Production of graphene nanoplate/polyetheretherketone composites by semi-industrial melt-compounding.

Current studies on nanocomposites have focused on their multifunctional properties and their industrial production. In this work, polyetheretherketone (PEEK)/graphene nanoplate (GNP) composites were produced by a direct semi-industrial process. Different percentages of untreated GNP (1, 5, and 10 wt.%) were added to PEEK by employing melt-compounding followed by injection-moulding. Despite the semi-industrial approach used, the modulus, strength, and Poisson coefficient of the nanocomposites (1 and 5 wt.%) were not significantly affected by the addition of GNP. However, there was a slight decrease in the strength at 10 wt.% GNP. Our study also shows that the thermal conductivities of PEEK/GNP composites are up to 2.5 times higher than that of pure PEEK.

Differences in circadian rhythmicity in CLOCK 3111T/C genetic variants in moderate obese women as assessed by thermometry, actimetry and body position.

INTRODUCTION: Genetics is behind our circadian machinery. CLOCK (Circadian Locomotor Output Cycles Kaput) 3111T/C single-nucleotide polymorphism (SNP) has been previously related to obesity and weight loss. However, phenotypic association and functionality of CLOCK 3111 locus is still unknown. The aim of this study was to determine, in free-living conditions, if the presence of CLOCK 3111C in overweight women could be related to (a) circadian disorders, and (b) changes in sleep quality, to improve understanding of the previously demonstrated associations with obesity and reduced weight loss of the C carriers. METHODS: Wrist temperature, actimetry and position (TAP) and TAP variables were measured as markers of circadian functionality during 8 consecutive days. A rest-activity and food diary was also completed, whereas sleep quality was determined by domiciliary polysomnography. We recruited 85 women who were overweight with body mass index (BMI) of 28.59±4.30 kg m(-2) and age 43±12 years. From this sample, we found that 43 women were carrying the minor allele (C) for CLOCK 3111T/C SNP and 42 women were TT carriers (major allele carriers). Both groups of patients were matched for number, age, obesity parameters and energy intake. RESULTS: Compared with TT subjects, who showed more robust circadian rhythm profiles, patients with the C allele displayed significant circadian abnormalities: lower amplitude and greater fragmentation of the rhythm, a less stable circadian pattern and a significantly weakened circadian function, as assessed by the circadian function index (CFI). C subjects were also less active, started their activities later in the morning and were sleepier during the day, showing a delayed acrophase that characterizes 'evening-type' subjects. CONCLUSION: C genetic variants in CLOCK 3111T/C display a less robust circadian rhythm than TT and a delayed acrophase that characterizes 'evening-type' subjects. We support the notion that identifying CLOCK genotypes in patients may assist the therapist in characterization of the roots of the metabolic problem.

Influence of gamma irradiation on carbon nanotube-reinforced polypropylene.

Single walled carbon nanotubes (SWNT) have been incorporated into a polypropylene (PP) matrix in different concentrations (range: 0.25-2.5 wt%). The nanotubes were blended with PP particles (approximately 500 microm in size) before mixing in an extruder. Finally, rectangular plates were obtained by compression moulding. PP-SWNT composites were gamma irradiated at different doses, 10 and 20 kGy, to promote crosslinking in the matrix and potentially enhance the interaction between nanotubes and PP. Extensive thermal, structural and mechanical characterization was conducted by means of DSC, X-ray diffraction, Raman spectroscopy, uniaxial tensile tests and dynamic mechanical thermal (DMTA) techniques. DSC thermograms reflected higher crystallinity with increasing nanotube concentration. XRD analysis confirmed the only presence of a monoclinic crystals and proved unambiguously that CNTs generated a preferred orientation. Raman spectroscopy confirmed that the intercalation of the polymer between bundles is favored at low CNTs contents. Elastic modulus results confirmed the reinforcement of the polypropylene matrix with increasing SWNT concentration, although stiffness saturation was observed at the highest concentration. Loss tangent DMTA curves showed three transitions for raw polypropylene. While gamma relaxation remained practically unchanged in all the samples, beta relaxation temperatures showed an increase with increasing CNT content due to the reduced mobility of the system. Gamma-irradiated PP exhibited an increase in the beta relaxation temperature, associated with changes in glass transition due to radiation-induced crosslinking. On the contrary, gamma-irradiated nanocomposites did not show this effect probably due to the reaction of radiative free radicals with CNTs.

