Effective generation of closed-form soliton solutions of the continuous classical Heisenberg ferromagnet equation

The non-topological, stationary and propagating, soliton solutions of the classical continuous Heisenberg ferromagnet equation are investigated. A general, rigorous formulation of the Inverse Scattering Transform for this equation is presented, under less restrictive conditions than the Schwartz class hypotheses and naturally incorporating the non-topological character of the solutions. Such formulation is based on a new triangular representation for the Jost solutions, which in turn allows an immediate computation of the asymptotic behaviour of the scattering data for large values of the spectral parameter, consistently improving on the existing theory. A new, general, explicit multi-soliton solution formula, amenable to computer algebra, is obtained by means of the matrix triplet method, producing all the soliton solutions (including breather-like and multipoles), and allowing their classification and descriptio

Cardiac function in borderline hypothyroidism: a study by pulsed wave tissue Doppler imaging

Objective: In subclinical hypothyroidism (SH), impaired diastolic function has been documented at rest and on effort, while systolic dysfunction has only been assessed on effort. Design: The aim of the present study was: (a) to further assess systolic function at rest in SH; and (b) to ascertain whether cardiac dysfunction could precede TSH increase in euthyroid patients with a high risk of developing SH. Methods: We studied 32 patients with classical Hashimoto's thyroiditis (22 with increased serum TSH (> 3 mU/ml – group A), and 10 with normal serum TSH (< 3 mU/ml – group B)); a third group (C), which included 13 healthy controls. All subjects underwent pulsed wave tissue Doppler imaging (PWTDI) to accurately quantify the global and regional left ventricular function. Results: When compared with group C, PWTDI indices showed that in both groups A and B there was a significant impairment of systolic ejection (P < 0.001 and P < 0.05, respectively), a delay in diastolic relaxation (P < 0.001 and P < 0.05, respectively) and a decrease in the compliance to the ventricular filling (P < 0.05). Several significant correlations were found between PWTDI parameters and serum-free T3 and T4 and TSH concentrations. Conclusion: PWTDI is a sensitive technique that allows detection of both diastolic and systolic abnormalities, not only in patients with SH, but also in euthyroid subjects with a high risk of developing thyroid failure. Futhermore, the significant correlations of several PWTDI indices with serum FT3 and TSH concentrations strongly support the concept of a continuum spectrum of a slight thyroid failure in autoimmune thyroiditis extending to subjects with serum TSH still within the normal range

Úlcera de pressão cuidados preventivos e curativos para pacientes em cuidados paliativos : uma revisão integrativa

O estudo tem como objetivo responder a questão norteadora como se caracterizam os cuidados preventivos e curativos para a Úlcera de Pressão nos pacientes em Cuidados Paliativos. A metodologia utilizada neste estudo foi uma revisão integrativa da literatura segundo Ganong (1987). A revisão integrativa propõe cinco passos as quais são: seleção das hipóteses ou questão para a revisão, estabelecimento de critérios para seleção da amostra, representação das características da pesquisa original, análise dos dados, interpretação dos resultados e apresentação da revisão. Na coleta de dados foram selecionados 13 artigos nas bases de dados da Web of Science, Lilacs, Pubmed, Scielo, Bireme, Medes e Medscape, no periodo de 2000 a 2009. Os resultados encontrados foram: fatores associados a úlcera de pressão constatando-se que a imobilidade, desnutrição, incontinência urinária e fecal são os maiores responsáveis pelo surgimento de uma lesão; utilização de instrumentos para avaliação dos pacientes e cuidado as feridas a qual a Escala de Braden foi a mais lembrada entre os autores; cuidados preventivos para úlcera de pressão onde a mudança de decúbito foi evidenciado como o método mais utilizado de prevenção embora para pacientes na terminalidade o manejo dessa situação deve ser avaliada entre a equipe e paciente para definir se ela será realizada ou não, uso de coxins piramidais para auxiliar na reposição e auxiliar na prevenção; as complicações da úlcera de pressão evidenciadas por esse estudo foram: odor, infecção, hemorragia, exsudato, dor e questões de imagem corporal e psicossocial. Constatouse durante a realização do trabalho que há muito por ser feito para beneficiar esses pacientes e que existem diversas estratégias propostas a fim de proporcionar o conforto almejado na terminalidade. A equipe de enfermagem precisa gerenciar os cuidados de maneira que a tomada de decisões suportem as inquietações tanto dos familiares quanto do paciente minimizando dessa forma suas angústias

