88 research outputs found
Random unitaries, Robustness, and Complexity of Entanglement
It is widely accepted that the dynamic of entanglement in presence of a
generic circuit can be predicted by the knowledge of the statistical properties
of the entanglement spectrum. We tested this assumption by applying a
Metropolis-like entanglement cooling algorithm generated by different sets of
local gates, on states sharing the same statistic. We employ the ground states
of a unique model, namely the one-dimensional Ising chain with a transverse
field, but belonging to different macroscopic phases such as the paramagnetic,
the magnetically ordered, and the topological frustrated ones. Quite
surprisingly, we observe that the entanglement dynamics are strongly dependent
not just on the different sets of gates but also on the phase, indicating that
different phases can possess different types of entanglement (which we
characterize as purely local, GHZ-like, and W-state-like) with different degree
of resilience against the cooling process. Our work highlights the fact that
the knowledge of the entanglement spectrum alone is not sufficient to determine
its dynamics, thereby demonstrating its incompleteness as a characterization
tool. Moreover, it shows a subtle interplay between locality and non-local
constraints.Comment: 14 pages, 11 figures, 1 tabl
Correlation between morphologic carotid plaque findings based on color-Doppler and CT multidetector angiography with intraopertive findings in carotid artery stenosis
Bacground/Aim. Vast majority of patients with corotid artery sclerosis do not have transitory ischemic attacks (TIA) as working to the persistent silent disease, but stroke is the first sign. Precise and early diagnosis of the carotid artery disease and plaques are very important. The aim of this study was to determine how the composition / identity of diagnostic methods, color-Doppler, ultrasonography (US) CT multidetector angio (MDCTA) scan and intraoperative (IO) findings, as well as the morphology of plaques in patients with haemodynamic significant stenosis of the internal carotid artery. Methods. Carotid plaques were observed by two diagnostic methods, US and MDCTA, and these findings were correlated with the IO findings. Results. In 62 patients both carotid artheries were examined and 83 plaques were observed. There were 68 surgical interventions. The structure of plaques was divided into four types: lipid, fibrous, fibrocalcified and calcified plaque. US showed: lipid plaques 10.8%; fibrous 1.2%; fibrocalcified 44.6% and calcified 43.4%, and the MDCTA lipid plaques 8.4%; fibrocalcified 48.2% and calcified 43.4%. Intraoperative findings were: lipid plaques 10.3%; fibrocalcified 41.2% and calcified 48.5%. A statistically highly significant agreement between the US and MDCTA in the diagnosis of plaque morphology was obtained (Cramer's V = 0.919, p < 0.01; Lambda = 0.921, p < 0.01) and also statistically significant agreement between US and IO findings (Cramer' s V = 0.831, p < 0.01; Lambda = 0.859, p < 0.01). A statistically highly significant agreement between MDCTA and IO findings in plaque morphology was found, as well (Cramer's V = 0.815, p < 0.01; Lambda = 0.829, p < 0.01). Conclusion. There is statistically highly significant correlation between US and MDCTA diagnostic methods in the evaluation of plaque morphology in surgically significant stenosis of internal carotid artery as well as their agreement with the intraoperative finding
The application of natural organic compounds in bakery industry
Investigations include the analysis of the impact of commercial products: complex additive (0.1, 0.3, and 0.5%), L-ascorbic acid (0.002, 0.004 and 0.012%), diacetyl ester of tartaric acid with monoglycerides (DATEM E472e, 0.1, 0.3, and 0.5%), α-amylase (0.002, 0.006 and 0.012%), xylanase (0.004, 0.012 and 0.024%), alcohol extract of rosemary, thyme or sage (0.5, 1.0 and 2.0%), as well as the combination of complex additive and rosemary, thyme and sage extract on rheological characteristics of dough. The study includes amylograph, farinograph and extensograph analysis of dough with and without additives (control sample). The volume of lost CO2 gas (mL) is the lowest in dough samples with an added combination of complex additive and thyme extract (0.05 and 0.5%) and rosemary extract (2.0%). In the samples with thyme extract (1.0%) added, the volume of lost gas is at a level of samples with added complex additive, DATEM, and L-ascorbic acid
Coherence loss and revivals in atomic interferometry: A quantum-recoil analysis
The coherence effects induced by external photons coupled to matter waves
inside a Mach-Zehnder three-grating interferometer are analyzed. Alternatively
to atom-photon entanglement scenarios, the model considered here only relies on
the atomic wave function and the momentum shift induced in it by the photon
scattering events. A functional dependence is thus found between the
observables, namely the fringe visibility and the phase shift, and the
transversal momentum transfer distribution. A good quantitative agreement is
found when comparing the results obtained from our model with the experimental
data.Comment: 18 pages, 4 figure
On the influence of resonance photon scattering on atom interference
Here, the influence of resonance photon-atom scattering on the atom
interference pattern at the exit of a three-grating Mach-Zehnder interferometer
is studied. It is assumed that the scattering process does not destroy the
atomic wave function describing the state of the atom before the scattering
process takes place, but only induces a certain shift and change of its phase.
