45 research outputs found
Coarse-grained model for the simulation of "active drops"
Micro-droplets of fluid can behave in peculiarly âactiveâ ways if subject to the action of external perturbations. The many possible applications and interesting properties they can express experimentally makes them the object of several studies. Water micro-droplets motion on small devices can be used for generating electrical currents and power simple electronic devices. Their motion can be also controlled for the creation of micro-reactors, micro-pumps and micro-fluidic devices. High interest is focused on the possibility to use them for mimicking the behavior of living systems, using a variety of experimental and computational set ups. My work was concerned with the development of a theoretical coarse-grained model for the simulation of some peculiar behaviour of active droplets. The model considers the mechanical response of the set of particles, here called beads, that interacts by proper combinations of forces. The visco-elastic nature of living cells makes the developed model useful both for the simulations of inanimate fluidic droplets and living cells. Cells are modelled as drops, made by beads of fluid aggregates. With the proper implementation of attractive forces and âactive particlesâ, drops can be active and spontaneously overcome their thermodynamic equilibrium status, closing the gap between inanimate and living matter behavior. In the dissertation, a deep investigation of the morphology and the forces involved in cell adhesion processes onto four different functionalized surfaces will be presented. Besides the work on cell adhesion, a study on neuritis growth, induced in the neuronal cell body by the presence of a chemical gradient on the surface, will be provided. The last part of my PhD thesis is concerned with the investigation of the guided movement and the morphological study of droplets onto solid surfaces, induced by the action of an external perturbation
Investigation of the GnRH antagonist degarelix isomerization in biological matrices
One of the main objectives of peptide drug design is the improvement of peptide
pharmacokinetics with maintaining biological activity, which can be achieved by the
complex modifications of the primary structure of the peptides. However, these
changes often lead to the formation of peculiar impurities in the peptide drugs and
their metabolites, which require the development of advanced analytical methods to
properly assess their content. Here, we investigated the degradation of the potent
long-acting GnRH antagonist degarelix in various biologic media by the tailor-made
HPLC method, which allows precise determination of 5-Aph(Hyd)-degarelix isomer,
an impurity found in the degarelix active pharmaceutical ingredient (API) during its
manufacturing. Unexpectedly, we discovered a rapid and irreversible conversion of
degarelix API into the corresponding hydantoin isomer in serum, suggesting that this
impurity can be also a potential drug metabolite in vivo. This finding underlines the
importance of the development of more accurate and performing analytical techniques to correctly characterize the chemical composition of the manufactured drugs and their behavior under physiological conditions
The Role of Adsorption and pH of the Mobile Phase on the Chromatographic Behavior of a Therapeutic Peptide
The impact of two different stationary phases and ion-pair reagents on the retention behavior of glucagon, a therapeutic peptide consisting of 29 amino acidic residues, has been investigated under reversed-phase elution conditions. Retention of glucagon was investigated under isocratic conditions by varying the fraction of the organic modifier in the range of 28â38% (v/v). The two stationary phases have been characterized in terms of excess adsorption isotherms to understand the preferential adsorption of eluent components on them. Results suggest that the ligand characteristics and the pH of the mobile phase play a pivotal role on retention
Neurocognition and social cognition in patients with schizophrenia spectrum disorders with and without a history of violence: results of a multinational European study
Objective: Neurocognitive impairment has been extensively studied in people with schizophrenia spectrum disorders and seems to be one of the major determinants of functional outcome in this clinical population. Data exploring the link between neuropsychological deficits and the risk of violence in schizophrenia has been more inconsistent. In this study, we analyse the differential predictive potential of neurocognition and social cognition to discriminate patients with schizophrenia spectrum disorders with and without a history of severe violence. Methods: Overall, 398 (221 cases and 177 controls) patients were recruited in forensic and general psychiatric settings across five European countries and assessed using a standardized battery. Results: Education and processing speed were the strongest discriminators between forensic and non-forensic patients, followed by emotion recognition. In particular, increased accuracy for anger recognition was the most distinctive feature of the forensic group. Conclusions: These results may have important clinical implications, suggesting potential enhancements of the assessment and treatment of patients with schizophrenia spectrum disorders with a history of violence, who may benefit from consideration of socio-cognitive skills commonly neglected in ordinary clinical practice
