Structure, bonding and morphology of hydrothermally synthesised xonotlite

The authors have systematically investigated the role of synthesis conditions upon the structure and morphology of xonotlite. Starting with a mechanochemically prepared, semicrystalline phase with Ca/Si=1, the authors have prepared a series of xonotlite samples hydrothermally, at temperatures between 200 and 250 degrees C. Analysis in each case was by X-ray photoelectron spectroscopy, environmental scanning electron microscopy and X-ray diffraction. The authors’ use of a much lower water/solid ratio has indirectly confirmed the ‘through solution’ mechanism of xonotlite formation, where silicate dissolution is a key precursor of xonotlite formation. Concerning the role of temperature, too low a temperature (~200 degrees C) fails to yield xonotlite or leads to increased number of structural defects in the silicate chains of xonotlite and too high a temperature (>250 degrees C) leads to degradation of the xonotlite structure, through leaching of interchain calcium. Synthesis duration meanwhile leads to increased silicate polymerisation due to diminishing of the defects in the silicate chains and more perfect crystal morphologies

Immunohistochemical subtypes predict the clinical outcome in high-risk node-negative breast cancer patients treated with adjuvant FEC regimen: results of a single-center retrospective study

Prognostic factors for disease-free survival in patients treated before 2005 September: multivariate analysis. (DOCX 15 kb

O-RADS MRI SCORE: An Essential First-Step Tool for the Characterization of Adnexal Masses

The ovarian-adnexal reporting and data system on magnetic resonance imaging (O-RADS MRI) score is now a well-established tool to characterize pelvic gynecological masses based on their likelihood of malignancy. The main added value of O-RADS MRI over O-RADS US is to correctly reclassify lesions that were considered suspicious on US as benign on MRI. The crucial issue when characterizing an adnexal mass is to determine the presence/absence of solid tissue and thus need to perform gadolinium injection. O-RADS MR score was built on a multivariate analysis and must be applied as a step-by-step analysis: 1) Is the mass an adnexal mass? 2) Is there an associated peritoneal carcinomatosis? 3) Is there any significant amount of fatty content? 4) Is there any wall enhancement? 5) Is there any internal enhancement? 6) When an internal enhancement is detected, does the internal enhancement correspond to solid tissue or not? 7) Is the solid tissue malignant? With its high value to distinguish benign from malignant adnexal masses and its high reproducibility, the O-RADS MRI score could be a valuable tool for timely referral of a patient to an expert center for the treatment of ovarian cancers. Finally, to make a precise diagnosis allowing optimal personalized treatment, the radiologist in gynecological imaging will combine the O-RADS MRI score with many other clinical, biological, and other MR criteria to suggest a pathological hypothesis. Level of Evidence: 5. Technical Efficacy Stage: 3

Probing thermalization and dynamics of high-energy quasiparticles in a superconducting nanowire by scanning critical current microscopy

Besides its fundamental interest, understanding the dynamics of pair breaking in superconducting nanostructures is a central issue to optimize the performances of superconducting devices such as qubits or photon detectors. However, despite substantial research efforts, these dynamics are still not well understood as this requires experiments in which quasiparticles are injected in a controlled fashion. Until now, such experiments have employed solid-state tunnel junctions with a fixed tunnel barrier. Here we use instead a cryogenic scanning tunnelling microscope to tune independently the energy and the rate of quasiparticle injection through, respectively, the bias voltage and the tunnelling current. For high energy quasiparticles, we observe the reduction of the critical current of a nanowire and show it is mainly controlled by the injected power and, marginally, by the injection rate. Our results prove a thermal mechanism for the reduction of the critical current and unveil the rapid dynamics of the generated hot spot.Comment: 25 pages, 14 figure

Microwave-synthesized freestanding iron-carbon nanotubes on polyester composites of woven Kevlar fibre and silver nanoparticle-decorated graphene

We synthesized Ag nanoparticle-decorated multilayered graphene nanosheets (Ag-graphene) from graphite nanoplatelets and silver nitrate through 90-100 s of microwave exposure, without the use of any mineral acids or harsh reducing agents. Fe nanoparticle-decorated carbon nanotubes (Fe-CNTs) were grown on polypyrrole (PPy) deposited on woven Kevlar fibre (WKF), using ferrocene as a catalyst, under microwave irradiation. Fe-CNTs grown on WKF and Ag-graphene dispersed in polyester resin (PES) were combined to fabricate Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites by vacuum-assisted resin transfer moulding. The combined effect of Fe-CNTs and Ag-graphene in the resulting composites resulted in a remarkable enhancement of tensile properties (a 192.56% increase in strength and 100.64% increase in modulus) as well as impact resistance (a 116.33% increase). The electrical conductivity significantly increased for Ag-graphene/Fe-CNT/PPy-coated WKF/PES composites. The effectiveness of electromagnetic interference shielding, which relies strongly on the Ag-graphene content in the composites, was 25 times higher in Ag-graphene/Fe-CNT/PPy-coated WKF/PES than in neat WKF/PES composites. The current work offers a novel route for fabricating highly promising, cost effective WKF/PES composites through microwave-assisted synthesis of Fe-CNTs and Ag-graphene.ope

Facile formation of highly mobile supported lipid bilayers on surface-quaternized pH-responsive polymer brushes

