941 research outputs found
Genetic structure of cultivated varieties of radicchio (Cichorium intybus l.): A comparison between F1 hybrids and synthetics
Cichorium intybus L., well known in Italy with the common name "Radicchio", is an important leafy vegetable that is prevalently reproduced by allogamy due to very efficient barriers of self-incompatibility. Marker-assisted breeding is widely used by seed firms to develop new hybrid varieties that manifest genetic distinctiveness, uniformity and stability. A total of 29 mapped microsatellite markers were used for genotyping 504 samples of the Red of Chioggia biotype: First, two synthetics, four F1 hybrids and two derived F2 populations were compared to assess the distinctiveness of their gene pool and structure; then, the uniformity and stability of 3 years of production of a commercial F1 variety were also investigated. Genetic similarity and diversity statistics as well as the genetic structure of populations were analysed, including allele and genotype frequencies. The mean estimates and ranges of genetic similarity enabled the molecular discrimination of OP synthetics from F1 varieties and their F2 progenies and the determination of individual plant memberships. Moreover, the genetic structure of F1 hybrids produced in 3 years unexpectedly revealed two main clusters that discriminate the first 2 years from the 3rd, mainly because of the presence of uncommon specific alleles and different allele frequencies. Overall, this molecular information will enable breeders to determine the genetic distinctness, uniformity and stability of commercial and experimental varieties, as well as their genetic relationships and relatedness. Hence, this work provides a useful tool for achieving the molecular characterisation and genetic identification of different radicchio populations
Early cross-sectional imaging following open and laparoscopic cholecystectomy : a primer for radiologists
Abstract: Performed on either an elective or urgent basis, cholecystectomy currently represents the most common abdominal operation due to the widespread use of laparoscopy and the progressively expanded indications. Compared to traditional open surgery, laparoscopic cholecystectomy minimised the duration of hospitalisation and perioperative mortality. Albeit generally considered safe, cholecystectomy may result in adverse outcomes with non-negligible morbidity. Furthermore, the incidence of worrisome haemorrhages and biliary complications has not been influenced by the technique shift. Due to the growing medico-legal concerns and the vast number of cholecystectomies, radiologists are increasingly requested to investigate recently operated patients. Aiming to increase familiarity with post-cholecystectomy cross-sectional imaging, this paper provides a brief overview of indications and surgical techniques and illustrates the expected early postoperative imaging findings. Afterwards, most iatrogenic complications following open, converted, laparoscopic and laparo-endoscopic rendezvous cholecystectomy are reviewed with examples, including infections, haematoma and active bleeding, residual choledocholithiasis, pancreatitis, biliary obstruction and leakage. Multidetector computed tomography (CT) represents the \u201cworkhorse\u201d modality to rapidly investigate the postoperative abdomen in order to provide a reliable basis for an appropriate choice between conservative, interventional or surgical treatment. Emphasis is placed on the role of early magnetic resonance cholangiopancreatography (MRCP) and additional gadoxetic acid-enhanced MRCP to provide a non-invasive anatomic and functional assessment of the operated biliary tract. Teaching Points: \u2022 Having minimised perioperative mortality and hospital stay, laparoscopy has now become the first-line approach to performing cholecystectomy, even in patients with acute cholecystitis. \u2022 Laparoscopic, laparo-endoscopic rendezvous, converted and open cholecystectomy remain associated with non-negligible morbidity, including surgical site infections, haemorrhage, residual lithiasis, pancreatitis, biliary obstruction and leakage. \u2022 Contrast-enhanced multidetector computed tomography (CT) is increasingly requested early after cholecystectomy and represents the \u201cworkhorse\u201d modality that rapidly provides a comprehensive assessment of the operated biliary tract and abdomen. \u2022 Magnetic resonance cholangiopancreatography (MRCP) is the best modality to provide anatomic visualisation of the operated biliary tract and is indicated when biliary complications are suspected. \u2022 Additional gadoxetic acid (Gd-EOB-DTPA)-enhanced MRCP non-invasively provides functional biliary assessment, in order to confirm and visualise bile leakage
TRANSCRIPTOMIC ANALYSIS OF WHOLE PISTILS AND OVULE CELLS TO IDENTIFY GENES RELATED TO APOSPORY IN HYPERICUM PERFORATUM L.
