Internal radiation dose assessment of radiopharmaceuticals prepared with cyclotron-produced 99m Tc

Technetium-99m (99m Tc) is the radioisotope most widely used in diagnostic nuclear medicine. It is readily available from 99 Mo/99m Tc generators as the \u3b2- decay product of the 99 Mo (T\ubd =66 h) parent nuclide. This latter is obtained as a fission product in nuclear reactors by neutron-induced reactions on highly enriched uranium. Alternative production routes, such as direct reactions using proton beams on specific target materials [100 Mo(p,2n)99m Tc], have the potential to be both reliable and relatively cost-effective. However, results showed that the 99m Tc extracted from proton-bombarded 100 Mo-enriched targets contains small quantities of several Tc radioisotopes (93m Tc, 93 Tc, 94 Tc, 94m Tc, 95 Tc, 95m Tc 96 Tc and 97m Tc). The aim of this work was to estimate the dose increase (DI) due to the contribution of Tc radioisotopes generated as impurities, after the intravenous injection of four radiopharmaceuticals prepared with cyclotron-produced 99m Tc (CP-99m Tc) using 99.05% 100 Mo-enriched metallic targets

Critical analysis of prefabricated reinforced concrete flat elements

openIl presente elaborato si propone di effettuare un'analisi critica degli elementi piani in c.a. prefabbricati, già da tempo sul mercato, in particolare per quanto riguarda solai e muri di sostegno. L'elaborato si propone di approfondire le caratteristiche dei giunti tra lastre prefabbricate e il getto di calcestruzzo in sito, la disposizione delle armature e le problematiche principali a cui sono soggette questo tipo di soluzioni. Viene infine fatto un breve excursus sulle soluzioni attualmente presenti sul mercato

Methods for providing purified viral particles of semliki forest virus (sfv), preparations obtainable thereby, and uses thereof.

The invention relates to purified vaccine preparations and methods for providing them. Provided is a method for providing purified viral particles of SFV, comprising the steps of i) providing a preparation of SFV replicon particles; ii) subjecting said preparation to an endonuclease treatment under conditions allowing for degradation of exogenous/host cell DNA and RNA; iii) bringing said endonuclease-treated preparation with a zwitterionic buffer solution to a conductivity of up to about 5.5 mS/cm; iv) contacting the preparation obtained in step (iii) with a strong anion exchange resin; v) eluting the bound SFV replicon particles from said anion exchange resin; vi) bringing the eluted SFV particles to a conductivity in the range of 7.0 to 9.0 mS/cm; vii) contacting the preparation obtained in step (vi) with a strong cation exchange resin under conditions and for a time sufficient to bind to said resin; viii) eluting the bound SFV replicon particles from said cation exchange resin with a zwitterionic buffer solution and collecting at least one fraction containing purified SFV replicon particles; and ix) stabilizing the at least one purified fraction by adding human serum albumin (HSA) to a final concentration in the range of about 0.5 - 2 w/v%, preferably about 1 w/v%

IPv4 address sharing mechanism classification and tradeoff analysis

The growth of the Internet has made IPv4 addresses a scarce resource. Due to slow IPv6 deployment, IANA-level IPv4 address exhaustion was reached before the world could transition to an IPv6-only Internet. The continuing need for IPv4 reachability will only be supported by IPv4 address sharing. This paper reviews ISP-level address sharing mechanisms, which allow Internet service providers to connect multiple customers who share a single IPv4 address. Some mechanisms come with severe and unpredicted consequences, and all of them come with tradeoffs. We propose a novel classification, which we apply to existing mechanisms such as NAT444 and DS-Lite and proposals such as 4rd, MAP, etc. Our tradeoff analysis reveals insights into many problems including: abuse attribution, performance degradation, address and port usage efficiency, direct intercustomer communication, and availability

Integración de los géneros discusivos y las alfabetizaciones académicas: una experiencia pedagógica en un curso de inglés con fines académicos en la Universidad de Buenos Aires

Este artículo describe la experiencia pedagógica y de aprendizaje de un cambio de enfoque del curso Inglés con Fines Académicos en la Facultad de Psicología de la Universidad de Buenos Aires. Desde el 2019, incorporamos las alfabetizaciones académicas (Lea y Street, 2016) al enfoque basado en los géneros discursivos. La pedagogía y la didáctica también se enmarcan en el desarrollo de las habilidades blandas que también guian a los estudiantes para que puedan visibilizar la interacción con los géneros y con la lectura crítica situada y a tener agencia en la participación académica legítima (Canagarajah, 2002)Palabras clave: géneros discursivos, alfabetizaciones académicas, habilidades blanda

