Working memory (WM) is essential for the temporary storage and processing of information required for complex cognitive tasks and relies on neuronal theta and gamma oscillations. Given the limited capacity of WM, researchers have investigated various methods to improve it, including transcranial alternating current stimulation (tACS), which modulates brain activity at specific frequencies. One particularly promising approach is theta-gamma peak-coupled-tACS (TGCp-tACS), which simulates the natural interaction between theta and gamma oscillations that occurs during cognitive control in the brain. The aim of this study was to improve WM in healthy young adults with TGCp-tACS, focusing on both behavioral and neurophysiological outcomes. Thirty-one participants completed five WM tasks under both sham and verum stimulation conditions. Electroencephalography (EEG) recordings before and after stimulation showed that TGCp-tACS increased power spectral density (PSD) in the high-gamma region at the stimulation site, while PSD decreased in the theta and delta regions throughout the cortex. From a behavioral perspective, although no significant changes were observed in most tasks, there was a significant improvement in accuracy in the 14-item Sternberg task, indicating an improvement in phonological WM. In conclusion, TGCp-tACS has the potential to promote and improve the phonological component of WM. To fully realize the cognitive benefits, further research is needed to refine the stimulation parameters and account for individual differences, such as baseline cognitive status and hormonal factors.

• MeSH
• chování fyziologie   MeSH
• dospělí MeSH
• elektrická stimulace MeSH
• elektroencefalografie MeSH
• gama rytmus EEG fyziologie   MeSH
• krátkodobá paměť * fyziologie   MeSH
• lidé MeSH
• mladý dospělý MeSH
• přímá transkraniální stimulace mozku * metody   MeSH
• theta rytmus EEG fyziologie   MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH

In recent years, the dynamics and function of cross-frequency coupling (CFC) in electroencephalography (EEG) have emerged as a prevalent area of investigation within the research community. One possible approach in studying CFC is to utilize non-invasive neuromodulation methods such as transcranial alternating current stimulation (tACS) and neurofeedback (NFB). In this study, we address (1) the potential applicability of single and multifrequency tACS and NFB protocols in CFC research; (2) the prevalence of CFC types, such as phase-amplitude or amplitude-amplitude CFC, in tACS and NFB studies; and (3) factors that contribute to inter- and intraindividual variability in CFC and ways to address them potentially. Here we analyzed research studies on CFC, tACS, and neurofeedback. Based on current knowledge, CFC types have been reported in tACS and NFB studies. We hypothesize that direct and indirect effects of tACS and neurofeedback can induce CFC. Several variability factors such as health status, age, fatigue, personality traits, and eyes-closed (EC) vs. eyes-open (EO)condition may influence the CFC types. Modifying the duration of the tACS and neurofeedback intervention and selecting a specific demographic experimental group could reduce these sources of CFC variability. Neurofeedback and tACS appear to be promising tools for studying CFC.

• Publikační typ
• časopisecké články MeSH

Working memory (WM) is the active retention and processing of information over a few seconds and is considered an essential component of cognitive function. The reduced WM capacity is a common feature in many diseases, such as schizophrenia, attention deficit hyperactivity disorder (ADHD), mild cognitive impairment (MCI), and Alzheimer's disease (AD). The theta-gamma neural code is an essential component of memory representations in the multi-item WM. A large body of studies have examined the association between cross-frequency coupling (CFC) across the cerebral cortices and WM performance; electrophysiological data together with the behavioral results showed the associations between CFC and WM performance. The oscillatory entrainment (sensory, non-invasive electrical/magnetic, and invasive electrical) remains the key method to investigate the causal relationship between CFC and WM. The frequency-tuned non-invasive brain stimulation is a promising way to improve WM performance in healthy and non-healthy patients with cognitive impairment. The WM performance is sensitive to the phase and rhythm of externally applied stimulations. CFC-transcranial-alternating current stimulation (CFC-tACS) is a recent approach in neuroscience that could alter cognitive outcomes. The studies that investigated (1) the association between CFC and WM and (2) the brain stimulation protocols that enhanced WM through modulating CFC by the means of the non-invasive brain stimulation techniques have been included in this review. In principle, this review can guide the researchers to identify the most prominent form of CFC associated with WM processing (e.g., theta/gamma phase-amplitude coupling), and to define the previously published studies that manipulate endogenous CFC externally to improve WM. This in turn will pave the path for future studies aimed at investigating the CFC-tACS effect on WM. The CFC-tACS protocols need to be thoroughly studied before they can be considered as therapeutic tools in patients with WM deficits.

