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171.
Ali Tahaei Paul Horley Mattia Merlin David Torres-Torres Gian Luca Garagnani Rolando Praga Felipe J. García Vázquez Ana Arizmendi-Morquecho 《Metallurgical and Materials Transactions A》2017,48(3):1053-1063
This work is dedicated to optimization of carbide particle system in a weld bead deposited by PTAW technique over D2 tool steel with high chromium content. The paper reports partial melting of the original carbide grains of the Ni-based filling powder, and growing of the secondary carbide phase (Cr, Ni)\(_3\)W\(_3\)C in the form of dendrites with wide branches that enhanced mechanical properties of the weld. The optimization of bead parameters was made with design of experiment methodology complemented by a complex sample characterization including SEM, EDXS, XRD, and nanoindentation measurements. It was shown that the preheat of the substrate to a moderate temperature 523 K (250 \(^\circ \)C) establishes linear pattern of metal flow in the weld pool, resulting in the most homogeneous distribution of the primary carbides in the microstructure of weld bead. 相似文献
172.
Mattia Pasqua Roberto Di Ges Cinzia Maria Chinnici Pier Giulio Conaldi Maria Giovanna Francipane 《International journal of molecular sciences》2021,22(15)
The possibility to reproduce key tissue functions in vitro from induced pluripotent stem cells (iPSCs) is offering an incredible opportunity to gain better insight into biological mechanisms underlying development and disease, and a tool for the rapid screening of drug candidates. This review attempts to summarize recent strategies for specification of iPSCs towards hepatobiliary lineages —hepatocytes and cholangiocytes—and their use as platforms for disease modeling and drug testing. The application of different tissue-engineering methods to promote accurate and reliable readouts is discussed. Space is given to open questions, including to what extent these novel systems can be informative. Potential pathways for improvement are finally suggested. 相似文献
173.
Assessing cortical functional connectivity by partial directed coherence: simulations and application to real data 总被引:1,自引:0,他引:1
Astolfi L Cincotti F Mattia D Marciani MG Baccalà LA de Vico Fallani F Salinari S Ursino M Zavaglia M Babiloni F 《IEEE transactions on bio-medical engineering》2006,53(9):1802-1812
The aim of this paper is to test a technique called partial directed coherence (PDC) and its modification (squared PDC; sPDC) for the estimation of human cortical connectivity by means of simulation study, in which both PDC and sPDC were studied by analysis of variance. The statistical analysis performed returned that both PDC and sPDC are able to estimate correctly the imposed connectivity patterns when data exhibit a signal-to-noise ratio of at least 3 and a length of at least 27 s of nonconsecutive recordings at 250 Hz of sampling rate, equivalent, more generally, to 6750 data samples. 相似文献
174.
Mattia Boiani Richard J. FitzGerald Phil M. Kelly 《Journal of dairy science》2018,101(12):10750-10758
Our previous study identified peaks in the 31P nuclear magnetic resonance (31P NMR) spectra of skim milk, denoting the interaction of different phosphate species such as inorganic and casein-associated phosphate during the separation of colloidal and serum phases of skim milk by microfiltration (MF) and diafiltration (DF). In the current study, we investigated the same samples generated by the aforementioned separation using attenuated total reflectance (ATR) Fourier transform infrared (FTIR) spectroscopy analysis. The results confirmed that the technique was not only capable of differentiating between the mineral equilibrium of the casein phosphate nanocluster (CPN) and milk serum, but also complemented the application of 31P NMR. An ATR-FTIR broad band in the region of 1,055 to 1,036 cm?1 and a specific band at 1,076 cm?1 were identified as sensitive to the repartitioning of different phosphate species in milk in accordance with the 31P NMR signals representing casein-associated phosphate and inorganic phosphate in the serum. A third ATR-FTIR signal at 1,034 cm?1 in milk, representing precipitated inorganic calcium phosphate, had not previously been detected by 31P NMR. Thus, the results indicate that a combination of ATR-FTIR and 31P NMR spectroscopies may be optimally used to follow mineral and protein phase changes in milk during membrane processing. 相似文献
175.
The antioxidant activity of the hydrophilic and lipophilic fraction of poultry meat was determined in terms of ‘radical scavenging activity’ (RSA) using a modified ABTS radical cation decolorization method.The method uses the extraction of hydrophilic and lipophilic fractions in water and methanol–chloroform, respectively. The determination of the RSA of the lipophilic fraction was conducted using a chloroform extract and maintaining a constant chloroform:ethanol ratio in the solution of analysis. The method was tested on nine samples of poultry breasts and thigh meats and permitted to quantify the RSA in terms of μmol Trolox equivalent antioxidant capacity (TEAC) with a mean relative standard deviation of less than 5%.The contribution of the hydrophilic fraction to the total RSA was much higher than that of the lipid soluble fraction. Breast showed a higher RSA than thigh meat due to its lower total lipids content. The total RSA value (TEAC = 2.4 μmol g−1) suggests that poultry meat could significantly contribute to the antioxidant activity of the diet. 相似文献
176.
