305 research outputs found
Thermobarometry, Geochronology and the Interpretation of P-T-t Data in the Britt Domain, Ontario Grenville Orogen, Canada
Hemodynamic and Metabolic Observations Associated with Intracoronary Stenting for Acute Closure Following Percutaneous Transluminal Coronary Angioplasty
Emergency stent implantation appears to be an effective method for restoring antegrade flow in case of an abrupt coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). In this case report, hemodynamic and metabolic changes throughout abrupt coronary closure and stent implantation were followed in order to study the efficacy of this bail out technique in restoring metabolic and hemodynamic disturbances due to acute coronary occlusion. Copyrigh
A multichannel reflectometer for edge density profile measurements at the ICRF antenna in ASDEX upgrade
A multichannel reflectometer will be built for the new three-straps ICRF antenna of ASDEX Upgrade (AUG), to study the density behavior in front of it. Ten different accesses to the plasma are available for the three reflectometer channels that can be interchanged without breaking the machine vacuum. Frequency is scanned from 40 GHz to 68 GHz, in 10 mu s, which corresponds to a cut-off density ranging from 10(18) divided by 10(19)m(-3) in the Right cut-off of the X-mode propagation, for standard toroidal magnetic field values of AUG
2D continuous spectrum of shear Alfven waves in the presence of a magnetic island
The radial structure of the continuous spectrum of shear Alfven modes is
calculated in the presence of a magnetic island in tokamak plasmas. Modes with
the same helicity of the magnetic island are considered in a slab model
approximation. In this framework, with an appropriate rotation of the
coordinates the problem reduces to 2 dimensions. Geometrical effects due to the
shape of the flux surface's cross section are retained to all orders. On the
other hand, we keep only curvature effects responsible of the beta induced gap
in the low-frequency part of the continuous spectrum. New continuum
accumulation points are found at the O-point of the magnetic island. The
beta-induced Alfven Eigenmodes (BAE) continuum accumulation point is found to
be positioned at the separatrix flux surface. The most remarkable result is the
nonlinear modification of the BAE continuum accumulation point frequency
Implementation of the new multichannel X-mode edge density profile reflectometer for the ICRF antenna on ASDEX Upgrade
A new multichannel frequency modulated continuous-wave reflectometry diagnostic has been successfully installed and commissioned on ASDEX Upgrade to measure the plasma edge electron density profile evolution in front of the Ion Cyclotron Range of Frequencies (ICRF) antenna. The design of the new three-strap ICRF antenna integrates ten pairs (sending and receiving) of microwave reflectometry antennas. The multichannel reflectometer can use three of these to measure the edge electron density profiles up to 2 x 10(19) m(-3), at different poloidal locations, allowing the direct study of the local plasma layers in front of the ICRF antenna. ICRF power coupling, operational effects, and poloidal variations of the plasma density profile can be consistently studied for the first time. In this work the diagnostic hardware architecture is described and the obtained density profile measurements were used to track outer radial plasma position and plasma shape
A rare case of cerebral venous thrombosis and disseminated intravascular coagulation temporally associated to the covid-19 vaccine administration
Globally, at the time of writing (20 March 2021), 121.759.109 confirmed COVID-19 cases have been reported to the WHO, including 2.690.731 deaths. Globally, on 18 March 2021, a total of 364.184.603 vaccine doses have been administered. In Italy, 3.306.711 confirmed COVID-19 cases with 103.855 deaths have been reported to WHO. In Italy, on 9 March 2021, a total of 6.634.450 vaccine doses have been administered. On 15 March 2021, Italian Medicines Agency (AIFA) decided to temporarily suspend the use of the AstraZeneca COVID-19 vaccine throughout the country as a precaution, pending the rulings of the European Medicines Agency (EMA). This decision was taken in line with similar measures adopted by other European countries due to the death of vaccinated people. On 18 March 2021, EMA’s safety committee concluded its preliminary review about thromboembolic events in people vaccinated with COVID-19 Vaccine AstraZeneca at its extraordinary meeting, confirming the benefits of the vaccine continue to outweigh the risk of side effects, however, the vaccine may be associated with very rare cases of blood clots associated with thrombocytopenia, i.e., low levels of blood platelets with or without bleeding, including rare cases of cerebral venous thrombosis (CVT). We report the case of a 54-year-old woman who developed disseminated intravascular coagulation (DIC) with multi-district thrombosis 12 days after the AstraZeneca COVID-19 vaccine administration. A brain computed tomography (CT) scan showed multiple subacute intra-axial hemorrhages in atypical locations, including the right frontal and the temporal lobes. A plain old balloon angioplasty (POBA) of the right coronary artery was performed, without stent implantation, with restoration of distal flow, but with persistence of extensive thrombosis of the vessel. A successive thorax angio-CT added the findings of multiple contrast filling defects with multi-vessel involvement: at the level of the left upper lobe segmental branches, of left interlobar artery, of the right middle lobe segmental branches and of the right interlobar artery. A brain magnetic resonance imaging (MRI) in the same day showed the presence of an acute basilar thrombosis associated with the superior sagittal sinus thrombosis. An abdomen angio-CT showed filling defects at the level of left portal branch and at the level of right suprahepatic vein. Bilaterally, it was adrenal hemorrhage and blood in the pelvis. An evaluation of coagulation factors did not show genetic alterations so as the nasopharyngeal swab ruled out a COVID-19 infection. The patient died after 5 days of hospitalization in intensive care
Helicobacter pylori Up-regulates Cyclooxygenase-2 mRNA Expression and Prostaglandin E2 Synthesis in MKN 28 Gastric Mucosal Cells in Vitro
Helicobacter pylori has been suggested to play a role in the development of gastric carcinoma in humans. Also, mounting evidence indicates that cyclooxygenase-2 overexpression is associated with gastrointestinal carcinogenesis. We studied the effect of H. pylori on the expression and activity of cyclooxygenase-1 and cyclooxygenase-2 in MKN 28 gastric mucosal cells. H. pylori did not affect cyclooxygenase-1 expression, whereas cyclooxygenase-2 mRNA levels increased by 5-fold at 24 h after incubation of MKN 28 cells with broth culture filtrates or bacterial suspensions from wild-type H. pylori strain. Also, H. pylori caused a 3-fold increase in the release of prostaglandin E2, the main product of cyclooxygenase activity. This effect was specifically related to H. pylori because it was not observed with Escherichia coli and was independent of VacA, CagA, or ammonia. H. pylori isogenic mutants specifically lacking picA or picB, which are responsible for cytokine production by gastric cells, were less effective in the up-regulation of cyclooxygenase-2 mRNA expression and in the stimulation of prostaglandin E2 release compared with the parental wild-type strain. This study suggests that development of gastric carcinoma associated with H. pylori infection may depend on the activation of cyclooxygenase-2-related events
The tunable resonant IC antenna concept and its design for DTT experiment
The intrinsic poor loading of Ion Cyclotron (IC) plasma-facing antennas makes the use of Tuning and Matching Systems (TMSs) a necessity. The antenna plus TMS is a resonant system; in the TMS and access lines high voltages (tens of kV) must be accounted for in the unavoidable unmatched part of the feeding lines. In this work, we propose and test an innovative type of IC launcher; it is based on achieving resonance of the self-standing antenna, i.e. without the TMS. A mechanical full-metal tuning mechanism is described and demonstrated to allow wide-band operation. A systematic analysis of possible antenna topologies has led to identifying a structure that can allow good impedance matching along with compliance with maximum electric field constraints. Most of the design is carried out using a simplified plasma and a commercial analysis tool and then validated with a realistic plasma using TOPICA code
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