Search

The development of flexible thermoelectric devices requires materials possessing ductility and high thermoelectric performance at room temperature. However, only a few existing materials meet both criteria. In this study, the ductile properties, electronic structure, and transport properties of the low-temperature phase α-AgCuS were elucidated using first-principles calculations combined with Boltzmann transport theory. With a layered zigzag structure similar to the well-known ductile semiconductor Ag2S, AgCuS is determined to have good metal-like ductility. Through consideration of various intrinsic scattering mechanisms, we found that electron–polar optical phonon interactions have the most significant impact on the transport behavior of AgCuS. The predominance of this type of interaction is also disclosed by the covalent–ionic bonding nature of the Ag–S and Cu–S bonds. Therefore, weakening this interaction via doping or alloying could optimize the thermoelectric performance of the system. At room temperature, a maximum dimensionless figure of merit ZT of up to 0.592 could be achieved under a tuning of hole concentration to 2 × 1019cm–3, suggesting that α-AgCuS could be a promising p-type candidate for flexible thermoelectric applications.

We apply a method [Phys. Rev. B108, 035141 (2023)], which can treat the multiplet excitations in the first-principles method, to a typical pressure indicator α-Al2O3:Cr3+. After optimizing the crystal structure under hydrostatic pressure from 0.0 to 35.0 GPa in the usual first-prinicple calculations, we obtain the multiplet energies in the method. That is, we conduct the exact diagonalization of the crystal-field model Hamiltonian which is directly determined based on the result of the quasiparticle self-consistent GW method. Our method has no parameters by hand. The calculated pressure dependences of the excitation energies agree well with those of experiments.

Deformation of silicene buckled structure attracts great interest for the possibility of ultrahigh thermoelectric power factor. Therefore, the control method of silicene buckled structure is needed. Here, we developed the method to control composition ratio in epitaxial Ca intercalated layered silicene (CaSi2) film formed by solid phase epitaxy through an atomic interdiffusion between Ca films and Si substrate because of the possible existence of the relation between silicene buckled structure in CaSi2film and the composition ratio. The interdiffusion is controlled by introducing hydrogen-terminated layer as an interface layer between Ca and Si substrate, resulting in the control of the composition ratio in CaSi2film. Moreover, we find that the CaSi2films with different composition ratio exhibit different thermoelectric power factors. This study reveals that introducing the interface layer for interdiffusion control is an effective way to control the composition ratio and to form metastable high-buckled silicene with high power factor.

In this work, we elucidated the electronic structure and thermoelectric properties of intermetallic XSi (X= Co, Rh) compounds. By combining first-principles calculations and the Boltzmann equation within electron–phonon average approximation, thermoelectric properties of XSi are well reproduced compared to experimental observations. We found that the considerable Seebeck coefficient and low electrical resistivity give XSi a large power factor, which has the potential for thermoelectric applications. We also discussed the electron mean free paths, a possible factor affecting electrical conductivity when using the nanostructuring approach to optimize the thermoelectric performance.

Extracellular glutamate concentration is a critical determinant of neuronal cell fate. We recently demonstrated that HT22 murine hippocampal cell viability was reduced by exposure to high concentrations of glutamate, whereas low concentrations promoted cell survival. Extracellular signal-regulated kinase (Erk)1/2 activation by glutamate is important for both glutamate-induced cell death and survival. In this study, we investigated the role of glutamate-induced or hydrogen peroxide (H2O2)-induced Erk1/2 activation in HT22 cell fate determination. Glutamate and H2O2treatment similarly induced early (<1 h) Erk1/2 phosphorylation regardless of concentration. On the other hand, persistent Erk1/2 phosphorylation (16–24 h) was observed only in the presence of excess glutamate. Only the latter contributed to glutamate-induced cell death, which involved metabolic glutamate receptor 5. Our findings suggest that glutamate concentration modulates two distinct phases of Erk1/2 activation, which can explain the glutamate concentration-dependent determination of HT22 cell fate.

