38 research outputs found
S-particles at their naturalness limits
We draw attention on a particular configuration of supersymmetric particle
masses, motivated by naturalness and flavour considerations. All its relevant
phenomenological properties for the LHC are described in terms of a few
physical parameters, irrespective of the underlying theoretical model. This
allows a simple characterization of its main features, useful to define a
strategy for its discovery.Comment: 13 pages, 8 figures, added reference
Impact of COVID-19 on cardiovascular testing in the United States versus the rest of the world
Objectives: This study sought to quantify and compare the decline in volumes of cardiovascular procedures between the United States and non-US institutions during the early phase of the coronavirus disease-2019 (COVID-19) pandemic.
Background: The COVID-19 pandemic has disrupted the care of many non-COVID-19 illnesses. Reductions in diagnostic cardiovascular testing around the world have led to concerns over the implications of reduced testing for cardiovascular disease (CVD) morbidity and mortality.
Methods: Data were submitted to the INCAPS-COVID (International Atomic Energy Agency Non-Invasive Cardiology Protocols Study of COVID-19), a multinational registry comprising 909 institutions in 108 countries (including 155 facilities in 40 U.S. states), assessing the impact of the COVID-19 pandemic on volumes of diagnostic cardiovascular procedures. Data were obtained for April 2020 and compared with volumes of baseline procedures from March 2019. We compared laboratory characteristics, practices, and procedure volumes between U.S. and non-U.S. facilities and between U.S. geographic regions and identified factors associated with volume reduction in the United States.
Results: Reductions in the volumes of procedures in the United States were similar to those in non-U.S. facilities (68% vs. 63%, respectively; p = 0.237), although U.S. facilities reported greater reductions in invasive coronary angiography (69% vs. 53%, respectively; p < 0.001). Significantly more U.S. facilities reported increased use of telehealth and patient screening measures than non-U.S. facilities, such as temperature checks, symptom screenings, and COVID-19 testing. Reductions in volumes of procedures differed between U.S. regions, with larger declines observed in the Northeast (76%) and Midwest (74%) than in the South (62%) and West (44%). Prevalence of COVID-19, staff redeployments, outpatient centers, and urban centers were associated with greater reductions in volume in U.S. facilities in a multivariable analysis.
Conclusions: We observed marked reductions in U.S. cardiovascular testing in the early phase of the pandemic and significant variability between U.S. regions. The association between reductions of volumes and COVID-19 prevalence in the United States highlighted the need for proactive efforts to maintain access to cardiovascular testing in areas most affected by outbreaks of COVID-19 infection
Glucans monomer-exchange dynamics as an open chemical network
We describe the oligosaccharides-exchange dynamics performed by the so-called D-enzymes on polysaccharides. To mimic physiological conditions, we treat this process as an open chemical network by assuming some of the polymer concentrations fixed (chemostatting). We show that three different long-time behaviors may ensue: equilibrium states, nonequilibrium steady states, and continuous growth states. We dynamically and thermodynamically characterize these states and emphasize the crucial role of conservation laws in identifying the chemostatting conditions inducing them
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Targeting liver lesions for radiofrequency ablation: an experimental feasibility study using a CT-US fusion imaging system
To investigate the feasibility and validity of real-time guidance using a fusion imaging system that combines ultrasound (US) and computed tomography (CT) in the targeting and subsequent radiofrequency (RF) ablation of a liver target inconspicuous on US.
The study was designed as an experimental ex vivo study in calf livers with radiopaque internal targets, inconspicuous at US, simulating a focal liver lesion. The study included 2 phases. The initial phase was to examine the feasibility of matching preprocedural volumetric CT data of the calf livers with real-time US using a commercially available multimodality fusion imaging system (Virtual Navigator System, Esaote SpA, Genoa, Italy), and to assess the accuracy of targeting using a 22 gauge cytologic needle. The second phase of the study was to validate such a technique using a 15 gauge RF multitined expandable needle (RITA Medical Systems, Mountain View, CA) and to examine the accuracy of the needle placement relative to the target. The tip of the trocar of the RF needle had to be placed 1 cm from the target and then the hooks had to be deployed to 3 cm. Unenhanced CT of the liver and multiplanar reconstructions were performed to calculate accuracy of positioning, ie, the lateral distance between the needle and the target, the distance between the tip of the trocar of the RF electrode and the target, and the lateral distance between the central tine of the RF electrode and the target.
All calf livers underwent successful CT-US registration with a mean registration error of 3.0 +/- 0.1 mm and 2.9 +/- 0.1 mm in the initial and second phase of the study, respectively. In the initial phase an overall number of 24 insertions were performed after the US-CT guidance. The mean needle to target distance was 1.9 +/- 0.7 mm (range, 0.8-3.0 mm). In the second phase an overall number of 12 ablations were performed. The mean target-trocar distance was 10.3 +/- 2.6 mm. The mean target-central tine lateral distance was 3.9 +/- 0.7 mm (range, 2.9-5.1 mm). After the dissection of the specimen the target was found unchanged in the center of the ablation zone in all cases.
Real-time registration and fusion of preprocedure CT volume images with intraprocedure US is feasible and accurate. The study was however conducted in an ideal experimental setting, without patient movements and breathing, and further studies are warranted to validate the system under clinical conditions