
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:180203
[St] Status:MEDLINE
[do] DOI:10.1097/MD.0000000000009120


  4 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
[PMID]:29254287
[Au] Autor:Jiang L; Li H; Zhao N
[Ad] Endereço:Department of Anesthesiology, No. 215 Hospital of Shaanxi Nuclear Industry, Xianyang, Shaanxi, China.
[Ti] Título:Thymoquinone protects against cobalt chloride-induced neurotoxicity via Nrf2/GCL-regulated glutathione homeostasis.
[So] Source:J Biol Regul Homeost Agents;31(4):843-853, 2017 Oct-Dec.
[Is] ISSN:0393-974X
[Cp] País de publicação:Italy
[La] Idioma:eng
[Ab] Resumo:The prevalence of neurodegenerative diseases worldwide has increased dramatically in the last decades. Hypoxia and oxidative stress play a central role in the pathogenesis of neurodegenerative diseases. Thymoquinone (TQ) is a monoterpenoid hydrocarbon compound that possesses potent antioxidant activity. In the current study, we investigated the neuroprotective effects of TQ against CoCl2, a widely used hypoxia-inducing agent. We found that TQ inhibited CoCl2-indcued cytotoxicity in vitro, as reflected by an increase of cell viability and decrease of apoptosis in CoCl2-treated PC12 cells. TQ exhibited a potent protective effect against CoCl2-induced neurotoxicity in vivo, as evidenced by decreased time spent to find the platform site in the Probe trials, reduced escape latencies, decreased traveling distance and reduction of apoptotic cell death in brains in CoCl2-treated rats. CoCl2-resulted decrease of glutathione (GSH) and increase of malondialdehyde (MDA) levels were significantly inhibited by TQ. Inhibition of GSH synthesis by buthionine sulphoximine (BSO) significantly attenuated TQ-induced neuroprotective effects against CoCl2 in rats and in PC12 cells. TQ could upregulate nuclear factor (erythroid-derived 2)-like 2 (Nrf2)/glutamate-cysteine ligase catalytic subunit (GCLc) and Nrf2/glutamate-cysteine ligase modifier subunit (GCLm) pathway which contributed to antioxidant and neuroprotective effects of TQ. In summary, we found that TQ exhibited protective effects against neurotoxicity via upregulation of Nrf2/GCL signaling. Upregulation of Nrf2/GCL signaling promoted the synthesis of GSH and contributed to attenuation of oxidative stress, neuronal cell apoptosis and neurotoxicity. These data have appointed a new path toward the understanding of the neuroprotective activities of TQ.
[Mh] Termos MeSH primário: Antioxidantes/farmacologia
Benzoquinonas/farmacologia
Cobalto/farmacologia
Hipóxia/prevenção & controle
Fármacos Neuroprotetores/farmacologia
[Mh] Termos MeSH secundário: Animais
Apoptose/efeitos dos fármacos
Butionina Sulfoximina/antagonistas & inibidores
Butionina Sulfoximina/farmacologia
Hipóxia Celular/efeitos dos fármacos
Sobrevivência Celular/efeitos dos fármacos
Comportamento Exploratório/efeitos dos fármacos
Regulação da Expressão Gênica/efeitos dos fármacos
Glutamato-Cisteína Ligase/genética
Glutamato-Cisteína Ligase/metabolismo
Glutationa/agonistas
Glutationa/metabolismo
Seres Humanos
Hipóxia/induzido quimicamente
Hipóxia/genética
Hipóxia/patologia
Masculino
Malondialdeído/antagonistas & inibidores
Malondialdeído/metabolismo
Fator 2 Relacionado a NF-E2/genética
Fator 2 Relacionado a NF-E2/metabolismo
Células PC12
Ratos
Ratos Wistar
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antioxidants); 0 (Benzoquinones); 0 (NF-E2-Related Factor 2); 0 (Neuroprotective Agents); 0 (Nfe2l2 protein, rat); 3G0H8C9362 (Cobalt); 490-91-5 (thymoquinone); 4Y8F71G49Q (Malondialdehyde); 5072-26-4 (Buthionine Sulfoximine); EC 6.3.2.2 (GCLM protein, rat); EC 6.3.2.2 (Glutamate-Cysteine Ligase); EC 6.3.2.2. (GCLC protein, rat); EVS87XF13W (cobaltous chloride); GAN16C9B8O (Glutathione)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180222
[Lr] Data última revisão:
180222
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171220
[St] Status:MEDLINE


