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  1. Article ; Online: Mechanistic Modelling and Bayesian Inference Elucidates the Variable Dynamics of Double-Strand Break Repair.

    Woods, Mae L / Barnes, Chris P

    PLoS computational biology

    2016  Volume 12, Issue 10, Page(s) e1005131

    Abstract: DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational ... ...

    Abstract DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational events. Despite DNA repair being of crucial importance, the relative contribution of these mechanisms and their regulatory interactions remain to be fully elucidated. Understanding these mutational processes will have a profound impact on our knowledge of genomic instability, with implications across health, disease and evolution. Here we present a new method to model the combined activation of non-homologous end joining, single strand annealing and alternative end joining, following exposure to ionising radiation. We use Bayesian statistics to integrate eight biological data sets of double-strand break repair curves under varying genetic knockouts and confirm that our model is predictive by re-simulating and comparing to additional data. Analysis of the model suggests that there are at least three disjoint modes of repair, which we assign as fast, slow and intermediate. Our results show that when multiple data sets are combined, the rate for intermediate repair is variable amongst genetic knockouts. Further analysis suggests that the ratio between slow and intermediate repair depends on the presence or absence of DNA-PKcs and Ku70, which implies that non-homologous end joining and alternative end joining are not independent. Finally, we consider the proportion of double-strand breaks within each mechanism as a time series and predict activity as a function of repair rate. We outline how our insights can be directly tested using imaging and sequencing techniques and conclude that there is evidence of variable dynamics in alternative repair pathways. Our approach is an important step towards providing a unifying theoretical framework for the dynamics of DNA repair processes.
    MeSH term(s) Bayes Theorem ; Computer Simulation ; DNA/genetics ; DNA/radiation effects ; DNA Breaks, Double-Stranded ; DNA Repair/physiology ; Models, Chemical ; Models, Genetic ; Models, Molecular ; Models, Statistical ; Radiation Dosage ; Radiation, Ionizing
    Chemical Substances DNA (9007-49-2)
    Language English
    Publishing date 2016-10-14
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2193340-6
    ISSN 1553-7358 ; 1553-734X
    ISSN (online) 1553-7358
    ISSN 1553-734X
    DOI 10.1371/journal.pcbi.1005131
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Ultralow-dose binary oncolytic/helper-dependent adenovirus promotes antitumor activity in preclinical and clinical studies.

    Wang, Daniel / Porter, Caroline E / Lim, Bora / Rosewell Shaw, Amanda / Robertson, Catherine S / Woods, Mae L / Xu, Ya / Biegert, Greyson G W / Morita, Daisuke / Wang, Tao / Grilley, Bambi J / Heslop, Helen / Brenner, Malcolm K / Suzuki, Masataka

    Science advances

    2023  Volume 9, Issue 13, Page(s) eade6790

    Abstract: We show that a binary oncolytic/helper-dependent adenovirus (CAdVEC) that both lyses tumor cells and locally expresses the proinflammatory cytokine IL-12 and PD-L1 blocking antibody has potent antitumor activity in humanized mouse models. On the basis of ...

    Abstract We show that a binary oncolytic/helper-dependent adenovirus (CAdVEC) that both lyses tumor cells and locally expresses the proinflammatory cytokine IL-12 and PD-L1 blocking antibody has potent antitumor activity in humanized mouse models. On the basis of these preclinical studies, we treated four patients with a single intratumoral injection of an ultralow dose of CAdVEC (NCT03740256), representing a dose of oncolytic adenovirus more than 100-fold lower than used in previous trials. While CAdVEC caused no significant toxicities, it repolarized the tumor microenvironment with increased infiltration of CD8 T cells. A single administration of CAdVEC was associated with both locoregional and abscopal effects on metastases and, in combination with systemic administration of immune checkpoint antibodies, induced sustained antitumor responses, including one complete and two partial responses. Hence, in both preclinical and clinical studies, CAdVEC is safe and even at extremely low doses is sufficiently potent to induce significant tumor control through oncolysis and immune repolarization.
    MeSH term(s) Mice ; Animals ; Oncolytic Virotherapy/adverse effects ; Oncolytic Viruses ; Adenoviridae/genetics ; Neoplasms/pathology ; Cytokines ; Cell Line, Tumor ; Tumor Microenvironment
    Chemical Substances Cytokines
    Language English
    Publishing date 2023-03-29
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2810933-8
    ISSN 2375-2548 ; 2375-2548
    ISSN (online) 2375-2548
    ISSN 2375-2548
    DOI 10.1126/sciadv.ade6790
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Mechanistic Modelling and Bayesian Inference Elucidates the Variable Dynamics of Double-Strand Break Repair.

