937 research outputs found
Detection of Intracluster Globular Clusters in the First JWST Images of the Gravitational Lens Cluster SMACS J0723.3-7327 at z = 0.39
We present a survey of globular clusters (GCs) in the massive gravitational
lens cluster SMACS J0723.3-7327 at based on the early released
JWST/NIRCam images. In the color-magnitude diagrams of the point sources we
find clearly a rich population of intracluster GCs that spread in a wide area
of the cluster. Their ages, considering the cluster redshift, are younger than
9.5 Gyr. The F200W (AB) magnitudes of these GCs, mag,
correspond to mag, showing that they belong to the
brightest GCs (including ultracompact dwarfs). The spatial distributions of
these GCs show a megaparsec-scale structure elongated along the major axis of
the brightest cluster galaxy. In addition, they show a large number of
substructures, some of which are consistent with the substructures seen in the
map of diffuse intracluster light. The GC number density map is, in general,
consistent with the dark matter mass density map based on the strong lensing
analysis in the literature. The radial number density profile of the GCs in the
outer region is steeper than the dark matter mass profile obtained from lensing
models. These results are consistent with those for the GCs found in the deep
HST images of Abell 2744, another massive cluster at , and in
simulated galaxy clusters. This shows that the intracluster GCs are an
excellent independent tool to probe the dark matter distribution in galaxy
clusters as well as to reveal the cluster assembly history in the JWST era.Comment: 25 pages, 12 figures, Accepted for publication in ApJ
Universal Approximation of Parametric Optimization via Neural Networks with Piecewise Linear Policy Approximation
Parametric optimization solves a family of optimization problems as a
function of parameters. It is a critical component in situations where optimal
decision making is repeatedly performed for updated parameter values, but
computation becomes challenging when complex problems need to be solved in
real-time. Therefore, in this study, we present theoretical foundations on
approximating optimal policy of parametric optimization problem through Neural
Networks and derive conditions that allow the Universal Approximation Theorem
to be applied to parametric optimization problems by constructing piecewise
linear policy approximation explicitly. This study fills the gap on formally
analyzing the constructed piecewise linear approximation in terms of
feasibility and optimality and show that Neural Networks (with ReLU
activations) can be valid approximator for this approximation in terms of
generalization and approximation error. Furthermore, based on theoretical
results, we propose a strategy to improve feasibility of approximated solution
and discuss training with suboptimal solutions.Comment: 17 pages, 2 figures, preprint, under revie
Early Dural Sac Termination with Lumbar Disc Herniation: A Mimic of Nerve Root Anomalies
The precise location of the dural sac (DS) end is necessary for preventing neural injury during spinal surgery or procedures. There has been no report on problems with spine surgery in patients with early DS termination. A 28-year-old woman presented with low back and leg pain involving the left S1 nerve root. Magnetic resonance imaging (MRI) revealed early DS termination at the lower one-third of the L5 vertebra and lumbar disc herniation at the L5/S1. Microscopic discectomy was performed instead of endoscopic discectomy to avoid unpredictable risks. Due to early DS termination, multiple nerve roots were identified, which look like nerve root congenital anomalies (Neidre and Macnab type II anomalies), and multiple separated nerve roots appeared to exit through a single foramen. After wide exposure by hemilaminectomy, which facilitated adequate visualization and mobilization of the involved nerve roots, the ruptured disc was identified and removed with gentle retraction, avoiding risk of excessive nerve root traction. Unlike other nerve root anomalies, early DS termination could be detected easily with preoperative MRI. Although this condition appears similar to other nerve root anomalies in the surgical field, it is possible to avoid inadvertent neural injury by closely investigating preoperative MRI. If early DS termination is suspected, it is necessary to consider a safer surgical approach
