Publications by authors named "Jacek A Majewski"

To speed up the implementation of the two-dimensional materials in the development of potential biomedical applications, the toxicological aspects toward human health need to be addressed. Due to time-consuming and expensive analysis, only part of the continuously expanding family of 2D materials can be tested in vitro. The machine learning methods can be used-by extracting new insights from available biological data sets, and provide further guidance for experimental studies.

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We study the effects of covalent functionalization of single wall carbon nanotubes (CNT) on their elastic properties. We consider simple organic molecules -NH, -NH2, -CH2, -CH3, -OH attached to CNTs' surface at various densities. The studies are based on the first principles calculations in the framework of density functional theory.

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We present results of extensive theoretical studies concerning stability, morphology, and band structure of single wall carbon nanotubes (CNTs) covalently functionalized by -CH(n) (for n = 2,3,4), -NH(n) (for n = 1,2,3,4), -COOH, and -OH groups. These studies are based on ab initio calculations in the framework of the density functional theory. For functionalized systems, we determine the dependence of the binding energies on the concentration of the adsorbed molecules, critical densities of adsorbed molecules, global and local changes in the morphology, and electronic structure paying particular attention to the functionalization induced changes of the band gaps.

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Owing to the variety of possible charge and spin states and to the different ways of coupling to the environment, paramagnetic centres in wide band-gap semiconductors and insulators exhibit a strikingly rich spectrum of properties and functionalities, exploited in commercial light emitters and proposed for applications in quantum information. Here we demonstrate, by combining synchrotron techniques with magnetic, optical and ab initio studies, that the codoping of GaN:Mn with Mg allows to control the Mn(n+) charge and spin state in the range 3≤n≤5 and 2≥S≥1. According to our results, this outstanding degree of tunability arises from the formation of hitherto concealed cation complexes Mn-Mg(k), where the number of ligands k is pre-defined by fabrication conditions.

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Background: MP4OX (oxygenated polyethylene glycol-modified hemoglobin) is an oxygen therapeutic agent with potential applications in clinical settings where targeted delivery of oxygen to ischemic tissues is required. The primary goal of this study was to investigate MP4OX for preventing hypotensive episodes. An additional goal was to establish the safety profile of MP4OX in a large surgical population.

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