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  1 / 1962 MEDLINE  
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[PMID]:29020107
[Au] Autor:Temprana CF; Prieto MJ; Igartúa DE; Femia AL; Amor MS; Alonso SDV
[Ad] Endereço:Laboratorio de Biomembranas (LBM), Departamento de Ciencia y Tecnología, Universidad Nacional de Quilmes, Bernal, Argentina.
[Ti] Título:Diacetylenic lipids in the design of stable lipopolymers able to complex and protect plasmid DNA.
[So] Source:PLoS One;12(10):e0186194, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Different viral and non-viral vectors have been designed to allow the delivery of nucleic acids in gene therapy. In general, non-viral vectors have been associated with increased safety for in vivo use; however, issues regarding their efficacy, toxicity and stability continue to drive further research. Thus, the aim of this study was to evaluate the potential use of the polymerizable diacetylenic lipid 1,2-bis(10,12-tricosadiynoyl)-sn-glycero-3-phosphocholine (DC8,9PC) as a strategy to formulate stable cationic lipopolymers in the delivery and protection of plasmid DNA. Cationic lipopolymers were prepared following two different methodologies by using DC8,9PC, 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), and the cationic lipids (CL) 1,2-dioleoyl-3-trimethylammonium-propane (DOTAP), stearylamine (SA), and myristoylcholine chloride (MCL), in a molar ratio of 1:1:0.2 (DMPC:DC8,9PC:CL). The copolymerization methodology allowed obtaining cationic lipopolymers which were smaller in size than those obtained by the cationic addition methodology although both techniques presented high size stability over a 166-day incubation period at 4°C. Cationic lipopolymers containing DOTAP or MCL were more efficient in complexing DNA than those containing SA. Moreover, lipopolymers containing DOTAP were found to form highly stable complexes with DNA, able to resist serum DNAses degradation. Furthermore, neither of the cationic lipopolymers (with or without DNA) induced red blood cell hemolysis, although metabolic activity determined on the L-929 and Vero cell lines was found to be dependent on the cell line, the formulation and the presence of DNA. The high stability and DNA protection capacity as well as the reduced toxicity determined for the cationic lipopolymer containing DOTAP highlight the potential advantage of using lipopolymers when designing novel non-viral carrier systems for use in in vivo gene therapy. Thus, this work represents the first steps toward developing a cationic lipopolymer-based gene delivery system using polymerizable and cationic lipids.
[Mh] Termos MeSH primário: Acetileno/química
DNA/metabolismo
Lipídeos/química
Plasmídeos/metabolismo
Polímeros/síntese química
[Mh] Termos MeSH secundário: Animais
Bioensaio
Células COS
Cátions
Sobrevivência Celular
Cercopithecus aethiops
Desoxirribonucleases/metabolismo
Ensaio de Desvio de Mobilidade Eletroforética
Citometria de Fluxo
Hemólise
Luz
Camundongos
Peso Molecular
Polimerização
Polímeros/química
Espalhamento de Radiação
Eletricidade Estática
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cations); 0 (Lipids); 0 (Polymers); 9007-49-2 (DNA); EC 3.1.- (Deoxyribonucleases); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171031
[Lr] Data última revisão:
171031
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:171012
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0186194


  2 / 1962 MEDLINE  
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[PMID]:28730737
[Au] Autor:Teong SP; Lim J; Zhang Y
[Ad] Endereço:Institute of Bioengineering and Nanotechnology, 31 Biopolis Way, The Nanos, Singapore, 138669, Singapore.
[Ti] Título:Vinylation of Aryl Ether (Lignin ß-O-4 Linkage) and Epoxides with Calcium Carbide through C-O Bond Cleavage.
[So] Source:ChemSusChem;10(16):3198-3201, 2017 Aug 24.
