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Depto. de Bioquímica y Biología Molecular, Fac. de Ciencias Químicas, TRUE, pub

OBJECTIVE: Evidence from preclinical and clinical studies has demonstrated that myocardial infarction promotes atherosclerosis progression. The impact of focal vascular inflammation on the progression and phenotype of remote atherosclerosis remains unknown. APPROACH AND RESULTS: We used a novel ApoE−/− knockout mouse model of sustained arterial inflammation, initiated by mechanical injury in the abdominal aorta. Using serial in vivo molecular MRI and ex vivo histology and flow cytometry, we demonstrate that focal arterial inflammation triggered by aortic injury, accelerates atherosclerosis in the remote brachiocephalic artery. The brachiocephalic artery atheroma had distinct histological features including increased plaque size, plaque permeability, necrotic core to collagen ratio, infiltration of more inflammatory monocyte subsets, and reduced collagen content. We also found that arterial inflammation following focal vascular injury evoked a prolonged systemic inflammatory response manifested as a persistent increase in serum IL-6 (interleukin 6). Finally, we demonstrate that 2 therapeutic interventions—pravastatin and minocycline—had distinct anti-inflammatory effects at the plaque and systemic level. CONCLUSIONS: We show for the first time that focal arterial inflammation in response to vascular injury enhances systemic vascular inflammation, accelerates remote atheroma progression and induces plaques more inflamed, lipid-rich, and collagenpoor in the absence of ischemic myocardial injury. This inflammatory cascade is modulated by pravastatin and minocycline treatments, which have anti-inflammatory effects at both plaque and systemic levels that mitigate atheroma progression., Engineering and Physical Sciences Research Council (EPSRC), British Heart Foundation (BHF), King’s BHF Centre for Research Excellence, EPSRC Centre for Medical Engineering, Depto. de Bioquímica y Biología Molecular, Fac. de Ciencias Químicas, TRUE, pub

Aims Dysfunctional matrix turnover is present at sites of abdominal aortic aneurysm (AAA) and leads to the accumulation of monomeric tropoelastin rather than cross-linked elastin. We used a gadolinium-based tropoelastin-specific magnetic resonance contrast agent (Gd-TESMA) to test whether quantifying regional tropoelastin turnover correlates with aortic expansion in a murine model. The binding of Gd-TESMA to excised human AAA was also assessed. Methods and results We utilized the angiotensin II (Ang II)-infused apolipoprotein E gene knockout (ApoE−/−) murine model of aortic dilation and performed in vivo imaging of tropoelastin by administering Gd-TESMA followed by late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) and T1 mapping at 3 T, with subsequent ex vivo validation. In a cross-sectional study (n = 66; control = 11, infused = 55) we found that Gd-TESMA enhanced MRI was elevated and confined to dilated aortic segments (control: LGE=0.13 ± 0.04 mm2, control R1= 1.1 ± 0.05 s−1 vs. dilated LGE =1.0 ± 0.4 mm2, dilated R1 =2.4 ± 0.9 s−1) and was greater in segments with medium (8.0 ± 3.8 mm3) and large (10.4 ± 4.1 mm3) compared to small (3.6 ± 2.1 mm3) vessel volume. Furthermore, a proof-of-principle longitudinal study (n = 19) using Gd-TESMA enhanced MRI demonstrated a greater proportion of tropoelastin: elastin expression in dilating compared to non-dilating aortas, which correlated with the rate of aortic expansion. Treatment with pravastatin and aspirin (n = 10) did not reduce tropoelastin turnover (0.87 ± 0.3 mm2 vs. 1.0 ± 0.44 mm2) or aortic dilation (4.86 ± 2.44 mm3 vs. 4.0 ± 3.6 mm3). Importantly, Gd-TESMA-enhanced MRI identified accumulation of tropoelastin in excised human aneurysmal tissue (n = 4), which was confirmed histologically. Conclusion Tropoelastin MRI identifies dysfunctional matrix remodelling that is specifically expressed in regions of aortic aneurysm or dissection and correlates with the development and rate of aortic expansi, British Heart Foundation, Chilean Agency of Technology and Science, Centre for Medical Engineering, Depto. de Bioquímica y Biología Molecular, Fac. de Ciencias Químicas, TRUE, pub

Reconfigurable intelligent surface (RIS) is an emerging tool for 5G and wireless communication technologies that have attracted researchers' interest. However, the passive nature and the high number of reflecting elements in RIS result in a large pilot overhead, which makes channel estimation challenging in multi-user multiple-input multiple-output (MU-MIMO) wireless communication systems. Previous works have shown an improvement in reducing the pilot overhead by exploiting the structured sparsity in rows and columns, which was further improved by compensating offset among users in angular cascaded channels of RIS aided system. To further reduce the pilot overhead, we analyze and adopt coherence-optimized pilots for channel estimation and propose an algorithm to analyze the combined effect of low-coherence pilots with an optimum size of RIS elements for a given number of users, transmit antennas, and normalized error threshold performance. The simulation results illustrate better NMSE performance as compared to contemporary techniques.

