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Improvement of structural and morphological stability of Ag layers has to be pursued for effective employment in solar coating technology for “parabolic trough” thermal plants. Starting from the consideration that stainless steel surface of a receiver tube does not behave as an excellent substrate for fabricating appropriate Ag layers in terms of adhesion strength and thermal stability, both substrate pre-treatments and adaptive layer deposition have been taken into account. Beneficial effect of substrate ionic etching pre-treatment on adhesion coupled with utilization of “α phase” tungsten film as adaptive layer gave evidence for large improvement both on adhesion strength and on morphological stability of Ag layers subjected to thermal cycles at 400 °C under vacuum. Using Ag as infrared reflector and W α as adaptive layer, an optimized cermet-based selective coating suitable for receiver tube operating at 400 °C has been fabricated. This coating, subjected to annealing processes at 400 °C under vacuum up to 29 days, showed excellent thermal and optical stability.

Objective To describe atypical longitudinal disease progression in Huntington’s disease (HD). Subjects and methods We selected two HD subjects from a cohort of 104 Italian patients participating in the REGISTRY-Enroll-HD study. Patient 1 is a 66 year-old man presenting depressive symptoms at age 46. First motor symptoms, noticed at age 51 (9 year later than expected from his CAG length), were mild eye movement defects and difficulties in tongue protrusion. He had very few choreic movements. Genetic test showed 20/45 CAG repeats. At age 56 UHDRS-TMS was 15 and TFC 11. In this subject both motor and cognitive impairment progressed very slowly during follow-up. After 10-year UHDRS-TMS was 28 and TFC 5. The change per year in the cognitive tests were: Symbol-Digit-Modalities-Test 0/y (baseline = 20); Verbal Fluency −0.3/year; Color-Naming −3.6/year; Word-Reading +0.7/year; and Stroop-Interferences −0.6/year. Patient 2 is a 59 year-old man, who presented motor symptoms at age 49 (11 years earlier than expected). At baseline TFC was 13 and UHDRS-TMS was 9. Genetic test showed 19/40 CAG repeats. After 10 years UHDRS-TMS was 18 and TFC 10. Cognitive tests are available only for the last 6 years of follow-up. The changes per year were: Symbol-Digit-Modalities-Test −2.3/year (baseline = 26); Verbal Fluency −1/year; Color-Naming −14.3/year; Word-Reading −2.8/year, and Stroop-Interferences −4.2/year. For both patients volumetric brain MRI and multi-tissue DNA analyses are performed. Conclusion The identification of HD individuals with atypically mild motor and/or cognitive progression may allow the study of possible genetic/epigenetic modifying factor/s significantly slowing the clinical disease progression.

Objectives Premanifest Huntington’s disease mutation carriers (preHD) are known to present functional and neuroradiological abnormalities before the motor onset. This study evaluated brain morphometry and posture in preHD. Participants and methods 29 preHD (13F/16 M, mean age 36.5 years, CAG range 37–48) and 25 sex-age matched controls were enrolled (14F/11 M, mean age 35.7 years). Inclusion criteria were: CAG expansion > 36; UHDRS-TMS Results PreHD and controls did not differ in total intracranial volume, caudate volumes, and cortical thickness. Only in close-to-onset preHD caudate volumes and occipital cortical thickness were reduced in comparison with controls (p = 0.002; p = 0.0098) and far-from-onset preHD (p = 0.002; p = 0.007). Caudate volumes and occipital cortical thickness directly correlated with years to onset (ρ = 0.58, 0.74; p = 0.003, p Posturography parameters were similar in pre-HD and controls for all conditions, except for wide-base-closed-eyes test, in which preHD presented a greater number of sway peaks (p = 0.006). In close-to-onset preHD the number of sway peaks was greater than controls (p = 0.001) and far-from-onset preHD (p = 0.016). Conclusions Our study confirms that caudate volumes and occipital cortical thickness are the earliest markers of brain degeneration in the preHD. Posturography may represent a simple and rapid test to investigate early stance abnormalities.

