Search

International audience; A new hybrid microwave (MW) and ultrasound (US)-assisted reactor concept was investigated. The 2.45 GHz microwaves were delivered by a semiconductor generator via a coaxial cable to a monomode Transverse Electric (TE) microwave resonant cavity within which the reactor was placed; the US (25 kHz) were delivered at the bottom of the TE cavity via a novel designed sonotrode consisting of a detachable metallic plate-probe (indirect sonication). The semiconductor microwave generator helped to optimize the absorbed energy via its automatic frequency tuning function. The dual MW/US device allowed the use of both technologies separately or in a simultaneous combined manner. The ring-closing metathesis of diethyl diallyl malonate in glycerol micellar conditions was studied as an example using this novel hybrid technology. The results were compared with those obtained when microwaves or ultrasound were applied individually. Various benzylidene-, indenylidene- and Hoveyda–Grubbs-type catalysts were screened. The novel reactor for combined MW/US irradiation showed beneficial effects on the outcome of the reaction.

The study was carried out on type 2 diabetic obese patients who underwent laparoscopic sleeve gastrectomy (LSG). Patients underwent regular glycemic controls throughout 3 years and all patients were defined cured from diabetes according to conventional criteria defined as normalization of fasting glucose levels and glycated hemoglobin in absence of antidiabetic therapy. After 3 years of follow-up, Continuous Glucose Monitoring (CGM) was performed in each patient to better clarify the remission of diabetes. In this study, we found that the diabetes resolution after LSG occurred in 40% of patients; in the other 60%, even if they showed a normal fasting glycemia and A1c, patients spent a lot of time in hyperglycemia. During the oral glucose tolerance test (OGTT), we found that 2 h postload glucose determinations revealed overt diabetes only in a small group of patients and might be insufficient to exclude the diagnosis of diabetes in the other patients who spent a lot of time in hyperglycemia, even if they showed a normal glycemia (

The development of magnetic nanoparticles for biomedical applications requires a detailed characterization of their magnetic properties, with relation not only to their chemical structure, but also their morphology and size. Magnetic force microscopy (MFM), thanks to its nanometric lateral resolution and its capability to detect weak magnetic fields, appears as a powerful tool for the characterization of the magnetic properties of single nanoparticles, together with their morphological characteristics. Nevertheless, the application of MFM to the quantitative measurements of magnetic properties at the nanoscale is still an open issue because of a certain incongruence between experimental data and existing theoretical models of the tip-sample magnetic interactions. In this work, MFM data acquired on different magnetic nanoparticles in different experimental conditions (magnetized and not magnetized probes, out-of-field and in-field measurements) are analyzed, with the aim of individuating the possible phenomena affecting MFM measurements. These include topography-induced artifacts resulting from the tip-sample capacitive coupling, which we propose here for the first time. In case of measurements performed in presence of an external magnetic field, much more intense MFM signals were detected as it produces the saturation of the magnetization of the nanoparticles, which is not completely obtained by the sole stray field produced by the tip. Nevertheless, even in in-field measurements, the results evidenced the presence of significant electrostatic effects in MFM images, which, therefore, appear as an important factor to be taken into account for the quantitative interpretation of MFM data.

The purpose of this article is to show that it is possible to make efficient optical tweezers using a properly modified single mode fiber. By using a micro-lens, fabricated directly on the cleaved end of an optical fiber, by a focused ion beam milling process, efficient optical tweezers can be obtained. A 30 keV focused Ga+ ion beam is used to mill a continuous profile microstructure. An axicon with 10 mu m diameters and 5 pm high is fabricated, which permits the transformation of a Gaussian mode in a Bessel mode beam. This particular mode was used to form an optical trap. Measures of the propagation profile and of the trapping effect will be discussed. (c) 2006 Elsevier B.V. All rights reserved.

The discovery of microRNAS (miRNAs) and of their mechanism of action has provided some very new clues on how gene expression is regulated. These studies established new concepts on how posttranscriptional control can fine-tune gene expression during differentiation and allowed the identification of new regulatory circuitries as well as factors involved therein. Because of the wealth of information available about the transcriptional and cellular networks involved in hematopoietic differentiation, the hematopoietic system is ideal for studying cell lineage specification. An interesting interplay between miRNAs and lineage-specific transcriptional factors has been found, and this can help us to understand how terminal differentiation is accomplished.

