Memory enhancement for emotional stimuli is impaired in early Alzheimer's disease.

Emotional arousal is associated with enhanced memory in neurologically intact individuals, but it is unknown whether this effect is obtained in Alzheimer's disease (AD). The current study compared emotional memory and emotional reactions in patients with early AD and in older controls. Participants viewed emotionally arousing (both pleasant and unpleasant) and neutral photographs while cognitive and electrophysiological reactions were assessed. Memory was tested by free recall and recognition. Emotional reactions were normal in the AD group, but the emotional memory effect (enhanced memory for emotional vs. neutral stimuli) was impaired. Recall results indicated that this effect was normal for pleasant stimuli but abnormal for unpleasant stimuli. These results suggest that the neural basis for the emotional memory effect may be disrupted in AD. Findings are discussed in terms of the role of the amygdala in mediating emotional memory. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Serial position effects in implicit and explicit tests of memory.

The effects of serial position at study on implicit and explicit tests of memory were investigated. Both primacy and recency effects were observed in implicit tests of word-stem completion. These effects, however, were transient. No serial position effects were found in the 2nd half of testing (Exps 1 and 3) or when testing followed a 1-min, filled delay (Exp 2). Serial position effects were also examined on explicit tests of cued recall. When performance on explicit cued recall was below ceiling levels, a primacy effect persisted throughout testing (Exp 3). Similarly, in explicit tests of free recall, primacy effects were consistently observed, both with immediate testing (Exps 1 and 3) and when testing followed a filled delay (Exp 2). (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

An Electronically Driven Improper Ferroelectric: Tungsten Bronzes as Microstructural Analogs for the Hexagonal Manganites

Since the observation that the properties of ferroic domain walls (DWs) can differ significantly from the bulk materials in which they are formed, it has been realized that domain wall engineering offers exciting new opportunities for nanoelectronics and nanodevice architectures. Here, a novel improper ferroelectric, CsNbW₂O₉, with the hexagonal tungsten bronze structure, is reported. Powder neutron diffraction and symmetry mode analysis indicate that the improper transition (T_C = 1100 K) involves unit cell tripling, reminiscent of the hexagonal rare earth manganites. However, in contrast to the manganites, the symmetry breaking in CsNbW₂O₉ is electronically driven (i.e., purely displacive) via the second‐order Jahn–Teller effect in contrast to the geometrically driven tilt mechanism of the manganites. Nevertheless CsNbW₂O₉ displays the same kinds of domain microstructure as those found in the manganites, such as the characteristic six‐domain “cloverleaf” vertices and DW sections with polar discontinuities. The discovery of a completely new material system, with domain patterns already known to generate interesting functionality in the manganites, is important for the emerging field of DW nanoelectronics.     

Intrinsically Conductive Polymers for Striated Cardiac Muscle Repair

One of the most important features of striated cardiac muscle is the excitability that turns on the excitation-contraction coupling cycle, resulting in the heart blood pumping function. The function of the heart pump may be impaired by events such as myocardial infarction, the consequence of coronary artery thrombosis due to blood clots or plaques. This results in the death of billions of cardiomyocytes, the formation of scar tissue, and consequently impaired contractility. A whole heart transplant remains the gold standard so far and the current pharmacological approaches tend to stop further myocardium deterioration, but this is not a long-term solution. Electrically conductive, scaffold-based cardiac tissue engineering provides a promising solution to repair the injured myocardium. The non-conductive component of the scaffold provides a biocompatible microenvironment to the cultured cells while the conductive component improves intercellular coupling as well as electrical signal propagation through the scar tissue when implanted at the infarcted site. The in vivo electrical coupling of the cells leads to a better regeneration of the infarcted myocardium, reducing arrhythmias, QRS/QT intervals, and scar size and promoting cardiac cell maturation. This review presents the emerging applications of intrinsically conductive polymers in cardiac tissue engineering to repair post-ischemic myocardial insult.     

