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1.
J Chromatogr A ; 1621: 461079, 2020 Jun 21.
Artigo em Inglês | MEDLINE | ID: mdl-32360061

RESUMO

Capto™ Core 700 is a core-shell chromatographic support with an adsorbing core contained within an inert shell layer designed to purify larger biomolecules and bioparticles in a flow-through mode. The present study aims to characterize the structure and functional properties of this resin using bovine serum albumin (BSA, Mr~65 kDa) and thyroglobulin (Tg, Mr~660 kDa) as model impurity proteins. The functionalized adsorbing core and the inert shell have the same fibrous structure typical of agarose-based beads. The resin average bead size is 90.7 µm with a range of 50-130 µm, the shell thickness is 4.18 µm with a range of 3-6 µm and a standard deviation of 0.55 µm, and the pore radius, obtained by inverse size exclusion chromatography, is 50.4 ± 1.3 nm. Both proteins present highly favorable binding isotherms with maximum binding capacities of 55 and 105 mg/mL of total bead volume for BSA and Tg, respectively. The addition of 500 mM NaCl reduces the binding capacity by less than 50%, showing the ability of the resin to operate at high salt conditions. For both proteins, the effective pore diffusivity in the core is smaller than in the shell due to additional hindrance by bound protein in the core area. Effective pore diffusivities values in the core are 1.6 × 10-7 and 0.16 × 10-7 cm2/s for BSA and Tg, respectively. The DBC10% at 2 min residence time are 24 and 2 mg/mL for BSA and Tg, respectively. This study provides qualitative and quantitative information about Capto™ Core 700 resin. This information could be used to predict and optimize the purification of large biomolecules and bioparticle in route to the establishment of more effective downstream processes.


Assuntos
Cromatografia em Gel/métodos , Tamanho da Partícula , Adsorção , Animais , Bovinos , Resinas Sintéticas/química , Soroalbumina Bovina/química , Temperatura , Tireoglobulina/química
2.
Chem Commun (Camb) ; 56(16): 2507-2510, 2020 Feb 25.
Artigo em Inglês | MEDLINE | ID: mdl-32003763

RESUMO

Radiolabeling of peptides with fluorine-18 is hurdled by their chemical sensitivity and complicated processes. Original triflyl-pyridine intermediates afforded ammonium precursors that were radiolabeled at low temperature. From that study, a generic tag has been designed to allow a simple one-step/late-stage radiolabelling of peptides. The strategy has been transposed to an automated "on-resin" radiolabelling.


Assuntos
Peptídeos/síntese química , Compostos Radiofarmacêuticos/síntese química , Resinas Sintéticas/síntese química , Radioisótopos de Flúor , Halogenação , Estrutura Molecular , Peptídeos/química , Compostos Radiofarmacêuticos/química , Resinas Sintéticas/química , Temperatura
3.
Artigo em Inglês | MEDLINE | ID: mdl-31918307

RESUMO

The aim of this work is to develop an efficient and economical method for the enrichment of total flavonoids from Pteris ensiformis Burm. extracts. Resin screening, adsorption kinetics, adsorption isotherms and thermodynamics were successively researched prior to the dynamic adsorption and desorption tests. NKA-II resin was chosen as the best adsorbent, and the adsorption data were best described by the pseudo-second-order kinetics model and Langmuir isotherm model. The optimum enrichment conditions were as follows: for adsorption the total flavonoids concentration, flow rate and volume of sample were 1.84 mg/mL, 2 BV/h and 5 BV, respectively, and for desorption the flavonoids-loaded NKA-II resin column was desorbed by 7 BV of 50% ethanol at a rate of 2 BV/h. The product had a 6.63-fold higher total flavonoids content than crude extracts, and the recovery yield of total flavonoids was 80.65%. Furthermore, flavonoids-enriched extracts exhibited higher in vitro scavenging activity against superoxide anion radical and hydroxyl radical than crude extracts. In addition, higher antiproliferative activity of flavonoids-enriched extracts against MCF-7 and HepG-2 cell lines was also found as compared to the crude extracts. The developed method is appropriate for large-scale enrichment of total flavonoids from Pteris ensiformis Burm. extracts in the food and pharmaceutical industries.


