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Zhurnal Nevrologii I Psikhiatrii Imeni... 2020Sleep-disordered breathing is associated with sleep fragmentation and reduced blood oxygenation due to apnea and hypopnea episodes. Multiple studies indicate that... (Review)
Review
Sleep-disordered breathing is associated with sleep fragmentation and reduced blood oxygenation due to apnea and hypopnea episodes. Multiple studies indicate that obstructive sleep apnea syndrome (OSAS) can have negative impact on cognitive functioning, primarily executive functions, attention, and episodic memory. The attention is also focused on cognition in patients with neurologic and psychiatric comorbidities. There are different explanatory models, which show the mechanisms of OSAS influence on cognition. However, it is still unclear how the initial severity of the disease and clinical outcomes interrelate, and which factors play role in the compensation of cognitive dysfunction. Better understanding of these issues is crucial for the prevention of cognitive impairment and rehabilitation of cognitive functioning.
Topics: Cognitive Dysfunction; Executive Function; Humans; Sleep Apnea, Obstructive
PubMed: 32105275
DOI: 10.17116/jnevro202012001190 -
Nano Letters Oct 2023Femtosecond (fs) time-resolved magneto-optics is applied to investigate laser-excited ultrafast dynamics of one-dimensional nickel gratings on fused silica and silicon...
Femtosecond (fs) time-resolved magneto-optics is applied to investigate laser-excited ultrafast dynamics of one-dimensional nickel gratings on fused silica and silicon substrates for a wide range of periodicities Λ = 400-1500 nm. Multiple surface acoustic modes with frequencies up to a few tens of GHz are generated. Nanoscale acoustic wavelengths Λ/ have been identified as -spatial harmonics of Rayleigh surface acoustic wave (SAW) and surface skimming longitudinal wave (SSLW), with acoustic frequencies and lifetimes being in agreement with theoretical calculations. Resonant magnetoelastic excitation of the ferromagnetic resonance (FMR) by SAW's third spatial harmonic, and, most interestingly fingerprints of the parametric resonance at 1/2 SAW frequency have been observed. Numerical solutions of Landau-Lifshitz-Gilbert (LLG) equation magnetoelastically driven by complex polychromatic acoustic fields quantitatively reproduce all resonances at once. Thus, our results provide a solid experimental and theoretical base for a quantitative understanding of ultrafast fs-laser-driven magnetoacoustics and tailoring the magnetic-grating-based metasurfaces at the nanoscale.
PubMed: 37820262
DOI: 10.1021/acs.nanolett.3c02336 -
Annals of Parasitology 2020The review provides data on species composition of nematodes in 50 species of birds from Armenia (South of Lesser Caucasus). Most of the studied birds belong to...
The review provides data on species composition of nematodes in 50 species of birds from Armenia (South of Lesser Caucasus). Most of the studied birds belong to Passeriformes and Charadriiformes orders. One of the studied species of birds (Larus armenicus) is an endemic. The taxonomy and host-specificity of nematodes reported in original papers are discussed with a regard to current knowledge about this point. In total, 52 nematode species parasitizing birds in Armenia are reported. Most of the reported species of nematodes are quite common in birds outside of Armenia. One species (Desmidocercella incognita from great cormorant) was first identified in Armenia. Great snipe was recorded as a new host for Hystrichis tricolor. Zoonotic nematode Trichinella pseudospiralis was reported in Armenia from Eurasian blackbird.
Topics: Animals; Armenia; Nematoda; Passeriformes
PubMed: 33646734
DOI: 10.17420/ap6604.285 -
Kardiologiia Mar 2020This review focuses on a new method for noninvasive, complex evaluation of left ventricular (LV) systolic function using an echocardiography-based technology of... (Review)
Review
This review focuses on a new method for noninvasive, complex evaluation of left ventricular (LV) systolic function using an echocardiography-based technology of computing indexes of myocardial performance by construction of pressure-deformation curves. Since this new method accounts for the effect of afterload on myocardial contractility, the article presents data demonstrating advantages of the evaluation of LV myocardial performance over the speckle-tracking echocardiography and other methods in diagnostics of several diseases. The review provides a description of this method and its advantages and limitations. The authors analyzed results of major studies on evaluation of LV performance. Prospects of implementation and practical use of the method are discussed in the aspects of diagnostics of cardiovascular diseases and risk stratification for different groups of patients.
Topics: Echocardiography; Heart Ventricles; Humans; Stroke Volume; Systole; Ventricular Dysfunction, Left; Ventricular Function, Left
PubMed: 32375619
DOI: 10.18087/cardio.2020.3.n925 -
Acta Naturae 2021The coronavirus disease outbreak in 2019 (COVID-19) has now achieved the level of a global pandemic and affected more than 100 million people on all five continents and...
