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1,075 results on '"Hata, Kenji"'

158. PIK3CA mutation correlates with mTOR pathway expression but not clinical and pathological features in Fibfibroipose vascular anomaly (FAVA).

Author

Hori, Yumiko, Hirose, Katsutoshi, Ozeki, Michio, Hata, Kenji, Motooka, Daisuke, Tahara, Shinichiro, Matsui, Takahiro, Kohara, Masaharu, Higashihara, Hiroki, Ono, Yusuke, Tanaka, Kaishu, Toyosawa, Satoru, and Morii, Eiichi

Subjects
LYMPHATIC abnormalities, GENETIC mutation, IMMUNOHISTOCHEMISTRY, NUCLEOTIDE sequencing, PROTEIN kinases
Abstract

Background: Fibro-adipose vascular anomaly (FAVA) is a rare and new entity of vascular anomaly. Activating mutations in the phosphatidylinositol-4,5-bisphosphate 3-kinase catalytic subunit alpha (PIK3CA) gene were identified at a frequency of 62.5% in FAVA cases. The PIK3CA mutations excessively activate mammalian target of rapamycin (mTOR) pathway, which promotes angiogenesis and lymphangiogenesis, implying that PIK3CA mutations may act as drivers of FAVAs. This study investigated the correlations between PIK3CA mutational status, clinicopathological features and immunohistochemical expression of the mTOR pathway in a series of FAVA. Methods: We retrospectively evaluated the clinical and pathological findings of four FAVA cases. We performed next-generation sequencing (NGS) with a custom panel of genes associated with the mTOR pathway and genes responsible for other vascular anomalies; followed by direct sequencing and immunohistochemical analysis of the mTOR pathway. Results: Two PIK3CA-mutation cases and two PIK3CA-wild-type (wt) cases exhibited similar typical clinical features of FAVA. Histological analysis revealed venous malformation, lymphatic malformation, nerves containing enlarged abnormal vessels and fibrofatty tissue were observed regardless of PIK3CA mutational status. In contrast to clinical and histological findings, the immunohistochemical expression of activated AKT and mTOR that are upstream of the mTOR pathway was detected in abnormal vessels of PIK3CA-mutation cases but not in those of PIK3CA-wt cases. However, activated eukaryotic translation initiation factor 4E-binding protein 1 (4EBP1) and ribosomal protein S6 kinase 1 (S6K1), both of which are downstream effectors of the mTOR pathway, were expressed in abnormal vessels of both PIK3CA-mutation and PIK3CA-wt cases. Furthermore, targeting NGS did not find any common genetic mutations involved in the mTOR pathway among PIK3CA-wt cases. Conclusions: There was no significant association between the presence of PIK3CA mutations and the clinicopathological features of FAVA, suggesting that the PIK3CA gene is not necessarily involved in the onset of FAVA. FAVAs lacking PIK3CA mutations may be caused by other gene mutations that activate 4EBP1 and S6K1. [ABSTRACT FROM AUTHOR]

Published
2022
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163. Sox9 regulates the luminal stem/progenitor cell properties of salivary glands

Author

Tanaka, Junichi, primary, Mabuchi, Yo, additional, Hata, Kenji, additional, Yasuhara, Rika, additional, Takamatsu, Koki, additional, Kujiraoka, Satoko, additional, Yukimori, Akane, additional, Takakura, Ikuko, additional, Sumimoto, Hidetoshi, additional, Fukada, Toshiyuki, additional, Azuma, Masayuki, additional, Akiyama, Haruhiko, additional, Nishimura, Riko, additional, Shimane, Toshikazu, additional, and Mishima, Kenji, additional

Published
2019
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171. Through-Silicon-Via Interposers with Cu-Level Electrical Conductivity and Si-Level Thermal Expansion Based on Carbon Nanotube-Cu Composites for Microelectronic Packaging Applications.

Author

Chen, Guohai, Sundaram, Rajyashree, Sekiguchi, Atsuko, Hata, Kenji, and Futaba, Don N.

Abstract

Through-silicon-via (TSV) interposers using silicon and copper represent a critical element in microelectronic packaging, as they bridge between fine-pitch inputs/outputs at the integrated circuit chips to the coarser-pitch packages at the substrate. High electrical conductivity is one of the required properties, but as with the continued miniaturization of electronics, thermal expansion match between the substrate (typically silicon) and copper becomes increasingly important to avoid device failure. A CNT-Cu composite TSV interposer was fabricated envisioning microelectronic packaging applications, which demonstrates both copper-level electrical conductivity (∼2.5 × 105 S/cm) and Si-level coefficient of thermal expansion (CTE) (∼7 × 10–6/K). The CTE mismatch between CNT-Cu and Si was measured to be less than 1/5 compared with that between Cu and Si. To realize this, numerous technologies were combined. Specifically, this included the precision synthesis of vertically aligned pillars perfectly normal to the growth substrate, structural reinforcement of the CNT bundles to retain alignment during processing, electrodeposition of Cu into the interstitial spaces of the CNT pillars, and insertion of the CNT-Cu pillar arras into a prefabricated TSV substrate. Finally, the functionality of the prepared CNT-Cu TSV interposer was demonstrated for several configurations. [ABSTRACT FROM AUTHOR]

