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The properties and thermal stability of thin films and nano-multilayers are generally governed by the in-depth stress (strain) gradients rather than the average stress state. In the present study, the effect of a variation of the strain gradient in Cu/W NMLs on the thermal stability in the range of 400-800°C was investigated. The strain distribution in the NML stacks was varied by combining Cu/W bilayers with different Cu and W nanolayer thickness-es of either 3 nm or 10 nm. The depth dependent strain profiles were experimentally derived by in-plane grazing X-ray diffraction with the relevant modelling approach. The mean residu-al stresses in Cu and W nanolayers in the as-deposited state and after annealing were found to be independent of the disposition of the different Cu/W bilayer substacks. On the contrary, the strain depth profile of the W nanolayers was found to strongly depend on the disposition of Cu/W bilayer substacks in the Cu/W NML, which resulted in different Cu outflow character-istics upon annealing. Thereby, combining different Cu/W bilayer units within the NML stack can be used to tailor the Cu outflow intensity. Moreover, the arrangement of bilayer units with various nanolayers thicknesses also provides a pathway for producing Cu/W nanocomposites with graded bulk microstructure by high-temperature thermal degradation.

Nano-multilayers (NMLs) are functional nano-architectures, which mechanical, chemical and physical properties can be tailored by smart microstructural and interfacial design. Upon thermal treatment, the layered structure of NMLs of immiscible metals degrades, forming the nanocomposite (NC) microstructure. The mechanical, electrical and thermal properties of NCs can be tailored by varying the formed microstructure through the change of initial thicknesses of constituent nanolayers in NMLs. The driving force of the degradation is of capillary nature, i.e. the system tends to decrease the energies of interfaces by wetting.

Heterostructures of transition metal oxides perovskites represent an ideal platform to explore exotic phenomena involving the complex interplay between the spin, charge, orbital and lattice degrees of freedom available in these compounds. At the interface between such materials, this interplay can lead to phenomena that are present in none of the original constituents such as the formation of the interfacial two-dimensional electron system (2DES) discovered at the LAO3/STO3 (LAO/STO) interface. In samples prepared by growing a LAO layer onto a STO substrate, the 2DES is confined in a band bending potential well, whose width is set by the interface charge density and the STO dielectric properties, and determines the electronic band structure. Growing LAO (2 nm)/STO (x nm)/LAO (2 nm) heterostructures on STO substrates allows us to control the extension of the confining potential of the top 2DES via the thickness of the STO layer. In such samples, we explore the electronic structure trend under an increase of the confining potential with using soft X-ray angle-resolved photoemission spectroscopy combined with ab initio calculations. The results indicate that varying the thickness of the STO film modifies the quantization of the 3dt2g bands and, interestingly, redistributes the charge between the dxy and dxz/dyz bands.

Heterostructures of transition metal oxides perovskites represent an ideal platform to explore exotic phenomena involving the complex interplay between the spin, charge, orbital and lattice degrees of freedom available in these compounds. At the interface between such materials, this interplay can lead to phenomena that are present in none of the original constituents such as the formation of the interfacial two-dimensional electron system (2DES) discovered at the LaAlO3 /SrTiO 3 (LAO/STO) interface. In samples prepared by growing a LAO layer onto a STO substrate, the 2DES is confined in a band bending potential well, whose width is set by the interface charge density and the STO dielectric properties, and determines the electronic band structure. Growing LAO (2 nm) /STO (x nm)/LAO (2 nm) heterostructures on STO substrates allows us to control the extension of the confining potential of the top 2DES via the thickness of the STO layer. In such samples, we explore the electronic structure trend under an increase of the confining potential with using soft x-ray angle-resolved photoemission spectroscopy combined with ab initio calculations. The results indicate that varying the thickness of the STO film modifies the quantization of the 3d t_2g bands and, interestingly, redistributes the charge between the d_xy and d_xz/d_yz bands.

Nanomultilayers (NMLs) and nanocomposites (NCs) are functional nanoarchitectures, which mechanical, chemical and/or physical properties can be tailored by smart microstructural and interfacial design 1. NMLs, constituted of alternating nanolayers of immiscible metals, can evolve upon thermal treatment in a NC (multilayer structure degradation) with tailored mechanical, electrical and/or thermal properties. Particularly, NMLtoNC transition was observed in Cu/W NMLs (alternating bilayers: 5 nm Cu 5 nm W) during high temperature annealing in vacuum 2. It was shown that the driving force for the transformation is provided by the minimization of the total Gibbs energy, as achieved by a reduction of internal interfaces.

Nanomultilayers (NMLs) and nanocomposites (NCs) are functional nanoarchitectures, which mechanical, chemical and/or physical properties can be tailored by smart microstructural and interfacial design 1. NMLs, constituted of alternating nanolayers of immiscible metals, can evolve upon thermal treatment in a NC (multilayer structure degradation) with tailored mechanical, electrical and/or thermal properties. Particularly, NMLtoNC transition was observed in Cu/W NMLs (alternating bilayers: 5 nm Cu 5 nm W) during high temperature annealing in vacuum

This contribution addresses recent advances in the experimental investigation of the phase stability, microstructural integrity and stress evolution of metal/metal (Cu/W) [1] and metal/ceramic (Ag/AlN, Ag60wt.%Cu40at.%/AlN, AgGe10at% /AlN) NML coatings during heating by advanced in-situ diffraction methods in combination with XPS, SEM and TEM analysis.

