ST-elevation myocardial infarction (STEMI) is one of the main reasons for morbidity and mortality worldwide. In addition to the classic biomarker NT-proBNP, new biomarkers like ST2 and Pentraxin-3 (Ptx-3) have emerged as potential tools in stratifying risk in cardiac patients. Indeed, multimarker approaches to estimate prognosis of STEMI patients have been proposed and their potential clinical impact requires investigation. In our study, in 147 patients with STEMI, NT-proBNP as well as serum levels of ST2 and Ptx-3 were evaluated. During two-year follow-up (FU; 734.2 ± 61.2 d) results were correlated with risk for cardiovascular mortality (CV-mortality). NT-proBNP (HR = 1.64, 95% CI = 1.21–2.21, p = 0.001) but also ST2 (HR = 1.000022, 95% CI = 1.00–1.001, p < 0.001) were shown to be reliable predictors of CV-mortality, while the highest predictive power was observed with Ptx-3 (HR = 3.1, 95% CI = 1.63–5.39, p < 0.001). When two biomarkers were combined in a multivariate Cox regression model, relevant improvement of risk assessment was only observed with NT-proBNP+Ptx-3 (AIC = 209, BIC = 214, p = 0.001, MER = 0.75, MEV = 0.64). However, the highest accuracy was seen using a three-marker approach (NT-proBNP + ST2 + Ptx-3: AIC = 208, BIC = 214, p < 0.001, MER = 0.77, MEV = 0.66). In conclusion, after STEMI, ST2 and Ptx-3 in addition to NT-proBNP were associated with the incidence of CV-mortality, with multimarker approaches enhancing the accuracy of prediction of CV-mortality.

No abstract

This article describes the process of dragging a pipeline through a channel. In the simulation of this process, the interactions between the pipeline, the drill rod, the soil and the bentonite mud are taken into account. Dragging of the pipeline through the well is hampered by frictional forces of the pipeline and the drill rod against the soil, as well as the drag force of the pipeline when it moves in the drilling fluid. In the construction of a mathematical model, the influence of these forces is taken into account. To determine the frictional forces, the pipeline and the drill rod were considered as a flexible non-stretch filament. An algorithm for determining the tractive effort is created and implemented. A separate stage of the work is devoted to the accounting of ballasting of the pipeline.

In this article, the process of overcoming the stony obstacle while dragging pipeline through the channel is considered. Depending on the size of the duct and the pipeline itself the permissible size of the obstacle that the pipeline can overcome without resting against the upper part of the channel, is considered. To solve this problem, the pipeline is conditionally divided into two sections: the site located up to the obstacle and resting on it, and a free area that is after the obstacle. Directly on the process of dragging through an obstacle are acting the forces and moments which have influence on the pipeline. Starting from the equations of moment equilibrium for different points of the pipeline, and also from the equations of bending beams the value of the obstacle is evaluated.