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  1. Article ; Online: Hepatic effects of tartrazine (E 102) after systemic exposure are independent of oestrogen receptor interactions in the mouse.

    Meyer, Stephanie K / Probert, Philip M E / Lakey, Anne F / Axon, Andrew R / Leitch, Alistair C / Williams, Faith M / Jowsey, Paul A / Blain, Peter G / Kass, George E N / Wright, Matthew C

    Toxicology letters

    2017  Volume 273, Page(s) 55–68

    Abstract: Tartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To ... ...

    Abstract Tartrazine is a food colour that activates the transcriptional function of the human oestrogen receptor alpha in an in vitro cell model. Since oestrogens are cholestatic, we hypothesised tartrazine will cause periportal injury to the liver in vivo. To test this hypothesis, tartrazine was initially administered systemically to mice resulting in a periportal recruitment of inflammatory cells, increased serum alkaline phosphatase activity and mild periportal fibrosis. To determine whether an oestrogenic effect may be a key event in this response, tartrazine, sulphonated metabolites and a food additive contaminant were screened for their ability to interact with murine oestrogen receptors. In all cases, there were no interactions as agonists or antagonists and further, no oestrogenicity was observed with tartrazine in an in vivo uterine growth assay. To examine the relevance of the hepatic effects of tartrazine to its use as a food additive, tartrazine was orally administered to transgenic NF-κB-Luc mice. Pre- and concurrent oral treatment with alcohol was incorporated given its potential to promote gut permeability and hepatic inflammation. Tartrazine alone induced NF- κB activities in the colon and liver but there was no periportal recruitment of inflammatory cells or fibrosis. Tartrazine, its sulphonated metabolites and the contaminant inhibited sulphotransferase activities in murine hepatic S9 extracts. Given the role of sulfotransferases in bile acid excretion, the initiating event giving rise to periportal inflammation and subsequent hepatic pathology through systemic tartrazine exposure is therefore potentially associated an inhibition of bile acid sulphation and excretion and not on oestrogen receptor-mediated transcriptional function. However, these effects were restricted to systemic exposures to tartrazine and did not occur to any significant effect after oral exposure.
    MeSH term(s) Administration, Oral ; Animals ; Cell Line ; Estradiol/pharmacology ; Estrogen Receptor alpha/genetics ; Estrogen Receptor alpha/metabolism ; Estrogen Receptor beta/genetics ; Estrogen Receptor beta/metabolism ; Ethanol/toxicity ; Female ; Food Coloring Agents/toxicity ; Injections, Intraperitoneal ; Liver/drug effects ; Liver/metabolism ; Liver Function Tests ; Luciferases, Firefly/genetics ; Male ; Mice, Inbred C57BL ; Mice, Transgenic ; NF-kappa B/genetics ; Tartrazine/toxicity
    Chemical Substances Estrogen Receptor alpha ; Estrogen Receptor beta ; Food Coloring Agents ; NF-kappa B ; Ethanol (3K9958V90M) ; Estradiol (4TI98Z838E) ; Luciferases, Firefly (EC 1.13.12.7) ; Tartrazine (I753WB2F1M)
    Language English
    Publishing date 2017-05-05
    Publishing country Netherlands
    Document type Journal Article
    ZDB-ID 433788-8
    ISSN 1879-3169 ; 0378-4274
    ISSN (online) 1879-3169
    ISSN 0378-4274
    DOI 10.1016/j.toxlet.2017.03.024
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  2. Article ; Online: Thermodynamics of hybrid quantum rotor devices.

    Leitch, Heather / Hammam, Kenza / De Chiara, Gabriele

    Physical review. E

    2024  Volume 109, Issue 2-1, Page(s) 24108

    Abstract: We investigate the thermodynamics of a hybrid quantum device consisting of two qubits collectively interacting with a quantum rotor and coupled dissipatively to two equilibrium reservoirs at different temperatures. By modeling the dynamics and the ... ...

