Publications in journals ranked by Journal Citation Reports (JCR) 
Publications in other journals ranked by Ministry of Science and Higher Education
Conference publications indexed in the Web of Science Core Collection
Publications in other journals and conference proceedings
Affiliation to IPPT PAN

1.Richter Ł., Żuk P.J., Szymczak P., Paczesny J., Bąk K.M., Szymborski T., Garstecki P., Stone H.A., Hołyst R., Drummond C., Ions in an AC electric field: strong long-range repulsion between oppositely charged surfaces, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.125.056001, Vol.125, No.5, pp.056001-1-5, 2020
Richter Ł., Żuk P.J., Szymczak P., Paczesny J., Bąk K.M., Szymborski T., Garstecki P., Stone H.A., Hołyst R., Drummond C., Ions in an AC electric field: strong long-range repulsion between oppositely charged surfaces, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.125.056001, Vol.125, No.5, pp.056001-1-5, 2020

Abstract:
Two oppositely charged surfaces separated by a dielectric medium attract each other. In contrast we observe a strong repulsion between two plates of a capacitor that is filled with an aqueous electrolyte upon application of an alternating potential difference between the plates. This long-range force increases with the ratio of diffusion coefficients of the ions in the medium and reaches a steady state after a few minutes, which is much larger than the millisecond timescale of diffusion across the narrow gap. The repulsive force, an order of magnitude stronger than the electrostatic attraction observed in the same setup in air, results from the increase in osmotic pressure as a consequence of the field-induced excess of cations and anions due to lateral transport from adjacent reservoirs.

2.Gupta A., Żuk P.J., Stone H.A., Charging dynamics of overlapping double layers in a cylindrical nanopore, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.125.076001, Vol.125, No.7, pp.076001-1-6, 2020
Gupta A., Żuk P.J., Stone H.A., Charging dynamics of overlapping double layers in a cylindrical nanopore, PHYSICAL REVIEW LETTERS, ISSN: 0031-9007, DOI: 10.1103/PhysRevLett.125.076001, Vol.125, No.7, pp.076001-1-6, 2020

Abstract:
The charging of electrical double layers inside a cylindrical pore has applications to supercapacitors, batteries, desalination and biosensors. The charging dynamics in the limit of thin double layers, i.e., when the double layer thickness is much smaller than the pore radius, is commonly described using an effective RC transmission line circuit. Here, we perform direct numerical simulations (DNS) of the Poisson-Nernst-Planck equations to study the double layer charging for the scenario of overlapping double layers, i.e., when the double layer thickness is comparable to the pore radius. We develop an analytical model that accurately predicts the results of DNS. Also, we construct a modified effective circuit for the overlapping double layer limit, and find that the modified circuit is identical to the RC transmission line but with different values and physical interpretation of the capacitive and resistive elements. In particular, the effective surface potential is reduced, the capacitor represents a volumetric current source, and the charging timescale is weakly dependent on the ratio of the pore radius and the double layer thickness.

3.Hat B., Jaruszewicz-Błońska J., Lipniacki T., Model-based optimization of combination protocols for irradiation-insensitive cancers, Scientific Reports, ISSN: 2045-2322, DOI: 10.1038/s41598-020-69380-6, Vol.10, pp.12652-1-14, 2020
Hat B., Jaruszewicz-Błońska J., Lipniacki T., Model-based optimization of combination protocols for irradiation-insensitive cancers, Scientific Reports, ISSN: 2045-2322, DOI: 10.1038/s41598-020-69380-6, Vol.10, pp.12652-1-14, 2020

Abstract:
Alternations in the p53 regulatory network may render cancer cells resistant to the radiation-induced apoptosis. In this theoretical study we search for the best protocols combining targeted therapy with radiation to treat cancers with wild-type p53, but having downregulated expression of PTEN or overexpression of Wip1 resulting in resistance to radiation monotherapy. Instead of using the maximum tolerated dose paradigm, we exploit stochastic computational model of the p53 regulatory network to calculate apoptotic fractions for both normal and cancer cells. We consider combination protocols, with irradiations repeated every 12, 18, 24, or 36 h to find that timing between Mdm2 inhibitor delivery and irradiation significantly influences the apoptotic cell fractions. We assume that uptake of the inhibitor is higher by cancer than by normal cells and that cancer cells receive higher irradiation doses from intersecting beams. These two assumptions were found necessary for the existence of protocols inducing massive apoptosis in cancer cells without killing large fraction of normal cells neighboring tumor. The best found protocols have irradiations repeated every 24 or 36 h with two inhibitor doses per irradiation cycle, and allow to induce apoptosis in more than 95% of cancer cells, killing less than 10% of normal cells.

