211 research outputs found

    Structural phase control of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 thin films by epitaxial growth technique

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    Epitaxial growth of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 thin films was studied by pulsed-laser deposition technique on three different substrates, SrTiO3_3 (100), LaSrAlO4_4 (001), and YAlO3_3 (001). The (Nd,Sr,Ce)2_2CuO4_4-type structure appears at the initial growth stage on SrTiO3_3 (100) when the film is deposited under the growth conditions optimized for (La,Sr)2_2CuO4_4. This (Nd,Sr,Ce)2_2CuO4_4-type structure can be eliminated by increasing the substrate temperature and the laser repetition frequency. Films on LaSrAlO4_4 (001) maintain a La2_2CuO4_4-type structure as bulk samples, but those on YAlO3_3 (001) show phase separation into La2_2CuO4_4- and Nd2_2CuO4_4-type structures. Such complicated results are explained in terms of the competition between lattice misfit and thermodynamic conditions. Interestingly the films with La2_2CuO4_4-type structure prepared on SrTiO3_3 and LaSrAlO4_4 show different surface structures and transport properties. The results indicate the possibility of controlling charge stripes of (La1.48_{1.48}Nd0.40_{0.40}Sr0.12_{0.12})CuO4_4 as was demonstrated in (La,Ba)2_2CuO4_4 thin films by Sato et al. (Phys. Rev. B {\bf 62}, R799 (2000)).Comment: 5 pages, 6 EPS figure, accepted for publication in Phys. Rev.

    Functional equations from generating functions: a novel approach to deriving identities for the Bernstein basis functions

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    The main aim of this paper is to provide a novel approach to deriving identities for the Bernstein polynomials using functional equations. We derive various functional equations and differential equations using generating functions. Applying these equations, we give new proofs for some standard identities for the Bernstein basis functions, including formulas for sums, alternating sums, recursion, subdivision, degree raising, differentiation and a formula for the monomials in terms of the Bernstein basis functions. We also derive many new identities for the Bernstein basis functions based on this approach. Moreover, by applying the Laplace transform to the generating functions for the Bernstein basis functions, we obtain some interesting series representations for the Bernstein basis functions.Comment: 1

    A patient with Graves' disease who survived despite developing thyroid storm and lactic acidosis

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    A 56-year-old woman with Graves' disease presented with the complaints of diarrhea and palpitations. Physical examination and laboratory data revealed hypothermia and signs of mild hyperthyroidism, heart failure, hepatic dysfunction with jaundice, hypoglycemia, and lactic acidosis. The patient was diagnosed as having developed the complication of thyroid storm in the absence of marked elevation of the thyroid hormone levels, because of the potential hepatic and cardiac dysfunctions caused by heavy alcohol drinking. A year later, after successful treatment, the patient remains well without any clinical evidence of heart failure or hepatic dysfunction. Thyroid storm associated with lactic acidosis and hypothermia is a serious condition and has rarely been reported. Prompt treatment is essential even if the serum thyroid hormone levels are not markedly elevated. We present a report about this patient, as her life could eventually be saved

    The association of APE1 −656T > G and 1349 T > G polymorphisms and cancer risk: a meta-analysis based on 37 case-control studies

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    <p>Abstract</p> <p>Background</p> <p>APE1 (apurinic/apyrimidinic endonuclease 1) is an important DNA repair protein in the base excision repair pathway. Polymorphisms in <it>APE1 </it>have been implicated in susceptibility to cancer; however, results from the published studies remained inconclusive. The objective of this study was to conduct a meta-analysis investigating the association between polymorphisms in <it>APE1 </it>and the risk for cancer.</p> <p>Methods</p> <p>The PubMed and Embase databases were searched for case-control studies published up to June, 2011 that investigated <it>APE1 </it>polymorphisms and cancer risk. Odds ratios (ORs) and 95% confidence intervals (CIs) were used to assess the strength of the associations.</p> <p>Results</p> <p>Two polymorphisms (−656 T > G, rs1760944 and 1349 T > G, rs1130409) in 37 case-control studies including 15, 544 cancer cases and 21, 109 controls were analyzed. Overall, variant genotypes (GG and TG/GG) of −656 T > G polymorphism were associated with significantly decreased cancer risk in homozygote comparison (OR = 0.81, 95%CI: 0.67-0.97), dominant model comparison (OR = 0.89, 95%CI: 0.81-0.97) and recessive model comparison (OR = 0.90, 95%CI: 0.82-0.98), whereas the 1349 T > G polymorphism had no effects on overall cancer risk. In the stratified analyses for −656 T > G polymorphism, there was a significantly decreased risk of lung cancer and among Asian populations.</p> <p>Conclusions</p> <p>Although some modest bias could not be eliminated, the meta-analysis suggests that <it>APE1 −</it>656 T > G polymorphism has a possible protective effect on cancer risk particularly among Asian populations whereas 1349 T > G polymorphism does not contribute to the development of cancer.</p

    A review of Fe-chalcogenide superconductors: the simplest Fe-based superconductor

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    Here we summarize the physical properties of the newly discovered Fe-chalcogenide superconductors. The Fe-chalcogenide superconductors attract us as the simplest Fe-based superconductors. Furthermore, Fe chalcogenides show a huge pressure effect on their superconducting properties. The origin of the high transition temperature was discussed with both the change in crystal structure and magnetism. The progress on the thin-film and superconducting-wire fabrications are also described.Comment: A review article of Fe-chalcogenide superconductor submitted to J. Phys. Soc. Jpn. 51 pages, 54 figures including reprinted from the published paper

    Colorimetric nanofibers as optical sensors

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    Sensors play a major role in many applications today, ranging from biomedicine to safety equipment, where they detect and warn us about changes in the environment. Nanofibers, characterized by high porosity, flexibility, and a large specific surface area, are the ideal material for ultrasensitive, fastresponding, and user-friendly sensor design. Indeed, a large specific surface area increases the sensitivity and response time of the sensor as the contact area with the analyte is enlarged. Thanks to the flexibility of membranes, nanofibrous sensors cannot only be applied in high-end analyte detection, but also in personal, daily use. Many different nanofibrous sensors have already been designed; albeit, the most straightforward and easiest-to-interpret sensor response is a visual change in color, which is of particular interest in the case of warning signals. Recently, many researchers have focused on the design of so-called colorimetric nanofibers, which typically involve the incorporation of a colorimetric functionality into the nanofibrous matrix. Many different strategies have been used and explored for colorimetric nanofibrous sensor design, which are outlined in this feature article. The many examples and applications demonstrate the value of colorimetric nanofibers for advanced optical sensor design, and could provide directions for future research in this area
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