Assuntos
Antioxidantes , Proliferação de Células/efeitos dos fármacos , Flavonoides , Pteris/química , Adsorção , Antineoplásicos/análise , Antineoplásicos/isolamento & purificação , Antineoplásicos/farmacologia , Antioxidantes/análise , Antioxidantes/isolamento & purificação , Antioxidantes/farmacologia , Flavonoides/análise , Flavonoides/isolamento & purificação , Flavonoides/farmacologia , Células Hep G2 , Humanos , Células MCF-7 , Extratos Vegetais/química , Resinas Sintéticas/química
4.
PLoS One ; 15(1): e0228249, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31990942

RESUMO

This ex vivo proof-of-concept study aimed to investigate the effect of nanosilver particles (AgNP) added to a conventional infiltrant resin (Icon) on external penetration into natural proximal enamel caries exceeding into dentin after internal tunnel preparation and internal infiltration. Carious lesions (ICDAS codes 2/3) of extracted human (pre-)molars revealing proximal caries radiographically exceeding into dentin (E2/D1 lesions) were preselected. Then, 48 of those specimens showing demineralized areas transcending the enamel-dentin border as assessed by means of near-infrared light transillumination (DIAGNOcam) were deproteinized (NaOCl, 5%). Using an internal tunnel approach, occlusal cavities central to the marginal ridge were prepared. Excavation of carious dentin, total etch procedure (H3PO4, 40%), and internal resin infiltration (FITC-labeled) followed, along with final restorations (flowable composite resin). Outer lesion surfaces were etched (HCl, 15%) prior to external infiltration (RITC-labeled). Group 1 (control; n = 24) used non-modified infiltrant, while an infiltrant/AgNP mixture (20 nm; 5.5 wt%) was used with experimental Group 2 (n = 24). Non-infiltrated pores of cut lesions were stained (Berberine), and specimens were analyzed using confocal laser scanning microscopy. Compared to the non-filled infiltrant, incorporation of AgNP had no effect on the resin's external penetration. Between the groups, no significant differences regarding internal or external infiltration could be detected, and non-infiltrated lesion areas did not differ significantly (p>0.109; t-test). The internal tunnel preparation in combination with both an internal resin infiltration and an additional external infiltration approach using a nanosilver-modified infiltrant resin leads to increased infiltrated lesion areas, thus occluding and adhesively stabilizing the porous volume of the demineralized enamel. While exerting antimicrobial effects by the nanosilver particles, this approach should have the potential as a viable treatment alternative for proximal lesions extending into dentin, thus avoiding the sacrifice of sound enamel, postponing the frequently inevitable restoration/re-restoration cycle of conventional proximal caries treatment, and improving dental health.


Assuntos
Cárie Dentária/metabolismo , Dentina/metabolismo , Nanopartículas Metálicas/química , Resinas Sintéticas/química , Resinas Sintéticas/metabolismo , Prata/química , Ouro/química , Teste de Materiais
5.
Chemosphere ; 241: 125122, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31683433

RESUMO

Resin adsorption is considered as a promising method to recover gold ions from wastewater, but further reduction reaction is required to convert gold ions into particles. In this study, a crosslinked polyethyleneimine resin (CPEIR) was developed via a suspension polymerization of polyethyleneimine (PEI) and ethylene glycol diglycidyl ether (EGDE) for gold recovery. The Au(III) adsorption capacities of CPEIR were significantly impacted by solution pH and initial Au(III) concentrations but unaffected by co-existing metal ions. Compared with commercial anion-exchange resin IRA400, the CPEIR exhibited higher sorption amount and selectivity for Au(III) due to its high density of amine and hydroxyl groups on the surfaces. The adsorption isotherm of Au(III) on CPEIR was well described by the Langmuir equation, and the maximum uptake amount of Au(III) was high up to 943.5 mg/g, much higher than the reported sorbents. The adsorption kinetic data on the CPEIR were fitted well by the Pseudo-second-order equation, and the intraparticle diffusion was found to be the rate-controlling process of Au(III) adsorption. X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD) analysis confirmed that Au(III) ions were adsorbed on the CPEIR via electrostatic attraction and chelating interaction, and subsequently the partial loaded Au(III) ions were reduced to elemental gold whereas the hydroxyl groups of CPEIR were oxidized to carbonyl groups.


