Fabrication and testing of negative-limited sealed nickel-cadmium cells

The design, construction, and testing of 100,20Ah and 100,3Ah negative-limited sealed cells are reported. The required physical dimensions of the hardware and components necessary to produce 20 and 3 Ah cells were established. The stainless steel cans and covers have been ordered. The covers contain two ceramic seals. The fabrication of electrodes was started. About 55% (879 electrodes) of the required cadmium electrodes has been prepared. About 44% of the porous nickel substrates (plaques) required for the preparation of the nickel oxide electrodes has been completed

Improved plaque materials for aerospace nickel-cadmium cells

Improved cadmium electrode substrates with precisely controlled microstructures for possible use in aerospace nickel-cadmium cells were prepared. The preparative technique was a powder metallurgical process in which a fugitive pore-former and a nickel powder were blended, then isostatically compacted, and subsequently sintered. Cadmium electrodes prepared from such substrates were cycle tested using an accelerated tortuous test regime. It was discovered that plaques of 60% or 80% porosity prepared with a 25 micron pore-former were better than state-of-the-art electrodes in terms of efficienty and/or mechanical strength. The 60% structures were particularly outstanding in this respect in that they had efficiencies only 5-10 percentage points lower than state-of-the-art electrodes and vastly superior mechanical properties. This added strength was observed to eliminate cracking and physical degradation of the electrodes during processing and cycling. The cadmium electrodes prepared from the 80% porous substrates proved to be the best electrodes made during the course of the work from the point of view of highest efficiency. Three-point bend tests were used to measure mechanical properties of the plaques produced and also as a general characterization tool. In addition, the BET surface areas of selected specimens was determined. The SEM was used for judging microscopic uniformity and quantitatively determining the induced pore size and various other fine structures in the substrates. The technique of X-ray radiography was used to follow the bulk uniformity of the substrates at various stages of their processing

PARAFFIN: AN ECONOMIC AND ECOLOGICAL ALTERNATIVE FOR BONE CONSERVATION

Fragile bone materials are ubiquitous in archaeological museum and forensic settings. Although there are many chemical and industrial options for conservation, these may adversely affect the bone objects undergoing preservative treatment. Here, paraffin is explored as a biologically friendly alternative to bone material conservation. Modern domestic pig ribs were subjected to paraffin treatment and then to isotopic analysis to quantify and investigate the chemical effects of paraffin. Although the results showed that paraffin had a limited impact, the sample size proved too small to display the definitive parameters of paraffin’s effects. The results were nevertheless compelling enough to warrant more research with a greater sample size

Long life, rechargeable nickel-zinc battery

A production version of the inorganic separator was evaluated for improving the life of the nickel-zinc system. Nickel-zinc cells (7-10 Ah capacities) of different electrode separator configurations were constructed and tested. The nickel-zinc cells using the inorganic separator encasing the zinc electrode, the nickel electrode, or both electrodes had shorter lives than cells using Visking and cellophane separation. Cells with the inorganic separation all fell below 70% of their theoretical capacity within 30 cycles, but the cells constructed with organic separation required 80 cycles. Failure of the cells using the ceramic separator was irreversible capacity degradation due to zinc loss through cracks developed in the inorganic separator. Zinc loss through the separator was minimized with the use of combinations of the inorganic separator with Visking and cellophane. Cells using the combined separation operated 130 duty cycles before degrading to 70% of their theoretical capacity

Mechanisms of Endothelial Dysfunction in Resistance Arteries from Patients with End-Stage Renal Disease

