Ústav biomedicínského inženýrství

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Virtual reality exposure effect in acrophobia: psychological and physiological evidence from a single experimental session
(Springer Nature, 2024-07-15) Varšová, Kristína; Szitás, Dagmar; Janoušek, Oto; Jurkovičová, Lenka; Bartošová, Kateřina; Juřík, Vojtěch
In recent years, virtual reality (VR) has gained attention from researchers in diverse fields, particularly in therapy of phobias. Currently, virtual reality exposure therapy therapy (VRET) is considered a promising cognitive-behavioral therapy technique. However, specific psychological and physiological responses of VR users to virtual exposure in such a context are still only vaguely explored. In this experimental study, we mapped VR exposure in a height environment in people with a moderate fear of heights–acrophobia. Thirty-six participants were divided into experimental and control groups–with and without psychological guidance during exposure. Participants' subjective level of anxiety was examined, and objective physiological response was captured via heart rate variability (HRV) measurement. Psychological assessments recorded an anticipated rise in participant anxiety following exposure to height; nevertheless, no distinctions were observed in self-reported anxiety concerning psychological guidance. Notably, objective physiological measures revealed that VR exposure prompts physiological responses akin to real-world scenarios. Moreover, based on the analysis of heart rate variability, participants who received psychological guidance were identified as better at compensating for anxiety compared to those without such support. These findings support VRET as a promising tool for psychotherapy and advocate for psychological guidance as beneficial in reducing anxiety and managing stress during exposure. The results may help improve our understanding of anxiety during exposure to phobic stimuli.
Whole genome sequencing and characterization of Pantoea agglomerans DBM 3797, endophyte, isolated from fresh hop (Humulus lupulus L.)
(Frontiers, 2024-02-08) Patáková, Petra; Vasylkivska, Maryna; Sedlář, Karel; Šabatová, Kateřina; Bezdíček, Matěj; Lovecká, Petra; Branská, Barbora; Kaštánek, Petr; Krofta, Karel
Background This paper brings new information about the genome and phenotypic characteristics of Pantoea agglomerans strain DBM 3797, isolated from fresh Czech hop (Humulus lupulus) in the Saaz hop-growing region. Although P. agglomerans strains are frequently isolated from different materials, there are not usually thoroughly characterized even if they have versatile metabolism and those isolated from plants may have a considerable potential for application in agriculture as a support culture for plant growth. Methods P. agglomerans DBM 3797 was cultured under aerobic and anaerobic conditions, its metabolites were analyzed by HPLC and it was tested for plant growth promotion abilities, such as phosphate solubilization, siderophore and indol-3-acetic acid productions. In addition, genomic DNA was extracted, sequenced and de novo assembly was performed. Further, genome annotation, pan-genome analysis and selected genome analyses, such as CRISPR arrays detection, antibiotic resistance and secondary metabolite genes identification were carried out. Results and discussion The typical appearance characteristics of the strain include the formation of symplasmata in submerged liquid culture and the formation of pale yellow colonies on agar. The genetic information of the strain (in total 4.8 Mb) is divided between a chromosome and two plasmids. The strain lacks any CRISPR-Cas system but is equipped with four restriction-modification systems. The phenotypic analysis focused on growth under both aerobic and anaerobic conditions, as well as traits associated with plant growth promotion. At both levels (genomic and phenotypic), the production of siderophores, indoleacetic acid-derived growth promoters, gluconic acid, and enzyme activities related to the degradation of complex organic compounds were found. Extracellular gluconic acid production under aerobic conditions (up to 8 g/l) is probably the result of glucose oxidation by the membrane-bound pyrroloquinoline quinone-dependent enzyme glucose dehydrogenase. The strain has a number of properties potentially beneficial to the hop plant and its closest relatives include the strains also isolated from the aerial parts of plants, yet its safety profile needs to be addressed in follow-up research.
