The effect of femtosecond laser treatment on the tribological properties of titanium nitride

The influence of femtosecond laser (fs-laser) processing on the structural-phase state of titanium nitride (TiN) coatings have been studied. It has been revealed using scanning electron microscopy and scanning probe microscopy that laser-induced periodic surface structures form on TiN coating surfaces. Depending on the laser scanning direction, two types of surface structures - parallel and cross-like ones have been obtained. Tribological tests showed that cross-like structures demonstrates better wear resistance properties in a dry friction, while parallel ones in a friction with lubricant

Influence of nitriding parameters in radio-frequency inductive discharge plasma on the structural-phase state and properties of H12MF steel

The influence of technological parameters of plasma nitriding on the structural-phase state and mechanical properties of H12MF steel has been investigated in this work. The possibility of improving the corrosion resistance of the reported material was demonstrated by changing the content of nitride phases (Fe3N, Fe4N, CrN) in the surface layer, depending on the nitriding mod

Correlation of the tribological properties of LIPSS on TiN surface with 3D parameters of roughness

The relationships between friction coefficients and 3D spatial roughness parameters, such as Sci (surface core fluid retention index), Svi (surface valley fluid retention index) and Sbi (surface bearing index), have been investigated for the laser-induced periodic surface structures (LIPSS) on the TiN coatings. Two types of the surface structures (cross-like and parallel ones) with different roughness levels were obtained using a fs-laser. It has been shown that the proposed roughness parameters correlate with the friction coefficients measured for the LIPSS

Polarity and structure of eight-membered organosilicon compounds with planar fragments

For the first time is determined the polarity of eight-membered silocyns with planar fragments. By the methods of dipole moments and theoretical calculations (DFT B3LYP/6-31G*) of 1,3,2-dioxasilocyns is established that in these compounds occurs the conformational equilibrium of the forms bath-chair and distorted bath with the predominance of the first, in this case the bonds C(sp 3)-S and C(sp 3)-H of the exocyclic MeSCH2 group are in the not eclipsed gauche orientation relative to each other. © 2009 Pleiades Publishing, Ltd

A process approach to management of an educational organization

© 2015, Review of European Studies. All right reserved. Directions for an educational organization development meet the requirements of society to the effectiveness and quality of educational activities in high dynamics of external and internal environment. The article examines the potential of the process approach, which considers management as a continuous performance of certain interrelated activities complex and general management functions when developing a quality management system of an educational organization. In the submitted article the components of the educational activities process are defined, which are based on the quality standard of the final product. This article is intended for educators, researchers, heads of educational institutions, employers, customers of educational services, education management organizations employees

The curriculum project on professional and pedagogical teachers’ communication culture formation

© 2015, Mediterranean Center of Social and Educational Research. All rights reserved. The changes in the socio-economic and spiritual spheres of modern society, trends in the renewal of the educational process put forward new demands to the level of modern teachers professional and pedagogical communication culture formation. The solution to this problem objectively requires the development of more flexible curricula of professional growth, aimed at the efficient formation of their professional and pedagogical communication culture. In this regard, this article presents the project of the curriculum "Fundamentals of professional and pedagogical communication culture formation", which allowed reveal its effectiveness for teachers who has two years of experience of professional activity. The materials of the articles are of theoretical and practical value for teachers of secondary schools, and for teachers - beginners of high schools and colleges of vocational education

Medical university students and facial masks usage. new aspects of safety in COVID-19 pandemic

Aspects of morphology, epidemiology and pathogen microorganism resistance of Covid-19 are presented in article. Data of the incidence and use of personal protective equipment are presented according to the survey of the student community of USMU. Current personal protective equipment requirements and standards are analyzed according with regulatory documents. Pharmacy and retail conditions of mask sales were discoveredВ статье рассмотрены вопросы морфологии, эпидемиологии и устойчивости во внешней среде вируса Covid-19. Представлены собственные данные по исследованию заболеваемости и использования средств индивидуальной защиты по данным анкетирования студенческого сообщества УГМУ. Проанализированы существующие требования и стандарты к средствам индивидуальной защиты в соответствии с нормативными документами. Проведены исследования условий реализации масок в различных аптечных и торговых сетях

