881 research outputs found

    Magnetic resonance imaging for localization of prostate cancer in the setting of biochemical recurrence

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    The clinical suspicion of local recurrence of prostate cancer after radical treatment is based on the onset of biochemical failure. The use of multiparametric magnetic resonance imaging (MRI) for prostate cancer has increased over recent years, mainly for detection, staging, and active surveillance. However, suspicion of recurrence in the set of biochemical failure is becoming a significant reason for clinicians to request multiparametric MRI. Radiologists should be able to recognize the normal posttreatment MRI findings. Fibrosis and atrophic remnant seminal vesicles (SV) after radical prostatectomy are often found and must be differentiated from local relapse. Moreover, brachytherapy, external beam radiotherapy, and focal therapies tend to diffusely decrease the signal intensity of the peripheral zone on T2-weighted images due to the loss of water content, consequently mimicking tumor and hemorrhage. The combination of T2-weighted images and functional studies like diffusion-weighted imaging and dynamic contrast-enhanced imaging improves the identification of local relapse. Tumor recurrence tends to restrict on diffusion images and avidly enhances after contrast administration. The authors provide a review of the normal findings and the signs of local tumor relapse after radical prostatectomy, external beam radiotherapy, brachytherapy and focal therapies

    A note on almost kähler manifolds

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    For anyn ≥ 2, we give examples of almost Kähler conformally flat manifoldsM 2n which are not Kähler. We discuss the meaning of these examples in the context of the Goldberg conjecture on almost Kahler manifold

    Use of the Peak-Detector mode for gain calibration of SiPM sensors with ASIC CITIROC read-out

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    The Cherenkov Imaging Telescope Integrated Read Out Chip (CITIROC) is a 32-channel fully analogue front-end ASIC dedicated to the read-out of silicon photo-multiplier (SiPM) sensors that can be used in a variety of experiments with different applications: nuclear physics, medical imaging, astrophysics, etc. It has been adopted as front-end for the focal plane detectors of the ASTRI-Horn Cherenkov telescope and, in this context, it was modified implementing the peak detector reading mode to satisfy the instrument requirements. For each channel, two parallel AC coupled voltage preamplifiers, one for the high gain and one for the low gain, ensure the read-out of the charge from 160 fC to 320 pC (i.e. from 1 to 2000 photo-electrons with SiPM gain = 106^{6}, with a photo-electron to noise ratio of 10). The signal in each of the two preamplifier chains is shaped and the maximum value is captured by activating the peak detector for an adjustable time interval. In this work, we illustrate the peak detector operation mode and, in particular, how this can be used to calibrate the SiPM gain without the need of external light sources. To demonstrate the validity of the method, we also present and discuss some laboratory measurements.Comment: 11 pages, 9 figures, 15th Topical Seminar on Innovative Particle and Radiation Detectors (IPRD19) 14-17 October 2019 Siena, Italy (Submitted to JINST peer review on 05 January 2020

    MitoRes: a resource of nuclear-encoded mitochondrial genes and their products in Metazoa

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    BACKGROUND: Mitochondria are sub-cellular organelles that have a central role in energy production and in other metabolic pathways of all eukaryotic respiring cells. In the last few years, with more and more genomes being sequenced, a huge amount of data has been generated providing an unprecedented opportunity to use the comparative analysis approach in studies of evolution and functional genomics with the aim of shedding light on molecular mechanisms regulating mitochondrial biogenesis and metabolism. In this context, the problem of the optimal extraction of representative datasets of genomic and proteomic data assumes a crucial importance. Specialised resources for nuclear-encoded mitochondria-related proteins already exist; however, no mitochondrial database is currently available with the same features of MitoRes, which is an update of the MitoNuc database extensively modified in its structure, data sources and graphical interface. It contains data on nuclear-encoded mitochondria-related products for any metazoan species for which this type of data is available and also provides comprehensive sequence datasets (gene, transcript and protein) as well as useful tools for their extraction and export. DESCRIPTION: MitoRes consolidates information from publicly external sources and automatically annotates them into a relational database. Additionally, it also clusters proteins on the basis of their sequence similarity and interconnects them with genomic data. The search engine and sequence management tools allow the query/retrieval of the database content and the extraction and export of sequences (gene, transcript, protein) and related sub-sequences (intron, exon, UTR, CDS, signal peptide and gene flanking regions) ready to be used for in silico analysis. CONCLUSION: The tool we describe here has been developed to support lab scientists and bioinformaticians alike in the characterization of molecular features and evolution of mitochondrial targeting sequences. The way it provides for the retrieval and extraction of sequences allows the user to overcome the obstacles encountered in the integrative use of different bioinformatic resources and the completeness of the sequence collection allows intra- and interspecies comparison at different biological levels (gene, transcript and protein)

