1,916 research outputs found

    Imaging dielectric relaxation in nanostructured polymers by frequency modulation electrostatic force microscopy

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    We have developed a method for imaging the temperature-frequency dependence of the dynamics of nanostructured polymer films with spatial resolution. This method provides images with dielectric compositional contrast well decoupled from topography. Using frequency-modulation electrostatic-force-microscopy, we probe the local frequency-dependent (0.1–100 Hz) dielectric response through measurement of the amplitude and phase of the force gradient in response to an oscillating applied electric field. When the phase is imaged at fixed frequency, it reveals the spatial variation in dielectric losses, i.e., the spatial variation in molecular/dipolar dynamics, with 40 nm lateral resolution. This is demonstrated by using as a model system; a phase separated polystyrene/polyvinyl-acetate (PVAc) blend. We show that nanoscale dynamic domains of PVAc are clearly identifiable in phase images as those which light-up in a band of temperature, reflecting the variations in the molecular/dipolar dynamics approaching the glass transition temperature of PVAc

    Активность лептина и интерлейкина­-6 в сыворотке крови у больных полиэндокринопатией

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    Установлена взаимосвязь лептина с метаболическими и некоторыми иммунологическими показателями у больных сахарным диабетом 2−го типа в сочетании с аутоиммунным тиреоидитом. Выявлены наличие иммуносупрессии и повышение уровней интерлейкина−6 и лептина при сопутствующем ожирении и дислипидемии.Встановлено взаємозв’язок лептину з метаболічними і деякими імунологічними показниками у хворих на цукровий діабет 2−го типу у поєднанні з аутоімунним тиреоідитом. Виявлено наявність імуносупресії та підвищення рівнів інтерлейкіну−6 і лептину при супутньому ожирінні та дисліпідемії.Association between leptin and some immunological parameters in patients with type 2 diabetes mellitus accompanied by autoimmune thyroiditis was established. The presence of immune suppression and increased levels of interleukin−6 and leptin was revealed at accompanying obesity and dyslipidemias

    Effect of helium pre- or postconditioning on signal transduction kinases in patients undergoing coronary artery bypass graft surgery

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    Background: The noble gas helium induces pre- and postconditioning in animals and humans. Volatile anesthetics induce cardioprotection in humans undergoing coronary artery bypass graft (CABG) surgery. We hypothesized that helium induces pre-and postconditioning in CABG-patients, affecting signaling molecules protein kinase C-epsilon (PKC-epsilon), p38 mitogen activated protein kinase (p38 MAPK), extracellular signal-regulated kinase 1/2 (ERK-1/2) and heat shock protein 27 (HSP-27) within cardiac tissue, and reducing postoperative troponin levels. Methods: After ethical approval and informed consent, 125 elective patients undergoing CABG surgery were randomised into this prospective, placebo controlled, investigator blinded, parallel arm single-centre study. Helium preconditioning (3 x 5 min of 70 % helium and 30 % oxygen) was applied before aortic cross clamping; postconditioning (15 min of helium) was applied before release of the aortic cross clamp. Signaling molecules were measured in right atrial appendix specimens. Troponin-T was measured at 4, 12, 24 and 48 h postoperatively. Results: Baseline characteristics of all groups were similar. Helium preconditioning did not significantly alter the primary outcome (molecular levels of kinases PKC-e and HSP-27, ratio of activated p38 MAPK or ERK 1/2). Postoperative troponin T was 11 arbitrary units [5, 31; area-under-the-curve (interquartile range)] for controls, and no statistically significant changes were observed after helium preconditioning [He-pre: 11 (6, 18)], helium postconditioning [He-post: 11 (8, 15)], helium pre-and postconditioning [He-PP: 14 (6, 20)] and after sevoflurane preconditioning [APC: 12 (8, 24), p = 0.13]. No adverse effects related to study treatment were observed in this study. Conclusions: No effect was observed of helium preconditioning, postconditioning or the combination thereof on activation of p38 MAPK, ERK 1/2 or levels of HSP27 and PKC-e in the human heart. Helium pre-and postconditioning did not affect postoperative troponin release in patients undergoing CABG surgery

    Prognosis and prognostic factors of patients with mesothelioma:A population-based study