The Effect of Dissimilatory Manganese Reduction on Lactate Fermentation and Microbial Community Assembly

Fermentation and dissimilatory manganese (Mn) reduction are inter-related metabolic processes that microbes can perform in anoxic environments. Fermentation is less energetically favorable and is often not considered to compete for organic carbon with dissimilatory metal reduction. Therefore, the aim of our study was to investigate the outcome of the competition for lactate between fermentation and Mn oxide (birnessite) reduction in a mixed microbial community. A birnessite reducing enrichment culture was obtained from activated sludge with lactate and birnessite as the substrates. This enrichment was further used to test how various birnessite activities (0, 10, 20, and 40 mM) affected the rates of fermentation and metal reduction, as well as community composition. Increased birnessite activity led to a decrease of lactate consumption rate. Acetate and propionate were the main products. With increasing birnessite activity, the propionate/acetate ratio decreased from 1.4 to 0.47. Significant CO2 production was detected only in the absence of birnessite. In its presence, CO2 concentrations remained close to the background since most of the CO2 produced in these experiments was recovered as MnCO3. The Mn reduction efficiency (Mn(II) produced divided by birnessite added) was the highest at 10 mM birnessite added, where about 50% of added birnessite was reduced to Mn(II), whereas at 20 and 40 mM approximately 21 and 16% was reduced. The decreased birnessite reduction efficiency at higher birnessite activities points to inhibition by terminal electron acceptors and/or its toxicity which was also indicated by retarded lactate oxidation and decreased concentrations of microbial metabolites. Birnessite activity strongly affected microbial community structure. Firmicutes and Bacteroidetes were the most abundant phyla at 0 mM of birnessite. Their abundance was inversely correlated with birnessite concentration. The relative sequence abundance of Proteobacteria correlated with birnessite concentrations. Most of the enriched populations were involved in lactate/acetate or amino acid fermentation and the only previously known metal reducing genus detected was related to Shewanella sp. The sequencing data confirmed that lactate consumption coupled to metal reduction was only one of the processes occurring and did not outcompete fermentation processes

Methane oxidation and methylotroph population dynamics in groundwater mesocosms

© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Kuloyo, O., Ruff, S. E., Cahill, A., Connors, L., Zorz, J. K., de Angelis, I. H., Nightingale, M., Mayer, B., & Strous, M. Methane oxidation and methylotroph population dynamics in groundwater mesocosms. Environmental Microbiology. (2020), doi:10.1111/1462-2920.14929.Extraction of natural gas from unconventional hydrocarbon reservoirs by hydraulic fracturing raises concerns about methane migration into groundwater. Microbial methane oxidation can be a significant methane sink. Here, we inoculated replicated, sand‐packed, continuous mesocosms with groundwater from a field methane release experiment. The mesocosms experienced thirty‐five weeks of dynamic methane, oxygen and nitrate concentrations. We determined concentrations and stable isotope signatures of methane, carbon dioxide and nitrate and monitored microbial community composition of suspended and attached biomass. Methane oxidation was strictly dependent on oxygen availability and led to enrichment of 13C in residual methane. Nitrate did not enhance methane oxidation under oxygen limitation. Methylotrophs persisted for weeks in the absence of methane, making them a powerful marker for active as well as past methane leaks. Thirty‐nine distinct populations of methylotrophic bacteria were observed. Methylotrophs mainly occurred attached to sediment particles. Abundances of methanotrophs and other methylotrophs were roughly similar across all samples, pointing at transfer of metabolites from the former to the latter. Two populations of Gracilibacteria (Candidate Phyla Radiation) displayed successive blooms, potentially triggered by a period of methane famine. This study will guide interpretation of future field studies and provides increased understanding of methylotroph ecophysiology.The authors acknowledge funding from the Alberta Innovates Technology Futures (AITF), and University of Calgary Eyes High Doctoral Scholarships (O.O.K., J.K.Z.) and AITF/Eyes High Postdoctoral Fellowships (S.E.R.), as well as the PROMOS Internship Abroad Scholarship by the German Academic Exchange Service (I.H.d.A.). Additional support was provided by the Natural Sciences and Engineering Research Council of Canada (NSERC), Strategic Project Grant no. 463045‐14, the Campus Alberta Innovation Chair Program (M.S.), Alberta Innovates, The Canadian Foundation for Innovation (M.S.), the Alberta Small Equipment Grant Program (M.S.) and an NSERC Discovery Grant (M.S. and B.M.)