272 research outputs found
Modifying of LiNi0.8Co0.2O2 Cathode Material by Chemical Vapor Deposition Coating to Improve Thermal Stability
In this paper, we tried to find answers to safety problems due to use of transition metal oxide as positive electrodes in the lithium ion batteries. The exothermic reaction at high temperature induced by the contact between positive electrode in the charged state, such as LiNi0.8Co0.2O2 and the liquid electrolyte solution based of LiPF6 (EC, DMC) is reduced by formation of ceramic oxide. Al2O3 – and ZnO-coated are synthesized on the surface of LiNi0.8Co0.2O2 particles by chemical vapor deposition. The influences of deposit on the properties of starting material, in particular the thermal stability, are characterized by using, X-ray diffraction, electrochemical measurements and differential scanning calorimeter (DSC). Al2O3-coated sample show fading specific capacity during the first cycle. However, after several cycles a retention capacity is observed. ZnO-coated LiNi0.8Co0.2O2 is inactive electrochemically as shown by X-rays diffraction pattern by the existence of two phases. With regard to DSC analysis in Al2O3-coated, one observe about 35% of reduction of heat flow during the exothermic reaction. The CVD method must be improved to obtain interesting results with regard to the electrochemical performances of treated material. Keywords: lithium-ion batteries, CVD coating; alumina, layered cathode; electrochemistry, X-ray diffraction Thermal stability
A psicanálise aplicada ao sintoma: uma resposta ética aos impasses enfrentados pelos psicanalistas na atualidade
Hyperproliferation and Dysregulation ofIL-4 Expression in NF-ATp-Deficient Mice
AbstractNF-ATp is a member of a family of genes that encodes the cytoplasmic component of the nuclear factor of activated T cells (NF-AT). In this study, we show that mice with a null mutation in the NF-ATp gene have splenomegaly with hyperproliferation of both B and T cells. They also display early defects in the transcription of multiple genes encoding cytokines and cell surface receptors, including CD40L and FasL. A striking defect in early IL-4 production was observed after ligation of the TCR complex by treatment with anti-CD3 in vivo. The transcription of other cytokines including IL-13, GM–CSF, and TNFα was also affected, though to a lesser degree. Interestingly, the cytokines IL-2 and IFNγ were minimally affected. Despite this early defect in IL-4 transcription, Th2 development was actually enhanced at later timepoints as evidenced by increased IL-4 production and IgE levels in situations that favor the formation of Th2 cells both in vitro and in vivo. These data suggest that NF-ATp may be involved in cell growth, and that it is important for the balanced transcription of the IL-4 gene during the course of an immune response.BDY
An open-source automatic survey of green roofs in London using segmentation of aerial imagery
Green roofs can mitigate heat, increase biodiversity, and attenuate storm water, giving some of the benefits of natural vegetation in an urban context where ground space is scarce.
To guide the design of more sustainable and climate-resilient buildings and neighbourhoods,
there is a need to assess the existing status of green roof coverage and explore the potential for future implementation.
Therefore, accurate information on the prevalence and characteristics of existing green roofs is needed, but this information is currently lacking.
Segmentation algorithms have been used widely to identify buildings and land cover in aerial imagery.
Using a machine learning algorithm based on U-Net (Ronneberger et al., 2015) to segment aerial imagery, we surveyed the area and coverage of green roofs in London, producing a geospatial dataset (https://doi.org/10.5281/zenodo.7603123, Simpson et al., 2023).
We estimate that there was 0.23 km2 of green roof in the Central Activities Zone (CAZ) of London,
1.07 km2 in Inner London, and 1.89 km2 in Greater London in the year 2021.
This corresponds to 2.0 % of the total building footprint area in the CAZ and 1.3 % in Inner London.
There is a relatively higher concentration of green roofs in the City of London, covering 3.9 % of the total building footprint area.
Test set accuracy was 0.99, with an FÂ score of 0.58.
When tested against imagery and labels from a different year (2019), the model performed just as well as a model trained on the imagery and labels from that year, showing that the model generalised well between different imagery.
We improve on previous studies by including more negative examples in the training data and by requiring coincidence between vector building footprints and green roof patches.
We experimented with different data augmentation methods and found a small improvement in performance when applying random elastic deformations, colour shifts, gamma adjustments, and rotations to the imagery.
The survey covers 1558 km2 of Greater London, making this the largest open automatic survey of green roofs in any city.
The geospatial dataset is at the single-building level, providing a higher level of detail over the larger area compared to what was already available.
