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Gdańsk University of Technology

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Publications from the year 2023

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  • Frequency Selective Surface Based MIMO Antenna Array for 5G Millimeter-Wave Applications
    • Iftikhar Din
    • Mohammad Alibakhshikenari
    • Bal S. Virdee
    • Renu Karthick Rajaguru Jayanthi
    • Sadiq Ullah
    • Chan Hwang See
    • Salahuddin Khan
    • Sławomir Kozieł
    • Sławomir Kozieł
    2023 Full text SENSORS

    Abstract: In this paper a radiating element consisting of a modified circular patch is proposed for MIMO arrays for 5G millimeter-wave applications. The radiating elements in the proposed 2×2 MIMO antenna array are orthogonally configured relative to each other to mitigate mutual coupling that would otherwise degrade the performance of the MIMO system. The MIMO array was fabri-cated on Rogers RT/Duroid high frequency substrate with dielectric constant of 2.2, thickness of 0.8 mm and loss tangent of 0.0009. The individual antenna in the array has a measured impedance bandwidth of 1.6 GHz from 27.25 to 28.85 GHz for S11 ≤ −10 dB, and the MIMO array has a gain of 7.2 dBi at 28 GHz with inter radiator isolation of greater than 26 dB. The gain of the MIMO array was increased by introducing frequency selective surface (FSS) consisting of 7×7 array of unit cells comprising rectangular C-shaped resonators one embedded inside the other with a central criss-cross slotted patch. With the FSS the gain of the MIMO array increased to 7.6 dBi at 28 GHz. The radiation from the array is directional and perpendicular to the plain of the MIMO array. Owing to the low coupling between the radiating elements in the MIMO array its Envelope Correlation Coefficient (ECC) is less than 0.002 and Diversity Gain (DG) is better than 9.99 dB in the 5G oper-ating band centered at 28 GHz between 26.5 GHz and 29.5 GHz.

  • Friction Stir Welding of Aluminum in the Aerospace Industry: The Current Progress and State-of-the-Art Review
    • Mohamed M. Z. Ahmed
    • Mohamed M. El-Sayed Seleman
    • Dariusz Fydrych
    • Gürel Çam
    2023 Full text Materials

    The use of the friction stir welding (FSW) process as a relatively new solid-state welding technology in the aerospace industry has pushed forward several developments in different related aspects of this strategic industry. In terms of the FSW process itself, due to the geometric limitations involved in the conventional FSW process, many variants have been required over time to suit the different types of geometries and structures, which has resulted in the development of numerous variants such as refill friction stir spot welding (RFSSW), stationary shoulder friction stir welding (SSFSW), and bobbin tool friction stir welding (BTFSW). In terms of FSW machines, significant development has occurred in the new design and adaptation of the existing machining equipment through the use of their structures or the new and specially designed FSW heads. In terms of the most used materials in the aerospace industry, there has been development of new high strength-to-weight ratios such as the 3rd generation aluminum–lithium alloys that have become successfully weldable by FSW with fewer welding defects and a significant improvement in the weld quality and geometric accuracy. The purpose of this article is to summarize the state of knowledge regarding the application of the FSW process to join materials used in the aerospace industry and to identify gaps in the state of the art. This work describes the fundamental techniques and tools necessary to make soundly welded joints. Typical applications of FSW processes are surveyed, including friction stir spot welding, RFSSW, SSFSW, BTFSW, and underwater FSW. Conclusions and suggestions for future development are proposed

  • From Scores to Predictions in Multi-Label Classification: Neural Thresholding Strategies
    • Karol Draszawka
    • Julian Szymański
    2023 Full text Applied Sciences-Basel

