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141.
Tommaso Mansi Xavier Pennec Maxime Sermesant Hervé Delingette Nicholas Ayache 《International Journal of Computer Vision》2011,92(1):92-111
Tracking soft tissues in medical images using non-linear image registration algorithms requires methods that are fast and
provide spatial transformations consistent with the biological characteristics of the tissues. LogDemons algorithm is a fast
non-linear registration method that computes diffeomorphic transformations parameterised by stationary velocity fields. Although
computationally efficient, its use for tissue tracking has been limited because of its ad-hoc Gaussian regularisation, which hampers the implementation of more biologically motivated regularisations. In this work, we
improve the logDemons by integrating elasticity and incompressibility for soft-tissue tracking. To that end, a mathematical
justification of demons Gaussian regularisation is proposed. Building on this result, we replace the Gaussian smoothing by
an efficient elastic-like regulariser based on isotropic differential quadratic forms of vector fields. The registration energy
functional is finally minimised under the divergence-free constraint to get incompressible deformations. As the elastic regulariser
and the constraint are linear, the method remains computationally tractable and easy to implement. Tests on synthetic incompressible
deformations showed that our approach outperforms the original logDemons in terms of elastic incompressible deformation recovery
without reducing the image matching accuracy. As an application, we applied the proposed algorithm to estimate 3D myocardium
strain on clinical cine MRI of two adult patients. Results showed that incompressibility constraint improves the cardiac motion
recovery when compared to the ground truth provided by 3D tagged MRI. 相似文献
142.
Baciu M Sebai SC Ces O Mulet X Clarke JA Shearman GC Law RV Templer RH Plisson C Parker CA Gee A 《Philosophical transactions. Series A, Mathematical, physical, and engineering sciences》2006,364(1847):2597-2614
Drug molecules must cross multiple cell membrane barriers to reach their site of action. We present evidence that one of the largest classes of pharmaceutical drug molecules, the cationic amphiphilic drugs (CADs), does so via a catalytic reaction that degrades the phospholipid fabric of the membrane. We find that CADs partition rapidly to the polar-apolar region of the membrane. At physiological pH, the protonated groups on the CAD catalyse the acid hydrolysis of the ester linkage present in the phospholipid chains, producing a fatty acid and a single-chain lipid. The single-chain lipids rapidly destabilize the membrane, causing membranous fragments to separate and diffuse away from the host. These membrane fragments carry the drug molecules with them. The entire process, from drug adsorption to drug release within micelles, occurs on a time-scale of seconds, compatible with in vivo drug diffusion rates. Given the rate at which the reaction occurs, it is probable that this process is a significant mechanism for drug transport. 相似文献
143.
Ricardo Toledo Ramon Baldrich Xavier Orriols Juan Sanchez Xavier Binefa 《Multimedia Tools and Applications》2006,31(2):119-144
Advertising activities are one of the main aspects of companies. Its global evaluation is an important index, not only within economic sectors, but also for public economic policies. The evaluation of the adverts is carried out by specialised companies, which deliver advertisement expenditure information. Their work consist in an exhaustive collection of adverts (e.g., all adverts from any media), and deliver information (integrated from every media) relevant for their clients. The delivered information can range from statistical data to bear witness of an advertisement campaign. Important quality indicators for the delivered information are the exhaustiveness, the delay of delivering and a correct identification of different versions of an advert. In this article, we present an advanced computer-aided system for collecting and delivering advertising information from magazines and daily press. The system provides computer-aided data validation and exploitation resources. Using computerised document image analysis and image database indexing and retrieval, the system is able to locate an advert in a page, extract relevant quality indicators and search the advert (or similar ones) in a database. This tool is configured as an intranet and offers resources for image data acquisition, storage/retrieval and advert quality indicators extraction, however, the key of the system is the underlying idea of incorporating computer-aided visual information management.The EU has funded the system construction within the program: European Take-up of essential Information Society Technologies, Integrated Machine Vision (EUTIST-IMV), task CV-AdControl. . 相似文献
144.
Biodegradable Ethylene‐Bis(Propyl)Disulfide‐Based Periodic Mesoporous Organosilica Nanorods and Nanospheres for Efficient In‐Vitro Drug Delivery 下载免费PDF全文
145.
Rehabilitating rivers and enhancing ecosystem services in a water-scarcity context: the Yarqon River
After the creation of the state of Israel in 1948, the increase in urban and agricultural water demand and the increased flow of poorly treated sewage had a severe impact in one of the most ecologically important rivers in Israel, the Yarqon. The attempt to reverse this situation began with the creation of the Yarqon River Authority in 1988. In the last 20 years, the authority has implemented or collaborated in several projects that have significantly contributed to enhancing the provision of ecological services. This article aims to analyze the case of the pollution and subsequent rehabilitation of aquatic ecosystem services in the Israeli water-scarcity context. 相似文献
146.