• Publikační typ
• časopisecké články MeSH
• přehledy MeSH

OBJECTIVES: This cross-sectional analysis from the CZecking Heart Failure in patients with advanced Chronic Kidney Disease trial (ISRCTN18275480) examined pulmonary hypertension and right ventricular-pulmonary arterial coupling in patients on chronic hemodialysis. The aims of this analysis were: 1. To analyze relations between pulmonary hypertension and right ventricular-pulmonary arterial coupling with dialysis access flow and current hydration; 2. To analyze structural heart changes associated with right ventricular-pulmonary arterial uncoupling; 3. To reveal the prevalence, etiology and severity of pulmonary hypertension in the Czech hemodialysis population. METHODS: We performed expert echocardiography, vascular access flow measurements, bioimpedance analysis, and laboratory testing in 336 hemodialysis patients. RESULTS: Pulmonary hypertension was present in 34% (114/336) patients and right ventricular-pulmonary arterial uncoupling was present in 25% of patients with pulmonary hypertension. Only weak associations between the flow of the dialysis arteriovenous access and estimated pulmonary arterial systolic pressure and right ventricular-pulmonary arterial coupling was proved. There was a strong association between hydration status assessed by estimated central venous pressure with pulmonary arterial systolic pressure (Rho 0.6, p < 0.0001) and right ventricular-pulmonary arterial coupling (Rho -0.52, p < 0.0001) and association between overhydration to extracellular water ratio with pulmonary arterial systolic pressure (Rho 0.31, p = 0.0001) and right ventricular-pulmonary arterial coupling (Rho -0.29, p = 0.002). The prevalence of heart failure was significantly higher in patients with right ventricular-pulmonary arterial uncoupling (88% vs. 52%, p = 0.0003). CONCLUSION: These findings suggest that optimizing volume status and treating heart failure should be prioritized in hemodialysis patients to prevent pulmonary hypertension progression and right ventricular-pulmonary arterial uncoupling.

• MeSH
• arteria pulmonalis * patofyziologie   MeSH
• chronické selhání ledvin * terapie   komplikace   patofyziologie   MeSH
• dialýza ledvin * škodlivé účinky   MeSH
• echokardiografie MeSH
• lidé středního věku MeSH
• lidé MeSH
• plicní hypertenze * etiologie   patofyziologie   MeSH
• průřezové studie MeSH
• senioři MeSH
• srdeční komory patofyziologie   diagnostické zobrazování   MeSH
• srdeční selhání patofyziologie   komplikace   etiologie   MeSH
• Check Tag
• lidé středního věku MeSH
• lidé MeSH
• mužské pohlaví MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• Geografické názvy
• Česká republika MeSH

Sleep manifests itself by the spontaneous emergence of characteristic oscillatory rhythms, which often time-lock and are implicated in memory formation. Here, we analyze a neural mass model of the thalamocortical loop in which the cortical node can generate slow oscillations (approximately 1 Hz) while its thalamic component can generate fast sleep spindles of σ-band activity (12-15 Hz). We study the dynamics for different coupling strengths between the thalamic and cortical nodes, for different conductance values of the thalamic node's potassium leak and hyperpolarization-activated cation-nonselective currents, and for different parameter regimes of the cortical node. The latter are listed as follows: (1) a low activity (DOWN) state with noise-induced, transient excursions into a high activity (UP) state, (2) an adaptation induced slow oscillation limit cycle with alternating UP and DOWN states, and (3) a high activity (UP) state with noise-induced, transient excursions into the low activity (DOWN) state. During UP states, thalamic spindling is abolished or reduced. During DOWN states, the thalamic node generates sleep spindles, which in turn can cause DOWN to UP transitions in the cortical node. Consequently, this leads to spindle-induced UP state transitions in parameter regime (1), thalamic spindles induced in some but not all DOWN states in regime (2), and thalamic spindles following UP to DOWN transitions in regime (3). The spindle-induced σ-band activity in the cortical node, however, is typically the strongest during the UP state, which follows a DOWN state "window of opportunity" for spindling. When the cortical node is parametrized in regime (3), the model well explains the interactions between slow oscillations and sleep spindles observed experimentally during Non-Rapid Eye Movement sleep. The model is computationally efficient and can be integrated into large-scale modeling frameworks to study spatial aspects like sleep wave propagation.

• Publikační typ
• časopisecké články MeSH

It has been suggested that slow oscillations in the subthalamic nucleus (STN) reflect top-down inputs from the medial prefrontal cortex, thus implementing behavior control. It is unclear, however, whether the STN oscillations are related to cortical activity in a bottom-up manner. To assess resting-state subcortico-cortical interactions, we recorded simultaneous scalp electroencephalographic activity and local field potentials in the STN (LFP-STN) in 11 patients with Parkinson's disease implanted with deep brain stimulation electrodes in the on-medication state during rest. We assessed the cross-structural phase-amplitude coupling (PAC) between the STN and cortical activity within a wide frequency range of 1 to 100 Hz. The PAC was dominant between the δ/θ STN phase and β/γ cortical amplitude in most investigated scalp regions and between the δ cortical phase and θ/α STN amplitude in the frontal and temporal regions. The cross-frequency linkage between the slow oscillations of the LFP-STN activity and the amplitude of the scalp-recorded cortical activity at rest was demonstrated, and similar involvement of the left and right STNs in the coupling was observed. Our results suggest that the STN plays a role in both bottom-up and top-down processes within the subcortico-cortical circuitries of the human brain during the resting state. A relative left-right symmetry in the STN-cortex functional linkage was suggested. Practical treatment studies would be necessary to assess whether unilateral stimulation of the STN might be sufficient for treatment of Parkinson's disease.

