221 research outputs found
Capillary condensation and adsorption of binary mixtures
31 pagesThe adsorption of equimolar binary mixtures of hydrogen-carbon dioxide, hydrogen-methane and methane-carbon dioxide in porous material models is determined by Grand Canonical Monte Carlo simulations. The material models have an adsorbent surface similar to that of nanofibers with a herringbone structure. Our main result, which is relevant for hydrogen purification and carbon dioxide capture, is that the adsorption selectivities calculated for the mixtures can differ significantly from those deduced from simulations of the adsorption of pure gases, in particular when one of the adsorbed gases presents a capillary condensation induced by confinement within the pore network. A comparison of our data is also made with theoretical models used in the literature for predicting the properties of the mixture adsorption
First report on tan spot disease (Pyrenophora tritici-repentis) of wheat in Syria
During the annual pest survey in 2001 severe leaf spotting was observed in two fields in the Efrin and
Akhtarin regions of northwestern Syria, where durum wheat cultivation has recently been introduced. The spots
observed were typical of tan spot disease. The causal agent was isolated and identified as Pyrenophora tritici-repentis
(anamorph Dreshlera tritici-repentis). To our knowledge this is the first report on this disease in Syria
LES UVEITES DE LâENFANT : A PROPOS DE 30 CAS
Uveitis is less frequent in children. The purpose of our study is to evaluate epidemiologic aspect, etiological profile and prognosis of children uveitis.We report 30 cases of uveitis in patients aged less than 16 years old followed in our department.Patients mean age is 9 years old (5 to 16 years) .We observed anterior uveitis in 46,7%, posterior uveitis in 26,7%, intermediate uveitis in 13,3% and panuveitis in 13,3%.Chronic juvenile arthritis is the main etiology followed by Behcet disease.Uveitis in children is rare but severe and can involve visual prognosis; it needs urgent diagnosis and adapted treatment. Principals etiologies are; idiopathic juvenile arthritis and spondiloarthropaties. Functional prognosis is variable and final visual acuity is less than 20/200 in 16 to 36% of cases.LâuvĂ©ite de lâenfant est rare. Le but de notre travail est dâĂ©valuer le profil Ă©pidĂ©miologique, Ă©tiologique et pronostic des uvĂ©ites de lâenfant.Nous rapportons 30 cas dâuvĂ©ites chez des patients dâĂąge infĂ©rieur Ă 16 ans et suivis dans notre unitĂ©.La moyenne dâĂąge des patients est de 9 ans (5 Ă 16 ans). Il sâagissait dâune uvĂ©ite antĂ©rieure dans 46,7% des cas, dâune uvĂ©ite postĂ©rieure dans 26,7%, dâune uvĂ©ite intermĂ©diaire dans 13,3% et dâune panuvĂ©ite dans 13,3%. Les principales causes retrouvĂ©es sont lâarthrite juvĂ©nile idiopathique suivie par la maladie de Behçet.LâuvĂ©ite de lâenfant est rare souvent grave engageant le pronostic visuel et imposant un diagnostic prĂ©coce et un traitement adaptĂ©. Les principales Ă©tiologies sont lâarthrite juvĂ©nile idiopathique et les spondyloarthropathies. Le pronostic visuel est variable et lâacuitĂ© visuelle est infĂ©rieure Ă 20/200 dans 16 Ă 36% des cas
Visualization of grapevine root colonization by the Saharan soil isolate Saccharothrix algeriensis NRRL B-24137 using DOPE-FISH microscopy
Background and aim There is currently a gap of
knowledge regarding whether some beneficial bacteria
isolated from desert soils can colonize epi- and
endophytically plants of temperate regions. In this
study, the early steps of the colonization process of
one of these bacteria, Saccharothrix algeriensis NRRL
B-24137, was studied on grapevine roots to determine
if this beneficial strain can colonize a non-natural host
plant. An improved method of fluorescence in situ
hybridization (FISH), the double labeling of oligonucleotide
probes (DOPE)-FISH technique was used to
visualize the colonization behavior of such bacteria as well as to determine if the method could be used to
track microbes on and inside plants.
Methods A probe specific to Saccharothrix spp. was
firstly designed. Visualization of the colonization behavior
of S. algeriensis NRRL B-24137 on and inside
roots of grapevine plants was then carried out with
DOPE-FISH microscopy.
Results The results showed that 10 days after inoculation,
the strain could colonize the root hair zone, root
elongation zone, as well as root emergence sites by
establishing different forms of bacterial structures as
revealed by the DOPE-FISH technique. Further observations
showed that the strain could be also endophytic
inside the endorhiza of grapevine plants.
Conclusions Taking into account the natural niches of
this beneficial strain, this study exemplifies that, in
spite of its isolation from desert soil, the strain can
establish populations as well as subpopulations on and
inside grapevine plants and that the DOPE-FISH tool
can allow to detect it
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Association of Genetic Variants With Primary Open-Angle Glaucoma Among Individuals With African Ancestry.
