Water adsorption dynamics on two TiO2 (1 1 0) rutile surfaces at room temperature has been investigated using the work function (WF) change as a function of time. The first surface was prepared in a standard way using sputtering/annealing cycles, whereas the second one was long term annealed at 620 K in moderate vacuum conditions (the residual gas pressure of about 1 × 10−7 mbar) and cleaned afterwards. The WF change show striking difference as compared to those obtained for highly reduced TiO2 (1 1 0) rutile or the (2 × 1) reconstructed surfaces. For the first kind of surface we show that the observed adsorption dynamics can be qualitatively explained by the present understanding of the water adsorption on non- reconstructed TiO2 (1 1 0) rutile surface according to which the bridging oxygen vacancies and Ti rows are the main adsorption sites. Although generally similar to the former results, water adsorption dynamics on the second kind of the surface has an additional feature that can be only explained by a new adsorption site, which we suggest to be due to (2 × 1) reconstructed regions coexisting with the non-reconstructed TiO2 (110)surface.

A new generation of scaffolds capable of acting not only as support for cells but also as a source of biological cues to promote tissue regeneration is currently a hot topic of in bone Tissue Engineering (TE) research. The inclusion of growth factor (GF) controlled release functionalities in the scaffolds is a possible strategy to achieve such goal. Platelet Lysate (PL) is an autologous source of GFs, providing several bioactive agents known to act on bone regeneration. In this study, chitosan-chondroitin sulfate nanoparticles loaded with PL were included in a poly(d,l-lactic acid) foam produced by supercritical fluid foaming. The tridimensional (3D) structures were then seeded with human adipose-derived stem cells (hASCs) and cultured in vitro under osteogenic stimulus. The osteogenic differentiation of the seeded hASCs was observed earlier for the PL-loaded constructs, as shown by the earlier alkaline phosphatase peak and calcium detection and stronger Runx2 expression at day 7 of culture, in comparison with the control scaffolds. Osteocalcin gene expression was upregulated in presence of PL during all culture period, which indicates an enhanced osteogenic induction. These results suggest the synergistic effect of PL and hASCs in combinatory TE strategies and support the potential of PL to increase the multifunctionality of the 3D hybrid construct for bone TE applications. © 2012 Elsevier B.V. All rights reserved.

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In this work, the ability to foam semi-crystalline natural-based polymers by supercritical fluid technology is evaluated. The application of this technique to natural polymers has been limited due to the fact that they are normally semi-crystalline polymers, which do not plasticize in the presence of carbon dioxide. This can be overcome by the use of plasticizers, such as glycerol, which is a commonly used plasticizer, or ionic liquids, which have recently been proposed as plasticizing agents for different polymers. Following the green chemistry principles, the main aim is, hereafter, the design and development of new 3D architectures of natural-based polymers, combining ionic liquids (IL) and supercritical fluid (SCF) technology. A polymeric blend of starch, one of the most abundantly occurring natural polymers, and poly-$ε$-caprolactone, a synthetic polymer, which is a biodegradable aliphatic polyester commonly used in an array of biomedical applications (SPCL), was processed by supercritical fluid foaming, at different operating conditions, namely pressure (10.0 up to 20.0 MPa), temperature (35 up to 60 °C) and soaking time (30 min up to 3 h). The ionic liquid tested in this work was 1-butyl-3-methylimidazolium acetate ([bmim]Ac). The interactions between SPCL and [bmim] Ac or glycerol were analysed by Fourier transform infrared spectroscopy, differential scanning calorimetry and by mechanical tests, using both tensile and compressive modes. Morphological analysis, porosity, interconnectivity and pore size distribution of the matrixes were evaluated and the morphology was analyzed by scanning electron microscopy and by micro-computed tomography. To our knowledge the use of ionic liquids as foaming agents is reported here for the first time. The results obtained suggest that this approach can further promote the development of composite polymer-IL materials, particularly for catalysis, chromatography, extraction and separation purposes. © The Royal Society of Chemistry 2012.