De novo assembly and analysis of the transcriptome of the Siberian wood frog Rana amurensis

The Siberian wood frog Rana amurensis Boulenger, 1886 is the most hypoxia-tolerant amphibian. It can survive for several months in an almost complete absence of oxygen. Little is known about the mechanisms of this remarkable resilience, in part because studies of amphibian genomes are impeded by their large size. To make the Siberian wood frog more amenable for genetic analysis, we performed transcriptome sequencing and de novo assembly for the R. amurensis brain under hypoxia and normoxia, as well as for the normoxic heart. In order to build a de novo transcriptome assembly of R. amurensis, we utilized 125-bp paired-end reads obtained from the brain under normoxia and hypoxia conditions, and from the heart under normoxia. In the transcriptome assembled from about 100,000,000 reads, 81.5 % of transcripts were annotated as complete, 5.3 % as fragmented, and 13.2 % as missing. We detected 59,078 known transcripts that clustered into 22,251 genes; 11,482 of them were assigned to specific GO categories. Among them, we found 6696 genes involved in protein binding, 3531 genes involved in catalytic activity, and 576 genes associated with transporter activity. A search for genes encoding receptors of the most important neurotransmitters, which may participate in the response to hypoxia, resulted in a set of expressed receptors of dopamine, serotonin, GABA, glutamate, acetylcholine, and norepinephrine. Unexpectedly, no transcripts for histamine receptors were found. The data obtained in this study create a valuable resource for studying the mechanisms of hypoxia tolerance in the Siberian wood frog, as well as for amphibian studies in general

Expanded expression of pro-neurogenic factor SoxB1 during larval development of gastropod Lymnaea stagnalis suggests preadaptation to prolonged neurogenesis in Mollusca

IntroductionThe remarkable diversity observed in the structure and development of the molluscan nervous system raises intriguing questions regarding the molecular mechanisms underlying neurogenesis in Mollusca. The expression of SoxB family transcription factors plays a pivotal role in neuronal development, thereby offering valuable insights into the strategies of neurogenesis.MethodsIn this study, we conducted gene expression analysis focusing on SoxB-family transcription factors during early neurogenesis in the gastropod Lymnaea stagnalis. We employed a combination of hybridization chain reaction in situ hybridization (HCR-ISH), immunocytochemistry, confocal microscopy, and cell proliferation assays to investigate the spatial and temporal expression patterns of LsSoxB1 and LsSoxB2 from the gastrula stage to hatching, with particular attention to the formation of central ring ganglia.ResultsOur investigation reveals that LsSoxB1 demonstrates expanded ectodermal expression from the gastrula to the hatching stage, whereas expression of LsSoxB2 in the ectoderm ceases by the veliger stage. LsSoxB1 is expressed in the ectoderm of the head, foot, and visceral complex, as well as in forming ganglia and sensory cells. Conversely, LsSoxB2 is mostly restricted to the subepithelial layer and forming ganglia cells during metamorphosis. Proliferation assays indicate a uniform distribution of dividing cells in the ectoderm across all developmental stages, suggesting the absence of distinct neurogenic zones with increased proliferation in gastropods.DiscussionOur findings reveal a spatially and temporally extended pattern of SoxB1 expression in a gastropod representative compared to other lophotrochozoan species. This prolonged and widespread expression of SoxB genes may be interpreted as a form of transcriptional neoteny, representing a preadaptation to prolonged neurogenesis. Consequently, it could contribute to the diversification of nervous systems in gastropods and lead to an increase in the complexity of the central nervous system in Mollusca

