Synthetic strategies and structural aspects of metal-mediated multiporphyrin assemblies

Porphyrins play a major role as active chromophores in artificial systems mimicking the natural photoinduced processes. The formation of coordination bonds between peripheral donor sites on the porphyrins and external metal fragments has proven to be an efficient alternative to covalent synthesis for the construction of multiporphyrin assemblies, whose complexity and beauty gradually approach those of the multichromophore systems found in nature. In a modular approach, relatively simple metal-mediated porphyrin adducts, owing to their thermodynamic and kinetic stability, can be exploited as building blocks in the construction of higher order architectures. Thus, multichromophore systems become accessible on demand, with a limited synthetic effort. The collection of solid-state structures reported here demonstrates that the flexibility of the porphyrins and the metal junctions, combined with the conformational freedom of the coordination bonds, may lead to assemblies with hardly predictable architectures. Examples in which X-ray structural determination was essential for establishing the real composition and geometry of the multiporphyrin assemblies are highlighted.     

Consolidation of soft clay foundation improved by geosynthetic-reinforced granular columns: Numerical evaluation

Soft clays are problematic soils as they present high compressibility and low shear strength. There are several methods for improving in situ conditions of soft clays. Based on the geotechnical problem's geometry and characteristics, the in situ conditions may require reinforcement to restrain instability and construction settlements. Granular columns reinforced by geosynthetic material are widely used to reduce settlements of embankments on soft clays. They also accelerate the consolidation rate by reducing the drainage path's length and increasing the foundation soil's bearing capacity. In this study, the performance of encased and layered granular columns in soft clay is investigated and discussed. The numerical results show the significance of geosynthetic stiffness and the column length on the embankment settlements. Furthermore, the results show that granular columns may play an important role in dissipating the excess pore water pressures and accelerating the consolidation settlements of embankments on soft clays.     

Negotiation from a near and distant time perspective.

Across 3 experiments, the authors examined the effects of temporal distance on negotiation behavior. They found that greater temporal distance from negotiation decreased preference for piecemeal, single-issue consideration over integrative, multi-issue consideration (Experiment 1). They also found that greater temporal distance from an event being negotiated increased interest in conceding on the lowest priority issue and decreased interest in conceding on the highest priority issue (Experiment 2). Lastly, they found increased temporal distance from an event being negotiated produced a greater proportion of multi-issue offers, a greater likelihood of conceding on the lowest priority issue in exchange for a concession on the highest priority issue, and greater individual and joint outcomes (Experiment 3). Implications for conflict resolution and construal level theory are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of the Coupling of Terahertz Radiation to Heterostructure Transistors with a Free Electron Laser Source

High electron mobility transistors can work as room-temperature direct detectors of radiation at frequency much higher than their cutoff frequency. Here, we present a tool based on a Free Electron Laser source to study the detection mechanism and the coupling of the high frequency signal into the transistor channel. We performed a mapping over a wide area of the coupling of 0.15 THz radiation to an AlGaN/GaN transistors with cut-off frequency of 30 GHz. Local, polarization-dependent irradiation allowed us to selectively couple the signal to the channel either directly or through individual transistor bias lines, in order to study the nonlinear properties of the transistor channel. Our results indicate that HEMT technology can be used to design a millimeter-wave focal plane array with integrated planar antennas and readout electronics.     

Investigation on the feasibility of integration of high temperature solar energy in a textile factory

Thermal energy production from fossil fuels is very common in many applications, especially in industrial processes. In a global context where great attention is being focused on reducing pollution and greenhouse gas production, the integration of renewable energy in industrial applications is very interesting. This is even more important considering that greenhouse gas emission for industrial processes is a great portion of their total emission. Considering the above, it appears that the integration of high temperature solar panels in industrial processes is quite an attractive prospect. The working temperatures of parabolic solar collectors are, for example, generally close to those of the thermal fluids used in many industrial processes, and parabolic solar collectors are a well known technology with several applications primarily used in electric production systems. Nonetheless, only a few examples of industrial integration have been studied or built. In this study, the integration of a concentrating solar thermal plant in a textile factory has been examined both from the thermodynamic and economic point of view. An existing textile factory was chosen as a case study and its annual consumption of thermal energy characterized. A model of the plant with solar energy integration was developed and simulated with TRNSYS over a one year time period. The plant was simulated considering the panel characteristics provided by the manufacturer and the local irradiation data. The influence of several plant parameters has been investigated in order to estimate their importance on performance and plant suitability.     

Natural radionuclides in the rocks of the Valle del Cervo Pluton in Piedmont

Monitoring of the gamma radiation in Valle del Cervo Pluton was performed by determining U and Th contents in the main rock types cropping out over the entire area and pertaining to the granitic complex, syenitic complex and monzonitic complex. In particular, syenitic rocks were largely used as building and ornamental materials (e.g. Sienite della Balma). All the samples are fresh and do not present joints or fractures filled with U minerals. In the crushed samples the activity of uranium varies from 346 to 764 Bq/kg. Concentration of thorium varies from 202 to 478 Bq/kg. For all the analysed rocks uranium activity is higher than thorium one. The lowest value of radioactive concentration is referred to rocks of the granitic complex. The most active rocks are syenites. The data confirm the high activities of Valle del Cervo rock types, strongly connected with high K content of the source magma (geochemical signature); on the contrary, the activity seems to be not related to the location of the samples.     

