1,721,095 research outputs found
Change in bi-directional plasticity at CA1 synapses in hippocampal slices taken from 6-hydroxydopamine-treated rats: the role of endogenous norepinephrine
No full textActivation of beta-adrenergic receptors enhances timing based long-term potentiation (LTP) at CA1 synapses.
No full textEnhancement of associative long-term potentiation by activation of beta-adrenergic receptors at CA1 synapses in rat hippocampal slices.
No full textIncrease of insulin sensitivity and reversal of age-dependent glucose intolerance with inhibition of ASIC3.
No full textThe effect of prior prolonged low frequency stimulation on the further synaptic plasticity at hippocampal CA1 synapses.
No full textUsing a layer-by-layer assembly technique to fabricate multicolored-light-emitting films of CdSe@CdS and CdTe quantum dots
No full text[[abstract]]The tunability of the colors and emissions of quantum-dot (QD) films—by controlling the deposition order and number of bilayers in (PDDA–CdSe@CdS)n and (PDDA–CdTe)n films (PDDA: poly(diallyldimethylammonium chloride))—is demonstrated. The photograph shows QD microstructures that exhibit different emission colors on a gold nanoparticle (AuNP)-treated indium tin oxide substrate, fabricated by combining layer-by-layer assembly with photolithography
Growth of Various Au–Ag Nanocomposites from Gold Seeds in Amino Acid Solutions
No full text[[abstract]]In this paper, we describe an easy procedure for the preparation of differently shaped and sized Au–Ag nanocomposites from gold nanorod (AuNR) seeds in various amino acid solutions—arginine (Arg), cysteine (Cys), glycine (Gly), glutamate (Glu), glutamine (Gln), histidine (His), lysine (Lys), and methionine (Met), respectively—at values of pH ranging from 8.0 to 11.5. Our results suggest that the pH, the nature of the amino acid, and its concentration all have significant impact on the preparation of Au–Ag nanocomposites; these factors exhibit their effects mainly through control over the reducing ability of ascorbate and/or its recognition capability, as well as through control over the surface charges of the amino acids on the AuNRs. Depending on the value of pH, we were able to prepare I-shaped, dumbbell-shaped, and/or sphere-shaped Au–Ag nanocomposites in 0.1 M solutions of Arg, Gly, Glu, Gln, Lys, and Met. In His solutions at pH 8.0 and 9.0, we obtained peanut-shaped Au–Ag nanocomposites. Corn-shaped Au–Ag nanocomposites were prepared in 0.1 M Met solutions (pH 9.0 and 10.0). By controlling the Lys concentration at pH 10.0, we synthesized pearl-necklace-shaped Au–Ag nanoparticles and Au–Ag wires. Based on the TEM images, we conclude that this simple and reproducible synthetic approach allows preparation of high-quality (>87%, beside>77% in His solutions) Au–Ag nanocomposites with various shapes and sizes under different conditions
Synthesis and Properties of Water-Soluble Core–Shell–Shell Silica–CdSe/CdS–Silica Nanoparticles
No full text[[abstract]]This paper describes the synthesis of highly water-soluble and fluorescent core–shell–shell silica–CdSe/CdS–silica nanoparticles (CSS silica–QDs–silica NPs). We used cadmium nitrate and 1,1-dimethyl-2-selenourea precursors to synthesize CdSe quantum dots (QDs)in aqueous solution under simultaneous illumination with a diode-pumped solid state green laser and a Xe–Hg lamp. After passivation of the CdSe QDs with CdS, the CdSe/CdS QDs were then conjugated covalently to (3-mercaptopropyl)trimethoxysilane (MPS); we call these nanoparticles "MPS-QDs". We mixed the MPS-QDs with tetraethoxysilane (TEOS), ethanol, and NH3. By controlling the concentrations of the reagents, the stirring speed, and the reaction time, we synthesized CSS silica–QDs–silica NPs having sizes ranging from 75 to 190 nm. The incubation time for preparing the MPS-QDs and their concentrations are important parameters in determining the morphologies of the CSS silica–QDs–silica NPs. When we mixed 50 nM MPS-QDs, 1.1 mM TEOS, and 78 mM NH3 and reacted them at a stirring speed of 750 rpm, we obtained 85-nm-diameter CSS silica–QDs–silica NPs having a QD shell thickness of about 20 nm. The CSS silica–QDs–silica NPs provide a strong photoluminescence intensity (quantum yield 88%)and exhibit enhanced stability both photochemically and in high-conductivity media (e.g., 1.0 M NaCl)
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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