DNA wrapping around MWNTs and graphene: a SERS study

In recent years, carbon nanostructure as nanotubes (CNTs) and graphene are at the centre of a significant research effort due to the strong scientific and technological interest because of their unique physical and chemical properties: large surface area, excellent thermal and electric conductivity, high electron transfer kinetics and strong mechanical strength. Recently, a great attention has been paid to the interaction of DNA with carbon-based nanostructures such as C60, multiwalled-nanotubes (MWNTs), single-walled nanotubes (SWNTs) and graphene. The development of these studies is motivated by a wide spectrum of possible use of these materials e.g. as biosensors, drug delivery agents and diagnosis tools. In this work, we applied surface-enhanced Raman spectroscopy (SERS) to the study of DNA/MWNTs and DNA/graphene systems

Prevalence of functional dyspepsia and its subgroups in patients with eating disorders

AIM: To study the prevalence of functional dyspepsia (FD) (Rome III criteria) across eating disorders (ED), obese patients, constitutional thinner and healthy volunteers. METHODS: Twenty patients affected by anorexia nervosa, 6 affected by bulimia nervosa, 10 affected by ED not otherwise specified according to diagnostic and statistical manual of mental disorders, 4th edition, nine constitutional thinner subjects and, thirty-two obese patients were recruited from an outpatients clinic devoted to eating behavior disorders. Twenty-two healthy volunteers matched for age and gender were enrolled as healthy controls. All participants underwent a careful clinical examination. Demographic and anthropometric characteristics were obtained from a structured questionnaires. The presence of FD and, its subgroups, epigastric pain syndrome and postprandial distress syndrome (PDS) were diagnosed according to Rome III criteria. The intensity-frequency score of broader dyspeptic symptoms such as early satiety, epigastric fullness, epigastric pain, epigastric burning, epigastric pressure, belching, nausea and vomiting were studied by a standardized questionnaire (0-6). Analysis of variance and post-hoc Sheffè tests were used for comparisons. RESULTS: 90% of patients affected by anorexia nervosa, 83.3% of patients affected by bulimia nervosa, 90% of patients affected by ED not otherwise specified, 55.6% of constitutionally thin subjects and 18.2% healthy volunteers met the Postprandial Distress Syndrome Criteria (χ2, P < 0.001). Only one bulimic patient met the epigastric pain syndrome diagnosis. Postprandial fullness intensity-frequency score was significantly higher in anorexia nervosa, bulimia nervosa and ED not otherwise specified groups compared to the score calculated in the constitutional thinner group (4.15 ± 2.08 vs 1.44 ± 2.35, P = 0.003; 5.00 ± 2.45 vs 1.44 ± 2.35, P = 0.003; 4.10 ± 2.23 vs 1.44 ± 2.35, P = 0.002, respectively), the obese group (4.15 ± 2.08 vs 0.00 ± 0.00, P < 0.001; 5.00 ± 2.45 vs 0.00 ± 0.00, P < 0.001; 4.10 ± 2.23 vs 0.00 ± 0.00, P < 0.001, respectively) and healthy volunteers (4.15 ± 2.08 vs 0.36 ± 0.79, P < 0.001; 5.00 ± 2.45 vs 0.36 ± 0.79, P < 0.001; 4.10 ± 2.23 vs 0.36 ± 0.79, P < 0.001, respectively). Early satiety intensity-frequency score was prominent in anorectic patients compared to bulimic patients (3.85 ± 2.23 vs 1.17 ± 1.83, P = 0.015), obese patients (3.85 ± 2.23 vs 0.00 ± 0.00, P < 0.001) and healthy volunteers (3.85 ± 2.23 vs 0.05 ± 0.21, P < 0.001). Nausea and epigastric pressure were increased in bulimic and ED not otherwise specified patients. Specifically, nausea intensity-frequency-score was significantly higher in bulimia nervosa and ED not otherwise specified patients compared to anorectic patients (3.17 ± 2.56 vs 0.89 ± 1.66, P = 0.04; 2.70 ± 2.91 vs 0.89 ± 1.66, P = 0.05, respectively), constitutional thinner subjects (3.17 ± 2.56 vs 0.00 ± 0.00, P = 0.004; 2.70 ± 2.91 vs 0.00 ± 0.00, P = 0.005, respectively), obese patients (3.17 ± 2.56 vs 0.00 ± 0.00, P < 0.001; 3.17 ± 2.56 vs 0.00 ± 0.00, P < 0.001 respectively) and, healthy volunteers (3.17 ± 2.56 vs 0.17 ± 0.71, P = 0.002; 3.17 ± 2.56 vs 0.17 ± 0.71, P = 0.001, respectively). Epigastric pressure intensity-frequency score was significantly higher in bulimic and ED not otherwise specified patients compared to constitutional thin subjects (4.67 ± 2.42 vs 1.22 ± 1.72, P = 0.03; 4.20 ± 2.21 vs 1.22 ± 1.72, P = 0.03, respectively), obese patients (4.67 ± 2.42 vs 0.75 ± 1.32, P = 0.001; 4.20 ± 2.21 vs 0.75 ± 1.32, P < 0.001, respectively) and, healthy volunteers (4.67 ± 2.42 vs 0.67 ± 1.46, P = 0.001; 4.20 ± 2.21 vs 0.67 ± 1.46, P = 0.001, respectively). Vomiting was referred in 100% of bulimia nervosa patients, in 20% of ED not otherwise specified patients, in 15% of anorexia nervosa patients, in 22% of constitutional thinner subjects, and, in 5.6% healthy volunteers (χ2, P < 0.001). CONCLUSION: PDS is common in eating disorders. Is it mandatory in outpatient gastroenterological clinics to investigate eating disorders in patients with PDS

