Posterior corneal surface stability after femtosecond laser-assisted keratomileusis

The purpose of this study was to evaluate posterior corneal surface variation after femtosecond laser-assisted keratomileusis in patients with myopia and myopic astigmatism. Patients were evaluated by corneal tomography preoperatively and at 1, 6, and 12 months. We analyzed changes in the posterior corneal curvature, posterior corneal elevation, and anterior chamber depth. Moreover, we explored correlation between corneal ablation depth, residual corneal thickness, percentage of ablated corneal tissue, and preoperative corneal thickness. During follow-up, the posterior corneal surface did not have a significant forward corneal shift: no significant linear relationships emerged between the anterior displacement of the posterior corneal surface and corneal ablation depth, residual corneal thickness, or percentage of ablated corneal tissue

Icarus Ensemble at hcmf//: Interview with Marco Pedrazzini

Icarus Ensemble was founded in 1994 in Reggio Emilia, Italy. Since then, they've been performingbasically everywhere in the world, giving a tremendous contribution to contemporary music in Italyand abroad. At hcmf// 2011 they present two concerts: the European Composers Spotlight onWednesday 23 November and the programme of Romitelli works on Thursday 24 November.Marco Pedrazzini, cofounderand artistic director of the ensemble, speaks to Marcello Messina, whohas been working with the ensemble this year as a composer on the European Composers'Professional Development Programme (ECPDP).Icarus Ensemble was founded in 1994 in Reggio Emilia, Italy. Since then, they've been performingbasically everywhere in the world, giving a tremendous contribution to contemporary music in Italyand abroad. At hcmf// 2011 they present two concerts: the European Composers Spotlight onWednesday 23 November and the programme of Romitelli's works on Thursday 24 November.Marco Pedrazzini, cofounder and artistic director of the ensemble, speaks to Marcello Messina, who has been working with the ensemble this year as a composer on the European Composers' Professional Development Programme (ECPDP)

Homogeneous and inhomogeneous contributions to the luminescence linewidth of point defects in amorphous solids: Quantitative assessment based on time-resolved emission spectroscopy

The article describes an experimental method that allows to estimate the inhomogeneous and homogeneous linewidths of the photoluminescence band of a point defect in an amorphous solid. We performed low temperature time-resolved luminescence measurements on two defects chosen as model systems for our analysis: extrinsic Oxygen Deficient Centers (ODC(II)) in amorphous silica and F+ 3 centers in crystalline Lithium Fluoride. Measurements evidence that only defects embedded in the amorphous matrix feature a dependence of the radiative decay lifetime on the emission energy and a time dependence of the first moment of the emission band. A theoretical model is developed to link these properties to the structural disorder typical of amorphous solids. Specifically, the observations on ODC(II) are interpreted by introducing a gaussian statistical distribution of the zero phonon line energy position. Comparison with the results obtained on F+ 3 crystalline defects strongly confirms the validity of the model. By analyzing experimental data within this frame, we obtain separate estimations of the homogenous and inhomogeneous contributions to the measured total linewidth of ODC(II), which results to be mostly inhomogeneous.Comment: 8 pages, 4 figure

Chemical communication between synthetic and natural cells: a possible experimental design

The bottom-up construction of synthetic cells is one of the most intriguing and interesting research arenas in synthetic biology. Synthetic cells are built by encapsulating biomolecules inside lipid vesicles (liposomes), allowing the synthesis of one or more functional proteins. Thanks to the in situ synthesized proteins, synthetic cells become able to perform several biomolecular functions, which can be exploited for a large variety of applications. This paves the way to several advanced uses of synthetic cells in basic science and biotechnology, thanks to their versatility, modularity, biocompatibility, and programmability. In the previous WIVACE (2012) we presented the state-of-the-art of semi-synthetic minimal cell (SSMC) technology and introduced, for the first time, the idea of chemical communication between synthetic cells and natural cells. The development of a proper synthetic communication protocol should be seen as a tool for the nascent field of bio/chemical-based Information and Communication Technologies (bio-chem-ICTs) and ultimately aimed at building soft-wet-micro-robots. In this contribution (WIVACE, 2013) we present a blueprint for realizing this project, and show some preliminary experimental results. We firstly discuss how our research goal (based on the natural capabilities of biological systems to manipulate chemical signals) finds a proper place in the current scientific and technological contexts. Then, we shortly comment on the experimental approaches from the viewpoints of (i) synthetic cell construction, and (ii) bioengineering of microorganisms, providing up-to-date results from our laboratory. Finally, we shortly discuss how autopoiesis can be used as a theoretical framework for defining synthetic minimal life, minimal cognition, and as bridge between synthetic biology and artificial intelligence.Comment: In Proceedings Wivace 2013, arXiv:1309.712

