University Im ckiewicza

Poznań, Poland

University Im ckiewicza

Poznań, Poland
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MacIejewski H.,University Im ckiewicza | Dutkiewicz M.,University Im ckiewicza | Byczynski L.,Poznanski Park Naukowo Technologiczny Fundacji UAM | Marciniec B.,University Im ckiewicza
Polimery/Polymers | Year: 2012

The paper is the first of a series of review articles on the use of polysilsesquioxanes (POSS) for the modification of various polymers in order to prepare nanocomposites with specific physico-chemical properties. It has been the aim of the authors, in this and the following parts, to present the current state of knowledge and directions for further investigation in this area of chemistry. This opening paper reports on the synthesis, properties and use of nanocomposites based on POSS and silicone matrix.

Oxidative stress has been involved in the toxicity of heavy metals in different plant species. Exposure to metal ions can intensify the production of reactive oxygen species (ROS) such as: superoxide radicals, hydroxyl radicals or hydrogen peroxide. These species can react with cellular components (lipids, proteins, nucleic acids) and cause lipid peroxidation, membrane damage and inactivation of enzymes thus affect many physiological processes as well as cell viability. Plants have evolved a complex array of mechanisms to maintain low ROS level and avoid the detrimental effects of excessively high ROS concentrations. This antioxidant network includes numerous soluble (ascorbate, glutathione) and membrane (tocopherol) compounds as well as enzymes involved in ROS scavenging (superoxide dismutase, catalase, ascorbate peroxidase). ROS must be efficiently detoxified to ameliorate the harmful effects of heavy metals in the cells. However they cannot be eliminated completely because plants use ROS as second messengers in signal transduction cascades in diverse physiological processes.

Skoluda P.,University Im ckiewicza
Zeitschrift fur Physikalische Chemie | Year: 2012

A study of the current-potential and capacity curves of Au(100) electrode prepared by flame method provide evidence that not only anions or organic molecules but also cations (protonated molecules of dopamine) can lift the reconstruction. Our investigation indicate also that coumarin hinders the adsorption of these cations and thus delays lifting of the reconstruction. It was found that the deprotonated form of dopamine also lifts the reconstruction but at much more negative potentials. © by Oldenbourg Wissenschaftsverlag, München.

Grabsztunowicz M.,University Im ckiewicza
Postepy biochemii | Year: 2011

For some chloroplast proteases ATP binding and hydrolysis is not necessary for their catalytic activity, most probably because even strongly unfolded substrates may penetrate their catalytic chamber. Deg1, 2, 5 and 8 are the best known of Arabidopsis thaliana ATP- independent chloroplast proteases, encoded by orthologues of genes coding for DegP, DegQ and DegS proteases of Escherichia coli. Current awareness in the area of structure and functions of chloroplast Degs is much more limited vs the one about their bacterial counterparts. Deg5 and Deg8 form a catalytic heterododecamer which is loosely attached to luminal side of thylakoid membrane. The complex catalyses--supported by Deg1 and one of FtsH proteases--the degradation of PsbA damaged due to plant exposition to elevated irradiance and thus these protease are of key importance for the plants' sensitivity to photoinhibition. Deg2 role in the disposal of damaged PsbA has not been elucidated. Recombinant Deg1 may degrade PsbO and plastocyanin in vitro but it is not clear whether this reaction is performed in vivo as well.

Arabidopsis thaliana proteome contains 667 proteases; some tens of them are chloroplast-targeted proteins, encoded by genes orthologous to the ones coding for bacterial proteolytic enzymes. It is thought that chloroplast proteases are involved in chloroplasts' proteins turnover and quality control (maturation of nucleus-encoded proteins and removal of nonfunctional ones). Some ATP-dependent chloroplast proteases belonging to FtsH family (especially FtsH2 and FtsH5) are considered to be involved in numerous aspects of chloroplast and whole plant maintenance under non-stressing as well as stressing conditions. This notion is supported by severe phenotype appearance of mutants deficient in these proteases. In contrast to seemingly high physiological importance of chloroplast members of FtsH protease family, only a few individual proteins have been identified so far as their physiological targets (i.e. Lhcb1, Lhcb3, PsbA and Rieske protein). Our knowledge regarding structure and molecular mechanisms of these enzymes' action is limited when compared with what is known about FtsHs of bacterial origin. Equally limited is the knowledge about ATP-dependent Lon4 protease being the single known chloroplast-targeted ortholog of Lon protease of Escherichia coli.

