Light emitting diodes containing Langmuir-Blodgett films of copolymer of a poly(p-phenylene-vinylene) derivative and poly(octaneoxide)

The properties of Langmuir and Langmuir-Blodgett (LB) films from a block copolymer with polyethylene oxide and phenylene-vinylene moieties are reported. The LB films were successfully transferred onto several types of substrates, with sufficient quality to allow for evaporation of a metallic electrode on top of the LB films to produce polymer light emitting diodes (PLEDs). The photoluminescence and electroluminescence spectra of the LB film and device were similar, featuring an emission at ca. 475 nm, from which we could infer that the emission mechanisms are essentially the same as in poly(p-phenylene) derivatives. Analogously to other PLEDs the current versus voltage characteristics of the LB-based device could be explained with the Arkhipov model according to which charge transport occurs among localized sites. The implications for nanotechnology of the level of control that may be achieved with LB devices will also be discussed.

Molecular characterization of Arabidopsis thaliana PUF proteins - binding specificity and target candidates

PUF proteins regulate both stability and translation through sequence-specific binding to the 3` UTR of target mRNA transcripts. Binding is mediated by a conserved PUF domain, which contains eight repeats of approximately 36 amino acids each. Found in all eukaryotes, they have been related to several developmental processes. Analysis of the 25 Arabidopsis Pumilio (APUM) proteins presenting PUF repeats reveals that 12 (APUM-1 to APUM-12) have a PUF domain with 50-75% similarity to the Drosophila PUF domain. Through three-hybrid assays, we show that APUM-1 to APUM-6 can bind specifically to the Nanos response element sequence recognized by Drosophila Pumilio. Using an Arabidopsis RNA library in a three-hybrid screening, we were able to identify an APUM-binding consensus sequence. Computational analysis allowed us to identify the APUM-binding element within the 3` UTR in many Arabidopsis transcripts, even in important mRNAs related to shoot stem cell maintenance. We demonstrate that APUM-1 to APUM-6 are able to bind specifically to APUM-binding elements in the 3` UTR of WUSCHEL, CLAVATA-1, PINHEAD/ZWILLE and FASCIATA-2 transcripts. The results obtained in the present study indicate that the APUM proteins may act as regulators in Arabidopsis through an evolutionarily conserved mechanism, which may open up a new approach for investigating mRNA regulation in plants.

Movies, Mind and Meaning : Studying Audience and Favourite Films

Construction of identity and meaning is becoming increasingly important in both media studies and religion scholarship. (Lövheim, 2004) Meaning construction outside traditional religion has become more interesting for religious studies and what individuals in the audience do with all messages circulated through media in everyday life has attended increasing interest within media studies (Stout and Buddenbaum, 2001). Motion pictures, soap operas and advertising are all examples of media contents which generate ideas among its audience which to a various degree are used as resources within the construction of identity (Jansson, 2001). The investigation of what modern humankind’s world views look like and what components they are composed of, in this context seems to be an important topic of investigation (Holm and Björkqvist, 1996). The ways in which the development of media has effected the daily lives of individuals is interest as is the nature of the self and the ways in which the process of self-formation is affected by the profusion of mediated materials (Thompson, 1995). Film and religion are my interest within this larger frame. The topic is not exactly new but the combination of film and religion has during the last ten years resulted in a rapidly growing number of books by scholars interested in this field (Lyden, 2003). One growing focus is on the role that films can and do play within the emerging and developing valuesystem of people in the West today (Marsh, 2004). The British theologian Clive Marsh’s point of departure is very similar to my own. Viewers bring to a film life-experience, immediate concerns and worldviews and the exploration of this interplay between movies and the interpreting process of meaning making is the very focus in this paper. Theoretically, the semeiological model of Alf Linderman is combined with cultural cognitive approaches used by a number of Scandinavian media scholars developing perspectives in audience theory (Linderman, 1996, Höijer and Werner, 1998). 13 individuals, their favourite movie and what it means to them in their life My aim is to examine how individuals comprehend film and what the meaning process look like. In this paper I present the outcome of 13 interviews with young people about their favourite film. I suggest how it is possible to interpret how they interrelate film comprehension with their personal beliefs and their culturally constructed worldview from a sociocognitive point of view. Examples of films chosen range from Disneys Lion King (1994), sciencefiction and fantasy successes like The Matrix (1999) and Lord of the Rings (2001) or the next best movie ever according to www.IMdb.com The Shawshank Redemption (1994) as well as the Swedish blockbuster Så som i himmelen (2004), aka “As in Heaven”.

