26 research outputs found

    Recent experiments on a small-angle/wide-angle X-ray scattering beam line at the ESRF

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    Recent results using a new combined small-angle/wide-angle X-ray scattering (SAXS/WAXS) beam line at the European Synchrotron Radiation Source (ESRF) will be presented. This beam line is specifically designed to be able to handle complicated sample environments required to perform time-resolved experiments mimicking processing conditions used in material science. Besides the attention that has been given to the interfacing of these sample environments to the beam line data acquisition system also the developments in detector technology will be discussed. The influence that a high count rate and low noise WAXS detector can have on the accuracy of experimental results in polymer crystallisation will be shown. It is shown that it is feasible to detect crystalline volume fractions as low as 10(-3)-10(-4) in polymeric systems

    A multi-technique study of altered granitic rock from the Krunkelbach Valley uranium deposit, Southern Germany

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    Herein, a multi-technique study was performed to reveal the elemental speciation and microphase composition in altered granitic rock collected from the Krunkelbach Valley uranium (U) deposit area near an abandoned U mine, Black Forest, Southern Germany. The former Krunkelbach U mine with 1–2 km surrounding area represents a unique natural analogue site with the rich accumulation of secondary U minerals suitable for radionuclide migration studies from a spent nuclear fuel (SNF) repository. Based on a micro-technique analysis using several synchrotron-based techniques such as X-ray fluorescence analysis, X-ray absorption spectroscopy, powder X-ray diffraction and laboratory-based scanning electron microscopy and Raman spectroscopy, the complex mineral assemblage was identified. While on the surface of granite, heavily altered metazeunerite–metatorbernite (Cu(UO2_{2})2_{2}(AsO4_{4})2−x_{2-x}(PO4_{4})x_{x}·8H2_{2}O) microcrystals were found together with diluted coatings similar to cuprosklodowskite (Cu(UO2_{2})2_{2}(SiO3_{3}OH)2_{2}·6H2_{2}O), in the cavities of the rock predominantly well-preserved microcrystals close to metatorbernite (Cu(UO2_{2})2_{2}(PO4_{4})2_{2}·8H2_{2}O) were identified. The Cu(UO2_{2})2_{2}(AsO4_{4})2−x_{2-x}(PO4_{4})x_{x}·8H2_{2}O species exhibit uneven morphology and varies in its elemental composition, depending on the microcrystal part ranging from well-preserved to heavily altered on a scale of ∼200 μm. The microcrystal phase alteration could be presumably attributed to the microcrystal morphology, variations in chemical composition, and geochemical conditions at the site. The occurrence of uranyl-arsenate-phosphate and uranyl-silicate mineralisation on the surface of the same rock indicates the signatures of different geochemical conditions that took place after the oxidative weathering of the primary U- and arsenic (As)-bearing ores. The relevance of uranyl minerals to SNF storage and the potential role of uranyl-arsenate mineral species in the mobilization of U and As into the environment is discussed

    Treatment of uterine prolapse stage 2 or higher: a randomized multicenter trial comparing sacrospinous fixation with vaginal hysterectomy (SAVE U trial)

