Аналитическое и экспериментальное исследование деформации деталей шарошечного долота

Distribution of load between the cutting elements of the roller cutter drill bit depends on several factors, among them on the stiffness of the drilling-bit assembly. To deduce the dependencies of the stiffness of the drilling-bit assembly on the drill bit design and the point of application of the external load, the scheme of static interaction of the rolling cutter drill bit with the non-deformable bottom hole is considered. The calculation results allow to conclude, that the vertical stiffness of the drilling bit assembly has a maximum value at the contact with the bottom hole of the middle teeth rows of the roller cutters. For verification of the results of the analytical calculations the experimental measurements of the vertical movements of the rolling cutters of the roller cutter drill bit at the contact of those with bottom hole with the teeth of the different teeth rows have been made. The proposed methodology can be used to optimize the design of the roller cutter drill bits at the blueprint stage.La distribución de la carga entre los elementos de un armamento de broca de rodillo depende de varios factores, incluida la rigidez del nudo de rodillo. Para obtener las dependencias de la rigidez de una junta de rodillo en el diseño de la broca y el punto de aplicación de una carga externa, se considera un esquema de interacción estática de una broca de rodillo con una cara no deformable. Los resultados del cálculo nos permiten concluir que la rigidez vertical del nudo del rodillo tiene un valor máximo en contacto con la parte inferior de los bordes centrales del cono del rodillo. Para verificar los resultados de los cálculos analíticos, se realizaron mediciones experimentales del movimiento vertical de los conos de bits cuando estaban en contacto con los dientes de varias coronas. La técnica propuesta se puede utilizar para optimizar el diseño de las brocas de rodillo en la etapa de diseño.Распределение нагрузки по элементам вооружения шарошечного долота зависит от ряда факторов, в том числе от жесткости шарошечного узла. Для получения зависимостей жесткости шарошечного узла от конструкции долота и точки приложения внешней нагрузки рассматривается схема статического взаимодействия шарошечного долота с недеформируемым забоем. Результаты расчетов позволяют сделать вывод о том, что вертикальная жесткость шарошечного узла имеет максимальное значение при контакте с забоем средних венцов шарошки. С целью проверки результатов аналитических расчетов проведены экспериментальные измерения вертикального перемещения шарошек долота при контакте их с забоем зубками различных венцов. Предлагаемая методика может использоваться для оптимизации конструкции шарошечных долот на стадии их проектирования

Neutrophil granulocytes: participation in homeostatic and reparative processes. Part II

A supportive homeostatic function of neutrophilic granulocytes is accomplished in the physiology of diverse tissues and body systems. Neutrophils are found along the entire female reproductive tract (FRT), gradually declining in numbers from the upper parts towards the vagina. At the same time, both quantity and activity of FRT mucosal neutrophils are controlled by hormonal changes at different phases of menstrual cycle. Tissue neutrophils serve as an important source of broad-spectrum proteolytic enzymes such as matrix metalloproteinases and elastase necessary for extracellular matrix remodeling as well as vascular endothelial growth factor (VEGF) required for physiological FRT angiogenesis. During pregnancy, decidual neutrophils play a prominent role in vascular remodeling in pregnant uterus as well as development of maternal-fetal immune tolerance. The influx of neutrophils into the intestinal mucosa due to its trauma or infection not only ensures defense against pathogens, but also leads to increased proliferation of intestinal epithelial cells. Neutrophilic granulocytes elicit signals and events protective for the epithelium by marking them with a “hypoxic signature” to trigger transcription of the gene set responsible for production of mucins, mucin-modifying peptides, antimicrobial proteins, в-defensins, ultimately contributing to lesion healing and recovery of epithelial barrier function. “Inflammatory hypoxia” initiated by neutrophils and subsequent stabilization of the transcription factor hypoxia-induced factor (HIF) in intestinal epithelial cells trigger mechanisms of self-limited and resolved inflammation, which prevent excessive accumulation of neutrophils in the intestinal lumen and development of chronic inflammatory process. Neutrophilic granulocytes dominate in the oral cavity mucosa and comprise more than 95% of total leukocyte population recruited into the gingival sulcus and gingival fluid. Neutrophils maintain physiological amount and stability of symbiotic microflora composition in dental and gingival biofilms, counteracting pathogenic bacteria via phagocytosis, degranulation and extracellular trap formation, thereby ensuring healthy state in periodontal structures. Finally, similar to some other congenital disorders affecting neutrophil quantity and functions it was shown that in case of leukocyte adhesion deficiency type 1 (LAD-1) pathogenesis of periodontitis may not only be associated with a defect in their protective effector activity, but also with altered immunoregulatory function of tissue neutrophils

Neutrophil granulocytes: participation in homeostatic and reparative processes. Part I

