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An epitaxial NdFeAs(O,F) thin film of 90 nm thickness grown by molecular beam epitaxy on MgO single crystal with Tc = 44.2 K has been investigated regarding a possible vortex glass–liquid transition. The voltage–current characteristics show excellent scalability according to the vortex-glass model with a static critical exponent ν of around 1.35 and a temperature-dependent dynamic exponent z increasing from 7.8 to 9.0 for the investigated temperature range. The large and non-constant z values are discussed in the frame of 3D vortex glass, thermally activated flux motion, and inhomogeneity broadening.
Background: We evaluate long-term post-operative hippocampal volume (HV) on non-epileptic hippocampus using MR volumetry as well as the neuropsychological outcome in patients with surgery for unilateral mesial temporal lobe epilepsy (MTLE) and achieved seizure-freedom. Methods: We studied 1.5-Tesla MRI before and after epilepsy surgery in 24 patients with MTLE. Serial MRI studies were scheduled at 4 post-operative consecutive periods; 6m-1y; 1-2y; 2-3y; 3-5y. We compared neuropsychological outcomes for memory and estimated IQ at the same periods with serial MRI up to 3 years. Results: The pre-operative non-epileptic HV was significantly smaller than HV in age-matched controls (n=14) (p<0.05). The HV became progressively atrophic after the surgery (p<0.05), correlating with the age at surgery (p<0.05) and pre-operative larger non-epileptic HV (p<0.05), but not with seizure duration. In 14 patients with non-dominant MTLE, the smaller dominant HV at 2-3y period correlated with decline of verbal memory (p<0.05). Conclusions: Post-operative progression of non-epileptic hippocampal atrophy was found with significantly more pronounce in patients with older age at surgery and larger pre-operative non-epileptic hippocampus. After the epileptogenic hippocampus is resected, the remaining hippocampus alone might exhaust to maintain the memory, especially in elders.
When intrathecally or epidurally administered, α2-adrenoceptor agonists produce potent antinociception by affecting the activity of primary afferent fibres and spinal cord neurons. Recent reports have indicated that in dorsal root ganglion neurons, tetrodotoxin-resistant Na+ channels play important roles in the conduction of nociceptive sensation. We therefore investigated the effects of α2-adrenoceptor agonists on tetrodotoxin-resistant Na+ currents.
Methods
Using the whole-cell patch-clamp technique, we recorded tetrodotoxin-resistant Na+ currents from rat dorsal root ganglion neurons.
Results
Both clonidine and dexmedetomidine reduced the peak amplitude of the tetrodotoxin-resistant Na+ current concentration- and use-dependently. The concentration required for a half-maximal effect was significantly lower for dexmedetomidine (58.0 ± 10.2 μmol) than for clonidine (257.2 ± 30.9 μmol) at holding potential −70 mV. The current inhibitions induced by these agonists were not prevented by 1 μmol yohimbine, an α2-adrenoceptor antagonist. Both clonidine and dexmedetomidine shifted the inactivation curve for the tetrodotoxin-resistant Na+ current in the hyperpolarizing direction. The combinations clonidine with lidocaine and dexmedetomidine with lidocaine produced an additive blockade-type interaction on the tetrodotoxin-resistant Na+ current.
Conclusions
The results suggest that a direct inhibition of tetrodotoxin-resistant Na+ channels may contribute to the antinociceptive effects of clonidine and dexmedetomidine when used as additives to regional anaesthesia.
To examine a possible mechanism for the antinociceptive action of the N-methyl-d-aspartate receptor antagonist ifenprodil, we compared its effects with those of ketamine on tetrodotoxin-resistant Na+ channels in rat dorsal root ganglion neurons, which play an important role in the nociceptive pain pathway.
Methods
Experiments were performed on dorsal root ganglion neurons from Sprague–Dawley rats, recordings of whole-cell membrane currents being made using patch-clamp technique.
Results
Both drugs blocked tetrodotoxin-resistant Na+ currents dose dependently, their half-maximal inhibitory concentrations being 145 ± 12.1 μmol (ketamine) and 2.6 ± 0.95 μmol (ifenprodil). Ifenprodil shifted the inactivation curve for tetrodotoxin-resistant Na+ channels in the hyperpolarizing direction and shifted the activation curve in the depolarizing direction. Use-dependent blockade of tetrodotoxin-resistant Na+ channels was more marked with ifenprodil than with ketamine. When paired with lidocaine, these drugs produced similar additive inhibitions of tetrodotoxin-resistant Na+ channel activity.
