Kinetic behavior of Desulfovibrio gigas aldehyde oxidoreductase encapsulated in reverse micelles

Biochemical and Biophysical Research Communications 308 (2003) 73–78We report the kinetic behavior of the enzyme aldehyde oxidoreductase (AOR) from the sulfate reducing bacterium Desulfovibrio gigas (Dg) encapsulated in reverse micelles of sodium bis-(2-ethylhexyl) sulfosuccinate in isooctane using benzaldehyde, octaldehyde, and decylaldehyde as substrates. Dg AOR is a 200-kDa homodimeric protein that catalyzes the conversion of aldehydes to carboxylic acids. Ultrasedimentation analysis of Dg AOR-containing micelles showed the presence of 100-kDa molecular weight species, confirming that the Dg AOR subunits can be dissociated. UV–visible spectra of encapsulated Dg AOR are indistinguishable from the enzyme spectrum in solution, suggesting that both protein fold and metal cofactor are kept intact upon encapsulation. The catalytic constant (kcat) profile as a function of the micelle size W0 (W0 ¼ ½H2O /[AOT]) using benzaldehyde as substrate showed two bell-shaped activity peaks at W0 ¼ 20 and 26. Furthermore, enzymatic activity for octaldehyde and decylaldehyde was detected only in reverse micelles. Like for the benzaldehyde kinetics, two peaks with both similar kcat values and W0 positions were obtained. EPR studies using spin-labeled reverse micelles indicated that octaldehyde and benzaldehyde are intercalated in the micelle membrane. This suggests that, though Dg AOR is found in the cytoplasm of bacterial cells, the enzyme may catalyze the reaction of substrates incorporated into a cell membrane

Особенности цифрового досуга учащихся школ, различающихся условиями обучения и воспитания, в период пандемии Covid-19

Introduction. There are a large number of facts in the scientific literature demonstrating the increasing influence of digital technologies on the involvement of adolescents in Internet activity. However, contradictions in the experimental material and the heterogeneity of research methods make it difficult to formulate certain conclusions about the nature of the impact of the Internet on adolescents. The peculiarity of our study is to study the behavior on the Internet of school students who are characterized by different learning and upbringing conditions using the same methodology in similar conditions of social restrictions due to the Covid-19 pandemic. We relied on the fact that every teenager has certain preferences for virtual leisure, and the choice of online activities is characterized by certain similarities in different educational institutions, but at the same time it may be related to the quality of physical and social activity in a real environment. Methods. The approved author\u27s questionnaire "Digital preferences of modern teenagers" was used, which allows quantifying the features of different types of students\u27 activities in a virtual environment. 96 students from three schools in Lipetsk took part in the survey, differing in learning conditions, different contributions of additional education (sports classes in sections) and active participation in public life of the city. Results. The activity of students in social networks is characterized by differences in preferred leisure activities and time spent on communication on the Internet. For the first time, it was established that overly enthusiastic visiting of social networks, which means using the Internet for 4 or more hours a day, is due to both the humanitarian specifics of the school\u27s educational program and the neglect of students outside of school life. Discussion. The article establishes the fundamental features of the activity of Russian teenagers on the Internet during the Covid-19 pandemic in comparison with their peers from other countries: Russians prefer communication in social networks to all other types of leisure in the virtual space. The practical and significant role of teenagers\u27 activity in real social life, passion for sports and physical culture as ways to prevent the formation of Internet addiction is discussed.Введение. В научной литературе имеется большое количество фактов, демонстрирующих возрастающее влияние цифровых технологий на вовлеченность подростков в Интернет-активность. Однако противоречия в экспериментальном материале и разнородность исследовательских методик затрудняют формулировку определенных выводов о характере воздействия Интернета на подростков. Особенность нашего исследования заключается в изучении поведения в Интернете учащихся школ, которые характеризуются различающимися условиями обучения и воспитания, с помощью одной и той же методики в сходных условиях социальных ограничений из-за пандемии Covid-19. Мы опирались на то, что у каждого подростка существуют определенные предпочтения виртуального досуга, и выбор деятельности в Интернете характеризуется определенным сходством в разных образовательных учреждениях, но при этом может быть связан с качеством физической и социальной активности в реальной среде. Методы. Использовалась апробированная авторская анкета «Цифровые предпочтения современных подростков», которая позволяет количественно оценивать особенности разных видов деятельности учащихся в виртуальной среде. В опросе приняло участие 96 обучающихся трех школ г. Липецка, различающихся условиями обучения, разным вкладом дополнительного образования (спортивных занятий в секциях) и активностью участия в общественной жизни города. Результаты. Активность учащихся в социальных сетях характеризуется различиями предпочитаемых видов досуга и временных затрат на общение в Интернете. Впервые установлено, что сверх увлеченное посещение социальных сетей, под которым понимается использование интернета 4 и более часов в день, обусловлено как гуманитарной спецификой образовательной программы школы, так и безнадзорностью учащихся вне школьной жизни. Обсуждение результатов. В статье установлены принципиальные особенности активности подростков России в Интернете во время пандемии Covid-19 по сравнению со своими сверстниками из других стран: россияне предпочитают общение в социальных сетях всем остальным видам досуга в виртуальном пространстве. Обсуждается практическая и значимая роль активности подростков в реальной социальной жизни, увлечение спортом и физической культурой в качестве способов профилактики формирования Интернет-зависимости

