2022 - Publications Repository - Gdańsk University of Technology

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Publications from the year 2022

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Galerkin formulations with Greville quadrature rules for isogeometric shell analysis: Higher order elements and locking
- T.j.r. Hughes
- Zhihui Zou
- M.a. Scott
- Roger Sauer
- E.j. Savitha
2022
We propose new Greville quadrature schemes that asymptotically require only four in-plane points for Reissner-Mindlin (RM) shell elements and nine in-plane points for Kirchhoff-Love (KL) shell elements in B-spline and NURBS-based isogeometric shell analysis, independent of the polynomial degree of the elements. For polynomial degrees 5 and 6, the approach delivers high accuracy, low computational cost, and alleviates membrane and transverse shear locking.
Game-based Sprint retrospectives: multiple action research
- Adam Przybyłek
- Marta Albecka
- Olga Springer
- Wojciech Kowalski
2022 Full text EMPIRICAL SOFTWARE ENGINEERING
In today’s fast-paced world of rapid technological change, software development teams need to constantly revise their work practices. Not surprisingly, regular reflection on how to become more effective is perceived as one of the most important principles of Agile Software Development. Nevertheless, running an effective and enjoyable retrospective meeting is still a challenge in real environments. As reported by several studies, the Sprint Retrospective is an agile practice most likely to be implemented improperly or sacrificed when teams perform under pressure to deliver. To facilitate the implementation of the practice, some agile coaches have proposed to set up retrospective meetings in the form of retrospective games. However, there has been little research-based evidence to support the positive effects of retrospective games. Our aim is to investigate whether the adoption of retrospective games can improve retrospective meetings in general and lead to positive societal outcomes. In this paper, we report on an Action Research project in which we implemented six retrospective games in six Scrum teams that had experienced common retrospective problems. The received feedback indicates that the approach helped the teams to mitigate many of the “accidental difficulties” pertaining to the Sprint Retrospective, such as lack of structure, dullness, too many complaints, or unequal participation and made the meetings more productive to some degree. Moreover, depending on their individual preferences, different participants perceived different games as having a positive impact on their communication, motivation-and-involvement, and/or creativity, even though there were others, less numerous, who had an opposite view. The advantages and disadvantages of each game as well as eight lessons learned are presented in the paper.
Gdańsk Urban Initiative Laboratory
- Joanna Bach-Głowińska
- Jacek Łubiński
- Karolina Krośnicka
- Joanna Tobolewicz
2022
Gdansk is Poland's principal seaport, situated on the southern edge of the Gdansk Bay on the Baltic Sea. The city is the capital and largest city of the Pomeranian Voivodeship. Gdansk, in a conurbation with the city of Gdynia and the resort town of Sopot, and suburban communities, jointly forms Poland's fourth largest metropolitan area, with a population approaching 1.4 million. The pathways towards the Micro ULL FWE Nexus Square were established together by academics, city experts, business partners, and international experts as stakeholders. The several thematic Urban Living Labs undertaken within carefully selected groups had created chances for user friendly innovations. The integrated multi-channel monitoring system will allow for the detailed tracking of individual use of media by devices on board.
Gender differences in the perception of the Quality of College Life in Spanish University
- Juan Jose Blazquez-Resino
- Edyta Gołąb-Andrzejak
- Santiago Gutierrez-Broncano
2022 Full text International Journal of Intelligent Enterprise
Through the current research, we intend to analyse how students differ in their levels of quality of college life (QCL) according to gender, and how this relates to overall quality of life (QoL) and loyalty [measured by Identification and word of mouth (WoM)] to their specific university. The survey included 243 students attending public university in Spain. The results obtained through the analysis of data allow affirming that there are differences between women and men both in the configuration of the quality of their college life and in its effect on the loyalty shown towards the college. This paper contributes towards an improved comprehension regarding the differences between the students according to their gender, so that managers can develop strategies better adapted to students.
