The extraction of the new components from electrogastrogram (EGG), using both adaptive filtering and electrocardiographic (ECG) derived respiration signal

Electrogastrographic examination (EGG) is a noninvasive method for an investigation of a stomach slow wave propagation. The typical range of frequency for EGG signal is from 0.015 to 0.15 Hz or (0.015–0.3 Hz) and the signal usually is captured with sampling frequency not exceeding 4 Hz. In this paper a new approach of method for recording the EGG signals with high sampling frequency (200 Hz) is proposed. High sampling frequency allows collection of signal, which includes not only EGG component but also signal from other organs of the digestive system such as the duodenum, colon as well as signal connected with respiratory movements and finally electrocardiographic signal (ECG). The presented method allows improve the quality of analysis of EGG signals by better suppress respiratory disturbance and extract new components from high sampling electrogastrographic signals (HSEGG) obtained from abdomen surface. The source of the required new signal components can be inner organs such as the duodenum and colon. One of the main problems that appear during analysis the EGG signals and extracting signal components from inner organs is how to suppress the respiratory components. In this work an adaptive filtering method that requires a reference signal is proposed.Electrogastrographic examination (EGG) is a noninvasive method for an investigation of a stomach slow wave propagation. The typical range of frequency for EGG signal is from 0.015 to 0.15 Hz or (0.015–0.3 Hz) and the signal usually is captured with sampling frequency not exceeding 4 Hz. In this paper a new approach of method for recording the EGG signals with high sampling frequency (200 Hz) is proposed. High sampling frequency allows collection of signal, which includes not only EGG component but also signal from other organs of the digestive system such as the duodenum, colon as well as signal connected with respiratory movements and finally electrocardiographic signal (ECG). The presented method allows improve the quality of analysis of EGG signals by better suppress respiratory disturbance and extract new components from high sampling electrogastrographic signals (HSEGG) obtained from abdomen surface. The source of the required new signal components can be inner organs such as the duodenum and colon. One of the main problems that appear during analysis the EGG signals and extracting signal components from inner organs is how to suppress the respiratory components. In this work an adaptive filtering method that requires a reference signal is proposed

Fast Time-Varying Linear Filters for Suppression of Baseline Drift in Electrocardiographic Signals

Realization of the high-pass (HP) filter is based on a narrow-band low-pass (LP) filter of which output is subtracted from the delayed input. The base of an LP filter is an extremely low computational cost Lynn’s filter with rectangular impulse response. The optimal cut-off frequency of an HP filter for baseline wander suppression is identical to an instantaneous heart rate

Terahertz time-domain spectroscopy for studying the kinetics of tissue adhesives

This study deals with the kinetics of tissue adhesives used for supporting the hemostasis and wound closure during surgical intervention. There are several types of adhesives of different composition which is closely related with their application. The time of curing plays an important role because some applications may require very fast glue for prompt vessel or wound closure; conversely some situations need slower solidification because of longer manipulation with the glue during surgery. Here, the terahertz time-domain spectroscopy is used for studying the kinetics of the glues. To slow the reaction rate, an oily substance is added to the glue samples. The technique of attenuated total reflection is used in this application; the defined amount of glue sample or its mixture is applied on the silicon crystal and the terahertz response is measured in time. This time dependences are analyzed to find time constants for mathematical description of the glue kinetics. © 2015 COPYRIGHT SPIE

Bipartite Graphs for Visualization Analysis of Microbiome Data

Visualization analysis plays an important role in metagenomics research. Proper and clear visualization can help researchers get their first insights into data and by selecting different features, also revealing and highlighting hidden relationships and drawing conclusions. To prevent the resulting presentations from becoming chaotic, visualization techniques have to properly tackle the high dimensionality of microbiome data. Although a number of different methods based on dimensionality reduction, correlations, Venn diagrams, and network representations have already been published, there is still room for further improvement, especially in the techniques that allow visual comparison of several environments or developmental stages in one environment. In this article, we represent microbiome data by bipartite graphs, where one partition stands for taxa and the other stands for samples. We demonstrated that community detection is independent of taxonomical level. Moreover, focusing on higher taxonomical levels and the appropriate merging of samples greatly helps improving graph organization and makes our presentations clearer than other graph and network visualizations. Capturing labels in the vertices also brings the possibility of clearly comparing two or more microbial communities by showing their common and unique parts

