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Publikacje z roku 2013

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  • The cytokine profile of mature milk from smoking and non-smoking mothers
    • Agnieszka Szlagatys-Sidorkiewicz
    • Ewa Woś
    • Ewa Aleksandrowicz
    • Grazyna Łuczak
    • Dorota Martysiak-Żurowska
    • Maciej Zagierski
    • Krzysztof Marek
    • Barbara Kamińska
    2013 JOURNAL OF PEDIATRIC GASTROENTEROLOGY AND NUTRITION

    Zweryfikowano wpływ palenia kobiet na poziom cytokin (IL-1α, IL-1β, IL-6, IL-8, IL-10 i TNF-α) w mleku ludzkim w 30-32 dni po porodzie. Badana grupa składała się z 24 kobiet po porodzie, które deklarowały palenie więcej niż pięciu papierosów dziennie. Grupę kontrolną stanowiło 45 niepalących kobiet. W porównaniu do kobiet niepalących w mleku kobiet palących stwierdzono znacznie wyższe stężenia cytokiny IL-1α (P = 0,04). Nie stwierdzono istotnych różnic między zawartością pozostałych analizowanych cytokin w mleku kobiet z obu obserwowanych grup.

  • The determinants of the Region's and its SMEs' Competitive Position in the Context of Mega Events - the Case of the Euro 2012
    • Julita Wasilczuk
    • Krystian Zawadzki
    2013 Pełny tekst Przedsiębiorstwo we współczesnej gospodarce - teoria i praktyka

    In this paper a modified Preuss model was used to assess the factors to enhance the competitiveness of the region and the SMEs located in the region. To accomplish the above, six types of event-structure were applied: infrastructure, knowledge, networks, culture, image and emotions. They were described in detail in reference to the case of Euro 2012 in Poland in general and Pomeranian region in particular. Finally the Authors take the attempt to describe the connection between the determinants and the possible competitive position of region and its SMEs.

  • The differential impact of a density of Polish pine wood on cutting forces with its origin region taken into consideration
    • Daniel Chuchała
    • Kazimierz Orłowski
    • Anna Sandak
    • Jakub Sandak
    2013 Pełny tekst Annals of WULS, Forestry and Wood Technology

    In the article the dependence of cutting forces in a function the density of wood with regard to the wood origin are presented. Samples used in experiment were with Scotch pine (Pinus sylvestris L.) originating from four provenances in Poland (Figure 1). Wood density was measured by two methods: stereometric method (global density) and radiometric method (local density). Stereometric method consists in measurements the volume of the sample by determination of the various dimensions (length, width, height), and weighting of the sample mass. Estimation of the local density was after experiments of cutting using a non-destructive methods of radiometric developed IVALSA \ CNR. Measurement of cutting forces made during the empirical cutting a samples of wood on the saw frame PRW15M.

  • The Education of Analytical Chemists in Polish Universities
    • Marek Biziuk
    • Jacek Namieśnik
    2013

    Analytical Chemistry plays a very important role in the modern world. The main reasons are; the need of environmental monitoring, quality of food and water control, human health, quality of industrial production control, nanotechnologies and material science. Together with Inorganic Chemistry, Organic Chemistry and Physical Chemistry, Analytical Chemistry is a fundamental chemical course. The education of Analytical Chemists is carried out in 52 Polish universities introduced already in the Bolonia Process, ECTS points and three steps of education: Bachelor’s degree (at universities of technology – Engineer’s degree), Master’s degree and Doctoral Studies. The first level, Bachelor’s degree, contains the basic knowledge: gravimetric analysis, electrogravimetry, acid-base titration, oxidation-reduction titration, precipitation titration, complexometric titration and quality assurance and quality control of results. The second level (Master’s degree) contains more developed analytical techniques: gas and liquid chromatography, spectrophotometric methods, electrochemical methods, elemental analysis etc. A bachelor’s projects as well as a diploma and doctoral thesis very often are prepared in the field of Analytical Chemistry. It is very popular with students, each year we have in Poland about 100 doctorate in this field. The laboratory on Polish universities are well equipped in specialist apparatuses, but it’s strongly depended on university profile and how big it is. Some students are doing studies and thesis abroad, in the frame of LLP ERASMUS Program or other international programs. It promotes the international dimension and improves the quality of education by encouraging innovation in education.