The study focuses on the mechanisms of endothelial dysfunction in the uremic milieu. Subcutaneous resistance arteries from 35 end-stage renal disease (ESRD) patients and 28 matched controls were studied ex-vivo. Basal and receptor-dependent effects of endothelium-derived factors, expression of endothelial NO synthase (eNOS), prerequisites for myoendothelial gap junctions (MEGJ), and associations between endothelium-dependent responses and plasma levels of endothelial dysfunction markers were assessed. The contribution of endothelium-derived hyperpolarizing factor (EDHF) to endothelium-dependent relaxation was impaired in uremic arteries after stimulation with bradykinin, but not acetylcholine, reflecting the agonist-specific differences. Diminished vasodilator influences of the endothelium on basal tone and enhanced plasma levels of asymmetrical dimethyl L-arginine (ADMA) suggest impairment in NO-mediated regulation of uremic arteries. eNOS expression and contribution of MEGJs to EDHF type responses were unaltered. Plasma levels of ADMA were negatively associated with endothelium-dependent responses in uremic arteries. Preserved responses of smooth muscle to pinacidil and NO-donor indicate alterations within the endothelium and tolerance of vasodilator mechanisms to the uremic retention products at the level of smooth muscle. We conclude that both EDHF and NO pathways that control resistance artery tone are impaired in the uremic milieu. For the first time, we validate the alterations in EDHF type responses linked to kinin receptors in ESRD patients. The association between plasma ADMA concentrations and endothelial function in uremic resistance vasculature may have diagnostic and future therapeutic implications

Marker assisted selection of potato breeding lines with combination of PVY resistance genes from different wild species

Potato virus Y (PVY) is considered as one of the most harmful virus infections of this crop. Thus, it is a topical problem to breed potato varieties resistant against a wide range of PVY strains and to create initial breeding material that will have a combination of resistance genes from different species. The aim of the study was: (1) to genotype a collection of 376 breeding lines (BL), developed from complex interspecific hybrids, using DNA markers of PVY resistance genes, (2) to identify accessions with markers of resistance genes from different species for subsequent use in marker assisted selection (MAS), (3) to evaluate the suitability of DNA markers of PVY resistance genes for genotyping BL developed through interspecific hybridization. It was ascertained that the markers most widely represented in the collection were RYSC3 of the Ryadg gene (49.7%), Ry364 and RAPD38-530 of the Rychc gene (50.5% and 45.2%, respectively), and Yes3-3A of the Rysto gene (29.8%). The markers Ry186 of Rychc and GP122/EcoRV780 of  Ryf-sto  were found only in some accessions. The frequency of occurrence of BL that had markers of PVY resistance genes from two different species varied between 2.7% (Yes3-3a marker of Rysto and both two markers of Rychc) and 8.5-9.0% (RYSC3 marker of Ryadg and both two markers of Rychc, or only Ry364 marker of this gene). In total, the collection was found to contain 134 BL (47.6%) with markers of resistance genes from two different species. A combination of four markers for three genes of different origin (Ryadg, Rysto and Rychc) was found in 27 BL (7.2%). Extreme resistance to PVY of most BL (302 out of 357) was obviously determined by the presence in them of the currently used resistance genes detected by DNA markers applied in the study. Nevertheless, a significant part of accessions (55 of 61) that did not have any markers was resistant to PVY. At the same time, 13 BL (3.5%) with the markers were susceptible to the virus. Such a level of discrepancies is considered as acceptable for the initial MAS of breeding material. The obtained data on the presence of the markers of PVY resistance genes of different origin and their combination in BL ensures a more effective use of such BL in breeding in comparison with the BL resistant to the virus, though lacking corresponding markers

ВЛИЯНИЕ ЭЛЕКТРОННОГО ОБЛУЧЕНИЯ НА ЭЛЕКТРИЧЕСКИЕ ХАРАКТЕРИСТИКИ p-n-СТРУКТУР НА ЯДЕРНО-ЛЕГИРОВАННОМ КРЕМНИИ

The article studies the effect of electron radiation with energy of 4 MeV on the characteristics of high-voltage (4.5 kV) silicon diode p-n-structures based on nuclear-doped silicon. During the research the dose dependences of the correlations between the static and dynamic characteristics of the p-n structures were built, and the radiation damage coefficient of minority carrier lifetime Kτ was determined. Using the DLTS-spectroscopy method, the formation in the band-gap of basic n-Si of six energy levels of radiation defects affecting the characteristics of irradiated p-n-structures was determined. В работе проведены исследования влияния электронного облучения с энергией 4 МэВ на характеристики высоковольтных (до 4,5 кВ) диодных кремниевых p-n-структур, изготовленных на ядерно-легированном кремнии. Получены дозовые зависимости статических и динамических характеристик p-n-структур, определен коэффициент радиационных повреждений времени жизни неосновных носителей заряда Kτ . С помощью метода DLTS-спектроскопии определено образование в запрещенной зоне базового n-Si шести энергетических уровней радиационных дефектов, влияющих на характеристики облученных p-n-структур.

