Risk factors for infection with Giardia duodenalis in pre-school children in the city of Salvador, Brazil.

A cross-sectional study of 694 children aged 2 to 45 months selected from 30 clusters throughout the city of Salvador, Bahia (pop. 2.3 million) was carried out as part of a longitudinal study of diarrhoea in order to identify risk factors for infection with Giardia duodenalis. Variables studied included three social and demographic factors (such as mother's education and marital status), five relating to the peri-domestic environment (rubbish disposal, open sewers, paving of the street), seven relating to the home itself (house construction, susceptibility to flooding, water supply and sanitation) as well as a score for hygiene behaviour based on structured observation. After multivariate analysis using a hierarchical model, only four significant risk factors were found: (a) number of children in the household under five years (b) rubbish not collected from the house (c) presence of visible sewage nearby, and (d) absence of a toilet. All four were significant at the 1% level

Multiresponsive spiropyran-based copolymer: synthesis and characterization

Photochromic copolymers carrying spiropyran side groups have attracted particular attention for potential applications in optical devices, photonic memory and photosensing, as well as, fluorescence imaging.[1] These materials allow overcoming many of the limitations inherent to traditional spiropyran doped polymers, such as, phase separation of the colorant and retardation of the decoloration of the open form.[2] The introduction of light sensitive moieties within responsive polymers has led to the development of sophisticated multiresponsive systems.[3] Block copolymers are important self-assembling systems that can assume a diversity of nanometer-scale morphologies due to the incompatibility and the connectivity constrains between the chemically distinct segments. Therefore, self-assembly of photochromic copolymers in the solid state or in solution allows the development of nanostructured materials. [4] The aim of this research study is the synthesis of a multiresponsive spiropyran-based copolymer, poly(styrene)- co-poly([1´,3´,3´-trimethyl-6-methacryloyloxyspiro(2H-1-benzopyran-2,2´-indoline)]4-vinylbenzoic acid) 2. The functionalized block copolymer poly(styrene)-block-poly(4-vinylbenzoic acid) (PSt-b-P4VBA) 1 synthesized by reversible addition fragmentation chain-transfer (RAFT) polymerization was coupled with 1,3,3-trimethyl-6- hydroxyspiro(2H-1-benzopyran-2,2-indoline). The link between the functionalized block copolymer and spiropyran was successfully obtained by Steglich esterification using DMAP/DCC as catalysts (Scheme 1).n-STeP ProjectNORTE-07-0124-FEDER-000039Programa Operacional Regional do Norte (ON.2)PEst-C/CTM/LA0025/2013 (Strategic Project - LA 25 - 2013-2014

Effect of clay mineral addition on properties of bio-based polymer blends

The effect of clay mineral addition to bio-based blends on morphology and physical properties of thermoplastic starch (TPS) and polypropylene grafted with maleic anhydride (PP-g-MA) was investigated. Blends and nanocomposites containing organoclay, Cloisite 30B, were prepared by melt mixing and characterized by several techniques. X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, STEM) and dynamic mechanical analysis (DMA) demonstrate a very good dispersion of the clay mineral in the polymer matrix, an increase of polymer compatibility and an improvement of mechanical properties. Biodegradation studies performed in compost revealed that Cloisite 30B addition enhanced the matrix biodegradability. Therefore clay minerals, which can be obtained from natural resources, can be efficiently used to improve the properties of bio-based materials and contribute to sustainability.The authors acknowledge the n-STeP - Nanostructured systems for Tail, with reference NORTE-07-0124-FEDER-000039, supported by the Programa Operacional Regional do Norte (ON.2), PEst-C/CTM/LA0025/2013 (Strategic Project - LA 25 - 2013-2014)

Thermoplastic starch-polypropy/lene reinforced with clay

In this study, bio-based blends of thermoplastic starch (TPS) and polypropylene grafted with maleic anhydride (PP-g-MA) without and with organoclay, Cloisite 30B, were prepared in an internal mixer. A TPS-g-PP copolymer was successfully obtained in melt and its formation was confirmed by SEM. The establishment of this copolymer creates an interpenetrating network leading an intercalated/exfoliated clay nanocomposite. Several analytical, angle X-ray diffraction (XRD), scanning and transmission electron microscopy (SEM, STEM) and dynamic mechanical analysis (DMA) were used to characterize the prepared materials. The nanocomposites mechanical properties were improved, showing an increase of about 11% for the nanocomposite when compared with the neat blend. Biodegradation studies performed in compost revealed good percentage of weight loss for the copolymer with clay addition

Development of silver and clay-starch bio-nanocomposites

Starch, among biopolymers is that had the lowest production cost, wide availability, fully biodegradability and is a renewable agriculture resource. Starch due to its sensitivity to humidity and poor mechanical properties cannot be used in many applications. For that, the dispersion of clays in this material improves their physical and mechanical properties, at very low filler loadings. On the other hand, the incorporation of silver nanoparticles into biocompatible and biodegradable matrices gives antimicrobial properties opening a new field for packaging applications. [...

