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Selected AbstractsSynthesis, Characterization and OFET Properties of Amphiphilic Mixed (Phthalocyaninato)(porphyrinato)europium(III) ComplexesEUROPEAN JOURNAL OF INORGANIC CHEMISTRY, Issue 7 2009Pan Ma Abstract Amphiphilic mixed (phthalocyaninato)(porphyrinato)europium(III) triple-decker complexes Eu2[Pc(15C5)4]2[T(C10H21)4P] (1) and Eu2[Pc(15C5)4]2[TPOPP] (2) [H2Pc(15C5)4 = 2,3,9,10,16,17,23,24-tetrakis(15-crown-5)phthalocyanine; H2T(C10H21)4P = meso -5,10,15,20-tetra- n -decylporphyrin, H2TPOPP = meso -5,10,15,20-tetrakis(4-pentyloxyphenyl)porphyrin] were designed and synthesized by the raise-by-one-story method. These novel sandwich triple-decker complexes were characterized by a wide range of spectroscopic methods, and they were also electrochemically studied. Highly ordered films were fabricated by the Langmuir,Blodgett (LB) technique into organic field-effect transistors (OFETs). The devices display good OFET performance with a carrier mobility in the range 0.03,0.78 cm2,V,1,s,1. As expected, the devices show a low threshold voltage range from ,1.19 to ,4.34 V. The mobility of compound 1 reaches 0.78 cm2,V,1,s,1, which is the highest value so far achieved for LB film-based OFETs, as a result of the narrow energy gap (1.04 eV) of this compound.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009) [source] Ionic currents underlying rhythmic bursting of ventral mossy cells in the developing mouse dentate gyrusEUROPEAN JOURNAL OF NEUROSCIENCE, Issue 7 2003Shozo Jinno Abstract The electrophysiological properties of mossy cells were examined in developing mouse hippocampal slices using whole-cell patch-clamp techniques, with particular reference to the dorsoventral difference. Dorsal mossy cells exhibited a higher spontaneous excitatory postsynaptic potential (EPSP) frequency and larger maximal EPSP amplitude than ventral mossy cells. On the other hand, the blockade of synaptic inputs with glutamatergic and GABAergic antagonists disclosed a remarkable dorsoventral difference in the intrinsic activity: none (0/27) of the dorsal mossy cells showed intrinsic bursting, whereas the majority (35/47) of the ventral mossy cells exhibited intrinsic rhythmic bursting. To characterize the ionic currents underlying the rhythmic bursting of mossy cells, we used somatic voltage-clamp recordings in the subthreshold voltage range. Ventral bursting cells possessed both hyperpolarization-activated current (Ih) and persistent sodium current (INaP), whereas dorsal and ventral nonbursting cells possessed Ih but no INaP. Blockade of Ih with cesium did not affect the intrinsic bursting of ventral mossy cells. In contrast, the blockade of INaP with tetrodotoxin or phenytoin established a stable subthreshold membrane potential in ventral bursting cells. The current,voltage curve of ventral bursting cells showed a region of tetrodotoxin-sensitive negative slope conductance between ,55 mV and a spike threshold (, ,45 mV). On the other hand, no subthreshold calcium conductances played a significant role in the intrinsic bursting of ventral mossy cells. These observations demonstrate the heterogeneous electrophysiological properties of hilar mossy cells, and suggest that the subthreshold INaP plays a major role in the intrinsic rhythmic bursting of ventral mossy cells. [source] Topotactic Conversion Route to Mesoporous Quasi-Single-Crystalline Co3O4 Nanobelts with Optimizable Electrochemical PerformanceADVANCED FUNCTIONAL MATERIALS, Issue 4 2010Li Tian Abstract The growth of mesoporous quasi-single-crystalline Co3O4 nanobelts by topotactic chemical transformation from , -Co(OH)2 nanobelts is realized. During the topotactic transformation process, the primary , -Co(OH)2 nanobelt frameworks can be preserved. The phases, crystal structures, morphologies, and growth behavior of both the precursory and resultant products are characterized by powder X-ray diffraction (XRD), electron microscopy,scanning electron (SEM) and transmission electron (TEM) microscopy, and selected area electron diffraction (SAED). Detailed investigation of the formation mechanism of the porous Co3O4 nanobelts indicates topotactic nucleation and oriented growth of textured spinel Co3O4 nanowalls (nanoparticles) inside the nanobelts. Co3O4 nanocrystals prefer [0001] epitaxial growth direction of hexagonal , -Co(OH)2 nanobelts due to the structural matching of [0001] , -Co(OH)2//[111] Co3O4. The surface-areas and pore sizes of the spinel Co3O4 products can be tuned through heat treatment of , -Co(OH)2 precursors at different temperatures. The galvanostatic cycling measurement of the Co3O4 products