44 research outputs found
A derivative of vitamin B3 applied several days after exposure reduces lethality of severely irradiated mice
Most, if not all, of the hitherto tested substances exert more or less pronounced pro-survival effects when applied before or immediately after the exposure to high doses of ionizing radiation. In the present study we demonstrate for the first time that 1-methyl nicotinamide (MNA), a derivative of vitamin B3, significantly (1.6 to 1.9 times) prolonged survival of BALB/c mice irradiated at LD30/30 (6.5 Gy), LD50/30 (7.0 Gy) or LD80/30 (7.5 Gy) of γ-rays when the MNA administration started as late as 7 days post irradiation. A slightly less efficient and only after the highest dose (7.5 Gy) of γ-rays was another vitamin B3 derivative, 1-methyl-3-acetylpyridine (1,3-MAP) (1.4-fold prolonged survival). These pro-survival effects did not seem to be mediated by stimulation of haematopoiesis, but might be related to anti-inflammatory and/or anti-thrombotic properties of the vitamin B3 derivatives. Our results show that MNA may represent a prototype of a radioremedial agent capable of mitigating the severity and/or progression of radiation-induced injuries when applied several hours or days after exposure to high doses of ionizing radiation
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An Investigation of the Effect of Graphite Degradation on the Irreversible Capacity in Lithium-ion Cells
The effect of surface structural damage on graphitic anodes, commonly observed in tested Li-ion cells, was investigated. Similar surface structural disorder was artificially induced in Mag-10 synthetic graphite anodes using argon-ion sputtering. Raman microscopy, scanning electron microscopy (SEM) and Brunauer Emmett Teller (BET) measurements confirmed that Ar-ion sputtered Mag-10 electrodes display similar degree of surface degradation as the anodes from tested Li-ion cells. Artificially modified Mag-10 anodes showed double the irreversible charge capacity during the first formation cycle, compared to fresh un-altered anodes. Impedance spectroscopy and Fourier transform infrared (FTIR) spectroscopy on surface modified graphite anodes indicated the formation of a thicker and slightly more resistive SEI layer. Gas chromatography/mass spectroscopy (GC/MS) analysis of solvent extracts from the electrodes detected the presence of new compounds with M{sub w} on the order of 1600 g mol{sup -1} for the surface modified electrode with no evidence of elevated M{sub w} species for the unmodified electrode. The structural disorder induced in the graphite during long-term cycling maybe responsible for the slow and continuous SEI layer reformation, and consequently, the loss of reversible capacity due to the shift of lithium inventory in cycled Li-ion cells
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Impact of carbon structure and morphology on the electrochemical performance of LiFePO4/C composites
The electrochemical performance of LiFePO4/C composites in lithium cells is closely correlated to pressed pellet conductivities measured by AC impedance methods. These composite conductivities are a strong function not only of the amount of carbon but of its structure and distribution. Ideally, the amount of carbon in composites should be minimal (less than about 2 wtpercent) so as not to decrease the energy density unduly. This is particularly important for plug-in hybrid electric vehicle applications (PHEVs) where both high power and moderate energy density are required. Optimization of the carbon structure, particularly the sp2/sp3 and disordered/graphene (D/G) ratios, improves the electronic conductivity while minimizing the carbon amount. Manipulation of the carbon structure can be achieved via the use of synthetic additives including ironcontaining graphitization catalysts. Additionally, combustion synthesis techniques allow co-synthesis of LiFePO4 and carbon fibers or nanotubes, which can act as"nanowires" for the conduction of current during cell operation
Toward a Unified Description of Battery Data
Battery research initiatives and giga-scale production generate an abundance of diverse data spanning myriad fields of science and engineering. Modern battery development is driven by the confluence of traditional domains of natural science with emerging fields like artificial intelligence and the vast engineering and logistical knowledge needed to sustain the global reach of battery Gigafactories. Despite the unprecedented volume of dedicated research targeting affordable, high-performance, and sustainable battery designs, these endeavours are held back by the lack of common battery data and vocabulary standards, as well as, machine readable tools to support interoperability. An ontology is a data model that represents domain knowledge as a map of concepts and the relations between them. A battery ontology offers an effective means to unify battery-related activities across different fields, accelerate the flow of knowledge in both human- and machine-readable formats, and support the integration of artificial intelligence in battery development. Furthermore, a logically consistent and expansive ontology is essential to support battery digitalization and standardization efforts, such as, the battery passport. This review summarizes the current state of ontology development, the needs for an ontology in the battery field, and current activities to meet this need.publishedVersio
Ionic conductivity, viscosity, and self-diffusion coefficients of novel imidazole salts for lithium-ion battery electrolytes