4.Moreira R., Chwastyk M., Baker J.L., Vargas Guzman H.A., Poma A., Quantitative determination of mechanical stability in the novel coronavirus spike protein, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/D0NR03969A, pp.1-6, 2020
Moreira R., Chwastyk M., Baker J.L., Vargas Guzman H.A., Poma A., Quantitative determination of mechanical stability in the novel coronavirus spike protein, NANOSCALE, ISSN: 2040-3364, DOI: 10.1039/D0NR03969A, pp.1-6, 2020

Abstract:
We report on the novel observation about the gain in mechanical stability of the SARS-CoV-2 (CoV2) spike (S) protein in comparison with SARS-CoV from 2002 (CoV1). Our findings have several biological implications in the subfamily of coronaviruses, as they suggest that the receptor binding domain (RBD) (~200 amino acids) plays a fundamental role as a damping element of the massive viral particle's motion prior to cell-recognition, while also facilitating viral attachment, fusion and entry. The mechanical stability via pulling of the RBD is 250 pN and 200 pN for CoV2 and CoV1 respectively, and the additional stability observed for CoV2 (~50 pN) might play a role in the increasing spread of COVID-19.

5.Ghalya N., Sellier A., Ekiel-Jeżewska M.L., Feuillebois F., Effective viscosity of a dilute homogeneous suspension of spheres in Poiseuille flow between parallel slip walls, JOURNAL OF FLUID MECHANICS, ISSN: 0022-1120, DOI: 10.1017/jfm.2020.429, Vol.899, pp.A13-1-36, 2020
Ghalya N., Sellier A., Ekiel-Jeżewska M.L., Feuillebois F., Effective viscosity of a dilute homogeneous suspension of spheres in Poiseuille flow between parallel slip walls, JOURNAL OF FLUID MECHANICS, ISSN: 0022-1120, DOI: 10.1017/jfm.2020.429, Vol.899, pp.A13-1-36, 2020

Abstract:
For flows in microchannels, a slip on the walls may be efficient in reducing viscous dissipation. A related issue, addressed in this article, is to decrease the effective viscosity of a dilute monodisperse suspension of spheres in Poiseuille flow by using two parallel slip walls. Extending the approach developed for no-slip walls in Feuillebois et al. (J. Fluid Mech., vol. 800, 2016, pp. 111–139), a formal expression is obtained for the suspension intrinsic viscosity [μ] solely in terms of a stresslet component and a quadrupole component exerted on a single freely suspended sphere. In the calculation of [μ], the hydrodynamic interactions between a sphere and the slip walls are approximated using either the nearest wall model or the wall-superposition model. Both the stresslet and quadrupole are derived and accurately calculated using bipolar coordinates. Results are presented for [μ] in terms of H/(2a) and ˜λ = λ/a ≤ 1, where H is the gap between walls, a is the sphere radius and λ is the wall slip length using the Navier slip boundary condition. As compared with the no-slip case, the intrinsic viscosity strongly depends on ˜λ for given H/(2a), especially for small H/(2a). For example, in the very confined case H/(2a) = 2 (a lower bound found for practical validity of single-wall models) and for ˜λ = 1, the intrinsic viscosity is three times smaller than for a suspension bounded by no-slip walls and five times smaller than for an unbounded suspension (Einstein, Ann. Phys., vol. 19, 1906, pp. 289–306). We also provide a handy formula fitting our results for [μ] in the entire range 2 ≤ H/(2a) ≤ 100 and ˜λ ≤ 1.

