193 research outputs found

    Comparison of Brain Networks based on Predictive Models of Connectivity

    Full text link
    In this study we adopt predictive modelling to identify simultaneously commonalities and differences in multi-modal brain networks acquired within subjects. Typically, predictive modelling of functional connectomes from structural connectomes explores commonalities across multimodal imaging data. However, direct application of multivariate approaches such as sparse Canonical Correlation Analysis (sCCA) applies on the vectorised elements of functional connectivity across subjects and it does not guarantee that the predicted models of functional connectivity are Symmetric Positive Matrices (SPD). We suggest an elegant solution based on the transportation of the connectivity matrices on a Riemannian manifold, which notably improves the prediction performance of the model. Randomised lasso is used to alleviate the dependency of the sCCA on the lasso parameters and control the false positive rate. Subsequently, the binomial distribution is exploited to set a threshold statistic that reflects whether a connection is selected or rejected by chance. Finally, we estimate the sCCA loadings based on a de-noising approach that improves the estimation of the coefficients. We validate our approach based on resting-state fMRI and diffusion weighted MRI data. Quantitative validation of the prediction performance shows superior performance, whereas qualitative results of the identification process are promising.Comment: 7 pages, 4 figure

    Épica, crónicas y genealogías. En torno a la historicidad de la Leyenda de los infantes de Lara

    Get PDF
    [ES] Este trabajo analiza la historicidad de la narración épica conocida como Leyenda de los Infantes de Lara. Frente a la visión tradicional, que atribuía a este relato una gran fidelidad a los hechos históricos, se sugiere una imagen más compleja, que mezcla elementos nuevos y más antiguos: 1) Un posible núcleo histórico consistente en la historia de Ruy Velázquez; 2) Una parte más compacta formada por la trama de la venganza de sangre, que enlaza la traición con la venganza de Mudarra. Frente a la idea tradicional de que la venganza es una completa ficción elaborada mucho tiempo después, se sugiere que traición y venganza constituyen una unidad lógica, aunque no se relacione con hechos históricos concretos. Es muy probable que el núcleo central de la leyenda, tal y como nos ha llegado, sea más bien un conjunto amplio de temas y motivos entretejidos con hechos históricos más o menos desfigurados. Finalmente, todas estas piezas cobran sentido en su contexto geográfico: la leyenda parece estar reflejando un conflicto entre Lara y Salas, leído desde el punto de vista de Salas, con una clara hostilidad hacia Lara.Peer reviewe

    Therapeutic Management: When and What

    Get PDF
    Migraine is a widespread brain disease that is classified as the second most disabling condition and has the third highest prevalence of all medical conditions. Despite its non-emergent or life-threatening nature, migraine can progress to chronic type, a subform associated with significant morbidity and drug overuse. In the management of migraine, it is important therefore to introduce early prophylactic treatment in order to limit migraine chronification. In this chapter, we will go through all the treatment options, both acute and preventive, pharmaceutical and non-pharmaceutical following this flowchart: 1. Introduction; 2. General principles; 2.1 Symptomatic therapy; 2.2 Prophylactic management; 3. Pharmaceutical therapies; 3.1 Symptomatic; 3.1.1 Disease-specific; 3.1.2 No disease-specific; 3.2 Prophylactic; 3.2.1 Disease-specific; 3.2.2 No disease-specific; 3.3 Non-Pharmaceutical therapies; 3.4 Neuromodulation; 3.4.1 Invasive; 3.4.5 Non-invasive; 3.5 Nutrient (nutraceuticals); 3.6 Dietary interventions; 3.7 Acupuncture; 3.8 Physical therapy; 4. Cognitive behavioral therapies; 5. Patient centricity and patient education

    Preventing infection of osseointegrated transcutaneous implants: Incorporation of silver into preconditioned fibronectin-functionalized hydroxyapatite coatings suppresses Staphylococcus aureus colonization while promoting viable fibroblast growth in vitro

