Water-Polymer Slide Electrification in Polyethylene Films Coated with Amphiphilic Compounds and Its Connection to Surface Properties Dependent on Water-Polymer Interactions.

Slide electrification experiments were performed on low-density polyethylene films () and sprayed with five amphiphilic compounds, including antistatic and slip additives. Drops of aqueous solutions were delivered on the films and after sliding spontaneously acquired a net electrical charge (), which is dependent on the pH and ionic strength. The slide electrification was detected in pristine films and those with five additives.

From the Lab to the Field: Organic Materials for Industrial Applications and Environmental Remediation.

Many new developments for different industries have their origin in basic science. In recent years, this trend has gained attention due to the increasing interaction between academic science and industry. This article presents some rational materials for chemical modifications that were developed by the basic science, then transferred to the productive sector.

Hemicelluloses hydrogel: Synthesis, characterization, and application in dye removal.

Novel materials using biowaste as adsorbents in wastewater treatment have been allocated considerable interest. Herein, we present the synthesis of different hydrogels of crosslinked polyacrylamide in presence of hemicelluloses with/ without bentonite, using a soft reaction condition. The structure of new hydrogels was characterized by spectroscopic, thermal and microscopic experiments.

Biofilm Formation of Two Different Marine Bacteria on Modified PDMS Surfaces is Affected by Surface Roughness and Topography.

Different strategies were tested to reduce biofilm formation of the model marine bacteria Cobetia marina and Marinobacter hydrocarbonoclasticus on cross-linked polydimethylsiloxane (PDMS) coated aluminum and cellulose acetate surfaces modified by addition of multi-walled carbon nanotubes (MWCNT) or exposure of the surfaces to bromine vapors in the presence and absence of UV irradiation. The three surface modifications explored led to important reductions in biofilm formation for the two marine bacteria, up to 30% in the case of exposure to Br(g). Biofouling reduction could be correlated to surface properties in all cases through the introduction of a quantitative theoretical model based on an effective roughness parameter, Ra, that accounted for the different morphological changes observed.

Liquid-Polymer Contact Electrification: Modeling the Dependence of Surface Charges and ξ-Potential on pH and Added-Salt Concentration.

Here, a mathematical model is presented, which accounts for the dependence of the surface electrical charge density (σ) on pH and the concentration of added salts (), generated when a water drop rolls or slides on the surface of a hydrophobic polymer, a process known as liquid-polymer contact electrification (LPCE). The same model was successfully applied to fit the isotherms of ξ-potential as a function of pH, reported in the literature by other authors for water-poly(tetrafluoroethylene) (PTFE) interfaces. Hence, the dependence of σ and ξ on pH was described using the same concept: acid-base equilibria at the water-polymer interface.

Antiviral activity against Zika virus of a new formulation of curcumin in poly lactic-co-glycolic acid nanoparticles.

Objectives: In the search of an effective antiviral formulation, the natural product curcumin (CUR) was encapsulated into poly(lactic-co-glycolic acid) nanoparticles, a non-toxic bioresorbable and biocompatible copolymer. The resulting CUR containing particles (PLGA-CUR NPs) were characterized and analysed for antiviral activity against Zika virus (ZIKV) infection.

Methods: The PLGA-CUR NPs were characterized by Fourier transform infrared, differential scanning calorimetry, dynamic light scattering, scanning electron microscopy and thermogravimetric analysis and release profile.

Application of Crosslinked Polybenzimidazole-Poly(Vinyl Benzyl Chloride) Anion Exchange Membranes in Direct Ethanol Fuel Cells.

Crosslinked membranes have been synthesized by a casting process using polybenzimidazole (PBI) and poly(vinyl benzyl chloride) (PVBC). The membranes were quaternized with 1,4-diazabicyclo[2.2.

Liquid-polymer triboelectricity: chemical mechanisms in the contact electrification process.

