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We report a fetus of 35 weeks gestation in which a continuous flow was detected in the lower portion of the right atrium with a peak velocity of 0.8 m/s. After delivery the echo-doppler study showed a dilated coronary sinus in the long axis parasternal view, and a bilateral superior vena cava in the short axis suprasternal notch view. Comments about the cause of this anomalous continuous flow are discussed. 相似文献
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MH Koolhaas G van der Zwan F van Mourik R van Grondelle 《Canadian Metallurgical Quarterly》1997,72(4):1828-1841
The origin of the nonconservative nature of the circular dichroism (CD) spectrum of bacteriochlorophyll dimers is investigated. It is shown that coupling between the Qy and Qx transitions can, under rather restricting circumstances, lead to an asymmetrical CD spectrum: only for a limited set of relative orientations of the monomers within the dimer is the spectrum found to be asymmetrical. The relation between intensity and asymmetry of the CD spectrum is elucidated. The results are applied to the B820 subunit of the LH1 antenna system and subsequently to the antenna system LH1 itself. Differences in the geometry of the BChls in LH1 versus the LH2 structure are discussed. 相似文献
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MH Buc-Caron 《Canadian Metallurgical Quarterly》1995,2(1):37-47
Analyses tested the following contrasting hypotheses: a) The occurrence of a new symptom in the presence of ongoing life stress increases the attribution of symptoms to illness and increases the use of health care; b) new symptoms occurring in the presence of ongoing life stress are attributed to stressors if they are ambiguous indicators of illness, and they are unlikely to motivate care-seeking if the stressor, i.e., the perceived cause, is of recent onset. The 43-to-92-year old subjects in this longitudinal study were less likely to seek care for the ambiguous symptoms they experienced during the previous week if there was a concurrent life stressor that began during the previous 3 weeks; these symptoms were attributed to stress rather than to illness, and subjects tolerated the emotional distress caused by the combination of a stressor and an ambiguous symptom. Subjects were less willing to tolerate the combined distress of an ambiguous symptom and a concurrent life stressor if the stressor onset was not recent; under such conditions, subjects were more likely to seek health care. Current life stressors did not affect care-seeking for symptoms that were clear signs of disease; these symptoms were readily identified as health threats in need of medical attention. The findings contribute to a better theoretical understanding of how individuals perceive their physical states and how they cope with stress. Practical implications of these findings for increasing efficient use of health care services are also discussed. 相似文献
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