Badanie stanu trzeźwości pracowników – dopuszczalna forma nadzoru nad pracownikami czy nieuzasadniona ingerencja w ich dobra osobiste

The purpose of this article eis both a legal assessment of the acceptability of examinatingsobriety of employees from the point of view of their legality and an attempt to characterize not onlythe sobriety control itself as a form of supervision over an employee, but also broadly understoodpersonal rights that are in a continuous development phase and are extremely associated with theemployer's supervision over the employee. The article is also intended to answer the question: whatentities are really entitled to examine the sobriety of employees.Celem niniejszego artykułu jest zarówno ocena prawna dopuszczalności badania stanu trzeźwości pracowników z punktu widzenia jego legalności, jak i próba scharakteryzowania nie tylko samej kontroli trzeźwości jako formy nadzoru nad pracownikiem, ale również szeroko pojmowanych dóbr osobistych, które są w fazie ciągłego rozwoju oraz niebywale są związane z nadzorem pracodawcy nad pracownikiem. Artykuł także ma za zadanie odpowiedzieć na pytanie: jakie podmioty tak naprawdę są uprawnione do badania stanu trzeźwości pracowników

The Effect of tensile stress on the conformational free energy landscape of disulfide bonds

Disulfide bridges are no longer considered to merely stabilize protein structure, but are increasingly recognized to play a functional role in many regulatory biomolecular processes. Recent studies have uncovered that the redox activity of native disulfides depends on their C-C-S-S dihedrals, and . Moreover, the interplay of chemical reactivity and mechanical stress of disulfide switches has been recently elucidated using force-clamp spectroscopy and computer simulation. The and angles have been found to change from conformations that are open to nucleophilic attack to sterically hindered, so-called closed states upon exerting tensile stress. In view of the growing evidence of the importance of C-C-S-S dihedrals in tuning the reactivity of disulfides, here we present a systematic study of the conformational diversity of disulfides as a function of tensile stress. With the help of force-clamp metadynamics simulations, we show that tensile stress brings about a large stabilization of the closed conformers, thereby giving rise to drastic changes in the conformational free energy landscape of disulfides. Statistical analysis shows that native TDi, DO and interchain Ig protein disulfides prefer open conformations, whereas the intrachain disulfide bridges in Ig proteins favor closed conformations. Correlating mechanical stress with the distance between the two -carbons of the disulfide moiety reveals that the strain of intrachain Ig protein disulfides corresponds to a mechanical activation of about 100 pN. Such mechanical activation leads to a severalfold increase of the rate of the elementary redox reaction step. All these findings constitute a step forward towards achieving a full understanding of functional disulfides

Le Sujet de l’Acteur. An Anthropological Outlook on Actor-Network Theory

In the past few years, the Actor-Network Theory of French philosopher and sociologist Bruno Latour has become a hotly debated topic in the humanities. From a philosophical perspective, his theory of things keeps being reevaluated: is it possible for ‘Human and Non-Human Actors’ (Latour) to be analyzed as equally important actors? Does Latour’s theory of a simultaneous ‘agency’ of things and concepts indeed move beyond a subject-object relation? If it does, how far does it in fact go? Is it possible to develop a common new ontology by moving away from the notion of substance, and instead reducing any kind of entities to what they reveal in the course of their (inter)action? The contributions to Le Sujet de l’Acteur are looking for interferences between the idea of ‘agency’ and cultural dynamics. How can we relate questions of (social) action with those of cultural manifestations? Focusing on questions of symmetry or dissymmetry between the world of ‘things’ and ‘human beings,’ the volume includes contributions from the fields of social studies, literary studies, and philosophy. Although the contents are categorized in systematic and historical aspects, all contributions draw on the importance of case studies for the theoretical framework, either starting with systematic questions that are then answered exemplary, or starting from historical cases as well as theoretical options

Polymer Mechanochemistry: A New Frontier for Physical Organic Chemistry

© 2018 Elsevier Ltd Polymer mechanochemistry aims at understanding and exploiting the unique chemistry that is possible when stretching macromolecular chains beyond their strain-free contour lengths. This happens when chains are subject to a mechanical load, in bulk, in solution, at interfaces or as single molecules in air. Simple polymers such as polystyrene or polymethacrylate fragment via homolysis of a backbone C–C bond, and much contemporary effort in polymer mechanochemistry has focused on creating polymers which undergo more complex and interesting reactions, with such productive mechanochemical responses including mechanochromism and load strengthening. Comparatively less progress has been achieved in creating an internally coherent, theoretically sound interpretational framework to organize, systematize, and generalize the existing manifestations of polymer mechanochemistry and to guide the design of new mechanochemical systems. The experimental, computational, and conceptual tools of physical organic chemistry appear particularly well suited to achieve this goal, benefiting both fields

