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C Morello

Publications and source records attributed to C Morello.

9 recordsLinked to original sources
PubMed2005

Detection and imaging of atmospheric radio flashes from cosmic ray air showers.

The nature of ultrahigh-energy cosmic rays (UHECRs) at energies >10(20) eV remains a mystery. They are likely to be of extragalactic origin, but should be absorbed within approximately 50 Mpc through interactions with the cosmic microwave background. As there are no sufficiently powerful accelerators within this distance from the Galaxy, explanations for UHECRs range from unusual astrophysical sources to exotic string physics. Also unclear is whether UHECRs consist of protons, heavy nuclei, neutrinos or gamma-rays. To resolve these questions, larger detectors with higher duty cycles and which combine multiple detection techniques are needed. Radio emission from UHECRs, on the other hand, is unaffected by attenuation, has a high duty cycle, gives calorimetric measurements and provides high directional accuracy. Here we report the detection of radio flashes from cosmic-ray air showers using low-cost digital radio receivers. We show that the radiation can be understood in terms of the geosynchrotron effect. Our results show that it should be possible to determine the nature and composition of UHECRs with combined radio and particle detectors, and to detect the ultrahigh-energy neutrinos expected from flavour mixing.

Journal Article↗
PubMed2005

Pharmacokinetics of ibafloxacin in healthy cats.

The pharmacokinetics of ibafloxacin following single and repeated administration of an oral gel formulation and the effect of food intake were investigated in cats. Ibafloxacin is a chiral fluoroquinolone available for clinical use as a racemic mixture of the R- and S-enantiomers. Plasma concentrations of ibafloxacin and its metabolites were determined using microbiological, LC-MS-MS and enantioselective capillary zone electrophoresis assays. Ibafloxacin was absorbed rapidly [time of maximum concentration (tmax) 2-3 h], reaching a mean maximum concentration (Cmax) of approximately 2.1 and 1.6 microg/mL for R- and S-ibafloxacin, respectively, following a single oral administration of the racemate at 15 mg/kg. Once absorbed, ibafloxacin was metabolized to 7-hydroxy-ibafloxacin and mainly to 8-hydroxy-ibafloxacin. Following repeated oral administration, significant increases in Cmax and AUC of ibafloxacin and its less active metabolites (racemic or enantiomers) were observed between the first and the tenth day of treatment. This twofold exposure increase in concentrations of ibafloxacin and its metabolites may contribute additionally to the efficacy of this drug in the treatment of feline bacterial infections. Single and repeated doses of ibafloxacin were well tolerated by cats. Food promoted the absorption of ibafloxacin, doubling Cmax and increasing AUC and slightly delaying tmax. High concentrations of the metabolites, mainly 8-hydroxy- and 7-hydroxy-ibafloxacin were excreted in urine, either unchanged or as glucurono-conjugates.

Administration, Oral↗
PubMed1986

Steroid and gonadotropin levels in women during the peri-menopausal years.

We obtained blood samples from 88 women 45-58 yr old who were having cyclic menses every 1-2 mth (37 women, 133 samples) or were amenorrheic for greater than 3 mth (51 women, 310 samples). Samples were obtained at intervals of 3-4 mth and analyzed for estrogens, androgens and gonadotropins using radioimmunoassay techniques. There was a gradual decline in the concentrations of estrone (E1), estradiol (E2), estrone sulfate (E1SO4) and progesterone (P) as the time from the last menses increased. A relatively stable concentration was reached in 12 mth for E1, E2, and E1SO4 and in 2 mth for P. The concentrations of testosterone, dihydrotestosterone, androstenedione, dehydroepiandrosterone and dehydroepiandrosterone sulfate remained relatively constant as the time from the last menses increased. There was no apparent difference in the mean values of any of these hormones for any time interval from the last menses. The concentrations of both luteinizing hormone (LH) and follicle stimulating (FSH) were noted to increase initially but they appeared to become stable after 12 mth for FSH and after only 6 mth for LH. Using only the measurements made on the initial blood samples obtained in all patients, we found significant correlations between FSH concentrations and the concentrations of E1, E2 and E1SO4 for women who were less than 3 mth from a menses as well as those whose last menses had occurred 3 or more mth previously. The correlations were generally not significant for LH in either groups of women.(ABSTRACT TRUNCATED AT 250 WORDS)

Androgens↗
PubMed1982

Delta infection and liver disease in hemophilic carriers of hepatitis B surface antigen.

The prevalence of infection with hepatitis B virus (HBV)-associated delta (delta) agent was assessed in 277 treated hemophiliacs (primarily adolescents and adults) and 24 treated hemophilic children. Hemophiliacs who carry hepatitis B surface antigen (HBsAg) are at high risk of delta infection. Antibody to delta (anti-delta) was found in 14 (49%) of 29 HBsAg-positive adult or adolescent hemophiliacs and four (25%) of 16 HBsAg-positive hemophilic children; it was identified in none of the patients without serologic evidence of exposure to HBV and only occasionally and in low titers in hemophiliacs convalescent from HBV infection. Either histologic or biochemical evidence of chronic hepatitis was found in 10 (56%) of 18 HBsAg-positive hemophiliacs with anti-delta. In two patients with anti-delta a potentially pathogenic role for delta was suggested by the intrahepatic expression of delta antigen, detected by immunofluorescence. It appears that delta infection is a major cause of chronic liver disease in hemophiliacs.

Adolescent↗