Synthesis of potassium–sodium niobate (KNN) from NbO2

KxNa1-xNbO3 (0 0.5) was obtained from 8 M total hydroxide concentration after 6 h of reaction at 200 °C. Rietveld refinement of the XRD data revealed that all samples exhibited the secondary NaNbO3 phase. However, the lowest amount (3.74 vol%) was obtained for 24 h of reaction under 10 M alkaline solution. After 3 h of reaction, dodecahedra shaped hexaniobate phase (KxNa8-xNb6O19.nH2O) was observed. Those structures were, subsequently, replaced by ~3 μm cube shaped KNN crystals, obtained under 10 M reaction in 24 h time period

Experiments and Models for physics learning in primary school

The project “Little scientists in the lab: Experiments & Models for science learning in primary school”, funded by the Ministry of Education and being currently under development in Italy, is addressed to primary school teachers of the Faculty of Science Education and consequently to pupils. This project proposes a “Model-centered Learning Environment” to build pilot activities for teaching and learning science and physics, based on experimental and modeling activities. The approach for teacher training is to assign group tasks that promote learning.We set up a website to support teachers’ school activities to facilitate and promote communication and exchange of materials between teachers and researchers of the University of Modena and Reggio Emilia, as well as between the teachers themselves. In this paper, we illustrate the general features of the project and focus on preliminary results of an in-service training for teachers in fluids and electricity

In Vivo Therapeutic Potential of Mesenchymal Stromal Cells Depends on the Source and the Isolation Procedure

SummaryOver the last several years, mesenchymal stromal cells (MSCs) have been isolated from different tissues following a variety of different procedures. Here, we comparatively assess the ex vivo and in vivo properties of MSCs isolated from either adipose tissue or bone marrow by different purification protocols. After MSC transplantation into a mouse model of hindlimb ischemia, clinical and histological analysis revealed that bone marrow MSCs purified on adhesive substrates exerted the best therapeutic activity, preserving tissue viability and promoting formation of new arterioles without directly transdifferentiating into vascular cells. In keeping with these observations, these cells abundantly expressed cytokines involved in vessel maturation and cell retention. These findings indicate that the choice of MSC source and purification protocol is critical in determining the therapeutic potential of these cells and warrant the standardization of an optimal MSC isolation procedure in order to select the best conditions to move forward to more effective clinical experimentation

Unacylated ghrelin normalizes skeletal muscle oxidative stress and prevents muscle catabolism by enhancing tissue mitophagy in experimental chronic kidney disease

Unacylated ghrelin (UnAG) may lower skeletal muscle oxidative stress, inflammation, and insulin resistance in lean and obese rodents. UnAG-induced autophagy activation may contribute to these effects, likely involving removal of dysfunctional mitochondria (mitophagy) and redox state maintenance. In chronic kidney disease (CKD) oxidative stress, inflammation and insulin resistance may negatively influence patient outcome by worsening nutritional state through muscle mass loss. Here we show in a 5/6 nephrectomy (Nx) CKD rat model that 4 d s.c. UnAG administration (200 \ub5g twice a day) normalizes CKD-induced loss of gastrocnemius muscle mass and a cluster of high tissue mitochondrial reactive oxygen species generation, high proinflammatory cytokines, and low insulin signaling activation. Consistent with these results, human uremic serum enhanced mitochondrial reactive oxygen species generation and lowered insulin signaling activation in C2C12 myotubes while concomitant UnAG incubation completely prevented these effects. Importantly, UnAG enhanced muscle mitophagy in vivo and silencing RNA-mediated autophagy protein 5 silencing blocked UnAG activities in myotubes. UnAG therefore normalizes CKD-induced skeletal muscle oxidative stress, inflammation, and low insulin signaling as well as muscle loss. UnAG effects are mediated by autophagy activation at the mitochondrial level. UnAG administration and mitophagy activation are novel potential therapeutic strategies for skeletal muscle metabolic abnormalities and their negative clinical impact in CKD.-Gortan Cappellari, G., Semolic, A., Ruozi, G., Vinci, P., Guarnieri, G., Bortolotti, F., Barbetta, D., Zanetti, M., Giacca, M., Barazzoni, R. Unacylated ghrelin normalizes skeletal muscle oxidative stress and prevents muscle catabolism by enhancing tissue mitophagy in experimental chronic kidney disease