Liquid-polymer contact electrification between sliding water drops and the surface of polytetrafluoroethylene (PTFE) was studied as a function of the pH and ionic strength of the drop as well as ambient relative humidity (RH). The PTFE surface was characterized by using SEM, water-contact-angle measurements, FTIR spectroscopy, XPS, and Raman spectroscopy. The charge acquired by the drops was calculated by detecting the transient voltage induced on a specifically designed capacitive sensor.

Development of carbohydrate functionalized magnetic nanoparticles for aminoglycosides magnetic solid phase extraction.

Magnetic nanoparticles decorated with d-galactose and galactitol (FeO@SiN-galactose and FeO@SiN-galactitol) were synthesized and employed as sorbent in a magnetic solid phase extraction (MSPE) procedure prior the analysis of aminoglycosides (AGs) in honey samples by LC-MS/MS. AGs are broad spectrum antibiotics, characterized by aminosugars, widespread used in therapeutic and veterinary applications. AGs can be found in the environment and food of animal origin.

Synthesis and antiviral activity of some imidazo[1,2-b][1,3,4]thiadiazole carbohydrate derivatives.

Herein we describe the synthesis of imidazo[2,1-b][1,3,4]thiadiazoles from carbohydrates with D-ribo and D-xylo configuration. The antiviral activity of these compounds was tested against Junín virus (the etiological agent of Argentine hemorrhagic fever). The p-chlorophenyl derivatives showed antiviral activity in a range of micromolar concentration.

Modified ribavirin analogues as antiviral agents against Junín virus.

In this work, several ribavirin analogues were synthesized and incorporated into a multivalent arrangement. Both were subsequently modified by the addition of polyhydroxylated residues. Their antiviral activity was tested against Junín virus, etiological agent responsible of Argentine hemorrhagic fever.

Synthesis and in vitro antiproliferative activities of (5-aryl-1,2,4-oxadiazole-3-yl) methyl d-ribofuranosides.

The emergence of multidrug resistance cell lines is one of the major obstacles in the success of cancer chemotherapeutic treatment. Therefore, it remains a big challenge the development of new and effective drugs to defeat cancer. The presence of nitrogen heterocycles in the architectural design of drugs has led to the discovery of new leading compounds.

High-Energy Dissipation Performance in Epoxy Coatings by the Synergistic Effect of Carbon Nanotube/Block Copolymer Conjugates.

Hierarchical assembly of hard/soft nanoparticles holds great potential as reinforcements for polymer nanocomposites with tailored properties. Here, we present a facile strategy to integrate polystyrene-grafted carbon nanotubes (PSgCNT) (0.05-0.

Improving bone cement toughness and contrast agent confinement by using acrylic branched polymers.

A new biomedical material to be used as part of acrylic bone cement formulations is described. This new material is tough, its Young's Modulus is similar to the one of poly (methylmethacrylate) and the contrast agent, usually employed in acrylic bone cements, is homogeneously distributed among the polymeric matrix. Additionally, its wear coefficient is 66% lower than the one measured in poly(methyl methacrylate).

Acrylic bone cements: the role of nanotechnology in improving osteointegration and tunable mechanical properties.

Nanotechnology is an extremely powerful emerging technology, which is expected to have a substantial impact on biomedical technology, especially in tissue engineering and drug delivery. The use of nanocompounds and nanoparticles in the synthesis of improved bone cements to be applied in vertebroplasty/kyphoplasty and arthroplasty, is of great interest due to the increasing incidence of osteoporosis and osteoarthritis. This review reports new advances in the development of acrylic bone cements, using different radio-opalescent nanomaterials taking into consideration their influence on the mechanical behavior and biocompatibility of the resulting acrylic bone cement.

Antiviral activity of an N-allyl acridone against dengue virus.

Background: Dengue virus (DENV), a member of the family Flaviviridae, is at present the most widespread causative agent of a human viral disease transmitted by mosquitoes. Despite the increasing incidence of this pathogen, there are no antiviral drugs or vaccines currently available for treatment or prevention. In a previous screening assay, we identified a group of N-allyl acridones as effective virus inhibitors.

Imidazothiazole and related heterocyclic systems. Synthesis, chemical and biological properties.

