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1.
J Food Sci Technol ; 58(11): 4263-4269, 2021 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34538909

RESUMO

Sonochemistry was applied in the last few years for coating surfaces of various substrates for imparting desired properties to the surface. In the current paper the coating of cucumbers with NaCl nanoparticles and apples with honey nanoparticles was accomplished by applying the sonochemical method. In both coating the nanoparticles were deposited from aqueous solutions. The products were characterized by Inductively coupled plasma, Dynamic light scattering, Scanning electron microscopy, and Nuclear magnetic resonance.

2.
Langmuir ; 36(16): 4280-4288, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32271580

RESUMO

Two crystalline and five amorphous benzimidazole polymers (BINP) were synthesized and conjugated to porous silica via amine and aldehyde-based materials by a simple reflux procedure. The resulting polymers were subject to thermal analysis for monitoring and quantification of the adsorption and desorption of CO2. All the polymers were capable of adsorbing CO2 from a flowing stream of only 80 mL/min at 25 °C. The adsorbed CO2 onto the polymers were effectively desorbed at room temperature, illustrating the potential application of such polymers for repeated adsorption/desorption of CO2. The CO2 adsorption capacities of these polymers were dependent upon their nitrogen content, specific surface area, and pore size. The available nitrogen atoms for binding to the carbon of CO2 via tetrel bonds also plays an important role in the capture of this gas. Minimal and much lower CO2 adsorption was also noted with two crystalline polymers, compared to the five amorphous counterparts. Intermolecular hydrogen bonding and π-π interaction effectively prevented the polymer N sites of the crystalline polymers from interacting with polarized CO2 molecules.

3.
Appl Microbiol Biotechnol ; 101(4): 1443-1454, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27744556

RESUMO

Chronic wound fluids have elevated concentration of human neutrophil elastase (HNE) which can be used as inflammation/infection marker. Our goal is to develop functional materials for fast diagnosis of wound inflammation/infection by using HNE as a specific marker. For that, fluorogenic peptides with a HNE-specific cleavage sequence were incorporated into traditional textile dressings, to allow real-time detection of the wound status. Two different fluorogenic approaches were studied in terms of intensity of the signal generated upon HNE addition: a fluorophore 7-amino-4-trifluormethylcoumarin (AFC) conjugated to a HNE-specific peptide and two fluorophore/quencher pairs (FAM/Dabcyl and EDANS/Dabcyl) coupled to a similar peptide as a Förster resonance energy transfer (FRET) strategy. Also, two immobilization methods were tested: sonochemistry immobilization onto a cotton bandage and glutaraldehyde (GTA)-assisted chemical crosslinking onto a polyamide dressing. The immobilized fluorogenic AFC peptide showed an intense fluorescence emission in the presence of HNE. HNE also induced an enhanced fluorescent signal with the EDANS/Dabcyl FRET peptide which showed to be a more sensitive and effective strategy than the AFC peptide. However, its chemical immobilization onto the polyamide dressing greatly decreased its detection, mainly due to the more difficult access of the enzyme to the cleavage sequence of the immobilized peptide. After optimization of the in situ immobilization, it will be possible to use these fluorescence-functionalized dressings for an effective and specific monitoring of chronic wounds by simply using a portable ultraviolet (UV) light source. We envision that the development of this point-of-care medical device for wound control will have a great impact on patient's life quality and reduction of costs on health care system.


Assuntos
Inflamação/enzimologia , Elastase de Leucócito/metabolismo , Bandagens , Transferência Ressonante de Energia de Fluorescência , Humanos , Raios Ultravioleta
4.
J Environ Manage ; 177: 20-5, 2016 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-27064733

RESUMO

A microwave assisted feasible process for the production of bioethanol from Ficus religiosa leaves was developed. Under the process conditions (8 min. microwave irradiation, 1 M HCl), 10.1 wt% glucose yield was obtained from the leaves. Microwave based hydrolysis process yielded higher glucose content (10.1 wt%) compared to the conventional hydrothermal process (4.1 wt%). Upon fermentation of the hydrolysate using Baker's yeast, 3 wt% (dry wt. basis) of bioethanol was produced.