Keywords:
complex fluids, low-Reynolds-number flows

6.Słowicka A.M., Stone H.A., Ekiel-Jeżewska M.L., Flexible fibers in shear flow approach attracting periodic solutions, PHYSICAL REVIEW E, ISSN: 2470-0045, DOI: 10.1103/PhysRevE.101.023104, Vol.101, No.2, pp.023104-1-14, 2020
Słowicka A.M., Stone H.A., Ekiel-Jeżewska M.L., Flexible fibers in shear flow approach attracting periodic solutions, PHYSICAL REVIEW E, ISSN: 2470-0045, DOI: 10.1103/PhysRevE.101.023104, Vol.101, No.2, pp.023104-1-14, 2020

Abstract:
The three-dimensional dynamics of a single non-Brownian flexible fiber in shear flow is evaluated numerically, in the absence of inertia. A wide range of ratios A of bending to hydrodynamic forces and hundreds of initial configurations are considered. We demonstrate that flexible fibers in shear flow exhibit much more complicated evolution patterns than in the case of extensional flow, where transitions to higher-order modes of characteristic shapes are observed when A exceeds consecutive threshold values. In shear flow, we identify the existence of an attracting steady configuration and different attracting periodic motions that are approached by long-lasting rolling, tumbling, and meandering dynamical modes, respectively. We demonstrate that the final stages of the rolling and tumbling modes are effective Jeffery orbits, with the constant parameter C replaced by an exponential function that either decays or increases in time, respectively, corresponding to a systematic drift of the trajectories. In the limit of C→0, the fiber aligns with the vorticity direction and in the limit of C→∞, the fiber periodically tumbles within the shear plane. For moderate values of A, a three-dimensional meandering periodic motion exists, which corresponds to intermediate values of C. Transient, close to periodic oscillations are also detected in the early stages of the modes.

7.Zalewska-Piątek B., Olszewski M., Lipniacki T., Błoński S., Wieczór M., Bruździak P., Skwarska A., Nowicki B., Nowicki S., Piątek R., A shear stress micromodel of urinary tract infection by the Escherichia coli producing Dr adhesin, PLoS Pathogens, ISSN: 1553-7366, DOI: 10.1371/journal.ppat.1008247, Vol.16, No.1, pp. e1008247-1-32, 2020
Zalewska-Piątek B., Olszewski M., Lipniacki T., Błoński S., Wieczór M., Bruździak P., Skwarska A., Nowicki B., Nowicki S., Piątek R., A shear stress micromodel of urinary tract infection by the Escherichia coli producing Dr adhesin, PLoS Pathogens, ISSN: 1553-7366, DOI: 10.1371/journal.ppat.1008247, Vol.16, No.1, pp. e1008247-1-32, 2020

Abstract:
In this study, we established a dynamic micromodel of urinary tract infection to analyze the impact of UT-segment-specific urinary outflow on the persistence of E. coli colonization. We found that the adherence of Dr+ E. coli to bladder T24 transitional cells and type IV collagen is maximal at lowest shear stress and is reduced by any increase in flow velocity. The analyzed adherence was effective in the whole spectrum of physiological shear stress and was almost irreversible over the entire range of generated shear force. Once Dr+ E. coli bound to host cells or collagen, they did not detach even in the presence of elevated shear stress or of chloramphenicol, a competitive inhibitor of binding. Investigating the role of epithelial surface architecture, we showed that the presence of budding cells–a model microarchitectural obstacle–promotes colonization of the urinary tract by E. coli. We report a previously undescribed phenomenon of epithelial cell "rolling-shedding" colonization, in which the detached epithelial cells reattach to the underlying cell line through a layer of adherent Dr+ E. coli. This rolling-shedding colonization progressed continuously due to "refilling" induced by the flow-perturbing obstacle. The shear stress of fluid containing free-floating bacteria fueled the rolling, while providing an uninterrupted supply of new bacteria to be trapped by the rolling cell. The progressive rolling allows for transfer of briefly attached bacteria onto the underlying monolayer in a repeating cascading event.