We address the problem of optimizing the delivery of multimedia services with different quality-of-service (QoS) requirements to mobile users. We assume that the network provides two distinct classes of service to which users may subscribe: Premium, or Economy. Subscribers to the Premium service pay more for their connections but receive a higher level of quality measured by a set of parameters such as call blocking probability, coding rate, and format of the multimedia services. By optimizing the delivery of the multimedia services, we mean that the network guarantees that all users receive their agreed-upon contractual level of quality, while maximizing the links' throughput, avoiding congestion, and maintaining the QoS requirements for each type of media (e.g., video, voice and data). Our proposed solution is based upon utilizing genetic algorithms to solve a multiobjective optimization function that adaptively selects the downloading bit-rate for each type of traffic flow subject to the constraints of the optimization function. A traffic flow is an abstract of aggregate traffic of the same type of media (e.g., voice, video, or data) that is downloaded to a group of users who share some common attribute such as the same class of service. The optimization function is adaptive in the sense that the selected downloading bit-rates are time-dependant according to the dynamics of the links' traffic-loads and users' requests. It is implemented on every output port of each node in the network. The function is used to control a filter that changes the coding rate of each media-type and, if necessary, performs transcoding of one, or more, media-types (i.e., video, voice, or data). Simulation results show significant improvement in terms of increasing the number of admitted users, while maintaining the QoS requirements, as well as target call blocking rates. An interesting result to report is that the performance improvement of the system (measured by the gain in the number of admitted users at a certain utilization factor) is not simply bounded by the maximum available link throughput. It is, rather, limited by the additional revenue gained by admitting more users. The increase in the revenue saturates at a certain offered traffic-load. Hence, it is not worth it, from a service provider perspective, to admit additional users above this traffic load despite the fact that the filtering algorithm results indicate otherwise.

We report on the correlation between structural and electrical properties of pentacene thin film transistors fabricated by the novel supersonic molecular beam epitaxy (SuMBE) technique. We exploited the ability of SuMBE that, through the control on the molecular precursors in the beam, allows improving the quality in terms of structure and morphology of the semi-conducting thin films compared to the more standard OMBE growth. Different growth conditions were explored to find the better range of beam parameters improving the performance of the TFT device whereas the quality of the films grown was studied by atomic force microscopy. We show that the initial kinetic energy of the pentacene molecule strongly affects both the morphology of the films and the electrical properties of the devices that result to be strongly correlated. With our FET devices prepared, on SiO 2 /Si and top Au contact, we achieved the very promising field effect mobility larger than 0.5 cm 2 V −1 s −1 for films grown at room temperature at a pentacene kinetic energy of about 5.5 eV that are characterized by large crystalline grains (>2 μm).

Nowadays the relevance of silicon chemistry is spreading due to the applications of Si, in particular in semiconductors, in order to obtain an increasing number of performing materials. A theoretical investigation based on the Density Functional Theory has been done on the reaction paths implied in the Pt-catalysed alkene hydrosilylation, a process through which the selective grafting of organic molecules to silicon can be obtained. We studied the Si-H oxidative addition of SiH 4 to a diphosphine molecule, the C 2 H 4 insertion on Pt-H and Pt-SiH 3 bonds, the isomerisation of the product of the C 2 H 4 insertion, and the two following Si-C and C-H reductive eliminations. The set of these processes are known as the Chalk-Harrod mechanism and the modified Chalk-Harrod mechanism, respectively. The main goal of this work has been to identify the rate determining step of both mechanisms. Moreover, by employing dynamics simulations, we have reached a possible alternative product in the oxidative addition step.

We report a DFT/TDDFT study on the geometric, electronic and optical properties of [Ru{4'-(4-pyridyl)-2,2':6',2"-terpyridine}2]2+. Because of the presence of the basic nitrogen atom on the terminal pyridyl ligands, in solution the complex can exist in three different protonation states depending on the pH, each with markedly different photophysical properties. We investigated the effect of protonation of the terminal pyridine groups on the electronic and optical properties of this RuII complex. TDDFT calculations in vacuo and aqueous solution were performed, finding good agreement between the simulated and the experimental absorption spectra, and reproducing the experimentally observed absorption redshift upon pyridine protonation. The calculated excited-state data provide a rationale for the luminescence properties observed by varying the solution pH, in terms of the different energy separation between MLCT and MC excited states in the complexes.

To assess the effects of preoperative patient characteristics on clinical outcomes of corneal collagen crosslinking (CXL) in patients with progressive keratoconus.Fifty-four eyes of 41 patients underwent CXL for progressive keratoconus between June 2011 and December 2012. Corneal topography (Orbscan(®)) was assessed at 1, 3, and 6 months and 1 year after CXL treatment and compared with preoperative data.A significant improvement in 1-year postoperative best-corrected visual acuity (BCVA) (0.16±0.21 LogMar preoperatively versus 0.09±0.16 LogMar postoperatively, P=0.007) and in 3mm topographic central irregular astigmatism (P=0.04) was demonstrated with CXL. No significant change was noted for refractive astigmatism (P=0.69), or for 1-year postoperative Kmax (48.4 D±4.1 at baseline versus 48.5 D±4.1 postoperatively, P=0.46). Predictive factors for BVCA improvement were low preoperative BCVA, high refractive astigmatism and advanced keratoconus. Predictive factors for stability of postoperative Kmax values were early keratoconus, and central cone ("nipple" morphology of the cone mainly located in the central 3mm of the cornea).This retrospective study confirms the efficacy of CXL for progressive keratoconus, from a refractive as well as topographic standpoint. While cone localization or its eccentricity seems to explain the variability of CXL efficacy reported in the literature, cone severity appears to be the main predictive factor for a lack of topographic stability after CXL treatment but must be weighted by the preferential localization of the cone (3 or 5mm central corneal zone).

