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排序方式: 共有1472条查询结果,搜索用时 586 毫秒
71.
Chersoni Emmanuele Santus Enrico Lenci Alessandro Blache Philippe Huang Chu-Ren 《Language Resources and Evaluation》2021,55(4):873-900
Language Resources and Evaluation - This work addresses some questions about language processing: what does it mean that natural language sentences are semantically complex? What semantic features... 相似文献
72.
Matteo Ottavian Pierantonio Facco Massimiliano Barolo Paolo Berzaghi Severino Segato Enrico Novelli Stefania Balzan 《Journal of food engineering》2012
This study investigated the possibility of using near-infrared spectroscopy (NIRS) for the authentication of Asiago d’allevo, a protected designation of origin cheese from northern Italy. Latent variable models applied on spectral data were developed and used to estimate several chemical properties and to classify the available dataset according to the location and management of the cheesemaking factory (lowland and alpine), the ripening age (6, 12, 18 and 36 months), the altitude of milk production (low, medium, medium–high and high), and the period of the year of the cheese production (May, July and September). The variable importance in projection index was used to identify the most informative spectral regions for discrimination. Results showed that NIR spectra can be used both to accurately estimate several chemical properties and to classify the samples according to the different experimental conditions under investigation with the same discrimination capacity provided by traditional chemical analysis. 相似文献
73.
Theme issue on personal projection 总被引:1,自引:0,他引:1
74.
Influence of olive ripening degree and crusher typology on chemical and sensory characteristics of Correggiolo virgin olive oil 下载免费PDF全文
75.
Mauro Marangoni Lukas Arnout Lieven Machiels Lieven Pandelaers Enrico Bernardo Paolo Colombo Yiannis Pontikes 《Journal of the American Ceramic Society》2016,99(6):1985-1991
The present paper deals with the synthesis of porous, sintered glass‐ceramics obtained at temperatures below 1150°C, originating from inorganic polymers based on fayalite slag. Firing led to the evaporation of water, dehydroxylation, and oxidation of Fe2+ above 345°C. For heating >700°C, the Si–O stretching band shifted from the 1160 and 750 cm?1 to the 1255 and 830 cm?1 region, due to a structural reorganization of the amorphous phase, whereas Fe–O bands appeared at 550 cm?1. The final microstructure consisted predominantly of an amorphous phase, hematite, and franklinite. The open porosity and compressive strength decreased and increased, respectively, as the firing temperature increased. The final values suggest properties comparable to that of structural lightweight concrete, still, the materials synthesized herein, are lighter, and made primarily from secondary resources. 相似文献
76.
Direct Ink Writing of a Preceramic Polymer and Fillers to Produce Hardystonite (Ca2ZnSi2O7) Bioceramic Scaffolds 下载免费PDF全文
Andrea Zocca Giorgia Franchin Hamada Elsayed Emilia Gioffredi Enrico Bernardo Paolo Colombo 《Journal of the American Ceramic Society》2016,99(6):1960-1967
The direct ink writing of an ink composed of a preceramic polymer and fillers was used to produce hardystonite (Ca2ZnSi2O7) bioceramic scaffolds. Suitable formulations were developed for the extrusion of fine filaments (350 μm diameter) through a nozzle. The preceramic polymer was employed with the double purpose of contributing to the rheology of the ink by increasing its viscosity and of forming the hardystonite phase upon heat treatment by reacting with the fillers. A control of the rheology is essential when spanning features have to be produced, and therefore the main rheological characteristics of the inks were measured (flow curves, dynamic oscillation tests, viscosity recovery tests) and compared to models reported in the literature. Highly porous scaffolds (up to 80% total porosity) were produced and heat treated in air or in nitrogen atmosphere. The influence of the heat‐treatment atmosphere on the morphology, crystalline phase assemblage, and compressive strength of the scaffolds was investigated. 相似文献
77.
The Casein Kinase 2‐Dependent Phosphorylation of NS5A Domain 3 from Hepatitis C Virus Followed by Time‐Resolved NMR Spectroscopy 下载免费PDF全文
Erica Secci Dr. Enrico Luchinat Prof. Lucia Banci 《Chembiochem : a European journal of chemical biology》2016,17(4):328-333
Hepatitis C virus (HCV) chronically affects millions of individuals worldwide. The HCV nonstructural protein 5A (NS5A) plays a critical role in the viral assembly pathway. Domain 3 (D3) of NS5A is an unstructured polypeptide responsible for the interaction with the core particle assembly structure. Casein kinase 2 (CK2) phosphorylates NS5A‐D3 at multiple sites that have mostly been predicted and only observed indirectly. In order to identify the CK2‐dependent phosphorylation sites, we monitored the reaction between NS5A‐D3 and CK2 in vitro by time‐resolved NMR. We unambiguously identified four serine residues as substrates of CK2. The apparent rate constant for each site was determined from the reaction curves. Ser408 was quickly phosphorylated, whereas the three other serine residues reacted more slowly. These results provide a starting point from which to elucidate the role of phosphorylation in the mechanisms of viral assembly—and in the modulation of the viral activity—at the molecular level. 相似文献
78.
