Synthesis and Characterization of a Low-Molecular-Weight Novolac Epoxy Derived from Lignin-Inspired Phenolics.

The need for renewable polymers capable of replacing their petrochemical counterparts continues to grow as sustainability concerns rise. Bisguaiacol (BG), a bioinspired alternative to bisphenol-A (BPA), has been synthesized using vanillyl alcohol and guaiacol via an electrophilic aromatic condensation. Purification provides both BG and an oligomeric coproduct with a consistent number average molecular weight and dispersity of ∼650 Da and ∼1.00, respectively. This coproduct has been well characterized as a low-molecular-weight novolac averaging five hydroxyls per molecule and was transformed into an epoxy resin suitable for use in thermosetting resins. The bioinspired thermoset produced in this work, consisting of the epoxidized coproduct and an amine curing agent (Epikure W), exhibited a glass transition temperature over 100 °C and glassy storage modulus value of ∼3 GPa at 25 °C. When compared to a commercial cresol novolac epoxy, the cured epoxidized coproduct resin shows comparable thermal and thermomechanical properties. When compared to a commercial BPA-based resin, the cured epoxidized coproduct resin shows improved mode 1 fracture values of 1.34 J m1/2 (K1C) and 448.16 J/m2 (G1C). By utilizing the coproduct strategically, the overall production of BG has the potential to become more economically feasible

Sepiolite with enhanced chemical reactivity as filler for rubber compounds

Reinforcing fillers are essential ingredients of rubber composites and, among them, inorganic oxides/hydroxides play a crucial role. Silica, with adequate coupling agents, is the best filler for tyre compounds with low energy dissipation and fuel consumption [1]. In recent years, interest has been increasing for biosourced fillers. Sepiolite is one of the most studied, thanks to its nanometric size and high aspect ratio [1-2]. However, sepiolite can hardly behave as a reinforcing filler, without establishing a chemical interaction with the rubber matrix. It is possible to pursue such objective by using an efficient coupling agent. In this study, sepiolite was functionalized with a pyrrole derivative, (2,5-dimethyl-1-(3-(triethoxysilyl) propyl)-1H-pyrrole) (APTESP), by simply mixing in water and heating, performing first evaporation and then the functionalization reaction. The Sepiolite/APTESP adduct was used as reinforcing filler in NR based composites, as the only filler or in a hybrid filler system with carbon black. The composites were prepared via melt blending in internal mixers. Sulfur based crosslinking was carried out and characterization was performed by means of dynamic-mechanical and tensile tests. Results The adduct Sepiolite/APTESP was successfully prepared, by using water as the reaction medium. The amount of APTESP was between 5 and 10% and the functionalization yield was higher than 70%. Sepiolite promoted the dynamic-mechanical reinforcement of the rubber composites, thanks to APTESP as coupling agent. The mechanical percolation threshold in sepiolite, as the only filler in NR, was observed at a sepiolite content of about 15 phr. When sepiolite/APTESP were used in place of CB, similar or lower values of hysteresis were obtained

Prevalence and molecular characterization of Aereomonas spp. in ready-to-eat foods in Italy

A survey was carried out in Italy to ascertain the prevalence of Aeromonas spp. in ready-to-eat foods (vegetables, cheeses, meat products, and ice creams) and the level of molecular heterogeneity of the isolates found by macrorestriction analysis of genomic DNA with pulsed-field gel electrophoresis (PFGE). In total, 46 (14.4%) of the 320 food samples examined were found positive for Aeromonas spp. The highest percentages of isolation were discovered in vegetables, particularly lettuce (45.0%), endive (40.0%), and rucola (20.0%). Ricotta was the only cheese type analyzed that showed a high frequency of isolation (45.0%). Among meat products, salami and raw ham (25.0% of samples positive) and, to a lesser extent, baloney (5.0%) were found positive for Aeromonas spp. Aeromonas hydrophila was the most common isolate from foods of animal origin, whereas Aeromonas caviae was the dominant species in vegetables. No motile aeromonads were found in ice cream samples. Aeromonas isolates showed a high level of genetic heterogeneity, because 24 PFGE patterns were identified among 27 A. hydrophila strains and 20 PFGE patterns were found in 23 A. caviae isolates. In conclusion, consumers of ready-to-eat foods in Italy are regularly exposed to many genetically distinct strains of A. hydrophila and A. caviae without evident signs of malaise, and therefore, few of these strains, if any, are likely to be pathogenic