• MeSH
• elektroencefalografie MeSH
• hluboká mozková stimulace * MeSH
• lidé MeSH
• nucleus subthalamicus * MeSH
• Parkinsonova nemoc * terapie   MeSH
• skalp MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH

It is unknown whether physiological ageing also goes along with electromechanical asynchrony of contraction. Aim of the study was to evaluate synchrony of contraction in older people with ("non-healthy") or without ("healthy") evidence for structural cardiac disease. In 547 persons (age 76.7+/-5.5 years, 306 male, 241 female) recruited from a population-based cohort of the ActiFE-Ulm study including a random sample of people >/=65 years old living in the region of Ulm, Germany, various PW- and TDI-Doppler based markers for asynchrony were obtained by echocardiography. Within a subgroup of 84 healthy subjects, at most minimal systolic and diastolic asynchrony was found. Concerning systolic asynchrony, similar observations were made within the non-healthy subgroup. However, extent of diastolic left ventricular intraventricular asynchrony and also - by tendency - diastolic interventricular asynchrony was increased in comparison to the healthy subgroup. To conclude, no evidence that physiological ageing might go along with relevant left or right ventricular systolic or diastolic electromechanical asynchrony was found in our study. Furthermore, our population-based data support the results from other clinical studies with rather selected cohorts that structural heart diseases might go along with increased diastolic asynchrony.

• MeSH
• diastola MeSH
• dopplerovská echokardiografie MeSH
• dysfunkce levé srdeční komory diagnostické zobrazování   epidemiologie   patofyziologie   MeSH
• dysfunkce pravé srdeční komory diagnostické zobrazování   epidemiologie   patofyziologie   MeSH
• funkce levé komory srdeční * MeSH
• funkce pravé komory srdeční * MeSH
• lidé MeSH
• průřezové studie MeSH
• rizikové faktory MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• spřažení excitace a kontrakce MeSH
• stárnutí MeSH
• systola MeSH
• věkové faktory MeSH
• Check Tag
• lidé MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Geografické názvy
• Německo epidemiologie   MeSH

The family environment is associated with religiosity and spirituality as well as many aspects of adolescent lives, including their health behaviour. Therefore, the aim of this study was to assess family environment associations with adolescent religious attendance (RA), i.e., weekly participation in religious services, and spirituality in a highly secular country. A nationally representative sample (n = 4182, 14.4 ± 1.1 years, 48.6% boys) of Czech adolescents participated in the 2014 Health Behaviour in School-aged Children cross-sectional study. RA, spirituality and the family environment, i.e., family communication, perceived emotional support, and parental monitoring, were measured. Higher adolescent RA was associated with lower self-reported easiness of communication with mother (odds ratio (OR) = 0.68; 99% confidence interval (99% CI) = 0.47-0.99; p < 0.01). In contrast, spiritual respondents were more likely to report both easier communication with their father (OR per standard deviation (SD) change = 1.12, 99% CI 1.02-1.23; p < 0.01) and mother (OR per SD change = 1.38 (1.23-1.55); p < 0.001) and higher perceived emotional support (OR per SD change = 1.73 (1.55-1.92); p < 0.001). Parents of respondents who attended religious services at least once a week, as well as parents of spiritual respondents, were generally more likely to monitor adolescent behaviour. Thus, this study provides information for parents, mental health workers, and pastoral carers. Further research should assess the association of a lower easiness of family communication with dissonances in adolescent-parent religiosity/spirituality and with higher parental monitoring.

