Publish in OALib Journal

ISSN: 2333-9721

APC: Only $99


Any time

2019 ( 365 )

2018 ( 518 )

2017 ( 535 )

2016 ( 764 )

Custom range...

Search Results: 1 - 10 of 325229 matches for " S. Nisi "
All listed articles are free for downloading (OA Articles)
Page 1 /325229
Display every page Item
First observation of alpha decay of 190-Pt to the first excited level (E_{exc}=137.2 keV) of 186-Os
P. Belli,R. Bernabei,F. Cappella,R. Cerulli,F. A. Danevich,A. Incicchitti,M. Laubenstein,S. S. Nagorny,S. Nisi,O. G. Polischuk,V. I. Tretyak
Statistics , 2011, DOI: 10.1103/PhysRevC.83.034603
Abstract: The alpha decays of naturally occurring platinum isotopes, which are accompanied by the emission of gamma quanta, have been searched for deep underground (3600 m w.e.) in the Gran Sasso National Laboratories of the INFN (Italy). A sample of Pt with mass of 42.5 g and a natural isotopic composition has been measured with a low background HP Ge detector (468 cm^3) during 1815 h. The alpha decay of 190-Pt to the first excited level of 186-Os (J^\pi = 2^+, E_{exc}=137.2 keV) has been observed for the first time, with the half-life determined as: T_{1/2} = 2.6_{-0.3}^{+0.4} (stat.) \pm 0.6 (syst.) \times 10^{14} yr. The T_{1/2} limits for the alpha decays of other Pt isotopes have been determined at level of T_{1/2} \simeq 10^{16}-10^{20} yr. These limits have been set for the first time or they are better than those known from earlier experiments.
Characterization and performances of new indium loaded organic liquid scintillators, based on novel indium carboxilate compounds
I. Barabanov,L. Bezrukov,C. Cattadori,N. Danilov,A. Di Vacri,N. Ferrari,V. Kornoukhov,Y. S. Krylov,N. Nesterova,S. Nisi,E. Yanovich
Physics , 2007,
Abstract: A novel formulation to dope organic liquid scintillators (OLS) with indium at concentrations up to 10% is presented: it is based on specific indium carboxylate compounds adequately synthesized. The produced In-OLS has been characterized: it has light yield 8500 ph/MeV at indium concentration 5.5% and light attenuation length of 2,5 m at wavelength of 430 nm. The scintillator properties were stable during all time of investigation (~ 1 years). The produced In-OLS is compared to other In-OLS formulations and shows superior performances. The developed methodic to metal dope OLS can be easily extended to other metals as Gd, Nd, Cd.
Characterization of a Nd-loaded organic liquid scintillator for neutrinoless double beta decay search of 150-Nd with a 10-ton scale detector
I. Barabanov,L. Bezrukov,C. Cattadori,N. Danilov,A. Di Vacri,A. Ianni,S. Nisi,F. Ortica,A. Romani,C. Salvo,O. Smirnov,E. Yanovich
Physics , 2009,
Abstract: Several liters of an organic liquid scintillator (LS) loaded with Nd have been made. We report on performances of this scintillator in terms of optical properties, radiopurity and light yield for a Nd concentration of 6.5 g/l. A possible application to search for the 150Nd neutrinoless double beta decay with a 10-ton scale LS detector is discussed together with further improvements.
New experimental limits on the alpha decays of lead isotopes
J. W. Beeman,F. Bellini,L. Cardani,N. Casali,S. Di Domizio,E. Fiorini,L. Gironi,S. S. Nagorny,S. Nisi,F. Orio,L. Pattavina,G. Pessina,G. Piperno,S. Pirro,E. Previtali,C. Rusconi,C. Tomei,M. Vignati
Physics , 2012, DOI: 10.1140/epja/i2013-13050-7
Abstract: For the first time a PbWO4 crystal was grown using ancient Roman lead and it was run as a cryogenic detector. Thanks to the simultaneous and independent read-out of heat and scintillation light, the detector was able to discriminate beta/gamma interactions with respect to alpha particles down to low energies. New more stringent limits on the alpha decays of the lead isotopes are presented. In particular a limit of T_{1/2} > 1.4*10^20 y at a 90% C.L. was evaluated for the alpha decay of 204Pb to 200Hg.
First search for double $β$ decay of dysprosium
P. Belli,R. Bernabei,F. Cappella,R. Cerulli,F. A. Danevich,S. d'Angelo,M. L. Di Vacri,A. Incicchitti,M. Laubenstein,S. S. Nagorny,S. Nisi,A. V. Tolmachev,V. I. Tretyak,R. P. Yavetskiy
Physics , 2011, DOI: 10.1016/j.nuclphysa.2011.04.003
