117 research outputs found
Termoablazione a radiofrequenze nell'adenocarcinoma pancreatico: studio TC della termolesione e del residuo tumorale tramite texture analysis
Lo scopo di questo lavoro consiste nello studio TC della termoablazione a radiofrequenza applicata all’adenocarcinoma pancreatico e nella valutazione tramite texture analysis delle modificazioni tissutali da essa indotte
Radiogenomica dell'adenocarcinoma duttale del Pancreas
Il tumore del pancreas ha una prognosi molto sfavorevole e il suo istotipo più frequente è l'adenocarcinoma duttale pancreatico (PDAC). Ci sono alcuni geni spesso mutati nella cancerogenesi del PDAC: KRAS, CDKN2a/INK4a, TP53 e DPC4/SMAD4. Lo scopo del nostro studio è trovare correlazioni tra parametri di texture analysis di TC e RM con i diversi geni mutati nel PDAC, in particolare con l'espressione di KRAS e TP53
Ablazione a radiofrequenza dell'epatocarcinoma: l'uso della texture analysis dell'area ablata per predire la recidiva
Valutare il ruolo della texture analysis nella valutazione del rischio di recidiva locale dopo radioablazione di HCC
Valutazione del danno epatico dopo chemioterapia mediante RM
lo scopo dello studio è di valutare mediante risonanza magnetica il danno epatico a lungo termine, come la sindrome da ostruzione sinusoidale e la steato-epatite, dopo trattamento chemioterapico neoadiuvante in pazienti con adenocarcinoma pancreatico duttale (PDAC)
Performance of LHC Main Dipoles for Beam Operation
At present about 90% of the main dipoles for the LHC have been manufactured and one of the three cold mass assemblers has already completed the production. 85% of the 1232 dipoles needed for the tunnel have been tested and accepted. In this paper we mainly deal with the performance results: the quench behaviour, the magnetic field quality, the electrical integrity quality and the geometry features will be summarized
The magnetic model of the LHC in the early phase of beam commissioning
The relation between field and current in each family of the Large Hadron Collider magnets is modelled with a set of empirical equations (FiDeL) whose free parameters are fit on magnetic measurements. They take into account residual magnetization, persistent currents, hysteresis, saturation, decay and snapback during initial part of the ramp. Here we give a first summary of the reconstruction of the magnetic field properties based on the beam observables (orbit, tune, coupling, chromaticity) and a comparison with the expectations. The most critical issues for the machine performance in terms of knowledge of the relation magnetic field vs current are pointed out.peer-reviewe
Axis measurements, field quality and quench performance of the first LHC short straight sections
The series testing at 1.9 K of the 360 Short Straight Sections (SSS) for the Large Hadron Collider have started at CERN in September 2003. The SSS contain the lattice quadrupoles and correction magnets in a common cryostat. The lattice quadrupoles feature two collared coils with 56 mm bore assembled in a common yoke. The coils are wound in two-layers from 15.1 mm wide NbTi cable, insulated with polyimide tape. The paper reviews the main test results performed in superfluid helium. The magnetic field and magnetic center position of the quadrupoles and associated correctors were measured with two independent systems, namely an automated scanner and a single stretched wire technique. The quench training, the field quality and the magnetic alignment measurements are presented and discussed in terms of the specifications and expected performances of these magnets in the LHC. We discuss in detail the field quality in terms of multipole errors measured at injection and nominal field and decomposed into geometric and persistent current magnetization errors. Warm/cold correlation for the geometric multipoles and the magnetic axis is also presented.peer-reviewe
A Collection of Target Mimics for Comprehensive Analysis of MicroRNA Function in Arabidopsis thaliana
Many targets of plant microRNAs (miRNAs) are thought to play important roles in plant physiology and development. However, because plant miRNAs are typically encoded by medium-size gene families, it has often been difficult to assess their precise function. We report the generation of a large-scale collection of knockdowns for Arabidopsis thaliana miRNA families; this has been achieved using artificial miRNA target mimics, a recently developed technique fashioned on an endogenous mechanism of miRNA regulation. Morphological defects in the aerial part were observed for ∼20% of analyzed families, all of which are deeply conserved in land plants. In addition, we find that non-cleavable mimic sites can confer translational regulation in cis. Phenotypes of plants expressing target mimics directed against miRNAs involved in development were in several cases consistent with previous reports on plants expressing miRNA–resistant forms of individual target genes, indicating that a limited number of targets mediates most effects of these miRNAs. That less conserved miRNAs rarely had obvious effects on plant morphology suggests that most of them do not affect fundamental aspects of development. In addition to insight into modes of miRNA action, this study provides an important resource for the study of miRNA function in plants
Activation of the Arabidopsis thaliana Immune System by Combinations of Common ACD6 Alleles
A fundamental question in biology is how multicellular organisms distinguish self and non-self. The ability to make this distinction allows animals and plants to detect and respond to pathogens without triggering immune reactions directed against their own cells. In plants, inappropriate self-recognition results in the autonomous activation of the immune system, causing affected individuals to grow less well. These plants also suffer from spontaneous cell death, but are at the same time more resistant to pathogens. Known causes for such autonomous activation of the immune system are hyperactive alleles of immune regulators, or epistatic interactions between immune regulators and unlinked genes. We have discovered a third class, in which the Arabidopsis thaliana immune system is activated by interactions between natural alleles at a single locus, ACCELERATED CELL DEATH 6 (ACD6). There are two main types of these interacting alleles, one of which has evolved recently by partial resurrection of a pseudogene, and each type includes multiple functional variants. Most previously studies hybrid necrosis cases involve rare alleles found in geographically unrelated populations. These two types of ACD6 alleles instead occur at low frequency throughout the range of the species, and have risen to high frequency in the Northeast of Spain, suggesting a role in local adaptation. In addition, such hybrids occur in these populations in the wild. The extensive functional variation among ACD6 alleles points to a central role of this locus in fine-tuning pathogen defenses in natural populations
First field test of FiDeL the magnetic field description for the LHC
The start-up of the LHC has provided the first field test for the concept, functionality and accuracy of FiDeL, the Field Description for the LHC. FiDeL provides a parametric model of the transfer function of the main field integrals generated by the series of magnets in the LHC powering circuits, comprising superconducting and normal-conducting main optical elements and high-order harmonic correctors. The same framework is used to predict harmonic errors of both static and dynamic nature, and forecast appropriate corrections. In this paper we make use of beam-based measurements taken on the first LHC beams to assess the first-shot accuracy in the prediction of the current setting for the main arc magnets.peer-reviewe
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