Assuntos
Ouro/isolamento & purificação , Polietilenoimina/química , Águas Residuárias/química , Adsorção , Ouro/química , Concentração de Íons de Hidrogênio , Cinética , Espectroscopia Fotoeletrônica , Resinas Sintéticas/química , Difração de Raios X
6.
Artigo em Inglês | MEDLINE | ID: mdl-31647745

RESUMO

B-type fumonisins (FBs) are water-soluble mycotoxins produced by Fusarium species, which are mainly found in maize products and threaten food safety. Toxicological studies and quantitative determinations of fumonisins require large amounts of pure toxins, and their high prices limit progress in FBs research. In this study, we used a macroporous resin column combined with high-speed countercurrent chromatography to separate large quantities of FBs. A fermented rice culture was extracted with 75% methanol. The dynamic adsorption capacity of FBs on XAD-2 resin was 27.5 mg/g resin at 25°C, pH 4.0, and then the FBs were desorbed with 60% methanol. The crude FBs were further purified using a biphasic system consisting of n-heptane/n-butanol/methanol/water (2:4:1:4, v/v/v/v). The method yielded 1.55 g of FB1 and 0.55 g of FB3 with purities of 96.8% and 95.6%, respectively, from 1 kg of rice culture, and the final overall yield of FBs was 74.8%.


Assuntos
Fumonisinas/isolamento & purificação , Resinas Sintéticas/química , Distribuição Contracorrente , Fumonisinas/química , Tamanho da Partícula , Porosidade , Propriedades de Superfície
7.
Chemosphere ; 241: 125023, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31606573

RESUMO

Zwitterionic pharmaceuticals and personal care products can interact with adsorbents in different ways due to their various properties. In this work, the effects of hydrophobicity and electrostatic potential were explored through the adsorption of ciprofloxacin (CPX) and tetracycline (TC) onto multifunctional resins. Nonionic surface interaction was dominant for the adsorption on high-surface-area resin GMA10. Thereinto, hydrophobic and π-π interaction dominant for hydrophobic CPX and hydrophilic TC, respectively. Electrostatic interaction played an important role for high-anion-exchange-capacity resin GMA90. Upon their adsorption onto GMA50 resin, the relatively separated positive and negative electrostatic potentials of CPX+- due to the greater distance (∼12.33 Å) between the anionic and cationic groups led to electrostatic attraction and interaction (Ea = 8.64 ±â€¯0.31 kJ/mol) and the vertical orientation of molecule on the surface. However, TC+-0 displayed nonionic surface interaction (Ea = 7.96 ±â€¯0.14 kJ/mol) due to its relatively neutral electrostatic potential arising from the adjacent functional groups. Hence, the surface of GMA50 was covered with TC+-0 molecules adsorbed parallel to the surface, thereby restricting TC+-0 adsorption. Coexisted with monovalent salts, CPX adsorption was facilitated due to the salting-out effect. By contrast, the salting-out effect for TC was extremely weak, and TC adsorption was restrained due to the competitive adsorption of salts.


Assuntos
Adsorção , Resinas de Troca de Ânions/química , Cosméticos/química , Tensoativos/química , Ciprofloxacino/química , Ciprofloxacino/isolamento & purificação , Interações Hidrofóbicas e Hidrofílicas , Resinas Sintéticas/química , Sais , Eletricidade Estática , Tetraciclina/química , Tetraciclina/isolamento & purificação
8.
J Chromatogr A ; 1613: 460697, 2020 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-31733896

RESUMO

S9570-Fe(III), a modified chelating resin containing sulphonated monophosphonic acid bifunctional groups, was used for the fluoride removal from aqueous phase for the first time. The results specified that S9570-Fe(III) exhibited better adsorption towards the fluoride ions as compared to the other commonly used chelating resins having monofunctional group such as iminodiacetic acid, sulfonic acid or carboxylic acid. Adsorption thermodynamic and kinetic studies of S9570-Fe(III) chelating resin for the fluoride also have been carried out. The thermodynamic results demonstrated that the adsorption was a spontaneous process accompanied with a gradual decrease in entropy and the low temperature was favorable for the fluoride ion adsorption. The kinetic experiments showed that the resin exhibited a rapid initial adsorption behavior and the adsorption process more complied with the pseudo-second order reaction model which indicating that the whole adsorption process was controlled by a combined mechanism of intraparticle diffusion and chemical sorption. Adsorption mechanism of S9570-Fe(III) resin for fluoride ions was predicted. The study demonstrated the effectiveness of the phosphoric-sulfonic acid bifunctional group chelating resin to remove fluoride, and provided a novel type removal method for the fluoride.