Oxidative stress is recognized as one of the pathogenic mechanisms involved in neurodegenerative disease. However, recent evidence has suggested that regulation of cellular fate in response to oxidative stress appears to be dependent on the stress levels. In this study, using HT22 cells, we attempted to understand how an alteration in the oxidative stress levels would influence neuronal cell fate. HT22 cell viability was reduced with exposure to high levels of oxidative stress, whereas, low levels of oxidative stress promoted cell survival. Erk1/2 activation induced by a low level of oxidative stress played a role in this cell protective effect. Intriguingly, subtoxic level of H2O2induced expression of a growth factor, progranulin (PGRN), and exogenous PGRN pretreatment attenuated HT22 cell death induced by high concentrations of H2O2in Erk1/2-dependent manner. Together, our study indicates that two different cell protection mechanisms are activated by differing levels of oxidative stress in HT22 cells.

We present a materials design of MgO-based d0ferromagnets with a high blocking temperature (TB) based on multiscale simulations. The chemical pair interactions between the N atoms in Mg(O,N) and the Mg vacancies (VMg) in (Mg,VMg)O were calculated using a generalized gradient approximation, and Monte Carlo simulations of the crystal growth were performed to predict the configurations of the dopant distribution. Our simulations showed that self-organized nanostructures could be formed both in Mg(O,N) and (Mg,VMg)O, which suggests that a high TBcan be obtained in these d0ferromagnets due to the superparamagnetic blocking phenomenon. Furthermore, depending on the crystal growth conditions, it was shown that various self-organized nanostructures, such as three-dimensional nanoclusters and one-dimensional nanowires, could appear.

Electrochemical performance of solid oxide fuel cells based on Ni0.75Co0.25-GDC (Gd0.1Ce0.9O1.95) and Ni-GDC anodes were investigated and compared in order to understand the effects of (i) alloying Ni with Co and (ii) anode microstructure on the cell performance under hydrogen fuel. At the sintering temperature of 1300°C for 5 h, the Ni0.75Co0.25-GDC anode showed a superior distribution and connection of grains to the Ni-GDC anode which had grain clustering structure in general. Grain growth and connection were found in both anodes when the sintering temperature was increased to 1350°C for 3 h. This resulted in significant improvement of the anodic polarization resistance for the Ni-GDC anode but only minor change for the Ni0.75Co0.25-GDC anode. This research, however, showed that the Ni-GDC anode had higher anodic polarization resistance than the Ni0.75Co0.25-GDC anode, resulting in the better cell power density at all sintering conditions. The maximum power density obtained at 800°C for the cell with the Ni0.75Co0.25-GDC anode was 118 mW•cm-2. Impedance spectroscopy analysis showed that the total cell resistance of both cell types became progressively larger when the operation time was prolonged to 10 h at 800°C, while the microstructure change was not observable by the SEM. The reason for the fast degradation will thus require further investigation.

The adsorptive abilities of Ni1-xCox-YSZ and Ni1-xCox-CeO2 cermet particles for CH4 and CO were affected by the amount of the Co atoms substituted for the Ni atoms. The CO molecules produced by the partial oxidation of adsorbed CH4 molecules by the O2- ions at the interface between the Ni1-xCox and YSZ (or CeO2) affect the cell performance for the direct oxidation of CH4 in solid oxide fuel cells. The partial substitution of Co for Ni in the fcc lattice increased the amount of the adsorbed species, and decreased the desorption activation energy for CO and CH4.

