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  1. Article ; Online: Bifunctional Onium and Potassium Iodides as Nucleophilic Catalysts for the Solvent-Free Syntheses of Carbonates, Thiocarbonates, and Oxazolidinones from Epoxides.

    Shirakawa, Seiji

    Chemical record (New York, N.Y.)

    2023  Volume 23, Issue 10, Page(s) e202300144

    Abstract: The catalytic potential of organo-onium iodides as nucleophilic catalysts is aptly demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide ( ... ...

    Abstract The catalytic potential of organo-onium iodides as nucleophilic catalysts is aptly demonstrated in the synthesis of cyclic carbonates from epoxides and carbon dioxide (CO
    Language English
    Publishing date 2023-05-26
    Publishing country United States
    Document type Journal Article ; Review
    ZDB-ID 2044646-9
    ISSN 1528-0691 ; 1527-8999
    ISSN (online) 1528-0691
    ISSN 1527-8999
    DOI 10.1002/tcr.202300144
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  2. Article: [6. Programming in the Field of Nuclear Medicine].

    Shirakawa, Seiji

    Nihon Hoshasen Gijutsu Gakkai zasshi

    2021  Volume 77, Issue 1, Page(s) 51–58

    MeSH term(s) Nuclear Medicine ; Radionuclide Imaging
    Language Japanese
    Publishing date 2021-01-21
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 2269092-X
    ISSN 1881-4883 ; 0369-4305
    ISSN (online) 1881-4883
    ISSN 0369-4305
    DOI 10.6009/jjrt.2021_JSRT_77.1.51
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Book ; Online: Simple Domain Generalization Methods are Strong Baselines for Open Domain Generalization

    Noguchi, Masashi / Shirakawa, Shinichi

    2023  

    Abstract: In real-world applications, a machine learning model is required to handle an open-set recognition (OSR), where unknown classes appear during the inference, in addition to a domain shift, where the distribution of data differs between the training and ... ...

    Abstract In real-world applications, a machine learning model is required to handle an open-set recognition (OSR), where unknown classes appear during the inference, in addition to a domain shift, where the distribution of data differs between the training and inference phases. Domain generalization (DG) aims to handle the domain shift situation where the target domain of the inference phase is inaccessible during model training. Open domain generalization (ODG) takes into account both DG and OSR. Domain-Augmented Meta-Learning (DAML) is a method targeting ODG but has a complicated learning process. On the other hand, although various DG methods have been proposed, they have not been evaluated in ODG situations. This work comprehensively evaluates existing DG methods in ODG and shows that two simple DG methods, CORrelation ALignment (CORAL) and Maximum Mean Discrepancy (MMD), are competitive with DAML in several cases. In addition, we propose simple extensions of CORAL and MMD by introducing the techniques used in DAML, such as ensemble learning and Dirichlet mixup data augmentation. The experimental evaluation demonstrates that the extended CORAL and MMD can perform comparably to DAML with lower computational costs. This suggests that the simple DG methods and their simple extensions are strong baselines for ODG. The code used in the experiments is available at https://github.com/shiralab/OpenDG-Eval.

    Comment: 18 pages, 5 figures
    Keywords Computer Science - Computer Vision and Pattern Recognition ; Computer Science - Artificial Intelligence ; Computer Science - Machine Learning
    Subject code 006
    Publishing date 2023-03-31
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: Catalytic asymmetric CO

    Nishiyori, Ryuichi / Mori, Taiki / Shirakawa, Seiji

    Organic & biomolecular chemistry

    2023  Volume 21, Issue 19, Page(s) 4002–4006

    Abstract: Catalytic asymmetric bromocyclizations ... ...

    Abstract Catalytic asymmetric bromocyclizations of
    Language English
    Publishing date 2023-05-17
    Publishing country England
    Document type Journal Article
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/d3ob00555k
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: Chiral sulfide and selenide catalysts for asymmetric halocyclizations and related reactions.

