Search results for "Solid"
showing 10 items of 3575 documents
The compliance modelling of the pathology aorta of the type of aneurism
2015
The Abdominal Aorta Aneurysm (AAA) is a pathology that is defined by a localized and permanent dilation of the artery and which involves over 8.8% of the seniors. Currently, when a patient has a dilatation of the aorta leading to a surgery because of the rupture risk, the therapeutic decision is made depending on the diameter of the aneurysm. To determine this diameter, it is usually conducted an examination by medical imaging (ultrasound, CT, MRI...). However, it notes that the diagnosis can’t be satisfied with a single dimensional measurement face to induced risks: first of all, when the diameter exceed a certain growth, the risk of rupture can reach 50% but more than 5% of surgical proce…
A molecular approach to remove lead from drinking water
2005
Abstract Corrosion of lead-containing plumbings is responsible for significant contamination of tap water, which can reach several hundreds of micrograms per liter. According to a decision of the European Council applicable in 2013, the maximal lead level in tap water should not exceed 10 μg l −1 . A new concept has been explored that relies on solid-phase extraction by covalent attachment of a lead-selective macrocyclic sequestering agent onto the surface of silica gel. An N -carbamoylmethyl substituted 1,4,8,11-tetraazacyclotetradecane (cyclam) derivative was shown to exhibit favorable protonation properties together with an almost 10 6 -fold selectivity for lead over calcium. Structural …
On-fibre solid-phase microextraction coupled to conventional liquid chromatography versus in-tube solid-phase microextraction coupled to capillary li…
2006
This paper compares the advantages and disadvantages of two different configurations for the extraction of triazines from water samples: (1) on-fibre solid-phase microextraction (SPME) coupled to conventional liquid chromatography (LC); and (2) in-tube SPME coupled to capillary LC. In-tube SPME has been effected either with a packed column or with an open capillary column. A critical evaluation of the main parameters affecting the performance of each method has been carried out in order to select the most suitable approach according to the requirements of the analysis. In the on-fibre SPME configuration the fibre coating was polydimethylsiloxane (PDMS)-divinylbenzene (DVB). The limits of de…
Gadd45α modulates aversive learning through post‐transcriptional regulation of memory‐related mRNA s
2018
Abstract Learning is essential for survival and is controlled by complex molecular mechanisms including regulation of newly synthesized mRNAs that are required to modify synaptic functions. Despite the well‐known role of RNA‐binding proteins (RBPs) in mRNA functionality, their detailed regulation during memory consolidation is poorly understood. This study focuses on the brain function of the RBP Gadd45α (growth arrest and DNA damage‐inducible protein 45 alpha, encoded by the Gadd45a gene). Here, we find that hippocampal memory and long‐term potentiation are strongly impaired in Gadd45a‐deficient mice, a phenotype accompanied by reduced levels of memory‐related mRNAs. The majority of the Ga…
The idea of international solidarity at UNESCO is dwingling
2015
UNESCO’s role to building solidarity, peace and security internationally seems to be threatened and weakened. In 1946, UNESCO made a social contract to use culture, education and science as a tool for buiding international solidarity, peace and security. Its trajectory presents challenges related to vopice, representation, power and hegemony which often result in conflict in most parts of the globe. For instance, the recent acceptance of Palestine to UNESCO has increased tensions amongst states because of Palestine’s positioning in global peace processes. This research surfaces some of these challenges and recomends further research on how to ensure the independents of UNESCO in fulfilling …
Identification of lipophilic pollutants discharged from a Finnish pulp and paper mill.
1998
Lipophilic organic compounds originating from kraft pulping and papermaking were identified by straight gas chromatography/mass spectrometry (GC/MS) analyses. Samples analyzed included a primary clarifier effluent (PE) and a secondary clarifier effluent (SE) from the activated sludge treatment plant of a Finnish ECF-bleached (Elementally Chlorine Free) kraft pulp and paper mill. Liquid-liquid extraction composition of PE was compared with solid phase extraction (SPE) and dialysis of a semipermeable membrane device (SPMD) exposed to PE. Dichloromethane extracts of particulate material isolated from PE, sludges from both the primary and secondary clarifier, a sediment collected in the vicinit…
Hygro-elasto-plastic model for planar orthotropic material
2015
An in-plane elasto-plastic material model and a hygroexpansivity-shrinkage model for paper and board are introduced in this paper. The input parameters for both models are fiber orientation anisotropy and dry solids content. These two models, based on experimental results, could be used in an analytical approach to estimate, for example, plastic strain and shrinkage in simple one-dimensional cases, but for studies of the combined and more complicated effects of hygro-elasto-plastic behavior, a numerical finite element model was constructed. The finite element approach also offered possibilities for studying different structural variations of an orthotropic sheet as well as buckling behavior…
Halloysite nanotubes as sustainable nanofiller for paper consolidation and protection
2014
We investigated the filling process of cellulose-based paper with natural clay nanotubes and their mixtures with hydroxypropyl cellulose (HPC) that is commonly used as glue and consolidant for degraded paper. A comprehensive characterization of the materials was carried out through morphology, wettability, thermal degradation, and tensile properties. The treatment with halloysite nanotubes generated a decrease of the paper mechanical performance and did not alter the thermal properties. The co-presence of HPC and nanoparticles generated a more uniform nanotubes distribution in the paper fibrous structure and a significant enhancement of both the mechanical properties and the surface hydroph…
Heterogeneity of Stem Cells in the Thyroid
2019
Identification of thyroid stem cells in the past few years has made important contributions to our understanding of the cellular and molecular mechanisms that induce tissue regeneration and repair. Embryonic stem (ES) cells and induced-pluripotent stem cells have been used to establish reliable protocols to obtain mature thyrocytes and functional follicles for the treatment of thyroid diseases in mice. In addition, the discovery of resident thyroid progenitor cells, along with other sources of stem cells, has defined in detail the mechanisms responsible for tissue repair upon moderate or severe organ injury.In this chapter, we highlight in detail the current state of research on thyroid ste…
Effect of cation disorder on the magnetic properties ofSr2Fe1−xGaxReO6(0<x<0.7)double perovskites
2007
The effect of diamagnetic dilution of the Fe sublattice on the structural and magnetic properties of the double perovskite Sr{sub 2}Fe{sub 1-x}Ga{sub x}ReO{sub 6} (0 =}0.4 is detected by x-ray structural analysis accompanied by the observation of a magnetically ordered and a paramagnetic phase in the corresponding Moessbauer spectra. Below 20% Ga content, Ga statistically dilutes the -Fe-O-Re-O-Fe- double-exchange pathways. Phase separation begins at 20% Ga substitution; between 20% and 40% ofmore » Ga content, the paramagnetic Ga-based phase does not contain any Fe. The Fe-containing, paramagnetic cubic phases which can be detected by Moessbauer spectroscopy first appear for x=0.4.« less