[Is] ISSN:1864-564X
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:Calcium carbide has been increasingly used as a sustainable, easy-to-handle, and low-cost feedstock in organic synthesis. Currently, methodologies of using calcium carbide as "solid acetylene" in synthesis are strictly limited to activation and reaction with X-H (X=C, N, O, S) bonds. Herein, a mild and transition-metal-free protocol was developed for the vinylation of epoxides and aryl ether linkage (ß-O-4 lignin model compound) with calcium carbide through C-O bond cleavage, forming valuable vinyl ether products. Calcium carbide plays a vital role in the C-O bond activation and cleavage, and in providing acetylide source for the formation of vinylated products. These exciting results may provide new methodologies for organic synthesis and new insights toward lignin- or biomassrelated degradation to useful products.
[Mh] Termos MeSH primário: Acetileno/análogos & derivados
Alcenos/química
Carbono/química
Compostos de Epóxi/química
Éteres/química
Lignina/química
Oxigênio/química
[Mh] Termos MeSH secundário: Acetileno/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Alkenes); 0 (Epoxy Compounds); 0 (Ethers); 7440-44-0 (Carbon); 846WNV4A5F (calcium carbide); 9005-53-2 (Lignin); OC7TV75O83 (Acetylene); S88TT14065 (Oxygen)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170904
[Lr] Data última revisão:
170904
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170722
[St] Status:MEDLINE
[do] DOI:10.1002/cssc.201701153


  3 / 1962 MEDLINE  
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[PMID]:28617272
[Au] Autor:Zhu L; Dong D; Hua X; Xu Y; Guo Z; Liang D
[Ad] Endereço:Key Laboratory of Groundwater Resources and Environment of Ministry of Education, Key Laboratory of Water Resources and Aquatic Environment of Jilin Province, College of Environment and Resources, Jilin University, Changchun 130012, China E-mail: huaxy@jlu.edu.cn.
[Ti] Título:Ammonia nitrogen removal and recovery from acetylene purification wastewater by air stripping.
[So] Source:Water Sci Technol;75(11-12):2538-2545, 2017 Jun.
[Is] ISSN:0273-1223
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Ammonia nitrogen (NH -N) contaminated wastewater has posed a great threat to the safety of water resources. In this study, air stripping was employed to remove and recover NH -N from acetylene purification wastewater (APW) in a polyvinylchloride manufacturing plant. Investigated parameters were initial APW pH, air flow rate, APW temperature and stripping time. The NH -N removal by air stripping has been modeled and the overall volumetric mass transfer coefficient (K a) of the stripping process has been calculated from the model equation obtained. In addition, the ability of H SO solution to absorb the NH stripped was also investigated. The results indicated that under the experimental conditions, the APW temperature and its initial pH had significant effects on the NH -N removal efficiency and the K a, while the effects of other factors were relatively minor. The removal efficiency and residual concentration of NH -N were about 91% and 12 mg/L, respectively, at the optimal operating conditions of initial APW pH of 12.0, air flow rate of 0.500 m /(h·L), APW temperature of 60 °C and stripping time of 120 min. One volume of H SO solution (0.2 mol/L) could absorb about 93% of the NH stripped from 54 volumes of the APW.
[Mh] Termos MeSH primário: Amônia/análise
Nitrogênio/análise
Eliminação de Resíduos Líquidos/métodos
Poluentes Químicos da Água/análise
[Mh] Termos MeSH secundário: Acetileno/química
Resíduos Industriais
Águas Residuais/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Industrial Waste); 0 (Waste Water); 0 (Water Pollutants, Chemical); 7664-41-7 (Ammonia); N762921K75 (Nitrogen); OC7TV75O83 (Acetylene)
[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:170616
[St] Status:MEDLINE
[do] DOI:10.2166/wst.2017.117


  4 / 1962 MEDLINE  
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[PMID]:28075122
[Au] Autor:Mao X; Oremland RS; Liu T; Gushgari S; Landers AA; Baesman SM; Alvarez-Cohen L
[Ad] Endereço:Department of Civil and Environmental Engineering, College of Engineering, University of California , Berkeley, California 94720-1710, United States.
[Ti] Título:Acetylene Fuels TCE Reductive Dechlorination by Defined Dehalococcoides/Pelobacter Consortia.
[So] Source:Environ Sci Technol;51(4):2366-2372, 2017 Feb 21.