Generalized Dobrushin Coefficients on Banach Spaces
- Wojciech Bartoszek
- Marek Beśka
- Wiktor Florek
2022 Full text Bulletin of the Iranian Mathematical Society
The asymptotic behavior of iterates of bounded linear operators (not necessarily positive), acting on Banach spaces, is studied. Through the Dobrushin ergodicity coefficient, we generalize some ergodic theorems obtained earlier for classical Markov semigroups acting on L1 (or positive operators on abstract state spaces).
Generalized Dold sequences on partially-ordered sets
- Grzegorz Graff
- Jacek Gulgowski
- Małgorzata Lebiedź
2022 Full text ELECTRONIC JOURNAL OF COMBINATORICS
Dold sequences constitute an important class of integer sequences that play an important role in combinatorics, number theory, topology and dynamical systems. We generalize the notion of Dold sequence for the case of partially ordered sets and describe their properties. In particular we give two alternative descriptions of generalized Dold sequences: by some class of elementary sequences as well as by different generalized arithmetical functions, both defined on a partially ordered set. We also define vector Dold sequences and show their combinatorial interpretation in terms of periodic points.
Generalized Formulation of Response Features for Reliable Optimization of Antenna Input Characteristics
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
2022 IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION
Electromagnetic (EM)-driven parameter adjustment has become imperative in the design of modern antennas. It is necessary because the initial designs rendered through topology evolution, parameter sweeping, or theoretical models, are often of poor quality and need to be improved to satisfy stringent performance requirements. Given multiple objectives, constraints, and a typically large number of geometry parameters, the design closure should be carried out through numerical optimization. Unfortunately, standard algorithms entail high CPU expenses and are prone to failure. Feature-based optimization (FBO) is one of the methods developed to alleviate these difficulties by reformulating the design task in terms of the characteristic points extracted from EM-simulated responses. FBO capitalizes on a less nonlinear relationship between the feature point coordinates and antenna dimensions as compared to the original responses (e.g., frequency characteristics). This leads to flattening the functional landscape to be handled, faster convergence of the optimization algorithms, and a possibility of mitigating the issues pertinent to multi-modality. Notwithstanding, the response features have to be individually defined for each type of antenna response and tailored to a particular type of design specifications. This requires user experience and hinders a widespread application of FBO. This paper proposes a generalized and unified feature point definition, which is suitable for majority of typical antenna input characteristics (narrow-, multi-band, enhanced bandwidth, wideband), and performance specifications (matching improvement, bandwidth enhancement, mixture thereof). Our framework allows for an automated definition of the feature points given the performance specifications, along with their extraction from EM-simulated responses. The operation of the framework is illustrated using a range of planar antennas and favorably compared to conventional (non-feature-based) design closure task formulation.
Generalized regression neural network and fitness dependent optimization: Application to energy harvesting of centralized TEG systems
- Adeel Mirza
- Syed Kamran Haider
- Abbas Ahmed
- Ateeq Ur Rehman
- Muhammad Shafiq
- Mohit Bajaj
- Hossam M. Zawbaa
- Paweł Szczepankowski
- Salah Kamel
2022 Full text Energy Reports
The thermoelectric generator (TEG) system has attracted extensive attention because of its applications in centralized solar heat utilization and recoverable heat energy. The operating efficiency of the TEG system is highly affected by operating conditions. In a series-parallel structure, due to diverse temperature differences, the TEG modules show non-linear performance. Due to the non-uniform temperature distribution (NUTD) condition, several maximum power points (MPPs) appear on the P/V curve. In multiple MPPs, the true global maximum power points (GMPP) are very important for optimum action. The existing conventional technologies have slow tracking speed, low productivity, and unwanted fluctuations in voltage curves. To overcome the TEG system behavior and shortcomings, A novel control technology for the TEG system is proposed, which utilizes the improved generalized regression neural network and fitness dependent optimization (GRNNFDO) to track the GMPP under dynamic operating conditions. Conventional TEG system control techniques are not likely to trace true GMPP. Our novel GRNNFDO can trace the true GMPP for NUTD and under varying temperature conditions In this article, some major contributions in the area of the TEG systems are investigated by solving the issues such as NUTD global maxima tracking, low efficiency of TEG module due to mismatch, and oscillations around optimum point. The results of GRNNFDO are compared with the Cuckoo-search algorithm (CSA), and grasshopper optimization (GHO) algorithm and particle swarm optimization (PSO) algorithm. Results of GRNNFDO are verified with experiments and authenticated with MATLAB/SIMULINK. The proposed GRNNFDO control technique generates up to 7% more energy than PSO and 60% fast-tracking than meta-heuristic algorithms.
