36 research outputs found

    Adiabatic passage with spin locking in Tm3+:YAG

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    International audienceIn low-concentration Tm 3+ :YAG, we observe efficient adiabatic rapid passage (ARP) of thulium nuclear spin over flipping times much longer than T 2. Efficient ARP with long flipping time has been observed in monoatomic solids for decades and has been analyzed in terms of spin temperature and of the thermodynamic equilibrium of a coupled spin ensemble. In low-concentration impurity-doped crystals the spin temperature concept may be questioned. A single spin model should be preferred since the impurity ions are weakly coupled together but interact with the numerous off-resonant matrix ions that originate the spin-spin relaxation. The experiment takes place in the context of quantum information investigation, involving impurity-doped crystals, spin hyperpolarization by optical pumping, and optical detection of the spin evolution

    Linear sweep voltammetry coupled to a quartz crystal microbalance for investigating the catalytic activity of the Mg (II) –water electrochemical system and managing the Mg oxy-hydroxide hydration state

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    This study provides an insight into the catalytic activity of the Mg(II)–water electrochemical system, from aqueous magnesium chloride hexa-hydrate to magnesium oxy-hydroxide electro-nucleation, growth and evolution, using Linear Sweep Voltammetry (LSV) coupled to a Quartz Crystal Microbalance (QCM) (−0.80>EV/SCE>−1.80). Interfacial phenomena occur at the gold resonator during cathodic polarization (−0.90>EV/SCE>−1.80).MgH2O62+→−0.90>EV/SCE>−1.25MgH2O4OH2→−1.25>EV/SCE>−1.50MgH2O2OH2→−1.50>EV/SCE>−1.70MgOH2 From −0.90V, reduction of the intramolecular water of the hexa-coordinated Mg(H2O)62+ cluster enhanced the cathodic current i°MgH2O62+/i°H2O. In the range −1.25>EV/SCE>−1.70, electrosynthesis of Mg(H2O)4(OH)2 and its simultaneous gradual dehydration to Mg(OH)2 take place. At lower potentials, experiments suggest intramolecular dehydroxylation of Mg(OH)2 to MgO. The applied potential thus allows fine control of the hydration state of the Mg oxy-hydroxide

    Déploiement de la démarche d'analyse de risques dans le secteur qualité d'une entreprise pharmaceutique

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    TOURS-BU Sciences Pharmacie (372612104) / SudocSudocFranceF

    Is distal locking screw necessary for intramedullary nailing in the treatment of humeral shaft fractures? A comparative cohort study

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    International audiencePURPOSE: The gold standard for intramedullary nailing (IMN) in humeral shaft fracture treatment is bipolar interlocking. The aim of this study was to compare clinical and radiographic outcomes in two cohorts of patients treated with IMN with or without distal interlocking. We hypothesized that there was no significant difference between isolated proximal interlocking and bipolar interlocking in terms of consolidation and clinical results.METHODS: One hundred twenty-one acute humeral shaft fractures were retrospectively included in group WDI (without distal interlocking screw, n=74) or in group DI (with distal interlocking screw, n=47). One hundred six patients (87.60%) could be verified by an X-ray, and 63 (52.07%) could be examined clinically. Fracture union at 6months was the primary outcome, and the second was the final clinical outcome for shoulder and elbow after at least 6months of follow-up. Pain, operating time, and radiation time were also analyzed.RESULTS: The two groups were not significantly different for population, fractures, or immobilization duration. No significant difference was found for bone union (WDI 89.06% vs DI 83.33%, p=0.51), shoulder or elbow functional outcomes, or pain. However, there were significant differences in advantage to the WDI group for operating time (WDI 63.09±21.30min vs DI 87.96±30.11min, p<0.01) and fluoroscopy time (WDI 59.06±30.30s vs DI 100.36±48.98s, p<0.01).CONCLUSIONS: Thus, it seems that there were no significant differences between proximal unipolar and bipolar interlocking for humeral shaft fractures in terms of consolidation and clinical outcomes. WDI avoided the additional operating time and fluoroscopy time and risks linked to DI

