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Publications from the year 2012
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Chromatographic lipophilicity determination using large volume injections of the solvents non-miscible with the mobile phase
- Costel Sarbu
- Rodica Domnica Nascu-Briciu
- Dorina Casoni
- Agata Kot-Wasik
- Andrzej Wasik
- Jacek Namieśnik
A new perspective in the lipophilicity evaluation through RP-HPLC is permitted by analysis of the retentionfactor (k) obtained by injecting large volumes of test samples prepared in solvents immiscible withmobile phase. The experiment is carried out on representative groups of compounds with increasedtoxicity (mycotoxins and alkaloids) and amines with important biological activity (naturally occurringmonoamine compounds and related drugs), which are covering a large interval of lipophilicity. Thestock solution of each compound was prepared in hexane and the used mobile phases were mixturesof methanol or acetonitrile and water, in suited volume ratio. The injected volume was between 10 and100 L, while the used stationary phases were RP-18 and RP-8. On both reverse stationary phases theretention factors were linearly decreasing while the injection volume was increasing. In all cases, thelinear models were highly statistically significant. On the basis of the obtained results new lipophilicityindices were purposed and discussed. The developed lipophilicity indices and the computationallyexpressed ones are correlated at a high level of statistical significance.
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Chromogenic amides of pyridine-2,6-dicarboxylic acid as anion receptors
- Ewa Wagner-Wysiecka
- Jarosław Chojnacki
The synthesis of simple, chromogenic pyridine-2,6-dicarboxylic acid amides, derivates of isomeric nitroanilines and aminonitrophenols, and their ion binding properties are described. The ligands' response to ionic species was examined by naked eye and was studied with the use of UV-Vis spectroscopy in DMSO and its mixture with water. The effect of the localisation and the type of the substituents in aromatic rings were discussed. 1H NMR experiments were carried out to probe the mechanism of anion recognition, i.e. complexation via hydrogen bond formation versus ligand deprotonation. A selective response of N,N'-bis(2-hydroxy-4-nitrophenyl)pyridine-2,6-dicarboxamide (L5)towards dihydrogen phosphate was found in both DMSO and DMSO-water (95:5) solvent mixture. The structure of N,N'-bis(2-hydroxy-5-nitrophenyl)pyridine-2,6-dicarboxamide (L4) was confirmed by X-ray crystalography.
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Chromogenic derivatives of new bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) - synthesis and properties
- Agnieszka Pazik
- Anna Skwierawska
Derivatives of bis(phenylhydrazono-1H-tetrazol-5-yl-acetonitriles) with oxygen and sulphur atoms in the structure of aliphatic chains were successfully synthesised. The correlation between the ligand structure and its complexation properties was investigated by absorption spectroscopy. The formation of complexes of presented compounds with metal cations (Cu2+, Ni2+, Zn2+, Co2+, Fe2+ and Pb2+) was studied. Ligands 5-8 were additionally applied as ion carriers in ion-selective membrane electrodes. Membranes of ion-selective electrodes doped with these ligands are selective to Cu2+ and Pb2+ cations.
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Classification and fingerprinting of kiwi and pomelo fruits by multivariate analysis of chromatographic and spectroscopic data
- Costel Sarbu
- Rodica Dominica Nascu-Birciu
- Agata Kot-Wasik
- Shela Gorinstein
- Andrzej Wasik
- Jacek Namieśnik
The fingerprinting capacity of two analytical techniques, HPLC and UV-Vis spectroscopy in the case of fruits samples (kiwi and pomelo) has been investigated. The multivariate exploratory techniques were used for sample discrimination according to the fruit species and subspecies. The combination of principal component analysis with linear discriminant analysis is opening new directions in the fingerprinting analysis. The classifications obtained were independent by the analytical techniques, which signalise that both of them may be successfully employed in the fingerprinting methodologies if they are combined with appropriate chemometric methods. One of the biggest advantages of the proposed chemometric method is the ability to discriminate different types and species and subspecies of fruits in just one analysis, which indicates that it is one of the simplest and less time consuming methods. It is strongly sustained by the good results obtained in the case of kiwi and pomelo fruit samples that were simultaneously analysed.