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    BACKGROUND: It is important to regularly update survival estimates of patients with malignant mesothelioma as prognosis may vary according to epidemiologic factors and diagnostic and therapeutic management. METHODS: We assessed overall (baseline) survival as well as related prognostic variables in a large cohort of 1353 patients with a confirmed diagnosis of malignant mesothelioma between 2005 and 2008. RESULTS: About 50% of the patients were 70 years or older at diagnosis and the median latency time since start of asbestos exposure was 49 years. One year after diagnosis, 47% of the patients were alive, 20% after 2 years and 15% after 3 years. Prognostic variables independently associated with worse survival were: older age (HR=1.04 per year 95% CI (1.03–1.06)), sarcomatoid subtype (HR=2.45 95% CI (2.06–2.90)) and non-pleural localisation (HR=1.67 95% CI (1.26–2.22)). CONCLUSION: Survival of patients with malignant mesothelioma is still limited and depends highly on patient age, mesothelioma subtype and localisation. In addition, a substantial part of the patients had a long latency time between asbestos exposure and diagnosis

    Sedimentological study of cold-water coral mounds on Pen Duick Escarpment (Gulf of Cadiz): preliminary results of the MD169 cruise

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    Cold-water corals are widely distributed along the Moroccan margin in the Northeast Atlantic Ocean. Within the Gulf of Cadiz mud volcanoes, submarine ridges and steep fault escarpments occur, which favour the settlement of scleractinians and build up coral mounds. One of these sites is the Pen Duick Escarpment, situated in the El Arraiche mud volcano field, 35 km offshore the city of Larache. Pen Duick Escarpment is a 6 km long, SSE-NNW oriented, 80 to 125 m high wall with a southwest-facing slope of 8 to 12°. Up to now, 15 coral mounds were recognized on top of the escarpment with an average estimated elevation of 15 m. Although cold-water corals are a common feature on the adjacent cliffs, mud volcanoes and seafloor, no actual living coral has been observed.This study is based upon three on-mound gravity cores (Alpha, Beta and Gamma mound) acquired by R/V Marion Dufresne in 2008 (MD169). Each mound was cored at least twice to recover both a core for biogeochemical and microbial studies, and another core for sedimentological purposes, in order to link both processes. The sedimentological cores were analysed using different techniques (medical CT scanning, XRF, U/Th dating, stable isotopes, grain-size analysis) in order to obtain a holistic view on the build-up of a mound. The coring, together with present-day seabed observations, revealed the architectural importance of open coral rubble plates in the role of mound building. These graveyards act not only as sediment trap but also as microhabitat for a wide range of benthic organisms

    Sex Differences in Adverse Drug Reactions of Metformin:A Longitudinal Survey Study

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    Introduction: In general, women more often experience metformin-associated adverse drug reactions (ADRs) than men. Objectives: We aimed to assess whether sex differences in reported ADRs for metformin are observed at different times after initiation, and to explore their concurrence with sex differences in the dose of metformin over time. This may guide future studies in assessing the involved mechanisms of sex differences in metformin-associated ADRs and may guide sex-specific management of ADRs in clinical practice. Methods: This study has a longitudinal design using data about patients initiating metformin collected by the Dutch National Pharmacovigilance Center Lareb through their Intensive Monitoring program. Patients were asked to complete a web-based questionnaire six times after initiation (i.e., at 2 weeks, 6 weeks and at 3, 6, 9, and 12 months). The outcome variables were the proportion of patients reporting any ADR (primary) and the dose of metformin (secondary). Sex differences in the proportions of ADRs and in the dose were tested at each assessment using Pearson Chi-Squared tests and Wilcoxon rank-sum tests, respectively. Using Bonferroni adjustment for multiple testing, a p value < 0.01 was considered statistically significant. Results: The number of included patients was 1712 (40.9% women). Women reported an ADR more often than men, which was statistically significant at the assessment at 2 weeks (34% vs 25%, p < 0.001), and 6 weeks (37% vs 28%, p = 0.001) after initiation. In general, women were reported to be prescribed a lower dose than men, which became statistically significant at the 9-month assessment (p < 0.01). Conclusions: Sex differences in reported ADRs were seen in the first weeks after metformin initiation, whereas statistically significant differences in self-reported prescribed dosing were observed after several months. Patients, in particular women, might benefit from being prescribed lower metformin doses at treatment initiation
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