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91.
92.
The application of alumino silicate alkali ion sources to the study of ion desorption of surface gas
Investigations are described which illustrate the compatibility of alumino silicate alkali ion sources with an UHV (~10?11 torr) vacuum environment. The application of the sources to the determination of ion desorption efficiency of surface gas is demonstrated, as well as their use as a basis for a technique of ion stimulated surface gas analysis. 相似文献
93.
94.
Results of follow-up examinations of 132 ears with serous or mucous middle ear effusions indicate that this disease is common in childhood and is also found in adults. In childhood adenoid growth as well as repeated catarrhal infection of the paranasal sinuses and the weakness of the levator palati play an important role in the development of middle ear effusions and deafness. With the aid of the operation microscope we were able to recognize this characteristic disease through the tympanic membrane. We perform regularly adenoidectomy together with paracentesis in this condition. In cases which had undergon several adenoidectomies we limit our treatment in the first instance to paracentesis. If cure is not so achieved we insert an inert tube into the tympanic membrane after the paracentesis. In persistent and difficult cases of glue ear radiation of the eustachion tube and antrotomy may be necessary. 相似文献
95.
EM Burns 《Canadian Metallurgical Quarterly》1976,57(12):48-54, 80
96.
Several viral isolates from ticks (Ornithodoros coriaceus) and from the blood of cattle which aborted after exposure to these ticks were found to be identical by reciprocal cross serum-neutralization tests. Characterization studies indicate that the virus is a member of the Togaviridae family, although specific identification is still incomplete. Whether its natural host is the tick or bovine animals is also unknown. Pregnant cows inoculated with the agent by all conventional parenteral routes, including intrafetal, delivered healthy calves at term. It was concluded, therefore, that it was not a bovine pathogen and that the abortions which occurred after tick-exposure were due to a 2nd agent in O coriaceus ticks which also harbor the virus. While several ciruses believed to be tick-borne have been isolated from cattle in various parts of the world, it is believed that the present report describes the first isolation in the Western Hemisphere for a viral agent from Argasid ticks which has been demonstrated to replicate in cattle. 相似文献
97.
Very low birth weight children at school age: comparison of neonatal management methods 总被引:1,自引:0,他引:1
ES Steiner EM Sanders EC Phillips CR Maddock 《Canadian Metallurgical Quarterly》1980,281(6250):1237-1240
The outcome of 293 infants born to a geographically defined community and weighing 501-1500 g was investigated. Medical intervention in the newborn period had been avoided. Morbidity was assessed at school age. Of the infants, 236 had been live born in the labour ward of this hospital; of these, 117 (49.6%) died in the neonatal period, one (0.4%) died in the first year, four (1.7%) were untraced, 13 (5.5%) had major handicap, 29 (12.3%) had minor handicap, and 72 (30.5%) were considered to be normal. In terms of survival, handicap, and intellectual with that of infants born over the same period (1963-71) in areas where intensive methods of perinatal care were used. These results imply that postnatal survival and potential of infants of very low birth weight are by no means prejudiced when only experienced nursing care is available. 相似文献
98.
P Puigdoménech P Martínez J Palau EM Bradbury C Crane-Robinson 《Canadian Metallurgical Quarterly》1976,65(2):357-363
Proton magnetic resonance and other measurements have been carried out in order to study the behaviour of the lysine-rich histones phi 1 in the sperm chromatin of certain marine invertebrates. Well defined particles (12 S) have been obtained from this chromatin by nuclease treatment. Chromatin solubility as a function of ionic strength shows a relaxation at salt concentrations higher than in the case of calf thymus nucleoprotein. Nuclear magnetic resonance (NMR) studies show that the release of histone from DNA occurs both in chromatin and in the reconstituted complexes at practically the same ionic strength as solubility relaxation. The higher the arginine content of a given phi 1, the higher the ionic strength at which both effects take place. The NMR results demonstrate that arginine residues are bound more strongly than lysine residues. The data overall show that phi 1 histones play a role in the contraction mechanism of sperm chromatin similar to that of H 1 histone in calf thymus chromatin. The highly contracted state of sperm chromatin is directly related to the increased arginine content of the phi 1 histone. 相似文献
99.
Starch gel electrophoresis of 55 donkey serum samples revealed three prealbumin (Pr) phenotypes temporarily designated Pr M, Pr MT and Pr T. The distribution was in agreement with a genetic theory of two codominant alleles of frequencies, PrM = 0.87 and PrT - 0.13. Variation was also observed for proteins migrating with the same rate as the Xh zones in the horse. 相似文献
100.
Biester H Martinez-Cortizas A Birkenstock S Kilian R 《Environmental science & technology》2003,37(1):32-39
Ombrotrophic peat bogs have been widely used to evaluate long-term records of atmospheric mercury (Hg) deposition. One of the major aims of these investigations is the estimation of the increase in atmospheric Hg fluxes during the industrial age compared to preindustrial fluxes. Comparability of Hg accumulation rates calculated from density, peat accumulation rates, and Hg concentrations requires linearity between these parameters. Peat formation is a dynamic process accompanied by intense mass loss and alteration of the organic material. Our investigations on three peat cores from the Magellanic Moorlands, Chile, indicate that Hg concentrations in peat strongly depend on peat humification. Moreover, differences in mass accumulation rates during peat evolution are not compensated by linear changes in density, peat accumulation, or Hg concentrations. We suggest that Hg accumulation rates be normalized to carbon accumulation rates to achieve comparability of Hg accumulation rates derived from differently altered peat sections. Normalization to the carbon accumulation rates reduces Hg accumulation rates in less degraded peat sections in the upper peat layers by factors of more than 2. Our results suggest that the increase in Hg deposition rates during modern times derived from ombrotrophic peat bogs are potentially overestimated if Hg accumulation rates are not corrected for mass accumulation rates. 相似文献