    In this paper, we propose a novel approach for obtaining predictions from per-class scores to improve the accuracy of multi-label classification systems. In a multi-label classification task, the expected output is a set of predicted labels per each testing sample. Typically, these predictions are calculated by implicit or explicit thresholding of per-class real-valued scores: classes with scores exceeding a given threshold value are added to a prediction set. In our work, we propose a neural network-based thresholding phase for multi-label classification systems and examine its influence on the overall classification performance measured by micro- and macro-averaged F1 scores on synthetic and real datasets. In contrast to classic thresholding methods, our approach has the unique property of being able to recover from scoring errors, because each decision about a given label prediction depends on the corresponding class score, as well as on all the other class scores for a given sample at once. The method can be used in combination with any classification system that outputs real-valued class scores. The proposed thresholding methods are trained offline, after the completion of the scoring phase. As such, it can be considered a universal fine-tuning step that can be employed in any multi-label classification system that seeks to find the best multi-label predictions based on class scores. In our experiments on real datasets, the input class scores were obtained from two third-party baseline classification systems. We show that our approach outperforms the traditional thresholding methods, which results in the improved performance of all tested multi-label classification tasks. In terms of relative improvement, on real datasets, the micro-F1 score is higher by up to 40.6%, the macro-F1 score is higher by up to 3.6%, and the averaged micro–macro-F1 score is higher by up to 30.1%, considering single models only. We show that ensembles and hybrid models give even better results. We show examples of successful extreme recoveries, where the system, equipped with our method, was able to correctly predict labels, which were highly underscored after the scoring phase.

  • Frontem do morza. Plan, budowa i architektura portu w Gdyni
    • Anna Orchowska
    2023

    Gdynia to port, a port to Gdynia. Tak na początku istnienia II Rzeczpospolitej ukształtowała się jej morska stolica. Monografia Anny Orchowskiej to pierwsza publikacja poświęcona całokształtowi jednej z największych realizacji międzywojnia. Realizacji, która nie tylko pełniła istotne funkcje gospodarcze, ale też szybko stała się wizytówką kraju. Zwrócone niejako frontem do morza budynki były awangardowe i śmiałe w formie. Budowane w duchu modernizmu, doskonale wpisywały się w światowe trendy lat dwudziestych i trzydziestych XX wieku. Autorka – jako architekt i historyk architektury – analizuje jakość zastosowanych w porcie rozwiązań zarówno estetycznych, jak i technicznych i technologicznych. Nie pomija także czynnika ludzkiego. Port nie powstałby przecież bez inicjatorów i organizatorów morskich przedsięwzięć, projektantów, inżynierów, budowniczych, a wreszcie – bez zwykłych pracowników. Czy udało im się stworzyć dzieło ponadczasowe?

  • Frontier education for a sustainable future - speculative design in architecture as a transdisciplinary experiment
    • Lucyna Nyka
    • Elżbieta Marczak
    2023 Full text Global Journal of Engineering Education

    In this article, the authors propose the term frontier education referring to the well-established notion of frontier research - one, that through opening unexpected transdisciplinary perspectives, may offer new insights and create a fertile ground for new discoveries and ground-breaking concepts. In answer to the question of how to get rid of normative thinking and extend architectural experimentations, a speculative design architectural studio was proposed to students of Gdańsk University of Technology (Gdańsk Tech), Gdańsk, Poland, in collaboration with a non-academic foresight institution. In this article, the authors discuss the effects of introducing the speculative design methodology as a transdisciplinary and frontier education experiment. They reflect on how this kind of experimentation contributed to enriching the student’s understanding of the constant process of adaptation of architecture to environmental challenges, social trends and technological innovations.

  • FTIR, Raman spectroscopy and HT-XRD in compatibility study between naproxen and excipients
    • Barbara Rojek
    • Maria Gazda
    • Anna Plenis
    2023 SPECTROCHIMICA ACTA PART A-MOLECULAR AND BIOMOLECULAR SPECTROSCOPY

    Detection of incompatibility between an active pharmaceutical ingredient (API) and excipients, including the selection of the most biopharmaceutical advantageous excipients is extremely important in the pre-formulation process of developing a solid dosage form technology. Therefore, having fast and reliable methods for identifying incompatibility is fundamental in pharmaceutical technology. For this purpose, combined Fourier transform infrared (FTIR) and Raman spectroscopy as well as high-temperature X-ray diffraction (HT-XRD) were used as a new approach for incompatibility detection, whereas differential scanning calorimetry (DSC) was applied as a reference method. In addition, to facilitate the interpretation of FTIR and Raman data, a multivariate analysis was used – hierarchical cluster analysis (HCA). The tests were carried out in mixtures of naproxen (NPX) with eight selected polymer excipients, mixed at a 1:1 ratio. The results of spectroscopic analyses have shown the physical incompatibility of NPX with methylcellulose (MC), hydroxypropylmethylcellulose (HPMC), hydroxyethylcellulose (HEC), sodium starch glycolate (SSG) and sodium carboxymethylcellulose (CMC). HT-XRD studies performed when these mixtures were heated to 156 °C and then cooled to 25 °C showed a decrease in naproxen crystallinity in these mixtures. Furthermore, the results obtained with spectroscopic methods were confirmed by DSC tests and an intrinsic dissolution rate study.

