Surgical management of pterygium verum-historical review, current approaches

Истинският птеригиум, традиционно описван като дегенеративна лезия на конюнктивата, представлява често срещано заболяване на очната повърхност. Представя се като криловидна по форма фиброваскуларна пролиферация на булбовата конюнктива, която инвазира роговицата в посока от корнеосклералния лимб към центъра й и предизвиква деструкция на повърхностните корнеални слоеве. Птеригиумът, подобно на други слънчево-обусловени очни заболявания (т.нар. офталмохелиози), се смята че се развива при продължително въздействие на УВ-лъчи върху очната повърхност. Основен момент в патогенезата на заболяването е локалният дефицит на лимбални стволови клетки в интерпалпебралната зона. Независимо от наличието на многобройни и разнообразни техники за хирургична лечение на птеригиума, все още сериозен проблем представлява високия процент на рецидиви, вероятно дължащ се на все още не напълно изяснената етнопатогенеза на заболяването, поради което търсенето на идеалната хирургична техника все още продължава. Целта на настоящата статия е да се направи кратък преглед на съществувалите в исторически аспект методи за лечение на птеригиума, както и на съвременните подходи за третиране на заболяването.Pterygium verum, traditionally described as a degenerative disorder of the conjunctiva, is a common disease of the ocular surface. It is a wing-shaped fibrovascular proliferation of the bulbar conjunctiva, which encroaches onto the adjacent cornea in direction from the corneoscleral limbus to the center of the cornea and leads to destruction of the surface corneal layers. Pterygium, as the other sun-related eye diseases (the ophthalmohelioses), is considered to develop after a long and intensive insolation (in? uence of sun radiation, mainly UV-B lights) into ocular surface. According to current concepts, the main cause for the development of pterygium is the local deficiency of lmbal stem cells in the interpalpebral area. Although, there are a great variety of different techniques and methods for surgical treatment, nowadays the pterygium is still a surgical problem because of the high percent of the recurrences, probably as a result of the incompletely understood ethiopathogenesis of the disease and searching for the perfect surgical procedure without recurrences continues. The aim of this article is to summarize the surgical techniques and approaches in historical plan and to reveal the current concepts and methods for surgical treatment of pterygium

The State and Moods of Civil Society on the Example of a Sociological Study of Public Organizations

The article presents the results of a study of the state and mood of civil society from the standpoint of a political and sociological approach. The definition of the state of civil society, its features and components is proposed. The complexity and inconsistency of attitudes among young people as a reference group is analyzed.The study also compared some indicators with previous similar studies and some dynamics of the state of the reference group in connection with the conduct of ITS. The competitive parameters that have received dynamics and their connection with the general mood in the youth environment are determined.The study was conducted in order to identify the parameters of subjects exclusively within the framework of civil society and did not consider the marginalizing component and processes outside civil society.For further research, a reference group is provided with a description of the properties of the group and parameters for segmentation and identification of related processes

Optimum design of hydrodynamic thrust bearings with rayleigh's pocket profiles

Optimum design problem for hydrodynamic self-aligning acting thrust bearings was considered. Based on results for rectangular region the problem for sector region was solved. As an objective function, the maximum of pressure integral over the lubricant layer surface was used and five geometrical parameters described Rayleigh's pocket shape were used as optimization variables during optimization procedure. The bearing pressure distribution was determined on the basis of the Navier-Stokes equations using the ANSYS / CFX software. Numerically the optimization problem was solved using three different methods: IOSO, SIMPLEX and pilOPT+AFilter SQP realized in two commercial optimization software IOSO and modeFRONTIER. The aim of this investigation was designing the technologically advanced profiles of thrust bearing sector microgeometry ensuring the maximum load capacity

Экспериментальная оценка состязательных атак на глубокие нейронные сети при решении задач распознавания медицинских изображений

