The progress over the 30 years since the first high-energy heavy-ion collisions at the BNL-AGS and CERN-SPS has been truly remarkable. Rigorous experimental and theoretical studies have revealed a ...new state of the matter in heavy-ion collisions, the quark-gluon plasma (QGP). Many signatures supporting the formation of the QGP have been reported. Among them are jet quenching, the non-viscous flow, direct photons, and Debye screening effects. In this article, selected signatures of the QGP observed at RHIC and the LHC are reviewed.
To evaluate visual fatigue when viewing stereoscopic TV, a technology expected to become the broadcasting display system of the future. Wide public acceptance of stereoscopic TV awaits resolution of ...many issues, including visual fatigue on viewing TV images. Visual fatigue was induced using a visual function simulator, consisting of prism and lens optical systems, while viewing stereoscopic TV. We assessed subject visual fatigue through subjective reports of symptoms and by the changes in visual functions. These functions included: viewer B Js fusional break point, recovery point, accommodation step response, and visual evoked cortical potentials (VECP). Significant changes of some visual functions were found after watching simulated stereoscopic TV when the vergence load was heavy or when it changed over time; relative vergence limits decreased and the latency of VECP increased after watching, reflecting visual fatigue. After subjects rested, relative vergence limits recovered to pre-viewing levels. Our findings lead us to conclude that, aside from excessive horizontal binocular parallax, discontinuous changes in parallax is also a major factor that contributes to visual fatigue in the viewing of stereoscopic images. It also causes a decreased range of relative vergence, accommodation response, and a delay in the P100 latency of VECP.
A reaction plane detector for PHENIX at RHIC Richardson, E.; Akiba, Y.; Anderson, N. ...
Nuclear instruments & methods in physics research. Section A, Accelerators, spectrometers, detectors and associated equipment,
04/2011, Letnik:
636, Številka:
1
Journal Article
Recenzirano
A plastic scintillator paddle detector with embedded fiber light guides and photomultiplier tube readout, referred to as the Reaction Plane Detector (RXNP), was designed and installed in the PHENIX ...experiment prior to the 2007 run of the Relativistic Heavy Ion Collider (RHIC). The RXNP's design is optimized to accurately measure the reaction plane (RP) angle of heavy-ion collisions, where, for mid-central sNN=200GeV Au+Au collisions, it achieved a 2nd harmonic RP resolution of ∼0.75, which is a factor of ∼2 greater than PHENIX's previous capabilities. This improvement was accomplished by locating the RXNP in the central region of the PHENIX experiment, where, due to its large coverage in pseudorapidity (1.0<|η|<2.8) and ϕ(2π), it is exposed to the high particle multiplicities needed for an accurate RP measurement. To enhance the observed signal, a 2-cm Pb converter is located between the nominal collision region and the scintillator paddles, allowing neutral particles produced in the heavy-ion collisions to contribute to the signal through conversion electrons. This paper discusses the design, operation and performance of the RXNP during the 2007 RHIC run.
Abstract
Background
It has been reported that young patients with diabetes mellitus (DM) had a higher mortality rate after myocardial infarction. However, plaque characteristics among different age ...groups in patients with acute coronary syndromes (ACS) with or without DM are unknown.
Purpose
The aim of this study was to investigate the plaque characteristics among different age groups in ACS patients with or without DM in a large population.
Methods
Patients who presented with ACS and underwent preintervention OCT imaging were included. The culprit plaque was categorized as plaque rupture (PR), plaque erosion (PE) or calcified plaque (CP), and stratified by 5 age groups. Features of plaque vulnerability were also analyzed.
Results
Among 1394 patients, 482 (34.6%) had DM. DM patients had a higher prevalence of lipid-rich plaque (71.2% vs. 64.8%, p=0.016), macrophage (72.0% vs. 62.6%, p<0.001), and cholesterol crystal (27.6% vs. 19.7%, p<0.001) than non-DM patients. Non-DM patients showed a significant ascending trend with age in PR (p=0.004), lipid-rich plaque (p=0.018), whereas DM patients had a high prevalence of these vulnerable features at early age, which plateaued across the different age groups. Both DM and non-DM groups showed a significant decreasing trend in PE with age (non-DM patients, p<0.001; DM patients, p=0.020).
Conclusions
DM patients had a high prevalence of lipid-rich plaque and a high incidence of plaque rupture at early age. This pattern persisted across the different age groups.
