New measurements of Ωm\Omega_m from gamma-ray bursts

Context: Data from cosmic microwave background radiation (CMB), baryon acoustic oscillations (BAO), and supernovae Ia (SNe-Ia) support a constant dark energy equation of state with $w_0 \sim -1$. Measuring the evolution of $w$ along the redshift is one of the most demanding challenges for observational cosmology. Aims: We discuss the existence of a close relation for GRBs, named Combo-relation, based on characteristic parameters of GRB phenomenology such as the prompt intrinsic peak energy $E_{p,i}$, the X-ray afterglow, the initial luminosity of the shallow phase $L_0$, the rest-frame duration $\tau$ of the shallow phase, and the index of the late power-law decay $\alpha_X$. We use it to measure $\Omega_m$ and the evolution of the dark energy equation of state. We also propose a new calibration method for the same relation, which reduces the dependence on SNe Ia systematics. Methods: We have selected a sample of GRBs with 1) a measured redshift $z$; 2) a determined intrinsic prompt peak energy $E_{p,i}$, and 3) a good coverage (0.3-10) keV afterglow light curves. The fitting technique of the rest.frame (0.3-10) keV luminosity light curves represents the core of the Combo-relation. We separate the early steep decay, considered a part of the prompt emission, from the X-ray afterglow additional component. Data with the largest positive residual, identified as flares, are automatically eliminated until the p-value of the fit becomes greater than 0.3. Results: We strongly minimize the dependency of the Combo-GRB calibration on SNe Ia. We also measure a small extra-Poissonian scatter of the Combo-relation, which allows us to infer from GRBs alone $\Omega_M =0.29^{+0.23}_{-0.15}$ (1$\sigma$) for the $\Lambda$CDM cosmological model, and $\Omega_M =0.40^{+0.22}_{-0.16}$, $w_0 = -1.43^{+0.78}_{-0.66}$ for the flat-Universe variable equation of state case.Comment: 10 pages, 9 figures, 3 tables. Accepted for publication in A&A. Truncated abstract tex

Nanomedicine applications mediated by electromagnetic fields

Recently, the introduction of nanotechnologies into medical applications has become more frequent due to the growing of several diseases originating from alteration of biological processes at molecular and nanoscale level (e.g. mutated genes, cell malfunction due to viruses or bacteria). The nanomedicine combines the innovation of the nanotechnology materials (shape and size of nm scale) to health care, providing new promising techniques for the diagnosis, the prevention, the tissue regeneration and therapeutic fields. Disorders like cancer, Alzheimer’s, Parkinson’s disease, cardiovascular problems or inflammatory diseases are serious challenges to be dealt with. For this reason researches are focusing their attention to the nanomaterials unique properties [Murty et al., 2013, Xia et al., 2009]. The progress in nanomedicine ranges from nanoparticles for molecular diagnostics, imaging and therapy to integrated medical nanosystems [Nune et al., 2009, Shi, 2009] to act at the cellular level inside the body. For a recent review on challenges, opportunities, and clinical applications in nanomedicine an interesting review is the one of Wicki et al. [Wicki et al., 2015]. Despite the concerns raised by the authors in their review, the expert opinion on clinical opportunities finds a generalized consensus on stimuli-responsive systems for targeting the compound (drug, gene, biomolecule) at the site of interest and on the use of lipid based nanosystems for the biocompatible platform to be used in clinical trials. In this scenario is placed the main activity of this Ph.D. thesis whose aim is to provide a multiscale and multidisciplinary approach to demonstrate the capability to activate lipid-based nanosystems by means of electromagnetic fields (EMFs). Specifically, the attention will be focused, on a first part, on the liposome-based systems mediated by EMF to provide a proof-of-concept of EMF stimuli-response systems for applications of drug delivery. This aspect will be approached both form a theoretic, technological and experimental point of view. Moreover, because proteins are considered a fundamental pattern as bio-sensors for signaling cell processes, a molecular dynamics simulation approach will be provided to study the interaction mechanisms between EMFs and proteins structures for potential protein activation