Conclusions
The observed suppressive effects on tetrodotoxin-resistant Na+ channel activity may, at least in part, underlie the antinociceptive effects of these N-methyl-d-aspartate receptor antagonists.
Coin-shaped multicrystalline Si1-xGex crystals were grown using a Brigdman method combined with die-casting growth. Si1-xGex alloy is known as a candidate material for producing Auger generation, which creates more than one electron/hole pair per absorbed photon. Since Si1-xGex alloy shows a complete series of solid solutions, precipitating crystals with a certain composition of silicon or germanium by conventional selective growth methods is burdensome. Using die-casting combined with Bridgman growth brought about Si1-xGex precipitation in a form completely different from that predicted by the Si-Ge phase diagram. By combining this growth with subsequent heat treatment of the precipitated Si1-xGex sample, Si1-xGex (x= 0.5 ± 3 %) could be obtained. Indirect band-gap energy was estimated by measuring room-temperature optical absorption coefficient of the grown samples.
Die-casting growth was used for manufacturing the multicrystalline silicon sheet with a size of 100 × 120 × 0.5 mm. During the growth, incorporation of contaminants such as iron, cobalt, nickel and chromium was well suppressed. The average etch-pit density values ranged from 1×104 cm-2 to 4x106 cm-2 for growth rates of 5 to 60 mm/h, respectively. Measurement of minority-carrier lifetime bye microwave-photoconductivity-decay (μ-PCD) method was 0.5 μs for as-grown specimens, suggesting that defects and residual strain exist in the grown sheet. Moreover, post heat treatment at 1473 K reduced the etch-pit density and improved carrier lifetime up to 2.2 μs.
We report the electrical resistivity and the Seebeck coefficient of AZn13 (A = Sr, Ba, and La) and LaCo13 measured over a wide temperature range and their thermal conductivity measured at room temperature. The electrical measurements of AZn13 and LaCo13 above room temperature reveal that the compounds show good metallic behavior. We find that the absolute value of Seebeck coefficient for AZn13 (A = Sr, Ba, and La) increases with increasing temperature, which is a typical metallic behavior and the absolute value is less than 3μVK−1 at room temperature. Accordingly, the power factor of AZn13 is quite low. Temperature dependence of the Seebeck coefficient for LaCo13 is similar to that of Co. The absolute value of the Seebeck coefficient for LaCo13 is high as a metallic conductor and approaches -30μVK−1 at 500K, which leads LaCo13 to large power factor of 1.8 × 10−3Wm−1K−2. We obtained lattice components of the thermal conductivity by subtracting electronic contributions from the total thermal conductivity. The electronic components of the thermal conductivity were estimated using Wiedemann-Frantz law assuming L (Lorentz number) is 2.45 × 10−8 V2K−2. The thermal conductivities of the lattice components for AZn13 (A = Sr, Ba, and La) and LaCo13 with NaZn13 type structure are about 10 Wm−1K−1, respectively. These values are high as compared with other thermoelectric materials.
We report transport properties of polycrystalline TMGa3 (TM = Fe and Ru) compounds in the temperature range 313K<T<973K. These compounds exhibit semiconductorlike behavior with relatively high Seebeck coefficient, electrical resistivity, and Hall carrier concentrations at room temperature in the range of 1017 - 1018cm−3. Seebeck coefficient measurements reveal that FeGa3 is n -type material, while the Seebeck coefficient of RuGa3 changes signs rapidly from large positive values to large negative values around 450K. The thermal conductivity of these compounds is estimated to be 3.5Wm−1K−1 at room temperature and decreased to 2.5Wm−1K−1 for FeGa3 and 2.0Wm−1K−1 for RuGa3 at high temperature. The resulting thermoelectric figure of merit, ZT, at 945K for RuGa3 reaches 0.18.