  • Fuel systems of high power stationary engine
    • Zbigniew Kneba
    2023 Full text Combustion Engines

    The use of alternative fuels and, in the future, synthetic fuels has forced changes in the design of fuel supply systems in internal combustion engines. When operating a stationary engine at constant load, the possibility of using lean fuel mixtures appears. The selection of a precise operating mixture ignition system requires changes in traditional fuel systems. The article presents the current designs of fuel supply systems and their properties. Attention was paid to operating parameters resulting in acceptable emissions of toxic exhaust gas components

  • Full-field in vivo experimental study of the strains of a breathing human abdominal wall with intra-abdominal pressure variation
    • Katarzyna Szepietowska
    • Mateusz Troka
    • Monika Lichodziejewska-Niemierko
    • Michał Chmielewski
    • Izabela Lubowiecka
    2023 Journal of the Mechanical Behavior of Biomedical Materials

    The presented study aims to assess the mechanical behaviour of the anterior abdominal wall based on an in vivo experiment on humans. Full-field measurement of abdominal wall displacement during changes of intra-abdominal pressure is performed using a digital image correlation (DIC) system. Continuous measurement in time enables the observation of changes in the strain field during breathing. The understanding of the mechanical behaviour of a living human abdominal wall is important for the proper design of surgical meshes used for ventral hernia repair, which was also a motivation for the research presented below. The research refers to the strain field of a loaded abdominal wall and presents the evolution of principal strains and their directions in the case of 12 subjects, 8 male and 4 female. Peritoneal dialysis procedure allows for the measurement of intra-abdominal pressure after fluid introduction. High variability among patients is observed, also in terms of principal strain direction. Subjects exhibit intra-abdominal pressure of values from 11 to 21 cmH2O. However, the strain values are not strongly correlated with the pressure value, indicated variability of material properties.

  • Fungal co-culture improves the biodegradation of hydrophobic VOCs gas mixtures in conventional biofilters and biotrickling filters
    • Milena Marycz
    • Anna Brillowska-Dąbrowska
    • Sara Cantera
    • Jacek Gębicki
    • Raúl Muñoz
    2023 CHEMOSPHERE

    The present study systematically evaluated the potential of Candida subhashii, Fusarium solani and their consortium for the abatement of n-hexane, trichloroethylene (TCE), toluene and α-pinene in biofilters (BFs) and biotrickling filters (BTFs). Three 3.2 L BFs packed with polyurethane foam and operated at a gas residence time of 77 s with an air mixture of hydrophobic volatile organic compounds (VOCs) were inoculated with C. subhashii, F. solani and a combination of thereof. The systems were also operated under a BTF configuration with a liquid recirculating rate of 2.5 L h-1. Steady state elimination capacities (ECs) of total VOCs of 17.4 ± 0.7 g m−3 h−1 for C. subhashii, 21.2 ± 0.8 g m−3 h−1 for F. solani and 24.4 ± 1.4 g m−3 h−1 for their consortium were recorded in BFs, which increased up to 27.2 ± 1.6 g m−3 h−1, 29.2 ± 1.9 g m−3 h−1, 37.7 ± 3.3 g m−3 h−1 in BTFs. BTFs supported a superior biodegradation performance compared to BF, regardless of the VOCs. Moreover, a more effective VOC biodegradation was observed when C. subhashii and F. solani were grown as a consortium. The microbial analysis conducted revealed that the fungi initially introduced in each BF represented the dominant species by the end of the experiment, with C. subhashii gradually overcoming F. solani in the system inoculated with the fungal consortium.