Poly(2-dimethylamino)ethyl methacrylate) (PDMA) brushes are grown from planar substrates via surface atom transfer radical polymerization (ATRP). Quaternization of these brushes is conducted using 1-iodooctadecane in n-hexane, which is a non-solvent for PDMA. Ellipsometry, AFM, and water contact angle measurements show that surface-confined quaternization occurs under these conditions, producing pH-responsive brushes that have a hydrophobic upper surface. Systematic variation of the 1-iodooctadecane concentration and reaction time enables the mean degree of surface quaternization to be optimized. Relatively low degrees of surface quaternization (ca. 10 mol % as judged by XPS) produce brushes that enable the formation of supported lipid bilayers, with the hydrophobic pendent octadecyl groups promoting in situ rupture of lipid vesicles. Control experiments confirm that quaternized PDMA brushes prepared in a good brush solvent (THF) produce non-pH-responsive brushes, presumably because the pendent octadecyl groups form micelle-like physical cross-links throughout the brush layer. Supported lipid bilayers (SLBs) can also be formed on the non-quaternized PDMA precursor brushes, but such structures proved to be unstable to small changes in pH. Thus, surface quaternization of PDMA brushes using 1-iodooctadecane in n-hexane provides the best protocol for the formation of robust SLBs. Fluorescence recovery after photobleaching (FRAP) studies of such SLBs indicate diffusion coefficients (2.8 ± 0.3 μm s–1) and mobile fractions (98 ± 2%) that are comparable to the literature data reported for SLBs prepared directly on planar glass substrates

European society of urogenital radiology (ESUR) guidelines: MR imaging of pelvic endometriosis

Endometriosis is a common gynaecological condition of unknown aetiology that primarily affects women of reproductive age. The accepted first-line imaging modality is pelvic ultrasound. However, magnetic resonance imaging (MRI) is increasingly performed as an additional investigation in complex cases and for surgical planning. There is currently no international consensus regarding patient preparation, MRI protocols or reporting criteria. Our aim was to develop clinical guidelines for MRI evaluation of pelvic endometriosis based on literature evidence and consensus expert opinion. This work was performed by a group of radiologists from the European Society of Urogenital Radiology (ESUR), experts in gynaecological imaging and a gynaecologist expert in methodology. The group discussed indications for MRI, technical requirements, patient preparation, MRI protocols and criteria for the diagnosis of pelvic endometriosis on MRI. The expert panel proposed a final recommendation for each criterion using Oxford Centre for Evidence Based Medicine (OCEBM) 2011 levels of evidence.info:eu-repo/semantics/publishedVersio

Promoter methylation analysis of O6-methylguanine-DNA methyltransferase in glioblastoma: detection by locked nucleic acid based quantitative PCR using an imprinted gene (SNURF) as a reference

<p>Abstract</p> <p>Background</p> <p>Epigenetic silencing of the <it>MGMT </it>gene by promoter methylation is associated with loss of <it>MGMT </it>expression, diminished DNA-repair activity and longer overall survival in patients with glioblastoma who, in addition to radiotherapy, received alkylating chemotherapy with carmustine or temozolomide. We describe and validate a rapid methylation sensitive quantitative PCR assay (MS-qLNAPCR) using Locked Nucleic Acid (LNA) modified primers and an imprinted gene as a reference.</p> <p>Methods</p> <p>An analysis was made of a database of 159 GBM patients followed between April 2004 and October 2008. After bisulfite treatment, methylated and unmethylated CpGs were recognized by LNA primers and molecular beacon probes. The <it>SNURF </it>promoter of an imprinted gene mapped on 15q12, was used as a reference. This approach was used because imprinted genes have a balanced copy number of methylated and unmethylated alleles, and this feature allows an easy and a precise normalization.</p> <p>Results</p> <p>Concordance between already described nested MS-PCR and MS-qLNAPCR was found in 158 of 159 samples (99.4%). The MS-qLNAPCR assay showed a PCR efficiency of 102% and a sensitivity of 0.01% for LNA modified primers, while unmodified primers revealed lower efficiency (69%) and lower sensitivity (0.1%). <it>MGMT </it>promoter was found to be methylated using MS-qLNAPCR in 70 patients (44.02%), and completely unmethylated in 89 samples (55.97%). Median overall survival was of 24 months, being 20 months and 36 months, in patients with <it>MGMT </it>unmethylated and methylated, respectively. Considering <it>MGMT </it>methylation data provided by MS-qLNAPCR as a binary variable, overall survival was different between patients with GBM samples harboring <it>MGMT </it>promoter unmethylated and other patients with any percentage of <it>MGMT </it>methylation (p = 0.003). This difference was retained using other cut off values for <it>MGMT </it>methylation rate (i.e. 10% and 20% of methylated allele), while the difference was lost when 50% of <it>MGMT </it>methylated allele was used as cut-off.</p> <p>Conclusions</p> <p>We report and clinically validate an accurate, robust, and cost effective MS-qLNAPCR protocol for the detection and quantification of methylated <it>MGMT </it>alleles in GBM samples. Using MS-qLNAPCR we demonstrate that even low levels of <it>MGMT </it>promoter methylation have to be taken into account to predict response to temozolomide-chemotherapy.</p