940 research outputs found
Adducts of functionalized Graphene layers with Ag nanoparticles for Antimicrobial applications
Health and environmental impacts of multi-drug resistance (MDR) pathogens are becoming more and
more relevant nowadays, thus increasing the need of developing new, safe and effective
antimicrobials.
This research was focused on the synthesis, the characterization and the evaluation of the
antimicrobial and cytotoxic activity of hybrid nanomaterials made up through a simple and
sustainable functionalization of three carbon substrates, namely Graphite, Carbon black and Carbon
nanotubes, with a pyrrole moiety (SP) and silver nanoparticles (Ag-NP) [1, 2]. The adducts were
analyzed by means of thermogravimetric analyses (TGA), transmission electron microscopy
(HRTEM) and X-ray diffraction analyses (WAXD), which confirmed the successful functionalization
of raw materials. UV-vis spectroscopy and dynamic/electrophoretic light scattering (DLS/ELS)
provided information regarding carbon suspensions stability, particles sizes and surface charge.
Results from microbiological tests revealed an outstanding enhancement of the antimicrobial activity
promoted by the functionalization with Ag nanoparticles, maintaining unaltered the cytotoxic levels
exerted by not-functionalized materials. In the light of these results, a possible bactericidal
mechanism based on the synergy between mechanical and oxidative stresses at the bacterial
membrane level is proposed
Decolonising the school experience through poetry to foreground truth-telling and cognitive justice
While attempts to decolonise the school curriculum have been ongoing since the 1970s, the recent Black Lives Matter protests around the world have drawn urgent attention to the vast inequities faced by Black and First Nations peoples and people of colour. Decolonising education and other public institutions has become a front-line public concern around the world. In this article, we argue that poetry offers generative possibilities for the decolonisation of Australian high school (and university) curricula. Inspired by Aboriginal and Torres Strait Islander approaches to knowledge creation as intergenerational, iterative and intercultural, and by postcolonial and decolonial theories, we explore ways in which poetry events can begin decolonising and diversifying the school curriculum. We suggest that poetry creates spaces for deep listening with the heart (dadirri) that can promote truth-telling about colonial histories and the strengths, achievements and contributions of First Nations Australians. These decolonising efforts underpin the Wandiny (Gathering Together) â Listen With the Heart: Uniting Nations Through Poetry research that we discuss in this article. In these ways, we argue that decolonised curricula create the conditions for cognitive justice in schooling that is an important precursor to other forms of social justice, such as equality, diversity and inclusion
Expansion of the Gene Ontology knowledgebase and resources
The Gene Ontology (GO) is a comprehensive resource of computable knowledge regarding the functions of genes and gene products. As such, it is extensively used by the biomedical research community for the analysis of -omics and related data. Our continued focus is on improving the quality and utility of the GO resources, and we welcome and encourage input from researchers in all areas of biology. In this update, we summarize the current contents of the GO knowledgebase, and present several new features and improvements that have been made to the ontology, the annotations and the tools. Among the highlights are 1) developments that facilitate access to, and application of, the GO knowledgebase, and 2) extensions to the resource as well as increasing support for descriptions of causal models of biological systems and network biology. To learn more, visit http://geneontology.org/
Immune-checkpoint inhibitors from cancer to COVIDâ19: A promising avenue for the treatment of patients with COVIDâ19