St. John\u2019s wort (Hypericum perforatum L.) is a medicinal plant that produces important
metabolites with antidepressant and anticancer activities. Beside the pharmaceutical interest,
recently gained information has shown that H. perforatum is also an attractive model system for the
study of aposporous apomixis, that is a reproductive strategy, which, unlike sexual reproduction,
permits the inheritance of the maternal genome over generations without genetic recombination
events. This asexual mode of seed formation is believed to be a trait with enormous economic and
social potential in agriculture. Its innovative use in this area relies upon the idea that indefinitely
fixing highly complex genotypes, including hybrid cultivars, through apomixis would have
tremendous advantages in plant breeding, biomass and seed production. During the last decades, the
understanding of the molecular basis of apomixis in this species has been complicated by the lack of
biological data, e.g. genomic or even transcriptomic sequences. The aim of our research project was
the sequencing, annotation and comparative investigation of the H. perforatum flower
transcriptome, as critical steps toward a better understanding of the genetic control of aposporic and
sexual reproduction in the facultative apomict H. perforatum. To this end, next generation
sequencing technologies have been used to sequence the flower transcriptomes of obligate sexual
and unrelated apomictic H. perforatum genotypes. This approach has enabled the assembly and
annotation of large cDNA repositories and their exploitation to design a custom array to be used in
flower expression studies. Global gene expression analysis of H. perforatum was initially
performed on ovaries collected from sexual and aposporic plant accessions for the purpose of
identifying genes and processes potentially associated with apomixis in this model species. Overall,
across two selected developmental stages, 224 and 973 unigenes were found to be significantly upand down-regulated. Ontological annotation of differentially expressed genes indicated that terms
related to cell cycle, single-organism cellular process DNA (cytosine-5-)-methyltransferase activity,
among others, were significantly enriched. In a following step, a laser-capture microdissection
approach was adopted in combination the RNA-seq technology with the aim of identifying genes
differentially expressed in the ovule cell types primarily involved in the differentiation of the
megaspore mother cells and aposporous initials. On the whole, our data suggest that phenotypic
expression of apospory is concomitant with the modulation of key genes involved in the sexual
reproductive pathway and the responsive to hormonal stimuli. Annotation of all identified flower
transcripts as well as their qualitative and quantitative expression data will be presented and
critically discussed as they prove a far better understanding of molecular bases of pistil
development, embyo sac and egg cell formation in sexual and apomictic H. perforatum
Nanostructured Lead Electrodes with Reduced Graphene Oxide for High-Performance Lead–Acid Batteries
Nanostructured Pb electrodes consisting of nanowire arrays were obtained by electrodeposition, to be used as negative electrodes for lead–acid batteries. Reduced graphene oxide was added to improve their performances. This was achieved via the electrochemical reduction of graphene oxide directly on the surface of nanowire arrays. The electrodes with and without reduced graphene oxide were tested in a 5 M sulfuric acid solution using a commercial pasted positive plate and an absorbed glass mat separator in a zero-gap configuration. The electrodes were tested in deep cycling conditions with a very low cut-off potential. Charge–discharge tests were performed at 5C. The electrode with reduced graphene oxide outperformed the electrode without reduced graphene oxide, as it was able to work with a very high utilization of active mass and efficiency. A specific capacity of 258 mAhg−1–very close to the theoretical one–was achieved, and the electrode lasted for more than 1000 cycles. On the other hand, the electrode without reduced graphene oxide achieved a capacity close to 230 mAhg−1, which corresponds to a 90% of utilization of active mass
High-performance lead-acid batteries enabled by Pb and PbO2 nanostructured electrodes: Effect of operating temperature
Lead-acid batteries are now widely used for energy storage, as result of an established and reliable technology. In the last decade, several studies have been carried out to improve the performance of this type of batteries, with the main objective to replace the conventional plates with innovative electrodes with improved stability, increased capacity and a larger active surface. Such studies ultimately aim to improve the kinetics of electrochemical conversion reactions at the electrode-solution interface and to guarantee a good electrical continuity during the repeated charge/discharge cycles. To achieve these objectives, our contribution focuses on the employment of nanostructured electrodes. In particular, we have obtained nanostructured electrodes in Pb and PbO2 through electrosynthesis in a template consisting of a nanoporous polycarbonate membrane. These electrodes are characterized by a wider active surface area, which allows for a better use of the active material, and for a consequent increased specific energy compared to traditional batteries. In this research, the performance of lead-acid batteries with nanostructured electrodes was studied at 10 C at temperatures of 25, −20 and 40 °C in order to evaluate the efficiency and the effect of temperature on electrode morphology. The batteries were assembled using both nanostructured electrodes and an AGM-type separator used in commercial batteries
Domain Walls and Metastable Vacua in Hot Orientifold Field Theories
We consider "Orientifold field theories", namely SU(N) gauge theories with
Dirac fermions in the two-index representation at high temperature. When N is
even these theories exhibit a spontaneously broken Z2 centre symmetry. We study
aspects of the domain wall that interpolates between the two vacua of the
theory. In particular we calculate its tension to two-loop order. We compare
its tension to the corresponding domain wall in a SU(N) gauge theory with
adjoint fermions and find an agreement at large-N, as expected from planar
equivalence between the two theories. Moreover, we provide a non-perturbative
proof for the coincidence of the tensions at large-N. We also discuss the
vacuum structure of the theory when the fermion is given a large mass and argue
that there exist N-2 metastable vacua. We calculate the lifetime of those vacua
in the thin wall approximation.Comment: 29 pages, 4 figures. v2: minor changes in the introduction section.
to appear in JHE
Gd-EOB-DTP-enhanced MRC in the preoperative percutaneous management of intra and extrahepatic biliary leakages: Does it matter?
Postoperative bile leakage is a common complication of abdominal surgical procedures and a precise localization of is important to choose the best management. Many techniques are available to correctly identify bile leaks, including ultrasound (US), computed tomography (CT) or magnetic resonance imaging (MRI), being the latter the best to clearly depict "active" bile leakages. This paper presents the state of the art algorithm in the detection of biliary leakages in order to plan a percutaneous biliary drainage focusing on widely available and safe contrast agent, the Gb-EOB-DPA. We consider its pharmacokinetic properties and impact in biliary imaging explain current debates to optimize image quality. We report common sites of leakage after surgery with special considerations in cirrhotic liver to show what interventional radiologists should look to easily detect bile leaks
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