Recycled cellulose from Tetra Pak packaging as reinforcement of polyester based composites

Addressing the environmental problems caused by waste generated by Tetra Pak packaging, in this work, polyester based composites with 80% of polyester resin and 20% of silica sand were elaborated; where the silica sand was partially replaced by recycled cellulose from waste Tetra Pak containers at concentrations of 1, 2, 4 and 6% by weight. Both recycled cellulose and composite specimens were subjected to ionizing radiation process by using gamma rays. The results show improvements on the mechanical properties (compressive and flexural strength as well as modulus of elasticity) of the composites when they are irradiated at 100 and 200 kGy. Such improvements can be related with the structural modifications caused by gamma irradiation on the cellulose fibers, including changes in the morphology and the crystallinity; which were analyzed through to SEM, IR and XRD techniques

Biocomponents from Opuntia robusta and Opuntia streptacantha fruits protect against diclofenac-induced acute liver damage in vivo and in vitro

This study aimed to investigate whether Opuntia spp-extracts protect against diclofenac (DF)-induced hepatotoxicity. Rats were pretreated with Opuntia extracts, betanin (Bet) and N-acetylcysteine (NAC) followed by a single challenge of diclofenac. Liver tissue was collected for biochemical and histological analysis. Primary rat hepatocytes were treated with diclofenac (400 mu mol/L) with and without pretreatment with Opuntia extract. Apoptosis was measured by caspase-3 activity and necrosis by Sytox green staining. RNA was isolated, and realtime qPCR was performed to assess mRNA levels of stress and apoptosis-related genes MnSOD (SOD2), GADD45B and P53. ROS production was measured using the fluorescent MitoSOX assay. Results demonstrated that Opuntia spp-extracts protect against DF-induced liver toxicity via reducing oxidative stress and the inhibition of P53

Gamma radiation as a recycling tool for waste materials used in concrete

Over the course of the last 50 years, a large number of major technological advances have contributed to the development of higher-strength, high-performance materials that provide excellent benefits. Nevertheless, in most cases, after a very short useful life, these products become waste material and contribute to environmental degra‐ dation. This situation has created an environmental crisis that has reached global proportions. In efforts to combat this issue and to promote sustainable development and reduce environmental pollution, some investigations have focused on recycling using innovative and clean technologies, such as gamma radiation, as an alternative to conventional mechanical and chemical recycling procedures. In this context, the reuse and recycling of waste materials and the use of gamma radiation are useful tools for improving the mechanical properties of concrete; for example, the compressive strength and modulus of elasticity are improved by the addition of waste particles and application of gamma radiation. In this chapter, we propose the use of gamma radiation as a method for modifying waste materials; for instance, polyethylene terephthalate plastic bottles, automotive tire rubber, and the cellulose in Tetra Pak containers, and their reuse to enhance the properties of concrete

Intrinsic Deviation from the Tri-bimaximal Neutrino Mixing in a Class of A_4 Flavor Models

It is well known that the tri-bimaximal neutrino mixing pattern V_0 can be derived from a class of flavor models with the non-Abelian A_4 symmetry. We point out that small corrections to V_0, which are inherent in the A_4 models and arise from both the charged-lepton and neutrino sectors, have been omitted in the previous works. We show that such corrections may lead the 3 \times 3 neutrino mixing matrix V to a non-unitary deviation from V_0, but they cannot result in a nonzero value of \theta_13 or any new CP-violating phases. Current experimental constraints on the unitarity of V allow us to constrain the model parameters to some extent.Comment: 11 pages, no figures; a reference added, accepted for publication in Phys. Lett.

Surface roughness dependent osteoblast and fibroblast response on poly(l-lactide) films and electrospun membranes

Poly(l-lactide) electrospun mats with random and aligned fiber orientation and films have been produced with degrees of crystallinity ranging from 0 up to nearly 50%. The overall surface roughness is practically constant irrespective of the sampling areas (1 × 1 µm to 20 × 20 µm) for degrees of crystallinity below 30%, increasing for higher degrees of crystallinity for the larger sampling areas. Further, due to fiber confinement, surface roughness variations are smaller in electrospun mats. Samples with 50% of crystallinity show the lowest osteoblast and the highest fibroblast proliferation. Therefore, it is verified that higher roughness promotes lower osteoblast but higher fibroblast proliferation. The overall results indicate the relevant role of the sub-microenvironment variations associated to the microscale roughness in determining the different cell responses.Portuguese Foundation for Science and Technology (FCT); contract grant numbers: C/FIS/UI607/2011, PTDC/CTM-NAN/112574/2009, contract grant numbers: SFRH/BPD/63148/2009, SFRH/BPD/90870/2012, Matepro—Optimizing Materials and Processes, Programa Operacional Regional do Norte, Quadro de Referência Estratégico Nacional” (QREN), “Fundo Europeu de Desenvolvimento Regional” (FEDER); contract grant number: NORTE-07–0124-FEDER-000037

