Orbital Ordering Structures in (Nd,Pr)0.5Sr0.5MnO3 Manganite Thin Films on Perovskite (011) Substrates

Structural study of orbital-ordered manganite thin films has been conducted using synchrotron radiation, and a ground state electronic phase diagram is made. The lattice parameters of four manganite thin films, Nd0.5Sr0.5MnO3 (NSMO) or Pr0.5Sr0.5MnO3 (PSMO) on (011) surfaces of SrTiO3 (STO) or [(LaAlO3){0.3}(SrAl0.5Ta0.5O3){0.7}] (LSAT), were measured as a function of temperature. The result shows, as expected based on previous knowledge of bulk materials, that the films' resistivity is closely related to their structures. Observed superlattice reflections indicate that NSMO thin films have an antiferro-orbital-ordered phase as their low-temperature phase while PSMO film on LSAT has a ferro-orbital-ordered phase, and that on STO has no orbital-ordered phase. A metallic ground state was observed only in films having a narrow region of A-site ion radius, while larger ions favor ferro-orbital-ordered structure and smaller ions stabilize antiferro-orbital-ordered structure. The key to the orbital-ordering transition in (011) film is found to be the in-plane displacement along [0-1 1] direction.Comment: 19pages, 11 figure

Synthesis of new organoelement copolymers based on polydimethylsiloxanes and aminophosphonates

© 2018 Based on commercially available 3-Aminopropyl (diethoxy)methylsilane new alkoxysilane with functional aminophosphonate group - diethyl (2-((3-(diethoxy (methyl)silyl)propyl)amino)propan-2-yl)phosphonate were synthesized and characterized. Obtained functional alkoxysilane were transformed to tetrasiloxane in active medium in the presence of acetic acid and then copolymerized with octamethylcyclotetrasiloxane (D4). The chemical structure of the resulting polymer was studied and confirmed by a combination of physical methods, namely,1H,13C,31P and29Si NMR, GPC, and IR spectroscopy. The thermophysical and rheological properties of the polymer were also studied

High magnetic field transport measurement of charge-ordered Pr0.5_{0.5}Ca0.5_{0.5}MnO3_3 strained thin films

We have investigated the magnetic-field-induced phase transition of charge-ordered (CO) Pr$_{0.5}$Ca$_{0.5}$MnO$_3$ thin films, deposited onto (100)-oriented LaAlO$_3$ and (100)-oriented SrTiO$_3$ substrates using the pulsed laser deposition technique, by measuring the transport properties with magnetic fields up to 22T. The transition to a metallic state is observed on both substrates by application of a critical magnetic field ($H_C>10T$ at 60K). The value of the field required to destroy the charge-ordered insulating state, lower than the bulk compound, depends on both the substrate and the thickness of the film. The difference of the critical magnetic field between the films and the bulk material is explained by the difference of in-plane parameters at low temperature (below the CO transition). Finally, these results confirm that the robustness of the CO state, depends mainly on the stress induced by the difference in the thermal dilatations between the film and the substrate.Comment: 10 pages, 6 figures. To be published in Phys. Rev.

DNA Methylation of the ABO Promoter Underlies Loss of ABO Allelic Expression in a Significant Proportion of Leukemic Patients

Background: Loss of A, B and H antigens from the red blood cells of patients with myeloid malignancies is a frequent occurrence. Previously, we have reported alterations in ABH antigens on the red blood cells of 55% of patients with myeloid malignancies. Methodology/Principal Findings: To determine the underlying molecular mechanisms of this loss, we assessed ABO allelic expression in 21 patients with ABH antigen loss previously identified by flow cytometric analysis as well as an additional 7 patients detected with ABH antigen changes by serology. When assessing ABO mRNA allelic expression, 6/12 (50%) patients with ABH antigen loss detected by flow cytometry and 5/7 (71%) of the patients with ABH antigen loss detected by serology had a corresponding ABO mRNA allelic loss of expression. We examined the ABO locus for copy number and DNA methylation alterations in 21 patients, 11 with loss of expression of one or both ABO alleles, and 10 patients with no detectable allelic loss of ABO mRNA expression. No loss of heterozygosity (LOH) at the ABO locus was observed in these patients. However in 8/11 (73%) patients with loss of ABO allelic expression, the ABO promoter was methylated compared with 2/10 (20%) of patients with no ABO allelic expression loss (P = 0.03). Conclusions/Significance: We have found that loss of ABH antigens in patients with hematological malignancies is associated with a corresponding loss of ABO allelic expression in a significant proportion of patients. Loss of ABO allelic expression was strongly associated with DNA methylation of the ABO promoter.Tina Bianco-Miotto, Damian J. Hussey, Tanya K. Day, Denise S. O'Keefe and Alexander Dobrovi

