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排序方式： 共有209条查询结果，搜索用时 15 毫秒
61.
The Weighted Gene Regulatory Network (WGRN) problem consists in pruning a regulatory network obtained from DNA microarray gene expression data, in order to identify a reduced set of candidate elements which can explain the expression of all other genes. Since the problem appears to be particularly hard for general-purpose solvers, we develop a Greedy Randomized Adaptive Search Procedure (GRASP) and refine it with three alternative Path Relinking procedures. For comparison purposes, we also develop a Tabu Search algorithm with a self-adapting tabu tenure. The experimental results show that GRASP performs better than Tabu Search and that Path Relinking significantly contributes to its effectiveness. 相似文献
62.
Arcangeli Giorgio Lombardini Pietro P. Lovisolo Giorgio A. Marsiglia Guglielmo Piattelli Maurizio 《IEEE transactions on bio-medical engineering》1984,(1):47-52
The distribution of ohmic power in a CAT scan section of a human chest irradiated with 915 MHz peripheral sources is calculated using the moment method. In the simulation, the chest section (assumed to be uniformally developed along the cranio-caudal axis for a height equivalent to the field penetration) is subdivided in 235 subvolumes of known electric constants. The focusing of power on a selected region of the chest is obtained by properly exciting the sources. An optimization method allows selecting the amplitudes and phases in such a way that the power level in all subvolumes outside the focal region is kept below a given threshold. 相似文献
63.
64.
Quantitative two-dimensional instantaneous Raman concentration measurements in a laminar methane jet
We have achieved quantitative two-dimensional Raman measurements of the concentration of methane in a laminar methane jet into nitrogen without multipassing the incident laser sheet with a coaxial flash-lamp-pumped dye laser. The measurements are compared with the results of direct numerical simulation for the particular flow field. We conclude that the accuracy of the technique is determined by limitations in the dynamic range and in the spatial resolution of the data acquired with an intensified camera. 相似文献
65.
Mario Guglielmo Giulio Modena Roberto Montagna 《Transactions on Emerging Telecommunications Technologies》1991,2(1):21-44
The paper is presenting a sketch of the main results achieved in the recent years and of the ongoing activities (mainly within the Standardization Bodies) in the areas of audio and video coding for bandwidth reduction. The evolution of the telecommunication Field and the needs which originate the different standards are also considered. The paper is organized in two main chapters: the first one is dealing with the techniques for audio and speech coding while the second presents the main achievements in terms of Recommendations and consolidate algorithms for image coding. Concerning speech and audio coding the paper presents and overview of the coding techniques and then examines the different environments of transmissions (network and mobile communication), the bandwidths required to satisfy the considered applications and the defined speech quality evaluation methods. A similar approach has been used for video coding and the evolution of the coding techniques appearing in the CCITT Recommendations is presented. The ongoing activities within CCIR, CMIT, CCITT and ISO towards new worldwide standards are also outlined providing indications on the areas which will require further developments. 相似文献
66.
Michele Celebrano Calogero Sciascia Giulio Cerullo Margherita Zavelani‐Rossi Guglielmo Lanzani Juan Cabanillas‐Gonzalez 《Advanced functional materials》2009,19(8):1180-1185
Space resolved Stark spectroscopy is introduced as a non invasive optical technique for imaging electric field distribution in organic semiconductors. Stark spectroscopy relies on the electric field induced change in the absorption/reflection. It is shown that local monitoring of Stark shift with confocal spatial resolution provides quantitative information on the strength of the local field as well as charge distribution within the transport channel. 相似文献
67.
68.