We find that the visibility of the interference strongly depends on the
statistical distribution of transferred momenta to the atom during the
photon-atom scattering event. This also explains the experimentally observed
(Chapman et al 1995 Phys. Rev. Lett. 75 2783) dependence of the visibility on
the ratio d_p/\lambda_i = y'_{12} (2\pi/kd\lambda_i), where y'_{12} is distance
between the place where the scattering event occurs and the first grating, k is
the wave number of the atomic center-of-mass motion, is the grating
constant and \lambda_i is the photon wavelength. Furthermore, it is remarkable
that photon-atom scattering events happen experimentally within the Fresnel
region, i.e. the near field region, associated with the first grating, which
should be taken into account when drawing conclusions about the relevance of
"which-way" information for the interference visibility.Comment: 9 pages, 1 figur
Spontaneous Magnetization and Electron Momentum Density in 3D Quantum Dots
We discuss an exactly solvable model Hamiltonian for describing the
interacting electron gas in a quantum dot. Results for a spherical square well
confining potential are presented. The ground state is found to exhibit
striking oscillations in spin polarization with dot radius at a fixed electron
density. These oscillations are shown to induce characteristic signatures in
the momentum density of the electron gas, providing a novel route for direct
experimental observation of the dot magnetization via spectroscopies sensitive
to the electron momentum density.Comment: 5 pages (Revtex4), 4 (eps) figure
Abdominal aortic aneurysm volume and relative intraluminal thrombus volume might be auxiliary predictors of rupture—an observational cross-sectional study
Objectives: The study aimed to identify differences and compare anatomical and biomechanical features between elective and ruptured abdominal aortic aneurysms (AAAs). Methods: Data (clinical, anatomical, and biomechanical) of 98 patients with AAA, 75 (76.53%) asymptomatic (Group aAAA) and 23 (23.46%) ruptured AAA (Group rAAA), were prospectively collected and analyzed. Anatomical, morphological, and biomechanical imaging markers like peak wall stress (PWS) and rupture risk equivalent diameter (RRED), comorbid conditions, and demographics were compared between the groups. Biomechanical features were assessed by analysis of Digital Imaging and Communication in Medicine images by A4clinics (Vascops), and anatomical features were assessed by 3Surgery (Trimensio). Binary and multiple logistic regression analysis were used and adjusted for confounders. Accuracy was assessed using receiving operative characteristic (ROC) curve analysis. Results: In a multivariable model, including gender and age as confounder variables, maximal aneurysm diameter [MAD, odds ratio (OR) = 1.063], relative intraluminal thrombus (rILT, OR = 1.039), and total aneurysm volume (TAV, OR = 1.006) continued to be significant predictors of AAA rupture with PWS (OR = 1.010) and RRED (OR = 1.031). Area under the ROC curve values and correct classification (cc) for the same parameters and the model that combines MAD, TAV, and rILT were measured: MAD (0.790, cc = 75%), PWS (0.713, cc = 73%), RRED (0.717, cc = 55%), TAV (0.756, cc = 79%), rILT (0.656, cc = 60%), and MAD + TAV + rILT (0.797, cc = 82%). Conclusion: Based on our results, in addition to MAD, other important predictors of rupture that might be used during aneurysm surveillance are TAV and rILT. Biomechanical parameters (PWS, RRED) as valuable predictors should be assessed in prospective clinical trials. Similar studies on AAA smaller than 55 mm in diameter, even difficult to organize, would be of even greater clinical value. 2023 Koncar, Nikolic, Milosevic, Bogavac-Stanojevic, Ilic, Dragas, Sladojevic, Markovic, Vujcic, Filipovic and Davidovic
Studies of spin-orbit scattering in noble-metal nanoparticles using energy level tunneling spectroscopy
The effects of spin-orbit scattering on discrete electronic energy levels are
studied in copper, silver, and gold nanoparticles. Level-to-level fluctuations
of the effective -factor for Zeeman splitting are characterized, and the
statistics are found to be well-described by random matrix theory predictions.
