Abstract Background A strong association has been reported between trait-impulsiveness and bipolar disorder (BD). Much attention has been focused on this association, but subgroup analysis has ...generated conflicting results, raising questions about the role of trait-impulsiveness in suicidal behavior and substance misuse in bipolar patients. Method We compared Barratt Impulsiveness Scale-10 scores between 385 euthymic bipolar patients and 185 healthy controls. We then investigated possible association between impulsiveness scores and the following clinical characteristics: suicide attempt (SA), lifetime alcohol/cannabis misuse, rapid cycling and mixed episodes. Results Bipolar patients and healthy controls had significantly different BIS-10 total score and subscores (motor, attentional and nonplanning impulsiveness) (all p values <0.0001). No association was observed between BIS-10 total score, personal history of SA, number of SA, age at first SA and history of violent SA. Higher BIS-10 total scores were associated with alcohol misuse ( p =0.005), cannabis misuse ( p <0.0001), with an additive effect for these two substances ( p =0.005). Higher BIS-10 total scores were also associated with rapid cycling ( p =0.006) and history of mixed episodes ( p =0.002), with an additive effect of these two variables ( p =0.0006). Limitations We used only one clinical measurement of impulsiveness and did not carry out cognitive assessment. Conclusion This study demonstrates that trait-impulsiveness may be considered as a dimensional feature associated with BD and with a more severe clinical expression of the disease, characterized by a history of substance misuse, rapid cycling and mixed episodes. We found no association between impulsiveness and SA characteristics in bipolar patients, confirming some previous negative results.
Objective
To identify the predictive factors of myocardial stunning as assessed by the drop in post-stress Left Ventricular Ejection Fraction (LVEF) in patients with a recent history of myocardial ...infarction (MI).
Methods
We prospectively included 215 consecutive patients admitted for acute MI who underwent percutaneous coronary intervention with a greater than or equal to grade-3 TIMI flow in the culprit vessel. Six months after discharge, a post-stress/rest
99m
Tc-sestamibi gated SPECT was performed. The perfusion score was evaluated visually using a 17-segment model. The LVEF drop was considered significant if the post-stress LVEF was ≥5 % below the rest LVEF (QGS
®
software).
Results
A post-stress LVEF drop was observed in 51 (24 %) patients. Patients with an LVEF drop were more likely than patients with a stable post-stress LVEF to have diabetes (22 % vs. 10 %,
p
= 0.048), significant ischemia (SDS > 2) (51 % vs. 28 %
p
= 0.003) and higher rest LVEF 62 % (56–69) vs. 56 % (49–63)
p
< 0.001. In contrast, summed rest score, related to infarct size, did not differ between the groups. Multivariate logistic regression analysis identified SDS > 2 (OR 3.78, 95 % CI 1.8–7.92,
p
< 0.001), diabetes (OR 3.35, 95 % CI 1.33–8.49;
p
= 0.011) and rest LVEF (OR 1.08, 95 % CI 1.04–1.12,
p
< 0.001) as independent explanatory variables of an LVEF drop.
Conclusion
In patients with recent MI and post-procedural grade-3 TIMI flow, ischemia and diabetes were independent predictive factors of myocardial stunning. The higher incidence of reversible perfusion abnormalities validates the model of myocardial stunning in the post-MI period, and excludes the potential involvement of myocardial necrosis.
Findings from efficacy trials of group psychoeducation (PE) for bipolar disorders (BD) led to its inclusion in evidence-based guidelines as a first-line mandatory treatment. However, pragmatic trials ...and observational studies are needed to determine its real-world effectiveness, impact on outcomes deemed important to patients and to clarify potential mediators of any benefits.
Individuals with BD were offered the opportunity to participate in 20h of PE and asked to complete pre- and post-intervention ratings of symptoms, knowledge about BD, medication adherence, and illness perception. A priori, two key patient outcomes were identified (social functioning and self-esteem); sample attrition due to dropout or relapse was recorded.
