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204 results on '"Ito, Ko"'

1. Frequency-multiplexed storage and distribution of narrowband telecom photon pairs over a 10-km fiber link with long-term system stability

Author

Ito, Ko, Kondo, Takeshi, Mannami, Kyoko, Niizeki, Kazuya, Yoshida, Daisuke, Minaguchi, Kohei, Zheng, Mingyang, Xie, Xiuping, Hong, Feng-Lei, and Horikiri, Tomoyuki

Subjects
Quantum Physics
Abstract

The ability to transmit quantum states over long distances is a fundamental requirement of the quantum internet and is reliant upon quantum repeaters. Quantum repeaters involve entangled photon sources that emit and deliver photonic entangled states at high rates and quantum memories that can temporarily store quantum states. Improvement of the entanglement distribution rate is essential for quantum repeaters, and multiplexing is expected to be a breakthrough. However, limited studies exist on multiplexed photon sources and their coupling with a multiplexed quantum memory. Here, we demonstrate the storing of a frequency-multiplexed two-photon source at telecommunication wavelengths in a quantum memory accepting visible wavelengths via wavelength conversion after 10-km distribution. To achieve this, quantum systems are connected via wavelength conversion with a frequency stabilization system and a noise reduction system. The developed system was stably operated for more than 42 h. Therefore, it can be applied to quantum repeater systems comprising various physical systems requiring long-term system stability., Comment: 10 pages

Published
2023
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2. Coupling of a quantum memory and telecommunication wavelength photons for high-rate entanglement distribution in quantum repeaters

Author

Mannami, Kyoko, Kondo, Takeshi, Tsuno, Tomoki, Miyashita, Takuto, Yoshida, Daisuke, Ito, Ko, Niizeki, Kazuya, Nakamura, Ippei, Hong, Feng-Lei, and Horikiri, Tomoyuki

Subjects
Quantum Physics
Abstract

Quantum repeaters are indispensable tools for long-distance quantum communication. However, frequency matching between entangled photon sources and remote quantum memories (QMs) is difficult, which is an obstacle to the implementation of quantum repeaters. In this paper, we demonstrate a method to achieve the coupling of a Pr:YSO as a fixed-time QM with a single telecommunication-wavelength photon through frequency stabilization using an optical frequency comb over all applied laser wavelengths. The demonstrated method can lead to the implementation of a quantum repeater scheme enabling an improvement of the entanglement generation rate, paving the way for long-distance quantum communication., Comment: 16 pages, 6 figures

Published
2021
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3. Two-photon comb with wavelength conversion and 20-km distribution for quantum communication

Author

Niizeki, Kazuya, Yoshida, Daisuke, Ito, Ko, Nakamura, Ippei, Takei, Nobuyuki, Okamura, Kotaro, Zheng, Ming-Yang, Xie, Xiu-Ping, and Horikiri, Tomoyuki

Subjects
Quantum Physics
Abstract

Quantum computing and quantum communication, have been greatly developed in recent years and expected to contribute to quantum internet technologies, including cloud quantum computing and unconditionally secure communication. However, long-distance quantum communication is challenging mainly because of optical fiber losses; quantum repeaters are indispensable for fiber-based transmission because unknown quantum states cannot be amplified with certainty. In this study, we demonstrate a versatile entanglement source in the telecom band for fiber-based quantum internet, which has a narrow linewidth of sub-MHz range, entanglement fidelity of more than 95%, and Bell-state generation even with frequency multimode. Furthermore, after a total distribution length of 20-km in fiber, two-photon correlation is observed with an easily identifiable normalized correlation coefficient, despite the limited bandwidth of the wavelength converter. The presented implementation promises an efficient method for entanglement distribution that is compatible with quantum memory and frequency-multiplexed long-distance quantum communication applications.

Published
2020
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6. Semi-algebraic partition and basis of Borel-Moore homology of hyperplane arrangements

Author

Ito, Ko-Ki and Yoshinaga, Masahiko

Subjects
Mathematics - Geometric Topology, Mathematics - Algebraic Geometry, Mathematics - Combinatorics
Abstract

We describe an explicit semi-algebraic partition for the complement of a real hyperplane arrangement such that each piece is contractible and so that the pieces form a basis of Borel-Moore homology. We also give an explicit correspondence between the de Rham cohomology and the Borel-Moore homology., Comment: corrected typos, 13 pages

