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[PMID]:28470260
[Au] Autor:Han Y; Zhang Z; Smith GS; Do C
[Ad] Endereço:Biology and Soft Matter Division, Neutron Sciences Directorate, Oak Ridge National Laboratory, Oak Ridge, TN 37831, USA. doc1@ornl.gov.
[Ti] Título:Effect of nucleoside analogue antimetabolites on the structure of PEO-PPO-PEO micelles investigated by SANS.
[So] Source:Phys Chem Chem Phys;19(24):15686-15692, 2017 Jun 21.
[Is] ISSN:1463-9084
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:The effect of three nucleoside analogue antimetabolites (5-fluorouracil, floxuridine, and gemcitabine) on the structure of Pluronic L62 copolymer micelles was investigated using small-angle neutron scattering. These antimetabolites used for cancer chemotherapy have analogous molecular structures but different molecular sizes and aqueous solubilities. It was found that the addition of the three antimetabolites slightly reduced the micellar size and aggregation number, and the micellar anisotropy. The added antimetabolites also changed the internal molecular distribution of the micelles as measured by the scattering length densities, resulting in enhanced hydration of the hydrophobic core region of the micelle. The strength of the effect was found to correlate with the molecular properties of the model drugs, i.e. a larger molecular size and a higher aqueous solubility lead to enhanced hydration of the micellar core.
[Mh] Termos MeSH primário: Antimetabólitos/química
Micelas
Difração de Nêutrons
Polietilenoglicóis/química
Propilenoglicóis/química
Espalhamento a Baixo Ângulo
[Mh] Termos MeSH secundário: Desoxicitidina/análogos & derivados
Desoxicitidina/química
Floxuridina/química
Fluoruracila/química
Poloxâmero/química
Temperatura de Transição
Água/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Antimetabolites); 0 (Micelles); 0 (PEO-PPO-PEO); 0 (Propylene Glycols); 039LU44I5M (Floxuridine); 059QF0KO0R (Water); 0W860991D6 (Deoxycytidine); 106392-12-5 (Poloxamer); 30IQX730WE (Polyethylene Glycols); B76N6SBZ8R (gemcitabine); U3P01618RT (Fluorouracil)
[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:170505
[St] Status:MEDLINE
[do] DOI:10.1039/c7cp02028g


  2 / 5315 MEDLINE  
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[PMID]:28957423
[Au] Autor:Chen L; Hatti-Kaul R
[Ad] Endereço:Division of Biotechnology, Center for Chemistry and Chemical Engineering, Lund University, Lund, Sweden.
[Ti] Título:Exploring Lactobacillus reuteri DSM20016 as a biocatalyst for transformation of longer chain 1,2-diols: Limits with microcompartment.
[So] Source:PLoS One;12(9):e0185734, 2017.
[Is] ISSN:1932-6203
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Lactobacillus reuteri metabolises glycerol efficiently to form 3-hydroxypropionic acid (3-HP) and 1,3-propanediol (1,3PDO) by the same mechanism as that for 1,2-propanediol (1,2PDO) conversion to propionic acid and propanol via its propanediol utilization (pdu) pathway. Pdu enzymes are encoded by the pdu-operon, which also contain genes encoding the shell proteins of the microcompartment housing the metabolic pathway. In this work the selectivity and kinetics of the reactions catalysed by L. reuteri DSM20016 Pdu enzymes glycerol dehydratase (GDH), 1,3-propanediol oxidoreductase (PduQ) and coenzyme-A acylating propionaldehyde dehydrogenase (PduP), produced recombinantly, was investigated against corresponding substrates of different chain lengths. Glycerol dehydratase exhibited activity against C2-C4 polyols, with the highest activity against glycerol and 1,2-propanediol (1,2-PDO). A double mutant of the pduC gene of GDH (PduC-S302A/Q337A) was constructed that displayed lowered activity against glycerol and 1,2PDO but extended the substrate range upto C6-diol. The best substrate for both PduQ and PduP was 3-hydroxypropanal (3HPA), although PduP exhibited nearly 10-fold higher specific activity. The enzymes also showed some activity against C3-C10 aliphatic aldehydes, with PduP having higher relative activity. Subsequently, transformation of polyols using whole cells of L. reuteri containing the wild type- and mutated GDH, respectively, confirmed the reduced activity of the mutant against glycerol and 1,2PDO, but its activity against longer substrates was negligible. In contrast, recombinant Escherichia coli BL21(DE3) cells harboring the GDH variant converted diols with up to C6 carbon chain length to their respective aldehydes, suggesting that the protein shell of the microcompartment in L. reuteri posed a barrier to the passage of longer chain substrate.