Fused heterobicyclic systems have gained much importance in the field of medicinal chemistry because of their broad spectrum of physiological activities. Among the heterocyclic rings containing bridgehead nitrogen atom, imidazothiazoles derivatives are especially attractive because of their different biological activities. Since many imidazothiazoles derivatives are effective for treating several diseases, is interesting to analyze the behavior of some isosteric related heterocycles, such as pirrolothiazoles, imidazothiadiazoles and imidazotriazoles.

Synthesis of imidazo[2,1-b]thiazoles linked to an unprotected carbohydrate moiety.

Two series of imidazo[2,1-b]thiazoles substituted on C-3 or C-5 with an unprotected carbohydrate moiety were synthesized. Different protective groups for position 3 of the carbohydrate moiety were tested (acetyl, tert-butyldimethylsilyl (TBDMS), and p-methoxybenzyl (PMB)) and the latter turn out to be the best strategy to obtain the desired products. Full deprotection of the carbohydrate was performed successfully in only one step.

1,2,4-Triazole D-ribose derivatives: design, synthesis and antitumoral evaluation.

Herein we report the design, synthesis and characterization of novel 1,2,4-triazole d-ribose derivatives, as well as their synthetic precursors. The antitumoral activity against T cell lymphoma cell line of these products was studied. Structures containing a 1,2,4-triazolic ring linked by sulfur to the carbohydrate moiety showed a moderate antiproliferative activity.

Inhibition of Junin virus RNA synthesis by an antiviral acridone derivative.

There are no specific approved drugs for the treatment of agents of viral hemorrhagic fevers (HF) and antiviral therapies against these viruses are urgently needed. The present study characterizes the potent and selective antiviral activity against the HF causing arenavirus Junin virus (JUNV) of the compound 10-allyl-6-chloro-4-methoxy-9(10H)-acridone, designated 3f. The effectiveness of 3f to inhibit JUNV multiplication was not importantly affected by the initial multiplicity of infection, with similar effective concentration 50% (EC(50)) values in virus yield inhibition assays performed in Vero cells in the range of 0.

Imidazo[2,1-b]thiazole carbohydrate derivatives: Synthesis and antiviral activity against Junin virus, agent of Argentine hemorrhagic fever.

Herein, we describe the syntheses of 3,5-disubstituted imidazo[2,1-b]thiazole. The cyclization step was performed in two different conditions by using either thermal or microwave heating. Comparing the results of both methodologies, we found that the microwave assistance is an improved alternative to obtain this family of heterocyclic compound.

In vitro effect of a new cinnamic acid derivative against the epimastigote form of Trypanosoma cruzi.

An intensive effort has been directed toward finding alternative drugs for treatment of Chagas' disease, caused by Trypanosoma cruzi (T. cruzi), and prophylaxis of blood in endemic areas. The preparation and in vitro evaluation as potential anti-protozoal agent of (2E)-N-(1,3-benzothiazol-2-yl)-3-(2,5-dimethoxyphenyl)-2-propenamide (CAD-1) is presented.

Effect of energy density on color stability in dental resin composites under accelerated aging.

The effects of the energy density that is used for polymerization on properties of dental resin composites are well known. However, few studies relate color stability to this factor. The aim of this study was to assess color changes (deltaE*), in vitro, in terms of accelerated aging under UV exposure of specimens prepared with different energy densities.

Synthesis and antiviral activity of azoles obtained from carbohydrates.

Herein we describe the synthesis of 1,2,4-triazolyl-3-thione;1,3,4-oxadiazole, and imidazo[2,1-b]thiazole derivatives from carbohydrates. The antiviral activity of these compounds was tested against Dengue and Junin virus (the etiological agent of Argentine hemorrhagic fever). The 3-(p-bromobenzoyl)-5-(1,2-O-isopropylidene-3-O-methyl-alpha-d-xylofuranos-5-ulos-5-yl)imidazo[2,1-b]thiazole was able to inhibit the replication of both viruses in Vero cells at concentration significantly lower than the CC(50).