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- Cowan, David, et al.
(författare)
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REFRIGERANT LEAKAGE AND CONTAINMENT - OVERVIEW OF THE ACTIVITIES OF THE IIR WORKING PARTY ON MITIGATION OF DIRECT EMISSIONS OF GREENHOUSE GASES IN REFRIGERATION
- 2011
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Ingår i: 23RD IIR INTERNATIONAL CONGRESS OF REFRIGERATION. - : INT INST REFRIGERATION. - 9782913149885 ; , s. 3833-
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Konferensbidrag (refereegranskat)abstract
- In recent years Global emissions due to leakage of F-Gases from refrigeration and air conditioning equipment have continued to increase as HCFC and CFC refrigerants are replaced by non-ozone depleting, but higher GWP, HFC refrigerants. Although lower GWP HFO and natural refrigerants such as CO2, ammonia and hydrocarbons are increasingly used in new system designs, the upward trend in the use of HFC refrigerant and consequent emissions are likely to continue for some years in the future. The environmental damage caused by direct emissions from escape of refrigerant can be 30% or more of the total environmental impact of a RAC system. However, effective mitigation measures can reduce this significantly, to the extent that the total equivalent warming impact (TEWI) of systems containing high GWP refrigerants can be similar to (or even lower than) systems containing lower GWP refrigerants. Mitigation measures can take several forms including legislative, fiscal, the use of alternative technologies and refrigerants, improvements in design and work practices and skills training. The IIR has set up a Working Party to research, collate and disseminate information on such mitigation measures. This will be made available via the FRIDOC database. The objectives and progress against these objectives are described in this paper.
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| 2. |
- Rydevik, Axel, 1984-
(författare)
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Drug Metabolites Formed by Cunninghamella Fungi : Mass Spectrometric Characterization and Production for use in Doping Control
- 2014
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This thesis describes the in vitro production of drug metabolites using fungi of the Cunninghamella species. The metabolites were characterized with mainly liquid chromatography-mass spectrometry using ion-trap and quadrupole-time-of-flight instruments. A fungal in vitro model has several advantages e.g., it is easily up-scaled and ethical problems associated with animal-based models are avoided.The metabolism of bupivacaine and the selective androgen receptor modulators (SARMs) S1, S4 and S24 by the fungi Cunninghamella elegans and Cunninghamella blakesleeana was investigated. The detected metabolites were compared with those formed in vitro and in vivo by human and horse and most phase I metabolites formed by mammals were also formed by the fungi. The higher levels of bupivacaine metabolites in the fungal samples allowed an extensive mass spectrometric structural characterization which shows that the fungi are relevant metabolic models.Glucuronides are important drug metabolites but they are difficult to synthesize. The discovery that the fungus Cunninghamella elegans formed large amounts of glucosides led to the idea that they could be used to form glucuronides. A new concept was developed where a fungal incubate containing a SARM S1 glucoside was mixed with the free radical tetramethylpiperidinyl-1-oxy (TEMPO), sodium bromide and sodium hypochlorite which produced a glucuronide. Isolation and characterization by nuclear magnetic resonance spectroscopy proved that the new method could produce glucuronides for use as reference material.An investigation of reactive metabolite formation of the drugs paracetamol, mefenamic acid and diclofenac by the fungus Cunninghamella elegans was performed. It was demonstrated for the first time that the fungus could produce glutathione, glutathione ethyl-ester, cysteine and N-acetylcysteine conjugates that are indicative of a preceding formation of reactive intermediates. A comparison with conjugates formed by human liver microsomes showed that both models formed identical metabolites.The presented investigations prove that Cunninghamella fungi are relevant drug metabolism models. They show that the fungi to a large extent forms the same metabolites as mammals and that they can produce metabolites for use as reference material in, e.g. doping control. It was also demonstrated that the fungal model can be used in the important assessment of drug toxicity.
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