Les préparations anatomiques sèches de l'Institut d'Anatomie Normale de la Faculté de Médecine de Strasbourg (Inventaire actuel et aspects techniques)

STRASBOURG-Medecine (674822101) / SudocPARIS-BIUM (751062103) / SudocSudocFranceF

Simulation of day-ahead electricity market prices using a statistically calibrated structural model

International audienceAnticipating electricity prices on the day-ahead market has become a key issue for both risk assessment and revenue optimization. In this paper, we propose to generate time series of prices with an hourly resolution using a structural model that simulates a simplified market clearing process. The aggregated supply curves in this model are composed of orders based on the available capacity of generation units. The ask prices are parametrized, and the calibration is performed by applying statistical learning to historical market and power system data. To reflect the strategic behavior of market participants, these prices depend on the scarcity of power at the national level. The model's performance is assessed based on the case of France with a one-year horizon and data from 2013-2015. This approach illustrates how open data on the electric power system enable links to be drawn between technical constraints and price formation

Tangible interactions in control centres for railway traffic management

International audienceA current trend in rail industry control centres is to move towards an increase in the number of digitaltools to assist operators. Our observations show that the information used by rail controllers is distributedamong different interfaces. Operators must assemble all this information themselves to understand thestate of the system. This task is often done mentally, resulting in difficult information sharing and aslower decision process. It is in this search for improvement of the operational centres that we realizeda prototype of a tangible touch table presented in this article. The first tests are underway and allowus to have rather positive feedback on this technology that operators are not familiar with. The nextiterations will focus on refining the prototype and on experimenting with a larger group of users

Exciton Cooling in 2D Perovskite Nanoplatelets: Rationalized Carrier-Induced Stark and Phonon Bottleneck Effects

International audienceUsing femtosecond transient absorption (fs-TA), we investigate the hot exciton relaxation dynamics in strongly confined lead iodide perovskite nanoplatelets (NPLs). The large quantum and dielectric confinement leads to discrete excitonic transitions and strong Stark features in the TA spectra. This prevents the use of conventional relaxation analysis methods extracting the carrier temperature or measuring the buildup of the band-edge bleaching. Instead, we show that the TA spectral line shape near the band-edge reflects the state of the system, which can be used to probe the exciton cooling dynamics. The ultrafast hot exciton relaxation in one- to three- monolayer-thick NPLs confirms the absence of intrinsic phonon bottleneck. However, excitation fluence-dependent measurements reveal a hot phonon bottleneck effect, which is found to be independent of the nature of the internal cations but strongly affected by the ligands and/or sample surface state. Together, these results suggest a role of the surface ligands in the cooling process

Exciton Cooling in 2D Perovskite Nanoplatelets: Rationalized exciton-induced Stark and Phonon Bottleneck Effects

International audienceHybrid halide perovskites have emerged as rising materials for solution-processed photovoltaics, photodetectors, and light-emitting devices. For these applications, a deep understanding of the relaxation mechanism within the photoactive material is crucial since the rate at which hot carriers relax to the band edge will directly impact the performance of the optoelectronic devices. Several groups have investigated the cooling process in hybrid perovskite bulk materials as thin films using pump-probe spectroscopy [1–3].More recently, the development of low dimensional perovskite structures has enabled the investigation of carrier cooling in confined materials. In these systems, slower cooling is expected even at low excitation density due to the larger energy level separation. An apparent intrinsic phonon bottleneck was observed in weakly confined nanocrystals (NCs) [4]. However, contradictory results were reported in strongly confined 2D perovskites: thin films and colloidal nanoplatelets (NPLs). [5,6] Thus, a clear understanding of the confinement effect in the ultrafast relaxation dynamics is lacking.Here, using fs transient absorption spectroscopy (TA), we investigate the cooling rate in lead iodide-based perovskite 2D nanostructures. For such strongly confined systems, we propose an alternative method to characterize the cooling process by analyzing the TA spectral lineshape evolution of the first excitonic transitions. Indeed, the strong Stark signals in the TA spectra and the discrete nature of the optical transitions prevent to use of the classical analysis model of relaxation by extracting the time-dependent carrier temperatures or measuring the build-up of the band state bleaching, as applied previously in bulk and bulk-like perovskites nanocrystals. Using global data analysis, we extracted the rates of carrier relaxation after pump excitation above the band edge, at low and high excitation density. The ultrafast hot exciton relaxation in one- and three-monolayer thick NPLs confirms the absence of intrinsic phonon bottleneck effect, which was found independent of the nature of the internals cations. Remarkably, we found an enhanced delayed cooling rate at higher carrier densities known as the hot phonon bottleneck effect, in the 2D layered perovskite thin films compared to colloidal n=1 NPLs. This fact suggested a role of the ligands y/o sample superficial state in the cooling process

EBV infection is common in gingival epithelial cells of the periodontium and worsens during chronic periodontitis.