    Mae L Woods / Chris P Barnes

    PLoS Computational Biology, Vol 12, Iss 10, p e

    2016  Volume 1005131

    Abstract: DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational ... ...

    Abstract DNA double-strand breaks are lesions that form during metabolism, DNA replication and exposure to mutagens. When a double-strand break occurs one of a number of repair mechanisms is recruited, all of which have differing propensities for mutational events. Despite DNA repair being of crucial importance, the relative contribution of these mechanisms and their regulatory interactions remain to be fully elucidated. Understanding these mutational processes will have a profound impact on our knowledge of genomic instability, with implications across health, disease and evolution. Here we present a new method to model the combined activation of non-homologous end joining, single strand annealing and alternative end joining, following exposure to ionising radiation. We use Bayesian statistics to integrate eight biological data sets of double-strand break repair curves under varying genetic knockouts and confirm that our model is predictive by re-simulating and comparing to additional data. Analysis of the model suggests that there are at least three disjoint modes of repair, which we assign as fast, slow and intermediate. Our results show that when multiple data sets are combined, the rate for intermediate repair is variable amongst genetic knockouts. Further analysis suggests that the ratio between slow and intermediate repair depends on the presence or absence of DNA-PKcs and Ku70, which implies that non-homologous end joining and alternative end joining are not independent. Finally, we consider the proportion of double-strand breaks within each mechanism as a time series and predict activity as a function of repair rate. We outline how our insights can be directly tested using imaging and sequencing techniques and conclude that there is evidence of variable dynamics in alternative repair pathways. Our approach is an important step towards providing a unifying theoretical framework for the dynamics of DNA repair processes.
    Keywords Biology (General) ; QH301-705.5
    Subject code 612
    Language English
    Publishing date 2016-10-01T00:00:00Z
    Publisher Public Library of Science (PLoS)
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article ; Online: A computational method for the investigation of multistable systems and its application to genetic switches.

    Leon, Miriam / Woods, Mae L / Fedorec, Alex J H / Barnes, Chris P

    BMC systems biology

    2016  Volume 10, Issue 1, Page(s) 130

    Abstract: Background: Genetic switches exhibit multistability, form the basis of epigenetic memory, and are found in natural decision making systems, such as cell fate determination in developmental pathways. Synthetic genetic switches can be used for recording ... ...

    Abstract Background: Genetic switches exhibit multistability, form the basis of epigenetic memory, and are found in natural decision making systems, such as cell fate determination in developmental pathways. Synthetic genetic switches can be used for recording the presence of different environmental signals, for changing phenotype using synthetic inputs and as building blocks for higher-level sequential logic circuits. Understanding how multistable switches can be constructed and how they function within larger biological systems is therefore key to synthetic biology.
    Results: Here we present a new computational tool, called StabilityFinder, that takes advantage of sequential Monte Carlo methods to identify regions of parameter space capable of producing multistable behaviour, while handling uncertainty in biochemical rate constants and initial conditions. The algorithm works by clustering trajectories in phase space, and iteratively minimizing a distance metric. Here we examine a collection of models of genetic switches, ranging from the deterministic Gardner toggle switch to stochastic models containing different positive feedback connections. We uncover the design principles behind making bistable, tristable and quadristable switches, and find that rate of gene expression is a key parameter. We demonstrate the ability of the framework to examine more complex systems and examine the design principles of a three gene switch. Our framework allows us to relax the assumptions that are often used in genetic switch models and we show that more complex abstractions are still capable of multistable behaviour.
    Conclusions: Our results suggest many ways in which genetic switches can be enhanced and offer designs for the construction of novel switches. Our analysis also highlights subtle changes in correlation of experimentally tunable parameters that can lead to bifurcations in deterministic and stochastic systems. Overall we demonstrate that StabilityFinder will be a valuable tool in the future design and construction of novel gene networks.
    MeSH term(s) Computational Biology/methods ; Gene Regulatory Networks ; Monte Carlo Method ; Stochastic Processes ; Synthetic Biology
    Language English
    Publishing date 2016-12-07
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 1752-0509
    ISSN (online) 1752-0509
    DOI 10.1186/s12918-016-0375-z
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: A Statistical Approach Reveals Designs for the Most Robust Stochastic Gene Oscillators.

