Properties of pulsed laser deposited fluorinated hydroxyapatite films on titanium

Fluorinated hydroxyapatite coated titanium was investigated for application as implant coating for bone substitute materials in orthopaedics and dentistry. Pulsed laser deposition technique was used for films preparation. Fluorinated hydroxyapatite target composition, Ca₁₀(PO₄)₆F_1.37(OH)_0.63, was maintained at 2 J/cm² of laser fluence and 500-600 °C of the substrate temperature. Prepared films had a compact microstructure, composed of spherical micrometric-size aggregates. The average surface roughness resulted to be of 3 nm for the film grown at 500 °C and of 10 nm for that grown at 600 °C, showing that the temperature increase did not favour the growth of a more fine granulated surface. The films were polycrystalline with no preferential growth orientation. The films grown at 500-600 °C were about 8 μm thick and possessed a hardness of 12-13 GPa. Lower or higher substrate temperature provides the possibility to obtain coatings with different fine texture and roughness, thus tayloring them for various applications.     

Hormonal receptors in mammary carcinoma: comparison between quantitative and qualitative methods

Alternatives to the traditional hormone receptor dosages for prognostic evaluation and clinical approach to breast cancer have been proposed for immunohistochemical determinations. For correlation purposes, such procedures were compared in 37 patients presenting 5 to 15 years of survival. Considering 30 fm/mg as the positivity index, the disagreement between both methods reached 35.1% with estrogen and 48.5% with progesterone receptors. When the positiveness level was changed to 20 fm/mg, the discrepancies were reduced to 32% with ER and increased to 57% with PgR. This study leads us to not recommend the immunohistochemical method applied to paraffin sections as an alternative procedure to the dextran-charcoal dosage for prognosis and therapeutic management of mammary carcinoma.     

Specifying mining algorithms with iterative user-defined aggregates

We present a way of exploiting domain knowledge in the design and implementation of data mining algorithms, with special attention to frequent patterns discovery, within a deductive framework. In our framework, domain knowledge is represented by way of deductive rules, and data mining algorithms are specified by means of iterative user-defined aggregates and implemented by means of user-defined predicates. This choice allows us to exploit the full expressive power of deductive rules without loosing in performance. Iterative user-defined aggregates have a fixed scheme, in which user-defined predicates are to be added. This feature allows the modularization of data mining algorithms, thus providing a way to integrate the proper domain knowledge exploitation in the right point. As a case study, we present how user-defined aggregates can be exploited to specify and implement a version of the a priori algorithm. Some performance analyzes and comparisons are discussed in order to show the effectiveness of the approach.     

Evidence for a Negative Correlation between Human Reactive Enamine-Imine Intermediate Deaminase A (RIDA) Activity and Cell Proliferation Rate: Role of Lysine Succinylation of RIDA

Reactive intermediate deaminase (Rid) proteins are enzymes conserved in all domains of life. UK114, a mammalian member of RidA subfamily, has been firstly identified as a component of liver perchloric acid-soluble proteins (L-PSP). Although still poorly defined, several functions have been attributed to the mammalian protein UK114/RIDA, including the reactive intermediate deamination activity. The expression of UK114/RIDA has been observed in some tumors, arousing interest in this protein as an evaluable tumor marker. However, other studies reported a negative correlation between UK114/RIDA expression, tumor differentiation degree and cell proliferation. This work addressed the question of UK114/RIDA expression in human non-tumor HEK293 cell lines and in some human tumor cell lines. Here we reported that human RIDA (hRIDA) was expressed in all the analyzed cell line and subjected to lysine (K-)succinylation. In HEK293, hRIDA K-succinylation was negatively correlated to the cell proliferation rate and was under the control of SIRT5. Moreover, K-succinylation clearly altered hRIDA quantification by immunoblotting, explaining, at least in part, some discrepancies about RIDA expression reported in previous studies. We found that hRIDA was able to deaminate reactive enamine-imine intermediates and that K-succinylation drastically reduced deaminase activity. As predicted by in silico analysis, the observed reduction of deaminase activity has been related to the drastic alterations of hRIDA structure inferred by K-succinylation. The role of hRIDA and the importance of its K-succinylation in cell metabolism, especially in cancer biology, have been discussed.     

Nondeterministic, nonmonotonic logic databases

We consider an extension of Datalog with mechanisms for temporal, nonmonotonic, and nondeterministic reasoning, which we refer to as Datalog++. We show, by means of examples, its flexibility in expressing queries concerning aggregates and data cube. Also, we show how iterated fixpoint and stable model semantics can be combined to the purpose of clarifying the semantics of Datalog++ programs and supporting their efficient execution. Finally, we provide a more concrete implementation strategy on which basis the design of optimization techniques tailored for Datalog++ is addressed     

Modulation on C‐ and N‐Terminal Moieties of a Series of Potent and Selective Linear Tachykinin NK2 Receptor Antagonists

Herein we describe the synthesis of a series of new potent tachykinin NK₂ receptor antagonists by the modulation of the C‐ and N‐terminal moieties of ibodutant (MEN 15596, 1 ). The N‐terminal benzo[b]thiophene ring was replaced by different substituted naphthalenes and benzofurans, while further modifications were evaluated at the C‐terminal tetrahydropyran moiety. Most compounds demonstrated a high affinity for the human NK₂ receptor and high in vitro antagonist potency, indicating that a wide range of substituents at both termini can be incorporated in the molecule without detrimental effects on the interactions with the NK₂ receptor. Selected compounds were tested in vivo confirming their activity as NK₂ antagonists. In particular, after both iv and id administration to guinea pig, compound 61 b was able to antagonize NK₂‐induced colonic contractions with a potency and duration‐of‐action fully comparable to the reference compound 1 (MEN 15596, ibodutant).     