An amplifying role for oral epithelial cells (ECs) in Epstein-Barr Virus (EBV) infection has been postulated to explain oral viral shedding. However, while lytic or latent EBV infections of oro/nasopharyngeal ECs are commonly detected under pathological conditions, detection of EBV-infected ECs in healthy conditions is very rare. In this study, a simple non-surgical tissue sampling procedure was used to investigate EBV infection in the periodontal epithelium that surrounds and attaches teeth to the gingiva. Surprisingly, we observed that the gingival ECs of the periodontium (pECs) are commonly infected with EBV and may serve as an important oral reservoir of latently EBV-infected cells. We also found that the basal level of epithelial EBV-infection is significantly increased in chronic periodontitis, a common inflammatory disease that undermines the integrity of tooth-supporting tissues. Moreover, the level of EBV infection was found to correlate with disease severity. In inflamed tissues, EBV-infected pECs appear to be prone to apoptosis and to produce larger amounts of CCL20, a pivotal inflammatory chemokine that controls tissue infiltration by immune cells. Our discovery that the periodontal epithelium is a major site of latent EBV infection sheds a new light on EBV persistence in healthy carriers and on the role of this ubiquitous virus in periodontitis. Moreover, the identification of this easily accessible site of latent infection may encourage new approaches to investigate and monitor other EBV-associated disorders

Hydrogenated diglucose detergents for membrane-protein extraction and stabilization

International audienceWe report herein the design and synthesis of a novel series of alkyl glycosides detergents consisting of a nonionic polar headgroup that comprises two glucose moieties in a branched arrangement (DG), onto which octane-, decane- and dodecanethiols were grafted leading to ODG, DDG, and DDDG detergents. Micellization in aqueous solution was studied by isothermal titration calorimetry (ITC), 1H NMR spectroscopy, and surface tensiometry (SFT). Critical micellar concentration values were found to decrease by a factor of ~10 for each pair of methylene groups added to the alkyl chain, ranging from ~0.05 mM to 9 mM for DDDG and ODG, respectively. Dynamic light scattering (DLS) and analytical ultracentrifugation sedimentation velocity (AUC-SV) experiments were used to investigate the size and the composition of the micellar aggregates, showing that the aggregation number significantly increased from ~40 for ODG to ~80 for DDDG. All new compounds were able to solubilize MPs from bacterial membranes, insect cells, as well as Madin Darby Canine Kidney (MDCK) cells. In particular, native human adenosine receptor (A2AR) and bacterial transporter BmrA were solubilized efficiently. A striking thermostability improvement of +13 and +9°C when ODG and DDG were respectively applied to wild type and full length A2AR. Taken together, this novel detergent series shows promising detergent potency for solubilization and stabilization of MPs and, thus, makes a valuable addition to the chemical toolbox available for extracting and handling these important but challenging membrane protein targets

EBV infection increases with disease severity.

<p>(A–B) EBER-ISH staining was performed on paired periodontal pocket DS and SS samples (n = 40) from CP patients (n = 20), and from HS samples from healthy gingival sulcus from HDs (n = 10). Two representative fields (x40) of EBER staining (EBER) is shown for (A) one selected CP patient and (B) for one selected HD. Negative controls (NEG) were processed using a random PNA probe, and for each individual, the same cell sampling was used for positive and negative staining. (C) EBER-ISH-based determination of the frequency of EBV-infected pECs (EBER^pos) in periodontal samples from healthy sites (HS), swallow sites (SS), and deep sites (DS). The graph (left part) shows the tendency curve of EBER^pos pECs and the clinical attachment level (CAL) in 40 paired-samples from 20 CP patients and 10 samples from healthy donors (same as in A and B). The dot-plot analysis (right part) shows the comparative analysis of the frequency of EBER^pos pECs in paired-samples (SS circles, DS triangles) collected from 20 CP patients (same samples as on graft). (D) The average levels of EBNA1 transcript were also compared between whole RNA from HS (n = 10) and 12 paired-samples (SS and DS, n = 6 for each) from 6 CP patients (same samples as in C). The 36B4 housekeeping gene was used for normalization, with results presented as relative to 36B4 using a LOG₁₀ scale. The p values were calculated using Wilcoxon signed-rank test.</p