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.

Quantification of Enzymatic Biofilm Removal Using the Sauerbrey Equation: Application to the Case of .

A methodology for the quantitative analysis of enzymatic removal of biofilms (BF) was developed, based on a quartz crystal microbalance (QCM) under stationary conditions. This was applied to the case of (PP) BFs, through a series of five enzymes, whose removal activity was screened using the presented methodology. The procedure is based on the following: when BFs can be modeled as rigid materials, QCM can be used as a balance under stationary conditions for determining the BFs mass reduction by enzymatic removal.

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.

Alternative modification by grafting in bamboo cellulose nanofibrils: A potential option to improve compatibility and tunable surface energy in bionanocomposites.

Chemical modification in surface of cellulose nanofibrils CNFs (20 nm) from an endemic and non-significant value-added, Argentine bamboo, was developed. The modification in the CNFs was carried out with three simple routes using a low molecular weight polylactic acid synthesized in our laboratory (PLA1). The first step comprises of protection of the hydroxyl groups of PLA1 through a benzoylation (PLA1Bz).

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.

Advances in drug delivery, gene delivery and therapeutic agents based on dendritic materials.

Dendrimers are synthetic polymers that grow in three dimensions into well-defined structures. Their morphological appearance resembles a number of trees connected by a common point. Dendritic nanoparticles have been studied for a large number of pharmaceutical and biomedical applications including gene and drug delivery, clinical diagnosis and MRI.

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.

Effect of radiant exposure and UV accelerated aging on physico-chemical and mechanical properties of composite resins.

Unlabelled: Currently, there is no consensus in terms of defining the minimum radiant exposure values necessary for achieving adequate properties of composite resin. In addition, the long-term influence that radiant exposure has on the properties of composite resins is still questionable.

Objective: The objective of this study was to evaluate the effect of radiant exposure and UV accelerated aging on the physico-chemical and mechanical properties of micro-hybrid and nanofilled composite resins.

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.

Game-changing restraint of Ros-damaged phenylalanine, upon tumor metastasis.

An abrupt increase in metastatic growth as a consequence of the removal of primary tumors suggests that the concomitant resistance (CR) phenomenon might occur in human cancer. CR occurs in murine tumors and ROS-damaged phenylalanine, meta-tyrosine (m-Tyr), was proposed as the serum anti-tumor factor primarily responsible for CR. Herein, we demonstrate for the first time that CR happens in different experimental human solid tumors (prostate, lung anaplastic, and nasopharyngeal carcinoma).

Increased Surface Roughness in Polydimethylsiloxane Films by Physical and Chemical Methods.

Two methods, the first physical and the other chemical, were investigated to modify the surface roughness of polydimethylsiloxane (PDMS) films. The physical method consisted of dispersing multi-walled carbon nanotubes (MWCNTs) and magnetic cobalt ferrites (CoFe₂O₄) prior to thermal cross-linking, and curing the composite system in the presence of a uniform magnetic field . The chemical method was based on exposing the films to bromine vapours and then UV-irradiating.

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.

Differential effect of heterocyclic D-ribofuranoside derivatives on human prostate cancer cell viability and cell cycle progression.

New d-ribofuranoside derivatives containing two five membered heterocycles, isoxazole and triazole or two triazole rings, were synthesized. The final products as well as the synthetic precursors were physically and spectroscopically characterized. These new diheterocyclic derivatives together with other d-riboside compounds were assessed for their impact on PC3 cell line viability.

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.