    Get PDF
    The success of transcutaneous implants depends on the achievement of a soft tissue seal by enabling fibroblasts to win the race for the surface against bacteria. Fibronectin-functionalized hydroxyapatite coatings (HAFn) have been shown to improve dermal tissue ingrowth and attachment. However, during the early postoperative period before a soft tissue seal has formed, bacterial colonization may occur. This study explored the incorporation of silver, a broad spectrum antimicrobial agent, into HAFn coatings with the aim of reducing bacterial colonization. Silver is known to have dose-dependent cytotoxic effects. Therefore, the effects of silver incorporation into HAFn coatings on both in vitro human dermal fibroblast viability and Staphylococcus aureus colonization were assessed. An electrochemical deposition technique was used to codeposit hydroxyapatite and silver (HAAg) and fibronectin was adsorbed onto this to produce HAAgFn coatings. Surfaces were preconditioned with serum to mimic the in vivo environment. Nonpreconditioned HAAg and HAAgFn coatings suppressed bacterial colonization but were cytotoxic. After serum-preconditioning, more than 90% of fibroblasts that grew on all HAAg and HAAgFn coatings were viable. The highest silver content coatings tested (HAAg100 and HAAgFn100) resulted in a greater than 99% reduction in biofilm and planktonic bacterial numbers compared to HA and HAFn controls. Although HAAg100 had greater antibacterial activity than HAAgFn100, the findings of this study indicate that fibroblasts would win the race for the surface against S aureus on both HAAg100 and HAAgFn100 after serum-preconditioning

    Appropriate use criteria for transesophageal echocardiography in Greece: A single center experience

    Get PDF
    Introduction The American College of Cardiology Foundation (ACCF) along with the American Society of Echocardiography (ASE) have enabled an accurate and clinically oriented evaluation of echocardiography indications by introducing Appropriate Use Criteria (AUC). Aim This study was designed to evaluate the degree of implementation of AUC for transesophageal echocardiography (TEE) during daily clinical practice in a tertiary university hospital in Greece during the era of economic recession. Materials and Methods From November 2014 to May 2014, we prospectively enrolled 300 patients who were examined in the Echocardiography Laboratory of the First University Cardiology. We recorded the participants' demographic and clinical characteristics using questionnaires and followed a scoring process according to ACCF guidelines to classify patients into an appropriate, inappropriate or uncertain category. The primary endpoint was to assess the association between the class of appropriateness and abnormal TEE results. Results In 89.4% of patients labelled appropriate, TEE was abnormal and significantly higher compared to patients of uncertain eligibility (50%) and to patients for whom TEE was considered to be inappropriate (35%) (p < 0.001). Subgroup analysis revealed a positive association between AUC and an increased possibility for abnormal TEE in female subjects (p = 0.001) as well as in patients who were younger than 50 years old (p < 0.001). A significant association was finally established between AUC and abnormal findings in TEE in patients with no risk factors (p = 0.028) and in patients with more than 3 risk factors (p = 0.013). Conclusion TEE constitutes a medical practice with an optimal cost/effectiveness ratio and should be further encouraged in our country in accordance with the austerity policy as long as the AUC are generally applied

    Functionalisation of Ti6Al4V components fabricated using selective laser melting with a bioactive compound

    Get PDF
    Surface modification of an implant with a biomolecule is used to improve its biocompatibility and to reduce post-implant complications. In this study, a novel approach has been used to functionalise phosphonic acid monolayers with a drug. Ti6Al4V components fabricated using selective laser melting (SLM) were functionalised with Paracetamol (a pharmaceutically relevant biomolecule) using phosphonic acid based self-assembled monolayers (SAMs). The attachment, stability of the monolayers on the SLM fabricated surface and functionalisation of SAMs with Paracetamol were studied using X-ray photoelectron spectroscopy (XPS) and surface wettability measurements. The obtained results confirmed that SAMs were stable on the Ti6Al4V surface for over four weeks and then began to desorb from the surface. The reaction used to functionalise the phosphonic acid monolayers with Paracetamol was noted to be successful. Thus, the proposed method has the potential to immobilise drugs/proteins to SAM coated surfaces and improve their biocompatibility and reduce post-implant complications

