New Method and Tool for TEM Samples Preparation

А new tool for TEM sample preparation, which allows preparing a thin lamella with thickness less than 20 nm surrounded by and embedded in bulk material, is presented. The main advantages of this system are low ion milling induced damage (less than 2 nm in depth), low process time (1—2 hours), in situ sample monitoring during ion milling (topography and sample thickness), and large treated area (5—30 μm along the area of interest). Comparison of few kinds of working substance of ion sources as well as schemes or drawings of key components of the tool are presented.Представлено нову методику і технологію виготовлення зразків для ПЕМ, яка уможливлює підготувати зразок завтовшки до 20 нм, оточений об’ємним матеріалом і втілений у нього. Головна перевага системи полягає в малій товщині шару пошкоджень, спричинених йонним обробленням (менше 2 нм), в малому часі оброблення (1—2 години), в моніторинґу зразка під час йонного фрезерування (топографія і товщина зразка) і у великій площі, що обробляється (5—30 мкм вздовж області, яка являє інтерес). Виконано порівняння декількох типів робочої речовини для йонних джерел, наведено схеми або креслення ключових вузлів пристрою.Представлена новая методика и технология приготовления образцов для ПЭМ, позволяющая подготовить образец толщиной до 20 нм, окружённый объёмным материалом и вмурованный в него. Главным преимуществом системы является малая толщина слоя повреждений, индуцированных ионной обработкой (меньше 2 нм), малое время обработки (1—2 часа), мониторинг образца во время ионного фрезерования (топография и толщина образца) и большая обрабатываемая площадь (5—30 мкм вдоль интересующей области). Проведено сравнение нескольких рабочих веществ для ионных источников, приведены схемы или чертежи ключевых узлов устройства.The authors would like to thank the staff of SELA and PETRC of Ukraine for taking part in the development and fabrication of Xact. In particular, D. Viazovsky and T. Krasovsky for electronics development, V. Kontorov and V. Isyanov for technical documentation development, D. Farhana, L. Berner for software development, A. Berner, A. Bekkerman, A. Eizner, V. Kuchik, S. Yakovlev, G. Aharonov, all who made this achievement real by their hard work and talent

Observation of narrow baryon resonance decaying into pKs0pK^0_s in pA-interactions at 70GeV/c70 GeV/c with SVD-2 setup

SVD-2 experiment data have been analyzed to search for an exotic baryon state, the $\Theta^+$-baryon, in a $pK^0_s$ decay mode at $70 GeV/c$ on IHEP accelerator. The reaction $pA \to pK^0_s+X$ with a limited multiplicity was used in the analysis. The $pK^0_s$ invariant mass spectrum shows a resonant structure with $M=1526\pm3(stat.)\pm 3(syst.) MeV/c^2$ and $\Gamma < 24 MeV/c^2$. The statistical significance of this peak was estimated to be of $5.6 \sigma$. The mass and width of the resonance is compatible with the recently reported $\Theta^+$- baryon with positive strangeness which was predicted as an exotic pentaquark ($uudd\bar{s}$) baryon state. The total cross section for $\Theta^+$ production in pN-interactions for $X_F\ge 0$ was estimated to be $(30\div120) \mu b$ and no essential deviation from A-dependence for inelastic events $(\sim A^{0.7})$ was found.Comment: 8 pages, 7 figures, To be submitted to Yadernaya Fizika. v3-v5 - Some references added, minor typos correcte

The Dipole Magnet Design for the ALICE DiMuon Arm Spectrometer

An essential part of the DiMuon Arm Spectrometer of the ALICE experiment is a conventional Dipole Magnet of about 890 tons which provides the bending power to measure the momenta of muons. The JINR engineering design of the Dipole Magnet, technical characteristics and description of the proposed manufacturing procedure are presented. The proposed Coil fabrication technique is based on winding of flat pancakes, which are subsequently bent on cylindrical mandrels. The pancakes are then stacked and cured with prepreg insulation. The method is demonstrated on hand of the prototype II, which consists of a pancake made with full-size aluminium conductor. Some details of electromagnetic and mechanical calculations are described. The results of measuring of mechanical and electrical characteristics of materials related to the coil composite structure are discussed

Başkortostan Cumhuriyeti Toratau Jeoparki bal arısı (apis mellifera) popülasyonunda tergit rengi değişimi