The severe acute respiratory syndrome associated coronavirusâ2 (SARSâCoVâ2) poses a threat to human life worldwide. Since early March, 2020, coronavirus disease 2019 (COVIDâ19), characterized by an acute and often severe form of pneumonia, has been declared a pandemic. This has led to a boom in biomedical research studies at all stages of the pipeline, from the in vitro to the clinical phase. In line with this global effort, known drugs, currently used for the treatment of other pathologies, including antivirals, immunomodulating compounds and antibodies, are currently used offâlabel for the treatment of COVIDâ19, in association with the supportive standard care. Yet, no effective treatments have been identified. A new hope stems from medical oncology and relies on the use of immuneâcheckpoint inhibitors (ICIs). In particular, amongst the ICIs, antibodies able to block the programmed deathâ1 (PDâ1)/PD ligand-1 (PDâL1) pathway have revealed a hidden potential. In fact, patients with severe and critical COVIDâ19, even prior to the appearance of acute respiratory distress syndrome, exhibit lymphocytopenia and suffer from Tâcell exhaustion, which may lead to viral sepsis and an increased mortality rate. It has been observed that cancer patients, who usually are immunocompromised, may restore their antiâtumoral immune response when treated with ICIs. Moreover, viral-infected mice and humans, exhibit a Tâcell exhaustion, which is also observed following SARSâCoVâ2 infection. Importantly, when treated with antiâPDâ1 and antiâPDâL1 antibodies, they restore their Tâcell competence and efficiently counteract the viral infection. Based on these observations, four clinical trials are currently open, to examine the efficacy of antiâPDâ1 antibody administration to both cancer and nonâcancer individuals affected by COVIDâ19. The results may prove the hypothesis that restoring exhausted Tâcells may be a winning strategy to beat SARSâCoVâ2 infection
Wind tunnel testing of the DeepWind demonstrator in design and tilted operating conditions
The DeepWind Project aims at investigating the feasibility of a new floating vertical-axis wind turbine (VAWT) concept, whose purpose is to exploit wind resources at deep-water offshore sites.The results of an extensive experimental campaign on the DeepWind reduced scale demonstrator are here presented for different wind speeds and rotor angular velocities, including also skewed flow operation due to a tilted rotor arrangement. To accomplish this, after being instrumented to measure aerodynamic power and thrust (both in streamwise and transversal directions), a troposkien three-bladed rotor was installed on a high precision test bench, whose axis was suitable to be inclined up to 15° with respect to the design (i.e. upright) operating condition.The experiments were performed at the large scale, high speed wind tunnel of the Politecnico di Milano (Italy), using a "free jet" (open channel) configuration. The velocity field in the wake of the rotor was also fully characterized by means of an instrumented traversing system, to investigate the flow distribution downstream of the test section.Special care is taken in the description of the experimental set-up and of the measured data, so that the present results can be used as a benchmark for the validation of simulation models
Colloidal-structured metallic micro-grids: High performance transparent electrodes in the red and infrared range
project PON_206_2
project PRN 2014/2020
ALTALUZ (PTDC/CTM-ENE/5125/2014
PTDC/NAN-OPT/28430/2017
PTDC/NAN-OPT/28837/2017
PTDC/EAM-PEC/29905/2017
SFRH/BPD/114833/2016
SFRH/BPD/115566/2016One of the most promising approaches to produce industrial-compatible Transparent Conducting Materials (TCMs) with excellent characteristics is the fabrication of TCO/metal/TCO multilayers. In this article, we report on the electro-optical properties of a novel high-performing TCO/metal/TCO structure in which the intra-layer is a micro-structured metallic grid instead of a continuous thin film. The grid is obtained by evaporation of Ag through a mask of polystyrene colloidal micro-spheres deposited by the Langmuir-Blodgett method and partially dry-etched in plasma. IZO/Ag grid/IZO structures with different thicknesses and mesh dimensions have been fabricated, exhibiting excellent electrical characteristics (sheet resistance below 10 Ω/âĄ) and particularly high optical transmittance in the near-infrared spectral region as compared to planar (unstructured) TCM multilayers. Numerical simulations were also used to highlight the role of the Ag mesh parameters on the electrical properties.preprintpublishe
Treatment of atrial fibrillation with a dual defibrillator in heart failure patients (TRADE HF): protocol for a randomized clinical trial.
