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Number of results: 12
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Abstract

The electromagnetic field (EMF) is an environmental factor affecting living organisms. The aim of this study was to demonstrate the effect of an extremely low frequency electro- magnetic field (ELF-EMF) on selected chemical components of the honeybee (Apis mellifera L.) using Fourier Transform Infrared (FTIR) spectroscopy. The FTIR method provides information on the chemical structure of compounds through identification and analysis of functional groups. The honeybees were treated with EMF at a frequency of 50 Hz and magnetic induction of 1.6 mT for 2, 6, 12, 24 and 48 hours. Analysis of FTIR spectra showed that EMF exposure longer than 2 hours induced changes in the structure of chemical compounds, especially in the IR region corresponding to DNA, RNA, phospholipids and protein vibrations, compared to control samples (bees not EMF treated). The results confirm the effect of EMF on bees depending on the duration of exposure.

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Authors and Affiliations

A. Koziorowska
J. Depciuch
J. Białek
I. Woś
K. Kozioł
S. Sadło
B. Piechowicz
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Abstract

The presented results describe the effect of severe plastic deformation on the structure and mechanical properties of AA5083 and AA5754 alloys. Both materials were subjected to single hydrostatic extrusion (HE) and cumulative hydrostatic extrusion in the case of AA5083 and a combination of plastic deformation by equal-channel angular pressing (ECAP) with the next HE for AA5754. After the deformation, both alloys featured a homogeneous and finely divided microstructure with average grain size deq = 140 nm and 125 nm for AA5083 and AA5754, respectively. The selection of plastic forming parameters enabled a significant increase in the UTS tensile strength and YS yield stress in both alloys – UTS =  510 MPa and YS = 500 MPa for alloy AA5083 after cumulative HE, and 450 MPa and 440 MPa for alloy AA5754 after the combination of ECAP and HE, respectively. It has been shown on the example of AA5083 alloy that after the deformation the threads of the fasteners made of this material are more accurate and workable at lower cutting speeds, which saves the cutting tools. The resultant properties of AA5083 and AA5754 alloys match the minimum requirements for the strongest Al-Zn alloys of the 7xxx series, which, however, due to the considerably lower corrosion resistance, can be replaced in many responsible structures by the AA5xxx series Al-Mg alloys presented in this paper.

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Authors and Affiliations

M. Kulczyk
J. Skiba
W. Pachla
J. Smalc-Koziorowska
S. Przybysz
M. Przybysz
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Abstract

The research presented in this paper concerns the influence of the rate of plastic deformation generated directly in the processes of severe plastic deformations on the microstructure and properties of three metals: copper, iron and zinc. The equal channel angular pressing (ECAP) method was used, and it was performed at a low plastic deformation rate of ∼ 0.04 s−1. The high plastic strain rate was obtained using the hydrostatic extrusion (HE) method with the deformation rate at the level of ∼ 170 s−1. For all three tested materials different characteristic effects were demonstrated at the applied deformation rates. The smallest differences in the mechanical properties were observed in copper, despite the dynamic recrystallization processes that occurred in the HE process. In Armco iron samples, dynamic recovery processes in the range of high plastic deformation rates resulted in lower mechanical properties. The most significant effects were obtained for pure zinc, where, regardless of the method used, the microstructure was clearly transformed into bimodal after the ECAP process, and homogenized and refined after the HE process. After the HE process, the material was transformed from a brittle state to a plastic state and the highest mechanical properties were obtained.
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Authors and Affiliations

Mariusz Kulczyk
1
ORCID: ORCID
Monika Skorupska
1
Jacek Skiba
1
Sylwia Przybysz
1
Julita Smalc-Koziorowska
1

  1. Institute of High Pressure Physics of the Polish Academy of Sciences UNIPRESS, Sokołowska 29/37, 01-142 Warsaw, Poland
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Abstract