    Microbiological identification by surface-enhanced Raman spectroscopy

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    International audienceNew methods for pathogens identification are of growing interest in clinical and food sectors. The challenge remains to develop rapid methods that are more simple, reliable, and specific. Surface-enhanced Raman spectroscopy (SERS) appears to be a promising tool to compete with current untargeted identification methods. This article presents the intensive research devoted to the use of SERS for bacterial identification, from the first to the very recent published results. Compared to normal Raman spectroscopy, the introduction of nanoparticles for SERS acquisition introduces a new degree of complexity. Bacterial Raman fingerprints, which are already subject to high spectral variability for a given strain, become then very dependent on numerous experimental parameters. To overcome these limitations, several approaches have been proposed to prepare the sample, from the microbiological culture conditions to the analysis of the spectrum including the coupling of nanoparticles on the bacterial membrane. Main strategies proposed over the last 20 years are examined here and discussed in the perspective of a protocol transfer towards industry

    Indirect evidence that drug brain targeting using polysorbate 80-coated polybutylcyanoacrylate nanoparticles is related to toxicity

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    International audiencePurpose. To investigate the mechanism underlying the entry of the analgesic peptide dalargin into brain using biodegradable polybutylcyanoacrylate (PBCA) nanoparticles (NP) overcoated with polysorbate 80. Methods. The investigations were carried out with PBCA NP and with non biodegradable polystyrene (PS) NP (200 nm diameter). Dalargin adsorption was assessed by HPLC. Its entry into the CNS in mice was evaluated using the tail-flick procedure. Locomotor activity measurements were performed to compare NP toxicities. BBB permeabilization by PBCA NP was studied in vitro using a coculture of bovine brain capillary endothelial cells and rat astrocytes. Results. Dalargin loading was 11.7 μg/mg on PBCA NP and 16.5 μg/ mg on PS NP. Adding polysorbate 80 to NP led to a complete desorption. Nevertheless, dalargin associated with PBCA NP and polysorbate 80 induced a potent and prolonged analgesia, which could not be obtained using PS NP in place of PBCA NP. Locomotor activity dramatically decreased in mice dosed with PBCA NP, but not with PS NP. PBCA NP also caused occasional mortality. In vitro, PBCA NP (10 μg/ml) induced a permeabilization of the BBB model. Conclusions. A non specific permeabilization of the BBB, probably related to the toxicity of the carrier, may account for the CNS penetration of dalargin associated with PBCA NP and polysorbate 80

    Functional Cerebral MRI Evaluation of Integration of Breast Reconstruction into the Body Schema

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    International audienceBackground: The objective of breast reconstruction (BR) is to erase the after-effects of total mastectomy by allowing patients to restore their breast shape. The aim of our study was to investigate the body map integration of different types of BR using functional magnetic resonance (fMRI). Patients and Methods: We prospectively enrolled all women undergoing BR for breast cancer to the Remasco study (NCT02553967). Participants were categorized into four groups according to the standard of care they required: immediate BR (IBR), delayed BR (DBR), flap (autologous), or implant BR. Each patient performed sensorimotor tasks during the fMRI acquisition. Results: Data of 38 patients were analyzed. We identified the cingulate region as the area of interest in the brain. In the case of DBR, the brain area activated during palpation of the total mastectomy scar (before BR) was different from the brain area activated during palpation of the reconstructed breast (Brodmann areas 31 versus 32). Palpation of the native breast and reconstructed breast activated the same Brodmann area 32. Comparing the brain activation signal during palpation of the native breast and the reconstructed breast did not reveal any significant difference in the overall population (P = 0.41) or in the groups: autologous (P = 0.32), implant (P = 0.10), IBR (P = 0.72), or DBR (P = 0.10). Conclusions: This experimental study allowed us to describe and understand the brain plasticity processes that accompany BR. The results suggest that the reconstructed breast is integrated into the body schema, regardless of the type of BR or the timing
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