Significant enhancement of ferromagnetism in Zn1−x_{1-x}Crx_{x}Te doped with iodine as an n-type dopant

The effect of additional doping of charge impurities was investigated in a ferromagnetic semiconductor Zn$_{1-x}$Cr$_{x}$Te. It was found that the doping of iodine, which is expected to act as an n-type dopant in ZnTe, brought about a drastic enhancement of the ferromagnetism in Zn$_{1-x}$Cr$_{x}$Te while the grown films remained electrically insulating. In particular, at a fixed Cr composition of x = 0.05, the ferromagnetic transition temperature Tc increased up to 300K at maximum due to the iodine doping from Tc = 30K of the undoped counterpart, while the ferromagnetism disappeared due to the doping of nitrogen as a p-type dopant. The observed systematic correlation of ferromagnetism with the doping of charge impurities of both p- and n-type, suggesting a key role of the position of Fermi level within the impurity d-state, is discussed on the basis of the double exchange interaction as a mechanism of ferromagnetism in this material.Comment: 5 figures, to be published in Phys. Rev. Let

Issues for application of virtual microscopy to cytoscreening, perspectives based on questionnaire to Japanese cytotechnologists

To clarify the issues associated with the applications of virtual microscopy to the daily cytology slide screening, we conducted a survey at a slide conference of cytology. The survey was conducted specifically to the Japanese cytology technologists who use microscopes on a routine basis. Virtual slides (VS) were prepared from cytology slides using NanoZoomer (Hamamatsu Photonics, Japan), which is capable of adjusting focus on any part of the slide. A total of ten layers were scanned from the same slides, with 2 micrometer intervals. To simulate the cytology slide screening, no marker points were created. The total data volume of six slides was approximately 25 Giga Bytes. The slides were stored on the Windows 2003 Server, and were made accessible on the web to the cytology technologists. Most cytotechnologists answered "Satisfied" or "Acceptable" to the VS resolution and drawing speed, and "Dissatisfied" to the operation speed. To the ten layered focus, an answer "insufficient" was slightly more frequent than the answer "sufficient", while no one answered "fewer is acceptable" or "no need for depth". As for the use of cytology slide screening, answers "usable, but requires effort" and "not usable" were about equal in number. In a Japanese cytology meeting, a unique VS system has been used in slide conferences with markings to the discussion point for years. Therefore, Japanese cytotechnologists are relatively well accustomed to the use of VS, and the survey results showed that they regarded VS more positively than we expected. Currently, VS has the acceptable resolution and drawing speed even on the web. Most cytotechnologists regard the focusing capability crucial for cytology slide screening, but the consequential enlargement of data size, longer scanning time, and slower drawing speed are the issues that are yet to be resolved

Controlling keywords and their positions in text generation

One of the challenges in text generation is to control generation as intended by a user. Previous studies have proposed to specify the keywords that should be included in the generated text. However, this is insufficient to generate text which reflect the user intent. For example, placing the important keyword beginning of the text would helps attract the reader's attention, but existing methods do not enable such flexible control. In this paper, we tackle a novel task of controlling not only keywords but also the position of each keyword in the text generation. To this end, we show that a method using special tokens can control the relative position of keywords. Experimental results on summarization and story generation tasks show that the proposed method can control keywords and their positions. We also demonstrate that controlling the keyword positions can generate summary texts that are closer to the user's intent than baseline. We release our code

A Sillén Oxyhalide SrBi₃O₄Cl₃ as a Promising Photocatalyst for Water Splitting: Impact of the Asymmetric Structure on Light Absorption and Charge Carrier Dynamics