Enhancing Clinical Efficiency: Autonomous Determination of Cardiac Effective Refractory Period Using ECG Signals
(Czech Medical Association J.E. Purkyne, 2024-06-30) Ředina, Richard; Filipenská, Marina
Electrophysiological procedures for managing arrhythmias remain time-consuming, causing patients to wait for critical interventions. To address this pressing need, we introduce a revolutionary algorithm that autonomously calculates the effective refractory period (ERP) of cardiac tissue from electrocardiogram (ECG). The algorithm principally comprises signal filtering techniques and the detection of local extrema within the signal waveform. This algorithm underwent rigorous assessment using an in-house database of ECG signals acquired from ten patients who underwent electrophysiological examinations. Fundamental digital signal processing methods, such as linear filtering and thresholding, were employed in the determination of ERP. The algorithm yielded results congruent with the ERP values established by electrophysiologists in nine out of ten cases, with a standard deviation of 18.97 milliseconds. By being accurate and easy to integrate., this algorithm holds promise for real-time deployment in clinical settings, where it could potentially streamline and automate stimulation protocols, thereby expediting the examination process.
The First Insight into Polyhydroxyalkanoates Accumulation in Multi-Extremophilic Rubrobacter xylanophilus and Rubrobacter spartanus
(MDPI, 2021-05-01) Kouřilová, Xenie; Schwarzerová, Jana; Buchtíková, Iva; Sedlář, Karel; Mrázová, Kateřina; Krzyžánek, Vladislav; Nebesářová, Jana; Obruča, Stanislav
Actinobacteria belonging to the genus Rubrobacter are known for their multi-extremophilic growth conditions-they are highly radiation-resistant, halotolerant, thermotolerant or even thermophilic. This work demonstrates that the members of the genus are capable of accumulating polyhydroxyalkanoates (PHA) since PHA-related genes are widely distributed among Rubrobacter spp. whose complete genome sequences are available in public databases. Interestingly, all Rubrobacter strains possess both class I and class III synthases (PhaC). We have experimentally investigated the PHA accumulation in two thermophilic species, R. xylanophilus and R. spartanus. The PHA content in both strains reached up to 50% of the cell dry mass, both bacteria were able to accumulate PHA consisting of 3-hydroxybutyrate and 3-hydroxyvalerate monomeric units, none other monomers were incorporated into the polymer chain. The capability of PHA accumulation likely contributes to the multi-extremophilic characteristics since it is known that PHA substantially enhances the stress robustness of bacteria. Hence, PHA can be considered as extremolytes enabling adaptation to extreme conditions. Furthermore, due to the high PHA content in biomass, a wide range of utilizable substrates, Gram-stain positivity, and thermophilic features, the Rubrobacter species, in particular Rubrobacter xylanophilus, could be also interesting candidates for industrial production of PHA within the concept of Next-Generation Industrial Biotechnology.
Non-steroidal anti-inflammatory drug consumption in a multi stage and a 24-h mountain bike competition
(Frontiers Editorial Office, 2018-09-10) Chlíbková, Daniela; Filipenská, Marina; Nikolaidis, Pantelis T.; Rosemann, Thomas; Knechtle, Beat
Purpose: Excessive or inappropriate non-steroidal anti-inflammatory drug (NSAID) use during ultra-endurance events could cause potential risk to athletes’ health. Reports on NSAID consumption in mountain bikers or ultra-mountain bikers are scarce. Therefore, the aim of this study was to investigate the prevalence of NSAID consumption immediately before, during and immediately after a mountain bike (MTB) race and to compare NSAID consumption in two different MTB competitions. Methods: This observational study took place at a three-stage MTB race (SMTB) (n = 63) and at a 24-h MTB race (24MTB) (n = 68), both held in the Czechia in 2017. NSAID consumption was evaluated via self-reported electronic questionnaires. Results: Of all finishers (n = 131), fourteen (10%) consumed NSAID at least once during the competition day (immediately before, during or immediately after the race). The number of NSAID consumers was the same in both competitions. Nevertheless, only three athletes (2%), all of them from the 24MTB, consumed NSAID during the race and 5% of all mountain bikers reported consumption after the race. In contrast to the SMTB, the intake reported by the 24MTB participants was quite homogeneous in terms of the timing of NSAID consumption. The NSAID users were older (p = 0.043) than the non-users. Ibuprofen was most commonly used by 79% of all consumers Conclusion: The prevalence of NSAID use was higher in the older participants and seems to be lower in comparison with results from studies about runners, ultra-runners and triathletes suggesting that it is determined by the discipline (i.e., cycling). On the other hand, the timing of NSAID consumption was probably affected by the competition character (e.g., MTBS or 24MTB). Future studies should focus on a larger sample size of cyclists from various disciplines.

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