4,654 research outputs found

    Liquid crystal anchoring transitions on aligning substrates processed by plasma beam

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    We observe a sequence of the anchoring transitions in nematic liquid crystals (NLC) sandwiched between the hydrophobic polyimide substrates treated with the plasma beam. There is a pronounced continuous transition from homeotropic to low tilted (nearly planar) alignment with the easy axis parallel to the incidence plane of the plasma beam (the zenithal transition) that takes place as the exposure dose increases. In NLC with positive dielectric anisotropy, a further increase in the exposure dose results in in-plane reorientation of the easy axis by 90 degrees (the azimuthal transition). This transition occurs through the two-fold degenerated alignment characteristic for the second order anchoring transitions. In contrast to critical behavior of anchoring, the contact angle of NLC and water on the treated substrates monotonically declines with the exposure dose. It follows that the surface concentration of hydrophobic chains decreases continuously. The anchoring transitions under consideration are qualitatively interpreted by using a simple phenomenological model of competing easy axes which is studied by analyzing anchoring diagrams of the generalized polar and non-polar anchoring models.Comment: revtex4, 18 pages, 10 figure

    “Plans for the Removal of Architectural Barriers (PEBAs) from a UD Perspective. An Interdisciplinary Process in the Italian Region Friuli Venezia Giulia”

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    It is more than thirty years since the Italian Law introduced the Plans for the Removal of Architectural Barriers (PEBAs). However, their implementation by municipalities is still limited, and accessibility is often understood as the result of the elimination of single physical obstacles, rather than the development of interconnected systems of urban spaces and collective equipment that are usable and inclusive according to Universal Design (UD) criteria. Since 2018, the Italian Friuli Venezia Giulia Autonomous Region has started a collaboration with the Universities of Trieste and Udine, in order to bring UD at the core of the implementation of the Regional Law no. 10/2018. This Law introduced significant innovations: the disposal of regional funds to support local administrations when drafting PEBAs; the delivery of a software application to facilitate the drawing of these plans; the establishment of a reference center in charge of training, information and consultancy activities on accessibility at a regional level (CRIBA); the delivery of a regional observatory for mapping and continuous monitoring of accessibility conditions and the implementation of PEBAs. The paper presents: i) an overview of the interdisciplinary work carried out by the Universities with the Region and CRIBA; ii) a focus on Universities’ research activities and the current state of the collaboration process; iii) reflections on further research and its operational outcomes

    Managment of diabetic ketoacidosis in children and adolescents in sub-Saharan Africa: A review

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    Background: Diabetic ketoacidosis (DKA) is a complex metabolic state of hyperglycaemia, ketosis, and acidosis. Diabetes in sub-Saharan Africa is, in many patients a serious disease with a poor prognosis. Most deaths, however, are due to preventable causes.Objective: To improve knowledge on the management of DKA in sub-Saharan Africa.Data sources: Literature review from different published sources. Data synthesis: Health systems in sub-Saharan Africa are currently organised for the treatment of episodes of illness and not long-term conditions like diabetes. Therefore the high rates of DKA is essentially due to lack of training of health professionals, lack of facilities in most hospitals, lack of public awareness as well as lack of health education to individual patients/families. In addition erratic insulin supply coupling with infections, low parental education, poor insulin storage and lack of facilities for self monitoring of blood glucose.Conclusion: A complex unfavourable social and economic environment is the basis of the high prevalence of DKA in sub-Saharan Africa. Several episodes of DKA can be prevented by effective public awareness programmes and education to healthcare providers

    Looking back and beyond the 2017 diagnostic criteria for hypermobile Ehlers-Danlos syndrome: A retrospective cross-sectional study from an Italian reference center

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    The most common conditions with symptomatic joint hypermobility are hypermobile Ehlers-Danlos syndrome (hEDS) and hypermobility spectrum disorders (HSD). Diagnosing these overlapping connective tissue disorders remains challenging due to the lack of established causes and reliable diagnostic tests. hEDS is diagnosed applying the 2017 diagnostic criteria, and patients with symptomatic joint hypermobility but not fulfilling these criteria are labeled as HSD, which is not officially recognized by all healthcare systems. The 2017 criteria were introduced to improve diagnostic specificity but have faced criticism for being too stringent and failing to adequately capture the multisystemic involvement of hEDS. Herein, we retrospectively evaluated 327 patients from 213 families with a prior diagnosis of hypermobility type EDS or joint hypermobility syndrome based on Villefranche and Brighton criteria, to assess the effectiveness of the 2017 criteria in distinguishing between hEDS and HSD and document the frequencies of extra-articular manifestations. Based on our findings, we propose that the 2017 criteria should be made less stringent to include a greater number of patients who are currently encompassed within the HSD category. This will lead to improved diagnostic accuracy and enhanced patient care by properly capturing the diverse range of symptoms and manifestations present within the hEDS/HSD spectrum

