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排序方式: 共有515条查询结果,搜索用时 23 毫秒
71.
Blanca Estela Zendejas-Leal Víctor Rodrigo Barrientos-Sotelo Rogelio Cano-Casas Margarita Lizeth Alvarado-Noguez Juan Hernández-Rosas Alfredo Cruz-Orea 《International Journal of Thermophysics》2018,39(7):80
In this work, the optical absorption spectrum of peppers was monitored by phase-resolved photoacoustic spectroscopy during a dehydration process based on hot-air drying, yielding simultaneous information about changes in the exocarp and mesocarp. Our results show that between all of the dehydration processes of green Capsicum annuum L. variety pasilla peppers, only very small changes occur in the different phase angles, which has been correlated with the small changes in the exocarp thickness. The phase-resolved spectra of mesocarp show more clearly the evolution of the carotenoid compounds with respect to the optical absorption spectrum without phase resolving, due to the last spectrum having a band broadening in that region with more signals convolved. We have shown that not only do the ripened chili peppers produce new carotenoid compounds, but also we are probing that the dehydration process, beginning with the green stage, preserves the nutrimental content, similar to changes that occur in the natural ripening process. 相似文献
72.
Sara A. Althubiti José Escorcia-Gutierrez Margarita Gamarra Roosvel Soto-Diaz Romany F. Mansour Fayadh Alenezi 《计算机、材料和连续体(英文)》2022,73(2):2423-2439
Smart healthcare has become a hot research topic due to the contemporary developments of Internet of Things (IoT), sensor technologies, cloud computing, and others. Besides, the latest advances of Artificial Intelligence (AI) tools find helpful for decision-making in innovative healthcare to diagnose several diseases. Ovarian Cancer (OC) is a kind of cancer that affects women’s ovaries, and it is tedious to identify OC at the primary stages with a high mortality rate. The OC data produced by the Internet of Medical Things (IoMT) devices can be utilized to differentiate OC. In this aspect, this paper introduces a new quantum black widow optimization with a machine learning-enabled decision support system (QBWO-MLDSS) for smart healthcare. The primary intention of the QBWO-MLDSS technique is to detect and categorize the OC rapidly and accurately. Besides, the QBWO-MLDSS model involves a Z-score normalization approach to pre-process the data. In addition, the QBWO-MLDSS technique derives a QBWO algorithm as a feature selection to derive optimum feature subsets. Moreover, symbiotic organisms search (SOS) with extreme learning machine (ELM) model is applied as a classifier for the detection and classification of ELM model, thereby improving the overall classification performance. The design of QBWO and SOS for OC detection and classification in the smart healthcare environment shows the study’s novelty. The experimental result analysis of the QBWO-MLDSS model is conducted using a benchmark dataset, and the comparative results reported the enhanced outcomes of the QBWO-MLDSS model over the recent approaches. 相似文献
73.
Michael Morin Margarita P. Castro Kyle E. C. Booth Tony T. Tran Chang Liu J. Christopher Beck 《Constraints》2018,23(3):335-354
We develop optimization approaches to the graph-clear problem, a pursuit-evasion problem where mobile robots must clear a facility of intruders. The objective is to minimize the number of robots required. We contribute new formal results on progressive and contiguous assumptions and their impact on algorithm completeness. We present mixed-integer linear programming and constraint programming models, as well as new heuristic variants for the problem, comparing them to previously proposed heuristics. Our empirical work indicates that our heuristic variants improve on those from the literature, that constraint programming finds better solutions than the heuristics in run-times reasonable for the application, and that mixed-integer linear programming is superior for proving optimality. Given their performance and the appeal of the model-and-solve framework, we conclude that the proposed optimization methods are currently the most suitable for the graph-clear problem. 相似文献
74.
de Lima de Mon M Cioccia AM González E Hevia P 《Archivos latinoamericanos de nutrición》2002,52(1):20-28
In order to compare intestinal morphology and function, diarrhea was produced in rats using laxatives in the diet. The 14 day study included two groups of rats with diarrhea (osmotic or secretory), two groups without diarrhea but with a degree of malnutrition which was similar to that seen in the rats with diarrhea (malnourished without diarrhea) and a well-nourished group (control). The inclusion of laxatives(lactose or bisoxatin acetate) cause a reduction in food intake, diarrhea an malnutrition. It also caused a reduction in dietary protein and fat digestibility which was proportional to the severity of diarrhea and more pronounced in secretory diarrhea. In the malnourished rats without diarrhea, malnutrition did not affect their absorptive function. Both in the rats with secretory and osmotic diarrhea an intestinal hypertrophy was observed. This hypertrophy was proportional to the severity of diarrhea and independent of its aetiology. In the intestines of the rats with both types of diarrhea there was inflammation, a greater number of mitotic figures but the flattening of the villi seen in the malnourished rats without diarrhea was not seen. In osmotic diarrhea there was, in addition, a patchy damage of the surface of the jejunal mucosa and an increment in the number of goblet cells, indicating a more severe intestinal deterioration. Since despite this greater deterioration, these rats absorbed more protein and fat we concluded that the alterations in intestinal morphology seen in this study was not predictive of intestinal function. The study also showed that diarrhea had a trophic effect on the intestine which did not occur in malnourished rats without diarrhea. 相似文献
75.