8.Pierini F., Guglielmelli A., Urbanek O., Nakielski P., Pezzi L., Buda R., Lanzi M., Kowalewski T.A., De Sio L., Thermoplasmonic‐activated hydrogel based dynamic light attenuator, Advanced Optical Materials, ISSN: 2195-1071, DOI: 10.1002/adom.202000324, pp.2000324-1-7, 2020
Pierini F., Guglielmelli A., Urbanek O., Nakielski P., Pezzi L., Buda R., Lanzi M., Kowalewski T.A., De Sio L., Thermoplasmonic‐activated hydrogel based dynamic light attenuator, Advanced Optical Materials, ISSN: 2195-1071, DOI: 10.1002/adom.202000324, pp.2000324-1-7, 2020

Abstract:
This work describes the morphological, optical, and thermo‐optical properties of a temperature‐sensitive hydrogel poly(N‐isopropylacrylamide‐co‐N‐isopropylmethacrylamide) [P(NIPAm‐co‐NIPMAm]) film containing a specific amount of gold nanorods (GNRs). The light‐induced thermoplasmonic heating of GNRs is used to control the optical scattering of an initially transparent hydrogel film. A hydrated P(NIPAm‐co‐NIPMAm) film is optically clear at room temperature. When heated to temperatures over 37 °C via light irradiation with a resonant source (λ = 810 nm) to the GNRs, a reversible phase transition from a swollen hydrated state to a shrunken dehydrated state occurs. This phenomenon causes a drastic and reversible change in the optical transparency from a clear to an opaque state. A significant red shift (≈30 nm) of the longitudinal band can also be seen due to an increased average refractive index surrounding the GNRs. This change is in agreement with an ad hoc theoretical model which uses a modified Gans theory for ellipsoidal nanoparticles. Morphological analysis of the composite film shows the presence of well‐isolated and randomly dispersed GNRs. Thermo‐optical experiments demonstrate an all‐optically controlled light attenuator (65% contrast ratio) which can be easily integrated in several modern optical applications such as smart windows and light‐responsive optical attenuators.

Keywords:
active plasmonics, gold nanorods, hydrogels, optical attenuators, optical transparency, plasmonic nanoparticles, polymers

9.Wang L., Lv H., Liu L., Zhang Q., Nakielski P., Si Y., Cao J., Li X., Pierini F., Yu J., Ding B., Electrospun nanofiber-reinforced three-dimensional chitosan matrices: architectural, mechanical and biological properties, JOURNAL OF COLLOID AND INTERFACE SCIENCE, ISSN: 0021-9797, DOI: 10.1016/j.jcis.2020.01.016, Vol.565, pp.416-425, 2020
Wang L., Lv H., Liu L., Zhang Q., Nakielski P., Si Y., Cao J., Li X., Pierini F., Yu J., Ding B., Electrospun nanofiber-reinforced three-dimensional chitosan matrices: architectural, mechanical and biological properties, JOURNAL OF COLLOID AND INTERFACE SCIENCE, ISSN: 0021-9797, DOI: 10.1016/j.jcis.2020.01.016, Vol.565, pp.416-425, 2020

Abstract:
The poor intrinsic mechanical properties of chitosan hydrogels have greatly hindered their practical applications. Inspired by nature, we proposed a strategy to enhance the mechanical properties of chitosan hydrogels by construction of a nanofibrous and cellular architecture in the hydrogel without toxic chemical crosslinking. To this end, electrospun nanofibers including cellulose acetate, polyacrylonitrile, and SiO2 nanofibers were introduced into chitosan hydrogels by homogenous dispersion and lyophilization. With the addition of 30% cellulose acetate nanofibers, the cellular structure could be maintained even in water without crosslinking, and integration of 60% of the nanofibers could guarantee the free-standing structure of the chitosan hydrogel with a low solid content of 1%. Moreover, the SiO2 nanofiber-reinforced chitosan (SiO2 NF/CS) three-dimensional (3D) matrices exhibit complete shape recovery from 80% compressive strain and excellent injectability. The cellular architecture and nanofibrous structure in the SiO2 NF/CS matrices are beneficial for human mesenchymal stem cell adhesion and stretching. Furthermore, the SiO2 NF/CS matrices can also act as powerful vehicles for drug delivery. As an example, bone morphogenetic protein 2 could be immobilized on SiO2 NF/CS matrices to induce osteogenic differentiation. Together, the electrospun nanofiber-reinforced 3D chitosan matrices exhibited improved mechanical properties and enhanced biofunctionality, showing great potential in tissue engineering.