In the last decade, several efforts have been spent in the study of near-field coupled systems, in order to induce hybridization of plasmonic modes. Within this context, particular attention has been recently paid on the possibility to couple conventional bright and dark modes. As a result of such phenomenon, a Fano resonance appears as a characteristic sharp dip in the scattering spectra. Here we show how, gradually coupling a single rod-like nanostructure to an aligned nanoantenna dimer, it is possible to induce the near-field activation of an anti-bonding dark mode. The high polarization sensitivity presented by the far-field response of T-shape trimer, combined with the sharp Fano resonance sustained by this plasmonic device, opens interesting perspectives towards a new era of photonic devices.

SUMMARY The purpose of this in vitro study was to compare the two-body wear resistance of human enamel, a pressable glass-ceramic (Imagine PressX), a type 3 gold alloy (Aurocast8), three resins composites currently available on the market (Enamel plus HRi, Filtek Supreme XTE, Ceram.X duo), and one recently introduced resin composite (Enamel plus HRi-Function). Resin composites were tested after simple light curing and after a further heat polymerization cycle. Ten cylindrical specimens (7 mm in diameter) were manufactured with each dental material according to standard laboratory procedures. Ten flat enamel specimens were obtained from freshly extracted human molars and included in the control group. All samples were subjected to a two-body wear test in a dual-axis chewing simulator over up to 120,000 loading cycles, against yttria stabilized tetragonal zirconia polycrystal cusps. Wear resistance was analyzed by measuring the vertical substance loss (mm) and the volume loss (mm3). Antagonist wear (mm) was also recorded. Data were statistically analyzed using one-way analysis of variance (ANOVA) (wear depth and volume loss) and Kruskal-Wallis one-way ANOVA on ranks (antagonist wear). Heat-cured HRi function and Aurocast8 showed similar mean values for wear depth and volumetric loss, and their results did not statistically differ in comparison with the human enamel.

The possibility to develop nanosystems with appreciable magnetic response at optical frequencies has been a matter of intense study in the past few years. This aim was strongly hindered by the saturation of the magnetic response of "natural" materials beyond the THz regime. Recently, in order to overcome such limitation, it has been considered to enhance the magnetic fields through the induction of displacement currents triggered by plasmonic resonances. Here we investigate a nanoassembly supporting the hybridization of an electric and magnetic plasmonic mode in Fano resonance conditions. Taking advantage of the enhancement properties owned by such interferential resonance, we have been able to generate an intense and localized magnetic hot-spot in the near-infrared spectral region.

The ability to confine light in small volumes, associated to low background signals, is an important technological achievement for a number of disciplines such as biology or electronics. In fact, decoupling the source position from the sample area allows an unprecedented sensitivity which can be exploited in different systems. The most direct implications are however related to either Surface Enhanced Raman Scattering (SERS) or Tip Enhanced Raman Scattering (TERS). Furthermore, while the combination with super-hydrophobic patterns can overcome the typical diffusion limit of sensors, focused surface plasmons decaying into hot electrons can be exploited to study the electronic properties of the sample by means of a Schottky junction. Within this paper these techniques will be briefly described and the key role played by both surface and localized plasmons will be highlighted.

The fabrication of complex 3D plasmonic nanostructures opens new scenarios towards the realization of high electric field confinement and enhancement. We exploit the unique properties of these nanostructures for performing Raman spectroscopy in the single/few molecules detection limit.

Modern medicine and biology search for new powerful tool for biomarkers discovery, appears one of the most promising approaches for early cancer diagnosis. Nowadays, the low molecular weight fraction of human serum is the most informative source of biomarkers, but their study and identification are very difficult due to the incredible complexity of the raw human serum. In this work we describe a novel tool for the filtration of crude human serum or other bio-fluid based on water soluble nanoparticles. Nanoparticles with a pore size of about 2–3 nm, and diameters of 200 nm were obtained by ultrasonication of nanoporous silicon. The porous nanoparticles act as a nanosieve able to exclusively harvest the low molecular weight fraction of the fluid thanks to a controllable pore size. After a short incubation, the infiltrated nanosieves can be extracted from the starting fluid by means of centrifugation, and dissolved in water in a few minutes to give the captured molecules back in their native state, without degradation and contamination. The raw fluid is so split in two components of high and low molecular weight, that are both available for further analyses with any other investigation technique. Here, fluorescence spectroscopy, 2D-gel electrophoresis, and mass spectrometry are exploited to show the split of different bio-fluids under physiological condition. A cut-off (or split level) of 13 kDa is demonstrated also for human serum.