The potential of eupraxia@sparc_lab for radiation based techniques
A proposal for building a Free Electron Laser, EuPRAXIA@SPARC_LAB, at the Laboratori Nazionali di Frascati, is at present under consideration. This FEL facility will provide a unique combination of a high brightness GeV-range electron beam generated in a X-band RF linac, a 0.5 PW-class laser system and the first FEL source driven by a plasma accelerator. The FEL will produce ultra-bright pulses, with up to 1012 photons/pulse, femtosecond timescale and wavelength down to 3 nm, which lies in the so called âwater windowâ. The experimental activity will be focused on the realization of a plasma driven short wavelength FEL able to provide high-quality photons for a user beamline. In this paper, we describe the main classes of experiments that will be performed at the facility, including coherent diffraction imaging, soft X-ray absorption spectroscopy, Raman spectroscopy, Resonant Inelastic X-ray Scattering and photofragmentation measurements. These techniques will allow studying a variety of samples, both biological and inorganic, providing information about their structure and dynamical behavior. In this context, the possibility of inducing changes in samples via pump pulses leading to the stimulation of chemical reactions or the generation of coherent excitations would tremendously benefit from pulses in the soft X-ray region. High power synchronized optical lasers and a TeraHertz radiation source will indeed be made available for THz and pumpâprobe experiments and a split-and-delay station will allow performing XUV-XUV pumpâprobe experiments.Fil: Balerna, Antonella. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Bartocci, Samanta. UniversitĂ degli studi di Sassari; ItaliaFil: Batignani, Giovanni. UniversitĂ degli studi di Roma "La Sapienza"; ItaliaFil: Cianchi, Alessandro. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Chiadroni, Enrica. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Coreno, Marcello. Istituto Nazionale Di Fisica Nucleare.; Italia. Istituto di Struttura della Materia; ItaliaFil: Cricenti, Antonio. Istituto di Struttura della Materia; ItaliaFil: Dabagov, Sultan. Istituto Nazionale Di Fisica Nucleare.; Italia. National Research Nuclear University; Rusia. Lebedev Physical Institute; RusiaFil: Di Cicco, Andrea. Universita Degli Di Camerino; ItaliaFil: Faiferri, Massimo. UniversitĂ degli studi di Sassari; ItaliaFil: Ferrante, Carino. UniversitĂ degli studi di Roma âLa Sapienzaâ; Italia. Center for Life Nano Science @Sapienza; ItaliaFil: Ferrario, Massimo. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Fumero, Giuseppe. UniversitĂ degli studi di Roma âLa Sapienzaâ; ItaliaFil: Giannessi, Luca. Elettra-Sincrotrone Trieste; Italia. ENEA C.R. Frascati; ItaliaFil: Gunnella, Roberto. Universita Degli Di Camerino; ItaliaFil: Leani, Juan Jose. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂsica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂsica Enrique Gaviola; ArgentinaFil: Lupi, Stefano. UniversitĂ degli studi di Roma âLa Sapienzaâ; Italia. Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Roma La Sapienza; ItaliaFil: Macis, Salvatore. UniversitĂ degli Studi di Roma Tor Vergata; Italia. Istituto Nazionale di Fisica Nucleare (INFN) Sezione di Roma Tor Vergata; ItaliaFil: Manca, Rosa. UniversitĂ degli studi di Sassari; ItaliaFil: Marcelli, Augusto. Istituto Nazionale Di Fisica Nucleare.; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Masciovecchio, Claudio. Elettra-Sincrotrone Trieste; ItaliaFil: Minicucci, Marco. Universita Degli Di Camerino; ItaliaFil: Morante, Silvia. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Perfetto, Enrico. Universita Tor Vergata; Italia. Consiglio Nazionale delle Ricerche; ItaliaFil: Petrarca, Massimo. UniversitĂ degli studi di Roma "La Sapienza"; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Pusceddu, Fabrizio. UniversitĂ degli studi di Sassari; ItaliaFil: Rezvani, Javad. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Robledo, JosĂ© Ignacio. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂsica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂsica Enrique Gaviola; ArgentinaFil: Rossi, Giancarlo. Centro FermiâMuseo Storico della Fisica e Centro Studi e Ricerche âEnrico Fermiâ; Italia. Istituto Nazionale Di Fisica Nucleare.; Italia. Universita Tor Vergata; ItaliaFil: Sanchez, Hector Jorge. Consejo Nacional de Investigaciones CientĂficas y TĂ©cnicas. Centro CientĂfico TecnolĂłgico Conicet - CĂłrdoba. Instituto de FĂsica Enrique Gaviola. Universidad Nacional de CĂłrdoba. Instituto de FĂsica Enrique Gaviola; ArgentinaFil: Scopigno, Tullio. Center for Life Nano Science @Sapienza; Italia. UniversitĂ degli studi di Roma "La Sapienza"; ItaliaFil: Stefanucci, Gianluca. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Stellato, Francesco. Universita Tor Vergata; Italia. Istituto Nazionale Di Fisica Nucleare.; ItaliaFil: Trapananti, Angela. Universita Degli Di Camerino; ItaliaFil: Villa, Fabio. Istituto Nazionale Di Fisica Nucleare.; Itali