Keywords:
chitosan hydrogel, electrospun nanofiber, mechanical property, nanofibrous matrix, tissue engineering

10.Pawłowska S., Rinoldi C., Nakielski P., Ziai Y., Urbanek O., Li X., Kowalewski T.A., Ding B., Pierini F., Ultraviolet light‐assisted electrospinning of core–shell fully cross‐linked P(NIPAAm‐co‐NIPMAAm) hydrogel‐based nanofibers for thermally induced drug delivery self‐regulation, Advanced Materials Interfaces, ISSN: 2196-7350, DOI: 10.1002/admi.202000247, Vol.7, No.12, pp.2000247-1-13, 2020
Pawłowska S., Rinoldi C., Nakielski P., Ziai Y., Urbanek O., Li X., Kowalewski T.A., Ding B., Pierini F., Ultraviolet light‐assisted electrospinning of core–shell fully cross‐linked P(NIPAAm‐co‐NIPMAAm) hydrogel‐based nanofibers for thermally induced drug delivery self‐regulation, Advanced Materials Interfaces, ISSN: 2196-7350, DOI: 10.1002/admi.202000247, Vol.7, No.12, pp.2000247-1-13, 2020

Abstract:
Body tissues and organs have complex functions which undergo intrinsic changes during medical treatments. For the development of ideal drug delivery systems, understanding the biological tissue activities is necessary to be able to design materials capable of changing their properties over time, on the basis of the patient's tissue needs. In this study, a nanofibrous thermal‐responsive drug delivery system is developed. The thermo‐responsivity of the system makes it possible to self‐regulate the release of bioactive molecules, while reducing the drug delivery at early stages, thus avoiding high concentrations of drugs which may be toxic for healthy cells. A co‐axial electrospinning technique is used to fabricate core–shell cross‐linked copolymer poly(N‐isopropylacrylamide‐co‐N‐isopropylmethacrylamide) (P(NIPAAm‐co‐NIPMAAm)) hydrogel‐based nanofibers. The obtained nanofibers are made of a core of thermo‐responsive hydrogel containing a drug model, while the outer shell is made of poly‐l‐lactide‐co‐caprolactone (PLCL). The custom‐made electrospinning apparatus enables the in situ cross‐linking of P(NIPAAm‐co‐NIPMAAm) hydrogel into a nanoscale confined space, which improves the electrospun nanofiber drug dosing process, by reducing its provision and allowing a self‐regulated release control. The mechanism of the temperature‐induced release control is studied in depth, and it is shown that the system is a promising candidate as a "smart" drug delivery platform.

Keywords:
biomimetic nanomaterials, electrospun core–shell nanofibers, hierarchical nanostructures, smart drug delivery, thermo‐responsive hydrogels

11.Sankaran A., Pawłowska S., Pierini F., Kowalewski T.A., Yarin A.L., Dynamics of electrospun hydrogel filaments in oscillatory microchannel flows: a theoretical and experimental approach, PHYSICS OF FLUIDS, ISSN: 1070-6631, DOI: 10.1063/5.0011005, Vol.32, No.7, pp.072008-1-13, 2020
Sankaran A., Pawłowska S., Pierini F., Kowalewski T.A., Yarin A.L., Dynamics of electrospun hydrogel filaments in oscillatory microchannel flows: a theoretical and experimental approach, PHYSICS OF FLUIDS, ISSN: 1070-6631, DOI: 10.1063/5.0011005, Vol.32, No.7, pp.072008-1-13, 2020

Abstract:
The dynamics of highly flexible micro- and nano-filaments are important to a variety of biological, medical, and industrial problems. The filament configuration variation and cross-stream migration in a microchannel are affected by thermal fluctuations in addition to elastic and viscous forces. Here, hydrogel nano-filaments with small bending Young's moduli are utilized to elucidate the transitional behavior of elastic Brownian filaments in an oscillatory microchannel flow. A numerical model based on chain elastic dumbbells similar to the Rouse-Zimm model accounting for elastic, viscous, and random Brownian forces is proposed and implemented. In addition, a theoretical model to describe the average orientation–deformation tensor evolution for an ensemble of filaments in an oscillatory flow is proposed. The results are compared with the evolution observed in the experiments.

