Spintronics: Fundamentals and applications

Spintronics, or spin electronics, involves the study of active control and manipulation of spin degrees of freedom in solid-state systems. This article reviews the current status of this subject, including both recent advances and well-established results. The primary focus is on the basic physical principles underlying the generation of carrier spin polarization, spin dynamics, and spin-polarized transport in semiconductors and metals. Spin transport differs from charge transport in that spin is a nonconserved quantity in solids due to spin-orbit and hyperfine coupling. The authors discuss in detail spin decoherence mechanisms in metals and semiconductors. Various theories of spin injection and spin-polarized transport are applied to hybrid structures relevant to spin-based devices and fundamental studies of materials properties. Experimental work is reviewed with the emphasis on projected applications, in which external electric and magnetic fields and illumination by light will be used to control spin and charge dynamics to create new functionalities not feasible or ineffective with conventional electronics.Comment: invited review, 36 figures, 900+ references; minor stylistic changes from the published versio

Экстранодальный рост в метастазах папиллярного рака щитовидной железы – ультразвуковые критерии диагностики и его клиническое значение

The purpose of the research was to identify ultrasound criteria of extranodal extension (ENE) in metastases of papillary thyroid cancer and to evaluate the clinical significance of ENE.Material and Methods. Ultrasound signs of ENE in 283 cervical lymph node metastases from papillary thyroid cancer were analyzed. Extranodal extension in 137 metastases was diagnosed by ultrasound and verified by histological examination. Micrometastases invisible on ultrasound were detected in 144 patients; metastases located inside the organ were detected in 147 patients; metastases located outside the organ were revealed in 136 patients; the size of 98 metastases was less than 1 cm; the size of 185 metastases was more than 1 cm; the age of 51 patients was under 55 years; 132 patients were older than 55 years. Diagnostic significance of ENE and its clinical significance were estimated according to χ2 Pirson criteria.Results: Two ultrasound criteria: shape change and blurred margins of metastases indicated the presence of ENE. The small number of ultrasound false-negative findings indicated the need for further research. The number of micrometastases not detected by ultrasound was 2-fold higher in patients who had metastases with ENE than in patients who had metastases without ENE. The number of patients with ENE in metastases inside the organ (T1a, T1b, T2 and T3b) was 2.7 times lower compared to patients with metastases developed outside the organ (T3a, T4a, T4b); ENE was observed in metastases of different size and did not depend on age groups.Conclusion. The ultrasound method allows intravital detection of ENE in metastases of papillary thyroid cancer. The extension is accompanied by a significantly high number of micrometastases in the neck tissue. It is detected more often in metastases located outside the organ, regardless of the size and age of the patients. The extra-nodal extension should be considered as a criterion for an unfavorable prognosis.Цель исследования – выявить ультразвуковые критерии экстранодального роста в метастазах папиллярного рака щитовидной железы (ПРЩЖ) и оценить его клиническое значение.Материал и методы. Проанализированы ультразвуковые признаки экстранодального роста (ЭР) в 283 метастазах ПРЩЖ в лимфатические узлы шеи. Экстранодальный рост диагностирован ультразвуковым методом в 137 метастазах и верифицирован гистологическим исследованием. Микрометастазы, не определяемые ультразвуковым методом, обнаружены у 144 больных; внутриорганные опухоли установлены у 147 больных; внеорганные – у 136; количество метастазов размером до 1 см – 98, более 1 см – 185; больных моложе 55 лет оказалось 151, старше 55 лет – 132. Диагностическая значимость признаков ЭР и их клиническое значение оценены по критерию χ2 Пирсона.Результаты. Два ультразвуковых критерия – изменение формы и нечеткость контура в метастазе – свидетельствуют об ЭР. Незначительное число ультразвуковых ложноотрицательных данных указывает на необходимость дальнейших исследований. У больных, имеющих метастазы с ЭР, количество микрометастазов в клетчатке шеи, не определяемых ультразвуковым методом, в 2 раза больше по сравнению с больными, у которых метастазы не имеют ЭР. При метастазах с ЭР количество больных с внутриорганным ростом (T1a,T1b,T2 и T3b) в 2,7 раза меньше по сравнению с больными, имеющими опухоли с внеорганным ростом (T3a,T4a,T4b); ЭР в метастазах любых размеров не зависит от возраста больных.Выводы. Ультразвуковой метод позволяет прижизненно выявлять ЭР в метастазах папиллярного рака щитовидной железы. Экстранодальный рост сопровождается значимо большим количеством микрометастазов в клетчатке шеи; он выявляется при внеорганных опухолях; не зависит от размеров и от возраста больных. Экстранодальный рост следует рассматривать как критерий неблагоприятного прогноза

GaSbBi alloys and heterostructures: fabrication and properties

International audienceDilute bismuth (Bi) III-V alloys have recently attracted great attention, due to their properties of band-gap reduction and spin-orbit splitting. The incorporation of Bi into antimonide based III-V semiconductors is very attractive for the development of new optoelectronic devices working in the mid-infrared range (2-5 µm). However, due to its large size, Bi does not readily incorporate into III-V alloys and the epitaxy of III-V dilute bismides is thus very challenging. This book chapter presents the most recent developments in the epitaxy and characterization of GaSbBi alloys and heterostructures

Experience in International Cooperation on Organization of Anti-Epidemic Measures by Health Care Institutions under COVID-19 Pandemic in the Republic of Uzbekistan