Assuntos
Biocombustíveis , Etanol/química , Ficus/química , Micro-Ondas , Biomassa , Fermentação , Glucose/metabolismo , Hidrólise , Folhas de Planta , Saccharomyces cerevisiae/metabolismo
5.
Phys Chem Chem Phys ; 16(16): 7521-30, 2014 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-24626876

RESUMO

The CuO-ZnO composite was deposited onto two kinds of titania supports, which are synthetic mesoporous TiO2 and commercial TiO2 P25 (Degussa), via the ultrasound assisted precipitation and incipient wetness impregnation (IWI) methods, respectively. The catalysts were tested for WGS reaction in the temperature range of 200-400 °C, and the best catalytic performance was achieved for the sonochemically prepared catalysts supported on the commercial TiO2 P25, which contains well crystallized anatase and rutile phases. Although the synthetic mesoporous TiO2 has a higher surface area, its textural structure is not stable under the reaction conditions, leading to gradual deactivation of the CuO-ZnO/TiO2 catalyst. It is found that the sonochemical preparation offers at least two advantages: (1) generation of mesopores on the catalyst surface and (2) doping of ZnO into the CuO phase. The doping of ZnO, particularly in the case of commercial TiO2 P25, provides high activity and extra stability to the active phase of Cu(0). These new findings provide new insights into the design and development of better heterogeneous catalysts for WGS reaction.

6.
ACS Appl Bio Mater ; 7(2): 990-998, 2024 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-38226433

RESUMO

Catheter-associated urinary tract infections (CAUTI) are among the most common bacterial infections associated with prolonged hospitalization and increased healthcare expenditures. Despite recent advances in the prevention and treatment of these infections, there are still many challenges remaining, among them the creation of a durable catheter coating, which prevents bacterial biofilm formation. The current work reports on a method of protecting medical tubing endowed with antibiofilm properties. Silicone catheters coated sonochemically with ZnO nanoparticles (NPs) demonstrated excellent antibiofilm effects. Toward approval by the European Medicines Agency, it was realized that the ZnO coating would not withstand the regulatory requirements of avoiding dissolution for 14 days in artificial urine examination. Namely, after exposure to urine for 14 days, the coating amount was reduced by 90%. Additional coatings with either carbon or silica maintained antibiofilm activity against Staphylococcus aureus while resisting dissolution in artificial urine for 14 days (C- or SiO2-protected catheters exhibited only 29% reduction). HR-SEM images of the protected catheters indicate the presence of the ZnO coating as well as the protective layer. Antibiofilm activity of all catheters was evaluated both before and after exposure to artificial urine. It was shown that before artificial urine exposure, all coated catheters showed high antibiofilm properties compared to the uncoated control. Exposure of ZnO-coated catheters, without the protective layer, to artificial urine had a significant effect exhibited by the decrease in antibiofilm activity by almost 2 orders of magnitude, compared to unexposed catheters. Toxicity studies performed using a reconstructed human epidermis demonstrated the safety of the improved coating. Exposure of the epidermis to ZnO catheter extracts in artificial urine affects tissue viability compared with control samples, which was not observed in the case of ZnO NPs coating with SiO2 or C. We suggest that silica and carbon coatings confer some protection against zinc ions release, improving ZnO coating safety.