Technological and theoretical aspects for testing electroporation on liposomes

Recently, the use of nanometer liposomes as nanocarriers in drug delivery systems mediated by nanoelectroporation has been proposed. This technique takes advantage of the possibility of simultaneously electroporating liposomes and cell membrane with 10-nanosecond pulsed electric fields (nsPEF) facilitating the release of the drug from the liposomes and at the same time its uptake by the cells. In this paper the design and characterization of a 10 nsPEF exposure system is presented, for liposomes electroporation purposes. The design and the characterization of the applicator have been carried out choosing an electroporation cuvette with 1 mm gap between the electrodes. The structure efficiency has been evaluated at different experimental conditions by changing the solution conductivity from 0.25 to 1.6 S/m. With the aim to analyze the influence of device performances on the liposomes electroporation, microdosimetric simulations have been performed considering liposomes of 200 and 400 nm of dimension with different inner and outer conductivity (from 0.05 to 1.6 S/m) in order to identify the voltage needed for their poration

Can pulsed electromagnetic fields trigger on-demand drug release from high-tm magnetoliposomes?

Recently, magnetic nanoparticles (MNPs) have been used to trigger drug release from magnetoliposomes through a magneto-nanomechanical approach, where the mechanical actuation of the MNPs is used to enhance the membrane permeability. This result can be effectively achieved with low intensity non-thermal alternating magnetic field (AMF), which, however, found rare clinic application. Therefore, a different modality of generating non-thermal magnetic fields has now been investigated. Specifically, the ability of the intermittent signals generated by non-thermal pulsed electromagnetic fields (PEMFS) were used to verify if, once applied to high-transition temperature magnetoliposomes (high-Tm MLs), they could be able to efficiently trigger the release of a hydrophilic model drug. To this end, hydrophilic MNPs were combined with hydrogenated soybean phosphatidylcholine and cholesterol to design high-Tm MLs. The release of a dye was evaluated under the effect of PEMFs for different times. The MNPs motions produced by PEMF could effectively increase the bilayer permeability, without affecting the liposomes integrity and resulted in nearly 20% of release after 3 h exposure. Therefore, the current contribution provides an exciting proof-of-concept for the ability of PEMFS to trigger drug release, considering that PEMFS find already application in therapy due to their anti-inflammatory effects

Nanosecond Pulsed Electric Signals Can Affect Electrostatic Environment of Protiens Below the Threshold of Conformational Effects: The Case Study of SOD1 With a Molecular Simulation Study

Electric fields can be a powerful tool to interact with enzymes or proteins, with an intriguing perspective to allow protein manipulation. Recently, researchers have focused the interest on intracellular enzyme modifications triggered by the application of nanosecond pulsed electric fields. These findings were also supported by theoretical predictions from molecular dynamics simulations focussing on significant variations in protein secondary structures. In this work, a theoretical study utilizing molecular dynamics simulations is proposed to explore effects of electric fields of high intensity and very short nanosecond duration applied to the superoxide dismutase (Cu/Zn-SOD or SOD-1), an important enzyme involved in the cellular antioxidant defence mechanism. The effects of 100-nanosecond pulsed electric fields, with intensities ranging from 108 to 7x108 V/m, on a single SOD1 enzyme are presented. We demonstrated that the lowest intensity of 108 V/m, although not inducing structural changes, can produce electrostatic modifications on the reaction centre of the enzyme, as apparent from the dipolar response and the electric field distribution of the protein active site. Electric pulses above 5x108 V/m produced a fast transition between the folded and a partially denatured state, as inferred by the secondary structures analysis. Finally, for the highest field intensity used (7x108 V/m), a not reversible transition toward an unfolded state was observed

Towards Knowledge in the Cloud

Knowledge in the form of semantic data is becoming more and more ubiquitous, and the need for scalable, dynamic systems to support collaborative work with such distributed, heterogeneous knowledge arises. We extend the “data in the cloud” approach that is emerging today to “knowledge in the cloud”, with support for handling semantic information, organizing and finding it efficiently and providing reasoning and quality support. Both the life sciences and emergency response fields are identified as strong potential beneficiaries of having ”knowledge in the cloud”

Transient Heavy Element Absorption Systems in Novae: Episodic Mass Ejection from the Secondary Star