After exiting from the bone marrow (BM) into the circulation, mature neutrophil granulocytes undergo a set of sequential phenotypic and physiological changes collectively called “aging” in the absence of inflammation, by constitutively sensing prime signals from commensal microbiota and acquiring higher functional alertness in case of activation upon tissue damage or pathogen invasion. Physiological aging of blood neutrophils and their subsequent return to the BM result in signals modulating size and function of the hematopoietic niche. Circadian physiological infiltration of BM by neutrophils contributes to maintaining baseline level of circulating hematopoietic progenitor cells capable of regeneration and immune surveillance. Apart from the BM, neutrophils actively enter other healthy tissues, probably exerting some effects on their baseline physiologic state. Using lung tissue, it has been shown that neutrophils can “govern” action of gene set regulating cell growth, migration, proliferation, differentiation, and carcinogenesis. Neutrophils participate in destruction of endometrial tissues during desquamation phase as well as subsequent repair and physiological angiogenesis during proliferative phase of the menstrual cycle; promote wall rupture of the preovulatory ovarian follicle and oocyte exit; contribute to degradation and resorption of the corpus luteum in pregnancy failure; play an important physiological role in vascular remodeling in pregnant uterus and developing maternal immune tolerance to semi-allogeneic fetus. Neutrophils actively migrating to the surface of intestinal epithelium during local infection and/or damage stimulate epithelial restitution and recovery of its barrier function. On the other hand, neutrophils recruited into the oral cavity regulate quantitative and qualitative composition of microbial communities in oral biofilms, and ensure healthy state of periodontal structures. Being a major player and regulator in healing of skin wounds at early stage, inflammation, neutrophils not only destroy potential pathogens, but also participate in cleansing wounds from cell debris, produce cytokines, enzymes, and growth factors affecting further stages in repair process. Both apoptosis and NETosis underlying neutrophil death greatly contribute to wound healing. However, dysregulation and imbalance in both apoptosis and NETosis may lead to unfavorable consequences as well as developing chronic non-healing wounds

Diagnosis of Epilepsy: from the Beginning to the New Hybrid PET/MR Technique

The problem of diagnosis and treatment of epilepsy concerns medical society for a several thousands of years. The understanding of the causes and pathological mechanisms of this condition underwent numerous and substantial changes during this time, that allowed reaching significant advances in both the diagnosis or treatment. At the present time, there is a wide spectrum of diagnostic methods that allow localizing the epileptogenic focus, that is essential for planning the surgical treatment in patients with pharmacoresistant epilepsy. The results of the surgical treatment are strongly dependent on the diagnostic accuracy in the detection of one or several epileptogenic foci and on the prognosis of their resection. In this connection, the research on the possibilities and perfection of new diagnostic methods hold the potential to improve the results of the surgical treatment and the life quality in patients with pharmacoresistant epilepsy. This review presents a detailed description of the evolution of epilepsy diagnostics from the first implementation of electroencephalography in the 1920-s to the modern hybrid methods such as SISCOM (Subtraction Ictal SPECT Co-Registered to MRI) and PET-MRI

Разнообразие субпопуляций регуляторных Т-клеток

Regulatory T-lymphocytes play a central role in the immunological tolerance system. To date, existence of many different subpopulations of regulatory T-cells have been described. However, a number of questions related to the function, differentiation, and homeostasis of these subpopulations in a body remain unclear. Interactions between the previously discovered pairs of helper and regulatory T-lymphocytes require further study. The main topic is identification and establishment of the functions of regulatory memory cells. Interstitial migration of activated regulatory T-lymphocytes is also a promising direction. In this review, we summarized the main findings in multiple subsets of regulatory T-lymphocytes, discussed unclear data that will require further studies, and  showed an application for regulatory T-lymphocytes in medicine.Регуляторные Т-лимфоциты являются центральными клетками системы иммунологической толерантности. В настоящее время описано существование множества различных субпопуляций регуляторных Т-клеток (Treg), однако большое количество вопросов, касающихся функционального назначения, путей дифференцировки и гомеостаза этих субпопуляций в организме, остаются неизученными. Продемонстрированные ранее пары хелперов и соответствующих им регуляторных Т-лимфоцитов требуют дальнейшего изучения их взаимодействий друг с другом. Актуальной темой является идентификация и установление функций клеток регуляторной памяти. Тканевая миграция активированных регуляторных Т-лимфоцитов также является перспективным направлением. В этом обзоре собраны и систематизированы данные о различных субпопуляциях регуляторных Т-лимфоцитов, выделены актуальные вопросы данной тематики, требующие дальнейшего изучения, а также затронуты пути развития области в клинической медицине

Evaluation of the metabolism properties of choline kinase alpha in neoplasms of the parathyroid glands. A pilot study