Lithium-ion battery performance and longevity depend critically on the conducting salt utilized in the electrolyte. With new avenues for multifunctional integration and optimization of functional properties, conducting salts beyond lithium hexafluorophosphate (LiPF) need to be studied. Herein we elucidate on viscosity, ionicity, anion self-diffusion and ionic conductivity through variation of the length of the perfluoroalkyl side chain present in the anions of the used lithium imidazole salts. Specifically, we study LiPF in comparison with lithium 4,5-dicyano-2-(trifluoromethyl)imidazolide (LiTDI), lithium 4,5-dicyano-2-(pentafluoroethyl)imidazolide (LiPDI), and lithium 4,5-dicyano-2-(n-heptafluoropropyl)imidazolide (LiHDI). We find that the ion mobility of LiPF depends the least on viscosity and its ionicity is the highest among the electrolytes investigated here. LiTDI shows the strongest correlation between ion mobility and viscosity and the lowest ionicity. LiPDI and LiHDI range between these two regarding their ionicity and the correlation of mobility with viscosity. The previously rarely studied anion self-diffusion coefficients exhibit a strong correlation with viscosity as it was to be expected. Differences between the LiTDI, LiPDI and LiHDI salts are minute
Revised data taking schedule with ion beams
This document presents the revised data taking schedule of NA61 with ion beams. The revision takes into account limitations due to the new LHC schedule as well as final results concerning the physics performance with secondary ion beams. It is proposed to take data with primary Ar and Xe beams in 2012 and 2014, respectively, and to test and use for physics a secondary B beam from primary Pb beam fragmentation in 2010, 2011 and 2013
Two-particle correlations in azimuthal angle and pseudorapidity in inelastic p + p interactions at the CERN Super Proton Synchrotron
Results on two-particle ΔηΔϕ correlations in inelastic p + p interactions at 20, 31, 40, 80, and 158 GeV/c are presented. The measurements were performed using the large acceptance NA61/SHINE hadron spectrometer at the CERN Super Proton Synchrotron. The data show structures which can be attributed mainly to effects of resonance decays, momentum conservation, and quantum statistics. The results are compared with the Epos and UrQMD models.ISSN:1434-6044ISSN:1434-605
Quality of academic libraries - funding bodies, librarians and users perspective: a common project of Polish research libraries on comparable measures
According to the ISO Standard 11620 Performance Indicators for Libraries, the quality means "totality of features and characteristics of a product or services that bear on the library's ability to satisfy stated or implied needs". Hence the quality assessment depends not only on the product or service as it is but also on a person or institution involved in the assessment process. High quality of library performance is crucial for each research library to survive. Wide on-line access to information makes researchers and students demand the highest quality library services. It is the quality of library services that decides on the perception of the library within its parent institution and the society. Comparable quality measures (which refer not only to library services but to all aspects of library performance) are of vital importance for efficient and effective library management. A library needs both to satisfy its users and to prove to its funding bodies that it is worth investment. Moreover, the State Accreditation Commission in the process of the assessment of higher education institutions takes the quality of library services into account. Therefore current efforts to determine unified standards and library performance indicators are a starting point to the full implementation of reliable analysis-based management and assessment. The main objective of the paper is to present the results of the on-going study of performance indicators for Polish research libraries. The report from the research together with background information on library statistical data collection reflects the overall situation of library quality measures and assessment in Poland. The study is a continuation of the activity realised in the frame of the EU Tempus Project "Development of Library Management as a Part of the University Total Quality Management". The Group for Standardisation presently conducts the research in the frame of the national project financed from the funds of the Ministry of National Education and Sport. Authors of the research encountered many difficulties implied by the lack of national patterns or standards for library statistics and effectiveness measurement to follow. Therefore they have been trying to adopt model foreign solutions to the Polish realities. The paper describes the tools for library performance evaluation applied in Poland in 2003. The authors discuss some issues related to the preparation of an online questionnaire for comparative studies and a computer program for a quantitative and qualitative data collection and analysis. Next, the results of the research for the years 2002-2003 are presented including tables and graphs. Finally, we present a proposal for new standard surveys to be used for the assessment of the quality of libraries by their users (according to the international standard 11620). Data received from users surveys will provide important complementary information to the raw data and the indicators derived from them
Management based on reliable comparative data. Library statistics and performance indicators. A common project of Polish research libraries
The paper reports the results of the on-going research on performance indicators and library statistics for Polish research libraries. It is a continuation of activity realised in the frame of the EU Tempus Project Development of Library Management as a Part of the University Total Quality Management . The Task Group for Standardisation presently conducts it in the frame of the national project financed from the funds of the Ministry of National Education and Sport. The first part of the paper presents the results of the EU Tempus Project. The second part describes the tools for library performance evaluation applied in 2003. The authors discuss some issues related to preparation of an online questionnaire for comparative studies and computer program for quantitative and qualitative data collection and analysis. The final part reports the analysis of data and performance indicators derived from technical university libraries. The paper presented on behalf of the Task Group for Standardisation