226 research outputs found
Cell transformation assays for prediction of carcinogenic potential: State of the science and future research needs
Copyright @ 2011 The Authors. This is an Open Access article distributed under the terms of the Creative Commons Attribution Non-Commercial License (http://creativecommons.org/licenses/by-nc/3.0), which permits
unrestricted non-commercial use, distribution, and reproduction in any medium, provided the original work is properly cited.Cell transformation assays (CTAs) have long been proposed as in vitro methods for the identification of potential chemical carcinogens. Despite showing good correlation with rodent bioassay data, concerns over the subjective nature of using morphological criteria for identifying transformed cells and a lack of understanding of the mechanistic basis of the assays has limited their acceptance for regulatory purposes. However, recent drivers to find alternative carcinogenicity assessment methodologies, such as the Seventh Amendment to the EU Cosmetics Directive, have fuelled renewed interest in CTAs. Research is currently ongoing to improve the objectivity of the assays, reveal the underlying molecular changes leading to transformation and explore the use of novel cell types. The UK NC3Rs held an international workshop in November 2010 to review the current state of the art in this field and provide directions for future research. This paper outlines the key points highlighted at this meeting
Методы мониторинга земель, занятых объектами для размещения отходов животноводства и птицеводства
The extraordinary evolutionary history of the reticuloendotheliosis viruses
The reticuloendotheliosis viruses (REVs) comprise several closely related amphotropic retroviruses isolated from birds. These viruses exhibit several highly unusual characteristics that have not so far been adequately explained, including their extremely close relationship to mammalian retroviruses, and their presence as endogenous sequences within the genomes of certain large DNA viruses. We present evidence for an iatrogenic origin of REVs that accounts for these phenomena. Firstly, we identify endogenous retroviral fossils in mammalian genomes that share a unique recombinant structure with REVs—unequivocally demonstrating that REVs derive directly from mammalian retroviruses. Secondly, through sequencing of archived REV isolates, we confirm that contaminated Plasmodium lophurae stocks have been the source of multiple REV outbreaks in experimentally infected birds. Finally, we show that both phylogenetic and historical evidence support a scenario wherein REVs originated as mammalian retroviruses that were accidentally introduced into avian hosts in the late 1930s, during experimental studies of P. lophurae, and subsequently integrated into the fowlpox virus (FWPV) and gallid herpesvirus type 2 (GHV-2) genomes, generating recombinant DNA viruses that now circulate in wild birds and poultry. Our findings provide a novel perspective on the origin and evolution of REV, and indicate that horizontal gene transfer between virus families can expand the impact of iatrogenic transmission events
Моделирование процесса синтеза в воздушной плазме оксидных композиций для дисперсионного плутоний-ториевого ядерного топлива
Целью работы являлось исследование процесса плазмохимического синтеза наноразмерных оксидных композиций для дисперсионного плутоний-ториевого ядерного топлива из водно-органических нитратных растворов (ВОНР). В результате было показано, что плазменная переработка диспергированных растворов ВОНР в воздушно-плазменном потоке позволяет осуществлять плазмохимический синтез наноразмерных порошков оксидных композиций с высокими физико-химическими и технологическими свойствами.The aim of this paper was to study the process of plasma-chemical synthesis of nanosized oxide compositions for dispersive plutonium-thorium nuclear fuel from water-organic nitrate solutions (WONS). As a result, it was shown that the plasma processing of dispersed WONS solutions in an air-plasma flow allows plasma-chemical synthesis of nanosized powders of oxide compositions with high physical, chemical and technological properties
Encrypted federated learning for secure decentralized collaboration in cancer image analysis.
