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Gdańsk University of Technology

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Publications from the year 2022

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  • Fe3–xInSnxO6 (x = 0, 0.25, or 0.5): A Family of Corundum Derivatives with Sn-Induced Polarization and Above Room Temperature Antiferromagnetic Ordering
    • Corey E. Frank
    • Emma E. McCabe
    • Fabio Orlandi
    • Pascal Manuel
    • Xiaoyan Tan
    • Zheng Deng
    • Changqing Jin
    • Mark Croft
    • Thomas Emge
    • Shukai Yu
    • Huaiyu Wang
    • Venkatraman Gopalan
    • Saul Lapidus
    • MeiXia Wu
    • Man-Rong Li
    • Juliane Gross
    • Paul Burger
    • Aleksandra Mielewczyk-Gryń
    • Tomasz Klimczuk
    • Weiwei Xie
    • David Walker
    • Martha Greenblatt
    2022 CHEMISTRY OF MATERIALS

    Three new double corundum derivative compounds, Fe3−xInSnxO6 (x = 0. 0.25, or 0.5), were synthesized at high pressure and temperature (6 GPa and 1400− 1450 °C). All of the compounds order antiferromagnetically well above room temperature (TN = 608, 532, and 432 K for x = 0, 0.25, and 0.5, respectively). The x = 0 phase crystallizes as centrosymmetric R3̅c, but the inclusion of closed-shell d10 Sn4+ induces x = 0.25 and 0.5 to crystallize as noncentrosymmetric R3c. Microprobe measurements indicate that for x = 0.25 and 0.5, the substitution of Sn4+ is not offset by vacancies, which implies the presence of Fe2+, as corroborated by X-ray absorption near-edge spectroscopy and single-crystal X-ray structure refinements. Neutron powder diffraction experiments on x = 0.5 indicate that these compounds are canted A-type antiferromagnets that, like Fe2O3 and InFeO3, consist of ferromagnetic layers that stack antiferromagnetically with a single magnetic transition. Weak ferromagnetic interactions persist to very high temperatures. Temperature-dependent second harmonic generation (SHG) measurements on x = 0.25 and 0.5 show a SHG response with ferroelectric-like hysteretic maxima that correspond with the respective magnetic transitions, which suggest coupling of the magnetic and polarization order. These new compounds provide more information about fine-tuning the electronic, magnetic, and structural properties of corundum-derived mutlferroics in the search for tunable high-temperature magnetoelectric materials.

  • Feature extraction in detection and recognition of graphical objects
    • Jerzy Dembski
    2022

    Detection and recognition of graphic objects in images are of great and growing importance in many areas, such as medical and industrial diagnostics, control systems in automation and robotics, or various types of security systems, including biometric security systems related to the recognition of the face or iris of the eye. In addition, there are all systems that facilitate the personal life of the blind people, visually impaired or people in full health, but who need devices to support them in the increasingly complex modern world, such as home monitoring systems or driving assistance systems.

  • Feature Weighted Attention-Bidirectional Long Short Term Memory Model for Change Detection in Remote Sensing Images
    • Raj Kumar Patra
    • Sujata N. Patil
    • Przemysław Falkowski-Gilski
    • Zbigniew Łubniewski
    • Rachana Poongodan
    2022 Full text Remote Sensing

    In remote sensing images, change detection (CD) is required in many applications, such as: resource management, urban expansion research, land management, and disaster assessment. Various deep learning-based methods were applied to satellite image analysis for change detection, yet many of them have limitations, including the overfitting problem. This research proposes the Feature Weighted Attention (FWA) in Bidirectional Long Short-Term Memory (BiLSTM) method to reduce the overfitting problem and increase the performance of classification in change detection applications. Additionally, data usage and accuracy in remote sensing activities, particularly CD, can be significantly improved by a large number of training models based on BiLSTM. Normalization techniques are applied to input images in order to enhance the quality and reduce the difference in pixel value. The AlexNet and VGG16 models were used to extract useful features from the normalized images. The extracted features were then applied to the FWA-BiLSTM model, to give more weight to the unique features and increase the efficiency of classification. The attention layer selects the unique features that help to distinguish the changes in the remote sensing images. From the experimental results, it was clearly shown that the proposed FWA-BiLSTM model achieved better performance in terms of precision (93.43%), recall (93.16%), and overall accuracy (99.26%), when compared with the existing Difference-enhancement Dense-attention Convolutional Neural Network (DDCNN) model.

