University of Aveiro

Spinal cord injury results in severe sensory and motor deficits, with a dramatic impact on lifespan and healthspan, due to the limited regenerative capacity of the central nervous system. Following the initial injury, glial scarring and extracellular matrix barriers prevent axonal regeneration, while secondary damage exacerbates inflammation and tissue loss. The gold standard treatment in the last decades is acute surgery and systemic drug administration. New technologies have been developed, such as stem cell therapies, or the combinatory use of biomaterials, nonetheless still offering limited recovery. Successful therapies must act directly on neurons, activating regenerative pathways, while simultaneously promoting a pro-regenerative environment. However, polymeric materials have, in recent years, shown a regenerative potential through a series of different processes, from promoting neural regeneration by supporting tissue repair and reducing inflammation, to local drug delivery mechanisms. In this work, we systematize the state-of-the-art, exploring recent advancements in polymer-based therapies for spinal cord injury, discussing their characteristics, limitations, and promising future applications.

Feline malignant mammary tumors are frequently aggressive and associated with poor clinical outcomes. Over the years, the prognostic value of various clinical and pathological parameters has been investigated, though findings are not always consensual. Histologically, feline malignant mammary tumors are heterogenous tumors, and a recent revision of the 1999 World Health Organization (WHO) classification of canine and feline mammary tumors may provide a more accurate picture of their biological behavior. This study aimed to analyze and compare the 1999 WHO classification and the 2019 updated surgical pathology classification in the same case series. Additionally, we seek to evaluate the prognostic value of several clinicopathological features, including both histological classification systems. Our findings revealed that the 2019 revised surgical pathology classification allowed for a greater stratification of feline mammary tumors (FMT) compared to the 1999 WHO classification system. Notably, longer survival times were observed in queens with ductal-associated carcinomas. Other clinicopathological features were associated with unfavorable clinical outcomes, namely presence of multiple synchronous malignant mammary tumors, larger tumor size, higher clinical stage, infiltrative tumor growth and lymphovascular invasion (p ≤ 0.05). Additionally, our findings suggest that the prognostic relevance of each parameter may vary according to the clinical endpoint, warranting careful consideration during clinical interpretation. DATA AVAILABILITY: The data presented in this study are available from the corresponding author upon reasonable request.

The authentication of commercial herbal products such as herbal teas and infusions is essential to ensure consumer safety and product integrity. In this study, 100 commercial herbal infusions, including 94 single-species products and six polyherbal formulations, were analysed using DNA barcoding ( matK and rbcL ) and ITS2 metabarcoding. Moreover, the performance of two custom reference databases (NCBI and BOLD) was compared in ITS2 metabarcoding. DNA extraction was successful for 94 samples, while six single-species products failed to amplify any of the tested barcodes. Among the 88 remaining single-species samples, ITS2 showed the highest amplification success (100 %), outperforming the barcodes rbcL (94 %) and matK (84 %). Sanger sequencing confirmed the labelled species in 69.3 % of cases with rbcL and 48.9 % with matK . While 63 samples would be considered authentic solely based on barcoding (i.e., if either rbcL or matK matched the label), ITS2 metabarcoding revealed that many of these contained additional undeclared species, indicating that barcoding alone overestimated product authenticity. Of the 85 samples successfully analysed by ITS2 metabarcoding, only 27 (32 %) fully matched their label, while 58 (68 %) contained either additional undeclared species or complete substitutions. Several products contained undeclared species in significant proportions, indicating potential economic adulteration. Analysis of mock-mixtures demonstrated that ITS2 metabarcoding can approximate ingredient proportions, though recovery bias may occur. Overall, the results revealed (i) the importance of curated and comprehensive databases, with a higher number of species being identified by NCBI database, (ii) the superior sensitivity of ITS2 metabarcoding, and (iii) the widespread mislabelling in commercial herbal products. • The authenticity of 100 commercial herbal infusions was evaluated. • Results from two approaches, DNA barcoding and metabarcoding, were compared. • Two custom reference databases (NCBI and BOLD) were developed for ITS2 metabarcoding. • ITS2 metabarcoding revealed a high level of adulteration (68 %). • ITS2 allowed the detection of fungal contaminants in some samples.

Bismuth ferrite (BiFeO3) is a promising material for developing the next generation of multifunctional electronic devices. However, the production of high-quality BiFeO3 thin films is compromised by the tendency for structural and electronic defects to form during synthesis, which degrades their functional properties. In this work, BiFeO3 thin films were prepared by chemical solution deposition to determine optimal conditions for minimizing oxygen vacancies and to evaluate the impact of these point defects on their physical properties. The films were pyrolyzed at 300 °C for 60 min and 360 °C for 10 min, and crystallized in air and in an O2 atmosphere, at 600 °C and 640 °C for 40 min. High oxygen vacancies were observed in films prepared at low pyrolysis temperatures and crystallized in air, whereas oxygen vacancies were minimized in the film pyrolyzed and crystallized at high temperatures in an O2 atmosphere. The oxygen vacancies markedly affected the films' physical properties, leading to increased dielectric loss, dielectric dispersion, dc conductivity, and leakage current, with consequent degradation of photovoltaic and magnetic performance. These findings highlight the critical importance of controlling synthesis parameters to suppress oxygen vacancy formation and achieve high-quality BiFeO3 thin films.

Abstract We consider matrix orthogonal polynomials related to Bessel type matrices of weights that can be defined in terms of a given matrix Pearson equation. From a Riemann–Hilbert problem we derive first and second order differential relations for the matrix orthogonal polynomials and functions of second kind. It is shown that the corresponding matrix recurrence coefficients satisfy a non-Abelian extension of a family of discrete Painlevé d-PIV equations. We present some nontrivial examples of matrix orthogonal polynomials of Bessel type.

Additive manufacturing, particularly 3D printing, is increasingly shaping the production of polymer-based components, enabling complex geometries and tailored functional performance.Yet, predicting their mechanical behavior remains challenging due to material anisotropy and sensitivity to processing conditions.This work presents an exploratory study designed to provide the experimental basis for the development and calibration of predictive models of mechanical properties in 3D-printed components.Standard ISO 527-2 Type 1A specimens were fabricated using thermoplastic PLA (polylactic acid) with systematic variations in layer orientation, infill overlap, and printing velocity.Mechanical characterization was carried out through uniaxial tensile testing to determine tensile strength and stiffness of the material specimens, while scanning electron microscopy (SEM) provided complementary insights into interlayer bonding, filament alignment, porosity, and fracture morphology.Results showed that material type and processing strategies strongly influenced mechanical response, with SEM highlighting microstructural features that govern interlayer adhesion and failure mechanisms.These findings contribute to a deeper understanding of process-structure-property relationships in additive manufacturing and establish the groundwork for predictive model development.Ongoing efforts will integrate these experimental insights into numerical simulations employing homogenized material models, thereby enhancing design optimization and reliability of 3D-printed structural components.