Cell adhesion evaluation of laser-sintered HAp and 45S5 bioactive glass coatings on micro-textured zirconia surfaces using MC3T3-E1 osteoblast-like cells

Laser texturing is a technique that has been increasingly explored for the surface modification of several materials on different applications. Laser texturing can be combined with conventional coating techniques to functionalize surfaces with bioactive properties, stimulating cell differentiation and adhesion. This study focuses on the cell adhesion of laser-sintered coatings of hydroxyapatite (HAp) and 45S5 bioactive glass (45S5 BG) on zirconia textured surfaces using MC3T3-E1 cells. For this purpose, zirconia surfaces were micro-textured via laser and then coated with HAp and 45S5 BG glass via dip coating. Afterwards, the bioactive coatings were laser sintered, and a reference group of samples was conventionally sintering. The cell adhesion characterisation was achieved by cell viability performing live/dead analysis using fluorescence stains and by SEM observations for a qualitative analysis of cell adhesion. The in vitro results showed that a squared textured pattern with 100μm width grooves functionalized with a bioactive coating presented an increase of 90% of cell viability compared to flat surfaces after 48h of incubation. The functionalized laser sintered coatings do not present significant differences in cell viability when compared to conventionally sintered coatings. Therefore, the results reveal that laser sintering of HAp and 45S5 BG coatings is a fast and attractive coating technique.publishe

Spider peptide toxin HwTx-IV engineered to bind to lipid membranes has an increased inhibitory potency at human voltage-gated sodium channel hNaV1.7

The human voltage-gated sodium channel sub-type 1.7 (hNaV1.7) is emerging as an attractive target for the development of potent and sub-type selective novel analgesics with increased potency and fewer side effects than existing therapeutics. HwTx-IV, a spider derived peptide toxin, inhibits hNaV1.7 with high potency and is therefore of great interest as an analgesic lead. In the current study we examined whether engineering a HwTx-IV analogue with increased ability to bind to lipid membranes would improve its inhibitory potency at hNaV1.7. This hypothesis was explored by comparing HwTx-IV and two analogues [E1PyrE]HwTx-IV (mHwTx-IV) and [E1G,E4G,F6W,Y30W]HwTx-IV (gHwTx-IV) on their membrane-binding affinity and hNaV1.7 inhibitory potency using a range of biophysical techniques including computational analysis, NMR spectroscopy, surface plasmon resonance, and fluorescence spectroscopy. HwTx-IV and mHwTx-IV exhibited weak affinity for lipid membranes, whereas gHwTx-IV showed improved affinity for the model membranes studied. In addition, activity assays using SH-SY5Y neuroblastoma cells expressing hNaV1.7 showed that gHwTx-IV has increased activity at hNaV1.7 compared to HwTx-IV. Based on these results we hypothesize that an increase in the affinity of HwTx-IV for lipid membranes is accompanied by improved inhibitory potency at hNaV1.7 and that increasing the affinity of gating modifier toxins to lipid bilayers is a strategy that may be useful for improving their potency at hNaV1.7

Isothermal section of the ternary phase diagram U–Fe–Ge at 900 °C and its new intermetallic phases

International audienc

Autopsy in adults with congenital heart disease (ACHD).

The adult congenital heart diseases (ACHD) population is exceeding the pediatric congenital heart diseases (CHD) population and is progressively expanding each year, representing more than 90% of patients with CHD. Of these, about 75% have undergone surgical and/or percutaneous intervention for palliation or correction. Autopsy can be a very challenging procedure in ACHD patients. The approach and protocol to be used may vary depending on whether the pathologists are facing native disease without surgical or percutaneous interventions, but with various degrees of cardiac remodeling, or previously palliated or corrected CHD. Moreover, interventions for the same condition have evolved over the last decades, as has perioperative myocardial preservations and postoperative care, with different long-term sequelae depending on the era in which patients were operated on. Careful clinicopathological correlation is, thus, required to assist the pathologist in performing the autopsy and reaching a diagnosis regarding the cause of death. Due to the heterogeneity of the structural abnormalities, and the wide variety of surgical and interventional procedures, there are no standard methods for dissecting the heart at autopsy. In this paper, we describe the most common types of CHDs that a pathologist could encounter at autopsy, including the various types of surgical and percutaneous procedures and major pathological manifestations. We also propose a practical systematic approach to the autopsy of ACHD patients