The Meyer‐Neldel rule in layered silicone‐silver nanocomposites

X‐Ray diffraction and X‐ray photoelectron spectroscopy studies, applied on some silicone‐silver nanocomposites, revealed the influence of the solvent used in preparation on the morphology of the resulted materials. It has been emphasized that dimethylformamide solvent favors the formation of silver nanoparticles and their migration at the surface, while water solvent favors the formation of a homogeneous composite with small silver nanoparticles. The places occupied by Ag nanoparticles (some prevent their oxidation and others that favor the oxidation process) are dependent on the mixture used in sol‐gel technique and have influence on the nanocomposite electrical conductivity. The temperature dependence of the electrical conductivity is investigated. A linear relationship between the pre‐exponential factor (σ₀) and activation energy (E_a) was observed, in the high temperature range (T > 315 K), for all the samples, indicating that the conductivity data obey Meyer‐Neldel rule. POLYM. COMPOS., 2011. © 2011 Society of Plastics Engineers     

Preparation and functional characterization of magnetoelectric Ba(Ti1-xFex)O3-x/2 ceramics. Application for a miniaturized resonator antenna

Diluted magnetic oxides attracted a great interest in the last years as materials for spintronics and magnetoelectric devices. We propose in the present paper such a magnetoelectric ceramic system for an application as miniaturized resonator antenna in GHz range. BaTi_1-xFe_xO_3-x/2 (0?≤?x?≤?0.02) polycrystalline ceramics have been produced by solid state reaction. X-ray diffraction analysis and Rietveld refinement have shown that Fe doping of BaTiO₃ lattice produces a transition from tetragonal crystalline symmetry (for x?≤?0.01) to a superposition of tetragonal and hexagonal phases for the compositions x?=?0.015 and 0.02. As result of Fe addition, the Curie temperature of BaTi_1-xFe_xO_3-x/2 ceramics exhibit a shift from 127?°C towards lower values and reaches 85?°C for x?=?0.02. A competition between weak ferromagnetic and antiferromagnetic character as a function of composition and temperature is determined both by the presence of transition metal ion and of the oxygen vacancies. Due to its electromagnetic properties, an optimized composition x?=?0.01 was used for producing a miniaturized antenna which was found to show a frequency dependent S₁₁ response similar to the simulated one.     

Undetected Toxicity Risk in Pharmacogenetic Testing for Dihydropyrimidine Dehydrogenase

Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%–30% of patients. Dihydropyrimidine dehydrogenase (DPD), a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD) polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T), fluoropyrimidines should be avoided or reduced according to the patients’ homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C), conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies’ results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer.     

Surface mass spectrometry of two component drug-polymer systems: novel chromatographic separation method using gentle-secondary ion mass spectrometry (G-SIMS)

In recent years, there has been an increase in the use of time-of-flight secondary ion mass spectrometry (TOF-SIMS) for characterizing material surfaces. A great advantage of SIMS is that the analysis is direct and has excellent spatial resolution approaching a few hundred nanometers. However, the lack of the usual separation methods in mass spectrometry such as chromatography or ion mobility combined with the complexity of the heavily fragmented ions in the spectra means that the interpretation of multicomponent spectra in SIMS is very challenging indeed. The requirements for high-definition imaging, with say 256 × 256 pixels, in around 10 min analysis time places significant constraints on the instrument design so that separation using methods such as ion mobility with flight times of milliseconds are incompatible. Clearly, traditional liquid and gas chromatographies are not at all possible. Previously, we developed a method known as Gentle-SIMS (G-SIMS) that simplifies SIMS spectra so that the dominant ions are simply related to the structure of the substances analyzed. The method uses a measurement of the fragmentation behavior under two different primary ion source conditions and a control parameter known as the g-index. Here, we show that this method may be used "chromatographically" to separate the mass spectra of a drug molecule from the matrix polymer. The method may be used in real-time and is directly compatible with the majority of TOF-SIMS instruments. The applicability to other imaging mass spectrometeries is discussed.     

Antecedents of Team Creativity: An Examination of Team Emotional Intelligence,Team Trust and Collaborative Culture

Teams represent a dominant approach to getting work done in a business environment. Creativity enables teams to solve problems and leverage opportunities through the integration of divergent thoughts and perspectives. Prior research indicates that a collaborative culture, which affects how team members interact and work together, is a critical antecedent of team creativity. This study explores other antecedents of team creativity, namely, team emotional intelligence and team trust, and investigates the relationships among these precursors to creative effort. Using a survey of 82 student teams at a large university in the northeast United States, our findings suggest that team emotional intelligence promotes team trust. Trust, in turn, fosters a collaborative culture which enhances the creativity of the team. Cognitive trust also moderates the relationship between collaborative culture and team creativity. Implications of these results for managers and academics are discussed.