Assuntos
Técnicas de Química Analítica/métodos , Fluoretos/isolamento & purificação , Ácidos Fosforosos/química , Resinas Sintéticas/química , Ácidos Sulfônicos/química , Adsorção , Quelantes/química , Compostos Férricos/química , Cinética , Termodinâmica , Água/química , Poluentes Químicos da Água/isolamento & purificação
9.
Food Chem ; 310: 125934, 2020 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31830713

RESUMO

Xylooligosaccharides (XOS) are booming in food, pharmacy and feed industries that they have attracted great interest in the high-value utilization of lignocellulose. Selective acidolysis dominates the commercial production of XOS except for intractable color contaminations derivate from ligoncellulosic degradation. Based on a detailed kinetics and thermodynamics investigation, Amberlite XAD-16N was designated as preferred decolorant because of its high adsorption-selectivity for XOS and the colored contaminants. The adsorption of the main compositions in lignocellulosic acidolysis solution was well described by Langmuir models, the kinetics were clearly fitted by Pseudo-second-order model, showing that the adsorption was controlled by electron sharing/transfer between the resin cross-linking groups and colorant. The adsorption mechanism was also verified by the adsorption-simulation of three detected typical colorants. The thermodynamics clearly indicated a spontaneous endothermic reaction. This study provides an important approach for industrial technology development to not only xylooligosaccharides production and lignocellulosic acidolysis, but also Amberlite XAD-16N adsorbent.


Assuntos
Glucuronatos/química , Oligossacarídeos/química , Resinas Sintéticas/química , Ácido Acético/química , Adsorção , Cor , Cinética , Lignina/química , Modelos Químicos , Pigmentos Biológicos/química , Termodinâmica , Zea mays/química
10.
Chem Commun (Camb) ; 56(6): 956-959, 2020 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-31858094

RESUMO

On-resin intramolecular native chemical ligation (NCL) assisted by N-ethylcysteine using Fmoc/SPPS to obtain cyclic peptides is described. N-terminal cysteine-containing peptides were subjected to NCL conditions leading to cyclization-cleavage reactions and consecutive S → N shift, rendering cyclic peptides in good yields and purities. The compounds were evaluated against P. falciparum 3D7.


Assuntos
Peptídeos Cíclicos/síntese química , Compostos de Sulfidrila/química , Cisteína/análogos & derivados , Cisteína/química , Estrutura Molecular , Peptídeos Cíclicos/química , Resinas Sintéticas/química
11.
Clin Nucl Med ; 45(2): e92-e93, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31876809

RESUMO

A 61-year-old woman with multiple hepatic metastases from uterus cervical cancer received Y radioembolization. The simultaneous time-of-flight (TOF) PET/MR clearly identified the untreated tumor parts on the posttherapeutic Y internal pair-production imaging. After another boosted Y injection, the metastatic hepatic tumors were well covered. The follow-up PET/MR revealed tumor shrinkage. The one-stop-shop TOF PET/MR provided useful follow-up information in patients receiving Y radioembolization.


Assuntos
Embolização Terapêutica , Neoplasias Hepáticas/diagnóstico por imagem , Imagem por Ressonância Magnética , Tomografia por Emissão de Pósitrons , Neoplasias do Colo do Útero/patologia , Radioisótopos de Ítrio/metabolismo , Radioisótopos de Ítrio/uso terapêutico , Feminino , Humanos , Cinética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/secundário , Microesferas , Pessoa de Meia-Idade , Imagem Multimodal , Resinas Sintéticas/química , Radioisótopos de Ítrio/química
12.
Int. j. morphol ; 37(4): 1557-1563, Dec. 2019. tab, graf
Artigo em Espanhol | LILACS | ID: biblio-1040169

