1,244 research outputs found

    Electron-phonon coupling in potassium-doped graphene: Angle-resolved photoemission spectroscopy

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    The electron-phonon coupling in potassium-doped graphene on Ir(111) is studied via the renormalization of the pi* band near the Fermi level, using angle-resolved photoemission spectroscopy. The renormalization is found to be fairly weak and almost isotropic, with a mass enhancement parameter of lambda= 0.28(6) for both the K-M and the K-G direction. These results are found to agree well with recent first principles calculations.Comment: 5 pages, 3 figure

    Salification Controls the In-Vitro Release of Theophylline

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    Sustained released formulation is the most used strategy to control the efficacy and the adverse reactions of an API (active pharmaceutical ingredient) with a narrow therapeutic index. In this work, we used a different way to tailor the solubility and diffusion of a drug. Salification of Theophylline with Squaric Acid was carried out to better control the absorption of Theophylline after administration. Salification proved to be a winning strategy decreasing the dissolution of the APIs up to 54% with respect to Theophylline. Most importantly, this was accomplished in the first 10 min of the dissolution process, which are the most important for the API administration. Two polymorphs were identified and fully characterized. Theophylline squarate was discovered as trihydrate (SC-XRD) and as a metastable anhydrous form. Indeed, during the Variable Temperature-XRPD experiment, the trihydrate form turned back into the two starting components after losing the three molecules of water. On the other hand, the synthesis of the trihydrate form was observed when a simple mixing of the two starting components were exposed to a high humidity relative percentage (90% RH)

    Uncover the Offensive Side of Disparagement Humor: An fMRI Study

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    Disparagement humor is a kind of humor that denigrates, belittles an individual or a social group. In the aim to unveil the offensive side of these kinds of jokes, we have run an event-related fMRI study asking 30 healthy volunteers to judge the level of fun of a series of verbal stimuli that ended with a sentence that was socially inappropriate but funny (disparagement joke -DJ), socially inappropriate but not funny (SI) or neutral (N). Behavioral results showed disparagement jokes are perceived as funny and at the same time offensive. However, the level of offense in DJ is lower than that registered in SI stimuli. Functional data showed that DJ activated the insula, the SMA, the precuneus, the ACC, the dorsal striatum (the caudate nucleus), and the thalamus. These activations suggest that in DJ a feeling of mirth (and/or a desire to laugh) derived from the joke (e.g., SMA and precuneus) and the perception of the jokes\u2019 social inappropriateness (e.g., ACC and insula) coexist. Furthermore, DJ and SI share a common network related to mentalizing and to the processing of negative feelings, namely the medial prefrontal cortex, the putamen and the right thalamus

    Surface Core Level Shifts of Clean and Oxygen Covered Ru(0001)

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    We have performed high resolution XPS experiments of the Ru(0001) surface, both clean and covered with well-defined amounts of oxygen up to 1 ML coverage. For the clean surface we detected two distinct components in the Ru 3d_{5/2} core level spectra, for which a definite assignment was made using the high resolution Angle-Scan Photoelectron Diffraction approach. For the p(2x2), p(2x1), (2x2)-3O and (1x1)-O oxygen structures we found Ru 3d_{5/2} core level peaks which are shifted up to 1 eV to higher binding energies. Very good agreement with density functional theory calculations of these Surface Core Level Shifts (SCLS) is reported. The overriding parameter for the resulting Ru SCLSs turns out to be the number of directly coordinated O atoms. Since the calculations permit the separation of initial and final state effects, our results give valuable information for the understanding of bonding and screening at the surface, otherwise not accessible in the measurement of the core level energies alone.Comment: 16 pages including 10 figures. Submitted to Phys. Rev. B. Related publications can be found at http://www.fhi-berlin.mpg.de/th/paper.htm

    Sulfur content in foods consumed in an Italian population and impact of diet quality on sulfur intake

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    Sulfur is an essential nutrient but data about its intake are scarce. We aimed to measure sulfur content in food samples and assess its habitual intake in relation to adherence to healthy dietary patterns in 719 Italian adults. Using a food frequency questionnaire, we estimated overall sulfur intake, and its relation with adherence to healthy dietary patterns. The highest sulfur content was found in preserved/canned fish (3.0 g/kg), seafood (2.8 g/kg), white meat (2.8 g/kg) and dairy products, particularly aged cheeses (2.1 g/kg) and lowest in fresh fruit (87 mg/kg), oils and fats (157 mg/kg), and beverages (141 mg/kg), with the exception of onion and garlic (1.3 g/kg). The mean sulfur intake in the study population was 1.1 g/day, slightly higher in men than women. The foods contributing most to sulfur intake were meat (29%) and cereals (19%), with also substantial contribution (>10%) from beverages and dairy products. Adherence to dietary patterns had little influence on sulfur intake, except for adherence to MIND diet positively and linearly associated with sulfur intake. Our study provides an updated overview of sulfur content in foods composing the Italian diet, as well as of sulfur intake in an Italian community of Northern Italy

    Secondary spontaneous pneumothorax and bullous lung disease in cannabis and tobacco smokers. A case-control study.