[Is] ISSN:1520-5851
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Acetylene (C H ) can be generated in contaminated groundwater sites as a consequence of chemical degradation of trichloroethene (TCE) by in situ minerals, and C H is known to inhibit bacterial dechlorination. In this study, we show that while high C H (1.3 mM) concentrations reversibly inhibit reductive dechlorination of TCE by Dehalococcoides mccartyi isolates as well as enrichment cultures containing D. mccartyi sp., low C H (0.4 mM) concentrations do not inhibit growth or metabolism of D. mccartyi. Cocultures of Pelobacter SFB93, a C H -fermenting bacterium, with D. mccartyi strain 195 or with D. mccartyi strain BAV1 were actively sustained by providing acetylene as the electron donor and carbon source while TCE or cis-DCE served as the electron acceptor. Inhibition by acetylene of reductive dechlorination and methanogenesis in the enrichment culture ANAS was observed, and the inhibition was removed by adding Pelobacter SFB93 into the consortium. Transcriptomic analysis of D. mccartyi strain 195 showed genes encoding for reductive dehalogenases (e.g., tceA) were not affected during the C H -inhibition, while genes encoding for ATP synthase, biosynthesis, and Hym hydrogenase were down-regulated during C H inhibition, consistent with the physiological observation of lower cell yields and reduced dechlorination rates in strain 195. These results will help facilitate the optimization of TCE-bioremediation at contaminated sites containing both TCE and C H .
[Mh] Termos MeSH primário: Acetileno/metabolismo
Tricloroetileno/metabolismo
[Mh] Termos MeSH secundário: Biodegradação Ambiental
Chloroflexi/metabolismo
Halogenação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
290YE8AR51 (Trichloroethylene); OC7TV75O83 (Acetylene)
[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:170112
[St] Status:MEDLINE
[do] DOI:10.1021/acs.est.6b05770


  5 / 1962 MEDLINE  
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[PMID]:28064366
[Au] Autor:Masukawa H; Sakurai H; Hausinger RP; Inoue K
[Ad] Endereço:The OCU Advanced Research Institute for Natural Science and Technology (OCARINA), Osaka City University, 3-3-138 Sugimoto, Sumiyoshi-ku, Osaka, 558-8585, Japan. masukawa@ocarina.osaka-cu.ac.jp.
[Ti] Título:Increased heterocyst frequency by patN disruption in Anabaena leads to enhanced photobiological hydrogen production at high light intensity and high cell density.
[So] Source:Appl Microbiol Biotechnol;101(5):2177-2188, 2017 Mar.
[Is] ISSN:1432-0614
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:The effects of increasing the heterocyst-to-vegetative cell ratio on the nitrogenase-based photobiological hydrogen production by the filamentous heterocyst-forming cyanobacterium Anabaena sp. PCC 7120 were studied. Using the uptake hydrogenase-disrupted mutant (ΔHup) as the parent, a deletion-insertion mutant (PN1) was created in patN, known to be involved in heterocyst pattern formation and leading to multiple singular heterocysts (MSH) in Nostoc punctiforme strain ATCC 29133. The PN1 strain showed heterocyst differentiation but failed to grow in medium free of combined-nitrogen; however, a spontaneous mutant (PN22) was obtained on prolonged incubation of PN1 liquid cultures and was able to grow robustly on N . The disruption of patN was confirmed in both PN1 and PN22 by PCR and whole genome resequencing. Under combined-nitrogen limitation, the percentage of heterocysts to total cells in the PN22 filaments was 13-15 and 16-18% under air and 1% CO -enriched air, respectively, in contrast to the parent ΔHup which formed 6.5-11 and 9.7-13% heterocysts in these conditions. The PN22 strain exhibited a MSH phenotype, normal diazotrophic growth, and higher H productivity at high cell concentrations, and was less susceptible to photoinhibition by strong light than the parent ΔHup strain, resulting in greater light energy utilization efficiency in H production on a per unit area basis under high light conditions. The increase in MSH frequency shown here appears to be a viable strategy for enhancing H productivity by outdoor cultures of cyanobacteria in high-light environments.
