Superconductivity and superconducting order parameter phase fluctuations in a weakly doped antiferromagnet

The superconducting properties of a recently proposed phenomenological model for a weakly doped antiferromagnet are analyzed, taking into account fluctuations of the phase of the order parameter. In this model, we assume that the doped charge carriers can't move out of the antiferromagnetic sublattice they were introduced. This case corresponds to the free carrier spectra with the maximum at ${\bf k}=(\pm \pi /2 ,\pm \pi /2)$, as it was observed in ARPES experiments in some of the cuprates in the insulating state [1]. The doping dependence of the superconducting gap and the temperature-carrier density phase diagram of the model are studied in the case of the $d_{x^{2}-y^{2}}$ pairing symmetry and different values of the effective coupling. A possible relevance of the results to the experiments on high-temperature superconductors is discussed.Comment: 16 pages, 4 figure

Rare earth elements materials production from apatite ores

The paper deals with the study of processing apatite ores with nitric acid and extraction of the rare earth elements. The rare earth elements can be successfully separated and recovered by extraction from the nitrate- phosphate solution, being an tributyl phosphate as extraction agent. The developed scheme of the processing apatite concentrate provides obtaining rare earth concentrates with high qualitative characteristics

Extraction of rare earth elements from hydrate-phosphate precipitates of apatite processing

The features of extraction of rare earth elements (REE) were considered from hydrate-phosphate precipitates of REE of apatite processing by nitric acid technology. The preliminary purification of nitrate solution of REE from impurities of titanium, aluminum, iron, uranium and thorium was suggested to obtain stable solutions not forming precipitates. Washing the extract was recommended with the evaporated reextract that allows to obtain directly on the cascade of REE extraction the concentrated solutions suitable for the separation into groups by the extraction method. Technical decisions were suggested for the separation of REE in groups without the use of salting-out agent

Quantum phase transitions and thermodynamic properties in highly anisotropic magnets

The systems exhibiting quantum phase transitions (QPT) are investigated within the Ising model in the transverse field and Heisenberg model with easy-plane single-site anisotropy. Near QPT a correspondence between parameters of these models and of quantum phi^4 model is established. A scaling analysis is performed for the ground-state properties. The influence of the external longitudinal magnetic field on the ground-state properties is investigated, and the corresponding magnetic susceptibility is calculated. Finite-temperature properties are considered with the use of the scaling analysis for the effective classical model proposed by Sachdev. Analytical results for the ordering temperature and temperature dependences of the magnetization and energy gap are obtained in the case of a small ground-state moment. The forms of dependences of observable quantities on the bare splitting (or magnetic field) and renormalized splitting turn out to be different. A comparison with numerical calculations and experimental data on systems demonstrating magnetic and structural transitions (e.g., into singlet state) is performed.Comment: 46 pages, RevTeX, 6 figure

Magnetic and quadrupolar order in a one-dimensional ferromagnet with cubic crystal-field anisotropy

The zero temperature phase diagram of a one-dimensional S=2 Heisenberg ferromagnet with single-ion cubic anisotropy is studied numerically using the density-matrix renormalization group method. Evidence is found that although the model does not involve quadrupolar couplings, there is a purely quadrupolar phase for large values of the anisotropy. The phase transition between the magnetic and quadrupolar phases is continuous and it seems to be characterized by Ising critical exponents.Comment: 11 pages, 7 figures, REVTeX, accepted in Phys. Rev. B (scheduled on June 99

Anomalous resistivity and the electron-polaron effect in the two-band Hubbard model with one narrow band

We search for anomalous normal and superconductive behavior in the two-band Hubbard model with one narrow band. We analyze the influence of electron-polaron effect and Altshuler-Aronov effect on effective mass enhancement and scattering times of heavy and light components in the clean case. We find anomalous behavior of resistivity at high temperatures $T>W_{h}^{*}$ both in 3D and 2D situation. The SC instability in the model is governed by enhanced Kohn-Luttinger effect for p-wave pairing of heavy electrons via polarization of light electrons.Comment: 8 pages, 4 figures, accepted for publication in Journal of Superconductivity and Novel Magnetism, based on the invited talk on Stripes XI Conference in Rome, July 201

Выживаемость больных раком ободочной кишки после радикальных операций, выполненных в медицинских организациях Архангельской области: популяционный анализ по данным регистра рака

