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We present a clear signature of the Schottky effect in a rf photoinjector using photons with energy lower than the Mg cathode work function. This signature is manifested by the shift in the rf phase angle for the onset of the detection of photoelectrons via single-photon absorption and allows for a reasonable estimate of the field enhancement factor. This is a viable method to generate an electron beam with very low thermal emittance and thus, a high brightness beam.

Objective: The aim of this study was to test the utility of serum alkaline phosphatase isoenzymes determination from patients with renal insufficiency., Material and Methods: Serum levels of alkaline phosphatase isoenzymes were determined in a group of 58 patients: 22 of them suffering acute renal insufficiency (ARI) and 36 with chronic renal failure (CRF) undergoing regular hemodialysis, results obtained were compared from a population of 30 healthy adults. Intestinal, bone, liver, macromolecular and intestinal variant isoenzymes, were separated by electrophoresis on agarose gel and quantified using a densitometer., Results: Were found a significant increase the total alkaline phosphatase activity in both pathologic groups (p < 0.05 in ARI and p < 0.01 in CRF). Isoenzymatic profiles showed: increase of the bone fraction (p < 0.05 in ARI and p < 0.001 in CRF), decrease of the liver isoenzyme (p < 0.001) in both groups, macromolecular fraction elevated in acute patients (p < 0.05) and a significant increase of the intestinal and intestinal variant isoenzyme in the chronic patients (p < 0.001)., Conclusion: The renal insufficiency modified the normal distribution of alkaline phosphatase isoenzymes and the study of their serum levels could be an effective non-invasive marker, for the evaluation of bone disease and intestinal disorders associated with renal failure.

We report on measurements of (11-18)-cm wavelength radio emission from interactions of 15.2 MeV pulsed electron bunches at the Argonne Wakefield Accelerator. The electrons were observed both in a configuration where they produced primarily transition radiation from an aluminum foil, and in a configuration designed for the electrons to produce Cherenkov radiation in a silica sand target. Our aim was to emulate the large electron excess expected to develop during an electromagnetic cascade initiated by an ultrahigh-energy particle. Such charge asymmetries are predicted to produce strong coherent radio pulses, which are the basis for several experiments to detect high-energy neutrinos from the showers they induce in Antarctic ice and in the lunar regolith. We detected coherent emission which we attribute both to transition and possibly Cherenkov radiation at different levels depending on the experimental conditions. We discuss implications for experiments relying on radio emission for detection of electromagnetic cascades produced by ultrahigh-energy neutrinos.

Objective: In this study, we are looking at the principal isoenzymes of alkaline phosphatase (ALP), as injury markers of cellular membranes from bronchial epithelium, in 80 patients diagnosed with bronchopulmonary pathology from different ethology, using serum samples and bronchoalveolar lavage fluid (BAL)., Method: Patients were grouped according to age as following: 26 preterm neonates suffering respiratory distress syndrome requiring mechanical ventilation; 32 children ranging from 2 to 12 years old, and 22 adults (30-65 years old) examined by bronchoscopy for the purpose of diagnosis. Results obtained from all pathological groups were compared with a control group showing similar characteristics. Isoenzymes were separated by electrophoresis on agarose gel and were quantified by desitometry. Total protein was measured in BAL; ALP activity was expressed in UI/mg x 10-3 of protein., Results: We found that macromolecular ALP fraction was significantly increased in the serum of neonates with distress (p < 0.01), in the patients 2-12 years and adults affected by pulmonary pathology (p < 0.001). The electrophoresis of ALP isoenzymes showed a unique isoenzymatic band corresponding with its macromolecular fraction in the BAL fluid., Conclusions: We conclude that increased macromolecular fraction of alkaline phosphatase found in the serum of patients diagnosed with respiratory problems could have its origin in damaged pulmonary tissue.

Objective: The aim of this study was to test the utility of serum creatine kinase (CK) isoenzyme determinations as a marker of tissue injury in preterm newborns with respiratory distress syndrome (RDS)., Patients and Methods: Two groups of neonates were studied, 26 suffering from RDS who required mechanical ventilation and 20 healthy newborns with gestational ages, hours of life and birth weights similar to the first group. The activity of CK and its isoenzymes was determined in the bronchial aspirate and serum samples that were obtained before and 24 hours after exogenous surfactant therapy. The isoenzymes were separated by electrophoresis on agarose gel and their activity expressed as a percentage of the total CK. Total proteins were quantified in the bronchial aspirate and CK enzymatic activity expressed in U/mg of protein x 10-3., Results: The CK-BB isoenzyme was significantly increased (p < 0.001) in the serum of infants with RDS compared with the control group. In the bronchial aspirate, the isoenzymatic study showed that the CK-BB isoenzyme represented 98-100% of the total enzymatic CK activity., Conclusions: The study shows significant differences in the CK isoenzyme patterns of neonates with RDS compared to controls. An increase in serum levels of the CK-BB isoenzyme could be an effective marker of tissue injury in lung disease in the newborn.