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1.
In a middle-aged woman with anginal chest pain and a normal-appearing angiogram, dypiridamole technetium-99m Sestamibi scintigraphy, a noninvasive method, provided the diagnosis of syndrome X and was used in follow-up to monitor the course of disease.  相似文献   
2.
Sensitivity analysis studies how the variation in model outputs can be due to different sources of variation. This issue is addressed, in this study, as an application of sensitivity analysis techniques to a crop model in the Mediterranean region. In particular, an application of Morris and Sobol' sensitivity analysis methods to the rice model WARM is presented. The output considered is aboveground biomass at maturity, simulated at five rice districts of different countries (France, Greece, Italy, Portugal, and Spain) for years characterized by low, intermediate, and high continentality. The total effect index of Sobol' (that accounts for the total contribution to the output variation due a given parameter) and two Morris indices (mean μ and standard deviation σ of the ratios output changes/parameter variations) were used as sensitivity metrics. Radiation use efficiency (RUE), optimum temperature (Topt), and leaf area index at emergence (LAIini) ranked in most of the combinations site × year as first, second and third most relevant parameters. Exceptions were observed, depending on the sensitivity method (e.g. LAIini resulted not relevant by the Morris method), or site-continentality pattern (e.g. with intermediate continentality in Spain, LAIini and Topt were second and third ranked; with low continentality in Portugal, RUE was outranked by Topt). Low σ values associated with the most relevant parameters indicated limited parameter interactions. The importance of sensitivity analyses by exploring site × climate combinations is discussed as pre-requisite to evaluate either novel crop-modelling approaches or the application of known modelling solutions to conditions not explored previously. The need of developing tools for sensitivity analysis within the modelling environment is also emphasized.  相似文献   
3.
We consider the problem of optimal design of semi-decentralized controllers for a special class of spatially distributed systems. This class includes spatially invariant and distributed discrete-time systems with an inherent temporal delay in the interaction of neighboring sites. We consider the problem of optimal design of distributed controllers that have the same information passing delay structure as the plant. We show how for stable plants, the YJBK parameterization of such stabilizing controllers yields a convex parameterization for this class. We then show how the optimal problem can be solved.  相似文献   
4.
Fruit pieces of some species have been processed to be used as ingredients in various food systems, either by partial dehydration alone or by osmosis and partial dehydration, to achieve different levels of water activity and solids contents in the final products.

The relationships existing among processing, phase composition after processing and functional properties of the products have been assessed within a useful range of water content and water activity.

The functional properties are expressed as diagrams relating the phase composition (soluble solids, insoluble solids and water) to the range of consistencies obtainable at various water activities. These diagrams provide a useful tool for preparing fruit ingredients suitable for specific food systems.  相似文献   

5.
Phytopathogenic fungi are among the main causes of productivity losses in agriculture. To date, synthetic chemical pesticides, such as hydroxyanilides, anilinopyrimidines and azole derivatives, represent the main treatment tools for crop plant defence. However, the large and uncontrolled use of these substances has evidenced several side effects, namely the resistance to treatments, environmental damage and human health risks. The general trend is to replace chemicals with natural molecules in order to reduce these side effects. Moreover, the valorisation of agri-food industry by-products through biotransformation processes represents a sustainable alternative to chemical synthesis in several sectors. This research is aimed at comparing the anti-phytopathogenic activity of waste bovine and porcine bile with secosteroids obtained by biotransformation of bile acids with Rhodococcus strains. The ultimate goal is to apply these natural products on food crops affected by phytopathogenic fungi.  相似文献   
6.
7.
Acquired arachnoid cysts of the spinal cord are uncommon causes of spinal cord compression in the pediatric group. Meningitis, trauma and hemorrhage are considered to be causative or contributing factors. Interestingly, no spinal arachnoid cysts have been reported in patients after subarachnoid hemorrhage or meningitis, conditions expected to cause arachnoid scarring. We describe a child of 1 year and 10 months with thoracic spine trauma with crural paraplegia and anesthesia at level T5 submitted to serial magnetic resonance imagery at 5 days and 18 months, after trauma showing evolution from subarachnoid hemorrhage and adhesions of the arachnoid space to a posterior hypertensive thoracic intradural arachnoid cyst.  相似文献   
8.
PDZ domains represent a large family of protein-interaction modules associated with a variety of unrelated proteins with different functions. We report a complete characterization of the kinetic folding mechanism of a fluorescent variant of PDZ2 from PTP-BL, investigated under a variety of different experimental conditions. For this purpose, we engineered a fluorescent variant of this protein Y43W (called pseudo-wild-type, pWT43). The results suggest the presence of a high-energy intermediate in the folding of PDZ2, as revealed by a pronounced non-linear dependence of the unfolding rate constant on denaturant concentration. Such an intermediate may or may not be detectable depending on the experimental conditions, giving rise to apparent two-state folding under stabilizing conditions (e.g. in the presence of sodium sulfate). Interestingly, even under these conditions, three-state folding can be restored by selectively destabilizing the native-like rate-limiting barrier by one specific mutation (V44A). Finally, we show that data taken on pWT43 under different experimental conditions (e.g. different pH values from 2.1 to 8.0 or in the presence of a stabilizing salt) and also data on a site-directed conservative mutant can be rationalized in terms of a simple reaction scheme involving a single set of intermediates and transition states.  相似文献   
9.
A structural model of Saccharomyces cerevisiae oxidosqualene cyclase (SceOSC) suggests that some residues of the conserved sequence Pro-Ala-Glu-Val-Phe-Gly (residues 524-529) belong to a channel constriction that gives access to the active-site cavity. Starting from the SceOSC C457D mutant, which lacks the cysteine residue next to the catalytic Asp456 residue Cys457 has been replaced but Asp456 is still there, we prepared two further mutants where the wild-type residues Ala525 and Glu526 were individually replaced by cysteine. These mutants, especially E526C, were very sensitive to the thiol-reacting agent dodecyl-maleimide. Moreover, both the specific activity and the thermal stability of E526C were severely reduced. A similar decrease of the enzyme functionality was obtained by replacing Glu526 with alanine, while substitution with the conservative residues aspartate or glutamine did not alter catalytic activity. Molecular modeling of the yeast wild-type OSC and mutants on the template structure of human OSC confirms that the channel constriction is an important aspect of the protein structure and suggests a critical structural role for Glu526.  相似文献   
10.
Summary: A fluorine containing hyperbranched polymer was synthesized by modifying an aromatic‐aliphatic hyperbranched polyester with a semifluorinated alcohol via a Mitsunobu reaction and was subsequently used as an additive in cationic photopolymerization of an epoxy resin. The remaining OH groups of the fluorinated hyperbranched polymer interact with the polymeric carbocation through a chain‐transfer mechanism inducing an increase in the final epoxy conversion. The fluorinated HBP induces modification of bulk and surface properties, with an increase in Tg and surface hydrophobicity already reached at very low concentration. The HBFP additive can, therefore, protect the coatings from aggressive solvents, increases hardness, and allows the preparation of a low energy surface coating.

Synthesis of fluorinated hyperbranched polyester.  相似文献   

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