Block copolymer assisted dispersion of single walled carbon nanotubes and integration into a trifunctional epoxy.

Arc discharge single walled carbon nanotubes were processed by acid treatment, dispersion in a Pluronic F68 block copolymer aqueous solution and centrifugation. The as-prepared material was characterized by transmission electron microscopy, X-ray diffraction and Raman spectroscopy, showing an important degree of debundling as well as the removal of most of the graphitic and metallic impurities from pristine nanotubes. The nanotube-Pluronic material was integrated into an advanced trifunctional epoxy resin, triglycidyl p-aminophenol, using 4,4'-diaminodiphenylsulfone as the curing agent. The material was incorporated into the epoxy system (0.1, 0.25, 0.50, 1.0, 2.0 wt%) throughout hot magnetic stirring and ultrasonication. Curing kinetics was studied using differential scanning calorimetry, applying the Vyazovkin's isoconversional method. In the early stages of curing, the kinetic study revealed a decrease in the activation energy for samples containing Pluronic, suggesting that Pluronic induced an improvement in the mobility of reactants. The cured composites were characterized by Raman spectroscopy, thermogravimetric analysis and scanning electron microscopy. Micrographs revealed successful integration and homogeneous distribution of the nanotube-Pluronic material in the epoxy matrix, while direct integration of bare nanotubes originated aggregates and inhomogeneity.

Prevención y tratamiento de la mucositis en el paciente onco-hematológico / Prevention and management of mucositis in the onco-haematologic patient

La mucositis es una reacción inflamatoria que afecta a todo el tracto gastrointestinal, desde la boca al ano, y es uno de los principales efectos adversos de la quimio y/o radioterapia.Con el fin de prevenir y tratar la mucositis se utilizan una gran variedad de tratamientos: fórmulas magistrales, fármacos comercializados y terapias no farmacológicas.En este trabajo se ha realizado una revisión de los tratamientos más habituales y otros de uso potencial utilizados para prevenir y tratar dicha patología. Se ha observado que no existen resultados concluyentes sobre la eficacia de los mismos.En el tratamiento de la mucositis ningún principio activo ha demostrado su superioridad respecto a los demás, sin embargo una correcta higiene bucal como profilaxis reduce su incidencia y gravedad. (AU)

[Pseudolymphoma caused by cholesterol embolism]. / Pseudo-lymphome par embolies de cholestérol.

We report the case of a 60-year old man who, during four years following surgical repair of an inguinal hernia (with transient antithrombotic therapy), suffered from an atypical inflammatory nodule on the dorsum of the left foot with an erythematous plaque on the first intermetatarsal space, together with an inflammatory plaque on the right fifth finger and hairless plaques on both wrists. An ultimate biopsy of the nodule made it possible to discover, unexpectedly, two shadows of cholesterol crystals in a vascular lumen and inside the cytoplasm of a giant multinucleate cell found on a single histological slice and at the deepest part of the fragment. The inflammatory lesions disappeared under a 250 mg/day aspirin treatment. We emphasize the uncommon clinical and pathological pseudo-lymphomatous features of this case and regard our description as original in view of the chronicity of the embolising process.

[Cerebrovascular accidents and sickle cell disease]. / Accidents vasculaires cérébraux et drépanocytose.

A 7 year-old girl, with homozygous sickle cell disease experienced two cerebrovascular strokes over an 8-month period. The diagnostic investigations were performed with highly sensitive imaging methods (MRI, angiography). Such a complication raises problems in curative and prophylactic treatment. New diagnostic methods are being evaluated.