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1.
Theriogenology ; 173: 48-55, 2021 Oct 01.
Artículo en Inglés | MEDLINE | ID: mdl-34332201

RESUMEN

We investigated the effect of the antioxidant lycopene supplemented into the in vitro maturation medium (TCM-199 with 20 ng/mL epidermal growth factor and 50 mg/mL gentamycin) in a heat shock (HS) model to mimic in vivo heat stress conditions. Bovine cumulus-oocyte complexes were supplemented with 0.2 µM lycopene (or not supplemented; control) under HS (40.5 °C) and non-HS (NHS; 38.5 °C) during maturation. After 22 h of maturation, we evaluated the nuclear status of the oocytes, the level of reactive oxygen species (ROS) production, and the respective blastocyst development and quality (via differential staining). Data were fitted in logistic and linear regression models, and the replicates were set as a random effect. The nuclear maturation was higher in NHS (84.0 ± 3.2%; least square mean ± standard error) than HS control (60.4 ± 4.3%; P < 0.001). Remarkably, the nuclear maturation in HS lycopene (71.7 ± 4.1%) was similar to NHS control (P = 0.7). Under HS conditions lycopene reduced ROS production (27.4 ± 4.8; relative fluorescence units (RFU)) in comparison to HS control (33.8 ± 1.8 RFU; P = 0.009). However, the ROS production in NHS lycopene (18.9 ± 2.0 RFU) was similar to NHS control (18.7 ± 1.8 RFU; P = 0.9). The cleavage rate in HS lycopene (76.1 ± 3.3%) was not lower than NHS lycopene (83.3 ± 2.5%; P > 0.1). On the day 8 of embryo development, the blastocyst rate was higher for NHS lycopene (55.2 ± 4.7%) versus NHS control (44.5 ± 4.7%; P = 0.04), but under HS the day 8 blastocyst rate was similar between control (29.9 ± 4.2%) and lycopene (32.3 ± 4.2%; P = 0.9). Lycopene supplementation increased the cell number of the embryos (total cell, trophectoderm, and inner cell mass numbers) under NHS conditions (P > 0.03). The apoptotic cell ratio was lower in lycopene (NHS and HS) versus control (NHS and HS) (P > 0.04). Lycopene has the ability to scavenge oocyte ROS and improved the cleavage rate of embryos under HS conditions. However, this could not be translated to a higher blastocyst development, which remained lower under HS. Results of our study indicate that antioxidant supplementation like lycopene during the maturation of bovine cumulus-oocyte complexes may be routinely used to improve blastocyst rate and quality under standard maturation conditions.


Asunto(s)
Técnicas de Maduración In Vitro de los Oocitos , Oocitos , Animales , Blastocisto , Bovinos , Suplementos Dietéticos , Desarrollo Embrionario , Respuesta al Choque Térmico , Técnicas de Maduración In Vitro de los Oocitos/veterinaria , Licopeno
7.
J Frailty Aging ; 9(2): 101-106, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32259184

RESUMEN

BACKGROUND: Frailty is a pre-disability condition in older persons providing a challenge to Health-Care Systems. Systematic reviews highlight the absence of a gold-standard for its identification. However, an approach based on initial screening by the General Practitioner (GP) seems particularly useful. On these premises, a 9-item Sunfrail Checklist (SC), was developed by a multidisciplinary group, in the context of European Sunfrail Project, and tested in the Community. OBJECTIVES: - to measure the concordance between the judgments of frailty (criterion-validity): the one formulated by the GP, using the SC, and the one subsequently expressed by a Comprehensive Geriatric Assessment Team (CGA-Team); - to determine the construct-validity through the correspondence between some checklist items related to the 3 domains (physical, cognitive and social) and the three tools used by the CGA-Team; - to measure the instrument's performance in terms of positive predictive value (PPV) and negative predictive value (NPV). DESIGN: Cross-sectional study, with a final sample-size of 95 subjects. SETTING: Two Community-Health Centers of Parma, Italy. PARTICIPANTS: Subjects aged 75 years old or more, with no disability and living in the community. MEASUREMENTS: We compared the screening capacity of the GP using the SC to that one of CGA-Team based on three tests: 4-meter Gait-Speed, Mini-Mental State Examination and Loneliness Scale. RESULTS: 95 subjects (51 women), with a mean age of 81±4 years were enrolled. According to GPs 34 subjects were frail; the CGA-Team expressed a frailty judgment on 26 subjects. The criterion-validity presented a Cohen's k of 0.353. Construct-validity was also low, with a maximum contingency-coefficient of 0.19. The analysis showed a PPV of 58.1% and a NPV equal to 84.6%. CONCLUSIONS: Our data showed a low agreement between the judgements of GP performed by SC and CGA-Team. However, the good NPV suggests the applicability of SC for screening activities in primary-care.