Thin-films of copper oxide @Cu OA were sputtered from a metallic copper (Cu) target and studied as a function of oxygen partial pressure @O??A. A metallic Cu film with cubic structure obtained from 0{%} O?? has been transformed to cubic CuPO phase for the increase in O?? to 9{%} but then changed to monoclinic CuO phase (for O?? PS7). The variation in crystallite size (calculated from x-ray diffraction data) was further substantiated by the variation in grain size (surface microstruc- tures). The Cu O films produced with O?? ranging between 9{%} and 75{%} showed p-type behavior, which were successfully applied to produce thin-film transistors.

A marine derived polysaccharide, ulvan, extracted from green algae, was combined with poly-d, l-lactic acid (PDLLA) in order to produce a novel scaffold for bone tissue engineering applications. Three dimensional (3D) scaffolds of PDLLA loaded with ulvan particles were originally prepared by subcritical fluid sintering with carbon dioxide at 40°C and 50 bar. Prepared matrixes were characterized in order to validate their suitability to be used as scaffolds for bone tissue regeneration. Characterization included micro-computed tomography, mechanical compression testing, water uptake and degradation testing, and cytotoxicity assays. In addition, ulvan particles loaded with dexamethasone, were also dispersed within the PDLLA matrix and the respective release profile from the samples was evaluated. Prepared PDLLA scaffolds enriched with ulvan particles demonstrated appropriate physicochemical and cytocompatible features to be used for the envisaged applications. On the other hand, the release of dexamethasone from ulvan particles embedded within the PDLLA matrix revealed that the designed systems can be potentially suitable for localized drug delivery. These results further contribute to the establishment of ulvan as a potential novel biomaterial. © 2012 Elsevier B.V. All rights reserved.

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High secondary emission yield (SEY), and the subse- quent build-up of a secondary electron cloud, may se- verely limit the stability of high-intensity particle beams inside particle accelerators. One of the best candidates of beam pipe coating for reduced SEY has been amorphous carbon (a-C) produced by direct current (D.C.) magne- tron sputtering. Here we used pulsed laser deposition (PLD), to prepare a-C films from a pure carbon target at substrate temperatures ranging from 300 K to 773 K. The ablating laser was a Nd:YAG system operating at 1064 nm wavelength. With increasing temperature the optical band gap dropped from about 2.1 eV to 1.0 eV. This trend indicates transition from predominantly a-C films to films with more graphitic content, which was also con- firmed by Raman measurements. SEY spectra were taken upto 1732 eV of primary electron energy. The maximum SEY value decreased from 1.9 in a-C films down to 1.4 in highly graphitic films deposited at higher temperatures

The aim of this study was to evaluate the possibility of preparing chitosan porous matrixes using supercritical fluid technology. Supercritical immersion precipitation technique was used to prepare scaffolds of a natural biocompatible polymer, chitosan for tissue engineering purposes. The physicochemical and biological properties of chitosan make it an excellent material for the preparation of drug delivery systems and for the development of new biomedical applications in many fields from skin to bone or cartilage. Supercritical assisted phase inversion experiments were carried out and the effect of different organic solvents on the morphology of the scaffolds was assessed. Chitosan scaffold morphology, porosity and pore size were evaluated by SEM and micro-CT. A thermodynamic analysis of the process was carried out and insights on the solubility parameter and Flory-Huggins interaction parameters are given. The preparation of a highly porous and interconnected structure of a natural material, chitosan, using a clean and environmentally friendly technology constitutes a new processing technology for the preparation of scaffolds for tissue engineering using these materials. © 2011 Elsevier B.V.

Two different human stones, cystine and cholesterol from the kidney and gall bladder, were examined by time-of-flight sec- ondary ion mass spectrometry using Ga+ primary ions as bombarding particles. The mass spectra of kidney stone were com- pared with those measured for the standard compounds, cystine and cysteine. Similar spectra were obtained for the stone and cystine. The most important identification was based on the existence of the protonated molecules [M+H]+ and deprotonated molecules [M-H]-. The presence of cystine salt was also revealed in the stone through the sodiated cystine [M+Na]+ and the associated fragments, which might be due to the patient treatment history. In the gallstone, the deprotonated molecules [M-H]+ of cholesterol along with relatively intense characteristic fragments [M-OH]+ were detected. Copyright © 2012 John Wiley & Sons, Ltd.

