Electronic structure of AlCrN films investigated using various photoelectron spectroscopies and ab initio calculations

The valence band (VB) structures of wurtzite AlCrN (Cr concentration: 0-17.1%), which show optical absorption in the ultraviolet-visible-infrared light region, were investigated via photoelectron yield spectroscopy (PYS), x-ray/ultraviolet photoelectron spectroscopy (XPS/UPS), and ab initio density of states (DOS) calculations. An obvious photoelectron emission threshold was observed ~5.3 eV from the vacuum level for AlCrN, whereas no emission was observed for AlN in the PYS spectra. Comparisons of XPS and UPS VB spectra and the calculated DOS imply that Cr 3d states are formed both at the top of the VB and in the AlN gap. These data suggest that Cr doping could be a viable option to produce new materials with relevant energy band structures for solar photoelectric conversion.

Experimental Identification of Electric Field Excitation Mechanisms in a Structural Transition of Tokamak Plasmas

Self-regulation between structure and turbulence, which is a fundamental process in the complex system, has been widely regarded as one of the central issues in modern physics. A typical example of that in magnetically confined plasmas is the Low confinement mode to High confinement mode (L-H) transition, which is intensely studied for more than thirty years since it provides a confinement improvement necessary for the realization of the fusion reactor. An essential issue in the L-H transition physics is the mechanism of the abrupt "radial" electric field generation in toroidal plasmas. To date, several models for the L-H transition have been proposed but the systematic experimental validation is still challenging. Here we report the systematic and quantitative model validations of the radial electric field excitation mechanism for the first time, using a data set of the turbulence and the radial electric field having a high spatiotemporal resolution. Examining time derivative of Poisson's equation, the sum of the loss-cone loss current and the neoclassical bulk viscosity current is found to behave as the experimentally observed radial current that excites the radial electric field within a few factors of magnitude.

Perpendicular magnetic tunnel junction with a strained Mn-based nanolayer

A magnetic tunnel junction with a perpendicular magnetic easy-axis (p-MTJ) is a key device for spintronic non-volatile magnetoresistive random access memory (MRAM). Co-Fe-B alloy-based p-MTJs are being developed, although they have a large magnetisation and medium perpendicular magnetic anisotropy (PMA), which make it difficult to apply them to a future dense MRAM. Here, we demonstrate a p-MTJ with an epitaxially strained MnGa nanolayer grown on a unique CoGa buffer material, which exhibits a large PMA of more than 5 Merg/cm³ and magnetisation below 500 emu/cm³; these properties are sufficient for application to advanced MRAM. Although the experimental tunnel magnetoresistance (TMR) ratio is still low, first principles calculations confirm that the strain-induced crystal lattice distortion modifies the band dispersion along the tetragonal c-axis into the fully spin-polarised state; thus, a huge TMR effect can be generated in this p-MTJ.

Long-Lasting Production of TGF-β1 by Alveolar Macrophages Exposed to Low Doses of Asbestos without Apoptosis

Alveolar macrophages (AMs) exposed to asbestos are well known to produce TNF-α, which induces the production of TGF-β1, leading to lung fibrogenesis. The present study examines the production of TGF-β1 by AMs exposed to chrysotile B asbestos (CH) in vivo or in vitro and the relationship between TGF-β1 production and apoptosis in cultures of AMs. Rats instilled with CH via the trachea showed increases in TNF-α, IL-1β and IL-6 in the bronchoalveolar lavage fluid (B ALF) 1 day after the instillation, followed by increases in TGF-β1 and apoptotic cells 5 days after. The AMs from these BALFs produced a significantly increased amount of TGF-β1 in culture compared to those from the control rats. The addition of 2.5 μg/cm2 of CH augmented the production of TGF-β1 by the AMs from the control to the same level as produced by the AMs from the CH-treated rats. The apoptosis of AMs was not induced at 2.5 μg/cm2 of CH, but was drastically induced at over 12.5 μg/cm2. In contrast, the production of TGF-β1 by AMs peaked at around 2.5 μg/cm2 of CH, and it lasted for 11 days. In addition, Bcl-2 and Bcl-xL increased in the AMs surviving under the exposure to CH. Taken together, these results indicate that AMs can autonomously, without other pulmonary cells, acquire the lasting ability to produce TGF-β1 independently of apoptosis under low exposure to CH. The AMs with the lasting production of TGF-β1 may contribute not only to lung fibrosis but also to immune suppression.

