Control of specific/nonspecific protein adsorption : functionalization of polyelectrolyte multilayer films as a potential coating for biosensors

Control of nonspecific/specific protein adsorption is the main goal in the design of novel biomaterials, implants, drug delivery systems, and sensors. The specific functionalization of biomaterials can be achieved by proper surface modification. One of the important strategies is covering the materials with functional coatings. Therefore, our work aimed to functionalize multilayer coating to control nonspecific/specific protein adsorption. The polyelectrolyte coating was formed using a layer-by-layer technique (LbL) with biocompatible polyelectrolytes poly-L-lysine hydrobromide (PLL) and poly-L-glutamic acid (PGA). Nonspecific protein adsorption was minimized/eliminated by pegylation of multilayer films, which was achieved by adsorption of pegylated polycations (PLL-g-PEG). The influence of poly (ethylene glycol) chain length on eliminating nonspecific protein adsorption was confirmed. Moreover, to achieve specific protein adsorption, the multilayer film was also functionalized by immobilization of antibodies via a streptavidin bridge. The functional coatings were tested, and the adsorption of the following proteins confirmed the ability to control nonspecific/specific adsorption: human serum albumin (HSA), fibrinogen (FIB), fetal bovine serum (FBS), carcinoembryonic antigen human (CEA) monitored by quartz crystal microbalance with dissipation (QCM-D). AFM imaging of unmodified and modified multilayer surfaces was also performed. Functional multilayer films are believed to have the potential as a novel platform for biotechnological applications, such as biosensors and nanocarriers for drug delivery systems

Determination of the dynamic critical maneuvering area in an encounter between two vessels

This paper introduces the concept of Collision Avoidance Dynamic Critical Area (CADCA) for onboard Decision Support Systems (DSS). The indicator proposed is derived via identification of a minimum required maneuvering zone in an encounter between two vessels. The CADCA model accounts for ship maneuvering dynamics and associated hydrodynamic actions emerging from different rudder angles and forward speed effects. The method presented is novel as it considers the variability of a critical area due to dynamic changes in operational parameters for both vessels. Results of the simulations carried out in negligible weather conditions confirm that computed zones may differ significantly in terms of shapes and limits. It is demonstrated that the size of the CADCA depends on the rudder angle, forward speed, as well as the dimensions of the vessels.Peer reviewe

Semi-dynamic ship domain in the encounter situation of two vessels

| openaire: EC/H2020/814753/EU//FLAREThere exist numerous examples of ship domains that are rooted in the concept of Fujii and Goodwin. However, over the years, the applicability of the conception has been significantly expanded. Nowadays, the ship domain is mainly used to assess the safety of navigation, not to evaluate the capacity of waterways as it was initially designed. In the safety-related approach, violation of domain in vessels encounter is recognized as an unsafe operation. Nevertheless, in the literature, there is a lack of proper justification for transferring the ship domain concept from the original application filed to the other, especially into the safety-critical areas. Therefore, in this paper, we undertake an attempt to specify the basic requirements for a concept that can be used to evaluate the safety of ship-ship encounter. The idea reflects the dynamics of two vessels involved in the close approach situation, their maneuvering, and operational characteristics.Peer reviewe

Mouse IgG3 binding to macrophage-like cells is prevented by deglycosylation of the antibody or by Accutase treatment of the cells

The binding of mouse IgG3 to Fc gamma receptors (Fc gamma R) and the existence of a mouse IgG3-specific receptor have been discussed for 40 years. Recently, integrin beta-1 (ITGB1) was proposed to be a part of an IgG3 receptor involved in the phagocytosis of IgG3-coated pathogens. We investigated the interaction of mouse IgG3 with macrophage-like J774A.1 and P388D1 cells. The existence of an IgG3-specific receptor was verified using flow cytometry and a rosetting assay, in which erythrocytes clustered around the macrophage-like cells coated with an erythrocyte-specific IgG3. Our findings confirmed that receptors binding antigen-free IgG3 are present on J774A.1 and P388D1 cells. We demonstrated for the first time that the removal of N-glycans from IgG3 completely abolished its binding to the cells. Moreover, we discovered that the cells treated with Accutase did not bind IgG3, indicating that IgG3-specific receptors are substrates of this enzyme. The results of antibody-mediated blocking of putative IgG3 receptors suggested that apart from previously proposed ITGB1, Fc gamma RII, Fc gamma RIII, also additional, still unknown, receptor is involved in IgG3 binding. These findings indicate that there is a complex network of glycan-dependent interactions between mouse IgG3 and the surface of effector immune cells

A framework for risk assessment for maritime transportation systems—A case study for open sea collisions involving RoPax vessels

VK: T20404Maritime accidents involving ships carrying passengers may pose a high risk with respect to human casualties. For effective risk mitigation, an insight into the process of risk escalation is needed. This requires a proactive approach when it comes to risk modelling for maritime transportation systems. Most of the existing models are based on historical data on maritime accidents, and thus they can be considered reactive instead of proactive. This paper introduces a systematic, transferable and proactive framework estimating the risk for maritime transportation systems, meeting the requirements stemming from the adopted formal definition of risk. The framework focuses on ship–ship collisions in the open sea, with a RoRo/Passenger ship (RoPax) being considered as the struck ship. First, it covers an identification of the events that follow a collision between two ships in the open sea, and, second, it evaluates the probabilities of these events, concluding by determining the severity of a collision. The riskframework is developed with the use of Bayesian Belief Networks and utilizes a set of analytical methods for the estimation of the risk model parameters. Finally, a case study is presented, in which the risk framework developed here is applied to a maritime transportation system operating in the Gulf of Finland (GoF). The results obtained are compared to the historical data and available models, in which a RoPax was involved in a collision, and good agreement with the available records is found.Peer reviewe

Agglutinating mouse IgG3 compares favourably with IgMs in typing of the blood group B antigen : functionality and stability studies

Mouse immunoglobulins M (IgMs) that recognize human blood group antigens induce haemagglutination and are used worldwide for diagnostic blood typing. Contrary to the current belief that IgGs are too small to simultaneously bind antigens on two different erythrocytes, we obtained agglutinating mouse IgG3 that recognized antigen B of the human ABO blood group system. Mouse IgG3 is an intriguing isotype that has the ability to form Fc-dependent oligomers. However, F(ab′)(2) fragments of the IgG3 were sufficient to agglutinate type B red blood cells; therefore, IgG3-triggered agglutination did not require oligomerization. Molecular modelling indicated that mouse IgG3 has a larger range of Fab arms than other mouse IgG subclasses and that the unique properties of mouse IgG3 are likely due to the structure of its hinge region. With a focus on applications in diagnostics, we compared the stability of IgG3 and two IgMs in formulated blood typing reagents using an accelerated storage approach and differential scanning calorimetry. IgG3 was much more stable than IgMs. Interestingly, the rapid decrease in IgM activity was caused by aggregation of the molecules and a previously unknown posttranslational proteolytic processing of the μ heavy chain. Our data point to mouse IgG3 as a potent diagnostic tool