TCT-703 Comparison of 5 Years Clinical Outcome of Drug-Eluting Stent Implantation in High-Angled (≥70°) Bifurcation and Lower-Angled (≤70°) Bifurcation Lesion of Unprotected Left Main Coronary Arteries
Inflammatory Burden of Cardiac Allograft Coronary Atherosclerotic Plaque Is Associated With Early Recurrent Cellular Rejection and Predicts a Higher Risk of Vasculopathy Progression
ObjectivesThis study was designed to investigate tissue characterization of the coronary allograft atherosclerotic plaque with virtual histology intravascular ultrasound (VH-IVUS) imaging to assess the presence and predictors of vessel wall inflammation and its significance in cardiac allograft vasculopathy (CAV) progression.BackgroundA unique form of accelerated atherosclerosis, CAV remains the leading cause of late morbidity and mortality in heart transplant patients. The pathogenesis of CAV is not fully elucidated.MethodsA total of 86 patients with coronary allograft vasculopathy underwent VH-IVUS examination of the left anterior descending coronary artery 3.61 ± 3.04 years following cardiac transplantation. Based on the VH-IVUS plaque characteristics, coronary allograft plaque was divided on virtual histology intravascular ultrasound-derived “inflammatory” (VHD-IP) (necrotic core and dense calcium ≥30%) and “noninflammatory” plaque (VHD-NIP) (necrotic core and dense calcium <30%). Total rejection scores were calculated based on the 2004 International Society of Heart and Lung Transplantation rejection grading system.ResultsIn the whole study population, the mean percentage of fibrous, fibrofatty, dense calcified, and necrotic core plaques in a mean length of 62.3 ± 17.4 mm of the left anterior descending coronary artery were 50 ± 17%, 16 ± 11%, 15 ± 11%, and 18 ± 9%, respectively. Patients with a 6-month total rejection score >0.3 had significantly higher incidence of VHD-IP than those with a 6-month total rejection score ≤0.3 (69% vs. 33%, p = 0.011). The presence of VHD-IP at baseline was associated with a significant increase in plaque volume (2.42 ± 1.78 mm3/mm vs. –0.11 ± 1.65 mm3/mm, p = 0.010), plaque index (7 ± 9% vs. 0 ± 8%, p = 0.04), and remodeling index (1.24 ± 0.44 vs. 1.09 ± 0.36, p = 0.030) during 12 months of follow-up when compared with the presence of VHD-NIP at baseline and during follow-up.ConclusionsThe presence of VHD-IP as assessed by VH-IVUS is associated with early recurrent rejection and with higher subsequent progression of CAV. A VH-IVUS assessment may add important information in the evaluation of transplant recipients
Rationale of decreasing low-density lipoprotein cholesterol below 70 mg/dL in patients with coronary artery disease: A retrospective virtual histology-intravascular ultrasound study
Background: The associations between statin and coronary plaque compositional changes were reported according to the use of high dose or not. An evaluation of the impact of low-density lipoprotein cholesterol (LDL-C) < 70 mg/dL by using real world dosages of statin on coronary plaque composition was undertaken.
Methods: The study subjects consisted of 61 patients (mean 59.9 years old, 45 males) who underwent percutaneous coronary intervention, baseline and follow-up (F/U; mean 8.4 months) virtual histology- -intravascular ultrasound (VH-IVUS) examination. Change of plaque composition at peri-stent area, which was selected in order to measure the identical site at F/U study, was compared according to the F/U LDL-C level.
Results: Body mass index, prevalence of dyslipidemia, baseline total cholesterol and baseline LDL-C were significantly lower in F/U LDL-C < 70 mg/dL group (14 segments in 10 patients) than F/U LDL-C ≥ 70 mg/dL group (79 segments in 51 patients). F/U high-density lipoprotein cholesterol (HDL-C, OR 1.06, 95% CI 1.00–1.11, p = 0.054) and F/U LDL-C < 70 mg/dL (OR 3.43, 95% CI 0.97–12.17, p = 0.056) showed strong tendency of regression of necrotic core volume (NCV) ≥ 10%. In multivariable logistic regression analysis, F/U HDL-C (OR 1.07, 95% CI 1.01–1.14, p = 0.020) and F/U LDL-C < 70 mg/dL (OR 8.02, 95% CI 1.58–40.68, p = 0.012) were the independent factors for regression of NCV ≥ 10%.