A high-resolution spectroscopic survey of postoutburst novae reveals short-lived heavy element absorption systems in a majority of novae near maximum light, having expansion velocities of 400-1000 km/s and velocity dispersions between 35-350 km/s. A majority of systems are accelerated outwardly, and they all progressively weaken and disappear over timescales of weeks. A few of the systems having narrow, deeper absorption reveal a rich spectrum of singly ionized Sc, Ti, V, Cr, Fe, Sr, Y, Zr, and Ba lines. Analysis of the richest such system, in Nova LMC 2005, shows the excitation temperature to be 104 K and elements lighter than Fe to have abundance enhancements over solar values by up to an order of magnitude. The gas causing the absorption systems must be circumbinary and its origin is most likely mass ejection from the secondary star. The absorbing gas pre-exists the outburst and may represent episodic mass transfer events from the secondary star that initiate the nova outburst(s). If SNe Ia originate in single degenerate binaries, such absorption systems could be detectable before maximum lightComment: 19 pages, 6 figures, accepted for publication in the Astrophysical Journa

The p75NTR-induced Apoptotic Program Develops through a Ceramide-Caspase Pathway Negatively Regulated by Nitric Oxide

SK-N-BE neuroblastoma cell clones transfected with p75(NTR) and lacking Trk neurotrophin receptors, previously reported to undergo extensive spontaneous apoptosis and to be protected by nerve growth factor (NGF) (Bunone, G., Mariotti, A., Compagni, A., Morandi, E., and Della Valle, G. (1997) Oncogene 14, 1463-1470), are shown to exhibit (i) increased levels of the pro-apoptotic lipid metabolite ceramide and (ii) high activity of caspases, the proteases of the cell death cascade. In the p75(NTR)-expressing cells, these parameters were partially normalized by prolonged NGF treatment, which, in addition, decreased apoptosis, similar to caspase blockers. Conversely, exogenous ceramide increased caspase activity and apoptosis in both wild-type and p75(NTR)-expressing cells. A new p75(NTR)-expressing clone characterized by low spontaneous apoptosis exhibited high endogenous ceramide and low caspase levels. A marked difference between the apoptotic and resistant clones concerned the very low and high activities of nitric-oxide (NO) synthase, respectively. Protection from apoptosis by NO was confirmed by results with the NO donor S-nitrosoacetylpenicillamine and the NO-trapping agent hemoglobin. We conclude that the p75(NTR) receptor, while free of NGF, triggers a cascade leading to apoptosis; the cascade includes generation of ceramide and increased caspase activity; and the protective role of NO occurs at step(s) in between the latter events

ENABLING COLLABORATIVE E-HEALTH THROUGH TRIPLESPACE COMPUTING

Abstract The design and promotion of electronic patient summaries as an instrument to facilitate the pervasive delivery of healthcare is emerging as a key technology in eHealth solutions. From the technical point of view this requires powerful middleware systems supporting interoperability, multi-lingualism, security and patient privacy. In this paper we present a semantic coordination model and describe how it can be used to support pervasive access to electronic patient summaries

Models for the Type Ic Hypernova SN 2003lw associated with GRB 031203

The Gamma-Ray Burst 031203 at a redshift z=0.1055 revealed a highly reddened Type Ic Supernova, SN 2003lw, in its afterglow light. This is the third well established case of a link between a long-duration GRB and a type Ic SN. The SN light curve is obtained subtracting the galaxy contribution and is modelled together with two spectra at near-maximum epochs. A red VLT grism 150I spectrum of the SN near peak is used to extend the spectral coverage, and in particular to constrain the uncertain reddening, the most likely value for which is E_{G+H}(B-V) about 1.07 +/- 0.05. Accounting for reddening, SN 2003lw is about 0.3 mag brighter than the prototypical GRB-SN 1998bw. Light curve models yield a 56Ni mass of about 0.55 solar mass. The optimal explosion model is somewhat more massive (ejecta mass about 13 solar mass) and energetic (kinetic energy about 6 times 10^52 erg) than the model for SN 1998bw, implying a massive progenitor (40 - 50 solar mass). The mass at high velocity is not very large (1.4 solar mass above 30000 km/s, but only 0.1 solar mass above 60000 km/s), but is sufficient to cause the observed broad lines. The similarity of SNe 2003lw and 1998bw and the weakness of their related GRBs, GRB031203 and GRB980425, suggest that both GRBs may be normal events viewed slightly off-axis or a weaker but possibly more frequent type of GRB.Comment: 19 pages, 8 figures, accepted for publication in Ap