Competing interactions in arrested states of colloidal clays

Using experiments, theory and simulations, we show that the arrested state observed in a colloidal clay at intermediate concentrations is stabilized by the screened Coulomb repulsion (Wigner glass). Dilution experiments allow us to distinguish this high-concentration disconnected state, which melts upon addition of water, from a low-concentration gel state, which does not melt. Theoretical modelling and simulations reproduce the measured Small Angle X-Ray Scattering static structure factors and confirm the long-range electrostatic nature of the arrested structure. These findings are attributed to the different timescales controlling the competing attractive and repulsive interactions.Comment: Accepted for publication in Physical Review Letter

Arrested state of clay-water suspensions: gel or glass?

The aging of a charged colloidal system has been studied by Small Angle X-rays Scattering, in the exchanged momentum range Q=0.03 - 5 nm-1, and by Dynamic Light Scattering, at different clay concentrations (Cw =0.6 % - 2.8 %). The static structure factor, S(Q), has been determined as a function of both aging time and concentration. This is the first direct experimental evidence of the existence and evolution with aging time of two different arrested states in a single system simply obtained only by changing its volume fraction: an inhomogeneous state is reached at low concentrations, while a homogenous one is found at high concentrations.Comment: 5 pages, 2 figure

Variação genética em progênies de segunda geração de Araucaria angustifolia Bert. O. Ktze.

Resumo

Juvenile diabetes and systemic sclerosis: just a coincidence?

Background: Limited joint mobility (LJM), previously known as cheiroarthropathy, refers to the presence of reduced extension at the finger joints in people with diabetes and may be associated with scleroderma-like syndromes such as diabetic sclerodactyly. While scleroderma-like syndromes and LJM have been observed in patients with long-term diabetes and associated complications, the coexistence of diabetes with Juvenile systemic sclerosis (jSSc) is rarely described. Case presentation: We describe the case of a 14-year-old boy with long-lasting type 1 diabetes (T1D) and suspected LJM associated with Raynaud phenomenon, sclerodactyly and tapering of the fingertips. A comprehensive work-up showed positive autoantibodies (ANA, anti-Ro-52, anti-Mi-2b), abnormal nailfold capillaroscopy with a scleroderma pattern, interstitial lung disease and cardiac involvement. The overall clinical picture was consistent with the diagnosis of jSSc. Conclusions: LJM can be the initial sign of underlying systemic sclerosis. Nailfold capillaroscopy may help differentiate jSSc from classical LJM in pediatric patients with T1D and finger contractures or skin induration of no clear origin. This case report provides a starting point for a novel hypothesis regarding the pathogenesis of jSSc. The association between T1D and jSSc may be more than a coincidence and could suggest a relationship between glucose metabolism, fibrosis and microangiopathy

Adopting a cross-scale approach for the deployment of a green infrastructure

The implementation of a Green Infrastructure (GI) involves several actors and governance scales that need adequate knowledge support. The multifunctionality of GI entails the implementation of a cross-scale approach, which combines assessments conducted at different levels and active stakeholder engagement. This paper provides a methodology to implement a cross-scale approach to support the deployment of a Regional GI. The methodology was tested in Lombardy Region (north-west of Italy), considering three relevant territorial scales and relative strategic and planning policies. The continental level representing the overall policy-context; the regional level, with its key role for guaranteeing landscape coherence and connectivity and the local level where planning actions are effectively designed and implemented. The EU Biodiversity Strategy for 2030 and the EU GI strategy were used as references for the continental level; at the regional level, a proposal of Regional GI was evaluated focusing on two Provinces (Varese and Lecco), three regional parks (Ticino, Adda Nord and Campo dei Fiori). At the local scale, the new development plan of the Municipality of Cassano d'Adda (Milan metropolitan area) was evaluated considering different possible scenarios. The regional GI was evaluated with respect to the capacity to provide Cultural Ecosystem Services (CES). CES were mapped using the ESTIMAP-recreation model. The model was adapted to the regional and local level with the active engagement of local stakeholders. Additionally, census data were analysed to obtain an overview of the equitable distribution of the CES amongst inhabitants. Results show that, in 78% of the census blocks of the study area, inhabitants have a high-value recreation resource within 4 km (31% within 4 km and 47% within 300 m). Unmet demand characterises 22% of the census blocks in the study area, clustered in zones with a high population density. The regional GI covers almost completely the two Provinces and the regional parks. In Varese Province: 68% of the territory is included in the regional GI, 82% of the census blocks local demand for recreation opportunities is met, but the population density is higher where the demand is unmet. The Province is characterised by a relatively old population (share of people older than 65 years 23.4%). In Lecco Province, 80% of the territory is included in the regional GI, in 96% of the blocks the local demand is met and the local population is relatively old (share of elderly population 22.12%). The three regional parks present significant differences, strongly influenced by the territorial context. The Campo dei Fiori Park is almost completely included in the regional GI. The entire local population has nature-based recreation opportunities in their close vicinity. Nevertheless, the population density is very low and citizens are relatively old. The majority of the Parco Adda Nord is included in the regional GI providing recreation opportunities to 90% of the census blocks within the Park boundaries. A total of 70% of Ticino Park is included in the regional GI, where local residents are relatively old (share of elderly population 23.78%) and 90% of local census blocks are close to nature-based opportunities. At local scale, we explored how the approach can be used to estimate changes in the CES potential provision and how this can be integrated into a site management plan. This paper demonstrated that the combination of studies in a cross-scale perspective enhances the understanding of GI multifunctionality. It provides a framework to adapt CES mapping models to the local setting with active stakeholders engagement. Moreover, it demonstrates that also highly urbanised areas, such as the Lombardy Region in Italy, can play a role in the deployment of a continental GI and can support biodiversity and nature protection