Objectives We aimed to identify markers of cognitive and structural brain abnormalities in premanifest Huntington’s disease subjects (preHD). Participants and methods We enrolled 29 preHD (13F/16 M, age 36.5 years, CAG range 37–48; UHDRS-TMS Results PreHD and controls did not differ in total intracranial volume, caudate volumes, and cortical thickness, and presented scores within normal range in all cognitive tests. However, preHD scored significantly worse than controls in SDMT (p = 0.048), in MMSE (p = 0.0013) and in Calculation test (p = 0.014). Analyses of sub-item of the Calculation test showed that preHD, and in particular the group of close-to-onset preHD (−16 years), made specifically more mistakes than controls in the subtraction task (p = 0.0089), while preHD and controls did not differ in multiplications. The SDMT score correlated with left occipital cortical thickness (p = 0.0029) and Calculation test total score with caudate nucleus volumes (p = 0.032). Conclusions We confirm that SDMT can identify very early abnormalities in preHD and the scores directly correlate with occipital cortical thickness. The results of the Calculation test suggest that preHD have selective executive deficits in calculation, as demonstrated in the subtraction process, while in the multiplication task, implying mainly memory retrieval, no differences were found.

We report on a new class of polymeric sensors based on a properly selected polysilsesquioxane filled with different conductive powders obtained by ball milling. These sensors exhibit excellent sensing properties with respect to both polar and apolar analytes and do not base their operating mechanism on the swelling. In fact, exposure to water molecules or hexane vapours determines an increase of conductivity. In particular the response in the full RH% range for devices obtained with different filler (Zn-Graphite, Zn, Cu) is of four magnitude orders variation between 0% and 100% RH in the conductivity of the sensors.

The synthesis of the new chromophores 2-{4-[4-(N,N-dihydroxyethylamino)-phenylazo]-phenyl}-6-nitrobenzoxazole (1) and 4-[4-(N,N-dihydroxyethylamino)phenylazo]-benzoic acid (2) is described. Three homopolymers obtained by the polycondensation of 1 with propyloxy-terephthalic acid and 1 and 2 with 2,4-tolylenediisocianate as well as two copolymers obtained by polycondensation of appropriate mixtures of chromophores 1 and 2 with 2,4-tolylene-diisocianate were prepared and characterized. All as-prepared polymers but one (homopolyurethane of 1) were amorphous and exhibited good optical clarity, good thermal stability above the glass transition, and solubility in organic solvents. The second-order nonlinear optical behavior of the amorphous polymers was investigated on spin-coated corona-poled films through second harmonic generation (SHG) experiments at 1064 nm. At this wavelength, resonance-enhanced values of the SHG coefficient d33 were found in the range between 6 and 34 pm/V where higher values were observed for polymers with a higher molar content of 1. © 2002 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 40: 1468–1475, 2002

Objective A functional MRI (fMRI) study to identify and localise the earliest neural changes, in a group of young premanifest Huntington’s disease (preHD) individuals, far from estimated clinical onset. Methods Sixteen preHD, and 18 age/sex matched healthy participants were enrolled. All preHD subjects previously underwent the predictive genetic testing for HD, and did not present neurological signs consistent with HD clinical onset (UHDRS TMS score = 0). Cognitive evaluation of both groups of subjects did not reveal abnormalities. The subjects were submitted to volumetric MRI and fMRI, during the execution of the exogenous covert orienting of attention task. Considering the fMRI task (Posner paradigm) correlation analyses were restricted to the frontal oculomotor cortex identified by the means of a prosaccadic task. In preHD group, multiple regression analysis was performed between fMRI results and the probability to develop the disease onset in the next 5 years (p5HD). Results fMRI task behavioural performance did not differ between the two groups, while, mean BOLD signal changes of oculomotor frontal cortex was significantly different in the two groups, and, in preHD, correlates with p5HD (r2 = 0.52). A modest correlation (r2 = 0.29) was observed between right putamen volume and p5HD. Conclusion fMRI activations in the right frontal cortex, correlates with p5HD in a group of preHD individuals very far from onset. This result needs to be confirmed in a larger cohort of preHD subjects enrolled in a longitudinal study, and could represent a possible fMRI biomarker for preHD.

