Homogeneity of Ge-rich nanostructures as characterized by chemical etching and transmission electron microscopy

The extension of SiGe technology towards new electronic and optoelectronic applications on the Si platform requires that Ge-rich nanostructures be obtained in a well-controlled manner. Ge deposition on Si substrates usually creates SiGe nanostructures with relatively low and inhomogeneous Ge content. We have realized SiGe nanostructures with a very high (up to 90%) Ge content. Using substrate patterning, a regular array of nanostructures is obtained. We report that electron microscopy reveals an abrupt change in Ge content of about 20% between the filled pit and the island, which has not been observed in other Ge island systems. Dislocations are mainly found within the filled pit and only rarely in the island. Selective chemical etching and electron energy-loss spectroscopy reveal that the island itself is homogeneous. These Ge-rich islands are possible candidates for electronic applications requiring locally induced stress, and optoelectronic applications which exploit the Ge-like band structure of Ge-rich SiGe.     

Wine yeast molecular typing using a simplified method for simultaneously extracting mtDNA,nuclear DNA and virus dsRNA

Quick and accurate methods are required for the identification of industrial, environmental, and clinical yeast strains. We propose a rapid method for the simultaneous extraction of yeast mtDNA, nuclear DNA, and virus dsRNA. It is simpler, cheaper, and faster than the previously reported methods. It allows one to choose among a broad range of molecular analysis approaches for yeast typing, avoiding the need to use of several different methods for the separate extraction of each nucleic acid type. The application of this method followed by the combined analysis of mtDNA and dsRNA (ScV-M and W) is a highly attractive option for fast and efficient wine yeast typing.     

Robust design of mass-uncertain rolling-pendulum TMDs for the seismic protection of buildings

Commonly used for mitigating wind- and traffic-induced vibrations in flexible structures, passive tuned mass dampers (TMDs) are rarely applied to the seismic control of buildings, their effectiveness to impulsive loads being conditional upon adoption of large mass ratios. Instead of recurring to cumbersome metal or concrete devices, this paper suggests meeting that condition by turning into TMDs non-structural masses sometimes available atop buildings. An innovative roof-garden TMD, for instance, sounds a promising tool capable of combining environmental and structural protection in one device.Unfortunately, the amount of these masses being generally variable, the resulting mass-uncertain TMD (MUTMD) appears prone to mistuning and control loss. In an attempt to minimize such adverse effects, robust analysis and synthesis against mass variations are applied in this study to MUTMDs of the rolling-pendulum type, a configuration characterized by mass-independent natural period.Through simulations under harmonic and recorded ground motions of increasing intensity, the performance of circular and cycloidal rolling-pendulum MUTMDs is evaluated on an SDOF structure in order to illustrate their respective advantages as well as the drawbacks inherent in their non-linear behavior. A possible implementation of a roof-garden TMD on a real building structure is described and its control efficacy numerically demonstrated, showing that in practical applications MUTMDs can become a good alternative to traditional TMDs.     

A Dynamic Logic of Agency II: Deterministic $${\mathcal{DLA}}$$ , Coalition Logic,and Game Theory

We continue the work initiated in Herzig and Lorini (J Logic Lang Inform, in press) whose aim is to provide a minimalistic logical framework combining the expressiveness of dynamic logic in which actions are first-class citizens in the object language, with the expressiveness of logics of agency such as STIT and logics of group capabilities such as CL and ATL. We present a logic called DDLA{\mathcal{DDLA}} (Deterministic Dynamic logic of Agency) which supports reasoning about actions and joint actions of agents and coalitions, and agentive and coalitional capabilities. In DDLA{\mathcal{DDLA}} it is supposed that, once all agents have selected a joint action, the effect of this joint action is deterministic. In order to assess DDLA{\mathcal{DDLA}} we prove that it embeds Coalition Logic. We then extend DDLA{\mathcal{DDLA}} with modal operators for agents’ preferences, and show that the resulting logic is sufficiently expressive to capture the game-theoretic concepts of best response and Nash equilibrium.     

Improved In Situ Characterization of Electrochemical Interfaces Using Metasurface-Driven Surface-Enhanced IR Absorption Spectroscopy

Electrocatalysis plays a crucial role in realizing the transition toward a zero-carbon future, driving research directions from green hydrogen generation to carbon dioxide reduction. Surface-enhanced infrared absorption spectroscopy (SEIRAS) is a suitable method for investigating electrocatalytic processes because it can monitor with chemical specificity the mechanisms of the reactions. However, it remains difficult to detect many relevant aspects of electrochemical reactions such as short-lived intermediates. Herein, an integrated nanophotonic-electrochemical SEIRAS platform is developed and experimentally realized for the in situ investigation of molecular signal traces emerging during electrochemical experiments. A platinum nano-slot metasurface featuring strongly enhanced electromagnetic near fields is implemented and spectrally targets the weak vibrational mode of the adsorbed carbon monoxide at ≈2033 cm⁻¹. The metasurface-driven resonances can be tuned over a broad range in the mid-infrared spectrum and provide high molecular sensitivity. Compared to conventional unstructured platinum films, this nanophotonic-electrochemical platform delivers a 27-fold improvement of the experimentally detected characteristic absorption signals, enabling the detection of new species with weak signals, fast conversions, or low surface concentrations. By providing a deeper understanding of catalytic reactions, the nanophotonic-electrochemical platform is anticipated to open exciting perspectives for electrochemical SEIRAS, surface-enhanced Raman spectroscopy, and other fields of chemistry such as photoelectrocatalysis.     

