119 research outputs found
Secondary peak on asymmetric magnetization loop of type-II superconductors
Asymmetric magnetization loops with a second peak effect were parameterized
by the extended critical state model. The magnetic field distribution in a
sample is considered. Expression is suggested for a peak of the critical
current density and corresponding depression on field dependence of the depth
of surface layer with equilibrium magnetization. These functions determine the
width and the asymmetry of a magnetization loop. Asymmetry of the secondary
peak height on magnetization branches for increasing and decreasing field is
reproduced on the computed magnetization curves.Comment: 6 pages, 2 figures, Equation 6 is modified to be f=0 at B=
МУЛЬТИПАРАМЕТРИЧЕСКАЯ МРТ У БОЛЬНЫХ ЛОКАЛИЗОВАННЫМ РАКОМ ПРЕДСТАТЕЛЬНОЙ ЖЕЛЕЗЫ ПОСЛЕ РАДИКАЛЬНОЙ ДИСТАНЦИОННОЙ ЛУЧЕВОЙ ТЕРАПИИ
Prostate cancer (PC) is the one of the most common and socially significant malignancies in men. Radiotherapy is currently one of the leading conservative special treatments for a localized and locally advanced PC. The frequency of biochemical recurrence after external beam radiotherapy (EBRT) is high. One of the main problems is a differentiation between local and systemic relapse of PC. Nevertheless, a local recurrence of PC after radiotherapy can occur without increasing PSA. Magnetic resonance imaging (MRI) is a highly informative imaging method, however, currently it is used mostly for the primary diagnosis and is not included into the recommendations for detecting recurrent prostate cancer after treatment. MR-pattern of the local progression after radical EBRT can be similar to that of primary PC. It is also difficult to diagnose local relapse of prostate cancer in some cases. Multiparametric MRI (mpMRI) has the greatest prospects in the diagnosis of local tumor recurrence in prostate cancer patients after radical external beam radiotherapy. The article provides an overview of domestic and foreign literature, in which we attempted to systematize current knowledge about the possibilities of the mpMRI in diagnosing local recurrence after radical EBRT and, based on the results of published studies, identify directions for further application of this approach.Рак предстательной железы (РПЖ) — распространенное и социально значимое онкологическое заболевание у мужчин. Дистанционная лучевая терапия (ДЛТ) является в настоящее время одним из ведущих консервативных специальных методов лечения локализованного и местно-распространенного РПЖ. Частота возникновения биохимического рецидива после радикальной лучевой терапии велика. Одной из основных проблем при выборе дальней- шей тактики лечения у данной категории пациентов является дифференциальная диагностика местного и системно- го рецидива РПЖ. Тем не менее развитие местного рецидива РПЖ после ДЛТ возможно и без повышения уровня простатспецифического антигена (ПСА) в сыворотке крови. Магнитно-резонансная томография (МРТ) является высокоинформативным методом визуализации, однако в настоящее время применяется в большинстве случаев для первичной диагностики РПЖ и не входит в рекомендации для выявления рецидива РПЖ после лечения. При мест- ном прогрессировании РПЖ после ДЛТ многие из МР-паттернов аналогичны таковым при первичном РПЖ. Однако на фоне постлучевых фиброзных изменений диагностировать местный рецидив РПЖ в ряде случаев сложно. Также трудно дифференцировать рецидив и фиброзные постлечебные изменения в предстательной железе и тканях малого таза. Мультипараметрическая МРТ (мпМРТ) имеет наибольшие перспективы в диагностике местного рецидива опухоли у больных РПЖ после радикальной дистанционной ЛТ. В статье приведен обзор данных отечественной и зарубежной литературы, в котором мы предприняли попытку систематизировать современные знания о возможностях мпМРТ в диагностике местного рецидива после радикальной ДЛТ и на основании результатов опубликованных исследований определить направления дальнейшего применения этого подхода
ЗАБОЛЕВАЕМОСТЬ РАКОМ ПРЯМОЙ КИШКИ В АРХАНГЕЛЬСКОЙ ОБЛАСТИ: ТРЕНДЫ И КРАТКОСРОЧНЫЙ ПРОГНОЗ (ПО ДАННЫМ ОБЛАСТНОГО КАНЦЕР-РЕГИСТРА)
