473 research outputs found

    Approaching the precursor nuclei of the third r-process peak with RIBs

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    The rapid neutron nucleosynthesis process involves an enormous amount of very exotic neutron-rich nuclei, which represent a theoretical and experimental challenge. Two of the main decay properties that affect the final abundance distribution the most are half-lives and neutron branching ratios. Using fragmentation of a primary 238U beam at GSI we were able to measure such properties for several neutron-rich nuclei from 208Hg to 218Pb. This contribution provides a short update on the status of the data analysis of this experiment, together with a compilation of the latest results published in this mass region, both experimental and theoretical. The impact of the uncertainties connected with the eta-decay rates and with beta-delayed neutron emission is illustrated on the basis of r-process network calculations. In order to obtain a reasonable reproduction of the third r-process peak, it is expected that both half-lives and neutron branching ratios are substantially smaller, than those based on FRDM+QRPA, commonly used in r-process model calculations. Further measurements around N 126 are required for a reliable modelling of the underlying nuclear structure, and for performing more realistic r-process abundance calculations.Postprint (published version

    The BRIKEN Project: extensive measurements of ß-delayed neutron emitters for the astrophysical r process

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    An ambitious program to measure decay properties, primarily ß-delayed neutron emission probabilities and half-lives, for a significant number of nuclei near or on the path of the rapid neutron capture process, has been launched at the RIKEN Nishina Center. We give here an overview of the status of the project.Postprint (published version

    Colonization and infection in the newborn infant: Does chlorhexidine play a role in infection prevention

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    Healthcare-Associated infections are a major problem in newborn infants, considering their high morbidity, mortality, and long-Term sequelae. In preterm infants, it has been shown that skin and gastrointestinal tract colonization undergoes variations compared to healthy term infants, and that preterm infants are more exposed to nosocomial microorganisms given their higher probability of being admitted to the neonatal intensive care unit where they are cared for. This document reviews normal colonization, the changes observed during hospitalization, prematurity, and the potential role of chlorhexidine in the prevention of resistant microorganism transmission, as well as its side effects in newborn infants admitted to the neonatal intensive care unit

    Matter-antimatter asymmetry without departure from thermal equilibrium

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    We explore the possibility of baryogenesis without departure from thermal equilibrium. A possible scenario is found, though it contains strong constraints on the size of the CPTCPT violation (CPTVCPTV) effects and on the role of the BB (baryon number) nonconserving interactions which are needed for it.Comment: Revtex, 4page

    Abscesos cerebrales por Nocardia spp. en una paciente inmunocompetente

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    The infection by Nocardia spp is not common in immunocompetent patients. The empirical antimicrobial treatment directed by anatomical regions does not contemplate the particularities of the germ and the microbiological analysis is necessary for the specific treatment. We present the case of a previously healthy and immunocompetent patient, without known risk factors for Nocardia spp. infection, with evidence of involvement of the pulmonary parenchyma and the skin and subsequent development of multiple brain abscesses. © 2020 Instituto Nacional de Salud

    Experimental setup and procedure for the measurement of the 7Be(n,p)7Li reaction at n_TOF

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    Following the completion of the second neutron beam line and the related experimental area (EAR2) at the n_TOF spallation neutron source at CERN, several experiments were planned and performed. The high instantaneous neutron flux available in EAR2 allows to investigate neutron induced reactions with charged particles in the exit channel even employing targets made out of small amounts of short-lived radioactive isotopes. After the successful measurement of the 7Be(n,) cross section, the 7Be(n,p)7Li reaction was studied in order to provide still missing cross section data of relevance for Big Bang Nucleosynthesis (BBN), in an attempt to find a solution to the cosmological Lithium abundance problem. This paper describes the experimental setup employed in such a measurement and its characterization.Séptimo Programa Marco de la Comunidad Europea de la Energía Atómica (Euratom)-Proyecto CHANDA (No. 605203)Narodowe Centrum Nauki (NCN)-UMO-2012/04/M/ST2/00700-UMO-2016/22/M/ST2/00183Croatian Science Foundation-HRZZ 168

    Differential expression of dnaA and dosR genes among members of the Mycobacterium tuberculosis complex under oxic and hypoxic conditions

