71 research outputs found

    Why Treat Apogeotropic BPPVs of the Horizontal Canal? About 30 Observations

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    Benign paroxysmal positional vertigo (BPPV), of the horizontal canal, in the apogeotropic form (AHBPPV) was described in 1995. Based on 30 observations of typical AHBPPVs of the horizontal canal, we endeavor to discuss the relevance of physiotherapy. Material and Method. Thirty observations of typical apogeotropic BPPVs of the horizontal canal treated with a 360° barbeque rotation on the BPPV side, reviewed in consultation at 1 and 3 weeks and reevaluated the following year. Results. Our cohort of 30 patients had an average age of 58.6 years. The apogeotropic BPPVs of the horizontal canal, which can be transformed into BPPVs of the posterior canal or into geotropic-type BPPVs of the horizontal canal do not recover more quickly. Patients who follow the positional advice do not recover more quickly than those who do not (P = 0.152). The 15 patients treated on average 13.73 days after the onset of the disease did not recover more quickly after the start of therapeutic treatment than those treated later (P = 0.032). Conclusion. Here, we demonstrate that the direction of rotation during the maneuvers is of no importance for the results. We show that transformability is not a guarantee of rapid recovery and that the therapist's effectiveness is limited when it comes to the short-term results

    Mechanisms of biogenic gas migration revealed by seep carbonate paragenesis, Panoche Hills, California

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    A comprehensive study of seep carbonates at the top of the organic-rich Maastrichtian to Danian Moreno Formation in the Panoche Hills (California) reveals the mechanisms of generation, expulsion, and migration of biogenic methane that fed the seeps. Two selected outcrops show that seep carbonates developed at the tip of sand dykes intrude up into the Moreno Formation from deeper sandbodies. Precipitation of methane-derived cements occurred in a succession of up to 10 repeated elementary sequences, each starting with a corrosion surface followed by dendritic carbonates, botryoidal aragonite, aragonite fans, and finally laminated micrite. Each element of the sequence reflects three stages. First, a sudden methane pulse extended up into the oxic zone of the sediments, leading to aerobic oxidation of methane and carbonate dissolution. Second, after consumption of the oxygen, anaerobic oxidation of methane coupled with sulfate reduction triggered carbonate precipitation. Third, progressive diminishment of the methane seepage led to the deepening of the reaction front in the sediment and the lowering of precipitation rates. Carbonate isotopes, with δ¹³C as low as −51‰ Peedee belemnite, indicate a biogenic origin for the methane, whereas a one-dimensional basin model suggests that the Moreno Formation was in optimal thermal conditions for bacterial methane generation at the time of seep carbonate precipitation. Methane pulses are interpreted to reflect drainage by successive episodes of sand injection into the gas-generating shale of the Moreno Formation. The seep carbonates of the Panoche Hills can thus be viewed as a record of methane production from a biogenic source rock by multiphase hydraulic fracturing

    Mask Induced Polarization Effects at High NA

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    It is important to understand how a photomask will polarize incident radiation. This paper presents data collected on binary mask and various attenuated phase shifting mask materials, feature sizes, duty ratios, and illumination schemes via rigorous coupled wave analysis, extinction spectroscopy, and 193nm lithographic evaluation. Additionally, the result of polarization effects due to the photomask on imaging has been studied. It was found that in the majority of the cases, higher NA led to greater polarization effects. All mask materials predominantly pass the TM polarization state for the 0 order, whereas different materials and duty ratios affect the polarization of the first diffracted orders differently. The polarization effects contributed by mask materials being considered for use in high NA imaging systems need to be examined. The degree of polarization as a function of n and k is presented, providing an introduction to the desirable properties of future mask materials. Materials with higher refractive indices and lower extinction coefficients tend to pass more of the TM polarization state, which is undesirable. Materials with lower indices and relatively wide range of extinction coefficients pass more TE polarized radiation. The duty ratio, critical dimension, mask material, material thickness, and illumination scheme all influence mask induced polarization effects

    Design of Functionalized Lipids and Evidence for Their Binding to Photosystem II Core Complex by Oxygen Evolution Measurements, Atomic Force Microscopy, and Scanning Near-Field Optical Microscopy

