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Neither cargo nor cult: Ritual politics and the colonial imagination in Fiji, by Martha Kaplan. Duke University Press, Durham NC, 1995. ISBN 0–8223–1593–9.  相似文献   

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There is basis for concern that applied psychophysiology, if not the field of biofeedback, is being coopted by, and merged into, a reborn inner model, with the return of cognition to preeminence in the psych and neuro disciplines. Despite currently fashionable views that such mentalistic inventions and neuro/psychological developments somehow illuminate behavior or offer simpler accounts of behavioral facts, there is little or no evidence that any such construction has ever told us anything new about behavior.Preparation of this article was supported in part by the following PHHS Grants: NHLBI HL 34034, NIDA DA 03476, NIDA DA 04130, NIDA DA 02490, NIDA DA 04133, NIDA DA 01147, NIDA DA 04731, and NIDA contract 271-86-8113.  相似文献   

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There is basis for concern that applied psychophysiology, if not the field of biofeedback, is being coopted by, and merged into, a reborn "inner" model, with the return of "cognition" to preeminence in the "psych" and "neuro" disciplines. Despite currently fashionable views that such mentalistic inventions and neuro/psychological developments somehow illuminate behavior or offer simpler accounts of behavioral facts, there is little or no evidence that any such construction has ever told us anything new about behavior.  相似文献   

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Background

New animal models of chronic pulmonary hypertension in mice are needed. The injection of monocrotaline is an established model of pulmonary hypertension in rats. The aim of this study was to establish a murine model of pulmonary hypertension by injection of the active metabolite, monocrotaline pyrrole.

Methods

Survival studies, computed tomographic scanning, histology, bronchoalveolar lavage were performed, and arterial blood gases and hemodynamics were measured in animals which received an intravenous injection of different doses of monocrotaline pyrrole.

Results

Monocrotaline pyrrole induced pulmonary hypertension in Sprague Dawley rats. When injected into mice, monocrotaline pyrrole induced dose-dependant mortality in C57Bl6/N and BALB/c mice (dose range 6–15 mg/kg bodyweight). At a dose of 10 mg/kg bodyweight, mice developed a typical early-phase acute lung injury, characterized by lung edema, neutrophil influx, hypoxemia and reduced lung compliance. In the late phase, monocrotaline pyrrole injection resulted in limited lung fibrosis and no obvious pulmonary hypertension.

Conclusion

Monocrotaline and monocrotaline pyrrole pneumotoxicity substantially differs between the animal species.  相似文献   

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This study aimed to clarify whether infants and preschool children show susceptibility to contagious yawning, a well-known effect that has been demonstrated experimentally in older children and adults by exposing them to video sequences showing yawns. In a first study, parents kept a log of their child's yawns for a one week period. None of the log entries reported any contagious yawns by the children. Although less frequent than in older children and adults, spontaneous yawning by infants and preschoolers showed the typical morning, post-wakening peak, and an increase before bedtime in the evening. In an experimental study, infants and preschoolers watched a presentation that included many images of yawning and a repeated video clip of their own mother yawning, but there was no evidence of contagious yawning. The results suggest that, even when witnessing yawns by someone with whom they have a strong and positive emotional relationship, very young children do not show contagious yawning.  相似文献   

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To examine the effect of obestatin, a recently identified peptide derived from preproghrelin, on pituitary hormone secretion, obestatin was administered in anesthetized male rats. Intravenous administration of obestatin did not show any effect on plasma GH, PRL, ACTH and TSH levels. Since obestatin has been reported to have opposite effects of ghrelin in regulating food intake, gastric emptying and intestinal contractility, GH suppressive effect, which is opposite effect of ghrelin, was tested. Intravenous administration of GHRH or GHRP-2, a ghrelin receptor ligand, resulted in a marked plasma GH elevation. However obestatin did not show any effect on GHRH- or GHRP-2-induced GH rise. Furthermore intracerebroventricular administration of obestatin also did not influence plasma GH, PRL, ACTH and TSH levels. These findings suggest that obestatin has no effect on pituitary hormone secretions despite the presence of GPR39, a receptor for obestatin, in the pituitary.  相似文献   

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J Stock  G Kersulis  D E Koshland 《Cell》1985,42(2):683-690
Clarification of the information processing system in bacterial sensing has been obtained by studying mutants that lack the capacity to modify receptors covalently. The remaining part of the system is able to receive signals from the receptor, to respond with partial adaptation, and to exhibit a chemotactic response. A cycle of chemical reactions analogous to the rhodopsin-transducin cycle in the visual system is shown to provide the proper characteristics to serve as the bridge between receptor and chemotactic output, which allows adaptation in the absence of covalent protein modifications.  相似文献   

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Iron homeostasis is essential for maintaining the physiological requirement for iron while preventing iron overload. Cell toxicity is caused by the generation of hydroxyl-free radicals that result from redox reactions involving Fe(II). Multicopper ferroxidases regulate the oxidation of Fe(II) to Fe(III), circumventing the generation of these harmful by-products. Ceruloplasmin (Cp) is the major multicopper ferroxidase in blood; however, hephaestin (Hp), a membrane-bound Cp homolog, was recently discovered and has been implicated in the export of iron from duodenal enterocytes into blood. In the intracellular milieu, it is likely that iron exists as reduced Fe(II), yet transferrin (Tf), the plasma iron transporter, is only capable of binding oxidized Fe(III). Due to the insoluble and reactive nature of free Fe(III), the oxidation of Fe(II) upon exiting the duodenal enterocyte may require an interaction between a ferroxidase and the iron transporter. As such, it has been suggested that as a means of preventing the release of unbound Fe(III), a direct protein-protein interaction may occur between Tf and Hp during intestinal iron export. In the present study, the putative interaction between Tf and both Cp and a soluble form of recombinant human Hp was investigated. Utilizing native polyacrylamide gel electrophoresis, covalent cross-linking and surface plasmon resonance (SPR), a stable interaction between the two proteins was not detected. We conclude that a stable complex between these ferroxidases and Tf does not occur under the experimental conditions used. We suggest alternative models for loading Tf with Fe(III) during intestinal iron export.  相似文献   

