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Severe freezing injury was produced in the hind foot of 26 mongrel dogs. All dogs were given daily whirlpool treatment and protective bandaging for 14 days following injury. In addition, certain dogs received a vasodilator, fasciotomy, or both vasodilator and fasciotomy following injury. Deep foot temperatures, foot volumes, tissue pressures, and 14 day tissue loss-salvage scores were compared. Significant differences between fasciotomy and nonfasciotomy dogs were seen in foot temperature, volume, and tissue pressure immediately following fasciotomy. Though there was no significant difference in 14 day tissue loss, there was clinically apparent prolongation of integrity of the local vascular system for 2 to 5 days following fasciotomy, and total foot salvage in several dogs receiving fasciotomy. 相似文献
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E Schubert P Mitznegg U Strunz W Domschke S Domschke E Wünsch E Jaeger L Demling F Heim 《Life sciences》1975,16(2):263-272
1. By the action of 1-methyl-3-isobutylxanthine (isobutyltheophylline, 2 - 3 × 10−4 M), the content of cyclic 3', 5'-AMP in the antral and duodenal muscles of the rabbit is increased by 72 % and 126 %, respectively; by 1.8 × 10−7 M 13-norleucine-motilin and 1.8 × 10−6 M acetylcholine it is not changed. 13-norleucine-motilin is an analogue of the recently discovered duodenal tissue hormone motilin and has identical effects. 1-methyl-3-isobutylxanthine has a more powerful inhibiting effect on phosphodiesterase than has theophylline.2. 3 × 10−4 M isobutyltheophylline reduces the tone of the duodenal muscle while simultaneously increasing the content of cyclic AMP and negates the tone-enhancing effect of nle-motilin on the duodenal muscle, while nle-motilin increases the muscle tone lowered by isobutyltheophylline.3. The basic tone of the antral muscle is not reduced by isobutyltheophylline. However, the contraction-promoting effect of nle-motilin after an increase in cyclic AMP due to isobutyltheophylline is significantly lower.4. It is assumed that the changes in the tone or in the response of the antral and duodenal muscles to nle-motilin observed after the administration of isobutyltheophylline, are due to the increase of cyclic AMP in the tissue.5. The antagonistic effects of cyclic AMP and motilin on the gastro-intestinal muscles might be of physiological importance for the regulation of the gastro-intestinal motor activity. 相似文献
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Summary The preparation of a mannan-iron complex is described. The mannan-iron complex can be used for electron microscopic demonstration of membrane bound Concanavalin A or Lens culinaris lectin because the high reactivity of these lectins toward the mannan. 相似文献
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Successful learning is the integration of new knowledge into existing schemes, leading to an integrated and correct scientific conception. By contrast, the co-existence of scientific and alternative conceptions may indicate a fragmented knowledge profile. Every learner is unique and thus carries an individual set of preconceptions before classroom engagement due to prior experiences. Hence, instructors and teachers have to consider the heterogeneous knowledge profiles of their class when teaching. However, determinants of fragmented knowledge profiles are not well understood yet, which may hamper a development of adapted teaching schemes. We used a questionnaire-based approach to assess conceptual knowledge of tree assimilation and wood synthesis surveying 885 students of four educational levels: 6th graders, 10th graders, natural science freshmen and other academic studies freshmen. We analysed the influence of learner’s characteristics such as educational level, age and sex on the coexistence of scientific and alternative conceptions. Within all subsamples well-known alternative conceptions regarding tree assimilation and wood synthesis coexisted with correct scientific ones. For example, students describe trees to be living on “soil and sunshine”, representing scientific knowledge of photosynthesis mingled with an alternative conception of trees eating like animals. Fragmented knowledge profiles occurred in all subsamples, but our models showed that improved education and age foster knowledge integration. Sex had almost no influence on the existing scientific conceptions and evolution of knowledge integration. Consequently, complex biological issues such as tree assimilation and wood synthesis need specific support e.g. through repeated learning units in class- and seminar-rooms in order to help especially young students to handle and overcome common alternative conceptions and appropriately integrate scientific conceptions into their knowledge profile. 相似文献
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Antonio Mauceri Laura Bassolino Antonio Lupini Franz Badeck Fulvia Rizza Massimo Schiavi Laura Toppino Maria Rosa Abenavoli Giuseppe L. Rotino Francesco Sunseri 《植物学报(英文版)》2020,62(4):487-508
Eggplant (Solanum melongena L.) yield is highly sensitive to N fertilization, the excessive use of which is responsible for environmental and human health damage. Lowering N input together with the selection of improved Nitrogen‐Use‐Efficiency (NUE) genotypes, more able to uptake, utilize, and remobilize N available in soils, can be challenging to maintain high crop yields in a sustainable agriculture. The aim of this study was to explore the natural variation among eggplant accessions from different origins, in response to Low (LN) and High (HN) Nitrate (NO3‐) supply, to identify NUE‐contrasting genotypes and their NUE‐related traits, in hydroponic and greenhouse pot experiments. Two eggplants, AM222 and AM22, were identified as N‐use efficient and inefficient, respectively, in hydroponic, and these results were confirmed in a pot experiment, when crop yield was also evaluated. Overall, our results indicated the key role of N‐utilization component (NUtE) to confer high NUE. The remobilization of N from leaves to fruits may be a strategy to enhance NUtE, suggesting glutamate synthase as a key enzyme. Further, omics technologies will be used for focusing on C‐N metabolism interacting networks. The availability of RILs from two other selected NUE‐contrasting genotypes will allow us to detect major genes/quantitative trait loci related to NUE. 相似文献