RESUMO

La plastinación es una técnica anatómica de conservación cadavérica creada en 1977 por Gunther von Hagens, en Heidelberg, Alemania, y que sustituye los líquidos biológicos y/o de fijación por acetona, para luego impregar las muestras con distintas resinas, dependiendo de la técnica de plastinación desarrollada, para finalmente llevar a cabo la polimerización de los componentes incorporados a las muestras, para obtener muestras biológicas secas y totalmente duraderas. El objetivo de este trabajo consistió en desarrollar un protocolo de plastinación de cortes con resina poliéster (Biodur® P40) en secciones de 3 mm de espesor de cerebro humano. La muestras fueron fijadas y conservadas con formalina al 10 %. Los cerebros luego fueron seccionados con una maquina cortadora de tejidos, obteniéndose láminas delgadas de 3 mm de espesor. Inmediatamente los cortes de cerebro fueron colocados en deshidratación en acetona al 100 %, a -25 ºC, durante 7 días el primer baño de acetona, y durante otros 3 días más, para el segundo baño de acetona. Una vez deshidratados los cortes, estos fueron colocados en resina poliéster Biodur® P40 y se llevó a cabo la impregnación forzada de los cortes, en cámara de vacío a temperatura ambiente (20 ºC). Una vez finalizada la impregnación forzada, se procedió a la etapa de curado, la cual en primer lugar consiste en el armado de las cámaras de curado dentro de las cuales se colocaran los cortes con resina poliéster. Las cámaras de curado fueron colocadas bajo luz UV para acelerar la polimerización del poliéster y finalizar el proceso de plastinación. Se logró desarrollar satisfactoriamente en el Laboratorio de Plastinación y Técnicas Anatómicas de la Universidad de La Frontera un protocolo de plastinación de cortes con resina poliéster, obteniendo una excelente conservación de cortes de cerebro, con diferenciación de sustancias gris y blanca, y conservación de todas las características morfológicas.


Plastination is an anatomical technique of cadaveric conservation created in 1977 by Gunther von Hagens, in Heidelberg, Germany, and that substitutes biological and / or fixation fluids with acetone, to then impregnate the samples with different resins, depending on the developed plastination technique, to finally carry out the polymerization of the components incorporated into the samples, to obtain dry and totally durable biological samples. The aim of this work was to develop a sheet plastination protocol with polyester resin (Biodur® P40) in 3 mm thick slices of human brain. The samples were fixed and preserved with 10 % formalin. The brains were sectioned with a slice cut machine, obtaining thin sheets of 3 mm thick. Immediately the slices of brain were placed in dehydration in 100 % acetone, at -25 °C, for 7 days the first acetone bath, and for another 3 more days, for the second acetone bath. Once the cuts were dehydrated, they were placed in Biodur® P40 polyester resin and the forced impregnation was carried out in a vacuum chamber at room temperature (20 °C). Once the forced impregnation was finished, the curing stage was carried out, which first consists in the assembly of the curing chambers within which the slices with polyester resin were placed. The curing chambers were placed under UV light to accelerate the polymerization of the polyester and finished the plastination process. A sheet plastination protocol with polyester resin was successfully developed in the Laboratory of Plastination and Anatomical Techniques of Universidad de La Frontera, obtaining excellent conservation of brain slices, with differentiation of gray and white substances, and conservation of all morphological characteristics.


Assuntos
Humanos , Poliésteres/química , Resinas Sintéticas/química , Encéfalo/anatomia & histologia , /métodos , Protocolos Clínicos
13.
Braz Oral Res ; 33: e101, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31778472

RESUMO

The aim of this study was to evaluate the influence of different calcium phosphates (CaPs) on the physical, biological, and remineralizing properties of experimental resin-based sealants (RBSs). Triethylene-glycol dimethacrylate (90wt%) and bisphenol A-glycidyl methacrylate (10wt%) were used to produce resin-based sealants. Hydroxyapatite (SHAp), α-tricalcium phosphate (Sα-TCP) and octacalcium phosphate (SOCP) were added to the sealants in a 10wt% concentration. One group without CaPs was used as the control group (SCG). The degree of conversion (DC) was assessed with Fourier-transformed infrared spectroscopy, whereas cytotoxicity was tested with the HaCaT keratinocyte cell line. The ultimate tensile strength (UTS) was used to assess the mechanical strength of the experimental RBSs. Sealed enamel was used for colorimetric assay. Mineral deposition was assessed with Raman spectroscopy after 7, 14, and 28 days of sample immersion in artificial saliva. Scanning electron microscopy was used to analyze the surface morphology after 28 days of immersion. The addition of 10wt% of fillers significantly reduced the DC of sealants. SOCP groups showed reduced cell viability. Higher UTS was found for Sα-TCP and SHAp. The color analysis showed that SGC and demineralized teeth presented higher mismatches with the sound tissue. Mineral deposition was observed for SHAp and Sα-TCP after 7 days, with increased phosphate content and mineral deposits for SHAp after 28 days. RBS with the addition of 10% HAp promoted increased mineralization in vitro after 28 days, and did not affect cell viability, DC, mechanical properties, or RBS color in the enamel.