Assuntos
Aparelho Sanitário , Óxido de Zinco , Humanos , Óxido de Zinco/farmacologia , Dióxido de Silício/farmacologia , Biofilmes , Antibacterianos/farmacologia , Catéteres , Carbono
7.
Small ; 9(23): 4069-76, 2013 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-23813908

RESUMO

Zinc-doped copper oxide nanoparticles are synthesized and simultaneously deposited on cotton fabric using ultrasound irradiation. The optimization of the processing conditions, the specific reagent ratio, and the precursor concentration results in the formation of uniform nanoparticles with an average size of ≈30 nm. The antibacterial activity of the Zn-doped CuO Cu0.88Zn0.12O in a colloidal suspension or deposited on the fabric is tested against Escherichia coli (Gram negative) and Staphylococcus aureus (Gram positive) bacteria. A substantial enhancement of 10,000 times in the antimicrobial activity of the Zn-CuO nanocomposite compared to the pure CuO and ZnO nanoparticles (NPs) is observed after 10 min exposure to the bacteria. Similar activities are observed against multidrug-resistant bacteria (MDR), (i.e., Methicillin-resistant S. aureus and MDR E. coli) further emphasizing the efficacy of this composite. Finally, the mechanism for this enhanced antibacterial activity is presented.


Assuntos
Antibacterianos/farmacologia , Cobre/química , Nanocompostos/química , Óxido de Zinco/química , Antibacterianos/química , Farmacorresistência Bacteriana Múltipla , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Staphylococcus aureus/efeitos dos fármacos
8.
Chemistry ; 18(15): 4575-82, 2012 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-22407609

RESUMO

Titanium oxide (TiO(2)) nanoparticles (NPs) in their two forms, anatase and rutile, were synthesized and deposited onto the surface of cotton fabrics by using ultrasonic irradiation. The structure and morphology of the nanoparticles were analyzed by using characterization methods such as XRD, TEM, STEM, and EDS. The antimicrobial activities of the TiO(2)-cotton composites were tested against Escherichia coli (gram-negative) and Staphylococcus aureus (gram-positive) strains, as well as against Candida albicans. Significant antimicrobial effect was observed, mainly against Staphylococcus aureus. In addition, the combination of visible light and TiO(2) NPs showed enhanced antimicrobial activity.


Assuntos
Anti-Infecciosos/química , Materiais Revestidos Biocompatíveis/química , Escherichia coli/efeitos dos fármacos , Nanopartículas/química , Staphylococcus aureus/efeitos dos fármacos , Titânio/química , Titânio/farmacologia , Materiais Revestidos Biocompatíveis/farmacologia , Têxteis
9.
ACS Appl Mater Interfaces ; 14(21): 24850-24855, 2022 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-35585796

RESUMO

The demand for improved indoor air quality, especially during the pandemic of Covid-19, has led to renewed interest in antiviral and antibacterial air-conditioning systems. Here, air filters of vehicles made of nonwoven polyester filter media were sonochemically coated with CuO nanoparticles by a roll-to-roll coating method. The product, aimed at providing commuters with high air quality, showed good stability and mechanical properties and potent activity against Escherichia coli and Staphylococcus aureus bacteria, H1N1 influenza, and two SARS-CoV-2 variants. The filtering properties of a coated filter were tested, and they were similar to those of the uncoated filter. Leaching tests as a function of airflow were conducted, and the main outcome was that the coating was stable and particles were not detached from the coated media. Extension to other air-conditioning systems was straightforward.


Assuntos
Filtros de Ar , COVID-19 , Vírus da Influenza A Subtipo H1N1 , Antibacterianos/química , Antibacterianos/farmacologia , Antivirais/química , Antivirais/farmacologia , Automóveis , Cobre , Escherichia coli , Humanos , SARS-CoV-2
10.
Langmuir ; 27(2): 720-6, 2011 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-21155556

RESUMO

Colloidal silver has gained wide acceptance as an antimicrobial agent, and various substrates coated with nanosilver such as fabrics, plastics, and metal have been shown to develop antimicrobial properties. Here, a simple method to develop coating of colloidal silver on paper using ultrasonic radiation is presented, and the coatings are characterized using X-ray diffraction (XRD), high resolution scanning electron microscope (HRSEM), and thermogravimetry (TGA) measurements. Depending on the variables such as precursor concentrations and ultrasonication time, uniform coatings ranging from 90 to 150 nm in thickness have been achieved. Focused ion beam (FIB) cross section imaging measurements revealed that silver nanoparticles penetrated the paper surface to a depth of more than 1 µm, resulting in highly stable coatings. The coated paper demonstrated antibacterial activity against E. coli and S. aureus, suggesting its potential application as a food packing material for longer shelf life.