Genetic and pharmacologic proteasome augmentation ameliorates Alzheimer’s-like pathology in mouse and fly APP overexpression models
- E. Sandra Chocron
- Erin Munkácsy
- Harper S. Kim
- Przemyslaw Karpowicz
- Nisi Jiang
- Candice E. Van Skike
- Nicholas DeRosa
- Andy Q. Banh
- Juan P. Palavicini
- Paweł Wityk
- Leszek Kalinowski
- Veronica Galvan
- Pawel A. Osmulski
- Elzbieta Jankowska
- Maria Gaczynska
- Andrew M. Pickering
2022 Full text Science Advances
The proteasome has key roles in neuronal proteostasis, including the removal of misfolded and oxidized proteins, presynaptic protein turnover, and synaptic efficacy and plasticity. Proteasome dysfunction is a prominent feature of Alzheimer’s disease (AD). We show that prevention of proteasome dysfunction by genetic manipulation delays mortality, cell death, and cognitive deficits in fly and cell culture AD models. We developed a transgenic mouse with neuronal-specific proteasome overexpression that, when crossed with an AD mouse model, showed reduced mortality and cognitive deficits. To establish translational relevance, we developed a set of TAT-based proteasome- activating peptidomimetics that stably penetrated the blood-brain barrier and enhanced 20 S /26 S proteasome activity. These agonists protected against cell death, cognitive decline, and mortality in cell culture, fly, and mouse Downloaded from https://www.science.org at Medical University of Gdansk on June 11, 2022 AD models. The protective effects of proteasome overexpression appear to be driven, at least in part, by the pro- teasome’s increased turnover of the amyloid precursor protein along with the prevention of overall proteostatic dysfunction.
Genetic and pharmacologic proteasome augmentation ameliorates Alzheimer’s-like pathology in mouse and fly APP overexpression models
- Paweł Wityk
- E. Sandra Chocron
- Erin Munkácsy
- Harper S. Kim
- Przemyslaw Karpowicz
- Nisi Jiang
- Van Skike E. Candice
- Nicholas DeRosa
- Banh Q. Andy
- Palavicini P. Juan
- Leszek Kalinowski
- Veronica Galvan
- Pawel A. Osmulski
- Elzbieta Jankowska
- Maria Gaczynska
- Andrew M. Pickering
2022 Full text Science Advances
The proteasome has key roles in neuronal proteostasis, including the removal of misfolded and oxidized proteins, presynaptic protein turnover, and synaptic efficacy and plasticity. Proteasome dysfunction is a prominent feature of Alzheimer’s disease (AD). We show that prevention of proteasome dysfunction by genetic manipulation delays mortality, cell death, and cognitive deficits in fly and cell culture AD models. We developed a transgenic mouse with neuronal-specific proteasome overexpression that, when crossed with an AD mouse model, showed reduced mortality and cognitive deficits. To establish translational relevance, we developed a set of TAT-based proteasome-activating peptidomimetics that stably penetrated the blood-brain barrier and enhanced 20S/26S proteasome activity. These agonists protected against cell death, cognitive decline, and mortality in cell culture, fly, and mouse AD models. The protective effects of proteasome overexpression appear to be driven, at least in part, by the proteasome’s increased turnover of the amyloid precursor protein along with the prevention of overall proteostatic dysfunction.
