Observation of Current-induced Nonlinear Spin Polarization in Pt-Py Bilayers

We experimentally observe nonlinear spin polarization in metallic bilayers of platinum and permalloy by means of spin-torque ferromagnetic resonance (ST-FMR) with the spin-Hall effects. The ST-FMR results under massive dc current injection contain striking features, which are not caused by extrinsic Joule heating, but by intrinsic nonlinear spin polarization. The emergence of nonlinear spin polarization is consistent with observation of unidirectional spin-Hall magnetoresistance due to magnon generation/annihilation. Moreover, the magnon generation (annihilation) leads to effective magnetization shrinkage (expansion) revealed by the ST-FMR measurements. The present study paves a way to spin-Hall effect based nonlinear spintronic devices as well as 6th-generation mobile communication light sources

Haze Formation on Triton

The largest moon of Neptune, Triton, possess a cold and hazy atmosphere. Since the discovery of near-surface haze layer during the Voyager fly in 1989, the haze formation mechanism has not been investigated in detail. Here, we provide the first haze microphysical model on Triton. Our model solves the evolution of both size and porosity distributions of haze particles in a self-consistent manner. We simulated the formation of sphere and aggregate hazes with and without condensation of the C$_2$H$_4$ ice. The haze particles can grow into fractal aggregates with mass-equivalent sphere sizes of $\sim0.1$--$1~{\rm {\mu}m}$ and fractal dimension of $D_{\rm f} = 1.8$--$2.2$. The ice-free hazes cannot simultaneously explain both UV and visible observations of Voyager 2, while including the condensation of C$_2$H$_4$ ices provides two better solutions. For ice aggregates, the required total haze mass flux is $\sim2\times{10}^{-15}~{\rm g~{cm}^{-2}~s^{-1}}$. For the icy sphere scenario, the column integrated C$_2$H$_4$ production rate is $\sim8\times{10}^{-15}~{\rm g~{cm}^{-2}~s^{-1}}$, and the ice-free mass flux of $\sim6\times{10}^{-17}~{\rm g~{cm}^{-2}~s^{-1}}$. The UV occultation observations at short wavelength $<0.15~{\rm {\mu}m}$ may slightly favor the icy aggregates. Observations of the haze optical depth and the degree of forward scattering in UV and visible should be able to distinguish whether Triton's hazes are icy spheres or ice aggregates in future Triton missions.Comment: 29 pages, 14 figures, accepted for publication in Ap

A base pair at the bottom of the anticodon stem is reciprocally preferred for discrimination of cognate tRNAs by Escherichia coli lysyl- and glutaminyl-tRNA synthetases

Although the yeast amber suppressor tRNA(Tyr) is a good candidate for a carrier of unnatural amino acids into proteins, slight misacylation with lysine was found to occur in an Escherichia coli protein synthesis system. Although it was possible to restrain the mislysylation by genetically engineering the anticodon stem region of the amber suppressor tRNA(Tyr), the mutant tRNA showing the lowest acceptance of lysine was found to accept a trace level of glutamine instead. Moreover, the glutamine-acceptance of various tRNA(Tyr) transcripts substituted at the anticodon stem region varied in reverse proportion to the lysine-acceptance, similar to a ‘seesaw’. The introduction of a C31–G39 base pair at the site was most effective for decreasing the lysine-acceptance and increasing the glutamine-acceptance. When the same substitution was introduced into E.coli tRNA(Lys) transcripts, the lysine-accepting activity was decreased by 100-fold and faint acceptance of glutamine was observed. These results may support the idea that there are some structural element(s) in the anticodon stem of tRNA, which are not shared by aminoacyl-tRNA synthetases that have similar recognition sites in the anticodon, such as E.coli lysyl- and glutaminyl-tRNA synthetases

Consistent map building in petrochemical complexes for firefighter robots using SLAM based on GPS and LIDAR