    Woods, Mae L / Leon, Miriam / Perez-Carrasco, Ruben / Barnes, Chris P

    ACS synthetic biology

    2016  Volume 5, Issue 6, Page(s) 459–470

    Abstract: The engineering of transcriptional networks presents many challenges due to the inherent uncertainty in the system structure, changing cellular context, and stochasticity in the governing dynamics. One approach to address these problems is to design and ... ...

    Abstract The engineering of transcriptional networks presents many challenges due to the inherent uncertainty in the system structure, changing cellular context, and stochasticity in the governing dynamics. One approach to address these problems is to design and build systems that can function across a range of conditions; that is they are robust to uncertainty in their constituent components. Here we examine the parametric robustness landscape of transcriptional oscillators, which underlie many important processes such as circadian rhythms and the cell cycle, plus also serve as a model for the engineering of complex and emergent phenomena. The central questions that we address are: Can we build genetic oscillators that are more robust than those already constructed? Can we make genetic oscillators arbitrarily robust? These questions are technically challenging due to the large model and parameter spaces that must be efficiently explored. Here we use a measure of robustness that coincides with the Bayesian model evidence, combined with an efficient Monte Carlo method to traverse model space and concentrate on regions of high robustness, which enables the accurate evaluation of the relative robustness of gene network models governed by stochastic dynamics. We report the most robust two and three gene oscillator systems, plus examine how the number of interactions, the presence of autoregulation, and degradation of mRNA and protein affects the frequency, amplitude, and robustness of transcriptional oscillators. We also find that there is a limit to parametric robustness, beyond which there is nothing to be gained by adding additional feedback. Importantly, we provide predictions on new oscillator systems that can be constructed to verify the theory and advance design and modeling approaches to systems and synthetic biology.
    MeSH term(s) Bayes Theorem ; Cell Cycle/genetics ; Circadian Rhythm/genetics ; Computer Simulation ; Gene Regulatory Networks/genetics ; Genetic Engineering/methods ; Models, Genetic ; Monte Carlo Method ; Proteins/genetics ; RNA, Messenger/genetics ; Research Design/statistics & numerical data ; Stochastic Processes ; Synthetic Biology/methods
    Chemical Substances Proteins ; RNA, Messenger
    Language English
    Publishing date 2016-02-17
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ISSN 2161-5063
    ISSN (online) 2161-5063
    DOI 10.1021/acssynbio.5b00179
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article: Engineered Immunogens to Elicit Antibodies Against Conserved Coronavirus Epitopes.

    Kapingidza, Brenda / Marston, Daniel J / Harris, Caitlin / Wrapp, Daniel / Winters, Kaitlyn / Mielke, Dieter / Xiaozhi, Lu / Yin, Qi / Foulger, Andrew / Parks, Rob / Barr, Maggie / Newman, Amanda / Schäfer, Alexandra / Eaton, Amanda / Flores, Justine Mae / Harner, Austin / Cantazaro, Nicholas J / Mallory, Michael L / Mattocks, Melissa D /
    Beverly, Christopher / Rhodes, Brianna / Mansouri, Katayoun / Itallie, Elizabeth Van / Vure, Pranay / Manness, Brooke / Keyes, Taylor / Stanfield-Oakley, Sherry / Woods, Christopher W / Petzold, Elizabeth A / Walter, Emmanuel B / Wiehe, Kevin / Edwards, Robert J / Montefiori, David / Ferrari, Guido / Baric, Ralph / Cain, Derek W / Saunders, Kevin O / Haynes, Barton F / Azoitei, Mihai L

    bioRxiv : the preprint server for biology

    2023  

    Abstract: Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing residues ... ...

    Abstract Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing residues 815-823 adjacent to the fusion peptide, are highly conserved across sarbecoviruses and are recognized by broadly reactive antibodies, providing hope that vaccines targeting these epitopes could offer protection against both current and emergent viruses. Here we employed computational modeling to design scaffolded immunogens that display the spike 815-823 peptide and the stem helix epitopes without the distracting and immunodominant RBD. These engineered proteins bound with high affinity and specificity to the mature and germline versions of previously identified broadly protective human antibodies. Epitope scaffolds interacted with both sera and isolated monoclonal antibodies with broadly reactivity from individuals with pre-existing SARS-CoV-2 immunity. When used as immunogens, epitope scaffolds elicited sera with broad betacoronavirus reactivity and protected as "boosts" against live virus challenge in mice, illustrating their potential as components of a future pancoronavirus vaccine.
    Language English
    Publishing date 2023-09-17
    Publishing country United States
    Document type Preprint
    DOI 10.1101/2023.02.27.530277
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: Engineered immunogens to elicit antibodies against conserved coronavirus epitopes.