Mature males of a wild boar-pig crossbreed, during the long and short day season, were used for the study which demonstrates that the chemical light carrier CO regulates the expression of biological clock genes in the hypothalamus via humoral pathways. Autologous blood with experimentally elevated concentrations of endogenous CO (using lamps with white light-emitting diodes) was infused into the ophthalmic venous sinus via the right dorsal nasal vein. Molecular biology methods: qPCR and Western Blot were used to determine the expression of genes and biological clock proteins. The results showed that elevated endogenous CO levels, through blood irradiation, induces changes in genes expression involved in the functioning of the main biological clock located in suprachiasmatic nuclei. Changes in the expression of the transcription factors Bmal1, Clock and Npas2 have a similar pattern in both structures, where a very large decrease in gene expression was shown after exposure to elevated endogenous CO levels. The changes in the gene expression of PER 1-2, CRY 1-2, and REV-ERB α-β and ROR β are not the same for both POA and DH hypothalamic structures, indicating that both structures respond differently to the humoral signal received.
The results indicate that CO is a chemical light molecule whose production in an organism depends on the amount of light. An adequate amount of light is an essential factor for the proper functioning of the main biological clock.
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Authors and Affiliations

P. Gilun
1
M. Koziorowska-Gilun
2
B. Wąsowska
1
M. Sowa-Kućma
3
K. Kozioł
4
M. Romerowicz-Misielak
4
W. Kordan
2
M. Koziorowski
4

  1. Department of Local Physiological Regulations, Institute of Animal Reproduction and Food Research of the Polish Academy of Sciences in Olsztyn, Tuwima 10, 10-748, Olsztyn, Poland
  2. Department of Animal Biochemistry and Biotechnology, Faculty of Animal Bioengineering, University of Warmia and Mazury, Oczapowskiego 5, 10-719 Olsztyn, Poland
  3. Department of Human Physiology, Institute of Medical Sciences, Medical College of Rzeszow University, Kopisto 2a, Rzeszow, 35-959, Poland
  4. Department of Animal Physiology and Reproduction, Institute of Biology and Biotechnology, Collegium Scientarium Naturalium, University of Rzeszow, Werynia 502, 36-100 Kolbuszowa, Poland
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Abstract

A field trial on the transfer of pyrimethanil, cyprodinil and cyflufenamid residues from apple trees of Idared cultivar to hives by honeybees Apis mellifera was carried out. Two days after spraying (Faban 500 SC and Kendo 50 EW), and on the day of spraying (Chorus 50 WG), the quantities of residues on leaves and flowers of apple trees and pollen were as follows: pyrimethanil: 1.45 μg per cm2 of leaves, 11.51 μg per single flower and 7.18 μg · g −1 of pollen, cyprodinil:1.35, 8.64 and 7.94 μg, and cyflufenamid: 0.064, 0.266 and 0.11 μg, respectively. All of them subsequently disappeared exponentially. Two days after, and on the day of spraying, pyrimethanil (1.81 μg · g −1), cyprodinil (up to 0.55 μg · g −1) and cyflufenamid (0.04 μg · g −1) were found in worker bees. Residues of all used chemicals were found in the brood, honey and wax samples. The residues of pyrimethanil, cyprodinil and cyflufenamid in worker bees exceeded the level of 0.2% of the LD50, which indicates that their application rates (doses) are safe for the honey bee.
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Authors and Affiliations

Bartosz Piechowicz
1 2
ORCID: ORCID
Aleksandra Kuliga
1
Damian Kobylarz
1
Anna Koziorowska
2 3
ORCID: ORCID
Lech Zaręba
4
ORCID: ORCID
Magdalena Podbielska
1
ORCID: ORCID
Iwona Piechowicz
5
Stanisław Sadło
6

  1. Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszów, Poland
  2. Interdisciplinary Center for Preclinical and Clinical Research, University of Rzeszów, Poland
  3. Institute of Material Engineering, College of Natural Sciences, University of Rzeszów, Poland
  4. Interdisciplinary Centre for Computational Modelling, College of Natural Sciences, University of Rzeszów, Poland
  5. Independent researcher, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszów, Poland
  6. Professor retired, Institute of Biology and Biotechnology, College of Natural Sciences, University of Rzeszów, Poland

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