Benthic diatom assemblages have been used to evaluate the water quality of two rivers subjected to marked human influences. These rivers, the Llobregat and the Ter, are located in N.E. Spain, and supply water for industrial, agricultural and urban requirements of roughly three million people. The diatom communities in the headwaters are similar in both rivers (Achnanthes minutissima, Cymbella ventricosa, Gomphonema anguslatum). Species of Navicula, Nitzschia and Gomphonema develop in the middle reaches of both rivers when not disrupted by extraneous factors. In the river Ter significant pollution modifies this community and Nitzschia palea, Nitzschia gandersheimiensis and Gomphonema parvulum appear as the most tolerant species. In the Llobregat, the pollution from the salt mine operations also modifies the diatom assemblage and Nitzschia frustulum, Surirella ovata, Navicula atomus are the most abundant species. Reservoirs in the river Ter improve the quality of water and a community of Fragilaria sp. pl. becomes dominant downstream. 相似文献
147.
Whey cheeses have been manufactured with probiotic bacteria - viz. Bifidobacterium animalis Bo and Lactobacillus casei LAFTI®L26, from combinations of bovine whey and milk, following protein denaturation at 90 °C; they were subsequently inoculated (at 10%) with those strains, and homogenized afterwards; additives such as salt and sugar were then incorporated; and the resulting solid matrices were stored at 7° C for up to 21 d. Oscillatory measurements and instrumental texture profile analyses were performed, and sensory analyses were carried out by a trained panel. Microstructural features were in addition ascertained by scanning electron microscopy.L. casei exhibited a higher acidifying activity than B. animalis, which produced distinct textures; higher firmness and viscoelasticity were indeed found in matrices inoculated with the former. Incorporation of sugar and L. casei favoured consumer acceptability, relative to plain matrices. Microstructural differences were detected between matrices at different times of storage and formulated with distinct additives. 相似文献
148.
Jacques G. Noudem Sophie Meslin Daniel Horvath Christelle Harnois Daniel Chateigner Bachir Ouladdiaf Sophie Eve Mousta Gomina Xavier Chaud Masato Murakami 《Journal of the American Ceramic Society》2007,90(9):2784-2790
The recently reported hole-patterned YBa2 Cu3 O y (Y123) bulks with improved superconducting properties are highly interesting from material quality and application variety points of view. It is well known that the core of plain bulk superconductors needs to be fully oxygenated and some defects like cracks, pores, and voids must be suppressed in order that the material can trap a high magnetic field or carry a high current density. To minimize the above defects, we have used a combination of standard superconducting ceramic processing and an infiltration technique to prepare regularly perforated YBa2 Cu3 O y (Y123) bulk superconductors. This process leads to negligible shrinkage upon annealing and a uniform distribution of Y211 inclusions. Texture was evidenced by neutron pole figure measurements. Flux mapping was used to verify the superconducting homogeneity of the samples and to investigate the field-trapping ability. In addition, the textured drilled samples were reinforced using resin or metal impregnation and the influence of the different processing steps on the hardness of the materials has been investigated. 相似文献
149.
Servando González Xavier Fernández‐Francos Josep Maria Salla Angels Serra Ana Mantecón Xavier Ramis 《应用聚合物科学杂志》2007,104(5):3406-3416
Mixtures of diglycidylether of bisphenol A (DGEBA) with different proportions of γ‐caprolactone (γ‐CL) were cured with ytterbium triflate as initiator. The curing was studied with differential scanning calorimetry (DSC) and thermo mechanical analysis (TMA). The results are presented in the form of a time–temperature–transformation diagram. The kinetic analysis was performed by means of the isoconversional integral procedure and the kinetic model was also determined using the Coats–Redfern method. Gelation was determined by means of combined experiences of DSC and TMA. The relationship between the glass transition temperature (Tg) and the degree of conversion α was determined by DSC. Using the isoconversional lines and the Tg‐α relationship, the vitrificacion curve was obtained. The methodology developed makes it possible to obtain the TTT diagram using only no‐isothermal experiments with equivalent results to those using classical isothermal procedures. The addition of γ‐CL accelerates the curing and reduces the shrinkage after gelation and consequently the internal stresses in the material. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci, 2007 相似文献
150.
Xavier Leroy 《Journal of Automated Reasoning》2009,43(4):363-446
This article describes the development and formal verification (proof of semantic preservation) of a compiler back-end from Cminor (a simple imperative intermediate language) to PowerPC assembly code, using the Coq proof assistant both for programming the compiler and for proving its soundness. Such a verified compiler is useful in the context of formal methods applied to the certification of critical software: the verification of the compiler guarantees that the safety properties proved on the source code hold for the executable compiled code as well. 相似文献