    Kapingidza, A Brenda / Marston, Daniel J / Harris, Caitlin / Wrapp, Daniel / Winters, Kaitlyn / Mielke, Dieter / Xiaozhi, Lu / Yin, Qi / Foulger, Andrew / Parks, Rob / Barr, Maggie / Newman, Amanda / Schäfer, Alexandra / Eaton, Amanda / Flores, Justine Mae / Harner, Austin / Catanzaro, Nicholas J / Mallory, Michael L / Mattocks, Melissa D /
    Beverly, Christopher / Rhodes, Brianna / Mansouri, Katayoun / Van Itallie, Elizabeth / Vure, Pranay / Dunn, Brooke / Keyes, Taylor / Stanfield-Oakley, Sherry / Woods, Christopher W / Petzold, Elizabeth A / Walter, Emmanuel B / Wiehe, Kevin / Edwards, Robert J / Montefiori, David C / Ferrari, Guido / Baric, Ralph / Cain, Derek W / Saunders, Kevin O / Haynes, Barton F / Azoitei, Mihai L

    Nature communications

    2023  Volume 14, Issue 1, Page(s) 7897

    Abstract: Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing residues ... ...

    Abstract Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing residues 815-823 adjacent to the fusion peptide, are highly conserved across sarbecoviruses and are recognized by broadly reactive antibodies, providing hope that vaccines targeting these epitopes could offer protection against both current and emergent viruses. Here we employ computational modeling to design scaffolded immunogens that display the spike 815-823 peptide and the stem helix epitopes without the distracting and immunodominant receptor binding domain. These engineered proteins bind with high affinity and specificity to the mature and germline versions of previously identified broadly protective human antibodies. Epitope scaffolds interact with both sera and isolated monoclonal antibodies with broadly reactivity from individuals with pre-existing SARS-CoV-2 immunity. When used as immunogens, epitope scaffolds elicit sera with broad betacoronavirus reactivity and protect as "boosts" against live virus challenge in mice, illustrating their potential as components of a future pancoronavirus vaccine.
    MeSH term(s) Humans ; Animals ; Mice ; Epitopes ; Antibodies, Viral ; SARS-CoV-2 ; Immunodominant Epitopes ; Peptides ; Spike Glycoprotein, Coronavirus ; Antibodies, Neutralizing
    Chemical Substances Epitopes ; Antibodies, Viral ; Immunodominant Epitopes ; Peptides ; Spike Glycoprotein, Coronavirus ; Antibodies, Neutralizing
    Language English
    Publishing date 2023-11-30
    Publishing country England
    Document type Journal Article
    ZDB-ID 2553671-0
    ISSN 2041-1723 ; 2041-1723
    ISSN (online) 2041-1723
    ISSN 2041-1723
    DOI 10.1038/s41467-023-43638-9
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  8. Article ; Online: Engineered immunogens to elicit antibodies against conserved coronavirus epitopes

    A. Brenda Kapingidza / Daniel J. Marston / Caitlin Harris / Daniel Wrapp / Kaitlyn Winters / Dieter Mielke / Lu Xiaozhi / Qi Yin / Andrew Foulger / Rob Parks / Maggie Barr / Amanda Newman / Alexandra Schäfer / Amanda Eaton / Justine Mae Flores / Austin Harner / Nicholas J. Catanzaro / Michael L. Mallory / Melissa D. Mattocks /
    Christopher Beverly / Brianna Rhodes / Katayoun Mansouri / Elizabeth Van Itallie / Pranay Vure / Brooke Dunn / Taylor Keyes / Sherry Stanfield-Oakley / Christopher W. Woods / Elizabeth A. Petzold / Emmanuel B. Walter / Kevin Wiehe / Robert J. Edwards / David C. Montefiori / Guido Ferrari / Ralph Baric / Derek W. Cain / Kevin O. Saunders / Barton F. Haynes / Mihai L. Azoitei

    Nature Communications, Vol 14, Iss 1, Pp 1-

    2023  Volume 18

    Abstract: Abstract Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing ... ...

