Modelling and Simulation of Charging and Discharging Processes in Nanocrystal Flash Memories During Program and Erase Operations

This work is focused on the understanding of charging and discharging processes in silicon nanocrystal flash memories during program and erase operations through time-dependent numerical simulations. Time dependent simulations of the program and erase operations are based on a description of the nanocrystal memory dynamics in terms of a master equation. The related transition rates are computed with a one dimensional Poisson-Schroedinger solver which allows the computation of the tunnelling currents and of generation and recombination rates between the outer reservoir and localized states in the dielectric layer. Comparison between simulations and experiments available in the literature provides useful insights of the storing mechanisms. In particular, simulations allow us to rule out that electrons are stored in confined states in the conduction band of silicon nanocrystals, whereas they suggest that electrons are actually trapped in localized states in the silicon gap at an energy close to the silicon valence band edge, and located at the interface between the nanocrystals and the surrounding silicon oxide.Comment: 10 pages, this is an extended version of a paper presented at the first International Conference on Memory Technology and Design, to be published on Solid State Electronic

Modelling of tunnelling currents in Hf-based gate stacks as a function of temperature and extraction of material parameters

In this paper we show that through electrical characterization and detailed quantum simulations of the capacitance-voltage and current-voltage characteristics it is possible to extract a series of material parameters of alternative gate dielectrics. We have focused on HfO2 and HfSiXOYNZ gate stacks and have extracted information on the nature of localized states in the dielectric responsible for a trap-assisted tunneling current component and for the temperature behavior of the I-V characteristics. Simulations are based on a 1D Poisson-Schrdinger solver capable to provide the pure tunneling current and Trap Assisted Tunneling component. Energy and capture cross section of traps responsible for TAT current have been extracted.Comment: Preprint version of a paper submitted to TED, Transaction on Electron Devices. this is the final reviewed version. This work studies HfO2 and HfSiXOYNZ gate stacks, their C-V and I-V characteristics. A temperature dependent Trap Assisted Tunnneling model was developed to explain the temperature dependence of the I-V chaacteristic

Vascular endothelial growth factor (VEGF) serological and lacrimal signaling in patients affected by vernal keratoconjunctivitis (VKC)

Background. Vernal keratoconjunctivitis (VKC) is a rare inflammatory disease involving the ocular surface, with seasonally exacerbated symptoms. Both type-1 and type-4 hypersensitivity reactions play a role in the development of VKC. Purpose. The aim of the present study was to assess the presence and evaluate the concentration of the vascular endothelial growth factor (VEGF) in tear and blood samples from patients with VKC, during the acute phase, based on the histopathological vasculostromal structure of the tarsal papillae. Methods. Two groups of children aged between 6 and 16 years of life were enrolled: 21 patients (16 males, 76%) affected by VKC, tarsal or mixed form, and 13 healthy children (5 males, 38%) used as controls. Blood and tear samples were obtained from all patients, in order to specifically assess the presence of VEGF. Statistical analyses were performed with one-way ANOVA, followed by post hoc comparisons with the Bonferroni tests. Pearson's correlation was chosen as statistical analysis to assess the relationship between the expression levels of VEGF in tears and blood and the clinical parameters measured. Results. Comparing the 2 groups for VEGF concentration, a statistically significant difference was found in tear samples: the mean value was 12.13 pg/mL (±5.54 SD) in the patient group and 7 pg/ml (±4.76 SD) in controls (p<0.05). However, no statistically significant difference was found when comparing VEGF concentration in blood samples (p>0.05), with a mean value of 45.17 pg/mL (±18.67 SD) in VKC patients and 38.08 pg/mL (±19.43 SD) in controls. Conclusions. This pilot study highlights the importance of lacrimal and vascular inflammatory biomarkers that can be detected in VKC patients during the acute phase, but not in healthy children. The small group of patients warrants additional studies on a larger sample, not only to further investigate the role of VEGF but also to evaluate the angiogenic biomarkers before and after topical treatment

Usefulness of Linear Mixed-Effects Models to Assess the Relationship between Objective and Subjective Internal Load in Team Sports