A phenetic analysis of the honey bee population of the Toratau Geopark (Russia) was performed. Over 1,000 worker and drone bee samples were collected from 250 colonies in 59 apiaries on the territory of the Toratau Geopark (Gafuriysky, Ishimbaysky, Meleuzovsky, and Sterlitamaksky districts of the Republic of Bashkortostan). Six phenes in worker bees and four phenes in drone bees were recognized. The phenes E, 1R, 2R, and 3R in workers and Is, I, and O-gray in drones were predominant in the honey bee population of the Toratau Geopark, which were associated with subspecies of the Clineage. These phenes can be used as indicators of introgressive hybridization in the local dark European honey bee population. The phenes allow for quick evaluation of certain honey bee colonies hybridization states.Toratau Jeoparkı'ndaki (Rusya) bal arısı popülasyonunun fenetik analizi yapılmıştır. Toratau Jeoparkı topraklarındaki (Başkurdistan Cumhuriyeti'nin Gafuriysky, Ishimbaysky, Meleuzovsky ve Sterlitamaksky bölgeleri) 59 arılıktaki 250 koloniden 1.000'den fazla işçi ve erkek arı örneği toplanmıştır. İşçi arılarda altı fen ve erkek arılarda dört tergit rengi tespit edilmiştir. İşçilerde E, 1R, 2R ve 3R ve erkek arılarda Is, I ve O-gri fenleri Toratau Jeoparkı'ndaki bal arısı popülasyonunda baskındı ve bunlar C soyunun alt türleriyle ilişkiliydi. Bu tergit rengi, yerel koyu Avrupa bal arısı popülasyonunda içsel melezleşmenin göstergeleri olarak kullanılabilir. Bu tergit renkleri, belirli bal arısı kolonilerinin melezleşme durumlarının hızlı bir şekilde değerlendirilmesine olanak sağlamaktadır.The article was prepared with supporting the grant of the head of the Republic of Bashkortostan Radiy Khabirov, grant title "Study of the Bashkir bee population on the territory of the Toratau Geopark

Разработка метода получения pd - содержащих частиц для последующего синтеза электрокатализаторов

Platinum metals and their compounds are now widely used as catalysts for water electrolysis and fuel cells. We propose a new approach to the synthesis of nanoparticles. As model experiment we realized synthesis of palladium diacetate nanoparticles of controlled size. As special condition for new phase grow was chosen far from equilibrium boundary between two liquids [2]. Under this condition gradient of chemical potential the water - tetrahydrofuran (THF) interface was a powerful regulating factor of the palladium diacetate (II) particle size.Описан метод получения наноматериалов в неравновесном переходном слое, возникающем при приведении в контакт двух различных по своей химической природе смешивающихся жидкостей. Метод апробирован для получения Pd-содержащих наночастиц контролируемого размера, которые будут в дальнейшем использованы для получения электрокатализаторов. Предложенный метод не предполагает применения поверхностно-активных добавок, модифицирующих поверхность, что является ключевым моментом в процессах синтеза катализаторов. Рассмотрено влияние различных факторов на размер частиц диацетата палладия(II), образующихся в переходном слое на границе раздела вода - тетрагидрофуран (ТГФ)

Cинтез наночастиц Y(OH)CO3 и Y2О3 при использовании жидких межфазных границ и дальнейшая модификация их поверхности палладием

The nano-composite materials with different morphology and structure, including yttrium basic carbonate or yttrium oxide and palladium metal are obtained. The optimal conditions for synthesis of stable nanoparticles of yttrium basic carbonate are defined. It is established that yttrium basic carbonate goes to the oxide at 900 °C. Samples of nanomaterials were characterized by transmission electron microscopy, infrared spectroscopy, X-ray diffraction, X-ray photoelectron spectroscopy.Получены наноразмерные композиционные материалы различной морфологии и структуры, включа-ющие гидроксокарбонат либо оксид иттрия и металлический палладий. Определены оптимальные условия синтеза стабильных наночастиц гидроксокарбоната иттрия, которые при температуре 900°С переходят в соответствующий оксид. Образцы наноматериалов охарактеризованы методами электронной просвечивающей микроскопии, ИК спектроскопии, рентгенофазового анализа, рентгеновской фотоэлектронной спектроскопии

Система двух смешивающихся жидкостей как генератор наночастиц. Синтез наночастиц BаSO4 при контакте растворов прекурсоров в воде и тетрагидрофуране