A Case of Reversed Robin Hood Syndrome: A Prognostic Indicator for an Urgent Therapy

Abstract Introduction In acute stroke, the diagnosis of reversed Robin Hood syndrome (RRHS) by transcranial Doppler (TCD) helps to identify patients at high risk for neurological deterioration. Report A patient with left intracranial internal carotid artery (ICA) dissection and concomitant inadequate collateral circulation suffered from recurrent ipsilateral ischaemic symptoms, not prevented by the best medical treatment. TCD showed an RRHS. Stenting of ICA could restore an adequate flow with disappearance of the RRHS and prevention of further episodes. Discussion An invasive emergency treatment should be considered in those stroke patients in which TCD detects an inadequate haemodynamic status

Monitorization of hexanal as lipid oxidation indicator in a processed meat product packaged with poly(lactic acid)/clay nanocomposite films

One of the most detrimental processes in fatty foodstuffs is lipid oxidation, which occurs during production and storage, and influences food composition and safety. Through the analysis of volatile lipid oxidation products we can have an insight into the oxidation, and some volatiles, such as hexanal, which can be markers of undergoing oxidation processes. Hexanal is formed when fatty acids are oxidized and is one of many well-documented aromatic components that contributes to flavour and aroma in common food products containing fatty acids. During the last decade, the interest in polymer layered silicate (PLS) nanocomposites has rapidly increased due to their potential for enhancing physical, chemical, and mechanical properties of conventional materials. Polymer nanocomposites are represented by a polymeric matrix reinforced with nanoscale fillers, among them the most common silicate clays are represented by montmorillonite (MMT), which is naturally occurring and readily available in large quantities. The presence of MMT can lead to materials which generally exhibit great property enhancements, mainly due to its intercalation or exfoliation into the polymer chains. In this work natural MMT Cloisite Na+ was incorporated in PLA. The PLA/Cloisite® Na+ films were prepared through a two-step process. In the first step, PLA pellets were fed into a corotating laboratory twin-screw extruder at 170 °C and 50 rpm for 2 min. Subsequently, Cloisite® Na+ powder (5%, w/w) were added and mixed. After extrusion, the melted matter was then pressed with a P300P hot press at 170 °C and 100 bar to obtain the PLA/Cloisite® Na+ films. Salami slices were packaged with PLA-OMMT film and with a control film (PLA). After different storage times (0, 15, 30, 60 and 90 days), salami slices were analysed regarding their hexanal content. The hexanal derivatization was performed in a solution of 2,4-dinitrophenylhydrazine in sulfuric acid during 4 h in the dark, and the hexanal extraction was performed with n-hexane and evaporation till dryness. The residue was dissolved in methanol, filtered and analysed. The quantification of hexanal was performed by Ultra High Performance Liquid Chromatography coupled with Diode Array Detector at 365 nm, with a Pre-column AcquityTM UPLC® BEH C18 (2.1 x 5 mm, 1.7 μm particle size) and a column AcquityTM UPLC® BEH C18 (2.1 × 50 mm, 1.7 μm particle size), the mobile-phase was acetonitrile-water (75:25, v/v). The amount of hexanal in packaged salami decreased in the first 60 days of storage. In this period of time the hexanal content of the salami packaged with the PLA/Cloisite® Na+ films was lower than the salami packaged with control film, except after 15 days of storage, where there was no difference between two films. After 90 days of storage, the amount of hexanal in the samples increased, although it was higher in the samples packaged with control film (94.7 ± 6.02 μg/100g salami) than salami packaged with PLA/Cloisite® Na+ films (65.1 ± 6.12 μg/100g salami). The presence of MMT in the polymer film can reduce the lipid oxidation of processed meat products, extending their shelf life. Further studies to evaluate differences between PLA and the nanocomposite (PLA-5%Cloisite®Na+) in what regards to the mechanical and barrier properties are in progress.This work was supported by the research project “Labelling and tracking of nanoclay from food packaging nanocomposites: a food safety issue – NanoPack4Food” (2014DAN1019) under the Cooperative Programme of the Agreement on Scientific Cooperation between National Research Council of Italy (CNR) and Foundation for Science and Technology of Portugal (FCT)N/

Enhanced in vitro antitumor activity of a titanocene complex encapsulated into polycaprolactone (PCL) electrospun fibers.

