Scaring the Already Scared: Some Problems With HIV/AIDS Fear Appeals in Namibia

Fear appeals are often used in public health campaigns in Africa to prevent further spread of HIV/AIDS. Based on the extended parallel processing model framework (K. Witte, 1991), this research assessed the impact of such messages in a high-fear situation. A 2 (high threat, low threat) × 2 (high efficacy, no efficacy) experiment with a no-message offset control and efficacy-only conditions tested several predictions. Participants demonstrated high preexisting fear about HIV/AIDS. As a likely consequence, statistical equivalence tests indicated that messages' threat levels had little impact on perceptions of fear or on outcome measures such as attitudes, intentions, or behaviors. It is concluded that the use of fear appeals to persuade audience with high levels of preexisting fear is ill-advised and ineffective.     

Synthesis of Li(1+x)V3O8 by chemical route and its characterization

Lithium trivanadate (Li(1+x)V3O8) nanorods have been synthesized by the simple polymer precursor route using the polymer, polyvinyl pyrrolidone (PVP) as the complexing agent. Thermal behavior of the precursor has been studied by the differential scanning calorimetry (DSC), thermogravimetric analysis (TGA) and differential thermal analysis (DTA) techniques. X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) studies confirm the formation of the compound. High resolution scanning electron microscopy (HRSEM) analysis reveals the synthesized Li1.2V3O8 particles to be nanorods with an average diameter of 50 nm.     

Molecularly self-assembled nucleic acid nanoparticles for targeted in vivo siRNA delivery

Nanoparticles are used for delivering therapeutics into cells. However, size, shape, surface chemistry and the presentation of targeting ligands on the surface of nanoparticles can affect circulation half-life and biodistribution, cell-specific internalization, excretion, toxicity and efficacy. A variety of materials have been explored for delivering small interfering RNAs (siRNAs)--a therapeutic agent that suppresses the expression of targeted genes. However, conventional delivery nanoparticles such as liposomes and polymeric systems are heterogeneous in size, composition and surface chemistry, and this can lead to suboptimal performance, a lack of tissue specificity and potential toxicity. Here, we show that self-assembled DNA tetrahedral nanoparticles with a well-defined size can deliver siRNAs into cells and silence target genes in tumours. Monodisperse nanoparticles are prepared through the self-assembly of complementary DNA strands. Because the DNA strands are easily programmable, the size of the nanoparticles and the spatial orientation and density of cancer-targeting ligands (such as peptides and folate) on the nanoparticle surface can be controlled precisely. We show that at least three folate molecules per nanoparticle are required for optimal delivery of the siRNAs into cells and, gene silencing occurs only when the ligands are in the appropriate spatial orientation. In vivo, these nanoparticles showed a longer blood circulation time (t(1/2) ≈ 24.2 min) than the parent siRNA (t(1/2) ≈ 6 min).     

Preparation and characterization of a imipramine-ß-cyclodextrin inclusion complex

This article characterizes the association between imipramine and ß-cyclodextrin. The formation of supramolecular host-guest inclusion complex of imipramine with the nano-hydrophobic cavity of ß-cyclodextrin was prepared by physical mixing and coprecipitation. The inclusion complex of imipramine and ß-cyclodextrin in solution was characterized by ultraviolet-visible and fluorescence spectroscopy. The inclusion complex was characterized by infrared spectroscopy, scanning electron microscopy, X-ray diffraction, thermogravimetric analysis, and differential scanning calorimetry. The spectral shifts showed that only a portion of the imipramine molecule was within the ß-cyclodextrin cavity. The binding constant and the 1:1 stoichiometry of the inclusion complex at 303 K was obtained using a Benesi-Hildebrand plot. The Gibbs free energy change of the complex formation process was determined and the complex formation was shown to be spontaneous. The changes observed in vibrational frequencies, morphology, diffraction, and thermal stability confirmed the formation of the solid inclusion complex. Molecular docking and semi-empirical studies were used to characterize the ß-cyclodextrin-associated inclusion complexes of imipramine. The results of molecular modeling were systematically analyzed to determine the stability of the complexes.     

Synthesis of eugenol‐based polybenzoxazine–POSS nanocomposites for low dielectric applications

Nanocomposites of eugenol‐based polybenzoxazines/amine containing polyhedral oligomeric silsesquioxane (POSS) have been prepared through copolymerization of allyl‐containing benzoxazine compounds and amine containing POSS. Their structures, curing behaviour, and thermomechanical properties were characterized by Fourier transform infrared, ¹H‐NMR, ¹³C‐NMR, X‐ray diffraction, differential scanning calorimetry (DSC), dynamic mechanical analysis (DMA), and thermogravimetric analysis (TGA). The nanoscale dispersion of POSS cores in the nanocomposites was verified by scanning electron microscopy, atomic force microscopy, and transmission electron microscopy studies. The results from DMA and TGA show that the thermal stability, crosslink density and flame retardance of the nanocomposites increased when small amounts of POSS cores (5 wt%) were incorporated into the system. Further the POSS incorporation reduces the dielectric constant of the benzoxazines to about 1.32. Hence, the prepared nanocomposites could be used as ultra‐low‐k materials for advanced microelectronics. POLYM. COMPOS., 36:1973–1982, 2015. © 2014 Society of Plastics Engineer     