ДИПЛОИДНЫЕ ГИБРИДЫ МЕЖДУ ДИКИМ АЛЛОТЕТРАПЛОИДНЫМ ВИДОМ КАРТОФЕЛЯ SOLANUM STOLONIFERUM SCHLDTL. & BOUCHET И ДИПЛОИДНЫМИ КЛОНАМИ КУЛЬТУРНОГО КАРТОФЕЛЯ S. TUBEROSUM L., ИМЕЮЩИЕ ГЕНОМ В ДИКОГО ВИДА

We were the first who demonstrated the possibility to produce diploid hybrids (along with triploid ones) while pollinating some wild allotetraploid potato species with the pollen of S. tuberosum diploid clones. It was determined that these hybrids only retained one of the genomes of wild species (genome A). Here, we present the results of revealing diploid interspecific hybrids having genome B of wild species. There were selected four hybrids producing the viable pollen among 235 hybrids between valuable for breeding accessions of S. stoloniferum and fertile diploid clone of S. tuberosum. The analysis of meiosis in pollen mother cells showed that they had 24chromosomes. The DNA marker SolB of genome B of wild species was detected in diploid hybrids, as well as in parental clones of S. stoloniferum and triploid interspecific hybrids. The diploid hybrids inherited the typical for wild species markers RYSC 3 and Yes3-3A of Y-virus resistance genes, as well as the markers of late blight resistance genes R1 and R3b. Two of the diploid hybrids inherited markers of late blight resistance gene Rpi-sto1 presented in parental clones of the wild species lossless. The marker 517/1519 of this gene was not detected in one diploid hybrid and both markers (517/1519 and 1521/518) − in another one. Production of the hybrids with genome B makes the version on a possible mechanism of their formation through the selective elimination of one of the genomes of wild species in ontogenesis of initially triploid interspecific hybrids to be priority. Среди гибридов между дикими тетраплоидными видами картофеля и диплоидными клонами S. tuberosum наряду с ожидаемыми триплоидными гибридами встречаются диплоидные гибриды. Ранее нами было показано, что у них сохраняется только один из геномов дикого вида (геном А). В сообщении впервые представлены результаты выявления диплоидных межвидовых гибридов, несущих геном В дикого вида. Среди 235 сеянцев гибридов от скрещивания ценных для селекции образцов S. stoloniferum и фертильного диплоидного клона S. tuberosum отобраны четыре гибрида, формирующих жизнеспособную пыльцу. Анализ мейоза в материнских клетках пыльцы показал наличие у них 24 хромосом. У всех диплоидных гибридов, как и у родительских клонов S. stoloniferum и триплоидных гибридов выявлен ДНК маркер генома В SolB. Все диплоидные гибриды наследовали характерные для дикого вида маркеры генов устойчивости к Y-вирусу картофеля RYSC 3 и Yes3-3A, а также маркеры генов устойчивости к фитофторозу R1 и R3b. Два гибрида без потерь наследовали маркеры гена устойчивости к фитофторозу Rpi-sto1, представленные у родительских клонов дикого вида. У одного диплоидного гибрида не детектировался маркер 517/1519, а у одного гибрида произошла утрата обоих маркеров (517/1519 и 1521/518). Получение гибридов с геномом В делает приоритетной версию о возможном механизме их формирования за счет избирательной элиминации одного из геномов дикого вида в процессе развития изначально триплоидных межвидовых гибридов.