PURPOSE: The purpose of this work was to achieve detailed biomaterials characterization of a drug delivery system for local cancer treatment based on electrospun titanocene trichloride-loaded resorbable polycaprolactone (PCL) fibers. METHODS: The PCL fibers were characterized for their structural, morphologic and physical properties. The drug release kinetics of the titanocene complex was investigated at different concentrations, to obtain a set of correlations between structure and tuneable release. After exposing cancer cells directly onto the surface of PCL fibers, the anti-proliferative effects of titanocene-loaded PCL were assessed by: (i) counting viable cells via live/dead staining methods, and (ii) analyzing cell apoptosis. RESULTS AND CONCLUSIONS: Titanocene concentration influenced fiber diameters reduced for PCL filled with titanocene. X-ray analysis suggested that the titanocene, encapsulated into the PCL fibers, is not allowed to crystallize and exists as amorphous aggregates into the fibers. The titanocene release curves presented two stages unrelated to PCL degradation: an initial burst release followed by a release linear with time, extending for a very long time. All of the titanocene-loaded fibers revealed sustained drug release properties suggesting their potential clinical applicability for the treatment of local cancer diseases

Levodopa-induced dyskinesia in Parkinson's disease: sleep matters

OBJECTIVE: The spectrum of clinical symptoms changes during the course of Parkinson's disease. Levodopa therapy, while offering remarkable control of classical motor symptoms, causes abnormal involuntary movements as the disease progresses. These levodopa-induced dyskinesias (LIDs) have been associated with abnormal cortical plasticity. Since slow wave activity (SWA) of nonrapid eye movement (NREM) sleep underlies adjustment of cortical excitability, we sought to elucidate the relationship between this physiological process and LIDs. METHODS: Thirty-six patients at different stages of Parkinson's disease (PD) underwent whole-night video polysomnography-high-density EEG (vPSG-hdEEG), preceded by 1 week of actigraphy. To represent the broad spectrum of the disease, patients were divided into three groups by disease stage, (i) de novo (DNV; n = 9), (ii) advanced (ADV; n = 13), and (iii) dyskinetic (DYS; n = 14) and were compared to an age-matched control group (CTL; n = 12). The SWA-NREM content of the PSG-hdEEG was then temporally divided into 10 equal parts, from T1 to T10, and power and source analyses were performed. T2-T3-T4 were considered early sleep and were compared to T7-T8-T9, representing late sleep. RESULTS: We found that all groups, except the DYS group, manifested a clear-cut SWA decrease between early and late sleep. INTERPRETATION: Our data demonstrate a strong pathophysiological association between sleep and PD. Given that SWA may be a surrogate for synaptic strength, our data suggest that DYS patients do not have adequate synaptic downscaling. Further analysis is needed to determine the effect of drugs that can enhance cortical SWA in LIDs

Brain overexpression of uncoupling protein-2 (Ucp2) delays renal damage and stroke occurrence in stroke-prone spontaneously hypertensive rats

The downregulation of uncoupling protein-2 (UCP2) is associated with increased brain and kidney injury in stroke-prone spontaneously hypertensive rats (SHRSP) fed with a Japanese style hypersodic diet (JD). Systemic overexpression of UCP2 reduces organ damage in JD-fed SHRSP. We examined the effect of brain-specific UCP2 overexpression on blood pressure (BP), stroke occurrence and kidney damage in JD-fed SHRSP. Rats received a single i.c.v. injection of a lentiviral vector encoding UCP2 (LV-UCP2), or an empty vector. The brain delivery of LV-UCP2 significantly delayed the occurrence of stroke and kidney damage. The large reduction of proteinuria observed after LV-UCP2 injection was unexpected, because BP levels were unchanged. At the time of stroke, rats treated with LV-UCP2 still showed a large UCP2 upregulation in the striatum, associated with increases in OPA1 and FIS1 protein levels, and reductions in PGC1-α, SOD2, TNFα mRNA levels and NRF2 protein levels. This suggested UCP2 overexpression enhanced mitochondrial fusion and fission and reduced oxidative damage and inflammation in the striatum of JD-fed SHRSP rats. Our data suggest the existence of central mechanisms that may protect against hypertension-induced organ damage independently of BP, and strengthen the suitability of strategies aimed at enhancing UCP2 expression for the treatment of hypertensive damage