Early results on the use of chitosan-N-acetylcysteine (Lacrimera®) in the management of dry eye disease of varied etiology

PurposeTo evaluate the effect of once daily administration of chitosan-N-acetylcysteine (Lacrimera®) in the management of dry eye disease (DED).MethodsEighteen patients (3 male, 15 female) aged 25–86 years (mean 61.1) and suffering from moderate to severe DED with superficial punctate keratitis (SPK) were retrospectively evaluated after a trial of Lacrimera® drops (1 drop in the morning for 5 days only). All the patients were using other artificial tears before the treatment. All lubricants were stopped, and Lacrimera® was started instead. Slit-lamp examination and images were taken before and at 1 and 3 weeks follow-up after the treatment. The subjective (Ocular Surface Disease Index, OSDI) and objective (Oxford Grading System, OGS) evaluation was recorded. A paired student’s t test was performed to analyse the data.ResultsAt baseline, the SPK grade was I to IV (OGS) and the OSDI ranged from 25 to 71.4. Fifteen patients showed a statistically significant (p < 0.0001) improvement in OGS and the OSDI at 3 weeks post-treatment. Three patients showed no improvement.ConclusionsA single-dose instillation of chitosan-N-acetylcysteine for five consecutive days improved signs and symptoms in patients affected from DED from a variety of causes, who were refractory to standard treatment with lubricants. Given its posology, the absence of side effects and the results obtained Lacrimera® should be taken into consideration as a viable option in patients with moderate to severe DED

The unintended consequences of an Italian labour protection law

Fewer people were hired; firms increased their capital stock but their productivity declined, write Federico Cingano, Marco Leonardi, Julián Messina and Giovanni Pic

Computational analysis and optimization of a MEMS-based piezoresistive accelerometer for head injuries monitoring.

This work focuses on the design improvement of a tri-axial piezoresistive accelerometer specifically designed for head injuries monitoring where medium-G impacts are common, for example in sports such as racing cars. The device requires the highest sensitivity achievable with a single proof mass approach, and a very low error as the accuracy for these types of applications is paramount. The optimization method differs from previous work as it is based on the progressive increment of the sensor mass moment of inertia (MMI) in all three axes. The work numerically demonstrates that an increment of MMI determines an increment of device sensitivity with a simultaneous reduction of cross-talk in the particular axis under study. The final device shows a sensitivity increase of about 80% in the Z-axis and a reduction of cross-talk of 18% respect to state-of-art sensors available in the literature. Sensor design, modelling and optimization are presented, concluding the work with results, discussion and conclusion

Effect of efflux pump inhibition on Pseudomonas aeruginosa transcriptome and virulence