  • The effect of depth of surface layers constituted by vacuum technologies on pitting
    • Beata Majkowska-Marzec
    • Witold Piekoszewski
    • M. Szczerek
    • E. Wołowiec
    2013 Pełny tekst Archives of Materials Science and Engineering

    The paper presents the results of a study of the effect of vacuum technologies of formation of surface layers on pitting of associated elements in a lubricated, heavy-load rolling contact. The study has shown that increase in a PVD coat depth is accompanied by decrease in the fatigue friction pair.

  • The Effect of Sterols on Amphotericin B Self-Aggregation in a Lipid Bilayer as Revealed by Free Energy Simulations
    • Anna Neumann
    • Maciej Bagiński
    • Szymon Winczewski
    • Jacek Czub
    2013 Pełny tekst BIOPHYSICAL JOURNAL

    Amphotericin B (AmB) is an effective but toxic antifungal drug, known to increase the permeability of the cell membrane, presumably by assembling into transmembrane pores in a sterol-dependent manner. The aggregation of AmB molecules in a phospholipid bilayer is, thus, crucial for the drug’s activity. To provide an insight into the molecular nature of this process, here, we report an atomistic molecular dynamics simulation study of AmB head-to-head dimerization in a phospholipid bilayer, a possible early stage of aggregation. To compare the effect of sterols on the thermodynamics of aggregation and the architecture of the resulting AmB-AmB complexes, free energy profiles for the dimerization in ergosterol- or cholesterol-containing and sterol-free membranes are derived from the simulations. These profiles demonstrate that although AmB dimers are formed in all the systems studied, they are significantly less favorable in the bilayer with ergosterol than in the cholesterol-containing or sterol-free ones. We investigate the structural and energetic determinants of this difference and discuss its consequences for the AmB mechanism of action.

  • The effect of the motor filters on earth fault current waveform in circuits with variable speed drives
    • Stanisław Czapp
    • Jarosław Guziński
    2013

    In circuits with variable speed drives distorted earth fault current flows. Earth fault current distortion influences the threshold of ventricular fibrillation. This paper presents earth fault current distortion in circuits with variable speed drives when motor filter is used. Two types of motor filter are analyzed. For every type of filter the effect of earth fault current distortion on ventricular fibrillation is evaluated.

  • The effect of the motor filters on earth fault current waveform in circuits with variable speed drives
    • Stanisław Czapp
    • Jarosław Guziński
    2013 Pełny tekst Przegląd Elektrotechniczny

    In circuits with variable speed drives distorted earth fault current flows. Earth fault current distortion influences the threshold of ventricular fibrillation. This paper presents earth fault current distortion in circuits with variable speed drives when motor filter is used. Two types of motor filter are analyzed. For every type of filter the effect of earth fault current distortion on ventricular fibrillation is evaluated.

  • The Efficiency of Polish Stock Market: Ordinal Patterns Approach
    • Grzegorz Graff
    • Agnieszka Kaczkowska
    2013 Pełny tekst ACTA PHYSICA POLONICA A

    Zunino et al. analyzed the problem of discrimination of developed and emergent markets by the use of ordinal patterns methods: number of forbidden patterns and ordinal pattern probability distribution as a basis for entropy and statistical measure of complexity. In this paper we apply the same methodology for the analysis of Polish stock market (index WIG). The results indicate that Polish market belongs neither to developed, nor to emergent groups of markets. It represents hybrid market, the third group distinguished in the paper by Zunino et al. DOI: 10.12693/APhysPolA.123.526

  • The electrochemical impedance spectroscopy studies of the anode material based on polymer and starch derived ceramic for lithium ion batteries
    • Andrzej Nowak
    • Anna Lisowska-Oleksiak
    2013 Biuletyn Polskiego Stowarzyszenia Wodoru i Ogniw Paliwowych