Margarita N. Shurupova Andrei A. Zverev 《The International journal of environmental studies》2017,74(5):724-731
AbstractThe criteria for assessing conservation categories of rare species are not identical in drafting the red lists of Russia and the IUCN. By the example of genus Saussurea (Compositae), we have shown that the conservation measures for some endangered species do not match their state. We conducted indicator analyses on two factors of more than 9000 relevés with Saussurea species with large ranges and determined their rarity types according to D. Rabinowitz. Only 2 Siberian Saussurea species are not characterised by any type of rarity. The other 54 taxa all feature a small range, low abundance or high habitat specificity. 相似文献
76.
Margarita Angelidou 《城市工程杂志》2017,24(4):3-28
This paper identifies the characteristics of smart cities as they emerge from the recent literature. It then examines whether and in what way these characteristics are present in the smart city plans of 15 cities: Amsterdam, Barcelona, London, PlanIT Valley, Stockholm, Cyberjaya, Singapore, King Abdullah Economic City, Masdar, Skolkovo, Songdo, Chicago, New York, Rio de Janeiro, and Konza. The results are presented with respect to each smart city characteristic. As expected, most strategies emphasize the role of information and communication technologies in improving the functionality of urban systems and advancing knowledge transfer and innovation networks. However, this research yields other interesting findings that may not yet have been documented across multiple case studies; for example, most smart city strategies fail to incorporate bottom-up approaches, are poorly adapted to accommodate the local needs of their area, and consider issues of privacy and security inadequately. 相似文献
77.
Gana JM Ordóñez R Zampini C Hidalgo M Meoni S Isla MI 《Journal of hazardous materials》2008,155(3):403-406
Assessment of water pollution and its effect upon river biotic communities and human health is indispensable to develop control and management strategies. The aim of this work was to ascertain the biotoxicity of water pollution in samples from industrial effluent discharge areas of Tucumán, Argentina by means of biological tests. Chemical characterization of the water pollution was verified by measuring dissolved oxygen concentration or levels of suspended matter and salts. Genotoxic/mutagenic potential was determined using Allium anaphase-telophase and Ames/Salmonella tests. All samples were phytotoxic and genotoxic for Allium roots. Micronucleus and anaphase aberrations were observed, but they did not show mutagenic effects on Salmonella typhimurium, TA98 and TA100 strains with and without metabolic activation (S9). Our results show the importance of testing industrial effluents by chemical methods and complementary biological tests to optimize the control policy on these environmental samples. 相似文献
78.
L.F. Gamarra W.M. Pontuschka E. Amaro A.J. Costa-Filho G.E.S. Brito E.D. Vieira S.M. Carneiro D.M. Escriba A.M.F. Falleiros V.L. Salvador 《Materials science & engineering. C, Materials for biological applications》2008,28(4):519-525
In this study, we evaluated the biodistribution and the elimination kinetics of a biocompatible magnetic fluid, Endorem™, based on dextran-coated Fe3O4 nanoparticles endovenously injected into Winstar rats. The iron content in blood and liver samples was recorded using electron paramagnetic resonance (EPR) and X-ray fluorescence (XRF) techniques. The EPR line intensity at g = 2.1 was found to be proportional to the concentration of magnetic nanoparticles and the best temperature for spectra acquisition was 298 K. Both EPR and XRF analysis indicated that the maximum concentration of iron in the liver occurred 95 min after the ferrofluid administration. The half-life of the magnetic nanoparticles (MNP) in the blood was (11.6 ± 0.6) min measured by EPR and (12.6 ± 0.6) min determined by XRF. These results indicate that both EPR and XRF are very useful and appropriate techniques for the study of kinetics of ferrofluid elimination and biodistribution after its administration into the organism. 相似文献
79.
Hernández-Padrón G García-Garduño M Canseco MA Castaño VM 《Journal of nanoscience and nanotechnology》2008,8(6):3142-3145
The synthesis, characterization and corrosion properties of a novel material, produced by the reaction of silica nanoparticles with a functionalized Phenol-Formaldehyde Resin (PFR), are presented. Carboxylic groups were attached in situ to the PFR skeleton to produce a functionalized resin (PFR-SA), which is then reacted with sol-gel-prepared silica nanoparticles, yielding a novel hybrid (organic/inorganic) material (PFR-SA-nanoSiO2). This hybrid material was characterized by FT-IR, FT-Raman, TGA, DSC, SEM and corrosion tests, whose results showed significant improvement of the thermal properties in comparison with the PFR coating. In addition, the new material was efficient and durable against corrosion of metals, with the anticorrosive performance of PFR-SA and PFR-SA/nanoSiO2 coating films being superior to those of the original PFR coating. 相似文献
80.