Pressure dependent friction on granular slopes close to avalanche

We investigate the sliding of objects on an inclined granular surface close to the avalanche threshold. Our experiments show that the stability is driven by the surface deformations. Heavy objects generate footprint-like deformations which stabilize the objects on the slopes. Light objects do not disturb the sandy surfaces and are also stable. For intermediate weights, the deformations of the surface destabilize the objects and generate sliding. A characteristic pressure for which the solid friction is minimal is evidenced. Applications to the locomotion of devices and animals on sandy slopes as a function of their mass are proposed

Features of gallstones in adult sickle cell patients

Morpho-constitutional analysis of gallstones revealed significant differences between sickle cell patients and other gallbladder stone formers. As expected, pigment stones, mainly composed of calcium bilirubinates, were the most common type of stones in the former (74.7 versus 22.5%, $p<10^{-6}$), which could be explained by haemolysis. However, if we consider that only 25% of sickle cell patients form stones in the bile ducts, this suggests that other factors could be involved such as mutations in the UGT1A1 gene. While calcium phosphates were found with the same frequency as the main component of gallstones in both groups, a high proportion of gallstones that had nucleated from carbapatite were observed in sickle cell patients in comparison to patients without sickle cell disease (23.5% versus 5.5%, $p<0.0001$). In addition, among sickle cell patients, those who were homozygous were more prone than heterozygous subjects to form pigment gallstones from calcium phosphate (31.4 versus 5.9%, $p<0.01$)

Features of gallstones in adult sickle cell patients

Morpho-constitutional analysis of gallstones revealed significant differences between sickle cell patients and other gallbladder stone formers. As expected, pigment stones, mainly composed of calcium bilirubinates, were the most common type of stones in the former (74.7 versus 22.5%, $p<10^{-6}$), which could be explained by haemolysis. However, if we consider that only 25% of sickle cell patients form stones in the bile ducts, this suggests that other factors could be involved such as mutations in the UGT1A1 gene. While calcium phosphates were found with the same frequency as the main component of gallstones in both groups, a high proportion of gallstones that had nucleated from carbapatite were observed in sickle cell patients in comparison to patients without sickle cell disease (23.5% versus 5.5%, $p<0.0001$). In addition, among sickle cell patients, those who were homozygous were more prone than heterozygous subjects to form pigment gallstones from calcium phosphate (31.4 versus 5.9%, $p<0.01$)

Relationship between calcinosis cutis in epidermal necrolysis and caspofungin, a physicochemical investigation

Epidermal necrolysis (EN) is a rare life-threatening condition, usually drug-induced and characterised by a diffuse epidermal and mucosal detachment. Calcinosis cutis is reported in various skin diseases, occurring preferentially with tissue damage, but has never been described in EN. Clinical, biological and histopathological characteristics of three patients were retrospectively obtained from medical charts. Immunohistochemistry of classical osteogenic markers was used to explore the pathogenesis of the calcifications; their chemical composition was determined by $\mu$Fourier transform infra-red ($\mu$FTIR) spectroscopy and their localization and morphology by field-emission scanning electron microscopy (FE-SEM). In a recent letter, part of the results of this investigation has been already presented. In this contribution, we have added original data to this previous letter. We have investigated a set of biopsies corresponding to patients who presented atypical healing retardation due to calcinosis cutis. Through FE-SEM observations at the nanometre scale, we describe different areas where are present voluminous calcifications at the surface, submicrometre spherical entities within the papillary dermis and then large “normal” fibres. FE-SEM observations show clearly that “large” calcifications are the result of an agglomeration of small spherical entities. Moreover, micrometre scale spherical entities are the results of an agglomeration of nanometer scale spherical entities. Finally, the last set of data seems to show that the starting point of the calcifications process is “distant” from the epidermis in part of the dermis which appears undamaged. Regarding the chemical composition of large calcifications, different $\mu$FTIR maps which underlined the presence of calcium-phosphate apatite have been gathered. Moreover, histopathology indicates that these pathological calcifications are not induced following a trans-differentiation of the skin cells into an osteochondrogenic phenotype. The association of caspofungin administration, known to induce in vitro intracellular calcium influx, and inflammation, induced by EN, known to favor dystrophic calcifications in various inflammatory skin diseases, could explain this never-before reported occurrence of calcinosis cutis

Relationship between calcinosis cutis in epidermal necrolysis and caspofungin, a physicochemical investigation

Epidermal necrolysis (EN) is a rare life-threatening condition, usually drug-induced and characterised by a diffuse epidermal and mucosal detachment. Calcinosis cutis is reported in various skin diseases, occurring preferentially with tissue damage, but has never been described in EN. Clinical, biological and histopathological characteristics of three patients were retrospectively obtained from medical charts. Immunohistochemistry of classical osteogenic markers was used to explore the pathogenesis of the calcifications; their chemical composition was determined by $\mu$Fourier transform infra-red ($\mu$FTIR) spectroscopy and their localization and morphology by field-emission scanning electron microscopy (FE-SEM). In a recent letter, part of the results of this investigation has been already presented. In this contribution, we have added original data to this previous letter. We have investigated a set of biopsies corresponding to patients who presented atypical healing retardation due to calcinosis cutis. Through FE-SEM observations at the nanometre scale, we describe different areas where are present voluminous calcifications at the surface, submicrometre spherical entities within the papillary dermis and then large “normal” fibres. FE-SEM observations show clearly that “large” calcifications are the result of an agglomeration of small spherical entities. Moreover, micrometre scale spherical entities are the results of an agglomeration of nanometer scale spherical entities. Finally, the last set of data seems to show that the starting point of the calcifications process is “distant” from the epidermis in part of the dermis which appears undamaged. Regarding the chemical composition of large calcifications, different $\mu$FTIR maps which underlined the presence of calcium-phosphate apatite have been gathered. Moreover, histopathology indicates that these pathological calcifications are not induced following a trans-differentiation of the skin cells into an osteochondrogenic phenotype. The association of caspofungin administration, known to induce in vitro intracellular calcium influx, and inflammation, induced by EN, known to favor dystrophic calcifications in various inflammatory skin diseases, could explain this never-before reported occurrence of calcinosis cutis