In this paper we report the fabrication and characterization of a plasmonic device for label-free detection of few molecules in sub-wavelength regime by means of Raman scattering. The device is based on the coupling between a gold nanocone and a photonic crystal cavity, that is able to excite surface plasmon polaritons (SPPs) at the base on the cone. During the propagation toward the tip of the cone, the SPPs experiment and adiabatic compression that allow the accumulation of a very high electric field at the tip end. Raman enhancement factor of more than five order of magnitude is reported for a tip with a radius of curvature of about 10nm. The present results open up future perspective on single molecule detection even in combination with AFM measurements.

We have implemented the polarizable continuum model for solute–solvent interactions into a plane-wave (PW) Car–Parrinello code. A comparison between PW and Gaussian-type orbitals (GTO) basis sets implementations, concerning solvation energies and dipole moments of a number of small systems, is reported. All the computations have been performed using the BPW91 exchange-correlation functional. GTO calculation has been performed using the 6-311G(d,p) basis set for geometry optimizations, and the aug-cc-pVTZ basis for energies and dipole moments. PW calculations were carried out on the Gaussian optimized geometries, up to an energy cutoff of 30 Ry. Excellent agreement between PW and GTO calculations is obtained, with average deviations of solute–solvent interaction energies lower than 0.5 kcal/mol.

Background Several lipid-lowering agents, when given topically, show a profound effect on skin morphology. Because of low bioavailability of these drugs for keratinocytes, the incidence is extremely low clinically. The most appropriate way to study the effect of hypolipidemic drugs on keratinocytes is by artificial exposure of the skin to high drug concentrations. Objective To study the effects of gemfibrozil on the morphology of in vitro cultured normal human skin explants. As gemfibrozil induces barrier disruption by inhibiting epidermal sterologenesis, essential for a competent permeability barrier, it is interesting to investigate the morphologic changes associated with this phenomenon. Studying the epidermal changes induced by lipid-lowering agents is important, not only because it might lead to a better understanding of the effects of these drugs on keratinocytes, but as it might also unlock the door to a wider knowledge of the pathomechanism of disorders of cornification. Methods Normal human skin from patients undergoing mastectomy was cultured in the presence of 2, 5, and 10 mM of gemfibrozil for 4 days The morphologic changes were evaluated by three blinded observers. Their reports were matched and collated. Results The cultured skin in the presence of gemfibrozil showed cell crowding of keratinocytes in the lower part of the epidermis, indicating epidermal hyperplasia and increased proliferation. Intercellular edema with the formation of small cavities in the epidermis, intracellular edema, and vacuolar alteration of keratinocytes in the upper portion of the epidermis were also observed. The intensity of these changes tended to parallel the gemfibrozil concentration. Some dermo-epidermal detachments did not correlate with the gemfibrozil concentration, but rather with tissue characteristics peculiar to each explant. Conclusions The morphologic changes caused by gemfibrozil to normal human skin were not characteristic of psoriasis, and included intracellular and intercellular edema in the upper portion of the epidermis and cell crowding, indicating epidermal hyperplasia in the lower portion of the epidermis. The present experimental study gives further support to the hypothesis that hypolipidemic drugs cause an initial break in the barrier function of the epidermis, followed by a physiologic epidermal response, aimed at barrier restoration. This rather nonspecific stimulus to epidermal proliferation may trigger psoriasis in predisposed patients.

In the analysis of weakly guiding single-mode optical fibers, Gaussian and modified-Gaussian approximations appear inadequate to obtain accurate results at low normalized frequency for general refractive index profiles. To overcome such limitations we propose an expansion in terms of Laguerre-Gauss functions to represent the field in the fiber core. A modified Bessel function is instead used to describe the field in the cladding. All parameters defining the approximate field are evaluated by a variational method. We show that the proposed approximation is very accurate in the low normalized frequency limit too and can be particularly valuable to analyze dispersion-shifted fibers with triangular refractive index profile.

This paper reports on the fabrication and characterization of a novel device for surface enhanced Raman scattering, fabricated using focused ion beam milling and electron beam induced deposition. The device exploits a photonic crystal cavity as an optical source to couple the incident laser with a metallic tapered nanolenses. The collected Raman measurements show that exploiting such approach is possible to overcome the difficulties related to scattering and diffraction phenomena occurring when visible laser illuminates nano-structures. A clear Raman scattering enhancement has been demonstrated for label-free detection of molecule in sub-wavelength regime.

Wastewater from a seasoning freeze-drying industry was electrolysed to increase its biodegradability. Stainless-steel electrodes were used at 9.09 A/m², for up to 80 min. Conductivity, pH, biochemical (BOD) and chemical (COD) oxygen demands, Daphnia similis acute toxicity bioassays, and bacteria counting through the plate count agar method were determined after different times of electrolysis. The results (e.g. higher BOD and lower COD) showed that the biodegradability of the wastewater was significantly increased; furthermore, Fe2+ ions liberated by the electrodes cause microorganisms to die and, when oxidised to Fe3+, contribute for the flocculation and sedimentation of solid residues.

