1,998 research outputs found

    In-plane anisotropy on the transport properties in the modulated Bi_2O_2-based conductors Bi-2212 and Bi-Sr-Co-O

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    We investigated the in-plane anisotropy on the resistivity and thermopower of the Bi_2Sr_2CaCu_2O_{8+\delta} (Bi-2212) and Bi-Sr-Co-O (BiCo) single crystals. In Bi-2212, the b-axis resistivity is higher than the a-axis resistivity, and is expressed as a sum of the a-axis resistivity and an additional residual resistivity. A downward deviation due to pseudogap is observed below a characteristic temperature T^*, which is isotropic in the form of conductivity. These results suggest that the modulation structure along the b-axis works as an anisotropic scattering center, but does not affect the pseudogap formation. On the other hand, the anisotropy of the resistivity and the thermopower in Pb-doped BiCo is substantial, probably owing to the misfit structure between the hexagonal CoO_2 layer and the rock salt Bi_2O_2 layer. However, the anisotropy in the resistivity in Pb-free BiCo is very small, suggesting that the in-plane anisotropy is averaged by the modulation structure, whose direction is tilted by 45 deg from the a- and b-axes.Comment: 4pages 5 figures, Proceedings of ISS2001, Physica C (in press

    Detection of CO(J=1-0) Emission from Barred Spiral Galaxies at z~0.1

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    We present the results of CO (J=1-0) observations towards nine barred spiral galaxies at z=0.08-0.25 using the 45-m telescope at Nobeyama Radio Observatory (NRO). This survey is the first one specialized for barred spiral galaxies in this redshift range. We detected CO emission from six out of nine galaxies, whose CO luminosity (L_CO') ranges (1.09-10.8)\times10^9 K km s^{-1} pc^2. These are the infrared (IR) dimmest galaxies that have ever been detected in CO at z~0.1 to date. They follow the L_CO'-L_IR relation among local spiral galaxies, Luminous Infrared Galaxies (LIRGs), Ultra-Luminous Infrared Galaxies (ULIRGs) and Sub-millimeter Galaxies (SMGs). Their L_CO' and L_IR are higher than that of local spiral galaxies which have been detected in CO so far, and L_IR/L'_CO, which is a measure of star formation efficiency, is comparable to or slightly higher than that of local ones. This result suggests that these galaxies are forming stars more actively than local spirals galaxies simply because they have more fuel.Comment: 9 pages, 5 figures, accepted for publication in PAS

    On convolution closure properties of subexponentiality approaching from densities

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    Non-closedness of subexponentiality by the convolution operation is well-known. We go a step further and show that subexponentiality and non-subexponentiality are generally changeable by the convolution. We also give several conditions, by which (non-) subexponentiality is kept. Most results are given with densities, which are easily converted to those for distributions. As a by-product, we give counterexamples to several past results, which were used to derive the non-closedness of the convolution, and modify the original proof.Comment: 23 page

    Si and GaAs dry etching utilizing showered electron-beam assisted etching through Cl2 gas

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    Electron-beam (EB) dry etching for Si and GaAs has been studied by utilizing showered electron-beam assisted etching in the presence of Cl 2 gas. Anisotropic etching has been demonstrated for both Si and GaAs EB dry etching. Si and GaAs patterns with 0.6 and 0.3 Ī¼m linewidths have been obtained at a dose of 2Ɨ10-2 C/cm2 and 1Ɨ10-3 C/cm2. It was confirmed, through measuring photoluminescence, that damage induced by EB dry etching is nearly the same as that caused by gas etching and less than damage induced by reactive ion-beam etching and ion-beam etching.Matsui S., Watanabe H.. Si and GaAs dry etching utilizing showered electron-beam assisted etching through Cl2 gas. Applied Physics Letters, 59, 18, 2284. https://doi.org/10.1063/1.106044

    Molecular Rheology of Glassy Polymers (FUNDAMENTAL MATERIAL PROPERTIES-Molecular Rheology)

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    Molecular origin of the viscoelasticity around the glass transition zone is investigated by means of dynamic birefringence and dynamic viscoelasticity measurements. The present study show that the viscoelasticity around the glass transition zone has two molecular origins: One is the orientation relaxation of main chain axis and the other one is the rotational motion of structure units about the main chain axis

    Fundamental and clinical evaluation of "SCC RIABEAD" kit for immuno radiometric assay of squamous cell carcinoma related antigen.

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    Classic vector control strategies target mosquitoes indoors as the main transmitters of malaria are indoor-biting and ā€“resting mosquitoes. However, the intensive use of insecticide-treated bed-nets (ITNs) and indoor residual spraying have put selective pressure on mosquitoes to adapt in order to obtain human blood meals. Thus, early-evening and outdoor vector activity is becoming an increasing concern. This study assessed the effect of a deltamethrin-treated net (100 mg/m2) attached to a one-meter high fence around outdoor cattle enclosures on the number of mosquitoes landing on humans. Mosquitoes were collected from four cattle enclosures: Pen A ā€“ with cattle and no net; B ā€“ with cattle and protected by an untreated net; C ā€“ with cattle and protected by a deltamethrin-treated net; D ā€“ no cattle and no net. A total of 3217 culicines and 1017 anophelines were collected, of which 388 were Anopheles gambiae and 629 An. ziemanni. In the absence of cattle nearly 3 times more An. gambiae (p<0.0001) landed on humans. The deltamethrin-treated net significantly reduced (nearly three-fold, p<0.0001) culicine landings inside enclosures. The sporozoite rate of the zoophilic An. ziemanni, known to be a secondary malaria vector, was as high as that of the most competent vector An. gambiae; raising the potential of zoophilic species as secondary malaria vectors. After deployment of the ITNs a deltamethrin persistence of 9 months was observed despite exposure to African weather conditions. The outdoor use of ITNs resulted in a significant reduction of host-seeking culicines inside enclosures. Further studies investigating the effectiveness and spatial repellence of ITNs around other outdoor sites, such as bars and cooking areas, as well as their direct effect on vector-borne disease transmission are needed to evaluate its potential as an appropriate outdoor vector control tool for rural Africa