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Cloning, Expression and Purification of Wild-Type Trehalose Synthase from Deinococcus geothermalis
- Anna Panek
- Paweł Filipkowski
- Józef Synowiecki
The aim of this study was isolation and cloning of trehalose synthase gene derived from extremophilic microorganism to the expression vectors in the Tabor-Studier system and its expression in Rosetta(DE3)pLysS Escherichia coli cells. The second phase of the study consisted of proteins purification using an initial denaturation of host proteins and salting-out proteins by ammonium sulfate.
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Coarse-grained simulation - an efficient approach for studying motions of large proteins
- Aleksandra Miszkiel
- Marek Wojciechowski
- Sławomir Milewski
One of the most important challenges in performing Molecular Dynamics (MD) simulations of large protein complexes is to accommodate the model accuracy and the simulation timescale. Hitherto, for the most relevant dynamics of protein aggregates in an explicit aqueous environment, the timescale reachable for the all-atoms simulations is of hundreds of nanoseconds. This range is four to six orders of magnitude smaller than processes occurring within the cell and thus computational results cannot be directly compared to experimental results. In order to increase the simulation performance, a less detailed description of the system could be used but it should be considered that the more simplified model used, the less accurate and predictive the results are. Nevertheless, as the fast and slow molecular motions are quite independent, it is possible to ignore fast vibrations for the study of slow motions. Thus, a simplified description can be applied to analyze the mechanisms, dynamics and structural changes of a protein.The principle of coarse-grained (CG) models is to reduce the number of degrees of freedom of the system by integrating some of them into a smaller number. A molecule is then described by the interaction sites representing groups of atoms - beads. Very different levels of CG models can be applied, ranging from the "united atoms" model, where only non-polar hydrogen atoms are ignored, to mesoscale approaches where the molecule is reduced to few rigid regions of well-defined equilibrium structures identified as the natural coarse grained elements. Therefore, applying CG models can significantly reduce the resolution description of the system and, consequently, increase the computations efficiency - the smaller the beads number is, the less computationally expensive the simulation and, consequently, the larger timescale can be applied.The method of coarse-graining has been known for years. The main challenge and limitation of this technique has always been to properly parameterize the force field. On one hand it should be accurate: effectively describing specific interactions with few parameters and functional forms; on the other hand, some extent of versatility is required: the force field must be independent from the reference configuration and transferable to different systems. Recently, some main advances in force field parameterization have been made, making it possible to achieve the order of accuracy comparable to the results obtained from atomistic models. The CG method, reinforced by enhanced computer power have recently become a point of high interest for the large, solvated protein dynamics study.
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Cofka ścieków
- Ziemowit Suligowski
Zagrożenie cofką ścieków w instalacjach. Potrzeby w zakresie ochrony. Charakterystyka urządzeń.
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Collaborative approach to WordNet and Wikipedia integration
- Julian Szymański
- Rafał Korytkowski
- Henryk Krawczyk
In this article we present a collaborative approach tocreating mappings between WordNet and Wikipedia. Wikipediaarticles have been first matched with WordNet synsets in anautomatic way. Then such associations have been evaluated andcomplemented in a collaborative way using a web application.We describe algorithms used for creating automatic mappingsas well as a system for their collaborative development. Theoutcome enables further integration of WordNet and Wikipedia,which can be used in Natural Language Processing algorithms
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Colorings of the Strong Product of Circulant Graphs
- Marcin Jurkiewicz
Graph coloring is one of the famous problems in graph theory and it has many applications to information theory. In the paper we present colorings of the strong product of several circulant graphs.