Assuntos
Fosfatos de Cálcio/química , Durapatita/química , Minerais/química , Selantes de Fossas e Fissuras/química , Resinas Sintéticas/química , Animais , Fosfatos de Cálcio/toxicidade , Bovinos , Linhagem Celular , Colorimetria , Esmalte Dentário/química , Esmalte Dentário/efeitos dos fármacos , Durapatita/toxicidade , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Selantes de Fossas e Fissuras/toxicidade , Valores de Referência , Reprodutibilidade dos Testes , Resinas Sintéticas/toxicidade , Saliva Artificial/química , Análise Espectral Raman , Propriedades de Superfície , Resistência à Tração , Fatores de Tempo
14.
Scanning ; 2019: 1289570, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31741697

RESUMO

The aim of this study was to evaluate the accuracy of two intraoral scanners used in the dental office. A molar fixed in a typodont was prepared for a ceramic onlay. The preparation was scanned using a high-resolution scanner (reference scanner) and saved as stereolithography (STL) format. The prepared resin molar was scanned again using the intraoral scanners, and all the scans were saved as well in STL format. All STL files were compared using metrology software (Geomagic Control X). Overlapping the meshes allowed the assessment of the scans in terms of trueness and precision. Based on the results of this study, the differences of trueness and precision between the intraoral scanners were minimal.


Assuntos
Armazenamento e Recuperação da Informação/normas , Microscopia Confocal/métodos , Dente Molar/diagnóstico por imagem , Tomografia de Coerência Óptica/métodos , Cerâmica/química , Humanos , Restaurações Intracoronárias/métodos , Lasers , Microscopia Confocal/instrumentação , Microscopia Confocal/normas , Resinas Sintéticas/química , Software , Tomografia de Coerência Óptica/instrumentação , Tomografia de Coerência Óptica/normas
15.
Colloids Surf B Biointerfaces ; 184: 110518, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31581054

RESUMO

A novel indole derivative (N-(1H-2-phenyl-indole-3-ylmethyl) acrylamide, NPI) synthesized by a Friedel-Crafts alkylation reaction was identified using IR spectroscopy, 1H NMR, 13C NMR and elemental analysis. The inhibitory effect of this novel indole derivative on bacteria and marine algae was studied. The results showed that the inhibition ratios of the indole derivative against Escherichia coli and Staphylococcus aureus were 95.93% and 94.91%, respectively, and the indole derivative possessed prominent inhibitory activity against Phaeodactylum tricornutum, Nitzschia Closterium and Skeletonema costatum. These findings indicate that the indole derivative has high biological activity. Subsequently, the indole derivative was introduced to acrylate resins by free-radical polymerization. The resulting acrylate resins were subjected to self-polishing, anti-algal and antifouling test, the results of which indicated that acrylate resins containing the synthesized indole derivative could exhibit significant antifouling properties because of the combination of the biofouling resistance of the indole derivative and the self-polishing properties of acrylate. This work provides an academic foundation for studying environmentally friendly and highly efficient antifouling coatings.


Assuntos
Acrilatos/farmacologia , Antibacterianos/farmacologia , Incrustação Biológica/prevenção & controle , Indóis/farmacologia , Resinas Sintéticas/farmacologia , Acrilatos/síntese química , Acrilatos/química , Antibacterianos/síntese química , Antibacterianos/química , Diatomáceas/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Indóis/química , Microalgas/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Tamanho da Partícula , Resinas Sintéticas/síntese química , Resinas Sintéticas/química , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície
16.
J Sep Sci ; 42(24): 3631-3639, 2019 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-31651081

