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排序方式: 共有463条查询结果,搜索用时 15 毫秒
1.
Francesco Di Girolamo Andrea Masotti Isabella Lante Margherita Scapaticci Cosima Damiana Calvano Carlo Zambonin Maurizio Muraca Lorenza Putignani 《International journal of molecular sciences》2015,16(9):20896-20912
Extra virgin olive oil (EVOO) with its nutraceutical characteristics substantially contributes as a major nutrient to the health benefit of the Mediterranean diet. Unfortunately, the adulteration of EVOO with less expensive oils (e.g., peanut and corn oils), has become one of the biggest source of agricultural fraud in the European Union, with important health implications for consumers, mainly due to the introduction of seed oil-derived allergens causing, especially in children, severe food allergy phenomena. In this regard, revealing adulterations of EVOO is of fundamental importance for health care and prevention reasons, especially in children. To this aim, effective analytical methods to assess EVOO purity are necessary. Here, we propose a simple, rapid, robust and very sensitive method for non-specialized mass spectrometric laboratory, based on the matrix-assisted laser desorption/ionization mass spectrometry (MALDI-TOF MS) coupled to unsupervised hierarchical clustering (UHC), principal component (PCA) and Pearson’s correlation analyses, to reveal corn oil (CO) adulterations in EVOO at very low levels (down to 0.5%). 相似文献
2.
Ferdinando Auricchio Lorenza Petrini 《International journal for numerical methods in engineering》2004,61(6):807-836
An always increasing knowledge on material properties as well as a progressively more sophisticated production technology make shape memory alloys (SMA) extremely interesting for the industrial world. At the same time, SMA devices are typically characterized by complex multi‐axial stress states as well as non‐homogeneous and non‐isothermal conditions both in space and time. This aspect suggests the finite element method as a useful tool to help and improve application design and realization. With this aim, we focus on a three‐dimensional macroscopic thermo‐mechanical model able to reproduce the most significant SMA features (Int. J. Numer. Methods Eng. 2002; 55 : 1255–1264), proposing a simple modification of such a model. However, the suggested modification allows the development of a time‐discrete solution algorithm, which is more effective and robust than the one previously discussed in the literature. We verify the computational tool ability to simulate realistic mechanical boundary value problems with prescribed temperature dependence, studying three SMA applications: a spring actuator, a self‐expanding stent, a coupling device for vacuum tightness. The effectiveness of the model to solve thermo‐mechanical coupled problems will be discussed in a forthcoming work. Copyright © 2004 John Wiley & Sons, Ltd. 相似文献
3.
Colzato Lorenza S.; Raffone Antonino; Hommel Bernhard 《Canadian Metallurgical Quarterly》2006,32(3):705
Four experiments were conducted to investigate the relationship between the binding of visual features (as measured by their aftereffects on subsequent binding) and the learning of feature-conjunction probabilities. Both binding and learning effects were obtained, but they did not interact. Interestingly, (shape-color) binding effects disappeared with increasing practice, presumably because of the fact that only 1 of the features involved was relevant to the task. However, this instability was only observed for arbitrary, not highly overlearned combinations of simple geometric features and not for real objects (colored pictures of a banana and strawberry), where binding effects were strong and resistant to practice. These findings suggest that learning has no direct impact on the strength or resistance of bindings or on speed with which features are bound; however, learning does affect the amount of attention particular feature dimensions attract, which again can influence which features are considered in binding. (PsycINFO Database Record (c) 2011 APA, all rights reserved) 相似文献
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Absorption and distribution of polyunsaturated fatty acids was investigated in rats receiving lysophospholipids per os (30 mg kg-1). Lysophosphatidylcholine (lysoPC) increased [3H]arachidonate absorption and its incorporation into mucosal phosphatidylcholine. Transport of [3H]arachidonate by the phospholipid fraction of lymph lipoproteins and the level of [3H]arachidonate in plasma and liver lipids was also increased by lyso PC. Lysophosphatidylserine also increased [3H]arachidonate absorption but channeled the fatty acids into the aminophospholipid fraction of mucosal phospholipids, thus decreasing its efflux in lymph lipoproteins. As a consequence, lysophosphatidylserine caused [3H]arachidonate accumulation in mucosa. As similar results were obtained with [14C]linoleate, the data suggest that the addition of an appropriate lysophospholipid to the diet may direct absorption and distribution of polyunsaturated fatty acids. 相似文献
7.