Conclusions: Follow-up LDL-C level < 70 mg/dL with any types of statins and increase of HDL-C were associated with regression of NCV ≥ 10% in patients with coronary artery disease
Initial serum sodium concentration determines the decrease in sodium level after terlipressin administration in patients with liver cirrhosis
BACKGROUND: Terlipressin, as a prodrug of vasopressin, has agonistic effects on the V1 receptor and partial agonistic effects on renal vasopressin V2 receptors. However, its effects on serum sodium concentration are controversial. METHODS: This study retrospectively investigated 127 patients with liver cirrhosis to examine the incidence and risk factors for the decrease in serum sodium level following terlipressin administration. RESULTS: Terlipressin was prescribed for bleeding control (99) and management of hepatorenal syndrome (28). Serum sodium level decreased from 134.0 ± 6.5 mmol/L to 130.4 ± 6.2 mmol/L during or after terlipressin treatment (P < 0.001) in all patients. In 45 patients (35.4%), the serum sodium concentration decreased by > 5 mmol/L, in 29 patients (22.8%); by 5–10 mmol/L; and in 16 patients (12.6%), by > 10 mmol/L. Five patients in the latter group showed neurological manifestations. In the univariate analysis, several factors including age, purpose of use, serum creatinine, and Model for End-Stage Liver Disease score, representing liver function, were significantly associated with the decrease in serum sodium after terlipressin administration. However, a multivariate analysis revealed that only initial sodium level was the most powerful predictor of terlipressin-induced reduction in serum sodium. CONCLUSION: An acute reduction in serum sodium concentration was not uncommon during terlipressin treatment, and the baseline serum sodium level was closely related to the reduction in serum sodium concentration
Study design and rationale of 'Influence of Cilostazol-based triple anti-platelet therapy on ischemic complication after drug-eluting stent implantation (CILON-T)' study: A multicenter randomized trial evaluating the efficacy of Cilostazol on ischemic vascular complications after drug-eluting stent implantation for coronary heart disease
<p>Abstract</p> <p>Background</p> <p>Current guidelines recommend dual anti-platelet therapy, aspirin and clopidogrel, for patients treated with drug-eluting stent for coronary heart disease. In a few small trials, addition of cilostazol on dual anti-platelet therapy (triple anti-platelet therapy) showed better late luminal loss. In the real-world unselected patients with coronary heart disease, however, the effect of cilostazol on platelet reactivity and ischemic vascular events after drug-eluting stent implantation has not been tested. It is also controversial whether there is a significant interaction between lipophilic statin and clopidogrel.</p> <p>Methods/Design</p> <p>CILON-T trial was a prospective, randomized, open-label, multi-center, near-all-comer trial to demonstrate the superiority of triple anti-platelet therapy to dual anti-platelet therapy in reducing 6 months' major adverse cardiovascular/cerebrovascular events, composite of cardiac death, nonfatal myocardial infarction, target lesion revascularization and ischemic stroke. It also tested whether triple anti-platelet therapy is superior to dual anti-platelet therapy in inhibiting platelet reactivity in patients receiving percutaneous coronary intervention with drug-eluting stent. Total 960 patients were randomized to receive either dual anti-platelet therapy or triple anti-platelet therapy for 6 months and also, randomly stratified to either lipophilic statin (atorvastatin) or non-lipophilic statin (rosuvastatin) indefinitely. Secondary endpoints included all components of major adverse cardiovascular/cerebrovascular events, platelet reactivity as assessed by VerifyNow P2Y12 assay, effect of statin on major adverse cardiovascular/cerebrovascular events, bleeding complications, and albumin-to-creatinine ratio to test the nephroprotective effect of cilostazol. Major adverse cardiovascular/cerebrovascular events will also be checked at 1, 2, and 3 years to test the 'legacy' effect of triple anti-platelet therapy that was prescribed for only 6 months after percutaneous coronary intervention.</p> <p>Discussion</p> <p>CILON-T trial will give powerful insight into whether triple anti-platelet therapy is superior to dual anti-platelet therapy in reducing ischemic events and platelet reactivity in the real-world unselected patients treated with drug-eluting stent for coronary heart disease. Also, it will verify the laboratory and clinical significance of drug interaction between lipophilic statin and clopidogrel.</p> <p>Trial Registration</p> <p>National Institutes of Health Clinical Trials Registry (ClinicalTrials.gov identifier# NCT00776828).</p
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