BIOLIF: Artrodese lombar intersomática - abordagem não instrumentada

Tese de doutoramento em MedicinaSpinal fusion (SF) is a surgical procedure conducted to promote bone growth in-between spinal segments, supported by fixation hardware, and complemented by bone graft or bone substitute. There are recognized risks and complications associated with instrumentation, such as damage to surrounding tissues, neurological deficits, material failure or migration and non-union. In this thesis, a novel approach is proposed based on the development of an adhesive, biodegradable and injectable foam, with the purpose to avoid instrumentation in SF. Carbon dioxide foaming was explored as processing methodology to generate, within physiologically compatible conditions, polycaprolactone (PCL) foams with morphological characteristics equivalent to those found in trabecular bone. A three-dimensional, mechanically stable and bioactive composite of PCL+βTCP+Dexamethasone was foamed at 45ºC and 5 MPa. This optimized PCL processing opened the possibility for creating a porous foam, delivered directly into the intervertebral space through a surgical tool designed and built for this purpose. The adhesive properties of PCL were further improved through modification with polydopamine (pDA) and polymethacrylic acid (pMAA). After tensile testing, PCL pDA pMAA material–bone interface remained intact at both ends (adhesivity significantly superior to non-modified PCL, p<0.05). Further in vitro assays confirmed the formulation as non-cytotoxic and bioactive (calcium phosphate (CaP) layer formation). Lastly, the surgical feasibility of PCL pDA pMAA foaming and its biological performance for non instrumented spinal fusion were assessed in a 6-month survival study using an interbody fusion porcine model. Segmental instrumented arthrodesis was used as control group. Minimally invasive in situ foaming of PCL pDA pMAA (BIOLIF) was technically achieved, leading to reduced surgical time (p<0.05) as compared to instrumentation. Animals in BIOLIF approach demonstrated no surgical complications and a higher mobility (p<0.05) at immediate post-op. Spinal fusion was determined by a set of assessments including: i) bone volume/ tissue volume percentage (BV/TV), superior in BIOLIF group (p<0.05); ii) reduced range of motion and increased stiffness of the treated spinal segment, equivalent in both groups; and iii) a relatively well-organized newly formed osseous structure identified by histological analysis at BIOLIF samples. As conclusion, the results obtained in this work could open a new perspective for lumbar instrumentation-free spinal fusion using biologic solutions.A artrodese da coluna vertebral é um procedimento cirúrgico que visa a indução de crescimento ósseo entre segmentos vertebrais, utilizando sistemas de fixação e suplementação com enxerto ósseo ou substituto sintético. São reconhecidos riscos e complicações associados à instrumentação, incluindo, danos nos tecidos circundantes, compromisso neurológico, risco de mobilização ou migração do material e pseudartrose. Nesta tese, é proposta uma nova abordagem, baseada no desenvolvimento de uma espuma adesiva, biodegradável e injetável, de forma de realizar artrodese intersomática lombar sem recurso a instrumentação. A tecnologia supercrítica/subcrítica foi explorada para a produção de uma espuma de policaprolactona (PCL), em condições fisiologicamente compatíveis, com características morfológicas equivalentes às encontradas no osso trabecular. Foi possível obter a 45ºC e 5 MPa, uma estrutura tridimensional de PCL+βTCP+Dexametasona mecanicamente estável e com propriedades bioativas. Estas condições tornaram possível a extrusão da espuma diretamente no espaço intersomático, através de um instrumento cirúrgico desenvolvido para esse efeito. As propriedades adesivas do PCL foram otimizadas através da modificação do polímero com polidopamina (pDA) e ácido polimetacrílico (pMAA), que se demonstrou significativamente mais adesivo do que o PCL p<0,05 em ensaios mecânicos de tração. As propriedades citocompatíveis e bioativas da formulação foram confirmadas em ensaios in vitro. Por fim, a exequibilidade cirúrgica da extrusão da espuma de PCL pDA pMAA, e o seu desempenho biológico, foram avaliados num estudo de sobrevida de 6 meses usando o porco doméstico como modelo animal. Como grupo de controlo foi realizada artrodese intersomática instrumentada. Foi tecnicamente possível efetuar extrusão in situ de PCL pDA pMAA (BIOLIF) por via minimamente invasiva, sendo o tempo de procedimento cirúrgico significativamente inferior (p<0,05) ao grupo da instrumentação. Os animais do grupo BIOLIF não demonstraram complicações cirúrgicas e apresentaram uma maior mobilidade (p<0,05) no pós-operatório imediato. A qualidade da artrodese foi avaliada por um conjunto de parâmetros: i) a relação volume ósseo/ volume total (BV/TV), superior no grupo BIOLIF (p<0,05); ii) a redução da amplitude de movimento e o aumento da rigidez do segmento vertebral intervencionado, equivalente em ambos os grupos; e iii) uma estrutura óssea recém-formada relativamente bem-organizada no grupo BIOLIF, identificada por análise histológica. Em conclusão, os resultados obtidos neste trabalho podem abrir uma nova perspectiva para a utilização de soluções biológicas como forma de realizar artrodese intersomática lombar sem recurso a instrumentação.Portuguese Foundation for Science and Technology (FCT) - projects UIDB/50026/2020 and UIDP/50026/2020

