Comparison Of Structure And Properties Of Femtosecond And Nanosecond Laser-Structured Silicon

We compare the optical properties,chemical composition, and crystallinity of siliconmicrostructures formed in the presence of SF6 by femtosecond laserirradiation and by nanosecond laser irradiation. In spite of very different morphology and crystallinity, the optical properties and chemical composition of the two types of microstructures are very similar. The structures formed with femtosecond (fs) pulses are covered with a disordered nanocrystalline surface layer less than 1 μm thick, while those formed with nanosecond (ns) pulses have very little disorder. Both ns-laser-formed and fs-laser-formed structures absorb near-infrared (1.1–2.5 μm) radiation strongly and have roughly 0.5% sulfur impurities

Species diversity promotes facilitation under stressful conditions

Climate change is expected to lead to a drier world, with more frequent and severe droughts, constituting a growing threat to biodiversity, especially in drylands. Positive plant−plant interactions, such as nurse plants facilitating beneficiary communities in their understorey, could mitigate such climate‐induced stress. However, testing the real‐world relevance of nurse facilitation under drought requires accounting for interactions within the diverse beneficiary communities, which may reduce, or amplify the buffering effect of a nurse. Here, we investigated when and how the interactions among nurse plants and beneficiary community members buffered drought effects in a Mediterranean semiarid abandoned cropland. We transplanted sapling beneficiary communities of either one or three species either under a nurse or in open microsites for different soil moisture levels through watering. Net facilitative effects on survival and biomass were only observed when beneficiary communities were species‐diverse and under drought (without watering), meaning that under these conditions, facilitation provided by the nurse had larger positive effects than the negative effects stemming from competition with the nurse and among beneficiary species. Nurses appear to be generating these increases in survival and biomass in drought conditions via two mechanisms commonly associated with watering in open sites: they generate complementarity among the beneficiaries and shift traits to lower stress profiles. Contrasting with watering, which was found to enhance competitive hierarchy, our study shows that nurses appear to alter species dominance, favouring the less competitive species. Our results highlight three mechanisms (complementarity, competitive dominance, and trait plasticity) by which nurse species could mitigate the loss of biodiversity and biomass production due to water stress. Maintaining and supporting nurse species is thus a potentially pivotal approach in the face of projected increase in drought conditions for many drylands across the world

Effect of Electric Field Distribution on the Morphologies of Laser-Induced Damage in Hafnia-Silica Multilayer Polarizers

Hafnia-silica multilayer polarizers were deposited by e-beam evaporation onto BK7 glass substrates. The polarizers were designed to operate at 1064 nm at Brewster`s angle (56{degree}). They were tested with a 3-ns laser pulse at 45, 56, and 65{degree} incidence angle in order to vary the electric field distribution in the multilayer, study their effects on damage morphology, and investigate possible advantages of off-use angle laser conditioning. Morphology of the laser-induced damage was characterized by optical and scanning electron microscopy. Four distinct damage morphologies (pit, flat bottom pit, scald, outer layer delamination) were observed; they depend strongly on incident angle of the laser beam. Massive delamination observed at 45 and 56{degree} incidence, did not occur at 65{degree}; instead, large and deep pits were found at 65{degree}. Electric field distribution, temperature rise, and change in stress in the multilayer were calculated to attempt to better understand the relation between damage morphology, electric field peak locations, and maximum thermal stress gradients. The calculations showed a twofold increase in stress change in the hafnia top layers depending on incident angle. Stress gradient in the first hafnia-silica interface was found to be highest for 45, 56, and 65{degree}, respectively. Finally, the maximum stress was deeper in the multilayer at 65{degree}. Although the limitations of such simple thermal mechanical model are obvious, the results can explain that outer layer delamination is more likely at 45 and 56{degree} than 65{degree} and that damage sites are expected to be deeper at 65{degree}

Mise à jour des recommandations du GEFPICS pour l’évaluation du statut HER2 dans les cancers du sein en France

En Europe, les patientes atteintes d’un cancer du sein invasif susceptibles de recevoir un traitement ciblé anti-HER2 sont actuellement sélectionnées sur la base d’un test immunohistochimique (IHC). Les techniques d’hybridation in situ (HIS) doivent être utilisées pour l’évaluation des cas IHC ambigus (2+) et pour l’étalonnage de la technique IHC. Les patientes éligibles au traitement ciblant HER2 présentent un statut HER2 positif défini par un test IHC 3+ ou un test 2+ amplifié. Une détection correcte du statut HER2 est indispensable à une utilisation optimale des thérapeutiques ciblées puisque leur efficacité est limitée aux patientes surexprimant HER2. Il est capital que l’évaluation du statut HER2 soit optimisée et fiable. Ces recommandations du groupe d’étude des facteurs pronostiques IHC dans le cancer du sein (GEFPICS) détaillent et commentent les différentes étapes des techniques IHC et HIS, les contrôles utilisables et les règles générales de l’apprentissage de la lecture. Une fois acquis, ce savoir-faire doit être pérennisé par l’observation de règles de bonnes pratiques techniques (utilisation rigoureuse de témoins internes et externes et participation régulière à des programmes d’Assurance qualité [AQ])., Summary In Europe, patients who may benefit from an HER2 targeted drug are currently selected by immunohistochemistry (IHC). In situ hybridization (ISH) techniques should be used for complementary assessment of ambiguous 2+ IHC cases and for the calibration of the IHC technique. Eligibility to an HER2 target treatment is defined by an HER2 positive status being IHC test 3+ or 2+ amplified. Reliable detection of HER2 status is essential to the appropriate usage of HER2 targeted drugs because its specificity is limited to tumors overexpressing HER2. It is essential that the IHC evaluation of the HER2 status of a mammary carcinoma is optimized and reliable. This GEFPICS’ guidelines look over the different steps of the IHC technique, the controls and, the rules for interpretation. Once acquired, this knowledge must be perpetuated by the observation of rules of good technical practice (internal and external controls, quality assurance programs)