    Abstract We investigate the thermodynamics of a hybrid quantum device consisting of two qubits collectively interacting with a quantum rotor and coupled dissipatively to two equilibrium reservoirs at different temperatures. By modeling the dynamics and the resulting steady state of the system using a collision model, we identify the functioning of the device as a thermal engine, a refrigerator, or an accelerator. In addition, we also look into the device's capacity to operate as a heat rectifier and optimize both the rectification coefficient and the heat flow simultaneously. Drawing an analogy to heat rectification and since we are interested in the conversion of energy into the rotor's kinetic energy, we introduce the concept of angular momentum rectification, which may be employed to control work extraction through an external load.
    Language English
    Publishing date 2024-03-15
    Publishing country United States
    Document type Journal Article
    ZDB-ID 2844562-4
    ISSN 2470-0053 ; 2470-0045
    ISSN (online) 2470-0053
    ISSN 2470-0045
    DOI 10.1103/PhysRevE.109.024108
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  3. Article ; Online: Designing Systems for E-Commerce

    Shona Leitch / Matthew Warren

    Australasian Journal of Information Systems, Vol 10, Iss

    2003  Volume 2

    Abstract: ... in the development and delivery of E-Commerce systems. There are many aspects of ethics that can affect E ... Commerce systems, but often research is focused on the ethics after the E-Commerce system has been implemented ... can affect the design of E-Commerce systems and how a framework designed for E-Commerce can be used to create ...

    Abstract Ethics is an important element in all aspects of computing, but proves to be a real problem in the development and delivery of E-Commerce systems. There are many aspects of ethics that can affect E-Commerce systems, but often research is focused on the ethics after the E-Commerce system has been implemented, focusing on issues such as trust, privacy and disclosure. This paper will discuss how ethical matters can affect the design of E-Commerce systems and how a framework designed for E-Commerce can be used to create and deliver effective, ethical E-Commerce systems.
    Keywords design ; ecommerce ; ethics ; framework ; Information technology ; T58.5-58.64 ; Electronic computers. Computer science ; QA75.5-76.95
    Language English
    Publishing date 2003-05-01T00:00:00Z
    Publisher Australasian Association for Information Systems
    Document type Article ; Online
    Database BASE - Bielefeld Academic Search Engine (life sciences selection)

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  4. Article: From genome size to trait evolution during angiosperm radiation.

    Bhadra, Sreetama / Leitch, Ilia J / Onstein, Renske E

    Trends in genetics : TIG

    2023  Volume 39, Issue 10, Page(s) 728–735

    Abstract: Angiosperm diversity arises from trait flexibility and repeated evolutionary radiations, but the role of genomic characters in these radiations remains unclear. In this opinion article, we discuss how genome size can influence angiosperm diversification ... ...

    Abstract Angiosperm diversity arises from trait flexibility and repeated evolutionary radiations, but the role of genomic characters in these radiations remains unclear. In this opinion article, we discuss how genome size can influence angiosperm diversification via its intricate link with cell size, tissue packing, and physiological processes which, in turn, influence the macroevolution of functional traits. We propose that integrating genome size, functional traits, and phylogenetic data across a wide range of lineages allows us to test whether genome size decrease consistently leads to increased trait flexibility, while genome size increase constrains trait evolution. Combining theories from molecular biology, functional ecology and macroevolution, we provide a framework to better understand the role of genome size in trait evolution, evolutionary radiations, and the global distribution of angiosperms.
    MeSH term(s) Phylogeny ; Biological Evolution ; Magnoliopsida/genetics ; Genome Size ; Ecology
    Language English
    Publishing date 2023-08-14
    Publishing country England
    Document type Journal Article ; Review ; Research Support, Non-U.S. Gov't
    ZDB-ID 619240-3
    ISSN 1362-4555 ; 0168-9525 ; 0168-9479
    ISSN (online) 1362-4555
    ISSN 0168-9525 ; 0168-9479
    DOI 10.1016/j.tig.2023.07.006
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  5. Article ; Online: New Zealand needs a Practice Based Research Network.

    Leitch, Sharon

    Journal of primary health care

    2016  Volume 8, Issue 1, Page(s) 9–12

    Abstract: ... in research. Development of an e-participation platform will facilitate stakeholder engagement. New Zealand is ...

    Abstract Practice Based Research Networks (PBRNs) are groups of general practices collaborating to produce research. Contemporary New Zealand health information technology systems are ideal for electronic data extraction for PBRN research. Stakeholders have a valuable, but typically underutilised, part to play in research. Development of an e-participation platform will facilitate stakeholder engagement. New Zealand is in a unique position to create an innovative, low cost, stakeholder-engaged PBRN. This type of PBRN would offer unparalleled research opportunities, and would strengthen New Zealand's general practice research capacity. The more research information we have based on our New Zealand population, the more appropriate care we can provide. Establishing a stakeholder-engaged PBRN in New Zealand will promote and support transformational change within our health system.
    MeSH term(s) Electronic Health Records/organization & administration ; General Practice/organization & administration ; Health Services Research/economics ; Health Services Research/organization & administration ; Humans ; New Zealand
    Language English
    Publishing date 2016-03
    Publishing country Australia
    Document type Journal Article
    ISSN 1172-6156
    ISSN (online) 1172-6156
    DOI 10.1071/HC15045
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  6. Article ; Online: Gene-disease relationship evidence: A clinical perspective focusing on ultra-rare diseases.