Background. surgery is the main method of treatment of colon cancer (cc). Radical surgery performed in non-specialized hospitals can lead to the adverse outcomes.The aim of this study was to assess CC survival after radical surgery performed in state hospitals of the arkhangelsk region (North-West Russia) in 2010–21.Material and Methods. data on all the 2142 cases of radical surgery of CC were obtained from the arkhangelsk regional cancer registry (ARCR). One- and five-year cancer-specific survival rates were estimated by the survival tables; cumulative survival function was calculated by the Kaplan–meier method. Univariate and multiple cox regression analysis was carried out to identify independent predictors associated with CC death risk after radical surgery in state hospitals (incl. sex, age at the time of diagnosis, topography, morphology and stage of CC).Results. less than half (42.8 %) of patients underwent surgery at the arkhangelsk clinical cancer center (accc), a single specialized hospital. one- and five-year survival rates of all patients were 86.5 % (95 % CI: 84.9–87.9 %) and 65.1 % (95 % ci: 62.7–67.4 %), respectively. The 5-year survival rate of patients who underwent surgery in the accc was significantly higher than that in patients who underwent surgery in other state non-specialized hospitals (76.0 % (95 % ci: 72.5–79.0 % versus 49.3–73.8 %, p<0.0001). The relative risk of death of CC patients depended on the state hospital where radical surgery was performed and the stage of CC; it did not depend on patients’ sex, morphology and topography of CC.Conclusion. our results demonstrate the need to search for specific reasons for the relatively low survival in patients after radical surgery performed in non-specialized hospitals.Актуальность. Хирургическое вмешательство является основным методом радикального лечения больных раком ободочной кишки (РОК). Выполнение радикальных хирургических операций в неспециализированных государственных медицинских организациях (ГМО) может оказывать неблагоприятное влияние на исход.Цель исследования – по данным Архангельского областного канцер-регистра (АОКР) оценить выживаемость больных РОК после радикального хирургического лечения в ГМО Архангельской области в 2010–21 гг.Материал и методы. Из базы данных АОКР извлечены записи о 2142 случаях радикального хирургического лечения РОК. Одно- и пятилетняя опухолеспецифическая выживаемость (ОСВ) пациентов оценена по таблицам дожития; кумулятивная функция выживаемости (КФВ) рассчитана методом Каплана–Мейера. В серии процедур одно- и многофакторного регрессионного анализа Кокса рассчитаны значения коэффициента относительного риска (ОР) смерти пациентов от РОК, оперированных в ГМО региона, в зависимости от величин факторов прогноза (пол, возраст на момент постановки диагноза, топография, морфология, стадия).Результаты. Менее половины (42,8 %) пациентов получили хирургическое лечение РОК в Архангельском клиническом онкологическом диспансере (АКОД) – профильной медицинской организации. Одно- и 5-летняя ОСВ всех пациентов составила 86,5 % (95 % ДИ: 84,9–87,9 %) и 65,1 % (95 % ДИ: 62,7–67,4 %) соответственно. Уровень пятилетней ОСВ пациентов, оперированных в АКОД, составил 76,0 % (95 % ДИ: 72,5–79,0 %), а оперированных в иных медицинских организациях варьировал в диапазоне 49,3–73,8 % и был значимо ниже, чем в АКОД (р<0,0001). В многофакторной модели риск смерти зависел от ГМО, где было выполнено хирургическое вмешательство, и стадии заболевания; не зависело от пола больных, морфологии и топографии новообразования.Заключение. Результаты исследования определяют необходимость поиска специфических причин относительно низкой ОСВ пациентов после хирургического лечения РОК, выполненного в непрофильных ГМО

RNF219 attenuates global mRNA decay through inhibition of CCR4-NOT complex-mediated deadenylation

The CCR4-NOT complex acts as a central player in the control of mRNA turnover and mediates accelerated mRNA degradation upon HDAC inhibition. Here, we explored acetylation-induced changes in the composition of the CCR4-NOT complex by purification of the endogenously tagged scaffold subunit NOT1 and identified RNF219 as an acetylation-regulated cofactor. We demonstrate that RNF219 is an active RING-type E3 ligase which stably associates with CCR4-NOT via NOT9 through a short linear motif (SLiM) embedded within the C-terminal low-complexity region of RNF219. By using a reconstituted six-subunit human CCR4-NOT complex, we demonstrate that RNF219 inhibits deadenylation through the direct interaction of the α-helical SLiM with the NOT9 module. Transcriptome-wide mRNA half-life measurements reveal that RNF219 attenuates global mRNA turnover in cells, with differential requirement of its RING domain. Our results establish RNF219 as an inhibitor of CCR4-NOT-mediated deadenylation, whose loss upon HDAC inhibition contributes to accelerated mRNA turnover

СОВРЕМЕННАЯ ЛУЧЕВАЯ ТЕРАПИЯ ЖЕЛУДКА

External beam radiation therapy (EBRT) is currently an important component of the treatment of gastric cancer (GC). In accordance with international and domestic recommendations, it can be used in the postoperative period, before the operation and as a sole option, with a curative and palliative purpose, usually in combination with chemotherapy. With the transition of RT to a new technological level, which involves the use of conformal, intensively modulated regimens, and image guidance the revision of indications for and doses of EBRT is required. The article discusses modern approaches to the determination of irradiated volumes in various clinical scenarios of current radiation therapy for GC and strategies aimed at reducing the dose in critical organs at risk and increasing the overall effectiveness of treatment.Дистанционная лучевая терапия (ЛТ) в настоящее время является важным компонентом лечения рака желудка (РЖ). В соответствии с международными и отечественными рекомендациями она может быть использована в послеоперационном периоде, перед операцией и самостоятельно, с лечебной и паллиативной целью, как правило, в сочетании с химиотерапией. В связи с переходом ЛТ на новый технологический уровень, предусматривающий использование конформных, интенсивно-модулированных режимов, требуется пересмотр показаний, доз и режимов дистанционного облучения. В статье рассмотрены современные подходы к определению облучаемых объемов при различных клинических сценариях современной ЛТ по поводу РЖ и обсуждены стратегии, направленные на снижение дозы в критических органах и повышение эффективности лечения