Electron Spin for Classical Information Processing: A Brief Survey of Spin-Based Logic Devices, Gates and Circuits

In electronics, information has been traditionally stored, processed and communicated using an electron's charge. This paradigm is increasingly turning out to be energy-inefficient, because movement of charge within an information-processing device invariably causes current flow and an associated dissipation. Replacing charge with the "spin" of an electron to encode information may eliminate much of this dissipation and lead to more energy-efficient "green electronics". This realization has spurred significant research in spintronic devices and circuits where spin either directly acts as the physical variable for hosting information or augments the role of charge. In this review article, we discuss and elucidate some of these ideas, and highlight their strengths and weaknesses. Many of them can potentially reduce energy dissipation significantly, but unfortunately are error-prone and unreliable. Moreover, there are serious obstacles to their technological implementation that may be difficult to overcome in the near term. This review addresses three constructs: (1) single devices or binary switches that can be constituents of Boolean logic gates for digital information processing, (2) complete gates that are capable of performing specific Boolean logic operations, and (3) combinational circuits or architectures (equivalent to many gates working in unison) that are capable of performing universal computation.Comment: Topical Revie

Charge inhomogeneities and transport in semiconductor heterostructures with a manganese δ\delta-layer

We study experimentally and theoretically the effects of disorder, nonlinear screening, and magnetism in semiconductor heterostructures containing a $\delta$-layer of Mn, where the charge carriers are confined within a quantum well and hence both ferromagnetism and transport are two-dimensional (2D) and differ qualitatively from their bulk counterparts. Anomalies in the electrical resistance observed in both metallic and insulating structures can be interpreted as a signature of significant ferromagnetic correlations. The insulating samples turn out to be the most interesting as they can give us valuable insights into the mechanisms of ferromagnetism in these heterostructures. At low charge carrier densities, we show how the interplay of disorder and nonlinear screening can result in the organization of the carriers in the 2D transport channel into charge droplets separated by insulating barriers. Based on such a droplet picture and including the effect of magnetic correlations, we analyze the transport properties of this set of droplets, compare it with experimental data, and find a good agreement between the model calculations and experiment. Our analysis shows that the peak or shoulder-like features observed in temperature dependence of resistance of 2D heterostructures $\delta$-doped by Mn lie significantly below the Curie temperature $T_{C}$ unlike the three-dimensional case, where it lies above and close to $T_{C}$. We also discuss the consequences of our description for understanding the mechanisms of ferromagnetism in the heterostructures under study.Comment: 13 pages, 12 figures, RevTe

Profile of Hepatitis B Virus Mutations Associated with HBsAg-Negative Disease in Patients of Hemodialysis Centers

The aim of this study was to characterize mutations in the hepatitis B virus (HBV) genome associated with HBsAg-negative form of the disease in patients receiving hemodialysis replacement therapy. Materials and methods. We used blood plasma samples obtained from hemodialysis centers in St. Petersburg, Russia – 173 patients and 108 patients from Belgrade, Republic of Serbia. The samples were examined for the presence of serological (HBsAg, antibodies anti-HBs IgG, anti-HBcore IgG) and molecular-genetic (HBV DNA) markers of HBV followed by whole-genome sequencing and determination of clinically significant virus mutations. Results and discussion. Antibodies to hepatitis B were detected in 7.5 % and 11.1 % of patients from St. Petersburg and Belgrade, respectively. HBsAg was identified only in 1.1 % of cases in the group from Russia and in 0.9 % of cases in the group from Serbia. HBV DNA was determined in 2.8 % of the studied samples from both, patients from Saint-Petersburg and Belgrade. Phylogenetic analysis of 9 viral isolates showed that genotype D virus (88.9 %) prevailed as compared to genotype A (11.1 %) in the examined group. Among the samples obtained from patients from St. Petersburg, four belonged to the D2 sub-genotype, one to the D3 genotype. Four samples obtained from Belgrade patients belonged to different sub-genotypes – D1, D2, D3, A2, respectively. When analyzing the nucleotide sequences of the HBV genomes, mutations in the MHR region were detected in all cases, but only in HBsAg-negative isolates, mutations were revealed in the region of 124–147 amino acids, including mutations P120T, R122K, A128V, Q129R, M133I, G145R affecting the recognition of HBsAg by anti-HBs antibodies and associated with the resistance of the virus to the vaccine. The results of this study indicate that transmission of blood-borne viral hepatitis agent in the hemodialysis departments of the Russian Federation and the Republic of Serbia still exists. The prevalence of the latent chronic hepatitis B, coupled with the presence of vaccine escape mutations in all identified cases, indicates the need to pay close attention to the occurrence of the virus mutant variants in hemodialysis centers