Association of VAV2 and VAV3 polymorphisms with cardiovascular risk factors

Hypertension, diabetes and obesity are cardiovascular risk factors closely associated to the development of renal and cardiovascular target organ damage. VAV2 and VAV3, members of the VAV family proto-oncogenes, are guanosine nucleotide exchange factors for the Rho and Rac GTPase family, which is related with cardiovascular homeostasis. We have analyzed the relationship between the presence of VAV2 rs602990 and VAV3 rs7528153 polymorphisms with cardiovascular risk factors and target organ damage (heart, vessels and kidney) in 411 subjects. Our results show that being carrier of the T allele in VAV2 rs602990 polymorphism is associated with an increased risk of obesity, reduced levels of ankle-brachial index and diastolic blood pressure and reduced retinal artery caliber. In addition, being carrier of T allele is associated with increased risk of target organ damage in males. On the other hand, being carrier of the T allele in VAV3 rs7528153 polymorphism is associated with a decreased susceptibility of developing a pathologic state composed by the presence of hypertension, diabetes, obesity or cardiovascular damage, and with an increased risk of developing altered basal glycaemia. This is the first report showing an association between VAV2 and VAV3 polymorphisms with cardiovascular risk factors and target organ damage

Non-standard interactions versus non-unitary lepton flavor mixing at a neutrino factory

The impact of heavy mediators on neutrino oscillations is typically described by non-standard four-fermion interactions (NSIs) or non-unitarity (NU). We focus on leptonic dimension-six effective operators which do not produce charged lepton flavor violation. These operators lead to particular correlations among neutrino production, propagation, and detection non-standard effects. We point out that these NSIs and NU phenomenologically lead, in fact, to very similar effects for a neutrino factory, for completely different fundamental reasons. We discuss how the parameters and probabilities are related in this case, and compare the sensitivities. We demonstrate that the NSIs and NU can, in principle, be distinguished for large enough effects at the example of non-standard effects in the $\mu$-$\tau$-sector, which basically corresponds to differentiating between scalars and fermions as heavy mediators as leading order effect. However, we find that a near detector at superbeams could provide very synergistic information, since the correlation between source and matter NSIs is broken for hadronic neutrino production, while NU is a fundamental effect present at any experiment.Comment: 32 pages, 5 figures. Final version published in JHEP. v3: Typo in Eq. (27) correcte

Health Measurement Scales: Methodological Issues

Health scales or indices are composite tools aiming to measure a variety of clinical conditions, behaviors, attitudes and beliefs that are difficult to be measured quantitatively. During the past years, these tools have been extensively used in cardiovascular disease prevention. The already proposed scales have shown good ability in assessing individual characteristics, but had moderate predictive ability in relation to the development of chronic diseases and various other health outcomes. In this review, methodological issues for the development of health scales are discussed. Specifically, the selection of the appropriate number of components, the selection of classes for each component, the use of weights of scale components and the role of intra- or inter-correlation between components are discussed. Based on the current literature the use of components with large number of classes, as well as the use of specific weights for each scale component and the low-to-moderate inter-correlation rate between the components, is suggested in order to increase the diagnostic accuracy of the tool

MiniBooNE and LSND data: non-standard neutrino interactions in a (3+1) scheme versus (3+2) oscillations

The recently observed event excess in MiniBooNE anti-neutrino data is in agreement with the LSND evidence for electron anti-neutrino appearance. We propose an explanation of these data in terms of a (3+1) scheme with a sterile neutrino including non-standard neutrino interactions (NSI) at neutrino production and detection. The interference between oscillations and NSI provides a source for CP violation which we use to reconcile different results from neutrino and anti-neutrino data. Our best fit results imply NSI at the level of a few percent relative to the standard weak interaction, in agreement with current bounds. We compare the quality of the NSI fit to the one obtained within the (3+1) and (3+2) pure oscillation frameworks. We also briefly comment on using NSI (in an effective two-flavour framework) to address a possible difference in neutrino and anti-neutrino results from the MINOS experiment.Comment: 28 pages, 9 figures, discussion improved, new appendix added, conclusions unchange