RIFT process analysis for the production of green composites in flax fibers and bio-based epoxy resin

In this work, a dual objective is carried out on composite materials in flax fiber and bio-based epoxy resin: to determine the process parameters and to develop a numerical model for highlighting the potential of and the limits in the production of “green” laminates through a RIFT process (Resin Infusion under Flexible Tool). For these reasons, compressibility tests were performed in order to evaluate the behavior of commercial flax woven under the vacuum bag. Subsequently, permeability tests were performed in order to evaluate the permeability curves necessary for the numerical study of the infusion process. For the numerical analyses, the commercial software PAM-RTM was adopted and validated. In this work, vaseline oil was used as the injected resin for the validation, and a bio-based epoxy commercial system was used for the study of the infusion process in a simple case study. The results were compared with a petroleum-based epoxy system typically used for infusion processes, showing the potentiality and the critical use of bio-based resins for infusion processes

Manufacturing and characterization of regenerated cellulose/curcumin based sustainable composites fibers spun from environmentally benign solvents

We report a novel manufacturing method for bio renewable regenerated cellulose fibres modified with curcumin, a molecule is known for its medicinal properties. Ionic liquid namely 1-Ethyl 3-Methyl Imidazolium diethyl phosphate (emim DEP) was found to be capable of dissolving cellulose as well as curcumin. Regenerated cellulose/curcumin composites fibres with curcumin concentration ranging from 1 to 10 wt% were manufactured using dry jet wet fibres spinning process using three different winding speeds. All the cellulose and curcumin composite fibres showed distinct yellow colour imparted by curcumin. The resultant fibres were characterised using scanning electron microscopy (SEM), infrared spectroscopy, mechanical testing, and X-Ray diffraction studies. Scanning electron microscopy of cellulose/curcumin fibres cross-section did not show curcumin aggregates in cellulose fibres indicating uniform dispersion of curcumin in cellulose matrix. The cellulose chain alignment in cellulose/curcumin composite fibres resulted in tensile strength ranging from 223 to 336 MPa and Young’s modulus ranging from 13 to 14.9 GPa. The mechanical properties of cellulose/curcumin composite fibres thus obtained are better than some of the commercially available regenerated cellulose viscose fibres. The wide-angle X-ray diffraction analysis of cellulose/curcumin composite fibres showed good alignment of cellulose chains along the fibre axis. Thus, our findings are a major step in manufacturing strong cellulose fibres with a pharmacologically potent drug curcumin which in future could be used for medicinal, cosmetic and food packaging applications

A study of asymmetric tensile properties of large area GEM foil

Gas Electron Multiplier (GEM) technology is being used in various applications, particularly in high energy physics experiments. The GEM is known as a reliable detector in high radiation environment which can maintain high temporal and position resolution. GEM foil is the basic part of the detector which consists of a composite material (polyimide and copper). Large size GEM foil has complex mechanical structure and asymmetries which mainly arises due to formation of the HV sectors in the foil. These asymmetries become very relevant when large size foils are stretched to build a detector. In this article asymmetry affects are presented that define the tensile properties of a large size segmented GEM foil

Switching Transport through Nanopores with pH-Responsive Polymer Brushes for Controlled Ion Permeability

