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排序方式: 共有2933条查询结果,搜索用时 187 毫秒
101.
Scaling of energy dissipation in crushing and fragmentation: a fractal and statistical analysis based on particle size distribution 总被引:4,自引:0,他引:4
Alberto Carpinteri Giuseppe Lacidogna Nicola Pugno 《International Journal of Fracture》2004,129(2):131-139
An extensive experimental investigation on concrete specimens under crushing and fragmentation over a large scale range (1:10) – exploring even very small specimen dimensions (1 cm) – was carried out to evaluate the influence of fragment size distribution on energy density dissipation and related size effect. To obtain a statistically significant fragment production as well as the total energy dissipated in a given specimen, the experimental procedure was unusually carried out up to a strain of approximately –95%, practically corresponding to the initial fragment compaction between the loading platens. The experimental fragment analysis suggests a fractal law for the distribution in particle size; this simply means that fragments derived from a given specimen appear geometrically self-similar at each observation scale. In addition, clear size effects on dissipated energy density are experimentally observed. Fractal concepts permit to quantify the correlation between fragment size distribution and size effect on dissipated energy density, the latter being governed by the total surface area of produced fragments. The experimental results agree with the proposed multi-scale interpretation satisfactorily. 相似文献
102.
Storm overflow structures in combined sewers are used to separate sewage from storm water. For subcritical approach flow, sideweirs are currently used; however, they often behave hydraulically poor. This study was conducted to explore a combined storm overflow structure able to improve the hydraulic performance of sewer sideweirs. Such a structure consists of a low-crested sideweir and a bottom opening just downstream from the sideweir end. First, the hydraulic design procedure is described, and then, based on laboratory experiments and by using the governing flow equations, the main hydraulic features are highlighted. The results indicate that the proposed device has advantageous characteristics in terms of hydraulic efficiency, reliability, and maintenance. 相似文献
103.
Proteins as biomarkers of oxidative/nitrosative stress in diseases: the contribution of redox proteomics 总被引:8,自引:0,他引:8
Dalle-Donne I Scaloni A Giustarini D Cavarra E Tell G Lungarella G Colombo R Rossi R Milzani A 《Mass spectrometry reviews》2005,24(1):55-99
Reactive oxygen species (ROS) and reactive nitrogen species (RNS) contribute to the pathogenesis and/or progression of several human diseases. Proteins are important molecular signposts of oxidative/nitrosative damage. However, it is generally unresolved whether the presence of oxidatively/nitrosatively modified proteins has a causal role or simply reflects secondary epiphenomena. Only direct identification and characterization of the modified protein(s) in a given pathophysiological condition can decipher the potential roles played by ROS/RNS-induced protein modifications. During the last few years, mass spectrometry (MS)-based technologies have contributed in a significant way to foster a better understanding of disease processes. The study of oxidative/nitrosative modifications, investigated by redox proteomics, is contributing to establish a relationship between pathological hallmarks of disease and protein structural and functional abnormalities. MS-based technologies promise a contribution in a new era of molecular medicine, especially in the discovery of diagnostic biomarkers of oxidative/nitrosative stress, enabling early detection of diseases. Indeed, identification and characterization of oxidatively/nitrosatively modified proteins in human diseases has just begun. 相似文献
104.
Eva Dreussi Erika Cecchin Jerry Polesel Vincenzo Canzonieri Marco Agostini Caterina Boso Claudio Belluco Angela Buonadonna Sara Lonardi Francesca Bergamo Sara Gagno Elena De Mattia Salvatore Pucciarelli Antonino De Paoli Giuseppe Toffoli 《International journal of molecular sciences》2016,17(9)
Background: Pathological complete response (pCR) to neoadjuvant chemoradiotherapy (CRT) in locally advanced rectal cancer (LARC) is still ascribed to a minority of patients. A pathway based-approach could highlight the predictive role of germline single nucleotide polymorphisms (SNPs). The primary aim of this study was to define new predictive biomarkers considering treatment specificities. Secondary aim was to determine new potential predictive biomarkers independent from radiotherapy (RT) dosage and cotreatment with oxaliplatin. Methods: Thirty germ-line SNPs in twenty-one genes were selected according to a pathway-based approach. Genetic analyses were performed on 280 LARC patients who underwent fluoropyrimidine-based CRT. The potential predictive role of these SNPs in determining pathological tumor response was tested in Group 1 (94 patients undergoing also oxaliplatin), Group 2 (73 patients treated with high RT dosage), Group 3 (113 patients treated with standard RT dosage), and in the pooled population (280 patients). Results: Nine new predictive biomarkers were identified in the three groups. The most promising one was rs3136228-MSH6 (p = 0.004) arising from Group 3. In the pooled population, rs1801133-MTHFR showed only a trend (p = 0.073). Conclusion: This exploratory study highlighted new potential predictive biomarkers of neoadjuvant CRT and underlined the importance to strictly define treatment peculiarities in pharmacogenetic analyses. 相似文献
105.