    Deciphering disease signatures and molecular targets in vascular Ehlers-Danlos syndrome through transcriptome and miRNome sequencing of dermal fibroblasts

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    Vascular Ehlers-Danlos syndrome (vEDS) is a severe connective tissue disorder caused by dominant mutations in the COL3A1 gene encoding type III collagen (COLLIII). COLLIII is primarily found in blood vessels and hollow organs, and its deficiency leads to soft connective tissues fragility, resulting in life-threatening arterial and organ ruptures. There are no current targeted therapies available. Although the disease usually results from COLLIII misfolding due to triple helix structure disruption, the underlying pathomechanisms are largely unknown. To address this knowledge gap, we performed a comprehensive transcriptome analysis using RNA- and miRNA-seq on a large cohort of dermal fibroblasts from vEDS patients and healthy donors. Our investigation revealed an intricate interplay between proteostasis abnormalities, inefficient endoplasmic reticulum stress response, and compromised autophagy, which may significantly impact the molecular pathology. We also present the first detailed miRNAs expression profile in patient cells, demonstrating that several aberrantly expressed miRNAs can disrupt critical cellular functions involved in vEDS pathophysiology, such as autophagy, proteostasis, and mTOR signaling. Target prediction and regulatory networks analyses suggested potential interactions among miRNAs, lncRNAs, and candidate target genes linked to extracellular matrix organization and autophagy-lysosome pathway. Our results highlight the importance of understanding the functional role of ncRNAs in vEDS pathogenesis, shedding light on possible miRNAs and lncRNAs signatures and their functional implications for dysregulated pathways related to disease. Deciphering this complex molecular network of RNA interactions may yield additional evidence for potential disease biomolecules and targets, assisting in the design of effective patient treatment strategies

    One-hour post-load plasma glucose levels associated with decreased insulin sensitivity and secretion and early makers of cardiometabolic risk.

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    PURPOSE: Obese adults with normal glucose tolerance (NGT) but with 1-hour post-load plasma glucose (1hPG) ≥ 155 mg/dl are at higher risk of developing type 2 diabetes (T2D) and cardiometabolic complications. Little information is available for the pediatric population, where recently, a lower cutoff, 132.5 mg/dl, has been suggested as being more sensitive to identify subjects at risk of T2D. Our aim was to assess whether obese Caucasian youth with 1hPG ≥ 132.5 mg/dl have worse insulin sensitivity and secretion and a worse cardiometabolic profile compared to obese youth with 1hPG < 132.5 mg/dl. METHODS: Medical records of 244 (43% male; age: 11.1 ± 2.7years) overweight/obese children and adolescents, who had undergone an oral glucose tolerance test (OGTT), were retrieved. Anthropometric and biochemical data were collected from the hard copy archive. Indexes of insulin resistance (HOMA-IR), insulin sensitivity (WBISI), and insulin secretion (Insulinogenic Index, Disposition Index) were calculated. RESULTS: Of the 244 records analyzed, 215 fulfilled criteria for NGT and had complete biochemical data. Among NGT patients, 42 (19.5%) showed 1hPG ≥ 132.5 mg/dL (high-NGT), while the remaining had 1hPG < 132.5 mg/dL (low-NGT). The high-NGT group showed a higher male prevalence (59.5 vs 37%), lower Disposition Index (0.54 [0.39-0.71] vs 0.79 [0.47-1.43]), and WBISI (0.24 [0.18-0.35] vs 0.33 [0.23-0.50]) than the low-NGT group. High-NGT subjects also showed a trend towards lower HDL-cholesterol and higher triglycerides/HDL-cholesterol ratio (2.13 [1.49-3.41] vs 1.66 [1.24-2.49]). CONCLUSIONS: In overweight/obese NGT Caucasian youth a 1hPG ≥ 132.5 mg/dL was able to identify those with impaired insulin sensitivity and secretion and a trend towards a worse cardio-metabolic profile, a group likely at risk for future T2D

    Toxicity induced by Gadolinium ions on sea urchin embryos: comparison among phylogenetically distant species and focus on stress response and skeletogenesis.