[Mh] Termos MeSH primário: Anabaena/genética
Anabaena/metabolismo
Hidrogênio/metabolismo
Fotobiorreatores/microbiologia
[Mh] Termos MeSH secundário: Acetileno/metabolismo
Proteínas de Bactérias/genética
Regulação Bacteriana da Expressão Gênica
Fixação de Nitrogênio/genética
Fixação de Nitrogênio/fisiologia
Nitrogenase/metabolismo
Nostoc/metabolismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Bacterial Proteins); 7YNJ3PO35Z (Hydrogen); EC 1.18.6.1 (Nitrogenase); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170227
[Lr] Data última revisão:
170227
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170109
[St] Status:MEDLINE
[do] DOI:10.1007/s00253-016-8078-3


  6 / 1962 MEDLINE  
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[PMID]:27981327
[Au] Autor:Ellis IT; Wolf EH; Jones G; Lo B; Meng-Jung Li M; York AP; Edman Tsang SC
[Ad] Endereço:Inorganic Chemistry Laboratory, University of Oxford, South Parks Road, Oxford, OX1 3QR, UK. edman.tsang@chem.ox.ac.uk.
[Ti] Título:Lithium and boron as interstitial palladium dopants for catalytic partial hydrogenation of acetylene.
[So] Source:Chem Commun (Camb);53(3):601-604, 2017 Jan 03.
[Is] ISSN:1364-548X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:It is demonstrated that light elements, including lithium and boron atoms, can take residence in the octahedral (interstitial) site of a Pd lattice by modifying the electronic properties of the metal nanoparticles, and hence the adsorptive strength of a reactant. The blocking of the sub-surface sites to H in the modified materials results in significantly higher selectivity for the partial catalytic hydrogenation of acetylene to ethylene.
[Mh] Termos MeSH primário: Acetileno/química
Boro/química
Lítio/química
Paládio/química
[Mh] Termos MeSH secundário: Catálise
Hidrogenação
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
5TWQ1V240M (Palladium); 9FN79X2M3F (Lithium); N9E3X5056Q (Boron); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170818
[Lr] Data última revisão:
170818
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161217
[St] Status:MEDLINE
[do] DOI:10.1039/c6cc08404d


  7 / 1962 MEDLINE  
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[PMID]:27827473
[Au] Autor:Freire F; Quiñoá E; Riguera R
[Ad] Endereço:Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Departamento de Química Orgánica, Universidade de Santiago de Compostela, 15782 Santiago de Compostela, Spain. felix.freire@usc.es ricardo.riguera@usc.es.
[Ti] Título:Chiral nanostructure in polymers under different deposition conditions observed using atomic force microscopy of monolayers: poly(phenylacetylene)s as a case study.
[So] Source:Chem Commun (Camb);53(3):481-492, 2017 01 03.
[Is] ISSN:1364-548X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Dynamic poly(phenylacetylene)s (PPAs) adopt helical structures with different elongation or helical senses depending on the types of pendants. Hence, a good knowledge of the parameters that define their structures becomes a key factor in the understanding of their properties and functions. Herein, the techniques used for the study of the secondary structure of PPAs using atomic-force microscopy (AFM) are presented, with special attention directed towards the methods used for the preparation of monolayers, and their consequences in the quality of the AFM images. Thus, monolayers formed by drop casting, spin coating followed by crystallization or annealing, Langmuir-Blodgett and Langmuir-Schaefer methods, onto highly oriented pyrolytic graphite (HOPG) or mica, are described, together with the AFM images and the resulting helical structure obtained for different PPAs. Furthermore, some conclusions are drawn both on the adequacy of the different techniques for the formation of monolayers and on the solid supports utilized to elucidate the secondary structure of different PPAs.
[Mh] Termos MeSH primário: Acetileno/análogos & derivados
Nanoestruturas/química
[Mh] Termos MeSH secundário: Acetileno/química
Microscopia de Força Atômica
Modelos Moleculares
Nanoestruturas/ultraestrutura
Estereoisomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T
[Nm] Nome de substância:
0 (poly(phenylacetylene)); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:170808
[Lr] Data última revisão:
170808
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161110
[St] Status:MEDLINE
[do] DOI:10.1039/c6cc05598b


  8 / 1962 MEDLINE  
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[PMID]:27700994
[Au] Autor:Li Y; Liu Q; Li W; Lu Y; Meng H; Li C
[Ad] Endereço:State Key Laboratory of Chemical Resource Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China; College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029, PR China.