OBJECTIVES To map the disease locus and to identify a gene mutation in a Japanese family with autosomal dominant cerebellar ataxia. DESIGN A genome-wide linkage analysis was performed using the Affymetrix genome-wide human single-nucleotide polymorphism array containing 909 622 single-nucleotide polymorphisms. Direct nucleotide sequencing of a candidate gene was performed. SETTING Hokkaido University Graduate School of Medicine and Tokyo University Graduate School of Medicine. PATIENTS Four affected and 6 healthy individuals in a family with autosomal dominant cerebellar ataxia. RESULTS One locus on chromosome 5q had a multipoint logarithm of odds score of 2.408, the theoretical maximum. This locus was flanked by markers rs681591 and rs32582 and includes PPP2R2B (protein phosphatase 2, regulatory subunit B, beta isoform), the causative gene of autosomal dominant spinocerebellar ataxia 12 (SCA12). However, unlike SCA12, no CAG repeat expansions in the promoter region and no nucleotide substitution or insertion-deletion mutations in the exons of the PPP2R2B gene were found. CONCLUSION Autosomal dominant cerebellar ataxia mapping to 5q31-q33.1 has no CAG repeat expansion or other mutations of the PPP2R2B gene.Arch Neurol. 2010;67(10):1257-1262--

This paper discusses on the Cr poisoning that occurs in solid oxide fuel cells with metallic alloy separators. The results of a series of experimental, including an analysis of cathodic overvoltage with loading time at a constant current density, observation of the cathode microstructure, and an experiment of chemical compatibility of the cathode material against Cr oxide, are presented. LNF cathodes are more stable against Cr poisoning than LSCF and LSM cathodes. Cr adhesives were observed near the cathode layer for all measured cells in the presence of the alloy. Furthermore, LNF was less reactive with Cr oxide than LSCF and LSM. The results of electrochemical measurements under the Cr poisoning condition agree with that of the chemical properties of the cathode material against Cr oxide.

Ti-doped CeO2 mixed oxide powders (CeO2-TiO2) were synthesized by a sol-gel method with varying amount of Ti. The XRD patterns of CeO2-TiO2 (10 and 20 mol% Ti) powders calcined at 800degC for 4 h did not show the TiO2 phase. The electrical conductivity of CeO2-TiO2 mixed oxide was higher than that of CeO2 between 650 and 750degC under reducing atmosphere. The electrocatalytic activity of Ni/CeO2 and Ni/CeO2-TiO2 cermet anodes were examined under the oxidation of methane for solid oxide fuel cells (SOFCs). The Ni/CeO2-TiO2 (20 mol% Ti) anode showed a higher power density than that Ni/CeO2 in both H2 and CH4 fuels. The enhancement of methane oxidation was most likely to be caused by the higher electrical conductivity of the mixed ionic and electronic CeO2-TiO2 oxide cermet. The electrode polarization of the Ti-doped CeO2 anode was lower than that of the non-doped CeO2 anode.

It has been theoretically predicted that the thermoelectric properties of silicene can be enhanced by deforming its atomic structure. In CaSi2, calcium-intercalated layered silicene, the silicene structure of the metastable 3R phase is a deformed silicene structure of the stable 6R phase. In this paper, our first-principle calculation reveals that the Seebeck coefficient is enhanced by transformation from stable 6R- to metastable 3R-CaSi2. We experimentally enhance the Seebeck coefficient by endotaxially introducing metastable 3R-CaSi2into single-crystalline 6R-CaSi2, leading to a high thermoelectric power factor. This study demonstrates that introducing the metastable phase can become an effective way to enhance the thermoelectric power factor.

Symmetric cells consisting of the LaNi0.6Fe0.4O3 (LNF)- Sm0.2Ce0.8O1.9 (SDC) composite cathodes and 8 mol%Y2O3- stabilized ZrO2 (YSZ) electrolyte have been investigated in order to evaluate the oxygen reduction performance of the composite cathode by AC impedance analysis. Cell performance and cathodic overvoltage were examined for cells consisting of the Ni-YSZ cermet anode, YSZ electrolyte, and composite cathode. The addition of 50 wt% SDC to LNF resulted in the lowest polarization resistance. A cell using the 50 wt% LNF + 50 wt% SDC composite cathode showed the maximum power density and the cathodic overvoltage for this cell showed as half as lower than that for a cell using the LNF cathode under the same condition. Enhancement of the electrochemical performance in the LNF-SDC composite cathode is most likely to be caused by the SDC particles connecting LNF particles with the electrolyte surface.