Antonio Magrì Alessia Munzone Massimiliano Peana Serenella Medici Maria Antonietta Zoroddu Orjan Hansson Cristina Satriano Enrico Rizzarelli Diego La Mendola 《International journal of molecular sciences》2016,17(8)
Angiogenin (Ang) is a potent angiogenic factor, strongly overexpressed in patients affected by different types of cancers. The specific Ang cellular receptors have not been identified, but it is known that Ang–actin interaction induces changes both in the cell cytoskeleton and in the extracellular matrix. Most in vitro studies use the recombinant form (r-Ang) instead of the form that is normally present in vivo (“wild-type”, wt-Ang). The first residue of r-Ang is a methionine, with a free amino group, whereas wt-Ang has a glutamic acid, whose amino group spontaneously cyclizes in the pyro-glutamate form. The Ang biological activity is influenced by copper ions. To elucidate the role of such a free amino group on the protein–copper binding, we scrutinized the copper(II) complexes with the peptide fragments Ang(1–17) and AcAng(1–17), which encompass the sequence 1–17 of angiogenin (QDNSRYTHFLTQHYDAK-NH2), with free amino and acetylated N-terminus, respectively. Potentiometric, ultraviolet-visible (UV-vis), nuclear magnetic resonance (NMR) and circular dichroism (CD) studies demonstrate that the two peptides show a different metal coordination environment. Confocal microscopy imaging of neuroblastoma cells with the actin staining supports the spectroscopic results, with the finding of different responses in the cytoskeleton organization upon the interaction, in the presence or not of copper ions, with the free amino and the acetylated N-terminus peptides. 相似文献
79.
Filippo Piccinini Michela Pierini Enrico Lucarelli Alessandro Bevilacqua 《Journal of materials science. Materials in medicine》2014,25(10):2395-2410
The analysis of cell confluence and proliferation is essential to design biomaterials and scaffolds to use as bone substitutes in clinical applications. Accordingly, several approaches have been proposed in the literature to estimate the area of the scaffold covered by cells. Nevertheless, most of the approaches rely on sophisticated equipment not employed for routine analyses, while the rest of them usually do not provide significant statistics about the cell distribution. This research aims at studying confluence and proliferation of mesenchymal stromal cells (MSC) adherent on OSPROLIFE®, a commercial biomaterial in the form of granules. In particular, we propose a Computer Vision approach that can routinely be employed to monitor the surface of the single granules covered by cells because only a standard widefield fluorescent microscope is required. In order to acquire significant statistics data, we analyse wide-area images built by using MicroMos v2.0, an updated version of a previously published software specific for stitching brightfield and phase-contrast images manually acquired via a widefield microscope. In particular, MicroMos v2.0 permits to build accurate “mosaics” of fluorescent images, after correcting vignetting and photo-bleaching effects, providing a consistent representation of a sample region containing numerous granules. Then, our method allows to make automatically a statistically significant estimate of the percentage of the area of the single granules covered by cells. Finally, by analysing hundreds of granules at different time intervals we also obtained reliable data regarding cell proliferation, confirming that not only MSC adhere onto the OSPROLIFE® granules, but even proliferate over time. 相似文献
80.
Pascal Steiner Enrico Gnecco Tobin Filleter Nitya Nand Gosvami Sabine Maier Ernst Meyer Roland Bennewitz 《Tribology Letters》2010,39(3):321-327
We review recent friction measurements on ordered superstructures performed by atomic force microscopy. In particular, we
consider ultrathin KBr films on NaCl(001) and Cu(001) surfaces, single and bilayer graphene on SiC(0001), and the herringbone
reconstruction of Au(111). Atomically resolved friction images of these systems show periodic features spanning across several
unit cells. Although the physical mechanisms responsible for the formation of these superstructures are quite different, the
experimental results can be interpreted within the same phenomenological framework. A comparison between experiments and modeling
shows that, in the cases of KBr films on NaCl(001) and of graphene films, the tip-surface interaction is well described by
a potential with the periodicity of the substrate which is modulated or, respectively, superimposed with a potential with
the symmetry of the superstructure. 相似文献