    Nishiyori, Ryuichi / Mori, Taiki / Okuno, Ken / Shirakawa, Seiji

    Organic & biomolecular chemistry

    2023  Volume 21, Issue 16, Page(s) 3263–3275

    Abstract: Asymmetric organocatalysis using well-designed artificial chiral molecular catalysts is one of the most reliable methods to create important chiral compounds in a highly enantioenriched form. A wide variety of efficient asymmetric transformations have ... ...

    Abstract Asymmetric organocatalysis using well-designed artificial chiral molecular catalysts is one of the most reliable methods to create important chiral compounds in a highly enantioenriched form. A wide variety of efficient asymmetric transformations have been developed by utilizing well-designed chiral organocatalysts. Among the wide variety of organocatalysts, chiral amine and phosphine catalysts that utilize the characteristics of group 15 elements are the most extensively employed for asymmetric transformations. In comparison with chiral amine and phosphine catalysts, the use of chiral sulfide catalysts has remained limited and under-developed. The catalytic abilities of chiral sulfide organocatalysts were initially investigated using Corey-Chaykovsky-type asymmetric epoxidations and related reactions
    Language English
    Publishing date 2023-04-26
    Publishing country England
    Document type Journal Article ; Review
    ZDB-ID 2097583-1
    ISSN 1477-0539 ; 1477-0520
    ISSN (online) 1477-0539
    ISSN 1477-0520
    DOI 10.1039/d3ob00292f
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Asymmetric Synthesis of α-Spiro-γ-lactones and α-Substituted γ-Lactones via Chiral Bifunctional Sulfide-Catalyzed Bromolactonizations.

    Mori, Taiki / Abe, Koki / Shirakawa, Seiji

    The Journal of organic chemistry

    2023  Volume 88, Issue 12, Page(s) 7830–7838

    Abstract: An efficient enantioselective synthesis of γ-chiral α-spiro-γ-lactones, which are important building blocks for pharmaceuticals, was achieved via BINOL-derived chiral bifunctional sulfide-catalyzed bromolactonizations of α-allyl carboxylic acids ... ...

    Abstract An efficient enantioselective synthesis of γ-chiral α-spiro-γ-lactones, which are important building blocks for pharmaceuticals, was achieved via BINOL-derived chiral bifunctional sulfide-catalyzed bromolactonizations of α-allyl carboxylic acids containing either hetero- or carbocyclic structures. Transformations of the resultant α-spiro-type bromolactonization product were examined to obtain optically active γ-functionalized α-spiro-γ-lactones. The utility of this catalytic system was also demonstrated in the asymmetric synthesis of α,α-diaryl- and dialkyl-substituted γ-lactones.
    MeSH term(s) Lactones ; Carboxylic Acids ; Catalysis ; Stereoisomerism
    Chemical Substances Lactones ; Carboxylic Acids
    Language English
    Publishing date 2023-01-25
    Publishing country United States
    Document type Journal Article
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.2c02283
    Database MEDical Literature Analysis and Retrieval System OnLINE

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    In stock of ZB MED Cologne/Königswinter

    Zs.A 4473: Show issues Location:
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  7. Article ; Online: Safety and Clinical Evaluation of a Sonic Tongue Brush.

    Shirakawa, Satoshi / Nagano, Takatoshi / Matsushima, Yuji / Yashima, Akihiro / Gomi, Kazuhiro

    International dental journal

    2023  Volume 74, Issue 2, Page(s) 321–327

    Abstract: Background: Tongue coating consists of oral bacteria, desquamated epithelium, blood cells, and food residues and is involved in periodontal disease, halitosis, and aspiration pneumonia. Recently, a tongue brush with sonic vibration was developed to ... ...

