Recently research shows that horseradish peroxidase, HRP, when combined with other compounds, is highly reactive toward different human tumour cells and that better understanding of catalytic mechanism and inhibition HPR could lead to a new targeted cancer therapy. Thus, the inhibition of HRP activity by dipotassium-trioxohydroxytetrafluorotriborate K2[B3O3F4OH] was investigated for possible explanation of previously observed antitumour activities of this promising drug. HRP activity was studied under steady-state kinetic conditions by a spectrophotometric method. In the absence of the inhibitor values of = 0.47 mM and = 0.34 mM min−1, respectively, were determined. The hydrogen peroxide H2O2 kinetic measurements show a competitive inhibition with the inhibition constant = 2.56 mM. The activation energy values were found to be very similar for both reactions; in the absence of inhibitor activation energy was 17.7 kJ mol−1 and in the presence of inhibitor activation energy was 16.3 kJ mol−1. The values of Arrhenius constants were found to be different; = 4.635 s−1 was measured in the absence of inhibitor while in the presence of inhibitor Arrhenius constant was 1.745 s−1 showing that K2[B3O3F4OH] initiates conformational change in the structure of the HRP and subsequently reduces its activity.

This paper describes an R package LeArEst that can be used for estimating object dimensions from a noisy image. The package is based on a simple parametric model for data that are drawn from uniform distribution contaminated by an additive error. Our package is able to estimate the length of the object of interest on a given straight line that intersects it, as well as to estimate the object area when it is elliptically shaped. The input data may be a numerical vector or an image in JPEG format. In this paper, background statistical models and methods for the package are summarized, and the algorithms and key functions implemented are described. Also, examples that demonstrate its usage are provided. Availability: LeArEst is available on CRAN.

Hybrid systems, which were created by integrating the structural systems of different behavior in the transfer of loads, represent a new efficient system, with low self-weight, increased capacity characteristics and reduced deformability compared to the systems of which they are made of. Applicable to all materialization and logical geometric forms, they represent transparent systems suitable for optimization of structures. In this paper is represented the original analysis of parameters, reduced to relative values of a hybrid system with and without pre-stressing of different geometric shapes, particularly in terms of deformability. The results of the research are represented through the practical expressions and diagrams for use in practice, and on the basis of which can be determined suitable constellation of system from a simple girder, strut type hybrid system with different geometrical characteristics and pre-stressed hybrid system, and in the case of wood-steel hybrid system for different percentage of moisture of wood girder. To give access presents the accurate method that can be applied to any combination of materials in the context of a hybrid system.