    The anode materials derived of preceramic polymer poly(1,2-dimethylsilazane) (PSN) and starch was study. Commercially available polysilazane (poly(1,2-dimethylsilazane (PSN 2M01 Gelest) was mixed with commercially available starch (POCH Gliwice). The ratio polymer/starch (PSN/starch) was 1/1 or 3/7. The polysialazane/starch blend was cross-linked at 230 ºC for 2 h followed by heating to the final temperature (500 ºC, 700 ºC and 900 ºC) and hold at the final temperature for 2 h. Materials were characterized using FTIR-ATR, Raman and SEM techniques. The Si-O and shifted Si-C stretching vibrations confirmed direct interaction between high temperature synthesis products of PSN and starch. The SEM images indicates that pyrolysed samples are consisted of spherical clusters of the diameter from a few to hundreds micrometers depending on the pyrolysis temperature. The electrochemical impedance spectroscopy was used in one compartment three-electrode Swagelok cell to determine the effect of morphology on the electrode response. The electrode was polarized in the potential range from 2 V to 0,02 V. The EIS measurements were taken as a function of electrode potential and temperature allowing evaluation of effective activation energy referred to diffusion impedance and charge transfer (χ2 ~ 1∙10-6). The impedance spectrum of intercalated material is typical for the electrode formed by spherical particles. Financial support from the National Science Centre Poland (grant no 1503/B/H03/2011/40 is gratefully acknowledged).

  • The evolving structure of Polish exports (1994-2010) - diversification of products and trade partners.
    • Aleksandra Parteka
    2013 Pełny tekst Bank i Kredyt

    This paper presents empirical evidence on the diversification process concerning Polish exports (1994–2010), compared to European and global samples of countries. It analyzes both the commodity structure of Polish trade and the geographical diversification of Poland’s trading partners. The analysis draws on highly disaggregated data on exports (HS 6 digit) and combines descriptive analysis with non-parametric, semi-parametric and parametric estimation models. The results suggest that Poland (exporting 84% of all goods present in the sample) can be placed among countries with well-diversified export products. In terms of geographical diversification, Poland exploits approximately one-fifth of its theoretical overall market reach potential (the best score among new member states) and the diversification of its partner countries increased in the period analyzed. The Polish export portfolio, in terms of the variety of both its products and receiving markets, is more diversified than what is typical for countries at approximately the same stage of economic development.

  • THE GENE CLONING, OVEREXPRESSION, PURIFICATION AND BIOCHEMICAL CHARACTERISATION OF A NEW COLD-ADAPTED β–GALACTOSIDASE FROM ARTHROBACTER SP. VII-4
    • Ewelina Krajewska
    • Marta Wanarska
    • Józef Kur
    2013 Postępy Mikrobiologii

    INTRODUCTION. β-Galactosidase [EC 3.2.1.23] is an enzyme that catalyzes the hydrolysis of O-glycosidic linkages in galactosides. It is commercially used in dairy industry for the production of milk with reduced lactose content. Potentially, the best method for lactose removal under cooling conditions should be carried out with a cold-adapted enzyme. AIM. The aim of this study was to determine the taxonomic affiliation of the isolate labeled as Spitzbergen VII-4, and obtain the sequence of the gene encoding cold-active β-galactosidase and the construction of expression system, biosynthesis and biochemical characterisation of the enzyme. MATERIALS AND METHODS. Research methods included the use of the PCR technique, cloning, and expression of the gene. The protein was purified to homogeneity by using ion exchange chromatography and gel filtration. Then an analysis of the enzyme was done. RESULTS. The isolate Spitzbergen VII-4 was classified as Arthrobacter sp. based on 16S rRNA gene sequence. Sequence of the gene encoding β-galactosidase was obtained by construction of genomic DNA library, and its analysis showed that it consists of 2064 bp, and encodes an enzyme belonging to the glycoside hydrolase family 42. The biosynthesis of protein was carried out in Escherichia coli. After purification the enzyme with specific activity of 9.2 U/mg was obtained. The enzyme is a trimer with molecular mass 227 kDa. Optimal conditions for enzyme activity are 32°C and pH 7.5. Cations Mg2+ are activators of β-galactosidase whereas Ca2+, Co2+, Mn2+ and Ni2+ are inhibitors of the enzyme. Moreover, the thiol group-containing compounds such as dithiotreitol, tris(2-carboxyethyl)phosphine, reduced glutathione and cysteine decreased the activity of the glycoside hydrolase. The enzyme exhibits hydrolytic activity with β-D-galactosides, β-D-glucuronide, and β-D-fucoside. CONCLUSIONS. Biochemical properties of β-galactosidase Arthrobacter sp. VII-4 show that enzyme can be potentially used for lactose removal from dairy products, however, comprehensive research must be done.