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    AbstractPhotosystem II core complex (PSII CC) absorbs light energy and triggers a series of electron transfer reactions by oxidizing water while producing molecular oxygen. Synthetic lipids with different alkyl chains and spacer lengths bearing functionalized headgroups were specifically designed to bind the QB site and to anchor this large photosynthetic complex (240 kDa) in order to attempt two-dimensional crystallization. Among the series of different compounds that have been tested, oxygen evolution measurements have shown that dichlorophenyl urea (DCPU) binds very efficiently to the QB site of PSII CC, and therefore, that moiety has been linked covalently to the headgroup of synthetic lipids. The analysis of the monolayer behavior of these DCPU-lipids has allowed us to select ones bearing long spacers for the anchoring of PSII CC. Oxygen evolution measurements demonstrated that these long-spacer DCPU-lipids specifically bind to PSII CC and inhibit electron transfer. With the use of atomic force microscopy (AFM) and scanning near-field optical microscopy (SNOM), it was possible to visualize domains of PSII CC bound to DCPU-lipid monolayers. SNOM imaging has enabled us to confirm that domains observed by AFM were composed of PSII CC. Indeed, the SNOM topography images presented similar domains as those observed by AFM, but in addition, it allowed us to determine that these domains are fluorescent. Electron microscopy of these domains, however, has shown that the bound PSII CC was not crystalline

    PI3Kγ is a molecular switch that controls immune suppression

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    Macrophages play critical, but opposite, roles in acute and chronic inflammation and cancer1,2,3,4,5. In response to pathogens or injury, inflammatory macrophages express cytokines that stimulate cytotoxic T cells, whereas macrophages in neoplastic and parasitic diseases express anti-inflammatory cytokines that induce immune suppression and may promote resistance to T cell checkpoint inhibitors1,2,3,4,5,6,7. Here we show that macrophage PI 3-kinase γ controls a critical switch between immune stimulation and suppression during inflammation and cancer. PI3Kγ signalling through Akt and mTor inhibits NFκB activation while stimulating C/EBPβ activation, thereby inducing a transcriptional program that promotes immune suppression during inflammation and tumour growth. By contrast, selective inactivation of macrophage PI3Kγ stimulates and prolongs NFκB activation and inhibits C/EBPβ activation, thus promoting an immunostimulatory transcriptional program that restores CD8+ T cell activation and cytotoxicity. PI3Kγ synergizes with checkpoint inhibitor therapy to promote tumour regression and increased survival in mouse models of cancer. In addition, PI3Kγ-directed, anti-inflammatory gene expression can predict survival probability in cancer patients. Our work thus demonstrates that therapeutic targeting of intracellular signalling pathways that regulate the switch between macrophage polarization states can control immune suppression in cancer and other disorders

    Rôle des progéniteurs vasculaires dans le processus de néovascularisation post-ischémique (applications thérapeutiques)

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    PARIS7-Bibliothèque centrale (751132105) / SudocSudocFranceF

    What makes seep carbonates ignore self-sealing and grow vertically: the role of burrowing decapod crustaceans

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    The mechanisms that govern the vertical growth of seep carbonates were deciphered by studying the sedimentary architecture of a 15m thick, 8m wide column of limestone encased in deep-water marl in the middle Callovian interval of the Terres Noires Formation in the SE France Basin. The limestone body, also called "pseudobioherm", records intense bioturbation, with predominant traces of the Thalassinoides/Spongeliomorpha suite, excavated by decapod crustaceans. Bioturbation was organized in four tiers. The uppermost tier, tier 1, corresponds to shallow homogenization of rather soft sediment. Tier 2 corresponds to pervasive burrows dominated by large Thalassinoides that were later passively filled by pellets. Both homogenized micrite and burrow-filling pellets are depleted in 13 C in the range from -5‰ to -10‰. Tier 3 is characterized by small Thalassinoides that have walls locally bored by Trypanites ; the latter represent tier 4. The diagenetic cements filling the tier-3 Thalassinoides are arranged in two phases. The first cement generation constitutes a continuous rim that coats the burrow wall and has consistent δ 13 C values of approximately -8‰ to -12‰, indicative of bicarbonate originating from the anaerobic oxidation of methane. In contrast, the second cement generation is dominated by saddle dolomite precipitated at temperatures > 80°C, at a time when the pseudobioherm was deeply buried. The fact that the tubes remained open until deep burial means that vertical fluid communication was possible over the whole vertical extent of the pseudobioherm up to the seafloor during its active development. Therefore, vertical growth was fostered by this open burrow network, providing a high density of localized conduits through the zone of carbonate precipitation, in particular across the sulfate-methane transition zone. Burrows prevented self-sealing from blocking upward methane migration and laterally deflecting fluid flow. One key aspect is the geometric complexity of the burrows with numerous subhorizontal segments that could trap sediment shed from above and, hence, prevent their passive fill