Assuntos
Anti-Infecciosos/química , Nanopartículas Metálicas/química , Prata/química , Anti-Infecciosos/farmacologia , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Papel , Tamanho da Partícula , Staphylococcus aureus/efeitos dos fármacos , Propriedades de Superfície , Ultrassom , Difração de Raios X
11.
Phys Chem Chem Phys ; 13(34): 15690-8, 2011 Sep 14.
Artigo em Inglês | MEDLINE | ID: mdl-21799973

RESUMO

The preferential oxidation (PROX) of CO in the presence of H(2) is an important step in the production of pure H(2) for industrial applications. In this report, two sonochemical methods (S1 and S2) were used to prepare highly dispersed Ru catalysts supported on mesoporous TiO(2) (TiO(2)(MSP)) for the PROX reaction, in which a reaction gas mixture containing 1% CO + 1% O(2) + 18% CO(2) + 78% H(2) was used. The supported Ru catalysts performed better than the supported Au and Pt catalysts, and the S1 and S2 methods are superior to the impregnation method. The Ru/TiO(2)(MSP) catalysts were active for the PROX reaction below 200 °C and good for the methanation reactions of CO and CO(2) above 200 °C. The presence of residual chlorine in the catalysts severely suppressed their PROX reaction activity, and a higher dispersion of Ru particles led to better catalytic performances. The addition of Au in the Ru/TiO(2)(MSP) catalyst also caused a poorer catalytic activity for both the PROX and the methanation reactions. TPR results showed that in the active catalysts prepared by the S1 and S2 methods, the well dispersed Ru particles, after calcination in air, had a stronger interaction with the support than those in the catalyst prepared by the impregnation method and in the Au-Ru/TiO(2)(MSP) catalyst. In situ CO absorption experiments performed with the diffusion reflectance Fourier transform infra red (DRIFT) method showed that the bridged adsorbed CO species on isolated Ru(0) sites correlated with the catalytic performances, indicating that these isolated Ru(0) sites are the most active sites of the Ru/TiO(2)(MSP) catalysts in the PROX reaction.

12.
Membranes (Basel) ; 11(7)2021 Jun 22.
Artigo em Inglês | MEDLINE | ID: mdl-34206493

RESUMO

Simultaneous water and ethanol-based synthesis and coating of copper and zinc oxide (CuO/ZnO) nanoparticles (NPs) on bandages was carried out by ultrasound irradiation. High resolution-transmission electron microscopy demonstrated the effects of the solvent on the particle size and shape of metal oxide NPs. An antibacterial activity study of metal-oxide-coated bandages was carried out against Staphylococcus aureus (Gram-positive) and Escherichia coli (Gram-negative). CuO NP-coated bandages made from both water and ethanol demonstrated complete killing of S. aureus and E. coli bacteria within 30 min., whereas ZnO NP-coated bandages demonstrated five-log reductions in viability for both kinds of bacteria after 60 min of interaction. Further, the antibacterial mechanism of CuO/ZnO NP-coated bandages is proposed here based on electron spin resonance studies. Nanotoxicology investigations were conducted via in vivo examinations of the effect of the metal-oxide bandages on frog embryos (teratogenesis assay-Xenopus). The results show that water-based coatings resulted in lesser impacts on embryo development than the ethanol-based ones. These bandages should therefore be considered safer than the ethanol-based ones. The comparison between the toxicity of the metal oxide NPs prepared in water and ethanol is of great importance, because water will replace ethanol for bulk scale synthesis of metal oxide NPs in commercial companies to avoid further ignition problems. The novelty and importance of this manuscript is avoiding the ethanol in the typical water:ethanol mixture as the solvent for the preparation of metal oxide NPs. Ethanol is ignitable, and commercial companies are trying the evade its use. This is especially important these days, as the face mask produced by sonochemistry (SONOMASK) is being sold all over the world by SONOVIA, and it is coated with ZnO.