Influence of graphene oxide on thermal,electrical, and morphological properties of new achiral polyimide

In this study, a new diamine N‐[2‐(1H‐indol‐3‐yl)ethyl]‐3,5‐diaminobenzamide (IEDAB) was synthesized using tryptamine as starting material and characterized by FT‐IR, ¹H‐NMR, ¹³C‐NMR, and mass spectroscopy. Then, it was polymerized with 3,3',4,4'‐benzophenone tetracarboxylic dianhydride (BTDA) via thermal imidization to produce polyimide (PI). A series PI/GO nanocomposite films were prepared by incorporating different ratios (1, 3, and 5 wt%) of synthesized GO by solution casting method. The synthesized PI was confirmed by Ubbelohde viscometer and FT‐IR spectroscopy. SEM and Raman spectroscopy showed that GO was well dispersed in the PI matrix. XRD patterns indicated the PI and PI/GO nanocomposite films were highly amorphous in nature. The synthesized PI and their nanocomposites show high thermal stability as their T_10% weight loss are in the range of 498 to 563°C with 30.6 to 40% of char yield and the glass transition temperatures (T_g s) are in the range of 188 to 262°C. The limited oxygen index (LOI) values increased from 31.4% to 56.0% with increases of 5% GO content in the PI/GO nanocomposite. They have high dielectric constant in the range of 2.6 to 5.1 at 1 MHz and also good mechanical properties with tensile strength of 81 to 116 MPa, elongation at break 5 to 9%. POLYM. ENG. SCI., 2017. © 2017 Society of Plastics Engineers     

Mode investigation of parasitic annular ring loaded dual band coplanar waveguide antenna with polarization diversity characteristics

This document presents a dual band dual polarized coplanar waveguide (CPW) antenna with single port feed. Lower resonating band is circular polarized, while the upper band is linear polarized. A novel concept of realizing dual polarization by suppressing the undesired modes is introduced in this work. Orthogonal Even/Odd modes are excited at lower band and a phase difference of 90° is maintained between them. Hence, circular polarization behavior is realized for lower operating band. For upper band, Odd mode is suppressed by introducing step shaped modifications in the ground plane at left side of the feed line, resulting in linear polarized upper band. Dual band nature of the antenna is confirmed by 10 dB impedance bandwidth extending from 3.91‐5.31 GHz to 7.51‐8.72 GHz. Circular polarized nature of lower band is confirmed by enclosure of lower band by 3 dB axial ratio bandwidth extending from 4.01 to 5.59 GHz. Advantages of proposed antenna involves the use of single port feed for generating dual polarization performance along with compact antenna size.(30 × 30 × 1.6 mm³).     

Reviewing automatic language identification

The Oregon Graduate Institute Multi-language Telephone Speech Corpus (OGI-TS) was designed specifically for language identification research. It currently consists of spontaneous and fixed-vocabulary utterances in 11 languages: English, Farsi, French, German, Hindi, Japanese, Korean, Mandarin, Spanish, Tamil, and Vietnamese. These utterances were produced by 90 native speakers in each language over real telephone lines. Language identification is related to speaker-independent speech recognition and speaker identification in several interesting ways. It is therefore not surprising that many of the recent developments in language identification can be related to developments in those two fields. We review some of the more important recent approaches to language identification against the background of successes in speaker and speech recognition. In particular, we demonstrate how approaches to language identification based on acoustic modeling and language modeling, respectively, are similar to algorithms used in speaker-independent continuous speech recognition. Thereafter, prosodic and duration-based information sources are studied. We then review an approach to language identification that draws heavily on speaker identification. Finally, the performance of some representative algorithms is reported     

Studies on the δ‐form complex in the syndiotactic polystyrene–organic molecule system. II. Structural investigation of the δ‐form with p‐ and m‐xylene isomers

Syndiotactic polystyrene (sPS) membranes containing different mole fractions of p‐xylene were prepared by a solution‐casting procedure. Complex formation between sPS and xylene was studied by thermogravimetric analysis and Fourier transform infrared spectroscopy. The stability and desorption behavior of the sPS–guest solvent and phase transitions were studied by differential scanning calorimetry. The formation of the δ‐form complex in the presence of different mole fractions of xylene isomers was analyzed and confirmed. The mole fraction of p‐xylene in the dried membrane was found to be higher than that of the corresponding mole fraction in the isomer solvent solution used for casting. This was attributed to the preferential complexing ability of p‐xylene with sPS. © 2003 Wiley Periodicals, Inc. J Appl Polym Sci 89: 2882–2887, 2003