  • The green waterfront of a city. Where are the limits of good planning? Gdansk case
    • Aleksandra Sas-Bojarska
    2013

    The aim of the article is to present the role of green public areas of waterfronts in shaping the image of cities, and the threats to such landscape which may be caused by wrong planning decisions. The case study of Gdansk sea-shore area in Poland is presented as an example to illustrate the values and potential of the waterfront landscape which can be easily destroyed by inadequate spatial development. Some theoretical studies have been conducted as a basis for case study analysis. Gdansk study case proves that there is a need for strategic planning of city landscape. The crucial conclusion relates to the need for prediction of environmental and landscape threats caused by inadequate development, and the need of reinterpreting the approaches related to city landscape, with the aim of restoring and enhancing the green and recreation areas within the cities. The presented thesis may support good practice in urban planning, especially in relation to landscape protection and shaping. The role of public participation and acceptance in decision-making is stressed as a crucial factor in influencing the city planning.

  • The hydration of the protein stabilizing agents: trimethylamine-N-oxide, glycine and its N-methylderivatives - the volumetric and compressibility studies
    • Joanna Krakowiak
    • Jarosław Wawer
    • Aneta Panuszko
    2013 JOURNAL OF CHEMICAL THERMODYNAMICS

    The densities at T = (288.15, 293.15, 298.15, 303.15, and 308.15) K and sound velocities at T = 298.15 K have been measured for aqueous solutions of trimethylamine-N-oxide, glycine, N-methylglycine (sarcosine), N,N-dimethylglycine, N,N,N-trimethylglycine (betaine). From these data the apparent molar volumes, VΦ, the apparent molar isentropic compressions, KS,Φ, and the solvation numbers of solutes have been determined. The concentration dependencies of the calculated quantities and their limiting values are discussed in terms of solute–solvent and solute–solute interactions. The obtained quantities are compared with the analogous data for urea and its derivatives. These two groups of osmolyties (stabilizers and denaturants of the proteins) reveal clearly different volumetric and compression features.

  • The impact of end-user participation in IT projects on product usability
    • Krzysztof Redlarski
    2013

    Many companies implementing new IT projects encounter numerous problems with ensuring good final product usability. The strong market competition they experience often results in necessity of undertaking difficult decisions with regard to cost minimization. This may force cuts in usability expertise and consulting, most often by limiting end-user participation in the project. However, it may also result in serious consequences for the final quality of the product being developed. The paper discusses the outcomes of a study conducted among Polish companies. The core analysis includes conclusions from a study done with fifteen IT project managers on end-user participation and their impact on the final product usability.

  • The impact of gender wage gap on sectoral economic growth – cross-country approach
    • Joanna Wolszczak-Derlacz
    2013 Pełny tekst EQUILIBRIUM Quarterly Journal of Economics and Economic Policy

    We propose an empirical analysis of testing the relationship between gender wage gap and economic growth. The study takes into account 12 manufacturing sectors in 18 OECD countries for the period between 1970 and 2005.We use industrial statistics (EU KLEMS, 2008) on female and male wages that distinguish between wages paid to different groups of workers classified according to skill level: high, medium and low. We estimate augmented production function where the male-female wage differentials constitute a potential channel influencing growth (positively or negatively). Our research is motivated by the ambiguous results of previous empirical studies (e.g.: Seguiono, 2000; Busse and Spielmann, 2006; Seguino, 2011; Schober and Winter-Ebmer, 2011). Our main findings indicate that gender wage gap for high, medium and low-skilled workers is negatively correlated with sectoral growth. This result are confirmed in number of robustness checks

  • The Impact of Sloshing Liquids on Ship Stability for Various Dimensions of Partly Filled Tanks
    • Przemysław Krata
    2013 Pełny tekst TransNav - The International Journal on Marine Navigation and Safety of Sea Transportation