[Mh] Termos MeSH primário: Lactobacillus reuteri/metabolismo
Propilenoglicóis/metabolismo
[Mh] Termos MeSH secundário: Anaerobiose
Biocatálise
Escherichia coli/genética
Escherichia coli/metabolismo
Lactobacillus reuteri/genética
Família Multigênica
Mutação
Propilenoglicóis/química
Especificidade por Substrato
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Propylene Glycols); 5965N8W85T (1,3-propanediol)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171107
[Lr] Data última revisão:
171107
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170929
[St] Status:MEDLINE
[do] DOI:10.1371/journal.pone.0185734


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[PMID]:28863426
[Au] Autor:Ko Y; Seol E; Sundara Sekar B; Kwon S; Lee J; Park S
[Ad] Endereço:School of Chemical and Biomolecular Engineering, Pusan National University, 2, Busandaehak-ro 63 beon-gil, Geumjeong-gu, Busan 46241, Republic of Korea.
[Ti] Título:Metabolic engineering of Klebsiella pneumoniae J2B for co-production of 3-hydroxypropionic acid and 1,3-propanediol from glycerol: Reduction of acetate and other by-products.
[So] Source:Bioresour Technol;244(Pt 1):1096-1103, 2017 Nov.
[Is] ISSN:1873-2976
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Production of 3-hydroxypropionic acid (3-HP) or 1,3-propanediol (1,3-PDO) production from glycerol is challenging due to the problems associated with cofactor regeneration, coenzyme B synthesis, and the instability of pathway enzymes. To address these complications, simultaneous production of 3-HP and 1,3-PDO, instead of individual production of each compound, was attempted. With over-expression of an aldehyde dehydrogenase, recombinant Klebsiella pneumoniae could co-produce 3-HP and 1,3-PDO successfully. However, the production level was unsatisfactory due to excessive accumulation of many by-products, especially acetate. To reduce acetate production, we attempted; (i) reduction of glycerol assimilation through the glycolytic pathway, (ii) increase of glycerol flow towards co-production, and (iii) variation of aeration rate. These efforts were partially beneficial in reducing acetate and improving co-production: 21g/L of 1,3-PDO and 43g/L of 3-HP were obtained. Excessive acetate (>150mM) was still produced at the end of bioreactor runs, and limited co-production efficiency.
[Mh] Termos MeSH primário: Glicerol
Klebsiella pneumoniae
Engenharia Metabólica
Propilenoglicóis
[Mh] Termos MeSH secundário: Acetatos
Ácido Láctico/análogos & derivados
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Acetates); 0 (Propylene Glycols); 33X04XA5AT (Lactic Acid); 5965N8W85T (1,3-propanediol); C4ZF6XLD2X (hydracrylic acid); PDC6A3C0OX (Glycerol)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171103
[Lr] Data última revisão:
171103
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170903
[St] Status:MEDLINE


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[PMID]:28847148
[Au] Autor:Jumaah F; Jedrkiewicz R; Gromadzka J; Namiesnik J; Essén S; Turner C; Sandahl M
[Ad] Endereço:Department of Chemistry, Centre for Analysis and Synthesis (CAS), Lund University , P.O. Box 124, 22100 Lund, Sweden.
[Ti] Título:Rapid and Green Separation of Mono- and Diesters of Monochloropropanediols by Ultrahigh Performance Supercritical Fluid Chromatography-Mass Spectrometry Using Neat Carbon Dioxide as a Mobile Phase.
[So] Source:J Agric Food Chem;65(37):8220-8228, 2017 Sep 20.