The coronavirus disease outbreak in 2019 (COVID-19) has now achieved the level of a global pandemic and affected more than 100 million people on all five continents and caused over 2 million deaths. Russia is, needless to say, among the countries affected by SARS-CoV-2, and its health authorities have mobilized significant efforts and resources to fight the disease. The paper presents the result of a functional analysis of 155 patients in the Moscow Region who were examined at the Central Clinical Hospital of the Russian Academy of Sciences during the first wave of the pandemic (February-July, 2020). The inclusion criteria were a positive PCR test and typical, computed tomographic findings of viral pneumonia in the form of ground-glass opacities. A clinical correlation analysis was performed in four groups of patients: (1) those who were not on mechanical ventilation, (2) those who were on mechanical ventilation, and (3) those who subsequently recovered or (4) died. The correlation analysis also considered confounding comorbidities (diabetes, metabolic syndrome, hypertension, etc.). The immunological status of the patients was examined (levels of immunoglobulins of the M, A, G classes and their subclasses, as well as the total immunoglobulin level) using an original SARS-CoV-2 antibody ELISA kit. The ELISA kit was developed using linear S-protein RBD-SD1 and NTD fragments, as well as the N-protein, as antigens. These antigens were produced in the prokaryotic system. Recombinant RBD produced in the eukaryotic CHO system (RBD CHO) was used as an antigen representing conformational RBD epitopes. The immunoglobulin A level was found to be the earliest serological criterion for the development of a SARS-CoV-2 infection and it yielded the best sensitivity and diagnostic significance of ELISA compared to that of class M immunoglobulin. We demonstrated that the seroconversion rate of "early" N-protein-specific IgM and IgA antibodies is comparable to that of antibodies specific to RBD conformational epitopes. At the same time, seroconversion of SARS-CoV-2 N-protein-specific class G immunoglobulins was significantly faster compared to that of other specific antibodies. Our findings suggest that the strong immunogenicity of the RBD fragment is for the most part associated with its conformational epitopes, while the linear RBD and NTD epitopes have the least immunogenicity. An analysis of the occurrence rate of SARS-CoV-2-specific immunoglobulins of different classes revealed that RBD- and N-specific antibodies should be evaluated in parallel to improve the sensitivity of ELISA. An analysis of the immunoglobulin subclass distribution in sera of seropositive patients revealed uniform induction of N-protein-specific IgG subclasses G1-G4 and IgA subclasses A1-A2 in groups of patients with varying severity of COVID-19. In the case of the S-protein, G1, G3, and A1 were the main subclasses of antibodies involved in the immune response.
PubMed: 33959390
DOI: 10.32607/actanaturae.11374 -
Kardiologiia Jan 2021Echocardiography allows evaluating left ventricular (LV) myocardial contractility; however, the visual assessment of contractility is subjective and requires... (Review)
Review
Echocardiography allows evaluating left ventricular (LV) myocardial contractility; however, the visual assessment of contractility is subjective and requires considerable experience. Modern technologies for assessment of LV myocardial contractility, such as tissue Doppler and speckle-tracking echocardiography, provide quantitative estimation of various parameters of myocardial strain, including the LV postsystolic shortening. Several studies have demonstrated the value of postsystolic shortening for evaluation of myocardial ischemia and "ischemic memory" in patients with cardiovascular diseases. This review analyzes experimental and clinical studies that addressed LV postsystolic shortening.
Topics: Echocardiography; Heart; Heart Ventricles; Humans; Myocardial Contraction; Myocardium; Systole; Ventricular Function, Left
PubMed: 33522475
DOI: 10.18087/cardio.2020.12.n1087 -
Kardiologiia May 2023Novel coronavirus infection has become one of urgent health problems of the 21st century. The associated disorders often result in the development of cardiopulmonary...
Novel coronavirus infection has become one of urgent health problems of the 21st century. The associated disorders often result in the development of cardiopulmonary pathology, which requires creation of a new paradigm in diagnosis and treatment. Studies performed during the pandemic have demonstrated an important role of echocardiography (EchoCG) in diagnosis of right ventricular (RV) dysfunction in patients with respiratory insufficiency in COVID-19. The analysis of EchoCG parameters with a high prognostic value showed that in EchoCG, a special attention should be paid to right heart dimensions, RV contractility, and pulmonary artery (PA) systolic pressure, which are the most sensitive indexes of RV afterload and indirect markers of pulmonary disease severity. RV FAC can be recommended for evaluation of the RV systolic function as the most informative variable. Also, it was demonstrated that the RV longitudinal strain has an additional significance for early identification of signs of systolic dysfunction and risk stratification in patients with COVID-19. In addition to the effectiveness and reproducibility of this method, an important advantage of EchoCG is its availability, possibility of saving images for remote interpretation by other specialists, and tracking changes in morphological and functional parameters of the heart. Thus, the analysis of international literature suggests that EchoCG plays an important role in prediction of severe cardiopulmonary disorders and timely selection of the treatment for patients with COVID-19. For these reasons, EchoCG should serve as an additional method of clinical evaluation, particularly in persons with moderate or severe disease.
Topics: Humans; COVID-19; Reproducibility of Results; Echocardiography; Heart; SARS-CoV-2
PubMed: 37307202
DOI: 10.18087/cardio.2023.5.n1806 -
Physical Review Letters Sep 2023More than twenty years ago, multiferroic compounds combining in particular magnetism and ferroelectricity were rediscovered. Since then, BiFeO_{3} has emerged as the...
