LIVIVO - The Search Portal for Life Sciences

zur deutschen Oberfläche wechseln
Advanced search

Search results

Result 1 - 10 of total 41847

Search options

  1. Book ; Online: BO-DBA

    Zhang, Zhuosheng / Yu, Shucheng

    Query-Efficient Decision-Based Adversarial Attacks via Bayesian Optimization

    2021  

    Abstract: ... gradient estimation require an excessive number of queries. Recently, Bayesian optimization (BO) has shown ... real-valued probability scores as outputs. However, extending BO to the setting of DBA is nontrivial ... because in DBA only output labels instead of real-valued scores, as needed by BO, are available to attackers ...

    Abstract Decision-based attacks (DBA), wherein attackers perturb inputs to spoof learning algorithms by observing solely the output labels, are a type of severe adversarial attacks against Deep Neural Networks (DNNs) requiring minimal knowledge of attackers. State-of-the-art DBA attacks relying on zeroth-order gradient estimation require an excessive number of queries. Recently, Bayesian optimization (BO) has shown promising in reducing the number of queries in score-based attacks (SBA), in which attackers need to observe real-valued probability scores as outputs. However, extending BO to the setting of DBA is nontrivial because in DBA only output labels instead of real-valued scores, as needed by BO, are available to attackers. In this paper, we close this gap by proposing an efficient DBA attack, namely BO-DBA. Different from existing approaches, BO-DBA generates adversarial examples by searching so-called \emph{directions of perturbations}. It then formulates the problem as a BO problem that minimizes the real-valued distortion of perturbations. With the optimized perturbation generation process, BO-DBA converges much faster than the state-of-the-art DBA techniques. Experimental results on pre-trained ImageNet classifiers show that BO-DBA converges within 200 queries while the state-of-the-art DBA techniques need over 15,000 queries to achieve the same level of perturbation distortion. BO-DBA also shows similar attack success rates even as compared to BO-based SBA attacks but with less distortion.
    Keywords Computer Science - Machine Learning ; Computer Science - Cryptography and Security ; 68T01 ; 68M25 ; I.2.10
    Subject code 006
    Publishing date 2021-06-04
    Publishing country us
    Document type Book ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

    More links

    Kategorien

  2. Article ; Online: BN/BO-Ullazines and Bis-BO-Ullazines: Effect of BO Doping on Aromaticity and Optoelectronic Properties.

    Guo, Yongkang / Zhang, Lei / Li, Chenglong / Jin, Mengjia / Zhang, Yanli / Ye, Jincheng / Chen, Yu / Wu, Xiaoming / Liu, Xuguang

    The Journal of organic chemistry

    2021  Volume 86, Issue 18, Page(s) 12507–12516

    Abstract: We have achieved substitutional doping of ullazine with either two BO units or with one BO unit and ... borylative cyclization as the key steps. Ullazine cores of both BN/BO-ullazines ( ...

    Abstract We have achieved substitutional doping of ullazine with either two BO units or with one BO unit and one BN unit. The synthesis of these B-doped ullazines is straightforward, using demethylation and borylative cyclization as the key steps. Ullazine cores of both BN/BO-ullazines (
    Language English
    Publishing date 2021-08-01
    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.1c00777
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  3. Article ; Online: Charge compensation engineering for high-performance dolomite-type BaTi(BO

    Yu, Bin / Chen, Jiale / Sun, Minghao / Chen, Nianmin / Li, Yuchan / Wang, Yunjian

    Dalton transactions (Cambridge, England : 2003)

    2022  Volume 51, Issue 7, Page(s) 2932–2942

    Abstract: Exploiting high color purity phosphors is a core problem in the development of phosphor conversion light-emitting diodes (pc-LEDs) for display devices. ... ...