13.
Nanomaterials (Basel) ; 10(7)2020 Jul 16.
Artigo em Inglês | MEDLINE | ID: mdl-32708543

RESUMO

There is a huge demand for materials capable of simple detection or separation after conjugation with specific biologic substances when applied as a diagnostic tools. Taking into account the photoluminescence properties of C-dots and the highly magnetic properties of Fe(0), a new hybrid composite of these components was synthesized via ultrasound irradiation. The material was fully characterized by various physicochemical techniques. The main goal of the current study was to obtain a highly magnetic and intense fluorescent hybrid material. The goal was achieved. In addition, magnetic particles tended to agglomerate. The new hybrid can be suspended in ethanol, which is an additional feature of the current research. The dispersion of the hybrid nanoparticles in ethanol was achieved by utilizing the interaction of iron particles with C-dots which were decorated with functional groups on their surface. The newly formed hybrid material has potential applications in diagnostic by conjugating with specific antibodies or with any other biologic compounds. Such application may be useful in detection of various diseases such as: cancer, tuberculosis, etc.

14.
Bioconjug Chem ; 20(8): 1497-502, 2009 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-21141805

RESUMO

Interactions between biomolecules and nanoparticles suggest the use of nanoparticles for various medical interventions. The attachment and entry of herpes simplex virus type 1 (HSV-1) into cells involve interaction between viral envelope glycoproteins and cell surface heparan sulfate (HS). Based on this mechanism, we designed silver nanoparticles that are capped with mercaptoethane sulfonate (Ag-MES). These nanoparticles are predicted to target the virus and to compete for its binding to cellular HS through their sulfonate end groups, leading to the blockage of viral entry into the cell and to the prevention of subsequent infection. Structurally defined Ag-MES nanoparticles that are readily redispersible in water were sonochemically synthesized. No toxic effects of these nanoparticles on host cells were observed. Effective inhibition of HSV-1 infection in cell culture by the capped nanoparticles was demonstrated. However, application of the soluble surfactant MES failed to inhibit viral infection, implying that the antiviral effect of Ag-MES nanoparticles is imparted by their multivalent nature and spatially directed MES on the surface. Our results suggest that capped nanoparticles may serve as useful topical agents for the prevention of infections with pathogens dependent on HS for entry.


Assuntos
Antivirais/farmacologia , Herpesvirus Humano 1/efeitos dos fármacos , Herpesvirus Humano 1/fisiologia , Mesna/farmacologia , Nanopartículas/química , Compostos Organometálicos/farmacologia , Prata/farmacologia , Antivirais/química , Herpesvirus Humano 1/isolamento & purificação , Mesna/química , Testes de Sensibilidade Microbiana , Compostos Organometálicos/síntese química , Compostos Organometálicos/química , Tamanho da Partícula , Prata/química , Propriedades de Superfície
15.
Ultrason Sonochem ; 16(1): 132-5, 2009 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-18567528

RESUMO

Sonochemical irradiation of iron (II) acetate aqueous solution in presence of silver nanopowder resulted in deposition of magnetite nanoparticles on silver nanocrystals, and imparted them with magnetic properties. The Ag-Fe(3)O(4) nanocomposite is well attracted to a permanent magnet, and demonstrates superparamagnetic behavior typical of nanomaterials in a magnetic field. The characterization of the product by X-ray diffraction (XRD), transmission electron microscopy (TEM), high resolution transmission electron microscopy (HR TEM), energy-dispersive X-ray analysis (EDX), and X-ray photoelectron spectroscopy (XPS) reveal the presence of two phases of the silver and the magnetite, but no chemical interaction between them has been found. The strong anchoring of magnetite to the nanosilver surface was explained as a result of local melting of silver when the magnetite nucleus is thrown at the silver surface by high speed sonochemical microjets.