Bioactive glass–ceramic coatings prepared by pulsed laser deposition from RKKP targets (sol–gel vs melt-processing route)

The deposition of innovative glass–ceramic composition (i.e. RKKP) coatings by Pulsed Lased Deposition (PLD) technique is reported. RKKP was synthesised following two methodologies: melt-processing and sol–gel, the latter being particularly suitable to tailor the compositional range. The PLD advantage with respect to other deposition techniques is the congruent transfer of the target composition to the coating. The physico-chemical properties of films were investigated by Scanning Electron and Atomic Force Microscopies, Fourier Transform Infrared Spectroscopy, Angular and Energy Dispersive X-ray Diffraction, and Vickers microhardness. The deposition performed at 12 J/cm² and 500 °C allows to prepare crystalline films with the composition that replicates rather well that of the initial targets. The 0.6 μm thin melt-processing RKKP films, possessing the hardness of 25 GPa, and the 4.3 μm thick sol–gel films with the hardness of 17 GPa were obtained.     

Morphology profiles obtained by reaction‐induced phase separation in epoxy/polysulfone/poly(ether imide) systems

The reaction‐induced phase separation in epoxy/aromatic diamine formulations simultaneously modified with two immiscible thermoplastics (TPs), poly(ether imide) (PEI) and polysulfone (PSF), has been studied. The epoxy monomer was based on the diglycidyl ether of bisphenol A (DGEBA) and the aromatic diamine was 4,4′‐methylenebis(3‐chloro 2,6‐diethylaniline) (MCDEA). Phase‐separation conversions are reported for various PSF/PEI proportions for blends containing 10 wt% total TP. On the basis of phase‐separation results, a conversion–composition phase diagram at 200 °C was compiled. This diagram was used to design particular cure cycles in order to generate different morphologies during the phase‐separation process. It was found that, depending on the PSF/PEI ratio employed, a particulate or a morphology characterized by a distribution of irregular PEI‐rich domains dispersed in an epoxy‐rich phase was obtained for initially miscible blends. Scanning electron microscopy (SEM) characterization revealed that the PEI‐rich phase exhibits a phase‐inverted structure and the epoxy‐rich matrix presents a bimodal size distribution of TP‐rich particles. For PSF/PEI ratios near the miscibility limit, slight temperature change result in morphology profiles. Copyright © 2005 Society of Chemical Industry     

Hybrid inorganic–organic proton conducting membranes based on Nafion and 5 wt% of MxOy (M = Ti,Zr, Hf,Ta and W). Part II: Relaxation phenomena and conductivity mechanism

In this report, we are presenting studies of the effect of M_xO_y nanopowders on the thermal, mechanical and electrical properties of [Nafion/(M_xO_y)_n] membranes with M = Ti, Zr, Hf, Ta and W and n = 5 wt%. Five homogeneous membranes with thicknesses ranging from 170 to 350 μm were studied. The thermal transitions characterizing [Nafion/(M_xO_y)_n] materials were investigated by modulated differential scanning calorimetry (MDSC). The mechanical parameters and relaxation processes were studied on temperature by dynamical mechanical analyses (DMA). Broadband dielectric spectroscopy (BDS) was used to study the conductivity mechanism and dielectric relaxation events in bulk materials. DMA investigations showed two distinct relaxation events. The first relaxation phenomenon, detected at about 19 °C, was attributed to the mechanical β-relaxation mode of Nafion. The second event, revealed in the temperature range 100–135 °C, was assigned to the mechanical α-relaxation mode of Nafion. The electric response of membranes was studied by BDS measurements in the frequency and temperature range respectively of 40 Hz–10 MHz and 5–135 °C. Real and imaginary components of permittivity (?*(ω) = ?′ (ω) − i?″(ω)) and conductivity spectra (σ*(ω) = σ′(ω) + iσ″(ω)) were analyzed. Conductivity spectra allowed us to accurately determine the σ_dc of membranes at 100% RH as a function of T. Two relaxation peaks were detected in the ?*(ω) profiles. The low frequency relaxation event was attributed to the α-relaxation mode of fluorocarbon chains of Nafion. The high frequency relaxation peak corresponds to the β-relaxation of acid side groups. The results allowed us to conclude that M_xO_y influences: (a) the relaxations of both the hydrophobic and the hydrophilic domains of Nafion polymer host; (b) the thermal stability range of conductivity (SRC) and the σ_dc of membranes.