Kobus J.,Nicolaus Copernicus University
Computer Physics Communications | Year: 2013
The newest version of the two-dimensional finite difference Hartree-Fock program for atoms and diatomic molecules is presented. This is an updated and extended version of the program published in this journal in 1996. It can be used to obtain reference, Hartree-Fock limit values of total energies and multipole moments for a wide range of diatomic molecules and their ions in order to calibrate existing and develop new basis sets, calculate (hyper)polarizabilities (αz, βz, γz, Az, Bzz,zz) of atoms, homonuclear and heteronuclear diatomic molecules and their ions via the finite field method, perform DFT-type calculations using LDA or B88 exchange functionals and LYP or VWN correlations ones or the self-consistent multiplicative constant method, perform one-particle calculations with (smooth) Coulomb and Krammers-Henneberger potentials and take account of finite nucleus models. The program is easy to install and compile (tarball+configure+make) and can be used to perform calculations within double- or quadruple-precision arithmetic. 7 © 2012 Elsevier B.V. All rights reserved.
Wojtkowski M.,Nicolaus Copernicus University
Applied Optics | Year: 2010
In the past decade we have observed a rapid development of ultrahigh-speed optical coherence tomography (OCT) instruments, which currently enable performing cross-sectional in vivo imaging of biological samples with speeds of more than 100,000 A-scans/s. This progress in OCT technology has been achieved by the development of Fourier-domain detection techniques. Introduction of high-speed imaging capabilities lifts the primary limitation of early OCT technology by giving access to in vivo three-dimensional volumetric reconstructions on large scales within reasonable time constraints. As result, novel tools can be created that add new perspective for existing OCT applications and open new fields of research in biomedical imaging. Especially promising is the capability of performing functional imaging, which shows a potential to enable the differentiation of tissue pathologies via metabolic properties or functional responses. In this contribution the fundamental limitations and advantages of time-domain and Fourier-domain interferometric detection methods are discussed. Additionally the progress of high-speed OCT instruments and their impact on imaging applications is reviewed. Finally new perspectives on functional imaging with the use of state-of-the-art high-speed OCT technology are demonstrated. © 2010 Optical Society of America.
Siomek A.,Nicolaus Copernicus University
Acta Biochimica Polonica | Year: 2012
The activation of NF-κB transcription factor is critical for a wide range of processes such as immunity, inflammation, cell development, growth and survival. It is activated by a variety of stimuli including cytokines, ionizing radiation and oxidative stress. Redox modulations of NF-κB pathway have been widely demonstrated. Studies carried out during last years have advanced our knowledge about possible connections between NF-κB pathway and the impact of free radicals. This review is an endeavor to gather recent results focused on this issue, although an important question, whether oxidative stress plays a physiological role in NF-κB activation, seems to be still unanswered.
Mazurek K.,Nicolaus Copernicus University
Hydrometallurgy | Year: 2013
A spent vanadium catalyst was leached in an oxalic acid solution to recover vanadium, potassium and iron. The effects of time, temperature, acid concentration, phase ratio and catalyst particle size were studied. The results showed that for a 180-250 μm catalyst leached for 4 h at 323 K in the presence of 2% oxalic acid solution at a liquid:solid ratio of 25:1, the extent of leaching of V, K and Fe was about 91%, 92% and 63%, respectively. Studies on the separation of vanadium from iron were conducted. The effect of pH on the concentration of the investigated compounds in post-leaching solution was presented. Additionally, separation of vanadium from such a solution was investigated by the ion exchange method. Three types of polymer strongly acidic ion exchangers were used. The ion exchange tests indicate that only potassium and iron were loaded from the post-leaching solution. On this basis a flowsheet for the proposed process of a complex utilization of spent vanadium catalyst is presented. © 2013 Elsevier B.V.
MacKowski S.,Nicolaus Copernicus University
Journal of Physics Condensed Matter | Year: 2010
Hybrid nanostructures are systems composed of two or more nanostructures designed for improving the performance over individual components. In this work we introduce the concept of bridging natural photosynthetic protein-pigment complexes with nanostructures fabricated in an artificial way, such as semiconductor nanocrystals, metallic nanoparticles or carbon nanotubes, with the purpose of enhancing the efficiency of light harvesting either via plasmon excitation in metals or absorption tunability characteristics of semiconductors. In addition to presenting basic features of inorganic nanostructures, we discuss recent advances in the field of hybrid nanostructures composed of photosynthetic pigment-protein complexes. © 2010 IOP Publishing Ltd.