More than twenty years ago, multiferroic compounds combining in particular magnetism and ferroelectricity were rediscovered. Since then, BiFeO_{3} has emerged as the most outstanding multiferroic by combining at room temperature almost all the fundamental or applicative properties that may be desired: electroactive spin wave excitations called electromagnons, conductive domain walls, or a low band gap of interest for magnonic devices. All these properties have so far only been discontinuously strain engineered in thin films according to the lattice parameter imposed by the substrate. Here we explore the ferroelectricity and the dynamic magnetic response of BiFeO_{3} bulk under continuously tunable uniaxial strain. Using elasto-Raman spectroscopy, we show that the ferroelectric soft mode is strongly enhanced under tensile strain and driven by the volume preserving deformation at low strain. The magnonic response is entirely modified with low energy magnon modes being suppressed for tensile strain above pointing out a transition from a cycloid to an homogeneous magnetic state. Effective Hamiltonian calculations show that the ferroelectric and the antiferrodistortive modes compete in the tensile regime. In addition, the homogeneous antiferromagnetic state becomes more stable compared to the cycloidal state above a +2% tensile strain close to the experimental value. Finally, we reveal the ferroelectric and magnetic orders of BiFeO_{3} under uniaxial strain and how the tensile strain allows us to unlock and to modify in a differentiated way the polarization and the magnetic structure.
PubMed: 37774288
DOI: 10.1103/PhysRevLett.131.116801 -
Zhurnal Nevrologii I Psikhiatrii Imeni... 2022To examine the characteristics of the event related potentials during the attention network test in patients with schizophrenia depending on the severity of positive and...
OBJECTIVE
To examine the characteristics of the event related potentials during the attention network test in patients with schizophrenia depending on the severity of positive and negative symptoms.
MATERIAL AND METHODS
The study included 20 patients with schizophrenia, 10 of them with a predominance of positive symptoms and 10 patients with a predominance of negative symptoms. All patients were diagnosed with paranoid schizophrenia (F20.0). Attention function was assessed using the attention network test with parallel recording of evoked responses. Differences in the amplitude and latency of N100 potential when presented with different types of cues, as well as P300 potential when identifying a congruent and incongruent flanker were analyzed.
RESULTS
A comparative analysis of N100 potential for neutral cues and flankers showed significantly lower amplitude and longer latency in the group of patients with a predominance of negative symptoms (Cz channel).The amplitude of the evoked N100 response upon presentation of central and spatial cues was significantly higher in the group of patients with a predominance of positive symptoms. An analysis of P300 potential in Fz channel with congruent and incongruent flankers revealed no differences in the amplitude of both stimuli in the group of patients with a predominance of negative symptoms, while the amplitude of the evoked response to congruent and incongruent flankers was significantly higher in the group with a predominance of positive symptoms. In the group of patients with a predominance of positive symptoms, an inverse flanker response was established - P300 amplitude was significantly higher upon presentation of an incongruent flanker.
CONCLUSION
The specific characteristics of evoked responses describing the features of such systems of attention as vigilance, orientation and conflict resolution have been established.
Topics: Evoked Potentials; Humans; Reaction Time; Schizophrenia, Paranoid
PubMed: 35271242
DOI: 10.17116/jnevro202212202188 -
Pathophysiology : the Official Journal... Apr 2022Cardiopulmonary disorders cause a significant increase in the risk of adverse events in patients with COVID-19. Therefore, the development of new diagnostic and...
Cardiopulmonary disorders cause a significant increase in the risk of adverse events in patients with COVID-19. Therefore, the development of new diagnostic and treatment methods for comorbid disorders in COVID-19 patients is one of the main public health challenges. The aim of the study was to analyze patient survival and to develop a predictive model of survival in adults with COVID-19 infection based on transthoracic echocardiography (TTE) parameters. We conducted a prospective, single-center, temporary hospital-based study of 110 patients with moderate to severe COVID-19. All patients underwent TTE evaluation. The predictors of mortality we identified in univariate and multivariable models and the predictive performance of the model were assessed using receiver operating characteristic (ROC) analysis and area under the curve (AUC). The predictive model included three factors: right ventricle (RV)/left ventricle (LV) area (odds ratio (OR) = 1.048 per 1/100 increase, p = 0.03), systolic pulmonary artery pressure (sPAP) (OR = 1.209 per 1 mm Hg increase, p < 0.001), and right ventricle free wall longitudinal strain (RV FW LS) (OR = 0.873 per 1% increase, p = 0.036). The AUC-ROC of the obtained model was 0.925 ± 0.031 (95% confidence interval (95% CI): 0.863−0.986). The sensitivity (Se) and specificity (Sp) measures of the models at the cut-off point of 0.129 were 93.8% and 81.9%, respectively. A binary logistic regression method resulted in the development of a prognostic model of mortality in patients with moderate and severe COVID-19 based on TTE data. It may also have additional implications for early risk stratification and clinical decision making in patients with COVID-19.
PubMed: 35645324
DOI: 10.3390/pathophysiology29020014