    In Vitro Generation of Cartilage-Carrier-Constructs on Hydroxylapatite Ceramics with Different Surface Structures

    Get PDF
    Tissue engineering approaches for healing cartilage defects are partly limited by the inability to fix cartilage to bone during implantation. To overcome this problem, cartilage can be - already in vitro - generated on a ceramic carrier which serves as bone substitute. In this study, the influence of a hydroxylapatite carrier and its surface structure on the quality of tissue engineered cartilage was investigated. Application of the carrier reduced significantly biomechanical and biochemical properties of the generated tissue. In addition, slight changes in the quality of the formed matrix, in the adhesive strength between cartilage and biomaterial and in attachment and proliferation of a chondrocyte monolayer could be observed for commercial grade carriers, with respect to modified topographies obtained by smooth grinding/polishing. These first results demonstrated an influence of the carrier and its surface structure, but further research is needed for explaining the described effects and for optimization of cartilage-carrier-constructs

    Regulation of Epithelial Cell Morphology and Functions Approaching To More In Vivo-Like by Modifying Polyethylene Glycol on Polysulfone Membranes

    Get PDF
    Cytocompatibility is critically important in design of biomaterials for application in tissue engineering. However, the currently well-accepted “cytocompatible" biomaterials are those which promote cells to sustain good attachment/spreading. The cells on such materials usually lack the self-assembled cell morphology and high cell functions as in vivo. In our view, biomaterials that can promote the ability of cells to self-assemble and demonstrate cell-specific functions would be cytocompatible. This paper examined the interaction of polyethylene glycol (PEG) modified polysulfone (PSf) membranes with four epithelial cell types (primary liver cells, a liver tumor cell line, and two renal tubular cell lines). Our results show that PSf membranes modified with proper PEG promoted the aggregation of both liver and renal cells, but the liver cells more easily formed aggregates than the renal tubular cells. The culture on PEG-modified PSf membranes also enhanced cell-specific functions. In particular, the cells cultured on F127 membranes with the proper PEG content mimicked the in vivo ultrastructure of liver cells or renal tubules cells and displayed the highest cell functions. Gene expression data for adhesion proteins suggest that the PEG modification impaired cell-membrane interactions and increased cell-cell interactions, thus facilitating cell self-assembly. In conclusion, PEG-modified membrane could be a cytocompatible material which regulates the morphology and functions of epithelial cells in mimicking cell performance in vivo

    Increased sporulation underpins adaptation of Clostridium difficile strain 630 to a biologically–relevant faecal environment, with implications for pathogenicity

    Get PDF
    Abstract Clostridium difficile virulence is driven primarily by the processes of toxinogenesis and sporulation, however many in vitro experimental systems for studying C. difficile physiology have arguably limited relevance to the human colonic environment. We therefore created a more physiologically–relevant model of the colonic milieu to study gut pathogen biology, incorporating human faecal water (FW) into growth media and assessing the physiological effects of this on C. difficile strain 630. We identified a novel set of C. difficile–derived metabolites in culture supernatants, including hexanoyl– and pentanoyl–amino acid derivatives by LC-MSn. Growth of C. difficile strain 630 in FW media resulted in increased cell length without altering growth rate and RNA sequencing identified 889 transcripts as differentially expressed (p < 0.001). Significantly, up to 300–fold increases in the expression of sporulation–associated genes were observed in FW media–grown cells, along with reductions in motility and toxin genes’ expression. Moreover, the expression of classical stress–response genes did not change, showing that C. difficile is well–adapted to this faecal milieu. Using our novel approach we have shown that interaction with FW causes fundamental changes in C. difficile biology that will lead to increased disease transmissibility
    corecore