We show that the calculation of Berezin integrals over anticommuting variables can be reduced to the evaluation of expectations of functionals of Poisson processes via an appropriate Feynman-Kac formula. In this way the tools of ordinary analysis can be applied to Berezin integrals and, as an example, we prove a simple upper bound. Possible applications of our results are briefly mentioned., Comment: 26 pages, amsTeX

The aim of this study was to determine if the severity of paranoid/belligerence was a major determinant of neuroleptic dosage in newly admitted patients with acute or exacerbated schizophrenia. Two clinical psychiatrists, who had no clinical responsibility for drug treatment and were blind to neuroleptic dosage regimens, jointly interviewed 155 patients who were cooperative enough to be carefully interviewed with the Structured Clinical Interview for the DSM-III-R, Positive and Negative Syndrome Scale (PANSS) Edition. The large majority of the patients were receiving moderate dosages of neuroleptics (mean peak dosage: 500 mg/day of chlorpromazine equivalents). There was a positive correlation between the score on the PANSS paranoid/belligerence cluster and the daily dosage of neuroleptic treatment. Splitting the sample by gender, the correlations remained highly significant. In a multivariate analysis controlling for the effects of other clinical variables, paranoid/belligerence and gender emerged as significant predictors of neuroleptic dosage. Clinicians prescribed lower doses of neuroleptics for female patients and higher doses for patients with higher ratings on the PANSS paranoid/belligerence cluster. These findings suggest that clinicians' strategy of increasing neuroleptic dosage at the manifestation of hostility is not limited to assaultive or uncooperative schizophrenic patients who are on very high dosages of neuroleptics.

The determination of S-carboxymethyl-(R)-cysteine (SCMC) in human plasma during extended bioequivalence studies demands a rapid, accurate and selective assay technique. A liquid chromatographic/mass spectrometric method was developed which involves rough protein precipitation followed by high-performance liquid chromatographic separation with an ion-exchange column and atmospheric pressure ionization (API) mass spectrometric detection, with the instrument operating with electrospray ionization (ESI) and in the selected-ion monitoring mode. The drug and the internal standard S-[(R)-1-carboxyethyl]-(R)-cysteine (SCEC) are detected by focusing the first quadrupole of the triple stage system on MH+ ions, thus permitting elimination of endogenous interfering substances and allowing a detection limit of 0.05 microgram ml-1. The chromatographic run time is 16 min and the method has sufficient sensitivity, precision, accuracy and selectivity for routine analyses of clinical plasma samples containing SCMC at concentrations in the range 0.2-20 micrograms ml-1. In summary, this LC/MS-based assay of SCMC demonstrates advantages of easy sample preparation, low limit of quantification (200 ng per ml of human plasma) without any derivatization step, high specificity and rapid sample analysis with an overall throughput of more than 60 analyses per day.

Summary Human Leucocyte Antigen (HLA) loci are widely known for their role in the generation of immune responses and are often considered to be effective in reconstructing human relationships. This is due to the high degree of polymorphism and the rarity of recombination observed at HLA loci. In this study, we have made an attempt to support the potential of HLA class II loci by analysing DQA1 and DQB1 in 52 Ecuadorians with ties to the Tsachilas community. Little is known about this populations either ethnologically or historically: they are considered retaining much of the ancient Chibchan culture in spite of the lack of significant genetic characterization. A total of 21 alleles were observed, with very low heterozygosity. The obtained data were then assessed for relationship reconstruction. The compiled database of 63 populations was segregated and resolved in clusters corresponding to the ethnogeographic distribution of the populations. This analysis of Central and Southern Amerindians allowed us to support a historical hypothesis related to the origin and migration of Ecuadorian people. Indeed, the relationships with neighbour human groups, especially Cayapas and Colombians, could shed light on the genetic similarity within ancient Chibchan culture that was dispersed by tribes coming up the Barbacoas. This indicates that if an appropriate analysis was to be carried out on a set of populations representative of different geographic locations, and that analysis was properly interpreted, then there would be a high possibility that HLA class II loci could infer accurate assessments, as revealed by uniparental markers.

Cascading failures are very disruptive events that can damage critical infrastructure such as electri- cal and telecommunication networks. They start with a single-point failure and spread fast through the networks, sometimes causing the collapse of the whole system. We study and classify three containment strategies for cas- cading failures. Additionally, we propose a simple dynamic model for cascading failures in scale-free networks considering random failures and targeted attack scenarios. Our results allowed us to mathematically describe the behavior of the process and to test three strategies to protect the network against the cascade.

