Qualitative Parameters of the Colonic Flora in Patients with HNF1A-MODY Are Different from Those Observed in Type 2 Diabetes Mellitus

Background. Type 2 diabetes mellitus (T2DM) is determined by genetic and environmental factors. There have been many studies on the relationship between the composition of the gastrointestinal bacterial flora, T2DM, and obesity. There are no data, however, on the gut microbiome structure in monogenic forms of the disease including Maturity Onset Diabetes of the Young (MODY). Methods. The aim of the investigation was to compare the qualitative parameters of the colonic flora in patients with HNF1A-MODY and T2DM and healthy individuals. 16S sequencing of bacterial DNA isolated from the collected fecal samples using the MiSeq platform was performed. Results. There were significant between-group differences in the bacterial profile. At the phylum level, the amount of Proteobacteria was higher ( = 0.0006) and the amount of Bacteroidetes was lower ( = 0.0005) in T2DM group in comparison to the control group. In HNF1A-MODY group, the frequency of Bacteroidetes was lower than in the control group ( = 0.0143). At the order level, Turicibacterales was more abundant in HNF1A-MODY group than in T2DM group. Conclusions. It appears that there are differences in the gut microbiome composition between patients with HNF1A-MODY and type 2 diabetes. Further investigation on this matter should be conducted

VIBRATION BASED METHOD FOR SHAFT CRACK DETECTION

Various excitation techniques have been developed to extract information on dynamic state of rotating machinery. This paper will address the effectiveness of selected excitations and analysed signals towards health monitoring of rotating machines from the cracked shaft dynamics point of view. The computer simulation study is based on the uncracked and cracked Jeffcott rotor models and the efficiency of the selected approaches is examined. As the excitation we have considered the rotor unbalance, additional harmonic forces, and input conditions. The combined resonances as diagnostic indicators of the crack in the shaft can be clearly seen in the total frequency spectrum being the difference between the spectrum of cracked and uncracked shaft. The introduced model of the rotor is convenient for application of various signal processing methods for crack detection and evaluation of its depth. Furthermore, in such a model one can take into account number of excitation planes and directions of the applied forces and can select the type of analyzed response (e.g. transient, steady-state)

VIBRATION BASED METHOD FOR SHAFT CRACK DETECTION

Various excitation techniques have been developed to extract information on dynamic state of rotating machinery. This paper will address the effectiveness of selected excitations and analysed signals towards health monitoring of rotating machines from the cracked shaft dynamics point of view. The computer simulation study is based on the uncracked and cracked Jeffcott rotor models and the efficiency of the selected approaches is examined. As the excitation we have considered the rotor unbalance, additional harmonic forces, and input conditions. The combined resonances as diagnostic indicators of the crack in the shaft can be clearly seen in the total frequency spectrum being the difference between the spectrum of cracked and uncracked shaft. The introduced model of the rotor is convenient for application of various signal processing methods for crack detection and evaluation of its depth. Furthermore, in such a model one can take into account number of excitation planes and directions of the applied forces and can select the type of analyzed response (e.g. transient, steady-state)

Thermomechanical Behavior of Rotor with Rubbing

This article presents an analytical study of the dynamics and stability of rotors subjected to rubbing due to contact with seals, taking account of associated thermal effects. The seal interaction force acting on the shaft gives rise to a friction force, which is a source of heating and can induce so-called spiral vibrations. A mathematical model that has been developed couples the heat-conduction equation with the equations for motion of the rotor. Numerical simulations have been conducted that show the thermomechanical behavior of the rotor at various operating conditions. A procedure for analyzing the stability of multibearing rotors based on the system eigenvalue analysis and the state-space approach has been proposed. Finally, the experimental data related to full annular rub have been presented