МАГНИТНЫЕ И ТЕРМИЧЕСКИЕ СВОЙСТВА НАНОМАТЕРИАЛОВ НА ОСНОВЕ ВЫСОКОРАЗВЕТВЛЕННЫХ ФЕРРОЦЕНСОДЕРЖАЩИХ ПОЛИМЕРОВ

New magnetic nanomaterials with magnetization up to 32 Gs·cm3/g were synthesized from highly branched ferrocene-containing polymers by thermal structural transformations in a field of 2.5 kOe. The structure and properties of the prepared polymers were studied by IR spectroscopy, transmission electron microscopy (TEM) and thermogravimetric analyses. According to IR spectroscopy the content of 1,3,5-substituted benzene rings in the ferrocene-containing polymer increases at 500°C. X-ray diffraction study showed that iron in such a sample is present exclusively in the form of Fe3O4 magnetite. As the heating temperature increased to 600°C, the composition of the samples became more complex: along with magnetite they contain cementite Fe3C and wustite FeO.97O. The magnetization of the ferrocene-containing polymer depends on the synthesis and heat treatment temperature. For a sample synthesized at 140°C the formation of a magnetically ordered phase begins at 500°C, and at 800°C the magnetization reaches a maximum value of 32 Gs·cm3/g. The average size of magnetic particles according to TEM analysis was 8-26 nm. The principal possibility of controlling the size and composition of the nanoparticles, as well as their magnetization depending on the conditions of production and the temperature of polymer structuring is shown. The obtained results provide a good basis for the directed synthesis of magnetic ferrocene-containing polymers with preset characteristics.Термоструктурированием высокоразветвленных ферроценсодержащих полимеров синтезированы новые магнитные наноматериалы с намагниченностью насыщения до 32 Гс·см3/г в магнитном поле 2.5 килоэрстед. Исследованы структура и свойства полученных соединений методами ИК-спектроскопии, просвечивающей электронной микроскопии (ПЭМ) и термогравиметрического анализа. По данным ИК-спектроскопии в ферроценсодержащем полимере, прогретом при 500 °С, содержание 1,3,5-замещенных бензольных колец возрастает. Рентгенодифракционное исследование показало, что железо в таком образце присутствует исключительно в форме магнетита Fe3O4. С повышением температуры прогрева до 600 °С состав образцов становился более сложным, наряду с магнетитом в них содержался цементит Fe3C и вюстит Fe0.97O. Намагниченность ферроценсодержащего полимера зависит от температуры синтеза и термообработки. Для образца, синтезированного при температуре 140 ºС, образование магнитоупорядоченной фазы начинается при прогреве от 500 ºС, и при 800 ºС намагниченность достигает максимального значения 32 Гс·см3/г. Среднестатистические размеры магнитных наночастиц по данным ПЭМ составляют 8-26 нм. Показана принципиальная возможность контроля размера и состава наночастиц, а также их намагниченности, в зависимости от условий получения и температуры структурирования полимеров. Полученные результаты создают хорошую основу направленного синтеза магнитных ферроценсодержащих полимеров с заданными характеристиками

Epidemiology of Doublet/Multiplet Mutations in Lung Cancers: Evidence that a Subset Arises by Chronocoordinate Events

BACKGROUND: Evidence strongly suggests that spontaneous doublet mutations in normal mouse tissues generally arise from chronocoordinate events. These chronocoordinate mutations sometimes reflect "mutation showers", which are multiple chronocoordinate mutations spanning many kilobases. However, little is known about mutagenesis of doublet and multiplet mutations (domuplets) in human cancer. Lung cancer accounts for about 25% of all cancer deaths. Herein, we analyze the epidemiology of domuplets in the EGFR and TP53 genes in lung cancer. The EGFR gene is an oncogene in which doublets are generally driver plus driver mutations, while the TP53 gene is a tumor suppressor gene with a more typical situation in which doublets derive from a driver and passenger mutation. METHODOLOGY/PRINCIPAL FINDINGS: EGFR mutations identified by sequencing were collected from 66 published papers and our updated EGFR mutation database (www.egfr.org). TP53 mutations were collected from IARC version 12 (www-p53.iarc.fr). For EGFR and TP53 doublets, no clearly significant differences in race, ethnicity, gender and smoking status were observed. Doublets in the EGFR and TP53 genes in human lung cancer are elevated about eight- and three-fold, respectively, relative to spontaneous doublets in mouse (6% and 2.3% versus 0.7%). CONCLUSIONS/SIGNIFICANCE: Although no one characteristic is definitive, the aggregate properties of doublet and multiplet mutations in lung cancer are consistent with a subset derived from chronocoordinate events in the EGFR gene: i) the eight frameshift doublets (present in 0.5% of all patients with EGFR mutations) are clustered and produce a net in-frame change; ii) about 32% of doublets are very closely spaced (< or =30 nt); and iii) multiplets contain two or more closely spaced mutations. TP53 mutations in lung cancer are very closely spaced (< or =30 nt) in 33% of doublets, and multiplets generally contain two or more very closely spaced mutations. Work in model systems is necessary to confirm the significance of chronocoordinate events in lung and other cancers