    Santen, Gijs W E / Leitch, Harry G / Cobben, Jan

    Human mutation

    2022  Volume 43, Issue 8, Page(s) 1082–1088

    Abstract: The ACMG framework for variant interpretation is well-established and widely used. Although formal guidelines have been published on the establishment of the gene-disease relationships as well, these are not nearly as widely acknowledged or utilized, and ...

    Abstract The ACMG framework for variant interpretation is well-established and widely used. Although formal guidelines have been published on the establishment of the gene-disease relationships as well, these are not nearly as widely acknowledged or utilized, and implementation of these guidelines is lagging. In addition, for many genes so little information is available that the framework cannot be used in sufficient detail. In this manuscript, we highlight the importance of distinguishing between phenotype-first and genotype-first gene-disease relationships. We discuss the approaches currently available to establish gene-disease relationships and suggest a checklist to assist in evaluating gene-disease relationships for genes with very little available information. Several real-life examples from clinical practice are given to illustrate the importance of a thorough thought process on gene-disease relationships. We hope that these considerations and the checklist will provide help for clinicians and clinical scientists faced which variants in genes without robustly ascertained gene-disease relationships.
    MeSH term(s) Humans ; Phenotype ; Rare Diseases/diagnosis ; Rare Diseases/genetics
    Language English
    Publishing date 2022-03-24
    Publishing country United States
    Document type Journal Article
    ZDB-ID 1126646-6
    ISSN 1098-1004 ; 1059-7794
    ISSN (online) 1098-1004
    ISSN 1059-7794
    DOI 10.1002/humu.24367
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  7. Article ; Online: [No title information]

    Bolt, Robert R A / Raby-Buck, Sarah E / Ingram, Katharine / Leitch, Jamie A / Browne, Duncan L

    Angewandte Chemie (International ed. in English)

    2022  , Page(s) e202210508

    Abstract: The nickel catalyzed Suzuki-Miyaura-type coupling of aryl sulfamates and boronic acid derivatives enabled by temperature-controlled mechanochemistry via the development of a programmable PID-controlled jar heater is reported. This base-metal-catalyzed, ... ...

    Title translation Temperature-Controlled Mechanochemistry for the Nickel-Catalyzed Suzuki-Miyaura-Type Coupling of Aryl Sulfamates via Ball Milling and Twin-Screw Extrusion.
    Abstract The nickel catalyzed Suzuki-Miyaura-type coupling of aryl sulfamates and boronic acid derivatives enabled by temperature-controlled mechanochemistry via the development of a programmable PID-controlled jar heater is reported. This base-metal-catalyzed, solvent-free, all-under-air protocol was also scaled 200-fold using twin-screw extrusion technology affording decagram quantities of material.
    Language English
    Publishing date 2022-09-09
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202210508
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  8. Article ; Online: Beyond Bioisosteres: Divergent Synthesis of Azabicyclohexanes and Cyclobutenyl Amines from Bicyclobutanes.

    Dhake, Kushal / Woelk, Kyla J / Becica, Joseph / Un, Andy / Jenny, Sarah E / Leitch, David C

    Angewandte Chemie (International ed. in English)

    2022  Volume 61, Issue 27, Page(s) e202204719

    Abstract: The development of two divergent and complementary Lewis acid catalyzed additions of bicyclobutanes to imines is described. Microscale high-throughput experimentation was integral to the discovery and optimization of both reactions. N-arylimines undergo ... ...

    Abstract The development of two divergent and complementary Lewis acid catalyzed additions of bicyclobutanes to imines is described. Microscale high-throughput experimentation was integral to the discovery and optimization of both reactions. N-arylimines undergo formal (3+2) cycloaddition with bicyclobutanes to yield azabicyclo[2.1.1]hexanes in a single step; in contrast, N-alkylimines undergo an addition/elimination sequence to generate cyclobutenyl methanamine products with high diastereoselectivity. These new products contain a variety of synthetic handles for further elaboration, including many functional groups relevant to pharmaceutical synthesis. The divergent reactivity observed is attributed to differences in basicity and nucleophilicity of the nitrogen atom in a common carbocation intermediate, leading to either nucleophilic attack (N-aryl) or E1 elimination (N-alkyl).
    MeSH term(s) Amines ; Butanes/chemistry ; Cycloaddition Reaction ; Imines ; Lewis Acids ; Molecular Structure
    Chemical Substances Amines ; Butanes ; Imines ; Lewis Acids
    Language English
    Publishing date 2022-05-03
    Publishing country Germany
    Document type Journal Article
    ZDB-ID 2011836-3
    ISSN 1521-3773 ; 1433-7851
    ISSN (online) 1521-3773
    ISSN 1433-7851
    DOI 10.1002/anie.202204719
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  9. Article ; Online: Direct Heterocycle C-H Alkenylation via Dual Catalysis Using a Palladacycle Precatalyst: Multifactor Optimization and Scope Exploration Enabled by High-Throughput Experimentation.