Objective To report a 6-year experience of a programme for predictive test (PT) in Huntington disease (HD). Participants and Methods At-risk individuals for HD, aged >18 years, performed three consecutive visits, and an optional follow-up visit at 4–6 months. Symptom Check List 90 Revised (SCL90 R), and Beck Depression Inventory (BDI) tests were administered. The psychiatrist/psychologist did not meet the at-risk subjects during the PT, but cooperated with the multidisciplinary team integrating psychological support at the disclosure of genetic results. Results From 2006 and 2011, 159 individuals (78M/81F) at-risk for HD underwent the programme for PT. The mean age was 37.4±11.6 years (range 16–77) Married subjects were 51.3%. Positive symptoms at the SCL90R test were 26.0± 17.6 (range 1–78). Age, sex, marital status and results at psychological tests were similar in each year of the study. Only years of education were significantly lower for the subjects asking for PT in 2011 (10 years) in comparison with the subjects performing PT in 2006 (13.3) (p=0.0065). None of the subjects had clinically relevant depressive symptoms (BDI scores Conclusions During the 6 years of the programme we did not observe significant adverse events. Socio-demographic characteristics of the at-risk HD population undergoing PT remained similar from 2006 to 2011, except for education.

Tungsten nitride (WNx) thin films were produced by reactive dc magnetron sputtering of tungsten in an Ar–N2 gas mixture. The influence of the deposition power on the properties of tungsten nitride has been analyzed and compared with that induced by nitrogen content variation in the sputtering gas. A combined analysis of structural, electrical and optical properties on thin WNx films obtained at different deposition conditions has been performed. It was found that at an N2 content of 14% a single phase structure of W2N films was formed with the highest crystalline content. This sputtering gas composition was subsequently used for fabricating films at different deposition powers. Optical analysis showed that increasing the deposition power created tungsten nitride films with a more metallic character, which is confirmed with resistivity measurements. At low sputtering powers the resulting films were crystalline whereas, with an increase of power, an amorphous phase was also present. The incorporation of an ...

We tested the ac electrical properties of dielectric poly(propylmetacril heptaisobutyl-POSS)-co-(N-butylmethacrylate) thin films in order to better understand their working mechanism as relative humidity sensing devices. Samples with a 15% and 25% of cage content in weigh have been characterized as a function of temperature and frequency. The different frequency responses are reported and discussed in terms of the existing models. The temperature glass transition (T-g) has been measured by means of an electrical method on films in the same sensor configuration and correlated with the electronic transport properties. Furthermore, the interest of the material with a 15% of cage content is discussed in the contest of basic studies concerning water confinement effects at the molecular scale, i.e., the supercooling of water. (C) 2008 American Institute of Physics.

In view of ITER operations, many experiments are being conducted on the EAST tokamak. In particular, new magnetic control approaches are being developed and need to be tested. In order to design and test a plasma current, position and shape control, an accurate modeling of EAST static equilibria and dynamic plasma evolution is required. Hence, a suite of simulation tools has been developed for the reconstruction of plasma equilibria, the generation of plasma linearized models and for the closed loop testing of magnetic control algorithms. These tools are meant to assess the reliability of such equilibria and models, in order to provide a robust tool for the purposes of control design.

Taking into account the functional relationship between visible radiation and its effects on human circadian system, an optical sensor system has been developed with capability of bio-miming human visual and non-visual stimuli by means of a simultaneous monitoring of particular radiation frequencies for indoor lighting. This optical sensor system is made of 5 photodiodes equipped with passband optical filters, based on sputtered AlN-Ag interferential layers and having the maximum transmission peak positioned at the response wavelengths of the human photoreceptors (cones, rods and ganglion cells). When exposed to different light sources this photosensor system is able to qualify the responses of the five photoreceptors, useful to evaluate lighting quality both as visual and non-visual effects are concerned.

We report the synthesis and physico-chemical characterization, including molecular second order nonlinear optical properties by the EFISH technique, of three new heterocycle based push–pull chromophores. Two chromophores contain the five membered 1,3,4-oxadiazole ring, the third a thiophene ring. The chromophores also contain azo or stilbene bridges between conjugated aromatic rings and are functionalized for covalent incorporation into polymer chains. The maximum observed μgβ is 1350 × 10−48 esu for the thiophene chromophore in conditions far from resonance enhancement (fundamental laser wavelength 1.907 µm). The crystal structure of one oxadiazole chromophore is also discussed.