The ability to optically initialize the electronic spin of the nitrogen-vacancy (NV) center in diamond has long been considered a valuable resource to enhance the polarization of neighboring nuclei, ...but efficient polarization transfer to spin species outside the diamond crystal has proven challenging. Here we demonstrate variable-magnetic-field, microwave-enabled cross-polarization from the NV electronic spin to protons in a model viscous fluid in contact with the diamond surface. Further, slight changes in the cross-relaxation rate as a function of the wait time between successive repetitions of the transfer protocol suggest slower molecular dynamics near the diamond surface compared to that in bulk. This observation is consistent with present models of the microscopic structure of a fluid and can be exploited to estimate the diffusion coefficient near a solid–liquid interface, of importance in colloid science.
Dispersions of the refractive index are measured in aqueous solutions of potassium halides at different salt concentrations and temperatures of the solutions. The specific effect of anions on the ...dynamic dielectric permittivity of the solutions is found. A model is proposed to evaluate the character of changes in the dynamic dielectric permittivity of the solutions and effective dynamic polarizabilities of ions in the solutions based on the data about the dispersion of refractive indices. The role of ion sizes and the character of their interaction with a solvent in the manifestation of specific ion effects are discussed.
The problem is considered on the injection of moist steam into a porous medium saturated in the initial state with gas and paraffin. Self-similar solutions describing hydrodynamic and temperature ...fields are constructed assuming that the intensity of injection is limited by the hydraulic drag of water plug formed because of condensation of vapor. Analysis is made of the effect of heat consumption on the process of development of heated zones during the melting of paraffin.
The ability to optically initialize the electronic spin of the nitrogen-vacancy (NV) center in diamond has long been considered a valuable resource to enhance the polarization of neighboring nuclei, ...but efficient polarization transfer to spin species outside the diamond crystal has proven challenging. Here we demonstrate variable-magnetic-field, microwave-enabled cross-polarization from the NV electronic spin to protons in a model viscous fluid in contact with the diamond surface. Slight changes in the cross-relaxation rate as a function of the wait time between successive repetitions of the transfer protocol suggest slower molecular diffusion near the diamond surface compared to that in bulk, an observation consistent with present models of the microscopic structure of a fluid close to a solid interface.
Clinical manifestations of COVID-19 in children Shagieva, D R; Rakhmatullin, A R; Kutlubaev, M A ...
Zhurnal nevrologii i psikhiatrii imeni S.S. Korsakova,
2021, Letnik:
121, Številka:
8
Journal Article
Recenzirano
The neurological symptoms of COVID-19 in children (in Dyurtyuli area, Republic of Bashkortostan) are analyzed and brief review of the literature is undertaken in the paper. 137 children underwent ...swab test for COVID-19. The disease was diagnosed in 9 of them. Only respiratory symptoms were observed in 3 children, a combination of respiratory with anosmia or/and headache - in 3, asymptomatic form - in another 3. A case of a 7-years old girl suffering from COVID-19 with respiratory symptoms as well as anosmia and headache is presented. According to the review of the literature, COVID - 19 in children is usually milder than in adults, but in some cases may lead to neurological consequences. Multisystem inflammatory syndrome may lead to the development symptoms of encephalopathy (altered mental status, headache) and stroke. Autoimmune complications such as Gillian-Barre syndrome develop simultaneously or after resolving of the infectious process. The development of viral meningoencephalitis in COVID-19 is questionable.
Introduction: Bronchial asthma is a disease characterized by chronic inflammation of the airways. At present, about 235-300 million people suffer from asthma, and this number continues to grow. This ...pathology is also common in children. It causes significant social and economic damage worldwide. Severe forms of asthma are difficult to treat. Thus, a continuous improvement of doctors’ knowledge in this field is of great importance.
Methods: The analysis of an anonymous survey of physicians and senior medical students was used in the research.
Results: The study revealed both an average level of basic knowledge in asthma etiology and pathogenesis among the physicians and senior medical students and the significant differences in their knowledge regarding clinical picture and treatment of asthma. Only 49.2% of students and 56.0% of doctors were able to choose the correct definition of asthma from the suggested answers; 65.7% of students and 69.9% of doctors correctly indicated the main clinical and laboratory markers of asthma; 60.2% of students and 91.0% of doctors determined the correct combination of drugs in one delivery device; and 75.9% of students and 91.2% of doctors selected the correct basic asthma therapy depending on the severity.
Conclusion: Basing on the results obtained it was recommended to introduce additional educational activities on the diagnosis and therapy of asthma among medical majors and physicians.
The relevance of the study is determined by the fact that university students very often face stressful situations in the learning process, especially during exams and testing times. Self-control and ...the features of coping strategies are those psychological phenomena that determine the stress-resistance, the nature and ways of overcoming stressful situations, the degree of its constructiveness and adequacy, which actualizes their study. Objective of the study: this paper is aimed at analyzing the relationship between self-control and coping strategies for university students with different levels of stress-resistance. Methods of research: The leading theoretical method for the study of this problem is the content analysis of scientific papers relevant to the research problem, which allows considering the analysis of factors contributing to the constructive overcoming of stressful situations. Empirical methods were the conduct of a study using valid diagnostic techniques appropriate to the purpose of the study, statistical analysis and generalization of the results obtained. Results of the research: The paper presents the results of an empirical study of the relationship between self-control and coping strategies for coping with stress for university students with low and high levels of stress resistance. It is established that students with high stress resistance have more developed self-control in the emotional sphere, in activity, social self-control, and also a higher propensity to self-control in general. They are dominated by constructive transformative and adaptive cognitive-behavioral strategies to overcome stress. Practical significance: The materials of the paper are of practical value for the development of psychological and pedagogical programs aimed at increasing the stress-resistance of university students in the educational process.
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