Achieving both deep penetration of photons into biological tissue and highly sensitive recording of optical probes' response are the key goals of non-invasive optical imaging. In comparison with the traditional fluorescence imaging in the visible (400–700 nm) and near-infrared (700–900 nm) regions, optical fluorescence imaging in the second optical tissue transparency window (1000–2300 nm) demonstrates low photon scattering, deeper penetration into the tissues and lower autofluorescence. In the present study, biocompatible upconversion nanoparticles with different contents of doping lanthanides, capable of luminescence in the visible and short-wave IR regions, were obtained and characterized. Also, targeted complexes based on Gd-containing nanophosphors were obtained as potential contrast agents for magnetic resonance imaging. Selective binding of targeted complexes to the surface of tumor cells expressing the HER2 receptor was shown.

The study aimed to evaluate the effectiveness of previously developed methods of adaptive neurostimulation in correcting stress-induced states in specialists who demonstrate signs of post-traumatic stress disorder (PTSD) and professional burnout syndrome (PBS). Materials and methods. Each of the 17 stressed subjects participated in three examinations, alternated in random order. In the control experiment (control), simple listening to classical music was used. In two other examinations, musical or light-musical stimulation was used, automatically modulated by feedback signals from the rhythmic components of the subject's electroencephalogram (EEG). In the first case (musical feedback), the subjects were presented with music-like stimuli formed on the basis of the subject's alpha EEG oscillator. In the second case (double feedback), such musical stimulation was supplemented by rhythmic light stimuli generated by on-line transformations of the native EEG of the subject. Results. Comparison of the effects of both experimental conditions with the control one allowed us to establish that only in the presence of feedback from the EEG, there is a significant increase in the power of alpha EEG rhythm, accompanied by positive emotional reactions, a decrease in the level of disadaptation and stress, as well as a significant increase in the assessments of health and mood of the subjects. The most pronounced psychophysiological effects were recorded under light-music stimulation with double feedback from the EEG. Conclusion. The obtained results make it possible to suggest the described methods of adaptive neurostimulation as a means of psychotherapeutic correction of PTSD and PBS, especially during the COVID-19 pandemic. © 2021, Lobachevsky State University of Nizhny Novgorod. All rights reserved.

Over the past two decades, developments in the field of nanobiomedicine have come a long way despite the unresolved hindrances. The creation and development of effective theranostic agents based on nanomaterials are urgent needs of modern medicine. Upconversion nanoparticles (UCNP) appear to be the most promising agents for developing theranostics due to their unique optical properties. There has been extensive research on new approaches to obtain stable colloids capable of prolonged circulation in the bloodstream, particularly with bovine serum albumin (BSA). The present work contributes to solving the problem of obtaining stable agents based on UCNP by coating water-soluble UCNPNOBF4 with a stable protein corona layer of BSA. The assembled nanocomplex is promising for usage as a diagnostic agent and is set for further investigation.

SCOPUS: no.j

Isolated brain tumors contain cells that exhibit stem cell features and a tissue microenvironment bearing remarkable similarities to the normal neurogenic niche. This supports the idea that neural stem (NSCs) or progenitor cells, and their progeny are the likely tumor cell(s) of origin. This prompted the investigation of the relationship between NSCs/progenitors and the initiation of tumorigenesis. These studies led to the identification of common signaling machineries underlying NSC development and tumor formation, particularly those with known roles in proliferation and cell fate determination. This review will explore the molecular mechanisms that regulate NSC behavior in the neurogenic niche of the forebrain, and how deregulation of the developmental potential of NSCs might contribute to tumorigenesis.

The common denominator of neurodegenerative diseases, which mainly affect humans, is the progressive death of neural cells resulting in neurological and cognitive deficits. Astroglial cells are the central elements of the homoeostasis, defence and regeneration of the central nervous system, and their malfunction or reactivity contribute to the pathophysiology of neurodegenerative diseases. Pathological remodelling of astroglia in neurodegenerative context is multifaceted. Both astroglial atrophy with a loss of function and astroglial reactivity have been identified in virtually all the forms of neurodegenerative disorders. Astroglia may represent a novel target for therapeutic strategies aimed at preventing and possibly curing neurodegenerative diseases.

Despite a long history of research involving some of the greater physicists the world has known (Ohm, von Helmholte, von Bekesy), the understanding of the mammalian, in particular human, hearing is still in its infancy. The present state of teaching of how we hear and listen is still centered around the Fourier analyzer partitioning incoming sounds into its frequency components, and that is it pretty much. We will, however see that the strong nonlinearities at work in the cochlea (providing a dynamical range of the signal up to 130 DB), demand this simple view to be dramatically changed. To show this, we follow a complex sound that enters the cochlea and consider what parts of the cochlea are elicited, and what turns out in the end to be responsible for human pitch perception. We do this on the basis of our biophysically detailed model of the cochlea [1-4] (based on Andronov-Hopf small signal amplifying outer hair cells [5]) that has been shown to reproduce all - even the most intricate - measured features of mammalian hearing (eg loudness dependence of pitch, pitch-shift effects, phase properties along the cochlea and much more [4, 6-7]), the measurements originating from laser-interferometry as well as results psychoacoustic roasts (for the latter, it is essential that the signal remains essential unaltered during the signal transduction from the continuous biophysics motions of the basilar membrane to the spike patterns at the upper end of the auditory nerve (to achieve this, biology exploits the potential of stochastic resonance [8]) . We look at this neuronal system (outer hair cells can be regarded as an archetype of such cells) from the angle of criticality, a viewpoint that is presently widely taken by neuroscientists with a physics background. A critical state of a (neuronal) network is characterized by power-law statistics, as the fingerprint of existing long-range correlation within the system at this state. We find, indeed, power-law distributions of links leading from already activated sites to consecutively activated sites within the cochlea, following the nonlinear interaction paradigm of combination tone generation.