Composites of 3 mol % Y2O3 in ZrO2, Ce0.9Gd0.1O1.95, and Sc0.1Ce0.01Zr0.89O1.95 were mixed with 8 mol % Yttria Stabilized Zirconia (YSZ) in 50:50 weight ratio to compare the influences in mechanical and electrical properties using a 3- point bending test and AC-impedance spectroscopy, respectively. An SEM was used for a morphological analysis and an XRD was used to identify phases. The composite of 3YSZ+8YSZ has shown a mixed phase between small and large grains referring to the cubic and tetragonal phases. From AC-impedance measurements, the composite of 8YSZ+ScSZ shows the maximum bulk and grain boundaries conductivities. The mechanical strength of 8YSZ has been proved to increase tremendously when mixed with the tetragonal phase of 3YSZ. However, The maximum bending strength is obtained from 8YSZ+ScSZ composite after sintering for 4 hours. The results have shown very positive solution using a composite of 8YSZ+ScSZ for the intermediate temperature electrolyte for SOFCs.

Polarization resistance of the LaNi0.6Fe0.4O3 (LNF) cathode has been investigated in relation to the electrical conductivity and thermochemical stability. Electrochemical properties of a solid oxide fuel cell using LNF as the cathode were compared to those using La0.8Sr0.2MnO3 (LSM). Temperature dependence of the cathodic polarization resistance was discussed in terms of the thermochemical stability. The electrical conductivity of bulk LNF sample was measured with the four-probe DC method at different oxygen partial pressures. Phase identification for the LNF powder samples treated at 900oC in the atmosphere of oxygen and argon was studied with time dependency of heat treatment by X- ray diffraction analysis. Although the rhombohedral crystal structure of the starting phase was maintained, the electrical conductivity of LNF sensitively changed with the partial pressure of oxygen.

We fabricated single cells with the LaNi0.6Fe0.4O3 cathode and scandia alumina doped zirconia electrolyte. Cells with a cathode consisting of current collecting LNF layer and active layer were also fabricated by using the screen printing technique. The active layer contains SDC or GDC and LNF particles. The LNF cathodes with this active layer exhibited good levels of performance including over potential and interface resistance from the start of the operation at 800C. With this configuration, adhesiveness of the cathode to the zirconia electrolyte was improved as well. It was found that the active layer is functional, when the ceria particle size is smaller or equal to that of LNF. SEM observation of the active layer shown high sintering temperature tends to break weak bonds around triple phase boundary and create strongly connected bonds of LNF and ceria particles in the active layer.

In an effort to reduce TEC of the LSC materials while maintaining enough conductivity Gd substitution on A site of La0.6Sr0.4Co0.4Fe0.6O3-d (LGSCF) perovskite materials were investigated as a potential cathode material for ITSOFCs in this study. La0.6-xGdxSr0.4Co0.4Fe0.6O3-d (LGSCF) powders with x = 0.1-0.6 were prepared via solid state reaction method by ball milling the starting precursor in ethanol and calcining the starting powder at 1100oC for 10 hours. X-ray diffraction analysis performed on the samples reveal the perovskite rhombohedral structure for all samples. An increase in Gd substitution amount was found to decrease thermal expansion coefficient and conductivity of the compounds.

Partial substitution of Co atoms for Ni atoms in the Ni-based cermet anode resulted in a decrease in the anodic overvoltage and interfacial resistance between the anode and electrolyte. This effect has been confirmed for yttria-stabilized zirconia (YSZ) and scandia-stabilized zirconia (ScSZ) electrolytes. The Ni1-XCoX-ScSZ (-YSZ) cermet anode showed an increase in the cell performance with increasing amount of Co content up to approximately 0.5. The decrease in the anodic overvoltage and the interfacial resistance contributes to an enhancement of the cell performance. The results of electrochemical measurements and microstructural characterization revealed that the enhancement of the direct oxidation of methane is caused by the modification of microstructure due to a solid- solutioning effect in the starting NiO-CoO binary system.