Published
2021
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172. 西島のトクサバモクマオウが優占する森林におけるトクサバモクマオウ駆除前後の土壌含水量の時間変化

Author

Hata, Kenji, Kawakami, Kazuto, and Kachi, Naoki

Subjects
invasive trees, 土壌体積含水率, 小笠原諸島, 操作実験, 外来植物, manipulative removal experiment, subtropical oceanic island, Ogasawara Islands, volumetric water content of soil, 侵略的外来樹木, 亜熱帯島嶼, exotic plants
Abstract

An invasive woody species, Casuarina equisetifolia Forst. (Casuarinaceae), is strongly dominant in the forests it invades in the Ogasawara Islands. For the restoration and management of these forest ecosystems, eradication and control programs aimed at C. equisetifolia are ongoing on the islands. The eradication can affect the water balance by altering hydrological processes, such as evapotranspiration, throughfall, stemflow, and rainfall canopy interception. In this study, we showed temporal changes in the water contents of surface soils in forests dominated by C. equisetifolia on Nishijima Island before and after their eradication. Volumetric water contents of surface soils at sites where all trees of C. equisetifolia were killed by herbicide and those of adjacent control sites were measured. The measurements of the soil water contents have been conducted from July 10, 2012 to August 31, 2013 at hourly interval. After August 2012, the soil water contents in the removal quadrats have trended to be higher than those in the control quadrats. The increases in soil water contents just after the removal treatment suggested that death of C. equisetifolia by the treatment would result in increase in soil water content. The complete data set of soil water contents in this study is available in electronic format with the permission of the Ogasawara Research Committee of Tokyo Metropolitan University (island@tmu.ac.jp).

Published
2014

190. Dense-Captioning Events in Videos

Author

Krishna, Ranjay, Hata, Kenji, Ren, Frederic, Fei-Fei, Li, Niebles, Juan Carlos, Krishna, Ranjay, Hata, Kenji, Ren, Frederic, Fei-Fei, Li, and Niebles, Juan Carlos

Abstract

Most natural videos contain numerous events. For example, in a video of a "man playing a piano", the video might also contain "another man dancing" or "a crowd clapping". We introduce the task of dense-captioning events, which involves both detecting and describing events in a video. We propose a new model that is able to identify all events in a single pass of the video while simultaneously describing the detected events with natural language. Our model introduces a variant of an existing proposal module that is designed to capture both short as well as long events that span minutes. To capture the dependencies between the events in a video, our model introduces a new captioning module that uses contextual information from past and future events to jointly describe all events. We also introduce ActivityNet Captions, a large-scale benchmark for dense-captioning events. ActivityNet Captions contains 20k videos amounting to 849 video hours with 100k total descriptions, each with it's unique start and end time. Finally, we report performances of our model for dense-captioning events, video retrieval and localization., Comment: 16 pages, 16 figures

Published
2017

191. ActivityNet Challenge 2017 Summary

Author

Ghanem, Bernard, Niebles, Juan Carlos, Snoek, Cees, Heilbron, Fabian Caba, Alwassel, Humam, Khrisna, Ranjay, Escorcia, Victor, Hata, Kenji, Buch, Shyamal, Ghanem, Bernard, Niebles, Juan Carlos, Snoek, Cees, Heilbron, Fabian Caba, Alwassel, Humam, Khrisna, Ranjay, Escorcia, Victor, Hata, Kenji, and Buch, Shyamal

Abstract

The ActivityNet Large Scale Activity Recognition Challenge 2017 Summary: results and challenge participants papers., Comment: 76 pages

Published
2017

192. A background level of oxygen-containing aromatics for synthetic control of carbon nanotube structure

Author

Futaba, Don N., Goto, Jundai, Yasuda, Satoshi, Yamada, Takeo, Yumura, Motoo, and Hata, Kenji

Subjects
Aromatic compounds -- Chemical properties, Aromatic compounds -- Electric properties, Nanotubes -- Chemical properties, Nanotubes -- Structure, Nanotubes -- Electric properties, Oxygen -- Chemical properties, Chemistry
Abstract

A highly selective double-walled carbon nanotube synthesis was performed by using oxygen-containing aromatics to demonstrate the function of water as a growth enhancer to control the structure of the carbon nanotube (CNT). The newly developed method provides an easy and convenient method to grow various kinds of nanotubes from the same catalyst and same growth conditions.