    Pipaón Fernández, Nahiane / Cruise, Odhran / Easton, Sarah E F / Kaplan, Justin M / Woodard, John L / Hruszkewycz, Damian P / Leitch, David C

    The Journal of organic chemistry

    2024  

    Abstract: One of the major challenges in developing catalytic methods for C-C bond formation is the identification of generally applicable reaction conditions, particularly if multiple substrate structural classes are involved. Pd-catalyzed direct arylation ... ...

    Abstract One of the major challenges in developing catalytic methods for C-C bond formation is the identification of generally applicable reaction conditions, particularly if multiple substrate structural classes are involved. Pd-catalyzed direct arylation reactions are powerful transformations that enable direct functionalization of C-H bonds; however, the corresponding direct alkenylation reactions, using vinyl (pseudo) halide electrophiles, are less well developed. Inspired by process development efforts toward
    Language English
    Publishing date 2024-01-11
    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.3c02311
    Database MEDical Literature Analysis and Retrieval System OnLINE

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  10. Article ; Online: Mega-sized pericentromeric blocks of simple telomeric repeats and their variants reveal patterns of chromosome evolution in ancient Cycadales genomes.

    Vozárová, Radka / Wang, Wencai / Lunerová, Jana / Shao, Fengqing / Pellicer, Jaume / Leitch, Ilia J / Leitch, Andrew R / Kovařík, Aleš

    The Plant journal : for cell and molecular biology

    2022  Volume 112, Issue 3, Page(s) 646–663

    Abstract: ... sized blocks of telomeric repeats (i.e., billions of copies) were identified. Fluorescent in situ ...

    Abstract Simple telomeric repeats composed of six to seven iterating nucleotide units are important sequences typically found at the ends of chromosomes. Here we analyzed their abundance and homogeneity in 42 gymnosperm (29 newly sequenced), 29 angiosperm (one newly sequenced), and eight bryophytes using bioinformatics, conventional cytogenetic and molecular biology approaches to explore their diversity across land plants. We found more than 10 000-fold variation in the amounts of telomeric repeats among the investigated taxa. Repeat abundance was positively correlated with increasing intragenomic sequence heterogeneity and occurrence at non-telomeric positions, but there was no correlation with genome size. The highest abundance/heterogeneity was found in the gymnosperm genus Cycas (Cycadaceae), in which megabase-sized blocks of telomeric repeats (i.e., billions of copies) were identified. Fluorescent in situ hybridization experiments using variant-specific probes revealed canonical Arabidopsis-type telomeric TTTAGGG repeats at chromosome ends, while pericentromeric blocks comprised at least four major telomeric variants with decreasing abundance: TTTAGGG>TTCAGGG >TTTAAGG>TTCAAGG. Such a diversity of repeats was not found in the sister cycad family Zamiaceae or in any other species analyzed. Using immunocytochemistry, we showed that the pericentromeric blocks of telomeric repeats overlapped with histone H3 serine 10 phosphorylation signals. We show that species of Cycas have amplified their telomeric repeats in centromeric and telomeric positions on telocentric chromosomes to extraordinary high levels. The ancestral chromosome number reconstruction suggests their occurrence is unlikely to be the product of ancient Robertsonian chromosome fusions. We speculate as to how the observed chromosome dynamics may be associated with the diversification of cycads.
    MeSH term(s) In Situ Hybridization, Fluorescence ; Cycadopsida/genetics ; Telomere/genetics ; Centromere/genetics ; Magnoliopsida/genetics
    Language English
    Publishing date 2022-10-11
    Publishing country England
    Document type Journal Article ; Research Support, Non-U.S. Gov't
    ZDB-ID 1088037-9
    ISSN 1365-313X ; 0960-7412
    ISSN (online) 1365-313X
    ISSN 0960-7412
    DOI 10.1111/tpj.15969
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