12.Paprocki B., Pręgowska A., Szczepański J., Optimizing information processing in brain-inspired neural networks, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.131844, Vol.68, No.2, pp.225-233, 2020
Paprocki B., Pręgowska A., Szczepański J., Optimizing information processing in brain-inspired neural networks, BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2020.131844, Vol.68, No.2, pp.225-233, 2020

Abstract:
The way brain networks maintain high transmission efficiency is believed to be fundamental in understanding brain activity. Brains consisting of more cells render information transmission more reliable and robust to noise. On the other hand, processing information in larger networks requires additional energy. Recent studies suggest that it is complexity, connectivity, and function diversity, rather than just size and the number of neurons, that could favour the evolution of memory, learning, and higher cognition. In this paper, we use Shannon information theory to address transmission efficiency quantitatively. We describe neural networks as communication channels, and then we measure information as mutual information between stimuli and network responses. We employ a probabilistic neuron model based on the approach proposed by Levy and Baxter, which comprises essential qualitative information transfer mechanisms. In this paper, we overview and discuss our previous quantitative results regarding brain-inspired networks, addressing their qualitative consequences in the context of broader literature. It is shown that mutual information is often maximized in a very noisy environment e.g., where only one-third of all input spikes are allowed to pass through noisy synapses and farther into the network. Moreover, we show that inhibitory connections as well as properly displaced long-range connections often significantly improve transmission efficiency. A deep understanding of brain processes in terms of advanced mathematical science plays an important role in the explanation of the nature of brain efficiency. Our results confirm that basic brain components that appear during the evolution process arise to optimise transmission performance.

Keywords:
neural network, entropy, mutual information, noise, inhibitory neuron

13.Boopathi S., Poma Bernaola A., Kolandaivel P., Novel 2019 coronavirus structure, mechanism of action, antiviral drug promises and rule out against its treatment, Journal of Biomolecular Structure and Dynamics, ISSN: 0739-1102, DOI: 10.1080/07391102.2020.1758788, pp.1-17, 2020
Boopathi S., Poma Bernaola A., Kolandaivel P., Novel 2019 coronavirus structure, mechanism of action, antiviral drug promises and rule out against its treatment, Journal of Biomolecular Structure and Dynamics, ISSN: 0739-1102, DOI: 10.1080/07391102.2020.1758788, pp.1-17, 2020

Abstract:
In the past two decades, the world has faced several infectious disease outbreaks. Ebola, Influenza A (H1N1), SARS, MERS, and Zika virus have had a massive global impact in terms of economic disruption, the strain on local and global public health. Most recently, the global outbreak of novel coronavirus 2019 (SARS-CoV-2) that causes COVID-19 is a newly discovered virus from the coronavirus family in Wuhan city, China, known to be a great threat to the public health systems. As of 15 April 2020, The Johns Hopkins University estimated that the COVID-19 affected more than two million people, resulting in a death toll above 130,000 around the world. Infected people in Europe and America correspond about 40% and 30% of the total reported cases respectively. At this moment only few Asian countries have controlled the disease, but a second wave of new infections is expected. Predicting inhibitor and target to the COVID-19 is an urgent need to protect human from the disease. Therefore, a protocol to identify anti-COVID-19 candidate based on computer-aided drug design is urgently needed. Thousands of compounds including approved drugs and drugs in the clinical trial are available in the literature. In practice, experimental techniques can measure the time and space average properties but they cannot be captured the structural variation of the COVID-19 during the interaction of inhibitor. Computer simulation is particularly suitable to complement experiments to elucidate conformational changes at the molecular level which are related to inhibition process of the COVID-19. Therefore, computational simulation is essential tool to elucidate the phenomenon. The structure-based virtual screening computational approach will be used to filter the best drugs from the literature, the investigate the structural variation of COVID-19 with the interaction of the best inhibitor is a fundamental step to design new drugs and vaccines which can combat the coronavirus. This mini-review will address novel coronavirus structure, mechanism of action, and trial test of antiviral drugs in the lab and patients with COVID-19.