Asunto(s)
Anciano Frágil , Fragilidad/diagnóstico , Evaluación Geriátrica/métodos , Atención Primaria de Salud , Anciano , Anciano de 80 o más Años , Estudios Transversales , Diagnóstico Precoz , Femenino , Humanos , Italia , Masculino , Valor Predictivo de las Pruebas
8.
Phys Rev Lett ; 122(8): 084801, 2019 Mar 01.
Artículo en Inglés | MEDLINE | ID: mdl-30932604

RESUMEN

Guiding of relativistically intense laser pulses with peak power of 0.85 PW over 15 diffraction lengths was demonstrated by increasing the focusing strength of a capillary discharge waveguide using laser inverse bremsstrahlung heating. This allowed for the production of electron beams with quasimonoenergetic peaks up to 7.8 GeV, double the energy that was previously demonstrated. Charge was 5 pC at 7.8 GeV and up to 62 pC in 6 GeV peaks, and typical beam divergence was 0.2 mrad.

9.
Phys Rev Lett ; 121(26): 264802, 2018 Dec 28.
Artículo en Inglés | MEDLINE | ID: mdl-30636157

RESUMEN

Mitigation of the beam hose instability in plasma-based accelerators is required for the realization of many applications, including plasma-based colliders. The hose instability is analyzed in the blowout regime including plasma ion motion, and ion motion is shown to suppress the hose instability by inducing a head-to-tail variation in the focusing force experienced by the beam. Hence, stable acceleration in plasma-based accelerators is possible, while, by use of proper bunch shaping, minimizing the energy spread and preserving the transverse beam emittance.

10.
Phys Rev Lett ; 119(10): 104801, 2017 Sep 08.
Artículo en Inglés | MEDLINE | ID: mdl-28949165

RESUMEN

Single-shot, charge-dependent emittance measurements of electron beams generated by a laser plasma accelerator (LPA) reveal that shock-induced density down-ramp injection produces beams with normalized emittances a factor of 2 smaller than beams produced via ionization injection. Such a comparison is made possible by the tunable LPA setup, which allows electron beams with nearly identical central energy and peak spectral charge density to be produced using the two distinct injection mechanisms. Parametric measurements of this type are essential for the development of LPA-based applications which ultimately require high charge density and low emittance.

11.
Nature ; 530(7589): 190-3, 2016 Feb 11.
Artículo en Inglés | MEDLINE | ID: mdl-26829223

RESUMEN

Laser-plasma accelerators (LPAs) are capable of accelerating charged particles to very high energies in very compact structures. In theory, therefore, they offer advantages over conventional, large-scale particle accelerators. However, the energy gain in a single-stage LPA can be limited by laser diffraction, dephasing, electron-beam loading and laser-energy depletion. The problem of laser diffraction can be addressed by using laser-pulse guiding and preformed plasma waveguides to maintain the required laser intensity over distances of many Rayleigh lengths; dephasing can be mitigated by longitudinal tailoring of the plasma density; and beam loading can be controlled by proper shaping of the electron beam. To increase the beam energy further, it is necessary to tackle the problem of the depletion of laser energy, by sequencing the accelerator into stages, each powered by a separate laser pulse. Here, we present results from an experiment that demonstrates such staging. Two LPA stages were coupled over a short distance (as is needed to preserve the average acceleration gradient) by a plasma mirror. Stable electron beams from a first LPA were focused to a twenty-micrometre radius--by a discharge capillary-based active plasma lens--into a second LPA, such that the beams interacted with the wakefield excited by a separate laser. Staged acceleration by the wakefield of the second stage is detected via an energy gain of 100 megaelectronvolts for a subset of the electron beam. Changing the arrival time of the electron beam with respect to the second-stage laser pulse allowed us to reconstruct the temporal wakefield structure and to determine the plasma density. Our results indicate that the fundamental limitation to energy gain presented by laser depletion can be overcome by using staged acceleration, suggesting a way of reaching the electron energies required for collider applications.