16.
Mater Sci Eng C Mater Biol Appl ; 102: 164-170, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31146987

RESUMO

Antimicrobial textiles can contribute to the fighting against antibiotic resistance pathogenic microorganisms. Polypyrrole is a conjugated polymer that exerts a biocidal action thanks to positive charges on its backbone chain produced during it synthesis. In this work, dispersions of stable polypyrrole nanoparticles were produced by chemical oxidative polymerization at room temperature in water. An ultrasound-assisted coating process was then used to effectively treat a polyester fabric with the nanoparticles to obtain an optimal antibacterial coating which efficiently eradicates the bacteria. The results showed that the treated fabric with about 4 g/m2 of polypyrrole had log bacteria reductions of 6.0 against Staphylococcus aureus and 7.5 against Escherichia coli. The combination of a polypyrrole synthesis in the form of water nanoparticles dispersions and a continuous coating of fabrics supported by ultrasound overcomes some issues of upscaling of the traditional in-situ chemical deposition used until now for the production of polypyrrole-coated textiles.


Assuntos
Antibacterianos/farmacologia , Polímeros/farmacologia , Pirróis/farmacologia , Têxteis , Ultrassom , Escherichia coli/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Nanopartículas/química , Espectroscopia de Infravermelho com Transformada de Fourier , Staphylococcus aureus/efeitos dos fármacos , Termogravimetria , Viscosidade
17.
Curr Med Chem ; 25(41): 5739-5754, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29284390

RESUMO

In this review, we report the functionalization of textiles composed of nanoscale reactive materials in the treatment of wounds and skin diseases such as acne. In view of the growing demand for high-quality textiles, much research is focused on the creation of antimicrobial finishings for fabrics, in order to protect customers from pathogenic or odorgenerating microorganisms. We present coatings from inorganic, organic and biochemical nanoparticles (NPs) on surfaces that impart the ability to kill bacteria, avoid biofilm formation and speed up the recovery of wounds. In all three cases, sonochemistry is used for immobilizing the nanoparticles on the surfaces. The Introduction broadly covers the progress of nanotechnology in the fields of wound and skin care. The first section of this review outlines the mechanism of the ultrasound-assisted deposition of nanoparticles on textiles. The coating can be performed by an in-situ process in which the nanoparticles are formed and subsequently thrown onto the surface of the fabrics at a very high speed. This approach was used in depositing metal-oxide NPs such as ZnO, CuO and Zn-CuO or the organic NPs of tannic acid, chitosan, etc. on textiles. In addition, the sonochemical process can be used as a "throwing stone" technique, namely, previously synthesized or commercially purchased NPs can be placed in the sonication bath and sonicated in the presence of the fabric. The collapse of the acoustic bubble in the solution causes the throwing of the immersed commercial NPs onto the textiles. This section will also outline why sonochemical deposition on textiles is considered the best coating technique. The second section will discuss new applications of the sonochemically- coated textiles in killing bacteria, avoiding biofilm formation and more. Two points should be noted: 1) the review will primarily report results obtained at Bar-Ilan University and 2) since for all textiles tested in our experiments (cotton, polyester, nylon, nonwoven) similar results were obtained, the type of textile used in a specific experiment will not be mentioned - textiles will be discussed in general. It is also worth emphasizing that this review concentrates only on the sonochemical coating of textiles, ignoring other deposition techniques.