Published
2011

7. Endoscopically-assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device.

Author

Iwai, Toshinori, Sugiyama, Satomi, Ohashi, Nobuhide, Hirota, Makoto, Ito, Ko, and Mitsudo, Kenji

Subjects
MANDIBULAR condyle, PIEZOELECTRIC devices, OSTEOCHONDROMA, SKULL base, PIEZOSURGERY, MANDIBLE surgery, MINIMALLY invasive procedures
Abstract

Background: Osteochondromas of the mandibular condyle show facial asymmetry and malocclusion. Because condylar osteochondromas are generally resected in a preauricular approach with risks of facial nerve injury and visible scar, the authors report endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device.Case presentation: A 38-year-old woman presented with malocclusion and facial asymmetry caused by deviation of the chin to the left. Computed tomography showed a hyperdense, well-circumscribed mass arising from the medial aspect of the right mandibular condyle with resorption of the skull base. The patient underwent an endoscopically-assisted intraoral condylectomy with a piezoelectric surgical device. The postoperative course was uneventful without trismus, malocclusion, or facial asymmetry, and there was no recurrence 4 years after surgery.Conclusion:Endoscopically assisted intraoral resection of osteochondroma of the mandibular condyle with a piezoelectric surgical device is a minimally invasive and safe surgery. [ABSTRACT FROM AUTHOR]

Published
2024
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9. The Elliptic Hypergeometric Functions Associated to the Configuration Space of Points on an Elliptic Curve I : Twisted Cycles

Author

Ito, Ko-Ki

Subjects
Mathematics - Classical Analysis and ODEs
Abstract

We consider the Euler type integral associated to the configuration space of points on an elliptic curve, which is an analogue of the hypergeometric function associated to the configuration space of points on a projective line. We calculate the {\it twisted homology group}, with coefficients in the local system associated to a power function $g^{\alpha}$ of an elliptic function $g$, and the intersection form. Applying these calculations, we describe the {\it connection matrices} representing the linear isomorphisms induced from analytic continuations of the functions defined by the integrations of $g^{\alpha}$ over twisted cycles.

Published
2008

13. Oral ulceration with bone exposure caused by percutaneous mental nerve block: A case report.

Author

Isozaki, Yuta, Ito, Ko, Okamura, Tomomichi, Takaku, Yuki, and Sato, Tsuyoshi

Abstract

The mental nerve block is one of the peripheral branches of the trigeminal nerve block used to treat idiopathic trigeminal neuralgia. Complications of mental nerve block include nerve injury, intravascular injection, and hematoma; however, reports describing oral ulceration are rare. A case of oral ulceration caused by mental nerve block is reported. An 84-year-old female was referred to the authors' department with the chief complaint of oral ulceration in the left mandible. She had a medical history of idiopathic trigeminal neuralgia and was regularly treated with mental nerve block under local anesthesia in the anesthesiology department of the authors' hospital. It was suspected that mental nerve block was the cause of the oral ulceration because the patient was treated immediately before ulceration occurred. The mental nerve block was discontinued after her first visit and the oral ulceration disappeared two months later. Subsequently, oral ulceration did not recur, although the mental nerve block was resumed. [ABSTRACT FROM AUTHOR]

Published
2024
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15. Gene expression profiling of the masticatory muscle tendons and Achilles tendons under tensile strain in the Japanese macaque Macaca fuscata

Author

Ito, Ko, primary, Go, Yasuhiro, additional, Tatsumoto, Shoji, additional, Usui, Chika, additional, Mizuno, Yosuke, additional, Ikami, Eiji, additional, Isozaki, Yuta, additional, Usui, Michihiko, additional, Kajihara, Takeshi, additional, Yoda, Tetsuya, additional, Inoue, Ken-ichi, additional, Takada, Masahiko, additional, and Sato, Tsuyoshi, additional

Published
2023
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17. Psychosocial Stress Induces Orofacial Mechanical Allodynia Due to the Enhancement of Transient Receptor Potential Ankyrin 1 Expression in Trigeminal Ganglion Neurons via the Increment of the Trace Amine-Associated Receptor 7f Expression

Author

Ito, Ko, primary, Shinoda, Masamichi, additional, Soma, Kumi, additional, Ikutame, Daisuke, additional, Ikami, Eiji, additional, Mizuno, Yosuke, additional, Usui, Michihiko, additional, Asoda, Seiji, additional, and Sato, Tsuyoshi, additional

Published
2022
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21. A case of contact stomatitis of the oral floor caused by magnesium oxide in an elderly with paralysis.