Of 156 individuals who completed the pre-PE assessments, 103 completed the program and post-PE assessments. Only 4 of 53 dropouts were associated with BD relapse. Post-intervention, the PE completers demonstrated a statistically significant improvement in social functioning (p = 0.003, Effect Size (ES) = 0.26) and a trend towards improved self-esteem (ES = 0.14). Whilst there were significant changes in medication adherence (p = 0.002, ES = 0.28), knowledge of BD (p < 0.001, ES = 1.20), and illness perception (p < 0.001, ES = −0.37), mediational analysis demonstrated that only change in illness perception was associated to change in functioning (p=0.03) with no contribution from changes in knowledge of BD or medication adherence.
In real-world settings, over 60% individuals completed 10-session course of PE. After controlling for demography and baseline clinical state, change in illness perception, rather than change in knowledge or medication adherence, emerged as a potential mediator of some benefits of PE.
•More than 60% individuals completed a group psychoeducation programme.•Completers showed improvement in functioning but not self-esteem.•Change in illness perception mediated the change in functioning.•Changes in knowledge and adherence did not mediate the effects of psychoeducation.•Most effect sizes for changes were low to moderate.
Based on previous work on the IDT solver, enhanced geometrical capabilities have been developed to handle accurate modeling of pressurized water reactors (PWRs). This work particularly focuses on the ...tridimensional model of the control rods. We propose a transport-based model to avoid the control rod cusping effect generated by homogenizations. Due to the geometry of a PWR core, the height of a node generally ranges from 10 to 20 cm. On the other hand, the control rods move along the vertical direction within the PWR core with axial steps of 1 to 2 cm. As a result, a control rod cluster may be partially inserted into a set of Cartesian nodes, thus requiring a heterogeneous representation of the cross sections along z.
In traditional three-dimensional (3-D) transport codes, piecewise distributed cross sections are not allowed within a single node. Consequently, despite the heterogeneous nature, the node has to be homogenized. Because of sharp axial heterogeneity, the cross sections cannot be represented by polynomial expansions at the interface between the control rod tip and the water. Currently, the solvers of APOLLO3® do not allow for nonconformal geometries along the z-axis, i.e., all two-dimensional regions have the same number of planes. Lately, high-fidelity transport-based core solvers have dealt with this issue by proposing flux-weighting homogenization techniques. Nevertheless, the simple homogenization triggers a discontinuity in the first derivative of the curve representing the variation of the fundamental eigenvalue as the control rods are inserted into the reactor. This nonphysical phenomenon is known as the control rod cusping effect. Several numerical remedies have been proposed over the years to remove it. For instance, in diffusion, the P
N
or SPN method, and Fanning and Palmiotti have proposed a heterogeneous variational nodal method (VNM). Another heterogeneous VNM was developed by Smith et al. in 2003. In this method, each heterogeneous node is split into subelements with uniform cross sections. The flux is then developed by finite spatial trial functions. The nodal functional is constructed by the functional of all subelements in the node.
In this work, discrete ordinates linear short characteristics are applied to 3-D heterogeneous Cartesian cells (HCCs). To ensure accurate representation of the control rod movements, each heterogeneous node, represented by a HCC, is the combination of an inner local tridimensional grid and a set of cylinders representing the fuel rod in its exact shape. The new geometrical model generates local nonconforming geometries. Spatial integrals over the HCC are performed using modular tridimensional ray tracing. The ray-tracing technique is based on the combinatorial geometry composed of cylinders and the local XYZ grid. In this manner, a single HCC can be equipped with several local steps to follow exactly the axial displacement of the control rod.
The IDT provides a conformal 3-D Cartesian mesh with heterogeneous nonconformal 3-D nodes to eliminate such an issue. Each node represents a geometrical pattern named HCC. Neither a homogenization procedure nor a mesh adjustment is needed by taking advantage of the geometrical model provided by the HCC. Numerical results show that the HCC transport model can eliminate the cusping effect and obtain accurate power distribution with relatively higher efficiency and accuracy.