  5 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29173357
[Au] Autor:Ghosh K; Muddeshwar MG; Ghosh K
[Ad] Endereço:Department of Clinical Biochemistry, (KG, MGM), Indira Gandhi Government Medical College Hospital, Maharashtra, India.
[Ti] Título:Ischemia Modified Albumin Test to Detect Early Diabetic Complications.
[So] Source:Am J Med Sci;354(5):467-470, 2017 11.
[Is] ISSN:1538-2990
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The objective of this study was to assess the albumin cobalt binding (ACB) test in a cohort of type 2 diabetes patients. The ACB test is a simple, inexpensive, sensitive and robust test that could have important clinical application in detecting complications of type 2 diabetes mellitus. MATERIALS AND METHODS: We tested patients with type 2 diabetes without any clinically detectable complications or without any other comorbid conditions for serum ACB levels along with an equal number of age- and sex-matched healthy control subjects. ACB levels were compared after the patients with diabetes were investigated for various complications using standard statistical tests of significance. RESULTS: A total of 100 patients with type 2 diabetes were studied with age- and sex-matched healthy control subjects. Of the 100 patients, 78 had different complications on detailed laboratory testing. The patients with complications had significantly higher ACB test results when compared to the patients with diabetes without complications and to that of the control subjects (0.62 ± 0.04, 0.42 ± 0.07, 0.30 ± 0.05absorbance units (ABSU)/mL, respectively. P < 0.001). All values in diabetics were significantly higher than that of controls. CONCLUSIONS: The serum ACB test is a sensitive indicator of complications developed in type 2 diabetes mellitus. Patients may be followed up with ACB results to detect early complications in this disease.
[Mh] Termos MeSH primário: Complicações do Diabetes/diagnóstico
Diabetes Mellitus Tipo 2/complicações
[Mh] Termos MeSH secundário: Adulto
Idoso
Biomarcadores/metabolismo
Cobalto/metabolismo
Feminino
Seres Humanos
Masculino
Meia-Idade
Albumina Sérica Humana/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Biomarkers); 0 (ischemia-modified albumin); 3G0H8C9362 (Cobalt); ZIF514RVZR (Serum Albumin, Human)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:180223
[Lr] Data última revisão:
180223
[Sb] Subgrupo de revista:AIM; IM
[Da] Data de entrada para processamento:171128
[St] Status:MEDLINE


