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1.
Martyna Zagrska-Dziok Patrycja Kleczkowska Ewa Oldzka Ramona Figat Marcin Sobczak 《International journal of molecular sciences》2021,22(7)
Polymeric hydrogels play an increasingly important role in medicine, pharmacy and cosmetology. They appear to be one of the most promising groups of biomaterials due to their favorable physicochemical properties and biocompatibility. The objective of the presented study was to synthesize new poly(chitosan-ester-ether-urethane) hydrogels and to study the kinetic release of genistein (GEN) from these biomaterials. In view of the above, six non-toxic hydrogels were synthesized via the Ring-Opening Polymerization (ROP) and polyaddition processes. The poly(ester-ether) components of the hydrogels have been produced in the presence of the enzyme as a biocatalyst. In some cases, the in vitro release rate of GEN from the obtained hydrogels was characterized by near-zero-order kinetics, without “burst release” and with non-Fickian transport. It is important to note that developed hydrogels have been shown to possess the desired safety profile due to lack of cytotoxicity to skin cells (keratinocytes and fibroblasts). Taking into account the non-toxicity of hydrogels and the relatively highly controlled release profile of GEN, these results may provide fresh insight into polymeric hydrogels as an effective dermatological and/or cosmetological tool. 相似文献
2.
Joanna Czajkowska Adam Junka Jakub Hoppe Monika Toporkiewicz Andrzej Pawlak Pawe Migda Monika Oleksy-Wawrzyniak Karol Fijakowski Marcin
miglak Agata Markowska-Szczupak 《International journal of molecular sciences》2021,22(11)
Staphylococcus aureus is one of the most prevalent pathogens associated with several types of biofilm-based infections, including infections of chronic wounds. Mature staphylococcal biofilm is extremely hard to eradicate from a wound and displays a high tendency to induce recurring infections. Therefore, in the present study, we aimed to investigate in vitro the interaction between S. aureus biofilm and fibroblast cells searching for metabolites that could be considered as potential biomarkers of critical colonization and infection. Utilizing advanced microscopy and microbiological methods to examine biofilm formation and the staphylococcal infection process, we were able to distinguish 4 phases of biofilm development. The analysis of staphylococcal biofilm influence on the viability of fibroblasts allowed us to pinpoint the moment of critical colonization—12 h post contamination. Based on the obtained model we performed a metabolomics analysis by 1H NMR spectroscopy to provide new insights into the pathophysiology of infection. We identified a set of metabolites related to the switch to anaerobic metabolism that was characteristic for staphylococcal biofilm co-cultured with fibroblast cells. The data presented in this study may be thus considered a noteworthy but preliminary step in the direction of developing a new, NMR-based tool for rapid diagnosing of infection in a chronic wound. 相似文献
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5.
The problem of computing the chromatic number of a P
5-free graph (a graph which contains no path on 5 vertices as an induced subgraph) is known to be NP-hard. However, we show
that for every fixed integer k, there exists a polynomial-time algorithm determining whether or not a P
5-free graph admits a k-coloring, and finding one, if it does. 相似文献
6.
Marcin Miłkowski 《Minds and Machines》2009,19(4):465-475
In Darwin’s Dangerous Idea, Daniel Dennett claims that evolution is algorithmic. On Dennett’s analysis, evolutionary processes are trivially algorithmic
because he assumes that all natural processes are algorithmic. I will argue that there are more robust ways to understand
algorithmic processes that make the claim that evolution is algorithmic empirical and not conceptual. While laws of nature
can be seen as compression algorithms of information about the world, it does not follow logically that they are implemented
as algorithms by physical processes. For that to be true, the processes have to be part of computational systems. The basic
difference between mere simulation and real computing is having proper causal structure. I will show what kind of requirements
this poses for natural evolutionary processes if they are to be computational. 相似文献
7.
Application of the OBD method for optimization of neural state variable estimators of the two-mass drive system 总被引:1,自引:0,他引:1
This paper presents neural estimators of the mechanical state variables of the electrical drive system with elastic joints. The non-measurable state variables, as the torsional torque and the load machine speed are estimated using multilayer feed-forward neural networks. The main stages of the design methodology of these neural estimators are presented. The optimal brain damage method is implemented for the structure optimization of each neural network. Then signals estimated by neural estimators are tested in the electrical drive control structure with additional feedbacks from the estimated shaft torque and the difference between the motor and the load speeds. The simulation results show good accuracy of both presented neural estimators for the wide range of changes of the reference speed and the load torque. The simulation results are then verified by laboratory experiments. 相似文献
8.
9.
Abstract The success of the testing of volatile organic compounds emitted by animals is dependent on the creation of appropriate conditions for air sampling subsequently used to assay and identify the compounds. These conditions play a particularly important role in the investigation of pheromones, which are secreted in extremely low concentrations. The authors have not come across any previous work which offers constructional solutions, which would allow avoidance of contamination of the air samples containing volatile substances secreted by animals. A constructional solution was developed, which provides optimal conditions for their sampling and isolation. Its main advantages are as follows: the exposure chamber (the chamber in which the animal is studied) is filled with synthetic air; the exposure chamber is separated from the atmospheric air with a synthetic air “jacket”; the exposure chamber has been constructed using materials which do not release chemicals and absorb them in trace quantities. 相似文献
10.
Tomasz Kostrzewa Jakub Joczyk Joanna Drzedon Dagmara Jacewicz Magdalena Grska-Ponikowska Marcin Koaczkowski Alicja Kuban-Jankowska 《International journal of molecular sciences》2022,23(13)
One of the main goals of recent bioinorganic chemistry studies has been to design and synthesize novel substances to treat human diseases. The promising compounds are metal-based and metal ion binding components such as vanadium-based compounds. The potential anticancer action of vanadium-based compounds is one of area of investigation in this field. In this study, we present five oxovanadium(IV) and dioxovanadium(V) complexes as potential PTP1B inhibitors with anticancer activity against the MCF-7 breast cancer cell line, the triple negative MDA-MB-231 breast cancer cell line, and the human keratinocyte HaCaT cell line. We observed that all tested compounds were effective inhibitors of PTP1B, which correlates with anticancer activity. [VO(dipic)(dmbipy)]·2 H2O (Compound 4) and [VOO(dipic)](2-phepyH)·H2O (Compound 5) possessed the greatest inhibitory effect, with IC50 185.4 ± 9.8 and 167.2 ± 8.0 nM, respectively. To obtain a better understanding of the relationship between the structure of the examined compounds and their activity, we performed a computer simulation of their binding inside the active site of PTP1B. We observed a stronger binding of complexes containing dipicolinic acid with PTP1B. Based on our simulations, we suggested that the studied complexes exert their activity by stabilizing the WPD-loop in an open position and limiting access to the P-loop. 相似文献