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排序方式: 共有480条查询结果,搜索用时 15 毫秒
1.
The computation of strongly connected components (SCCs) in discrete-state models is a critical step in formal verification
of LTL and fair CTL properties, but the potentially huge number of reachable states and SCCs constitutes a formidable challenge.
We consider the problem of computing the set of states in SCCs or terminal SCCs in an asynchronous system. We employ the idea
of saturation, which has shown clear advantages in symbolic state-space exploration (Ciardo et al. in Softw Tools Technol Transf 8(1):4–25,
2006; Zhao and Ciardo in Proceedings of 7th international symposium on automated technology for verification and analysis, pp
368–381, 2009), to improve two previously proposed approaches. We use saturation to speed up state exploration when computing each SCC
in the Xie-Beerel algorithm, and we compute the transitive closure of the transition relation using a novel algorithm based on saturation. Furthermore, we show that the techniques we developed
are also applicable to the computation of fair cycles. Experimental results indicate that the improved algorithms using saturation achieve a substantial speedup over previous
BFS algorithms. In particular, with the new transitive closure computation algorithm, up to 10150 SCCs can be explored within a few seconds. 相似文献
2.
Bibiana C. Mota Nathan Ashburner Laura Abelleira-Hervas Liyueyue Liu Robertas Aleksynas Lucio Claudio Rovati Gianfranco Caselli Magdalena Sastre 《International journal of molecular sciences》2022,23(13)
Recent evidence suggests that I2-imidazoline ligands have neuroprotective properties in animal models of neurodegeneration, such as Alzheimer’s disease (AD). We recently demonstrated that the I2-ligand BU224 reversed memory impairments in AD transgenic mice and this effect was not because of reductions in amyloid-β (Aβ) deposition. In this study, our aim was to determine the therapeutic potential of the powerful analgesic I2-imidazoline ligand CR4056 in the 5xFAD model of AD, since this ligand has been proven to be safely tolerated in humans. Sub-chronic oral administration of CR4056 (30 mg/kg for 10 days) led to an improvement in recognition memory in 6-month-old 5xFAD mice, but not in wild-type littermates, without affecting Aβ levels or deposition. Our results also revealed a change in the profile of microglia by CR4056, resulting in a suppression of pro-inflammatory activated microglia, but increased the density of astrocytes and the expression of ApoE, which is mainly produced by these glial cells. In addition, CR4056 restored fibrinogen extravasation, affecting the distribution of markers of astrocytic end feet in blood vessels. Therefore, these results suggest that CR4056 protects against Aβ-mediated neuroinflammation and vascular damage, and offers therapeutic potential at any stage of AD. 相似文献
3.
4.
Bellavista P. Corradi A. Stefanelli C. 《Selected Areas in Communications, IEEE Journal on》2000,18(5):676-685
Technological and human factors have contributed to increase the complexity of the network management problem. Heterogeneity and globalization of network resources, on one hand, have increased user expectations for flexible and easy-to-use environments; on the other hand, they have suggested entirely novel ways to face the management problem. Several research efforts recognize the need for integrated solutions to manage both network resources and services in open, global, and untrusted environments. In addition, these solutions should permit the coexistence of different management models and should interoperate with legacy systems. In the paper, we define a general architecture based on a distributed processing environment (DFE) that offers a large set of facilities to the application level. We have developed the MESIS management environment shaped after the above architecture and its DPE facilities with mobile agents technology. MESIS handles, in a uniform way, both resources and services, and focuses on two crucial properties: interoperability to overcome heterogeneity, and security to grant users safe and protected operations. The Agent Interoperability Facility supports compliance with CORBA-based management systems and with MASIF agent platforms. The Agent Security Facility provides authentication, integrity, privacy, authorization, and secure interoperation with CORBA systems 相似文献
5.
During neuronal circuit formation, axons progressively develop into a presynaptic compartment aided by extracellular signals. Axons display a remarkably high degree of autonomy supported in part by a local translation machinery that permits the subcellular production of proteins required for their development. Here, we review the latest findings showing that microRNAs (miRNAs) are critical regulators of this machinery, orchestrating the spatiotemporal regulation of local translation in response to cues. We first survey the current efforts toward unraveling the axonal miRNA repertoire through miRNA profiling, and we reveal the presence of a putative axonal miRNA signature. We also provide an overview of the molecular underpinnings of miRNA action. Our review of the available experimental evidence delineates two broad paradigms: cue-induced relief of miRNA-mediated inhibition, leading to bursts of protein translation, and cue-induced miRNA activation, which results in reduced protein production. Overall, this review highlights how a decade of intense investigation has led to a new appreciation of miRNAs as key elements of the local translation regulatory network controlling axon development. 相似文献
6.
7.