  6 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29396269
[Au] Autor:Sezer N; Kocaoglan HO; Kiliç Ö; Lacoue-Labarthe T; Belivermis M
[Ad] Endereço:Department of Biology, Faculty of Science, Istanbul University, 34134 Vezneciler, Istanbul, Turkey.
[Ti] Título:Acidified seawater increases accumulation of cobalt but not cesium in manila clam Ruditapes philippinarum.
[So] Source:J Environ Radioact;184-185:114-121, 2018 Apr.
[Is] ISSN:1879-1700
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The pH of seawater around the world is expected to continue its decline in the near future in response to ocean acidification that is driven by heightened atmospheric CO emissions. Concomitantly, economically-important molluscs that live in coastal waters including estuaries and embayments, may be exposed to a wide assortment of contaminants, including trace metals and radionuclides. Seawater acidification may alter both the chemical speciation of select elements as well as the physiology of organisms, and may thus pose at risk to many shellfish species, including the manila clam Ruditapes philippinarum. The bioconcentration efficiency of two common radionuclides associated with the nuclear fuel cycle, Cs and Co, were investigated by exposing live clams to dissolved Cs and Co at control (pH = 8.1) and two lowered pH (pH = 7.8 and 7.5) levels using controlled aquaria. The uptake and depuration kinetics of the two radionuclides in the whole-body clam were followed for 21 and 35 days, respectively. At steady-state equilibrium, the concentration factor (CF ) for Co increased as the pH decreased (i.e. 130 ± 5, 194 ± 6, and 258 ± 10 at pH levels 8.1, 7.8 and 7.5, respectively), whereas the Cs uptake was not influenced by a change in pH conditions. During depuration, the lowest depuration rate constant of Co by the manila clam was observed at the intermediate pH of 7.8. An increase in the accumulation of Co at the intermediate pH value was thought to be caused mainly by the aragonitic shell of the clam, as well as the low salinity and alkalinity of seawater used in the experiment. Considering that accumulation consists of uptake and depuration, among the three pH conditions moderately acidified seawater enhanced most the accumulation of Co. Accumulation of Cs was not strongly influenced by a reduced pH condition, as represented by an analogous uptake constant rate and CF in each treatment. Such results suggest that future seawater pH values that are projected to be lower in the next decades, may pose a risk for calcium-bearing organisms such as shellfish.
[Mh] Termos MeSH primário: Bivalves/metabolismo
Cobalto/análise
Água do Mar/química
Poluentes Químicos da Água/análise
[Mh] Termos MeSH secundário: Animais
Césio/metabolismo
Cobalto/metabolismo
Concentração de Íons de Hidrogênio
Salinidade
Alimentos Marinhos
Poluentes Químicos da Água/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Water Pollutants, Chemical); 1KSV9V4Y4I (Cesium); 3G0H8C9362 (Cobalt)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180220
[Lr] Data última revisão:
180220
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180204
[St] Status:MEDLINE


  7 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29311512
[Au] Autor:Murakami N; Yoshida M; Yoshino T; Matsunaga S
[Ad] Endereço:Faculty of Pharmaceutical Sciences, Hokkaido University.
[Ti] Título:Synthesis of Fluorine-Containing 6-Arylpurine Derivatives via Cp*Co(III)-Catalyzed C-H Bond Activation.
[So] Source:Chem Pharm Bull (Tokyo);66(1):51-54, 2018.
[Is] ISSN:1347-5223
[Cp] País de publicação:Japan
[La] Idioma:eng
[Ab] Resumo:Cp*Co(III)-catalyzed (Cp*=pentamethylcyclopentadienyl) C-H bond functionalization of 6-arylpurines using gem-difluoroalkenes and allyl fluorides is described. The reaction with gem-difluoroalkenes afforded monofluoroalkenes with high (Z)-selectivity, while the reaction with allyl fluorides led to C-H allylation in moderate (Z)-selectivity. Both reactions proceeded using a user-friendly single-component catalyst [Cp*Co(CH CN) ](SbF ) in fluorinated alcohol solvents without any additives. Robustness was also demonstrated by a preparative-scale reaction under air.
[Mh] Termos MeSH primário: Cobalto/química
Ciclopentanos/química
Flúor/química
Compostos Organometálicos/química
Purinas/síntese química
[Mh] Termos MeSH secundário: Catálise
Estrutura Molecular
Purinas/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cyclopentanes); 0 (Organometallic Compounds); 0 (Purines); 284SYP0193 (Fluorine); 3G0H8C9362 (Cobalt); W60KTZ3IZY (purine)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180213
[Lr] Data última revisão:
180213
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:180110
[St] Status:MEDLINE
[do] DOI:10.1248/cpb.c17-00797


