Ti6Al4V-PEEK multi-material structures – design, fabrication and tribological characterization focused on orthopedic implants

Acknowledgements: This work was supported by FCT through the grants SFRH/BD/128657/2017 and SFRH/BPD/112111/2015, the project PTDC/EMSTEC/5422/2014 and also by project NORTE 01-0145_FEDER-000018. Additionally, this work was supported by FCT with the reference project UID/EEA/04436/2013, by FEDER funds through the COMPETE 2020 – Programa Operacional Competitividade e Internacionalização (POCI) with the reference project POCI-01-0145-FEDER-006941.A multi-material concept that gathers Ti6Al4V and PEEK properties in a cellular structured component was designed, fabricated and investigated targeting hip implants. SLM and pressure assisted injection techniques were used to obtain Ti6Al4V-PEEK multi-material structures. Aiming to reproduce to some extension the tribological phenomena occurring during and after hip implant insertion, five tribological tests were outlined and performed. The obtained results showed that the presence of PEEK on the Ti6Al4V-PEEK cellular structures led to a substantial improvement on the wear resistance (62% reduction in the mass loss) when compared to the material currently available on market for hip implants. The multi-material solution here investigated shows a good compromise between the primary stability after implant insertion and the wear performance.info:eu-repo/semantics/publishedVersio

Heavy Baryonic Decays of \Lambda_b \to \Lambda \eta^{(\prime)} and Nonspectator Contribution

We calculate the branching ratios of the hadronic \Lambda_b decays to \eta and \eta^\prime in the factorization approximation where the form factors are estimated via QCD sum rules and the pole model. Our results indicate that, contrary to B\to K\eta^{(\prime)} decays, the branching ratios for \Lambda_b\to\Lambda\eta and \Lambda_b\to\Lambda\eta^\prime are more or less the same in the hadronic \Lambda_b transitions. We estimate the branching ratio of \Lambda_b\to\Lambda\eta^{(\prime)} to be 10.80 (10.32)\times 10^{-6} in QCD sum rules, and 2.78 (2.96)\times 10^{-6} in the pole model. We also estimate the nonfactorizable gluon fusion contribution to \Lambda_b\to\Lambda\eta^\prime decay by dividing this process into strong and weak vertices. Our results point to an enhancement of more than an order of magnitude due to this mechanism.Comment: 16 pages, ReVTeX, 5 eps figure

Nutritional, chemical and bioactive profiles of different parts of a Portuguese common fig (Ficus carica L.) variety

This study aims to give an unprecedented contribution on the chemical composition and bioactivities of the most produced and appreciated Portuguese fig variety (“Pingo de Mel”) with the view of expanding the knowledge on its potentialities. An advanced characterization of its peel and pulp parts was carried out. Four free sugars (glucose, fructose, trehalose and sucrose), 5 organic acids (oxalic, quinic, malic, citric, and succinic acids), tocopherols in all their 4 forms, besides 23 fatty acids were detected in the samples. Fifteen different phenolic components were found in the peel hydroethanolic extract; whereas 12 were detected in the pulp hydroethanolic extract. Quercetin-3-O-rutinoside (rutin) was the major constituent of the peel, accounting for 33.8% of its phenolic content, followed by 5-O-caffeoylquinic acid and vanillic acid malonyl di-deoxyhexoside. Caffeic acid derivatives, such as caffeic acid hexosides, were the major components of pulp, followed by vanillic acid derivatives and O-caffeoylquinic acid. Both extracts displayed promising antioxidant capacities in all methods used, namely the 2,2-diphenyl-1-picrylhydrazyl radical-scavenging, the reducing power, the inhibition of β-carotene bleaching assays, the thiobarbituric acid reactive substances assay and the oxidative haemolysis inhibition assay; however, the peel presented significantly lower IC50 values than pulp. The extracts showed practically identical antibacterial capacities, being effective against methicillin-sensitive Staphylococcus aureus (MICs=2.5 mg/mL), besides methicillin-resistant S. aureus, Escherichia coli and Morganella morganii (MICs=5 mg/mL). The obtained results evidence that the fig peel is superior to the corresponding pulp as it relates to nutritional and phenolic profiles as well as bioactivities, endorsing the urgency in valorising and exploiting this usually discarded industrial by-product.The authors are grateful to the Foundation for Science and Technology (FCT, Portugal) and FEDER under Programme PT2020 for financial support to CIMO (UID/AGR/00690/2019); national funding by FCT, P.I., through the institutional scientific employment programcontract for L. Barros, R. C. Calhelha, and M.I. Dias contracts, and Carla Pereira's contract though the celebration of program-contract foreseen in No. 4, 5 and 6 of article 23° of Decree-Law No. 57/2016, of 29th August, amended by Law No. 57/2017, of 19th July; to FEDER-Interreg España-Portugal programme for financial support through the project 0377_Iberphenol_6_E; the European Regional Development Fund (ERDF) through the Regional Operational Program North 2020, within the scope of Project NORTE-01-0145-FEDER-023289: DeCodE.info:eu-repo/semantics/publishedVersio

Extraction of anthocyanins from red raspberry for natural food colorants development: Processes optimization and in vitro bioactivity