BACKGROUND: Primary hyperparathyroidism (PHPT) is a widespread endocrine disease characterized by excessive production of parathyroid hormone (PTH) due to parathyroid gland hyperplasia (PGH) or tumor lesions (adenoma or cancer of the parathyroid gland (PG) in 80% and 1–5% of cases respectively). Choline kinase α–alpha (XKα) overexpression is described in tumors of different localization, but there is no data on its expression in PG tumors. AIMS: To study the character of XKα expression in PG neoplasms and its relationship with clinical, laboratory, and visualization characteristics (positron emission tomography combined with computed tomography (PET/CT) with 18F–fluorocholine (18F–FC)). MATERIALS AND METHODS: The material for the study was based on tissue samples from 10 patients of 34–70 years old (Me = 61.5; [48; 66]), with a laboratory–confirmed diagnosis of PHT. An immunohistochemical study (IHC) was carried out on materials from 2 patients with hyperplasia of the main cells, from 5 patients with adenoma of PG, from 1 patient with atypical adenoma and 1 with carcinoma of PG; in 1 case the metastasis of cancer of the neck with lymph node was examined. RESULTS: The expression of XKα is spotted in all types of PG cells (chief cells: active and inactive forms), transitional forms between the chief cells and oxyphil; oxyphil cells, but it was most intense in active chief cells. The expression of XKα was observed in neoplasms of PG of various degrees of malignancy. In the most numerous group of PG formations with a favorable prognosis (11 samples from 7 patients), no statistically significant correlation (p> 0.05) was obtained between the intensity expression of the XKα, of the PTH and the proliferative activity index Ki–67, the level of radiopharmaceutical accumulation in PET/CT with 18F–FC (SUVmax) and laboratory data (PTH, Ca, Ca++). CONCLUSIONS: In the majority of investigated cases, moderate and intensive expression of the XKα was detected in PG cells. A small amount of studied cases does not allow us to identify the connection between the intensity of XKα expression and the malignant potential for the formation of PG

The formation process of extracellular DNA - additional diagnostic criterion for definition grade of breast carcinoma

Neutrophil granulocytes, being a permanent structure in the palette of the «microenvironment» tumors lay a different role in oncogenes. In response to tumor cells incentives neutrophils actively shape in the extracellular space setuptable structure consisting of nucleic acids and enzymes - neutrophil extracellular nets. It was noticed, that in the tumor tissue, breast carcinoma near the tumor cells is diffuse and clusters distributed free cell DNA.lt has been shown that neutrophils when meeting with tumor cells become activated and begin to form a free cell extracellular DNA around themwith various level proliferation activity.Нейтрофильные гранулоциты, являясь постояннымэлементом в составе микроокружения опухолей, играют неоднозначную роль в онкогенезе. В ответ на появление опухолевых клеток, нейтрофилы активно формируют во внеклеточном пространстве сетеподобные структуры, состоящие из нуклеиновых кислот и ферментов - нейтрофильные внеклеточные ловушки. Нами было показано, что в ткани карциномы молочной железы рядом с опухолевыми клетками диффузно и скоплениями распределяется внеклеточная ДНК.Установлено, что нейтрофилы при встрече с опухолевыми клетками активируются иначинают формироватьвнеклеточные сети ДНКвокругних с различной интенсивностью в зависимости от уровня пролиферативной активности опухоли

Possible climate-related signals in high-resolution topography of lobate debris aprons in Tempe Terra, Mars

Lobate debris aprons are common features in the midlatitudes of Mars that are assumed to be the result of the flow of ice-rich material. We produce high-resolution digital elevation models of two of these features in the Tempe Terra region of Mars using HiRISE stereo images. We identify two main topographic features of different wavelength using a power spectrum analysis approach. Short wavelength features, between approximately 10 and 20 m in length, correspond to a polygonal surface texture present throughout our study area. Long wavelength features, between approximately 700 and 1800 m in length, correspond to broad ridges that are up to 20 m in amplitude. We interpret both topographic signals to be the likely result of climate change affecting the debris contribution and/or the flow regime of the lobate debris aprons. The apparent surface age of about 300 Ma could be evidence of an astronomical forcing mechanism recorded in these lobate debris aprons at this time in Mars' history. Citation: Grindrod, P. M., and S. A. Fawcett (2011), Possible climate-related signals in high-resolution topography of lobate debris aprons in Tempe Terra, Mars, Geophys. Res. Lett., 38, L19201, doi: 10.1029/2011GL049295

Clinical immunological characteristics of the patients with chronic generalized parodontitis

Clinical immunological study of 99 patients with CHGP and 25 clinically healthy persons with intact paradont was carried out. A number ot disorders of cellular and humoral immunity and functional neutrophils activity of peripheral blood is revealed among the patients with chronic generalized parodontitis. The intensity of immune disorders depends on the severity of parodontitis. The interrelation of inflammatory destructive processes in parodontium tissues and disorders in cellular and humoral immunity chains as well as functional neutrophils activity is proved by the correlation relationship.Проведено клинико-иммунологическое обследование 99 пациентов с ХГП и 25 клинически здоровых лиц с интактным пародонтом. У пациентов с ХГП выявлены нарушения ряда показателей клеточного и гуморального иммунитета, функциональной активности нейтрофилов периф ерической крови. Выраженность нарушений иммунитета зависела от степени тяжести пародонтита. Взаимозависимость воспалительно-деструктивных процессов в тканях пародонта и нарушений в клеточном и гуморальном звеньях иммунитета, функциональной активности нейтрофилов подтверждена корреляционной связью