indicates that their charge,discharge performance can be optimized. In the voltage range of 0.0,3.0,V versus Li+/Li at 40,mA g,1, reversible capacities of a sample consisting of mesoporous quasi-single-crystalline Co3O4 nanobelts can reach up to 1400,mA h g,1, much larger than the theoretical capacity of bulk Co3O4 (892,mA h g,1). [source] Fabrication and properties of crosslinked poly(propylene carbonate maleate) gel polymer electrolyte for lithium-ion batteryJOURNAL OF APPLIED POLYMER SCIENCE, Issue 4 2010Xiaoyuan Yu Abstract The poly(propylene carbonate maleate) (PPCMA) was synthesized by the terpolymerization of carbon dioxide, propylene oxide, and maleic anhydride. The PPCMA polymer can be readily crosslinked using dicumyl peroxide (DCP) as crosslinking agent and then actived by absorbing liquid electrolyte to fabricate a novel PPCMA gel polymer electrolyte for lithium-ion battery. The thermal performance, electrolyte uptake, swelling ratio, ionic conductivity, and lithium ion transference number of the crosslinked PPCMA were then investigated. The results show that the Tg and the thermal stability increase, but the absorbing and swelling rates decrease with increasing DCP amount. The ionic conductivity of the PPCMA gel polymer electrolyte firstly increases and then decreases with increasing DCP ratio. The ionic conductivity of the PPCMA gel polymer electrolyte with 1.2 wt % of DCP reaches the maximum value of 8.43 × 10,3 S cm,1 at room temperature and 1.42 × 10,2 S cm,1 at 50°C. The lithium ion transference number of PPCMA gel polymer electrolyte is 0.42. The charge/discharge tests of the Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3O2 cell were evaluated at a current rate of 0.1C and in voltage range of 2.8,4.2 V at room temperature. The results show that the initial discharge capacity of Li/PPCMA GPE/LiNi1/3Co1/3Mn1/3 O2 cell is 115.3 mAh g,1. © 2010 Wiley Periodicals, Inc. J Appl Polym Sci, 2010 [source] Characteristics of anodic coatings oxidized to different voltage on AZ91D Mg alloy by micro-arc oxidization techniqueMATERIALS AND CORROSION/WERKSTOFFE UND KORROSION, Issue 2 2005Y. Wang Abstract With increasing applied voltage, three types of anodic coatings, passive film, micro-spark ceramic coating and spark ceramic coating were made by micro-arc oxidization (MAO) technique on AZ91D magnesium alloy in alkali-silicate solution. The structure, composition characteristics and the electrochemical properties of coatings were also studied with SEM, XRD and EIS (electrochemical impedance spectroscopy) technique, respectively. It is found that the electrochemical properties are closely related to the structure and composition characteristics of the anodic coatings. At the same time, the characteristics of the three types of anodic coatings differ significantly, among them, the micro-spark ceramic coating, prepared in the voltage range of 170~220V exhibits compact, homogeneous structure and highest corrosion-resistance. [source] Porous anodic alumina thin films on Si: interface characterizationPHYSICA STATUS SOLIDI (C) - CURRENT TOPICS IN SOLID STATE PHYSICS, Issue 12 2008V. Gianneta Abstract Porous anodic alumina (PAA) thin films (thickness , 50nm) were fabricated on Si by anodization of thin Al films under constant voltage of 20 V in sulphuric acid aqueous solution. The films exhibit cylindrical vertical pores of diameter , 13,15 nm, arranged in hexagonal close packed structure. Electrochemical oxidation of the Si substrate through PAA, used as masking layer with openings in the pores, resulted in the formation of SiO2 dots at each pore tip. Two different kinds of films, namely with or without SiO2 dots at pore tips, were fabricated. In order to characterize the electrical quality of the interface of PAA thin films with Si, C-V and G-V measurements were performed on Metal-Insulator-Semiconductor (MIS) structures with Al metallization. The measurements were carried out in the voltage range +1.0 V to ,3.0 V in steps of 0.05 V and in the frequency range 1 MHz to 100 Hz. The typical form of C-V and G-V curves of a MIS structure was obtained. In order to determine the interface trap density Dit, C-f and G-f measurements were performed as a function of the applied gate voltage in the depletion region. Dit was evaluated following the Conductance Method (E. H. Nicollian, and J. R. Brews, MOS Physics and Technology (J. Wiley & Sons, New York, 1982), p. 222 [1]). Both types of samples exhibit values of Dit in the order of 1011 eV,1cm,2. