New photoactive oligo- and poly-alkylthiophenes

A new type of ω-methoxy-functionalized oligo-(OCT) and poly-(PQ) hexylthiophene characterized by a tetrameric repeating unit was synthesized and characterized. The configurational regularity and the mean degree of functionalization per thiophenic ring, lower than in commonly synthesized PATs, permitted the obtainment of more ordered chain conformations especially in the solid (film) state. Solar cells based on OCT and PQ films (as p-donor polymeric layer) mixed with Single-walled Carbon Nanotubes (SWCNTs, used as electron-acceptor system) were prepared and investigated. A power conversion efficiency of 0.52% with a fill factor of 0.42, an open-circuit voltage of 0.48 V and a short-circuit current of 1.93 mA/cm² under 70 mW/cm² white light illumination is reported for the polymeric sample. The obtained performance is comparable with that of devices made with regioregular P3HT but the easiness of the monomer synthesis and polymer preparation, giving OCT and PQ with good yields, as well as the enhanced workability and filmability of the latters from diluted solutions of common organic solvents together with their low sensitivity to the environmental conditions (air oxygen, moisture, temperature) makes the synthesized materials very promising for the set-up of polymer photovoltaic cells.     

Finite-element modeling of bones from CT data: sensitivity to geometry and material uncertainties

The aim of this paper is to analyze how the uncertainties in modelling the geometry and the material properties of a human bone affect the predictions of a finite-element model derived from computed tomography (CT) data. A sensitivity analysis, based on a Monte Carlo method, was performed using three femur models generated from in vivo CT datasets, each subjected to two different loading conditions. The geometry, the density and the mechanical properties of the bone tissue were considered as random input variables. Finite-element results typically used in biomechanics research were considered as statistical output variables, and their sensitivity to the inputs variability assessed. The results showed that it is not possible to define a priori the influence of the errors related to the geometry definition process and to the material assignment process on the finite-element analysis results. The errors in the geometric representation of the bone are always the dominant variables for the stresses, as was expected. However, for all the variables, the results seemed to be dependent on the loading condition and to vary from subject to subject. The most interesting result is, however, that using the proposed method to build a finite-element model of a femur from a CT dataset of the quality typically achievable in the clinical practice, the coefficients of variation of the output variables never exceed the 9%. The presented method is hence robust enough to be used for investigating the mechanical behavior of bones with subject-specific finite-element models derived from CT data taken in vivo.     

Psychic retreats or psychic pits?: Unbearable states of mind and technological addiction.

New technologies are highly interactive. They promote imaginative involvement and allow the experience of different self-states, such as those involving withdrawal or “psychic retreat”. According to Steiner, psychic retreats are areas of the mind populated by imagination and ideas which are poorly aligned with reality. Psychic retreats are not necessarily pathological in themselves—for instance, they can be used positively for counteracting anxiety or enhancing creativeness. However, with technological addiction there is a misuse of psychic retreat: here the total absorption with computer applications serves to hide painful or unbearable states of mind, and to protect the patient from overwhelming feelings through segregating self-states with a disconnection in their representations. Therefore, in clinical work with individuals suffering from technological addiction exploring the use of psychic retreats can serve as an aid to both diagnosis and treatment. Where the dysfunctional use of new technologies constitutes a temporary withdrawal from a specific painful event, this can have the function of protecting the individual from inner conflict; in the most serious cases however, technological addiction is grounded in more chronic and pathological dissociative mechanisms, and serves to prevent the mind from reactivating traumatic states connected to childhood experience of emotional neglect or abuse. While it is likely that the first condition can be positively handled with appropriate identification and treatment, the latter is much more difficult to deal with, particularly where the addictive behavior hides the weakness of the self, and psychic retreats are pervasively used to protect the patient from mental breakdown. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Residue analysis of thyreostats in baby foods via matrix solid phase dispersion and liquid chromatography – dual-polarity electrospray – tandem mass spectrometry

This paper describes a rapid method for confirming residues of thyreostats in meat-based baby foods by using liquid chromatography – dual polarity electrospray – tandem mass spectrometry (LC-ES(±)-MS/MS). Six thioureylenes, belonging to the group of thiouracil and imidazole, were selected for this work: thiouracil (TU), methylthiouracil (MTU), propylthiouracil (PTU), phenylthiouracil (PhTU), mercaptobenzimidazole (MBI) and tapazole (TAP).

The amphoteric nature of these compounds allows their electrospray detection in both positive and negative ionisation. Nevertheless, MS detection is not favoured by their low molecular weights, while their chromatographic retention is also thwarted by their high polarity. A pentafluorophenyl (PFP) core-shell phase column was selected to avoid peak asymmetry or peak splitting, and a dual-polarity ionisation method was optimised to obtain a sensitivity as high as possible. The method was validated according to the Commission Decision 657/2002/EC. A simple and fast procedure based on matrix solid phase dispersion (MSPD) was optimised to extract analytes from baby foods with recoveries exceeding 82%. Limit of decision (CCα) and detection capability (CCβ) were lower than the permissible maximum concentration (10 ng g^?1). The validated method was then applied to assess the potential occurrence of the six selected thyreostats in nine commercial products. All the samples were found free of contamination.     