Artificial intelligence (AI) has a multitude of applications in cancer research and oncology. However, the training of AI systems is impeded by the limited availability of large datasets due to data protection requirements and other regulatory obstacles. Federated and swarm learning represent possible solutions to this problem by collaboratively training AI models while avoiding data transfer. However, in these decentralized methods, weight updates are still transferred to the aggregation server for merging the models. This leaves the possibility for a breach of data privacy, for example by model inversion or membership inference attacks by untrusted servers. Somewhat-homomorphically-encrypted federated learning (SHEFL) is a solution to this problem because only encrypted weights are transferred, and model updates are performed in the encrypted space. Here, we demonstrate the first successful implementation of SHEFL in a range of clinically relevant tasks in cancer image analysis on multicentric datasets in radiology and histopathology. We show that SHEFL enables the training of AI models which outperform locally trained models and perform on par with models which are centrally trained. In the future, SHEFL can enable multiple institutions to co-train AI models without forsaking data governance and without ever transmitting any decryptable data to untrusted servers
Технологические решения для строительства эксплуатационной наклонно-направленной скважины с горизонтальным участком на целевой пласт Ю1 нефтяного месторождения
Объектом исследования является эксплуатационная наклонно-направленная скважина с горизонтальным участком глубиной 3894 метров. Целью работы является- проектирование технологического решения для бурения эксплуатационной наклонно-направленной скважины с горизонтальным участком глубиной 3894 метров. Для достижения цели были поставлены следующие задачи:
1. Детальный анализ общей геологической части месторождения;
2. Проектирование актуальной конструкции скважины для данных геологических условий;
3. Проектирование оптимального оборудования для бурения скважины параметров и свойств бурового раствора;
4. Проектирование процессов закачивания скважины;
5. Финансовый расчёт сметной стоимости бурения и крепления скважины;
6. Анализ вредных факторов на производстве и их влияние на человека.The object of the research is an operational directional borehole with a horizontal section 3894 meters deep. The purpose of the work is to design a technological solution for drilling an operational directional borehole with a horizontal section with a depth of 3894 meters. To achieve this goal, the following tasks were set:
1. A detailed analysis of the general geological part of the field;
2. Designing the actual design of the hole for given geological conditions;
3. Designing optimal equipment for drilling borehole parameters and properties of the drilling fluid;
4. Design of well injection processes;
5. Financial calculation of the estimated cost of drilling and borehole fixing;
6. Analysis of harmful factors in the workplace and their impact on humans
Protocol of a randomized, double-blind, placebo-controlled, parallel-group, multicentre study of the efficacy and safety of nicotinamide in patients with Friedreich ataxia (NICOFA)
Introduction: Currently, no treatment that delays with the progression of Friedreich ataxia is available. In the
majority of patients Friedreich ataxia is caused by homozygous pathological expansion of GAA repeats in the first
intron of the FXN gene. Nicotinamide acts as a histone deacetylase inhibitor. Dose escalation studies have shown,
that short term treatment with dosages of up to 4 g/day increase the expression of FXN mRNA and frataxin protein
up to the levels of asymptomatic heterozygous gene carriers. The long-term effects and the effects on clinical
endpoints, activities of daily living and quality of life are unknown.
Methods: The aim of the NICOFA study is to investigate the efficacy and safety of nicotinamide for the treatment of
Friedreich ataxia over 24 months. An open-label dose adjustment wash-in period with nicotinamide (phase A: weeks 1–4)
to the individually highest tolerated dose of 2–4 g nicotinamide/day will be followed by a 2 (nicotinamide group): 1
(placebo group) randomization (phase B: weeks 5–104). In the nicotinamide group, patients will continue with their
individually highest tolerated dose between 2 and 4 g/d per os once daily and the placebo group patients will be
receiving matching placebo. Safety assessments will consist of monitoring and recording of all adverse events and serious
adverse events, regular monitoring of haematology, blood chemistry and urine values, regular measurement of vital signs
and the performance of physical examinations including cardiological signs. The primary outcome is the change in the
Scale for the Assessment and Rating of Ataxia (SARA) over time as compared with placebo in patients with Friedreich
ataxia based on the linear mixed effect model (LMEM) model. Secondary endpoints are measures of quality of life,
functional motor and cognitive measures, clinician’s and patient’s global impression-change scales as well as the upregulation of the frataxin protein level, safety and survival/death.
Perspective: The NICOFA study represents one of the first attempts to assess the clinical efficacy of an epigenetic
therapeutic intervention for this disease and will provide evidence of possible disease modifying effects of nicotinamide
treatment in patients with Friedreich ataxia
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