    Abstract Exploiting high color purity phosphors is a core problem in the development of phosphor conversion light-emitting diodes (pc-LEDs) for display devices. Eu
    Language English
    Publishing date 2022-02-14
    Publishing country England
    Document type Journal Article
    ZDB-ID 1472887-4
    ISSN 1477-9234 ; 1364-5447 ; 0300-9246 ; 1477-9226
    ISSN (online) 1477-9234 ; 1364-5447
    ISSN 0300-9246 ; 1477-9226
    DOI 10.1039/d1dt04286f
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  4. Article: BN/BO-Ullazines and Bis-BO-Ullazines: Effect of BO Doping on Aromaticity and Optoelectronic Properties

    Guo, Yongkang / Zhang, Lei / Li, Chenglong / Jin, Mengjia / Zhang, Yanli / Ye, Jincheng / Chen, Yu / Wu, Xiaoming / Liu, Xuguang

    Journal of organic chemistry. 2021 Aug. 01, v. 86, no. 18

    2021  

    Abstract: We have achieved substitutional doping of ullazine with either two BO units or with one BO unit and ... borylative cyclization as the key steps. Ullazine cores of both BN/BO-ullazines (2) and bis-BO-ullazines (3 ...

    Abstract We have achieved substitutional doping of ullazine with either two BO units or with one BO unit and one BN unit. The synthesis of these B-doped ullazines is straightforward, using demethylation and borylative cyclization as the key steps. Ullazine cores of both BN/BO-ullazines (2) and bis-BO-ullazines (3) are very close to being planar. Their electronic and photophysical properties were investigated by ultraviolet–visible, fluorescence spectroscopy, cyclic voltammetry, and density functional theory calculations.
    Keywords demethylation ; density functional theory ; fluorescence emission spectroscopy ; organic chemistry ; voltammetry
    Language English
    Dates of publication 2021-0801
    Size p. 12507-12516.
    Publishing place American Chemical Society
    Document type Article
    ZDB-ID 123490-0
    ISSN 1520-6904 ; 0022-3263
    ISSN (online) 1520-6904
    ISSN 0022-3263
    DOI 10.1021/acs.joc.1c00777
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  5. Article ; Online: Direct Experimental Evidence for Abundant BO

    Yu, Yang / Stevensson, Baltzar / Edén, Mattias

    The journal of physical chemistry letters

    2018  Volume 9, Issue 21, Page(s) 6372–6376

    Abstract: By using double-quantum-single-quantum ... ...

    Abstract By using double-quantum-single-quantum correlation
    Language English
    Publishing date 2018-10-24
    Publishing country United States
    Document type Journal Article
    ISSN 1948-7185
    ISSN (online) 1948-7185
    DOI 10.1021/acs.jpclett.8b02907
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  6. Article: [Enzymatic characteristics of peroxidase from Chrysanthemum morifolium cv. Bo-ju].

    Zhu, Yu-Yun / Lyu, Xin-Lin / Li, Xiang-Wei / Zhang, Dong / Dong, Li-Hua / Zhu, Jing-Jing / Wang, Zhi-Min / Zhang, Jin-Zhen

    Zhongguo Zhong yao za zhi = Zhongguo zhongyao zazhi = China journal of Chinese materia medica

    2018  Volume 43, Issue 8, Page(s) 1596–1601

    Abstract: The enzymatic browning is one of the main reasons for affecting the quality of medicinal flowers. In the process of chrysanthemum harvesting and processing, improper treatment will lead to the browning and severely impact the appearance and quality of ... ...