Efflux pumps of the resistance-nodulation-cell-division (RND) family increase antibiotic resistance in many bacterial pathogens, representing candidate targets for the development of antibiotic adjuvants. RND pumps have also been proposed to contribute to bacterial infection, implying that efflux pump inhibitors (EPIs) could also act as anti-virulence drugs. Nevertheless, EPIs are usually investigated only for their properties as antibiotic adjuvants, while their potential anti-virulence activity is seldom taken into account. In this study it is shown that RND efflux pumps contribute to Pseudomonas aeruginosa PAO1 pathogenicity in an insect model of infection, and that the well-characterized EPI Phe-Arg-β-naphthylamide (PAβN) is able to reduce in vivo virulence of the P. aeruginosa PAO1 laboratory strain, as well as of clinical isolates. The production of quorum sensing (QS) molecules and of QS-dependent virulence phenotypes is differentially affected by PAβN, depending on the strain. Transcriptomic and phenotypic analyses showed that the protection exerted by PAβN from P. aeruginosa PAO1 infection in vivo correlates with the down-regulation of key virulence genes (e.g. genes involved in iron and phosphate starvation). Since PAβN impacts P. aeruginosa virulence, anti-virulence properties of EPIs are worthy to be explored, taking into account possible strain-specificity of their activit

Developing Inorganic Approaches to Polymerization and Bioconjugation

Multi-disciplinary approaches to problem solving are needed given the increasing complexity of fundamental scientific questions. This dissertation undertakes a holistic approach to research and tackles challenges spanning the biology, chemistry, and materials interface. The central theme for most projects involves applying inorganic and main group chemistry to develop new bioconjugation strategies or polymerization methodologies to access novel materials. Chapter One describes efforts in understanding the effects of trehalose polymers towards protein stabilization. The stabilization capability of polymers made from a set of styrenyl-based trehalose monomer regioisomers were studied. Polymers of each trehalose monomer regioisomer and one polymer which contained all three isomers combined were synthesized. All polymer regioisomers stabilized insulin to a similar degree towards agitation and heat stress.Chapter Two details the initial discovery that icosahedral boron-rich cluster compounds of the type B12(OR12)—where “R” can be any alkyl or aryl group— could be utilized as strong one-electron photooxidants thereby initiating the polymerization of olefins. The perfunctionalized clusters are able to initiate polymerization of a range of styrene substrates under blue LED irradiation. Also demonstrated, is the visible light initiated, metal free cationic polymerization of isobutylene into poly(isobutylene).Chapter Three introduces a new class of carborane-based chain-transfer agents (CTA’s) to be used in reversible addition-fragmentation chain-transfer (RAFT) polymerization. The carborane-based CTA’s mediate the controlled polymerization of monomers such as styrene, N-isopropylacrylamide, and methyl acrylate to produce monodisperse carborane terminated polymers. The carborane-based scaffold, appended on the polymer chain end, serves as a general 1H NMR spectroscopic handle used to elucidate polymer molecular weight. Binding of carborane into the hydrophobic cavity of β-cyclodextrin was demonstrated by isothermal titration calorimetry thereby validating its potential use as an affinity label. The carborane RAFT agents also act as Raman active probes.Chapter Four explores the reactivity of gold(III) organometallic complexes in the context of bioconjugation chemistry. The gold(III) organometallic complexes mediated the conjugation of small molecule substrates which included heterocycles, an anti-cancer drug, biotin, and low molecular weight PEG to cysteine residues on biomolecules. The bioconjugation reactions proceeded rapidly, with high efficiency, and in a broad pH range

Intelligenza artificiale: i primi 50 anni

La tesi tratta dell'origine e dello sviluppo dell'intelligenza artificiale. Il primo capitolo si sofferma sulla cibernetica, disciplina scientifica nata negli anni Quaranta che può essere vista come la matrice originale da cui nacque l'intelligenza artificiale. Nel secondo capitolo, viene presa in esame la collaborazione tra John McCarthy e Claude Shannon per la stesura degli Automata Studies, una raccolta di articoli aventi come tema le macchine intelligenti; la delusione per il risultato finale avrebbe spinto McCarthy a organizzare la Conferenza di Dartmouth del 1956, argomento principale del terzo capitolo. Il quarto capitolo si sofferma invece sugli effetti di queste nuove scoperte in Italia durante gli anni Cinquanta-Sessanta. Infine, nell'ultimo capitolo viene presa in esame la conferenza del 2006 AI@50, nata per celebrare la Conferenza di Dartmouth originale e per analizzare gli sviluppi dell'intelligenza artificiale nell'intervallo di tempo intercorso tra i due eventi