Nanodroplets Impacting on Graphene

The unique and remarkable properties of graphene can be exploited as the basis to a wide range of applications. However, in spite of years of investigations there are some important graphene properties that are not still fully understood, as for example, its wettability. There are controversial reported results whether graphene is really hydrophobic or hydrophilic. In order to address this problem we have carried out classical molecular dynamics simulations of water nanodroplets shot against graphene surface. Our results show that the contact angle values between the nanodroplets and graphene surfaces depend on the initial droplet velocity value and these angles can change from 86 degrees (hydrophobic) to 35 degrees (hydrophilic). Our preliminary results indicate that the graphene wettability can be dependent on spreading liquid dynamics and which can explain some of the apparent inconsistencies reported in the literature

Antimicrobial coatings for implant surfaces

Body-foreign materials are used more and more frequently in our lives: joint implants (hips, knees, fingers, etc.), catheters, pacemakers, dental and aesthetic implants, etc. The increasing numbers of patients requiring such implants also raises the absolute numbers of implant-related infections. Thus, it is known that body-foreign materials are prone to bacterial adhesion and subsequent biofilm formation, either via bacterial debris on implant materials, infections during implantation or, later on, via haematogenous seeding. Biofilms, once formed, are impossible to treat with antibiotics, and the immune system response leads to implant loosening, requiring total replacement. The strategy is thus to prevent bacterial adhesion to implant materials' surfaces. Different strategies have been tested in this context and will be presented here, together with our own approach, using a combination of different anti-microbial compounds

Cellular-Automata model for dense-snow avalanches

This paper introduces a three-dimensional model for simulating dense-snow avalanches, based on the numerical method of cellular automata. This method allows one to study the complex behavior of the avalanche by dividing it into small elements, whose interaction is described by simple laws, obtaining a reduction of the computational power needed to perform a three-dimensional simulation. Similar models by several authors have been used to model rock avalanches, mud and lava flows, and debris avalanches. A peculiar aspect of avalanche dynamics, i.e., the mechanisms of erosion of the snowpack and deposition of material from the avalanche is taken into account in the model. The capability of the proposed approach has been illustrated by modeling three documented avalanches that occurred in Susa Valley (Western Italian Alps). Despite the qualitative observations used for calibration, the proposed method is able to reproduce the correct three-dimensional avalanche path, using a digital terrain model, and the order of magnitude of the avalanche deposit volume

The effect of copper toxicity on synergisms and antagonisms between nutrients in grapevine plants

Copper (Cu) accumulation in soils can induce toxicity and nutrient imbalances in several plant species. The aim of this work was thus to evaluate the effect of Cu toxicity on two grapevine rootstocks, Fercal and 196.17, and to elucidate if intercropping with oat can alleviate grapevine Cu toxicity using hydroponic trials and rhizobox experiments. The hydroponic trial revealed that Cu-induced root exudation was correlated with genes expression (VvPEZlike); furthermore the ionome analysis revealed that both mono- and intercropped L96.t7 rootstocks display a synergistic effect on Zn and Mn in the root tissues at high Cu concentrations. An increase of Zn and Mn in roots was also reported for the intercropped FercaJ rootstock at high Cu concentrations while an antagonistic relation was observed for root Zn in the monocropped Fercal rootstock. The rhizobox experiments further confirmed these results showing a different nutrient concentration depending on the rootstock and on the soil characteristics. lndeed, Cu availability is shaped by rhizosphere processes, which depend on soil properties and/or the co-cultivation of different plant species. The soil-based experiments revealed that nutrient availability and dissolved organic carbon including root exudates differ depending on soil properties and the rootstock rather than on the cultivation system, ln particular, we did not observe any apparent competition between the two plant species in the alkaline soil; on the other hand, in the acid soil, the intercropping revealed a beneficial etfect reducing the available Cu in the rhizosphere. Our results revealed that Fercal rootstock is able to take advantage from oat, while 196.17 seems disadvantaged by the intercropping system. Yet, even though the intercropping system seems to be a valuable tool to counteract grapevine Cu toxicity, the application of this agricultural practice has shown to be species and mostly soil type dependent and should be evaluated for each rootstock