Assuntos
Anti-Infecciosos/farmacologia , Higiene da Pele/métodos , Têxteis , Ondas Ultrassônicas , Cicatrização/efeitos dos fármacos , Animais , Quitosana/química , Materiais Revestidos Biocompatíveis/química , Cobre/química , Humanos , Nanopartículas/química , Nylons/química , Preparações Farmacêuticas , Poliésteres/química , Propriedades de Superfície , Taninos/química , Óxido de Zinco/química
18.
Bioresour Technol ; 224: 333-341, 2017 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-27810248

RESUMO

This report presents a method for producing large quantities of biodiesel from waste cooking oil (WCO). Preliminary studies on optimization of the WCO transesterification process in a continuous-flow microwave reactor are carried out using commercial SrO as a catalyst. The SrO catalyst can be separated and reused for five reaction cycles without loss in activity. Challenges like mass flow and pressure drop constraints need to be surmounted. SrO nanoparticles deposited on millimeter-sized (3-6mm) silica beads (41wt% SrO/SiO2) are prepared and evaluated as a substitute for the SrO catalyst. A WCO conversion value to biodiesel as high as 99.2wt% was achieved with the reactor packed with 15g of 41wt% SrO/SiO2 catalyst in 8.2min with 820mL of feed. Excellent performance of the fixed-bed catalyst without loss in activity for a lifetime of 24.6min converting a feed of 2.46L to FAME was observed.


Assuntos
Biocombustíveis , Micro-Ondas , Nanopartículas/química , Óleos de Plantas/química , Estrôncio/química , Gerenciamento de Resíduos , Catálise , Esterificação , Óxidos/química
19.
Otol Neurotol ; 38(8): e224-e231, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28806330

RESUMO

: Cochlear implants (CI) restore functional hearing in the majority of deaf patients. Despite the tremendous success of these devices, some limitations remain. The bottleneck for optimal electrical stimulation with CI is caused by the anatomical gap between the electrode array and the auditory neurons in the inner ear. As a consequence, current devices are limited through 1) low frequency resolution, hence sub-optimal sound quality and 2), large stimulation currents, hence high energy consumption (responsible for significant battery costs and for impeding the development of fully implantable systems). A recently completed, multinational and interdisciplinary project called NANOCI aimed at overcoming current limitations by creating a gapless interface between auditory nerve fibers and the cochlear implant electrode array. This ambitious goal was achieved in vivo by neurotrophin-induced attraction of neurites through an intracochlear gel-nanomatrix onto a modified nanoCI electrode array located in the scala tympani of deafened guinea pigs. Functionally, the gapless interface led to lower stimulation thresholds and a larger dynamic range in vivo, and to reduced stimulation energy requirement (up to fivefold) in an in vitro model using auditory neurons cultured on multi-electrode arrays. In conclusion, the NANOCI project yielded proof of concept that a gapless interface between auditory neurons and cochlear implant electrode arrays is feasible. These findings may be of relevance for the development of future CI systems with better sound quality and performance and lower energy consumption. The present overview/review paper summarizes the NANOCI project history and highlights achievements of the individual work packages.


Assuntos
Implante Coclear/instrumentação , Implantes Cocleares , Estimulação Elétrica/instrumentação , Nanotecnologia/instrumentação , Animais , Cóclea/fisiologia , Implantes Cocleares/tendências , Cobaias , Audição/fisiologia , Humanos , Neurônios/fisiologia
20.
Artigo em Inglês | MEDLINE | ID: mdl-26925347

RESUMO

The sonochemical technique has already been proven as one of the best coating methods for stable functionalization of substrates over a wide range of applications. Here, we report for the first time on the simultaneous sonochemical dyeing and coating of textiles with antibacterial metal oxide (MO) nanoparticles. In this one-step process the antibacterial nanoparticles are synthesized in situ and deposited together with dye nanoparticles on the fabric surface. It was shown that the antibacterial behavior of the metal oxides was not influenced by the presence of the dyes. Higher K/S values were achieved by sonochemical deposition of the dyes in comparison to a dip-coating (exhaustion) process. The stability of the antibacterial properties and the dye fastness was studied for 72 h in saline solution aiming at medical applications.

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