Orazio A. Attanasi Stefano Berretta Lucia De Crescentini Gianfranco Favi Gianluca Giorgi Fabio Mantellini Simona Nicolini 《Advanced Synthesis \u0026amp; Catalysis》2011,353(4):595-605
The zinc(II) triflate‐catalyzed synthesis of highly functionalized pyrroles is described. The sequence involves the preliminary preparation of α‐aminohydrazones by Michael addition of primary amines to 1,2‐diaza‐1,3‐dienes. The treatment of these intermediates with dialkyl acetylenedicarboxylates produces α‐(N‐enamino)‐hydrazones that are converted into the corresponding pyrroles. The substituents on the carbon in position four of 1,2‐diaza‐1,3‐dienes drive the regioselectivity of the ring closure process. Starting from 4‐aminocarbonyl‐1,2‐diaza‐1,3‐dienes only dialkyl 1‐substituted 5‐aminocarbonyl‐1H‐pyrrole‐2,3‐dicarboxylates are achieved by Lewis acid‐catalyzed ring closure. A screening of several Lewis/Brønsted acid catalysts is performed. Zinc(II) triflate is the most efficient catalyst. Under similar reaction conditions, employing 4‐alkoxycarbonyl‐1,2‐diaza‐1,3‐dienes, only 4‐hydroxy‐1H‐pyrrole‐2,3‐dicarboxylates are synthesized. These latter reactions can be accomplished regioselectively also in one pot. Using 4‐aminocarbonyl‐1,2‐diaza‐1,3‐dienes, diamines and dialkyl acetylenedicarboxylates the sequence provides the corresponding α,ω‐di(N‐pyrrolyl)alkanes. 相似文献
8.
Paola Riolo Roxana L. Minuz Gianfranco Anfora Marco V. Rossi Stacconi Silvia Carlin Nunzio Isidoro Roberto Romani 《Journal of chemical ecology》2012,38(8):1017-1030
The Palearctic planthopper Hyalesthes obsoletus is the natural vector of the grapevine yellow disease Bois noir. Grapevine is an occasional host plant of this polyphagous planthopper. To deepen our knowledge of the role of plant volatile organic compounds for H. obsoletus host plant searching, we carried out behavioral, morphological, and electrophysiological studies. We tested the attraction of H. obsoletus to nettle, field bindweed, hedge bindweed, chaste tree, and grapevine by using a Y-shaped olfactometer. The results showed a significant attraction of male H. obsoletus to chaste tree, and of the females to nettle. Male H. obsoletus were repelled by odor from hedge bindweed. Ultrastructural studies of the antennae showed at least two types of olfactory sensilla at the antennal pedicel: plaque organs and trichoid sensilla. Volatile organic compounds from nettle and chaste tree were collected, and the extracts were analyzed by coupling gas-chromatography to both mass-spectrometry and electroantennography. The volatile organic compounds that elicited electrophysiological responses in male and female antennae were identified. These findings are discussed with respect to behavior of H. obsoletus males and females in the field. 相似文献
9.
Luisa Barbieri Cristina Leonelli Tiziano Manfredini Cristina Siligardi Anna Bonamartini Corradi Piercarlo Mustarelli Corrado Tomasi 《Journal of the American Ceramic Society》1997,80(12):3077-3083
An aluminosilicate glass of composition 61SiO2 6Al2 O3 10MgO6ZnO·12Li2 O·5TiO2 (mol%) has been prepared by a melting process and investigated as far as crystallization is concerned. Glass-ceramic is easily obtained because glass shows a high tendency to crystallize starting from 700°C. The crystalline phases evolve with temperature, showing the aluminosilicates to be the main phase up to 1050°C, followed by metasilicates and silicates, some of which have lower melting points. The titanates of Mg and Zn develop from the phase-separated glass, soon after T g , and grow to form nucleation centers for the other crystalline phases. The evolution from phase-separated glass to glass-ceramic has been followed by many thermal, diffractometric, spectroscopic, and microscopic techniques. 相似文献
10.
Sintering behavior of Ba/Sr celsian precursor obtained from zeolite‐A by ion‐exchange method 下载免费PDF全文
Mattia Biesuz Luca Spiridigliozzi Antonello Marocco Gianfranco Dell'Agli Vincenzo M. Sglavo Michele Pansini 《Journal of the American Ceramic Society》2017,100(12):5433-5443
(Ba, Sr)‐exchanged zeolite A with composition Ba0.74Sr0.22Na0.04Al2Si2O8 was prepared by cation exchange; a mild thermal treatment converts into an amorphous phase. Successive crystallization and sintering behavior was studied by XRD, DTA, and thermodilatometric analysis. The results point out the activation of viscous flow sintering mechanisms between 900°C and 1050°C. The densification process starts when the amorphous phase reaches its glass transition temperature (897°C) and finishes when the material crystallizes forming hexacelsian. The application of an external pressure in such temperature range allows to achieve an almost complete densification, the material transforming at 1300°C into dense monoclinic celsian much below the typical processing temperature. 相似文献