Interplay between disorder and intersubband collective excitations in the two-dimensional electron gas

Intersubband absorption in modulation-doped quantum wells is usually appropriately described as a collective excitation of the confined two-dimensional electron gas. At sufficiently low electron density and low temperatures, however, the in-plane disorder potential is able to damp the collective modes by mixing the intersubband charge-density excitation with single-particle localized modes. Here we show experimental evidence of this transition. The results are analyzed within the framework of the density functional theory and highlight the impact of the interplay between disorder and the collective response of the two-dimensional electron gas in semiconductor heterostructures.Comment: 5 pages, 4 figures, RevTeX. Accepted for publication in Phys. Rev. B (Rapid. Comm.

Governance and banking system morphology in China: the evolution over the last two decades (1995-2015)

Over the past two decades in the Chinese banking system substantial progress has been made, and reforms have been mainly aimed at improving its governance and efficiency, but many governance problems still exist and hinder a complete transition to a market economy. Through the analysis of the economic freedom and the global governance indicators, in the context of a comparative analysis with European and North American countries, this paper shows that, despite a considerable economic growth, economic and financial reforms, Chinese governance variables are likely to have a second order effect in comparison with fundamental economic variables in favouring (or not) Chinese growth. However the high rate of growth, over the years of the financial turmoil as well, may have paradoxically prevented the improvement of governance indexes, meanwhile financial sector and global governance issues will have to be improved in order to promote efficient financial intermediation and sustainable growth in China

Psychiatric Emergency in Children and Adolescents: A Retrospective Study in Parma Local Health Unit

The mental health care system in Italy is based on Law 180/70 which leaves great regional autonomy about the management of adolescent patients suffering from psychiatric diseases. The aim of this study is the evaluation of demographic, social, and clinical features of minors admitted to psychiatric wards, as starting point to improve individualized services for them. Data about all under 18s consecutively admitted to Parma’s psychiatric wards from 2013 to 2015 were retrospectively collected from medical records. Diagnoses were classified according to ICD-10 criteria, and statistical analysis was performed using SPSS statistical software (IBM SPSS Statistics 22.0) for Windows. Clinical samples include 51 cases, 30 males (mean age: 15.5 years, ranging from 12 to 17 years) and 21 females (mean age: 15.9, ranging from 14 to 17 years). The most frequent diagnosis is conduct disorder (39.2%), with higher prevalence among males. Following this, 23.5% of the patients present comorbidity issues and 9.8% suffer from personality disorders, which is more frequent among females. High percentages of foreigners (31.4%), adopted minors (15.7%), and drug users (40%) are reported. Furthermore, data reveal that unprotective family environment, registered in 80.4% of cases, plays an important role as risk factor for the development of mental disease, readmissions in psychiatric wards, and discharge to residential facilities. Readmissions, as well as compulsory treatments (11 cases), are mainly required in case of conduct disorders and comorbidity diagnosis. Lastly, in contrast with the situation before hospital admission, most patients (63.3%) are discharged and sent to community residential facilities. Findings can be useful to improve the management of psychiatric emergencies in minors, focusing on their specific needs, such as conduct disorders and substance abuse, and to face emerging challenges, for example, mental health disease associated with the growing phenomenon of immigration

Pharmaceutical approaches to normal tension glaucoma

Normal tension glaucoma (NTG) is defined as a subtype of primary open-angle glaucoma (POAG) in which the intraocular pressure (IOP) values are constantly within the statistically normal range without treatment and represents approximately the 30-40% of all glaucomatous cases. The pathophysiology of this condition is multifactorial and is still not completely well known. Several theories have been proposed to explain the onset and progression of this disease, which can be divided into IOP-dependent and IOP-independent factors, suggesting different therapeutic strategies. The current literature strongly supports the fundamental role of IOP in NTG. The gold standard treatment for NTG tends to be based on the lowering IOP even if "statistically normal". Numerous studies have shown, however, that the IOP reduction alone is not enough to slow down or stop the disease progression in all cases, suggesting that other IOP-independent risk factors may contribute to the NTG pathogenesis. In addition to IOP-lowering strategies, several different therapeutic approaches for NTG have been proposed, based on vaso-active, antioxidant, anti-inflammatory and/or neuroprotective substances. To date, unfortunately, there are no standardized or proven treatment alternatives for NTG when compared to traditional IOP reduction treatment regimes. The efficacy of the IOP-independent strategies in decreasing the risk or treating NTG still remains inconclusive. The aim of this review is to highlight strategies reported in the current literature to treat NTG. The paper also describes the challenges in finding appropriate and pertinent treatments for this potentially vision-threatening disease. Further comprehension of NTG pathophysiology can help clinicians determine when to use IOP-lowering treatments alone and when to consider additional or alternatively individualized therapies focused on particular risk factors, on a case-by-case basis

A lithium-ion battery based on a graphene nanoflakes ink anode and a lithium iron phosphate cathode

Li-ion rechargeable batteries have enabled the wireless revolution transforming global communication. Future challenges, however, demands distributed energy supply at a level that is not feasible with the current energy-storage technology. New materials, capable of providing higher energy density are needed. Here we report a new class of lithium-ion batteries based on a graphene ink anode and a lithium iron phosphate cathode. By carefully balancing the cell composition and suppressing the initial irreversible capacity of the anode, we demonstrate an optimal battery performance in terms of specific capacity, i.e. 165 mAhg-1, estimated energy density of about 190 Whkg-1 and life, with a stable operation for over 80 charge-discharge cycles. We link these unique properties to the graphene nanoflake anode displaying crystalline order and high uptake of lithium at the edges, as well as to its structural and morphological optimization in relation to the overall battery composition. Our approach, compatible with any printing technologies, is cheap and scalable and opens up new opportunities for the development of high-capacity Li-ion batteries.Comment: 17 pages, 10 figure

Circular Economy Approach: The benefits of a new business model for European Firms

This study investigates the relationship between Firms’ Performance and the adoption of a Circular Economy (CE) Approach. Considering different “recovery-recycling” models embraced by European countries between 2003 and 2016, the empirical analysis aims to highlight benefits related to CE approach. Specifically, we built a sample of panel data, which involved 60 European listed companies producing several types of packaging (including plastic, glass, cardboard and metal), and raw materials (glass and paper). Over the last decades, the increasing attention to Circular Economy issues in Europe has been followed by an important regulation’s activity aimed to define a common policy on the production and treatment of waste. However, European countries due to their different economic conditions, experienced more or less effectively benefits of CE models which are still under-explored. Our empirical findings confirm previous economic literature (Ferreira N. et al. 2014; CIWM, 2016), pointing out better Perfomances for European companies adopting “Extended Producer Responsability” (ERP) scheme, such as PRO's Competition model. Empirical evidences suggested a positive and highly significant impact on Firms’ Performance as results of more competition among recovery organizations which can be justified by lower costs for companies joining collective recovery schemes