The system of two miscible liquids is presented as a generator of nanoparticles. This approach was tested experimentally with the synthesis of barium sulfate nanoparticles under non-equilibrium conditions after contact of perfectly miscible solutions as an example.The experimental results were compared with the dynamic model of transition layer. According to this model the smallest size of obtained particles is determined by the size of associates in the nucleation stage formed inside the rotating Bernard cells. The hypothesis of BaSO4 creation is based on the idea that the interface between a Bernard cell and the surrounding solution has barrier properties. The permeability of this barrier depends on the viscosity of the solution. The influence of the solvent polarity on the structure and size of nanoparticles was investigated. The dependence of the structure and size of the nanoparticles on the water/THF ratio was found. The influence of viscosity of the solution on the size of the nanoparticles was found and explained in terms of dynamic transition layer.Система двух смешивающихся жидкостей предложена в качестве генератора наночастиц. Действенность этого подхода проверена экспериментально на примере синтеза наночастиц сульфата бария при приведении в контакт растворов прекурсоров, содержащихся в разных фазах: фаза 1 - (H2O + TГФ) и фаза 2 - (H2O). Для объяснения полученных результатов привлечена развитая в настоящей работе динамическая модель переходного слоя, согласно которой наименьший размер получившихся частиц определяется размером ассоциатов предфазы, сформировавшихся во вращающихся ячейках Бенара. Высказано предположение, что граница раздела ячейки Бенара с окружающим раствором обладает определенными барьерными свойствами, которые зависят от вязкости. Получена зависимость размера нанокристаллических частиц от соотношения H2O/ТГФ

Reorganization of the nuclear lamina and cytoskeleton in adipogenesis

A thorough understanding of fat cell biology is necessary to counter the epidemic of obesity. Although molecular pathways governing adipogenesis are well delineated, the structure of the nuclear lamina and nuclear-cytoskeleton junction in this process are not. The identification of the ‘linker of nucleus and cytoskeleton’ (LINC) complex made us consider a role for the nuclear lamina in adipose conversion. We herein focused on the structure of the nuclear lamina and its coupling to the vimentin network, which forms a cage-like structure surrounding individual lipid droplets in mature adipocytes. Analysis of a mouse and human model system for fat cell differentiation showed fragmentation of the nuclear lamina and subsequent loss of lamins A, C, B1 and emerin at the nuclear rim, which coincides with reorganization of the nesprin-3/plectin/vimentin complex into a network lining lipid droplets. Upon 18 days of fat cell differentiation, the fraction of adipocytes expressing lamins A, C and B1 at the nuclear rim increased, though overall lamin A/C protein levels were low. Lamin B2 remained at the nuclear rim throughout fat cell differentiation. Light and electron microscopy of a subcutaneous adipose tissue specimen showed striking indentations of the nucleus by lipid droplets, suggestive for an increased plasticity of the nucleus due to profound reorganization of the cellular infrastructure. This dynamic reorganization of the nuclear lamina in adipogenesis is an important finding that may open up new venues for research in and treatment of obesity and nuclear lamina-associated lipodystrophy

Altered adipocyte differentiation and unbalanced autophagy in type 2 Familial Partial Lipodystrophy: an in vitro and in vivo study of adipose tissue browning

Type-2 Familial Partial Lipodystrophy is caused by LMNA mutations. Patients gradually lose subcutaneous fat from the limbs, while they accumulate adipose tissue in the face and neck. Several studies have demonstrated that autophagy is involved in the regulation of adipocyte differentiation and the maintenance of the balance between white and brown adipose tissue. We identified deregulation of autophagy in laminopathic preadipocytes before induction of differentiation. Moreover, in differentiating white adipocyte precursors, we observed impairment of large lipid droplet formation, altered regulation of adipose tissue genes, and expression of the brown adipose tissue marker UCP1. Conversely, in lipodystrophic brown adipocyte precursors induced to differentiate, we noticed activation of autophagy, formation of enlarged lipid droplets typical of white adipocytes, and dysregulation of brown adipose tissue genes. In agreement with these in vitro results indicating conversion of FPLD2 brown preadipocytes toward the white lineage, adipose tissue from FPLD2 patient neck, an area of brown adipogenesis, showed a white phenotype reminiscent of its brown origin. Moreover, in vivo morpho-functional evaluation of fat depots in the neck area of three FPLD2 patients by PET/CT analysis with cold stimulation showed the absence of brown adipose tissue activity. These findings highlight a new pathogenetic mechanism leading to improper fat distribution in lamin A-linked lipodystrophies and show that both impaired white adipocyte turnover and failure of adipose tissue browning contribute to disease.We thank FPLD2 patients for donating biological samples. We thank the Italian Network for Laminopathies and the European Consortium of Lipodystrophies (ECLip) for support and helpful discussion. We thank Aurelio Valmori for the technical support. The studies were supported by Rizzoli Orthopedic Institute “5 per mille” 2014 project to MC, AIProSaB project 2016 and Fondazione Del Monte di Bologna e Ravenna grant 2015–2016 “New pharmacological approaches in bone laminopathies based on the use of antibodies neutralizing TGF beta 2” to GL. GL is also supported by PRIN MIUR project 2015FBNB5Y.S