[Is] ISSN:1520-5118
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:This study demonstrates the effect of column selectivity and density of supercritical carbon dioxide (SC-CO ) on the separation of monochloropropanediol (MCPD) esters, known as food toxicants, using SC-CO without addition of cosolvent in ultrahigh performance supercritical fluid chromatography-mass spectrometry (UHPSFC-MS). This study shows that over 20 2-monochloropropanediol (2-MCPD) and 3-monochloropropanediol (3-MCPD) mono- and diesters are separated on a 2-picolylamine column in less than 12 min. The presence and position of a hydroxyl group in the structure, the number of unsaturated bonds, and the acyl chain length play a significant role in the separation of MCPD esters. The flow rate, backpressure, and column oven temperature, which affect the density of the mobile phase, were shown to have a substantial impact on retention, efficiency, and selectivity. The developed method was successfully applied for the determination of MCPD esters in refined oils and showed a close to excellent green analysis score using the Analytical Eco-Scale.
[Mh] Termos MeSH primário: Cromatografia com Fluido Supercrítico/métodos
Química Verde/métodos
Espectrometria de Massas/métodos
Propilenoglicóis/química
Propilenoglicóis/isolamento & purificação
[Mh] Termos MeSH secundário: Dióxido de Carbono/química
Cromatografia com Fluido Supercrítico/instrumentação
Contaminação de Alimentos/análise
Química Verde/instrumentação
Espectrometria de Massas/instrumentação
Estrutura Molecular
[Pt] Tipo de publicação:EVALUATION STUDIES; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Propylene Glycols); 142M471B3J (Carbon Dioxide)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171113
[Lr] Data última revisão:
171113
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170830
[St] Status:MEDLINE
[do] DOI:10.1021/acs.jafc.7b02857


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[PMID]:28719877
[Au] Autor:Guan M; Zhang X
[Ad] Endereço:State Key Laboratory of Pollution Control & Resource Reuse, School of the Environment, Nanjing University, Nanjing, 210023, PR China.
[Ti] Título:Functional genomic assessment of 2, 2-bis (bromomethyl)-1, 3-propanediol induced cytotoxicity in a single-gene knockout library of E. coli.
[So] Source:Chemosphere;185:582-588, 2017 Oct.
[Is] ISSN:1879-1298
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:Functional gene fingerprinting of chemicals could be used to understand the direct gene-chemical interaction in the process of toxification from a genome-wide scale. 2, 2-bis (bromomethyl)-1, 3-propanediol (BMP) is a brominated flame retardant with widespread production but with very limited toxicological data. Here the cytotoxicity of BMP was assessed by Escherichia coli (E. coli) functional genome-wide knockout mutants screening and the underlying molecular mechanism was investigated. The median inhibition concentration (IC50) of BMP was 1.608 ± 0.078 mg/ml after 24 h exposure. 119 initial, including 66 sensitive and 53 resistant single gene mutants, were identified by a full library screening of BMP at the concentration of IC50. The resistant genes were significantly enriched in nucleobase-containing compound biosynthetic process (GO: 0034654) by gene ontology (GO) biological process analyses, which suggested that the pathway of DNA repair is a critical cellular process in the survival of cells exposed to BMP. Meanwhile, function annotation of all BMP responsive genes suggested the mechanism of BMP was associated with DNA damage, oxidative stress and cellular transmembrane transport process. Many genes were exclusively responsive to BMP comparing with other chemicals that has been assessed by E. coli mutant screening approach, which indicated that BMP has a distinct mode of toxic action. Overall, the functional genomic screening approach presented here provides a great tool to assess the cellular toxicological mechanism of environmental chemicals.
[Mh] Termos MeSH primário: Escherichia coli/efeitos dos fármacos
Retardadores de Chama/toxicidade
Propilenoglicóis/toxicidade
[Mh] Termos MeSH secundário: Dano ao DNA
Escherichia coli/genética
Técnicas de Inativação de Genes
Genômica
Estresse Oxidativo
Propilenoglicol
Testes de Toxicidade
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Flame Retardants); 0 (Propylene Glycols); 3296-90-0 (2,2-bis(bromomethyl)-1,3-propanediol); 6DC9Q167V3 (Propylene Glycol)
[Em] Mês de entrada:1710
[Cu] Atualização por classe:171017
[Lr] Data última revisão:
171017
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170719
[St] Status:MEDLINE


  6 / 5315 MEDLINE  
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[PMID]:28718506
[Au] Autor:Shi LL; Dong J; Ni H; Geng J; Wu T
[Ad] Endereço:Evidence-based Medicine Center, Medical School of Nantong University, Nantong, China.