Subcritical carbon dioxide foaming of polycaprolactone for bone tissue regeneration

Accepted manuscriptThe preparation of three-dimensional polycaprolactone scaffolds using dense CO2 as foaming agent, without supercritical conditions, was evaluated in this study towards future applications in bone repair. Herein, 3D foams were obtained at 5.0 MPa and 45 °C. To induce bioactivity, β-tricalcium phosphate (β-TCP, 10 wt%) and dexamethasone (5 and 10 wt%) were dispersed in the scaffolds. Foams revealed a pore size range of 164–882 μm, 73–99% porosity and 79–99% interconnectivity, assessed by micro-computed tomography, and a Young modulus of 1.76–2.92 MPa. Dexamethasone did not impair morphology of the matrices in comparison with PCL+β-TCP, which presented a water uptake of nearly 100% after 14 days. A sustained release of dexamethasone was achieved over 35 days in physiologic solution. This study reports the feasibility of using dense CO2 to produce in one-step a porous matrix loaded with active agents opening new possibilities towards injectable systems for in situ foamingEuropean Union Seventh Framework Programme (FP7/2007-2013) under grant agreement number REGPOT-CT2012-316331-POLARIS. It was also funded by the project “Novel smart and biomimetic materials for innovative regenerative medicine approaches” (RL1-ABMR-NORTE-01-0124-FEDER-000016) co-financed by North Portugal Regional Operational Programme (ON.2 – O Novo Norte), under the National Strategic Reference Framework (NSRF), through the European Regional Development Fund (ERDF) and the project NORTE‐01‐0145‐FEDER‐000013, supported by the Northern Portugal Regional Operational Programme (NORTE 2020), under the Portugal 2020 Partnership Agreement. The authors would like to acknowledge the funding of the project Associate Laboratory ICVS/3B’s, under grant agreement number POCI-01-0145-FEDER-007038 supported by FEDER, through the Competitiveness Factors Operational Programme (COMPETE), and by National funds, through the Foundation for Science and Technology (FCT)info:eu-repo/semantics/publishedVersio

Characterization of polymorphic microsatellite loci in the Antarctic krill Euphausia superba

Background: The Antarctic krill, Euphausia superba is a pelagic crustacean, abundant in high-density swarms (10 000 – 30 000 ind/m2) with a circumpolar distribution and a key role in the food web of the Southern Ocean. Only three EST derived microsatellite markers have been used in previous genetic studies, hence we developed additional highly polymorphic microsatellite markers to allow robust studies of the genetic variability and population differentiation within this species. Findings: The microsatellite markers described here were obtained through an enriched genomic library, followed by 454 pyrosequencing. A total of 10 microsatellite markers were tested in 32 individuals from the Antarctic Peninsula. One of the tested loci was fixed for one allele while the other was variable. Of the remaining nine markers, seven showed no departure from Hardy-Weinberg equilibrium. The mean number of alleles was 14.9. Conclusions: These markers open perspectives for population genetic studies of this species to unravel genetic structure, dispersal and population biology, vital information for future conservation.Peer Reviewe

Development of new vocational training modules on sustainable buildings maintenance and refurbishment