  • Featured based CAVE software factory
    • Jacek Lebiedź
    • Bogdan Wiszniewski
    2022 Full text

    In the paper we convey the lessons learned along the path we have gone through several years since establishing a room-sized CAVE installation at our university, from craft manufacturing and ad-hoc software reuse of VR software products to the robust feature driven software product line (SPL) implementing the Product Line Engineering (PLE) factory paradigm. With that we can serve all our departments and other entities from the region by rapidly instantiating different VR products based on a standard set of core assets and driven by a set of common features of VR applications destined to be deployed in the same target CAVE system – with the minimal budget and time to market requirements. A comprehensive survey of the most representative CAVE applications created in Gdansk Tech Immersive 3D Visualization Lab (I3DVL) according to PLE paradigm presented in the paper provides evidence supporting this claim.

  • Features of irregularity in examples of Polish multi-family architecture constructed in 2011–2021 and nominated for the Mies van der Rohe award
    • Michał Malewczyk
    • Piotr Czyż
    2022 Full text Czasopismo Techniczne

    This article is devoted to the analysis of contemporary Polish multi-family architecture in the context of aesthetic irregularity. The research was limited to constructions from 2011–2021 and nominated for the Mies van der Rohe award as the objects with the greatest potential impact on shaping further trends. In their research, the authors focused on searching for the features of irregularities, which, in their opinion, have become a distinguishing feature of contemporary architectural aesthetics. The analyses in this study refer to three planes of the aesthetic dimension of architecture, namely the form, facade composition and material.

  • Featuring Semitransparent p–i–n Perovskite Solar Cells for High-Efficiency Four-Terminal/Silicon Tandem Solar Cells
    • Pei-Huan Lee
    • Ting-Tzu Wu
    • Chia-Feng Li
    • Damian Głowienka
    • Yu-Xuan Huang
    • Shih-Han Huang
    • Yu-Ching Huang
    • Wei-Fang Su
    2022 Full text Solar RRL

    Two issues need to be resolved when fabricating p–i–n semitransparent perovskite solar cells (ST-PVSCs) for four-terminal (4 T) perovskite/silicon tandem solar cells: 1) damage to the underlying absorber (MAPbI3), electron transporting layer ([6,6]-phenyl-C61-butyric acid methyl ester, PCBM), and work function (WF) modifier (polyethylenimine, PEI), resulting from the harsh sputtering conditions for the transparent electrodes (TEs) and 2) low average near-infrared transmittance (ANT) of TEs. Herein, a unique SnO2 layer to protect the MAPbI3 and PCBM layers is developed and functions as a WF modifier for a new TE (cerium-doped indium oxide, ICO), which exhibits an excellent ANT of 86.7% in the range of 800−1200 nm. Moreover, a MAPbI3-based p–i–n ST-PVSC is prepared, achieving an excellent power conversion efficiency (PCE) of 17.23%. When it is placed over the Si solar cell, a 4 T tandem solar cell with a PCE of 26.14% is obtained.

  • FEM and experimental investigations of concrete temperature field in the massive stemwall of the bridge abutment
    • Aleksandra Kuryłowicz-Cudowska
    • Krzysztof Wilde
    2022 Full text CONSTRUCTION AND BUILDING MATERIALS

    The paper deals with the prediction of early-age concrete temperature of cast-in-place stemwall of the bridge abutment. The considered object is an arch bridge located in Gda´nsk. In the case of massive structures, it is particularly important to not exceed the temperature difference between the core and the concrete surface. Too high temperature gradient generates an increase in thermal stresses, what could be the reason of exceeding the tensile strength and as a consequence cracking occurrence. Therefore, the numerical simulations of concrete hardening were conducted using own codes of finite difference and finite elements method. Based on numerical results the project of monitoring system was developed. The concrete temperature of stemwall was registered during 12 days by using fifteen 1-wire digital sensors. The recorded thermal data are highly consistent with FE results, which confirms the accuracy of the finite element model. The conducted calculations and in-situ measurements allowed to determine guidelines for proper curing of massive abutment’s wall.

