DSC perfusion has been evaluated in the discrimination between low-grade and high-grade glioma but the diagnostic potential to discriminate beween glioma grades II and III remains unclear.
Our aim ...was to evaluate the diagnostic accuracy of relative maximal CBV from DSC perfusion MR imaging to discriminate glioma grades II and III.
A systematic literature search was performed in PubMed/MEDLINE, Embase, Web of Science, and ClinicalTrials.gov.
Eligible studies reported on patients evaluated with relative maximal CBV derived from DSC with a confirmed neuropathologic diagnosis of glioma World Health Organization grades II and III. Studies reporting on mean or individual patient data were considered for inclusion.
Data were analyzed by using inverse variance with the random-effects model and receiver operating characteristic curves describing optimal cutoffs and areas under the curve. Bivariate diagnostic random-effects meta-analysis was used to calculate diagnostic accuracy.
Twenty-eight studies evaluating 727 individuals were included in the meta-analysis. Individual data were available from 10 studies comprising 190 individuals. The mean difference of relative maximal CBV between glioma grades II and III (
= 727) was 1.76 (95% CI, 1.27-2.24;
< .001). Individual patient data (
= 190) had an area under the curve of 0.77 for discriminating glioma grades II and III at an optimal cutoff of 2.02. When we analyzed astrocytomas separately, the area under the curve increased to 0.86 but decreased to 0.61 when we analyzed oligodendrogliomas.
A substantial heterogeneity was found among included studies.
Glioma grade III had higher relative maximal CBV compared with glioma grade II. A high diagnostic accuracy was found for all patients and astrocytomas; however, the diagnostic accuracy was substantially reduced when discriminating oligodendroglioma grades II and III.
SU(2) operations are recurrently required in quantum information because of their simplicity. The SU(2) formalism states that quantum systems can be controlled easily, step by step, by means of such ...operations if convenient vector bases (normally composed by entangled states) are used as grammar. In this work, we explore the entanglement gained under such operations for the classes GHZ and W, as two well known representatives of maximal entangled states for larger systems.
The gate version of quantum computation exploits several quantum key resources as superposition and entanglement to reach an outstanding performance. In the way, this theory was constructed adopting ...certain supposed processes imitating classical computer gates. As for optical as well as magnetic systems, those gates are obtained as quantum evolutions. Despite, in certain cases they are attained as an asymptotic series of evolution effects. The current work exploits the direct sum of the evolution operator on a non-local basis for the driven bipartite Heisenberg-Ising model to construct a set of equivalent universal gates as straight evolutions for this interaction. The prescriptions to get these gates are reported as well as a general procedure to evaluate their performance.
•We review the literature on planning and network design of urban transport focusing on bus service.•We review the literature on operation, and control of urban transport focusing on bus service.•We ...provide a comprehensive classification of the studies presented in this field.
The efficiency of a transport system depends on several elements, such as available technology, governmental policies, the planning process, and control strategies. Indeed, the interaction between these elements is quite complex, leading to intractable decision making problems. The planning process and real-time control strategies have been widely studied in recent years, and there are several practical implementations with promising results. In this paper, we review the literature on Transit Network Planning problems and real-time control strategies suitable to bus transport systems. Our goal is to present a comprehensive review, emphasizing recent studies as well as works not addressed in previous reviews.
The addition of rituximab to standard combination chemotherapy in children with high-grade (mainly Burkitt’s) lymphoma improved 3-year event-free survival (94% vs. 82%). The incidence of myelotoxic ...effects was somewhat higher, without a higher incidence of death from toxic effects; the incidence of hypogammaglobulinemia was higher.
This paper provides a review of recent scientific research on the removal by activated carbon (AC) in drinking water (DW) treatment of 1) two classes of currently unregulated trace level contaminants ...with potential chronic toxicity—pharmaceutically activate compounds (PhACs) and endocrine disrupting compounds (EDCs); 2) cyanobacterial toxins (CyBTs), which are a group of highly toxic and regulated compounds (as microcystin-LR); and 3) the above mentioned compounds by the hybrid system powdered AC/membrane filtration. The influence of solute and AC properties, as well as the competitive effect from background natural organic matter on the adsorption of such trace contaminants, are also considered. In addition, a number of adsorption isotherm parameters reported for PhACs, EDCs and CyBTs are presented herein. AC adsorption has proven to be an effective removal process for such trace contaminants without generating transformation products. This process appears to be a crucial step in order to minimize PhACs, EDCs and CyBTs in finished DW, hence calling for further studies on AC adsorption removal of these compounds. Finally, a priority chart of PhACs and EDCs warranting further study for the removal by AC adsorption is proposed based on the compounds' structural characteristics and their low removal by AC compared to the other compounds.
