371 research outputs found

    Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation

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    We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed

    Efficient out-coupling and beaming of Tamm optical states via surface plasmon polariton excitation

    Get PDF
    We present evidence of optical Tamm states to surface plasmon polariton (SPP) coupling. We experimentally demonstrate that for a Bragg stack with a thin metal layer on the surface, hybrid Tamm-SPP modes may be excited when a grating on the air-metal interface is introduced. Out-coupling via the grating to free space propagation is shown to enhance the transmission as well as the directionality and polarization selection for the transmitted beam. We suggest that this system will be useful on those devices, where a metallic electrical contact as well as beaming and polarization control is needed

    Faecalibacterium prausnitzii A2-165 has a high capacity to induce IL-10 in human and murine dendritic cells and modulates T cell responses

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    Acknowledgements This work was financially supported by the EC FP7 Cross-talk project (PITN-GA-2008-215553). The authors thank the Histology Platform from GABI research unit and especially Abdelhak Boukadiri for their technical support in the histology sample preparation and Marlène Héry, Charline Pontlevoy, Jerome Pottier and André Tiffoche (UE0907 IERP, Jouy en Josas) for their help during animal experiments. The authors thank Rafael Muñoz-Tamayo (INRA) for his help in performing the PCA.Peer reviewedPublisher PD

    The right ventricle in tetralogy of Fallot:adaptation to sequential loading

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    Right ventricular dysfunction is a major determinant of outcome in patients with complex congenital heart disease, as in tetralogy of Fallot. In these patients, right ventricular dysfunction emerges after initial pressure overload and hypoxemia, which is followed by chronic volume overload due to pulmonary regurgitation after corrective surgery. Myocardial adaptation and the transition to right ventricular failure remain poorly understood. Combining insights from clinical and experimental physiology and myocardial (tissue) data has identified a disease phenotype with important distinctions from other types of heart failure. This phenotype of the right ventricle in tetralogy of Fallot can be described as a syndrome of dysfunctional characteristics affecting both contraction and filling. These characteristics are the end result of several adaptation pathways of the cardiomyocytes, myocardial vasculature and extracellular matrix. As long as the long-term outcome of surgical correction of tetralogy of Fallot remains suboptimal, other treatment strategies need to be explored. Novel insights in failure of adaptation and the role of cardiomyocyte proliferation might provide targets for treatment of the (dysfunctional) right ventricle under stress.</p

    Patient and public involvement: how much do we spend and what are the benefits?

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    BACKGROUND AND OBJECTIVES: Patient and public involvement (PPI) is seen as a way of helping to shape health policy and ensure a patient-focused health-care system. While evidence indicates that PPI can improve health-care decision making, it also consumes monetary and non-monetary resources. Given the financial climate, it is important to start thinking about the costs and benefits of PPI and how to evaluate it in economic terms. DESIGN: We conducted a literature review to assess the potential benefits and costs of involvement and the challenges in carrying out an economic evaluation of PPI. RESULTS: The benefits of PPI include effects on the design of new projects or services, on NHS governance, on research design and implementation and on citizenship and equity. Economic evaluation of PPI activities is limited. The lack of an appropriate analytical framework, data recording and understanding of the potential costs and benefits of PPI, especially from participants' perspectives, represent serious constraints on the full evaluation of PPI. CONCLUSIONS: By recognizing the value of PPI, health-care providers and commissioners can embed it more effectively within their organizations. Better knowledge of costs may prompt organizations to effectively plan, execute, evaluate and target resources. This should increase the likelihood of more meaningful activity, avoid tokenism and enhance organizational efficiency and reputation

    Tachyarrhythmia in patients with congenital heart disease:inevitable destiny?

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    Contains fulltext : 171611.pdf (publisher's version ) (Open Access)The prevalence of patients with congenital heart disease (CHD) has increased over the last century. As a result, the number of CHD patients presenting with late, postoperative tachyarrhythmias has increased as well. The aim of this review is to discuss the present knowledge on the mechanisms underlying both atrial and ventricular tachyarrhythmia in patients with CHD and the advantages and disadvantages of the currently available invasive treatment modalities

    Oral Glucose Tolerance Test for the Screening of Glucose Intolerance Long Term Post‐Heart Transplantation

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    Post-transplant diabetes mellitus (PTDM) is a frequent complication post-heart transplantation (HT), however long-term prevalence studies are missing. The aim of this study was to determine the prevalence and determinants of PTDM as well as prediabetes long-term post-HT using oral glucose tolerance tests (OGTT). Also, the additional value of OGTT compared to fasting glucose and glycated hemoglobin (HbA1c) was investigated. All patients > 1Β year post-HT seen at the outpatient clinic between August 2018 and April 2021 were screened with an OGTT. Patients with known diabetes, an active infection/rejection/malignancy or patients unwilling or unable to undergo OGTT were excluded. In total, 263 patients were screened, 108 were excluded. The included 155 patients had a median age of 54.3 [42.2–64.3]Β years, and 63 (41%) were female. Median time since HT was 8.5 [4.8–14.5]Β years. Overall, 51 (33%) had a normal range, 85 (55%) had a prediabetes range and 19 (12%) had a PTDM range test. OGTT identified prediabetes and PTDM in more patients (18% and 50%, respectively), than fasting glucose levels and HbA1c. Age at HT (OR 1.03 (1.00–1.06), p = 0.044) was a significant determinant of an abnormal OGTT. Prediabetes as well as PTDM are frequently seen long-term post-HT. OGTT is the preferred screening method