Viola G. Ortega R. Banavar R. Acosta J.A. Astolfi A. 《Automatic Control, IEEE Transactions on》2007,52(6):1093-1099
Total energy shaping is a controller design methodology that achieves (asymptotic) stabilization of mechanical systems endowing the closed-loop system with a Lagrangian or Hamiltonian structure with a desired energy function - that qualifies as Lyapunov function for the desired equilibrium. The success of the method relies on the possibility of solving two PDEs which identify the kinetic and potential energy functions that can be assigned to the closed loop. Particularly troublesome is the partial differential equation (PDE) associated to the kinetic energy which is nonlinear and inhomogeneous and the solution, that defines the desired inertia matrix, must be positive-definite. In this note, we prove that we can eliminate or simplify the forcing term in this PDE by modifying the target dynamics and introducing a change of coordinates in the original system. Furthermore, it is shown that, in the particular case of transformation to the Lagrangian coordinates, the possibility of simplifying the PDEs is determined by the interaction between the Coriolis and centrifugal forces and the actuation structure. The examples of pendulum on a cart and Furuta's pendulum are used to illustrate the results. 相似文献
8.
F Velardi A Di Chirico C Di Rocco C Fundarò O Genovese C Rendeli G Menichella R Serafini M Piastra L Viola D Pietrini A Pusateri F Stoppa 《Canadian Metallurgical Quarterly》1998,14(12):732-9; discussion 740-1
The authors describe the results obtained in 13 consecutive cases of craniosynostosis operated on according to a protocol devised at avoiding allogeneic blood transfusion. The protocol is based on pre- and postoperative treatment with erythropoietin, preoperative autologous blood donation, preoperative normovolemic hemodilution and intraoperative blood salvage. Nine subjects were affected by simple forms of craniosynostosis, whereas the remaining 4 presented with oxycephaly or craniofacial syndromes. Five of the 13 children were under 7 months and a further 3, under 10 months of age at the time of the surgical operation. Seven children weighed less than 10 kg. Allogeneic blood transfusion was avoided in 11 of the 13 children considered. Two failures - defined as the necessity to reinfuse the patient with an allogeneic blood transfusion - were recorded, 1 of them resulting from an unexpected hemorrhage during surgery. The results obtained indicate that this protocol designed to avoid allogeneic blood transfusion can be safely applied in the great majority of children with craniosynostosis, even when the surgical correction is carried out early in life. 相似文献
9.
Monica Bianco Ilenia Viola Miriam Cezza Francesca Pietracaprina Giuseppe Gigli Rosaria Rinaldi Valentina Arima 《Microfluidics and nanofluidics》2012,13(3):399-409
Solid surface/liquid interactions play an important role in microfluidics and particularly in manipulation of films, drops and bubbles, a basic requirement for a number of lab-on-chip applications. The behavior of solvents in coated microchannels is difficult to be predicted considering theories; therefore, experimental methods able to estimate the properties at the interface in real time and during the operational regime are amenable. Here, we propose to use an experimental setup to evaluate the effective dynamics of solvents inside PDMS microchannels. The influence of the solvent properties as well as of the channel wall’s wettability on the fluid movements was evaluated. Modification of the channel properties was achieved by introducing Teflon coatings that allow producing stable hydrophobic microchannel walls. The results were fitted according to Washburn-type power-law and compared with theoretical calculations of the parameter β that expresses the dependence of capillary dynamics on surface tension γ, liquid viscosity η, contact angles θ and the hydraulic radius R H. A comparison between the calculated and the experimental values reveled that parameters other than the contemplated ones influenced the measurements. The main parameter that affects the flow of solvents such as water, methanol ethanol, dimethylformamide, acetonitrile and acetone was found to be the γ/η ratio. Considering these results, the investigation tool described here is believed to be promising to predict the dynamics of common organic solvents inside integrated functional fluidic devices and to accurately control solvent flow, particularly in capillary-driven pumpless systems, a basic requirement for widening the application range of PDMS lab-on-chip devices. 相似文献
10.
Modeling guided wave propagation with application to the long-range defect detection in railroad tracks 总被引:2,自引:0,他引:2
Ivan Bartoli Francesco Lanza di Scalea Mahmood Fateh Erasmo Viola 《NDT & E International》2005,38(5):325-334
The aim of this work is to demonstrate the use of a commercial finite element package, ABAQUS EXPLICIT, to model ultrasonic guided waves in structural components. The particular application of interest is modeling the interaction of a broadband vertical bending mode with transverse-type defects in railroad tracks. This topic is part of a broader project on high-speed defect detection in rails by long-range ultrasonic inspections. Reflection coefficient spectra in the 20–45 kHz range are obtained for four different sizes and three different orientations of transverse head flaws. A preliminary study of Lamb waves in a free plate helps drawing modeling guidelines for the rail. 相似文献