122 research outputs found
Synthesis of Highly Porous Catalytic Layers for Polymer Electrolyte Fuel Cell Based on Carbon Aerogels
International audienceRecent studies of the PEMFC catalytic layer electrocatalystsupport showed that high surface area carbon blacks cannot beused efficiently (1) because they have necessarily small primarypores that yield high diffusion limitation for the oxygenreduction reaction (ORR). In the present paper, we firstsynthesized and characterized carbon aerogels which exhibit highsurface area, high porous volume and adjustable pore-sizedistribution. In that way, they enable to decouple betweensurface area and porosity, while they are also promisingelectrocatalyst supports (2). Second, we elaborated newcatalytic layers made from 2 different carbon aerogels with 2different Nafion loadings. Finally, we characterized thestructure of such catalytic layers, and evaluated their activitytowards the oxygen reduction reaction (ORR). Finally, anappropriate catalyst support should display large pore-size andhigh surface area in order to reduce the PEMFC cathode platinumloadings without loosing activity, following the reduction ofoxygen diffusion limitation
Tickborne Relapsing Fever Caused by Borrelia persica, Uzbekistan and Tajikistan
International audienc
Gitelman syndrome and glomerular proteinuria: a link between loss of sodium-chloride cotransporter and podocyte dysfunction?
We report on a 27-year-old patient presenting with chronic hypokalaemia, inappropriate kaliuresis, hypomagnesaemia and alkalosis, associated with moderate proteinuria. Genetic analysis evidenced a homozygous mutation (p.Arg399Cys) in the SLC12A3 gene coding for the sodium-chloride cotransporter (NCC), confirming the diagnosis of Gitelman syndrome. Further genetic testing did not show any mutation in NPHS2. A renal biopsy was performed in view of the unusual association with proteinuria. Light microscopy showed hypertrophy of the juxtaglomerular apparatus and discrete mesangial thickening. In addition to possible focal segmental glomerular sclerosis lesions, electron microscopy showed extensive segments of variably thickened glomerular basement membrane (GBM), contrasting with segments of regular GBM of low range thickness, and effacement of podocyte foot processes. Of interest, alterations of the GBM were also observed in a Slc12a3 knock-out mouse model for Gitelman syndrome. These data suggest that the association between Gitelman syndrome and secondary changes of the GBM is probably not coincidental. Possible mechanisms include angiotensin II- or renin-induced podocyte lesions, as well as chronic hypokalaemi
Thermal maturity estimation of carbonaceous material from proterozoic organic-walled microfossils assemblages (DRCongo, Mauritania and Australia) by using Raman spectroscopy
Biostratigraphie, Chémostratigraphie et caractérisation de la matiÚre organique du Supergroupe de Mbuji-May
Structural and optical properties of (In,Ga)As/GaP quantum dots and (GaAsPN/GaPN) diluted-nitride nanolayers coherently grown onto GaP and Si substrates for photonics and photovoltaics applications
San Francisco, California, United StatesInternational audienceLattice-matched GaP-based nanostructures grown on silicon substrates is a highly rewarded route for coherent integration of photonics and high-efficiency photovoltaic devices onto silicon substrates. We report on the structural and optical properties of selected MBE-grown nanostructures on both GaP substrates and GaP/Si pseudo-substrates. As a first stumbling block, the GaP/Si interface growth has been optimised thanks to a complementary set of thorough structural analyses. Photoluminescence and time-resolved photoluminescence studies of self-assembled (In,Ga)As quantum dots grown on GaP substrate demonstrate a proximity of two different types of optical transitions interpreted as a competition between conduction band states in X and Î valleys. Structural properties and optical studies of GaAsP(N)/GaP(N) quantum wells coherently grown on GaP substrates and GaP/Si pseudo substrates are reported. Our results are found to be suitable for light emission applications in the datacom segment. Then, possible routes are drawn for larger wavelengths applications, in order to address the chip-to-chip and within-a-chip optical interconnects and the optical telecom segments. Finally, results on GaAsPN/GaP heterostructures and diodes, suitable for PV applications are reporte
Worldwide trends in population-based survival for children, adolescents, and young adults diagnosed with leukaemia, by subtype, during 2000â14 (CONCORD-3) : analysis of individual data from 258 cancer registries in 61 countries
Background Leukaemias comprise a heterogenous group of haematological malignancies. In CONCORD-3, we analysed
data for children (aged 0â14 years) and adults (aged 15â99 years) diagnosed with a haematological malignancy
during 2000â14 in 61 countries. Here, we aimed to examine worldwide trends in survival from leukaemia, by age and
morphology, in young patients (aged 0â24 years).