Modeling Living Cells Response to Surface Tension and Chemical Patterns
Mechanobiology is an important epigenetic factor. It influences cell functioning and bears on gene induction, protein synthesis, cell growth, and differentiation. In the presence of patterned chemical cues, living cells can take shapes that are far from that of a drop of fluid. These shapes are characterized by inward curvatures that are pinned at the points of location of the cues. The mechanochemical interactions that orchestrate cell behavior is simulated and controlled by modeling the cells as made by parcels of fluid. Cells become drops that are then endowed with the presence of additional forces, generated on the fly, that effectively make them active. With the proper choice of the forces, the phenomena that emerge from the dynamics match quantitatively the experiments. A combination of hydrophilic and lipophilic forces acting between the beads of fluid allows the active drop to respond to patterned cues and form squares, pentagons, hexagons, and flowers, just as living cells do
Which achievements are associated with a better offensive performance in NBA? A survival analysis study
Data analytics spread consistently over the years for answering several questions in all the fields, included sports. The aim of this work is to analyze the offensive performance of NBA players in terms of the amount of minutes taken to exceed a given point threshold during the post All-Star season segment. The final goal is to perform variable selection, identifying which are the main playersâ achievements that significantly impact the outcome. Survival analysis methods, in particular Cox regression and LASSO Cox have been used. Results suggest that attempting a higher number of two- and three-point shots, having been selected for the All-Stars game and gaining more double doubles increase the probability of exceeding the threshold and of doing it in a shorter time. Another interesting result regards the number of steals, the only variable selected by the models related to defense and game construction, which was negatively associated to the outcome
Modeling Living Cells Response to Surface Tension and Chemical Patterns
Mechanobiology is an important epigenetic
factor. It influences cell functioning and bears on gene induction,
protein synthesis, cell growth, and differentiation. In the presence
of patterned chemical cues, living cells can take shapes that are
far from that of a drop of fluid. These shapes are characterized by
inward curvatures that are pinned at the points of location of the
cues. The mechanochemical interactions that orchestrate cell behavior
is simulated and controlled by modeling the cells as made by parcels
of fluid. Cells become drops that are then endowed with the presence
of additional forces, generated on the fly, that effectively make
them active. With the proper choice of the forces, the phenomena that
emerge from the dynamics match quantitatively the experiments. A combination
of hydrophilic and lipophilic forces acting between the beads of fluid
allows the active drop to respond to patterned cues and form squares,
pentagons, hexagons, and flowers, just as living cells do
A 0.07 mm2 asynchronous logic CMOS pulsed receiver based on radio events self-synchronization
Modeling Living Cells Response to Surface Tension and Chemical Patterns
Mechanobiology is an important epigenetic
factor. It influences cell functioning and bears on gene induction,
protein synthesis, cell growth, and differentiation. In the presence
of patterned chemical cues, living cells can take shapes that are
far from that of a drop of fluid. These shapes are characterized by
inward curvatures that are pinned at the points of location of the
cues. The mechanochemical interactions that orchestrate cell behavior
is simulated and controlled by modeling the cells as made by parcels
of fluid. Cells become drops that are then endowed with the presence
of additional forces, generated on the fly, that effectively make
them active. With the proper choice of the forces, the phenomena that
emerge from the dynamics match quantitatively the experiments. A combination
of hydrophilic and lipophilic forces acting between the beads of fluid
allows the active drop to respond to patterned cues and form squares,
pentagons, hexagons, and flowers, just as living cells do