[Ti] Título:Efficient destruction of hexachlorobenzene by calcium carbide through mechanochemical reaction in a planetary ball mill.
[So] Source:Chemosphere;166:275-280, 2017 Jan.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Mechanochemical destruction (MCD) is a good alternative to traditional incineration for the destruction of persistent organic pollutants (POPs), like hexachlorobenzene (HCB), and the key is to find an efficient co-milling reagent. Toward this aim, HCB was milled with various reagents in a planetary ball mill at room temperature, and CaC was found to be the best one. HCB can be destroyed completely within 20 min at a mass ratio of CaC /HCB = 0.9 and a rotation speed of 300 rpm. The ground samples were characterized by X-ray diffraction, X-ray photoelectron spectroscopy and Fourier transform infrared spectroscopy. The results show that the destruction products are nonhazardous CaCl and carbon material with both crystalline and amorphous structures. On these bases, possible reaction pathways were proposed. Considering its excellent efficiency and safety, CaC may be the most feasible co-milling regent for MCD treatment of HCB. Further, the results are instructive for the destruction of other POPs.
[Mh] Termos MeSH primário: Acetileno/análogos & derivados
Hexaclorobenzeno/química
Eliminação de Resíduos/métodos
[Mh] Termos MeSH secundário: Acetileno/química
Recuperação e Remediação Ambiental
Incineração
Resíduos Industriais
Compostos Orgânicos/química
Espectroscopia Fotoeletrônica
Espectroscopia de Infravermelho com Transformada de Fourier
Estresse Mecânico
Temperatura Ambiente
Fatores de Tempo
Difração de Raios X
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Industrial Waste); 0 (Organic Chemicals); 4Z87H0LKUY (Hexachlorobenzene); 846WNV4A5F (calcium carbide); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1703
[Cu] Atualização por classe:170912
[Lr] Data última revisão:
170912
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161005
[St] Status:MEDLINE


  9 / 1962 MEDLINE  
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[PMID]:27157880
[Au] Autor:Osikoya AO; Parlak O; Murugan NA; Dikio ED; Moloto H; Uzun L; Turner AP; Tiwari A
[Ad] Endereço:Biosensors and Bioelectronics Centre, IFM, Linköping University, 58183 Linköping, Sweden; Applied Chemistry and Nanoscience Laboratory, Department of Chemistry, Vaal University of Technology, Private Bag X021, Vanderbijlpark, South Africa.
[Ti] Título:Acetylene-sourced CVD-synthesised catalytically active graphene for electrochemical biosensing.
[So] Source:Biosens Bioelectron;89(Pt 1):496-504, 2017 Mar 15.
[Is] ISSN:1873-4235
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:In this study, we have demonstrated the use of chemical vapour deposition (CVD) grown-graphene to develop a highly-ordered graphene-enzyme electrode for electrochemical biosensing. The graphene sheets were deposited on 1.00mm thick copper sheet at 850°C using acetylene (C H ) as carbon source in an argon (Ar) and nitrogen (N ) atmosphere. An anionic surfactant was used to increase wettability and hydrophilicity of graphene; thereby facilitating the assembly of biomolecules on the electrode surface. Meanwhile, the theoretical calculations confirmed the successful modification of hydrophobic nature of graphene through the anionic surface assembly, which allowed high-ordered immobilisation of glucose oxidase (GOx) on the graphene. The electrochemical sensing activities of the graphene-electrode was explored as a model for bioelectrocatalysis. The bioelectrode exhibited a linear response to glucose concentration ranging from 0.2 to 9.8mM, with sensitivity of 0.087µA/µM/cm and a detection limit of 0.12µM (S/N=3). This work sets the stage for the use of acetylene-sourced CVD-grown graphene as a fundamental building block in the fabrication of electrochemical biosensors and other bioelectronic devices.