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Combinatorial scheme of finding minimal number of periodic points for smooth self-maps of simply connected manifolds
- Grzegorz Graff
- Jerzy Jezierski
Let M be a closed smooth connected and simply connected manifold of dimension m at least 3, and let r be a fixed natural number. The topological invariant D^m_r [f], defined by the authors in [Forum Math. 21 (2009), 491-509], is equal to the minimal number of r-periodic points in the smooth homotopy class of f, a given self-map of M. In this paper, we present a general combinatorial scheme of computing D^m_r [f] for arbitrary dimension m ≥ 4. Using this approach we calculate the invariant in case r is a product of different odd primes. We also obtain an estimate for D^m_r [f] from below and above for some other natural numbers r.
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Combined chemical-biological treatment of effluents from soil remediation processes by surfactants solutions flushing
- Elżbieta Hallmann
- Renata Tomczak-Wandzel
- Krystyna Mędrzycka
Ścieki powstające podczas procesu remediacji gruntu zawierają surfaktanty o wysokim stężeniu oraz oleje w postaci zemulgowanej i zsolubilizowanej lub wolnej. Do oczyszczenia takich ścieków zastosowano chemiczne utlenianie, biologiczne oczyszczanie oraz zintegrowany proces chemiczno biologiczny. Efektywność procesu oceniono na podstawie redukcji ChZT oraz zmiany stężenia surfaktantu w oczyszczanych ściekach. Chemiczne utlenienie pozwoliło na 80% redukcję ChZT oraz stężenia surfaktantu w ściekach, w przypadku biologicznego oczyszczania parametry te zredukowano odpowiednio o 60% i 50 %. Jednak w zintegrowanym procesie biologiczno chemicznym redukcja zarówno ChZT jak i stężenia surfaktantu wyniosła ponad 90%.
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Common methods for the chiral determination of amphetamine and related compounds II: Capillary electrophoresis and nuclear magnetic resonance
- Justyna Małgorzata Płotka
- Calum Morrison
- Marek Biziuk
Amphetamine group and related ring-substituted substances are generally synthetic compounds, belonging to one of the most heavily abused drug groups in recent years. Some compounds in this class also originate from plants. Analysis of the enantiomers of AM-type compounds and metabolites is extremely important for a number of scientific disciplines. From studies of biological activity or mechanisms through determination of precursor molecules in a criminal investigation all use analytical procedures. This article reviews capillary electrophoresis and nuclear magnetic resonance as among the most common, useful methods for the chiral determination of AMs and AM-derived designer drugs in different matrices including blood, hair, urine and medicaments. Papers published in the last 15 years were considered including commonly used types of chiral derivatization reagent and chiral stationary phase. Tables summarize basic information about conditions and reference data of each procedure. Other methods (e.g. gas chromatography, liquid chromatography and high performance liquid chromatography, and thin layer chromatography) were described in Part 1 (Trends Anal. Chem. 30 (2011) 1139).
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Commonly Accessible Web Service Platform - Wiki-WS
- Henryk Krawczyk
- Marek Downar
Web Service technology on the basis had to supply complete and reliable system components. Nowadays this technology is commonly used by companies providing results of their work to end users and hiding implementation details. This paper presents a SOA-enabled platform - Wiki-WS - that empowers users to deploy, modify, discover and invoke web services. Moreover it discusses concepts and functionalities of this open source management platform being developed. Main concept of the Wiki-WS platform is searching and invocation of web services written by different workgroups in different technologies deployed on different servers. Wiki-based web service code modification allows engineers from any place to construct and to implement components, which are mature and ready to use. Components deployed in the platform cover different functionalities from various knowledge domains. Service categorization done by users and by the platform classification engine in the early deployment and every modification time tunes up future searching and usage decision processes. Fundamental architecture components and user categories characterization are described in this paper. There is also included presentation of sample scenarios of Wiki-WS usage and advantages derived from its deployment.
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Community innovators: 'shock troops' of the new order or safety brake in the era of 'fast policy'?
- Łukasz Pancewicz
Artykuł zawiera krytyczną analizę zinstytucjonalizowanej innowacji w zakresie polityki przestrzennej. Hasło kongresu ''szybkie planowanie'' jest interpretowane jako strategia modernizacyjna, mogąca w efekcie preferować ograniczoną liczbę prorynkowych modeli rozwoju i rolę głosu eksperckiego. Artykuł podsumowuje pierwsze doświadczenia związane ze społecznym oporem przeciwko takim formom kształtowania polityki rozwoju miast w Polsce.
