754 research outputs found
An innovative technique for the investigation of the 4-fold forbidden beta-decay of V
For the first time a Vanadium-based crystal was operated as cryogenic
particle detector. The scintillating low temperature calorimetric technique was
used for the characterization of a 22 g YVO crystal aiming at the
investigation of the 4-fold forbidden non-unique decay of V.
The excellent bolometric performance of the compound together with high light
output of the crystal makes it an outstanding technique for the study of such
elusive rate process. The internal radioactive contaminations of the crystal
are also investigated showing that an improvement on the current status of
material selection and purification are needed, U and Th
are measured at the level of 28 mBq/kg, 1.3 Bq/kg and 28 mBq/kg, respectively.
In this work, we also discuss a future upgrade of the experimental set-up which
may pave the road for the detection of the rare V decay
A new investigation of half-lives for the decay modes of V
A new search for the decay modes of the 4-fold forbidden non-unique decay of
V has been performed at the Gran Sasso Underground Laboratory (LNGS). In
total an exposure of 197 kg d has been accumulated. The half-life for
the electron capture into the first excited state of Ti has been
measured with the highest precision to date as yr (68% C.I.) in which systematics uncertainties dominate. The search
for the -decay into the first excited state of Cr resulted in a
lower limit of yr (90% C.I.), which is an improvement of
almost one order of magnitude compared to existing results. The sensitivity of
the new measurement is now in the region of theoretical predictions
Hemostatic Agents for the Management of Bleeding Risk Associated with Oral Anticoagulant Therapy Following Tooth Extraction: A Systematic Review
The occurrence of bleeding following dental extraction is a relatively common complication. A history of therapy with oral anticoagulants represents a major favoring factor, both in patients treated with vitamin K-antagonists (especially warfarin) and with direct oral anticoagulants (DOACs). Several local hemostatic measures can be applied to limit the bleeding risk in these patients. The aim of this systematic review is to evaluate what measures can be adopted to limit the bleeding risk following dental extractions in patients treated with oral anticoagulants. A literature search was performed, and 116 articles were retrieved. Titles and abstract analyses excluded 91 articles, and three more articles were excluded following full-text analysis. The systematic review was performed on 22 articles. Among the included articles, 20 studies reported on patients treated with warfarin, and two studies on patients treated with DOACs. The agents employed included local intra-alveolar agents, tranexamic acid, and PRF. The included studies were all at moderate/high risk of bias. Moreover, limited evidence is available on hemostasis in patients treated with DOACs. The available evidence hinders stating the superiority of one agent over the others. Further research is advised to increase the level of evidence of the application of hemostatic agents in patients treated with oral anticoagulants
Copper electroforming service at Laboratorio Subterráneo de Canfranc
Electroforming of copper can be very effective to obtain high radio-purity copper parts for low-background experiments. To support the construction of experiments at the Laboratorio Subterráneo de Canfranc in Spain, a Copper Electroforming Service (CES) set-up is in operation. In this work the electroforming system is described and results on the radio-purity of parts made are presented
Relativistic electrons from sparks in the laboratory
Discharge experiments were carried out at the Eindhoven University of
Technology in 2013. The experimental setup was designed to search for electrons
produced in meter-scale sparks using a 1 MV Marx generator. Negative voltage
was applied to the high voltage (HV) electrode. Five thin (1 mm) plastic
detectors (5 each) were distributed in various configurations close
to the spark gap. Earlier studies have shown (for HV negative) that X-rays are
produced when a cloud of streamers is developed 30-60 cm from the negative
electrode. This indicates that the electrons producing the X-rays are also
accelerated at this location, that could be in the strong electric field from
counterstreamers of opposite polarity. Comparing our measurements with modeling
results, we find that 300 keV electrons produced about 30-60 cm from the
negative electrode are the most likely source of our measurements. A
statistical analysis of expected detection of photon bursts by these fiber
detectors indicates that only 20%-45% of the detected bursts could be from soft
(10 keV) photons, which further supports that the majority of detected
bursts are produced by relativistic electrons
Updated and novel limits on double beta decay and dark matter-induced processes in platinum
A 510 day long-term measurement of a 45.3 g platinum foil acting as the
sample and high voltage contact in an ultra-low-background high purity
germanium detector was performed at Laboratori Nazionali del Gran Sasso
(Italy). The data was used for a detailed study of double beta decay modes in
natural platinum isotopes. Limits are produced in the range
a for double beta decay to excited states (90%
C.L.) confirming, and partially extending existing limits. The highest
sensitivity, greater than a, was achieved for the and resonant
modes of double electron capture involving KL shell electrons.