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    Major differences regarding the pathology and host immune response of the Beijing and Canettii genotypes of Mycobacterium tuberculosis have been reported; however, studies on the genetic expression of these genotypes during in vitro dormancy are scarce. This study examined the expression of five cell-cycle-related genes and two dormancy-related genes in M. canettii, M. tuberculosis H37Rv, and M. tuberculosis Beijing during the Wayne model of dormancy. The results showed that under hypoxic conditions the three tuberculosis genotypes were able to transcribe genes involved in DNA replication and cellular division. In addition, dosR was found to be up-regulated in M. tuberculosis Beijing during the exponential growth phase but down-regulated under hypoxic conditions. In this genotype, the replication-related gene dnaA was also strongly down-regulated. These latter two findings suggest that, compared to M. tuberculosis H37Rv and M. canettii, the Beijing genotype has a lower capacity to synthesize dosR, hspX, and dnaA mRNAs during in vitro dormancy. [Int Microbiol 2010;13(1):9-13

    Synthesis and Characterization of a Coagulating Agent from Plantain Peel Starch (Musa paradisiaca), as Coadjuvant in Water Treatment

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    Coagulation processes are widely used for water treatment, mainly with chemical coagulants. In this research, starch derived from a waste (unripe plantain peel, Musa paradisiaca) was used as a starting point for a chemical modifcation. Through acetylation, its chemical structure was modifed and characterized by infrared spectrophotometry, for its evaluation as a coadjuvant in coagulation operations to reduce the turbidity of raw water. Two experimental designs were developed to evaluate the incidence of modifed starch as the main coagulant, or in conjunction with a conventional coagulant (Al2(SO4)3), at diferent (Al2(SO4)3)/acetylated starch ratios, in jar-test experiments. In the frst experimental design, with the acetylated starch as the main coagulant, turbidity removal percentages reached 47.93% (average value, 41.18%). For the (Al2(SO4)3)/acetylated starch coagulation process, 98.91% turbidity removal was reached in the second experimental design (average value, 97.16%). The impact of starch chemical substitution degree and the (Al2(SO4)3)/acetylated starch ratio on the fnal turbidity obtained in the jar-tests was determined using ANOVA test. There was a great infuence of the chemical substitution degree and the concentration of acetylated starch utilized, when modifed starch was used as the main coagulant. For the second experimental design, the (Al2(SO4)3)/acetylated starch ratio had a greater incidence on the turbidity removal. Thus, modifed starch obtained from plantain peel waste is a promising coadjuvant material for water coagulation processes

    The effects of whole-body muscle stimulation on body composition and strength parameters: a PRISMA systematic review and meta-analysis

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    Background: This systematic review and meta-analysis set out to determine the efficacy of whole-body muscle electrostimulation on body composition, strength, and muscle power in active and non-active adults (aged ≥18 years). Method: This review was reported in accordance with the Protocol Statement of Preferred Reporting Element Guidelines for Systematic Reviews and Meta-Analysis included controlled trials; whole-body electromyostimulation trials with at least 1 exercise and control group; participants >18 years old. Outcome measures were defined as standardized mean differences for muscle mass, body fat mass, strength, and power. Studies were searched in the following electronic databases: PubMed, Web of Science, Scopus, SPORTDiscus, and EMBASE for all articles published up to July 30, 2021. The risk of bias was assessed by 2 independent researchers using the Physiotherapy Evidence Database scale and Grading of Recommendations, Assessment, Development and Evaluations approach. Analyses were performed using the metafor package of the statistical software R (version 4.0.3; R Core Team, 2020). Random effects models, forest, and funnel plots to quantify the asymmetry associated with publication bias were fitted using the metafor library in R. Statistical heterogeneity was assessed using I 2 statistics. Results: In total, 26 studies representing 1183 participants were included (WB-electromyostimulation: n = 586 and control group: n = 597). The mean age of the participants ranged from a minimum of 20.4 to a maximum of 77.4 years old. Interventions lasted a minimum of 4 and a maximum of 54 weeks. Standardized mean difference was 0.36 (95% confidence interval [CI]: 0.16–0.57) for muscle mass, −0.38 (95% CI: −0.62–0.15) for body fat, 0.54 (95% CI: 0.35–0.72) for strength, and 0.36 (95% CI: 0.02–0.71) for power with significant differences between groups (all P < .04). I 2 revealed low heterogeneity of muscle mass (15%) and power (0%) between trials and medium heterogeneity of body fat (45%) and strength (55%). Conclusion: We concluded that WB-electromyostimulation has significant positive effects on muscle mass, body fat, strength, and power.info:eu-repo/semantics/publishedVersio
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