Prevalence of Markers of Certain Blood-Borne Viral Infections in Pregnant Women and Their Partners in the Republic of Guinea

The aim of the work was to estimate the prevalence of HIV, HBV and HCV markers among pregnant women and their male partners in the Republic of Guinea.Materials and methods. The material of the study was blood plasma samples from 140 pregnant women living in Kindia prefecture and N’Zerekore prefecture, as well as 60 male partners who reported sexual contact with HIV-infected persons. The samples were examined for the presence of serological (HBsAg, HBeAg, antibodies anti-HBs IgG, anti-HBcore IgG, anti-HBe IgG, anti-HCV IgG, Ag/Ab-HIV) and molecular (HBV DNA, HCV RNA, HIV RNA) markers.Results and discussion. The age of the examined pregnant women ranged from 13 to 55 years and was on average (26.29±9.67) years. The age of men varied from 15 to 60 years, on average – (29.05±11.99) years. When assessing the prevalence of serological markers, antibodies to HCV were detected in 2.14 % cases in women and in 3.33 % cases in men. Antibodies to HIV were found in 6.43 % and 6.67 % women and men, respectively. Serological markers associated with HBV were detected in 80.71 % (HBsAg – 13.57 %) of women and 81.67 % (15 %) of men. In the pregnant women, HCV RNA was not detected, HIV RNA was revealed in 1 case, HBV DNA was identified in 26 cases (18.57 %), including 5 % HBsAg-negative hepatitis B cases. In the men group, HCV RNA and HIV RNA were detected in 3.33 % and 6.67 % cases, respectively. HBV DNA was determined in 16.67 % of men, including latent hepatitis B in one person. A significantly higher incidence of HIV in men compared to women is shown (χ2=3.907 at p<0.05). The relative risk of HIV infection in men is nine times higher than in women: RR=9.333; p=0.0291; 95 % CI: 1.065–81.815 %. Four out of five identified HIV infection cases were co-infected with HBV and/or HCV. There is an obvious need to introduce screening for HIV, HCV, HBV, including latent hepatitis B, into routine laboratory diagnostics during examination of pregnant women and their partners, followed by couples counseling and vaccination against hepatitis B virus

Бронхиальная астма: федеральные клинические рекомендации по диагностике и лечению

Bronchial asthma is a heterogeneous disease that requires identification of its phenotype and a personalized approach to therapy. At the same time, despite a wide range of therapeutic options, many patients with asthma cannot achieve control over the disease.Methodology. The target audience of these clinical recommendations are general practitioners, therapists, pediatricians, allergologists-immunologists, pulmonologists, and functional diagnostics doctors. Each thesis-recommendation about diagnostic and therapeutic procedures has been scored according to the scales of classes of recommendations from 1 to 5 and A, B, C scale of the levels of evidence. The clinical recommendations also contain comments and explanations to the theses, algorithms for the diagnosis and treatment of bronchial asthma, and reference materials.Conclusion. The presented clinical guidelines cover current information about the etiology and pathogenesis, classification, clinical manifestations, diagnosis, treatment, and prevention of bronchial asthma. These guidelines were approved by the Scientific and Practical Council of the Ministry of Health of the Russian Federation in 2021. Бронхиальная астма (БА) является гетерогенным заболеванием, при котором требуется выделение различных фенотипов и персонифицированный подход к терапии. При этом несмотря на широкий выбор терапевтических возможностей, у многих пациентов с БА не удается достичь контроля над заболеванием.Методы. Целевой аудиторией данных клинических рекомендаций являются врачи общей практики, терапевты, педиатры, аллергологи-иммунологи, пульмонологи и врачи функциональной диагностики. Каждый тезис-рекомендация по проведению диагностических и лечебных мероприятий оценивается по шкалам уровней достоверности доказательств от 1 до 5 и шкале оценки уровней убедительности рекомендаций по категориям А, В, С. Клинические рекомендации содержат также комментарии и разъяснения к указанным тезисам-рекомендациям, алгоритмы по диагностике и лечению БА, справочные материалы.Заключение. По данным представленных клинических рекомендаций освещаются современные сведения об этиологии и патогенезе, классификации, клинических проявлениях, диагностике, лечении и профилактике БА. Клинические рекомендации одобрены Научно-практическим Советом Министерства здравоохранения Российской Федерации (2021).