Bismuth-based oxyhalides with layered Sillén(–Aurivillius) structures have attracted significant attention as photocatalysts. Recent studies have unveiled a part of the structure–property relationship of the materials; however, it has not been fully understood. In the present study, we investigated a Sillén-type oxyhalide SrBi₃O₄Cl₃ with single and double halogen layers. Interestingly, SrBi₃O₄Cl₃ showed a visible light response up to ∼460 nm, whereas SrBiO₂Cl and BiOCl with single and double halogen layers, respectively, did not. Rietveld refinement and STEM-EDX mapping determined the asymmetric Bi occupation in the fluorite [Sr₀.₅Bi₁.₅O₂] layer of SrBi₃O₄Cl₃, which was derived from the coexistence of the halogen layers. DFT calculations and Madelung potential calculations showed that the asymmetric Bi occupation affords both the Bi–Bi interaction across the single halogen layer and the electrostatic destabilization of Cl in the double halogen layer, probably leading to the narrow bandgap of SrBi₃O₄Cl₃. Another merit of possessing the two different halogen layers was revealed by time-resolved microwave conductivity measurements as well as DFT calculations; the spatial separation of the conduction band minimum and valence band maximum based on the coexistence of the halogen layers would promote charge carrier separation. Visible-light-driven Z-scheme water splitting was accomplished using a RuO₂-loaded SrBi₃O₄Cl₃ sample as an O₂-evolving photocatalyst. This study provides another option for engineering band structures and promoting the charge carrier separation of layered oxyhalides for efficient water splitting under visible light

SBRT FOR CENTRAL LUNG TUMORS WITH 56 Gy/7 fr

Stereotactic body radiotherapy (SBRT) for centrally‑located lung tumors remains a challenge because of the increased risk of treatment‑related adverse events (AEs), and uncertainty around prescribing the optimal dose. The present study reported the results of central tumor SBRT with 56 Gy in 7 fractions (fr) at the University of Tokyo Hospital. A total of 35 cases that underwent SBRT with or without volumetric‑modulated arc therapy consisting of 56 Gy/7 fr for central lung lesions between 2010 and 2016 at the University of Tokyo Hospital were reveiwed. A central lesion was defined as a tumor within 2 cm of the proximal bronchial tree (RTOG 0236 definition) or within 2 cm in all directions of any critical mediastinal structure. Local control (LC), overall survival (OS), and AEs were investigated. The Kaplan‑Meier method was used to estimate LC and OS. AEs were scored per the Common Terminology Criteria for Adverse Events Version 4.0. Thirty‑five patients with 36 central lung lesions were included. Fifteen lesions were primary non‑small cell lung cancer (NSCLC), 13 were recurrences of NSCLC, and 8 had oligo‑recurrences from other primaries. Median tumor diameter was 29 mm. Eighteen patients had had prior surgery. At a median follow‑up of 13.1 months for all patients and 18.3 months in surviving patients, 22 patients had died, ten due to primary disease (4 NSCLC), while three were treatment‑related. The 1‑ and 2‑year OS were 57.3 and 40.4%, respectively, and median OS was 15.7 months. Local recurrence occurred in only two lesions. 1‑ and 2‑year LC rates were both 96%. Nine patients experienced grade ≥3 toxicity, representing 26% of the cohort. Two of these were grade 5, one pneumonitis and one hemoptysis. Considering the background of the subject, tumor control of our central SBRT is promising, especially in primary NSCLC. However, the safety of SBRT to central lung cancer remains controversial

Confluent hepatic fibrosis in liver cirrhosis: Possible relation with middle hepatic venous drainage

Purpose: Our aim was to retrospectively analyze the location of confluent hepatic fibrosis in relation to the portal and hepatic venous anatomy using multidetector computed tomography (CT) and to clarify the influence of the hepatic venous drainage on confluent fibrosis. Materials and methods: The study population consisted of 879 patients diagnosed with cirrhosis: 539 men and 340 women (65.9 ± 10.6 years) and 633 with Child-Pugh class A, 161 with class B, and 85 with class C. The cause of cirrhosis was hepatitis C (n = 528) and hepatitis B (n = 122) virus infection, alcoholism (n = 114), and others (n = 115). The confluent fibrosis was diagnosed using CT images according to previous reports and statistically analyzed (p < 0.05). Results: Thirty-five confluent fibrosis lesions in 30 patients (3.4 %) were identified. The predictive factors were alcoholic cirrhosis [odds ratio (OR), 7.25; p < 0.0001], Child-Pugh class C (OR, 6.95; p < 0.0001), and Child-Pugh class B (OR, 2.91; p < 0.0023). Confluent fibrosis was most frequently seen in the middle hepatic venous drainage area (n = 21) or at the boundary between the medial and anterior segments (n = 17), and each distribution of the location of confluent fibrosis was significantly unequal (p < 0.0001). Conclusion: Confluent fibrosis was most commonly located in the middle hepatic venous drainage area. © 2013 Japan Radiological Society