[Ti] Título:Felbamate as an add-on therapy for refractory partial epilepsy.
[So] Source:Cochrane Database Syst Rev;7:CD008295, 2017 07 18.
[Is] ISSN:1469-493X
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: This review is an update of a previously published review in the Cochrane Database of Systematic Reviews (Issue 7, 2014) on 'Felbamate as an add-on therapy for refractory epilepsy'. Epilepsy is a chronic and disabling neurologic disorder, affecting approximately 1% of the population. Up to 30% of people with epilepsy have seizures that are resistant to currently available drugs. Felbamate is one of the second-generation antiepileptic drugs and we have assessed its effects as an add-on therapy to standard drugs in this review. OBJECTIVES: To evaluate the efficacy and tolerability of felbamate versus placebo when used as an add-on treatment for people with refractory partial-onset epilepsy. SEARCH METHODS: For the latest update we searched the Cochrane Epilepsy Specialized Register, CENTRAL, MEDLINE, ClinicalTrials.gov and the WHO International Clinical Trials Registry Platform, up to 20 October 2016. There were no language and time restrictions. We reviewed the reference lists of retrieved studies to search for additional reports of relevant studies. We also contacted the manufacturers of felbamate and experts in the field for information about any unpublished or ongoing studies. SELECTION CRITERIA: Randomised placebo-controlled add-on studies of people of any age with refractory partial-onset seizures. The studies could be double-blind, single-blind or unblinded and could be of parallel or cross-over design. DATA COLLECTION AND ANALYSIS: Two review authors independently selected studies for inclusion and extracted information. We resolved disagreements by discussion. If disagreements persisted, the third review author arbitrated. We assessed the following outcomes: 50% or greater reduction in seizure frequency; absolute or percentage reduction in seizure frequency; treatment withdrawal; adverse effects; quality of life. MAIN RESULTS: We included four randomised controlled trials with a total of 236 participants. Two trials were parallel design, the third had a two-period cross-over design, and the fourth had a three-period cross-over design. Two studies were at an unclear risk of bias for random sequence generation and allocation concealment. These two studies did not include any description of their methods for outcome assessment and performance blinding (i.e. participants or doctors). Two studies were at high risk of bias for incomplete outcome data. Due to significant methodological heterogeneity, clinical heterogeneity and differences in outcome measures, it was not possible to perform a meta-analysis of the results. Only one study reported 50% or greater reduction in seizure frequency. One study reported absolute and percentage reduction in seizure frequency compared to placebo, P values were 0.046 and 0.018, respectively. One study reported percentage reduction in seizure frequency compared to placebo, but there were no P values. Adverse effects rates were higher during the felbamate period than the placebo period, particularly headache, nausea and dizziness. AUTHORS' CONCLUSIONS: In view of the methodological deficiencies, limited number of individual studies and differences in outcome measures, we have found no reliable evidence to support the use of felbamate as an add-on therapy in people with refractory partial-onset epilepsy. A large-scale, randomised controlled trial conducted over a longer period of time is required to inform clinical practice.
[Mh] Termos MeSH primário: Anticonvulsivantes/uso terapêutico
Epilepsias Parciais/tratamento farmacológico
Fenilcarbamatos/uso terapêutico
Propilenoglicóis/uso terapêutico
[Mh] Termos MeSH secundário: Anticonvulsivantes/efeitos adversos
Resistência a Medicamentos
Seres Humanos
Fenilcarbamatos/efeitos adversos
Propilenoglicóis/efeitos adversos
Ensaios Clínicos Controlados Aleatórios como Assunto
[Pt] Tipo de publicação:JOURNAL ARTICLE; RESEARCH SUPPORT, NON-U.S. GOV'T; REVIEW
[Nm] Nome de substância:
0 (Anticonvulsants); 0 (Phenylcarbamates); 0 (Propylene Glycols); X72RBB02N8 (felbamate)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170912
[Lr] Data última revisão:
170912
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170719
[St] Status:MEDLINE
[do] DOI:10.1002/14651858.CD008295.pub4


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[PMID]:28424096
[Au] Autor:Groeger C; Wang W; Sabra W; Utesch T; Zeng AP
[Ad] Endereço:Institute of Bioprocess and Biosystems Engineering, Hamburg University of Technology, Denickestr.15, 21073, Hamburg, Germany.