This paper addresses the problem of dependence of the success rate of adversarial attacks to the deep neural networks on the biomedical image type and control parameters of generation of adversarial examples. With this work we are going to contribute towards accumulation of experimental results on adversarial attacks for the community dealing with biomedical images. The white-box Projected Gradient Descent attacks were examined based on 8 classification tasks and 13 image datasets containing more than 900 000 chest X-ray and histology images of malignant tumors. An increase of the amplitude and the number of iterations of adversarial perturbations in generating malicious adversarial images leads to a growth of the fraction of successful attacks for the majority of image types examined in this study. Histology images tend to be less sensitive to the growth of amplitude of adversarial perturbations. It was found that the success of attacks was dropping dramatically when the original confidence of predicting image class exceeded 0,95.Исследуются обнаруженные несколько лет назад проблемы уязвимости глубоких нейронных сетей к так называемым состязательным атакам, которые заставляют сеть принимать ошибочные классификационные решения. Состязательные атаки осуществляются с помощью «атакующих» изображений – незначительно модифицированных версий исходных. Целью работы является изучение зависимости успеха состязательных атак от типа распознаваемых биомедицинских изображений и значений управляющих параметров алгоритмов генерации их атакующих версий. Экспериментальные исследования проводились на примере решения восьми типичных задач медицинской диагностики с использованием глубокой нейронной сети InceptionV3, а также 13 наборов, содержащих более чем 900 000 рентгеновских изображений грудной клетки и гистологических изображений злокачественных опухолей. С увеличением амплитуды вредоносного возмущения и количества итераций генерации зловредного шума вероятность ошибки классификации растет. В то же время различные типы изображений демонстрируют разную чувствительность к данном параметрам. Изображения, которые изначально классифицировались сетью с уверенностью более 95 %, гораздо более устойчивы к атакам. Нейронные сети, обученные для классификации гистологических изображений, оказались более устойчивы к состязательным атакам нежели сети, обученные для классификации рентгеновских изображений

Компьютеризированная диагностика рака простаты на основе полнослайдовых гистологических изображений и методов глубокого обучения

This paper presents the results of an experimental study and the development of tools for automatic analysis and recognition of histological images in order to obtain quantitative estimates of the presence and degree of aggressiveness of prostate cancer in the commonly used Gleason and ISUP scales. The input data consisted of 10 616 whole-slide histological images with the size of the largest side up to 100 000 pixels and22 089 of their image tiles of 256×256 pixels in size. Two solutions were chosen as the final ones. The first solution is based on sequential analysis of image fragments and includes feature extraction using the ResNet50 network and the subsequent generalization of particular recognition results using a small convolutional network. The second solution is based on the simultaneous analysis of the selected informative sections, presented in the form of an intermediate pseudo-image, and its subsequent recognition using an ensemble of four variants of convolutional networks with the EfficientNetB0 architecture. Being independently tested on an unknown image dataset that was not available for authors, these approaches achieved the prediction accuracy of 0,9277 according to the ISUP scale.Представлены результаты экспериментальных исследований и разработки средств автоматического анализа и распознавания гистологических изображений с целью получения количественных оценок наличия и степени агрессивности рака простаты в общепринятых шкалах Глисона  и ISUP. В качестве исходных данных использовались 10 616 полнослайдовых гистологических изображений с размером большей стороны до 100 000 пикселов и 22 089 их фрагментов размером 256×256 пикселов. Проведена оценка эффективности решения задачи с применением как традиционных методов, так и методов глубокого обучения. В качестве финальных выбраны два решения. Первое решение основано на последовательном анализе фрагментов изображений и включает выделение признаков с использованием сети ResNet50 и последующим обобщением частных результатов распознавания с помощью небольшой сверточной сети. Второе решение базируется на одновременном анализе отобранных информативных участков, представленных в виде промежуточного псевдоизображения, и последующем его распознавании с использованием ансамбля из четырех вариантов сверточных сетей с архитектурой EfficientNetB0. В результате независимого тестирования на закрытом наборе изображений, недоступных авторам, достигнута точность предсказания финальной оценки по шкале ISUP, равная 0,9277

INVESTIGATION OF THE DOSE DEPENDENCE OF DETECTORS BASED ON Аl2O3

Thermostimulated luminescence occurs when a solid is heated, which is previously irradiated by ionizing radiation. Dose limit is proportional to the maximum number of electrons captured by detector traps. Thermooptical processing allows to change concentration of oxygen vacancies

Genome Instability and Transcription Elongation Impairment in Human Cells Depleted of THO/TREX

THO/TREX connects transcription with genome integrity in yeast, but a role of mammalian THO in these processes is uncertain, which suggests a differential implication of mRNP biogenesis factors in genome integrity in yeast and humans. We show that human THO depletion impairs transcription elongation and mRNA export and increases instability associated with DNA breaks, leading to hyper-recombination and γH2AX and 53BP1 foci accumulation. This is accompanied by replication alteration as determined by DNA combing. Genome instability is R-loop–dependent, as deduced from the ability of the AID enzyme to increase DNA damage and of RNaseH to reduce it, or from the enhancement of R-loop–dependent class-switching caused by THOC1-depletion in CH12 murine cells. Therefore, mammalian THO prevents R-loop formation and has a role in genome dynamics and function consistent with an evolutionary conservation of the functional connection between these mRNP biogenesis factors and genome integrity that had not been anticipated