Non–alcohol-dependent heavy drinkers, as well as alcohol-dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel-based morphometry (VBM) among Japanese non-alcohol–dependent male individuals.

Background: Non–alcohol‐dependent heavy drinkers, as well as alcohol‐dependent individuals, show brain atrophy. The purpose of this study was to evaluate whether there are correlations between global and regional gray matter volumes and the lifetime alcohol intake using volumetric analysis and voxel‐based morphometry (VBM) among Japanese non‐alcohol–dependent male individuals.

Not Available

Thromboxane (TX) A2exerts contraction and proliferation of vascular smooth muscle cells (VSMCs) via its specific membrane TX receptor (TXR), possibly leading to the progression of atherosclerosis. A nuclear hormone receptor, peroxisome proliferator-activated receptor (PPAR)-γ, has recently been reported to be expressed in VSMCs. Here we examined a role of PPAR-γ in TXR gene expression in VSMCs. PPAR-γ ligands 15-deoxy-Δ12,14-prostaglandin J2and troglitazone reduced TXR mRNA expression levels as well as cell growth as assessed by [3H]thymidine incorporation. Transcriptional activity of the TXR gene promoter was suppressed with PPAR-γ ligands, and the suppression was augmented further by PPAR-γ overexpression. By deletion and mutation analyses, the transcription suppression was shown to be the result of a −22/−7 GC box-related sequence (upstream of transcription start site). Electrophoretic mobility shift assays also showed that the sequence was bound by Sp1 but not by PPAR-γ, and the formation of a Sp1·DNA complex was inhibited either by coincubation with PPAR-γ or PPAR-γ ligand treatment of VSMCs. Moreover, glutathione S-transferase pull-down assays demonstrated a direct interaction between PPAR-γ and Sp1. In conclusion, PPAR-γ suppresses TXR gene transcription via an interaction with Sp1. PPAR-γ may possibly have an antiatherosclerotic action by inhibiting TXR gene expression in VSMCs.

Sensorimotor association is an essential aspect of behavior. The dorsal part of the premotor cortex (PMd) is known to have an important role in sensorimotor association. Although it is suggested that the partially segregated groups of neurons are involved in sensorimotor association in different sensory modalities, it is not yet clear whether these groups occupy the PMd to the same or different extent. Therefore, we performed a functional magnetic resonance imaging study to compare activated regions in the PMd during simple reaction-time tasks with visual and auditory cues. Eight normal volunteers performed two simple reaction time tasks with a conventional on–off design; one is with a visual cue and the other is with an auditory cue. In both tasks, two regions in the left primary motor area (M1) (4a and 4p) and the bilateral PMd were activated. The two activated regions in the left M1 occupied the same areas in both the visual and the auditory tasks. However, in the PMd, the activated regions were situate medially during the visual task and laterally during the auditory task, along the precentral sulci. There was no overlap of significantly activated regions between two tasks, and areas specifically activated during the visual task were observed in the middle of the precentral sulci, bilaterally. The results suggest that the distribution of PMd subregions involved in sensorimotor association differ when the sensory cues are in different modalities.