Keywords:
coronavirus, computational simulation, coronavirus spike, ACE2 receptor, antiviral drugs, COVID-19

14.Błoński S., Zaremba D., Jachimek M., Jakiela S., Wacławczyk T., Korczyk P.M., Impact of inertia and channel angles on flow distribution in microfluidic junctions, MICROFLUIDICS AND NANOFLUIDICS, ISSN: 1613-4982, DOI: 10.1007/s10404-020-2319-6, Vol.24, No.2, pp.14-1-15, 2020
Błoński S., Zaremba D., Jachimek M., Jakiela S., Wacławczyk T., Korczyk P.M., Impact of inertia and channel angles on flow distribution in microfluidic junctions, MICROFLUIDICS AND NANOFLUIDICS, ISSN: 1613-4982, DOI: 10.1007/s10404-020-2319-6, Vol.24, No.2, pp.14-1-15, 2020

Abstract:
In the present paper, we provide evidence of the vital impact of inertia on the flow in microfluidic networks, which is disclosed by the appearance of nonlinear velocity–pressure coupling. The experiments and numerical analysis of microfluidic junctions within the range of moderate Reynolds number (1 < Re < 250) revealed that inertial effects are of high relevance when Re > 10. Thus, our results estimate the applicability limit of the linear relationship between the flow rate and pressure drop in channels, commonly described by the so-called hydraulic resistance. Herein, we show that neglecting the nonlinear in their nature inertial effects can make such linear resistance-based approximation mistaken for the network operating beyond Re < 10. In the course of our research, we investigated the distribution of flows in connections of three channels in two flow modes. In the splitting mode, the flow from a common channel divides between two outputs, while in the merging mode, streams from two channels join together in a common duct. We tested a wide range of junction geometries characterized by parameters such as: (1) the angle between bifurcating channels (45°, 90°, 135° and 180°); (2) angle of the common channel relative to bifurcating channels (varied within the available range); (3) ratio of lengths of bifurcating channels (up to 8). The research revealed that the inertial effects strongly depend on angles between the channels. Additionally, we observed substantial differences between the distributions of flows in the splitting and merging modes in the same geometries, which reflects the non-reversibility of the motion of an inertial fluid. The promising aspect of our research is that for some combinations of both lengths and angles of the channels, the inertial contributions balance each other in such a way that the equations recover their linear character. In such an optimal configuration, the dependence on Reynolds number can be effectively mitigated.

15.Suwa T., Kurniawan T., Redesigning a commercial combined cycle in an undergraduate thermodynamics course: connecting theory to practical cycle design, International Journal of Mechanical Engineering Education, ISSN: 0306-4190, DOI: 10.1177/0306419020904647, pp.1-20, 2020
Suwa T., Kurniawan T., Redesigning a commercial combined cycle in an undergraduate thermodynamics course: connecting theory to practical cycle design, International Journal of Mechanical Engineering Education, ISSN: 0306-4190, DOI: 10.1177/0306419020904647, pp.1-20, 2020

Abstract:
Due to various reasons, the concepts of thermodynamics are not easy to grasp for undergraduate students. One of the major reasons is that the students are mostly unfamiliar with the thermodynamics devices discussed in the courses. Offering courses with experiments is an effective approach to solve this issue. However, it is not practical or possible for universities to own devices that operate at high temperatures and with high pressure fluids. With the cooperation of a nearby electric company, undergraduate students of a thermodynamics course from the Department of Mechanical Engineering measured thermal performances of a commercial combined cycle and its sub-systems at the President University. After learning about the theory of thermal cycles, the students analyzed the thermal performances of actual thermodynamics cycles. Subsequently, they analyzed the thermal efficiency improvements when reheating or regeneration is applied to the simple Rankine cycle in the combined cycle. At the end of the course, the students gave presentations before the electric company’s management and engineering personnel, akin to professional engineers. This course is structured to familiarize undergraduate students with thermodynamics cycles and devices.

