Cyclododecane exposure in the field of conservation and restoration of art objects

PURPOSE: Recent work practices in the conservation and restoration involve the use of cyclododecane (CDD, CAS 294-62-2) to protect fragile artifacts during their handling or transportation. Little is known about its toxicity, and no previous exposure has been reported. A short field investigation was conducted to characterize the exposure conditions to both CDD vapors and aerosols.METHODS: Measurements were conducted in the laboratory of conservation and restoration of the archeological service in Bern (Switzerland). Three indoor and four outdoor typical work situations, either during brush or spray gun applications, were investigated. Measurements were performed on charcoal adsorbent tube and analyzed by a gas chromatograph equipped with a flame ionization detector.RESULTS: Measurements have been conducted during both brush and spray gun applications. Indoor exposures were of 0.75-15.5 mg/m(3), while outdoors exposures were 19.5-53.9 mg/m(3). Exposures appear to be extremely localized due to both physicochemical properties and application methods of the CDD. Vapor exposure increases dramatically with the confinement of the workplace.CONCLUSION: Preventive measures should be undertaken to limit as much as possible these exposures. Field work in confined areas (ditches, underground) is of particular concern. CDD-coated artifacts or materials should be stored in ventilated areas to avoid delayed exposures. [Authors]]]> Air Pollutants, Occupational ; Cyclododecanes ; Art ; Inhalation Exposure ; Occupational Exposure ; Environmental Monitoring ; Occupational Diseases ; Volatilization ; eng https://serval.unil.ch/resource/serval:BIB_7CBB5E92B108.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_7CBB5E92B1080 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_7CBB5E92B1080 info:eu-repo/semantics/acceptedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_7C9FD57E2554 2023-07-29T01:28:22Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_7C9FD57E2554 L’appréciation des engagements des entreprises participantes à une concentration d’entreprises : L’exemple de Sunrise/Liberty Global et de CFF/Hupac/Rethmann/GBN Canapa, Damiano info:eu-repo/semantics/bookPart incollection 2021-12-02 Nouveaux développement en matière de concentrations et d’accords de durabilité fre https://serval.unil.ch/resource/serval:BIB_7C9FD57E2554.P001/REF.pdf http://nbn-resolving.org/urn/resolver.pl?urn=urn:nbn:ch:serval-BIB_7C9FD57E25547 info:eu-repo/semantics/altIdentifier/urn/urn:nbn:ch:serval-BIB_7C9FD57E25547 info:eu-repo/semantics/publishedVersion info:eu-repo/semantics/openAccess Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_7CA098000546 2023-07-29T01:28:22Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_7CA098000546 Création et fonctionnement du service d'analgésie épidurale à la maternité du Centre Hospitalier Universitaire Vaudois à Lausanne Couchepin, Georges-Claude Université de Lausanne, Faculté de médecine info:eu-repo/semantics/doctoralThesis phdthesis 1983 fre https://serval.unil.ch/resource/serval:BIB_7CA098000546.P001/REF.pdf info:eu-repo/semantics/restrictedAccess Restricted: indefinite embargo Copying allowed only for non-profit organizations https://serval.unil.ch/disclaimer application/pdf oai:serval.unil.ch:BIB_7CA0FE232298 2023-07-29T01:28:22Z <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_7CA0FE232298 Les allergies oculaires Guex-Crosier, Y. info:eu-repo/semantics/bookPart incollection 2009 Le guide suisse des allergies 2009-2010, pp. 94-96 Hofer, M. (ed.) fre oai:serval.unil.ch:BIB_7CA24711D1A5 2023-07-29T01:28:22Z openaire documents urnserval <oai_dc:dc xmlns:dc="http://purl.org/dc/elements/1.1/" xmlns:xs="http://www.w3.org/2001/XMLSchema" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:oai_dc="http://www.openarchives.org/OAI/2.0/oai_dc/" xsi:schemaLocation="http://www.openarchives.org/OAI/2.0/oai_dc/ http://www.openarchives.org/OAI/2.0/oai_dc.xsd"> https://serval.unil.ch/notice/serval:BIB_7CA24711D1A5 Ribose-Binding Protein Mutants With Improved Interaction Towards the Non-natural Ligand 1,3-Cyclohexanediol. info:doi:10.3389/fbioe.2021.705534 info:eu-repo/semantics/altIdentifier/doi/10.3389/fbioe.2021.705534 info:eu-repo/semantics/altIdentifier/pmid/34368100 Tavares, D. van der Meer, J.R. info:eu-repo/semantics/article article 2021 Frontiers in bioengineering and biotechnology, vol. 9, pp. 705534 info:eu-repo/semantics/altIdentifier/pissn/2296-4185 urn:issn:2296-4185 <![CDATA[Bioreporters consist of genetically modified living organisms that respond to the presence of target chemical compounds by production of an easily measurable signal. The central element in a bioreporter is a sensory protein or aptamer, which, upon ligand binding, modifies expression of the reporter signal protein. A variety of naturally occurring or modified versions of sensory elements has been exploited, but it has proven to be challenging to generate elements that recognize non-natural ligands. Bacterial periplasmic binding proteins have been proposed as a general scaffold to design receptor proteins for non-natural ligands, but despite various efforts, with only limited success. Here, we show how combinations of randomized mutagenesis and reporter screening improved the performance of a set of mutants in the ribose binding protein (RbsB) of Escherichia coli, which had been designed based on computational simulations to bind the non-natural ligand 1,3-cyclohexanediol (13CHD). Randomized mutant libraries were constructed that used the initially designed mutants as scaffolds, which were cloned in an appropriate E. coli bioreporter system and screened for improved induction of the GFPmut2 reporter fluorescence in presence of 1,3-cyclohexanediol. Multiple rounds of library screening, sorting, renewed mutagenesis and screening resulted in 4.5-fold improvement of the response to 1,3-cyclohexanediol and a lower detection limit of 0.25 mM. All observed mutations except one were located outside the direct ligand-binding pocket, suggesting they were compensatory and helping protein folding or functional behavior other than interaction with the ligand. Our results thus demonstrate that combinations of ligand-binding-pocket redesign and randomized mutagenesis can indeed lead to the selection and recovery of periplasmic-binding protein mutants with non-natural compound recognition. However, current lack of understanding of the intermolecular movement and ligand-binding in periplasmic binding proteins such as RbsB are limiting the rational production of further and better sensory mutants