A interculturalidade no cinema: um estudo da legendagem e da dublagem brasileiras em um filme francês contemporâneo

In this research we present a study of cultural aspects in dubbed and subtitled films. As a case study, we chose to compare the original French version of "Le fabuleux destin d'Amelie Poulain" with both the subtitled and the dubbed versions in Portuguese, with focus on the interaction between the French and the Brazilian cultures. First we considered that (i) the translation process interferes on the perception of cultural relationships; and that (ii) dubbing and subtitling are two methods of translation that result in distinct perceptions from the spectator. Then, we adopted the translation interpretative theory (Seleskovicth; Lederer, 2001; Deslile, 1980) as the general theoretical framework, since it emphasizes the extralinguistic equivalence on the translation process. Furthermore, we based this research on three analytical procedures, which are: the four-step translating operation, the contrastive perception and a translation's typology based on Vinay and Dalbernet's linguistic procedures (Srpová, 1991, 1995, 2004). We extracted forty-six culture-related elements from the film and identified those belonging to the French ethno-universe. Then, the elements were classified with respect to a theoretical typology, based on concepts found in the Ethnography of Communication and a general typology, based on five general thematic groups, defined by the corpus. The results showed that both Brazilian versions tend to preserve those culture-related elements by using lexical loan and literal translation. The visual context, in its association with the linguistic procedures in both Brazilian versions, was also observed as an important element to the comprehension of the culture-related elements as they are considered in the French culture. As a general observation, the perception of culture-related elements in the film seems effectively be oriented by the translation methods

A layer-by-layer film of chitosan in a taste sensor application

Chitosan is alternated with sulfonated polystyrene (PSS) to build layer-by-layer (LBL) films that are used as sensing units in an electronic tongue. Using impedance spectroscopy as the principle method of detection, an array using chitosan/PSS LBL film and a bare gold electrode as the sensing units was capable of distinguishing the basic tastes - salty, sweet, bitter, and sour - to a concentration below the human threshold. The suitability of chitosan as a sensing material was confirmed by using this sensor to distinguish red wines according to their vintage, vineyard, and brands.

Nanostructured hybrid films containing nanophosphor: Fabrication and electronic spectral properties

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Structural and Electronic Effects of Incorporating Mn in TiO2 Films Grown by Sputtering: Anatase versus Rutile

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Light emitting diodes containing Langmuir-Blodgett films of copolymer of a poly(p-phenylene-vinylene) derivative and poly(octaneoxide)

The properties of Langmuir and Langmuir-Blodgett (LB) films from a block copolymer with polyethylene oxide and phenylene-vinylene moieties are reported. The LB films were successfully transferred onto several types of substrates, with sufficient quality to allow for evaporation of a metallic electrode on top of the LB films to produce polymer light emitting diodes (PLEDs). The photoluminescence and electroluminescence spectra of the LB film and device were similar, featuring an emission at ca. 475 nm, from which we could infer that the emission mechanisms are essentially the same as in poly(p-phenylene) derivatives. Analogously to other PLEDs the current versus voltage characteristics of the LB-based device could be explained with the Arkhipov model according to which charge transport occurs among localized sites. The implications for nanotechnology of the level of control that may be achieved with LB devices will also be discussed.