Methane and Nitrogen Abundances On Pluto and Eris

We present spectra of Eris from the MMT 6.5 meter telescope and Red Channel Spectrograph (5700-9800 angstroms; 5 angstroms per pix) on Mt. Hopkins, AZ, and of Pluto from the Steward Observatory 2.3 meter telescope and Boller and Chivens spectrograph (7100-9400 angstroms; 2 angstroms per pix) on Kitt Peak, AZ. In addition, we present laboratory transmission spectra of methane-nitrogen and methane-argon ice mixtures. By anchoring our analysis in methane and nitrogen solubilities in one another as expressed in the phase diagram of Prokhvatilov and Yantsevich (1983), and comparing methane bands in our Eris and Pluto spectra and methane bands in our laboratory spectra of methane and nitrogen ice mixtures, we find Eris' bulk methane and nitrogen abundances are about 10% and about 90%, and Pluto's bulk methane and nitrogen abundances are about 3% and about 97%. Such abundances for Pluto are consistent with values reported in the literature. It appears that the bulk volatile composition of Eris is similar to the bulk volatile composition of Pluto. Both objects appear to be dominated by nitrogen ice. Our analysis also suggests, unlike previous work reported in the literature, that the methane and nitrogen stoichiometry is constant with depth into the surface of Eris. Finally, we point out that our Eris spectrum is also consistent with a laboratory ice mixture consisting of 40% methane and 60% argon. Although we cannot rule out an argon rich surface, it seems more likely that nitrogen is the dominant species on Eris because the nitrogen ice 2.15 micron band is seen in spectra of Pluto and Triton.Comment: The manuscript has 44 pages, 15 figures, and four tables. It will appear in the Astrophysical Journa

Abordagem computacional para a identificação de elementos cis-regulatóriso no genoma da soja.

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Subperiostial orbital abscess and apex syndrome as a complication after a mandibular molar extraction

Indexación: Web of Science; ScieloIntroducción: La diseminación de las infecciones que se extienden de dientes mandibulares y estructuras adyacentes hacia la órbita y tejido periorbitario son infrecuentes, pero graves ya que tienen el potencial de causar la pérdida de la visión. Objetivos: El propósito de este artículo es publicar un caso clínico muy interesante por lo infrecuente, y explicar a juicio de los autores las vías de diseminación de la infección, a su vez alertar a los diferentes especialistas involucrados sobre las severas consecuencias que pueden resultar tras la extracción de piezas dentales, como es la pérdida definitiva de la visión. Reporte del caso: Se trata de un paciente masculino de 43 años, sin antecedentes mórbidos relevantes, que fue enviado al Servicio Médico Legal para examen clínico forense con pérdida total de la visión del ojo derecho por atrofia óptica como complicación de un síndrome del vértice orbitario, luego de la exodoncia del tercer molar mandibular derecho. Conclusiones: Es fundamental el tratamiento oportuno y agresivo para detener la diseminación de una infección desde las estructuras adyacentes hacia la órbita. La comunicación efectiva interdisciplinaria entre los profesionales involucrados evita complicaciones de tipo médico-legales y secuelas definitivas al paciente.Introduction: Infection dissemination from mandibular teeth to the orbit and adjacent structures is infrequent, but nevertheless serious, as they may cause severe problems, including vision loss. Aim: The purpose of this study is to present a rare and interesting case of such a dissemination, to discuss the possible routes of infection propagation, and to alert the different specialists involved on the possible complications after dental extractions, such as visual loss. Report of the case: The case of a 43-year-old previously healthy male is presented. The patient was sent to the Medical Legal Service for clinical forensic examination after total vision loss of the right eye, caused by optic atrophy as a complication of orbital apex syndrome, after the extraction of the third right mandibular molar. Conclusions: Opportune and aggressive treatment is crucial to stop infection spread from adjacent structures to the orbit. Effective communication among the professionals involved avoids medical - legal complications and precludes permanent sequels to the patient.http://ref.scielo.org/yz5gt

A new experimental snow avalanche test site at Seehore peak in Aosta Valley (NW Italian Alps) - Part II: Engineering aspects

The estimate of the effects produced by the impact of a snow avalanche against an obstacle is of the utmost importance in designing safe mountain constructions. For this purpose, an ad-hoc instrumented obstacle was designed and built in order to measure impact forces of small and medium snow avalanches at Seehore peak (NW Italian Alps). The structural design had to consider several specific and unusual demands dictated by the difficult environment. In this article, the new test facility is described from the engineering point of view, discussing the most important aspects of the analyzed problems which were solved before and after the construction. The performance of the instrumented obstacle in the first two operating seasons, and some proposals for future upgrading are eventually illustrate