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    Pharmaceuticals are a class of emerging environmental contaminants. Gadolinium (Gd) is a lanthanide metal whose chelates are employed as contrast agents for magnetic resonance imaging, and subsequently released into the aquatic environment. We investigated the effects of exposure to sublethal Gd concentrations on the development of four phylogenetically and geographically distant sea urchin species: two Mediterranean, Paracentrotus lividus and Arbacia lixula, and two from Australia, Heliocidaris tuberculata and Centrostephanus rodgersii. Sensitivity to Gd greatly varied, with EC50 ranging from 56 nM to 132 µM across the four species. Measures of the Gd and Ca content inside embryos showed a time- and dose-dependent increase in Gd, in parallel with a reduction in Ca. In all the four species, we observed a general delay of embryo development at 24h post-fertilization, and a strong inhibition of skeleton growth at 48h. Further experiments were carried out on P. lividus embryos: RT-PCR gene expression analysis showed the misregulation of several genes implicated both in the skeletogenic and the left-right axis specification networks. WB analysis showed an increase of the LC3 autophagic marker at 24 and 48h. Confocal microscopy studies confirmed the increased number of autophagosomes and autophagolysosomes and showed no apoptotic induction. The results show the hazard of Gd in the marine environment, indicating that Gd is able to affect three different levels in sea urchin embryos: morphogenesis, stress response such as autophagy, and gene expression. Results highlight that pollution assays based on only one species can be misleading with respect to hazard risk assessment

    In Vitro Cytotoxic Effect of Aqueous Extracts from Leaves and Rhizomes of the Seagrass Posidonia oceanica (L.) Delile on HepG2 Liver Cancer Cells: Focus on Autophagy and Apoptosis

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    Aqueous extracts from Posidonia oceanica’s green and brown (beached) leaves and rhizomes were prepared, submitted to phenolic compound and proteomic analysis, and examined for their potential cytotoxic effect on HepG2 liver cancer cells in culture. The chosen endpoints related to survival and death were cell viability and locomotory behavior, cell-cycle analysis, apoptosis and autophagy, mitochondrial membrane polarization, and cell redox state. Here, we show that 24 h exposure to both green-leaf- and rhizome-derived extracts decreased tumor cell number in a dose– response manner, with a mean half maximal inhibitory concentration (IC50) estimated at 83 and 11.5 µg of dry extract/mL, respectively. Exposure to the IC50 of the extracts appeared to inhibit cell motility and long-term cell replicating capacity, with a more pronounced effect exerted by the rhizomederived preparation. The underlying death-promoting mechanisms identified involved the downregulation of autophagy, the onset of apoptosis, the decrease in the generation of reactive oxygen species, and the dissipation of mitochondrial transmembrane potential, although, at the molecular level, the two extracts appeared to elicit partially differentiating effects, conceivably due to their diverse composition. In conclusion, P. oceanica extracts merit further investigation to develop novel promising prevention and/or treatment agents, as well as beneficial supplements for the formulation of functional foods and food-packaging material with antioxidant and anticancer propertie

    Rv0579 Is Involved in the Resistance to the TP053 Antitubercular Prodrug

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    Tuberculosis remains one of the leading causes of death from a single pathogen globally. It is estimated that 1/4 of the world’s population harbors latent tuberculosis, but only a 5–10% of patients will develop active disease. During latent infection, Mycobacterium tuberculosis can persist unaffected by drugs for years in a non-replicating state with low metabolic activity. The rate of the successful tuberculosis treatment is curbed by the presence of these non-replicating bacilli that can resuscitate after decades and also by the spread of M. tuberculosis drug-resistant strains. International agencies, including the World Health Organization, urge the international community to combat this global health emergency. The thienopyrimidine TP053 is a promising new antitubercular lead compound highly active against both replicating and non-replicating M. tuberculosis cells, with an in vitro MIC of 0.125 mg/ml. TP053 is a prodrug activated by the reduced form of the mycothiol-dependent reductase Mrx2, encoded by Rv2466c gene. After its activation, TP053 releases nitric oxide and a highly reactive metabolite, explaining its activity also against M. tuberculosis non-replicating cells. In this work, a new mechanism of TP053 resistance was discovered. M. tuberculosis spontaneous mutants resistant to TP053 were isolated harboring the mutation L240V in Rv0579, a protein with unknown function, but without mutation in Rv2466c gene. Recombineering method demonstrated that this mutation is linked to TP053 resistance. To better characterize Rv0579, the protein was recombinantly produced in Escherichia coli and a direct interaction between the Mrx2 activated TP053 and Rv0579 was shown by an innovative target-fishing experiment based on click chemistry. Thanks to achieved results, a possible contribution of Rv0579 in M. tuberculosis RNA metabolism was hypothesized, linked to toxin antitoxin system. Overall, these data confirm the role of Rv0579 in TP053 resistance and consequently in the metabolism of this prodrug
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