Geodezyjne wyznaczanie przemieszczeń pionowych obiektów inżynierskich z pomiarów uzyskanych metodą niwelacji hydrostatycznej
- Waldemar Kamiński
2022 Inżynieria Morska i Geotechnika
Niwelacja hydrostatyczna (NH) jest obecnie często stosowaną metodą wyznaczenia przemieszczeń pionowych obiektów inżynierskich takich jak: mosty, wiadukty, estakady, tunele, wysokie budynki, obiekty zabytkowe, specjalistyczne obiekty inżynierskie (np. synchrotron), hale sportowe, widowiskowe, itp. Zastosowane w systemach niwelacji hydrostatycznej (SNH) sensory (czujniki) pomiarowe obejmują sensor referencyjny (RS) oraz czujniki umieszczone w punktach kontrolowanych (PK). Sensor referencyjny jest to czujnik umieszczony w takim miejscu i w takim punkcie, który w założeniach teoretycznych nie podlega przemieszczeniom pionowym i w stosunku do jego wysokości wyznaczane są przemieszczenia PK. Zasada NH wynika z prawa Bernoulliego. Wykorzystując w NH prawo Bernoulliego, należy uwzględnić między innymi następujące parametry: ciśnienie atmosferyczne, siłę grawitacji, gęstość cieczy przepływającej przez sensory pomiarowe. Wymienione parametry wyznaczane są z pewnymi błędami średnimi mającymi wpływ na oszacowanie dokładności rezultatów przemieszczeń pionowych. Należy dodać, że w literaturze przedmiotu przedstawiono szereg prac dotyczących między innymi analiz dokładności indywidualnych wymienionych wyżej parametrów i ich wpływu na otrzymane przemieszczenia pionowe. W niniejszym artykule przedstawiono koncepcję geodezyjnego wyznaczania przemieszczeń SNH, oceny dokładności i istotności otrzymanych wielkości. Do oceny dokładności wykorzystano macierze kofaktorów (estymatorów wariancji). Posługując się modelem kinematycznym przemieszczających się PK badanego obiektu inżynierskiego przedstawiono problematykę predykcji przemieszczeń pionowych na dowolną epokę pomiarową. Wyznaczono także współczynnik korelacji liniowej Pearsona dla analizowanych w artykule parametrów. Przemieszczenia pionowe i analizę dokładności uzyskanych wartości wykonano dla zmodyfikowanego przykładu praktycznego zaczerpniętego z literatury przedmiotu [2]. Natomiast problem predykcji przedstawiono w oparciu o symulowane wyniki pomiaru przyspieszeń trzech PK badanego obiektu i ich błędów średnich. Prezentowane opracowanie jest uzupełnieniem i rozszerzeniem teoretyczno- empirycznych analiz przedstawionych w pracy [5].
Glass-ceramic joining of Fe22Cr porous alloy to Crofer22APU: interfacial issues and mechanical properties
- Fabiana D'Isanto
- Milena Salvo
- Sebastian Molin
- Damian Koszelow
- Hassan Javed
- Sufyan Akram
- Andreas Chrysanthou
- Federico Smeacetto
2022 Full text CERAMICS INTERNATIONAL
This work deals with the joining of porous Fe22Cr ferritic stainless steel to a dense Crofer22APU plate by using a silica-based, Ba-containing glass-ceramic. The chemical and interfacial stability and the mechanical properties of the joints were evaluated before and after thermal ageing at 700 ◦C for 500hrs. The sintering behaviour of the glass was assessed by using heating stage microscopy (HSM) to study the influence of a porous metal substrate on the shrinkage of the joining material. Scanning electron microscopy revealed that there were no defects or cracks at the porous alloy/glass-ceramic interface for both the as-joined samples and the samples after thermal ageing at 700 ◦C for 500 h. However, at this exposure temperature, the porous alloy started to form an oxide scale at the interface with the glass-ceramic and the internal surface of the porous alloy. Finally, the evaluation of the mechanical properties by tensile testing showed that the properties were not affected by thermal ageing at 700 ◦C.
