La prévalence et les facteurs de risque de la maladie d’Osgood-Schlatter, revue de la littérature et méta-analyse

La maladie d’Osgood-Schlatter est l’ostéochondrose de croissance la plus fréquente. Elle touche les enfants et adolescents entre 7 et 21 ans. Cette revue vise à définir la prévalence dans différentes populations et à identifier les facteurs de risque importants de cette pathologie

Hydrogen bioelectrooxidation on gold nanoparticle-based electrodes modified by Aquifex aeolicus hydrogenase: Application to hydrogen/oxygen enzymatic biofuel cells

International audienceFor the first time, gold nanoparticle-based electrodes have been used as platforms for efficient immobilization of the [NiFe] hydrogenase from the hyperthermophilic bacterium Aquifex aeolicus. AuNPs were characterized by electronic microscopy, dynamic light scattering and UV-Vis spectroscopy. Two sizes around 20.0 ± 5.3 nm and 37.2 ± 4.3 nm nm were synthesized. After thiol-based functionalization, the AuNPs were proved to allow direct H2 oxidn. over a large range of temps. A high c.d. up to 1.85 ± 0.15 mA·cm- 2 was reached at the smallest AuNPs, which is 170 times higher than the one recorded at the bare gold electrode. The catalytic current was esp. studied as a function of the AuNP size and amt., and procedure for deposition. A synergetic effect between the AuNP porous deposit and the increase surface area was shown. Compared to previously used nanomaterials such as carbon nanofibers, the covalent grafting of the enzyme on the thiol-modified gold nanoparticles was shown to enhance the stability of the hydrogenase. This bioanode was finally coupled to a biocathode where BOD from Myrothecium verrucaria was immobilized on AuNP-based film. The performance of the so-mounted H2/O2 biofuel cell was evaluated, and a power d. of 0.25 mW·cm- 2 was recorded. [on SciFinder(R)

Plasmodium falciparum parasite population structure and gene flow associated to anti-malarial drugs resistance in Cambodia

Background: Western Cambodia is recognized as the epicentre of emergence of Plasmodium falciparum multi-drug resistance. The emergence of artemisinin resistance has been observed in this area since 2008–2009 and molecular signatures associated to artemisinin resistance have been characterized in k13 gene. At present, one of the major threats faced, is the possible spread of Asian artemisinin resistant parasites over the world threatening millions of people and jeopardizing malaria elimination programme efforts. To anticipate the diffusion of artemisinin resistance, the identification of the P. falciparum population structure and the gene flow among the parasite population in Cambodia are essential. Methods: To this end, a mid-throughput PCR-LDR-FMA approach based on LUMINEX technology was developed to screen for genetic barcode in 533 blood samples collected in 2010–2011 from 16 health centres in malaria endemics areas in Cambodia. Results: Based on successful typing of 282 samples, subpopulations were characterized along the borders of the country. Each 11-loci barcode provides evidence supporting allele distribution gradient related to subpopulations and gene flow. The 11-loci barcode successfully identifies recently emerging parasite subpopulations in western Cambodia that are associated with the C580Y dominant allele for artemisinin resistance in k13 gene. A subpopulation was identified in northern Cambodia that was associated to artemisinin (R539T resistant allele of k13 gene) and mefloquine resistance. Conclusions: The gene flow between these subpopulations might have driven the spread of artemisinin resistance over Cambodia

Bias in carbon concentration and δ13C measurements of organic matter due to cleaning treatments with organic solvents

We acknowledge the financial support from the UnivEarths Labex program of Sorbonne Paris Cite (ANR 11-IDEX-00005-02). CH and AL acknowledge support from the Max Planck Society. EES and RB were funded by the NASA Exobiology grant NNX16AI37G and the Virtual Planetary Laboratory of the NASA Astrobiology Institute and were technically assisted by Andy Schauer.Interpreting the organic carbon content (TOC) and stable carbon isotopic composition (δ13C) of organic matter in the sedimentary rock record depends on our capability to accurately measure them, while excluding sources of contamination. This however becomes increasingly problematic as we analyze samples with ever-lower organic carbon content. Accordingly, organic solvents are sometimes used to remove contaminating traces of modern organic matter from ancient rock samples. However, especially for very low TOC samples, traces of solvents or their impurities remaining in the sample may contribute a significant organic contamination that can impact the bulk measurements of both TOC and δ13C values. This study, including three independent investigations performed in different laboratories, is the first detailed examination of the effect of cleaning treatments on the reliability of TOC and δ13C values in a range of natural rock samples and synthetic materials with low TOC content from below detection limit to 3330 ppm. We investigated the four most common organic solvents used to remove modern organic matter: dichloromethane (DCM), n-hexane, methanol and ethanol, and evaluated the effect of grain size and mineralogy. We find that (i) cleaning treatments with methanol, n-hexane and dichloromethane contaminate rock samples when used directly on sample powder, regardless of the grain size; (ii) this pollution buffers the natural variability and homogenizes the δ13C values of samples around the isotopic composition of the solvent, i.e. between −27 and −29‰; (iii) the extent of contamination depends on the solvent used, DCM being the most contaminating (up to 6000 ppm) and ethanol the only solvent that does not seem to contaminate rock samples above our detection limit; (iv) sample mineralogy also exerts an influence on the extent of contamination, clay minerals being more prone to adsorb contaminants. We conclude that the response of carbon concentrations and the stable carbon isotopic composition of organic matter in geological samples to cleaning treatments is neither negligible nor systematic when investigating samples with low carbon content.PostprintPeer reviewe