Free-Living Enterobacterium Pragia fontium 24613: Complete Genome Sequence and Metabolic Profiling

Pragia fontium is one of the few species that belongs to the group of atypical hydrogen sulfide-producing enterobacteria. Unlike other members of this closely related group, P. fontium is not associated with any known host and has been reported as a free-living bacterium. Whole genome sequencing and metabolic fingerprinting confirmed the phylogenetic position of P. fontium inside the group of atypical H2S producers. Genomic data have revealed that P. fontium 24613 has limited pathogenic potential, although there are signs of genome decay. Although the lack of specific virulence factors and no association with a host species suggest a free-living style, the signs of genome decay suggest a process of adaptation to an as-yet-unknown host

Phenotypic and genomic analysis of Clostridium beijerinckii NRRL B-598 mutants with increased butanol tolerance

N-Butanol, a valuable solvent and potential fuel extender, can be produced via acetone-butanol-ethanol (ABE) fermentation. One of the main drawbacks of ABE fermentation is the high toxicity of butanol to producing cells, leading to cell membrane disruption, low culture viability and, consequently, low produced concentrations of butanol. The goal of this study was to obtain mutant strains of Clostridium beijerinckii NRRL B-598 with improved butanol tolerance using random chemical mutagenesis, describe changes in their phenotypes compared to the wild-type strain and reveal changes in the genome that explain improved tolerance or other phenotypic changes. Nine mutant strains with stable improved features were obtained by three different approaches and, for two of them, ethidium bromide (EB), a known substrate of efflux pumps, was used for either selection or as a mutagenic agent. It is the first utilization of this approach for the development of butanol-tolerant mutants of solventogenic clostridia, for which generally there is a lack of knowledge about butanol efflux or efflux mechanisms and their regulation. Mutant strains exhibited increase in butanol tolerance from 36 % up to 127 % and the greatest improvement was achieved for the strains for which EB was used as a mutagenic agent. Additionally, increased tolerance to other substrates of efflux pumps, EB and ethanol, was observed in all mutants and higher antibiotic tolerance in some of the strains. The complete genomes of mutant strains were sequenced and revealed that improved butanol tolerance can be attributed to mutations in genes encoding typical stress responses (chemotaxis, autolysis or changes in cell membrane structure), but, also, to mutations in genes X276_07980 and X276_24400, encoding efflux pump regulators. The latter observation confirms the importance of efflux in butanol stress response of the strain and offers new targets for rational strain engineering

Phenotypic and genomic analysis of isopropanol and 1,3-propanediol producer Clostridium diolis DSM 15410

Clostridium diolis DSM 15410 is a type strain of solventogenic clostridium capable of conducting isopropanol-butanol-ethanol fermentation. By studying its growth on different carbohydrates, we verified its ability to utilize glycerol and produce 1,3-propanediol and discovered its ability to produced isopropanol. Complete genome sequencing showed that its genome is a single circular chromosome and belongs to the cluster I (sensu scricto) of the genus Clostridium. By cultivation analysis we highlighted its specific behavior in comparison to two selected closely related strains. Despite the fact that several CRISPR loci were found, 16 putative prophages showed the ability to receive foreign DNA. Thus, the strain has the necessary features for future engineering of its 1,3-propanediol biosynthetic pathway and for the possible industrial utilization in the production of biofuels

