Vaccination, immunity and breakthrough: quantitative effects in individual immune responses illustrated by a simple kinetic model. - In: Applied Sciences, ISSN 2076-3417, Bd. 12 (2022), 1, 31, S. 1-15
The personal risks of infection, as well as the conditions for achieving herd immunity, are strongly dependent on an individual’s response to the infective agents on the one hand, and the individual’s reactions to vaccination on the other hand. The main goal of this work is to illustrate the importance of quantitative individual effects for disease risk in a simple way. The applied model was able to illustrate the quantitative effects, in the cases of different individual reactions, after exposition to viruses or bacteria and vaccines. The model was based on simple kinetic equations for stimulation of antibody production using different concentrations of the infective agent, vaccine and antibodies. It gave a qualitative explanation for the individual differences in breakthrough risks and different requirements concerning a second, third or further vaccinations, reconsidering different efficiencies of the stimulation of an immune reaction.
https://doi.org/10.3390/app12010031
Bio-inspired 3D micro structuring of a liver lobule via direct laser writing: a comparative study with SU-8 and SUEX. - In: Journal of laser applications, ISSN 1938-1387, Bd. 34 (2022), 1, 012007, S. 012007-1-012007-12
Real biological tissues show a great variety of different geometric morphologies with special features on different geometric scales. An interesting example is the liver lobule that is the basic subunit of a liver. The lobule is a quasihexagonal macroscopic structure with periodic like so-called sinusoidal elements with structural features on the micro- and macroscale made of proteins, cells, and fluids. Various tools from micromachining and nanotechnology have demonstrated their capabilities to construct micromorphologies precisely, but even the reconstruction of such a system in technical polymers is challenging. In this work, the rapidly evolving technique of multiphoton polymerization has been explored for the construction of a scaffold that mimics the micromorphology of the liver with high resolution and detail up to the millimeter scale. At the end, a highly complex fluidically perfusable structure was achieved and simulations showed that the occurring shear stress, fluid velocity, and stream lines are comparable to the native liver lobule. Hereby, the photoresists SU-8 and SUEX TDFS were compared in terms of their processability, achievable resolution, and suitability for the intended application. Our results have shown that SUEX needs lower writing velocities but is easier to process and achieves a considerable higher resolution than SU-8. The scaffold could provide a base frame with a geometrically defined morphology for hepatic cells to adhere to, which could act as a starting point for cells to build new liver tissue for further integration in more complex systems.
https://doi.org/10.2351/7.0000433
Connecting reservoir computing with statistical forecasting and deep neural networks. - In: Nature Communications, ISSN 2041-1723, Bd. 13 (2022), 227, S. 1-3
Among the existing machine learning frameworks, reservoir computing demonstrates fast and low-cost training, and its suitability for implementation in various physical systems. This Comment reports on how aspects of reservoir computing can be applied to classical forecasting methods to accelerate the learning process, and highlights a new approach that makes the hardware implementation of traditional machine learning algorithms practicable in electronic and photonic systems.