The molecular mechanism underlying the renal expression localization of the thiazide-sensitive Na-Cl cotransporter (TSC) gene was studied. TheTSCgene was localized to chromosome 19p12–14. In cultured cells, tissue-specific transcription activity of the 5′-flanking region of the rat rTSCgene (5′FL/rTSC) was demonstrated, and the major promoter region was located between position −580 and −141. To further examine the tissue-specific transcription, transgenic rats harboring the 5′FL/rTSC fused upstream of the LacZgene were generated. Immunohistochemical analysis clearly showed that LacZgene expression was co-localized to distal convoluted tubules (DCT) with TSC, indicating that the 5′FL/rTSC regulates the renal tubule-specific TSC expression. Because a transcription factor, HFH-3 (hepatocyte nuclear factor-3/folk head homologue-3), had also been localized to DCT, a possible role of the putative cis-acting element (HFH-3/rTSC, −400/−387 position) for HFH-3 binding in the tissue-specific transcription was examined. Deletion and mutation analyses suggested that transcription of the HFH-3/rTSC was actually responsive to HFH-3, and electrophoretic mobility shift assay showed a direct binding of in vitrosynthesized HFH-3 to the HFH-3/rTSC. In conclusion, therTSCgene is localized to rat chromosome 19p12–24. The transcription regulatory region of the TSCgene confers DCT-specific gene expression. DCT-specific transcription factor HFH-3 may be involved in the renal tubule-specific transcription ofTSCgene.

Personality traits are a variance of behavioral patterns among individuals and may reflect a variance of brain activity, but their neurobiological explanation is still a matter of debate. Cloninger proposed three dimensions of personality traits, each of which has strong correlation with activity in a specific central monoaminergic system. Although this theory has been supported by physiological and genetic studies, it is still unclear how these personality parameters are correlated with the activity of the cortical networks which control human behavior. Here we measured the regional cerebral blood flow (rCBF) at rest in 30 normal volunteers who completed the personality inventory of Cloninger. Voxel-by-voxel analysis was employed to identify cortical regions where the rCBF showed significant correlation with any of the three personality parameters. Statistically significant correlation was observed in several paralimbic and neocortical regions and was consistent with the assumed monoaminergic influence on neural activity and the distribution of its projections, in each personality dimension. The results suggest that activity in a variety of cortical regions is associated with human personality traits and lend support to Cloninger's theory concerning central monoaminergic influence on human personality traits.

We propose a novel method to generate p-type conduction and low resistivity in wide- and ultrawide-bandgap III-nitride semiconductors via doping of a magnetic element. This method is based on the energetic competition between the covalency of the magnetic element and the ligand nitrogen atoms and the exchange-correlation energy of the magnetic impurity. Using magnetic elements with large exchange-correlation energy, we can obtain p-type wide- and ultrawide-bandgap semiconductors, which are basically difficult to synthesize due to the unipolarity.

The photocatalytic properties of RuO2-dispersed M2Ti6O13 (M=Na, K, Rb, Cs) were investigated as to the photoexcitation ability of the hexatitanates and the role of the dispersed RuO2. An EPR signal with g=2.020, g=2.018 and g=2.004 produced by UV irradiation of the hexatitanates at 77 K had a short life time in vacuum but remained stable upon exposure to gaseous molecules such as H2, He, N2, O2 and Ar. These gases brought about different stability and pressure dependence of the signal intensity, by which the radical is assigned to O- resulting from the surface lattice oxygen. The efficiency of the radical formation is associated with the presence of internal fields in the distorted TiO6 octahedra forming the rectangular tunnels of M2Ti6O13 (M=Na, K, Rb). RuO2 was dispersed on the hexatitanates by impregnation with either RuCl3(aq) solution or Ru3(CO)12 in tetrahydrofuran and the subsequent oxidation in the temperature range 573–823 K. The photocatalytic activity for water decomposition was higher for RuO2/M2Ti6O13 (M=Na, K, Rb) photocatalysts prepared using Ru3(CO)12 than for RuCl3. High resolution transmission electron microscopic images showed that uniformly distributed smaller RuO2 particles were formed for the former photocatalyst, which is considered to be responsible for the higher activity. The correlation between the concentration of the O- radical and photocatalytic activity is established, thus indicating that the O- radical is proposed to work as a hole site in the photocatalytic reaction, and the ability to separate photoexcited charges reflects the photocatalytic activity order of M2Ti6O13.