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Comparative Analysis of Exoskeletal Actuators
- Grzegorz Redlarski
- Krzysztof Blecharz
- Mariusz Dąbkowski
- Aleksander Pałkowski
- Piotr Mateusz Tojza
Since the beginning of the development of exoskeletons in the early 1960s there was a constant need for improving their actuators technology. Requirements for high power and torque for the lower body and very high precision for the hand motion, while maintaining the flexibility of biological muscles, are still not fully satisfied. The problem lies not just in the lack of appropriate actuator technology, but also in the inability to meet their energy needs. This paper contributes to this problem, first by describing the most commonly used technologies and then by presenting simulation results for lower limb exoskeleton motion. In addition the energy requirements of the modeled devices and their control possibilities along with their usage in various parts of the exoskeleton construction are analyzed.
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Comparative field test for measurement of PM10 dust in atmospheric air using gravimetric (reference) method and b-absorption method (Eberline FH 62-1)
- Jacek Gębicki
- Krystyna Szymańska
The paper presents the results of a field test carried out in Gdansk region between 01-01-2010 and 31-12-2010 in order to demonstrate equivalence of the Eberline FH 62-1 sampler to the reference gravimetric method of suspended PM10 dust measurement. The differences in PM10 dust concentration provided by both methods have been discussed for different seasons of the year. A method of estimation of the correction factors/correction equations has been described based on the European Union guide "Demonstration of Equivalence of Ambient Air Monitoring Methods. EC Working Group on Guidance for the Demonstration of Equivalence". The results obtained from Eberline sampler are equivalent to the ones from gravimetric method, but after application of data correction. The investigation revealed different correction factors/correction equations for winter and summer season. The winter season is characterized by higher PM10 concentration and bigger discrepancies between both methods. A lack of equivalence has been found for PM10 dust concentration higher than 30 mgm-3.
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Comparative study of flow condensation in conventional and small diameter tubes
- Dariusz Mikielewicz
- Rafał Andrzejczyk
Flow boiling and flow condensation are often regarded as two opposite or symetrical phenomena. Their description however with a single correlation has yet to be suggested.In the case of flow boiling in minichannels there is mostly encountered the annular flow structure, where the buble generetion is not present. Similar picture holds for the case of inside tube condensation, where annular flow structure predominates. In such case the heat transfer coefficient is prilimary dependent on the convective mechanism.
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Comparative study with magnetic techniques of P91 and 13HMF steels properties subjected to fatigue tests
- Bolesław Augustyniak
- Leszek Piotrowski
- Marek Chmielewski
- Zbigniew Kowalewski
Wykonano badania porównawcze technikami magnetycznymi właściwości stali P91 i 13HMF poddanych testowi zmęczenia
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Comparision of mechanical properties of nitrided cases and remelted layers of austenitic stainless steel
- Artur Sitko
- Marek Szkodo
- Beata Śniegocka
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comparison of circular and rectangular narrow esps with longitudinal wire electrode
- Anna Niewulis
- Artur Berendt
- Janusz Podliński
- Jerzy Mizeraczyk
Diesel engines emit fine particles, which are harmful to human and animal health. There are several methods for decrease particulate emission from a diesel engines, but up to now, these methods are not enough effective or very expensive. An electrostatic precipitation was proposed as an alternative method for control of a diesel particulate emission. Therefore, narrow electrostatic precipitators (ESPs) have become a subject of interest because of their possible application for a particle removal from diesel engines exhaust gases.In this paper, results of the electrohydrodynamic (EHD) flow patterns in circular and rectangular narrow ESPs with longitudinally-to-flow wire electrode are presented. The EHD secondary flow was measured using 2-dimensional particle image velocimetry (PIV) method. Moreover, results of the collection efficiency measurements of submicron particles are shown.