    Abstract The enzymatic browning is one of the main reasons for affecting the quality of medicinal flowers. In the process of chrysanthemum harvesting and processing, improper treatment will lead to the browning and severely impact the appearance and quality of chrysanthemum. Peroxidase enzyme is one of the oxidoreductases that cause enzymatic browning of fresh chrysanthemum. The enzymatic characteristics of peroxidase (POD) in chrysanthemum were studied in this paper. In this experiment, the effects of different reaction substrates and their concentrations, PH value of buffer and reaction temperatures on the activity of POD enzyme were investigated. The results showed that the optimal substrate of POD was guaiacol, and the optimal concentration of POD was 50 mmol·L⁻¹. The optimal pH value and reaction temperature were 4.4 and 30-35 °C, respectively. Michaelis-Menten equation was obtained to express the kinetics of enzyme-catalyzed reaction of POD, Km=0.193 mol·L⁻¹, Vmax=0.329 D·min⁻¹. In addition, the results of POD enzyme thermal stability test showed that the POD enzyme activity was inhibited when being treated at 80 °C for 4 min or at 100 °C for 2 min. The above results were of practical significance to reveal the enzymatic browning mechanism, control the enzymatic browning and improve the quality of chrysanthemum, and can also provide the basis for the harvesting and processing of medicinal materials containing polyphenols.
    MeSH term(s) Chrysanthemum ; Flowers ; Kinetics ; Peroxidase ; Temperature
    Chemical Substances Peroxidase (EC 1.11.1.7)
    Language Chinese
    Publishing date 2018-05-11
    Publishing country China
    Document type Journal Article
    ZDB-ID 1004649-5
    ISSN 1001-5302 ; 0254-0029
    ISSN 1001-5302 ; 0254-0029
    DOI 10.19540/j.cnki.cjcmm.2018.0059
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  7. Article: Ba₆BO₃Cl₉ and Pb₆BO₄Cl₇: structural insights into ortho-borates with uncondensed BO₄ tetrahedra

    Li, Wei / Wu, Hongping / Yu, Hongwei / Hu, Zhanggui / Wang, Jiyang / Wu, Yicheng

    Chemical communications. 2020 June 4, v. 56, no. 45

    2020  

    Abstract: ... Interestingly, Pb₆BO₄Cl₇ contains rare uncondensed BO₄ tetrahedra. The structure analyses indicate ... play key roles in the formation of the uncondensed BO₄ tetrahedra. ...

    Abstract Two new halogen-rich ortho-borates, Ba₆BO₃Cl₉ and Pb₆BO₄Cl₇, were synthesized and characterized. Interestingly, Pb₆BO₄Cl₇ contains rare uncondensed BO₄ tetrahedra. The structure analyses indicate that the large cation/boron ratio, the stereochemically active lone pairs on Pb²⁺ cations and the rich Cl⁻ anions play key roles in the formation of the uncondensed BO₄ tetrahedra.
    Keywords anions ; boron ; cations ; chemical reactions ; chlorides ; geometry ; lead ; stereochemistry
    Language English
    Dates of publication 2020-0604
    Size p. 6086-6089.
    Publishing place The Royal Society of Chemistry
    Document type Article
    ZDB-ID 1472881-3
    ISSN 1364-548X ; 1359-7345 ; 0009-241X
    ISSN (online) 1364-548X
    ISSN 1359-7345 ; 0009-241X
    DOI 10.1039/d0cc01927e
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  8. Article ; Online: Targeting autophagy enhances BO-1051-induced apoptosis in human malignant glioma cells.

    Chu, Pei-Ming / Chen, Li-Hsin / Chen, Ming-Teh / Ma, Hsin-I / Su, Tsann-Long / Hsieh, Pei-Chen / Chien, Chian-Shiu / Jiang, Bo-Hua / Chen, Yu-Chih / Lin, Yi-Hui / Shih, Yang-Hsin / Tu, Pang-Hsien / Chiou, Shih-Hwa

    Cancer chemotherapy and pharmacology

    2012  Volume 69, Issue 3, Page(s) 621–633

    Abstract: Purpose: BO-1051 is an N-mustard derivative that is conjugated with DNA-affinic 9-anilinoacridine ... Since BO-1051 was reported to have strong anticancer activity, we investigated the effect and underlying ... mechanism of BO-1051 in human glioma cell lines.: Methods: Human glioma cell lines U251MG and U87MG were ...