    PI3Kgamma activates integrin alpha4 and promotes immune suppressive myeloid cell polarization during tumor progression

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    Immunosuppressive myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs) accumulate in tumors where they inhibit T cell-mediated antitumor immune responses and promote tumor progression. Myeloid cell PI3Kγ plays a role in regulating tumor immune suppression by promoting integrin α4-dependent MDSC recruitment to tumors and by stimulating the immunosuppressive polarization of MDSCs and TAMs. Here, we show that integrin α4 promotes immunosuppressive polarization of MDSCs and TAMs downstream of PI3Kγ, thereby inhibiting antitumor immunity. Genetic or pharmacological suppression of either PI3Kγ or integrin α4 blocked MDSC recruitment to tumors and also inhibited immune suppressive myeloid cell polarization, thereby reducing expression of IL10 and increasing expression of IL12 and IFNγ within tumors. Inhibition of PI3Kγ or integrin α4 within tumors stimulated dendritic cell and CD8+ T-cell recruitment and maturation, as well as tumor cell cytotoxicity in vivo, thereby inhibiting tumor growth. As blockade of PI3Kγ or integrin α4 prevents accumulation of MDSC and reduces myeloid cell expression of immunosuppressive factors that stimulate tumor immune escape, these results highlight PI3Kγ and integrin α4 as targets for the design of cancer therapeutics. Cancer Immunol Res; 5(11); 957-68. ©2017 AACR

    Transmission horizontale de Escherichia coli multirésistants favorisée via l’environnement, sans transmission verticale directe dans la pyramide de l’élevage de poulets

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    International audienceLe taux d’antibiorésistance diminue depuis plusieurs années dans les élevages de volailles en France, en corrélation avec un moindre recours aux antibiotiques en santé animale. Cependant le tube digestif des animaux de rente et l’environnement d’élevage sont considérés comme potentiels réservoirs de bactéries multirésistantes. Cette étude évalue la transmission verticale ou horizontale ou la persistance de l’antibiorésistance tout au long de la chaîne de production de poulets. Des prélèvements de fientes de poulets sains, de surfaces des bâtiments et d’eau ont été réalisés en 2018 - 2019 dans un élevage expérimental qui permet l’accès à l’ensemble des étapes la filière avicole. Le suivi de l’antibiorésistance a été réalisé sur trois générations successives de poules reproductrices élevées en bâtiment protégé afin d’entretenir la lignée (lot reproducteur) ainsi que sur leurs descendants élevés dans des conditions standards pour la production de viande (lot testage). Malgré la non-utilisation d’antibiotiques dans cet élevage depuis une décennie, des E. coli antibiorésistants ont été isolés des prélèvements biologiques et environnementaux. Le phénotype majoritaire de multirésistance aux sulfamides, tétracycline, triméthoprime et ampicilline présentait un taux de 45,5 % chez les isolats de fientes. Une diversité plus importante des phénotypes de multirésistance a été observée chez les isolats du lot testage, telle que les résistances supplémentaires à la streptomycine, aux quinolones et/ou aux phénicolés. L’analyse de séquences des génomes entiers pour 152 isolats d’E. coli a montré qu’ils appartiennent majoritairement au phylogroupe A (55,9%), exclusivement associé au lot reproducteur et au phylogroupe B1 (36,2%), très fortement associé au lot testage. Les trois séquence types majoritaires sont ST162 (B1), ST93 et ST2701 (A) et sont partagés entre générations, de plus chaque ST est associé à un seul sérotype, excepté ST162 associé à deux sérotypes. Les gènes d’antibiorésistance identifiés corroborent les profils phénotypiques des isolats et les plasmides identifiés indiquent une possible transmission horizontale de l’antibiorésistance plasmidique entre bactéries portées par les animaux d’un même lot. Les E. coli multirésistants isolés de l’élevage présentent donc une faible diversité génétique. Ils semblent persister dans l’environnement d’élevage et s’implanter chez les animaux des lots successifs, sans transmission verticale inter-générationnelle directe
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