Chalcogen bonds : origins and importance in biological systems

The chalcogen bond is analogous to the halogen and hydrogen bond and it produces favorable interactions between 16th group of elements, that play a role in catalysis, medical chemistry, design of materials and biological processes. In the solid state, the chalcogen bond was used to build nano-sized structures and in solution is responsible mainly for intramolecular interactions, which stabilize the structures of intermediates and reagents. Recently, chalcogen bonds have been increasingly used in the recognition and transport of anions and in organic synthesis

Ab initio molecular dynamics study of overtone excitations in formic acid and its water complex

In this article, we present results from ab initio molecular dynamics simulation of overtone excitation in formic acid monomer and its water complex in the gas phase. For the monomer, a conformation change is observed employing both OH and CH vibrational excitations, which supports experimental findings. In the formic acid–water complex, interconversion also takes place, but it proceeds via hydrogen exchange rather than via intramolecular reaction. Simulations raise a question on effect of quantum and matrix effects to the results. Also, a brief test of different computation methods was done on the system.peerReviewe

Mechanochemical disulfide reduction reveals imprints of noncovalent sulfur⋯oxygen chalcogen bonds in protein-inspired mimics in aqueous solution

The surprisingly rich chemistry of mechanically activated cleavage of disulfide bonds has been uncovered only recently. Using a disulfide protein mimic together with Cleland's reagent (DTT) as the attacking nucleophile in aqueous solution, our isotensional ab initio simulations add another surprise to the list. They unveil that noncovalent chalcogen-chalcogen 1,5-type S⋯O interactions involving the S-S bridge and γ-carbonyl O are controlling the mechanochemical reactivity of disulfides at very low forces, thus adding a third reactivity regime to the hitherto known ones. In stark contrast to what is found in aqueous solution, no such chalcogen bonding arrangements are observed in the gas phase, which supports the conclusion that water plays a crucial role in stabilizing preferred conformations that support noncovalent S⋯O bonds. These findings open the door to investigate chalcogen bonding in the realm of proteins using single-molecule force spectroscopy.Fil: Dopieralski, Przemyslaw. Uniwersytet Wrocławski; PoloniaFil: Zoloff Michoff, Martin Eduardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Investigaciones en Físico-química de Córdoba. Universidad Nacional de Córdoba. Facultad de Ciencias Químicas. Instituto de Investigaciones en Físico-química de Córdoba; ArgentinaFil: Marx, Dominik. Ruhr Universität Bochum; Alemani

On the Overwhelming Complexity of Mechanochemical Disulphide Bond Reduction in Alkaline Solution

The coupling between mechanical stress and the reactivity of disulphide bridges has recently received a great deal of attention due to its broad relevance in biochemistry and materials science. Here, we will highlight the main findings of our computational studies on mechanochemistry of disulphide bridges, which have been carried out in the past few years in the framework of GCS Large Scale Projects. Our investigations have disclosed a very complex mechanistic scenario for the mechanochemistry of disulphides in aqueous alkaline solution. In the low-force regime, external forces play a dual role in the reduction of disulphide bridges via a bimolecular SN2 attack of a hydroxide ion at a sulphur atom. On the one hand, the external tensile force accelerates the reaction by virtue of the mechanical work performed on the system as the reaction proceeds. On the other hand, tensile forces can induce a conformational distortion of the disulphide moiety that drives the system into a spatial arrangement that is less prone to a nucleophilic attack due to steric hindrance. In the high-force regime, in turn, the tensile force gives rise to a competition between bimolecular SN2 and unimolecular C–S bond breaking mechanisms as well as to drastic changes in the free energy landscape of the system as a result of which bimolecular reaction pathways transform into pure bond-breaking processes. Our results not only provide a rationale for the enigmatic outcome of certain single-molecule force spectroscopy experiments but also suggest new experiments to continue unravelling the intricacies of the mechanochemistry of disulphide bridges

Force-induced reversal of beta-eliminations: stressed disulfide bonds in alkaline solution

Understanding the impact of tensile forces on disulfide bond cleavage is not only crucial to the breaking of cross-linkers in vulcanized materials such as strained rubber, but also to the regulation of protein activity by disulfide switches. By using ab initio simulations in the condensed phase, we investigated the response of disulfide cleavage by β-elimination to mechanical stress. We reveal that the rate- determining first step of the thermal reaction, which is the abstraction of the β- proton, is insensitive to external forces. However, forces larger than about 1 nN were found to reshape the free-energy landscape of the reaction so dramatically that a second channel is created, where the order of the reaction steps is reversed, turning β-deprotonation into a barrier-free follow-up process to C−S cleavage. This transforms a slow and force-independent process with second-order kinetics into a unimolecular reaction that is greatly accelerated by mechanical forces