Electronically modified single wall carbon nanohorns with iodine adsorption

Tailoring electronic properties of single wall carbon nanohorn (SWCNH) is expected to develop the application potential in various fields. SWCNH is efficiently modified with iodine molecules by liquid phase adsorption. The adsorption isotherm of iodine on SWCNH was Langmuirian with the saturated adsorption amount of 185 +/- 10 mg g (1) (coverage 0.18), indicating a specific interaction between SWCNH and iodine. The DC electrical conductivity of SWCNH film prepared by dip-coating method increased with the iodine adsorption amount almost by a factor 10.ArticleCHEMICAL PHYSICS LETTERS. 501(4-6):485-490 (2011)journal articl

23-Valent Polysaccharide Vaccine (PPSV23)-Targeted Serotype-Specific Identification Of Streptococcus Pneumoniae using the Loop-Mediated Isothermal Amplification (LAMP) Method

Reports of invasive disease due to Streptococcus pneumoniae have declined since the introduction of pneumococcal conjugate vaccines (PCV7 and PCV13). The incidence of invasive diseases due to S. pneumoniae that are not addressed by the vaccines, however, has increased in children and adults, creating a global public health problem. Previously, we established the loop-mediated isothermal amplification (LAMP) method for a PCV13 serotype-specific assay. In the current study, we developed a rapid, simple, and cost-effective assay to detect serotypes in the 23-valent pneumococcal polysaccharide vaccine (PPSV23) using the LAMP method. In this study, LAMP primer sets for serotypes 2, 8, 9N, 10A, 11A, 12F, 15B, 17F, 20, 22F, and 33F of S. pneumoniae were developed. The reactivity, specificity, and sensitivity of LAMP assays were determined and compared to those of conventional PCR. The feasibility of LAMP assays in clinical application in patients with invasive pneumococcal diseases was validated by defining the detection limit of the LAMP assay with bacterial genomic DNA-spiked blood specimens. The specificity of each LAMP assay was determined using 44 serotypes of pneumococcal strains. Their sensitivity was 100 copies per reaction versus 103 to 106 copies per reaction for PCR assays. Using DNA-spiked blood specimens, excluding the LAMP assay that targeted serotype 22F (103 copies per reaction), the limit of detection of the LAMP assay was similar to that with purified DNA as the template (102 copies per reaction), compared with 103 to \u3e 106 copies per reaction for PCR assays. In conclusion, a rapid and simple LAMP-based PPSV23-targeted serotype detection assay was developed for use in many countries. This study is the first report of a LAMP-based assay for identification of PPSV23 serotypes. Further evaluation of this assay is needed through surveillance and vaccine efficacy studies

Electronically modified single wall carbon nanohorns with iodine adsorption

Tailoring electronic properties of single wall carbon nanohorn (SWCNH) is expected to develop the application potential in various fields. SWCNH is efficiently modified with iodine molecules by liquid phase adsorption. The adsorption isotherm of iodine on SWCNH was Langmuirian with the saturated adsorption amount of 185 +/- 10 mg g (1) (coverage 0.18), indicating a specific interaction between SWCNH and iodine. The DC electrical conductivity of SWCNH film prepared by dip-coating method increased with the iodine adsorption amount almost by a factor 10.ArticleCHEMICAL PHYSICS LETTERS. 501(4-6):485-490 (2011)journal articl

Gate-Voltage-Induced Switching of the Spin-Relaxation Rate in a Triple-Quantum-Well Structure

Switching of the Dyakonov-Perel spin relaxation owing to the Rashba spin-orbit interaction (SOI) is theoretically studied in a semiconductor heterostructure with three quantum wells. The action of the present spin-relaxation switching is based on the gate-voltage induced electron transfer from the central well with vanishing Rashba SOI to the left or right well with large Rashba SOL The spin-relaxation rate is calculated by extending the Dyakonov-Perel theory of the spin relaxation in a single subband to that in more than one subband in order to take into account the contribution from electrons in excited subbands at higher temperatures. It is shown that the on:off ratio of the spin-relaxation rate at room temperature reaches 10(6) by choosing widths and compositions of well and barrier layers so as to reduce electron population in excited subbands, which gives an undesirable spin relaxation. The present spin-relaxation switching is expected to improve the on:off ratio of the current in the spin-lifetime field effect transistor

Spin-splitting surface states of strained GaAs(001) and spontaneous spin current from breaking of twofold symmetry

We theoretically study the electronic structure and spin splitting of a strained GaAs(001) surface with broken twofold symmetry. We introduce a surface electron Hamiltonian of our model. By k·p theory, we qualitatively evaluate the electronic structure of GaAs(001) surface, demonstrating that the spin degeneracy of the bottom of the surface-state conduction bands is split. Additionally, by the spin current operator, we evaluate the spin current of electrons in the bottom of the surface-state conduction bands, demonstrating that for n-type GaAs the spin current flows in the parallel direction to a mirror plane spontaneously. This is a new mechanism to generate the spin current

Suppressing effective magnetic field and spin-relaxation rate by tuning barrier compositions in a (111) quantum well

Adjusting compositions of two barriers forming a (111)-oriented InGaAs/AlGaAsSb quantum well (QW) is proposed as a method to eliminate the effective magnetic field due to the Rashba and linear-in-momentum Dresselhaus spin-orbit interactions in the zeroth and first orders in the gate electric field. The resulting suppressed Dyakonov-Perel spin relaxation is used to achieve a high on/off ratio of the spin-relaxation rate at room temperature in a double-QW structure

Enhanced Arctic moisture transport toward Siberia in autumn revealed by tagged moisture transport model experiment

Rapid Arctic warming has altered the regional hydrological cycle through reduction in Arctic sea ice. Observational and modeling efforts provided evidence that the enhanced evaporation from the Arctic Ocean could increase snowfall over high latitude terrestrial zones. However, questions remain regarding the amount of equatorward moisture transport and its change over the decadal timescale. Here we show that the transport of atmospheric moisture to Siberia that originated from Arctic Ocean evaporation has increased significantly in autumn to early winter during 1981-2019 when substantial sea ice retreat was observed. The enhanced Arctic moisture content is found in western Siberia in September, consistent with the observed increase in snow cover investigated in earlier studies. Meanwhile, the annual maximum daily amount of Arctic moisture shows a sharp increase in eastern Siberia during October-December associated with cyclonic activities along coastal regions. Our results suggest the importance of monitoring equatorward moisture transport during snow accumulation seasons because it could enhance local snowstorms as evaporation from the Arctic Ocean increases in the near future