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    Contains fulltext : 97471.pdf (publisher's version ) (Open Access)BACKGROUND: Pelvic organ prolapse is a common health problem, affecting up to 40% of parous women over 50 years old, with significant negative influence on quality of life. Vaginal hysterectomy is currently the leading treatment method for patients with symptomatic uterine prolapse. Several studies have shown that sacrospinous fixation in case of uterine prolapse is a safe and effective alternative to vaginal hysterectomy. However, no large randomized trials with long-term follow-up have been performed to compare efficacy and quality of life between both techniques.The SAVE U trial is designed to compare sacrospinous fixation with vaginal hysterectomy in the treatment of uterine prolapse stage 2 or higher in terms of prolapse recurrence, quality of life, complications, hospital stay, post-operative recovery and sexual functioning. METHODS/DESIGN: The SAVE U trial is a randomized controlled multi-center non-inferiority trial. The study compares sacrospinous fixation with vaginal hysterectomy in women with uterine prolapse stage 2 or higher. The primary outcome measure is recurrence of uterine prolapse defined as: uterine descent stage 2 or more assessed by pelvic organ prolapse quantification examination and prolapse complaints and/or redo surgery at 12 months follow-up. Secondary outcomes are subjective improvement in quality of life measured by generic (Short Form 36 and Euroqol 5D) and disease-specific (Urogenital Distress Inventory, Defecatory Distress Inventory and Incontinence Impact Questionnaire) quality of life instruments, complications following surgery, hospital stay, post-operative recovery and sexual functioning (Pelvic Organ Prolapse/Urinary Incontinence Sexual Questionnaire). Analysis will be performed according to the intention to treat principle. Based on comparable recurrence rates of 3% and considering an upper-limit of 7% to be non-inferior (beta 0.2 and one sided alpha 0.025), 104 patients are needed per group. DISCUSSION: The SAVE U trial is a randomized multicenter trial that will provide evidence whether the efficacy of sacrospinous fixation is similar to vaginal hysterectomy in women with uterine prolapse stage 2 or higher. TRIAL REGISTRATION: Netherlands Trial Register (NTR): NTR1866

    Combined time-resolved SAXS and X-ray Spectroscopy methods

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    Recently developed equipment suitable for quasi simultaneous data collection of SAXS/WAXS and X-ray spectroscopy is discussed. The main applications for this technique are foreseen to be time-resolved studies in inorganic materials relevant for catalysis research and ceramics. The equipment is described and experimental limitations are discussed. Experiments on nanoparticle synthesis and the formation of inorganic materials for catalysis are used as examples of the usefulness of the developed equipment

    Combined time-resolved SAXS and X-ray Spectroscopy methods

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    Recently developed equipment suitable for quasi simultaneous data collection of SAXS/WAXS and X-ray spectroscopy is discussed. The main applications for this technique are foreseen to be time-resolved studies in inorganic materials relevant for catalysis research and ceramics. The equipment is described and experimental limitations are discussed. Experiments on nanoparticle synthesis and the formation of inorganic materials for catalysis are used as examples of the usefulness of the developed equipment

    Surgical management of pelvic organ prolapse and uterine descent in the Netherlands

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    Contains fulltext : 117705.pdf (publisher's version ) (Closed access)INTRODUCTION AND HYPOTHESIS: To evaluate current practice in the surgical treatment of uterine descent among members of the Dutch Urogynecological Society and to analyze possible trends in the surgical treatment of pelvic organ prolapse in the Netherlands during the last decade. METHODS: A questionnaire, including case scenarios, was sent to the members of the Dutch Urogynecological Society. Using a nationwide registry from the Netherlands, we assessed the number and type of surgical procedures performed for pelvic organ prolapse between 1997 and 2009. RESULTS: The response rate was 73%, with 161 questionnaires completed. Vaginal hysterectomy, sacrospinous hysteropexy, and the Manchester Fothergill procedure were the most frequently performed surgical interventions for uterine descent. In the case of lower stage uterine descent, uterus preservation was preferred, but in the case of higher stage there was wide variation. Two thirds of the respondents stated that in recent years they tended to save the uterus more often. The registered number of hospital admissions for uterine descent increased by 30% between 1997 and 2009 and the number of surgical procedures almost doubled. The number of vaginal hysterectomies performed because of uterine descent increased by only 15% in this period. CONCLUSIONS: In the Netherlands, surgical policy in the case of uterine descent is very variable, with no clear preference for either hysterectomy or uterus preservation. There was a high increase in hospital admissions and pelvic organ prolapse procedures in the last decade. The number of vaginal hysterectomies performed because of uterine descent did not follow this change, which reflects a trend toward preserving the uterus
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