Objective Few studies have examined behavioural changes in the early phase of multiple sclerosis (MS). The aim of the study is to investigate mood alterations and to explore coping strategies regarding patients with clinically isolated syndrome (CIS) and relapsing-remitting MS (RRMS). Materials and Methods The communication of diagnosis was made by one neurologist using a standardized approach. Depression, anxiety and coping questionnaires were filled in within 1 month from the diagnosis and at 3, 6, 12, 18 and 24 months subsequently. Results Thirty-nine patients were examined (11 CIS, 28 RRMS), also 39 healthy controls. At entry, patients showed a lower degree of hostile behaviour and a higher level of depression than the controls. At follow-up, a reduction in depression, anxiety and a better coping adjustment was observed. A higher reliance on ‘Accepting responsibilities’ coping score was seen in patients with higher levels of depression and anxiety. No significant differences were revealed by group comparisons between CIS and RRMS. Conclusions This study highlights transient mood alterations and an improving of adaptive coping over a period of time in patients with CIS and RRMS. Similar emotional reactions and coping in clinical subgroups suggest that these factors are independent from the type of information provided during the communication of the diagnosis.

A portable model potential, representing the intermolecular interaction of acetonitrile with itself and with ions, is proposed. Such model, formulated as a combination of a few effective components, given in terms of the polarizability and dipole moment values of the molecular partners, is here adopted as a building block of the force field of acetonitrile clusters in molecular dynamics simulations. Its reliability is tested by comparing the predicted features for both small ionic and neutral clusters containing acetonitrile with ab initio results and experimental information. Its application to molecular dynamics simulations of liquid acetonitrile and of the solvated Li(+), Na(+), K(+), and I(-), performed at several values of the temperature, discloses an ample and interesting phenomenology, described in an internally consistent way. Such model will be useful to assess the effect of intermolecular interactions on the dynamics of acetonitrile processes occurring in various environments of applied relevance, with emphasis on the dye-sensitized solar cell framework.

Several studies have demonstrated the clinical and technical benefits of the laparoscopic surgery for complicated and uncomplicated appendicitis. Our retrospective study included 12 patient who underwent SILS appendectomy (SILS-A), 14 who received conventional laparoscopic surgery (VL-A), and 12 who received laparotomic appendectomy (OA); performed in all cases by the same surgeon (C.F.). The aim of this study was the comparison between this three different surgical techniques on same features: post operative leukocytosis, post operative pain, need abdominal drainage, esthetic viewpoint, incidence of complication, hospital stay. The results showed no significant differences between SILS-A and VLS-A, while an evident improvement shows versus O-A, even though not statistically significative. SILS was more effective in decreasing the risk of postoperative wound infection.

In this work the design, fabrication and optical characterization of a polarization-sensitive L-shape nanoantenna device are reported. Such configuration supports plasmon-polariton modes that are combinations of in-phase and out-of-phase single antenna long-axis surface plasma oscillations. In the former case charges distributions induce in the gap region an intense hot spot while in the latter one a "zero-field spot"occurs in a plasmonic mode which can be referred to a non-zero dipolar momentum.

Push-pull Zn(II)-porphyrinates have recently shown attracting performances as light harvesting systems in dye-sensitized solar cells (DSSCs). To fully exploit their intrinsically high efficiency it is important to finely tune their HOMO and LUMO levels, which can be achieved by proper choice of the push and pull substituents. Of course such target-oriented molecular design requires the availability of reliable relationships between molecular structure and electronic properties; therefore we have carried out a detailed electrochemical investigation, also supported by spectroscopy and theoretical computations, on a wide, systematic range of Zn(II)-porphyrinates: (a) a family of 5,15-meso substituted ones with phenylethynyl linkers, including a first "benchmark" symmetric series carrying on the opposite terminals the same substituent (N(CH3)2, OCH3, COOCH3, COOH, NO2); and a second push-pull one, with the terminal positions carrying one donor and one acceptor group belonging to the series above. Moreover, two suitably modified porphyrins allowed evaluation of the effects of (i) the presence or absence of the phenyl group in the linker between the porphyrin core and the acceptor group, and (ii) the effect of perfluorination on the same phenyl group; (b) a family of mono and, for the first time, disubstituted push-pull ZnIIporphyrinates bearing a variety of ethynyl-phenyl moieties in ?-pyrrolic position, which were compared with their meso analogues, producing evidence that, although the HOMO-LUMO energy gap of the meso substituted push-pull dyes is lower, the ? mono or disubstituted push-pull porphyrinic dyes show comparable or better efficiencies when acting as sensitizers in DSSCs, possibly on account of a more facile charge injection into TiO2. A rationalization scheme is proposed concerning relationship between structure and redox properties, affording inter alia interesting clues on the different localization of the redox centres and the effective conjugation between the porphyrin core and the side chains as a function of the molecular design.

