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1

Biodegradation of polyethylene film in the presence of fungi and in soil

100%
Pajak J., Nowak B., Labuzek S.
Biotechnologia
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2003
|
issue 4
214-227
EN
The aim of the investigation was the biodegradation of low-density polyethylene (LDPE) film modified with Bionolle?. The samples in the form of composite films were prepared by homogenization and extrusion. The biodegradation process was performed in the laboratory scale or under environmental conditions. The examined films were placed into different media and incubated in the presence of fungi Aspergillus niger, Penicillium funiculosum and mixed fungi inoculum. Any changes in the various properties of the films after biodegradation were monitored by weight loss, optical and scanning electron microscopy and FTIR spectroscopy. The results of the study have proved that fungal growth on the polymer samples containing low amount of polyester depends on the presence of nutrients in media. Sucrose inhibited polymer disintegration more strongly than nutrient broth. FTIR analysis revealed that filamentous fungi biodegraded not only polyester, but also polyethylene. On the contrary, LDPE incubated in soil did not exhibit any chemical changes. This highly hydrophobic polymer was more susceptible to biodegradation only in the presence of Bionolle?.
2

Enzymes involved in polymer biodegradation

100%
Nowak B., Pajak J., Plociniczak T., Labuzek S.
Biotechnologia
|
2008
|
issue 1
45-52
EN
Most widely used plastics are considered to be resistant to environmental factors. Degradation of most popular packaging polymer is slow and may take hundreds of years. To enhance their environmental degradation a number of different approaches, among them copolymerisation or compounding with additives susceptible to environmental factors such as polyesters are used. Enzymes involved in decomposition of polyesters are mainly hydrolases f.ex. esterases, lipases, cutinases. Research team in the Department of Biochemistry is working on polyethylene and poly(ethylene terephtalate) films modified with synthetic aliphatic polyester Bionolle? and mechanisms of their biodegradation using fungal extracellular hydrolytic enzymes.
3

Villous trophoblast cell turnover in placentas from preterm pregnancy and pregnancy complicated by intrauterine growth restriction (IUGR)

100%
Zadrozna M., Nowak B., Marcinek A., Duc J.
Folia Biologica
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2010
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vol. 58
|
issue 1-2
79-83
EN
Disturbed trophoblast turnover, a key process in placental physiology, may lead to a number of pregnancy-associated pathologies. This study examines PCNA expression and describes and quantifies morphological changes during trophoblast turnover in preterm placentas and termplacentas complicated by IUGR. The number of CTF cells increased two-fold in preterm and IUGR placentas. A concurrent and slightly reduced proliferation rate of these cells was also found. The number of STF nuclei of terminal villi was lower by 21%in IUGR and by 18% in pretermplacentas (P>0.05). A statistically significant reduction of the number of syncytial knots by 50% as compared to the control placentas was observed. Correlations between PCNA-reactive CTF nuclei and syncytial knots, PCNA-reactive CTF nuclei and CCO activity, and CCO activity and syncytial knots were found. Moreover, a strong inverse relation was observed between syncytial knots and CTF cells, and CCO activity and CTF cells.
4

Synthetic modified polyethylene polymers and their biodegradation

100%
Labuzek S., Nowak B., Pajak J.
Biotechnologia
|
2003
|
issue 4
110-123
EN
In this paper, clasification of commercial polymer depending on their ability to biodegradation and factors which influence biodegradation processes are described. The examples of modification of polyethylene with natural and synthetic polymers are presented. On the basis of polyethylene films modified with starch and synthetic polyester, the methods of biodegradation processes are shown.
5
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An analytical model of a system with priorities servicing a mixture of different elastic traffic streams

89%
Nowak B., Piechowiak M., Stasiak M., Zwierzykowski P., Nowak B., Piechowiak M., Stasiak M., Zwierzykowski P.
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