Background: Heart failure(HF) and atrial fibrillation(AF) frequently coexist in the same patient and are associated with increased mortality and frequent hospitalizations. As the concomitance of AF and HF is often associated with a poor prognosis, the prompt treatment of AF in HF patients may significantly improve outcome.Methods/design: Recent implantable cardiac resynchronization (CRT) devices allow electrical therapies to treat AF automatically. TRADE-HF (trial registration: NCT00345592; http://www.clinicaltrials.gov) is a prospective, randomized, double arm study aimed at demonstrating the efficacy of an automatic, device-based therapy for treatment of atrial tachycardia and fibrillation(AT/AF) in patients indicated for CRT. The study compares automatic electrical therapy to a traditional more usual treatment of AT/AF: the goal is to demonstrate a reduction in a combined endpoint of unplanned hospitalizations for cardiac reasons, death from cardiovascular causes or permanent AF when using automatic atrial therapy as compared to the traditional approach involving hospitalization for symptoms and in-hospital treatment of AT/AF.Discussion: CRT pacemaker with the additional ability to convert AF as well as ventricular arrhythmias may play a simultaneous role in rhythm control and HF treatment. The value of the systematic implantation of CRT ICDs with the capacity to deliver atrial therapy in HF patients at risk of AF has not yet been explored. The TRADE-HF study will assess in CRT patients whether a strategy based on automatic management of atrial arrhythmias might be a valuable option to reduce the number of hospital admission and to reduce the progression the arrhythmia to a permanent for
Breakup Conditions of Projectile Spectators from Dynamical Observables
Momenta and masses of heavy projectile fragments (Z >= 8), produced in
collisions of 197Au with C, Al, Cu and Pb targets at E/A = 600 MeV, were
determined with the ALADIN magnetic spectrometer at SIS. An analysis of
kinematic correlations between the two and three heaviest projectile fragments
in their rest frame was performed. The sensitivity of these correlations to the
conditions at breakup was verified within the schematic SOS-model. The data
were compared to calculations with statistical multifragmentation models and to
classical three-body calculations. Classical trajectory calculations reproduce
the dynamical observables. The deduced breakup parameters, however, differ
considerably from those assumed in the statistical multifragmentation models
which describe the charge correlations. If, on the other hand, the analysis of
kinematic and charge correlations is performed for events with two and three
heavy fragments produced by statistical multifragmentation codes, a good
agreement with the data is found with the exception that the fluctuation widths
of the intrinsic fragment energies are significantly underestimated. A new
version of the multifragmentation code MCFRAG was therefore used to investigate
the potential role of angular momentum at the breakup stage. If a mean angular
momentum of 0.75/nucleon is added to the system, the energy fluctuations
can be reproduced, but at the same time the charge partitions are modified and
deviate from the data.
PACS numbers: 25.70.Mn, 25.70.Pq, 25.75.Ld, 25.75.-qComment: 38 pages, RevTeX with 21 included figures; Also available from
http://www-kp3.gsi.de/www/kp3/aladin_publications.htm
Optical bandgap of semiconductor nanostructures: Methods for experimental data analysis
Determination of the optical bandgap (Eg) in semiconductor nanostructures is a key issue in understanding the extent of quantum confinement effects (QCE) on electronic properties and it usually involves some analytical approximation in experimental data reduction and modeling of the light absorption processes. Here, we compare some of the analytical procedures frequently used to evaluate the optical bandgap from reflectance (R) and transmittance (T) spectra. Ge quantum wells and quantum dots embedded in SiO2 were produced by plasma enhanced chemical vapor deposition, and light absorption was characterized by UV-Vis/NIR spectrophotometry. R&T elaboration to extract the absorption spectra was conducted by two approximated methods (single or double pass approximation, single pass analysis, and double pass analysis, respectively) followed by Eg evaluation through linear fit of Tauc or Cody plots. Direct fitting of R&T spectra through a Tauc-Lorentz oscillator model is used as comparison. Methods and data are discussed also in terms of the light absorption process in the presence of QCE. The reported data show that, despite the approximation, the DPA approach joined with Tauc plot gives reliable results, with clear advantages in terms of computational efforts and understanding of QCE. © 2017 Author(s)
New detectors for the kaon and hypernuclear experiments with KaoS at MAMI and with PANDA at GSI
The KaoS spectrometer at the Mainz Microtron MAMI, Germany, is perceived as
the ideal candidate for a dedicated spectrometer in kaon and hypernuclei
electroproduction. KaoS will be equipped with new read-out electronics, a
completely new focal plane detector package consisting of scintillating fibres,
and a new trigger system. First prototypes of the fibre detectors and the
associated new front-end electronics are shown in this contribution. The Mainz
hypernuclei research program will complement the hypernuclear experiments at
the planned FAIR facility at GSI, Germany. At the proposed antiproton storage
ring the spectroscopy of double Lambda hypernuclei is one of the four main
topics which will be addressed by the PANDA Collaboration. The experiments
require the operation of high purity germanium (HPGe) detectors in high
magnetic fields (B= 1T) in the presence of a large hadronic background. The
performance of high resolution Ge detectors in such an environment has been
investigated.Comment: Presentation at International Symposium on the Development of
Detectors for Particle, Astroparticle and Synchrotron Radiation Experiments,
Stanford, Ca (SNIC06), 6 pages, LaTeX, 11 eps figure
- âŠ