479 research outputs found

    Decision-making in advanced heart failure patients requiring LVAD insertion: can preoperative simulation become the way forward? A case study

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    Clinical practice heavily relies on results from randomized controlled trials, which may not reflect completely individual patients. Patient-specific modelling has received increasing attention in recent years. Although still far from clinical application on a daily basis, the potential of this approach is significant. The treatment of advanced heart failure may benefit from a modelling framework to guide device treatment and predict outcome. The role of mechanical circulatory support as a long-term solution is increasing in view of the evolving technology and worsening heart failure patient population. Therefore, a preoperative strategy with the ability to predict the course of events in a simulation setting may be justified. Here we present a heart failure patient discussed at a multidisciplinary team meeting whose outcome was compared with simulations carried out with CARDIOSIM (C) software to investigate the role of this approach as a planning strategy to guide intervention and predict outcome. The clinical decision process is complex and many factors are involved. Patient-specific modelling may have a role to play as part of a preoperative planning strategy with more quantitative evaluation to smooth decision-making

    Simulation as a preoperative planning approach in advanced heart failure patients. A retrospective clinical analysis

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    Background: Modelling and simulation may become clinically applicable tools for detailed evaluation of the cardiovascular system and clinical decision-making to guide therapeutic intervention. Models based on pressure-volume relationship and zero-dimensional representation of the cardiovascular system may be a suitable choice given their simplicity and versatility. This approach has great potential for application in heart failure where the impact of left ventricular assist devices has played a significant role as a bridge to transplant and more recently as a long-term solution for non eligible candidates. Results: We sought to investigate the value of simulation in the context of three heart failure patients with a view to predict or guide further management. CARDIOSIM© was the software used for this purpose. The study was based on retrospective analysis of haemodynamic data previously discussed at a multidisciplinary meeting. The outcome of the simulations addressed the value of a more quantitative approach in the clinical decision process. Conclusions: Although previous experience, co-morbidities and the risk of potentially fatal complications play a role in clinical decision-making, patient-specific modelling may become a daily approach for selection and optimisation of device-based treatment for heart failure patients. Willingness to adopt this integrated approach may be the key to further progress

    The Number of Endothelial Progenitor Cell Colonies in the Blood Is Increased in Patients With Angiographically Significant Coronary Artery Disease

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    ObjectivesThe objective of this study was to determine whether the number of endothelial progenitor cells (EPCs) and circulating angiogenic cells (CACs) in peripheral blood was associated with the presence and severity of coronary artery disease (CAD) in patients undergoing coronary angiography.BackgroundPrevious studies have suggested an inverse relationship between levels of circulating EPCs/CACs and the presence of CAD or cardiovascular risk factors, whereas other studies have observed increased numbers of EPCs in the setting of acute ischemia. However, the criteria used to identify specific angiogenic cell subpopulations and methods of evaluating CAD varied in these studies. In the present study, we used rigorous criteria to identify EPCs and CACs in the blood of patients undergoing coronary angiography.MethodsThe number of EPCs and CACs were measured in the blood of 48 patients undergoing coronary angiography. Patients with acute coronary syndromes were excluded.ResultsCompared with patients without angiographically significant CAD, the number of EPCs was increased (1.11 ± 2.50 vs. 4.01 ± 3.70 colonies/well, p = 0.004) and the number of CACs trended higher (175 ± 137 vs. 250 ± 160 cells per mm2, p = 0.09) among patients with significant CAD. The highest levels of EPCs were isolated from patients subsequently selected for revascularization (5.03 ± 4.10 colonies/well).ConclusionsIn patients referred for coronary angiography, higher numbers of EPCs, and a trend toward higher numbers of CACs, were associated with the presence of significant CAD, and EPC number correlated with maximum angiographic stenosis severity. Endothelial progenitor cell levels were highest in patients with CAD selected for revascularization

    Triangular Sierpinski Microwave Band-Stop Resonators for K-Band Filtering

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    Triangular resonators re-shaped with Sierpinski geometry were designed, manufactured, and tested for potential applications in the K-Band. Prototypes of band-stop filters working around 20 GHz and 26 GHz, interesting for RADAR and satellite communications, were studied in a coplanar waveguide (CPW) configuration. Single and coupled structures were analyzed to give evidence for: (i) the tuning of the resonance frequency by increasing the internal complexity of the triangle and (ii) resonance enhancement when coupled structures are considered. The exploited devices were part of the more extended family of metamaterial-inspired structures, and they were studied for their heuristic approach to the prediction of the spectrum using experimental results supported by electromagnetic simulations. As a result, a Sierpinski resonator, not only fed into but also fully embedded into a CPW environment, had a frequency response that was not easily determined by classical theoretical approaches

    MEMS-Switched Triangular and U-Shaped Band-Stop Resonators for K-Band Operation

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    Triangular resonators re-shaped into Sierpinski geometry and U-shaped resonators were designed, linking them with single-pole-double-through (SPDT) RF MEMS switches to provide frequency tuning for potential applications in the K-Band. Prototypes of band-stop narrowband filters working around 20 GHz and 26 GHz, interesting for RADAR and satellite communications, were studied in a coplanar waveguide (CPW) configuration, and the tuning was obtained by switching between two paths of the devices loaded with different resonators. As a result, dual-band operation or fine-tuning could be obtained depending on the choice of the resonator, acting as a building block. The studied filters belong to the more general group of devices inspired by a metamaterial design

