6,844 research outputs found
Rare decays at B-factories
We report the latest results from BABAR and Belle on leptonic decays of B mesons and B → K(∗)νν
Finite Temperature Effective Potential for Gauge Models in de Sitter Space
The one-loop effective potential for gauge models in static de Sitter space
at finite temperatures is computed by means of the --function method. We
found a simple relation which links the effective potentials of gauge and
scalar fields at all temperatures.
In the de Sitter invariant and zero-temperature states the potential for the
scalar electrodynamics is explicitly obtained, and its properties in these two
vacua are compared. In this theory the two states are shown to behave similarly
in the regimes of very large and very small radii a of the background space.
For the gauge symmetry broken in the flat limit () there is a
critical value of a for which the symmetry is restored in both quantum states.
Moreover, the phase transitions which occur at large or at small a are of the
first or of the second order, respectively, regardless the vacuum considered.
The analytical and numerical analysis of the critical parameters of the above
theory is performed. We also established a class of models for which the kind
of phase transition occurring depends on the choice of the vacuum.Comment: 23 pages, LaTeX, 5 figure.ep
Avaliação do efeito do Baculovirus anticarsia sobre Podisus nigrispinus (DALLAS, 1851), predador da lagarta da soja Anticarsia gemmatalis (HUBNER, 1818).
Este trabalho tem como objetivo conhecer os efeitos da ingestão de lagartas da soja infectadas com B. anticarsia pelo predador Podisus nigrispinus, avaliando-se os parâmetros biológicos de cada inseto.bitstream/CNPMA/5854/1/baculovirus_anticarsia.pd
Radiation effective dose assessment of [51Mn]- and [52Mn]-chloride
In order to establish the potential of [51/52Mn]Cl2 as safe PET brain tracers, the radiation effective dose (ED) of [51Mn]- and [52Mn]-chloride has been assessed by using biokinetic models in anthropomorphic phantoms. Results showed that [52Mn]-chloride releases one hundred thirty times more radiation dose (ED = 1.35 mSv/MBq) than [51Mn]-chloride (ED = 1.02E-02 mSv/MBq). Although the maximum positron energy of 52Mn allows a PET image resolution similar to that of 18F, activities below 15 MBq should be administered
Immune response in peripheral axons delays disease progression in SOD1(G93A) mice.
BACKGROUND: Increasing evidence suggests that the immune system has a beneficial role in the progression of amyotrophic lateral sclerosis (ALS) although the mechanism remains unclear. Recently, we demonstrated that motor neurons (MNs) of C57SOD1(G93A) mice with slow disease progression activate molecules classically involved in the cross-talk with the immune system. This happens a lot less in 129SvSOD1(G93A) mice which, while expressing the same amount of transgene, had faster disease progression and earlier axonal damage. The present study investigated whether and how the immune response is involved in the preservation of motor axons in the mouse model of familial ALS with a more benign disease course. METHODS: First, the extent of axonal damage, Schwann cell proliferation, and neuromuscular junction (NMJ) denervation were compared between the two ALS mouse models at the disease onset. Then, we compared the expression levels of different immune molecules, the morphology of myelin sheaths, and the presence of blood-derived immune cell infiltrates in the sciatic nerve of the two SOD1G93A mouse strains using immunohistochemical, immunoblot, quantitative reverse transcription PCR, and rotating-polarization Coherent Anti-Stokes Raman Scattering techniques. RESULTS: Muscle denervation, axonal dysregulation, and myelin disruption together with reduced Schwann cell proliferation are prominent in 129SvSOD1(G93A) compared to C57SOD1(G93A) mice at the disease onset, and this correlates with a faster disease progression in the first strain. On the contrary, a striking increase of immune molecules such as CCL2, MHCI, and C3 was seen in sciatic nerves of slow progressor C57SOD1(G93A) mice and this was accompanied by heavy infiltration of CD8(+) T lymphocytes and macrophages. These phenomena were not detectable in the peripheral nervous system of fast-progressing mice. CONCLUSIONS: These data show for the first time that damaged MNs in SOD1-related ALS actively recruit immune cells in the peripheral nervous system to delay muscle denervation and prolong the lifespan. On the contrary, the lack of this response has a negative impact on the disease course
Effects of the equilibrium atmosphere on Taleggio cheese storage in micro perforated packaging
Taleggio is an Italian smear-ripened cheese, whose complex microbiota demands the optimisation of the packaging system to avoid excessive changes during storage. Metabolic processes of the cheese rind microbiota can be usefully exploited in equilibrium modified atmosphere packaging (EMAP) by balancing microbiota respiration and film permeation. Here, we present the application of three different micro perforated EMAPs as models for smear-ripened cheese compared to two control packaging configurations. Analyses of the main microbial groups, headspace gas, textural profile, and sensory properties were performed to find the best packaging for storage. Results showed that two of the alternative micro perforated packaging systems were able to control the excessive changes during storage, thus limiting fungal overgrowth and allowing the typical development of smear microbiota with minor changes to hardness and cohesiveness. Finally, the sensory evaluation positively favoured one of the alternatively packed cheeses based on its compactness, typical dairy traits, and minor off-flavours. These findings showed that EMAP can be a valid alternative solution to control the storage of Taleggio cheese. Further studies could be conducted to evaluate this system on other smear cheeses
