2,133 research outputs found

    Structural characterization of Sol-Gel derived Sr-substituted calcium phosphates with anti-osteoporotic and anti-inflammatory properties.

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    International audienceSol-Gel chemistry has been successfully used to prepare un-doped and Sr-doped calcium phosphate ceramics exhibiting a porous structure. The samples composition is very close to the nominal one. All samples present phase mixtures mainly Hydroxyapatite (HAp) and Tri Calcium Phosphate (Β-TCP). Doping with Sr2+ ions has a clear effect on the proportions of the different phases, increasing the amount of Β-TCP. An amorphous phase is also observed incorporating some 40 % of the total amount of strontium. Strontium ions also substitute for calcium both in HAp and Β-TCP in specific sites that have been determined from Rietveld refinement on synchrotron powder diffraction data. The soluble amorphous and TCP phases are responsible for a beneficial partial release of strontium ions in solution during interactions between the material and biological fluids. Preliminary in vitro study demonstrates anti-inflammatory effect of strontium for human monocytes cultured in contact with calcium phosphates

    Genome Sequence of Rickettsia bellii Illuminates the Role of Amoebae in Gene Exchanges between Intracellular Pathogens

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    The recently sequenced Rickettsia felis genome revealed an unexpected plasmid carrying several genes usually associated with DNA transfer, suggesting that ancestral rickettsiae might have been endowed with a conjugation apparatus. Here we present the genome sequence of Rickettsia bellii, the earliest diverging species of known rickettsiae. The 1,552,076 base pair–long chromosome does not exhibit the colinearity observed between other rickettsia genomes, and encodes a complete set of putative conjugal DNA transfer genes most similar to homologues found in Protochlamydia amoebophila UWE25, an obligate symbiont of amoebae. The genome exhibits many other genes highly similar to homologues in intracellular bacteria of amoebae. We sought and observed sex pili-like cell surface appendages for R. bellii. We also found that R. bellii very efficiently multiplies in the nucleus of eukaryotic cells and survives in the phagocytic amoeba, Acanthamoeba polyphaga. These results suggest that amoeba-like ancestral protozoa could have served as a genetic “melting pot” where the ancestors of rickettsiae and other bacteria promiscuously exchanged genes, eventually leading to their adaptation to the intracellular lifestyle within eukaryotic cells

    Interobserver Variation Study of the Rutgeerts Score to Assess Endoscopic Recurrence after Surgery for Crohn's Disease.

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    BACKGROUND: After resection surgery for Crohn's disease, recurrence of endoscopic lesions at the site of the anastomosis or in the neoterminal ileum is graded according to the Rutgeerts score (RS). The goal of this study was to test the interobserver variability for RS. METHODS: Thirteen trained endoscopists evaluated the RS on 39 videotapes of patients who had undergone resection for Crohn's disease with an ileocolonic anastomosis 6 months earlier. Videotapes were randomly assigned to endoscopists through a balanced incomplete block design. Each videotape was scored independently by four endoscopists, and each endoscopist evaluated 12 videotapes, making a total of 156 videotape assessments. Reproducibility levels of the RS were assessed through unweighted kappa estimates among multiple raters. The proportion of inappropriate therapeutic initiation was estimated by randomly selecting one endoscopist for each videorecording, assuming that the majority of endoscopists correctly classified endoscopic recurrence. RESULTS: The kappa estimates were 0.43 (95% confidence interval: 0.33-0.52) for the RS on a 5-grade scale, 0.47 (0.28-0.66) for RS /= i2, and 0.64 (0.42-0.85) for RS i2. The percentages of inappropriate therapeutic initiation were 12.8% (3.8-21.9) when initiation was triggered by a RS >/= i2 and 8.3% (1.1-15.6) when initiation was triggered by a RS > i2 (p = 0.41). CONCLUSION: The reproducibility of the RS was moderate, especially when differentiating /=i2, which may lead to incorrect therapeutic decisions in >10% of patients

    Intraoperative ketorolac in high-risk breast cancer patients : A prospective, randomized, placebo-controlled clinical trial

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    Funding: This work is financed by grants received by PF, in the name of his institution: the Anticancer Fund (no grant number) (www.anticancerfund.org); the Belgian Society of Anaesthesia and Resuscitation (no grant number) (www.sarb.be); the Fondation Saint-Luc (no grant number) (www.uclouvain.be); the Commission du Patrimoine of the Université catholique de Louvain, St-Luc Hospital (exceptional grant, no number) (www.uclouvain.be). None of the funders had any role in the study design, data collection and analysis, decision to publish or preparation of the manuscript except the scientific advise of GB, scientific director of the Anticancer Fund.Peer reviewedPublisher PD

    Superconducting routing platform for large-scale integration of quantum technologies

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    To reach large-scale quantum computing, three-dimensional integration of scalable qubit arrays and their control electronics in multi-chip assemblies is promising. Within these assemblies, the use of superconducting interconnections, as routing layers, offers interesting perspective in terms of (1) thermal management to protect the qubits from control electronics self-heating, (2) passive device performance with significant increase of quality factors and (3) density rise of low and high frequency signals thanks to minimal dispersion. We report on the fabrication, using 200 mm silicon wafer technologies, of a multi-layer routing platform designed for the hybridization of spin qubit and control electronics chips. A routing level couples the qubits and the control circuits through one layer of Al0.995Cu0.005 and superconducting layers of TiN, Nb or NbN, connected between them by W-based vias. Wafer-level parametric tests at 300 K validate the yield of these technologies and low temperature electrical measurements in cryostat are used to extract the superconducting properties of the routing layers. Preliminary low temperature radio-frequency characterizations of superconducting passive elements, embedded in these routing levels, are presented