Giuseppe Olivieri Piero Salatino Antonio Marzocchella 《Journal of chemical technology and biotechnology (Oxford, Oxfordshire : 1986)》2014,89(2):178-195
Over the past ten years a great deal of literature has focused on the biotechnological potential of microalgal commercial applications, mainly in the field of biofuel production. However, the biofuel production is not yet competitive, mainly due to the incidence of the photobioreactor technology on the process cost. Besides, major advances in classic photobioreactor design, several novel configurations have been proposed in the last 20 years to improve their performance expressed in terms of light absorption, biomass productivity, light to biomass yield and photosynthetic efficiency. This review aims at analyzing and classifying the most recent advances and the several novel approaches to the design, development, control and modeling of photobioreactors. The diverse approaches are grouped considering irradiance strategies, multiphase hydrodynamics, mass transfer mechanisms, modeling approaches and control strategies. Some innovative applications of the photobioreactor technology are also reported. © 2013 Society of Chemical Industry 相似文献
106.
K. Erik J. Olofsson Anton Soppelsa Tommaso Bolzonella Giuseppe Marchiori 《Control Engineering Practice》2013,21(7):917-929
Input–output datasets from two magnetic confinement fusion (MCF) experiments of the reversed-field pinch (RFP) type are examined. The RFP datasets, which are samples of the distributed magnetic field dynamics, are naturally divided into many smaller batches due to the pulsed-plasma operation of the experiments. The two RFP experiments considered are (i) EXTRAP T2R (T2R) with 64 inputs and 64 outputs and (ii) RFX-mod (RFX) with 192 inputs and 192 outputs. Both T2R and RFX are magnetohydrodynamically unstable and operates under magnetic feedback with optional dither injection. Using subspace system identification techniques and randomised cross-validation (CV) methods to minimise the generalisation error, state-space orders of the empirical systems are suggested. These system orders are compared to “stabilisation diagrams” commonly used in experimental modal analysis practice. The relation of the CV system order to the decay of the singular values from the subspace method is observed. Both (i) stable vacuum diffusion and (ii) unstable plasma response datasets are analysed. Apparent simulation and prediction errors are quantified for both cases using a deviation-accounted-for index. These results are purely data-driven. A simple approach towards exploitation of the subspace techniques for finite-element model refinement and data confrontation is presented. 相似文献
107.
108.
Marco Sanduzzi Zamparelli Debora Compare Pietro Coccoli Alba Rocco Olga Maria Nardone Giuseppe Marrone Antonio Gasbarrini Antonio Grieco Gerardo Nardone Luca Miele 《International journal of molecular sciences》2016,17(8)
The prevalence of metabolic disorders, such as type 2 diabetes (T2D), obesity, and non-alcoholic fatty liver disease (NAFLD), which are common risk factors for cardiovascular disease (CVD), has dramatically increased worldwide over the last decades. Although dietary habit is the main etiologic factor, there is an imperfect correlation between dietary habits and the development of metabolic disease. Recently, research has focused on the role of the microbiome in the development of these disorders. Indeed, gut microbiota is implicated in many metabolic functions and an altered gut microbiota is reported in metabolic disorders. Here we provide evidence linking gut microbiota and metabolic diseases, focusing on the pathogenetic mechanisms underlying this association. 相似文献
109.
Elia Bari Ilaria Roato Giuseppe Perale Filippo Rossi Tullio Genova Federico Mussano Riccardo Ferracini Marzio Sorlini Maria Luisa Torre Sara Perteghella 《International journal of molecular sciences》2021,22(8)
SmartBone® (SB) is a biohybrid bone substitute advantageously proposed as a class III medical device for bone regeneration in reconstructive surgeries (oral, maxillofacial, orthopedic, and oncology). In the present study, a new strategy to improve SB osteoinductivity was developed. SB scaffolds were loaded with lyosecretome, a freeze-dried formulation of mesenchymal stem cell (MSC)-secretome, containing proteins and extracellular vesicles (EVs). Lyosecretome-loaded SB scaffolds (SBlyo) were prepared using an absorption method. A burst release of proteins and EVs (38% and 50% after 30 min, respectively) was observed, and then proteins were released more slowly with respect to EVs, most likely because they more strongly adsorbed onto the SB surface. In vitro tests were conducted using adipose tissue-derived stromal vascular fraction (SVF) plated on SB or SBlyo. After 14 days, significant cell proliferation improvement was observed on SBlyo with respect to SB, where cells filled the cavities between the native trabeculae. On SB, on the other hand, the process was still present, but tissue formation was less organized at 60 days. On both scaffolds, cells differentiated into osteoblasts and were able to mineralize after 60 days. Nonetheless, SBlyo showed a higher expression of osteoblast markers and a higher quantity of newly formed trabeculae than SB alone. The quantification analysis of the newly formed mineralized tissue and the immunohistochemical studies demonstrated that SBlyo induces bone formation more effectively. This osteoinductive effect is likely due to the osteogenic factors present in the lyosecretome, such as fibronectin, alpha-2-macroglobulin, apolipoprotein A, and TGF-β. 相似文献
110.
Giuseppe Della Penna Daniele Magazzeni Sergio Orefice 《Knowledge and Information Systems》2012,30(3):667-692
The Spatial Relation Query (SRQ) tool is a graphical software environment, supported by a SQL-like language, which enables
users to perform information extraction driven by the visual appearance and the spatial arrangement of the information. The
tool has been initially customised to work on specific application domains, like web pages and geospatial data. In this paper,
we present the theoretical formalisation of the visual information extraction (VIE) task and accordingly the redesign of the
SRQ tool, which is now a full-featured, general-purpose information extraction system. Moreover, we show a new application
of the VIE framework to the analysis and visual information extraction from PDF files. 相似文献