7. Biological Effectiveness of 12 C and 20 Ne Ions with Very High LET

Knowledge of radiobiological effects of heavy ions at the cellular and molecular level is of fundamental importance in the field of radiation therapy (for example C ions) and space radiation biology (for example Ne ions). One of the issues that require deeper investigations is a determination of RBE values for a wide range of LET, for all relevant doses, for many cell types and various kinds of radiations During recent years, the biological effectiveness of heavy ions has been widely investigated with the aim to identify physical characteristics relevant to biological actions. These investigations are pertinent to the use of heavy ions in radiosurgery and radiotherapy. What has not been investigated so thoroughly is the biological effectiveness of heavy ions at low energies and very high LET values. The LET, which is equal to the stopping power of heavy particles, increases sharply at the end of the particle's path, forming a so-called Bragg peak. The shape of the Bragg peak depends on the particle type. Because overlying beams with different energies and components of primary and secondary particles are used in radiotherapy, the knowledge of RBE values of very high LET radiation need to be well characterized. An experimental set-up designed for such investigations was constructed at the isochronic cyclotron in Heavy Ion Laboratory. A more detailed description of the set-up can be found in Ref. CHO-K1 cells have been used as a suitable biological system for our studies. The cell line is characterized by genetic stability, the ability to form colonies, a relatively rapid growth rate with a cell cycle of 12-14 hours. For exposure to ions the cells were seeded in specially designed Petri dishes, which were filled with medium, sealed by a parafilm cover and placed in a vertical sample holder mounted in an x-y-z table that was connected to a special stepping motor. The irradiated sample moved under the beam according to a planned route. Movement was initiated when the number of counts detected by the 20 o particle detector reached the preset value. When all fields have been exposed the sample holder returned to the start position. Stored information enabled to evaluate the beam stability and intensity. The whole set-up was surveyed by a digital camera. The total time of exposure per dish was between 1-5 min. depending on the dose and beam intensity. The dose rates were changed from 0.05 Gy/min. to 1 Gy/min depending on the dose. Cell survival was estimated according to standard procedure

Zastosowanie liniowych sieci neuronowych w wycenie nieruchomości – możliwości aplikacyjne

Transactional price is the result of some kind of free market game, and of independent decisions taken by the parties to the transaction. Prices depend on a number of factors, specific to the local real estate market. The impact of some factors is fixed, while others are dependent on the location of the property. Therefore, research into the determination of rules that would describe the relationship between the market price of the real estate, and its market characteristics, remain valid. The article presents the possibilities of applying linear artificial neural networks to real estate valuation. Using a database, the artificial linear neural network is developing a regression model, which produces the results that oscillate close to the market value of the property. The necessary condition is the creation of a database that is representative of the given real estate market.Cena transakcyjna to wynik pewnego rodzaju gry rynkowej oraz suwerennych decyzji podejmowanych przez strony transakcji. Ceny uzależnione są od szeregu czynników charakterystycznych dla danego lokalnego rynku nieruchomości. Wpływ pewnych czynników jest niezmienny, inne zaś zależne są od lokalizacji nieruchomości. Dlatego badania nad określeniem reguł opisujących zależność pomiędzy ceną rynkową nieruchomości a jej cechami rynkowymi są wciąż aktualne. Artykuł przedstawia możliwości aplikacyjne sztucznych liniowych sieci neuronowych w wycenie nieruchomości. Sztuczna liniowa sieć neuronowa na podstawie bazy danych, opracowuje model regresyjny uzyskujący wyniki oscylujące w pobliżu rynkowej wartości nieruchomości. Warunkiem koniecznym jest utworzenie bazy danych, reprezentatywnej dla danego rynku nieruchomości

Infrastructural investments as a factor which determines the location of storage facilities

Implementation of infrastructural investments is a key factor contributing to the development potential of a region. The current law in force, regulating the implementation of infrastructural public purpose investments, simplifies the actions leading to terrain acquisition for road investments. The research shows a significant dependence between access to public roads and demand for storage facilities. From an entrepreneur’s point of view, the necessary condition for further development is implementation of infrastructural investments. Locating the investments in the vicinity of traffic routes is a strategic decision, closely related to the field of business. Too long distances combined with poor condition of road infrastructure generate additional transport costs. This fact is directly reflected in the limited economic and development potential of particular regions. In the studied case, the theoretical value of statistics (27.868) is almost a half of the calculated value (54.27). Therefore, the null hypothesis is rejected. Calculations carried out at assumed significance level α = 0.0005, clearly prove, that there is a close correlation between the size of the company, and the choice of the location of the additional storage space with regard to access to infrastructure such as public roads. The carried out analysis confirms the fact, that the enterprise size is directly linked with the selection of location for its additional storage facilities and the transport costs between the locations significantly influence the decisions

Application of cyanobacteria as biocatalysts for the reduction of diethy-l2-oxopropylphosphonate