Autonomous agents and multi-agent systems applied in healthcare

Artificial Intelligence in Medicine collects work on applications of AI algorithms, theories, approaches to medical domai

Refractory ventricular tachycardia caused by inflow cannula mechanical injury in a patient with left ventricular assist device: Catheter ablation and pathological findings

In patients with left ventricular assist device (LVAD), a minority of post-operative ventricular tachycardias (VTs) is caused by contact between the inflow cannula and the endocardium. Currently, electrophysiologic characteristics and pathologic features of this condition are lacking. We report on a case of a successfully ablated mechanical VT. After VT recurrence, heart transplantation took place. Pathologic observations were consistent with direct tissue injury and inflammation, eventually contributing to persisting arrhythmias. Radiofrequency catheter ablation can be a safe and effective option to treat arrhythmias caused by inflow cannula interference in the short term, although a high recurrence rate is expected

Refractory ventricular tachycardia caused by inflow cannula mechanical injury in a patient with left ventricular assist device: Catheter ablation and pathological findings

In patients with left ventricular assist device (LVAD), a minority of post-operative ventricular tachycardias (VTs) is caused by contact between the inflow cannula and the endocardium. Currently, electrophysiologic characteristics and pathologic features of this condition are lacking. We report on a case of a successfully ablated mechanical VT. After VT recurrence, heart transplantation took place. Pathologic observations were consistent with direct tissue injury and inflammation, eventually contributing to persisting arrhythmias. Radiofrequency catheter ablation can be a safe and effective option to treat arrhythmias caused by inflow cannula interference in the short term, although a high recurrence rate is expected

BDNF Overexpression Increases Striatal D3 Receptor Level at Striatal Neurons and Exacerbates D1-Receptor Agonist-Induced Dyskinesia

BACKGROUND: We recently showed that striatal overexpression of brain derived neurotrophic factor (BDNF) by adeno-associated viral (AAV) vector exacerbated L-DOPA-induced dyskinesia (LID) in 6-OHDA-lesioned rats. An extensive sprouting of striatal serotonergic terminals accompanied this effect, accounting for the increased susceptibility to LID.OBJECTIVE: We set to investigate whether the BDNF effect was restricted to LID, or extended to dyskinesia induced by direct D1 receptor agonists.METHODS: Unilaterally 6-OHDA-lesioned rats received a striatal injection of an AAV vector to induce BDNF overexpression. Eight weeks later, animals received daily treatments with a low dose of SKF82958 (0.02 mg/kg s.c.) and development of dyskinesia was evaluated. At the end of the experiment, D1 and D3 receptors expression levels and D1 receptor-dependent signaling pathways were measured in the striatum.RESULTS: BDNF overexpression induced significant worsening of dyskinesia induced by SKF82958 compared to the GFP group and increased the expression of D3 receptor at striatal level, even in absence of pharmacological treatment; by contrast, D1 receptor levels were not affected. In BDNF-overexpressing striata, SKF82958 administration resulted in increased levels of D1-D3 receptors co-immunoprecipitation and increased phosphorylation levels of Thr34 DARPP-32 and ERK1/2.CONCLUSION: Here we provide evidence for a functional link between BDNF, D3 receptors and D1-D3 receptor close interaction in the augmented susceptibility to dyskinesia in 6-OHDA-lesioned rats. We suggest that D1/D3 receptors interaction may be instrumental in driving the molecular alterations underlying the appearance of dyskinesia; its disruption may be a therapeutic strategy for treating dyskinesia in PD patients

Acute Exercise with Moderate Hypoxia Reduces Arterial Oxygen Saturation and Cerebral Oxygenation without Affecting Hemodynamics in Physically Active Males