This work presents an asymptotic method based on angular flux expansion in a Neumann series. The technique is aimed at effective reduction of the memory imprint of numerical methods based on ...collision probabilities (CPs). The asymptotic method has been implemented in the heterogeneous Cartesian cells of the integro-differential transport solver (IDT). The IDT solves the neutral-particle transport equation by discrete ordinates combined with angular-dependent CP matrices. In lattice depletion calculations, because of the change of isotopic concentration along the burnup, methods based on CP discretization, such as current-coupling CP or the one presented in this paper, would require construction and storage of a set of CP coefficients for any depleted pin cell. When the number of media grows, the performances of the solver are bounded by the memory pressure caused by the growth of coefficients. Application of the asymptotic technique, presented in this paper, transforms by two user's parameters the memory-bound solver in a compute-bound application, where the principal workload is transferred from coefficients to source iterations. In this work, a theoretical study of the method is presented together with two applications to two-dimensional assembly simulations. The effects on self-shielded and depleted materials are highlighted. Preliminary results show an encouraging reduction of memory occupation by a factor 10 without any significant loss of accuracy.
Abstract
Aims
Extra-atrial injury can cause complications after catheter ablation for atrial fibrillation (AF). Pulsed field ablation (PFA) has generated preclinical data suggesting that it ...selectively targets the myocardium. We sought to characterize extra-atrial injuries after pulmonary vein isolation (PVI) between PFA and thermal ablation methods.
Methods and results
Cardiac magnetic resonance (CMR) imaging was performed before, acutely (<3 h) and 3 months post-ablation in 41 paroxysmal AF patients undergoing PVI with PFA (N = 18, Farapulse) or thermal methods (N = 23, 16 radiofrequency, 7 cryoballoon). Oesophageal and aortic injuries were assessed by using late gadolinium-enhanced (LGE) imaging. Phrenic nerve injuries were assessed from diaphragmatic motion on intra-procedural fluoroscopy. Baseline CMR showed no abnormality on the oesophagus or aorta. During ablation procedures, no patient showed phrenic palsy. Acutely, thermal methods induced high rates of oesophageal lesions (43%), all observed in patients showing direct contact between the oesophagus and the ablation sites. In contrast, oesophageal lesions were observed in no patient ablated with PFA (0%, P < 0.001 vs. thermal methods), despite similar rates of direct contact between the oesophagus and the ablation sites (P = 0.41). Acute lesions were detected on CMR on the descending aorta in 10/23 (43%) after thermal ablation, and in 6/18 (33%) after PFA (P = 0.52). CMR at 3 months showed a complete resolution of oesophageal and aortic LGE in all patients. No patient showed clinical complications.
Conclusion
PFA does not induce any signs of oesophageal injury on CMR after PVI. Due to its tissue selectivity, PFA may improve safety for catheter ablation of AF.
Graphical Abstract
We demonstrate that the use of high duty cycle time-of-flight (HDC-TOF) neutron transmission imaging allows a spatially resolved analysis of the aggregate state of water during isothermal cold starts ...of polymer electrolyte fuel cells (PEFCs). Neutron attenuation at long wavelengths depends on the mobility of protons and is therefore lower for ice compared to liquid water. With the experimental setup used in our experiment (chopper disk duty cycle of 30%) attenuation at long wavelengths normalized to attenuation at short wavelengths leads to a contrast between ice and super-cooled water higher than 6% and a measurement time of a few minutes is sufficient to detect reliably phase changes of thick water layers ( 0.5 mm), i.e. when water is present in the flow field channels. Using this method, local freezing events were identified during an isothermal cold start, which was corroborated by locally resolved measurements of the latent heat released during freezing. The impact of systematic biases such as the scattered background was evaluated, showing that a precise correction is of utmost importance if the aggregate state is to be determined in an absolute way. If such a highly precise correction is not possible, the detection of freezing events is still possible by observing relative changes during time series.
Summary
Background
Psoriasis has been linked to metabolic syndrome and non‐alcoholic fatty liver disease (NAFLD). Data suggest that the prevalence of NAFLD is increased in patients with psoriasis. ...The aim of this study was to determine the prevalence and severity of NAFLD in this patient population.
Aim
To determine the prevalence of both NAFLD and non‐alcoholic steatohepatitis (NASH) in patients with psoriasis.