Global defensive secure structures
- Michał Małafiejski
- Kacper Wereszko
2022
Let S ⊂ V (G) for a given simple non-empty graph G. We define for any nonempty subset X of S the predicate SECG,S(X) = true iff |NG[X]∩S| ≥ |NG[X]\S|. Let H be a non-empty family of graphs such that for each vertex v ∈ V (G) there is a subgraph H of G containing v and isomorphic to a member of H. We introduce the concept of H-alliance extending the concept of global defensive secure structures. By an H-alliance in a graph G we mean a set S ⊂ V (G) such that (1) each vertex v ∈ S belongs to a subgraph H of G that is isomorphic to a member of H, and (2) for each H ⊂ G[S] isomorphic to a member of H, SECG,S(V (H)) = true. If S is also a dominating set of G, we call it a global H-alliance of G. If H = {K1}, then such an H-alliance we call a defensive alliance (GA) [1] or a vertex alliance. If H = {K2}, then such an H-alliance we call an edge alliance [2]. In the case of H is a class of all complete graphs (i.e., K1, K2, . . .), then an H-alliance we call a complete alliance [3]. If H = {K1, . . . , Kk}, then an H-alliance we call k-complete alliance. In this talk we present general properties of global defensive secure structures (i.e., H-alliances), algorithms for H-alliance problems (exact and approximation ones), and we provide new N P-complete results for global defensive secure structures for bounded degree graphs. We formulate also H-alliance problem in some special cases as ILP problem and study a few algorithmic approaches.
Global Design Optimization of Microwave Circuits Using Response Feature Inverse Surrogates
- Anna Pietrenko-Dąbrowska
- Sławomir Kozieł
- Leifur Leifsson
2022
Modern microwave design has become heavily reliant on full-wave electromagnetic (EM) simulation tools, which are necessary for accurate evaluation of microwave components. Consequently, it is also indispensable for their development, especially the adjustment of geometry parameters, oriented towards performance improvement. However, EM-driven optimization procedures incur considerable computational expenses, which may become impractical even in the case of local tuning, and prohibitive whenever global search is vital (e.g., multi-model tasks, simulation-based miniaturization, circuit re-design within extended ranges of operating frequencies). This work presents a novel approach to a computationally-efficient globalized parameter tuning of microwave components. Our framework employs the response feature technology, along with the inverse surrogate models. The latter permit low-cost exploration of the parameter space, and identification of the most advantageous regions that contain designs featuring performance parameters sufficiently close to the assumed target. The initial parameter vectors rendered in such a way undergo then local, gradient-based tuning. The incorporation of response features allows for constructing the inverse model using small training data sets due to simple (weakly-nonlinear) relationships between the operating parameters and dimensions of the circuit under design. Global optimization of the two microstrip components (a coupler and a power divider) is carried out for the sake of verification. The results demonstrate global search capability, excellent success rate, as well as remarkable efficiency with the average optimization cost of about a hundred of EM simulations of the circuit necessary to conclude the search process.
Global Surrogate Modeling by Neural Network-Based Model Uncertainty
- Leifur Leifsson
- Jethro Nagawkar
- Laurel Barnet
- Kenneth Bryden
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
2022
This work proposes a novel adaptive global surrogate modeling algorithm which uses two neural networks, one for prediction and the other for the model uncertainty. Specifically, the algorithm proceeds in cycles and adaptively enhances the neural network-based surrogate model by selecting the next sampling points guided by an auxiliary neural network approximation of the spatial error. The proposed algorithm is tested numerically on the one-dimensional Forrester function and the two-dimensional Branin function. The results demonstrate that global surrogate modeling using neural network-based function prediction can be guided efficiently and adaptively using a neural network approximation of the model uncertainty.