Introduction. More than 1 million new cases of rectal cancer (RC) are annually detected worldwide, and together with colon cancer this tumor is the 4th most frequent cause of cancer death.Objective: To analyze short-term prognosis of RC incidence for certain population subgroups in the Arkhangelsk region, Russia.Material and methods. The data on all primary RC cases in the Arkhangelsk region in the time period from 2000 to 2015 were selected. Crude (whole population) and age-standardized incidence rates were calculated depending on gender and place of residence (urban or rural). The ARIMA model (autoregressive integrated moving average) was chosen to analyze the variations of the time series and to estimate prognosis. To transform the series to a stationary form and to reduce dispersion, the first or second differences of their values and the natural logarithms were taken. The incidence values for the period 2016–2018 were predicted on stationary series of RC incidence from 2000 to 2015.Results. Crude and age-standardized RC incidence rates in Arkhangelsk region increased from 14.4 and 11.4 in 2000 to 23.5 and 15.1 per 100,000 in 2015. Age-standardized RC incidence rates for males, females, urban and rural populations increased from 14.8, 10.1, 9.3 and 15.1 to 20.3, 12.6, 12.3 and 20.4 per 100, 000, respectively. Actual values of incidence rates among all population, male/female and rural/urban population in 2015 were within the confidence interval of the prognosis. The constructed prognosis model assumes an increase in the RC incidence among all population groups, which may cause the detection of 279 new cases by 2018; i.e. 16 cases (6%) more than in 2015.Conclusion. The incidence rates of RC have been steadily increasing in all population groups, and the rate of growth depends only partly on the population ageing. The number of new patients is expected to increase by 6 % in 2018.Ежегодно в мире выявляется более 1 000 000 новых случаев рака прямой кишки (РПК), вместе с раком ободочной кишки эта опухоль является четвертой по частоте причиной онкологической смертности.Цель исследования – анализ временных рядов и кратковременный прогноз заболеваемости раком прямой кишки у отдельных групп населения Архангельской области (АО).Материал и методы. Отобраны данные обо всех первичных случаях РПК в АО в 2000–15 гг. Рассчитаны грубые (вся популяция) и стандартизованные по мировому возрастному стандарту показатели (СВП) заболеваемости в зависимости от пола и района проживания (город или сельская местность). Для анализа вариаций использованных временных рядов и прогноза выбрана статистическая интегрированная модель авторегрессии скользящего среднего (ARIMA, autoregressive integrated moving average). Для приведения рядов к стационарному виду и уменьшения их дисперсии были взяты первые или вторые разности их значений и натуральные логарифмы. На стационарных рядах заболеваемости РПК в 2000–15 гг. построены модели и спрогнозированы значения для проверки точности прогноза. Построен прогноз для изучаемых уровней заболеваемости на период 2016–18 гг.Результаты. Грубые и стандартизованные по возрасту показатели заболеваемости РПК в АО возросли с 14,4 и 11,4 в 2000 г. до 23,5 и 15,1 на 100 000 населения в 2015 г. Соответствующие СВП для мужского, женского, городского, сельского населения возросли с 14,8; 10,1; 9,3 и 15,1 до 20,3; 12,6; 12,3 и 20,4 на 100 000 населения. Фактические значения уровней заболеваемости всего населения, мужского/женского и сельского/городского населения в 2015 г. находились в доверительном интервале прогноза. Построенная модель прогноза предполагает повышение уровней заболеваемости РПК во всех группах населения, что может привести к выявлению 279 новых случаев в 2018 г., или на 16 (6 %) больше, чем в 2015 г.Заключение. Показатели заболеваемости неуклонно повышались во всех анализируемых подгруппах, этот рост лишь частично связан со старением населения. Количество пациентов, нуждающихся в специальном лечении, в 2018 г. возрастет на 6 %
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
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
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
Usefulness of the updated logistic clinical SYNTAX score after percutaneous coronary intervention in patients with prior coronary artery bypass graft surgery: Insights from the GLOBAL LEADERS trial