The results of the joint work of a panel of experts from Rospotrebnadzor and healthcare professionals of the Republic of Uzbekistan on organizing activities to counter the spread of the SARS-CoV-2 virus are described in the paper.The goal of the study was to determine the main driving forces of COVID-19 spread in the Republic of Uzbekistan and develop an action plan to reduce the incidence of coronavirus infection caused by the SARS-CoV-2 virus.Materials and methods. The organization of work in 14 health care institutions in Tashkent and Samarkand, as well as in Tashkent and Samarkand Regions, was analyzed: in 7 laboratories, 6 hospitals and 1 polyclinic. The routes for the movement of personnel, the demarcation of green and red zones, the features of disinfection and the use of personal protective equipment were studied. Attention is drawn to the diagnosis of COVID-19, the use of therapy aimed at reducing the period of virus shedding, the criteria for lifting quarantine restrictions for patients.Results and discussion. The main factors in the organization of work of institutions that contribute to the spread of COVID-19 among medical personnel and the population have been identifed: the lack of equipped gateways between the red and green zones with the accessibility of adequate disinfection, the wrong choice of personal protective equipment, monitoring of contact persons for 10 days, discharge from hospitals based on clinical improvement. The incorrect use of antiviral therapy, the lack of differentiated approaches to the selection of optimal regimens have been noted. Proposals are formulated for organizing the work of healthcare institutions, taking into account the requirements of biological safety. The introduction of targeted measures in addition to those previously adopted has led to a signifcant improvement in the epidemic situation: the total number of active cases in the Republic of Uzbekistan, despite the increase in testing volumes, decreased from 3,686 people on August 23 to 2335 on October 27. Towards December 20, 2020, 97 % of patients recovered completely. All diagnostic triage centers in the Republic of Uzbekistan are closed due to the absence of patients with COVID-19, most of the country’s medical institutions previously re-profled for patients with coronavirus infection have returned to the routine operations

An update of the Worldwide Integrated Assessment (WIA) on systemic insecticides. Part 2: impacts on organisms and ecosystems

New information on the lethal and sublethal effects of neonicotinoids and fipronil on organisms is presented in this review, complementing the previous WIA in 2015. The high toxicity of these systemic insecticides to invertebrates has been confirmed and expanded to include more species and compounds. Most of the recent research has focused on bees and the sublethal and ecological impacts these insecticides have on pollinators. Toxic effects on other invertebrate taxa also covered predatory and parasitoid natural enemies and aquatic arthropods. Little, while not much new information has been gathered on soil organisms. The impact on marine coastal ecosystems is still largely uncharted. The chronic lethality of neonicotinoids to insects and crustaceans, and the strengthened evidence that these chemicals also impair the immune system and reproduction, highlights the dangers of this particular insecticidal classneonicotinoids and fipronil. , withContinued large scale – mostly prophylactic – use of these persistent organochlorine pesticides has the potential to greatly decreasecompletely eliminate populations of arthropods in both terrestrial and aquatic environments. Sublethal effects on fish, reptiles, frogs, birds and mammals are also reported, showing a better understanding of the mechanisms of toxicity of these insecticides in vertebrates, and their deleterious impacts on growth, reproduction and neurobehaviour of most of the species tested. This review concludes with a summary of impacts on the ecosystem services and functioning, particularly on pollination, soil biota and aquatic invertebrate communities, thus reinforcing the previous WIA conclusions (van der Sluijs et al. 2015)

Ultrasound diagnosis of cervical lymph node metastases in patients with first diagnosed papillary thyroid cancer and in patients previously treated surgically and admitted for radioactive iodine therapy

Purpose of the study. To evaluate the potentialities of ultrasound method in diagnosing cervical lymph node metastasis in patients with first diagnosed papillary thyroid cancer (group 1) and in patients previously treated surgically at different clinics of the Russian Federation and subsequently admitted to the A.F.Tsyb Medical Radiological Research Center — Branch of the National Medical Research Radiological Center to receive radioactive iodine therapy (group 2).Patients and methods. Patients with PTC were divided into two groups. Group 1 included 649 patients with first diagnosed PTC. All the patients underwent thyroidectomy and level VI lymph node neck dissection at the clinic of the A.F.Tsyb Medical Radiological Research Center — Branch of the National Medical Research Radiological Center. Of these patients, 92 patients underwent cervical lymph node dissection including levelsII–III–IV and 9 patients underwent cervical lymph node dissection including level VB. Group 2 consisted of 2875 patients who had previously received surgery at different clinics of the Russian Federation. Subsequently, they were admitted to our institution to receive radioactive iodine therapy. In 291 of these patients, cervical lymph node metastases were found and reoperations were performed: in 89 cases at level VI, in 170 cases at levels II–III–IV and in 32 cases at level VB. The detected metastases were verified histologically.Results. Histology confirmed the presence of nodal metastasis in 57.6% of 649 patients in group 1, and in 10.1% of 241 patients in group 2. In group 1, the incidence of metastatic disease in level VI nodes was 73% and in group 2, it was 30.6%. Metastases in levels II–III–IV were noted in 24.6% of patients in group 1, and in 58.4% of patients in group 2. Level VB metastasis was found in 2.4% of patients in group 1, and in 11% of patients in group 2. Multiple metastases were detected in 75.4% of patients in group 1, and in 20.3% of patients in group 2.Conclusion. Central lymph node metastasis was observed in 73% of patients who were first diagnosed with PTC and treated with thyroidectomy and prophylactic level VI cervical lymph node dissection. In group 2, solitary metastases to lateral lymph nodes occurred more frequently after surgical treatment for PTC, which suggested that the primary treatment was insufficiently radical