Global value chains and labour markets – simultaneous analysis of wages and employment
- Sabina Szymczak
- Joanna Wolszczak-Derlacz
2022 Full text Economic Systems Research
This study examines the overall effect of global value chains (GVCs) on wages and labour demand. It exploits the World Input–Output Database to measure GVC involvement via recently developed participation indices (using both backward and forward linkages) and the relative GVC position using three-stage least squares regression. We find that the relative GVC position is negatively correlated with wages and employment and that the GVC participation effect depends on whether backward or forward linkages are considered. Moreover, we find heterogeneity across both countries (middle- vs high-income) and sectors (manufacturing versus services). Notably, the effect of GVC involvement on the labour market differs from that produced by traditional domestic trade.
Globalized Simulation-Driven Miniaturization of Microwave Circuits by Means of Dimensionality-Reduced Constrained Surrogates
- Sławomir Kozieł
- Anna Pietrenko-Dąbrowska
- Marzieh Mahrokh
2022 Full text Scientific Reports
Small size has become a crucial prerequisite in the design of modern microwave components. Miniaturized devices are essential for a number of application areas, including wireless communications, 5G/6G technology, wearable devices, or the internet of things. Notwithstanding, size reduction generally degrades the electrical performance of microwave systems. Therefore, trade-off solutions have to be sought that represent acceptable compromises between the ability to meet the design targets and physical compactness. From an optimization perspective, this poses a constrained task, which is computationally expensive because a reliable evaluation of microwave components has to rely on full-wave electromagnetic (EM) analysis. Furthermore, due to its constrained nature, size reduction is a multimodal problem, i.e., the results are highly dependent on the initial design. Thus, utilization of global search algorithms is advisable in principle, yet, often undoable in practice because of the associated computational expenses, especially when using nature-inspired procedures. This paper introduces a novel technique for globalized miniaturization of microwave components. Our technique starts by identifying the feasible region boundary, and by constructing a dimensionality-reduced surrogate model therein. Global optimization of the metamodel is followed by EM-driven local tuning. Application of the domain-confined surrogate ensures low cost of the entire procedure, further reduced by the incorporation of variable-fidelity EM simulations. Our framework is validated using two microstrip couplers, and compared to nature-inspired optimization, as well as gradient-based size reduction. The results indicate superior miniaturization rates and low running cost, which make the presented algorithm a potential candidate for efficient simulation-based design of compact structures.
Glossary [Intellectual Output 1] Glossary as a method for reflection on complex research questions
- Małgorzata Kostrzewska
- Justyna Borucka
- Bartosz Macikowski
- Dorota Kamrowska-Załuska
- Lotte Bjerregaard Jensen
2022
Globalization and digitization are strongly influencing the process of shaping the built environment. The latter is causing the new design tools to emerge faster than ever before in history, while the former is speeding up not only the development, but also the broad roll-out of more agile and interdisciplinary methodologies and work approaches. The design process is also becoming more and more inter- and trans-disciplinary. This is leading to the formation of design teams, in which team members bring together not only very different backgrounds and experiences but also different sets of vocabulary, which is one of the causes impeding flawless cooperation and a lack of common understanding within the team. These trends call for a shared platform of understanding and clarification of professional terms and concepts in order to make the design process not only efficient, but also fully relatable and well-founded. In today’s highly specialized world, professionals and specialists immerse themselves deeply into their fields, using a highly specialized, often hermetic vocabulary that is becoming less accessible and comprehensible to the wider public. The BuildDigiCraft project explores what concepts and notions researchers and participants use who are involved in design processes aimed at a high-quality built environment. The question is whether engineers, architects, planners, builders, designers, craftsmen, artists, environmental engineers and other experts, regardless of whether they deal with digitally-driven or traditionally-based methods and tools, are actually able to understand each other today using a mutually comprehensible linguistic corpus. Therefore, the aim of this intellectual output is to create a foundation for a shared understanding of the main concepts explored within the BuildDigiCraft project. The aim of the intellectual output Glossary is to create a common foundation for shared understanding of the main concepts explored within the BuildDigiCraft project. Unlike classical glossaries based on jointly developed vocabulary definitions, the BuildDigiCraft Glossary offers a method for reflection on complex research questions by applying a Glossary Matrix Tool for a temporal and scale-oriented exploration of terms, concepts and ideas used in the project.