Importance:Primary open-angle glaucoma presents with increased prevalence and a higher degree of clinical severity in populations of African ancestry compared with European or Asian ancestry. Despite this, individuals of African ancestry remain understudied in genomic research for blinding disorders. Objectives:To perform a genome-wide association study (GWAS) of African ancestry populations and evaluate potential mechanisms of pathogenesis for loci associated with primary open-angle glaucoma. Design, Settings, and Participants:A 2-stage GWAS with a discovery data set of 2320 individuals with primary open-angle glaucoma and 2121 control individuals without primary open-angle glaucoma. The validation stage included an additional 6937 affected individuals and 14âŻ917 unaffected individuals using multicenter clinic- and population-based participant recruitment approaches. Study participants were recruited from Ghana, Nigeria, South Africa, the United States, Tanzania, Britain, Cameroon, Saudi Arabia, Brazil, the Democratic Republic of the Congo, Morocco, Peru, and Mali from 2003 to 2018. Individuals with primary open-angle glaucoma had open iridocorneal angles and displayed glaucomatous optic neuropathy with visual field defects. Elevated intraocular pressure was not included in the case definition. Control individuals had no elevated intraocular pressure and no signs of glaucoma. Exposures:Genetic variants associated with primary open-angle glaucoma. Main Outcomes and Measures:Presence of primary open-angle glaucoma. Genome-wide significance was defined as Pâ<â5âĂâ10-8 in the discovery stage and in the meta-analysis of combined discovery and validation data. Results:A total of 2320 individuals with primary open-angle glaucoma (mean [interquartile range] age, 64.6 [56-74] years; 1055 [45.5%] women) and 2121 individuals without primary open-angle glaucoma (mean [interquartile range] age, 63.4 [55-71] years; 1025 [48.3%] women) were included in the discovery GWAS. The GWAS discovery meta-analysis demonstrated association of variants at amyloid-ÎČ A4 precursor protein-binding family B member 2 (APBB2; chromosome 4, rs59892895T>C) with primary open-angle glaucoma (odds ratio [OR], 1.32 [95% CI, 1.20-1.46]; Pâ=â2âĂâ10-8). The association was validated in an analysis of an additional 6937 affected individuals and 14âŻ917 unaffected individuals (OR, 1.15 [95% CI, 1.09-1.21]; Pâ<â.001). Each copy of the rs59892895*C risk allele was associated with increased risk of primary open-angle glaucoma when all data were included in a meta-analysis (OR, 1.19 [95% CI, 1.14-1.25]; Pâ=â4âĂâ10-13). The rs59892895*C risk allele was present at appreciable frequency only in African ancestry populations. In contrast, the rs59892895*C risk allele had a frequency of less than 0.1% in individuals of European or Asian ancestry. Conclusions and Relevance:In this genome-wide association study, variants at the APBB2 locus demonstrated differential association with primary open-angle glaucoma by ancestry. If validated in additional populations this finding may have implications for risk assessment and therapeutic strategies
Bioencapsulation and Colonization Characteristics of Lactococcus lactis subsp. lactis CF4MRS in Artemia franciscana: a Biological Approach for the Control of Edwardsiellosis in Larviculture
Predominance of beneficial bacteria helps to establish a healthy microbiota in fish gastrointestinal system and thus to reduce emerging pathogen. In this study, the colonization efficacy of Lactococcus lactis subsp. lactis CF4MRS in Artemia franciscana and its potential as a probiotic in suppressing Edwardsiella sp. infection were investigated in vivo. The colonization extent of the bioencapsulated L. lactis was established through visualization of gfp gene-transformed L. lactis in A. franciscana. Here, we demonstrate that when A. franciscana is administrated with L. lactis at 108 CFU mLâ1 for 8 h, the highest relative percentage of survival (RPS =â50.0) is observed after inoculation with Edwardsiella sp. The total counts of L. lactis entrapped in Artemia were the highest (ranged from 3.2 to 5.1âĂâ108 CFU mLâ1), when 108â109 CFU mLâ1 of L. lactis was used as starting inoculum, with the bioencapsulation performed within 8â24 h. Fluorescent microscopy showed gfp-transformed L. lactis colonized the external trunk surfaces, mid-gut and locomotion antennules of the A. franciscana nauplii. These illustrations elucidate the efficiency of colonization of L. lactis in the gastrointestinal tract and on the body surfaces of Artemia. In conclusion, L. lactis subsp. lactis CF4MRS shows a good efficacy of colonization in Artemia and has the potential for biocontrol/probiotic activity against Edwardsiella sp. infection
Predicting the outcome of grade II glioma treated with temozolomide using proton magnetic resonance spectroscopy
