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

Model of broadband metamaterial for microwaves

In this work are presented, results of computer model operation of the structure executed from triangular elements with openings in the center. Results of mathematical calculation of amplitude and phase distribution of an electric field with use of CST Microwave studio are given. Also, calculation of the equivalent index of refraction when passing a plane wave through this structure is given

A comprehensive study of underground animals habitat

This paper describes a method of studying the natural habitats of underground animals by the example of zokor. The purpose of the research is to find habitation of animals using unmanned aircraft and investigate networks of tunnels and burrows with ground penetrating radar "OKO-2". Geolocation data were processed by techniques developed by the authors

Pancreatic fistula risk assessment after distal pancreatectomy: a retrospective controlled study

Background. Despite declining mortality, postoperative pancreatic fistula (PPF) remains a common complication of distal pancreatic resection surgery challenging to clinical prediction.Objectives. Prognostic analysis of the postoperative pancreatic fistula risk factors in patients with previous distal pancreatectomy.Methods. A retrospective controlled assay enrolled 107 patients, including 63 (58.9%) male and 44 (41.1%) female patients. All patients underwent distal pancreatectomy followed by a morphological examination of resected material. All patients had a general and biochemical blood panel profiling. Pancreatic tissue density at a putative resection zone was assessed with computed tomography. The patients were allocated to two cohorts: (1) not developing PPF (77 patients) and (2) having postoperative PPF complications (30 patients.Results. No statistically significant differences by age, gender, ASA and BMI scores were observed in study cohorts. Multivariate analysis revealed a statistically significant correlation of the PPF rate with the following factors: main pancreatic duct diameter <3 mm (odds ratio (OR) 1.02, 95% confidence interval (CI) 1.01–1.05, p = 0.01), pancreatic density at putative resection zone <30 HU in CT (OR 3.18, 95% CI 1.38–7.74, p < 0.01) and differential albumin of postoperative day 1 vs. pre-surgery >14 g/L (OR 3.13, 95% CI 1.19–8.24, p < 0.01).Conclusion. A main pancreatic duct diameter <3 mm, pancreatic density at putative resection zone <30 HU in CT and differential albumin of postoperative day 1 vs. pre-surgery >14 g/L are independent risk factors of postoperative fistulae

Application of broadband microwave near-field sensors for glucose monitoring in biological media

The paper presents results of numerical simulation and experimental testing of a microwave sensor for non-invasive glucose monitoring. The sensor represents a conical horn with a conical conductor inside expanding toward the horn aperture. Such a sensor has a significantly wider passband in comparison with sensors of other designs. It is essential that the sensor geometry provides formation of an extended near-field zone with high electric field strength near the sensor aperture. A clear relationship between the dielectric permittivity of the phantom biological tissue and the frequency dependence of the parameter S11 of the sensor is observed at frequencies in the range from 1.4 to 1.7 GHz. This circumstance can be used to develop a procedure for measuring the glucose level in blood that correlates with the parameter S11 of the sensor. From the viewpoint of monitoring of the glucose content in blood, the most convenient body sensor location is on the hands or feet, in particular, wrists

Study of oligotrophic bog by ground-penetrating radar

The work deals with study of peat deposits of oligotrophic bog and spatial distribution of snow cover by geolocation. Data from ground penetrating radar were compared with the data of conventional measurements of a peat depth and snow cover. A fairly good agreement between the thickness of the peat deposits, snow depth by using ground penetrating radar and the data of conventional measurements has been obtained