The oxidation of Iron-Chromium-Manganese alloys at 900°C

The oxidation of nine ternary iron-chromium-manganese alloys was studied at 900°C in an oxygen partial pressure of 26.7 kPa. The manganese concentration was set at 2, 6, and 10 wt. %, and chromium at 5, 12, and 20 wt. %. The scales formed on the low-chromium alloys consisted of (Mn,Fe)₂O₃, -Fe₂O₃, and Fe₃O₄. These alloys all exhibited internal oxidation and scale detachment upon cooling. The scales formed on the higher-chromium alloys were complicated by nodule formation. Initially, these scales had an outer layer of MnCr₂O₄ with Cr₂O₃ underneath, adjacent to the alloy. With the passage of time, however, nodules formed, and the overall reaction rate increased. This tendency was more marked at higher manganese contents. Although these alloys contained a high chromium content, the product chromia scale usually contained manganese. It was concluded that the presence of manganese in iron-chromium alloys had an adverse effect on the oxidation resistance over a wide range of chromium levels.     

Self-Assembling Peptides: From Design to Biomedical Applications

Self-assembling peptides could be considered a novel class of agents able to harvest an array of micro/nanostructures that are highly attractive in the biomedical field. By modifying their amino acid composition, it is possible to mime several biological functions; when assembled in micro/nanostructures, they can be used for a variety of purposes such as tissue regeneration and engineering or drug delivery to improve drug release and/or stability and to reduce side effects. Other significant advantages of self-assembled peptides involve their biocompatibility and their ability to efficiently target molecular recognition sites. Due to their intrinsic characteristics, self-assembled peptide micro/nanostructures are capable to load both hydrophobic and hydrophilic drugs, and they are suitable to achieve a triggered drug delivery at disease sites by inserting in their structure’s stimuli-responsive moieties. The focus of this review was to summarize the most recent and significant studies on self-assembled peptides with an emphasis on their application in the biomedical field.     

A Fast Marching Method for Hamilton-Jacobi Equations Modeling Monotone Front Propagations

In this paper we present a generalization of the Fast Marching method introduced by J.A. Sethian in 1996 to solve numerically the eikonal equation. The new method, named Buffered Fast Marching (BFM), is based on a semi-Lagrangian discretization and is suitable for Hamilton-Jacobi equations modeling monotonically advancing fronts, including Hamilton-Jacobi-Bellman and Hamilton-Jacobi-Isaacs equations which arise in the framework of optimal control problems and differential games. We also show the convergence of the algorithm to the viscosity solution. Finally we present several numerical tests comparing the BFM method with other existing methods. This research was partially supported by the MIUR Project 2006 “Modellistica Numerica per il Calcolo Scientifico ed Applicazioni Avanzate” and by INRIA–Futurs and ENSTA, Paris, France.     

Double-blind study of a multivitamin complex supplemented with ginseng extract

To remedy the deterioration in quality of life in large cities, the addition of ginseng root extract to a multivitamin base appears to produce a promising dietary supplement. The aim of the present study was to compare the quality-of-life parameters in subjects receiving multivitamins plus ginseng with those found in subjects receiving multivitamins alone. The study was comparative, randomized and double-blind, and it involved 625 patients of both sexes divided into two groups taking one capsule per day for 12 weeks. Group A received vitamins, minerals, trace elements and ginseng extract G115 (Pharmaton Capsules) while group B received vitamins, minerals and trace elements (multivitamin capsules) only. The resulting quality-of-life was assessed by a standardized 11-item questionnaire, validated by the Medical School of the National Autonomous University of Mexico (UNAM). Of the 625 patients recruited, 124 were excluded from the study due to lack of compliance with the treatment, so that 338 patients in group A and 163 patients in group B completed the study. By the end of the study, the 4th of the monthly assessments showed that both the group-A and the group-B treatments had induced a significant increase in the quality-of-life index, the change being 11.9 points for Pharmaton Capsules in group A which was significantly superior to the 6.4 average increase with the group-B capsules containing multivitamins alone. Group A showed significant improvement in every one of the 11 questionnaire items, whereas group B did not show significant improvement in any of these items. Significant increases in body weight and in diastolic blood pressure were recorded in the group B treated with the multivitamin alone. Adverse effects of the capsules were minimal in both groups. This study has demonstrated that Pharmaton Capsules were more effective than the multivitamin capsules alone in improving the quality-of-life in a population subjected to the stress of high physical and mental activity.