Sub-exponential mixing rate for a class of Markov chains

We establish sub-exponential bounds for the β-mixing rate and for the rate of convergence to invariant measures for discrete time Markov processes under recurrence type conditions weaker than used for exponential inequalities and stronger than for polynomial ones

Комбинированный способ дифференциальной диагностики кистозных неоплазий поджелудочной железы

Objective. The frequency of detection of cystic neoplasm of the pancreas (CNP) has recently increased. Some of these neoplasms are benign, while others are malignant. Differential diagnosis between benign and malignant CNP remains challenging.Aim: to develop a combined method for differential diagnosis of CNP and to evaluate the role of the neutrophil to leukocyte ratio (NLR) as a diagnostic criterion of malignant CNP.Material and Methods. A retrospective analysis of the treatment of 82 patients with CNP, who underwent surgery between 2008 and 2018, was carried out. Benign lesions were detected in 62 patients and malignant tumors were diagnosed in 20 patients. The NLR and the serum levels of CA 19-9 as well as the presence of intracystic lesions were assessed as predictors of malignant CNP.Results. The presence of intracystic lesions detected by contrast-enhanced computed tomography and the elevated levels of serum CA 19-9 (>39 U/mL) and NLI (>1.876) were proven to be independent predictors of malignant CNP with statistical significance. The combination of all three criteria indicated malignant cystic neoplasm. The sensitivity, specificity and overall accuracy of the combined method were 71.4 %, 95.6 % and 86.5%, respectively.Conclusions. The combined method for differential diagnosis of malignant CNP is easy to use and has high accuracy. There is a direct correlation between NLI and malignant CNP.Актуальность. Частота выявления кистозных неоплазий поджелудочной железы (КНПЖ) в последнее время растет. Некоторые из этих образований являются доброкачественными, в то время как другие имеют злокачественный характер. Дифференциальная диагностика доброкачественных и злокачественных КНПЖ остается серьезной клинической проблемой.Цель исследования - разработка комбинированного метода дифференциальной диагностики КНПЖ, а также изучение роли нейтрофильно-лейкоцитарного индекса (НЛИ) как диагностического критерия злокачественных КНПЖ.Материал и методы. Произведён ретроспективный анализ лечения 82 пациентов с КНПЖ, проходивших обследование и лечение в период с 2008 по 2018 г Все пациенты были прооперированы, у 62 из них диагностирован доброкачественный процесс, в 20 случаях обнаружены злокачественные образования на фоне КНПЖ. Произведен анализ НЛИ, уровня СА 19-9 в плазме крови, а также наличия контрастных внутрикистозных образований по данным компьютерной томографии как предикторов злокачественных КНПЖ.Результаты. Наличие контрастных внутрикистозных образований, по данным компьютерной томографии, повышение уровня СА 19-9 более 39 Ед/мл в плазме крови, а также уровня НЛИ >1,867 являются независимыми, статистически значимыми предикторами злокачественных КНПЖ. При сочетании всех трех параметров кистозное образование расценивается как злокачественное. Чувствительность, специфичность и общая точность разработанного комбинированного способа составляют 71,4, 95,6 и 86,5 % соответственно.Заключение. Разработанный комбинированный способ дифференциальной диагностики злокачественных КНПЖ является простым в применении, обладает достаточно высокой точностью. Имеется прямая корреляция НЛИ со злокачественными КНПЖ

γ-H2AX in recognition and signaling of DNA double-strand breaks in the context of chromatin

DNA double-strand breaks (DSBs) are extremely dangerous lesions with severe consequences for cell survival and the maintenance of genomic stability. In higher eukaryotic cells, DSBs in chromatin promptly initiate the phosphorylation of the histone H2A variant, H2AX, at Serine 139 to generate γ-H2AX. This phosphorylation event requires the activation of the phosphatidylinositol-3-OH-kinase-like family of protein kinases, DNA-PKcs, ATM, and ATR, and serves as a landing pad for the accumulation and retention of the central components of the signaling cascade initiated by DNA damage. Regions in chromatin with γ-H2AX are conveniently detected by immunofluorescence microscopy and serve as beacons of DSBs. This has allowed the development of an assay that has proved particularly useful in the molecular analysis of the processing of DSBs. Here, we first review the role of γ-H2AX in DNA damage response in the context of chromatin and discuss subsequently the use of this modification as a surrogate marker for mechanistic studies of DSB induction and processing. We conclude with a critical analysis of the strengths and weaknesses of the approach and present some interesting applications of the resulting methodology

Hypersound tomography of graphitized layers buried into diamond matrix

Acoustic properties of buried graphitized layers in diamond formed by ion implantation followed by annealing were studied using the picosecond ultrasonic technique with spatial resolution. Two methods of elastic pulse generation were used: heating an aluminum film deposited on a diamond sample by femtosecond laser pulses and direct illumination of the graphitized layers by these pulses. We applied a multilayered model of the acousto-optical response to fit experimental results and estimate the distribution of the acoustical parameters (wave resistance, viscoelastic damping, and longitudinal sound speed) of the structures under study in depth. It was found that unique sets of spectral lines are present in the Fourier spectra of measured responses in regions with different internal structures. Mapping of the Fourier spectra made it possible to visualize regions with different internal structures. The combined use of depth profiling and mapping can serve as a tool for hypersound tomography

RELAPSING POLYCHONDRITIS IN RHEUMATOLOGY PRACTICE

The paper provides a clinical description of relapsing polychondritis, a rare systemic immunoinflammatory disease that was characterized by fever episodes, cartilage damage, and reactive arthritis. Diagnostic searching could rule out an infectious disease (by determining a wide variety of potential pathogens), as well as a septic condition due to a pronounced leukemoid reaction of the myeloid type, and the presence of toxigenic neutrophil granulation in peripheral blood and bone marrow. All available clinical, functional, and radiological studies were used to make a differential diagnosis with paraneoplastic syndrome due to blood disease, primarily with myeloma. The data obtained could interpret the changes only as reactive. No increased autoantibody titers were identified. Clinical symptoms and the good effect of prednisolone therapy allowed a diagnosis of relapsing polychondritis, a rare disease that belongs to the group of immunoinflammatory diseases according to the current ideas. It is suggested that autoinflammation plays a role in its pathogenesis

Combined method for differential diagnosis of pancreatic cystic neoplasm

Objective. The frequency of detection of cystic neoplasm of the pancreas (CNP) has recently increased. Some of these neoplasms are benign, while others are malignant. Differential diagnosis between benign and malignant CNP remains challenging.Aim: to develop a combined method for differential diagnosis of CNP and to evaluate the role of the neutrophil to leukocyte ratio (NLR) as a diagnostic criterion of malignant CNP.Material and Methods. A retrospective analysis of the treatment of 82 patients with CNP, who underwent surgery between 2008 and 2018, was carried out. Benign lesions were detected in 62 patients and malignant tumors were diagnosed in 20 patients. The NLR and the serum levels of CA 19-9 as well as the presence of intracystic lesions were assessed as predictors of malignant CNP.Results. The presence of intracystic lesions detected by contrast-enhanced computed tomography and the elevated levels of serum CA 19-9 (>39 U/mL) and NLI (>1.876) were proven to be independent predictors of malignant CNP with statistical significance. The combination of all three criteria indicated malignant cystic neoplasm. The sensitivity, specificity and overall accuracy of the combined method were 71.4 %, 95.6 % and 86.5%, respectively.Conclusions. The combined method for differential diagnosis of malignant CNP is easy to use and has high accuracy. There is a direct correlation between NLI and malignant CNP