RESUMO

The interactive behavior of an amphipathic peptide with the Cu2+ , Ni2+ , and Zn2+ complexes of 1,4-bis(triazacyclonon-1-yl)butane), bis(tacn)but , immobilized onto Sepharose CL-4B, has been investigated. The effects of incubation time, as well as the incubation buffer pH and ionic strength, have been examined. The binding data have been interrogated using Langmuir, Langmuir-Freundlich, bi-Langmuir, and Temkin isothermal models and Scatchard plots. These results confirm that this amphipathic peptide binds with relatively high capacities to the immobilized Cu2+ - and Ni2+ -1,4-bis(triazacyclonon-1-yl)butane)-Sepharose CL-4B sorbents via at least two discrete sites. However, the corresponding immobilized Zn2+ -sorbent had low binding capacity. Moreover, the magnitude of the binding capacities of these sorbents was dependent on the pH and ionic strength of the incubation buffer. These results are relevant to the isolation of E. coli expressed recombinant proteins that incorporate this and related amphipathic peptide tags, containing two or more histidine residues, located at the N- or C-terminus of the recombinant protein, and the co-purification of low abundance host cell proteins of diverse structure, by immobilized metal ion affinity chromatographic methods.


Assuntos
Quelantes/química , Ciclobutanos/química , Compostos Organometálicos/química , Tensoativos/química , Zinco/química , Adsorção , Cromatografia de Afinidade , Ciclobutanos/síntese química , Histidina/química , Concentração de Íons de Hidrogênio , Ligantes , Metais Pesados/química , Compostos Organometálicos/síntese química , Peptídeos/química , Resinas Sintéticas/química , Cloreto de Sódio/química , Propriedades de Superfície
17.
ACS Appl Mater Interfaces ; 11(45): 42594-42606, 2019 Nov 13.
Artigo em Inglês | MEDLINE | ID: mdl-31618002

RESUMO

Wearable pressure sensors are in great demand with the rapid development of intelligent electronic devices. However, it is still a huge challenge to obtain high-performance pressure sensors with high sensitivity, wide response range, and low detection limit simultaneously. Here, a polyimide (PI)/carbon nanotube (CNT) composite aerogel with the merits of superelastic, high porosity, robust, and high-temperature resistance was successfully prepared through the freeze drying plus thermal imidization process. Benefiting from the strong chemical interactions between PI and CNT and stable electrical property, the composite aerogel exhibits versatile and superior brilliant sensing performance, which includes wide sensing range (80% strain, 61 kPa), ultrahigh sensitivity (11.28 kPa-1), ultralow detection limit (0.1% strain, <10 Pa), fast response time (50 ms) and recovery time (70 ms), remarkable long-term stability (1000 cycles), and exceptional detection ability toward different deformations (compression, distortion, and bending). Furthermore, the composite aerogel also shows stable sensing performance after annealing under different high temperatures and good thermal insulation property, making it workable in various harsh environments. As a result, the composite aerogel is suitable for the full-range human motion detection (including airflow, pulse, vocal cord vibration, and human movement) and precise detection of the pressure distribution when it is assembled into E-skin, demonstrating its great potential to serve as a high-performance wearable pressure sensor.


Assuntos
Eletrônica/instrumentação , Nanotubos de Carbono/química , Resinas Sintéticas/química , Géis/química , Humanos , Limite de Detecção , Porosidade , Pressão
18.
Int J Biol Macromol ; 141: 738-746, 2019 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499105

RESUMO

Dextran-chitosan (DC) macromolecule resin was synthesized by ultrasonic heating and applied to adsorb various heavy metal ions (Cu2+, Co2+, Ni2+, Pb2+, Cd2+). The morphology and structure of the samples were characterized by various testing methods. The effects of five factors on the adsorption properties were studied. The adsorption kinetics, thermodynamics and isotherm models were discussed theoretically. The results show that the adsorption of heavy metal ions by DC resin is a spontaneous single molecule chemical adsorption, and the adsorption capacities of DC resin for Cu2+, Co2+, Ni2+, Pb2+ and Cd2+ were 342 mg g-1, 232 mg g-1, 184 mg g-1, 395 mg g-1, and 269 mg g-1, respectively at 20 °C, pH = 7 and adsorbent dose is 0.01 g. In addition, DC resin adsorbent has good reusability.