Abstract: A search for double $\beta$ decay of dysprosium was realized for the first time with the help of an ultra low-background HP Ge $\gamma$ detector. After 2512 h of data taking with a 322 g sample of dysprosium oxide limits on double beta processes in $^{156}$Dy and $^{158}$Dy have been established on the level of $T_{1/2}\geq 10^{14}-10^{16}$ yr. Possible resonant double electron captures in $^{156}$Dy and $^{158}$Dy were restricted on a similar level. As a by-product of the experiment we have measured the radioactive contamination of the Dy$_2$O$_3$ sample and set limits on the $\alpha$ decay of dysprosium isotopes to the excited levels of daughter nuclei as $T_{1/2}\geq 10^{15} - 10^{17}$ yr.
Highly sensitive gamma-spectrometers of GERDA for material screening: Part I
D. Budjá?,C. Cattadori,A. Gangapshev,W. Hampel,M. Heisel,G. Heusser,M. Hult,A. Klimenko,V. Kuzminov,M. Laubenstein,W. Maneschg,S. Nisi,S. Sch?nert,H. Simgen,A. Smolnikov,C. Tomei,A. di Vacri,S. Vasiliev,G. Zuzel
Physics , 2008,
Abstract: The GERDA experiment aims to search for the neutrinoless double beta-decay of 76Ge and possibly for other rare processes. The sensitivity of the first phase is envisioned to be more than one order of magnitude better than in previous neutrinoless double beta-decay experiments. This implies that materials with ultra-low radioactive contamination need to be used for the construction of the detector and its shielding. Therefore the requirements on material screening include high-sensitivity low-background detection techniques and long measurement times. In this article, an overview of material-screening laboratories available to the GERDA collaboration is given, with emphasis on the gamma-spectrometry. Additionally, results of an intercomparison of the evaluation accuracy in these laboratories are presented.
First search for double beta decay of platinum by ultra-low background HP Ge gamma spectrometry
P. Belli,R. Bernabei,F. Cappella,R. Cerulli,F. A. Danevich,A. Di Marco,A. Incicchitti,M. Laubenstein,S. S. Nagorny,S. Nisi,O. G. Polischuk,V. I. Tretyak
Physics , 2011, DOI: 10.1140/epja/i2011-11091-6
Abstract: A search for double beta processes in 190Pt and 198Pt was realized with the help of ultra-low background HP Ge 468 cm^3 gamma spectrometer in the underground Gran Sasso National Laboratories of the INFN (Italy). After 1815 h of data taking with 42.5 g platinum sample, T_{1/2} limits on 2beta processes in 190Pt (\epsilon\beta^+ and 2\epsilon) have been established on the level of 10^{14}-10^{16} yr, 3 to 4 orders of magnitude higher than those known previously. In particular, a possible resonant double electron capture in 190Pt was restricted on the level of 2.9 \times 10^{16} yr at 90% C.L. In addition, T_{1/2} limit on 2 beta^- decay of 198Pt (2\nu+0\nu) to the 2^+_1 excited level of 198Hg has been set at the first time: T_{1/2}>3.5 \times 10^{18} yr. The radiopurity level of the used platinum sample is reported.
Investigation of SNPs in the ATP1A2, CA3and DECR1 genes mapped to porcine chromosome 4: analysis in groups of pigs divergent for meat production and quality traits
Roberta Davoli,Luca Fontanesi,Silvia Braglia,Irma Nisi
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2006.249
Abstract: Three genes (ATPase, Na+/K+transporting, α2(+) polypeptide, ATP1A2; carbonic anhydrase III, CA3; 2,4- dienoyl CoA reductase 1, mitochondrial, DECR1), isolated from a porcine skeletal muscle cDNA library and mapped on porcine chromosome 4 (SSC4), were investigated. A new single nucleotide polymorphism (SNP) was identified in the 3’-untranslated region of the CA3 gene and used to genetically map this locus on SSC4 together with the ATP1A2and DECR1loci for which SNPs were already reported. Allele frequencies of the three loci were reported for 11 pig breeds (Italian Large White, Italian Landrace, Italian Duroc, Belgian Landrace, Hampshire, Piétrain, Meishan, Cinta Senese, Casertana, Calabrese and Nero Siciliano). Radiation hybrid mapping of these genes confirmed the linkage mapping results as well as mapping information reported by other authors. Then, the SNPs identified in the ATP1A2, CA3and DECR1genes were genotyped in Italian Large White and Italian Duroc animal groups with extreme and divergent estimated breeding value for several production traits. For CA3significant differences in allele frequencies (P< 0.05) were observed between the extreme groups of pigs for the lean cuts (Italian Large White) and visible intermuscular fat (Italian Duroc) traits. For DECR1, a significant difference in allele frequencies was observed only for the vis- ible intermuscular fat trait. ATP1A2, which maps close to the FAT1locus, did not show any significant dif- ference. A very high linkage disequilibrium (D’= 0.967; P< 0.0001) was identified between CA3and DECR1 in the Italian Duroc population. Further investigations are needed to evaluate the effect of CA3and DECR1 on the considered traits.