Влияние никотинамида на течение глаукомы

The literature review dwells on the role of nicotinamide (vitamin B3) in providing neuroprotective and antioxidant protection of the retina in glaucoma optic neuropathy. It presents the data of foreign studies on its positive influence on the condition of retinal ganglion cells and axons of the optic nerve. There is a revival of interest to nicotinamide use in glaucoma in foreign literature of recent years. This is due to its active influence on metabolic processes. As a cofractor of enzymes, it is involved in cell metabolism, tissue respiration, gene expression, redox processes and the repair of deoxyribonucleic acid. Due to direct neuroprotection nicotinamide prevents and slows down the processes that cause apoptosis, such as ischemia, oxidative stress, inflammation, mitochondrial dysfunction, excitotoxicity, impaired axonal transport and loss of neurotrophins. In the central nervous system, vitamin B3 is recognized as a key mediator of the development and survival of neurons. It promotes the differentiation of nerve cells from embryonic stem cells into mature neurons, increases the synaptic plasticity of neurons and promotes the growth of axonal processes. It also shows significant anti-inflammatory, antioxidant and anti-apoptotic effects in various cells and tissues. Nicotinamide counteracts amyloid toxicity and the formation of reactive oxygen species, and its bioavailability plays a crucial role in normal functioning of neurons and in the prevention of neurodegeneration processes.Particular attention is paid to the antioxidant and neuroprotective role of niacin, as well as its deficiency in neurodegenerative diseases, and other neuropathological conditions. Plasma nicotinamide deficiency was also detected in glaucoma. This allowes suggesting that nicotinamide supplements could be the future therapeutic strategy for glaucoma (as an adjunctive to antihypertensive therapy). It was found that oral administration of niacin has a pronounced neuroprotective effect, protects retinal ganglion cells in chronic ocular hypertension. Niacin consumption correlats with an improvement of vascular endothelium and an oxidative stress reduction. Thus, nicotinamide can be a valuable addition to the antihypertensive therapy of glaucoma and other neurodegenerative diseases, as well as conditions associated with aging.В литературном обзоре обсуждается роль никотинамида (витамина В3) в обеспечении нейропротекторной и антиоксидантной защиты сетчатки при глаукомной оптической нейропатии. Приводятся данные зарубежных исследований, посвященных изучению положительного влияния данного вещества на состояние ганглиозных клеток сетчатки и аксонов зрительного нерва. В зарубежной литературе последних лет отмечается возрождение интереса к применению никотинамида при глаукоме. Это связано с его активным влиянием на обменные процессы. В качестве кофактора энзимов он задействован в метаболизме клетки, тканевом дыхании, экспрессии генов, окислительно-восстановительных процессах и репарации дезоксирибонуклеиновой кислоты. Никотинамид предотвращает и замедляет процессы, вызывающие апоптоз, такие как: ишемия, окислительный стресс, воспаление, митохондриальная дисфункция, эксайтотоксичность, нарушение аксонального транспорта и потеря нейротрофинов, обеспечивая прямую нейропротекцию. В центральной нервной системе витамин B3 признан ключевым медиатором развития и выживания нейронов. Он способствует дифференцировке нервных клеток из эмбриональных стволовых в зрелые нейроны, повышает синаптическую пластичность нейронов и способствует росту аксональных отростков. Он показал существенное противовоспалительное, антиоксидантное и антиапоптотическое действие в различных клетках и тканях. Никотинамид также противодействует амилоидной токсичности и образованию активных форм кислорода, а его биодоступности принадлежит решающая роль для нормального функционирования нейронов и профилактики процессов нейродегенерации.Особое внимание уделяется антиоксидантной и нейропротекторной роли ниацина и его производных, а также его дефициту при нейродегенеративных заболеваниях и других невропатологических состояниях. Дефицит никотинамида в плазме был выявлен и при глаукоме (независимо от уровня внутриглазного давления). Это позволило ученым предположить, что добавки никотинамида могут стать будущей терапевтической стратегией при глаукоме (как дополнение к гипотензивной терапии). Было выявлено, что пероральное применение ниацина оказывает выраженное нейропротекторное действие, защищает ганглиозные клетки сетчатки при хронической глазной гипертензии. Потребление ниацина положительно коррелировало с улучшением состояния сосудистого эндотелия и снижением окислительного стресса. Таким образом, никотинамид может стать ценным дополнением к гипотензивной терапии глаукомы и других нейродегенеративных заболеваний, а также состояний, связанных с процессами старения