This dataset will enable future work exploring the potential of green roofs in London and on urban climate modelling.</p
Epstein-Barr Virus-Induced Gene 3 (EBI3): A Novel Diagnosis Marker in Burkitt Lymphoma and Diffuse Large B-Cell Lymphoma
The distinction between Burkitt lymphoma (BL) and diffuse large B-cell lymphoma (DLBCL), two types of mature aggressive B-cell lymphomas that require distinct treatments, can be difficult because of forms showing features intermediate between DLBCL and BLÂ (here called BL/DLBCL). They can be discriminated by the presence of c-myc translocations characteristic of BL. However, these are not exclusive of BL and when present in DLBCL are associated with lower survival. In this study, we show that Epstein-Barr virus-induced gene 3 (EBI3) is differentially expressed among BL and DLBCL. Analysis of gene expression data from 502 cases of aggressive mature B-cell lymphomas available on Gene Expression Omnibus and immunohistochemical analysis of 184 cases of BL, BL/DLBCL or DLBCL, showed that EBI3 was not expressed in EBV-positive or -negative BL cases, whereas it was expressed by over 30% of tumoral cells in nearly 80% of DLBCL cases, independently of their subtypes. In addition, we show that c-myc overexpression represses EBI3 expression, and that DLBCL or BL/DLBCL cases with c-myc translocations have lower expression of EBI3. Thus, EBI3 immunohistochemistry could be useful to discriminate BL from DLBCL, and to identify cases of BL/DLBCL or DLBCL with potential c-myc translocations
Restauration morpho-dynamique et redynamisation de la section court-circuitée du Rhin en aval du barrage de Kembs (projet INTERREG / EDF)
National audienceThe Upper Rhine River has been heavily impacted by channelization for flood protection and navigation, and then by damming for hydropower generation. In normal non flooding conditions, most of the flows are diverted in a canalized section whereas the regulated “old Rhine” bypassed reach runs a minimum flow. Between Huningue and Neuf-Brisach, engineering works induced simplification and stabilization of the channel pattern from a formerly braiding sector to a single incised channel, hydrological modifications, bottom armouring due to bedload decrease, and thus ecological alterations. Two complementary and interdisciplinary projects have been initiated to restore alluvial morphodynamics: i) the international “INTERREG IV - Redynamisation of the old Rhine” project (2009-2012) coordinated by the Alsace region, France; ii) the left bank “controlled erosion” project launched by Electricité de France (EDF) within Kembs hydroelectric station relicensing process since 2003-2004. The purpose of these projects is to evaluate the feasibility of an important hydro-morphological and ecological restoration plan on a 45 km long reach, through both field testing of bank erosion techniques at favourable locations, and artificial sediments input from right bank excavations. This will help define possible long term prospective scenarios, in order to restore sustainable sediment transport, morphodynamics variability and associated ecological functions. The study will involve historical analysis, hydro-morphological / hydraulic physical and numerical modelling, physical and ecological monitoring, and sociological aspectsLe Rhin alsacien-allemand a enregistré de profondes modifications morphologiques et hydrologiques à la suite de sa correction et de sa régularisation pour la protection contre les crues et la navigation, puis après la construction de barrages hydro-électriques. Les aménagements réalisés entre Huningue et Neuf-Brisach ont engendré une simplification et une stabilisation du style fluvial. Un fleuve en tresses a cédé la place à un chenal unique incisé. Le fond de chenal est devenu pavé à cause d’une diminution des apports de charge de fond et des altérations écologiques ont été observées (simplification des habitats aquatiques et riverains). Deux projets complémentaires et interdisciplinaires ont été engagés afin de restaurer une dynamique des formes alluviales : i) le projet international INTERREG IV – Redynamisation du Vieux Rhin (2009-2012) sous l’impulsion de la région Alsace ; ii) le projet d’érosion maitrisée des berges de la rive gauche conduit par Electricité de France (EDF) dans le cadre du renouvellement de la concession de l’aménagement de Kembs. L’objectif des deux projets est de définir un plan de restauration hydro-morphologique et écologique conduisant à la redynamisation d’un tronçon de 45 km. L’étude repose sur une analyse historique, l’exploitation de modèles à la fois physiques et numériques, et les suivis morphologiques in situ d’une recharge artificielle en sédiments et d’érosions de berge contrôlées. Ces études de faisabilité sont complétées par des analyses écologique et sociologique pour apprécier l’impact socio-environnemental de ces projets
Frequency and distribution of mixed Plasmodium falciparum-vivax infections in French Guiana between 2000 and 2008
Rationales, design and recruitment for the Elfe longitudinal study
Background
Many factors act simultaneously in childhood to influence health status, life chances and well being, including pre-birth influences, the environmental pollutants of early life, health status but also the social influences of family and school. A cohort study is needed to disentangle these influences and explore attribution.
Methods
Elfe will be a nationally representative cohort of 20 000 children followed from birth to adulthood using a multidisciplinary approach. The cohort will be based on the INSEE Permanent Demographic Panel (EDP) established using census data and civil records. The sample size has been defined in order to match the representativeness criteria and to obtain some prevalence estimation, but also to address the research area of low exposure/rare effects. The cohort will be based on repeated surveys by face to face or phone interview (at birth and each year) as well as medical interview (at 2 years) and examination (at 6 years). Furthermore, biological samples will be taken at birth to evaluate the foetal exposition to toxic substances, environmental sensors will be placed in the child's homes. Pilot studies have been initiated in 2007 (500 children) with an overall acceptance rate of 55% and are currently under progress, the 2-year survey being carried out in October this year.
Discussion
The longitudinal study will provide a unique source of data to analyse the development of children in their environment, to study the various factors interacting throughout the life course up to adulthood and to determine the impact of childhood experience on the individual's physical, psychological, social and professional development
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