Giuseppe M. Patern Luca Moretti Alex J. Barker Qiang Chen Klaus Müllen Akimitsu Narita Giulio Cerullo Francesco Scotognella Guglielmo Lanzani 《Advanced functional materials》2019,29(21)
In the last two decades, the three‐beam pump–push–probe (PPP) technique has become a well‐established tool for investigating the multidimensional configurational space of a molecule, as it permits disclosure of precious information about the multiple and often complex deactivation pathways of the excited molecule. From the spectroscopic point of view, such a tool has revealed details about the efficiency of charge pair generation and conformational relaxation in π‐conjugated molecules and macromolecules. In addition, PPP is effectively utilized for modulating the gain signal in conjugated materials by taking advantage of the spectral overlap between stimulated emission and charge absorption in those systems. However, the relatively low stability of conjugated polymers under intense photoexcitation is a crucial limitation for their real employment in plastic optical fibers (POFs) and for signal control applications. Herein, the role of PPP for achieving ultrafast all‐optical switching in π‐conjugated systems is highlighted. Furthermore, new experimental data on optical switching of a newly synthesized nanographene molecule, namely dibenzo[hi,st]ovalene (DBOV), is reported. The superior environmental and photostability of DBOV and, in general, of graphene nanostructures can represent a great advantage for their effective applications in POFs and information and communications technology. 相似文献
69.
Dr. Ilaria Bargigia Dr. Elena Zucchetti Dr. Ajay Ram Srimath Kandada Dr. Miguel Moreira Dr. Caterina Bossio Dr. Walter P. D. Wong Prof. Paulo Barbeitas Miranda Dr. Paolo Decuzzi Prof. Cesare Soci Prof. Cosimo D'Andrea Prof. Guglielmo Lanzani 《Chembiochem : a European journal of chemical biology》2019,20(4):532-536
In this work the photophysics of poly(3-hexylthiophene) nanoparticles (NPs) is investigated in the context of their biological applications. The NPs, made as colloidal suspensions in aqueous buffers, present a distinct absorption band in the low-energy region. On the basis of systematic analysis of absorption and transient absorption (TA) spectra taken under different pH conditions, this band is associated with charge-transfer states generated by the polarization of loosely bound polymer chains and originating from complexes formed with electron-withdrawing species. Importantly, the ground-state depletion of these states upon photoexcitation is active even on microsecond timescales, thus suggesting that they act as precursor states for long-living polarons; this could be beneficial for cellular stimulation. Preliminary transient absorption microscopy results for NPs internalized within the cells reveal the presence of long-living species, further substantiating their relevance in biointerfaces. 相似文献
70.
Katia Pane Cristina Quintavalle Silvia Nuzzo Francesco Ingenito Giuseppina Roscigno Alessandra Affinito Iolanda Scognamiglio Birlipta Pattanayak Enrico Gallo Antonella Accardo Guglielmo Thomas Zoran Minic Maxim V. Berezovski Monica Franzese Gerolama Condorelli 《International journal of molecular sciences》2022,23(7)
Extracellular vesicles (EVs) shuttle proteins, RNA, DNA, and lipids crucial for cell-to-cell communication. Recent findings have highlighted that EVs, by virtue of their cargo, may also contribute to breast cancer (BC) growth and metastatic dissemination. Indeed, EVs are gaining great interest as non-invasive cancer biomarkers. However, little is known about the biological and physical properties of EVs from malignant BC lesions, and even less is understood about EVs from non-malignant lesions, such as breast fibroadenoma (FAD), which are clinically managed using conservative approaches. Thus, for this pilot study, we attempted to purify and explore the proteomic profiles of EVs from benign breast lesions, HER2+ BCs, triple–negative BCs (TNBCs), and continuous BC cell lines (i.e., BT-549, MCF–10A, and MDA-MB-231), combining experimental and semi-quantitative approaches. Of note, proteome-wide analyses showed 49 common proteins across EVs harvested from FAD, HER2+ BCs, TNBCs, and model BC lines. This is the first feasibility study evaluating the physicochemical composition and proteome of EVs from benign breast cells and primary and immortalized BC cells. Our preliminary results hold promise for possible implications in precision medicine for BC. 相似文献