  • Fusion-based Representation Learning Model for Multimode User-generated Social Network Content
    • Arsalan Muhammad Soomar
    2023 ACM Journal of Data and Information Quality

    As mobile networks and APPs are developed, user-generated content (UGC), which includes multi-source heterogeneous data like user reviews, tags, scores, images, and videos, has become an essential basis for improving the quality of personalized services. Due to the multi-source heterogeneous nature of the data, big data fusion offers both promise and drawbacks. With the rise of mobile networks and applications, UGC, which includes multi-source heterogeneous data including ratings, marks, scores, images, and videos, has gained importance. This information is very important for improving the calibre of customized services. The key to the application's success is representational learning of fusing and vectorization on the multi-source heterogeneous UGC. Multi-source text fusion and representation learning have become the key to its application. In this regard, a fusion representation learning for multi-source text and image is proposed. The convolutional fusion technique, in contrast to splicing and fusion, may take into consideration the varied data characteristics in each size. This research proposes a new data feature fusion strategy based on the convolution operation, which was inspired by the convolutional neural network. Using Doc2vec and LDA model, the vectorized representation of multi-source text is given, and the deep convolutional network is used to obtain it. Finally, the proposed algorithm is applied to Amazon's commodity dataset containing UGC content based on the classification accuracy of UGC vectorized representation items and shows the feasibility and impact of the proposed algorithm

  • g-C3N4 for Photocatalytic Degradation of Parabens: Precursors Influence, the Radiation Source and Simultaneous Ozonation Evaluation
    • Eryk Fernandes
    • Paweł Mazierski
    • Tomasz Klimczuk
    • Adriana Zaleska-Medynska
    • Rui F. Martins
    • João Gomes
    2023 Full text Catalysts

    Graphitic carbon nitride (g-C3N4) is a promising catalyst for contaminants of emerging concern removal applications, especially as a visible-light-driven material. In this study, g-C3N4 catalysts were effectively synthesized through a simple thermal polymerization method, using melamine, urea, and thiourea as precursors to elucidate the influence of these compounds on the final product’s photocatalytic performance. The degradation of a mixture of three parabens was investigated under different types of radiation: two artificial, ultraviolet-A (UVA) and visible LED, and natural sunlight. The urea-based catalyst (UCN) presented better results under all radiation sources, followed by thiourea, and finally, melamine. Among the artificial light sources, the degradation of parabens under UVA was considerably higher than visible—up to 51% and 21%, respectively—using UCN; however, the broader spectrum of natural sunlight was able to achieve the highest removals, up to 92%, using UCN. Comparing artificial radiation sources, UVA lamps presented 45% lower energy consumption and associated costs. Photocatalytic ozonation was tested using UCN and MCN, with UCN once more possessing superior performance and a synergetic effect between photocatalysis and ozonation, with complete removal under 12 min. The use of g-C3N4 was then successfully tested in initial screening and found to be an efficient alternative in more low-cost and feasible solar photocatalysis water treatment.

  • Gdynia, wczesnomodernistyczne centrum miasta
    • Maria Sołtysik
    • Robert Hirsch
    • Marek Stępa
    2023

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  • Gelatin and gelatin/starch-based films modified with sorbitol for wound healing
    • Justyna Kozłowska
    • Joanna Skopińska-Wiśniewska
    • Beata Kaczmarek-Szczepańska
    • Sylwia Grabska-Zielińska
    • Balbina Makurat-Kasprolewicz
    • Anna Michno
    • Anna Ronowska
    • Marcin Wekwejt
    2023 Journal of the Mechanical Behavior of Biomedical Materials

    Gelatin-based films modified with sorbitol were produced from gelatin solution or gelatin/starch blends using a simple and low-cost solvent casting method, and subsequently, their physicochemical, mechanical, and biocompatibility properties were characterized. This work focused on developing and optimizing a biopolymeric blend to improve the pure biopolymers’ properties for potential biomedical applications such as wound dressing. The films were characterized in terms of morphology and transparency, mechanical, moisture and swelling properties, thermal stability, and degradation potential. Moreover, hemocompatibility, as well as cytocompatibility of prepared films, were examined. The addition of sorbitol contributed to improving mechanical properties, swelling reduction, and increasing biostability over time. The cytocompatibility of obtained films was confirmed in vitro with two different human cell lines, fibroblastic and osteoblastic, and a more favorable cellular response was received for fibroblasts. Further, in hemocompatibility studies, it was found that all films may be classified as non-hemolytic as they did not have a negative effect on the human erythrocytes. The obtained results indicate the great potential of the gelatin/starch blends modified with sorbitol as regenerative biomaterials intended for wound healing applications.