Published
2009

193. Molecular Mechanisms Involved in the Progression and Protection of Osteoarthritis

Author

Takahata, Yoshifumi, Murakami, Tomohiko, Hata, Kenji, and Nishimura, Riko

Abstract

Objective: Osteoarthritis is a common disease of the joint cartilage. Since the molecular pathogenesis of osteoarthritis is not clearly understood, early diagnostic markers and effective therapeutic agents have not been developed. Methods and Results: In recent years, there are several studies to elucidate the molecular aspects based on mouse genetics by using a stress-induced mechanical load model. Chondrocyte hypertrophy, which is usually seen in growth plate chondrocyte, is also induced in articular cartilage and involved in the onset of osteoarthritis. Additionally, signal molecules involved in inflammatory cytokine and matrix proteinase are expected to be target molecules for the fundamental treatment of early osteoarthritis. Some additional signal molecules, transcription factors and compounds have been reported to be involved in cartilage homeostasis. Conclusion: This review sheds light on the current status of various signal molecules for the management of osteoarthritis.

Published
2021
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194. Nanocomposite ion gels based on silica nanoparticles and an ionic liquid: ionic transport, viscoelastic properties, and microstructure

Author

Ueno, Kazuhide, Hata, Kenji, Katakabe, Toru, Kondoh, Masashi, and Watanabe, Masayoshi

Subjects
Silica gel -- Chemical properties, Nanoparticles -- Chemical properties, Nanoparticles -- Structure, Ionic liquids -- Chemical properties, Ionic liquids -- Structure, Chemicals, plastics and rubber industries
Abstract

A study was conducted to determine the ionic transport and viscoelastic properties of nanocomposite ion gels consisting of interconnected networks of silica nanoparticles and an IL, [[C.sub.2]mim][NT[f.sub.2]]. The results revealed that the elastic modulus and viscoelastic response could be controlled by adjusting the silica concentration without causing a considerable decrease in the ionic conductivity.

Published
2008

195. 父島において外来木本種モクマオウが優占する林分におけるリターフォール

Author

Hata, Kenji, Kato, Hidetoshi, and Kachi, Naoki

Subjects
invasive trees, 侵略的外来木本種, リターの堆積, 小笠原諸島, 外来種, Ogasawara (Bonin) Islands, exotic plants, litter accumulation
Abstract

To quantify litterfall in forests invaded by the alien woody species Casuarina equisetifolia in the Bonin Islands, the amount of annual litterfall and its seasonal changes at forested sites dominated by C. equisetifolia (n = 30 sites) were compared with those at sites dominated by native species (n = 30) on Chichijima Island. Litterfall collected in traps was sampled every two months between August 2007 and August 2008, oven-dried, and weighed. The total amount of annual litterfall at the C. equisetifolia sites was significantly larger than that at the sites dominated by native species. Approximately 70% of the total litterfall at the C. equisetifolia sites was dead leaves of that species, indicating that the greater accumulation of litter in forests dominated by C. equisetifolia is due to large amounts of dead C. equisetifolia leaves., 小笠原諸島において、外来木本種であるモクマオウが侵入した林分におけるリターフォールを定量的な情報に基づいて把握するために、父島の洲崎の二次林の中で、モクマオウが優占する林分（モクマオウ林、30調査区）とモクマオウが優占せずに在来種が優占する林分（在来林、30調査区）において年間のリターフォール量とその季節的な変化を比較した。2007年8月に各調査区においてリタートラップを設置して、2008年8月まで約2カ月おきにトラップ内のリター回収し、各器官ごとに乾燥重量を測定した。モクマオウ林における年間総リターフォール量は、在来林におけるそれよりも有意に大きかった。モクマオウ林における総リターフォールの約70%は、モクマオウの落葉であった。これらの結果は、モクマオウ林における厚いリターの堆積は、大量のモクマオウの落葉によることを示唆する。

Published
2010

196. 84% catalyst activity of water-assisted growth of single walled carbon nanotube forest characterization by a statistical and macroscopic approach

Author

Futaba, Don N., Hata, Kenji, Namai, Tatsunori, Iijima, Sumio, Yamada, Takeo, Yumura, Motoo, Mizuno, Kohei, and Hayamizu, Yuhei

Subjects
Water -- Chemical properties, Nanotechnology -- Research, Catalysis -- Analysis, Chemicals, plastics and rubber industries
Abstract

A statistical and macroscopic analysis to estimate the catalyst activity of water-assisted growth of single-walled nanotubes (SWNT) and to characterize SWNT forests is proposed. The catalyst activity is estimated to be 84% (plusmn 6%), the highest ever reported.

Published
2006

197. Selective matching of catalyst element and carbon source in single-walled carbon nanotube synthesis on silicon substrates

Author

Mizuno, Kohei, Hata, Kenji, Saito, Takeshi, Ohshima, Satoshi, Yumura, Motoo, and Iijima, Sumio

Subjects
Alcohol -- Chemical properties, Alcohol, Denatured -- Chemical properties, Chemical vapor deposition -- Observations, Silicon compounds -- Chemical properties, Chemicals, plastics and rubber industries
Abstract

The compatibility of various catalysts for ethylene and ethanol chemical vapor deposition (CVD) syntheses of single-walled carbon nanotubes (SWNTs) on Si substrates is studied. A strong selectivity between the catalyst elemental species and carbon source is found and SWNT yield for Fe(Co) catalysts is much higher for ethylene (ethanol) CVD than for ethanol (ethylene) CVD.

Published
2005

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