    Abstract Purpose: BO-1051 is an N-mustard derivative that is conjugated with DNA-affinic 9-anilinoacridine. Since BO-1051 was reported to have strong anticancer activity, we investigated the effect and underlying mechanism of BO-1051 in human glioma cell lines.
    Methods: Human glioma cell lines U251MG and U87MG were studied with BO-1051 or the combination of BO-1051 and autophagic inhibitors. Growth inhibition was assessed by MTT assay. Apoptosis was measured by annexin V staining followed by flow cytometry and immunoblotting for apoptosis-related molecules. Induction of autophagy was detected by acridine orange labeling, electron microscopy, LC3 localization and its conversion. Transfection of shRNA was used to determine the involvement of Beclin1 in apoptotic cell death.
    Results: MTT assay showed that BO-1051 suppressed the viability of four glioma cell lines (U251MG, U87MG, GBM-3 and DBTRG-05MG) in a dose-dependent manner. The IC(50) values of BO-1051 for the glioma cells were significantly lower than the values for primary neurons cultures and normal fibroblast cells. Moreover, BO-1051 not only induced apoptotic cell death, but also enhanced autophagic flux via inhibition of Akt/mTOR and activation of Erk1/2. Importantly, suppression of autophagy by 3-methyladenine or bafilomycin A1 significantly increased BO-1051-induced apoptotic cell death in U251MG and U87MG cells. In addition, the proportion of apoptotic cells after BO-1051 treatment was enhanced by co-treatment with shRNA against Beclin1.
    Conclusions: BO-1051 induced both apoptosis and autophagy, and inhibition of autophagy significantly augmented the cytotoxic effect of BO-1051. Thus, a combination of BO-1051 and autophagic inhibitors offers a potentially new therapeutic modality for the treatment of malignant glioma.
    MeSH term(s) Antineoplastic Agents/chemistry ; Antineoplastic Agents/pharmacology ; Apoptosis/drug effects ; Autophagy/drug effects ; Blotting, Western ; Brain Neoplasms/drug therapy ; Brain Neoplasms/metabolism ; Brain Neoplasms/pathology ; Cell Culture Techniques ; Cell Survival/drug effects ; Dose-Response Relationship, Drug ; Glioma/drug therapy ; Glioma/metabolism ; Glioma/pathology ; Humans ; MAP Kinase Signaling System/drug effects ; Membrane Potential, Mitochondrial/drug effects ; Microscopy, Electron, Transmission ; Microscopy, Fluorescence ; Microscopy, Phase-Contrast ; Molecular Structure ; Nitrogen Mustard Compounds/chemistry ; Nitrogen Mustard Compounds/pharmacology ; Proto-Oncogene Proteins c-akt/antagonists & inhibitors ; TOR Serine-Threonine Kinases/antagonists & inhibitors
    Chemical Substances Antineoplastic Agents ; BO-1051 ; Nitrogen Mustard Compounds ; MTOR protein, human (EC 2.7.1.1) ; TOR Serine-Threonine Kinases (EC 2.7.1.1) ; Proto-Oncogene Proteins c-akt (EC 2.7.11.1)
    Language English
    Publishing date 2012-03
    Publishing country Germany
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 6820-2
    ISSN 1432-0843 ; 0344-5704 ; 0943-9404
    ISSN (online) 1432-0843
    ISSN 0344-5704 ; 0943-9404
    DOI 10.1007/s00280-011-1747-0
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

  9. Article: The luminescence properties of Sr₃Gd(BO ₃) ₃: Tb ³⁺ phosphors under vacuum ultraviolet excitation

    Zhao, WenYu / Gao, SongWei / An, ShengLi / Fan, Bin / Li, SongBo

    Chinese science bulletin Kexue tongbao.. 2012 Dec., v. 57, no. 34

    2012  

    Abstract: Tb³⁺-activated Sr₃Gd(BO₃)₃ green phosphors were prepared by conventional solid-state reaction ... BO₃)₃:0.1Tb³⁺ was comparable to that of commercial Zn₂SiO₄:Mn²⁺. The strongest emission peak of Sr₃Gd₀ ... BO₃)₃:0.1Tb³⁺ was at 543 nm with chromaticity coordinates of (0.2626, 0.4922) and a lifetime of 2.32 ...