This article presents the methodology and main results obtained in Spain within the FORMAR project, a European-funded project under the Leonardo Da Vinci scheme (Lifelong Learning Programme), whose main goal is to jointly develop training resources and modules to improve the skills on sustainability issues of buildings maintenance and refurbishment workers, in three different European countries: Spain, Portugal (Project Coordinator) and France. The Units of Short-term Training (UST) developed within this project are focused on the VET of carpenters, painters, bricklayers, building technicians and installers of solar panels, and a transversal unit containing basic concepts on sustainable construction and nearly Zero Energy Buildings (n-ZEB) is also developed. In parallel, clients’ guides for the aforementioned professionals are also implemented to improve the information provided to clients and owners in order to support the procurement decisions regarding building products and materials. Therefore, the project provides an opportunity to exchange experiences between organizations of these three European countries, as the UST will be developed simultaneously in each of them, exploring opportunities for training, guidance and exchange of experience. Even though the UST will have a common structure and contents, they will be slightly different in each country to adapt them to the different specific training needs and regulations of Spain, Portugal and France. This paper details, as a case study, the development process of the UST for carpenters and building technicians in Spain, including the analysis of needs and existing training materials, the main contents developed and the evaluation and testing process of the UST, which involves the active participation of several stakeholders of this sector as well as a classroom testing to obtain the students’ feedback

Decavanadate interactions with actin: cysteine oxidation and vanadyl formation

Incubation of actin with decavanadate induces cysteine oxidation and oxidovanadium(IV) formation. The studies were performed combining kinetic with spectroscopic (NMR and EPR) methodologies. Although decavanadate is converted to labile oxovanadates, the rate of deoligomerization can be very slow (half-life time of 5.4 h, at 25 ◦C, with a first order kinetics), which effectively allows decavanadate to exist for some time under experimental conditions. It was observed that decavanadate inhibits F-actin-stimulated myosin ATPase activity with an IC50 of 0.8 mMV10 species, whereas 50 mMof vanadate or oxidovanadium(IV) only inhibits enzyme activity up to 25%. Moreover, from these three vanadium forms, only decavanadate induces the oxidation of the so called “fast” cysteines (or exposed cysteine, Cys-374) when the enzyme is in the polymerized and active form, F-actin, with an IC50 of 1 mMV10 species. Decavanadate exposition to F- and G-actin (monomeric form) promotes vanadate reduction since a typical EPR oxidovanadium(IV) spectrum was observed. Upon observation that V10 reduces to oxidovanadium(IV), it is proposed that this cation interacts with G-actin (Kd of 7.48 ± 1.11 mM), and with F-actin (Kd = 43.05 ± 5.34 mM) with 1:1 and 4:1 stoichiometries, respectively, as observed by EPR upon protein titration with oxidovanadium(IV). The interaction of oxidovanadium(IV) with the protein may occur close to the ATP binding site of actin, eventually with lysine-336 and 3 water molecules

Models with extended Higgs sectors at future e⁺e⁻ colliders

We discuss the phenomenology of several beyond the Standard Model (SM) extensions that include extended Higgs sectors. The models discussed are the SM extended by a complex singlet field, the 2-Higgs-doublet model with a CP-conserving and a CP-violating scalar sector, the singlet extension of the 2-Higgs-doublet model, and the next-to-minimal supersymmetric SM extension. All the above models have at least three neutral scalars, with one being the 125 GeV Higgs boson. This common feature allows us to compare the production and decay rates of the other two scalars and therefore to compare their behavior at future electron-positron colliders. Using predictions on the expected precision of the 125 GeV Higgs boson couplings at these colliders we are able to obtain the allowed admixtures of either a singlet or a pseudoscalar to the observed 125 GeV scalar. Therefore, even if no new scalar is found, the expected precision at future electron-positron colliders, such as CLIC, will certainly contribute to a clearer picture of the nature of the discovered Higgs boson

Staining techniques for ageing tope shark, Galeorhinus galeus (Linnaeus, 1758), from the Azores : a comparison based on precision analysis.