Effect of different butyrate supplementations on growth and health of weaning pigs challenged or not with E. coli K88
Paolo Bosi,Stefano Messori,Irma Nisi,Domenico Russo
Italian Journal of Animal Science , 2010, DOI: 10.4081/ijas.2009.s2.268
Abstract: In a full factorial design (4 diets X challenge, Yes/No), 72 weaning pigs were assigned to one of the diets: Control; experimental diets, obtained with the addition of 2 g/kg free sodium butyrate (fNaB), or 0.6 g/kg fat-protected sodium butyrate (pNaB), or 2 g/kg INVE-NutriAd commercial mixture (Mix, based on 75 g/kg protected butyrate). Oral challenge with Escherichia coli K88 was done on 2/3 of pigs on d 7. Pigs were slaughtered on d 13. The mortality in challenged pigs, tended to be higher in control group (50.0%) than in the three supplemented groups (23.5%). Growth tended to be increased averagely by the supplements (p=0.100) after the challenge, that also significantly reduced growth. In general the diet did not affect the fecal shedding of Escherichia coli and Lactobacilli, the K88-specific IgA activity in blood, the morphology of oxyntic mucosa and the expression of H+/K+-ATPase gene. The supplementations tended to increase villous length of jejunum (p=0.101). On the whole, growth, villous height and surviving rate can be positively affected either when the supplementation is done by free butyrate, by protected butyrate or by the special Inve Nutri-Ad product and these effects are distributed both on pigs infected or not with Escherichia coli K88.
Fe deficiency differentially affects the vacuolar proton pumps in cucumber and soybean roots
Marta Dell’Orto,Patrizia De Nisi,Gianpiero Vigani,Graziano Zocchi
Frontiers in Plant Science , 2013, DOI: 10.3389/fpls.2013.00326
Abstract: Iron uptake in dicots depends on their ability to induce a set of responses in root cells including rhizosphere acidification through H+ extrusion and apoplastic Fe(III) reduction by Fe(III)-chelate reductase. These responses must be sustained by metabolic rearrangements aimed at providing the required NAD(P)H, ATP and H+. Previous results in Fe-deficient cucumber roots showed that high H+ extrusion is accompanied by increased phosphoenolpyruvate carboxylase (PEPC) activity, involved in the cytosol pH-stat; moreover 31P-NMR analysis revealed increased vacuolar pH and decreased vacuolar [inorganic phosphate (Pi)]. The opposite was found in soybean: low rhizosphere acidification, decreased PEPC activity, vacuole acidification, and increased vacuolar [Pi]. These findings, highlighting a different impact of the Fe deficiency responses on cytosolic pH in the two species, lead to hypothesize different roles for H+ and Pi movements across the tonoplast in pH homeostasis. The role of vacuole in cytosolic pH-stat involves the vacuolar H+-ATPase (V-ATPase) and vacuolar H+-pyrophosphatase (V-PPase) activities, which generating the ΔpH and ΔΨ, mediate the transport of solutes, among which Pi, across the tonoplast. Fluxes of Pi itself in its two ionic forms, H2PO4- predominating in the vacuole and HPO42- in the cytosol, may be involved in pH homeostasis owing to its pH-dependent protonation/deprotonation reactions. Tonoplast enriched fractions were obtained from cucumber and soybean roots grown with or without Fe. Both V-ATPase and V-PPase activities were analyzed and the enrichment and localization of the corresponding proteins in root tissues were determined by Western blot and immunolocalization. V-ATPase did not change its activity and expression level in response to Fe starvation in both species. V-PPase showed a different behavior: in cucumber roots its activity and abundance were decreased, while in Fe-deficient soybean roots they were increased. The distinct role of the two H+ pumps in Pi fluxes between cytoplasm and vacuole in Fe-deficient cucumber and soybean root cells is discussed.
Page 1 /325229
Display every page Item

Copyright © 2008-2017 Open Access Library. All rights reserved.