  8 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28451667
[Au] Autor:Chen Q; Svenum IH; Qi Y; Gavrilovic L; Chen; Holmen A; Blekkan EA
[Ad] Endereço:Department of Chemical Engineering, Norwegian University of Science and Technology (NTNU), 7491 Trondheim, Norway. edd.a.blekkan@ntnu.no.
[Ti] Título:Potassium adsorption behavior on hcp cobalt as model systems for the Fischer-Tropsch synthesis: a density functional theory study.
[So] Source:Phys Chem Chem Phys;19(19):12246-12254, 2017 May 17.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Potassium (K), an important impurity in syngas from biomass, can have a large influence on the activity and selectivity of cobalt-based Fischer-Tropsch synthesis (FTS) catalysts in Biomass to Liquids (BTL) processes. In this work, the potassium adsorption behavior on hcp cobalt was systematically studied using density functional theory. The surface energy calculations and Wulff construction of the equilibrium shape of hcp cobalt showed it is dominated by 10 facets. The interaction of K with these facets has been investigated. The results showed that the stepped facet (10-12) has the highest K adsorption energy of -2.40 eV. The facets (0001), (10-10), (10-11), (10-15), and (21-30) also showed relatively high K adsorption energies in the range of -2.28 to -2.34 eV. The corrugated facets exhibited comparatively lower K adsorption energies (-2.04 to -2.18 eV), and would be less favorable for K adsorption. It was also found that the adsorption properties depend on coverage, where the K adsorption energy decreased with increasing coverage. Diffusion energy barrier calculations indicated that K was mobile on typical facets (0001) and (10-11) with very low diffusion barriers (<0.15 eV). On stepped facets, although K could move freely along the same step (diffusion barrier <0.01 eV), diffusion from one step to another had a significantly higher barrier of 0.56 eV. This suggested that K atoms would be mobile to some extent during FTS reaction conditions, and tend to occupy the most favorable sites independent of their initial position. The results obtained in this work provide valuable information on the interaction of K with cobalt surfaces, relevant for practical cobalt catalysts and their application in BTL processes.
[Mh] Termos MeSH primário: Cobalto/química
Modelos Químicos
Potássio/química
[Mh] Termos MeSH secundário: Adsorção
Biomassa
Catálise
Termodinâmica
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
3G0H8C9362 (Cobalt); RWP5GA015D (Potassium)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180213
[Lr] Data última revisão:
180213
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170429
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp00620a


  9 / 15881 MEDLINE  
              first record previous record next record last record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:29245121
[Au] Autor:Hosseini-Zori M
[Ad] Endereço:Department of Inorganic Pigments and Glazes, Institute for Color Science and Technology (ICST), Tehran, Iran. Electronic address: mhosseini@icrc.ac.ir.
[Ti] Título:Co-doped TiO nanostructures as a strong antibacterial agent and self-cleaning cover: Synthesis, characterization and investigation of photocatalytic activity under UV irradiation.
[So] Source:J Photochem Photobiol B;178:512-520, 2018 Jan.
[Is] ISSN:1873-2682
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:The aim of this work was synthesis and investigation of various properties of Co-doped titanium dioxide nanostructures. However, dopant has no effect on XRD pattern of the host but it can influence on the various characteristics of host such as optical and electrical properties. The results of optical properties showed that absorption energy of TiO decreases in presence of cobalt as dopant. Red-shift in absorption spectrum that may be due to the excitation of 3d electrons of Co ions to the conduction band of TiO can be considered as a strong evidence to confirm the presence of Co as dopant in TiO lattice. Photocatalytic activity of products was examined by degradation of three dyes including: Acid Red 1 (A.R.1.), Reactive Blue 21 (R.A.21.) and Acid Blue 74 (A.B.74.) under UV irradiation and antibacterial activity of this product was tested by inhibition of the growth of three bacteria: Pseudomonas aeruginosa, S. aureus and E. coli. High percent of dye degradation and decreasing the contact angle of surfaces in the presence of this product as a cover confirm that Co-doped TiO can be used as a self-cleaning cover on various surfaces. The antibacterial activity is another property of this product as an antibacterial agent.
[Mh] Termos MeSH primário: Cobalto/química
Nanoestruturas/química
Titânio/química
Raios Ultravioleta
[Mh] Termos MeSH secundário: Catálise
Corantes/química
Escherichia coli/efeitos dos fármacos
Escherichia coli/efeitos da radiação
Concentração de Íons de Hidrogênio
Microscopia Eletrônica de Varredura
Microscopia Eletrônica de Transmissão
Nanoestruturas/toxicidade
Pseudomonas aeruginosa/efeitos dos fármacos
Pseudomonas aeruginosa/efeitos da radiação
Staphylococcus aureus/efeitos dos fármacos
Staphylococcus aureus/efeitos da radiação
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Coloring Agents); 15FIX9V2JP (titanium dioxide); 3G0H8C9362 (Cobalt); D1JT611TNE (Titanium)
[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:171216
[St] Status:MEDLINE


