Effect of C60 fullerene on recovery of muscle soleus in rats after atrophy induced by achillotenotomy. - In: Life, ISSN 2075-1729, Bd. 12 (2022), 3, 332, S. 1-13
Biomechanical and biochemical changes in the muscle soleus of rats during imitation of hind limbs unuse were studied in the model of the Achilles tendon rupture (Achillotenotomy). Oral administration of water-soluble C60 fullerene at a dose of 1 mg/kg was used as a therapeutic agent throughout the experiment. Changes in the force of contraction and the integrated power of the muscle, the time to reach the maximum force response, the mechanics of fatigue processes development, in particular, the transition from dentate to smooth tetanus, as well as the levels of pro- and antioxidant balance in the blood of rats on days 15, 30 and 45 after injury were described. The obtained results indicate a promising prospect for C60 fullerene use as a powerful antioxidant for reducing and correcting pathological conditions of the muscular system arising from skeletal muscle atrophy.
https://doi.org/10.3390/life12030332
Model predictive control for singular differential-algebraic equations. - In: International journal of control, ISSN 1366-5820, Bd. 95 (2022), 8, S. 2141-2150
We study model predictive control for singular differential-algebraic equations with higher index. This is a novelty when compared to the literature where only regular differential-algebraic equations with additional assumptions on the index and/or controllability are considered. By regularisation techniques, we are able to derive an equivalent optimal control problem for an ordinary differential equation to which well-known model predictive control techniques can be applied. This allows the construction of terminal constraints and costs such that the origin is asymptotically stable w.r.t. the resulting closed-loop system.
https://doi.org/10.1080/00207179.2021.1900604
Impact of neurite alignment on organelle motion. - In: Interface, ISSN 1742-5662, Bd. 19 (2022), 187, 20210617, S. 1-13
Intracellular transport is pivotal for cell growth and survival. Malfunctions in this process have been associated with devastating neurodegenerative diseases, highlighting the need for a deeper understanding of the mechanisms involved. Here, we use an experimental methodology that leads neurites of differentiated PC12 cells into either one of two configurations: a one-dimensional configuration, where the neurites align along lines, or a two-dimensional configuration, where the neurites adopt a random orientation and shape on a flat substrate. We subsequently monitored the motion of functional organelles, the lysosomes, inside the neurites. Implementing a time-resolved analysis of the mean-squared displacement, we quantitatively characterized distinct motion modes of the lysosomes. Our results indicate that neurite alignment gives rise to faster diffusive and super-diffusive lysosomal motion than the situation in which the neurites are randomly oriented. After inducing lysosome swelling through an osmotic challenge by sucrose, we confirmed the predicted slowdown in diffusive mobility. Surprisingly, we found that the swelling-induced mobility change affected each of the (sub-/super-)diffusive motion modes differently and depended on the alignment configuration of the neurites. Our findings imply that intracellular transport is significantly and robustly dependent on cell morphology, which might in part be controlled by the extracellular matrix.
https://doi.org/10.1098/rsif.2021.0617
Low chromatic spanning sub(di)graphs with prescribed degree or connectivity properties. - In: Journal of graph theory, ISSN 1097-0118, Bd. 99 (2022), 4, S. 615-636
https://doi.org/10.1002/jgt.22755
Efficient organic solar cells enabled by simple non-fused electron donors with low synthetic complexity. - In: Small, ISSN 1613-6829, Bd. 18 (2022), 3, 2104623, insges. 10 S.
https://doi.org/10.1002/smll.202104623
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