    Novel results in STM, ARPES, HREELS, Nernst, neutron, Raman, and isotope substitution experiments and their relation to bosonic modes and charge inhomogeneity, from perspective of negative-Ueff boson-fermion modelling of HTSC

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    This paper seeks to synthesize much recent work on the HTSC materials around the latest STM results from Davis and coworkers. The conductance diffuse scattering results in particular are used as point of entry to discuss bosonic modes, both of condensed and uncondensed form. The bosonic mode picture is essential to understanding an ever growing range of observations within the HTSC field. The work is expounded within the context of the negative-U, boson-fermion modelling long advocated by the author. This general approach is presently seeing much theoretical development, into which I have looked to couple many of the experimental advances. While the formal theory is not yet sufficiently detailed to cover adequately all the experimental complexities presented by the real cuprate systems, it is clear that it affords very appreciable support to the line taken. An attempt is made throughout to say why and how it is that these events are tied so very closely to this particular set of materials.Comment: 36 pages pdf with 3 figures and 1 table included, Submitted to J. Phys. Cond. Mat

    Risk factor analysis of thoracic endovascular repair using the Matsui-Kitamura stent graft for acute aortic emergencies in the descending thoracic aorta

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    ObjectiveIn recent years, thoracic endovascular aneurysm repair (TEVAR) has been attempted for acute aortic emergencies (AAEs). However, the risk factors for achieving good results have not been identified. Besides focusing on Acute Physiology and Chronic Health Evaluation (APACHE) II score as a general indicator of patient condition, we analyzed both preoperative factors and intraoperative/postoperative factors. The purpose of this study was to identify those factors affecting the results of TEVAR using our Matsui-Kitamura stent graft (MKSG) for AAEs involving descending thoracic aortic aneurysm.MethodsBetween July 2000 and June 2008, a total of 32 patients (23 men, 9 women) with AAEs underwent endovascular repair. AAE was a result of aortic aneurysm rupture in 16 cases, rupture of penetrating atherosclerotic ulcer in 2 cases, traumatic aortic injury in 9 cases, complicated type B dissection in 4 cases, and aortic infiltration of sarcoma in 1 case. Low blood pressure in 6 patients, acute renal failure in 7 patients, anemia due to bleeding in 12 patients were found at the time of operation. Urgent TEVAR using the MKSG was performed. Perioperative and long-term results for these patients were investigated.ResultsThe delivery and technical success rate for TEVAR using the MKSG, was 100%. Perioperative mortality was 12.5%, and 5-year survival rate was 71%. In both univariate and multivariate analysis, the APACHE II score clarified a risk factor. Among the various elements of an APACHE II score, age, hematocrit, and total score were identified as significant factors. The mean of an APACHE II score was 9.5. Patients with an APACHE II score ā‰„10 showed significantly lower 5-year survival rates than patients with an APACHE II score ā‰¤9.ConclusionsGood results were obtained using TEVAR to treat AAEs with MKSGs, both perioperatively and during medium-term follow-up. Evaluation of risk factors for TEVAR of AAEs showed the utility of APACHE II score (particularly age, hematocrit, and total score) with a score ā‰„10 indicating high risk

    Biosynthetic Pathway for Sex Pheromone Components Produced in a Plusiinae Moth, Plusia festucae

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    While many Plusiinae species commonly secrete (Z)-7-dodecenyl acetate (Z7-12:OAc) as a key pheromone component, female moths of the rice looper (Plusia festucae) exceptionally utilize (Z)-5-dodecenyl acetate (Z5-12:OAc) to communicate with their partners. GCā€“MS analysis of methyl esters derived from fatty acids included in the pheromone gland of P. festucae showed a series of esters monounsaturated at the Ļ‰7-position, i.e., (Z)-5-dodecenoate, (Z)-7-tetradecenoate, (Z)-9-hexadecenoate (Z9-16:Me), and (Z)-11-octadecenoate (Z11-18:Me). By topical application of D3-labled palmitic acid (16:Acid) and stearic acid (18:Acid) to the pheromone glands, similar amounts of D3-Z5-12:OAc were detected. The glands treated with D13-labeled monoenoic acids (Z9-16:Acid and Z11-18:Acid), which were custom-made by utilizing an acetylene coupling reaction with D13-1-bromohexane, also produced similar amounts of D13-Z5-12:OAc. These results suggested that Z5-12:OAc was biosynthesized by Ļ‰7-desaturase with low substrate specificity, which could introduce a double bond at the 9-position of a 16:Acid derivative and the 11-position of an 18:Acid derivative. Additional experiments with the glands pretreated with an inhibitor of chain elongation supported this speculation. Furthermore, a comparative study with another Plusiinae species (Chrysodeixis eriosoma) secreting Z7-12:OAc indicated that the Ī²-oxidation systems of P. festucae and C. eriosoma were different
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