How does the substrate affect the Raman and excited state spectra of a carbon nanotube?

We study the optical properties of a single, semiconducting single-walled carbon nanotube (CNT) that is partially suspended across a trench and partially supported by a SiO2-substrate. By tuning the laser excitation energy across the E33 excitonic resonance of the suspended CNT segment, the scattering intensities of the principal Raman transitions, the radial breathing mode (RBM), the G-mode and the D-mode show strong resonance enhancement of up to three orders of magnitude. In the supported part of the CNT, despite a loss of Raman scattering intensity of up to two orders of magnitude, we recover the E33 excitonic resonance suffering a substrate-induced red shift of 50 meV. The peak intensity ratio between G-band and D-band is highly sensitive to the presence of the substrate and varies by one order of magnitude, demonstrating the much higher defect density in the supported CNT segments. By comparing the E33 resonance spectra measured by Raman excitation spectroscopy and photoluminescence (PL) excitation spectroscopy in the suspended CNT segment, we observe that the peak energy in the PL excitation spectrum is red-shifted by 40 meV. This shift is associated with the energy difference between the localized exciton dominating the PL excitation spectrum and the free exciton giving rise to the Raman excitation spectrum. High-resolution Raman spectra reveal substrate-induced symmetry breaking, as evidenced by the appearance of additional peaks in the strongly broadened Raman G band. Laser-induced line shifts of RBM and G band measured on the suspended CNT segment are both linear as a function of the laser excitation power. Stokes/anti-Stokes measurements, however, reveal an increase of the G phonon population while the RBM phonon population is rather independent of the laser excitation power.Comment: Revised manuscript, 20 pages, 8 figure

Chaperone-mediated autophagy in neuronal dendrites utilizes activity-dependent lysosomal exocytosis for protein disposal

Summary: The complex morphology of neurons poses a challenge for proteostasis because the majority of lysosomal degradation machinery is present in the cell soma. In recent years, however, mature lysosomes were identified in dendrites, and a fraction of those appear to fuse with the plasma membrane and release their content to the extracellular space. Here, we report that dendritic lysosomes are heterogeneous in their composition and that only those containing lysosome-associated membrane protein (LAMP) 2A and 2B fuse with the membrane and exhibit activity-dependent motility. Exocytotic lysosomes dock in close proximity to GluN2B-containing N-methyl-D-aspartate-receptors (NMDAR) via an association of LAMP2B to the membrane-associated guanylate kinase family member SAP102/Dlg3. NMDAR-activation decreases lysosome motility and promotes membrane fusion. We find that chaperone-mediated autophagy is a supplier of content that is released to the extracellular space via lysosome exocytosis. This mechanism enables local disposal of aggregation-prone proteins like TDP-43 and huntingtin

600 MW MARS Nuclear Power Plant

The design of MARS (Multipurpose Advanced “inherently” Safe Reactor) plant started in 1983 at the Department of Nuclear Engineering and Energy Conversion of the University of Rome "La Sapienza", with the aim of proposing a new concept of fission-type nuclear plant to be used for a wide range of applications, including desalination and district heating. The possibility of utilization of the plant in high-density population areas or in developing areas was the main reason for the search for improved safety requirements: the plant had to be simple, with an easy-to-understand and incontrovertible capacity to avoid any radiological hazards to the population. Typically, the safety approach had to be a clearly understandable, deterministic one. The design was focused on a nuclear power generation capacity of 600 MWth, corresponding to about 170 Mwe in the case of only electrical production, with a modular solution to satisfy progressively increasing power requirements

COGNITIVE-HD study: protocol of an observational study of neurocognitive functioning and association with clinical outcomes in adults with end-stage kidney disease treated with haemodialysis.

INTRODUCTION:The prevalence of cognitive impairment may be increased in adults with end-stage kidney disease compared with the general population. However, the specific patterns of cognitive impairment and association of cognitive dysfunction with activities of daily living and clinical outcomes (including withdrawal from treatment) among haemodialysis patients remain incompletely understood. The COGNITIVE impairment in adults with end-stage kidney disease treated with HemoDialysis (COGNITIVE-HD) study aims to characterise the age-adjusted and education-adjusted patterns of cognitive impairment (using comprehensive testing for executive function, perceptual-motor function, language, learning and memory, and complex attention) in patients on haemodialysis and association with clinical outcomes.METHODS AND ANALYSIS:A prospective, longitudinal, cohort study of 750 adults with end-stage kidney disease treated with long-term haemodialysis has been recruited within haemodialysis centres in Italy (July 2013 to April 2014). Testing for neurocognitive function was carried out by a trained psychologist at baseline to assess cognitive functioning. The primary study factor is cognitive impairment and secondary study factors will be specific domains of cognitive function. The primary outcome will be total mortality. Secondary outcomes will be cause-specific mortality, major cardiovascular events, fatal and non-fatal myocardial infarction and stroke, institutionalisation, and withdrawal from treatment at 12\u2005months.ETHICS AND DISSEMINATION:This protocol was approved before study conduct by the following responsible ethics committees: Catania (approval reference 186/BE; 26/09/2013), Agrigento (protocol numbers 61-62; 28/6/2013), USL Roma C (CE 39217; 24/6/2013), USL Roma F (protocol number 0041708; 23/7/2013), USL Latina (protocol number 20090/A001/2011; 12/7/2013), Trapani (protocol number 3413; 16/7/2013) and Brindisi (protocol number 40259; 6/6/2013). All participants have provided written and informed consent and can withdraw from the study at any time. The findings of the study will be disseminated through peer-reviewed journals and national and international conference presentations and to the participants through communication within the dialysis network in which this study is conducted

Nutrition and dietary intake and their association with mortality and hospitalisation in adults with chronic kidney disease treated with haemodialysis: protocol for DIET-HD, a prospective multinational cohort study

INTRODUCTION: Adults with end-stage kidney disease (ESKD) treated with haemodialysis experience mortality of between 15% and 20% each year. Effective interventions that improve health outcomes for long-term dialysis patients remain unproven. Novel and testable determinants of health in dialysis are needed. Nutrition and dietary patterns are potential factors influencing health in other health settings that warrant exploration in multinational studies in men and women treated with dialysis. We report the protocol of the "DIETary intake, death and hospitalisation in adults with end-stage kidney disease treated with HaemoDialysis (DIET-HD) study," a multinational prospective cohort study. DIET-HD will describe associations of nutrition and dietary patterns with major health outcomes for adults treated with dialysis in several countries.METHODS AND ANALYSIS: DIET-HD will recruit approximately 10,000 adults who have ESKD treated by clinics administered by a single dialysis provider in Argentina, France, Germany, Hungary, Italy, Poland, Portugal, Romania, Spain, Sweden and Turkey. Recruitment will take place between March 2014 and June 2015. The study has currently recruited 8000 participants who have completed baseline data. Nutritional intake and dietary patterns will be measured using the Global Allergy and Asthma European Network (GA(2)LEN) food frequency questionnaire. The primary dietary exposures will be n-3 and n-6 polyunsaturated fatty acid consumption. The primary outcome will be cardiovascular mortality and secondary outcomes will be all-cause mortality, infection-related mortality and hospitalisation.ETHICS AND DISSEMINATION: The study is approved by the relevant Ethics Committees in participating countries. All participants will provide written informed consent and be free to withdraw their data at any time. The findings of the study will be disseminated through peer-reviewed journals, conference presentations and to participants via regular newsletters. We expect that the DIET-HD study will inform large pragmatic trials of nutrition or dietary interventions in the setting of advanced kidney disease