Thermal Conductivity Enhancement of Al2O3 Nanofluid in Ethylene Glycol and Water Mixture
AbstractThe ability of nanofluids that exhibits enhanced thermal performance is acknowledged by researchers through studies since decades ago. However, the observation of thermal properties for nanofluids in water and ethylene glycol based is not fully explored yet. Hence, this paper presents the thermal conductivity of water and ethylene glycol (EG) based Al2O3 nanofluid. The 13 nm sized Al2O3 nanoparticles were dispersed into three different volume ratio of water: EG such as 40:60, 50:50 and 60:40 using a two-step method. The measurement of thermal conductivity was performed using KD2 Pro Thermal Properties Analyzer at working temperatures of 30 to 70 ÌŠC for volume concentration of 0.5 to 2.0%. The results indicate that the thermal conductivity increases with the increase of nanofluid concentration and temperature. While the percentage of ethylene glycol increase, the range of thermal conductivity decreases due to ethylene glycol properties. The measurement data of the nanofluids give maximum enhancement of thermal conductivity at condition 2.0% volume concentration, temperature of 70 ÌŠC and for all base fluid
Radioisotopic purity and imaging properties of cyclotron-produced 99mTc using direct 100Mo(p,2n) reaction
Evaluation of the radioisotopic purity of technetium-99m (99mTc) produced in GBq amounts by proton bombardment of enriched molibdenum-100 (100Mo) metallic targets at low proton energies (i.e. within 15\u201320 MeV) is conducted. This energy range was chosen since it is easily achievable by many conventional medical cyclotrons already available in the nuclear medicine departments of hospitals. The main motivation for such a study is in the framework of the research activities at the international level that have been conducted over the last few years to develop alternative production routes for the most widespread radioisotope used in medical imaging. The analysis of technetium isotopes and isomeric states (9xTc) present in the pertechnetate saline Na99mTcO4 solutions, obtained after the extraction/purification procedure, reveals radionuclidic purity levels basically in compliance with the limits recently issued by European Pharmacopoeia 9.3 (2018 Sodium pertechnetate (99mTc) injection 4801\u20133). Moreover, the impact of 9xTc contaminant nuclides on the final image quality is thoroughly evaluated, analyzing the emitted high-energy gamma rays and their influence on the image quality. The spatial resolution of images from cyclotron-produced 99mTc acquired with a mini-gamma camera was determined and compared with that obtained using technetium-99m solutions eluted from standard 99Mo/99mTc generators. The effect of the increased image background contribution due to Compton-scattered higher-energy gamma rays (E \u3b3 \u2009\u2009>\u2009\u2009200\u2009keV), which could cause image-contrast deterioration, was also studied. It is concluded that, due to the high radionuclidic purity of cyclotron-produced 99mTc using 100Mo(p,2n)99mTc reaction at a proton beam energy in the range 15.7\u201319.4 MeV, the resulting image properties are well comparable with those from the generator-eluted 99mTc
Is there a relationship between joint hypermobility and gastrointestinal disorders in children?
Background. The main aim of the study was to assess the association between joint hypermobility (JH) and gastrointestinal (GI) disorders in children. Methods. All children aged 4-17 years attending the clinics of the participating Pediatric Gastroenterology Centres for functional GI disorders (FGIDs) and inflammatory bowel disease (IBD) were screened for joint laxity. JH diagnosis was inferred using the Beighton Score. JHS diagnosis was inferred based on the Brighton Criteria. Rome III Diagnostic Criteria were used to diagnose possible FGIDs. Ulcerative colitis and Crohn’s disease diagnoses were made according to the Porto Criteria. Age and sex- matched healthy children were enrolled as controls. Results. One-hundred-seventy children with GI disorders (70 with FGIDs, 50 with Crohn’s disease, and 50 with ulcerative colitis) and 100 healthy controls were enrolled in the study. JH was reported in 7/70 (10%) children with FGIDs (p=0.26 compared to controls), 4/50 (8%) children with Crohn’s disease (p=0.21 compared to controls) and 15/50 (30%) children with ulcerative colitis (p=0.09 compared to controls; p=0.01 compared to FGIDs; p=0.01 compared to Crohn’s). Conclusions. JH is more prevalent in patients suffering from ulcerative colitis compared to the healthy general population, yet the difference did not reach statistical significance. Likely, a proportion of children with ulcerative colitis and JH may show connective tissue abnormalities. However, whether JH can be considered a possible feature of pediatric GI disorders deserves further investigation
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