    Abstract Background: Tongue coating consists of oral bacteria, desquamated epithelium, blood cells, and food residues and is involved in periodontal disease, halitosis, and aspiration pneumonia. Recently, a tongue brush with sonic vibration was developed to clean the tongue. This comparative study examined the extent of tongue coating, its effects on the tongue, bacterial count particularly on the posterior dorsum of the tongue, and the degree of pain using a manual tongue brush and the newly developed sonic tongue brush.
    Materials and methods: Patients' extent of tongue coating and the quantity of bacteria were analysed before and after brushing with a sonic or manual nylon tongue brush. Moreover, the impressions of the dorsum linguae were obtained before and after brushing to establish models that were observed under a stereo microscope to evaluate tongue trauma. Pain caused during the use of these brushes was evaluated based on the numerical rating scale (NRS).
    Results: The extent of tongue coating and number of bacteria decreased in both the sonic and manual nylon brush groups after tongue cleaning; however, no significant differences were noted. Tongue trauma evaluation revealed that the tongue surface was significantly scratched in the manual brush group compared with the sonic brush group. NRS-based pain evaluation revealed no significant differences.
    Conclusions: The sonic brush was equally effective in removing tongue coating and bacteria compared with the manual brush. As the sonic brush does not cause tongue trauma, it may be considered a safe and effective cleaning tool of the tongue.
    MeSH term(s) Humans ; Nylons ; Toothbrushing ; Halitosis/microbiology ; Bacteria ; Tongue/microbiology ; Pain
    Chemical Substances Nylons
    Language English
    Publishing date 2023-11-19
    Publishing country England
    Document type Journal Article
    ZDB-ID 218262-2
    ISSN 1875-595X ; 0020-6539
    ISSN (online) 1875-595X
    ISSN 0020-6539
    DOI 10.1016/j.identj.2023.10.002
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    Zs.A 205: Show issues Location:
    Je nach Verfügbarkeit (siehe Angabe bei Bestand)
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  8. Article ; Online: Chiral Bifunctional Selenide Catalysts for Asymmetric Iodolactonizations.

    Nishiyori, Ryuichi / Okuno, Ken / Chan, Bun / Shirakawa, Seiji

    Chemical & pharmaceutical bulletin

    2022  Volume 70, Issue 9, Page(s) 599–604

    Abstract: 1,1'-Bi-2-naphthol (BINOL)-derived chiral bifunctional sulfide and selenide catalysts that possess a hydroxy group are known to be effective catalysts for enantioselective bromolactonizations. When applied to asymmetric iodolactonizations of 4-pentenoic ... ...

    Abstract 1,1'-Bi-2-naphthol (BINOL)-derived chiral bifunctional sulfide and selenide catalysts that possess a hydroxy group are known to be effective catalysts for enantioselective bromolactonizations. When applied to asymmetric iodolactonizations of 4-pentenoic acids, these catalysts yield chiral γ-butyrolactone products that are important compounds in medicinal chemistry. Although chiral bifunctional selenides have shown good catalytic performances in enantioselective iodolactonizations, reactions with BINOL-derived chiral sulfide catalysts unexpectedly gave iodolactonization products in nearly racemic forms. The roles of chalcogenide moieties and hydroxy groups on bifunctional catalysts were investigated, and the importance of both a selenide moiety and a hydroxy group on chiral bifunctional selenide catalysts to achieve enantioselective iodolactonizations was clarified. An optimized chiral bifunctional selenide catalyst was applied to the asymmetric synthesis of chiral γ-butyrolactones and phthalides. Furthermore, the utility of chiral bifunctional selenides was also demonstrated in the catalytic enantioselective desymmetrizing iodolactonization of α,α-diallyl carboxylic acids.
    MeSH term(s) Carboxylic Acids/chemistry ; Catalysis ; Stereoisomerism ; Sulfides
    Chemical Substances Carboxylic Acids ; Sulfides
    Language English
    Publishing date 2022-09-02
    Publishing country Japan
    Document type Journal Article
    ZDB-ID 213307-6
    ISSN 1347-5223 ; 0009-2363
    ISSN (online) 1347-5223
    ISSN 0009-2363
    DOI 10.1248/cpb.c22-00049
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    In stock of ZB MED Cologne/Königswinter

    Zs.A 770: Show issues Location:
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  9. Article ; Online: Evaluation of text-to-gesture generation model using convolutional neural network.

