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981.
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The quality of epitaxial Si layers grown by solid phase reactions was studied by MeV 4He backscattering spectrometry and transmission electron microscopy. The grown layers are essentially epitaxial with the underlying Si crystals. Defects in the grown layers are mainly twins, i.e. primary twins in the layers grown during the initial stage of growth and additional secondary twins in the layers grown during the later stages. The amount of Pd trapped in the grown layers is strongly temperature dependent, with an activation energy of 1.8 eV. However, the size of the Pd inclusions is temperature insensitive. 相似文献
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The effects of three monomethoxyamphetamines, dl-para-methoxyamphetamine (dl-PMA), dl-meta-methoxyamphetamine (dl-MMA) and dl-ortho-methyoxyamphetamine (dl-OMA), and d-amphetamine (d-A) on the myoclonic twitch activity (MTA) of PMA, MMA and d-A were found to increase the MTA but OMA was ineffective. The increased MTA induced by d-A was not influenced by the blockade of 5-hydroxytryptamine (5-HT) receptor by methysergide or inhibition of 5-HT synthesis by para chlorophenylalamine (PCPA) but was reduced by haloperidol which blocked the dopamine receptor. On the other hand, the increased MTA produced by PMA was not influenced by haloperidol but was reduced by methysergide and PCPA. The increased MTA induced by MMA was not effectively blocked by either PCPA or haloperidol but was blocked by the combination of both PCPA and haloperidol. The results indicate that whereas the increased MTA produced by d-A is not dependent on the availability of 5-HT, PMA exerts by a release of 5-HT and that the MMA effect is due to a release of both 5-HT and dopamine. High doses of PMA and MMA increased the locomotor activity arevious biochemical findings that PMA releases 5-HT in brain tissue and suggests that PMA exerts its pharmacological effects by releasing 5-HT. 相似文献
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A 5-year-old Quarter Horse was examined after it developed signs of abdominal discomfort as a result of a training accident. Oral mucous membranes were pale, and capillary refill time was > 3 seconds. Hematologically, the PCV was low, and abdominocentesis yielded a serosanguineous fluid. Abdominal ultrasonography was performed and revealed a large hypoechoic mass associated with the cranial margin of the spleen. Because differentiation between subcapsular hematoma and extracapsular hematoma could not be made with certainty, further evaluation of the spleen was indicated. Abdominal laparoscopy was performed, with the horse standing, to evaluate the extent, severity, and nature of the splenic hematoma. Laparoscopic examination revealed a 7.5-cm-diameter splenic hematoma contained within the splenic capsule, confirming the diagnosis of subcapsular splenic hematoma. Abdominal laparoscopy provided excellent observation of the spleen and allowed for thorough evaluation and determination of the extent of the lesion. This information aided the clinician in reaching a definitive diagnosis and choosing between splenectomy and medical treatment. 相似文献