Cognitive Performances Are Selectively Enhanced during Chronic Caloric Restriction or Resveratrol Supplementation in a Primate

Effects of an 18-month treatment with a moderate, chronic caloric restriction (CR) or an oral supplementation with resveratrol (RSV), a potential CR mimetic, on cognitive and motor performances were studied in non-human primates, grey mouse lemurs (Microcebus murinus)

Mise à jour 2014 des recommandations du GEFPICS pour l’évaluation du statut HER2 dans les cancers du sein en France

De nouvelles recommandations internationales pour l’évaluation du statut HER2 dans les cancers du sein, basées sur plus de dix ans d’expérience et sur les résultats d’études cliniques et de concordance entre les différentes techniques de détection, viennent tout juste de voir le jour. Le présent article a pour objet de faire le point sur ces nouvelles recommandations, à la lumière de la publication récente du groupe de travail de l’American Society of Clinical Oncology (ASCO) et du Collège des pathologistes américains (CAP), adaptées à la pratique de la pathologie en France et revues par le groupe GEFPICS. À l’ère de la médecine personnalisée, la détermination du statut HER2 reste un élément phare dans le panel des biomarqueurs théranostiques des cancers du sein. Si l’interprétation du statut HER2 dans les cancers du sein est aisée dans la majorité des cas, un certain nombre de situations anatomocliniques est d’interprétation plus délicate, telles que la possibilité rare mais réelle de l’hétérogénéité intra-tumorale du statut de HER2, les formes à différenciation micropapillaire ou la ré-évaluation du statut des biomarqueurs lors de la rechute métastatique. Ces nouvelles recommandations abordent ces différentes questions, reprécisent les conditions pré-analytiques optimales et les critères d’interprétation (notamment des cas 2+), afin de réduire au maximum le risque de faux négatifs. Plus que jamais, la mobilisation de la spécialité d’anatomo-cytopathologie autour de la qualité des tests théranostiques témoigne de son implication dans la chaîne des soins en cancérologie., Summary International guidelines on HER2 determination in breast cancer have just been updated by the American Society of Clinical Oncology (ASCO) and College of American Pathologists (CAP), on the basis of more than ten-year practice, results of clinical trials and concordance studies. The GEFPICS group, composed of expert pathologists in breast cancer, herein presents these recommendations, adapted to the French routine practice. These guidelines highlight the possible diagnosis difficulties with regards to HER2 status determination, such as intra-tumor heterogeneity, special histological subtypes and biomarker re-evaluation during metastatic relapse. Pre-analytical issues and updated scoring criteria (especially for equivocal cases) are detailed, in order to decrease the occurrence of false negative cases. In the era of personalized medicine, pathologists are more than ever involved in the quality of oncotheranostic biomarker evaluation.

SLITRK2, an X-linked modifier of the age at onset in C9orf72 frontotemporal lobar degeneration

The G4C2-repeat expansion in C9orf72 is the most common cause of frontotemporal dementia and of amyotrophic lateral sclerosis. The variability of age at onset and phenotypic presentations is a hallmark of C9orf72 disease. In this study, we aimed to identify modifying factors of disease onset in C9orf72 carriers using a family-based approach, in pairs of C9orf72 carrier relatives with concordant or discordant age at onset. Linkage and association analyses provided converging evidence for a locus on chromosome Xq27.3. The minor allele A of rs1009776 was associated with an earlier onset (P = 1 × 10-5). The association with onset of dementia was replicated in an independent cohort of unrelated C9orf72 patients (P = 0.009). The protective major allele delayed the onset of dementia from 5 to 13 years on average depending on the cohort considered. The same trend was observed in an independent cohort of C9orf72 patients with extreme deviation of the age at onset (P = 0.055). No association of rs1009776 was detected in GRN patients, suggesting that the effect of rs1009776 was restricted to the onset of dementia due to C9orf72. The minor allele A is associated with a higher SLITRK2 expression based on both expression quantitative trait loci (eQTL) databases and in-house expression studies performed on C9orf72 brain tissues. SLITRK2 encodes for a post-synaptic adhesion protein. We further show that synaptic vesicle glycoprotein 2 and synaptophysin, two synaptic vesicle proteins, were decreased in frontal cortex of C9orf72 patients carrying the minor allele. Upregulation of SLITRK2 might be associated with synaptic dysfunctions and drives adverse effects in C9orf72 patients that could be modulated in those carrying the protective allele. How the modulation of SLITRK2 expression affects synaptic functions and influences the disease onset of dementia in C9orf72 carriers will require further investigations. In summary, this study describes an original approach to detect modifier genes in rare diseases and reinforces rising links between C9orf72 and synaptic dysfunctions that might directly influence the occurrence of first symptoms