► Pharmaceutical compounds, endocrine disrupting compounds and cyanobacterial toxins ► Removal by activated carbon (AC) in drinking water (DW) treatment ► AC adsorption appears to be a crucial step to minimize such contaminants in DW. ► Need for further studies on adsorption removal of such trace contaminants. ► A chart including ten trace contaminants is proposed for further AC removal studies.
A
bstract
The Dimension-5 Seesaw Portal is a Type-I Seesaw model extended by
d
= 5 operators involving the sterile neutrino states, leading to new interactions between all neutrinos and the Standard ...Model neutral bosons. In this work we focus primarily on the implications of these new operators at the GeV-scale. In particular, we recalculate the heavy neutrino full decay width, up to three-body decays. We also review bounds on the dipole operator, and revisit LEP constraints on its coefficient. Finally, we turn to heavy neutrino pair production from Higgs decays, where the former are long-lived and disintegrate into a photon and a light neutrino. We probe this process by recasting two ATLAS searches for non-pointing photons, showing the expected event distribution in terms of arrival time
t
γ
and pointing variable
|
∆
z
γ
|
.
We review the problem of spin decoherence of magnetic atoms deposited on a surface. Recent breakthroughs in scanning tunnelling microscopy (STM) make it possible to probe the spin dynamics of ...individual atoms, either isolated or integrated in nanoengineered spin structures. Transport pump and probe techniques with spin polarized tips permit measuring the spin relaxation time T1, while novel demonstration of electrically driven STM single spin resonance has provided a direct measurement of the spin coherence time T2 of an individual magnetic adatom. Here we address the problem of spin decoherence from the theoretical point of view. First we provide a short general overview of decoherence in open quantum systems and we discuss with some detail ambiguities that arise in the case of degenerate spectra, relevant for magnetic atoms. Second, we address the physical mechanisms that allows probing the spin coherence of magnetic atoms on surfaces. Third, we discuss the main spin decoherence mechanisms at work on a surface, most notably, Kondo interaction, but also spin–phonon coupling and dephasing by Johnson noise. Finally, we briefly discuss the implications in the broader context of quantum technologies.
The spin dynamics of all ferromagnetic materials are governed by two types of collective phenomenon: spin waves and domain walls. The fundamental processes underlying these collective modes, such as ...exchange interactions and magnetic anisotropy, all originate at the atomic scale. However, conventional probing techniques based on neutron and photon scattering provide high resolution in reciprocal space, and thereby poor spatial resolution. Here we present direct imaging of standing spin waves in individual chains of ferromagnetically coupled S = 2 Fe atoms, assembled one by one on a Cu(2)N surface using a scanning tunnelling microscope. We are able to map the spin dynamics of these designer nanomagnets with atomic resolution in two complementary ways. First, atom-to-atom variations of the amplitude of the quantized spin-wave excitations are probed using inelastic electron tunnelling spectroscopy. Second, we observe slow stochastic switching between two opposite magnetization states, whose rate varies strongly depending on the location of the tip along the chain. Our observations, combined with model calculations, reveal that switches of the chain are initiated by a spin-wave excited state that has its antinodes at the edges of the chain, followed by a domain wall shifting through the chain from one end to the other. This approach opens the way towards atomic-scale imaging of other types of spin excitation, such as spinon pairs and fractional end-states, in engineered spin chains.
We construct and analyze Kerr black holes (BHs) with synchronized axionic hair. These are the BH generalizations of the recently constructed rotating axion boson stars J. F. Delgado, C. A. Herdeiro, ...and E. Radu, Rotating axion boson stars, J. Cosmol. Astropart. Phys. 06 (2020) 037. Such BHs are stationary, axially symmetric, asymptotically flat solutions of the complex Einstein-Klein-Gordon theory with a QCD axionlike potential. They are regular everywhere on and outside the event horizon. The potential is characterized by two parameters: the mass of the axionlike particle, ma, and the decay constant, fa. The limit fa → ∞ recovers the original example of Kerr BHs with synchronized scalar hair C. A. R. Herdeiro and E. Radu, Kerr Black Holes with Scalar Hair, Phys. Rev. Lett. 112, 221101 (2014). The effects of the nonlinearities in the potential become important for fa ≲ 1. We present an overview of the parameter space of the solutions together with a study of their basic geometric and phenomenological properties, for an illustrative value of the coupling that yields a non-negligible impact of the self-interactions.