246 research outputs found
Lightweight, self-evacuated insulation panels
Multilayer insulation of prefabricated panels is developed for cryogenic storage tanks. System utilizes panels of aluminized Mylar separated by sheets of low conductivity polyurethane foam. Panels are self-evacuated by cryopumping of gaseous carbon dioxide at time of use
Rigid open-cell polyurethane foam for cryogenic insulation
Lightweight polyurethane foam assembled in panels is effective spacer material for construction of self-evacuating multilayer insulation panels for cryogenic liquid tanks. Spacer material separates radiation shields with barrier that minimizes conductive and convective heat transfer between shields
Влияние ширины реза на радиальную проекцию силы резания
В статье обосновывается влияние ширины реза на проекцию составляющей силы резания на плоскость, перпендикулярную оси вращения геохода. Рассмотрена актуальность исследования. Для постановки цели и задач исследования определена проекция составляющей силы резания на плоскость, перпендикулярную оси вращения геохода. На основании проведенного исследования построена зависимость радиальной проекции силы резанию ножевого исполнительного органа геохода (RИО.СВ) от от x до Rг
Property Optimization for TWIP Steels – Effect of Pre-deformation Temperature on Fatigue Properties
The current work investigates the impact of pre-deformation temperatures on the microstructure evolution and the subsequent cyclic stress-strain response of high-manganese steel showing twinning-induced plasticity (TWIP) at room temperature (RT). Deformation at low temperatures increases the hardening rate at low to medium degrees of deformation through concurrent martensitic transformation. In contrast, high temperatures promote dislocation slip. Thus, employing pre-treatments at temperatures below and above RT leads to the evolution of considerably different microstructures. Low-cycle fatigue experiments revealed distinct differences for the pre-treated TWIP steels
Presence and Diversity of Different Enteric Viruses in Wild Norway Rats (Rattus norvegicus)
Abstract:
Rodents are common reservoirs for numerous zoonotic pathogens, but knowledge about
diversity of pathogens in rodents is still limited. Here, we investigated the occurrence and genetic
diversity of enteric viruses in 51 Norway rats collected in three different countries in Europe. RNA of
at least one virus was detected in the intestine of 49 of 51 animals. Astrovirus RNA was detected
in 46 animals, mostly of rat astroviruses. Human astrovirus (HAstV-8) RNA was detected in one,
rotavirus group A (RVA) RNA was identified in eleven animals. One RVA RNA could be typed as
rat G3 type. Rat hepatitis E virus (HEV) RNA was detected in five animals. Two entire genome
sequences of ratHEV were determined. Human norovirus RNA was detected in four animals
with the genotypes GI.P4-GI.4, GII.P33-GII.1, and GII.P21. In one animal, a replication competent
coxsackievirus A20 strain was detected. Additionally, RNA of an enterovirus species A strain was
detected in the same animal, albeit in a different tissue. The results show a high detection rate and
diversity of enteric viruses in Norway rats in Europe and indicate their significance as vectors for
zoonotic transmission of enteric viruses. The detailed role of Norway rats and transmission pathways
of enteric viruses needs to be investigated in further studies.Peer Reviewe
Meeting Highlights of the 11th Annual Scientific Sessions of the Society for Cardiovascular Magnetic Resonance, Los Angeles, February 1–3, 2008
This paper features the most interesting presentations and discussions of the 2008 Annual Sessions of the Society for Cardiovascular Magnetic Resonance, which were held in Los Angeles from February 1 to 3, 2008
ERK1 as a therapeutic target for dendritic cell vaccination against high-grade gliomas
Glioma regression requires the recruitment of potent anti-tumor immune cells into the tumor microenvironment. Dendritic cells (DCs) play a role in immune responses to these tumors. The fact that DC vaccines do not effectively combat high-grade gliomas, however, suggests that DCs need to be genetically modified especially to promote their migration to tumor relevant sites. Previously, we identified extracellular signal-regulated kinase (ERK1) as a regulator of DC immunogenicity and brain autoimmunity. In the present study, we made use of modern magnetic resonance methods to study the role of ERK1 in regulating DC migration and tumor progression in a model of high-grade glioma. We found that ERK1-deficient mice are more resistant to the development of gliomas, and tumor growth in these mice is accompanied by a higher infiltration of leukocytes. ERK1-deficient DCs exhibit an increase in migration that is associated with sustained Cdc42 activation and increased expression of actin-associated cytoskeleton-organizing proteins. We also demonstrated that ERK1 deletion potentiates DC vaccination and provides a survival advantage in high-grade gliomas. Considering the therapeutic significance of these results, we propose ERK1-deleted DC vaccines as an additional means of eradicating resilient tumor cells and preventing tumor recurrence
Проблемы обеспечения пожарной безопасности в образовательных учреждениях
В статье рассматриваются актуальные вопросы и мероприятия по обеспечению пожарной безопасности в образовательных учреждениях.In article topical issues and actions for ensuring fire safety in educational institutions are considered
High temporal resolution parametric MRI monitoring of the initial ischemia/reperfusion phase in experimental acute kidney injury
Ischemia/reperfusion (I/R) injury, a consequence of kidney hypoperfusion or temporary interruption of blood flow is a common cause of acute kidney injury (AKI). There is an unmet need to better understand the mechanisms operative during the initial phase of ischemic AKI. Non-invasive parametric magnetic resonance imaging (MRI) may elucidate spatio-temporal pathophysiological changes in the kidney by monitoring the MR relaxation parameters T* and T, which are known to be sensitive to blood oxygenation. The aim of our study was to establish the technical feasibility of fast continuous T*/T mapping throughout renal I/R. MRI was combined with a remotely controlled I/R model and a segmentation model based semi-automated quantitative analysis. This technique enabled the detailed assessment of changes in all kidney regions during ischemia and early reperfusion. Significant changes in T* and T were observed shortly after induction of renal ischemia and during the initial reperfusion phase. Our study demonstrated for the first time that continuous and high temporal resolution parametric MRI is feasible for monitoring and characterization of I/R induced AKI in rats. This technique may help in the identification of the timeline of key events responsible for development of renal damage in hypoperfusion-induced AKI
Genetic Diversity of Enteric Viruses in Children under Five Years Old in Gabon
Enteric viruses are the leading cause of diarrhea in children globally. Identifying viral agents and understanding their genetic diversity could help to develop effective preventive measures. This study aimed to determine the detection rate and genetic diversity of four enteric viruses in Gabonese children aged below five years. Stool samples from children <5 years with (n = 177) and without (n = 67) diarrhea were collected from April 2018 to November 2019. Norovirus, astrovirus, sapovirus, and aichivirus A were identified using PCR techniques followed by sequencing and phylogenetic analyses. At least one viral agent was identified in 23.2% and 14.9% of the symptomatic and asymptomatic participants, respectively. Norovirus (14.7%) and astrovirus (7.3%) were the most prevalent in children with diarrhea, whereas in the healthy group norovirus (9%) followed by the first reported aichivirus A in Gabon (6%) were predominant. The predominant norovirus genogroup was GII, consisting mostly of genotype GII.P31-GII.4 Sydney. Phylogenetic analysis of the 3CD region of the aichivirus A genome revealed the presence of two genotypes (A and C) in the study cohort. Astrovirus and sapovirus showed a high diversity, with five different astrovirus genotypes and four sapovirus genotypes, respectively. Our findings give new insights into the circulation and genetic diversity of enteric viruses in Gabonese children.Peer Reviewe
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