The strength of spin-orbit scattering increases with atomic number and also
varies between nanoparticles made of the same metal. The spin-orbit scattering
rates in the nanoparticles are in order-of-magnitude agreement with bulk
measurements on disordered samples.Comment: 4 pages, 3 figures, 1 in colo
Protocol for the development and validation procedure of the managing the link and strengthening transition from child to adult mental health care (MILESTONE) suite of measures
Background:
Mental health disorders in the child and adolescent population are a pressing public health concern. Despite the high prevalence of psychopathology in this vulnerable population, the transition from Child and Adolescent Mental Health Services (CAMHS) to Adult Mental Health Services (AMHS) has many obstacles such as deficiencies in planning, organisational readiness and policy gaps. All these factors contribute to an inadequate and suboptimal transition process. A suite of measures is required that would allow young people to be assessed in a structured and standardised way to determine the on-going need for care and to improve communication across clinicians at CAMHS and AMHS. This will have the potential to reduce the overall health economic burden and could also improve the quality of life for patients travelling across the transition boundary. The MILESTONE (Managing the Link and Strengthening Transition from Child to Adult Mental Health Care) project aims to address the significant socioeconomic and societal challenge related to the transition process. This protocol paper describes the development of two MILESTONE transition-related measures: The Transition Readiness and Appropriateness Measure (TRAM), designed to be a decision-making aide for clinicians, and the Transition Related Outcome Measure (TROM), for examining the outcome of transition.
Methods:
The TRAM and TROM have been developed and were validated following the US FDA Guidance for Patient-reported Outcome Measures which follows an incremental stepwise framework. The study gathers information from service users, parents, families and mental health care professionals who have experience working with young people undergoing the transition process from eight European countries.
Discussion:
There is an urgent need for comprehensive measures that can assess transition across the CAMHS/AMHS boundary. This study protocol describes the process of development of two new transition measures: the TRAM and TROM. The TRAM has the potential to nurture better transitions as the findings can be summarised and provided to clinicians as a clinician-decision making support tool for identifying cases who need to transition and the TROM can be used to examine the outcomes of the transition process.
Trial registration:
MILESTONE study registration: ISRCTN83240263 Registered 23-July-2015 - ClinicalTrials.gov NCT03013595 Registered 6 January 2017
Localization and Capacitance Fluctuations in Disordered Au Nano-junctions
Nano-junctions, containing atomic-scale gold contacts between strongly
disordered leads, exhibit different transport properties at room temperature
and at low temperature. At room temperature, the nano-junctions exhibit
conductance quantization effects. At low temperatures, the contacts exhibit
Coulomb-Blockade. We show that the differences between the room-temperature and
low temperature properties arise from the localization of electronic states in
the leads. The charging energy and capacitance of the nano-junctions exhibit
strong fluctuations with applied magnetic field at low temperature, as
predicted theoretically.Comment: 20 pages 8 figure
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