Hemodynamic changes during exercise in acute hypoxia (AH) have not been completely elucidated. The present study aimed to investigate hemodynamics during an acute bout of mild, dynamic exercise during moderate normobaric AH. Twenty-two physically active, healthy males (average age; range 23&ndash;40 years) completed a cardiopulmonary test on a cycle ergometer to determine their maximum workload (Wmax). On separate days, participants performed two randomly assigned exercise tests (three minutes pedaling at 30% of Wmax): (1) during normoxia (NORMO), and (2) during normobaric AH at 13.5% inspired oxygen (HYPO). Hemodynamics were assessed with impedance cardiography, and peripheral arterial oxygen saturation (SatO2) and cerebral oxygenation (Cox) were measured by near-infrared spectroscopy. Hemodynamic responses (heart rate, stroke volume, cardiac output, mean arterial blood pressure, ventricular emptying rate, and ventricular filling rate) were not any different between NORMO and HYPO. However, the HYPO test significantly reduced both SatO2 (96.6 &plusmn; 3.3 vs. 83.0 &plusmn; 4.5%) and Cox (71.0 &plusmn; 6.6 vs. 62.8 &plusmn; 7.4 A.U.) when compared to the NORMO test. We conclude that an acute bout of mild exercise during acute moderate normobaric hypoxia does not induce significant changes in hemodynamics, although it can cause significant reductions in SatO2 and Cox

Arrhythmic Risk Stratification in Cardiac Amyloidosis: A Review of the Current Literature

Cardiac amyloidosis is the most frequent infiltrative disease caused by the deposition of misfolded proteins in the cardiac tissue, leading to heart failure, brady- and tachyarrhythmia and death. Conduction disorders, atrial fibrillation (AF) and ventricular arrhythmia (VA) significantly impact patient outcomes and demand recognition. However, several issues remain unresolved regarding early diagnosis and optimal management. Extreme bradycardia is the most common cause of arrhythmic death, while fast and sustained VAs can be found even in the early phases of the disease. Risk stratification and the prevention of sudden cardiac death are therefore to be considered in these patients, although the time for defibrillator implantation is still a subject of debate. Moreover, atrial impairment due to amyloid fibrils is associated with an increased risk of AF resistant to antiarrhythmic therapy, as well as recurrent thromboembolic events despite adequate anticoagulation. In the last few years, the aging of the population and progressive improvements in imaging methods have led to increases in the diagnosis of cardiac amyloidosis. Novel therapies have been developed to improve patients’ functional status, quality of life and mortality, without data regarding their effect on arrhythmia prevention. In this review, we consider the latest evidence regarding the arrhythmic risk stratification of cardiac amyloidosis, as well as the available therapeutic strategies

Cardiovascular Magnetic Resonance in Patients with Cardiac Electronic Devices: Evidence from a Multicenter Study

Background: Most recent cardiac implantable electronic devices (CIEDs) can safely undergo a cardiovascular magnetic resonance (CMR) scan under certain conditions, but metal artifacts may degrade image quality. The aim of this study was to assess the overall diagnostic yield of CMR and the extent of metal artifacts in a multicenter, multivendor study on CIED patients referred for CMR. Methods: We analyzed 309 CMR scans from 292 patients (age 57 +/- 16 years, 219 male) with an MR-conditional pacemaker (n = 122), defibrillator (n = 149), or loop recorder (n = 38); CMR scans were performed in 10 centers from 2012 to 2020; MR-unsafe implants were excluded. Clinical and device parameters were recorded before and after the CMR scan. A visual analysis of metal artifacts was performed for each sequence on a segmental basis, based on a 5-point artifact score. Results: The vast majority of CMR scans (n = 255, 83%) were completely performed, while only 32 (10%) were interrupted soon after the first sequences and 22 (7%) were only partly acquired; CMR quality was non-diagnostic in 34 (11%) scans, poor (&lt;1/3 sequences were diagnostic) in 25 (8%), or acceptable (1/3 to 2/3 sequences were diagnostic) in 40 (13%), while most scans (n = 201, 68%) were of overall good quality. No adverse event or device malfunctioning occurred, and only nonsignificant changes in device parameters were recorded. The most affected sequences were SSFP (median score 0.32 [interquartile range 0.07-0.91]), followed by GRE (0.18 [0.02-0.59]) and LGE (0.14 [0.02-0.55]). ICDs induced more artifacts (median score in SSFP images 0.87 [0.50-1.46]) than PMs (0.11 [0.03-0.28]) or ILRs (0.11 [0.00-0.56]). Moreover, most artifacts were located in the anterior, anteroseptal, anterolateral, and apical segments of the LV and in the outflow tract of the RV. Conclusions: CMR is a versatile imaging technique, with a high safety profile and overall good image quality even in patients with MR-conditional CIEDs. Several strategies are now available to optimize image quality, substantially enhancing overall diagnostic yield