2008 Inter-laboratory Comparison Study of a Reference Material for Nutrients in Seawater

Autoclaved natural seawater collected in the North Pacific Ocean was used as a reference material for nutrients in seawater (RMNS) during an inter-laboratory comparison (I/C) study conducted in 2008. This study was a follow-up to previous studies conducted in 2003 and 2006. A set of six samples was distributed to each of 58 laboratories in 15 countries around the globe, and results were returned by 54 of those laboratories (15 countries). The homogeneities of samples used in the 2008 I/C study, based on analyses for three determinants, were improved compared to those of samples used in the 2003 and 2006 I/C studies. Results of these I/C studies indicate that most of the participating laboratories have an analytical technique for nutrients that is sufficient to provide data of high comparability. The differences between reported concentrations from the same laboratories in the 2006 and 2008 I/C studies for the same batch of RMNS indicate that most of the laboratories have been maintaining internal comparability for two years. Thus, with the current high level of performance in the participating laboratories, the use of a common reference material and the adaptation of an internationally accepted nutrient scale system would increase comparability among laboratories worldwide, and the use of a certified reference material would establish traceability. In the 2008 I/C study we observed a problem of non-linearity of the instruments of the participating laboratories similar to that observed among the laboratories in the 2006 I/C study. This problem of non-linearity should be investigated and discussed to improve comparability for the full range of nutrient concentrations. For silicate comparability in particular, we see relatively larger consensus standard deviations than those for nitrate and phosphate

A MAP6-Related Protein Is Present in Protozoa and Is Involved in Flagellum Motility

In vertebrates the microtubule-associated proteins MAP6 and MAP6d1 stabilize cold-resistant microtubules. Cilia and flagella have cold-stable microtubules but MAP6 proteins have not been identified in these organelles. Here, we describe TbSAXO as the first MAP6-related protein to be identified in a protozoan, Trypanosoma brucei. Using a heterologous expression system, we show that TbSAXO is a microtubule stabilizing protein. Furthermore we identify the domains of the protein responsible for microtubule binding and stabilizing and show that they share homologies with the microtubule-stabilizing Mn domains of the MAP6 proteins. We demonstrate, in the flagellated parasite, that TbSAXO is an axonemal protein that plays a role in flagellum motility. Lastly we provide evidence that TbSAXO belongs to a group of MAP6-related proteins (SAXO proteins) present only in ciliated or flagellated organisms ranging from protozoa to mammals. We discuss the potential roles of the SAXO proteins in cilia and flagella function

Genetic effects on gene expression across human tissues

Characterization of the molecular function of the human genome and its variation across individuals is essential for identifying the cellular mechanisms that underlie human genetic traits and diseases. The Genotype-Tissue Expression (GTEx) project aims to characterize variation in gene expression levels across individuals and diverse tissues of the human body, many of which are not easily accessible. Here we describe genetic effects on gene expression levels across 44 human tissues. We find that local genetic variation affects gene expression levels for the majority of genes, and we further identify inter-chromosomal genetic effects for 93 genes and 112 loci. On the basis of the identified genetic effects, we characterize patterns of tissue specificity, compare local and distal effects, and evaluate the functional properties of the genetic effects. We also demonstrate that multi-tissue, multi-individual data can be used to identify genes and pathways affected by human disease-associated variation, enabling a mechanistic interpretation of gene regulation and the genetic basis of diseas

Multi-Platform Next-Generation Sequencing of the Domestic Turkey (Meleagris gallopavo): Genome Assembly and Analysis

The combined application of next-generation sequencing platforms has provided an economical approach to unlocking the potential of the turkey genome