[Mh] Termos MeSH primário: Aspergillus niger/enzimologia
Técnicas Biossensoriais/instrumentação
Técnicas Eletroquímicas/instrumentação
Enzimas Imobilizadas/química
Glucose Oxidase/química
Grafite/química
[Mh] Termos MeSH secundário: Acetileno/química
Aspergillus niger/química
Técnicas Biossensoriais/métodos
Técnicas Eletroquímicas/métodos
Eletrodos
Desenho de Equipamento
Glucose/análise
Limite de Detecção
Modelos Moleculares
Tensoativos/química
Volatilização
Molhabilidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Surface-Active Agents); 7782-42-5 (Graphite); EC 1.1.3.4 (Glucose Oxidase); IY9XDZ35W2 (Glucose); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1702
[Cu] Atualização por classe:170224
[Lr] Data última revisão:
170224
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:160510
[St] Status:MEDLINE


  10 / 1962 MEDLINE  
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[PMID]:27879637
[Au] Autor:Zhou Y; Zhang C; Qiu Y; Liu L; Yang T; Dong H; Satoh T; Okamoto Y
[Ad] Endereço:Polymer Materials Research Center, Key Laboratory of Superlight Materials and Surface Technology, Ministry of Education, College of Materials Science and Chemical Engineering, Harbin Engineering University, Harbin 150001, China. zhouyanli0808022@163.com.
[Ti] Título:Temperature-Triggered Switchable Helix-Helix Inversion of Poly(phenylacetylene) Bearing l-Valine Ethyl Ester Pendants and Its Chiral Recognition Ability.
[So] Source:Molecules;21(11), 2016 Nov 21.
[Is] ISSN:1420-3049
[Cp] País de publicação:Switzerland
[La] Idioma:eng
[Ab] Resumo:A phenylacetylene containing the l-valine ethyl ester pendant (PAA-Val) was synthesized and polymerized by an organorhodium catalyst (Rh(nbd)BPh4) to produce the corresponding one-handed helical -poly(phenylacetylene) (PPAA-Val). PPAA-Val showed a unique temperature-triggered switchable helix-sense in chloroform, while it was not observed in highly polar solvents, such as , '-dimethylformamide (DMF). By heating the solution of PPAA-Val in chloroform, the sign of the CD absorption became reversed, but recovered after cooling the solution to room temperature. Even after six cycles of the heating-cooling treatment, the helix sense of the PPAA-Val's backbone was still switchable without loss of the CD intensity. The PPAA-Val was then coated on silica gel particles to produce novel chiral stationary phases (CSPs) for high-performance liquid chromatography (HPLC). These novel PPAA-Val based CSPs showed a high chiral recognition ability for racemic mandelonitrile ( = 2.18) and racemic - , '-diphenylcyclohexane-1,2-dicarboxamide ( = 2.60). Additionally, the one-handed helical -polyene backbone of PPAA-Val was irreversibly destroyed to afford PPAA-Val-H by heating in dimethyl sulfoxide (DMSO) accompanied by the complete disappearance of the Cotton effect. Although PPAA-Val-H had the same l-valine ethyl ester pendants as its -isomer PPAA-Val, it showed no chiral recognition. It was concluded that the one-handed helical -polyene backbone of PPAA-Val plays an important role in the chiral recognition ability.
[Mh] Termos MeSH primário: Acetileno/análogos & derivados
Etil-Éteres/química
Conformação Molecular
Temperatura Ambiente
Valina/química
[Mh] Termos MeSH secundário: Acetileno/síntese química
Acetileno/química
Dicroísmo Circular
Espectroscopia Fotoeletrônica
Polimerização
Espectroscopia de Prótons por Ressonância Magnética
Estereoisomerismo
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Ethyl Ethers); 0 (poly(phenylacetylene)); HG18B9YRS7 (Valine); OC7TV75O83 (Acetylene)
[Em] Mês de entrada:1704
[Cu] Atualização por classe:170411
[Lr] Data última revisão:
170411
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:161124
[St] Status:MEDLINE



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