Stable Polyglutamine Dimers Can Contain β-Hairpins with Interdigitated Side Chains But Not α-Helices, β-Nanotubes, β-Pseudohelices, or Steric Zippers

AbstractA common thread connecting nine fatal neurodegenerative protein aggregation diseases is an abnormally expanded polyglutamine tract found in the respective proteins. Although the structure of this tract in the large mature aggregates is increasingly well described, its structure in the small early aggregates remains largely unknown. As experimental evidence suggests that the most toxic species along the aggregation pathway are the small early ones, developing strategies to alleviate disease pathology calls for understanding the structure of polyglutamine peptides in the early stages of aggregation. Here, we present a criterion, grounded in available experimental data, that allows for using kinetic stability of dimers to assess whether a given polyglutamine conformer can be on the aggregation path. We then demonstrate that this criterion can be assessed using present-day molecular dynamics simulations. We find that although the α-helical conformer of polyglutamine is very stable, dimers of α-helices lack the kinetic stability necessary to support further oligomerization. Dimers of steric zipper, β-nanotube, and β-pseudohelix conformers are also too short-lived to initiate aggregation. The β-hairpin-containing conformers, instead, invariably form very stable dimers when their side chains are interdigitated. Combining these findings with the implications of recent solid-state NMR data on mature fibrils, we propose a possible pathway for the initial stages of polyglutamine aggregation, in which β-hairpin-containing conformers act as templates for fibril formation

Electron mobility in surface- and buried- channel flatband In_0.53Ga_0.47As MOSFETs with ALD Al₂O₃ gate dielectric.

In this paper, we investigate the scaling potential of flatband III-V MOSFETs by comparing the mobility of surface and buried In<sub>0.53</sub>Ga<sub>0.47</sub>As channel devices employing an Atomic Layer Deposited (ALD) Al<sub>2</sub>O<sub>3</sub> gate dielectric and a delta-doped InGaAs/InAlAs/InP heterostructure. Peak electron mobilities of 4300 cm<sup>2</sup>/V·s and 6600 cm<sup>2</sup>/V·s at a carrier density of 3×1012 cm<sup>-2</sup> for the surface and buried channel structures respectively were determined. In contrast to similarly scaled inversion-channel devices, we find that mobility in surface channel flatband structures does not drop rapidly with electron density, but rather high mobility is maintained up to carrier concentrations around 4x10<sup>12</sup> cm<sup>-2</sup> before slowly dropping to around 2000 cm<sup>2</sup>/V·s at 1x10M<sup>13</sup> cm<sup>-2</sup>. We believe these to be world leading metrics for this material system and an important development in informing the III-V MOSFET device architecture selection process for future low power, highly scaled CM

On the leaf development in Oedipodium (Oedipodiales, Bryophyta)

Leaf development in Oedipodium griffithianum was studied based on herbarium and living material, using microscopic observations of plants at different stages of development and series of sections. It turned out that the apical cell may lose its bifacial structure, thus the leaves develop the bilaterally symmetric areolation pattern, similar to that seen in Oedipodium protonematayesBelgorod State National Research Universit

Digitalisation of the flm industry in the context of the COVID-19 pandemic

The structure of the flm industry has changed signifcantly over the past two years. The decline in cinema attendance, the activation of flm distribution on digital platforms, the decline in the level of flm production and other reasons have led to a transformation in the production and consumption of audiovisual content. The change of the main content customer has become an important trend in 2021. Online platforms have replaced production and television companies. Neither the personnel nor the infrastructure of the flm industry was ready for such a volume of orders for production from online cinemas. This caused a sharp rise in prices and an increase in the cost of flm production. The industry is actually in crisis. Based on the study, the authors concluded that today state pays quite a lot of attention to the issues of the digitalization of the flm industry. The study notes the strengthening of state control over digital video platforms, a change in the scheme of state fnancing of the industry, the allocation of large fnancial resources for the digitalization of video archives, the introduction of electronic document management in the feld of flm production, flm distribution, in the process of submitting flm copies to the archive, etc. The authors of the article offer a partial solution to one of the main current problems of the industry – the crisis of traditional cinema distribution with the strengthening of digital distribution. According to the study, the participation of the state can also help with it. For example, by strengthening state funding of audiovisual products intended for cinema rental, as well as strengthening support for cinemas in times of crisis

Elastic constants of borocarbides. New approach to acoustic Measurement technique

A new version of the phase method of determining the sound velocity is proposed and implemented. It utilizes the ``Nonius'' measurement technique and can give acceptable accuracy (~1%) in samples of submillimeter size. Measurements of the sound velocity are made in single-crystal samples of the borocarbides RNi2B2C (R = Y,Lu,Ho). The elastic constants and the Debye temperature are calculated.Comment: 5 figures, 2 table

The Technique of Formation of Valuable Attitude for Amateur Theatre by Future Leaders

The dynamic development of theater culture in Russia, including the culture of Amateur theater, the growing popularity of Amateur theater in modern society, and the awareness of Amateur theater as a phenomenon of Russian national culture makes it urgent to improve the training of managers of Amateur theater groups in institutions of arts and culture. The study of literature, generalization of practical experience, and experimental research data led the authors to the conclusion that the direction of this improvement is to educate students in a value attitude to Amateur theater and their chosen profession. The functions of value attitude education: epistemological (knowledge), axiological (value), regulatory-normative and creative. Components of the pedagogical model: adaptive-diagnostic, planned-correctional, informational-activity, variative-creative, evaluative-effective. The results of the chosen pedagogical model gave positive results, which makes it possible to consider the proposed way to improve the training of specialists correct and appropriate

Vertical thermal structure of the Venus atmosphere from temperature and pressure measurements

Accurate temperature and pressure measurements were made on the Vega-2 lander during its entire descent. The temperature and pressure at the surface were 733 K and 89.3 bar, respectively. A strong temperature inversion was found in the upper troposphere. Several layers with differing static stability were visible in the atmospheric structure

Role of Plant Carbonic Anhydrases under Stress Conditions

Carbonic anhydrases (CAs) are enzymes catalyzing the reversible hydration of carbon dioxide with the generation of protons and bicarbonate. The components of the reaction are involved in almost all metabolic processes in higher plants and algae, maintaining the balance of electrolytes and pH, gluconeogenesis, lipogenesis, ethylene synthesis, and others. The CAs may take part in transmitting signals to activate cascades of protective response genes. Our findings reveal significant changes in the content of carbonic anhydrase gene transcripts in response to changes in environmental conditions. Here we discuss the functions of CAs located in the plasma membrane, chloroplast envelope, chloroplast stroma, and in thylakoids in plant protection under stress conditions, such as high illumination, low and high concentration of carbon dioxide in the environment, drought, and salinity

On the analyticity and Gevrey class regularity up to the boundary for the Euler Equations

We consider the Euler equations in a three-dimensional Gevrey-class bounded domain. Using Lagrangian coordinates we obtain the Gevrey-class persistence of the solution, up to the boundary, with an explicit estimate on the rate of decay of the Gevrey-class regularity radius