Development and implementation of a highly-multiplexed SNP array for genetic mapping in maritime pine and comparative mapping with loblolly pine

<p>Abstract</p> <p>Background</p> <p>Single nucleotide polymorphisms (SNPs) are the most abundant source of genetic variation among individuals of a species. New genotyping technologies allow examining hundreds to thousands of SNPs in a single reaction for a wide range of applications such as genetic diversity analysis, linkage mapping, fine QTL mapping, association studies, marker-assisted or genome-wide selection. In this paper, we evaluated the potential of highly-multiplexed SNP genotyping for genetic mapping in maritime pine (<it>Pinus pinaster </it>Ait.), the main conifer used for commercial plantation in southwestern Europe.</p> <p>Results</p> <p>We designed a custom GoldenGate assay for 1,536 SNPs detected through the resequencing of gene fragments (707 <it>in vitro </it>SNPs/Indels) and from Sanger-derived Expressed Sequenced Tags assembled into a unigene set (829 <it>in silico </it>SNPs/Indels). Offspring from three-generation outbred (G2) and inbred (F2) pedigrees were genotyped. The success rate of the assay was 63.6% and 74.8% for <it>in silico </it>and <it>in vitro </it>SNPs, respectively. A genotyping error rate of 0.4% was further estimated from segregating data of SNPs belonging to the same gene. Overall, 394 SNPs were available for mapping. A total of 287 SNPs were integrated with previously mapped markers in the G2 parental maps, while 179 SNPs were localized on the map generated from the analysis of the F2 progeny. Based on 98 markers segregating in both pedigrees, we were able to generate a consensus map comprising 357 SNPs from 292 different loci. Finally, the analysis of sequence homology between mapped markers and their orthologs in a <it>Pinus taeda </it>linkage map, made it possible to align the 12 linkage groups of both species.</p> <p>Conclusions</p> <p>Our results show that the GoldenGate assay can be used successfully for high-throughput SNP genotyping in maritime pine, a conifer species that has a genome seven times the size of the human genome. This SNP-array will be extended thanks to recent sequencing effort using new generation sequencing technologies and will include SNPs from comparative orthologous sequences that were identified in the present study, providing a wider collection of anchor points for comparative genomics among the conifers.</p

Liquid state properties and solidification features of the pseudo binary BaS-La2S3

The high temperature thermodynamic properties of chalcogenides materials based on BaS remain elusive. Herein the pseudo binary BaS-La(2)S(3) is investigated above 1573 K. The liquid properties of BaS-La(2)S(3) are measured by means of high resolution in-situ visualization coupled with thermal arrest measurements in a thermal imaging furnace. This enables to report the first observation of such melts in a container-less setting. The melting points of BaS and La(2)S(3) are revisited at 2454 K and 2004 K respectively. La(2)S(3) demonstrates a high stability in its liquid state, in strike difference with the sublimation observed for BaS. BaS is however partially stabilized with the addition of few percents of La(2)S(3). The remarkable chemical and thermal stability of La(2)S(3)-rich samples contrasts with the partial decomposition and high vapor pressure observed for BaS-rich samples. Observations and analysis of the solidified samples suggest three different solid solutions. Solid and liquid densities are investigated along the different compositions, supporting a first estimate of the volumetric thermal expansion coefficient for La(2)S(3)

Synthesis of degradable polyphosphoester copolymers for templating calcium carbonate drug delivery carriers

Degradable acid bearing polyphosphoester (PPE) copolymers were prepared by combination of organocatalyzed ring opening polymerization and click chemistry. Their solution behavior and ability to complex calcium ions were studied as well as their capacity to template CaCO3 particles dedicated to drug delivery

Production of Metallic Tungsten and Tungsten Carbide from Natural Wolframite and Scheelite via Sulfide Chemistry

Abstract The development of sulfide-based chemistry and physical separation in the last decade opens new processes to produce metals at the industrial scale. Herein, a new route to produce metallic tungsten and tungsten carbides particles from natural wolframite (Fe,Mn)WO4 and scheelite CaWO4 is presented. Sulfidation of mineral concentrates breaks the tungstate crystal structure into a mix of sulfides, in particular tungsten disulfide WS2. The thermal instability of WS2 at high temperature allows for its subsequent, selective, thermal reduction to tungsten particles at around 1500 °C. Similar thermal reduction in the presence of carbon result in the production of tungsten carbides, WC and W2C, obtained at around 1250 °C. The other major components of the sulfidized concentrate remain un-reduced under the proposed conditions, demonstrating selective reduction of WS2 as a possible new route for W recovery. Similar findings are reported for the carburization of WS2