https://doi.org/10.1038/s41467-021-27715-5
A novel water-soluble C60 fullerene-based nano-platform enhances efficiency of anticancer chemotherapy. - In: Biomedical nanomaterials, (2022), S. 59-93
Im Titel ist "60" tiefgestellt
Noncovalent water-soluble nanocomplexes of C60 fullerene (C60) with chemotherapeutic drugs (Doxorubicin (Dox), Cisplatin (Cis), and herbal alkaloid Berberine (Ber)) were created. Their anticancer action toward various tumor cells was studied in vitro, addressing specifically their biological synergy, compared with the action of these drugs in the non-immobilized form. Different theoretical and experimental (SEM and AFM microscopy, UV-Vis, DLS, NMR and SANS spectroscopy, ITC calorimetry) methods were applied for getting insight into the nature of the nanocomplexes with drug molecules, as well as into the physical forces enabling stabilization of these complexes. Physicochemical mechanisms were proposed for drug interaction with C60. An enhancement of the toxic action of the created water-soluble C60-drug nanocomplexes toward cancer cells, compared to the action of free drug, was found. Specifically, the C60-Dox nanocomplexes demonstrated ˜3.5 higher cytotoxic potential in the leukemic cell lines (CCRF-CEM, Jurkat, THP1, and Molt-16) in comparison with free Dox in the nanometer range of concentrations. Besides, C60 doubled the intracellular level of the up-taken Dox, which also evidenced its function as a nanocarrier. The toxic effect of C60-Cis nanocomplex toward Lewis lung carcinoma (LLC) cells was shown to be higher with IC50 values 3.3 and 4.5 times at 48 h and 72 h, respectively, as compared to the IC50 of free drug. 12.5 [my] Cis had no effect on LLC cells' viability. The C60-Cis nanocomplex in Cis-equivalent concentration substantially decreased the viability of tumor cells, impaired their shape and adhesion, inhibited migration, and induced their accumulation in the pro-apoptotic sub-G1 phase of cell cycle. An induction of apoptosis by the C60-Cis nanocomplex was confirmed by the activation of caspase 3/7 and externalization of phosphatidylserine on the outer membrane of LLC cells after their double staining with the Annexin V-FITC/PI. The complexation with C60 promoted intracellular uptake of the Ber. An increase in C60 concentration in the C60-Ber nanocomplexes was accompanied by the elevation of their antiproliferative potential toward CCRF-CEM cells in the order: free Ber < 1:2 < 1:1 < 2:1.These findings suggest a universal potential of water-soluble pristine C60 as a unique nano-platform for the delivery of the chemotherapeutic drugs in cytotoxic effect of these drugs.
A note on completely positive relaxations of quadratic problems in a multiobjective framework. - In: Journal of global optimization, ISSN 1573-2916, Bd. 82 (2022), 3, S. 615-626
In a single-objective setting, nonconvex quadratic problems can equivalently be reformulated as convex problems over the cone of completely positive matrices. In small dimensions this cone equals the cone of matrices which are entrywise nonnegative and positive semidefinite, so the convex reformulation can be solved via SDP solvers. Considering multiobjective nonconvex quadratic problems, naturally the question arises, whether the advantage of convex reformulations extends to the multicriteria framework. In this note, we show that this approach only finds the supported nondominated points, which can already be found by using the weighted sum scalarization of the multiobjective quadratic problem, i.e. it is not suitable for multiobjective nonconvex problems.
https://doi.org/10.1007/s10898-021-01091-2
An approximation algorithm for multi-objective optimization problems using a box-coverage. - In: Journal of global optimization, ISSN 1573-2916, Bd. 83 (2022), 2, S. 329-357
For a continuous multi-objective optimization problem, it is usually not a practical approach to compute all its nondominated points because there are infinitely many of them. For this reason, a typical approach is to compute an approximation of the nondominated set. A common technique for this approach is to generate a polyhedron which contains the nondominated set. However, often these approximations are used for further evaluations. For those applications a polyhedron is a structure that is not easy to handle. In this paper, we introduce an approximation with a simpler structure respecting the natural ordering. In particular, we compute a box-coverage of the nondominated set. To do so, we use an approach that, in general, allows us to update not only one but several boxes whenever a new nondominated point is found. The algorithm is guaranteed to stop with a finite number of boxes, each being sufficiently thin.
https://doi.org/10.1007/s10898-021-01109-9
A highly robust self-supporting nickel nanoarray based on anodic alumina oxide template for determination of dopamine. - In: Sensors and actuators, ISSN 0925-4005, Bd. 350 (2022), 130835
Ratiometric electrochemical sensors can effectively reduce system errors and environmental interference during the detection of a target, affording good sensitivity, reproducibility, and a linear response range. However, traditional proportional electrochemical sensors are limited by the need for complex modifications and the lack of internal reference probes. In this study, we developed a ratiometric electrochemical sensing platform based on nickel nanoarrays as a self-supporting electrode (NiNASSE) by using an anodic alumina oxide template method. An internal reference probe was developed based on nickel nanoparticles (NiNPs) as nickel nanoarrays, presenting a facile modification process and stable redox signal. Furthermore, the highly ordered nanoarray structure expands the specific surface area of NiNASSE and accelerates the electron transfer rate. This new self-supporting proportional electrochemical sensor was successfully applied for the detection of dopamine and displayed good electrocatalytic ability, stability, and feasibility.
https://doi.org/10.1016/j.snb.2021.130835
Construction of Co0.85Se@nickel nanopores array hybrid electrode for high-performance asymmetric supercapacitors. - In: Chemical engineering science, Bd. 247 (2022), 117081, insges. 9 S.