Angiotensin (Ang) II stimulates proliferation of vascular smooth muscle cells (VSMC) via its specific receptor AT1 subtype, possibly leading to atherosclerosis in hypertension. On the other hand, a cytokine interferon (IFN)-γ has been shown to have an anti-atherosclerotic effect. In the present study, we examined a possible role of IFN-γ in AT1 receptor gene regulation in VSMC. A firefly luciferase expression vector driven by the rat AT1a receptor gene promoter (∼3.2 kb) was transfected into the cultured rat VSMC, and luciferase expression was determined to estimate the transcription function of the AT1a receptor gene promoter. RT-PCR was also carried out to determine mRNA expression of AT1a receptor in VSMC. IFN-γ treatment decreased AT1a receptor mRNA expression as well as luciferase expression in a dose-dependent manner. The analysis with deletion DNA fragments showed that the IFN-responsive element was located between −987 and −331 positions, where multiple GAS (gamma interferon activated site)-like elements were identified. The expression suppression was reversed by either a MAPKK inhibitor PD98059 or a Jak-2 inhibitor AG-490. These results suggest that IFN-γ can inhibit AT1 receptor expression at gene transcription level, and that the transcription suppression is dependent on MAP kinase and Jak-2. Inhibition of AT1a receptor expression may possibly be implicated in the anti-atherosclerotic action of IFN-γ in VSMC.

14: C-2-deoxyglucose (2DG) and 14C-methionine (Met). The study was performed using control rats with the AH109A tumour and rats with the same tumour under local hypoxia. Tumour uptake of FMISO was constant between 30 min and 2 h after injection, and the tumour to muscle ratio was 2 from 2 to 4 h. A tumour study with FMISO was scheduled at 2 h. Double-tracer autoradiography of the tumour demonstrated that in the areas of high FMISO uptake, there was low uptake of Met, while areas of low FMISO uptake showed high Met uptake. FMISO showed high grain density in the rim of the tumour surrounding the necrotic area. 2DG showed a more uniform distribution over the entire section of viable cells. The mean uptake of FMISO by hypoxic, radioresistant tumours was significantly higher than that by the control tumours (P<0.05), while both 2DG and Met uptake by the control tumours was higher than uptake by hypoxic tumours. When individual tumours were examined, the uptake of FMISO was inversely correlated with that of Met (r = –0.507, P<0.02), while 2DG showed almost uniform uptake with no significant correlation to FMISO. In conclusion, hypoxic and radioresistant tumours could be identified by increased FMISO uptake in our model, consistent with findings reported by others. We found a large overlap in the distribution of FMISO and 2DG within the tumour, but only a small overlap in the distribution of FMISO and Met. A combination of FMISO and other tracers in positron emission tomography or single-photon emission tomography studies might be more helpful than single-tracer studies in predicting the response of tumour tissues to radiotherapy.

Whole-cell/voltage-clamp recordings were made from dissociated bullfrog sympathetic neurons to examine the sensitivity of potassium currents to a potassium channel blocker quinine (1–500 μM). Among three currents tested, a rapidly inactivating A-type current (IA) was the most sensitive to the block by quinine (IC50≈22 μM). A non-inactivating M-type current (IM) was the least sensitive (IC50≈445 μM), and the sensitivity of a slowly inactivating delayed rectifier-type current (IK) was in between (IC50≈115 μM). Results suggest that the ability of quinine to block different types of potassium currents such as IAand IMwith significantly different IC50values would be of help for the potassium channel pharmacology in amphibian autonomic ganglion cells.

Photocatalytic activities for water decomposition were examined for photocatalysts using hexa- and octa-titanates and TiO2(B) with different tunnel space in the structure. Using RuO2 as promoter, M2Ti6O13 (M = Li, Na, K, Rb) showed the stoichiometric production of Hz and O2 except for Li, whereas H2Ti8O17 and TiO2(B) had very low activity producing only hydrogen as a product. The effects of promoters on Na2Ti6O13 showed that the activity increased in the order of RuO2 > RuO2 + IrO2 > IrO2 > RuO2 + Pt > MnO2. These effects along with other related ones are discussed: it emerges that the presence of the tunnels is important for the achievement of high photocatalytic activity.