A vertebrae sample of tope shark, Galeorhinus galeus (Linnaeus, 1758), stratified by sizeclasses,was used to test between different staining techniques of enhancing vertebral growth ring visibility. Four techniques were tested: alizarin red, silver nitrate and cobalt nitrate staining, and the “deep-coned vertebrae” technique. The latter was discarded due to its unsuitability for tope shark vertebrae. The cobalt nitrate original protocol was modified. Upon staining, each vertebra was subject to three replicated independent readings, by a single reader. Within-reader consistency and bias of growth ring counts determination were evaluated using four different precision indices: percent of agreement (PA), average percent error (APE), coefficient of variation (V) and index of precision (D). Results indicated that the vertebrae stained with the cobalt nitrate technique showed both better optic enhancement of growth rings and higher degree of count consistency, comparatively to the alizarin red and silver stained vertebrae. Conclusively, the cobalt nitrate was the most efficient staining technique upon tope shark vertebrae, among the methods tested herein

Engineering students can use the words “calculus” and “love” in the same sentence: using active learning the impossible can happen

Teaching Calculus can be one of the most challenging practices in the engineering context for a number of reasons, namely: taught at the beginning of engineering courses, introducing to the student in a critical phase of his/her transition between high school and university, not understanding the meaning of some contents in relation to Engineering. The disciplines of Calculus are responsible for high failure rates and students’ dropout. Lectures are predominantly used to teach Calculus in engineering context, with rigid contents centered on the blackboard and in the book. Therefore, students have low interaction with teachers and they have difficult to build their own knowledge and to understand the importance of mathematical methods, and procedures. However, project based learning was used to teach Calculus to engineering students. Students were asked to choose a phenomenon of their Engineering area of knowledge and explain why and how it needs integrals and derivatives to be explained. 127 students from six engineering courses were involved in the experiment. The students were organized in teams and tutored by other professors. This paper aims to describe the experience and analyze the outcomes terms of the perception of learning and development of transversal competences. The evaluation was based on content analysis of the reports delivered by the students. 100% of the groups evaluated the experience as positive. The students used adjectives such as "excellent", "extraordinary" to characterize the experience. In addition, students reported the following learning outcomes: knowledge and understanding; analysis; problem-solving; creativity/originality; communication and presentation; evaluation; planning and organization; interactive and group competences. Some groups reported that, in this project, they created prototypes that they will keep on researching and developing to take these ideas to the market. Yet, in this experience, the failure rate of this disciplThis work has been partially supported by projects COMPETE-POCI-01-0145-FEDER-007043 and FCT-UID-CEC-00319-2013, from Portugal

CP in the dark

We build a model containing two scalar doublets and a scalar singlet with a specific discrete symmetry. After spontaneous symmetry breaking, the model has Standard Model-like phenomenology, as well as a hidden scalar sector which provides a viable dark matter candidate. We show that CP violation in the scalar sector occurs exclusively in the hidden sector, and consider possible experimental signatures of this CP violation.We acknowledge the contribution of the research training group GRK1694 'Elementary particle physics at highest energy and highest precision'. PF and RS are supported in part by the National Science Centre, Poland, the HARMONIA project under contract UMO-2015/18/M/ST2/00518 and by a CERN fund grant CERN/FIS-PAR/0002/2017. JW gratefully acknowledges funding from the PIER Helmholtz Graduate School.info:eu-repo/semantics/publishedVersio

Evaluation of the psychometric properties of the portuguese peabody developmental motor scales - 2 edition: a study with children aged 12 to 48 months

The purpose of this study was to examine the psychometric properties of Peabody Developmental Motor Scales II (PDMS-2-Folio and Fewell, 2000) using a Portuguese sample. The validation of the Portuguese version of the PDMS-2 was applied according to the manual, for 392 children, from two institutions, from 12 to 48 months, with an analysis of the internal consistency (α Cronbach), of test–retest reliability (ICC) and construct validity (confirmatory factor analysis). The results of the confirmatory factorial analysis (χ2 = 55.614; df = 4; p = 0.06; χ2/df =13.904; SRMR (Standardized Root Mean Square Residual) = 0.065; CFI (Comparative Fit Index) = 0.99, TLI = 0.99, RMSEA (Root Mean Square Error of Approximation) = 0.068) of two factors (Gross Motor and Fine Motor) as the original version but correlated. Most of the subtests had good internal consistency (α = 0.85) and good test–retest stability (ICC = 0.98 to 0.99). The results indicated that the Portuguese version of the PDMS-2 is adequate and valid for assessing global and fine motor skills in children aged 12 to 48 months, and can be used as a reference tool by health and education professionals to assess motor skills and, thus, allowing to detect maladjustments, deficiencies or precocity, so that children can later receive appropriate intervention.info:eu-repo/semantics/publishedVersio