    An evaluation of morphological and functional multi-parametric MRI sequences in classifying non-muscle and muscle invasive bladder cancer

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    Objectives: Our goal is to determine the ability of multi-parametric magnetic resonance imaging (mpMRI) to differentiate muscle invasive bladder cancer (MIBC) from non-muscle invasive bladder cancer (NMIBC). Methods: Patients underwent mpMRI before tumour resection. Four MRI sets, i.e. T2-weighted (T2W) + perfusion-weighted imaging (PWI), T2W plus diffusion-weighted imaging (DWI), T2W + DWI + PWI, and T2W + DWI + PWI + dif-fusion tensor imaging (DTI) were interpreted qualitatively by two radiologists, blinded to histology results. PWI, DWI and DTI were also analysed quantitatively. Accuracy was determined using histopathology as the reference standard. Results: A total of 82 tumours were analysed. Ninety-six percent of T1-labeled tumours by the T2W + DWI + PWI image set were confirmed to be NMIBC at histopathology. Overall accuracy of the complete mpMRI protocol was 94% in differentiating NMIBC from MIBC. PWI, DWI and DTI quantitative parameters were shown to be significantly different in cancerous versus non-cancerous areas within the bladder wall in T2-labelled lesions. Conclusions: MpMRI with DWI and DTI appears a reliable staging tool for bladder cancer. If our data are validated, then mpMRI could precede cystoscopic resection to allow a faster recognition of MIBC and accelerated treatment pathways. Key Points: • A critical step in BCa staging is to differentiate NMIBC from MIBC. • Morphological and functional sequences are reliable techniques in differentiating NMIBC from MIBC. • Diffusion tensor imaging could be an additional tool in BCa staging

    Distal radius fractures: treatment using the Epibloc system.

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    Summary The Epibloc™ system of percutaneous endomedullary internal fixation is best indicated for AO type A2-3 extra-articular fractures of the distal radius and AO type C1 slightly comminuted articular fractures. This system includes pins that can be inserted into the medullary canal and advanced without breaking through the second cortex. This fixation is stabilised by an external plate and rendered dynamic by the pins' elasticity which compresses the fractured surfaces. Moreover, this system results in transversal ligamentotaxis which helps prevent secondary reduction losses. The result of a preliminary series of 326 cases is evaluated

    A Review on the Antimicrobial Activity of Schiff Bases: Data Collection and Recent Studies

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    Schiff bases (SBs) have extensive applications in different fields such as analytical, inor‐ ganic and organic chemistry. They are used as dyes, catalysts, polymer stabilizers, luminescence chemosensors, catalyzers in the fixation of CO2 biolubricant additives and have been suggested for solar energy applications as well. Further, a wide range of pharmacological and biological applica‐ tions, such as antimalarial, antiproliferative, analgesic, anti‐inflammatory, antiviral, antipyretic, an‐ tibacterial and antifungal uses, emphasize the need for SB synthesis. Several SBs conjugated with chitosan have been studied in order to enhance the antibacterial activity of chitosan. Moreover, the use of the nanoparticles of SBs may improve their antimicrobial effects. Herein, we provide an ana‐ lytical overview of the antibacterial and antifungal properties of SBs and chitosan‐based SBs as well as SBs‐functionalized nanoparticles. The most relevant and recent literature was reviewed for this purpose
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