315 research outputs found

    El internado en la educacion

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    Memoria leida en la Academia de ciencias morales i polĂ­ticas por M. Saint-Claire Deville, miembro del Instituto de Francia - Sobre la pertinencia de los internados en la educacion - Datos para Colombi

    Improved procedures for production and purification of 135La from enriched [135Ba]BaCO3 on a 16.5 MeV cyclotron

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    Lanthanum-135 (135La) is a favorable Auger electron emitter with a high Auger electron yield and low gamma emission, making it promising for Auger electron radiotherapy. However, successful application requires reliable and scalable 135La production. Up to now, metallic natural barium (natBa) is a commonly used target material, but this material is sensitive to moisture and oxidation. BaCO3 has also been tested, due to its higher chemical stability. However, BaCO3 has poor thermal conductivity, limiting the applicable current and making high yield production challenging. In this study, we pressed a mixture of enriched [135Ba]BaCO3 and fine aluminum (Al) powder to provide a stable target with improved thermal conductivity compared to pure BaCO3. After 4 h of irradiation with a 16.5 MeV proton beam at 20 μA current, 1.62 ± 0.18 GBq was produced from a 200 mg [135Ba]BaCO3:Al (1:2, w/w) target. This corresponded to a saturation yield of 11.91 ± 1.31 GBq (or 596 ± 66 MBq/μA). A purification procedure involving initial precipitation, followed by a single composite column containing a layer of TK200 resin and a second layer of branched DGA resin was developed, with 97.1 ± 3.6 % decay corrected 135La recovery. [135La]LaCl3 was obtained in an effective molar activity of 79.6 ± 25.3 MBq/nmol (DOTA titration), 104.0 ± 40.4 MBq/nmol (DTPA titration) and 186.5 ± 83.8 MBq/nmol (CHX-A″-DTPA titration), and a radionuclidic purity (RNP) of >99.9 % at end of purification, hereby demonstrating a purity suitable for radiopharmaceutical use

    Intermediate-term results after en bloc double-lung transplantation with bronchial arterial revascularization

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    AbstractObjective: Between May 1990 and January 1994, 18 patients underwent en bloc double-lung transplantation with tracheal anastomosis and bronchial arterial revascularization. Because at that time it was already suggested that chronic ischemia could be a contributing factor in occurrence of obliterative bronchiolitis, the purpose of this study was to evaluate, with a follow-up ranging from 22 to 69 months, the midterm effects of bronchial arterial revascularization on development of obliterative bronchiolitis. Results: Results were assessed according to tracheal healing, functional results, rejection, infection, and incidence of obliterative bronchiolitis. There were no intraoperative deaths or reexplorations for bleeding related to bronchial arterial revascularization, but there were three hospital deaths and five late deaths, two of them related to obliterative bronchiolitis. According to the criteria previously defined, tracheal healing was assessed as grade I, IIa, or IIb in 17 patients and grade IIIa in only one patient. Early angiography (postoperative days 20 to 40) demonstrated a patent graft in 11 of the 14 patients in whom follow-up information was obtained. Ten patients are currently alive with a 43-month mean follow-up. Among the 15 patients surviving more than 1 year, functional results have been excellent except in five in whom obliterative bronchiolitis has developed and who had an early or late graft thrombosis. Furthermore, those patients had a significantly higher incidence of late acute rejection (p < 0.02), cytomegalovirus disease (p < 0.006), and bronchitis episodes (p < 0.0008) than patients free from obliterative bronchiolitis. Conclusion: We conclude that besides its immediate beneficial effect on tracheal healing, long-lasting revascularization was, at least in this small series, associated with an absence of obliterative bronchiolitis, thus suggesting but not yet proving the possible role of chronic ischemia in this multifactorial disease. (J THORAC CARDIOVASC SURG 1996;112:1292-300

    Glymphatic-assisted perivascular brain delivery of intrathecal small gold nanoparticles