The objective of this study was to achieve simultaneous localization and mapping (SLAM) of firefighter robots for petrochemical complexes. Consistency of the SLAM map is important because human operators compare the map with aerial images and identify target positions on the map. The global positioning system (GPS) enables increased consistency. Therefore, this paper describes two Rao-Blackwellized particle filters (RBPFs) based on GPS and light detection and ranging (LIDAR) as SLAM solutions. Fast-SLAM 1.0 and Fast-SLAM 2.0 were used in grid maps for RBPFs in this study. We herein propose the use of Fast-SLAM to combine GPS and LIDAR. The difference between the original Fast-SLAM and the proposed method is the use of the log-likelihood function of GPS; the proposed combination method is implemented using a probabilistic mathematics formulation. The proposed methods were evaluated using sensor data measured in a real petrochemical complex in Japan ranging in size from 550–380 m. RTK-GPS data was used for the GPS measurement and had an availability of 56%. Our results showed that Fast-SLAM 2.0 based on GPS and LIDAR in a dense grid map produced the best results. There was significant improvement in alignment to aerial data, and the mean square root error was 0.65 m. To evaluate the mapping consistency, accurate 3D point cloud data measured by Faro Focus 3D (± 3 mm) was used as the ground truth. Building sizes were compared; the minimum mean errors were 0.17 and 0.08 m for the oil refinery and management building area and the area of a sparse building layout with large oil tanks, respectively. Consequently, a consistent map, which was also consistent with an aerial map (from Google Maps), was built by Fast-SLAM 1.0 and 2.0 based on GPS and LIDAR. Our method reproduced map consistency results for ten runs with a variance of ± 0.3 m. Our method reproduced map consistency results with a global accuracy of 0.52 m in a low RTK-Fix-GPS environment, which was a factory with a building layout similar to petrochemical complexes with 20.9% of RTK-Fix-GPS data availability

子宮癌治療における抗腫瘍活性マクロファージの誘導

金沢大学医薬保健研究域医学系本研究は、婦人科悪性腫瘍組織内における腫瘍関連マクロファージ(tumor-associated macrophage : TAM)の機能、特に宿主免疫能に与える影響に関して検討することでがんの免疫療法の発展を目指すことを目的としている。1.悪性腫瘍細胞が産生する因子とマクロファージ機能との関係ヒト子宮体癌原発巣組織(70例)を用いて、in vitro等の実験系でマクロファージの細胞傷害活性・抗原提示能を抑制するとされているcycloocygenase (COX) -2およびmucinの腫瘍細胞における発現量と腫瘍細胞巣へのTAMの浸潤の程度および固形腫瘍における抗腫瘍免疫の指標とされる腫瘍細胞巣への細胞傷害性T細胞(cytotoxic T lymphoxyte : CTL)の浸潤の程度に及ぼす影響について検討を行った。その結果、腫瘍細胞のCOX-2高発現群において、腫瘍細胞巣へのTAMおよびCTLの浸潤の程度は、低発現群に比べ低値となった(それぞれ、p<0.01、p<0.001)。また、腫瘍細胞のmucin高発現群において腫瘍細胞巣へのCTLの浸潤の程度は、低発現群に比べ低値となった(p<0.05)。また腫瘍細胞のmucin発現は、腫瘍細胞およびTAMにおけるCOX-2の発現と相関しており、腫瘍細胞の産生するmucinが、COX-2を介した免疫抑制に関与していることが示唆された。2.マクロファージを活性化させる天然物質の探索抗腫瘍活性マクロファージの誘導を目的として、ヒト単球由来の培養細胞(THP-1)を用いて、天然物質による活性化を検討した。当年度はフランス海岸松エキス(ピクノジェノール)による、THP-1の形態的・機能的変化を検討したところ、CD86の発現増強などTHP-1の樹状細胞化が確認された。研究課題/領域番号:17791108, 研究期間(年度):2005 – 2006出典：「子宮癌治療における抗腫瘍活性マクロファージの誘導」研究成果報告書　課題番号17791108（KAKEN：科学研究費助成事業データベース（国立情報学研究所））（https://kaken.nii.ac.jp/ja/grant/KAKENHI-PROJECT-17791108/)を加工して作