Abstract P5-12-11: Duration of ovarian function suppression for premenopausal women with hormone receptor-positive breast cancer: Retrospective study

Background: Although tamoxifen (TAM) plus ovarian function suppression (OFS) is one of standard adjuvant treatments in premenopausal women with hormone receptor-positive breast cancer, the optimal duration of OFS has not been clearly established.

Patients and Methods: We retrospectively reviewed data of premenopausal patients with breast cancer, who received TAM and OFS (goserelin or leuprorelin) as adjuvant therapy between February 2004 and April 2015. The primary analysis was to compare disease-free survival (DFS) between patients who received OFS shorter than 3 years and those who received OFS longer than 3 years. The analyses were performed with Cox proportional hazards models and propensity score matching models.

Results: We analyzed 206 premenopausal patients with hormone receptor-positive breast cancer. Median follow-up time was 56 months. Median age was 42 years (range, 24-52 years). Twenty six per cent of the patients had positive axillary nodes and 30% had received neo-adjuvant or adjuvant chemotherapy. Median duration of OFS was 26 months. Duration of OFS was shorter than three years (OFS < 3y) in 74% patients, and longer than three years (OFS > 3y) in 26% patients. Patients with node-positive disease were more in OFS > 3y group than in OFS < 3y group, and more patients received chemotherapy in OFS > 3y group than in OFS < 3y group. 5-year disease-free survival (DFS) was 96.1%. DFS in patients aged ≤ 40 years and aged > 40 years were 91.8% and 99.0%, respectively (p=0.0223). Propensity score matching model showed that DFS was not significantly different between patients in OFS < 3y group and those in OFS > 3y group (97.4%, 91.6%; p=0.2406). In patients aged ≤ 40 years and/or those who received chemotherapy, 5-year DFS was 96.7% in OFS < 3y group, 90.1% in OFS > 3y group (p=0.3011).

Conclusions: Our data suggest that OFS < 3y is not inferior to OFS > 3y for premenopausal women with hormone receptor-positive breast cancer as adjuvant endocrine therapy. A randomized trial is needed to establish the optimal OFS duration for these patients.

Citation Format: Ozaki Y, Tamura N, Utiyama M, Masuda J, Koganemaru S, Miura Y, Tanabe Y, Ogura T, Kadowaki M, Miura D, Kawabata H, Takano T. Duration of ovarian function suppression for premenopausal women with hormone receptor-positive breast cancer: Retrospective study. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P5-12-11.

Polyacrylamide backbones for polyvalent bioconjugates using “post-click” chemistry

This paper reports the synthesis and application of acrylamide-type neoglycoconjugates interacting with practical targets.

Temporal dynamics of intersexual conflict and the effect of male quality on female fecundity in the marine isopod Cleantiella isopus

Crustacean males grasp and/or guard females before copulation to ensure mating, but females typically resist males during pair formation. The benefit of resistance for females might allow (1) females to optimize mate quality, or (2) to avoid costs incurred during guarding. However, it has not been fully investigated which benefits actually improve female fitness. Here we investigated female resistance, temporal dynamics of intersexual conflict during reproduction, and the effect of male size and male mating frequency on female fecundity in the marine isopod,Cleantiella isopusto examine the relative importance of the two mechanisms mentioned before. Females resisted even after they had become receptive. Females which mated with small males showed lower fecundity than the ones with large males, and small males were frequently unable to form pairs. These results suggest that female resistance ofC. isopusagainst males can function as a way to optimize mate quality.