We report a reproducible plasmonic SERS device, composed of nanostars fabricated by means of electron beam lithography. Cresyl violet dye is used as a probing molecule, deposited on SERS device. Optical transmission measurements show a broad plasmonic resonance around 900 nm. SERS measurements were performed for this device using 633 nm and 830 nm excitation laser lines which are, respectively, far from and close to the plasmonic resonance band position. The estimated SERS enhancement is 1.7 104 and 5.9 104 with respect to the flat Au surface, when excited by 633 nm and 830 nm,respectively.

Early detection of diseases has great importance in terms of success of the disease treatment. In fact, it has a profound positive influence on the response provided by the patient, leading to shorter and less invasive treatment regimes. We consider here the Raman detection of low (atto-molar) concentrates of molecules by applying nanofabrication techniques in the fabrication of plasmonic devices fulfilling the requirement of superhydrophobicity. Plasmonic resonances will have the effect of substantially increasing the local electric field around the fabricated nano-device which, in turn, will positively affect the Raman signal. Similarly, the superhydrophobicity will play the crucial role in localizing the few molecules of the analyte around the plasmonic device, therefore allowing their detection in a manner otherwise impossible in diffusion-based devices. We will theoretically explain the concept of superhydrophobicity by providing also a roadmap for defining the optimal superhydrophobic device, then we will introduce the fabrication process to realize such a device and, finally, we will provide the Raman counting of a series of analytes together with electromagnetic simulations illustrating the role of the electric field in the formation of the Raman signal.

The goal of maxillofacial surgery is to restore the shape and functionality of maxillofacial region. In the past years, there has been a tremendous progress in this field because of significant advances in biotechnology that provided innovative biomaterials to efficiently reconstruct the maxillofacial injured region. By using appropriate selection of the implant biomaterial, it is possible to reconstruct the native tissue, both in form and function. The ideal biomaterial should mimic native tissues regarding density, strength, and modulus of elasticity. Autografts are currently the gold standard for replacement of missing tissues, but synthetic biomaterials have been widely used because they eliminate the discomfort to take the replacement tissue from the donor site. Among synthetic biomaterials, different metals may be utilized to efficiently reconstruct the maxillofacial injured region. This article makes an effort to summarize the most important metals in use in maxillofacial surgery, and point out advantages and disadvantage of each type.

Inflamed human pulp tissue presents an increase in the level of nitric oxide synthase (NOS). The aim of this study is to verify the presence of NOS in human pulp of teeth that are subject to orthodontic force. 20 healthy subjects, wearers of fixed braces on the upper arch, were selected. An open coil-spring in NiTi was applied on the upper premolar test tooth (TT); the controlateral control tooth (CCT) was subjected to orthodontic treatment but not to the further force of the open coil-spring; the antagonist control tooth (ACT) did not undergo any orthodontic treatment. Pulps were taken from test, contralateral control and antagonist control teeth immediately after the extractions which were done at 15 and 30 days from the start of application of the orthodontic force. The pulp tissue was analyzed through immunohistochemical and molecular biology examinations. The results showed tooth pulps subject to orthodontic treatment were very inflamed in the first 15 days with high levels of iNOS and low levels of eNOS; after 30 days a decrease of the inflammation and an increase of the pulp vascularization were observed together with a reduction of iNOS and an increase of eNOS respectively.

Few/single molecule detection is of great importance in fields including biomedicine, safety and eco-pollution in relation to rare and dangerous chemicals. Superhydrophobic surfaces incorporated with the nanoplasmonic structure enable this device to overcome the diffusion limit of molecules dissolved in water with the concentration down to 10 attomolar. In this paper demonstrated the fabrication of hydrophobic surfaces using optical lithography/reactive ion etching and its application to overcome the diffusion limit. Various experiments such as contact angle measurements, SEM, fluorescence, Raman and FTIR absorption spectroscopy were performed which indicate that utilizing this device it could be possible to perform the measurements for the sample with extremely low dilution. The major application of this novel family of devices would be the early detection of tumors or other important pathologies, with incredible advances in medicine.

Many relevant questions in biology and medicine require both topography and chemical information with high spatial resolution. Several biological events that occur at the nanometer scale level need to be investigated in physiological conditions. In this regard Atomic Force Microscopy (AFM) is one of the most powerful tools for label-free nanoscale characterization of biological samples in liquid environment. Recently, the coupling of Raman spectroscopy to scanning probe microscopies has opened new perspectives on this subject; however, the coupling of quality AFM spectroscopy with Raman spectroscopy in the same probe is not trivial. In this work we report about the AFM capabilities of an advanced high-resolution probe that has been previously nanofabricated by our group for coupling with Raman spectroscopy applications. We investigate its use for liquid AFM measurements on biological model samples like lipid bilayers, amyloid fibrils, and titin proteins. We demonstrate topography resolution down to nanometer level, force measurement and stable imaging capability. We also discuss about its potential as nanoscale chemical probe in liquid phase.

