Extraction of the fetal ECG in noninvasive recordings by signal decompositions.

No signal processing technique has been able to reliably deliver an undistorted fetal electrocardiographic (fECG) signal from electrodes placed on the maternal abdomen because of the low signal-to-noise ratio of the fECG recorded from the maternal body surface. As a result, this led to increased rates of Caesarean deliveries of healthy infants. In an attempt to solve the problem, Physionet/Computing in Cardiology announced the 2013 Challenge: noninvasive fetal ECG.We are suggesting a method for cancellation of the maternal ECG consisting of: maternal QRS detection, heart rate dependant P-QRS-T interval selection, location of the fiducial points inside this interval for best matching by cross correlation, superimposition of the intervals, calculation of the mean signal of the P-QRS-T interval, and sequential subtraction of the mean signal from the whole fECG recording. Three signal decomposition methods were further applied in order to enhance the fetal QRSs (fQRS): principal component analysis, root-mean-square and Hotelling's T-squared. A combined lead of all decompositions was synthesized and fQRS detection was performed on it.The current research differs from the Challenge in that it uses three signal decomposition methods to enhance the fECG. The new results for 97 recordings of test set B are: 305.657 for Event 4: Fetal heart rate (FHR) and 23.062 for Event 5: Fetal RR interval (FRR).

Q-onset and T-end delineation: assessment of the performance of an automated method with the use of a reference database.

The aim of the study is to assess the performance of an automated method for Q-onset and T-end delineation, as well as QT measurement with the use of a 'gold standard' of a manually created reference database. The data to be used comprise 548 recordings of the PTB Diagnostic ECG Database. The ECG signals are preprocessed, suppressing power-line interference, electromyographic noise and baseline drift according to our previously published investigations, guaranteeing accurate Q-onset and T-end locality preservation. Our method for automatic detection of Q-onset and T-end is based on the minimum value of the angle between two segments having a common mid point and equal lengths of 10 ms. The minimum of the angle is searched in defined time intervals delimited separately for the Q-onset and T-end. All measurements are performed on lead II only. Mean +/- standard deviations are obtained for 95% of the recordings: -0.08 +/- 2.71 for Q-onset, 5.10 +/- 9.22 for T-end and 4.40 +/- 9.93 for QT interval, as well as for 100% of the recordings: 0.46 +/- 4.84 for Q-onset, 1.28 +/- 16.75 for T-end and 0.83 +/- 16.67 for QT interval.

[Insertion mutations in Pseudomonas pseudomallei genome induced by transposons Tn10. Tn9, and Tn5]. / Insertsionnye mutatsii v genome Pseudomonas pseudomallei, indutsirovannye transpozonami Tn10, Tn9, Tn5.

Tn10 and Tn9 from temperature-sensitive replicons RPI::Tn10 Rep is and RP1::Tn9 Rep ts and Tn5 from the "suicidal" vector pSUP5011 may integrate in the P. pseudomallei chromosome. Transposons induced auxotrophic mutations of different spectrum, depending on the strain, Tn element, and defects in the genes responsible for the mobility sign, function of some extracellular elements (lecithinase and lipase), hemolytic activity, and antigen 8 synthesis, which are considered as the potential factors of the pathogenicity of melioidosis agent. No secondary restructuring induced by Tn elements were detected in the domains adjacent to insertion sites. Plasmids RP1::Tn10 Rep ts and RP1::Tn9 Rep ts were stable in insertion mutant cells, mediating the variable TR-TS phenotype probably indicating that plasmid integration with the chromosome is unstable.