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The decay of fluorescence of Tb3+ bound to DNA was measured in the absence and presence of adriamycin and actinomycin D. The decay for Tb3+ bound to DNA was mainly exponential (lifetime: tau = 0.96 ms). In the presence of adriamycin or actinomycin D, the Tb3+ fluorescence decayed much faster, indicating that excitation energy was transferred from Tb3+ to the drugs. Extrapolation of the decay curves to zero time showed that the number of strongly emitting, DNA-bound terbium ions was not reduced by the presence of adriamycin or actinomycin D. Hence, these drugs do not seem to displace Tb3+ bound to DNA.  相似文献   

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This study was designed to compare the effects of different ways of administering carbon monoxide (intravenous and inhalative) on gastric mucosal oxygenation in a canine model of hemorrhage. Six chronically instrumented dogs were repeatedly anesthetized and randomized to each of the following protocols: In a first series the animals were ventilated either with 100 ppm carbon monoxide (CO) or without followed by hemorrhage and re-transfusion. In a second series a saturated CO solution was infused, compared to normal saline, again followed by hemorrhage and re-transfusion. In a control series, animals received either CO-saline or saline without any further intervention. Microvascular oxygenation of the gastric mucosa (μHbO2) was assessed continuously by tissue reflectance spectrophotometry. Cardiac output was measured intermittently and oxygen delivery (DO2) was calculated. The application of CO, inhalative and intravenous, increased carboxyhemoglobin levels without effect on μHbO2. Hemorrhage reduced μHbO2 in all groups, paralleled by a reduction in DO2 without any differences between groups related to the application of CO. Neither intravenous nor inhalative application of CO alters μHbO2 during physiological conditions or during hemorrhage. Thus, independent of the application way, low dose CO does not seem to modulate regional mucosal oxygenation in cytoprotective concentrations.  相似文献   

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It is commonly accepted that the major effect of nitroglycerin (NG) is realized through the release of nitric oxide (NO) catalyzed by aldehyde dehydrogenase-2 (ALDH2). In addition, it has been shown that NG inhibits mitochondrial respiration. The aim of this study was to clarify whether NG-mediated inhibition of mitochondrial respiration is mediated by NO. In rat liver mitochondria, NG inhibited complex-I-dependent respiration and induced reactive oxygen species (ROS) production, preferentially at complex I. Both effects were insensitive to chloral hydrate, an ALDH2 inhibitor. Nitrite, an NG intermediate, had no influence on either mitochondrial respiration or the production of ROS. NO inhibited preferentially complex I but did not elevate ROS production. Hemoglobin, an NO scavenger, and blue light had contrary effects on mitochondria inhibited by NO or NG. In summary, our data suggest that although NG induces vasodilatation via NO release, it causes mitochondrial dysfunction via an NO-independent pathway.  相似文献   

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O''Leary et al. (O''Leary et al. 2013 Science 339, 662–667. (doi:10.1126/science.1229237)) performed a fossil-only dating analysis of mammals, concluding that the ancestor of placentals post-dated the Cretaceous–Palaeogene boundary, contradicting previous palaeontological and molecular studies that placed the ancestor in the Cretaceous. They incorrectly used fossil ages as species divergence times for crown groups, while in fact the former should merely form minimum-age bounds for the latter. Statistical analyses of the fossil record have shown that crown groups are significantly older than the oldest ingroup fossil, so that fossils do not directly reflect the true ages of clades. Here, we analyse a 20 million nucleotide genome-scale alignment in conjunction with a probabilistic interpretation of the fossil ages from O''Leary et al. Our combined analysis of fossils and molecules demonstrates that Placentalia originated in the Cretaceous.  相似文献   

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Emergentism is often misleadingly described as a monolithic “third way” between radical monism and pluralism. In the particular case of biology, for example, emergentism is perceived as a middle course between mechanicism and vitalism. In the present paper I propose to show that the conceptual landscape between monism and pluralism is more complex than this classical picture suggests. On the basis of two successive analyses—distinguishing three forms of tension between monism and pluralism and a distinction between derivational and functional reduction—I define three different versions of emergentism that can be considered as consistent middle courses between monism and pluralism (respectively theoretical, explanatory and causal emergence). I then emphasise the advantage of this taxonomy of the concepts of emergence by applying the results of my analysis to the historical controversy that pertains to the relationship between life and matter.  相似文献   

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Heparin is a carbohydrate anticoagulant used clinically to prevent thrombosis, however impurities can limit its efficacy. Here we report the biosynthesis of heparin-like heparan sulfate via the recombinant expression of human serglycin in human cells. The expressed serglycin was also decorated with chondroitin/dermatan sulfate chains and the relative abundance of these glycosaminoglycan chains changed under different concentrations of glucose in the culture medium. The recombinantly expressed serglycin produced with 25 mM glucose present in the culture medium was found to possess anticoagulant activity one-seventh of that of porcine unfractionated heparin, demonstrating that bioengineered human heparin-like heparan sulfate may be a safe next-generation pharmaceutical heparin.  相似文献   

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