Oncogene advance online publication

Inadvertent mammalian tissue exposures to low doses of ionizing radiation (IR) after radiation accidents, remediation of radioactive-contaminated areas, space travel or a dirty bomb represent an interesting trauma to an organism. Possible low-dose IR-induced bystander effects could impact our evaluation of human health effects, as cells within tissue are not equally damaged after doses of IR p10 cGy. To understand tissue responses after low IR doses, we generated a reporter system using the human clusterin promoter fused to firefly luciferase (hCLUp-Luc). Secretory clusterin (sCLU), an extracellular molecular chaperone, induced by low doses of cytotoxic agents, clears cell debris. Low-dose IR (X2 cGy) exposure induced hCLUp-Luc activity with peak levels at 96 h, consistent with endogenous sCLU levels. As doses increased (X1 Gy), sCLU induction amplitudes increased and time-to-peak response decreased. sCLU expression was stimulated by insulin-like growth factor-1, but suppressed by p53. Responses in transgenic hCLUp-Luc reporter mice after low IR doses showed that specific tissues (that is, colon, spleen, mammary, thymus and bone marrow) of female mice induced hCLUp-Luc activity more than male mice after whole body (X10 cGy) irradiation. Tissue-specific, non-linear dose-and time-responses of hCLUp-Luc and endogenous sCLU levels were noted. Colon maintained homeostatic balance after 10 cGy. Bone marrow responded with delayed, but prolonged and elevated expression. Intraperitoneal administration of a-transforming growth factor (TGF)b1 (1D11), but not control (13C4) antibodies, immediately following IR exposure abrogated CLU induction responses. Induction in vivo also correlated with Smad signaling by activated TGFb1 after IR. Mechanistically, media with elevated sCLU levels suppressed signaling, blocked apoptosis and increased survival of TGFb1-exposed tumor or normal cells. Thus, sCLU is a pro-survival bystander factor that abrogates TGFb1 signaling and most likely promotes wound healing

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

К ВОПРОСУ ВЫБОРА ТАКТИКИ ЛЕЧЕНИЯ ПРИ МЕТАСТАТИЧЕСКОМ КОЛОРЕКТАЛЬНОМ РАКЕ

Treatment outcomes of 176 colorectal cancer patients with liver metastases were retrospectivelly analyzed. There were 86 men and 90 women in the age range 28 to 84 years. Multiple metastasis was detected in 79.5 % of patients and solitary metastasis in 20.5 % of patients. Cytoreductive surgery was performed in 30.7 % of patients and palliative surgery in 57.9 %. Surgical treatment was not performed in 5.1% of patients. The median survival time of patients after symptomatic surgeries was 10.8 months (1.5-26 months). Cytoreductive surgery increased the median survival time by more than 2 months (13 months, 2–44 months). Thus, radical surgery for colorectal cancer patients with liver metastases is justified by the increase in the median survival time of the patients.Проведен ретроспективный анализ результатов лечения 176 больных колоректальным раком с метастатическим поражением печени, в возрасте от 28 до 84 лет, в том числе 86 мужчин и 90 женщин. Множественное метастатическое поражение выявлено у 79,5 %, солитарное – у 20,5 % пациентов. Циторедуктивные операции выполнены у 30,7 % больных, паллиативные – у 57,9 %, у 5,1 % пациентов оперативное лечение не проводилось. Продолжительность жизни пациентов после симптоматических операций составила в среднем 10,8 мес (1,5–26 мес). Выполнение циторедуктивной операции увеличивает медиану жизни более чем на два месяца – до 13 мес (2–44 мес). Таким образом, целесообразность проведения радикальных оперативных вмешательств у пациентов с колоректальным раком и метастазами в печень подтверждается увеличением средней продолжительности жизни пациентов

H2AX phosphorylation screen of cells from radiosensitive cancer patients reveals a novel DNA double-strand break repair cellular phenotype

BACKGROUND: About 1-5% of cancer patients suffer from significant normal tissue reactions as a result of radiotherapy (RT). It is not possible at this time to predict how most patients' normal tissues will respond to RT. DNA repair dysfunction is implicated in sensitivity to RT particularly in genes that mediate the repair of DNA double-strand breaks (DSBs). Phosphorylation of histone H2AX (phosphorylated molecules are known as gammaH2AX) occurs rapidly in response to DNA DSBs, and, among its other roles, contributes to repair protein recruitment to these damaged sites. Mammalian cell lines have also been crucial in facilitating the successful cloning of many DNA DSB repair genes; yet, very few mutant cell lines exist for non-syndromic clinical radiosensitivity (RS).\ud \ud METHODS: Here, we survey DNA DSB induction and repair in whole cells from RS patients, as revealed by gammaH2AX foci assays, as potential predictive markers of clinical radiation response.\ud \ud RESULTS: With one exception, both DNA focus induction and repair in cell lines from RS patients were comparable with controls. Using gammaH2AX foci assays, we identified a RS cancer patient cell line with a novel ionising radiation-induced DNA DSB repair defect; these data were confirmed by an independent DNA DSB repair assay.\ud \ud CONCLUSION: gammaH2AX focus measurement has limited scope as a pre-RT predictive assay in lymphoblast cell lines from RT patients; however, the assay can successfully identify novel DNA DSB repair-defective patient cell lines, thus potentially facilitating the discovery of novel constitutional contributions to clinical RS