Approach on the Electrochemical Reactivity of Poly-L-Glutamic Acid Against Doxorubicin and Its Application in the Development of a Voltammetric Sensor

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Biotransformation of poly (epsilon-caprolactone) and poly (vinyl chloride) blend

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Microstructural, dielectric and ferroelectric properties of calcium-modified lead titanate thin films derived by chemical processes

Ferroelectric Pb1-xCaxTiO3 (x = 0.24) thin films were formed on a Pt/Ti/SiO2/Si substrate by the polymeric precursor method using the dip-coating technique for their deposition. Characterization of the films bq X-ray diffraction showed a perovskite single phase with a tetragonal structure after annealing at 700 degreesC. Atomic force microscopy (AFM) analyses showed that the film had a smooth and crack-free surface with low surface roughness. In addition, the PCT thin film had a granular structure with an 80 nm grain size. The thickness of the films observed by the scanning electron microscopy (SEM) is 550 nm and there is a good adhesion between the film and substrate. For the electrical measurements metal-ferroelectric-metal of the type capacitors were obtained, where the thin films showed good dielectric and ferroelectric properties. The dielectric constant and dissipation factor at 1 kHz and measured at room temperature were found to be 457 and 0.03. respectively. The remanent polarization and coercive field for the: deposited films were P-r = 17 muC/cm(2) and E-c = 75 kV/cm, respectively. Moreover. The 550-nm-thick film showed a current density in the order of 10(-8) A/cm(2) at the applied voltage of 2 V. The high values of the thin film's dielectric properties are attributed to its excellent microstructural quality and the chemical homogeneity obtained by the polymeric precursor method. (C) 2001 Elsevier science Ltd. All rights reserved.

Relating propelinear and binary G-linear codes

In this paper we establish the connections between two different extensions of Z(4)-linearity for binary Hamming spaces, We present both notions - propelinearity and G-linearity - in the context of isometries and group actions, taking the viewpoint of geometrically uniform codes extended to discrete spaces. We show a double inclusion relation: binary G-linear codes are propelinear codes, and translation-invariant propelinear codes are G-linear codes. (C) 2002 Elsevier B.V. B.V. All rights reserved.

Theoretical and experimental study of the relation between photoluminescence and structural disorder in barium and strontium titanate thin films

Thin films of barium and strontium titanate (BST), synthesized by the polymeric precursor solution and spin coated on [Pt (140nm)/Ti (10 nM)/SiO2(1000 nm)/Si] substrates were found to be photoluminescent at room temperature when heat treated below 973 K, i.e. before their crystallization. First principles quantum mechanical techniques, based on density functional theory (DFT) were employed to study the electronic structure of two periodic models: one is standing for the crystalline BST thin film and the other one for the structurally disordered thin film. The aim is to compare the photoluminescence (PL) spectra of the crystalline and disordered thin films with their UV-vis spectra and with their computed electronic structures. The calculations show that new localized states are created inside the band gap of the crystalline model, as predicted by the UV-vis spectra. The study of the charge repartition in the structure before and after deformation of the periodic model shows that a charge gradient appears among the titanate clusters. This charge gradient, together with the new localized levels, gives favorable conditions for the trapping of holes and electrons in the structure, and thus to a radiative recombination process. Our models are not only consistent with the experimental data, they also allow to explain the relations between structural disorder and photoluminescence at room temperature. (c) 2005 Elsevier Ltd. All rights reserved.

Competition between anchoring and reversible photo-induced alignment of a nematic liquid crystal

We investigated the alignment induced on a nematic liquid crystal (LC) by a photo-aligned polymer film with azo-dye side groups. The orientation of the LC molecules can be manipulated in a reversible manner by irradiating the film with polarized light. We analyzed the competition between the orientation induced by the main chain, through rubbing of the film and that induced by the photo-aligned polymer. Anchoring strength for the different processing conditions are reported. The changes in film morphology caused by rubbing or photo-alignment could be captured by atomic force microscopy. The reversibility of the photo-induced alignment and the competition between the two anchoring mechanisms may allow recording and erasing of information in a LC display.

Study of the Electrochemical Behavior of Histamine Using a Nafion (R)-Copper(II) Hexacyanoferrate Film-Modified Electrode.

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)