Reducing the impact of radioactivity on quantum circuits in a deep-underground facility

As quantum coherence times of superconducting circuits have increased from nanoseconds to hundreds of microseconds, they are currently one of the leading platforms for quantum information processing. However, coherence needs to further improve by orders of magnitude to reduce the prohibitive hardware overhead of current error correction schemes. Reaching this goal hinges on reducing the density of broken Cooper pairs, so-called quasiparticles. Here, we show that environmental radioactivity is a significant source of nonequilibrium quasiparticles. Moreover, ionizing radiation introduces time-correlated quasiparticle bursts in resonators on the same chip, further complicating quantum error correction. Operating in a deep-underground lead-shielded cryostat decreases the quasiparticle burst rate by a factor fifty and reduces dissipation up to a factor four, showcasing the importance of radiation abatement in future solid-state quantum hardware

Criteria to predict carriers of a novel SCN5A mutation in a large Portuguese family affected by the Brugada syndrome

Brugada syndrome (BrS) is a life-threatening arrhythmia disorder associated with autosomal-dominant mutations in the SCN5A gene. We aimed to characterize the diagnostic challenges and clinical manifestations of a novel SCN5A mutation associated with BrS.info:eu-repo/semantics/publishedVersio

Disability-adjusted life years lost due to ischemic heart disease in mainland Portugal, 2013

Introdução e objetivos: A carga de doença atribuível à doença isquémica do coração (DIC), nomeadamente possíveis diferenças regionais, deve orientar políticas de saúde. Pretendemos estimar a carga de doença atribuível a DIC em Portugal continental em 2013, através do cálculo dos anos de vida saudável perdidos (DALY) e comparar estas estimativas entre regiões. Métodos: Calcularam-se os anos de vida perdidos (YLL) multiplicando o número de mortes por DIC em 2013 (Instituto Nacional de Estatística) pela esperança média de vida à idade da morte. Estimaram-se os anos vividos com incapacidade (YLD) através do número de casos de síndrome coronária aguda, angina estável e insuficiência cardíaca isquémica. Os DALY brutos e padronizados para a idade (método direto, população-padrão europeia) foram calculados para Portugal continental e para as regiões Norte, Centro, Lisboa, Alentejo e Algarve. Resultados: Em 2013, perderam-se 95 413 DALY em Portugal por DIC. Destes, 88,3% foram por morte prematura. A taxa de DALY perdidos por 1000 habitantes padronizada para a idade foi mais elevada nos homens em todo o país (8,9 nos homens; 3,4 nas mulheres) e em cada região, variando de 7,3 no Norte e Centro até 11,8 no Algarve nos homens, e de 2,6 no Norte a 4,6 em Lisboa nas mulheres. Conclusões: Quase 100 mil DALY foram perdidos em Portugal devido a DIC, essencialmente por mortalidade prematura. Este estudo permite comparar a carga de doença com outros países e entre regiões, salientando-se, no entanto, a necessidade de estudos de base populacional que forneçam informação específica de morbilidade.This project was supported by FEDER funds from Programa Operacional Factores de Competitividade --- COMPETE (FCOMP-01-0124-FEDER-028709) and by national funds from the Portuguese Foundation for Science and Technology, Lisbon, Portugal (PTDC/DTP-EPI/0434/2012) and by the Epidemiology Research Unit --- Institute of Public Health, University of Porto (UID/DTP/047507/2013). We would like to thank the Central Administration of the Health System (ACSS) for data from the National Hospital Discharge Register

Photoluminescence investigations of 2D hole Landau levels in p-type single Al_{x}Ga_{1-x}As/GaAs heterostructures

We study the energy structure of two-dimensional holes in p-type single Al_{1-x}Ga_{x}As/GaAs heterojunctions under a perpendicular magnetic field. Photoluminescence measurments with low densities of excitation power reveal rich spectra containing both free and bound-carrier transitions. The experimental results are compared with energies of valence-subband Landau levels calculated using a new numerical procedure and a good agreement is achieved. Additional lines observed in the energy range of free-carrier recombinations are attributed to excitonic transitions. We also consider the role of many-body effects in photoluminescence spectra.Comment: 13 pages, 10 figures, accepted to Physical Review