Quantitative electrical homogeneity assessment of nanowire transparent electrodes.

The homogeneous distribution of electric current (electrical homogeneity) is not guaranteed in nanowire electrodes but is crucial for the stability of the electrode and actually desirable in most applications. Despite the relevance of this feature, it is common practice to perform qualitative assessments at the electrode scale, thus masking local effects. To address this issue, we have developed a computational strategy to aid in the design of nanowire electrodes with improved electrical homogeneity. Nanowire electrodes are modeled as two-dimensional networks of stick and junction resistors (with resistance Rw and Rj, respectively) to simulate the electric conduction process. Electrodes are discretized into regular grids of squares and the electrical power of the network contained in each square is computed. The mismatch between the areal power density of the entire electrode and that of the squares provides a quantitative electrical homogeneity evaluation. Repeating the analysis with squares of different size yields an evaluation that spans across length scales. A scalar indicator, coined the homogeneity index, summarizes the results of the multiscale evaluation. The proposed strategy is employed to assess the electrical homogeneity of silver nanowire electrodes through the analysis of scanning electron microscopy images. Our results agree with the outcomes of the experimental assessment performed on the same electrodes. Parametric studies are performed by varying nanowire content and nanowire-to-junction resistance ratio Rw/Rj. We observe that a significant reduction of contact resistance is not necessary to ensure a high degree of homogeneity. The ideal condition of negligible junction resistance (Rw ≫ Rj) leads to the best-case scenario, a situation which is closely approached if Rw ≈ Rj (15% difference at the most in terms of homogeneity index).

An efficient computational approach for three-dimensional modeling and simulation of fibrous battery electrodes.

Fibrous electrodes are a promising alternative to conventional particle-based lithium-ion battery electrodes. In this contribution, we propose an efficient computational approach for the modeling and simulation of electrochemical phenomena taking place in fibrous electrodes during battery charge/discharge processes. Since each fiber is explicitly modeled by means of a dimensionally reduced embedded fiber model, the framework enables simulations in a three-dimensional setting with relatively modest discretization and computational requirements compared to simulations with fully resolved fiber discretizations. The approach is applied to electrodes with high volume fractions of high aspect ratio fibers. Various local and global quantities are analyzed and results are compared to those obtained with the standard finite element method and the pseudo-2D model.

Liver disease and heart failure.

INTRODUCTION: Several systemic conditions, inflammatory disease, infections and alcoholism, may affect both the heart and the liver. Common conditions, such as the non-alcoholic fatty liver disease (NAFLD), may increase the risk of cardiac dysfunction. Patients with acute decompensated HF (ADHF) may develop acute ischemic hepatitis and, chronic HF patients may develop congestive hepatopathy (CH). EVIDENCE ACQUISITION: Laboratory anomalies of hepatic function may predict the outcome of patients with advanced HF and the evaluation of both cardiac and hepatic function is very important in the management of these patients. In clinically apparent ischemic hepatitis more than 90% of patients have some right-sided HF. There are systemic disorders characterized by the accumulation of metals or by metabolism defects that may affect primarily the liver but also the heart leading to symptomatic hypertrophic cardiomyopathy (HCM). EVIDENCE SYNTHESIS: Abnormal LFTs indicate the mechanism of liver injury: liver congestion or liver ischemia. In AHF, it's important an adequate evaluation of heart and liver function in order to choose the treatment in order to ensure stable hemodynamic as well as optimal liver function. CONCLUSIONS: Measurements of LFTs should be recommended in the early phase of ADHF management. Physicians with interest in HF should be trained in the evaluation of LFTs. It's very important for cardiologists to know the systemic diseases affecting both heart and liver and the first imaging or laboratory findings useful for a diagnosis. it is very important for internists, nephrologists, cardiologists, primary physicians and any physicians with interest in treating HF to recognize such signs and symptoms belong to rare diseases and liver diseases that could be mistaken for HF.

Drug-Induced Pulmonary Arterial Hypertension: Mechanisms and Clinical Management.

Pulmonary arterial hypertension is a rare disease, with drug-induced causes even more uncommon, accounting for only 10% of cases in large registry series. Predisposing factors for drug-induced PAH have not been completely defined. This review summarizes drugs with definite, possible, or likely association to pulmonary hypertension and possible mechanisms involved in the occurrence of pulmonary hypertension. Controversies on mechanisms and on their role in pathophysiology were also shown. The possible synergism between drug abuse and HIV was discussed and the possible interactions of antiretroviral therapy in HIV subjects were analyzed. Furthermore, we reported clinical findings and possible management, specific for each class of drugs, in case of drug-induced PAH. Finally, we summarized into a unified algorithm possible management of drug-induced PAH.

Hospitalization cost reduction with sacubitril-valsartan implementation in a cohort of patients from the Daunia Heart Failure Registry.

INTRODUCTION: Aim of this study was to assess the impact of the introduction of new class of drugs (ARNI: angiotensin receptor-neprilysin inhibitor) on hospital related costs in a real world cohort of patients with chronic heart failure (CHF). METHODS: Seventy-three consecutive patients with CHF and systolic dysfunction eligible for the treatment with ARNIs from the Daunia Heart Failure Registry were enrolled. Incidence of hospitalizations before and after treatment with ARNI, costs for drug and hospitalization for HF were recorded, indexed per year and compared. RESULTS: Indexed mean number of hospitalizations per year was 0.93 ±â€¯1.70 before and 0.19 ±â€¯0.70 after introduction of ARNI (p < 0.001, -80%), 2.26 ±â€¯1.95 before and 0.38 ±â€¯1.2 after ARNI in the subgroup of patients with at least one hospitalization for HF in the year before treatment with ARNI (p < 0.001, -83%).Mean indexed cost for hospitalization was 2067 ±â€¯3715 euros before and 1847 ±â€¯1549 after ARNI (p n.s., -11%); in the subgroup with at least one hospitalization for HF 5175 ±â€¯4345 before and 2311 ±â€¯2308 after ARNI (p < 0.001, -55%). Cost reduction increased with the number of indexed hospitalization per year before ARNI from 11% to 66%. CONCLUSION: In a real world scenario, treatment with ARNI is associated with lower indexed rates of hospitalizations and hospitalization related costs. Cost reduction increases with at least one indexed hospitalization for heart failure before treatment with ARNI.

Endothelin-receptor antagonists in the management of pulmonary arterial hypertension: where do we stand?

Pulmonary arterial hypertension, a disease largely neglected until a few decades ago, is presently the object of intense studies by several research teams. Despite considerable progress, pulmonary arterial hypertension remains a major clinical problem, because it is not always easy to diagnose, treat, and prevent. The disease was considered incurable until the late 1990s, when Epoprostenol was introduced as the first tool against this illness. More recently, therapy for pulmonary arterial hypertension gained momentum after publication of the SERAPHIN and AMBITION trials, which also highlighted the importance of upfront therapy. This review also focuses on recent substudies from these trials and progress in drugs targeting the endothelin pathway. Future perspectives with regard to endothelin-receptor antagonists are also discussed.