Assuntos
Quitosana/química , Dextranos/química , Metais Pesados/química , Metais Pesados/isolamento & purificação , Resinas Sintéticas/química , Purificação da Água/métodos , Água/química , Adsorção , Cinética , Soluções , Poluentes Químicos da Água/química , Poluentes Químicos da Água/isolamento & purificação
19.
PLoS One ; 14(7): e0220258, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31339963

RESUMO

Implantable neural probes are widely used to record and stimulate neural activities. These probes should be stiff enough for insertion. However, it should also be flexible to minimize tissue damage after insertion. Therefore, having dynamic control of the neural probe shank flexibility will be useful. For the first time, we have successfully fabricated flexible neural probes with embedded microfluidic channels for dynamic control of neural probe stiffness by controlling fluidic pressure in the channels. The present hybrid neural probes consisted of polydimethylsiloxane (PDMS) and polyimide (PI) layers could provide the required stiffness for insertion and flexibility during operation. The PDMS channels were fabricated by reversal imprint using a silicon mold and bonded to a PI layer to form the embedded channels in the neural probe. The probe shape was patterned using an oxygen plasma generated by an inductively coupled plasma etching system. The critical buckling force of PDMS/PI neural probes could be tuned from 0.25-1.25 mN depending on the applied fluidic pressure in the microchannels and these probes were successfully inserted into a 0.6% agarose gel that mimicked the stiffness of the brain tissue. Polymer-based neural probes are typically more flexible than conventional metal wire-based probes, and they could potentially provide less tissue damage after implantation.


Assuntos
Dimetilpolisiloxanos/química , Eletrodos Implantados , Microfluídica/instrumentação , Neurônios/fisiologia , Resinas Sintéticas/química , Fenômenos Biomecânicos , Técnicas de Diagnóstico Neurológico/instrumentação , Desenho de Equipamento , Humanos , Teste de Materiais , Microtecnologia/métodos , Neurônios/efeitos dos fármacos , Maleabilidade , Polímeros/síntese química , Polímeros/química , Pressão
20.
Molecules ; 24(14)2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-31340484

RESUMO

In order to enrich and separate three coumarins (columbianetin acetate, osthole and columbianadin) from Angelicae Pubescentis Radix (APR), an efficient method was established by combining macroporous resins (MARs) with preparative high-performance liquid chromatography (PHPLC). Five different macroporous resins (D101, AB-8, DA-201, HP-20 and GDX-201) were used to assess the adsorption and desorption characteristics of three coumarins. The result demonstrated that HP-20 resin possessed the best adsorption and desorption capacities for these three coumarins. Moreover, the adsorption dynamics profiles of three coumarins were well fitted to the pseudo second order equation (R2 > 0.99) for the HP-20 resin. The adsorption process was described by the three isotherms models including Langmuir (R2 > 0.98, 0.046 ≤ RL ≤ 0.103), Freundlich (R2 > 0.99, 0.2748 ≤ 1/n ≤ 0.3103) and Dubinin Radushkevich (R2 > 0.97). The contents of columbianetin acetate, osthole and columbianadin in the product were increased 10.69-fold, 19.98-fold and 19.68-fold after enrichment, respectively. Three coumarins were further purified by PHPLC and the purities of them reached above 98%. Additionally, the anti-inflammatory effects of these three coumarins were assessed by Lipopolysaccharide (LPS)-induced RAW 264.7 cells. It was found that the production of NO and MCP-1 was obviously inhibited by three coumarins. Columbianetin acetate, osthole and columbianadin could be used as potentially natural anti-inflammatory ingredients in pharmaceutical products. It was concluded that the new method combining MARs with PHPLC was efficient and economical for enlarging scale separation and enrichment of columbianetin acetate, osthole and columbianadin with anti-inflammatory effect from the APR extract.


Assuntos
Angelica/química , Anti-Inflamatórios/farmacologia , Cumarínicos/farmacologia , Medicamentos de Ervas Chinesas/química , Furocumarinas/farmacologia , Adsorção , Animais , Anti-Inflamatórios/isolamento & purificação , Quimiocina CCL2/genética , Quimiocina CCL2/imunologia , Cromatografia Líquida de Alta Pressão/instrumentação , Cromatografia Líquida de Alta Pressão/métodos , Cumarínicos/isolamento & purificação , Furocumarinas/isolamento & purificação , Expressão Gênica/efeitos dos fármacos , Lipopolissacarídeos/antagonistas & inibidores , Lipopolissacarídeos/farmacologia , Camundongos , Óxido Nítrico/antagonistas & inibidores , Óxido Nítrico/biossíntese , Óxido Nítrico/imunologia , Porosidade , Células RAW 264.7 , Resinas Sintéticas/química
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