Additionally, novel limits for inelastic dark matter scattering on Pt
are placed up to mass splittings of approximately 500 keV. We analyze several
techniques to extend the sensitivity and propose a few approaches for future
medium-scale experiments with platinum-group elements.Comment: 15 pages, 3 figure
Sustainable Production of Stiff and Crystalline Bacterial Cellulose from Orange Peel Extract
In this work, a potentially economic and environmentally friendly method for the synthesis of bacterial cellulose (BC) by Gluconacetobacter xylinus from a biomass containing orange peel extract was evaluated. Orange peel extract was used as a culture medium without any hydrolysis treatment, thus speeding up the synthesis procedure. The efficacy of orange peel as a carbon source was compared with that of sucrose. The orange peel extract formed thicker cellulose gels than those formed using sucrose. X-ray diffraction (XRD) revealed both a high crystallinity index and crystallite size of BC nanofibers in samples obtained from orange peel (BC_Orange). Field emission scanning electron microscopy (FE-SEM) revealed a highly densely packed nanofibrous structure (50 nm in diameter). BC_Orange presented a two-fold increase in water holding capacity (WHC), and dynamic mechanical analysis (DMA) showed a 44% increase in storage modulus compared to sucrose derived BC. These results showed that the naturally available carbon sources derived from orange peel extract can be effectively used for BC production. The orange-based culture medium can be considered a profitable alternative to the generation of high-value products in a virtuous circular economy model
New experimental limits on the alpha decays of lead isotopes
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
Investigation of SNPs in the ATP1A2, CA3 and DECR1 genes mapped to porcine chromosome 4: analysis in groups of pigs divergent for meat production and quality traits
STUDIO DI TRE GENI (ATP1A2, CA3E DECR1) LOCALIZZATI SUL CROMOSOMA SUINO 4: ANALISIDELLE FREQUENZE ALLELICHE DI SNP IN SUINI ESTREMI PER ALCUNI CARATTERI PRODUTTIVITre geni (ATPase, Na+/K+transporting, \u3b12(+) polypeptide, ATP1A2; carbonic anhydrase III, CA3; 2,4-die-noyl CoA reductase 1, mitochondrial, DECR1), isolati da una libreria a cDNA ottenuta da muscolo scheletri-co di suino, sono stati scelti per questo studio sulla base del ruolo fisiologico della proteina codificata in pro-cessi cellulari e metabolici collegabili in modo diretto o indiretto con alcuni caratteri produttivi. La scelta dei tre geni \ue8 stata anche basata sulla loro localizzazione sul cromosoma 4 dove diversi QTL per caratteri pro-duttivi sono gi\ue0 stati identificati.Nella regione 3\u2019 non tradotta del gene CA3\ue8 stato identificato, mediante analisi SSCP, un polimorfismo bial-lelico. Il sequenziamento dei due alleli ha permesso di identificare una nuova mutazione puntiforme, che \ue8stata successivamente analizzata mediante PCR-RFLP. Per questo gene \ue8 stato effettuato il mappaggiogenetico sul cromosoma 4 mediante l\u2019analisi della mutazione nei campioni delle famiglie di riferimento delprogetto europeo di mappaggio del genoma suino (PiGMaP). Utilizzando il polimorfismo PCR-RFLP del geneATP1A2, gi\ue0 decritto in un precedente lavoro come SSCP, sono state tipizzate diverse famiglie di riferimen-to PiGMaP ed \ue8 stato confermato il mappaggio genetico di ATP1A2. Utilizzando queste informazioni e quel-le gi\ue0 disponibili per DECR1, per la prima volta, \ue8 stata ottenuta una mappa di linkage del cromosoma 4che comprende tutti e tre i geni analizzati. Il mappaggio genetico dei tre geni \ue8 stato anche confermatomediante tipizzazione di un pannello di ibridi di cellule irradiate (IMpRH 7000 rad).Le frequenze alleliche delle mutazioni identificate nei tre loci sono state studiate in 11 razze suine (LargeWhite Italiana, Landrace Italiana, Duroc Italiana, Landrace Belga, Hampshire, Pi\ue9train, Meishan, CintaSenese, Casertana, Calabrese and Nero Siciliano) per un totale di 272 animali. Inoltre, come approccio ini-ziale per poi scegliere i geni da analizzare in futuri studi di associazione, abbiamo confrontato le frequenzealleliche di mutazioni puntiformi per questi tre loci in gruppi di suini di razza Large White Italiana e DurocItaliana, analizzando animali con valori degli indici genetici estremi e divergenti per alcuni caratteri produt-tivi (accrescimento, spessore lardo dorsale, tagli magri e grasso intermuscolare visibile). Per il gene CA3 \ue8stata osservata una differenza nella distribuzione delle frequenze alleliche (P< 0,05) per i due caratteri taglimagri (nella razza Large White Italiana) e grasso intermusculare visibile (nella razza Duroc Italiana). Per ilgene DECR1, differenze significative sono state osservate per il carattere grasso intermuscolare visibile. Ilgene ATP1A2, che mappa vicino al locus FAT1, non ha presentato differenze statisticamente significativenelle frequenze tra i gruppi estremi per i caratteri oggetto di studio. Analizzando il livello di linkage disequi-librium(LD) tra i tre loci, \ue8 stato evidenziato un elevato livello di LD (D\u2019= 0,967; P< 0,0001) tra i geni CA3e DECR1, solo nella popolazione Duroc Italiana. Questi primi risultati pongono le basi per ulteriori studi perverificare se i geni CA3e DECR1sono associati con i caratteri oggetto di selezione nel suino pesante.Three genes (ATPase, Na+/K+ transporting, \u3b1 2(+) 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\u2019-untranslated region of the CA3 gene and used to genetically map this locus on SSC4 together with the ATP1A2 and DECR1 loci 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, Pi\uf9train, 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, CA3 and DECR1 genes were genotyped in Italian Large White and Italian Duroc animal groups with extreme and divergent estimated breeding value for several production traits. For CA3 significant 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 visible intermuscular fat trait. ATP1A2, which maps close to the FAT1 locus, did not show any significant difference. A very high linkage disequilibrium (D\u2019= 0.967; P< 0.0001) was identified between CA3 and DECR1 in the Italian Duroc population. Further investigations are needed to evaluate the effect of CA3 and DECR1 on the considered trait
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