  • Femtosecond Er-doped fiber laser source tunable from 872 to 1075 nm for two-photon vision studies in humans
    • Dorota Stachowiak
    • Marcin Marzejon
    • Jakub Bogusławski
    • Zbigniew Łaszczych
    • Katarzyna Komar
    • Maciej Wojtkowski
    • Grzegorz Soboń
    2022 Full text Biomedical Optics Express

    We report the development of a widely-tunable femtosecond fiber laser system and its application for two-photon vision studies. The source is based on an Er-doped fiber laser with spectral shift up to 2150 nm, followed by a second harmonic generation module to generate a frequency-doubled beam tunable from 872 to 1075 nm. The source delivers sub-230 fs pulses with nearly-constant duration over the entire tuning range, with output powers between 0.68–1.24 mW, which corresponds to a pulse energy of 13.2–24.1 pJ. Such pulse energy is sufficient for employing a system for measurements of two-photon scotopic spectral sensitivity of two-photon vision in humans. The laser parameters allow for very efficient and safe two-photon stimulation of the human visual system, as proved by a good separation between one- and two-photon thresholds for wavelengths below 950 nm, which we have confirmed for 3 healthy subjects.

  • Ferromagnetism in Pr-rich binary Pr7Ru3 intermetallic compound
    • Szymon Królak
    • Hanna Świątek
    • Karolina Górnicka
    • Michał Winiarski
    • Weiwei Xie
    • Robert J. Cava
    • Tomasz Klimczuk
    2022 Full text JOURNAL OF ALLOYS AND COMPOUNDS

    We present the synthesis and experimental characterization of the binary intermetallic compound Pr7Ru3. The polycrystalline sample was prepared by arc melting pure Pr and Ru, followed by homogenization at 500 °C and 600 °C for 48 and 89 h, respectively. Powder x-ray diffraction confirms that Pr7Ru3 crystallizes in an orthorhombic crystal structure (Pnma, space group no. 62) with the lattice parameters: a = 7.3606(7) Å, b = 23.120(1) Å and c = 6.5959(5) Å. Magnetization, resistivity, and heat capacity measurements reveal a ferromagnetic transition in Pr7Ru3 with the Curie temperature TC ∼ 24.5 K. The bulk transition is confirmed by a large λ-shape anomaly observed in the specific heat measurement. The magnetic susceptibility above the transition obeys the modified Curie-Weiss law with a positive Curie-Weiss temperature ϴCW = 30(1) K and an effective magnetic moment of 3.39(1) μB/Pr. Resistivity data for Pr7Ru3 reveals metallic-like behavior with a clear anomaly at the transition temperature which is smeared by an applied magnetic field. We also synthesized high-quality nonmagnetic analog La7Ru3 for which superconducting transition is observed with Tc = 1.95 K, in agreement with the literature.

  • Field Evaluation of High Modulus Asphalt Concrete Resistance to Low-Temperature Cracking
    • Marek Pszczoła
    • Dawid Ryś
    • Mariusz Jaczewski
    2022 Full text Materials

    High-modulus asphalt concrete has numerous advantages in comparison to conventional asphalt concrete, including increased resistance to permanent deformations and increased pavement fatigue life. However, previous studies have shown that the construction of road pavements with High Modulus Asphalt Concrete (HMAC) may significantly increase the risk of low-temperature cracking. Those observations were the motivation for the research presented in this paper. Four test sections with HMAC used in base and binder courses were evaluated in the study. Field investigations of the number of low-temperature cracks were performed over several years. It was established that the number of new low-temperature cracks is susceptible to many random factors, and the statistical term “reversion to the mean” should be considered. A new factor named Increase in Cracking Index was developed to analyze the resistance of pavement to low-temperature cracking. For all the considered field sections, samples were cut from each asphalt layer, and Thermal Stress Restrained Specimen Tests were performed in the laboratory. Correlations of temperature at failure and cryogenic stresses with the cracking intensity observed in the field were analyzed. The paper provides practical suggestions for pavement designers. When the use of high modulus asphalt concrete is planned for binder course and asphalt base, which may result in lower resistance to low-temperature cracking of pavement than in the case of conventional asphalt concrete, it is advisable to apply a wearing course with improved resistance to low-temperature cracking. Such an approach may compensate for the adverse effects of usage of high modulus asphalt concrete.