Мужская фертильность растений сортов картофеля с различным типом цитоплазм

The predominance of varieties and parental lines having low male fertility is a characteristic feature of potatoes as a culture with asexual reproduction. The growth of the share of male sterile varieties has been recently noticed as a result of use in breeding interspecific hybrids with sterile-type cytoplasm. It leads to narrowing the genetic basis of modern potato varieties since it limits the choice of pollinators for breeding. The objectives of this research were to assess male fertility characters of 130 potato varieties from the collection of the Institute of Genetics and Cytology of the National Academy of Sciences of Belarus and identify their cytoplasm type using the set of DNA markers. The obtained results are intended for selection of pollinators for conventional breeding of potato, as well as of varieties for production of dihaploids with fertile-type cytoplasm suitable for hybrid breeding at the diploid level. It was revealed that the accessions with T- and D-type cytoplasm prevailed in the collection (46.0 and 35.4 %, respectively), the share of the accessions with W-type cytoplasm was 18.5 %. Most of the effective pollinators were selected among the varieties having T/β-type cytoplasm (44.6 %). The varieties Aksamit, Briz, Dubrava, Uladar, Alwara, Ausonia, Carlita, Fresco, Labadia, Latona, Liu, Lyra, Quarta, Satina, Sissi with this cytoplasm type were selected as most promising for our purposes according to the combination of breeding characters. The potato varieties with D/α-type cytoplasm were present in the collection under study. Approximately one third (32.6 %) was able to produce functionally fertile pollen (PFF), however the level of its fertility was as a rule low. Nevertheless, the varieties Bashkirski, Delfin, Olga and Ponto formed pollen with PFF suitable to guarantee seed production in crosses. Most of the studied varieties with W/α-, W/β-, and W/γ-type cytoplasm were male sterile. The varieties Atlant and Vesna Belaya were revealed among them that were able to produce functionally fertile pollen.Для картофеля как вегетативно размножаемой культуры характерно преобладание сортов и родительских линий с пониженной мужской фертильностью. В последние годы отмечается рост доли мужски стерильных сортов, что связывают с широким использованием в селекции межвидовых гибридов, имеющих цитоплазмы стерильного типа. Это ведет к сужению генетической базы современных сортов картофеля, так как ограничивает выбор опылителей для комбинативной селекции. Целью работы являлась оценка показателей мужской фертильности 130 сортов картофеля из коллекции Института генетики и цитологии НАН Беларуси и определение типа их цитоплазм с помощью набора молекулярных маркеров. Результаты исследования предполагается использовать для выделения сортов-опылителей для традиционной селекции картофеля, а также отбора сортов для получения первичных дигаплоидов картофеля с фертильным типом цитоплазмы, пригодных для гетерозисной селекции на диплоидном уровне. Установлено, что в коллекции преобладают образцы с цитоплазмой T- и D-типа (46,0 и 35,4 % соответственно), доля образцов с типом цитоплазмы W составила 18,5 %. Наибольшее число эффективных опылителей выделено среди образцов с цитоплазматическим типом T/β (44,6 %). По комплексу селекционных признаков выбраны как наиболее перспективные для названных выше целей сорта с цитоплазмой этого типа Аксамит, Бриз, Дубрава, Уладар, Alwara, Ausonia, Carlita, Fresco, Labadia, Latona, Liu, Lyra, Quarta, Satina, Sissi. В изученной нами коллекции представлены сорта с цитоплазмой D/α. Около трети из них (32,6 %) были способны образовывать функционально фертильную пыльцу (ФФП), однако уровень ФФП был, как правило, невысоким. Тем не менее, сорта Башкирский, Дельфин, Olga, Ponto формировали пыльцу с фертильностью, достаточной для гарантированного получения семян. Большинство изученных сортов с типами цитоплазмы W/α, W/β и W/γ были мужски стерильны. Однако и среди них выявлены сорта Атлант и Весна Белая, способные образовывать функционально фертильную пыльцу

Late pleistocene sedimentation history of the Shirshov Ridge, Bering Sea

The analysis of the lithology, grain-size distribution, clay minerals, and geochemistry of Upper Pleistocene sediments from the submarine Shirshov Ridge (Bering Sea) showed that the main source area was the Yukon–Tanana terrane of Central Alaska. The sedimentary materials were transported by the Yukon River through Beringia up to the shelf break, where they were entrained by a strong northwestward-flowing sea current. The lithological data revealed several pulses of ice-rafted debris deposition, roughly synchronous with Heinrich events, and periods of weaker bottom-current intensity. Based on the geochemical results, we distinguished intervals of an increase in paleoproductivity and extension of the oxygen minimum zone. The results suggest that there were three stages of deposition driven by glacioeustatic sea-level fluctuations and glacial cycles in Alaska