Author

Okubo, Masahiko, Kamimura, Hideyuki, Fukushima, Yosuke, Ito, Ko, Sato, Tsuyoshi, and Kokabu, Shoichiro

Abstract

Background: On the mucosa, the retention of drugs including magnesium oxide for laxative sometimes causes drug‐induced contact mucositis. Case presentation: A 72‐year‐old man presented with discomfort in the oral floor. He suffered from paralysis on the right side of his body. After his meal, it was observed magnesium oxide were retained on the right side of the oral floor. After our instruction of taking drugs with food thickening agents, his mucosa became normal soon. Conclusion: We realized that the supervising of taking medicine in the right way is important for the patients such as oral dysphagia especially with elderly and paralysis. [ABSTRACT FROM AUTHOR]

Published
2023
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22. Psychosocial Stress Induces Orofacial Mechanical Allodynia Due to the Enhancement of Transient Receptor Potential Ankyrin 1 Expression in Trigeminal Ganglion Neurons via the Increment of the Trace Amine-Associated Receptor 7f Expression.

Author

Ito, Ko, Shinoda, Masamichi, Soma, Kumi, Ikutame, Daisuke, Ikami, Eiji, Mizuno, Yosuke, Usui, Michihiko, Asoda, Seiji, and Sato, Tsuyoshi

Subjects
*PSYCHOSOCIAL factors, *ALLODYNIA, *ANKYRINS, *OROFACIAL pain, *IMMUNOHISTOCHEMISTRY
Abstract

(1) Background: Chronic psychosocial stress can lead to oral dysesthesia with tongue pain. We examined whether psychosocial stress causes orofacial pain, and analyzed the comprehensive gene expression patterns of circulating cells and transient receptor potential ankyrin 1 (TRPA1) expression in trigeminal ganglion (TG) neurons in a mouse model of psychosocial stress. (2) Methods: Mice were divided into two groups: one group was kept in confrontational housing, and the other group was kept in single housing. Blood, adrenal gland, and tongue were collected. The head withdrawal threshold (HWT) of mechanical stimulation to the whisker pad skin was measured. TRPA1-positive TG neurons were immunohistochemically examined. DNA microarray analysis and quantitative reverse transcription polymerase chain reaction analysis were performed. (3) Results: The HWT was significantly lower in mice under the psychosocial stress condition compared to non-stressed mice. In stress-loaded mice, the number of TRPA1-positive TG neurons was significantly increased. Moreover, we showed that trace amine-associated receptor 7f expression was upregulated in circulating cells in blood and downregulated in the tongue. (4) Conclusions: Our results indicated that chronic psychosocial stress induced the orofacial mechanical allodynia through enhancement of TRPA1 expression in TG neurons with changes in the levels of trace amine-associated receptor 7f. [ABSTRACT FROM AUTHOR]

Published
2023
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30. A Case of Ameloblastic Fibrodentinoma in the Posterior Mandible

Author

Yamazaki Fumie, Eda Takashi, Tajima Mai, Watanabe Suguru, Okudaira Yuko, Suzuki Mayu, Kondoh Toshirou, Kato Yugo, Ito Ko, Aoki Akinobu, Ogura Naomi, and Takahashi Kosuke

Subjects
Mixed tumor, Posterior mandible, Ameloblastic fibrodentinoma, business.industry, medicine, Odontogenic tumor, Anatomy, medicine.disease, business
Published
2019

33. Bone phenotype in melanocortin 2 receptor-deficient mice

Author

Sato, Tsuyoshi, primary, Iwata, Takanori, additional, Usui, Michihiko, additional, Kokabu, Shoichiro, additional, Sugamori, Yasutaka, additional, Takaku, Yuki, additional, Kobayashi, Takashi, additional, Ito, Ko, additional, Matsumoto, Masahito, additional, Takeda, Shu, additional, Xu, Ren, additional, and Chida, Dai, additional

Published
2020
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48. Two Cases of Supernumerary Teeth in the Posterior Mandible

Author

Takahashi, Kosuke, primary, Watanabe, Suguru, additional, Ito, Ko, additional, Eda, Takashi, additional, Tajima, Mai, additional, Yano, Teruo, additional, Kato, Yugo, additional, Suzuki, Mayu, additional, Yamazaki, Fumie, additional, Aoki, Akinobu, additional, Ogura, Naomi, additional, and Kondoh, Toshirou, additional

Published
2019
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