Keywords:
thermodynamics, combined cycle, Brayton cycle, gas-turbine engine, Rankine cycle

16.Proniewska K., Pręgowska A., Malinowski P., Identification of human vital functions directly relevant to the respiratory system based on the cardiac and acoustic parameters and random forest, IRBM, ISSN: 1959-0318, DOI: 10.1016/j.irbm.2020.02.006, pp.1-6, 2020
Proniewska K., Pręgowska A., Malinowski P., Identification of human vital functions directly relevant to the respiratory system based on the cardiac and acoustic parameters and random forest, IRBM, ISSN: 1959-0318, DOI: 10.1016/j.irbm.2020.02.006, pp.1-6, 2020

Abstract:
Regarding sleep research, polysomnography (PSG) also called a sleep study, is a gold standard. It incorporates brain waves, the oxygen level in the blood, heart rate and breathing, and leg movement recordings. PSG is a complicated and expensive laboratory-based procedure, usually done in hospitals or special sleep center. In this study, an alternative technique for Sleep-Related Breathing Disorders (SRBD) based on selected cardiac and acoustic parameters and the Random Forest (RF) has been studied. A system dedicated to the detection of simultaneously acquired ECG and acoustic signals, which are collected during sleep at home environment is proposed. Results obtained indicate that classification and regression tree models such as RF are appropriate for the evaluation of sleep disorders like SRBD. The best identification of sleep irregularities at level 89.00 percent for the raw database was obtained. Thus, statistical predictive models allow identification of breathing events with high levels of sensitivity and specificity, providing an inexpensive and accurate diagnosis.

Keywords:
patient monitoring, random forest, disorders, biomarkers

17.Proniewska K., Pręgowska A., Dołęga-Dołęgowski D., Dudek D., Immersive technologies as a solution for general data protection regulation in Europe and impact on the COVID-19 pandemic, Cardiology Journal, ISSN: 1897-5593, DOI: 10.5603/CJ.a2020.0102, pp.1-21, 2020
Proniewska K., Pręgowska A., Dołęga-Dołęgowski D., Dudek D., Immersive technologies as a solution for general data protection regulation in Europe and impact on the COVID-19 pandemic, Cardiology Journal, ISSN: 1897-5593, DOI: 10.5603/CJ.a2020.0102, pp.1-21, 2020

Abstract:
Background: General data protection regulation (GDPR) provides rules according to which data should be managed and processed in a secure and appropriate way for patient requirements and security. Currently, everyone in Europe is covered by GDPR. Thus, the medical practice also requires access to patient data in a safe and secure way. Methods: Holographic technology allows users to see everything visible ona computer screen in a new and less restricted way, i. e. without the limitations of traditional computers and screens. Results: In this study, a three-dimensional holographic doctors' assistant is designed and implemented in a way that meets the GDPR requirements. The HoloView application, which is tailored to run on Microsoft HoloLens, is proposed toallow display and access to personal data and so-called sensitive information of all individual patients without the risk that it will be presented to unauthorized persons. Conclusions: To enhance the user experience and remain consistent with GSPR, a holographic desk is proposed that allows displaying patient data and sensitive information only in front of the doctor's eyes using mixed reality glasses. Last but not least, it boasts of a reduction in infection risk for the staff during the COVID-19 pandemic, affording medical care to be carried out by as few doctors as possible.

Keywords:
augmented reality, mixed reality, pandemic

18.Auguścik-Królikowska M., Ryszkowska J., Szczepkowski L., Kwiatkowski D., Kołbuk-Konieczny D., Szymańska J., Viscoelastic polyurethane foams with the addition of mint, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2020.3.4, Vol.65, No.3, pp.196-207, 2020
Auguścik-Królikowska M., Ryszkowska J., Szczepkowski L., Kwiatkowski D., Kołbuk-Konieczny D., Szymańska J., Viscoelastic polyurethane foams with the addition of mint, POLIMERY, ISSN: 0032-2725, DOI: 10.14314/polimery.2020.3.4, Vol.65, No.3, pp.196-207, 2020

Abstract:
The article presents an assessment of the possibilities of producing viscoelastic open cell polyurethane (PUR) foams produced with a natural filler in the form of mint leaves. PUR foams containing from 10 to 30 wt % of mint were produced. Chemical structure, thermal and mechanical properties of the foams were assessed. It was found that the filler containing 7 wt % of water caused significant changes in the foam characteristics. In composite foams, the content of urea and hydrogen bonds increased with higher mint contents. The hardness and comfort factor of composite foams also increased. The introduction of a filler containing a significant amount of water caused a change in the porosity and wall thickness of composite foams resulting in a significant increase in their permanent deformations.

Keywords:
open cell viscoelastic polyurethane foams, mint, cytocompatibility