The Compton neutron Hafnium detector: electric charge generation rate

The properties of a Compton neutron detector with the emitter of metallic Hf were studying in this work. Using the previously calculated the emitter material nuclide composition during reactor irradiation, the dependence of the emitter signal value on the irradiation time was obtained with a step of 1 year for 5 years. It is shown that the composition modification due to nuclear transmutations changes the rate of an electric charge generation in the emitter.Досліджувалися властивості комптонівського нейтронного детектора з емітером із металічного Hf. Використовуючи розрахований раніше нуклідний склад матеріалу емітера в умовах реакторного опромінення, отримано залежність значення сигналу емітера від часу опромінення з кроком 1 рік протягом 5 років. Показано, що модифікація складу внаслідок ядерних трансмутацій змінює швидкість генерації електричного заряду в емітері.Изучались свойства комптоновского детектора нейтронов с эмиттером из металлического Hf. Используя ранее рассчитанный нуклидный состав материала эмиттера при облучении реактора, была получена зависимость величины сигнала эмиттера от времени облучения с шагом 1 год в течение 5 лет. Показано, что модификация состава за счет ядерных трансмутаций изменяет скорость генерации электрического заряда в эмиттере

Simple, Efficient CRISPR-Cas9-Mediated Gene Editing in Mice: Strategies and Methods.

Genetic modification of almost any species is now possible using approaches based on targeted nucleases. These novel tools now bypass previous limited species windows, allowing precision nucleotide modification of the genome at high efficiency, rapidly and economically. Here we focus on the modification of the mouse genome; the mouse, with its short generation time and comparatively low maintenance/production costs is the perfect mammal with which to probe the genome to understand its functions and complexities. Further, using targeted nucleases combined with homologous recombination, it is now possible to precisely tailor the genome, creating models of human diseases and conditions directly and efficiently in zygotes derived from any mouse strain. Combined these approaches make it possible to sequentially and progressively refine mouse models to better reflect human disease, test and develop therapeutics. Here, we briefly review the strategies involved in designing targeted nucleases (sgRNAs) providing solutions and outlining in detail the practical processes involved in precision targeting and modification of the mouse genome and the establishing of new precision genetically modified mouse lines. Methods Mol Biol 2016; 1438:19-5

Compton-emissive hafnium detector of neutrons for in-core monitoring

The work is devoted to substantiating the use of metallic hafnium as the emitter of the Compton (prompt-response) in-core detector of thermal and resonant neutrons. The main trends in the development of nuclear power engineering, which raise the interest in the use of hafnium, are considered. The known data on the behavior of both Compton and β-emission self-powered neutron detectors (SPND) are generalized. The Compton SPND signal formation mechanism for the case of the irradiation by reactor-type fluxes of neutrons and gamma quanta is considered. The paper presents the calculation result of the hafnium burning-out degree for the conditions of WWER and RBMK reactors. The influence of the gamma radiation “sources”, which provide the largest contribution to the electrons production in the detector is considered

The perfect host: a mouse host embryo facilitating more efficient germ line transmission of genetically modified embryonic stem cells.

There is a continual need to improve efficiency in creating precise genetic modifications in mice using embryonic stem cells (ESCs). We describe a novel approach resulting in 100% germline transmission from competent injected ESCs. We developed an F1 mouse host embryo (Perfect Host, PH) that selectively ablates its own germ cells via tissue-specific induction of diphtheria toxin. This approach allows competent microinjected ESCs to fully dominate the germline, eliminating competition for this critical niche in the developing and adult animal. This is in contrast to conventional methods, where competition from host germ cells results in offspring derived from host cells and ESCs, necessitating extensive breeding of chimeras and genotyping to identify germline. The germline transmission process is also complicated by variability in the actual number of ESCs that colonize the germline niche and the proportion that are germline competent. To validate the PH approach we used ESC lines derived from 129 F1, BALB/cByJ, and BTBR backgrounds as well as an iPS line. Resulting chimeric males produced 194 offspring, all paternally derived from the introduced stem cells, with no offspring being derived from the host genome. We further tested this approach using eleven genetically modified C57BL/6N ESC lines (International Knockout Mouse Consortium). ESC germline transmission was observed in 9/11 (82%) lines using PH blastocysts, compared to 6/11 (55%) when conventional host blastocysts were used. Furthermore, less than 35% (83/240) of mice born in the first litters from conventional chimeras were confirmed to be of ESC-origin. By comparison, 100% (137/137) of the first litter offspring of PH chimeras were confirmed as ESC-derived. Together, these data demonstrate that the PH approach increases the probability of germline transmission and speeds the generation of ESC derived animals from chimeras. Collectively, this approach reduces the time and costs inherent in the production of genetically modified animals. PLoS One 2013; 8(7):e6782

Transport properties and spectrometric performances of CdZnTe gamma-ray detectors

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