Experiments were carried out to investigate the drop formation behaviour of a hydrophobic hydrate-forming liquid, HCFC-141b (CH3CCl2F), at a single nozzle in a water stream under hydrate-formable thermodynamic conditions. Attention was focused on the relation between the clathrate-hydrate formation and the drop formation. It was observed that two discrete hydrate crusts grow along the liquid–liquid interface; one forms a frontal cap and the other forms a cylindrical root on each growing drop before its detachment from the nozzle. Most of the latter crust remains at the tip of the nozzle after the detachment of the drop so that it grows into a bell-shaped or nearly cylindrical funnel composed of hydrate deposits in the course of successive growth/detachment of drops. The size of these drops is dependent on the instantaneous diameter of the hydrate-funnel tip rather than the diameter of the nozzle itself. Thus, the size of the drops successively released into the water stream generally varies synchronously with quasi-periodical alternation of growth and breaking of the hydrate funnels. The growth and breaking of the hydrate funnels and the resultant drop-size variation are significantly dependent on the system temperature (or the system subcooling from the liquid/liquid/hydrate equilibrium temperature), the nozzle diameter, and the velocity of the drop-forming liquid through the nozzle.
Crystals of CoSb3 were grown using the vertical Bridgman method at growth rates that varied from 0.4 to 2.8 mm/h. Thermoelectric properties were analyzed for both as-grown and post-annealed samples. Polycrystalline CoSb3 surrounded by Sb was obtained. Samples grown at the rate of 0.4 mm/h had larger CoSb3 grains than samples grown at the 2.8 mm/h rate. For the as-grown samples, the Seebeck coefficient was smaller than 200 μ/K, which is a nominal value [1–3]. The presence of residual Sb resulted in a decrease in the Seebeck coefficient and an increase in the samples' electrical conductivity. A subsequent heat treatment at 800 °C for 20 h eliminated the residual Sb, resulting in a significant increase in the Seebeck coefficients (ranging from > 200 μV/K) in the annealed samples, as compared with the as-grown samples. The samples with a higher growth rate had larger Seebeck coefficients of ∼500 μ/K after annealing.
The structure of the human gene for deoxyribonuclease II (DNase II; EC 3.1.22.1) was determined using several specific primers based on the human DNase II cDNA sequence [Yasuda et al. (1998). J. Biol. Chem.273, 2610–2616] in a polymerase chain reaction-based strategy. The gene spanned about 6 kb and consisted of 6 exons. No canonical TATA or CAAT boxes could be identified within the 1341 nucleotides upstream of the putative transcription start site, although the 5′-flanking region contained a CpG island and several putative binding motifs for transcription factors Sp1 and ETF. These properties indicate that the DNase II gene is a housekeeping gene and this is compatible with its ubiquitous expression in human tissues. Three different cleavage/polyadenylation sites were identified in the 3′-flanking region, leading to the production of multiple DNase II mRNA species. However, a comparison of the entire translated sequences of the gene from a pair of subjects with homozygous DNase II phenotypes H and L revealed no differences in the nucleotide sequences.
The changes in the valence electron states of CaSi2 during the chemical reaction with H2O have been investigated by Auger Valence Electron Spectroscopy (AVES). In order to study the reaction process, the reaction was precisely controlled by applying dc voltage between Pt electrode and CaSi2 specimen. The Si[2s, 2p,V] Auger spectra of CaSi2 specimen remain unchanged under the applied voltage lower than −15 V relative to the Pt electrode in H2O. At higher applied voltage, 3p components of Si[2s, 2p, V] (V = 3s, 3p) Auger spectra get weak while the 3s components increase drastically. The peak position due to Ca[2p, 3p, 3p] transitions gradually shifted toward the lower energy side by raising the applied voltage. The peak shift is due to the formation of Ca–O bonds in CaSi2. A new peak, which arises from the split of the valence electron states in Ca atoms due to the Ca–O bonds, appeared in Ca[2p, 3p,V] Auger spectra for CaSi2 after the reaction with H2O.
Introduction. According to the analysis of grandmaster-like strategies in Shogi [Iida and Uiterwijk 1993], it is important for a teacher, at the beginning stages of teaching, to intentionally lose an occasional game against a novice opponent, or to play less than optimally in order to give the novice some prospects of winning, without this being noticed by the opponent. Such a strategy is called a tutoring strategy in game-tree search.