Internal load can be objectively measured by heart rate-based models, such as Edwards' summated heart rate zones, or subjectively by session rating of perceived exertion. The relationship between internal loads assessed via heart rate-based models and session rating of perceived exertion is usually studied through simple correlations, although the Linear Mixed Model could represent a more appropriate statistical procedure to deal with intrasubject variability. This study aimed to compare conventional correlations and the Linear Mixed Model to assess the relationships between objective and subjective measures of internal load in team sports. Thirteen male youth beach handball players (15.9 ± 0.3 years) were monitored (14 training sessions; 7 official matches). Correlation coefficients were used to correlate the objective and subjective internal load. The Linear Mixed Model was used to model the relationship between objective and subjective measures of internal load data by considering each player individual response as random effect. Random intercepts were used and then random slopes were added. The likelihood-ratio test was used to compare statistical models. The correlation coefficient for the overall relationship between the objective and subjective internal data was very large (r = 0.74; ρ = 0.78). The Linear Mixed Model using both random slopes and random intercepts better explained (p < 0.001) the relationship between internal load measures. Researchers are encouraged to apply the Linear Mixed Models rather than correlation to analyze internal load relationships in team sports since it allows for the consideration of the individuality of players

La tombe monumentale de Grotte Scalina (Viterbe)

La campagne de fouille de 2012 (2 juillet-15 août), à laquelle ont participé 14 archéologues, a été menée en collaboration avec la Soprintendenza per i Beni Archeologici dell’Etruria Meridionale, sous le contrôle de l’inspectrice de la zone, la dott.ssa Valeria D’Atri. Les travaux ont été financés pour partie par le CNRS (UMR 8546-AOROC), pour partie par un Plan Pluri-Formation (PPF) du département des Sciences de l’Antiquité de l’École normale supérieure de Paris ; l’École française de Rome ..

RNA sequencing-based whole-transcriptome analysis of friesian cattle fed with grape pomace-supplemented diet

Grape pomace (GPO), the main by-product of the wine making process, is a rich source of polyphenols with potent antioxidant properties. Recently, GPO has emerged as a potential feed additive in livestock nutrition, with several reports describing its beneficial effects on animals’ overall health status or production traits. However, little is known about it from a molecular biology standpoint. In the present study, we report the first RNA sequencing-based whole-transcriptome profiling of Friesian calves fed with a GPO-supplemented diet. We identified 367 differentially expressed genes (p < 0.05) in the GPO-supplemented calves (n = 5), when compared with unsupplemented control group (n = 5). The pathway analysis showed that ‘cholesterol lipid biosynthesis’ was the most negatively-enriched (p < 0.001) pathway in the GPO-supplemented animals. In specific terms, five important genes coding for cholesterol biosynthesis enzymes, namely the Farnesyl-diphosphate Farnesyltransferase 1 (FDFT-1), Squalene Epoxidase (SQLE), NAD(P)-dependent Steroid Dehydrogenase-like (NSDHL), Methylsterol Monooxygenase (MSMO)-1, and Sterol-C5-desaturase (SC5D), two major transcription factors (the Sterol Regulatory Element-binding Transcription Factor 1 and 2), as well as the Low-Density Lipoprotein Receptor (LDLR), were all downregulated following GPO supplementation. Such an effect was mirrored by a reduction of blood cholesterol levels (p = 0.07) and a lowered (p < 0.001) Malondialdehyde (lipid oxidation marker) level in carcasses. We provide evidence on the effects of GPO-supplemented diets on the whole-transcriptome signature in veal calves, which mainly reflects an antioxidant activity

Rehabilitation of COVID-19 patients

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GLI1 genotypes do not predict basal cell carcinoma risk: a case control study

<p>Abstract</p> <p>Background</p> <p>Susceptibility to basal cell carcinoma results from complex interactions between ultraviolet radiation exposure and genetic factors. The <it>GLI1 </it>oncogene is believed to play a role in the genesis of these tumors. We determined whether <it>GLI1 </it>polymorphisms were risk factors for developing basal cell carcinoma, either alone or in combination with patterns of past sun exposure, and whether there were functional differences among different <it>GLI1 </it>haplotypes.</p> <p>Results</p> <p><it>GLI1 </it>genotypes at c.2798 and c.3298 from 201 basal cell carcinoma patients were compared to 201 age and sex-matched controls. Neither genotype nor haplotype frequencies differed between cases and controls. However, the odds of developing basal cell carcinoma on the trunk compared to the head/neck appeared somewhat lower with carriers of the c.3298GC than the CC genotype. There was no evidence for interactions between skin type, childhood sunburning, average adult sun exposure, adult sunbathing, or intermittency of sun exposure and <it>GLI1 </it>haplotype. Additionally, we found no significant differences in transcription activation or cell transforming ability among the four <it>GLI1 </it>haplotypes.</p> <p>Conclusion</p> <p>These results suggest that different <it>GLI1 </it>genotypes alone or in combination with past sun exposure patterns as assessed in this study do not affect basal cell carcinoma risk.</p