• MeSH
• charakteristiky rodiny * MeSH
• chování mladistvých * MeSH
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• náboženství * MeSH
• odds ratio MeSH
• průřezové studie MeSH
• rodinné vztahy * MeSH
• spiritualita * MeSH
• zpráva o sobě MeSH
• Check Tag
• dítě MeSH
• lidé MeSH
• mladiství MeSH
• mužské pohlaví MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Geografické názvy
• Česká republika MeSH

BACKGROUND: Global research suggests that persons with disabilities face barriers when accessing health care services. Yet, information regarding the nature of these barriers, especially in low-income and middle-income countries is sparse. Rural contexts in these countries may present greater barriers than urban contexts, but little is known about access issues in such contexts. There is a paucity of research in South Africa looking at "triple vulnerability" - poverty, disability and rurality. This study explored issues of access to health care for persons with disabilities in an impoverished rural area in South Africa. METHODS: The study includes a quantitative survey with interviews with 773 participants in 527 households. Comparisons in terms of access to health care between persons with disabilities and persons with no disabilities were explored. The approach to data analysis included quantitative data analysis using descriptive and inferential statistics. Frequency and cross tabulation, comparing and contrasting the frequency of different phenomena between persons with disabilities and persons with no disabilities, were used. Chi-square tests and Analysis of Variance tests were then incorporated into the analysis. RESULTS: Persons with disabilities have a higher rate of unmet health needs as compared to non-disabled. In rural Madwaleni in South Africa, persons with disabilities faced significantly more barriers to accessing health care compared to persons without disabilities. Barriers increased with disability severity and was reduced with increasing level of education, living in a household without disabled members and with age. CONCLUSIONS: This study has shown that access to health care in a rural area in South Africa for persons with disabilities is more of an issue than for persons without disabilities in that they face more barriers. Implications are that we need to look beyond the medical issues of disability and address social and inclusion issues as well.

• MeSH
• charakteristiky rodiny MeSH
• chudoba MeSH
• disparity zdravotní péče statistika a číselné údaje   MeSH
• dítě MeSH
• dospělí MeSH
• dostupnost zdravotnických služeb statistika a číselné údaje   MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• postižení statistika a číselné údaje   MeSH
• průřezové studie MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• venkovské obyvatelstvo MeSH
• zdravotnické služby pro venkov zásobování a distribuce   MeSH
• Check Tag
• dítě MeSH
• dospělí MeSH
• lidé středního věku MeSH
• lidé MeSH
• mladiství MeSH
• mladý dospělý MeSH
• mužské pohlaví MeSH
• senioři nad 80 let MeSH
• senioři MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• Geografické názvy
• Jihoafrická republika epidemiologie   MeSH

BACKGROUND: Specific attention on the musculoskeletal impact of wearing high-heeled shoes (HHS) has mainly focused on knee osteoarthritis and the literature is limited to biomechanical changes. The distal femoral cartilage has not been morphologically studied. Additionally, although heel elevation is coupled with a shear stress at the heel and overloaded calf muscles, Achilles tendon (AT) and plantar fascia (PF) thicknesses have not been assessed either. OBJECTIVE: To investigate whether the distal femoral cartilage, AT, and PF were different in women wearing HHS and flat-heeled shoes (FHS) and specifically, different in terms of AT/PF and distal femoral cartilage thicknesses. DESIGN: Cross-sectional observational study. SETTING: Tertiary care center. PARTICIPANTS: There were 34 women (mean age; 31.1 ± 6.4, body mass index [BMI]; 21.6 ± 2.4 kg/m2 ) in the HHS group and 54 women (mean age; 29.5 ± 7.2 years, BMI 22.5 ± 2.9 kg/m2 ) in the FHS group (P = .271, P = .102, respectively). Women wearing shoes with a heel height of >5 cm were enrolled in the HHS group, and those wearing shoes with a heel height of <1.4 cm were included in the FHS group. MAIN OUTCOME MEASUREMENTS: Distal femoral cartilage from the lateral condyle, intercondylar area and medial condyle (MFC), AT and PF thicknesses, and any abnormalities were evaluated bilaterally by ultrasound. RESULTS: Within-group comparisons yielded thicker right MFC (P = .022) and left AT (P = .028) only in the HHS group. Between-group comparisons yielded thicker left AT in the HHS group (P = .040). PF thicknesses were similar both within and between group comparisons (all P > .05). Right AT thickness was positively correlated with right (r = .469, P = .005) and left (r = .402, P = .018) PF thicknesses only within the HHS group. Only calcaneal irregularity/spur was found to be common in the HHS group (P = .038). CONCLUSIONS: We found thickening of the right MFC and left AT in those wearing HHS, whereas PF thickness was not significantly different between those wearing HHS and those wearing FHS. LEVEL OF EVIDENCE: III.

• MeSH
• Achillova šlacha diagnostické zobrazování   MeSH
• aponeuróza diagnostické zobrazování   MeSH
• chrupavka diagnostické zobrazování   MeSH
• dospělí MeSH
• lidé MeSH
• noha (od hlezna dolů) diagnostické zobrazování   MeSH
• obuv škodlivé účinky   MeSH
• průřezové studie MeSH
• ultrasonografie MeSH
• Check Tag
• dospělí MeSH
• lidé MeSH
• ženské pohlaví MeSH
• Publikační typ
• časopisecké články MeSH
• pozorovací studie MeSH
• srovnávací studie MeSH