Strategic use of levofolinic acid for methotrexate-induced side effects in juvenile idiopathic arthritis: a prospective observational study

Objective: To evaluate the efficacy of levofolinic acid (LVF) administered 48 h before methotrexate (MTX) in reducing gastrointestinal side effects without interference with drug efficacy. Methods: A prospective observational study was performed including patients with Juvenile Idiopathic Arthritis (JIA) reporting significant gastrointestinal discomfort after MTX despite taking a dose of LVF 48 h after MTX. Patients with anticipatory symptoms were excluded. A LVF supplemental dose was added 48 h before MTX and patients were followed every 3–4 months. At each visit data on gastrointestinal symptoms, disease activity (JADAS, ESR, CRP values) and treatment changes were collected. Friedman test for repeated measures analyzed differences between these variables over time. Results: Twenty-one patients were recruited and followed for at least 12 months. All patients received MTX subcutaneously (mean 9.54 mg/m2) and LVF 48 h before and after MTX (mean 6.5 mg/dose), 7 received a biological agent too. Complete remission of gastrointestinal side effects was reported in 61.9% of study patients at first visit (T1) and increased over time (85.7%, 95.2%, 85.7% and 100% at T2, T3, T4, T5, respectively). MTX efficacy was maintained as showed by significant reduction of JADAS and CRP (p = 0.006 and 0.008) from T1 to T4 and it was withdrawn for remission in 7/21. Conclusions: LVF given 48 h before MTX significantly reduced gastrointestinal side effects and did not reduce drug’s efficacy. Our results suggest that this strategy may improve compliance and quality of life in patients with JIA and other rheumatic diseases treated with MTX

Mycophenolate mofetil for methotrexate-resistant juvenile localized scleroderma

Objectives: To investigate safety and efficacy of MMF in patients with severe or MTX-refractory juvenile localized scleroderma. Methods: Consecutive juvenile localized scleroderma patients undergoing systemic treatment were included in a retrospective longitudinal study. Patients treated with MMF because they were refractory or intolerant to MTX (MMF-group) were compared with responders to MTX (MTX-group). Disease activity was assessed by Localized Scleroderma Cutaneous Assessment Tool and thermography. Disease course was established on the number of relapses and treatment changes. Relapse-free survival was examined by Kaplan-Meier analysis. Results: MMF and MTX groups included 22 and 47 patients, respectively. No significant difference in demographics, follow-up duration and treatment before diagnosis was observed between groups. The most represented clinical subtypes in the MMF-group were pansclerotic morphea and mixed subtype (P = 0.008 and P = 0.029, respectively), and linear scleroderma of the face in the MTX-group (P = 0.048). MMF was started because of MTX resistance (18 patients), relapse during MTX tapering/withdrawal (3 patients) and anaphylaxis to MTX (1 patient). After mean 9.4 years of follow-up, 90.9% of patients on MMF and 100% of those on MTX had inactive disease. No significant difference in relapse-free survival between the groups was found (P = 0.066, log-rank test), although MMF likely induced more persistent remission. MMF was well tolerated and combination of MMF and MTX did not increase its efficacy. Conclusion: The present study adds strong evidence on the efficacy and tolerance of MMF in severe and/or MTX-refractory juvenile localized scleroderma. Further controlled studies are needed to prove its efficacy as first line treatment

Early detection of ventricular dysfunction in juvenile systemic sclerosis by speckle tracking echocardiography

Objective: Cardiac involvement is the most important cause of mortality in juvenile systemic sclerosis (JSSc). Recent reports in adult patients underline that traditional techniques of imaging are inadequate to assess the subclinical cardiac involvement, while speckle tracking echocardiography (STE) is able to identify ventricular dysfunctions in the early stages. The aim of our study was to assess the role of STE in JSSc. Methods: Demographic, clinical and laboratory data were collected from patients with JSSc. Cardiac investigations performed at baseline (T0) and 18 (T18) and 36 months (T36) follow-up included electrocardiography, conventional echocardiography with measurement of the ejection fraction (EF) and STE with assessment of left and right ventricular global longitudinal strain (LV-GLS and RV-GLS). Cardiac parameters have been compared with demographic characteristics and disease severity, assessed by the Juvenile Systemic Sclerosis Severity Score (J4S). Results: A total of 18 patients, 12 (67%) females, entered the study. At T0, electrocardiography was abnormal in three patients, EF was reduced in one, LV-GLS was abnormal in three (16.7%) and RV-GLS was abnormal in five (27.8%). At T18, EF remained stable while at T36 the result decreased in seven of nine patients. At the same time, LV-GLS also worsened (from -21.6% to -18.2%, P = 0.01). LV-GLS and RV-GLS at baseline showed a significant correlation with J4S (P = 0.012 and P = 0.02, respectively). Conclusion: STE is more sensitive than standard echocardiography to identify cardiac involvement in JSSc. Over time, we observed a gradual worsening of LV-GLS, a sign of left ventricular dysfunction, that anticipated by several months the decrease of EF