[Ti] Título:Metabolic and proteomic analyses of product selectivity and redox regulation in Clostridium pasteurianum grown on glycerol under varied iron availability.
[So] Source:Microb Cell Fact;16(1):64, 2017 Apr 19.
[Is] ISSN:1475-2859
[Cp] País de publicação:England
[La] Idioma:eng
[Ab] Resumo:BACKGROUND: Clostridium pasteurianum as an emerging new microbial cell factory can produce both n-butanol (BuOH) and 1,3-propanediol (1,3-PDO), and the pattern of product formation changes significantly with the composition of the culture medium. Among others iron content in the medium was shown to strongly affect the products selectivity. However, the mechanism behind this metabolic regulation is still unclear. For a better understanding of such metabolic regulation and for process optimization, we carried out fermentation experiments under either iron excess or iron limitation conditions, and performed metabolic, stoichiometric and proteomic analyses. RESULTS: 1,3-PDO is most effectively produced under iron limited condition (Fe-), whereas 1,3-PDO and BuOH were both produced under iron rich condition (Fe+). With increased iron availability the BuOH/1,3-PDO ratio increased significantly from 0.27 mol/mol (at Fe-) to 1.4 mol/mol (at Fe+). Additionally, hydrogen production was enhanced significantly under Fe+ condition. Proteomic analysis revealed differentiated expression of many proteins including several ones of the central carbon metabolic pathway. Among others, pyruvate: ferredoxin oxidoreductase, hydrogenases, and several electron transfer flavoproteins was found to be strongly up-regulated under Fe+ condition, pointing to their strong involvement in the regeneration of the oxidized form of ferredoxin, and consequently their influences on the product selectivity in C. pasteurianum. Of particular significance is the finding that H formation in C. pasteurianum is coupled to the ferredoxin-dependent butyryl-CoA dehydrogenase catalyzed reaction, which significantly affects the redox balance and thus the product selectivity. CONCLUSIONS: The metabolic, stoichiometric and proteomic results clearly show the key roles of hydrogenases and ferredoxins dependent reactions in determining the internal redox balance and hence product selectivity. Not only the NADH pool but also the regulation of the ferredoxin pool could explain such product variation under different iron conditions.
[Mh] Termos MeSH primário: Clostridium/efeitos dos fármacos
Clostridium/metabolismo
Glicerol/metabolismo
Ferro/farmacologia
[Mh] Termos MeSH secundário: 1-Butanol/metabolismo
Clostridium/genética
Clostridium/crescimento & desenvolvimento
Meios de Cultura/química
Fermentação
Ferredoxinas/genética
Ferredoxinas/metabolismo
Flavoproteínas/genética
Hidrogênio/metabolismo
Hidrogenase/genética
Redes e Vias Metabólicas
Metabolômica/métodos
Oxirredução
Propilenoglicóis/metabolismo
Proteômica/métodos
Piruvato Sintase/genética
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Culture Media); 0 (Ferredoxins); 0 (Flavoproteins); 0 (Propylene Glycols); 5965N8W85T (1,3-propanediol); 7YNJ3PO35Z (Hydrogen); 8PJ61P6TS3 (1-Butanol); E1UOL152H7 (Iron); EC 1.12.7.2 (Hydrogenase); EC 1.2.7.1 (Pyruvate Synthase); PDC6A3C0OX (Glycerol)
[Em] Mês de entrada:1711
[Cu] Atualização por classe:171108
[Lr] Data última revisão:
171108
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170421
[St] Status:MEDLINE
[do] DOI:10.1186/s12934-017-0678-9


  8 / 5315 MEDLINE  
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[PMID]:28411641
[Au] Autor:Suthiwangcharoen N; Nagarajan R
[Ad] Endereço:Natick Soldier Research, Development and Engineering Center, Natick, MA, United States.