Многоуровневые инъекции ботулинического токсина типа А (Абоботулотоксина) при лечении спастических форм детского церебрального паралича: ретроспективное исследование опыта 8 российских центров

Background: The contemporary application of Botulinum toxin A (BTA) in cerebral palsy (CP) implies multilevel injections both in on-label and off-label muscles. However, there is no single international opinion on the effective and safe dosages, target muscles, and intervals between the injections.Objective: Our aim was to analyze the Russian multicenter independent experience of single and repeated multilevel injections of Abobotulinum toxin А in patients with spastic forms of CP.Methods: 8 independent referral CP-centers (10 hospitals) in different regions of Russia. Authors evaluated intervals between the injections, dosages of the BTA for the whole procedure, for the body mass, for the each muscle, and functional segment of the extremities.Results: 1872 protocols of effective BTA injections (1–14 repeated injections) for 724 patients with spastic CP were included. The age of the patients was between 8 months to 17 years 4 months at the beginning of the treatment (with a mean of 3 years 10 months). Multilevel BTA injections were indicated for the majority (n = 634, 87.6%) of the patients in all the centers. The medians of the dosages for the first BTA injection were between 30–31 U/kg (500 U), the repeated injections doses up to 45 U/kg (1000 U) (in most centers). The median intervals between the repeated injections were 180–200 days in 484 (66.9%) patients and 140–180 days in 157 (24.7%) patients. In 2 centers, children with GMFCS IV–V were injected more often than others.Conclusion: Multilevel BTA injections were indicated for the most patients. The initial dose of Abobotulinum toxin A was 30–31 U/kg. The repeated injections dose could increase up to 40 U/kg. The repeated injections were done in 140–200 days after the previous injection.Современная концепция ботулинотерапии при детском церебральном параличе (ДЦП) предлагает использование многоуровневых инъекций в расширенное число мышц. Однако по-прежнему отсутствует консенсус относительно выбора оптимальных доз, мышц и интервалов между инъекциями.Цель исследования: изучить российский опыт применения однократных и повторных многоуровневых инъекций абоботулотоксина при лечении спастичности у пациентов с ДЦП.Методы: в ретроспективном исследовании проанализирован опыт ботулинотерапии при ДЦПв 8 специализированных центрах России. Изучали протоколы клинически эффективных инъекций. Оценивали общие дозы препарата БТА, дозы на единицу массы тела пациентов, на всю инъекционную сессию и отдельные мышцы, а также интервалы между инъекциями.Результаты: изучено 1872 протокола клинически эффективных инъекций, всего от 1 до 14 повторных инъекций, сделанных 724 пациентам в возрасте от 8 мес до 17 лет 4 мес (медиана возраста на момент первой инъекции БТА — 3 года 10 мес) на момент начала ботулинотерапии. Большинство пациентов (n = 634; 87,6% инъекций) получили многоуровневую ботулинотерапию. Во всех центрах при первичных инъекциях БТА медиана доз находилась в пределах 30–31 Ед/кг массы тела (общая — 500 Ед). При повторных инъекциях в большинстве учреждений максимальные дозы превышали 45 Ед/кг (1000 Ед). Средние интервалы между повторными инъекциями колебались в пределах 140–180 сут для 157 (24,7%) и 180–200 сут для 484 (66,9%) пациентов. В 2 из 8 центров пациенты с наиболее выраженными двигательными нарушениями (GMFCS IV–V) требовали более частых повторных инъекций БТА.Заключение: в специализированных центрах большинству пациентов с ДЦП ботулинотерапию проводили по многоуровневой схеме. Общая доза абоботулотоксина при первичных инъекциях составляла 30–31 Ед/кг; при повторных инъекциях она могла быть увеличена до 40 Ед/кг и более. Вопрос о повторном проведении инъекции БТА рассматривался в интервале 140–200 сут после предшествующей инъекции

Enzymatic oligomerization and polymerization of arylamines: state of the art and perspectives

The literature concerning the oxidative oligomerization and polymerization of various arylamines, e.g., aniline, substituted anilines, aminonaphthalene and its derivatives, catalyzed by oxidoreductases, such as laccases and peroxidases, in aqueous, organic, and mixed aqueous organic monophasic or biphasic media, is reviewed. An overview of template-free as well as template-assisted enzymatic syntheses of oligomers and polymers of arylamines is given. Special attention is paid to mechanistic aspects of these biocatalytic processes. Because of the nontoxicity of oxidoreductases and their high catalytic efficiency, as well as high selectivity of enzymatic oligomerizations/polymerizations under mild conditions-using mainly water as a solvent and often resulting in minimal byproduct formation-enzymatic oligomerizations and polymerizations of arylamines are environmentally friendly and significantly contribute to a "green'' chemistry of conducting and redox-active oligomers and polymers. Current and potential future applications of enzymatic polymerization processes and enzymatically synthesized oligo/polyarylamines are discussed