Ледотехнические аспекты создания объектов транспортной инфраструктуры и разведочного бурения в Арктике

Starting from the mid 2000-s the increase of sustained development of the Russian Arctic is observed, in many cases the technologies using the ice cover as an infrastructure element and the ice as the construction materials are used. In the present time the different approaches of use of natural and artificial ice for applied tasks on the Arctic offshore exist. For example, the clearance of the upper surface of ice from snow and ridges is used for the purposes of the vessel unloading on the fast ice or constructing the airstrips on the drifting ice cover. In case of insufficient thickness of the level ice the latter is increased by the means of preliminary freezing (natural on the bottom side of ice and artificial by pouring the fresh or saline water on the upper surface). By constructing the artificial ice islands the ice body is made by spraying the sea water with the partial freezing of the water drops in the air and further freezing of the 2-phase elements (i.e. ice crystals in the liquid film) on the surface of the ice cover. The problem of cracks in the ice cover is solved by different means according to the proper task. When it is possible, the cracks are “healed”— i.e. are filled with the snow and ice gravel and then freezed. In case of impossibility of use of such method (for example — presence of tidal cracks or relatively high air temperature) the cracks are overlapped with the help of different covers made of different materials and of different sizes. The promising trend of ice technology is involving the reinforced or composite ice, having the increased strength, into the ice engineering practice. By unloading the cargo ships on the fast ice the ice strength is decreased locally for the purpose of easy berthing of the vessel with safekeeping the original strength of the surrounding ice for the aims of the vessel unloading. This problem is solved by creating the system of notches in the ice cover according to the vessel dimensions. The specialized hydrometeorological support on every stage of the ice engineering operation is an essential element of the ice engineering activities on the ice cover of lakes, rivers and seas.Рассматриваются направления ледотехники, связанные с использованием ледяного покрова природных водоемов как несущей площадки для создания транспортной инфраструктуры (ледовые причалы, аэродромы, искусственные ледяные острова и т.п.). Обсуждаются общие вопросы организации и проведения инженерно-технических работ на льду и некоторые частные проблемы, связанные с решением отдельных конкретных задач. Особое внимание уделено специальному гидрометеорологическому обеспечению операций как неотъемлемой части ледотехнических работ

Production of {\pi}+ and K+ mesons in argon-nucleus interactions at 3.2 AGeV

First physics results of the BM@N experiment at the Nuclotron/NICA complex are presented on {\pi}+ and K+ meson production in interactions of an argon beam with fixed targets of C, Al, Cu, Sn and Pb at 3.2 AGeV. Transverse momentum distributions, rapidity spectra and multiplicities of {\pi}+ and K+ mesons are measured. The results are compared with predictions of theoretical models and with other measurements at lower energies.Comment: 29 pages, 20 figure

Three-dimensional super-resolution microscopy of the inactive X chromosome territory reveals a collapse of its active nuclear compartment harboring distinct Xist RNA foci

Background: A Xist RNA decorated Barr body is the structural hallmark of the compacted inactive X territory in female mammals. Using super resolution three-dimensional structured illumination microscopy (3D-SIM) and quantitative image analysis, we compared its ultrastructure with active chromosome territories (CTs) in human and mouse somatic cells, and explored the spatio-temporal process of Barr body formation at onset of inactivation in early differentiating mouse embryonic stem cells (ESCs). Results: We demonstrate that all CTs are composed of structurally linked chromatin domain clusters (CDCs). In active CTs the periphery of CDCs harbors low-density chromatin enriched with transcriptionally competent markers, called the perichromatin region (PR). The PR borders on a contiguous channel system, the interchromatin compartment (IC), which starts at nuclear pores and pervades CTs. We propose that the PR and macromolecular complexes in IC channels together form the transcriptionally permissive active nuclear compartment (ANC). The Barr body differs from active CTs by a partially collapsed ANC with CDCs coming significantly closer together, although a rudimentary IC channel system connected to nuclear pores is maintained. Distinct Xist RNA foci, closely adjacent to the nuclear matrix scaffold attachment factor-A (SAF-A) localize throughout Xi along the rudimentary ANC. In early differentiating ESCs initial Xist RNA spreading precedes Barr body formation, which occurs concurrent with the subsequent exclusion of RNA polymerase II (RNAP II). Induction of a transgenic autosomal Xist RNA in a male ESC triggers the formation of an `autosomal Barr body' with less compacted chromatin and incomplete RNAP II exclusion. Conclusions: 3D-SIM provides experimental evidence for profound differences between the functional architecture of transcriptionally active CTs and the Barr body. Basic structural features of CT organization such as CDCs and IC channels are however still recognized, arguing against a uniform compaction of the Barr body at the nucleosome level. The localization of distinct Xist RNA foci at boundaries of the rudimentary ANC may be considered as snap-shots of a dynamic interaction with silenced genes. Enrichment of SAF-A within Xi territories and its close spatial association with Xist RNA suggests their cooperative function for structural organization of Xi