    Asakawa, Eiichi / Kaneko, Naoshi / Hasegawa, Dai / Shirakawa, Shinichi

    Neural networks : the official journal of the International Neural Network Society

    2022  Volume 151, Page(s) 365–375

    Abstract: Conversational gestures have a crucial role in realizing natural interactions with virtual agents and robots. Data-driven approaches, such as deep learning and machine learning, are promising in constructing the gesture generation model, which ... ...

    Abstract Conversational gestures have a crucial role in realizing natural interactions with virtual agents and robots. Data-driven approaches, such as deep learning and machine learning, are promising in constructing the gesture generation model, which automatically provides the gesture motion for speech or spoken texts. This study experimentally analyzes a deep learning-based gesture generation model from spoken text using a convolutional neural network. The proposed model takes a sequence of spoken words as the input and outputs a sequence of 2D joint coordinates representing the conversational gesture motion. We prepare a dataset consisting of gesture motions and spoken texts by adding text information to an existing dataset and train the models using specific speaker's data. The quality of the generated gestures is compared with those from an existing speech-to-gesture generation model through a user perceptual study. The subjective evaluation shows that the model performance is comparable or superior to those by the existing speech-to-gesture generation model. In addition, we investigate the importance of data cleansing and loss function selection in the text-to-gesture generation model. We further examine the model transferability between speakers. The experimental results demonstrate successful model transferability of the proposed model. Finally, we show that the text-to-gesture generation model can produce good quality gestures even when using a transformer architecture.
    MeSH term(s) Gestures ; Machine Learning ; Motion ; Neural Networks, Computer ; Speech
    Language English
    Publishing date 2022-04-04
    Publishing country United States
    Document type Journal Article
    ZDB-ID 740542-x
    ISSN 1879-2782 ; 0893-6080
    ISSN (online) 1879-2782
    ISSN 0893-6080
    DOI 10.1016/j.neunet.2022.03.041
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    In stock of ZB MED Cologne/Königswinter

    Zs.A 2365: Show issues Location:
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  10. Article: Chiral Bifunctional Sulfide-Catalyzed Enantioselective Synthesis of α-Substituted γ-Lactones Bearing a γ-Quaternary Stereocenter

    Mori, Taiki / Sumida, Sao / Furuya, Yasuaki / Shirakawa, Seiji

    Synlett

    2023  Volume 35, Issue 04, Page(s) 479–483

    Abstract: Catalytic highly enantioselective syntheses of α-spiro-γ-lactones and α-substituted γ-lactones bearing a γ-quaternary stereocenter have been achieved through chiral bifunctional sulfide-catalyzed asymmetric bromolactonizations. The synthetic utility of ... ...

    Abstract Catalytic highly enantioselective syntheses of α-spiro-γ-lactones and α-substituted γ-lactones bearing a γ-quaternary stereocenter have been achieved through chiral bifunctional sulfide-catalyzed asymmetric bromolactonizations. The synthetic utility of the optically active γ-lactone products was demonstrated by transformations into functionalized γ-lactones and epoxides possessing a quaternary stereocenter.
    Keywords asymmetric synthesis ; halogenation ; lactones ; organocatalysis ; sulfides ; bromolactonization
    Language English
    Publishing date 2023-08-29
    Publisher Georg Thieme Verlag KG
    Publishing place Stuttgart ; New York
    Document type Article
    ZDB-ID 2042012-2
    ISSN 1437-2096 ; 0936-5214
    ISSN (online) 1437-2096
    ISSN 0936-5214
    DOI 10.1055/a-2161-9513
    Database Thieme publisher's database

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