The extreme energy densities generated by ultra-relativistic collisions between heavy atomic nuclei produce a state of matter that behaves surprisingly like a fluid, with exceptionally high ...temperature and low viscosity. Non-central collisions have angular momenta of the order of 1,000ћ, and the resulting fluid may have a strong vortical structure that must be understood to describe the fluid properly. The vortical structure is also of particular interest because the restoration of fundamental symmetries of quantum chromodynamics is expected to produce novel physical effects in the presence of strong vorticity. However, no experimental indications of fluid vorticity in heavy ion collisions have yet been found. Since vorticity represents a local rotational structure of the fluid, spin-orbit coupling can lead to preferential orientation of particle spins along the direction of rotation. Here we present measurements of an alignment between the global angular momentum of a non-central collision and the spin of emitted particles (in this case the collision occurs between gold nuclei and produces Λ baryons), revealing that the fluid produced in heavy ion collisions is the most vortical system so far observed. (At high energies, this fluid is a quark-gluon plasma.) We find that Λ and hyperons show a positive polarization of the order of a few per cent, consistent with some hydrodynamic predictions. (A hyperon is a particle composed of three quarks, at least one of which is a strange quark; the remainder are up and down quarks, found in protons and neutrons.) A previous measurement that reported a null result, that is, zero polarization, at higher collision energies is seen to be consistent with the trend of our observations, though with larger statistical uncertainties. These data provide experimental access to the vortical structure of the nearly ideal liquid created in a heavy ion collision and should prove valuable in the development of hydrodynamic models that quantitatively connect observations to the theory of the strong force.
Global polarization of Λ hyperons has been measured to be of the order of a few tenths of a percent in Au+Au collisions at √SNN = 200 GeV, with no significant difference between Λ and Λ¯. These new ...results reveal the collision energy dependence of the global polarization together with the results previously observed √SNN = 7.7 – 62.4 GeV and indicate noticeable vorticity of the medium created in non-central heavy-ion collisions at the highest RHIC collision energy.
Abstract
Backgrounds
Previous studies have suggested that periodontitis is associated with cardiovascular disease (CVD), partly through exaggerated systematic inflammation through pathogens breaking ...into the bloodstream and their metabolic products. However, the clinical evidence in the cardiovascular secondary prevention is limited. In addition, there is a paucity of data about the contribution of comprehensively assessed dental health, including dental caries or teeth loss, to CVD incidence. Consequently, current ESC guideline for CVD prevention just briefly refers the contribution of dental health 1.
Objective
To investigate the associations between teeth loss, periodontitis, and dental caries and incident major adverse cardiovascular events (MACE) in patients with existing CVD.
Methods
Patients with known CVD who were admitted to the Department of Cardiology between May 2012 and August 2015 were prospectively, consecutively enrolled. Patients underwent comprehensive dental examinations, including counts of lost teeth, dental caries, and periodontal measurements of clinical attachment loss (CAL), periodontal probing pocket depth (PPD), and bleeding on probing (BOP) by trained periodontists during the hospital stay. We assessed the associations between these dental measures and MACE, defined as a composite of cardiac death, acute myocardial infarction, stroke, and hospital re-admission for worsened congestive heart failure, using multivariate COX proportional hazard models and restricted mean survival time (RMST) analyses. P-values were adjusted by Bonferroni methods.
Results
Among 888 patients included for the present analyses, the mean age was 63.9 (SD: 13.1) years and there were 242 (27.3%) women. During a median follow-up of 4.6 (IQR: 1.4, 6.7) years, incident MACE was confirmed in 142 patients. In multivariate COX proportional hazard models, one more tooth loss was associated with 3 (95% CI: 1, 5) % higher hazard of MACE (adjusted p=0.020). Kaplan-Meier curves showing survival from MACE according to the quartiles of teeth loss were described in Figure 1. Compared with patients with 0 to ≤4 lost teeth, periods free from MACE (95% CI) by 5-years of follow-up were on average shorter by 0.17 (−0.04, 0.37) years, 0.26 (0.04, 0.49) years, and 0.59 (0.34, 0.85) years in patients with 5 to ≤7, 8 to ≤13, and >13 lost teeth, respectively. The RMST differences with varied cutoff years were shown in Figure 2. There were no significant associations between the number of dental caries, CAL, PPD, and BOP and MACE incidence.
Conclusion
In hospitalized patients due to existing cardiovascular diseases, total number of lost teeth was associated with incident MACE. Given that teeth loss is an ultimate consequence of periodontitis or dental caries, the present findings imply that efforts to prevent losing teeth by maintaining dental health would be effective measures for cardiovascular secondary prevention.
Funding Acknowledgement
Type of funding sources: None.
Abstract
Background
Plaque erosion is the underlying pathology in up to 50% of patients with non-ST-segment elevation acute coronary syndromes (ACS). Previous studies suggest that patients with ...erosion might be treated conservatively without stenting. Currently, a diagnosis of plaque erosion requires invasive intracoronary imaging.
Purpose
We sought to develop a deep learning (DL) model that enables an accurate diagnosis of plaque erosion using coronary computed tomography angiography (CTA).