International audienceBACKGROUND: This study was designed to evaluate proton magnetic resonance spectroscopy ((1)H-MRS) for monitoring the WHO grade II glioma (low-grade glioma (LGG)) treated with temozolomide (TMZ).METHODS: This prospective study included adult patients with progressive LGG that was confirmed by magnetic resonance imaging (MRI). Temozolomide was administered at every 28 days. Response to TMZ was evaluated by monthly MRI examinations that included MRI with volumetric calculations and (1)H-MRS for assessing Cho/Cr and Cho/NAA ratios. Univariate, multivariate and receiver-operating characteristic statistical analyses were performed on the results.RESULTS: A total of 21 LGGs from 31 patients were included in the study, and followed for at least n=14 months during treatment. A total of 18 (86%) patients experienced a decrease in tumour volume with a greater decrease of metabolic ratios. Subsequently, five (28%) of these tumours resumed growth despite the continuation of TMZ administration with an earlier increase of metabolic ratios of 2 months. Three (14%) patients did not show any volume or metabolic change. The evolutions of the metabolic ratios, mean(Cho/Cr)(n) and mean(Cho/NAA)(n), were significantly correlated over time (Spearman Ï=+0.95) and followed a logarithmic regression (P>0.001). The evolutions over time of metabolic ratios, mean(Cho/Cr)(n) and mean(Cho/NAA)(n), were significantly correlated with the evolution of the mean relative decrease of tumour volume, mean(ÎV(n)/V(o)), according to a linear regression (P<0.001) in the 'response/no relapse' patient group, and with the evolution of the mean tumour volume (meanV(n)), according to an exponential regression (P<0.001) in the 'response/relapse' patient group. The mean relative decrease of metabolic ratio, mean(Î(Cho/Cr)(n)/(Cho/Cr)(o)), at n=3 months was predictive of tumour response over the 14 months of follow-up. The mean relative change between metabolic ratios, mean((Cho/NAA)(n)-(Cho/Cr)(n))/(Cho/NAA)(n), at n=4 months was predictive of tumour relapse with a significant cutoff of 0.046, a sensitivity of 60% and a specificity of 100% (P=0.004).CONCLUSIONS: The (1)H-MRS profile changes more widely and rapidly than tumour volume during the response and relapse phases, and represents an early predictive factor of outcome over 14 months of follow-up. Thus, (1)H-MRS may be a promising, non-invasive tool for predicting and monitoring the clinical response to TMZ
Spintronics: Fundamentals and applications
Spintronics, or spin electronics, involves the study of active control and
manipulation of spin degrees of freedom in solid-state systems. This article
reviews the current status of this subject, including both recent advances and
well-established results. The primary focus is on the basic physical principles
underlying the generation of carrier spin polarization, spin dynamics, and
spin-polarized transport in semiconductors and metals. Spin transport differs
from charge transport in that spin is a nonconserved quantity in solids due to
spin-orbit and hyperfine coupling. The authors discuss in detail spin
decoherence mechanisms in metals and semiconductors. Various theories of spin
injection and spin-polarized transport are applied to hybrid structures
relevant to spin-based devices and fundamental studies of materials properties.
Experimental work is reviewed with the emphasis on projected applications, in
which external electric and magnetic fields and illumination by light will be
used to control spin and charge dynamics to create new functionalities not
feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes
from the published versio
Clinical Experience with OctagamÂź 10Â %, a solvent detergent virus inactivated intravenous immunoglobulin: a Canadian retrospective review of utilization
Combined assessment of DYRK1A, BDNF and homocysteine levels as diagnostic marker for Alzheimerâs disease
Early identification of Alzheimerâs disease (AD) risk factors would aid development of interventions to delay the onset of dementia, but current biomarkers are invasive and/or costly to assess. Validated plasma biomarkers would circumvent these challenges. We previously identified the kinase DYRK1A in plasma. To validate DYRK1A as a biomarker for AD diagnosis, we assessed the levels of DYRK1A and the related markers brain-derived neurotrophic factor (BDNF) and homocysteine in two unrelated AD patient cohorts with age-matched controls. Receiver-operating characteristic curves and logistic regression analyses showed that combined assessment of DYRK1A, BDNF and homocysteine has a sensitivity of 0.952, a specificity of 0.889 and an accuracy of 0.933 in testing for AD. The blood levels of these markers provide a diagnosis assessment profile. Combined assessment of these three markers outperforms most of the previous markers and could become a useful substitute to the current panel of AD biomarkers. These results associate a decreased level of DYRK1A with AD and challenge the use of DYRK1A inhibitors in peripheral tissues as treatment. These measures will be useful for diagnosis purposes.This work was supported by the FEANS. We acknowledge the platform accommodation and animal testing of the animal facility at the Institute Jacques-Monod
(University Paris Diderot) and the FlexStation3 facility of the Functional and Adaptive
Biology (BFA) LaboratoryPeer reviewe
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