Tailor-Made Zinc-Finger Transcription Factors Activate FLO11 Gene Expression with Phenotypic Consequences in the Yeast Saccharomyces cerevisiae

Cys2His2 zinc fingers are eukaryotic DNA-binding motifs, capable of distinguishing different DNA sequences, and are suitable for engineering artificial transcription factors. In this work, we used the budding yeast Saccharomyces cerevisiae to study the ability of tailor-made zinc finger proteins to activate the expression of the FLO11 gene, with phenotypic consequences. Two three-finger peptides were identified, recognizing sites from the 5′ UTR of the FLO11 gene with nanomolar DNA-binding affinity. The three-finger domains and their combined six-finger motif, recognizing an 18-bp site, were fused to the activation domain of VP16 or VP64. These transcription factor constructs retained their DNA-binding ability, with the six-finger ones being the highest in affinity. However, when expressed in haploid yeast cells, only one three-finger recombinant transcription factor was able to activate the expression of FLO11 efficiently. Unlike in the wild-type, cells with such transcriptional activation displayed invasive growth and biofilm formation, without any requirement for glucose depletion. The VP16 and VP64 domains appeared to act equally well in the activation of FLO11 expression, with comparable effects in phenotypic alteration. We conclude that the functional activity of tailor-made transcription factors in cells is not easily predicted by the in vitro DNA-binding activity

Variation in the provision and practice of implant-based breast reconstruction in the UK: Results from the iBRA national practice questionnaire

Introduction The introduction of biological and synthetic meshes has revolutionised the practice of implant-based breast reconstruction (IBBR) but evidence for effectiveness is lacking. The iBRA (implant Breast Reconstruction evAluation) study is a national trainee-led project that aims to explore the practice and outcomes of IBBR to inform the design of a future trial. We report the results of the iBRA National Practice Questionnaire (NPQ) which aimed to comprehensively describe the provision and practice of IBBR across the UK. Methods A questionnaire investigating local practice and service provision of IBBR developed by the iBRA Steering Group was completed by trainee and consultant leads at breast and plastic surgical units across the UK. Summary data for each survey item were calculated and variation between centres and overall provision of care examined. Results 81 units within 79 NHS-hospitals completed the questionnaire. Units offered a range of reconstructive techniques, with IBBR accounting for 70% (IQR:50–80%) of participating units' immediate procedures. Units on average were staffed by 2.5 breast surgeons (IQR:2.0–3.0) and 2.0 plastic surgeons (IQR:1.0–3.0) performing 35 IBBR cases per year (IQR:20-50). Variation was demonstrated in the provision of novel different techniques for IBBR especially the use of biological (n = 62) and synthetic (n = 25) meshes and in patient selection for these procedures. Conclusions The iBRA-NPQ has demonstrated marked variation in the provision and practice of IBBR in the UK. The prospective audit phase of the iBRA study will determine the safety and effectiveness of different approaches to IBBR and allow evidence-based best practice to be explored

Multiple Signals Converge on a Differentiation MAPK Pathway

An important emerging question in the area of signal transduction is how information from different pathways becomes integrated into a highly coordinated response. In budding yeast, multiple pathways regulate filamentous growth, a complex differentiation response that occurs under specific environmental conditions. To identify new aspects of filamentous growth regulation, we used a novel screening approach (called secretion profiling) that measures release of the extracellular domain of Msb2p, the signaling mucin which functions at the head of the filamentous growth (FG) MAPK pathway. Secretion profiling of complementary genomic collections showed that many of the pathways that regulate filamentous growth (RAS, RIM101, OPI1, and RTG) were also required for FG pathway activation. This regulation sensitized the FG pathway to multiple stimuli and synchronized it to the global signaling network. Several of the regulators were required for MSB2 expression, which identifies the MSB2 promoter as a target “hub” where multiple signals converge. Accessibility to the MSB2 promoter was further regulated by the histone deacetylase (HDAC) Rpd3p(L), which positively regulated FG pathway activity and filamentous growth. Our findings provide the first glimpse of a global regulatory hierarchy among the pathways that control filamentous growth. Systems-level integration of signaling circuitry is likely to coordinate other regulatory networks that control complex behaviors