    Liquid sloshing phenomenon taking place in partly filled ships' tanks directly affects the stability of a vessel. However, only static calculations are carried out onboard ships nowadays and static transfer of liquid weight is taken into account in the course of routine stability calculation. The paper is focused on a dynamic heeling moment due to liquid sloshing in tanks onboard ships. A number of numerical simulations of liquid sloshing taking place in a moving tank is carried out. The wide range of ship's tanks is taken into account. The conducted CFD simulations are experimentally verified. Finally, the method of an assessment of the liquid sloshing impact on ship transverse stability is worked out. The key point of the method is a dynamic coefficient describing relation of the researched dynamic heeling moment and the quasi-static one in terms of dynamic stability of a vessel which is related to the weather criterion of ship stability assessment.

  • The impact of slowly biodegradable organic compounds on the oxygen uptake rate in activated sludge systems
    • Jakub Drewnowski
    2013

    The hydrolysis process of slowly biodegradable substrate (Xs) have impact on the efficiencies of nutrient removal in activated sludge systems. Measurement of OUR and corresponding COD is accepted as a very useful tool to reflect the consumption of biodegradable substrates. The influence of the readily biodegradable substrate (Ss) in biological wastewater treatment systems has been extensively investigated, but little is known about the impact of Xs. The aim of this study was to determine the immediate effects of particulate and colloidal (Xs) biodegradable compounds on oxygen utilization for a full-scale process mixed liquor from large WWTP located in northern Poland. Since it is difficult to distinguish Xs in direct way, a novel procedure, based on the standard batch tests, was developed and run in parallel reactors with settled wastewater (SWW) and pretreated SWW sample. Two types of aerobic OUR tests with low and high substrat/biomass (So/Xo ratio) concentration, were carried out with the SWW without pretreatment and pretreated with coagulation-flocculation (C-F) method. The removal of colloidal and particulate fractions by C-F resulted in the reduced process rates. The major discrepancy in the rate reductions (over 300% referred to the OURmax) were observed during OUR batch test with high So/Xo ratio.

  • The Impact of Trade Integration with the European Union on Productivity in a Posttransition Economy: The Case of Polish Manufacturing Sectors
    • Aleksandra Parteka
    • Joanna Wolszczak-Derlacz
    2013 EMERGING MARKETS FINANCE AND TRADE

    This paper addresses the relationship between productivity growth in Polish manufacturing sectors and forces stemming from trade integration with the European Union. Empirical analysis (1995-2006) is based on sector-level bilateral data concerning both domestic (Polish) and foreign (partner countries from the enlarged European Union) markets' characteristics and their degree of openness. The main results indicate that, both in the short run and the long run, an increase in domestic sectors' openness exerts a positive effect on productivity growth in Poland (the opposite effect is exhibited by foreign sectors' openness). In addition, expansion in relative size of Polish sectors versus foreign ones boosts domestic labor productivity growth.

  • The influence of feed rate and shear forces on the devulcanization process of ground tire rubber (GTR) conducted in a co-rotating twin screw extruder
    • Krzysztof Formela
    • Magdalena Formela
    • Józef Haponiuk
    • Andrzej Stasiek
    2013 Pełny tekst Polimery

    The search for new ways to recycling of rubber waste has been the aim of many studies conducted by research centers and companiesworldwide. The results of our investigations on the process of continuous thermomechanical devulcanization of ground tire rubber using a twin screw extruder are presented.We used a co-rotating twin screw extruder with a special configuration of plasticizing unit, enabling generation of considerable shear forces. Various properties were characterized, such as the influence of the ground tire rubber feed rate and screw speed (shear forces) on the screw torque, acetone extract, sol fraction, and the degree of devulcanization in the resulting products. The effect of a secondary vulcanization on the vulcametric curves was determined, and the mechanical properties (tensile strength, elongation at break, hardness, resilience and abrasivity) of the revulcanized materialwere studied. It has been determined that the devulcanization process depends on the values of shear force and residence time acting on ground tire rubber. The devulcanization degree increases with increasing screw speed and feed rate. The results of repeatability of continous devulcanization process of ground tire rubber were also determine. Obtained products possess the quality comparable to that of reclaim rubber available on the market. Keywords: recycling, rubber waste, devulcanization, twin screw extruder, revulcanization.