  • Finite-window RLS algorithms
    • Lu Shen
    • Yuriy Zakharov
    • Maciej Niedźwiecki
    • Artur Gańcza
    2022 Full text SIGNAL PROCESSING

    Two recursive least-squares (RLS) adaptive filtering algorithms are most often used in practice, the exponential and sliding (rectangular) window RLS algorithms. This popularity is mainly due to existence of low-complexity versions of these algorithms. However, these two windows are not always the best choice for identification of fast time-varying systems, when the identification performance is most important. In this paper, we show how RLS algorithms with arbitrary finite-length windows can be implemented at a complexity comparable to that of exponential and sliding window RLS algorithms. Then, as an example, we show an improvement in the performance when using the proposed finite-window RLS algorithm with the Hanning window for identification of fast time-varying systems.

  • Fire Protection and Materials Flammability Control by Artificial Intelligence
    • Henri Vahabi
    • Mohammad Naser Eldine
    • Mohammad Saeb
    2022 FIRE TECHNOLOGY

    Fire safety has become a major challenge of materials developers because of the massive production of organic materials, often combustibles, and their use for different purposes. In this sense, fire safety is critically considered in the development of engineering materials [1, 2]. The multiplicity of parameters contributing to the development of formulation of flame-retardant materials from one side and the sustainability concerns from the other side make the innovations cumbersome. Typically, there are variety of flame-retardant materials that are different in terms of the type, the amount, and the size, along with processing (e.g., extrusion, and additive manufacturing), and practical (e.g., ultimate price, recyclability, and life cycle) parameters that should be optimized to reach a desired product. On a parallel front, the instructions, standards, and safety requirements bring about further difficulties and limitations with materials design and fire protection. For instance, Scientific Committee on Consumer Safety (SCCS) claasifies materials as non-food products and risky materials as well as consumer services, to highlight health considerations. Correspondingly, fire suppression, fire fighting, fire extinguishing or other terms are defined, but controlling all parameters contributing to consumer safety and customer services requires identification and integration of materials and safety factors into an intelligent system capable of searching, ranking and classifying them in a very disciplined yet quick manner for emergency needs. The performance of a material under fire, both fire reaction and fire resistance, significantly depends on the shape and the geometry of structures, more specifically on the fire dynamics during a defined fire situation along with the material, ventilated, and under-ventilated situations. The selection of testing methodology, would also affect the success of strategies used for fire protection. These all would necessitate a bewildering of scenarios to be identified, classified, and examined by researchers working in the field, which wastes a great deal of time, investment, and practice.

  • FIRE RISK ASSESSMENT IN INDUSTRIAL PREMISES
    • Mariusz Jaczewski
    • Marek Pszczoła
    • Maciej Sawicki
    2022

    Chapter presents different aspects of fire risk assessment in industrial sites

  • Flame-Retardant Polymer Materials Developed by Reactive Extrusion: Present Status and Future Perspectives
    • Henri Vahabi
    • Fouad Laoutid
    • Krzysztof Formela
    • Mohammad Saeb
    • Philippe Dubois
    2022 Polymer Reviews

    The development of flame retardant polymer materials has two roots, one in materials design, and the other in materials processing. Over recent decades, different types and classes of flame retardant polymer materials have been commercialized to meet safety requirements in the construction, automotive, and coatings industries. In the vast majority of cases, the design and fabrication of new materials presenting low fire hazards could be obtained through the incorporation of one, two or more flame retardants with similar or different natures into polymers. Nevertheless, the presence of these new phases, often used at high loading levels, usually impact the polymer’s other functional properties, such as mechanical, aging and transparency. These limitations could be partially or totally overcome using reactive extrusion, which is a promising process for developing new polymers or modifying the chemical structure of existing ones. Amongst other possibilities, reactive extrusion can be used for enhancing the fire behavior of existing polymers or for the synthesis of new ones presenting inherent flame retardant properties. In recent years, several new flame retardant polymers have been developed by reactive extrusion, but these developments have not been systematically described with regard to their technical circumstances, properties, and commercial potential. This short review attempts to overview and classify the available reports on the development of flame-retardant polymeric materials through reactive extrusion processes.