Several nanoporous platforms were functionalized with pH-responsive poly(methacrylic acid) (PMAA) brushes using surface-initiated atom transfer radical polymerization (SI-ATRP). The growth of the PMAA brush and its pH-responsive behavior from the nanoporous platforms were confirmed by scanning electron microscopy (SEM), Fourier transform infrared (FTIR) spectroscopy, and atomic force microscopy (AFM). The swelling behavior of the pH-responsive PMAA brushes grafted only from the nanopore walls was investigated by AFM in aqueous liquid environment with pH values of 4 and 8. AFM images displayed open nanopores at pH 4 and closed ones at pH 8, which rationalizes their use as gating platforms. Ion conductivity across the nanopores was investigated with current–voltage measurements at various pH values. Enhanced higher resistance across the nanopores was observed in a neutral polymer brush state (lower pH values) and lower resistance when the brush was charged (higher pH values). By adding a fluorescent dye in an environment of pH 4 or pH 8 at one side of the PMAA-brush functionalized nanopore array chips, diffusion across the nanopores was followed. These experiments displayed faster diffusion rates of the fluorescent molecules at pH 4 (PMAA neutral state, open pores) and slower diffusion at pH 8 (PMAA charged state, closed pores) showing the potential of this technology toward nanoscale valve applications

Key role of SMN/SYNCRIP and RNA-Motif 7 in spinal muscular atrophy: RNA-Seq and motif analysis of human motor neurons

Spinal muscular atrophy is a motor neuron disorder caused by mutations in SMN1. The reasons for the selective vulnerability of motor neurons linked to SMN (encoded by SMN1) reduction remain unclear. Therefore, we performed deep RNA sequencing on human spinal muscular atrophy motor neurons to detect specific altered gene splicing/expression and to identify the presence of a common sequence motif in these genes. Many deregulated genes, such as the neurexin and synaptotagmin families, are implicated in critical motor neuron functions. Motif-enrichment analyses of differentially expressed/spliced genes, including neurexin2 (NRXN2), revealed a common motif, motif 7, which is a target of SYNCRIP. Interestingly, SYNCRIP interacts only with full-length SMN, binding and modulating several motor neuron transcripts, including SMN itself. SYNCRIP overexpression rescued spinal muscular atrophy motor neurons, due to the subsequent increase in SMN and their downstream target NRXN2 through a positive loop mechanism and ameliorated SMN-loss-related pathological phenotypes in Caenorhabditis elegans and mouse models. SMN/SYNCRIP complex through motif 7 may account for selective motor neuron degeneration and represent a potential therapeutic target

A single amino acid residue regulates PTEN-binding and stability of the Spinal Muscular Atrophy protein SMN

Spinal Muscular Atrophy (SMA) is a neuromuscular disease caused by decreased levels of the survival of motoneuron (SMN) protein. Post-translational mechanisms for regulation of its stability are still elusive. Thus, we aimed to identify regulatory phosphorylation sites that modulate function and stability. Our results show that SMN residues S290 and S292 are phosphorylated, of which SMN pS290 has a detrimental effect on protein stability and nuclear localization. Furthermore, we propose that phosphatase and tensin homolog (PTEN), a novel phosphatase for SMN, counteracts this effect. In light of recent advancements in SMA therapies, a significant need for additional approaches has become apparent. Our study demonstrates S290 as a novel molecular target site to increase the stability of SMN. Characterization of relevant kinases and phosphatases provides not only a new understanding of SMN function, but also constitutes a novel strategy for combinatorial therapeutic approaches to increase the level of SMN in SMA

Facile formation of highly mobile supported lipid bilayers on surface-quaternized pH-responsive polymer brushes

Poly(2-dimethylamino)ethyl methacrylate) (PDMA) brushes are grown from planar substrates via surface atom transfer radical polymerization (ATRP). Quaternization of these brushes is conducted using 1-iodooctadecane in n-hexane, which is a non-solvent for PDMA. Ellipsometry, AFM, and water contact angle measurements show that surface-confined quaternization occurs under these conditions, producing pH-responsive brushes that have a hydrophobic upper surface. Systematic variation of the 1-iodooctadecane concentration and reaction time enables the mean degree of surface quaternization to be optimized. Relatively low degrees of surface quaternization (ca. 10 mol % as judged by XPS) produce brushes that enable the formation of supported lipid bilayers, with the hydrophobic pendent octadecyl groups promoting in situ rupture of lipid vesicles. Control experiments confirm that quaternized PDMA brushes prepared in a good brush solvent (THF) produce non-pH-responsive brushes, presumably because the pendent octadecyl groups form micelle-like physical cross-links throughout the brush layer. Supported lipid bilayers (SLBs) can also be formed on the non-quaternized PDMA precursor brushes, but such structures proved to be unstable to small changes in pH. Thus, surface quaternization of PDMA brushes using 1-iodooctadecane in n-hexane provides the best protocol for the formation of robust SLBs. Fluorescence recovery after photobleaching (FRAP) studies of such SLBs indicate diffusion coefficients (2.8 ± 0.3 μm s–1) and mobile fractions (98 ± 2%) that are comparable to the literature data reported for SLBs prepared directly on planar glass substrates