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Resistance tests for Salmonella enteritidis in respect to ionizing radiations
Conference
399
Abstracts
Resistance Tests for Salmonella enteritidis in Respect to Ionizing Radiations* M. E. GUERZONI,’
M. A. CASADEI, B. ABDULLAH, P. G. FUOCHI and M. ADAM0
‘Dipartimento di Protezione
e Valorizzazione Via S. Giacomo
Agroalimentare, Universita 7, 40100 Bologna, Italy
G. MANFREDA, degli Studi di Bologna,
of SulmoneZluenteritidis to different irradiation doses. Two different experiments were performed on a S. enteritidis nalidixic acid-resistant strain, inoculated in deboned ground poultry meat packaged under vacuum and in ordinary atmosphere. The irradiation of the samples was performed by using a 12 MeV Dickers linear electron beam accelerator. The dosimetry was performed by using the “Super Fricke” chemical dosimeter. The samples were irradiated at doses of 1, 1.5, 2, 2.5 kGy. After the treatment both the irradiated and the unirradiated samples were stored at 2°C. It was possible to observe that the initial knocking down of cell number is not followed by any subsequent growth. Evidently S. enteritidis is not able to grow at 2°C at least for the period under consideration (18 days). The dose-effect curve was constructed and the DlO value was constructed as the reciprocal value of the curve slope. In most of the cases the DlO value was about 0.80. It means that 0.80 kGy are required in order to knock down the cell number of one logarithmic cycle. This experiment demonstrated the efficiency of ionizing treatments even at low doses (l-2 kGy). Another very important factor to be considered is the control of storage temperature.
The aim of the work was to verify the sensitivity
Radiation Grafting of Hydrophilic Monomers onto Polyphosphazenes and Assessment of the Biocompatibility of the Modified Samples M. CARENZA,’
S. LORA,’
G. PALMA,’
‘Istituto FRAE, C.N.R., Sezione di Legnaro, di Padova, Padova, Italy and ‘Dipartimento Farmaco e dei Prodotti Biologicamente
G. PEZZIN’
and
P. CALICET13
Padova, Italy, *Dipartimento di Chimica Fisica, Universita di Scienze Farmaceutiche, Centro di Studio di Chimica de1 Attivi, C.N.R., Universita di Padova, Padova, Italy
The paper summarizes recent work carried out in the authors’ laboratory on the radiation-induced graft copolymerization of hydrophilic monomers onto polyphosphazenes. Kinetics of grafting by the mutual irradiation method at room temperature of the pure monomers and of the monomer-methanol mixtures were followed. Hydrophilicity, structure, mechanical properties, biocompatibility and anticoagulating properties of the modified samples were assayed. Some experiments on the grafted polymer, to which heparin was ionically bonded with a high yield, were also carried out.
Compatibilization of Polyethylene/Polyamide Blends Through Gamma-radiation G. SPADARO,’
E. CALDERARO’
and
6
A. VALENZA’
‘Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universiti di Palermo, Viale delle Scienze, 90128 Palermo, Italy and rDipartimento di Ingegneria Nucleare, Universita di Palermo, Viale delle Scienze, 90128 Palermo, Italy
In this work the use of gamma-radiation in air in order to insert reactive groups in a polymer for functionalized blends is presented. In particular, two different polyethylenes (a low density and a linear low density) were irradiated in air at various integrated doses and dose rates, and then blended with a polyamide 6. The molecular behaviours of irradiated polyethylenes were studied by means of gel extraction and i.r. analysis.
*The research
has been performed
by the financial
support
ENEA No. 644/90-O.
399
Abstracts
Resistance Tests for Salmonella enteritidis in Respect to Ionizing Radiations* M. E. GUERZONI,’
M. A. CASADEI, B. ABDULLAH, P. G. FUOCHI and M. ADAM0
‘Dipartimento di Protezione
e Valorizzazione Via S. Giacomo
Agroalimentare, Universita 7, 40100 Bologna, Italy
G. MANFREDA, degli Studi di Bologna,
of SulmoneZluenteritidis to different irradiation doses. Two different experiments were performed on a S. enteritidis nalidixic acid-resistant strain, inoculated in deboned ground poultry meat packaged under vacuum and in ordinary atmosphere. The irradiation of the samples was performed by using a 12 MeV Dickers linear electron beam accelerator. The dosimetry was performed by using the “Super Fricke” chemical dosimeter. The samples were irradiated at doses of 1, 1.5, 2, 2.5 kGy. After the treatment both the irradiated and the unirradiated samples were stored at 2°C. It was possible to observe that the initial knocking down of cell number is not followed by any subsequent growth. Evidently S. enteritidis is not able to grow at 2°C at least for the period under consideration (18 days). The dose-effect curve was constructed and the DlO value was constructed as the reciprocal value of the curve slope. In most of the cases the DlO value was about 0.80. It means that 0.80 kGy are required in order to knock down the cell number of one logarithmic cycle. This experiment demonstrated the efficiency of ionizing treatments even at low doses (l-2 kGy). Another very important factor to be considered is the control of storage temperature.
The aim of the work was to verify the sensitivity
Radiation Grafting of Hydrophilic Monomers onto Polyphosphazenes and Assessment of the Biocompatibility of the Modified Samples M. CARENZA,’
S. LORA,’
G. PALMA,’
‘Istituto FRAE, C.N.R., Sezione di Legnaro, di Padova, Padova, Italy and ‘Dipartimento Farmaco e dei Prodotti Biologicamente
G. PEZZIN’
and
P. CALICET13
Padova, Italy, *Dipartimento di Chimica Fisica, Universita di Scienze Farmaceutiche, Centro di Studio di Chimica de1 Attivi, C.N.R., Universita di Padova, Padova, Italy
The paper summarizes recent work carried out in the authors’ laboratory on the radiation-induced graft copolymerization of hydrophilic monomers onto polyphosphazenes. Kinetics of grafting by the mutual irradiation method at room temperature of the pure monomers and of the monomer-methanol mixtures were followed. Hydrophilicity, structure, mechanical properties, biocompatibility and anticoagulating properties of the modified samples were assayed. Some experiments on the grafted polymer, to which heparin was ionically bonded with a high yield, were also carried out.
Compatibilization of Polyethylene/Polyamide Blends Through Gamma-radiation G. SPADARO,’
E. CALDERARO’
and
6
A. VALENZA’
‘Dipartimento di Ingegneria Chimica dei Processi e dei Materiali, Universiti di Palermo, Viale delle Scienze, 90128 Palermo, Italy and rDipartimento di Ingegneria Nucleare, Universita di Palermo, Viale delle Scienze, 90128 Palermo, Italy
In this work the use of gamma-radiation in air in order to insert reactive groups in a polymer for functionalized blends is presented. In particular, two different polyethylenes (a low density and a linear low density) were irradiated in air at various integrated doses and dose rates, and then blended with a polyamide 6. The molecular behaviours of irradiated polyethylenes were studied by means of gel extraction and i.r. analysis.
*The research
has been performed
by the financial
support
ENEA No. 644/90-O.