  • Flexomagneticity in buckled shear deformable hard-magnetic soft structures
    • Mohammad Malikan
    • Victor Eremeev
    2022 Full text CONTINUUM MECHANICS AND THERMODYNAMICS

    This research work performs the first time exploring and addressing the flexomagnetic property in a shear deformable piezomagnetic structure. The strain gradient reveals flexomagneticity in a magnetization phenomenon of structures regardless of their atomic lattice is symmetrical or asymmetrical. It is assumed that a synchronous converse magnetization couples both piezomagnetic and flexomagnetic features into the material structure. The mathematical modeling begins with the Timoshenko beam model to find the governing equations and non-classical boundary conditions based on shear deformations. Flexomagneticity evolves at a small scale and dominant at micro/nanosize structures. Meanwhile, the well-known Eringen’s-type model of nonlocal strain gradient elasticity is integrated with the mathematical process to fulfill the scaling behavior. From the viewpoint of the solution, the displacement of the physical model after deformation is carried out as the analytical solution of the Galerkin weighted residual method (GWRM), helping us obtain the numerical outcomes on the basis of the simple end conditions. The best of our achievements display that considering shear deformation is essential for nanobeams with larger values of strain gradient parameter and small amounts of the nonlocal coefficient. Furthermore, we showed that the flexomagnetic (FM) effect brings about more noticeable shear deformations’ influence.

  • Flexomagneticity in Functionally Graded Nanostructures
    • Mohammad Malikan
    • Tomasz Wiczenbach
    • Victor Eremeev
    2022 Full text

    Functionally graded structures have shown the perspective of materials in a higher efficient and consistent manner. This study reports a short investigation by concentrating on the flexomagnetic response of a functionally graded piezomagnetic nano-actuator, keeping in mind that the converse magnetic effect is only taken into evaluation. The rule of mixture assuming exponential composition of properties along with the thickness is developed for the ferromagnetic bulk. Nonlocal effects are assigned to the model, respecting Eringen’s hypothesis. The derived equations deserve to be analytically solved. Therefore, numerical results are generated for fully fixed ends. It is denoted that the functionality grading feature of a magnetic nanobeam can magnify the flexomagnetic effect leading to high-performance nanosensors/actuators.

  • Fluconazole resistant Candida auris clinical isolates have increased levels of cell wall chitin and increased susceptibility to a glucosamine-6-phosphate synthase inhibitor
    • Garima Shahi
    • Mohit Kumar
    • Andrzej Skwarecki
    • Matt Edmondson
    • Atanu Banerjee
    • Jane Usher
    • Neil A.R. Gow
    • Sławomir Milewski
    • Rajendra Prasad
    2022 Full text Cell Surface

    In 2009 Candida auris was first isolated as fungal pathogen of human disease from ear canal of a patient in Japan. In less than a decade, this pathogen has rapidly spread around the world and has now become a major health challenge that is of particular concern because many strains are resistant to multiple class of antifungal drugs. The lack of available antifungals and rapid increase of this fungal pathogen provides an incentive for the development of new and more potent anticandidal drugs and drug combinatorial treatments. Here we have explored the growth inhibitory activity against C. auris of a synthetic dipeptide glutamine analogue, L-norvalyl-N3-(4-methoxyfumaroyl)-L-2,3- diaminopropanoic acid (Nva-FMDP), that acts as an inhibitor of glucosamine-6-phosphate (GlcN-6-P) synthase - a key enzyme in the synthesis of cell wall chitin. We observed that in contrast to FLC susceptible isolates of C. auris, FLC resistant isolates had elevated cell wall chitin and were susceptible to inhibition by Nva-FMDP. The growth kinetics of C. auris in RPMI-1640 medium revealed that the growth of FLC resistant isolates were 50–60% more inhibited by Nva-FMDP (8 g/ml) compared to a FLC susceptible isolate. Fluconazole resistant strains displayed increased transcription of CHS1, CHS2 and CHS3, and the chitin content of the fluconazole resistant strains was reduced following the Nva-FMDP treatment. Therefore, the higher chitin content in FLC resistant C. auris isolates may make the strain more susceptible to inhibition of the antifungal activity of the Nva-FMDP peptide conjugate

  • Fluid structure interaction study of non-Newtonian Casson fluid in a bifurcated channel having stenosis with elastic walls
    • Hasan Shahzad
    • Xinhua Wang
    • Abuzar Ghaffari
    • Kaleem Iqbal
    • Muhammad Bilal Hafeez
    • Marek Krawczuk
    • Wiktoria Wojnicz
    2022 Full text Scientific Reports

