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81.
FK Marcondes LC Vanderlei LL Lanza RC Spadari-Bratfisch 《Canadian Metallurgical Quarterly》1996,74(6):663-669
In this article we compare how sensitivity to the chronotropic effect of noradrenaline and adrenaline of right atria isolated from female rats is modified after repeated swimming or foot-shock stress, under the influence of the estrous cycle. Right atria from stressed female rats sacrificed at diestrus were subsensitive to both catecholamines, irrespective of the stressor agent. However, although subsensitivity to noradrenaline was of similar intensity, subsensitivity to adrenaline was more pronounced in right atria from foot shock stressed rats as opposed to swimming-stressed rats. Identical stress protocols did not induce any alteration in atrial sensitivity to catecholamines when the stressed female rats were sacrificed at estrus. We conclude that the stress reaction concerning the mediation of cardiac chronotropism by catecholamines is related to the severity of the stressor agent and is strongly influenced by the estrous cycle. 相似文献
82.
BA Reiling LL Berger DB Faulkner FK McKeith TG Nash FA Ireland 《Canadian Metallurgical Quarterly》1996,74(9):2043-2051
Three studies were designed using a 2 x 2 factorial arrangement of treatments within each experiment to evaluate the effects of various management techniques on growth and carcass traits of once-calved heifers. In Exp. 1, 33 yearling (16 control [C] and 17 prenatally androgenized [PA]) and 39 once-calved (20 C and 19 PA) nonpregnant heifers were used to evaluate the effects of age and PA. Once-calved heifers were approximately 31 kg heavier (P < .03) on-test, initially consumed 11% more (P < .01) DM, and gained 11% faster (P < .08), but had similar (P = .44) gain to feed ratios (.138 vs. .131) as yearlings. Growth performance was not affected by PA. The yearling and once-calved heifers were then slaughtered at approximately 707 and 1,080 d of age, respectively. Despite maturity differences (P < .01), marbling scores (P = .26) and percentage of choice carcasses (P = .27) were similar. However, on the basis of newly accepted grading changes, percentage of once-calved heifer carcasses grading choice decreased from 57.3 to 34.4%. Organoleptic properties did not differ. Experiments 2 and 3 were then conducted to evaluate effects of commercially available products (melengestrol acetate [MGA] and Synovex-H) on feedlot characteristics of heifers following weaning of their first calf. In Exp. 2, 48 once-calved Simmental-based heifers were fed during the summer to a constant compositional fat thickness of .8 cm. Experiment 3 was conducted in the late fall and early winter, during which 52 moderately sized heifers were fed for 116 d postweaning and slaughtered. Performance of heifers in Exp. 2 was not affected by MGA. However, heifers fed MGA in Exp. 3 gained 9% faster (P < .05) than controls. In Exp. 2, Synovex-H tended to improve ADG (P < .09) and feed efficiency (P < .07), but did not affect performance in Exp. 3. Most carcass traits were not affected by either treatment. Nonpregnant, once-calved heifers seem to have a large capacity for efficient weight gain as compared with yearling heifers. However, hormonal compounds, such as testosterone propionate provided pre- or postnatally (Synovex-H), and MGA do not appear to provide the consistent, positive responses often seen with younger, more typical feedlot heifers. 相似文献
83.
FK Port RA Wolfe WE Bloembergen PJ Held EW Young 《Canadian Metallurgical Quarterly》1996,16(6):628-633
Tacrine [1,2,3,4-tetrahydro-9-acridinamine monohydrochloride monohydrate (THA), Cognex] is a potent acetylcholinesterase inhibitor recently approved for treatment of mild-to-moderate Alzheimer's disease. The potential for THA and/or a metabolite of THA to accumulate in brain tissue was investigated by autoradiographic and metabolic profiling techniques in rats given single and multiple doses of [14C]THA. In addition, the brain-to-plasma distribution time course of orally administered 1-hydroxy-THA (1-OH-THA, 24 mg/kg), a primary rat metabolite with anticholinesterase activity, was also examined. Results from a 16 mg/kg single-dose study showed THA to cross the blood-brain barrier readily and concentrate in brain tissue, approximately 5-fold compared with plasma. The metabolite 1-OH-THA was found in much lower amounts relative to THA and when given separately at a similar dose the levels in brain tissue were comparable with plasma concentrations. After multiple-dose administration, THA concentrations in brain tissue were approximately 3-fold higher than those achieved after a single oral dose. However, concentration of 1-OH-THA metabolite increased only 50%. These data suggest a marked difference between the ability of THA and 1-OH-THA to accumulate in brain tissue and may reflect differences in lipophilicity as estimated by calculated log p values. The relevance of THA accumulation in brain tissue to delays observed in THA clinical management of Alzheimer's disease remains to be established. 相似文献
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BACKGROUND: Multifocal intraocular lenses show a reduction of contrast due to the simultaneous projection of different images to the retina. In this study we examined if there is also a loss of contrast in bilateral implantation of multifocal lenses. MATERIAL AND METHODS: We examined 22 patients with bilateral AMO ARRAY multifocal intraocular lens and compared these to 20 patients with bilateral monofocal intraocular lens. We performed a monocular and binocular examination of contrast acuify by means of Regan's contrast charts and contrast sensitivity by means of B-VAT-II-SG-Video-acuity-tester. RESULTS: Monocular examination of contrast acuity showed significant superiority of the monofocal intraocular lens at the lowest contrast. Bilateral examination of contrast acuity did not show any significant difference. Monocular contrast sensitivity of the monofocal intraocular lens was significantly superior to the multifocal intraocular lens at two spatial frequencies, but under the bilateral condition there was only a significant difference between the two lenses at the highest spatial frequency. CONCLUSIONS: Bilateral implantation of multifocal intraocular lenses enables contrast acuity and contrast sensitivity that comes very close to the performance of the monofocal intraocular lenses. 相似文献
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Alexios Lekidis Emmanouela Stachtiari Panagiotis Katsaros Marius Bozga Christos K. Georgiadis 《Software》2018,48(6):1167-1194
The design of software for networked systems with nodes running an Internet of things operating system faces important challenges due to the heterogeneity of interacting things and the constraints stemming from the often limited amount of available resources. In this context, it is hard to build confidence that a design solution fulfills the application's requirements. This paper introduces a design flow for web service applications of the representational state transfer style that is based on a formal modeling language, the behaviour, interaction, priority (BIP) component framework. The proposed flow applies the principles of separation of concerns in a component‐based design process that supports the modular design and reuse of model artifacts. The BIP tools for state‐space exploration allow verifying qualitative properties for service responsiveness, ie, the timely handling of events. Moreover, essential quantitative properties are validated through statistical model checking of a stochastic BIP model. All properties are preserved in actual implementation by ensuring that the deployed code is consistent with the validated model. We illustrate the design of a representational state transfer sense‐compute‐control application for a Wireless Personal Area Network architecture with nodes running the Contiki operating system. The results validate qualitative and quantitative properties for the system and include the study of error behaviours. 相似文献
90.
Suspected to be a syndrome rather than an authentic clinical entity, the "desquamative interstitial pneumonia" (DIP) exhibits typical anatomo-pathological aspects of intra-alveolar proliferation of granular pneumocytes, type II pneumocytes, leaving the alveolar interstitium unaffected. In absence of superinfection, it remains almost free of fibrous or inflammatory manifestations. The association of DIP to 4 other fundamental histological varieties of diseases of the pulmonary interstitium (UIP, BIP, LIP, GIP) is at the origin of Liebow's classification. The clinical individualization of these entities is still questioned. 相似文献