[Ti] Título:Nanoarmoring of Proteins by Conjugation to Block Copolymer Micelles.
[So] Source:Methods Enzymol;590:277-304, 2017.
[Is] ISSN:1557-7988
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:The creation of polymer nanoparticles with protein functionality is of great interest to many applications such as targeted drug or gene delivery, diagnostic imaging, cancer theranostics, delivery of protein therapeutics, sensing chemical and biomolecular analytes in complex environments, and design of protective clothing resembling a second skin. Many approaches to achieving this goal are being explored in the current literature. In this chapter, we describe a relatively simple and flexible approach of conjugating the protein to an amphiphilic block copolymer and creating polymer nanoparticles with protein functionality by taking advantage of the intrinsic self-assembly behavior of the amphiphilic block copolymer. The commercially available and biocompatible polyethylene oxide-polypropylene oxide-polyethylene oxide triblock copolymer is used as the polymer building block. For demonstrative purposes, bovine serum albumin was chosen as the protein. We determine the molecular weight of the protein-polymer conjugate and thereby the degree of conjugation using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry measurements. Retention of protein secondary structure in the conjugate was determined by circular dichroism spectroscopy, and the biological activity of the protein in the conjugated state has been evaluated by kinetic assay involving hydrolysis of an organophosphate compound. Dynamic light scattering and zeta potential measurements were used to characterize the size and charge of the protein-polymer conjugate micelle. Precise control of the size of the micelle and surface number density of the proteins on the micelle surface by coassembling with a second block copolymer have been demonstrated. These studies document a rational approach to armor the protein by conjugation with a block copolymer micelle, as a general approach.
[Mh] Termos MeSH primário: Proteínas Imobilizadas/química
Polietilenoglicóis/química
Propilenoglicóis/química
Soroalbumina Bovina/química
[Mh] Termos MeSH secundário: Sistemas de Liberação de Medicamentos
Hidrólise
Micelas
Nanopartículas/química
Tamanho da Partícula
Estabilidade Proteica
Estrutura Secundária de Proteína
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Immobilized Proteins); 0 (Micelles); 0 (PEO-PPO-PEO); 0 (Propylene Glycols); 27432CM55Q (Serum Albumin, Bovine); 30IQX730WE (Polyethylene Glycols)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170417
[St] Status:MEDLINE


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[PMID]:28411639
[Au] Autor:Premaratne G; Coats L; Krishnan S
[Ad] Endereço:Oklahoma State University, Stillwater, OK, United States.
[Ti] Título:NanoArmoring of Enzymes by Polymer-Functionalized Iron Oxide Nanoparticles.
[So] Source:Methods Enzymol;590:225-257, 2017.
[Is] ISSN:1557-7988
[Cp] País de publicação:United States
[La] Idioma:eng
[Ab] Resumo:Polymer-armored enzymes loaded onto magnetic nanoparticles, as efficient nanobioreactors with enhanced properties, are described in this chapter. Polymers are useful macromolecules carrying a large number of surface charges and repeating units of desired chemical functional groups for linking enzymes onto them. Magnetic micro/nanoparticles have been widely used as enzyme carriers with the incorporation of suitable polymer layers. Synthesized iron oxide magnetic nanoparticles have been used to immobilize a peroxide-catalyzing enzyme-like heme protein: myoglobin using covalent and noncovalent strategies. The stability, scalability, and kinetics of the conjugate were studied in detail using spectroscopic and electrochemical analysis. Compared to the free myoglobin in solution, myoglobin conjugated to magnetic nanoparticles demonstrated high catalytic stability and easy recovery from the reaction medium for further use. Due to the large surface area offered by the magnetic nanoparticles, a large amount of myoglobin could be loaded with a small amount of magnetic nanoparticles. Selected examples of polymer-enzyme and polymer-magnetic nanoparticle-enzyme conjugates developed by us and others are presented in this chapter, and representative methods for making cost-effective scalable and reusable enzymatic reactors have been described.