[Background] Cardiac MRI plays an important role in the diagnosis and follow-up of patients with congenital heart disease (CHD). Gadolinium-based contrast agents are often needed to overcome flow-related and off-resonance artifacts that can impair the quality of conventional noncontrast 3D imaging. As serial imaging is often required in CHD, the development of robust noncontrast 3D MRI techniques is desirable., [Purpose] To assess the clinical utility of noncontrast enhanced magnetization transfer and inversion recovery prepared 3D free-breathing sequence (MTC-BOOST) compared to conventional 3D whole heart imaging in patients with CHD., [Study type] Prospective, image quality., [Population] A total of 27 adult patients (44% female, mean age 30.9 ± 14.8 years) with CHD., [Field Strength/Sequence] A 1.5 T; free-breathing 3D MTC-BOOST sequence., [Assessment] MTC-BOOST was compared to diaphragmatic navigator-gated, noncontrast T2 prepared 3D whole-heart imaging sequence (T2prep-3DWH) for comparison of vessel dimensions, lumen-to-myocardium contrast ratio (CR), and image quality (vessel wall sharpness and presence and type of artifacts) assessed by two experienced cardiologists on a 5-point scale., [Statistical Tests] Mann–Whitney test, paired Wilcoxon signed-rank test, Bland–Altman plots. P < 0.05 was considered statistically significant., [Results] MTC-BOOST significantly improved image quality and CR of the right-sided pulmonary veins (PV): (CR: right upper PV 1.06 ± 0.50 vs. 0.58 ± 0.74; right lower PV 1.32 ± 0.38 vs. 0.81 ± 0.73) compared to conventional T2prep-3DWH imaging where the PVs were not visualized in some cases due to off-resonance effects. MTC-BOOST demonstrated resistance to degradation of luminal signal (assessed by CR) secondary to accelerated or turbulent flow conditions. T2prep-3DWH had higher image quality scores than MTC-BOOST for the aorta and coronary arteries; however, great vessel dimensions derived from MTC-BOOST showed excellent agreement with standard T2prep-3DWH imaging., [Data Conclusion] MTC-BOOST allows for improved contrast-free imaging of pulmonary veins and regions characterized by accelerated or turbulent blood flow compared to standard T2prep-3DWH imaging, with excellent agreement of great vessel dimensions., [Evidence Level] 1, [Technical Efficacy] Stage 2

Mm-wave MIMO communication makes a hybrid combination of analog RF and digital baseband processing more attractive, where digital baseband precoders/combiners able to adapt to the pre-defined analog (switch based) RF processors. Non-uniform two-dimensional quantized azimuth and elevation angle grid antenna array responses are suggested for uniform planar array (UPA) and are proven orthogonal. Training vectors (or sensing matrix) are designed for suggested antenna array response with unitary RF processing for UPA in mm-wave hybrid MIMO system. Proposed training vectors achieve minimized total coherence of the equivalent sensing matrix for hybrid MIMO system. Open-loop channel estimation of the mm-wave channel is done by using iterative re-weight based super resolution algorithm to exploit its sparse nature. Extensive simulations reveal the benefit of coherence optimization where normalized mean squared error is reduced and spectral efficiency is improved in comparison to existing methods.

Best Complex Antipodal Spherical Codes (BCASC) and Coherence Based Grassmannian Codebooks (CBGC) are state of the art algorithms to produce minimal coherence codebooks, however have high running time (relatively more in BCASC search than CBGC algorithm) which restricts their wider application. BCASC and CBGC algorithms are modified in a novel way by incorporating additional parameters adapted to three categories of codebooknovercompleteness to check stagnance of optimization and divergent behaviour to achieve faster convergence. The proposed algorithms are compared with BCASC and CBGC algorithms to achieve similar coherence results in much less time.

The purpose of this study was to explore the relationship between recidivism and adaptive functioning in a short-term psychiatric population. Specific variables studied included number of previous psychiatric hospitalization, social support, substance abuse, violent/aggressive behavior, utilization of outpatient services, employment history, and use of leisure time. The sample consisted of 65 recidivists and 65 non-recidivists hospitalized on the inpatient psychiatric units of Interfaith Medical Center. Relevant data were obtained by interviewing patients, as well as outside corroborating sources, such as family members. Social support and substance abuse were assessed by using the Family/Social and Substance Abuse subscales of the Addiction Severity Index (McLellan, Luborsky, Woody, & O'Brien, 1980; McLellan, et al., 1990). Subjects were also administered the Revised UCLA Loneliness Scale (Russell, Peplau, & Cutrona, 1980). Data were subjected to t-tests and regression analysis. The present study not only confirmed the oft-reported finding that the number of previous hospitalizations is the best predictor or recidivism, but was unique in that the regression analysis revealed this one variable to account for an overwhelming 66% of the variance. The t-tests showed recidivists to have poorer social support, report greater loneliness, be more likely to use drugs, report a greater number of violent incidents, have worked fewer months in the past year, and spend more time in unstructured activities than non-recividists. The number of hours spent in unstructured activities and number of months worked in the last made a slight but significant contribution to the total variance (2.7% and 0.9%, respectively). Alcohol abuse and utilization of substance abuse did not differentiate between recidivists and non-recidivists. However, alcohol abuse was unexpectedly counterpredictive of recidivism, contributing 1.9% to the variance.