Celem przeprowadzonych badań było zastosowanie mikroorganizmów fotoautotroficznych jako biokatalizatora w redukcji -ketoalkilofosfonianu dietylu. Przeprowadzone badania przesiewowe wskazały szczepy cyjanobakterii Arthrospira maxima CCALA 027 oraz Nodularia sphaerocarpa CCALA 114 jako zdolne do redukcji 2-oksopropanofosfonianu dietylu do odpowiedniego 2-hydroksypropanofosfonianu dietylu. W trakcie 7-dniowego procesu biokonwersji stopień przereagowania substratu w przypadku zastosowania wymienionych szczepów wynosił odpowiednio 26,4% oraz 12,9%, zaś czystość optyczna produktu w obu przypadkach wyniosła ponad 99%.The aim of the study was applying of autotrophic microorganisms as a biocatalyst in the reduction of oxoalkylphosphonates. Cyanobacteria strains Arthrospira maxima CCALA 027 and Nodularia sphaerocarpa CCALA 114 are capable to reduce diethyl 2- oxopropylphosphonate to the corresponding diethyl 2- hydroxypropylphosphonate. The degree of conversion of the substrate was respectively 26.4% and 12.9%, and the optical purity of the product in both cases was over 99%

Modification of Chitin Particles with Ionic Liquids Containing Ethyl Substituent in a Cation

Chitin cannot be dissolved in conventional solvents due to the strong inter- and intrasheet network of hydrogen bonds and the large number of crystalline regions. Some ionic liquids (ILs) have been suggested in the literature as possible solvents for chitin. Seven of them, all having an ethyl group as substituent in the cationic ring, have been tested in this work: [Emim][Cl], [Emim][Br], [Emim][I], [Emim][OAc], [Emim][Lact], [Epyr][I], and [EMS][BFSI]. Chitin was insoluble in [EMS][BFSI] while for all other ILs solubility was limited due to high viscosity of solutions and equilibria have not been reached. Changes in physical structure, particle size distribution, and crystallinity of recovered chitin depended on ionic liquid used. Increase in porosity was observed for chitin treated with [Emim][Cl], [Emim][I], [Emim][Br], and [Emim][Lact]; changes in particle size distribution were observed for [Emim][AcOH] and [EMS][BFSI]; increase in crystallinity was noticed for chitin treated with [Epyr][I] while decrease in crystallinity for [Emim][I] was noticed. All tested ionic liquids were reused four times and changes in FTIR spectra could be observed for each IL

Biocatalitic Transformation of epoxy- and vinylphosphonates

Przedmiotem badań była selektywna transformacja dwóch grup związków fosforoorganicznych epoksy- oraz winylofosfonianów do odpowiednich pochodnych, z wykorzystaniem całych komórek bakterii lub grzybów. Aktywność hydrolityczną względem modelowego epoksyfosfonianu wykazywał tylko szczep Aspergillus niger, podczas gdy szczepy Cladosporium herbarum oraz Fusarium oxysporum zdolne były do degradacji trwałego wiązania C-P w winylofosfonianach, w zadanych warunkach procesu.The subject of research was the selective transformation of the two groups of organophosphorus compounds, epoxy- and vinylphosphonates, to the corresponding derivatives, using whole cells of bacteria or fungi. Hydrolytic activity towards model epoxphosphonate was observed only in the case of Aspergillus niger, whereas Cladosporium herbarum and Fusarium oxysporum were able to degrade stable C-P bond in vinylphosphonates, under defined experimental conditions

Partitioning of cerrena unicolor laccase activity in an aqueous two-phase system

Culture supernatant containing laccase produced by Cerrena unicolor strain was used to examine laccase partitioning between phases in an aqueous two-phase system. The investigated system consisted of polyethylene glycol 3000 and sodium phosphate buffer adjusted to pH = 7. Influence of several parameters on partitioning was measured, including phase forming components’ concentrations, tie line lengths, phase volume ratio, supernatant dilution, process temperature and halogen salt supplementation. Partitioning coefficients up to 78 in the bottom phase were achieved with yields of over 90%. Tie line length and phase volume ratio had significant effect on enzyme partitioning

Laccase concentration by foam fractionation of Cerrena unicolor and Pleurotus sapidus culture supernatants

Foam fractionation process for concentration of laccases from two Basidiomycete strains under different process conditions was investigated. Culture supernatants of Cerrena unicolor and Pleurotus sapidus containing active laccase were used with and without surfactant additives. Two surfactants: cationic cetrimonium bromide (CTAB) and non-ionic Polysorbate 80 were applied in the range from 0.2 mM to 1.5 mM. The pH levels ranging from 3 to 10 were examined with particular attention to pH=4, which is close to the pI of the enzymes. Results show that the source of the enzyme is significant in terms of partitioning efficiency in a foam fractionation process. Laccase from Cerrena unicolor showed the best activity partitioning coefficients between foamate and retentate of almost 200 with yields reaching 50% for pH 7.5 and concentration of CTAB cCTAB = 0.5 mM, whereas laccase from Pleurotus sapidus showed partitioning coefficients of up to 8 with 25% yield for pH 4 and cCTAB = 0.5 mM