In this work we consider a loss-oriented search strategy (LO-search for short), by which a player attempts to lose a game, and we show an algorithm for LOsearch based on the minimax strategy and OM-search (opponent-model search; see [Iida et al. 1993]). We further describe characteristics of LO-search, including the concept of intentional error. We next discuss the situation in which a player will notice such an intentional error. We then describe a tutoring search (TUsearch for short) by which a player attempts to lose a game without this being noticed by the opponent.
LO-search is based on OM-search, since LO-search also takes the opponent model into account. OM-search is predicated on the assumption that one has complete knowledge of the opponent's strategy and that this strategy is completely contained in the opponent's evaluation function. In OM-search, two values are computed for all positions in a search tree. For clarity, the players are distinguished as a max player and a min player.
Loss-Oriented Search. In order to play games, the minimax strategy or variations thereof have been used by many game-playing programs.
CaSi2 and CaSi have been investigated by Auger Valence Electron Spectroscopy (AVES). Some drastic differences of the Auger peak due to 3s states in the Si atoms were observed in the Si[2s, 2p, V] Auger spectra. The peak that arised from valence electron states in the Ca atoms was observed in the Ca[2p, 3p, V] Auger spectra for both Ca-silicides. This result suggests that the Ca–Si bonds are partially ionic. However, the number of the valence electrons in Ca atoms for CaSi was larger than that for CaSi2. This result implies that the part of homopolar bonds between the Si and Ca atoms in CaSi is stronger than that in CaSi2. Based on these results, it has been concluded that the change of the Si [2s, 2p,V] Auger spectra is associated with the difference of the part of homopolar bonds between the Si and Ca atoms.
Hg (mercury) in GaAs is known to be a moderately deep acceptor impurity, having a 52 meV activation energy. Optical properties of Hg acceptors in GaAs were systematically investigated as a function of Hg concentration, [Hg]. Samples were prepared by high-energy ion-implantation of Hg+ into GaAs grown by the liquid encapsulated Czochralski (LEC) method. Heat treatment was made by furnace annealing and rapid thermal annealing. Photoluminescence measurements at 2K revealed that the Hg-related so-called “g” line is formed in addition to the well-defined conduction band-to-Hg acceptor transition, (e, Hg). Additionally, three shallow emissions are formed for net hole concentrations INA-NDI greater than 2×1017cm−3 . This is the first demonstration that even Hg in GaAs makes multiple shallow emissions due to acceptor-acceptor pairs and LEC GaAs can be used for the investigations of these emissions.
Furnace annealing (FA) and rapid thermal annealing (RTA) were made for Cd+ ion-implanted GaAs with Cd concentration, [Cd] from 1×1016cm−3 to 3×1021 cm−3. In FA samples, Raman scattering spectra exhibited a single peak at 292 cm−1 for entire [Cd] range which is LO-phonon mode from (100) GaAs. In RTA samples, LO-phonon mode is a single peak for [Cd]<1×1019cm−3 but with growing [Cd], TO-phonon mode appears for [Cd] 1×1020cm3 and becomes a dominant signal for [Cd]=3×1021 cm−3. The quenching of LO-phonon mode with increasing [Cd] was more clearly observed in RTA samples than in FA ones. Hall-effects results, however, showed that activation rate of RTA samples is 6–7 times larger than that of FA ones for [Cd] 1×1021 cm−3. 2K photoluminescence spectra revealed that in FA samples multiple shallow emissions associated with Cd are formed while in RTA ones the dominant emission is the band to Cd acceptor transition.
The complication rate after emergency tracheostomy is two to five times greater than after elective procedures. One of the main causes of the high risk of complications in emergency tracheostomy appears to be the amount of time required to open the trachea. Therefore, simple and fast procedures are mandatory. We have developed a new procedure as follows: A horizontal skin incision is performed. Strap muscles are dissected and retracted laterally. A transverse cut between tracheal rings below the thyroid isthmus is performed up to membranous portion of the trachea. The cut ends of the trachea remain open naturally because of the elasticity of the trachea. Skin and tracheal cut-ends are then joined by interrupted sutures.
We have used this procedure during the past three years and have not experienced any major complications. This demonstrates the clear advantage and the more physiological nature of the procedure over various other incisions of the tracheal wall.