    Abstract Abstract Immune responses to SARS-CoV-2 primarily target the receptor binding domain of the spike protein, which continually mutates to escape acquired immunity. Other regions in the spike S2 subunit, such as the stem helix and the segment encompassing residues 815-823 adjacent to the fusion peptide, are highly conserved across sarbecoviruses and are recognized by broadly reactive antibodies, providing hope that vaccines targeting these epitopes could offer protection against both current and emergent viruses. Here we employ computational modeling to design scaffolded immunogens that display the spike 815-823 peptide and the stem helix epitopes without the distracting and immunodominant receptor binding domain. These engineered proteins bind with high affinity and specificity to the mature and germline versions of previously identified broadly protective human antibodies. Epitope scaffolds interact with both sera and isolated monoclonal antibodies with broadly reactivity from individuals with pre-existing SARS-CoV-2 immunity. When used as immunogens, epitope scaffolds elicit sera with broad betacoronavirus reactivity and protect as “boosts” against live virus challenge in mice, illustrating their potential as components of a future pancoronavirus vaccine.
    Keywords Science ; Q
    Subject code 570
    Language English
    Publishing date 2023-11-01T00:00:00Z
    Publisher Nature Portfolio
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  9. Article ; Online: In vivo confinement promotes collective migration of neural crest cells.

    Szabó, András / Melchionda, Manuela / Nastasi, Giancarlo / Woods, Mae L / Campo, Salvatore / Perris, Roberto / Mayor, Roberto

    The Journal of cell biology

    2016  Volume 213, Issue 5, Page(s) 543–555

    Abstract: Collective cell migration is fundamental throughout development and in many diseases. Spatial confinement using micropatterns has been shown to promote collective cell migration in vitro, but its effect in vivo remains unclear. Combining computational ... ...

    Abstract Collective cell migration is fundamental throughout development and in many diseases. Spatial confinement using micropatterns has been shown to promote collective cell migration in vitro, but its effect in vivo remains unclear. Combining computational and experimental approaches, we show that the in vivo collective migration of neural crest cells (NCCs) depends on such confinement. We demonstrate that confinement may be imposed by the spatiotemporal distribution of a nonpermissive substrate provided by versican, an extracellular matrix molecule previously proposed to have contrasting roles: barrier or promoter of NCC migration. We resolve the controversy by demonstrating that versican works as an inhibitor of NCC migration and also acts as a guiding cue by forming exclusionary boundaries. Our model predicts an optimal number of cells in a given confinement width to allow for directional migration. This optimum coincides with the width of neural crest migratory streams analyzed across different species, proposing an explanation for the highly conserved nature of NCC streams during development.
    MeSH term(s) Animals ; Cell Aggregation/drug effects ; Cell Movement/drug effects ; Computer Simulation ; Female ; Fibronectins/metabolism ; Models, Biological ; Neural Crest/cytology ; Neural Crest/drug effects ; Time-Lapse Imaging ; Versicans/pharmacology ; Xenopus
    Chemical Substances Fibronectins ; Versicans (126968-45-4)
    Language English
    Publishing date 2016-05-30
    Publishing country United States
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 218154-x
    ISSN 1540-8140 ; 0021-9525
    ISSN (online) 1540-8140
    ISSN 0021-9525
    DOI 10.1083/jcb.201602083
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article: Mirrored stainless steel substrate provides improved signal for Raman spectroscopy of tissue and cells.

    Lewis, Aaran T / Gaifulina, Riana / Isabelle, Martin / Dorney, Jennifer / Woods, Mae L / Lloyd, Gavin R / Lau, Katherine / Rodriguez-Justo, Manuel / Kendall, Catherine / Stone, Nicholas / Thomas, Geraint M

    Journal of Raman spectroscopy : JRS

    2016  Volume 48, Issue 1, Page(s) 119–125

    Abstract: Raman spectroscopy (RS) is a powerful technique that permits the non-destructive chemical analysis of cells and tissues without the need for expensive and complex sample preparation. To date, samples have been routinely mounted onto calcium fluoride ( ... ...

    Abstract Raman spectroscopy (RS) is a powerful technique that permits the non-destructive chemical analysis of cells and tissues without the need for expensive and complex sample preparation. To date, samples have been routinely mounted onto calcium fluoride (CaF
    Language English
    Publishing date 2016-07-29
    Publishing country England
    Document type Journal Article
    ZDB-ID 1481008-6
    ISSN 1097-4555 ; 0377-0486
    ISSN (online) 1097-4555
    ISSN 0377-0486
    DOI 10.1002/jrs.4980
    Database MEDical Literature Analysis and Retrieval System OnLINE

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