12.
Phys Rev Lett ; 115(18): 184802, 2015 Oct 30.
Artículo en Inglés | MEDLINE | ID: mdl-26565471

RESUMEN

Compact, tunable, radially symmetric focusing of electrons is critical to laser-plasma accelerator (LPA) applications. Experiments are presented demonstrating the use of a discharge-capillary active plasma lens to focus 100-MeV-level LPA beams. The lens can provide tunable field gradients in excess of 3000 T/m, enabling cm-scale focal lengths for GeV-level beam energies and allowing LPA-based electron beams and light sources to maintain their compact footprint. For a range of lens strengths, excellent agreement with simulation was obtained.

13.
Artículo en Inglés | MEDLINE | ID: mdl-26382537

RESUMEN

The self-consistent laser evolution of an intense, short-pulse laser exciting a plasma wave and propagating in a preformed plasma channel is investigated, including the effects of pulse steepening and energy depletion. In the weakly relativistic laser intensity regime, analytical expressions for the laser energy depletion, pulse self-steepening rate, laser intensity centroid velocity, and phase velocity of the plasma wave are derived and validated numerically.


Asunto(s)
Rayos Láser , Modelos Teóricos , Simulación por Computador
14.
J Toxicol Environ Health A ; 78(10): 617-27, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26039679

RESUMEN

Levels of iron (Fe), manganese (Mn), chromium (Cr), copper (Cu), zinc (Zn), mercury (Hg), cadmium (Cd), and lead (Pb) in several types of honey produced in a region of Central Italy were determined by atomic absorption spectroscopy (AAS). The degree of humidity, sugar content, pH, free acidity, combined acidity (lactones), and total acidity were also measured. These elements were found to be present in honey in various proportions depending upon (1) the area foraged by bees, (2) flower type visited for collection of nectar, and (3) quality of water in the vicinity of the hive. Strong positive correlations occurred between Pb and Hg, Pb and Cd, Pb and Fe, Pb and Cr, Hg and Cd, and Hg and Fe. The honey products synthesized in Central Italy were of good quality, but not completely free of heavy metal contamination. Compared with established recommended daily intakes, heavy metals or trace element intoxication following honey consumption in Italy was found not to be a concern for human health.


Asunto(s)
Contaminación de Alimentos/análisis , Calidad de los Alimentos , Miel/análisis , Metales Pesados/metabolismo , Oligoelementos/metabolismo , Monitoreo del Ambiente , Italia , Espectrofotometría Atómica
15.
Phys Rev Lett ; 113(24): 245002, 2014 Dec 12.
Artículo en Inglés | MEDLINE | ID: mdl-25541775

RESUMEN

Multi-GeV electron beams with energy up to 4.2 GeV, 6% rms energy spread, 6 pC charge, and 0.3 mrad rms divergence have been produced from a 9-cm-long capillary discharge waveguide with a plasma density of ≈7×10¹7 cm⁻³, powered by laser pulses with peak power up to 0.3 PW. Preformed plasma waveguides allow the use of lower laser power compared to unguided plasma structures to achieve the same electron beam energy. A detailed comparison between experiment and simulation indicates the sensitivity in this regime of the guiding and acceleration in the plasma structure to input intensity, density, and near-field laser mode profile.