HRV in Isolated Rabbit Hearts and In Vivo Rabbit Hearts

Abstract Heart rate variability of seven isolated and five in-vivo rabbit hearts was compared. Heart rate of isolated hearts is lower and RR-intervals longer than those of in-vivo hearts. Characteristic peaks in characteristic frequency bands are different and powers of these bands are almost twice higher in in-vivo hearts than in isolated ones. LF/HF ratio is more than five-times higher in isolated heart than in in-vivo hearts. Introduction Heart rate variability (HRV) is a diagnostic tool based on evaluation of consecutive RR intervals. RR intervals are extracted from standard electrocardiogram; thus, HRV belongs to a group of non-invasive diagnostic methods. Despite decades of usage of HRV as experimental tool, it hasn't been clinically used until 1996, when Task Force society [1] standardized HRV parameters and their evaluation. HRV reflects behaviour of both parts of autonomous nervous system: sympathetic and parasympathetic Method Isolated hearts All experiments followed the guidelines for animal treatment approved by local authorities and conformed to the EU law. Seven New Zealand rabbits were included in the study. Their isolated hearts were perfused according to Langendorff in the mode of constant perfusion pressure (85mmHg) ECG signal was measured by touch-less method Three ECG signals with duration approximately two hours were recorded. Five minutes long part was extracted in Matlab R2006a (MathWorks, 2006), beginning immediately after 30 minutes of heart stabilization. R-peaks were detected automatically by own R-wave detector designed in Matlab R2006a (MathWorks, 2006). The results of automatic analysis were reviewed and any errors in detection were corrected manually by human revision. HRV parameters were computed from RR series interpolated with cubic spline method and resampled at fs=30Hz. Slow trends were removed by detrending procedure based on smoothness priors regularization with regularization parameter =3000. Signals were further analysed by Kubios HRV software 2.2. In-vivo hearts ECG signals of five New Zealand rabbits were included in the study. The signals were recorded using a SEIVA recording system. Body surface wire electrodes were attached to the skin with miniature clips. These electrodes did not restrict free posturing. In order to ge

Effects of Voltage-Sensitive Dye di-4-ANEPPS on Isolated Rat Heart Electrogram

Abstract Mapping of cardiac electrical activity from Langendorff-perfused hearts using the voltage-sensitive dye (VSD) di-4-ANEPPS has yielded important new information. However, data about response of the heart to staining with VSD are scarce. Voltage-sensitive dye di-4-ANEPPS is currently used in our laboratory for recording of monophasic action potentials by optical method in isolated hearts. The most often used species in basic cardiology is the rat heart. In order to describe in more detail the response of the heart tissue exposed to di-4-ANEPPS, heart rate changes and arrhythmia-preceding parameters in isolated rat heart electrogram during staining with di-4-ANEPPS and washout period, were followed. Introduction Mapping of cardiac electrical activity employing the voltage-sensitive dyes (VSDs) represents one of new and promising methods in basic cardiology laboratories. The electrical changes on the membrane either of one cardiomyocyte or from small area on the surface of the heart can be recorded. This approach is now considered as a valuable tool for electrophysiological studies focused on numerous, frequently studied topics in cardiovascular system physiology and pathophysiology, such as ischemia, reperfusion, arrhythmias triggering, preconditioning, postconditioning, etc. Voltage-sensitive dyes undergo changes in their electronic structure, and as a consequence also in their fluorescence spectra. These changes result from changes in the surrounding electric field, in excitable tissues such as myocardium or neurons. Therefore, VSD may be used successfully for recording of monophasic action potentials (MAPs) in such models. Various VSDs have been introduced into everyday laboratory practice (merocyanine, ANEPPS, etc.). Dyes from ANEPPS group (amino-naphthyl-ethenyl-pyridinium) are the most frequently used in cardiac preparations In our previous papers Methods In this study, five adult male Wistar rats (average body mass 322.4 ± 29.49 g) were included. Each experiment consisted of five phases: isolation of the heart, control perfusion, loading with the dye (staining), washout period, and MAPs recording under control conditions (37°C, spontaneously beating heart). In brief, the animals were deeply anaesthetised by inhalation of ether. After subsequent cervical dislocation, the chest was quickly opened and the heart excised with a sufficiently long segment of ascending aorta. After the heart isolation, the heart was firmly fixed to perfusion set-up by the stump of aorta and then placed in thermostat-controlled bath (37°C) filled with KrebsHenseleit (K-H) solution of following composition (in mM): NaCl 118, NaHCO 3 24, KCl 4.2, KH 2 PO 4 1.2, MgCl 2 1.2, glucose 5.5, Taurine 10, and CaCl 2 1.2. The solution was continuously oxygenated with 95% O 2 and 5% CO 2 . The heart was then perfused with the same solution at the constant perfusion pressure (80 mmHg) for 25 -30 minutes -control period. The perfusion was performed on Langendorff apparatus modified previously in our laborator