Nanostructured current collectors have larger specific surface area and short ion/electron transport path, which are highly desirable for supercapacitors applications. Herein, Co0.85SeNiNPs (Co0.85Se@NiNP) hybrid electrodes are proposed and fabricated, in which NiNP is served as nanostructured current collectors. NiNP has a vertical pore structure and a large specific surface area, which could effectively promote the ion/electron transport efficiency and reduce internal electrical resistance. Compared with Ni foam and Ni foil as current collectors, NiNP enables Co0.85Se@NiNP electrodes show significantly improved specific capacity, rate performance and cycle stability. Finally, an asymmetric supercapacitor device was assembled with Co0.85Se@NiNP hybrid electrode as the binder-free positive electrode and activated carbon (AC) coated on nickel foam as negative electrode. The Co0.85Se@NiNP//AC asymmetric supercapacitors can work in a wide potential window of 0 - 1.6 V with an ultrahigh specific capacity of 182.3 F g^-1 at 1 A g^-1. Most importantly, Co0.85Se@NiNP//AC has a high energy density of 64.81 Wh kg^-1 at 800 W kg^-1 and an outstanding cycle stability of up to 12000 cycles, indicating that Co0.85Se@NiNP electrode has great application potential in supercapacitors.
https://doi.org/10.1016/j.ces.2021.117081
Optimality conditions for set optimization using a directional derivative based on generalized Steiner sets. - In: Optimization, ISSN 1029-4945, Bd. 71 (2022), 8, S. 2273-2314
Set-optimization has attracted increasing interest in the last years, as for instance uncertain multiobjective optimization problems lead to such problems with a set-valued objective function. Thereby, from a practical point of view, most of all the so-called set approach is of interest. However, optimality conditions for these problems, for instance using directional derivatives, are still very limited. The key aspect for a useful directional derivative is the definition of a useful set difference for the evaluation of the numerator in the difference quotient. We present here a new set difference which avoids the use of a convex hull and which applies to arbitrary convex sets, and not to strictly convex sets only. The new set difference is based on the new concept of generalized Steiner sets. We introduce the Banach space of generalized Steiner sets as well as anembedding of convex sets in this space using Steiner points.In this Banach space we can easily define a difference and a directional derivative. We use the latter for new optimality conditions for set optimization. Numerical examples illustrate the new concepts.
https://doi.org/10.1080/02331934.2020.1812605
Effect of HIT components on the development of breast cancer cells. - In: Life, ISSN 2075-1729, Bd. 11 (2021), 8, 832, S. 1-13
Cancer cells circulating in blood vessels activate platelets, forming a cancer cell encircling platelet cloak which facilitates cancer metastasis. Heparin (H) is frequently used as an anticoagulant in cancer patients but up to 5% of patients have a side effect, heparin-induced thrombocytopenia (HIT) that can be life-threatening. HIT is developed due to a complex interaction among multiple components including heparin, platelet factor 4 (PF4), HIT antibodies, and platelets. However, available information regarding the effect of HIT components on cancers is limited. Here, we investigated the effect of these materials on the mechanical property of breast cancer cells using atomic force microscopy (AFM) while cell spreading was quantified by confocal laser scanning microscopy (CLSM), and cell proliferation rate was determined. Over time, we found a clear effect of each component on cell elasticity and cell spreading. In the absence of platelets, HIT antibodies inhibited cell proliferation but they promoted cell proliferation in the presence of platelets. Our results indicate that HIT complexes influenced the development of breast cancer cells.
https://doi.org/10.3390/life11080832