Methods
Patients between the ages of 18 and 70 years with a diagnosis of psoriasis or psoriatic arthritis and followed by either the Dermatology or Rheumatology Division within the Department of Medicine at San Antonio Military Medical Center were considered for enrollment. Each patient completed a questionnaire, underwent a thorough skin evaluation, and had a right upper quadrant ultrasound and fasting blood work. If the liver enzymes were elevated or fatty liver detected on imaging, percutaneous liver biopsy was recommended.
Results
One hundred and twenty‐nine patients were enrolled and 103 completed all necessary studies. The participants were predominantly middle aged (52.7 ± 12) and overweight or obese (average BMI 30.1 ± 5.9, range: 19.8–52.5 kg/m2). 53% (n = 54) were male while 15% (n = 15) of participants identified themselves as being a diabetic. The overall prevalence of NAFLD was 47%. The overall prevalence of NASH was 22% in those who underwent biopsy.
Conclusions
Non‐alcoholic fatty liver disease is very common among our cohort of patients with psoriasis, occurring in roughly 47% of patients. The more progressive form of the disease, NASH, is found in approximately one in five patients. Health care providers should be mindful of this association given the high prevalence of both NAFLD and NASH in this cohort of patients.
This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes ...assessed with 18F‐fluorodeoxyglucose (FDG). In the neoadjuvant setting of breast cancer, the metabolic response can predict the final complete pathologic response after the first cycles of chemotherapy. Because tumor metabolic behavior highly depends on cancer subtype, studies are ongoing to define the optimal metabolic criteria of tumor response in each subtype. The recent multicentric randomized AVATAXHER trial has suggested, in the human epidermal growth factor 2‐positive subtype, a clinical benefit of early tailoring the neoadjuvant treatment in women with poor metabolic response after the first course of treatment. In the bone‐dominant metastatic setting, there is increasing clinical evidence that FDG‐PET/computed tomography (CT) is the most accurate imaging modality for assessment of the tumor response to treatment when both metabolic information and morphologic information are considered. Nevertheless, there is a need to define standardized metabolic criteria of response, including the heterogeneity of response among metastases, and to evaluate the costs and health outcome of FDG‐PET/CT compared with conventional imaging. New non‐FDG radiotracers highlighting specific molecular hallmarks of breast cancer cells have recently emerged in preclinical and clinical studies. These biomarkers can take into account the heterogeneity of tumor biology in metastatic lesions. They may provide valuable clinical information for physicians to select and monitor the effectiveness of novel therapeutics targeting the same molecular pathways of breast tumor.
This review considers the potential utility of positron emission tomography (PET) tracers in the setting of response monitoring in breast cancer, with a special emphasis on glucose metabolic changes assessed with 18F‐fluorodeoxyglucose. It discusses the different PET timing and metabolic criteria to define response that have been evaluated in previous studies. The development of new radiotracers of specific molecular pathways of breast cancer cells is also a challenging and promising research area.
In-depth understanding of water management is essential for the optimization of the performance and durability of polymer electrolyte fuel cells (PEFCs). Neutron imaging of liquid water has proven to ...be a powerful diagnostic technique, but it cannot distinguish between ‘legacy’ water that has accumulated in the system over time and ‘nascent’ water recently generated by reaction. Here, a novel technique is introduced to investigate the spatially resolved water exchange characteristics inside PEFCs. Hydro-electrochemical impedance imaging (HECII) involves making a small AC-sinusoidal perturbation to a cell and measuring the consequential water generated, using neutron radiographs, associated with the stimulus frequency. Subsequently, a least-squares estimation (LSE) analysis is applied to derive the spatial amplitude ratio and phase shift. This technique provides a complementary view to conventional neutron imaging and provides information on the source and ‘history’ of water in the system. By selecting a suitable perturbation frequency, HECII can be used to achieve an alternative image ‘contrast’ and identify different features involved in the water dynamics of operational fuel cells.
•Hydro-electrochemical impedance imaging applied to water management of PEFC.•HECII distinguish between 'legacy' and 'nascent' water in the PEFC.•The perturbation frequency of HECII affects water dynamics features.
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