    High-resolution tracking in a GEM-Emulsion detector

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    SHiP (Search for Hidden Particles) is a beam dump experiment proposed at the CERN SPS aiming at the observation of long lived particles very weakly coupled with ordinary matter mostly produced in the decay of charmed hadrons. The beam dump facility of SHiP is also a copious factory of neutrinos of all three kinds and therefore a dedicated neutrino detector is foreseen in the SHiP apparatus. The neutrino detector exploits the Emulsion Cloud Chamber technique with a modular structure, alternating walls of target units and planes of electronic detectors providing the time stamp to the event. GEM detectors are one of the possible choices for this task. This paper reports the results of the first exposure to a muon beam at CERN of a new hybrid chamber, obtained by coupling a GEM chamber and an emulsion detector. Thanks to the micrometric accuracy of the emulsion detector, the position resolution of the GEM chamber as a function of the particle inclination was evaluated in two configurations, with and without the magnetic fiel

    22q11 Deletion Syndrome and Urogenital Manifestations: A Clinicopathological Case Report.

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    Deletion in the chromosomal region 22q11 results from the abnormal development of the third and fourth pharyngeal pouches during embryonic life and presents an expansive phenotype with more than 180 clinical features described that involve every organ and system. A 23-year-old African woman presented for the first trimester echography, which revealed an isolated anechoic structure suggesting a ureteral dilatation. The suspicion of a malposition of great arteries in the second trimester indicated an amniocentesis leading to a diagnosis of 22q11 deletion. At 32 weeks, the patient was admitted for premature rupture of membranes and gave birth 2 weeks later to a male newborn who presented a respiratory distress syndrome and probably died secondary to a tracheal stenosis. Necropsy revealed typical clinical features of 22q11 deletion associated with left renal agenesis, hypospadias, and penile hypoplasia. We report a case of 22q11 deletion syndrome with typical clinical features associated with urogenital manifestations suspected at the first trimester ultrasound

    Is Type 2 Diabetes Really Resolved after Laparoscopic Sleeve Gastrectomy? Glucose Variability Studied by Continuous Glucose Monitoring

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    The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (<140 mg/dL) at 120 minutes OGTT. These interesting data could help clinicians to better individualize patients in which diabetes is not resolved and who could need more attention in order to prevent chronic complications of diabetes

    An evidence map and synthesis review with meta-analysis on the risk of incisional hernia in colorectal surgery with standard closure.

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    Purpose To assess the incidence of incisional hernia (IH) across various type of incisions in colorectal surgery (CS) creating a map of evidence to define research trends, gaps and areas of future interest. Methods Systematic review of PubMed and Scopus from 2010 onwards. Studies included both open (OS) and laparoscopic (LS). The primary outcome was incidence of IH 12 months after index procedure, secondary outcomes were the study features and their influence on reported proportion of IH. Random effects models were used to calculate pooled proportions. Meta-regression models were performed to explore heterogeneity. Results Ninetyone studies were included reporting 6473 IH. The pooled proportions of IH for OS were 0.35 (95% CI 0.27–0.44) I2 0% in midline laparotomies and 0.02 (95% CI 0.00–0.07), I2 52% for off-midline. In case of LS the pooled proportion of IH for midline extraction sites were 0.10 (95% CI 0.07–0.16), I2 58% and 0.04 (95% CI 0.03–0.06), I2 86% in case of off-midline. In Port-site IH was 0.02 (95% CI 0.01–0.04), I2 82%, and for single incision surgery (SILS) of 0.06—95% CI 0.02–0.15, I2 81%. In case of stoma reversal sites was 0.20 (95% CI 0.16–0.24). Conclusion Midline laparotomies and stoma reversal sites are at high risk for IH and should be considered in research of preventive strategies of closure. After laparoscopic approach IH happens mainly by extraction sites incisions specially midline and also represent an important area of analysis.pre-print3102 K

    Characterization and Performance of PADME's Cherenkov-Based Small-Angle Calorimeter

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    The PADME experiment, at the Laboratori Nazionali di Frascati (LNF), in Italy, will search for invisible decays of the hypothetical dark photon via the process e+e−→γAâ€Če^+e^-\rightarrow \gamma A', where the Aâ€ČA' escapes detection. The dark photon mass range sensitivity in a first phase will be 1 to 24 MeV. We report here on measurement and simulation studies of the performance of the Small-Angle Calorimeter, a component of PADME's detector dedicated to rejecting 2- and 3-gamma backgrounds. The crucial requirement is a timing resolution of less than 200 ps, which is satisfied by the choice of PbF2_2 crystals and the newly released Hamamatsu R13478UV photomultiplier tubes (PMTs). We find a timing resolution of 81 ps (with double-peak separation resolution of 1.8 ns) and a single-crystal energy resolution of 5.7%/E\sqrt{E} with light yield of 2.07 photo-electrons per MeV, using 100 to 400 MeV electrons at the Beam Test Facility of LNF. We also propose the investigation of a two-PMT solution coupled to a single PbF2_2 crystal for higher-energy applications, which has potentially attractive features.Comment: 12 pages, 19 figures. v2: added section on radiation damage studie
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