Interplay of spin, charge, orbital and lattice degrees of freedom in oxide heterostructures results in a plethora of fascinating properties, which can be exploited in new generations of electronic devices with enhanced functionalities. The paradigm example is the interface between the two band insulators LaAlO3 and SrTiO3 that hosts a two-dimensional electron system. Apart from the mobile charge carriers, this system exhibits a range of intriguing properties such as field effect, superconductivity and ferromagnetism, whose fundamental origins are still debated. Here we use soft-X-ray angle-resolved photoelectron spectroscopy to penetrate through the LaAlO3 overlayer and access charge carriers at the buried interface. The experimental spectral function directly identifies the interface charge carriers as large polarons, emerging from coupling of charge and lattice degrees of freedom, and involving two phonons of different energy and thermal activity. This phenomenon fundamentally limits the carrier mobility and explains its puzzling drop at high temperatures.

Interplay of spin, charge, orbital and lattice degrees of freedom in oxide heterostructures results in a plethora of fascinating properties, which can be exploited in new generations of electronic devices with enhanced functionalities. The paradigm example is the interface between the two band insulators LaAlO3 and SrTiO3 that hosts a two-dimensional electron system. Apart from the mobile charge carriers, this system exhibits a range of intriguing properties such as field effect, superconductivity and ferromagnetism, whose fundamental origins are still debated. Here we use soft-X-ray angle-resolved photoelectron spectroscopy to penetrate through the LaAlO3 overlayer and access charge carriers at the buried interface. The experimental spectral function directly identifies the interface charge carriers as large polarons, emerging from coupling of charge and lattice degrees of freedom, and involving two phonons of different energy and thermal activity. This phenomenon fundamentally limits the carrier mobility and explains its puzzling drop at high temperatures.

We carried out a prospective observational study on clinical features of bacterial meningitis. Between October 2002 and June 2005, 322 adult bacterial meningitis cases in 49 infectious disease wards in Italy (MENTORE study group) were enrolled in the study. 133 cases were due to Streptococcus pneumoniae, 44 to Neisseria meningitidis and 145 to other microorganisms. A high SAPS score and coma on admission, as well as need for mechanical ventilation, were more frequent in the pneumococcal meningitis group. Neurological impairment was present in 151 out of 311 patients, and was more frequent in pneumococcal meningitis. A single antibiotic was employed in only 90 of 315 cases; a combination of ceftriaxone and ampicillin was the most frequently administered treatment. Ceftriaxone was also the single most used drug. Adjunctive treatment with steroids was administered in 210 out of 303 patients for a median duration of 7 days. Median duration of fever was 4 days, and median hospital stay was 16 days; hospitalization was significantly longer in the pneumococcal meningitis group. At discharge, neurological impairment was still present in 59 (21%) of 277 patients. Twenty (6.9%) out of 289 patients died during hospitalization. Distribution of adverse outcome (death and neurological impairment) in patients treated with or without steroids and within different time zones between onset of symptoms and commencement of antibiotics was studied; a trend toward a worse prognosis was seen in patients treated more than 24 hours after onset of the disease.In our study, infectious disease clinicians made extensive use of steroids as adjuvant therapy for bacterial meningitis, even in absence of detailed national and local guidelines. Mortality seemed to be lower in comparison with the literature.

Chronic hepatitis C is frequent and aggressive in HIV-positive patients. Identification of early predictors of response to anti-HCV therapy is needed for a lower rate of response and higher discontinuations, compared to HCV mono-infected subjects. The aim of our study was to evaluate the predictive value of virological response (VR) at week 4-8-12 of Pegylated interferon alpha-2b (PEG-IFN) plus ribavirin (RBV) on sustained virological response (SVR) in HIV-HCV co-infected patients. 100 patients were treated with PEG-IFN (1.5 mcg/Kg/w) plus RBV (> or =10.6 mg/kg/d) and randomized for 24-48 or 48-72 weeks, respectively for genotype 2-3 and 1-4, in case of response (HCV-RNA PCR negativity) at the end of standard therapy (24 weeks for genotype 2-3, 48 weeks for genotype 1-4). Transcription-Mediated Amplification (TMA) assay for HCV-RNA was also applied. 27 patients reached end-of-treatment response (9 genotype 1-4, 18 genotype 2-3), 21 achieved SVR (8 genotype 1-4, 13 genotype 2-3). 35 patients dropped, 15 due to side-effects. SVR was statistically related to lower baseline HCV-RNA and to VR at week 4-8-12, with PPV 64%, 53% and 58%, and NPV 81%, 96% and 88%, respectively. In 27 patients, TMA was performed and confirmed standard PCR, except in two cases of relapse, who were PCR negative but TMA positive at week-12. In conclusion, VR at week 8 showed the highest NPV on SVR (96%). The study of viral kinetics requires further investigations in HIV-positive patients to guarantee a cost-effective therapy and to guide individually the duration of treatment. In this setting, TMA might be useful.

We report the results of second harmonic optical spectroscopy of LaAlO 3 films grown on SrTiO3 (001) substrates having either TiO2 or SrO atomic terminations. The atomic termination is found to have a large effect on the observed spectra with a strong dependence on the ? 2? light polarizations. These results are analyzed through a model based on symmetry controlled selection rules and atomic orbital overlaps. The analysis shows that as suspected from transport measurements the SrO termination prevents the formation of a mobile interfacial electron gas. Yet by explicitly probing and identifying the electronic states at the O2 Ti3+ band gap we now obtain unique and direct evidence that this is caused by the absence of any detectable charge injection in the interfacial region rather than by carrier localization. © 2013 American Physical Society.