A VLBI experiment using a remote atomic clock via a coherent fibre link

We describe a VLBI experiment in which, for the first time, the clock reference is delivered from a National Metrology Institute to a radio telescope using a coherent fibre link 550 km long. The experiment consisted of a 24-hours long geodetic campaign, performed by a network of European telescopes; in one of those (Medicina, Italy) the local clock was alternated with a signal generated from an optical comb slaved to a fibre-disseminated optical signal. The quality of the results obtained with this facility and with the local clock is similar: interferometric fringes were detected throughout the whole 24-hours period and it was possible to obtain a solution whose residuals are comparable to those obtained with the local clock. These results encourage further investigation of the ultimate VLBI performances achievable using fibre dissemination at the highest precision of state-of-the-art atomic clocks

The Substrate is a pH-Controlled Second Gate of Electrolyte-Gated Organic Field-Effect Transistor

Electrolyte-gated organic field-effect transistors (EGOFETs), based on ultra-thin pentacene films on quartz, were operated with electrolyte solutions whose pH was systematically changed. Transistor parameters exhibit non-monotonic variation vs pH, which cannot be accounted for by capacitive coupling through the Debye-Helmholtz layer. The data were fitted with an analytical model of the accumulated charge in the EGOFET where Langmuir adsorption was introduced to describe the (pH-dependent) charge build-up at the quartz surface. The model provides an excellent fit to the threshold voltage and transfer characteristics as a function of pH, which demonstrates that quartz acts as a second gate controlled by pH, and is mostly effective at neutral or alkaline pH. The effective capacitance of the device is always greater than the capacitance of the electrolyte, thus highlighting the role of the substrate as an important active element for amplification of the transistor response

Are multiple-choice questions a good tool for the assessment of clinical competence in Internal Medicine?

There are many feasible tools for the assessment of clinical practice, but there is a wide consensus on the fact that the simultaneous use of several different methods could be strategic for a comprehensive overall judgment of clinical competence. Multiple-choice questions (MCQs) are a well-established reliable method of assessing knowledge. Constructing effective MCQ tests and items requires scrupulous care in the design, review and validation stages. Creating high-quality multiple-choice questions requires a very deep experience, knowledge and large amount of time. Hereby, after reviewing their construction, strengths and limitations, we debate their completeness for the assessment of professional competence

Project of a multibeam UHF receiver to improve survey capabilities

The Institute of Radioastronomy (IRA-Bologna) of the National Institute for Astrophysics of Italy (INAF – Rome) joined the European group for the Square Kilometer Array Design Study (SKA-DS) in the frame of the FP6 program. One of the goals of the Design Study was the construction and test of a state of the art very small SKA prototype. A segment (1/8) of the N/S arm of the large Northern Cross array (408 MHz+/−8 MHz) was exploited to obtain a prototype array, made up by 8 cylindrical concentrators (23.5 mt×7.5 mt) equipped with 4 receivers each. In this way a 32 receivers array with a total collecting area of about 1400 m2 was obtained. Signals are directly carried from the receivers, located on the focal lines, down to the back end, located in the processing room, via a very cost effective analog optical links. Here a fast back end, presently based on Field Programmable Gate Array (FPGA) Berkeley-Roach boards, takes care of running the required complex algorithms to perform (non-adaptive) multi-beamforming with a 2D FFT. The main advantage of such an already working array is to produce 21 independent 31’×104’ beams located inside a 38 deg2 Field Of View (FoV). Our plan is to search for funds to refit the remaining 56 cylinders of the N/S arm, to dramatically increase both the sensitivity and number of beams (pixels) placed in the same FoV. In this way, it could be possible to perform a deep SETI survey in the UHF band by an about 11.200 m2 antenna (equivalent to a 119 m dish), a 37.6 deg2 FOV and 189 independent beams. The system could be further expanded by installing more receivers on each N/S focal line, increasing the FOV and the number of pixels with the same sensitivity. Assuming that adequate funds could be found for refitting the giant E/W arm as well, an equivalent 180 m dish could be obtained to perform a very deep SETI sky survey with a 120 deg2 FOV at high sensitivity. This would allow a very fast and deep sky survey in the UHF band