The paper addresses the problem of lead and platinum occurrence in the soil along roads and highways, the case in point being the main exit routes from the city of Poznan. While the soil concentrations of lead have been monitored not only along recently constructed roads but also those used over a long period, the presence of platinum in those soils was left without due consideration. The study reported on in this paper has revealed that despite the common use of unleaded petrol, the soil concentrations of lead along main roads are still high although they do not exceed the admissible levels. Another major finding of this study is that the soil concentrations of platinum exceed the geochemical background values. This corroborates the necessity of monitoring the presence of this noble metal, since its emission from the catalytic systems in motor vehicles continues to increase.

Objectives:The aim of paper was to explore the attitudes of Polish psychology students towards lesbian mothers whose children undergo psychological intervention, in an imaginary situation of providing professional support to the child. The authors found 3 types of psychologist behaviour: contact omission (withdrawal from the intervention, mother's partner exclusion), apparent appreciation of mother's partner and authentic appreciation of mother's partner (with women comparable participation). The authors explored an interaction between these attitudes and the support for gay and lesbian rights, the origin of the child (from a previous heterosexual relationship or present, homosexual one) and demographic variables. Methods: 97 students of psychology were examined at the Adam Mickiewicz University in Poznan, using the custom survey. Results : Respondents were most likely to include mother's partner to intervention, and the least - to avoid contact. Based on cluster analysis we found three types of attitude: unconditional acceptance, conditional acceptance, dependent on whether the child was born due in heterosexual or lesbian relationship and avoidance / rejection. The attitude of participants was associated with the declared support for gay rights, there was no correlation with gender and age. Conclusions: Due to the significant level of social prejudice against gays and lesbians in Poland, the issue of homosexual parenting and social functioning of gay and lesbians' children should become an area of research and scientific debate. There is a necessity of the introduction of this issue to the curricula of higher education and the implementation of formal, systematic training on sexual diversity for the professionals supporting families. © 2014, Polish Psychiatric Association. All rights reserved.

The influence of tetrabutylammonium (TBA) cations on lifting of reconstruction and phase transitions within adsorbed adlayers at Au(100) electrode in halide electrolytes has been studied by cyclic voltammetry and differential capacity measurements. The presence of TBA cation increases the stability range of the reconstructed surface more in chloride electrolyte than in bromide one in contrast to I- anions which have no impact on stability range. Besides, TBA cations shift the spikes corresponding to the incommensurate structures of Br- and Cl- anion adlayers to less positive potentials and the spike assigned to the commensurate structure of Br- anions in the opposite direction. In iodide electrolyte the two spikes connected most likely with the formation of the ordered cation/anion adlayers occur at less negative potential than the corresponding ones in TBA free solution. © 2015 Published by Elsevier B.V.

The impact of the structure of electrode surface on the behaviour of tetrabutylammonium cations on gold (1 0 0) and (1 1 1) electrodes has been studied using the cyclic voltammetry and differential capacity measurements. The adsorption features of these cations were found to be structure sensitive and resemble those of simple organic molecules rather than those of ions. It was also suggested that adsorption of anions from supporting electrolyte lifts the reconstruction which is modified by the tetrabutylammonium cations on the surface. © 2014 Elsevier B.V. All rights reserved.

Aim: This article addresses the problem of explaining emotional pathology (levels of personality organization) using the concepts of theory of mind (ToM) and mentalization. Although these terms are used interchangeably to describe the "ability to interpret the behavior of others in terms of mental states," they do not have identical status in emotional disorders. ToM refers to a "cold" knowledge, whereas mentalization requires the activation of relational and emotional representations, as well as processing of emotional experience (whether reflection or defense). The aim of the study was to compare the cognitive (ToM) and affective (mentalization) aspects of "understanding the behavior of others in terms of mental states" in the clinical group - consisting of patients with borderline personality organization (N = 30); and the control group (N = 30). Method: The Borderline Personality Inventory was used as a diagnostic questionnaire for the organization of personality, the Strange Stories Test was employed to measure ToM, and the Mental States Task instrument measured mentalization. Results: With respect to mentalization, different patterns of results were obtained: the activation of overwhelming mental states and primitive defenses in the clinical group; as well as the inhibition of the recognition of mental content by defenses, such as denial and suppression of emotions, in the control group. No differences were observed in ToM between groups. Conclusions: In explaining the personality organization levels, only the affective, and not the cognitive, aspects of "understanding the behavior of others in terms of mental states" are significant. People with borderline personality organization, as well as healthy individuals, use "cold" knowledge about internal states. However, the activation of relational and emotional representations triggers different mental states in both groups.

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