Methods We analysed data from 258 population-based cancer registries in 61 countries participating in CONCORD-3
that submitted data on patients diagnosed with leukaemia. We grouped patients by age as children (0â14 years),
adolescents (15â19 years), and young adults (20â24 years). We categorised leukaemia subtypes according to the
International Classification of Childhood Cancer (ICCC-3), updated with International Classification of Diseases
for Oncology, third edition (ICD-O-3) codes. We estimated 5-year net survival by age and morphology, with 95% CIs,
using the non-parametric Pohar-Perme estimator. To control for background mortality, we used life tables by
country or region, single year of age, single calendar year and sex, and, where possible, by race or ethnicity. All-age
survival estimates were standardised to the marginal distribution of young people with leukaemia included in the
analysis.
Findings 164563 young people were included in this analysis: 121328 (73·7%) children, 22963 (14·0%) adolescents, and
20272 (12·3%) young adults. In 2010â14, the most common subtypes were lymphoid leukaemia (28205 [68·2%] patients)
and acute myeloid leukaemia (7863 [19·0%] patients). Age-standardised 5-year net survival in children, adolescents, and
young adults for all leukaemias combined during 2010â14 varied widely, ranging from 46% in Mexico to more than
85% in Canada, Cyprus, Belgium, Denmark, Finland, and Australia. Individuals with lymphoid leukaemia had better
age-standardised survival (from 43% in Ecuador to â„80% in parts of Europe, North America, Oceania, and Asia) than
those with acute myeloid leukaemia (from 32% in Peru to â„70% in most high-income countries in Europe,
North America, and Oceania). Throughout 2000â14, survival from all leukaemias combined remained consistently
higher for children than adolescents and young adults, and minimal improvement was seen for adolescents and young
adults in most countries.
Interpretation This study offers the first worldwide picture of population-based survival from leukaemia in children,
adolescents, and young adults. Adolescents and young adults diagnosed with leukaemia continue to have lower
survival than children. Trends in survival from leukaemia for adolescents and young adults are important indicators
of the quality of cancer management in this age group.peer-reviewe
Global survival trends for brain tumors, by histology: analysis of individual records for 556,237 adults diagnosed in 59 countries during 2000â2014 (CONCORD-3)
Background:
Survival is a key metric of the effectiveness of a health system in managing cancer. We set out to provide a comprehensive examination of worldwide variation and trends in survival from brain tumors in adults, by histology.
Methods:
We analyzed individual data for adults (15â99 years) diagnosed with a brain tumor (ICD-O-3 topography code C71) during 2000â2014, regardless of tumor behavior. Data underwent a 3-phase quality control as part of CONCORD-3. We estimated net survival for 11 histology groups, using the unbiased nonparametric Pohar Perme estimator.
Results:
The study included 556,237 adults. In 2010â2014, the global range in age-standardized 5-year net survival for the most common sub-types was broad: in the range 20%â38% for diffuse and anaplastic astrocytoma, from 4% to 17% for glioblastoma, and between 32% and 69% for oligodendroglioma. For patients with glioblastoma, the largest gains in survival occurred between 2000â2004 and 2005â2009. These improvements were more noticeable among adults diagnosed aged 40â70 years than among younger adults.
Conclusions:
To the best of our knowledge, this study provides the largest account to date of global trends in population-based survival for brain tumors by histology in adults. We have highlighted remarkable gains in 5-year survival from glioblastoma since 2005, providing large-scale empirical evidence on the uptake of chemoradiation at population level. Worldwide, survival improvements have been extensive, but some countries still lag behind. Our findings may help clinicians involved in national and international tumor pathway boards to promote initiatives aimed at more extensive implementation of clinical guidelines
Gendergevoelig budgetteren: syntheserapport van het project Gender Budgeting in het kader van het globaal project Gender Mainstreaming opgericht door het Federale Beleidsniveau
Gendergevoelig budgetteren: ongelijkheid verminderen en effici\uebntie verhogen: een uitdaging voor openbare instellingen = Analyse budg\ue9taire en terme de genre et d'\ue9galit\ue9 hommes/femmes: r\ue9duire les in\ue9galit\ue9s et am\ue9liorer ses performances: un d\ue9fi pour les services publics
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