Methods
A total of 532 coronary CTA scans (143 coronary CTA scans with plaque rupture, 113 with plaque erosion, and 276 with reference segment) from 395 patients were included to develop a model: 426 coronary CTA scans from 316 patients for training and internal validation, and 106 separate scans from 79 patients for test set validation. Among ACS patients, the diagnosis of plaque rupture or erosion identified by OCT was used as the ground truth, and the corresponding site on the CTA image matched with OCT image was determined to be the culprit lesion. A novel DL, Momentum Distillation Composite Transformer Attention (MD-CTA) model, was developed that can effectively process the whole CTA scans to diagnose plaque erosion.
Results
The novel DL model showed diagnostic performance in the five-fold cross-validation with an area under the receiver-operating characteristic curve (AUC) of 0.901 (0.873-0.930), a sensitivity of 81.2 (72.8-88.0), and a specificity of 86.6 (82.4-90.2), all of which were significantly higher than those of convolutional neural network (CNN) model with an AUC of 0.621 (0.567-0.675), the sensitivity of 59.8 (50.1-69.0), and specificity of 60.2 (54.5-65.7) in training validation. Similarly, in the test set validation, the AUC, sensitivity, and specificity of the MD-CTA model were 0.899 (0.841-0.957), 87.1 (70.2-96.4), and 85.3 (75.3-92.4), respectively, higher than those of 0.724 (0.622-0.826), 71.0 (52.0-85.8), and 68.0 (56.2-78.3) of the CNN model. At the slice level, the MD-CTA model was also superior in the five-fold cross-validation and the test set validation compared to the CCN model. This model significantly outperformed experienced cardiologists, especially for sensitivity.
Conclusions
The newly developed DL model enables an accurate CTA diagnosis of plaque erosion, which might enable the cardiologist to provide tailored therapy without invasive procedures. This algorithm might lead to a major shift in managing millions of patients with plaque erosion each year.Table 1Figure 1
Abstract
Background
Coronary artery disease reporting and data system (CAD-RADS), which is widely used to report the severity of coronary artery disease on coronary computed tomography angiography ...(CTA), predicts the risk of future cardiovascular events. However, the relationship between the CAD-RADS score and vascular inflammation and plaque vulnerability has not been investigated.
Objective
The aim of this study was to correlate the CAD-RADS score with vascular inflammation and plaque vulnerability.
Methods
This is an observational, single-center cohort study with prospective clinical follow-up. Patients who underwent both coronary CTA and optical coherence tomography (OCT) before coronary intervention were enrolled. All OCT and CTA images were analyzed at the core laboratory. Patients were categorized into two groups according to the CAD-RADS score (≤4a or 4b/5). All coronary arteries were analyzed for high-risk plaque features (positive remodeling, low-attenuation plaque, napkin-ring sign, and spotty calcification) and peri-coronary adipose tissue (PCAT) attenuation. PCAT attenuation was measured around the culprit lesion and in the proximal segment of all 3 coronary arteries. OCT features of plaque vulnerability were evaluated in culprit vessels. Major adverse cardiovascular and cerebrovascular events (MACCE) were defined as composite endpoints of unplanned target vessel revascularization, unplanned non-target vessel revascularization, nonfatal acute coronary syndrome, stroke, and cardiac death.
Results
Among 369 patients with 902 lesions, 104 (28.2%) were categorized in CAD-RADS 4b/5 and 265 (61.8%) in CAD-RADS ≤4a. Patients with CAD-RADS 4b/5 had higher PCAT attenuation than those with CAD-RADS ≤4a at all three levels (mean of 3 coronary vessels: -67.9 ± 6.9 HU vs. -70.2 ± 6.5, P=0.004; culprit vessel: -67.4 ± 7.9 vs. -70.2 ± 7.6, P=0.004; culprit plaque: -67.0 ± 9.3 vs. -69.9 ± 10.5, P=0.009; respectively) (Figure 1 A). Lipid-rich plaque and macrophage, as detected by OCT, were more prevalent in the culprit vessel in patients with CAD-RADS 4b/5 than in those with CAD-RADS ≤4a (89.0% vs. 78.5%, P=0.001; 76.6% vs. 64.9%, P=0.001; respectively) (Figure 1B). All HRP features, as detected by CTA, were more frequently observed in patients with CAD-RADS 4b/5 than those with CAD-RADS ≤4a (P for all <0.001) (Figure 2). The cumulative incidence of MACCE was higher in patients with CAD-RADS 4b/5 than in those with CAD-RADS ≤4a (15.0% vs. 5.8%, P=0.045).
Conclusions
Higher CAD-RADS score was associated with a higher level of pan-coronary vascular inflammation and plaque vulnerability.Figure 1Figure 2