Value of determining the cerebrospinal fluid protein markers of amyloidosis and neurodegeneration in the diagnosis of vascular and neurodegenerative cognitive impairments

The article presents data on different forms of moderate cognitive impairments (MCI) and the specific features of their transformation to dementia. Cerebrospinal fluid (CSF) was investigated in 60 patients with the amnestic and neurodynamic types of MCI, in 15 patients with vascular dementia (VD), 50 patients with Alzheimer’s disease (AD), and 23 patients with mixed vascular and neurodegenerative dementia (MVND). The specific features of β-amyloid and τ-protein concentrations were established in the preclinical stages of dementia, which reflects the main components of the pathogenesis of neurodegeneration. In the amnestic form of MCI and AD, there was drastically decreased Aβ-42 and increased τ-protein levels in SCF. As cognitive impairments progressed, there was a rise in the concentration of τ-protein; its level correlated with the severity of dementia. In MND, the level of Aβ-42 was significantly reduced while the concentration of τ-protein was much increased; moreover, to a greater extent than in AD and VD. Cerebrovascular damage and neurodegeneration were related to each other and mutually worsened clinical and pathogenic effects

Analytic Description of the High-Energy Plateau in Harmonic Generation by Atoms: Can the Harmonic Power Increase with Increasing Laser Wavelengths?

A closed-form analytic formula for high-order harmonic generation (HHG) rates for atoms (that generalizes an HHG formula for negative ions [M.V. Frolov et al., J. Phys. B 42, 035601 (2009)]) is used to study laser wavelength scaling of the HHG yield for harmonic energies in the cutoff region of the HHG plateau. We predict increases of the harmonic power for HHG by Ar, Kr, and Xe with increasing wavelength λ over atom-specific intervals of λ in the infrared region, λ ~ (0.8–2.0) μm

Capacities for the drug correction of functional disorders in posthypoxic encephalopathy

Отражены данные литературы о патогенезе постгипоксической энцефалопатии (ПЭ), каскаде патобиохимических реакций, развивающихся в головном мозге при ишемии/гипоксии. Особое внимание уделено возникновению синаптической дисфункции в условиях энергетического дефицита и дестабилизации мембран нервных клеток. Представлены сведения об основных клинических синдромах, алгоритме диагностики, принципах лечения ПЭ. Обсуждается применение актовегина в комплексной терапии ПЭ

High-efficiency generation of attosecond pulses during atomic ionization from excited electronic states

We show that the efficiency of single attosecond pulse generation during atomic ionization by an intense few-optical-cycle laser pulse can be enhanced dramatically when pre-excited electronic states are used. This is due to the slowed-down spreading of the laser-driven free-electron wave packet. We develop an analytical approach to the treatment of the attosecond burst production due to the electron recollision with a parent ion, assuming that the atom is fully ionized during one optical cycle. Our analytical and numerical simulations show that, when a hydrogen atom is ionized from the $2s$-state by an ultrashort pulse of a Ti:sapphire (800\un{nm}) laser, the energy of the generated attosecond pulse is several tens of times higher, its duration is much shorter, and the spectral intensity of radiation in the VUV and soft–X-ray range is several orders of magnitude superior to that in the case of ionization from the ground state. We determine the excited states preferable for experiments using the fundamental or the second harmonic of a Ti:sapphire laser

Invader's portrait: Biological characteristics of walleye pollock Gadus chalcogrammus in the western Chukchi Sea

Presented here are data on the size composition and age structure, the sex ratio, the state of maturity of the gonads, and the composition of the diet and feeding habits of walleye pollock in the western Chukchi Sea, based on 2003-2020 bottom and mid-water trawl surveys conducted onboard Russian research vessels. During all years of research, mid-water trawl catches in this area were dominated by juveniles with FL 5-12 cm, while the size composition of walleye pollock in bottom trawl catches was bimodal with the dominance of fish 7-14 cm and 50-62 cm long. Females were considerably larger than males (on average by almost 10 cm), with mean FL 56.0-58.3 cm and 52.1-56.4 cm, respectively, in different years. The age structure of walleye pollock was significantly different from that of both the western and eastern Bering Sea since fingerlings and yearlings predominated there in the mid-water trawl catches, and fish under the age of 1 year and 6-17 years were the most numerous in the bottom trawl catches. In the western Chukchi Sea in 2018-2020, the proportion of females in bottom trawl catches ranged from 1.8 to 2.7 females per male. This is probably because walleye pollock here were represented mainly by large fish, while in the mature part of the population, females are usually larger than males. The proportion of fish with gonads at different stages of maturity varied significantly in different years. Immature individuals were extremely few among the fish analyzed. Individuals with developing and postspawning gonads accounted for a major part of the catches. In recent years, walleye pollock of both sexes have been observed in pre-spawning, spawning, and post-spawning condition, which may indicate the possibility of spawning of individual specimens in the western Chukchi Sea. The survival of eggs, larvae, and fry in conditions of low temperatures is unlikely. However, if the warming in the Arctic continues, it is possible that new walleye pollock spawning grounds may appear in the Chukchi Sea. In the western Chukchi Sea, the proportion of euphausiids in the diet of large walleye pollock (>40 cm in 2018 and > 60 cm in 2019) was significantly higher than that of small fish (60 cm) and only in 2019 with small number juveniles consumed. Such a low level of cannibalism was probably due to the spatial separation of juveniles and adults, as well as the presence of a sufficient amount of other prey

he amyloid hypothesis of Alzheimer's disease: past and present, hopes and disappointments

In 1887, S.A. Belyakov, a physician of the Imperial Medical and Surgical Academy, first described amyloid deposits in the brain of patients with dementia. Later, in 1906, A. Alzheimer revealed amyloid plaques and tau tangles in a patient with clinical signs of dementia. Over the following 100 years, the development of the concept of the amyloid origin of Alzheimer's disease (AD) confirmed numerous relationships between the brain accumulation of APs and cognitive decline. And if at the beginning of the amyloid era many researchers considered that the disease was caused by amyloid beta (Aβ) protein overproduction, in recent years they have increasingly pointed to a defect in the mechanisms of Aβ clearance, especially after the discovery of the lymphatic system of the brain. The role of disturbed homeostasis of redox-active metals, primarily iron and copper, in the development of the disease is also considered.The amyloid hypothesis of AD has served as the basis for several areas in the design of drugs, such as secretase inhibitors, immunomodulatory drugs for active and passive immunization. However, only one drug (Akatinol memantine, an inhibitor of NMDA receptors and glutamatergic excitotoxicity) for the treatment of AD has been introduced into clinical practice over the past 20 years. Of interest are the data obtained in new studies of Akatinol memantine, which suggest that the latter is able to some extent affect the main pathophysiological processes underlying the development of cognitive impairment in Alzheimer-type pathology