    Running from Paris to Beijing: biomechanical and physiological consequences

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    Abstract The purpose of this study was to examine the physiological and biomechanical changes occurring in a subject after running 8,500 km in 161 days (i.e. 52.8 km daily). Three weeks before, 3 weeks after (POST) and 5 months after (POST?5) running from Paris to Beijing, energy cost of running (Cr), knee flexor and extensor isokinetic strength and biomechanical parameters (using a treadmill dynamometer) at different velocities were assessed in an experienced ultra-runner. At POST, there was a tendency toward a 'smoother' running pattern, as shown by (a) a higher stride frequency and duty factor, and a reduced aerial time without a change in contact time, (b) a lower maximal vertical force and loading rate at impact and (c) a decrease in both potential and kinetic energy changes at each step. This was associated with a detrimental effect on Cr (?6.2%) and a loss of strength at all angular velocities for both knee flexors and extensors. At POST?5, the subject returned to his original running patterns at low but not at high speeds and maximal strength remained reduced at low angular velocities (i.e. at high levels of force). It is suggested that the running pattern changes observed in the present study were a strategy adopted by the subject to reduce the deleterious effects of long distance running. However, the running pattern changes could partly be linked to the decrease in maximal strength

    a retrospective multicenter study

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    Funding This study was supported in part by a grant from the French government through the « Programme Investissement d’Avenir» (I-SITE ULNE) managed by the Agence Nationale de la Recherche (coVAPid project). Prof. Ignacio Martin-Loeches has been supported by SFI (Science Foundation Ireland), Grant number 20/COV/0038. The funders of the study had no role in the study design, data collection, analysis or interpretation, writing of the report or deci sion to submit for publication.BACKGROUND: Ventilator-associated pneumonia (VAP) is common in patients with severe SARS-CoV-2 pneumonia. The aim of this ancillary analysis of the coVAPid multicenter observational retrospective study is to assess the relationship between adjuvant corticosteroid use and the incidence of VAP. METHODS: Planned ancillary analysis of a multicenter retrospective European cohort in 36 ICUs. Adult patients receiving invasive mechanical ventilation for more than 48 h for SARS-CoV-2 pneumonia were consecutively included between February and May 2020. VAP diagnosis required strict definition with clinical, radiological and quantitative microbiological confirmation. We assessed the association of VAP with corticosteroid treatment using univariate and multivariate cause-specific Cox's proportional hazard models with adjustment on pre-specified confounders. RESULTS: Among the 545 included patients, 191 (35%) received corticosteroids. The proportional hazard assumption for the effect of corticosteroids on the incidence of VAP could not be accepted, indicating that this effect varied during ICU stay. We found a non-significant lower risk of VAP for corticosteroid-treated patients during the first days in the ICU and an increased risk for longer ICU stay. By modeling the effect of corticosteroids with time-dependent coefficients, the association between corticosteroids and the incidence of VAP was not significant (overall effect p = 0.082), with time-dependent hazard ratios (95% confidence interval) of 0.47 (0.17-1.31) at day 2, 0.95 (0.63-1.42) at day 7, 1.48 (1.01-2.16) at day 14 and 1.94 (1.09-3.46) at day 21. CONCLUSIONS: No significant association was found between adjuvant corticosteroid treatment and the incidence of VAP, although a time-varying effect of corticosteroids was identified along the 28-day follow-up.publishersversionpublishe

    Relationship between ventilator-associated pneumonia and mortality in COVID-19 patients: a planned ancillary analysis of the coVAPid cohort

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    Background Patients with SARS-CoV-2 infection are at higher risk for ventilator-associated pneumonia (VAP). No study has evaluated the relationship between VAP and mortality in this population, or compared this relationship between SARS-CoV-2 patients and other populations. The main objective of our study was to determine the relationship between VAP and mortality in SARS-CoV-2 patients. Methods Planned ancillary analysis of a multicenter retrospective European cohort. VAP was diagnosed using clinical, radiological and quantitative microbiological criteria. Univariable and multivariable marginal Cox's regression models, with cause-specific hazard for duration of mechanical ventilation and ICU stay, were used to compare outcomes between study groups. Extubation, and ICU discharge alive were considered as events of interest, and mortality as competing event. Findings Of 1576 included patients, 568 were SARS-CoV-2 pneumonia, 482 influenza pneumonia, and 526 no evidence of viral infection at ICU admission. VAP was associated with significantly higher risk for 28-day mortality in SARS-CoV-2 group (adjusted HR 1.65 (95% CI 1.11-2.46), p = 0.013), but not in influenza (1.74 (0.99-3.06), p = 0.052), or no viral infection groups (1.13 (0.68-1.86), p = 0.63). VAP was associated with significantly longer duration of mechanical ventilation in the SARS-CoV-2 group, but not in the influenza or no viral infection groups. VAP was associated with significantly longer duration of ICU stay in the 3 study groups. No significant difference was found in heterogeneity of outcomes related to VAP between the 3 groups, suggesting that the impact of VAP on mortality was not different between study groups. Interpretation VAP was associated with significantly increased 28-day mortality rate in SARS-CoV-2 patients. However, SARS-CoV-2 pneumonia, as compared to influenza pneumonia or no viral infection, did not significantly modify the relationship between VAP and 28-day mortality
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