    Abstract Tb³⁺-activated Sr₃Gd(BO₃)₃ green phosphors were prepared by conventional solid-state reaction. The vacuum ultraviolet (VUV) excitation, photoluminescence (PL) and decay properties of the phosphors in the visible range were investigated. The excitation spectrum showed a strong broad band from 160 to 200 nm with a maximum at 183 nm which was adjacent to the VUV excitation light source of 172 nm. Under excitation at 172 nm, the optimum co-doping concentration of Tb³⁺ was 10 mol%, and the emission intensity of Sr₃Gd₀.₉(BO₃)₃:0.1Tb³⁺ was comparable to that of commercial Zn₂SiO₄:Mn²⁺. The strongest emission peak of Sr₃Gd₀.₉(BO₃)₃:0.1Tb³⁺ was at 543 nm with chromaticity coordinates of (0.2626, 0.4922) and a lifetime of 2.32 ms. The optical properties of the green phosphor Sr₃Gd(BO₃)₃: Tb³⁺ make it suitable for use in Hg-free fluorescent lamps and plasma display panels.
    Keywords luminescence ; optical properties ; terbium ; ultraviolet radiation ; wavelengths
    Language English
    Dates of publication 2012-12
    Size p. 4513-4516.
    Publishing place Springer-Verlag
    Document type Article
    ZDB-ID 1021576-1
    ISSN 1861-9541 ; 1001-6538 ; 0250-7862
    ISSN (online) 1861-9541
    ISSN 1001-6538 ; 0250-7862
    DOI 10.1007/s11434-012-5418-2
    Database NAL-Catalogue (AGRICOLA)

    More links

    Kategorien

  10. Article ; Online: Recognizing the Chinese Pioneer of Neuraxial Labor Analgesia: Dr Guang-Bo Zhang and Her Unpublished Manuscript From More Than a Half-Century Ago.

    Cai, Zhen-Yu / Hu, Ling-Qun / Stellaccio, Francis S / Wang, Dong-Xin

    Anesthesia and analgesia

    2018  Volume 128, Issue 1, Page(s) 119–122

    Abstract: Dr Guang-Bo Zhang was the first anesthesiologist to administer and study the effects of labor ...

    Abstract Dr Guang-Bo Zhang was the first anesthesiologist to administer and study the effects of labor epidural analgesia in China. Between September 1963 and March 1964, she conducted an observational study evaluating the effects of neuraxial analgesia for laboring women. She presented her research and prepared an article; however, due to the Great Proletarian Cultural Revolution (Cultural Revolution), which began in 1966, her work went unpublished. She successfully preserved her unpublished article, notes, and slides throughout the Cultural Revolution by hiding them in a countryside location near Beijing. These 54-year-old, previously unpublished documents represent the first known clinical trial of neuraxial labor analgesia conducted in China.
    MeSH term(s) Analgesia, Epidural/history ; Analgesia, Obstetrical/history ; Biomedical Research/history ; China ; Female ; History, 20th Century ; Humans ; Labor Pain/history ; Labor Pain/therapy ; Physicians, Women/history ; Pregnancy
    Language English
    Publishing date 2018-10-09
    Publishing country United States
    Document type Biography ; Historical Article ; Journal Article ; Portrait ; Research Support, Non-U.S. Gov't ; Video-Audio Media
    ZDB-ID 80032-6
    ISSN 1526-7598 ; 0003-2999
    ISSN (online) 1526-7598
    ISSN 0003-2999
    DOI 10.1213/ANE.0000000000003845
    Database MEDical Literature Analysis and Retrieval System OnLINE

    More links

    Kategorien

To top