The lipid fraction of goat milk was subjected to transesterification using a commercially available immobilized lipase to decrease the amount of short- and medium-chain fatty acids (C4–C14) by enrichment of the reaction mixture with long-chain (C18:1 and C18:2) fatty acids. Aliquots were taken during, transesterification at different reaction times and analyzed for triglycerides and their fatty acid components. The gas chromatographic analyses of triglycerides (previously isolated by thinlayer chromatography) showed that at 6 h reaction under the experimental conditions led to the greatest reduction of the low molecular weight triglycerides (C22–C38) and concomitantly to the greatest increase in the higher molecular weight triglycerides (C48–C54). These changes correlated with the variations observed in the fatty acids of the triglyceride fraction. 相似文献
Di Lecce, V., and Guerriero, A., Spectral Estimation by AFT Computation,Digital Signal Processing6(1996) 213–223.At the beginning of this century Bruns developed a method for computing the coefficients of the Fourier series of a periodic functiony(t) using the Möbius inversion formula. This idea for Fourier analysis was considered again by Wintner from an arithmetical point of view in 1945. In recent papers, many authors have shown that the arithmetic Fourier transform (AFT) computation is more convenient in signal processing, requiring a reduced computation load, than are fast Fourier transform and convolution algorithms. The data dependence in the AFT is not uniform (this algorithm requires nonequidistant inputs to produce equidistant spectral coefficients). To have a series of suitable values as AFT inputs, oversampling or interpolation is used. In these papers, bases on algorithms, evaluations of errors in the spectral coefficients computation using AFT, and the complexity of different hardware and software solutions for the AFT computation are proposed. The spectral coefficients computed via AFT and via discrete Fourier transform are compared in terms of accuracy. AFT computation proves to be an easy task but its software or hardware implementation is much more complex. Furthermore there is not a complete evaluation of AFT in any of the papers. Our aim is to provide a complete evaluation of this algorithm. 相似文献
Ion exchange can be used to mechanically reinforce dental glass-ceramics to reduce the problems associated to the flaws created upon various processing steps and handling. This work introduces a novel ion exchange method to the field of dental glass-ceramic to increase the possibilities of preparing highly reliable glass-ceramic restorations. The aim of the study was to compare Electric Field-Assisted Ion Exchange with conventional method, for newly developed nepheline based dental glass-ceramic. Multicomponent glass system was synthesized using melt-quench method and then prepared into glass-ceramic specimens via powder sinter-crystallisation route. The prepared glass-ceramic specimens were tested for bi-axial flexural strength before and after ion exchange according to the dental ceramics ISO 6872:2015. Ion exchange process was carried out in molten potassium nitride and the potassium penetration depth determined by EDXS was found greater and occurring in a matter of minutes within the nepheline crystal structure during electrical field assisted ion exchange compared with several hours of conventional treatment. The newly developed nepheline glass-ceramic system and the results achieved by electrical field assisted ion exchange may renew the ion exchange concept for dental application. 相似文献
In the last decades, the comprehension of the pathophysiology of bone metabolism and its interconnections with multiple homeostatic processes has been consistently expanded. The branch of osteoimmunology specifically investigating the link between bone and immune system has been developed. Among molecular mediators potentially relevant in this field, vitamin D has been recently pointed out, and abnormalities of the vitamin D axis have been described in both in vitro and in vivo models of inflammatory bowel diseases (IBD) and arthritis. Furthermore, vitamin D deficiency has been reported in patients affected by IBD and chronic inflammatory arthritis, thus suggesting the intriguing possibility of impacting the disease activity by the administration vitamin D supplements. In the present review, the complex interwoven link between vitamin D signaling, gut barrier integrity, microbiota composition, and the immune system was examined. Potential clinical application exploiting vitamin D pathway in the context of IBD and arthritis is presented and critically discussed. A more detailed comprehension of the vitamin D effects and interactions at molecular level would allow one to achieve a novel therapeutic approach in gastro-rheumatologic inflammatory diseases through the design of specific trials and the optimization of treatment protocols. 相似文献
AbstractThis work is motivated by the recent interest in using strain gradient theory to model the chiral behavior of elastic materials. In this paper, we derive a linear strain gradient theory for Cosserat thermoelastic materials according to the three models (types I, II and III) of Green-Naghdi theory. Models II and III permit propagation of thermal waves at finite speeds, while model I coincides with the classical Fourier’s law. The thermal field is influenced by the displacement and the microrotation fields and by some additional parameters that describe the chiral behavior. We prove the well-posedness for the three models and the asymptotic behavior for models I and III by the semigroup theory of linear operators. 相似文献