Copolymeric systems with pendant thioxanthone and α-morpholinoacetophenone moieties as photosensitizing and photoinitiating agents for UV-curable pigmented coatings

The synthesis and structural characterization of copolymers of 1-[(2-acryloyloxy) ethoxycarbonyl]thioxanthone (ATX) with 1-[4-(2-acryloyloxyethylthio)phenyl]-2-methyl-2-morpholino-propan-1-one (AMMP), as well as ATX, AMMP and n-butyl acrylate (BA) terpolymers, is reported. These copolymeric systems have been checked in the photoinitiated polymerization in film matrix of the 1,6-hexanediol diacrylate (HDDA)–BA equimolar mixture under UV irradiation over 380 nm, i.e., under conditions simulating a TiO₂-pigmented acrylic coating formulation, and compared with the corresponding mixture of low-molecular-weight structural models 1-[(2-isobutyroyloxy)ethoxycarbonyl]thioxanthone (ITX) and 1-[4-(2-isobutyroyloxyethylthio)phenyl]-2-methyl-2-morpholino-propan-1-one (IMMP). The much higher photoinitiation activity shown by the copolymers is discussed in terms of close vicinity of thioxanthone and α-morpholinoacetophenone moieties along the backbone, which favors the excitation energy transfer from the former to the latter photosensitive group. © 1995 John Wiley & Sons, Inc.     

Muscle discretization affects the loading transferred to bones in lower-limb musculoskeletal models

Modelling the mechanical effect of muscles is important in several research and clinical contexts. However, few studies have investigated the effect of different muscle discretizations from a mechanical standpoint. The present study evaluated the errors of a reduced discretization of the lower-limb muscles in reproducing the muscle loading transferred to bones. Skeletal geometries and a muscle data collection were derived from clinical images and dissection studies of two cadaver specimens. The guidelines of a general method previously proposed for a different anatomical district were followed. The data collection was used to calculate the mechanical effect of muscles, i.e. the generalized force vectors, and the errors between a large and a reduced discretization, in a reference skeletal pose and in the extreme poses of the range of motion of joints. The results showed that the errors committed using a reduced representation of muscles could be significant and higher than those reported for a different anatomical region. In particular, the calculated errors were found to be dependent on the individual anatomy and on the skeletal pose. Since different biomechanical applications may require different discretization levels, care is suggested in identifying the number of muscle lines of action to be used in musculoskeletal models.     

Chiral Resolution and Pharmacological Characterization of the Enantiomers of the Hsp90 Inhibitor 2‐Amino‐7‐[4‐fluoro‐2‐(3‐pyridyl)phenyl]‐4‐methyl‐7,8‐dihydro‐6H‐quinazolin‐5‐one Oxime

Heat‐shock protein 90 (Hsp90) is a molecular chaperone involved in the stabilization of key oncogenic signaling proteins, and therefore, inhibition of Hsp90 represents a new strategy in cancer therapy. 2‐Amino‐7‐[4‐fluoro‐2‐(3‐pyridyl)phenyl]‐4‐methyl‐7,8‐dihydro‐6H‐quinazolin‐5‐one oxime is a racemic Hsp90 inhibitor that targets the N‐terminal adenosine triphosphatase site. We developed a method to resolve the enantiomers and evaluated their inhibitory activity on Hsp90 and the consequent antitumor effects. The (S) stereoisomer emerged as a potent Hsp90 inhibitor in biochemical and cellular assays. In addition, this enantiomer exhibited high oral bioavailability in mice and excellent antitumor activity in two different human cancer xenograft models.     

Production of polyhydroxyalcanoates (PHAs) using milk whey and dairy wastewater activated sludge: Production of bioplastics using dairy residues

The production of polyhydroxyalcanoates (PHAs), which are biodegradable plastics, was studied using milk whey and dairy wastewater activated sludge to define a suitable C/N ratio, the pre-treatments required to reduce the protein content, and the effect of pH correction. The results show good production of PHAs at a C/N = 50 and without pH correction. The use of dairy wastewater activated sludge has the advantage of not requiring aseptic conditions.     

Study of the microstructure of inkjet-printed P3HT:PCBM blend for photovoltaic applications

Recently, great interest has been devoted to cost-effective alternative energy sources such as organic solar cells because of the mechanical flexibility and the versatility of chemical structure, the low cost of fabrication, and ease of processing. As regards this last point, the possibility to deposit organic materials from solutions at low temperatures makes them employable for fabricating printed solar cells by direct printing methods. In this study, we used the inkjet-printing technology to deposit P3HT blends with various fullerene acceptors ([60]PCBM, [70]PCBM and bis[60]PCBM) dissolved in single solvents, 1,2-dichlorobenzene (DCB) and chlorobenzene (CB), and their mixtures. After optimizing the printing parameters (printhead speed, drop emission frequency, and substrate temperature), the effect of the solvents on the morphology of the photoactive layers was analyzed through Raman spectroscopy and atomic force microscopy. Polymer solar cells with the structure glass/ITO/PEDOT:PSS/blend/Ca/Al were fabricated and characterized by current–voltage (I–V) measurements under 100 mW/cm² AM 1.5G illumination. A comparative study of the performances of the devices was performed based on three different fullerene derivatives, correlating them to the microstructure of the printed blend films. The optimal devices were obtained when the blend films were deposited from a mixture of DCB:CB 4:1 by volume: this was in agreement with the most favorable morphology of these films.     

Resource allocation for network-controlled device-to-device communications in LTE-Advanced

Network-controlled device-to-device (D2D) communication allows cellular users to communicate directly, i.e., without passing through the eNodeB, while the latter retains control over resource allocation. This allows the same time–frequency resources to be allocated to spatially separated D2D flows simultaneously, thus increasing the cell throughput. This paper presents a framework for: (1) selecting which communications should use the D2D mode, and when, and (2) allocating resources to D2D and non-D2D users, exploiting reuse for the former. We show that the two problems, although apparently similar, should be kept separate and solved at different timescales in order to avoid problems, such as excessive packet loss. We model both as optimization problems, and propose a heuristic solution to the second, which must be solved at millisecond timescales. Simulation results show that our framework is practically viable, it avoids the problem of packet losses, increases throughput and reduces delays.