Synthesis of bio-based Polyester from microbial lipidic residue intended for biomedical application

In the last decade, selectively tuned bio-based polyesters have been increasingly used for their clinical potential in several biomedical applications, such as tissue engineering, wound healing, and drug delivery. With a biomedical application in mind, a flexible polyester was produced by melt polycondensation using the microbial oil residue collected after the distillation of β-farnesene (FDR) produced industrially by genetically modified yeast, Saccharomyces cerevisiae. After characterization, the polyester exhibited elongation up to 150% and presented Tg of −51.2 °C and Tm of 169.8 °C. In vitro degradation revealed a mass loss of about 87% after storage in PBS solution for 11 weeks under accelerated conditions (40 °C, RH = 75%). The water contact angle revealed a hydrophilic character, and biocompatibility with skin cells was demonstrated. 3D and 2D scaffolds were produced by salt-leaching, and a controlled release study at 30 °C was performed with Rhodamine B base (RBB, 3D) and curcumin (CRC, 2D), showing a diffusion-controlled mechanism with about 29.3% of RBB released after 48 h and 50.4% of CRC after 7 h. This polymer offers a sustainable and eco-friendly alternative for the potential use of the controlled release of active principles for wound dressing applications.info:eu-repo/semantics/publishedVersio

Sugarcane straw polyphenols as potential food and nutraceutical ingredient

The sugarcane processing industry generates a large amount of straw, which has a negative environmental impact, and high costs are associated with their elimination, wasting their potential bioactive value attributed to their richness in polyphenols. In this study, an ethanolic extract produced from sugarcane straw was screened for its phenolic compounds content, and the potential use of this extract in the development of a food ingredient was further evaluated. Fifty different secondary metabolites belonging to the hydroxybenzoic acids, hydroxycinnamic acids, and flavonoids were identified by liquid chromatography–electrospray ionization–ultrahigh-resolution—quadrupole time of flight–mass spectrometry (LC-ESI-UHR-QqTOF-MS). The predominant phenolic compounds found were 4-hydroxybenzaldehyde, chlorogenic acid, and 5-O-feruloylquinic acid. The obtained extracts showed strong potential as food preservatives by exhibiting (a) antioxidant activity using both 2.2′-azino-bis (3-ethylbenzothiazoline-6-sulphonic acid) diammonium salt radical cation (ABTS) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) methods; and (b) antimicrobial capacity, with a minimum inhibitory concentration of 50 mg/mL for Staphylococcus aureus, 74% inhibition for Bacillus cereus, and 44% for Salmonella enterica; and (c) the capacity to inhibit a food browning enzyme, tyrosinase (28–73% for 1–8 mg/ mL). Moreover, the extracts showed antidiabetic potential by inhibiting the enzymes α-glucosidase (15–38% for 1.25–5.00 mg/mL) and dipeptidyl peptidase-IV (DPP-IV) (62–114% for 0.31–5.00 mg/mL). The extract (0.625 mg/mL) also exhibited the capacity to reduce proinflammatory mediators (i.e., interleukins 6 and 8, and tumor necrosis factor alpha) when Caco-2 cells were stimulated with interleukin 1 beta. Thus, sugarcane straw extract, which is rich in phenolic compounds, showed high potential to be used in the development of food-preservative ingredients owing to its antioxidant and antimicrobial potential, and to be explored as a food supplement in diabetes prevention and as coadjuvant to reduce intestinal inflammation by reducing proinflammatory mediators.info:eu-repo/semantics/publishedVersio

Development of pH-sensitive magnetoliposomes containing shape anisotropic magnetic nanoparticles for applications in dual cancer therapy

In this work, anisotropic magnetic nanoparticles of mixed calcium/magnesium ferrite were synthesized and characterized. These nanoparticles were encapsulated in pH-sensitive liposomes loaded with doxorubicin, and the resulting nanosystems were characterized by DLS. Fluorescence emission assays were performed to elucidate the structural characterization and study the release profile of doxorubicin at different pH values and promising results were obtained for application in combined cancer therapy.FCT under Strategic funding of CF-UM-UP (UIDB/04650/2020)

Numerical study on the performance of improved masonry-to-timber connections in traditional masonry buildings

This paper deals with a numerical study on the structural performance of masonry-to-timber connections in ancient buildings. The work is supported on an experimental campaign carried out at University of Minho, which aims at characterising a strengthening solution based on the use of injected anchors for the improvement of the connection between masonry and timber frame walls. The numerical study resorts to a detailed 3D finite element model, which reproduces the experimental test setup and proce- dure. The modelling approach adopted allows an accurate characterisation of the behaviour of all struc- tural elements, in terms of stress field and displacement distribution. The 3D model was validated against the available experimental results, which was then used to perform parametric analyses in order to eval- uate the influence of key parameters. Finally, simplified analytical approaches to estimate the strength capacity of injected anchors on masonry are presented and discussed.This work was partly funded by Project FP7-ENV-2009-1244123-NIKER. The first author also acknowledges the financial support from the Portuguese Science Foundation (Fundacao de Ciencia e Tecnologia, FCT), through Grant SFRH/BD/71599/2010