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    Nanoparticles are ultrafine particulate matter having considerable potential for treatment of central nervous system (CNS) disorders. Despite their tiny size, the blood-brain barrier (BBB) restricts their access to the CNS. Their direct cerebrospinal fluid (CSF) administration bypasses the BBB endothelium, but still fails to give adequate brain uptake. We present a novel approach for efficient CNS delivery of 111In-radiolabelled gold nanoparticles (AuNPs; 10-15 nm) via intra-cisterna magna administration, with tracking by SPECT imaging. To accelerate CSF brain influx, we administered AuNPs intracisternally in conjunction with systemic hypertonic saline, which dramatically increased the parenchymal AuNP uptake, especially in deep brain regions. AuNPs entered the CNS along periarterial spaces as visualized by MRI of gadolinium-labelled AuNPs and were cleared from brain within 24 h and excreted through the kidneys. Thus, the glymphatic-assisted perivascular network augment by systemic hypertonic saline is a pathway for highly efficient brain-wide distribution of small AuNPs.Peer reviewe

    Impact of organised programs on colorectal cancer screening

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    <p>Abstract</p> <p>Purpose</p> <p>Colorectal cancer (CRC) screening has been shown to decrease CRC mortality. Organised mass screening programs are being implemented in France. Its perception in the general population and by general practitioners is not well known.</p> <p>Methods</p> <p>Two nationwide observational telephone surveys were conducted in early 2005. First among a representative sample of subjects living in France and aged between 50 and 74 years that covered both geographical departments with and without implemented screening services. Second among General Practionners (Gps). Descriptive and multiple logistic regression was carried out.</p> <p>Results</p> <p>Twenty-five percent of the persons(N = 1509) reported having undergone at least one CRC screening, 18% of the 600 interviewed GPs reported recommending a screening test for CRC systematically to their patients aged 50–74 years. The odds ratio (OR) of having undergone a screening test using FOBT was 3.91 (95% CI: 2.49–6.16) for those living in organised departments (referent group living in departments without organised screening), almost twice as high as impact educational level (OR = 2.03; 95% CI: 1.19–3.47).</p> <p>Conclusion</p> <p>CRC screening is improved in geographical departments where it is organised by health authorities. In France, an organised screening programs decrease inequalities for CRC screening.</p

    Geochemical Study of Natural CO2 Emissions in the French Massif Central: How to Predict Origin, Processes and Evolution of CO2 Leakage

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    International audienceThis study presents an overview of some results obtained within the French ANR (National Agency of Research) supported GĂ©ocarbone-Monitoring research program. The measurements were performed in Sainte-Marguerite, located in the French Massif Central. This site represents a natural laboratory for CO2/fluid/rock interactions studies, as well as CO2 migration mechanisms towards the surface. The CO2 leaking character of the studied area also allows to test and validate measurements methods and verifications for the future CO2 geological storage sites. During these surveys, we analyzed soil CO2 fluxes and concentrations. We sampled and analyzed soil gases, and gas from carbo-gaseous bubbling springs. A one-month continuous monitoring was also tested, to record the concentration of CO2 both in atmosphere and in the soil at a single point. We also developed a new methodology to collect soil gas samples for noble gas abundances and isotopic analyses, as well as carbon isotopic ratios. Our geochemical results, combined with structural geology, show that the leaking CO2 has a very deep origin, partially mantle derived. The gas rises rapidly along normal and strike-slip active faults. CO2 soil concentrations (also showing a mantle derived component) and CO2 fluxes are spatially variable, and reach high values. The recorded atmospheric CO2 is not very high, despite the important CO2 degassing throughout the whole area

    Complexes polynucléaires formés en utilisant des ligands mono et bisbenzimidazole dérivés des acides malique et tartarique avec le manganèse(II), le cobalt(II), le cuivre(II) et le zinc(II)

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    Ce travail de thèse présente la synthèse et la caractérisation de complexes nouveaux formés avec des ligands contenant au moins une fonction benzimidazole ainsi qu'un groupement alcool. Les conditions de synthèse ont été optimisée afin de favoriser la formation de complexes tétranucléaires de type cubane. Les composés sont caractérisés à l'état solide d'une part, mais également en solution. Les analyses effectuées montrent que la plupart du temps, la structure des complexes formés reste stable en solution. Tous les ligands utilisés sont chiraux et ont été synthétisés sous forme énantiomériquement pure. Par spectrométrie de masse, l'influence de la chiralité du ligand sur la stabilité des espèces formées en solution a pu être étudiée et un assemblage rapide des complexes suivi d'un échange lent menant progressivement à la formation des espèces les plus stables a pu être mis en évidence

    Coléoptères nouveaux pour la faune française

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    Sainte-Claire-Deville Jean. Coléoptères nouveaux pour la faune française. In: Bulletin de la Société entomologique de France, volume 27 (5),1922. pp. 67-68
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