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    Background The notion that smoking cannabis may damage the respiratory tract has been introduced in recent years but there is still a paucity of studies on this subject. The aim of this study was to investigate the relationship between cannabis smoking, pneumothorax and bullous lung disease in a population of operated patients. Methods and findings We performed a retrospective study on patients operated on for spontaneous pneumothorax. Patients were divided into three groups according to their smoking habit: cannabis smokers, only-tobacco smokers and nonsmokers. Cannabis lifetime exposure was expressed in dose-years (1d/y = 1 gram of cannabis/week for one year). Clinical, radiological and perioperative variables were collected. The variables were analyzed to find associations with smoking habit. The impact of the amount of cannabis consumption was also investigated by ROC curves analysis. Of 112 patients, 39 smoked cannabis, 23 smoked only tobacco and 50 were nonsmokers. Median cannabis consumption was 28 dose/years, median tobacco consumption was 6 pack/years. Cannabis smokers presented with more severe chronic respiratory symptoms and bullous lung disease and with a higher incidence of tension pneumothorax than both tobacco smokers and nonsmokers. Cannabis smokers also developed a larger pneumothorax, experienced prolonged postoperative stay and demonstrated a higher incidence of pneumothorax recurrence after the operation than nonsmokers did. The risk of occurrence of chronic respiratory symptoms and bullous lung disease in cannabis smokers was dose-related. Conclusions Cannabis smoking seems to increase the risk of suffering from respiratory complaints and can have detrimental effects on lung parenchyma, in a dose-dependent manner. Cannabis smoking also negatively affected the outcome of patients operated for spontaneous pneumothorax. A history of cannabis abuse should always be taken in patients with pneumothorax. There may be need for a specific treatment for pneumothorax in cannabis smokers

    Core level shifts of undercoordinated Pt atoms

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    We present the results of high-energy resolution core level photoelectron spectroscopy experiments paralleled by density functional theory calculations to investigate the electronic structure of highly undercoordinated Pt atoms adsorbed on Pt(111) and its correlation with chemical activity. Pt4f(7/2) core level binding energies corresponding to atoms in different configurations are shown to be very sensitive not only to the local atomic coordination number but also to the interatomic bond lengths. Our results are rationalized by introducing an indicator, the effective coordination, which includes both contributions. The calculated energy center of the valence 5d-band density of states, which is a well known depicter of the surface chemical reactivity, shows a noteworthy correlation with the Pt4f(7/2) core level shifts and with the effective coordination

    Infectious Risks Related to Umbilical Venous Catheter Dwell Time and Its Replacement in Newborns: A Narrative Review of Current Evidence

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    The use of umbilical venous catheters (UVCs) has become the standard of care in the neonatal intensive care unit (NICU) to administer fluids, medications and parenteral nutrition. However, it is well known that UVCs can lead to some serious complications, both mechanical and infective, including CLABSI (Central Line-Associated Bloodstream Infections). Most authors recommend removing UVC within a maximum of 14 days from its placement. However, the last Infusion Therapy Standards of Practice (INS) guidelines recommends limiting the UVC dwell time to 7 to 10 days, to reduce risks of infectious and thrombotic complications. These guidelines also suggest as an infection prevention strategy to remove UVC after 4 days, followed by the insertion of a PICC if a central line is still needed. Nevertheless, the maximum UVC dwell time to reduce the risk of CLABSI is still controversial, as well as the time of its replacement with a PICC. In this study we reviewed a total of 177 articles, found by using the PubMed database with the following search strings: “UVC AND neonates”, “(neonate* OR newborn*) AND (UVC OR central catheter*) AND (infection*)”. We also analyze the INS guidelines to provide the reader an updated overview on this topic. The purpose of this review is to give updated information on CVCs infectious risks by examining the literature in this field. These data could help clinicians in deciding the best time to remove or to replace the UVC with a PICC, to reduce CLABSIs risk. Despite the lack of strong evidence, the risk of CLABSI seems to be minimized when UVC is removed/replaced within 7 days from insertion and this indication is emerging from more recent and larger studies

    O- and H- induced surface core level shifts on Ru(0001): Prevalence of the additivity rule

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    In previous work on adsorbate-induced surface core level shifts (SCLSs), the effects caused by O atom adsorption on Rh(111) and Ru(0001) were found to be additive: the measured shifts for first layer Ru atoms depended linearly on the number of directly coordinated O atoms. Density-functional theory calculations quantitatively reproduced this effect, allowed separation of initial and final state contributions, and provided an explanation in terms of a roughly constant charge transfer per O atom. We have now conducted similar measurements and calculations for three well-defined adsorbate and coadsorbate layers containing O and H atoms: (1 x 1)-H, (2 x 2)-(O+H), and (2 x 2)-(O+3H) on Ru(0001). As H is stabilized in fcc sites in the prior two structures and in hcp sites in the latter, this enables us to not only study coverage and coadsorption effects on the adsorbate-induced SCLSs, but also the sensitivity to similar adsorption sites. Remarkably good agreement is obtained between experiment and calculations for the energies and geometries of the layers, as well as for all aspects of the SCLS values. The additivity of the next-neighbor adsorbate-induced SCLSs is found to prevail even for the coadsorbate structures. While this confirms the suggested use of SCLSs as fingerprints of the adsorbate configuration, their sensitivity is further demonstrated by the slightly different shifts unambiguously determined for H adsorption in either fcc or hcp hollow sites.Comment: 9 pages including 4 figures; related publications can be found at http://www.fhi-berlin.mpg.de/th/th.htm

    Zn-doped titania nanoparticles as building blocks for solid foam filters of water and air via photocatalytic oxidation

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    Photocatalytic oxidation (PCO) could provide energy-efficient purification of water and air. Its efficacy is constrained mainly by limited photocatalytic activity and active surface. To address both, solid foams with hierarchic porous structures spanning multiple length-scales, stabilized by photocatalytic Zn-doped titania nanoparticles (NP) were synthesized and tested. The NP were characterized by SEM, EDS, DLS, XRD, Raman and UV–Vis spectroscopies. Solid foams were stabilized by NP complexes with cationic surfactants. The foam morphology was characterized and photocatalytic activity was demonstrated in water. The present work paves the way for the development of efficient systems for air and water purification in demanding technological sectors, such as aerospace
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