H-alpha emission lines in high-redshift quasars

peer-reviewedInfrared spectra have been obtained of the H-alpha lines in 18 medium- to high-redshift QSOs and optical spectra taken nearly simultaneously to measure the strong UV line. It is found that the H-alpha line is redshifted by an average of 1000 km/s with respect to the lines from high ionization species such as C IV. Low ionization lines from ions like O I and Mg II are shifted by similar, or slightly smaller, amounts with respect to the high ionization lines. These results are difficult to reconcile with any simple models currently available, including those where dust obscuration is solely responsible for the observed velocity shifts. The similarity between the velocities of H-alpha and Mg II, O I provides some support for models in which the Balmer lines are produced predominantly in a warm H I region, while the Lyman lines arise mainly in a population of optically thin clouds. A velocity separation between the two cloud populations, along with some obscuration, could explain the main features

Trapidil, an inhibitor for phosphodiesterase and platelet-derived-growth factor, ameliorates corrosive esophageal burn in rats

WOS: 000232286600004PubMed: 16210831Corrosive esophageal burn is a common health problem in the pediatric age group and causes serious esophageal injuries. The medical treatment In acute phase of corrosive esophageal injury is of particular importance for prevention of esophageal stricture. We therefore aimed to investigate the possible beneficial effect of trapidil (triazolopyrimidine), an inhibitor for phosphodiesterase and platelet-derived-growth-factor, during acute phase of esophageal corrosive injury. Wistar albino rats were randomly allocated to untreated, treated, and sham-operated groups (n = 10 for each group). Corrosive esophageal burn was generated with 10% NaOH solution. The rats were left untreated (untreated group) or treated with trapidil as a single dose of 40 mg/kg intraperitoneally after one hour of the injury (treated group). Abdominal esophageal segment was isolated and tied in sham-control group. The studied esophageal segment was removed from each animal after 24 hours. Malondialdehyde (MDA) and nitric oxide (NO) levels were measured in the esophageal tissues. The ulcer depth was graded by histopathologic examination. MDA and NO levels were significantly higher in the untreated group than in the treated group. Namely, trapidil treatment significantly decreased MDA and NO levels in the injured tissues, the levels of which are similar to those in the tissues of control animals. The grades of ulcer depth were significantly improved in the treated group. These results indicate that the reactive oxygen radicals increase in the early phase of corrosive esophagitis and cause tissue damage. We suggest that trapidil treatment may be useful in acute phase of corrosive esophageal injury