  • Gender Disparity in the FinTech Sector: Systematic Literature Review
    • Błażej Prusak
    • Łukasz Wacławek
    2023

    The main objective of this chapter is to identify research areas of FinTech activity in which gender disparity has been observed. In addition, we shall identify how the development of FinTech reduces the gender gap. A systematic literature review using the PRISMA concept is the preferred research method. Publications were searched in the following databases: Web of Science, Scopus and Google Scholar using the formula “FinTech AND gender”. After removing less significant records from the Google Scholar database and performing a screening, a detailed literature analysis was carried out on the basis of 22 publications. The research shows that the topic of gender disparity in FinTech is relatively little recognised as: the oldest publications date back to 2018, there are few publications in the major databases, and the topic is often covered as a side issue. Five areas were identified in the research on gender disparity in FinTech: (1) FinTech and entrepreneurship; (2) FinTech and wages/earnings; (3) FinTech and CEOs/managers; (4) FinTech and the role of women in society; and (5) FinTech and users. The main findings of the research are: gender discrimination can be observed: among FinTech managers and users of certain services; in the intention of people of both genders to use certain services; and in the software used by FinTech institutions. In turn, the positive impact of the development of the FinTech sector relates to reducing the gender wage gap, increasing the level of entrepreneurship and the social status of women.

  • General Provisioning Strategy for Local Specialized Cloud Computing Environments
    • Piotr Orzechowski
    • Henryk Krawczyk
    2023 Full text

    The well-known management strategies in cloud computing based on SLA requirements are considered. A deterministic parallel provisioning algorithm has been prepared and used to show its behavior for three different requirements: load balancing, consolidation, and fault tolerance. The impact of these strategies on the total execution time of different sets of services is analyzed for randomly chosen sets of data. This makes it possible to improve the project and to implement the proper strategies for the local TASKcloud environment used in our institution.

  • Generalization of Phylogenetic Matching Metrics with Experimental Tests of Practical Advantages
    • Damian Bogdanowicz
    • Krzysztof Giaro
    2023 Full text JOURNAL OF COMPUTATIONAL BIOLOGY

    The ability to quantify a dissimilarity of different phylogenetic trees is required in various types of phylogenetic studies, for example, such metrics are used to assess the quality of phylogeny construction methods and to define optimization criteria in supertree building algorithms. In this article, starting from the already described concept of matching metrics, we define three new metrics for rooted phylogenetic trees. One of them, Matching Pair Jaccard (MPJ) distance, is still purely topological, but we now utilize the Jaccard index set dissimilarity measure in its construction. This modification substantially changes the structural features of the metric space. In particular, we investigate the properties of the previously known Matching Cluster Jaccard (MCJ) and the new MPJ metrics, such as the asymptotic behavior of their expected distance between two random trees, the space diameter, and the change of a distance after a single leaf relocation. The other two metrics, Matching Cluster Weight-aware (MCW) and Matching Cluster Jaccard Weight-aware (MCJW) distances, are the first propositions of generalization of matching metrics designed for rooted phylogenies with branch lengths. The experimental tests of the practical utility of the phylogenetic metrics show the superiority of MCJ, MPJ over the previous best tree comparison method. To define the MCW and MCJW metrics, we introduce a general method for constructing matching metrics for weighted rooted phylogenetic trees.