    Fluid–structure interaction (FSI) gained a huge attention of scientists and researchers due to its applications in biomedical and mechanical engineering. One of the most important applications of FSI is to study the elastic wall behavior of stenotic arteries. Blood is the suspension of various cells characterized by shear thinning, yield stress, and viscoelastic qualities that can be assessed by using non-Newtonian models. In this study we explored non-Newtonian, incompressible Casson fluid flow in a bifurcated artery with a stenosis. The two-dimensional Casson model is used to study the hemodynamics of the flow. The walls of the artery are supposed to be elastic and the stenosis region is constructed in both walls. Suitable scales are used to transform the nonlinear differential equations into a dimensionless form. The problem is formulated and discretized using Arbitrary Lagrangian–Eulerian (ALE) approach. The finite element method (FEM) technique is used to solve the system of equations, together with appropriate boundary conditions. The analysis is carried out for the Bingham number, Hartmann number, and Reynolds number. The graphical results of pressure field, velocity profile, and load on the walls are assessed and used to study the influence of hemodynamic effects on stenotic arteries, bifurcation region, and elastic walls. This study shows that there is an increase in wall shear stresses (WSS) with increasing values of Bingham number and Hartmann number. Also, for different values of the Bingham number, the load on the upper wall is computed against the Hartmann number. The result indicate that load at the walls increases as the values of Bingham number and Hartmann number increase.

  • Fluid–Structure Interaction methods for the progressive anatomical and artificial aortic valve stenosis
    • Marcin Nowak
    • Eduardo Divo
    • Wojciech P. Adamczyk
    2022 INTERNATIONAL JOURNAL OF MECHANICAL SCIENCES

    Cardiovascular system diseases, as aortic valve stenosis, are the main cause of mortality and morbidity among patients. There is still a room for enhancement of the diagnostic and therapeutic procedures, which will lead to improvement of the treatment. One of the remedies are the computer tools to support the medical diagnoses and prostheses design. The development of a procedure for modeling the aortic valves: anatomical tricuspid valve and artificial bileaflet valve, still is a very challenging task. In presented work, the application of the novel, advanced moving mesh model, that consists of the coupling of the dynamic mesh smoothing and the overset mesh technique, to speed up the computation and improve the convergence and stability was shown. The real 2D and 3D vasculature and valve geometries were created based on the echocardiography images available in literature. The calculations of anatomical and artificial valve models were performed for the various severity of the atherosclerosis — not previously published for the bileaflet mechanical valve. The impact of calcification process onto natural and artificial aortic valves was assessed and compared.

  • Fluorescence Imaging Using Methylene Blue Sentinel Lymph Node Biopsy in Melanoma
    • Tomasz Cwalinski
    • Jarosław Skokowski
    • Wojciech Polom
    • Luigi Marano
    • Maciej Swierblewski
    • Kamil Drucis
    • Giandomenico Roviello
    • Natalia Cwalina
    • Leszek Kalinowski
    • Franco Roviello
    • Karol Polom
    2022 Surgical Innovation

    Introduction: Fluorescence imaging of sentinel node biopsy in melanoma is a novel method. Both indocyanine green (ICG) and methylene blue (MB) have fl uorescent properties. The aim of this study was to present, for the fi rst time in a clinical series of patients, the possible usage of MB as a fl uorescent dye for sentinel node biopsy during surgery for melanoma. Material and methods: Twenty patients with skin melanoma, who were candidates for sentinel node biopsy were enrolled in our study. All patients underwent simultaneous use of standard nanocolloid and blue dye. Transcutaneous visualization of the sentinel node, visualization of lymphatic channels as well as sentinel node fl uorescent visualization were all measured. We also performed calculations of Signal to Background ratios (SBR). Results: In 15% (3/20) of patients, the fl uorescent sentinel node was visible through the skin. The median SBR for the sentinel node visualization by fl uorescence was 3.15 (range, 2.7 – 3.5). Lymphatic channels were visible in lymphatic tissue via fl uorescence before visualization by the naked eye in 4 patients (20%). The median SBR ratio was 3.69 (range, 2.7 – 4.2). Sentinel nodes were visible by fl uorescence in 13 cases (65%). The median SBR ratio was 2.49 (range, 1.5 – 5.7). No factors were found to be associated with fl uorescent MB visualization of a sentinel node during biopsy. Conclusion: This is the fi rst clinical study presenting the usefulness of fl uorescent sentinel node biopsy in melanoma patients using MB as a fl uorophore. Further studies are necessary to provide methods for its ’ clinical implementation.