Alterations of bone turnover and bone mass at different skeletal sites due to pure glucocorticoid excess: study in eumenorrheic patients with Cushing's syndrome

The aim of the present investigation was to study the effect of glucocorticoid excess on bone mass and turnover not influenced by other diseases known to affect skeleton and/or by different gonadal status and sex. We studied several markers of bone turnover and bone mineral density (BMD) by both quantitative computed tomography (at spine and forearm) and dual x-ray absorptiometry (at spine and three femoral sites) in 18 eugonadal female patients affected by Cushing's syndrome (CS) compared to 24 eugonadal healthy female subjects matched for age and body mass index. In CS patients, serum bone Gla protein, a marker of osteoblastic function, was reduced (3.28 +/- 2.3 vs. 6.47 +/- 2.5; P < 0.01), and bone resorption was increased, as indicated by increased urinary hydroxyproline (36.6 +/- 12 vs. 29.0 +/- 9.1, P < 0.05) and urinary deoxypyridinoline (22.1 +/- 8.0 vs. 16.4 +/- 6.3; P < 0.05). BMD was significantly (P < 0.05 or P < 0.01) reduced at all sites, except cortical forearm, in CS patients compared to controls. By comparing z-scores of reduced BMD in CS patients, spinal trabecular BMD was found to be the most severely affected. Furthermore, disease activity, as measured by urinary free cortisol, was significantly correlated with bone Gla protein (r = -0.57; P < 0.02), urinary hydroxyproline (r = 0.57; P < 0.02), urinary deoxypyridinoline (r = 0.48, P < 0.05), and BMD measured at spine and femur. Our results show that compared to matched control subjects, female eumenorrheic CS patients have reduced osteoblastic function, increased bone resorption, and reduced BMD, and that the severity of these abnormalities is statistically related to the severity of disease activity, as indicated by urinary free cortisol. Moreover, our data suggest a site and tissue specificity of the effect of glucocorticoid excess on bone mass.     

Treatment of deep and shallow intrabony defects. A multicenter randomized controlled clinical trial

This prospective multicenter intra-individual randomized controlled clinical trial was designed to compare the efficacy of guided tissue regeneration (GTR) with bioresorbable barrier membranes versus access flap surgery, in intrabony defects. 2 similar defects were selected in each of 23 patients and randomly assigned to 1 of the 2 treatments. Surgery consisted of an identical procedure except for the omission of the barrier membrane in the flap control sites. At 1-year, probing pocket depth reductions were 4.3+/-2.3 mm in GTR treated sites and 3.0+/-1.5 mm in the flap control sites (p=0.02, paired t-test). Clinical attachment level (CAL) gains were 3.0+/-1.7 mm in the GTR sites and 1.6+/-1.8 mm in the control sites (p=0.009, paired t-test). A subset analysis, performed according to the initial depth of the intrabony component of the defects (INFRA), indicated that in shallow defects (INFRA < or =3 mm) treated with the access flap alone, CAL gains were 1+/-1.5 mm, while in deep ones (INFRA > or =4 mm) they were consistently greater (1.9+/-1.9 mm). The % CAL gains, calculated as the % of the baseline intrabony component depth, however, were almost identical in the 2 subpopulations (45.8+/-64.7% in shallow and 43.8+/-37.6% in deep defects). Similarly, in the GTR sites, linear CAL gains were greater in deep (3.7+/-1.7 mm) than in shallow defects (2.2+/-1.3 mm), but no differences were observed in terms of % CAL gains (76.7+/-27.7% and 75.8+/-45%, respectively). The frequency distribution of CAL changes expressed as %s of the baseline INFRA indicates that most of the sites treated with GTR (73% in shallow and 92% in deep defects) gained 50% or more CAL. Furthermore, many defects (64% of shallow and 33% of deep defects) reached 100% of CAL gain. The present study demonstrated that: (i) GTR with bioresorbable barrier membranes resulted in a significant added benefit in comparison with access flap alone; (ii) the linear amounts of CAL gains were greater in deep than in shallow defects; (iii) CAL gains expressed as %s of the baseline depths of the intrabony component, were similar in shallow and deep defects; (iii) the regenerative procedure tested in the present study resulted in CAL gains equal to the depth of the intrabony component of the defect in some, but not in most of the instances.     

MARTe at FTU: The new feedback control

Keeping in mind the necessities of a modern control system for fusion devices, such as modularity and a distributed architecture, an upgrade of the present FTU feedback control system was planned, envisaging also a possible reutilization in the proposed FAST experiment [1]. For standardization and efficiency purposes we decided to adopt a pre-existent ITER-relevant framework called MARTe [2], already used with success in other European Tokamak devices [3]. Following the developments shown in [4], in this paper we report on the structure of the new feedback system, and how it was integrated in the current control structure and pulse programming interface, and in the other MARTe systems already in FTU: RT-ODIN [5] and the ECRH and LH [6] satellite stations. The new feedback system has been installed in the FTU backup station (known as “Feedback B”), which shares the input signals with the actual feedback system, in order to simplify the validation and debug of the new controller by testing it in parallel with the current one. Experimental results are then presented.