Objectives: We aimed to investigate the prognostic utility of the anatomical CABG SYNTAX and logistic clinical SYNTAX scores for mortality after percutaneous coronary intervention (PCI) in patients with prior coronary artery bypass grafts (CABG). Background: The anatomical SYNTAX score evaluated the anatomical complexity of coronary artery disease and helped predict the prognosis of patients undergoing PCI. The anatomical CABG SYNTAX score was derived from the anatomical SYNTAX score in patients with prior CABG, whilst the logistic clinical SYNTAX score was developed by incorporating clinical factors into the anatomical SYNTAX score. Methods: We calculated the anatomical CABG SYNTAX score and logistic clinical SYNTAX score in 205 patients in the GLOBAL LEADERS trial. The predictive abilities of these scores for 2-year all-cause mortality were evaluated. Results: Using the median scores as categorical thresholds between low and high score groups, the logistic clinical SYNTAX score was able to discriminate the risk of 2-year mortality, unlike the anatomical CABG SYNTAX score. The logistic clinical SYNTAX was significantly better at predicting 2-year mortality, compared to the anatomical CABG SYNTAX score, as evidenced by AUC values in receiver-operating characteristic curve analysis (0.806 vs. 0.582, p <.001) and integrated discrimination improvement (0.121, p <.001). Conclusions: The logistic clinical SYNTAX score was superior to the anatomical CABG SYNTAX score in predicting 2-year mortality
Structural Insights into TIR Domain Specificity of the Bridging Adaptor Mal in TLR4 Signaling
MyD88 adaptor-like protein (Mal) is a crucial adaptor that acts as a bridge to recruit the MyD88 molecule to activated TLR4 receptors in response to invading pathogens. The specific assembly of the Toll/interleukin-1 receptor (TIR) domains of TLR4, Mal and MyD88 is responsible for proper signal transduction in the TLR4 signaling pathway. However, the molecular mechanism for the specificity of these TIR domains remains unclear. Here, we present the crystal structure of the TIR domain of the human Mal molecule (Mal-TIR) at a resolution of 2.4 Å. Unexpectedly, Mal-TIR exhibits an extraordinarily long AB loop, but no αB helix or BB loop, distinguishing it from other TIR domains. More importantly, the Mal-TIR AB loop is capable of mediating direct binding to the TIR domains of TLR4 and MyD88 simultaneously. We also found that Mal-TIR can form a back-to-back dimer that may resemble the dimeric assembly of the entire Mal molecule. Our data demonstrate the bridge role of the Mal-TIR domain and provide important information about TIR domain specificity
Prognostic impact of peritumoral lymphocyte infiltration in soft tissue sarcomas
<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to clarify the prognostic significance of peritumoral lymphocyte infiltration in the capsule of soft tissue sarcomas (STS). Multiple observations in preclinical and clinical studies have shown that the immune system has a role in controlling tumor growth and progression. Prognostic markers in potentially curable STS should guide therapy after surgical resection. The immune status at the time of resection may be important, but the prognostic significance of peritumoral lymphocytes is unknown.</p> <p>Methods</p> <p>Tissue microarrays from 80 patients with STS were constructed from duplicate cores of tissue from the tumor and the peritumoral capsule. Immunohistochemistry was used to evaluate the CD3+, CD4+, CD8+ and CD20+ lymphocytes in the tumor and the peritumoral capsule.</p> <p>Results</p> <p>In univariate analyses, increasing numbers of CD20+ (<it>P </it>= 0.032) peritumoral lymphocytes were associated with a reduced disease free survival (DSS). In multivariate analyses, a high number of CD20+ peritumoral lymphocytes (<it>P </it>= 0.030) in the capsule was an independent negative prognostic factor for DSS. There were no such associations of lymphocyte infiltration in the tumor.</p> <p>Conclusions</p> <p>A high density of CD20+ peritumoral lymphocytes is an independent negative prognostic indicator for patients with STS. Further research is needed to determine whether CD20 cells in the peritumoral capsule of STS may promote tumor invasion in the surrounding tissue and increase the metastatic potential.</p
Treatment of acquired drug resistance in multiple myeloma by combination therapy with XPO1 and topoisomerase II inhibitors
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