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Heat (HAE)-and ultrasound (UAE)-assisted extraction methods were implemented to recover anthocyanins from red raspberry. Processing time, ethanol concentration, and temperature or ultrasonic power were the independent variables combined in five-level rotatable central composite designs coupled with response surface methodology (RSM) for processes optimization. The extraction yield and levels of cyanidin-3-O-sophoroside (C3S) and cyanidin-3-O-glucoside (C3G) were monitored by gravimetric and HPLC-DAD-ESI/MSn methods, respectively, and used as response criteria. The constructed theoretical models were successfully fitted to the experimental data and used to determine the optimal extraction conditions. When maximizing all responses simultaneously, HAE originated slightly higher response values (61% extract weight and 8.7 mg anthocyanins/g extract) but needed 76 min processing at 38â—¦ C, with 21% ethanol (v/v), while the UAE process required 16 min sonication at 466 W, using 38% ethanol (v/v). The predictive models were experimentally validated, and the purple-red extracts obtained under optimal condition showed antioxidant activity through lipid peroxidation and oxidative hemolysis inhibition, and antibacterial effects against food-related microorganisms, such as Escherichia coli and Enterococcus faecalis. These results highlight the potential of red raspberry extracts as natural food colorants with bioactive effects and could be exploited by industries interested in the production of anthocyanin-based products.info:eu-repo/semantics/publishedVersio

Bounds on the mass of the b' quark, revisited

Recent results from the DELPHI collaboration led us to review the present bounds on the b' quark mass. We use all available experimental data for m_b' > 96 GeV to constrain the b' quark mass as a function of the Cabibbo-Kobayashi-Maskawa elements in a sequential four generations model. We find that there is still room for a b' with a mass larger than 96 GeV.Comment: 9 pages and 7 figures. REVTEX

Scaling violations: Connections between elastic and inelastic hadron scattering in a geometrical approach

Starting from a short range expansion of the inelastic overlap function, capable of describing quite well the elastic pp and $\bar{p}p$ scattering data, we obtain extensions to the inelastic channel, through unitarity and an impact parameter approach. Based on geometrical arguments we infer some characteristics of the elementary hadronic process and this allows an excellent description of the inclusive multiplicity distributions in $pp$ and $\bar{p}p$ collisions. With this approach we quantitatively correlate the violations of both geometrical and KNO scaling in an analytical way. The physical picture from both channels is that the geometrical evolution of the hadronic constituents is principally reponsible for the energy dependence of the physical quantities rather than the dynamical (elementary) interaction itself.Comment: 16 pages, aps-revtex, 11 figure

Photon polarization in radiative B decays

We study decay distributions in B -> K pi pi gamma, combining contributions from several overlapping resonances in a K pi pi mass range near 1400 MeV, (1^+) K_1(1400), (2^+) K^*_2(1430) and (1^-) K^*(1410). A method is proposed for using these distributions to determine a photon polarization parameter in the effective radiative weak Hamiltonian. This parameter is measured through an up-down asymmetry of the photon direction relative to the K pi pi decay plane. We calculate a dominant up-down asymmetry of 0.33 +- 0.05 from the K1(1400) resonance, which can be measured with about 10^8 B B-bar pairs, thus providing a new test for the Standard Model and a probe for some of its extensions.Comment: 22 pages, 3 figures, version to appear in Phys. Rev.

Nuclear effects in the Drell-Yan process at very high energies

We study Drell-Yan (DY) dilepton production in proton(deuterium)-nucleus and in nucleus-nucleus collisions within the light-cone color dipole formalism. This approach is especially suitable for predicting nuclear effects in the DY cross section for heavy ion collisions, as it provides the impact parameter dependence of nuclear shadowing and transverse momentum broadening, quantities that are not available from the standard parton model. For p(D)+A collisions we calculate nuclear shadowing and investigate nuclear modification of the DY transverse momentum distribution at RHIC and LHC for kinematics corresponding to coherence length much longer than the nuclear size. Calculations are performed separately for transversely and longitudinally polarized DY photons, and predictions are presented for the dilepton angular distribution. Furthermore, we calculate nuclear broadening of the mean transverse momentum squared of DY dileptons as function of the nuclear mass number and energy. We also predict nuclear effects for the cross section of the DY process in heavy ion collisions. We found a substantial nuclear shadowing for valence quarks, stronger than for the sea.Comment: 46 pages, 18 figures, title changed and some discussion added, accepted for publication in PR

Charm multiplicity and the branching ratios of inclusive charmless b quark decays in the general two-Higgs-doublet models

In the framework of general two-Higgs-doublet models, we calculate the branching ratios of various inclusive charmless b decays by using the low energy effective Hamiltonian including next-to-leading order QCD corrections, and examine the current status and the new physics effects on the determination of the charm multiplicity $n_c$ and semileptonic branching ratio $B_{SL}$. Within the considered parameter space, the enhancement to the ratio $BR(b \to s g)$ due to the charged-Higgs penguins can be as large as a factor of 8 (3) in the model III (II), while the ratio $BR(b \to no charm)$ can be increased from the standard model prediction of 2.49% to 4.91% (2.99%) in the model III (II). Consequently, the value of $B_{SL}$ and $n_c$ can be decreased simultaneously in the model III. The central value of $B_{SL}$ will be lowered slightly by about 0.003, but the ratio $n_c$ can be reduced significantly from the theoretical prediction of $n_c= 1.28 \pm 0.05$ in the SM to $n_c= 1.23 \pm 0.05$, $1.18 \pm 0.05$ for $m_{H^+}=200, 100$ GeV, respectively. We find that the predicted $n_c$ and the measured $n_c$ now agree within roughly one standard deviation after taking into account the effects of gluonic charged Higgs penguins in the model III with a relatively light charged Higgs boson.Comment: 25 pages, Latex file, axodraw.sty, 6 figures. Final version to be published in Phys.Rev.

Severe feed restriction increases permeability of mammary gland cell tight junctions and reduces ethanol stability of milk.

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