203 research outputs found

    Performance tests of an AGIPD 0.4 assembly at the beamline P10 of PETRA III

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    The Adaptive Gain Integrating Pixel Detector (AGIPD) is a novel detector system, currently under development by a collaboration of DESY, the Paul Scherrer Institute in Switzerland, the University of Hamburg and the University of Bonn, and is primarily designed for use at the European XFEL. To verify key features of this detector, an AGIPD 0.4 test chip assembly was tested at the P10 beamline of the PETRA III synchrotron at DESY. The test chip successfully imaged both the direct synchrotron beam and single 7.05 keV photons at the same time, demonstrating the large dynamic range required for XFEL experiments. X-ray scattering measurements from a test sample agree with standard measurements and show the chip's capability of observing dynamics at the microsecond time scale.Comment: revised version after peer revie

    Direct observation of nanoscale interface phase in the superconducting chalcogenide Kx_{x}Fe2y_{2-y}Se2_2 with intrinsic phase separation

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    We have used scanning micro x-ray diffraction to characterize different phases in superconducting Kx_{x}Fe2y_{2-y}Se2_2 as a function of temperature, unveiling the thermal evolution across the superconducting transition temperature (Tc_c\sim32 K), phase separation temperature (Tps_{ps}\sim520 K) and iron-vacancy order temperature (Tvo_{vo}\sim580 K). In addition to the iron-vacancy ordered tetragonal magnetic phase and orthorhombic metallic minority filamentary phase, we have found a clear evidence of the interface phase with tetragonal symmetry. The metallic phase is surrounded by this interface phase below \sim300 K, and is embedded in the insulating texture. The spatial distribution of coexisting phases as a function of temperature provides a clear evidence of the formation of protected metallic percolative paths in the majority texture with large magnetic moment, required for the electronic coherence for the superconductivity. Furthermore, a clear reorganization of iron-vacancy order around the Tps_{ps} and Tc_c is found with the interface phase being mostly associated with a different iron-vacancy configuration, that may be important for protecting the percolative superconductivity in Kx_{x}Fe2y_{2-y}Se2_2.Comment: 6 pages, 4 figure

    A study of soft tissue sarcomas after childhood cancer in Britain

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    Among 16 541 3-year survivors of childhood cancer in Britain, 39 soft tissue sarcomas (STSs) occurred and 1.1 sarcomas were expected, yielding a standardised incidence ratio (SIR) of 16.1. When retinoblastomas were excluded from the cohort, the SIR for STSs was 15.9, and the cumulative risk of developing a soft tissue tumour after childhood cancer within 20 years of 3-year survival was 0.23%. In the case–control study, there was a significant excess of STSs in those patients exposed to both radiotherapy (RT) and chemotherapy, which was five times that observed among those not exposed (P=0.02). On the basis of individual radiation dosimetry, there was evidence of a strong dose–response effect with a significant increase in the risk of STS with increasing dose of RT (P<0.001). This effect remained significant in a multivariate model. The adjusted risk in patients exposed to RT doses of over 3000 cGy was over 50 times the risk in the unexposed. There was evidence of a dose–response effect with exposure to alkylating agents, the risk increasing substantially with increasing cumulative dose (P=0.05). This effect remained after adjusting for the effect of radiation exposure

    Discovery of Pod Shatter-Resistant Associated SNPs by Deep Sequencing of a Representative Library Followed by Bulk Segregant Analysis in Rapeseed

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    Background: Single nucleotide polymorphisms (SNPs) are an important class of genetic marker for target gene mapping. As of yet, there is no rapid and effective method to identify SNPs linked with agronomic traits in rapeseed and other crop species. Methodology/Principal Findings: We demonstrate a novel method for identifying SNP markers in rapeseed by deep sequencing a representative library and performing bulk segregant analysis. With this method, SNPs associated with rapeseed pod shatter-resistance were discovered. Firstly, a reduced representation of the rapeseed genome was used. Genomic fragments ranging from 450–550 bp were prepared from the susceptible bulk (ten F2 plants with the silique shattering resistance index, SSRI,0.10) and the resistance bulk (ten F2 plants with SSRI.0.90), and also Solexa sequencingproduced 90 bp reads. Approximately 50 million of these sequence reads were assembled into contigs to a depth of 20-fold coverage. Secondly, 60,396 ‘simple SNPs ’ were identified, and the statistical significance was evaluated using Fisher’s exact test. There were 70 associated SNPs whose –log10p value over 16 were selected to be further analyzed. The distribution of these SNPs appeared a tight cluster, which consisted of 14 associated SNPs within a 396 kb region on chromosome A09. Our evidence indicates that this region contains a major quantitative trait locus (QTL). Finally, two associated SNPs from this region were mapped on a major QTL region

    Myalgic encephalomyelitis/chronic fatigue Syndrome (ME/CFS) : Investigating care practices pointed out to disparities in diagnosis and treatment across European Union

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    ME/CFS is a chronic, complex, multisystem disease that often limits the health and functioning of the affected patients. Diagnosing patients with ME/CFS is a challenge, and many different case definitions exist and are used in clinical practice and research. Even after diagnosis, medical treatment is very challenging. Symptom relief and coping may affect how patients live with their disease and their quality of life. There is no consensus on which diagnostic criteria should be used and which treatment strategies can be recommended for patients. The purpose of the current project was to map the landscape of the Euromene countries in respect of national guidelines and recommendations for case definition, diagnosis and clinical approaches for ME/CFS patients. A 23 items questionnaire was sent out by email to the members of Euromene. The form contained questions on existing guidelines for case definitions, treatment/management of the disease, tests and questionnaires applied, and the prioritization of information for data sampling in research. We obtained information from 17 countries. Five countries reported having national guidelines for diagnosis, and five countries reported having guidelines for clinical approaches. For diagnostic purposes, the Fukuda criteria were most often recommended, and also the Canadian Consensus criteria, the International Consensus Criteria and the Oxford criteria were used. A mix of diagnostic criteria was applied within those countries having no guidelines. Many different questionnaires and tests were used for symptom registration and diagnostic investigation. For symptom relief, pain and anti-depressive medication were most often recommended. Cognitive Behavioral Therapy and Graded Exercise treatment were often recommended as disease management and rehabilitative/palliative strategies. The lack of consistency in recommendations across European countries urges the development of regulations, guidance and standards. The results of this study will contribute to the harmonization of diagnostic criteria and treatment for ME/CFS in Europe

    Multiple scanning electrochemical microscopy mapping of tyrosinase in micro-contact printed fruit samples on polyvinylidene fluoride membrane

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    Herein, we introduce three orthogonal and compatible methods for detecting tyrosinase, a key factor in fruit browning and skin disorders, with high spatial resolution by means of scanning electrochemical microscopy (SECM). All methods are performed subsequently on the same substrate area providing a wide range of relevant information. The first SECM approach that relies on the mapping of a differential pore oxygen concentration induced by the local hydrophobic changes that the adsorption of tyrosinase generates on a porous polyvinylidene fluoride (PVDF) membrane. The second approach is based on the direct monitoring of the enzymatic activity of tyrosinase by detecting amperometrically the reaction products from the enzymatic conversion of L-3,4-dihydroxyphenylalanine (L-DOPA). Finally, tyrosinase was visualized implementing a tyrosinase sandwich immunoassay readout by SECM. The multiple SECM detection strategies were successfully applied to map unequivocally the tyrosinase enzymatic activity of a micro-contact printed banana sample. Furthermore, differential pulse voltammetry and mass spectrometry analyses were employed to elucidate the nature of the electrochemical response obtained during the tyrosinase enzymatic activity experiments
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