16.
G Ital Dermatol Venereol ; 149(3): 355-61, 2014 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-24819764

RESUMEN

AIM: Psoriasis is a multifactorial chronic inflammatory skin disease that often occurs in patients who are overweight or obese. In literature the connections between obesity and eating disorders are well known, but few studies have investigated the link between eating disorders and psoriasis. We hypothesized that Eating Disorders (ED) can be considered a psychogenic cofactors, which contribute to the development of obesity and metabolic syndrome in psoriatic patients, who are frequently prone to psychiatric comorbidity. METHODS: From January to April 2011 we enrolled 100 consecutive psoriatic outpatients and a control group of 100 selected non-psoriatic outpatients, matched by age, gender, and BMI to the study group. The assessment battery was composed by the Psoriasis Area Severity Index (PASI) score, the Eating Disorder Inventory (EDI) and the Symptom Checklist-90 Revised (SCL-90-R®). RESULTS: Our data showed that most of EDI and SCL-90R subscales was mostly altered in psoriatic population compared to patients without psoriasis. Moreover, we noticed in patients with psoriasis an association between the progressive weight increase and an impairment on most of EDI subscales. CONCLUSION: Psoriasis is associated with psychopathological traits, which are frequently found in EDs. Since obesity makes psoriasis less susceptible to therapy and weight loss improves drug response, dermatologists should be alert to suspect the presence of this condition.


Asunto(s)
Trastornos de Alimentación y de la Ingestión de Alimentos/psicología , Síndrome Metabólico/psicología , Obesidad/psicología , Psoriasis/psicología , Adulto , Anciano , Índice de Masa Corporal , Estudios de Casos y Controles , Trastornos de Alimentación y de la Ingestión de Alimentos/complicaciones , Femenino , Humanos , Masculino , Síndrome Metabólico/etiología , Persona de Mediana Edad , Obesidad/etiología , Psoriasis/complicaciones , Psoriasis/diagnóstico , Escalas de Valoración Psiquiátrica , Índice de Severidad de la Enfermedad , Encuestas y Cuestionarios
17.
Phys Rev Lett ; 112(12): 125001, 2014 Mar 28.
Artículo en Inglés | MEDLINE | ID: mdl-24724654

RESUMEN

A method is proposed to generate femtosecond, ultralow emittance (∼10-8 m rad), electron beams in a laser-plasma accelerator using two lasers of different colors. A long-wavelength pump pulse, with a large ponderomotive force and small peak electric field, excites a wake without fully ionizing a high-Z gas. A short-wavelength injection pulse, with a small ponderomotive force and large peak electric field, copropagating and delayed with respect to the pump laser, ionizes a fraction of the remaining bound electrons at a trapping wake phase, generating an electron beam that is accelerated in the wake.

18.
Phys Rev E Stat Nonlin Soft Matter Phys ; 86(2 Pt 2): 026402, 2012 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-23005864

RESUMEN

Transverse stability of the drive beam is critical to plasma wakefield accelerators. A long, relativistic particle beam propagating in an overdense plasma is subject to beam envelope modulation and centroid displacement (hosing) instabilities. Coupled equations for the beam centroid and envelope are derived and solved. It is shown that the hosing growth rate is comparable to self-modulation, and coupling of the self-modulation enhances beam hosing and induces harmonic content. Large amounts of hosing significantly alters the structure of the plasma wakefields.

19.
Phys Rev Lett ; 109(6): 064802, 2012 Aug 10.
Artículo en Inglés | MEDLINE | ID: mdl-23006273

RESUMEN

X-ray spectroscopy is used to obtain single-shot information on electron beam emittance in a low-energy-spread 0.5 GeV-class laser-plasma accelerator. Measurements of betatron radiation from 2 to 20 keV used a CCD and single-photon counting techniques. By matching x-ray spectra to betatron radiation models, the electron bunch radius inside the plasma is estimated to be ~0.1 µm. Combining this with simultaneous electron spectra, normalized transverse emittance is estimated to be as low as 0.1 mm mrad, consistent with three-dimensional particle-in-cell simulations. Correlations of the bunch radius with electron beam parameters are presented.

20.
Phys Rev Lett ; 108(9): 094801, 2012 Mar 02.
Artículo en Inglés | MEDLINE | ID: mdl-22463644

RESUMEN

Laser plasma accelerators have produced femtosecond electron bunches with a relative energy spread ranging from 100% to a few percent. Simulations indicate that the measured energy spread can be dominated by a correlated spread, with the slice spread significantly lower. Measurements of coherent optical transition radiation are presented for broad-energy-spread beams with laser-induced density and momentum modulations. The long-range (meter-scale) observation of coherent optical transition radiation indicates that the slice energy spread is below the percent level to preserve the modulations.

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