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Internal carotid flow velocity with exercise before and after acclimatization to 4,300 m. 总被引:2,自引:0,他引:2
S Y Huang K W Tawney P R Bender B M Groves R E McCullough R G McCullough A J Micco M Manco-Johnson A Cymerman E R Greene 《Journal of applied physiology》1991,71(4):1469-1476
Cerebral blood flow and O2 delivery during exercise are important for well-being at altitude but have not been studied. We expected flow to increase on arrival at altitude and then to fall as O2 saturation and hemoglobin increased, thereby maintaining cerebral O2 delivery. We used Doppler ultrasound to measure internal carotid artery flow velocity at sea level and on Pikes Peak, CO (4,300 m). In an initial study (1987, n = 7 men) done to determine the effect of brief (5-min) exercises of increasing intensity, we found at sea level that velocity [24.8 +/- 1.4 (SE) cm/s rest] increased by 15 +/- 7, 30 +/- 6, and 22 +/- 8% for cycle exercises at 33, 71, and 96% of maximal O2 uptake, respectively. During acute hypobaric hypoxia in a decompression chamber (inspired PO2 = 83 Torr), velocity (23.2 +/- 1.4 cm/s rest) increased by 33 +/- 6, 20 +/- 5, and 17 +/- 9% for exercises at 45, 72, and 98% of maximal O2 uptake, respectively. After 18 days on Pikes Peak (inspired PO2 = 87 Torr), velocity (26.6 +/- 1.5 cm/s rest) did not increase with exercise. A subsequent study (1988, n = 7 men) of the effect of prolonged exercise (45 min at approximately 100 W) found at sea level that velocity (24.8 +/- 1.7 cm/s rest) increased by 22 +/- 6, 13 +/- 5, 17 +/- 4, and 12 +/- 3% at 5, 15, 30, and 45 min.(ABSTRACT TRUNCATED AT 250 WORDS) 相似文献
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Misty W Stevens Misty W Stevens Misty W Stevens Misty W Stevens Rachel L Tawney Rachel L Tawney Rachel L Tawney Rachel L Tawney C Michael West C Michael West C Michael West C Michael West Alicia D Kight Alicia D Kight Alicia D Kight Alicia D Kight Ralph L Henry Ralph L Henry Ralph L Henry Ralph L Henry S Michael Owens S Michael Owens S Michael Owens S Michael Owens W Brooks Gentry W Brooks Gentry W Brooks Gentry W Brooks Gentry 《MABS-AUSTIN》2014,6(2):547-555
Ch-mAb7F9, a human-mouse chimeric monoclonal antibody (mAb) designed to bind (+)-methamphetamine (METH) with high affinity and specificity, was produced as a treatment medication for METH abuse. In these studies, we present the preclinical characterization that provided predictive evidence that ch-mAb7F9 may be safe and effective in humans. In vitro ligand binding studies showed that ch-mAb7F9 is specific for and only binds its target ligands (METH, (+)-amphetamine, and 3,4-methylenedioxy-N-methylamphetamine) with high affinity. It did not bind endogenous neurotransmitters or other medications and was not bound by protein C1q, thus it is unlikely to stimulate in vivo complement-dependent cytotoxicity. Isothermal titration calorimetry potency studies showed that METH binding by ch-mAb7F9 is efficient. Pharmacokinetic studies of METH given after ch-mAb7F9 doses in rats demonstrated the in vivo application of these in vitro METH-binding characteristics. While METH had little effect on ch-mAb7F9 disposition, ch-mAb7F9 substantially altered METH disposition, dramatically reducing the volume of distribution and clearance of METH. The elimination half-life of METH was increased by ch-mAb7F9, but it was still very fast compared with the elimination of ch-mAb7F9. Importantly, the rapid elimination of unbound METH combined with previous knowledge of mAb:target ligand binding dynamics suggested that ch-mAb7F9 binding capacity regenerates over time. This finding has substantial therapeutic implications regarding the METH doses against which ch-mAb7F9 will be effective, on the duration of ch-mAb7F9 effects, and on the safety of ch-mAb7F9 in METH users who use METH while taking ch-mAb7F9. These results helped to support initiation of a Phase 1a study of ch-mAb7F9. 相似文献
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Ilisa Barbash 《Visual Anthropology: Published in cooperation with the Commission on Visual Anthropology》2013,26(4):369-413
Anthropological evaluations of the film work of Robert Gardner have been compromised by their reluctance to engage with it as art, and more broadly, to celebrate rather than vilify the aesthetic possibilities of the genre of ethnographic film. Even recent experiments with reflexivity have done little to challenge the realism that undergirds anthropological reception of non‐fiction film. By contrast, this article and interview considers Gardner's work as both anthropology and art. In particular, it addresses the evolving dialectic of the verbal and the visual in his films, from Bhinden Harbour (1951) to Passenger (1998). It also argues that recent efforts by anthropologists to rethink the concept of culture from a post‐semiotic perspective, foregrounding corporeal embodiment in the constitution of culture as much as the self, expand the theoretical boundaries of visual anthropology. In turn, it suggests that this reorientation towards sensation and perception should allow for a more approbatory understanding of Gardner's films. 相似文献
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Ilisa Tawney Jennifer G. Becker Andrew H. Baldwin 《International journal of phytoremediation》2008,10(5):455-471
The anaerobic biodegradation of tetrachloroethene commonly results in the accumulation of chlorinated intermediates such as cis-1,2-dichloroethene (cDCE). Frequently, groundwater contaminated with chlorinated ethenes discharges to natural wetlands. The goal of this study was to quantitatively evaluate the effects of wetland plants and microorganisms on the fate of cDCE in the wetland rhizosphere. To accomplish this goal, a novel dual-compartment wetland microcosm was designed. A Phragmites australis individual was maintained in the microcosm, which was operated with continuous flows of air and mineral medium through the foliar and rhizosphere compartments, respectively, to incorporate mass transfer/transport processes that are important in natural wetlands and allow steady-state assessment of changes in dissolved O2 and cDCE or [1,2–14C]cDCE levels. Substantial amounts of [14C]cDCE were phytovolatilized through a healthy P. australis individual to the foliar chamber. Rhizodegradation by native microorganisms associated with P. australis roots also converted substantial amounts of [14C]cDCE to 14C-labeled CO2 and non-volatile compounds, presumably through cometabolic reactions that could be enhanced by the release of O2 and exudates by P. australis. These results suggest that, in some cases, the intrinsic capacity of native wetland plants and microorganisms to remove cDCE from the rhizosphere may be substantial. 相似文献
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