TOF-SIMS VG Ionex IX23LS with upgraded data acquisition and control system was used to study the real urinary stones along with calcium oxalate (COX) and four different calcium phosphate (CP) references. Reliable phase identification of CPs was achieved in the positive SIMS mode on basis of the PO+/POH+ and CaPO2+/Ca2O+ peak ratios. In real urinary stones, pure COX was distinguished from calcium phosphates with confidence via the presence of its characteristic ion peaks. We also quantified the calcium phosphate in the human calculi containing calcium oxalate as major or minor component, which is of a great interest for medical community

Suppose \(\alpha\) is an orientation-preserving diffeomorphism (shift) of \(\mathbb{R}_+=(0,\infty)\) onto itself with the only fixed points \(0\) and \(\infty\). In [KKL11] we found sufficient conditions for the Fredholmness of the singular integral operator with shift \[(aI-bW_\alpha)P_++(cI-dW_\alpha)P_-\] acting on \(L^p(\mathbb{R}_+)\) with \( 1 < p < \infty\), where \(P_\pm=(I\pm S)/2\), \(S\) is the Cauchy singular integral operator, and \(W_\alpha f=f\circ\alpha\) is the shift operator, under the assumptions that the coefficients \(a,b,c,d\) and the derivative \(\alpha'\) of the shift are bounded and continuous on \(\mathbb{R}_+\) and may admit discontinuities of slowly oscillating type at \(0\) and \(\infty\). Now we prove that those conditions are also necessary.

We correct Theorem 3.2 and Corollary 3.3 from [KMS]. This correction ammounts to the observation that the proof of the main result in [KMS] contains a gap in Lemma~10.6 for \(p\ne 2\). The results of [KMS] are true for \(p=2\).

Let \(a\) be a semi-almost periodic matrix function with the almost periodic representatives \(a_l\) and \(a_r\) at \(-\infty\) and \(+\infty\), respectively. Suppose \(p:\mathbb{R}\to(1,\infty)\) is a slowly oscillating exponent such that the Cauchy singular integral operator \(S\) is bounded on the variable Lebesgue space \(L^{p(\cdot)}(\mathbb{R})\). We prove that if the operator \(aP+Q\) with \(P=(I+S)/2\) and \(Q=(I-S)/2\) is Fredholm on the variable Lebesgue space \(L_N^{p(\cdot)}(\mathbb{R})\), then the operators \(a_lP+Q\) and \(a_rP+Q\) are invertible on standard Lebesgue spaces \(L_N^{q_l}(\mathbb{R})\) and \(L_N^{q_r}(\mathbb{R})\) with some exponents \(q_l\) and \(q_r\) lying in the segments between the lower and the upper limits of \(p\) at \(-\infty\) and \(+\infty\), respectively.

Suppose \(\alpha\) is an orientation preserving diffeomorphism (shift) of \(\mathbb{R}_+=(0,\infty)\) onto itself with the only fixed points \(0\) and \(\infty\). We establish sufficient conditions for the Fredholmness of the singular integral operator with shift \[ (aI-bW_\alpha)P_++(cI-dW_\alpha)P_- \] acting on \(L^p(\mathbb{R}_+)\) with \( 1 < p < \infty \), where \(P_\pm=(I\pm S)/2\), \(S\) is the Cauchy singular integral operator, and \(W_\alpha f=f\circ\alpha\) is the shift operator, under the assumptions that the coefficients \(a,b,c,d\) and the derivative \(\alpha'\) of the shift are bounded and continuous on \(\mathbb{R}_+\) and may admit discontinuities of slowly oscillating type at \(0\) and \(\infty\).

{{A series of cationic gold(I) alpha-diimine complexes of the type {[}(NHC)Au(alpha-diimine)]X or {[}(PPh(3))Au(alpha-diimine)]X, where NHC = IPr

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