  10 / 15881 MEDLINE  
              first record previous record
seleciona
para imprimir
Fotocópia
Texto completo
[PMID]:28746830
[Au] Autor:Gilardi A; Bhamidimarri SP; Brönstrup M; Bilitewski U; Marreddy RKR; Pos KM; Benier L; Gribbon P; Winterhalter M; Windshügel B
[Ad] Endereço:Fraunhofer Institute for Molecular Biology and Applied Ecology IME, Department Screening Port, Schnackenburgallee 114, 22525 Hamburg, Germany; Jacobs University Bremen, Campus Ring 1, 28759 Bremen, Germany.
[Ti] Título:Biophysical characterization of E. coli TolC interaction with the known blocker hexaamminecobalt.
[So] Source:Biochim Biophys Acta;1861(11 Pt A):2702-2709, 2017 11.
[Is] ISSN:0006-3002
[Cp] País de publicação:Netherlands
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: The tripartite efflux pump AcrAB-TolC in E. coli is involved in drug resistance by transporting antibiotics out of the cell. The outer membrane protein TolC can be blocked by various cations, including hexaamminecobalt, thereby TolC represents a potential target for reducing antimicrobial resistance as its blockage may improve efficacy of antibiotics. METHODS: We utilized single channel electrophysiology measurements for studying TolC conductance in the absence and presence of the known TolC blocker hexaamminecobalt. Association and dissociation constants of hexaamminecobalt were determined using surface plasmon resonance measurements. Minimum inhibitory concentration (MIC) assays in the absence and presence of antibiotics were carried out for investigating the antibacterial effect of hexaamminecobalt and its potential to reduce MICs. RESULTS: TolC gating in the absence of any ligand is voltage dependent and asymmetric at high applied voltages. Hexaamminecobalt binds to TolC with high affinity and kinetic data revealed fast association and dissociation rates. Despite potent binding to TolC, hexaamminecobalt does not possess an intrinsic antimicrobial activity against E. coli nor does it reduce MIC values of antibiotics erythromycin and fusidic acid. CONCLUSIONS: TolC opening can be effectively blocked by small molecules. More potent channel blockers are needed in order to investigate the eligibility of TolC as drug target. GENERAL SIGNIFICANCE: TolC, a potentially interesting pharmaceutical target can be addressed by small molecules, blocking the channel. Biophysical characterization of the binding processes will support future identification and optimisation of more potent TolC blockers in order to validate TolC as a pharmaceutical target.
[Mh] Termos MeSH primário: Proteínas da Membrana Bacteriana Externa/química
Farmacorresistência Bacteriana Múltipla/genética
Proteínas de Escherichia coli/química
Escherichia coli/efeitos dos fármacos
Proteínas de Membrana Transportadoras/química
[Mh] Termos MeSH secundário: Proteínas da Membrana Bacteriana Externa/antagonistas & inibidores
Proteínas da Membrana Bacteriana Externa/efeitos dos fármacos
Proteínas da Membrana Bacteriana Externa/genética
Fenômenos Biofísicos
Cobalto/farmacologia
Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos
Escherichia coli/genética
Proteínas de Escherichia coli/antagonistas & inibidores
Proteínas de Escherichia coli/genética
Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos
Proteínas de Membrana Transportadoras/genética
Ressonância de Plasmônio de Superfície
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (Bacterial Outer Membrane Proteins); 0 (Escherichia coli Proteins); 0 (Membrane Transport Proteins); 0 (tolC protein, E coli); 15365-75-0 (hexaamminecobalt(II)); 3G0H8C9362 (Cobalt)
[Em] Mês de entrada:1802
[Cu] Atualização por classe:180208
[Lr] Data última revisão:
180208
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170727
[St] Status:MEDLINE



página 1 de 1589 ir para página                         
   


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