Infant formula contains thermal processing contaminants, such as dietary advanced glycation end-products (dAGEs), glycidyl esters (GEs), 2-monochloropropane-1,3-diol esters and 3-monochloropropane-1,2-diol esters (MCPDEs). This systematic review aimed to gain insights into the occurrence of these contaminants in different types of infant formula, to understand potential effects of the formulation and processing of infant formulas on these contaminants, as well as into possible mitigation strategies. The occurrence of dAGEs in infant formula depends on the recipes and processing conditions. Hydrolyzed protein formulations promote dAGEs formation in infant formula since peptides are more prone to glycation than intact proteins, which is reflected in high dAGEs concentration in hypoallergenic infant formula. Different carbohydrates in recipes result into different glycation extents of infant formula: maltodextrin containing formulas contained less dAGEs than those with lactose. Concerning mitigation strategies, applying ultra-high-temperature (UHT) treatment during milk processing leads to less dAGEs formation than using in-bottle sterilization. Although data are limited, evidence showed that encapsulation of raw ingredients or the use of antioxidants or enzymes in recipes is promising. The occurrence of MCPDEs and GEs in infant formula fully depends on the vegetable oils used in the recipe. High levels of these contaminants can be found when relatively high amounts of palm oils or fats are used. The mitigation of MCPDEs and GEs should therefore be performed on fats and oils before their application to infant formula recipes. Data and knowledge gaps identified in this review can be useful to guide future studies. 相似文献
International Journal on Software Tools for Technology Transfer - Recent research on spatial and spatio-temporal model checking provides novel image analysis methodologies, rooted in logical... 相似文献
This paper proposes a novel approach for the evaluation of the performance achieved by trainees involved in cyber security exercises implemented in modern cyber ranges. Our main contributions include: the definition of a distributed monitoring architecture for gathering relevant information about trainees activities; an algorithm for modeling the trainee activities using directed graphs; novel scoring algorithms, based on graph operations, that evaluate different aspects (speed, precision) of a trainee during an exercise. With respect to previous work, our proposal allows to measure exactly how fast a user is progressing towards an objective and where he does wrong. We highlight that this is currently not possible in the most popular cyber ranges.
In this paper, a design methodology based on the theory of plastic mechanism control (TPMC) is presented for dual systems combined by moment resisting frames and concentrically braced frames (MRF–CBF dual systems). The study is focused on the design of structures failing in global mode, i.e. whose collapse mechanism is characterised by the yielding of all the tensile diagonals, the buckling of the compressed ones, and the development of plastic hinges at all the beam ends and at the base of first-storey columns. The results of push-over analyses and nonlinear dynamic analyses carried out with reference to MRF–CBF dual systems designed according to the proposed procedure are compared with those obtained with reference to the same structural scheme designed according to Eurocode 8. The advantages obtained in terms of seismic performances are outlined and also economic issues are investigated pointing out the convenience of seismic design based on TPMC. 相似文献
Metasurfaces are artificially engineered ultrathin structures that can finely tailor and control electromagnetic wavefronts. There is currently a strong interest in exploring their capability to lift some fundamental limitations dictated by Lorentz reciprocity, which have strong implications in communication, heat management, and energy harvesting. Time‐varying approaches have emerged as attractive alternatives to conventional schemes relying on magnetic or nonlinear materials, but experimental evidence is currently limited to devices such as circulators and antennas. Here, the recently proposed concept of space‐time‐coding digital metasurfaces is leveraged to break reciprocity. Moreover, it is shown that such nonreciprocal effects can be controlled dynamically. This approach relies on inducing suitable spatiotemporal phase gradients in a programmable way via digital modulation of the metasurface‐elements' phase repsonse, which enable anomalous reflections accompanied by frequency conversions. A prototype operating at microwave frequencies is designed and fabricated for proof‐of‐concept validation. Measured results are in good agreement with theory, hence providing the first experimental evidence of nonreciprocal reflection effects enabled by space‐time‐modulated digital metasurfaces. The proposed concept and platform set the stage for “on‐demand” realization of nonreciprocal effects, in programmable or reconfigurable fashions, which may find several promising applications, including frequency conversion, Doppler frequency illusion, optical isolation, and unidirectional transmission. 相似文献