Results of a three-year follow-up and quality of life dynamics after pulmonary thromboendarterectomy

Aim. To evaluate the results of a three-year follow-up of patients with chronic thromboembolic pulmonary hypertension (CTEPH) and quality of life (QOL) dynamics after pulmonary thromboendarterectomy (PTE).Material and methods. The study included 125 patients with CTEPH aged 49,7± 11,9 years. Three-year follow-up included the recording of adverse cardiovascular events, surgeries, death during the period from the end of hospitalization and up to three years. The SF-36 questionnaire was used to assess physical and mental wellbeing before and three years after PTE. Multivariate linear regression was used to assess the factors affecting QOL in the long-term postoperative period.Results. During a three-year follow-up, adverse cardiovascular events was recorded in 1,9% of patients. One patient underwent coronary artery bypass graft surgery and one patient — cholecystectomy. Reoperative PTE was not carried out. The overall three-year survival rate was 90,4%.At baseline, patients with CTEPH had a low level of physical and mental well-being (<40 points). Three years after the operation, these parameters significantly increased (p<0,05), but did not exceed 50 points. Multivariate linear regression revealed an unfavorable effect of early postoperative residual pulmonary hypertension on the physical health three years after PTE. Other factors (age, sex, body weight, comorbidity, hospital acquired complications) did not affect the physical and emotional aspects of QOL.Conclusion. Three-year survival rate in patients with CTEPH after PTE was 90,4%. During the follow-up period, no recurrent thromboembolic events were recorded. Adverse cardiovascular events were recorded in 1,9% of patients. Three years after surgery, the physical and mental health increased in comparison with preoperative values, but did not exceed 50 points on the SF-36 questionnaire. The physical aspect of QOL after surgery is affected by early postoperative residual pulmonary hypertension

Language as Lens: Plurality Marking and Numeral Learning

this paper argues that, for one kind of concept (numbers), during one developmental period (ages 2-4), one part of language (plurality marking) plays a lens-like role in conceptual formation. Specifically, speakers pay more attention to the numerical distinctions marked by their grammar than to other numerical distinction

POLYMORBIDITY IN CLINICAL PRACTICE

The interaction of diseases for their clinical features, severity type, quality of life of patients and preferable drug therapy are reviewed on the example of clinical case. Clinical examination, diagnosis and choice of optimal drug management are outlined in patient with polymorbid pathology