[Mh] Termos MeSH primário: Enzimas Imobilizadas/química
Nanopartículas Metálicas/química
Polietilenoglicóis/química
Propilenoglicóis/química
[Mh] Termos MeSH secundário: Estabilidade Enzimática
Compostos Férricos/química
Cinética
Micelas
Nanoconjugados/química
Tamanho da Partícula
Soroalbumina Bovina/química
[Pt] Tipo de publicação:JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Enzymes, Immobilized); 0 (Ferric Compounds); 0 (Micelles); 0 (Nanoconjugates); 0 (PEO-PPO-PEO); 0 (Propylene Glycols); 1K09F3G675 (ferric oxide); 27432CM55Q (Serum Albumin, Bovine); 30IQX730WE (Polyethylene Glycols)
[Em] Mês de entrada:1708
[Cu] Atualização por classe:171116
[Lr] Data última revisão:
171116
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170417
[St] Status:MEDLINE


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[PMID]:28402060
[Au] Autor:Macente BI; Toniollo GH; Apparicio M; Mansano C; Thomé HE; Canella CL; Tozato M; Gutierrez RR
[Ad] Endereço:Departamento de Medicina Veterinária Preventiva e Reprodução Animal, UNESP, Jaboticabal, São Paulo, Brazil.
[Ti] Título:Evaluation of different fragment sizes and cryoprotectants for cryopreservation of feline testicular tissues.
[So] Source:Reprod Domest Anim;52 Suppl 2:242-247, 2017 Apr.
[Is] ISSN:1439-0531
[Cp] País de publicação:Germany
[La] Idioma:eng
[Ab] Resumo:This study aimed to evaluate tissue damage of feline testicles sectioned in two different sizes (0.3 or 0.5 cm ) and submitted to different cryoprotectants (propanediol or glycerol). Testicles obtained from 12 domestic cats were sectioned in 0.3 and 0.5 cm sized pieces and immediately evaluated by TBARS and semi-quantitatively by histomorphology. The remaining fragments were placed in cryotubes with 1 ml Egg yolk Tris Equex STM extender containing 3% glycerol or 3% propanediol and cryopreserved by fast-freezing technique. Frozen-thawed fragments were also evaluated by TBARS and histomorphology. Statistical analysis was performed using one-way ANOVA with Student-Newmann-Keuls post hoc test, with p < .05. Fresh and cryopreserved tissues generally exhibited a similar morphology concerning detachment of cells from the basement membrane and observation of nucleoli, with a great proportion scored as 0 (no alteration). When present, alterations were slight and the morphology was considered to be good (most classified in scores 1). Pyknosis was the main anomaly observed as score 2 in 54.6% and 58.4% of 0.3-cm fragments cryopreserved in propanediol and glycerol, respectively (16.7% scored 2 in fresh tissue). In TBARS evaluation, 0.5-cm fragments cryopreserved in glycerol produced less free radical compared to the 0.3 cm cryopreserved in glycerol or propanediol. Our results showed that glycerol was more efficient than propanediol to cryopreserve 0.5-cm fragments; this might be attributed to the fact that glycerol molecular weight is larger than propanediol and so its perfusion in the testicular tissue is slower.
[Mh] Termos MeSH primário: Gatos
Criopreservação/veterinária
Crioprotetores
Testículo/anatomia & histologia
[Mh] Termos MeSH secundário: Animais
Criopreservação/métodos
Gema de Ovo
Radicais Livres/metabolismo
Glicerol
Masculino
Propilenoglicóis
Testículo/química
Testículo/metabolismo
Substâncias Reativas com Ácido Tiobarbitúrico/análise
[Pt] Tipo de publicação:COMPARATIVE STUDY; EVALUATION STUDIES; JOURNAL ARTICLE
[Nm] Nome de substância:
0 (Cryoprotective Agents); 0 (Free Radicals); 0 (Propylene Glycols); 0 (Thiobarbituric Acid Reactive Substances); 5965N8W85T (1,3-propanediol); PDC6A3C0OX (Glycerol)
[Em] Mês de entrada:1709
[Cu] Atualização por classe:170906
[Lr] Data última revisão:
170906
[Sb] Subgrupo de revista:IM
[Da] Data de entrada para processamento:170413
[St] Status:MEDLINE
[do] DOI:10.1111/rda.12828



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