Modern real-time systems are required to operate in complex applications and dynamically adapt to a wide range of changes in the environment. One strategy that allows the implementation of these systems in complex scenarios is the partitioning of their applications into modes of operation. Flexibility of operation is achieved by having the system execute in several modes of operation and undergo transitions between modes in response to external or internal events. A mode of operation can be seen as a specific configuration of the computational resources that is optimal for the operational phase that the system executes. As conditions in the environment change, resource allocations may become inadequate. Therefore, the systemmust reconfigure itself through amode change, reallocating its resources in an efficient manner. A classic example of modes lies in the area of aviation where most aircraft undergo at least three basic modes of operation: take-off, level-flight, and landing modes. Having the system designed with a single mode of operation does not explore the fact that some operations, and thus resource usage, are mutually exclusive. The allocation of all these resources, as if they could be needed at the same time, leads to inefficiency. More importantly, the resulting system is not scalable. The so called "all-modes-in-one" system is usually feasible for simple systems with limited functionality.

Exosomes are very small vesicles that are shed from a variety of cell types. They are present in body fluids comprising blood, urine and ascites, and they hold the potential to serve as indicators in the diagnosis, prognosis and surveillance of a variety of health conditions. In consideration of this, there is broad interest worldwide in deriving and understanding their biochemical composition. Here, small drops of solutions containing exosomes, isolated from either healthy (CCD841-CoN) or tumor (HCT116) colon cells, were manipulated using super-hydrophobic surfaces (SHSs) decorated with nano-geometry based photonics structures. SHSs are surfaces with superior properties, including a reduced friction coefficient, on account of which they can be used to control diluted solutions of biological or medical interest. The combination of this technology with optical resonance phenomena, open up terrific opportunities in the detection, analysis or characterization of biological compounds. Therefore, exosomes were conveniently concentrated and conveyed onto the Surface Enhanced Raman Spectroscopy (SERS) active areas of the substrate, whereby they were analyzed and characterized with extreme precision. Results indicate a difference in the concentration of some biological compounds, and namely: exosomes derived from healthy cells exhibit higher intensities of the peaks corresponding to lipids vibrations, while exosomes extracted from tumor cell lines exhibit a richer RNA content.

Noble metal tapered waveguides supporting plasmon-polariton modes are able to localize the optical fields at nanometer level producing a remarkable local electromagnetic field enhancement, which enables the realization of highsensitivity biochemical sensing devices. Here we report on the design, fabrication and experimental test of a novel photonic-plasmonic device that can be operated as an Atomic Force Microscopy tip and simultaneously for local probing of Raman scattering spectra. This result has made possible by recent approaches in nano-fabrication methods, which allow 3D nanostructuring of metals down to the nanoscale. The device demonstrates label-free detection capabilities on single inorganic nanoparticles and on monolayers of organic compounds in label-free conditions and native environments, allowing a topographic and chemical mapping of the materials with spatial resolution of a few nanometers.

Nanoparticles can be composed of many different types of material, however in order to be considered as suitable candidates for drug delivery purpose, they need to follow a precise tailored biological behavior. Here we propose nanoporous silicon nanoparticles as optimal nanocarriers with tunable physicochemical properties, and we present a simple few-step fabrication process and an accurate description of nanoparticles considerable features. The performed measurements show that proposed water soluble nanoparticles have excellent loading capacity with no chemical modification on the adsorbed drug. Furthermore, they can degrade releasing the carried drug in a reasonable period of time producing non toxic substances, and show photoluminescent and Raman scattering properties that are useful tools for monitoring them. Raman analyses indicate that nanoporous silicon nanoparticles are distinguished from bulk silicon by a Raman shift to low frequencies and that annealing processes at 260^oC allows to maintain intact the crystalline structure, while complete disappearance appears for annealing at 700^oC. In this way Raman spectroscopy is a useful technique to follow the changes in composition of the nanoparticles after treatments.

The aim of this study is to explore human leukocyte antigen (HLA)-DQ variability in two populations (Cayapas Amerindians and Afro-Ecuadorians) who live near one another along the Cayapa River and who are exposed to the same environmental stresses, such as infection by Onchocerca volvulus. HLA-DQA1 and HLA-DQB1 of 149 unrelated individuals (74 Cayapas and 75 Afro-Ecuadorians) have been analyzed. HLA high-resolution molecular typing was performed by sequence-based typing, sequence-specific oligonucleotides hybridization and sequence-specific primer (SSP) amplification. The comparison between affected (cases) and unaffected people (controls) in both populations shows the key role of several HLA-DQA1 alleles in susceptibility and protection against onchocerciasis. In both populations, there is strong evidence related to the protective role of DQA1*0401 against onchocerciasis. Alleles HLA-DQA1*0102 and *0103 seem to represent risk factors in Afro-Ecuadorians, while HLA-DQA1*0301 is only a suggestive susceptibility allele in Cayapas. These findings represent new positive/negative associations with onchocerciasis in South America, whereas previous findings pertained only to African populations.