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source] Characterization of the A-type potassium current in murine gastric antrumTHE JOURNAL OF PHYSIOLOGY, Issue 2 2002Gregory C. Amberg A-type currents are rapidly inactivating potassium currents that operate at subthreshold potentials. A-type currents have not been reported to occur in the phasic muscles of the stomach. We used conventional voltage-clamp techniques to identify and characterize A-type currents in myocytes isolated from the murine antrum. A-type currents were robust in these cells, with peak current densities averaging 30 pA pF,1 at 0 mV. These currents underwent rapid inactivation with a time constant of 83 ms at 0 mV. Recovery from inactivation at ,80 mV was rapid, with a time constant of 252 ms. The A-type current was blocked by 4-aminopyridine (4-AP) and was inhibited by flecainide, with an IC50 of 35 ,M. The voltage for half-activation was ,26 mV, while the voltage of half-inactivation was ,65 mV. There was significant activation and incomplete inactivation at potentials positive to ,60 mV, which is suggestive of sustained current availability in this voltage range. Under current-clamp conditions, exposure to 4-AP or flecainide depolarized the membrane potential by 7-10 mV. In intact antral tissue preparations, flecainide depolarized the membrane potential between slow waves by 5 mV; changes in slow waves were not evident. The effect of flecainide was not abolished by inhibiting enteric neurotransmission or by blocking delayed rectifier and ATP-sensitive K+ currents. Transcripts encoding Kv4 channels were detected in isolated antral myocytes by RT-PCR. Immunocytochemistry revealed intense Kv4.2- and Kv4.3-like immunoreactivity in antral myocytes. These data suggest that the A-type current in murine antral smooth muscle cells is likely to be due to Kv4 channels. This current contributes to the maintenance of negative resting membrane potentials. [source] Multiple effects of mefenamic acid on K+ currents in smooth muscle cells from pig proximal urethraBRITISH JOURNAL OF PHARMACOLOGY, Issue 8 2003N Teramoto The effects of mefenamic acid on both membrane potential and K+ currents in pig urethral myocytes were investigated using patch-clamp techniques (conventional whole-cell, cell-attached, outside-out and inside-out configuration). In the current-clamp mode, mefenamic acid caused a concentration-dependent hyperpolarization, which was inhibited by preapplication of 1 ,M glibenclamide. In the voltage-clamp mode, mefenamic acid induced an outward current that was blocked by glibenclamide even in the presence of iberiotoxin (IbTX, 300 nM) at ,50 mV. ATP-sensitive K+ channels (KATP channels) could be activated in the same patch by mefenamic acid and levcromakalim, with the same unitary amplitude and the similar opening gating at ,50 mV in cell-attached configuration. In outside-out recording, external application of mefenamic acid activated intracellular Ca2+ -activated IbTX-sensitive large-conductance K+ channels (BKCa channels). Mefenamic acid (30 ,M) activated spontaneous transient outward currents (STOCs). In contrast, mefenamic acid (100 ,M) increased sustained outward currents, diminishing the activity of STOCs. Over the whole voltage range, mefenamic acid caused opposite effects on the membrane currents in the absence and presence of 5 ,M glibenclamide. In the presence of 10 mM 4-aminopyridine (4-AP), mefenamic acid only increased the outward currents. These results indicate that mefenamic acid increases the channel activities of two distinct types of K+ channels (i.e. BKCa channels and KATP channels) and decreased 4-AP-sensitive K+ channels in pig urethral myocytes. British Journal of Pharmacology (2003) 140, 1341,1350. doi:10.1038/sj.bjp.0705524 [source] Synthesis and Electrochemical Performance of Ti4+ Doped LiV3O8CHINESE JOURNAL OF CHEMISTRY, Issue 5 2009Junli SUN Abstract Layered LiTiyV3,0.8yO8 cathode materials with y=0, 0.04, 0.06, 0.08 were prepared by a sol-gel process following a calcination at 350°C in air for 16 h, and show differences in morphological properties (shape, particle size and specific surface area) and electrochemical properties (first charge profile, reversible capacity and rate capability). The LiTiyV3,0.8yO8 powders were characterized by means of X-ray diffraction (XRD), charge/discharge cycling, cyclic voltammetry (CV), and scanning electron microscopy (SEM). LiTiyV3,0.8yO8 was crystallized to a well layered structure. Its initial specific discharge capacity was higher than that of pristine material. When y=0.04, the sample showed the highest initial discharge capacity of 348.9 mAh·g,1 at a current density of 60 mA·g,1 in the voltage range 1.8,4.0 V, and also higher discharge capacity and better cycle ability. [source] | ||||||||||||||||