  • Generalized Einstein relation in disordered organic semiconductors: Influence of the acoustic phonons–charge carriers scattering
    • Jędrzej Szmytkowski
    2023 COMPUTATIONAL MATERIALS SCIENCE

    In this work, we analyze the generalized Einstein relation for disordered organic semiconductors with a non-equilibrium Druyvesteyn-type distribution function. The Druyvesteyn behavior of hot electrons in a solid state is associated with the acoustic phonons–charge carriers scattering. Such a case has been experimentally demonstrated in electroluminescent inorganic rare–earth–doped zinc chalcogenides. Therefore, we can assume that, in a part of organic materials used in organic light-emitting diodes (OLEDs), we can also find the Druyvesteyn-type distribution of charge carriers under external electric fields. It looks that the electric-field-dependent diffusion coefficient, which is observed in the phonon-induced hopping electron transport, plays a key role here. The theoretical analysis of the Einstein relation shows that for lower concentrations of charge carriers, the diffusivity–mobility ratio (D/\mu) reaches a value lower than 1 (in kT/q units). The temperature dependencies of D/\mu are similar to the tendencies reported for the equilibrium conditions. The obtained satisfactory agreement between experimental results and calculations based on the Druyvesteyn-type distribution function confirms the usefulness of the presented model.

  • Generating actionable evidence from free-text feedback to improve maternity and acute hospital experiences: A computational text analytics & predictive modelling approach
    • Adegboyega Ojo
    • Nina Rizun
    • Mona Isazad Mashinchi
    • Grace Walsh
    • Jon Gruda
    • Manohar Narayana Narayana
    • Maria Venosa
    • Conor Foley
    • Daniela Rohde
    • Rachel Flynn
    2023 EUROPEAN JOURNAL OF PUBLIC HEALTH

    Background Patient experience surveys are a key source of evidence for supporting decision-making and quality improvement in healthcare services. These surveys contain two main types of questions: closed and open-ended, asking about patients’ care experiences. Apart from the knowledge obtained from analysing closed-ended questions, invaluable insights can be gleaned from free-text data. Advanced analytics techniques are increasingly used to harness free-text data, yet existing approaches do not offer the rigour required to support formal decision-making through free-text. Methods This study addresses the challenge of effectively and rigorously analysing patients’ free-text feedback to improve maternity and acute hospital services in Ireland. Aspects of healthcare services (i.e. themes) that could be improved were determined using computational text analytics and predictive modelling. Themes extracted from comments were prioritised based on volume, the intensity of negative affect expressed in the texts, and the estimated influence of the themes on overall patient satisfaction. Results Results demonstrate the viability of producing rigorous evidence for prioritising interventions to improve healthcare services based on free-text feedback. Specifically, consistency in advice and support in breastfeeding were among the most important issues for maternity services. For acute hospital services, meals quality and access, A&E waiting time, ward hygiene and communication at discharge were among the most important issues. Women also wanted more emphasis on prior birth experience and complications in future maternity care surveys. Conclusions Advances in computational text modelling enable the extraction of concrete and actionable insights from the analysis of free-text data. This approach also allows decision-makers to prioritise emergent themes and inform actions that will positively impact overall patient satisfaction

  • Genome-Wide DNA Methylation and Gene Expression in Patients with Indolent Systemic Mastocytosis
    • Aleksandra Górska
    • Maria Urbanowicz
    • Łukasz Grochowalski
    • Michał Seweryn
    • Marta Sobalska-Kwapis
    • Tomasz K. Wojdacz
    • Magdalena Lange
    • Marta Gruchała-Niedoszytko
    • Justyna Jarczak
    • Dominik Strapagiel
    • Magdalena Górska-Ponikowska
    • Iwona Pelikant-Malecka
    • Leszek Kalinowski
    • Bogusław Nedoszytko
    • Danuta Gutowska-Owsiak
    • Marek Niedoszytko
    2023 Full text INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES

    Mastocytosis is a clinically heterogenous, usually acquired disease of the mast cells with a survival time that depends on the time of onset. It ranges from skin-limited to systemic disease, including indolent and more aggressive variants. The presence of the oncogenic KIT p. D816V gene somatic mutation is a crucial element in the pathogenesis. However, further epigenetic regulation may also affect the expression of genes that are relevant to the pathology. Epigenetic alterations are re-sponsible for regulating the expression of genes that do not modify the DNA sequence. In general, it is accepted that DNA methylation inhibits the binding of transcription factors, thereby down-regulating gene expression. However, so far, little is known about the epigenetic factors leading to the clinical onset of mastocytosis. Therefore, it is essential to identify possible epigenetic predictors, indicators of disease progression, and their link to the clinical picture to establish appropriate management and a therapeutic strategy. The aim of this study was to analyze genome-wide methylation profiles to identify differentially methylated regions (DMRs) in patients with mastocytosis compared to healthy individuals, as well as the genes located in those regulatory regions. Genome-wide DNA methylation profiling was performed in peripheral blood collected from 80 adult patients with indolent systemic mastocytosis (ISM), the most prevalent subvariant of mastocytosis, and 40 healthy adult volunteers. A total of 117 DNA samples met the criteria for the bisulfide conversion step and microarray analysis. Genome-wide DNA methylation analysis was performed using a MethylationEPIC BeadChip kit. Further analysis was focused on the genomic regions rather than individual CpG sites. Co-methylated regions (CMRs) were assigned via the CoMeBack method. To identify DMRs between the groups, a linear regression model with age as the covariate on CMRs was performed using Limma. Using the available data for cases only, an association analysis was performed between methylation status and tryptase levels, as well as the context of allergy, and anaphylaxis. KEGG pathway mapping was used to identify genes differentially expressed in anaphylaxis. Based on the DNA methylation results, the expression of 18 genes was then analyzed via real-time PCR in 20 patients with mastocytosis and 20 healthy adults. A comparison of the genome-wide DNA methylation profile between the mastocytosis patients and ...

  • Geosyntetyki w konstrukcji drogi kolejowej - modelowanie
    • Eligiusz Mieloszyk
    • Anita Milewska
    • Sławomir Grulkowski
    2023

    Geosyntetyki, tzn. geowłókniny, geotkaniny, geosiatki, geomembrany, geowykładziny itp. są powszechnie stosowane w budownictwie, w tym przy budowie, modernizacji i remontach linii transportowych: przesyłowych (rurociągi), komunikacyjnych (drogi kolejowe, drogi kołowe itp.). Liniowe budowle transportowe mają charakter wielowarstwowy, przez co każda kolejna warstwa posiada inne warunki obciążenia. W wyniku działających na drogę kolejową obciążeń w trakcie bieżącej eksploatacji następuje jej osiadanie, często nierównomierne. Z tego wynika, że zmieniają swoje położenie w czasie punkty leżące na geosyntetyku. W każdym przypadku w analizie ich zachowań możemy je traktować jako membrany sprężyste lub powłoki posadowione na różnych rodzajach podłoża. np. typu Winklera, Eulera, Pasternaka, Kerra, bowiem modelowanie układu rzeczywistego oznacza jego idealizację pod kątem uwzględnienia tych cech ośrodka, które wydają się najistotniejsze z punktu widzenia analizowanego problemu. Przedstawione rozważania uprawniają do wykorzystania utworzonych opisów matematycznych do modelowania zmian w czasie położenia punktów analizowanego obszaru Ω, a w szczególności interesujących nas punktów (x,y,g(x,y)) geosyntetyków, gdzie z=g(x,y) jest równaniem powierzchni geosyntetyku, natomiast (x,y) należą do zbioru D⊂R^2, który jest rzutem Ω na płaszczyznę XOY układu współrzędnych i punktów leżących w warstwach położonych dostatecznie blisko powierzchni geosyntetyku. Wielkości u(x,y,z,t) można wyznaczać numerycznie, a także z wykorzystaniem metod mieszanych na bazie przedstawionych wzorów lub stosować modele powłokowe MES. Można je wykorzystywać do badań symulacyjnych i eksperymentalnych. W celu przeprowadzenia identyfikacji modelu trzeba przeprowadzić badania eksperymentalne wykorzystując eksperyment czynny, bierny lub mieszany i przeprowadzić walidację modelu. Wykorzystując otrzymane wzory można prowadzić analizę ilościową i jakościową problemu, po przeprowadzeniu identyfikacji, kalibracji i walidacji modelu, najlepiej z wykorzystaniem badań in situ w celu określenia parametrów układu zastępczego. Analizę problemu dodatkowo komplikuje wzajemne oddziaływanie poszczególnych elementów konstrukcji drogi kolejowej. Np. nawierzchni kolejowej, podtorza z geosyntetykami i podłoża gruntowego. Jednak wyjściem z tej sytuacji może być wykorzystanie układów analogowych i zastępczych.