Mattia PolliMarco Di Stanislao Roberto BagatinEiman Abu Bakr Maurizio Masi 《Chemical engineering science》2002,57(1):197-205
It is well known that the gas distributor can play an important role on the evolution of the bubble size distribution (BSD) in gas-liquid reactors, strippers and absorbers. Therefore, the main subject of the present work was to study the influence of sparger design and process parameters on the BSD in the sparger region of the considered apparatus. For this purpose, both detailed measurements and prediction of the size of bubbles produced at the sparger were carried out in three different experimental apparatuses.The unique set of BSD curves were obtained by analyzing a large amount of bubbles with a measurement based on image analysis technique.Additionally, Colella's model of BSD evolution in bubble columns was further developed by implementing a detailed physical model for predicting the initial BSD at the sparger where the model input is only based on design/process parameters. A validation of the model was carried out using data from two different columns. The comparison between calculated and experimental BSD shows good agreement. 相似文献
177.
As increasing amounts of data flow within and between organizations, the problems that can result from poor data management practices are becoming more apparent. Studies have shown that such poor practices are widespread. All organizations have data architectures, whether explicitly documented or implicitly assumed. An important data management process is to document the architecture's capabilities, making it more useful to the organization. Increasing data management practice maturity levels can positively impact the coordination of data flow among organizations, individuals, and systems. Results from a self-assessment provide a roadmap for improving organizational data management practices 相似文献
178.
This paper studies the flexibility available with thermostatically controlled loads (TCLs) to provide power system services by demand response (DR) activation. Although the DR activation on TCLs can provide power system ancillary services, it is important to know how long such services can be provided for when different levels of power reduction are imposed. The flexibility change with different levels of power reduction is tested experimentally with domestic fridges used by real customers with unknown user interaction. The investigation quantifies the flexibility of household fridges and the impact of DR activation in terms of deviation in the average temperature. The maximum possible power reduction with the cluster of refrigerators is 67% and the available flexibility with the cluster of refrigerators is 10%. The resulting deviation in the average temperature is 14%. 相似文献
179.
Stefano Girotti Mattia Muratori Fabiana Fini Elida Nora Ferri Giacomo Carrea Michal Koran Pavel Rauch 《European Food Research and Technology》2000,210(3):216-219
A bioluminescent flow sensor, previously developed for the determination of both d- and l-lactate in clinical samples, was utilized to carry out the same assay in beer. The sensor monitored the reduced form of nicotinamide
adenine dinucleotide, produced by nylon-immobilized d- and l-lactate dehydrogenase, by means of bacterial bioluminescent enzymes immobilized on a separate nylon coil. The preparation
of beer samples was very simple as only a modification of pH and a dilution were necessary. The recoveries ranged from 91%
to 104%, and the relative standard deviations at the 1 mmol 1–1 level were 4.6% and 6.7% for l- and d-lactate respectively. The response was linear in the range 0.1–10 mmol 1–1 for both d- and l-lactate. The total amount of lactate determined by bioluminescent biosensor (x) and by HPLC (y) showed a very good correlation (y=0.654 x+88.1, n=29, r=0.918). The flow injection system developed allowed the determination of not only the total but also the individual contents
of d- and l-lactate in beer, and the timely discovery of the unwanted presence of lactic acid bacteria.
Received: 14 January 1999 / Revised version: 29 April 1999 相似文献
180.
Savina Apolloni Paola Fabbrizio Susanna Amadio Giulia Napoli Mattia Freschi Francesca Sironi Paolo Pevarello Paola Tarroni Chiara Liberati Caterina Bendotti Cinzia Volont 《International journal of molecular sciences》2021,22(19)
Amyotrophic lateral sclerosis (ALS) is a disease with a resilient neuroinflammatory component caused by activated microglia and infiltrated immune cells. How to successfully balance neuroprotective versus neurotoxic actions through the use of anti-inflammatory agents is still under debate. There has been a boost of awareness regarding the role of extracellular ATP and purinergic receptors in modulating the physiological and pathological mechanisms in the nervous system. Particularly in ALS, it is known that the purinergic ionotropic P2X7 receptor plays a dual role in disease progression by acting at different cellular and molecular levels. In this context, we previously demonstrated that the P2X7 receptor antagonist, brilliant blue G, reduces neuroinflammation and ameliorates some of the pathological features of ALS in the SOD1-G93A mouse model. Here, we test the novel, noncommercially available, and centrally permeant Axxam proprietary P2X7 antagonist, AXX71, in SOD1-G93A mice, by assessing some behavioral and molecular parameters, among which are disease progression, survival, gliosis, and motor neuron wealth. We demonstrate that AXX71 affects the early symptomatic phase of the disease by reducing microglia-related proinflammatory markers and autophagy without affecting the anti-inflammatory markers or motor neuron survival. Our results suggest that P2X7 modulation can be further investigated as a therapeutic strategy in preclinical studies, and exploited in ALS clinical trials. 相似文献