Glucose oxidase as an important yet overlooked factor determiningthe antibacterial activity of bee pollen and bee bread
- Karolina Pełka
- Marcela Bucekova
- Jana Godocikova
- Piotr Szweda
- Juraj Majtan
2022 EUROPEAN FOOD RESEARCH AND TECHNOLOGY
Bee pollen (BP) and bee bread (BB) have attracted great attention due to their biological activities including antibacterial activity. However, the mechanism of antibacterial activity is largely unknown. Therefore, we aimed to characterise the antibacterial effect of BP and BB aqueous extracts against bacterial pathogens (Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Proteus mirabilis and Enterococcus faecalis) and identify the key compound(s) responsible for this effect. Here, we demonstrate that BP and particularly BB extracts display antibacterial activity which is significantly increased in the presence of glucose. Immunoblot analysis of extracts revealed the presence of MRJP1 in all analysed BP and BB samples and the enzyme glucose oxidase (GOX) in the majority of BB samples. Treatment of extracts with catalase resulted in the restoration of bacterial growth but only in those samples where glucose supplementation caused the enhancement of antibacterial activity. Our findings provide a deeper understanding of antibacterial activity of BP/BB which is mediated by the enzymatic activity of bee-derived GOX.
Glucosinolates from lepidium peruvianum as potential antiamnestic drugs
- Dominik Tarabasz
- Dominik Szwajgier
- Paweł Szczeblewski
- Tomasz Laskowski
- Wojciech Płaziński
- Ewa Baranowska-Wójcik
- Wirginia Kukula-Koch
- Henry O. Meissner
2022
Lepidium peruvianum (maca) (Brassicaceae) is a naturally occurring plant mainly in the high Andes of Peru. In recent years, it has been intensively researched in terms of its influence on various diseases and towards health improvement. Alzheimer’s disease is an incurable disease that most often affects adults over the age of 60. As since 2003 the US Food and Drug Administration (FDA) did not approve any new drug for Alzheimer’s disease (AD) until 2021, there is still a need for new drugs to slow down the progress of the disease. The study focuses on glucosinolates that are present in different cultivars of L. peruvianum tubers and evaluates their inhibitory properties against two cholinesterases: acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE). By comparing the HPLC-ESI-QTOF-MS/MS fingerprints of different extracts, the phenotypes that were the most rich in glucosinolates were selected. Qualitative analysis of the sulphur-containing metabolites in 50% ethanolic extracts confirmed the presence of ten major components that belonged to the groups of: aliphatic, indolyl, and aromatic glucosinolates, with glucotropaeolin being the leading one, detected at levels between 0–1.57% depending on phenotype, size, processing, and collection site. The PCA analysis showed important variations in glucosinolate content between the samples and different ratios of the detected compounds. The color and size of maca tubers have been shown to have a significant effect on the glucosinolate content. The applied in vitro activity tests confirmed inhibitory properties of extracts and single glucosinolates against AChE and BuChE. The molecular activity of glucosinolates has been explained in relation to both enzymes: AChE and BuChE showing that these metabolites most likely work by blocking the catalytic sites of the enzymes. Based on the obtained results and described mechanism of action, it could be concluded that glucosinolates exhibit inhibitory properties against two cholinesterases present in the synaptic cleft, which indicates that selected phenotypes of L. peruvianum cultivated under well-defined environmental and ecological conditions may present a valuable plant material to be considered for the development of therapeutic products with memory-stimulating properties.