    Structure Dependent-Immunomodulation by Sugar Beet Arabinans via a SYK Tyrosine Kinase-Dependent Signaling Pathway

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    There is much interest in the immunomodulatory properties of dietary fibers but their activity may be influenced by contamination with microbial-associated molecular patterns (MAMPs) such as lipopolysaccharide (LPS) and lipoteichoic acids, which are difficult to remove completely from biological samples. Bone marrow-derived dendritic cells (BMDCs) from TLR2x4 double-KO mice were shown to be a reliable approach to analyse the immunomodulatory properties of a diverse range of dietary fibers, by avoiding immune cell activation due to contaminating MAMPs. Several of the 44 tested dietary fiber preparations induced cytokine responses in BMDCs from TLR2x4 double-KO mice. The particulate fractions of linear arabinan (LA) and branched arabinan (BA) from sugar beet pectin were shown to be strongly immune stimulatory with LA being more immune stimulatory than BA. Enzymatic debranching of BA increased its immune stimulatory activity, possibly due to increased particle formation by the alignment of debranched linear arabinan. Mechanistic studies showed that the immunostimulatory activity of LA and BA was independent of the Dectin-1 recognition but Syk kinase-dependent

    Identification of Genetic Loci in Lactobacillus plantarum That Modulate the Immune Response of Dendritic Cells Using Comparative Genome Hybridization

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    Contains fulltext : 88219.pdf (publisher's version ) (Open Access)BACKGROUND: Probiotics can be used to stimulate or regulate epithelial and immune cells of the intestinal mucosa and generate beneficial mucosal immunomodulatory effects. Beneficial effects of specific strains of probiotics have been established in the treatment and prevention of various intestinal disorders, including allergic diseases and diarrhea. However, the precise molecular mechanisms and the strain-dependent factors involved are poorly understood. METHODOLOGY/PRINCIPAL FINDINGS: In this study, we aimed to identify gene loci in the model probiotic organism Lactobacillus plantarum WCFS1 that modulate the immune response of host dendritic cells. The amounts of IL-10 and IL-12 secreted by dendritic cells (DCs) after stimulation with 42 individual L. plantarum strains were measured and correlated with the strain-specific genomic composition using comparative genome hybridisation and the Random Forest algorithm. This in silico "gene-trait matching" approach led to the identification of eight candidate genes in the L. plantarum genome that might modulate the DC cytokine response to L. plantarum. Six of these genes were involved in bacteriocin production or secretion, one encoded a bile salt hydrolase and one encoded a transcription regulator of which the exact function is unknown. Subsequently, gene deletions mutants were constructed in L. plantarum WCFS1 and compared to the wild-type strain in DC stimulation assays. All three bacteriocin mutants as well as the transcription regulator (lp_2991) had the predicted effect on cytokine production confirming their immunomodulatory effect on the DC response to L. plantarum. Transcriptome analysis and qPCR data showed that transcript level of gtcA3, which is predicted to be involved in glycosylation of cell wall teichoic acids, was substantially increased in the lp_2991 deletion mutant (44 and 29 fold respectively). CONCLUSION: Comparative genome hybridization led to the identification of gene loci in L. plantarum WCFS1 that modulate the immune response of DCs

    Action selection in early stages of psychosis: an active inference approach

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    BACKGROUND: To interact successfully with their environment, humans need to build a model to make sense of noisy and ambiguous inputs. An inaccurate model, as suggested to be the case for people with psychosis, disturbs optimal action selection. Recent computational models, such as active inference, have emphasized the importance of action selection, treating it as a key part of the inferential process. Based on an active inference framework, we sought to evaluate previous knowledge and belief precision in an action-based task, given that alterations in these parameters have been linked to the development of psychotic symptoms. We further sought to determine whether task performance and modelling parameters would be suitable for classification of patients and controls. METHODS: Twenty-three individuals with an at-risk mental state, 26 patients with first-episode psychosis and 31 controls completed a probabilistic task in which action choice (go/no-go) was dissociated from outcome valence (gain or loss). We evaluated group differences in performance and active inference model parameters and performed receiver operating characteristic (ROC) analyses to assess group classification. RESULTS: We found reduced overall performance in patients with psychosis. Active inference modelling revealed that patients showed increased forgetting, reduced confidence in policy selection and less optimal general choice behaviour, with poorer action-state associations. Importantly, ROC analysis showed fair-to-good classification performance for all groups, when combining modelling parameters and performance measures. LIMITATIONS: The sample size is moderate. CONCLUSION: Active inference modelling of this task provides further explanation for dysfunctional mechanisms underlying decision-making in psychosis and may be relevant for future research on the development of biomarkers for early identification of psychosis
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