770 research outputs found
trans-4,5-DihydrÂoxy-1,3-bisÂ(4-methoxyÂphenÂyl)imidazolidine-2-thione
In the title compound, C17H18N2O4S, where one of the N-4-methoxyÂphenyl fragments is disordered over two sets of sites, the five-membered ring exhibits a nearly half-chair conformation and the two hydroxyl groups lie on opposite sides of the five-membered ring. In the crystal, the molÂecules are linked into sheets parallel to (100) via O—H⋯O and O—H⋯S hydrogen bonds
Fooling an Unbounded Adversary with a Short Key, Repeatedly: The Honey Encryption Perspective
This article is motivated by the classical results from Shannon that put the simple and elegant one-time pad away from practice: key length has to be as large as message length and the same key could not be used more than once. In particular, we consider encryption algorithm to be defined relative to specific message distributions in order to trade for unconditional security. Such a notion named honey encryption (HE) was originally proposed for achieving best possible security for password based encryption where secrete key may have very small amount of entropy.
Exploring message distributions as in HE indeed helps circumvent the classical restrictions on secret keys.We give a new and very simple honey encryption scheme satisfying the unconditional semantic security (for the targeted message distribution) in the standard model (all previous constructions are in the random oracle model, even for message recovery security only). Our new construction can be paired with an extremely simple yet "tighter" analysis, while all previous analyses (even for message recovery security only) were fairly complicated and require stronger assumptions. We also show a concrete instantiation further enables the secret key to be used for encrypting multiple messages
Dimethyl 2,6-dimethyl-1,4-dihydroÂpyridine-3,5-dicarboxylÂate
In the crystal of the title compound, C11H15NO4, the molÂecules are linked into sheets by N—H⋯O and C—H⋯O hydrogen bonds. Within the molÂecule, the 1,4-dihydroÂpyridine ring exhibits a distinctive planar conformation [r.m.s. deviation from the mean plane of 0.009 (3)Ã…], and the other non-H atoms are almost coplanar [r.m.s. deviation = 0.021 (3) Å] with the 1,4-dihydroÂpyridine ring. The conformation of the latter is governed mainly by two intraÂmolecular C—H⋯O non-classical interÂactions
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Transcriptional activation of CBFβ by CDK11p110 is necessary to promote osteosarcoma cell proliferation.
BACKGROUND:Aberrant expression of cyclin-dependent protein kinases (CDK) is a hallmark of cancer. CDK11 plays a crucial role in cancer cell growth and proliferation. However, the molecular mechanisms of CDK11 and CDK11 transcriptionally regulated genes are largely unknown. METHODS:In this study, we performed a global transcriptional analysis using gene array technology to investigate the transcriptional role of CDK11 in osteosarcoma. The promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay were used to identify direct transcriptional targets of CDK11. Clinical relevance and function of core-binding factor subunit beta (CBFβ) were further accessed in osteosarcoma. RESULTS:We identified a transcriptional role of protein-DNA interaction for CDK11p110, but not CDK11p58, in the regulation of CBFβ expression in osteosarcoma cells. The CBFβ promoter luciferase assay, chromatin immunoprecipitation assay, and Gel Shift assay confirmed that CBFβ is a direct transcriptional target of CDK11. High expression of CBFβ is associated with poor outcome in osteosarcoma patients. Expression of CBFβ contributes to the proliferation and metastatic behavior of osteosarcoma cells. CONCLUSIONS:These data establish CBFβ as a mediator of CDK11p110 dependent oncogenesis and suggest that targeting the CDK11- CBFβ pathway may be a promising therapeutic strategy for osteosarcoma treatment
Behavior of innovative T-shaped multi-partition steel-concrete composite columns under concentric and eccentric compressive loadings
[EN] T-shaped multi-partition steel-concrete composite column, composed of several concrete-filled rectangular steel hollow sections, is considered as an innovative composite member with the ability to accommodate neighboring wall thickness with great easiness. This paper intends to study the behavior of this innovative composite member under concentric and eccentric compressive loadings. A finite element (FE) analysis model accounting for the influences of confinement effects, geometric and material nonlinearities is developed using the program ABAQUS. The ultimate strength and load-strain responses predicted from the analysis are validated against the test results in the experiments conducted by the authors. The comparisons indicate that the FE model reasonably estimates the responses of the concentrically and eccentrically loaded T-shaped multi-partition steel-concrete composite columns. The verified model is then utilized to numerically investigate the working mechanism of the columns. The load distribution between the infilled concrete and the steel tubes and the stress distribution of the concrete during the loading process are analyzed. Moreover, parametric studies are performed to investigate the behavior of T-shaped multi-partition steel-concrete composite columns under different loadings. The studied parameters include steel to concrete area ratio, concrete compressive strength, steel yield strength and load eccentricity. Combined with the experimental results, FE analysis and parametric studies, the design recommendations for T-shaped multi-partition steel-concrete composite columns under different loadings are proposed.The research work reported in this paper were supported by National Key Research and Development Program (2016YFC0701201), and National Natural Science Foundation of China (Grant No. 51578187); their financial supports are highly appreciated.Chen, J.; Zhang, S.; Huang, Z.; Zhang, X.; Guo, L. (2018). Behavior of innovative T-shaped multi-partition steel-concrete composite columns under concentric and eccentric compressive loadings. En Proceedings of the 12th International Conference on Advances in Steel-Concrete Composite Structures. ASCCS 2018. Editorial Universitat Politècnica de València. 289-296. https://doi.org/10.4995/ASCCS2018.2018.7004OCS28929
trans-4,5-DihydrÂoxy-1,3-diphenylÂimidazolidine-2-thione
In the title compound, C15H14N2O2S, the five-membered ring adopts an envelope conformation and the two hydrÂoxy groups lie on opposite sides of the ring. The six-membered rings are oriented at a dihedral angle of 22.63 (3)°. In the crystal structure, interÂmolecular O—H⋯S and O—H⋯O hydrogen bonds link the molÂecules into a two-dimensional network
Fatigue evaluation of metallic components based on chaotic characteristics of second harmonic generation signal
In the nonlinear ultrasonic technique, the nonlinear received signal, such as second harmonic generation (SHG) signal in higher harmonic experiments, is complicated and non-stationary time series which reflects the fatigue damage of metal components. To effectively evaluate the fatigue damage of metal components, especially the earlier fatigue damage, the chaos and fractal theory are proposed to analyze the received signal of higher harmonic experiments. Chaotic characteristics, for example Lyapunov exponent, correlation dimension and Kolmogorov entropy, are extracted to evaluate the fatigue damage. Experiments results indicate that chaotic characteristics can reasonably characterize and evaluate the fatigue state of beams, which the variation trend of chaotic characteristics has a close relationship with fatigue crack propagation. Furthermore, chaotic characteristics are very sensitive to earlier fatigue damage of used connecting rods, especially the Lyapunov exponent. Therefore, chaos and fractal theory could effectively extract the nonlinear received signals, and chaotic characteristics could reasonably evaluate the fatigue damage state of metal components
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Adaptive neural control of MIMO nonlinear systems with a block-triangular pure-feedback control structure
This paper presents adaptive neural tracking control for a class of uncertain multi-input-multi-output (MIMO) nonlinear systems in block-triangular form. All subsystems within these MIMO nonlinear systems are of completely nonaffine purefeedback form and allowed to have different orders. To deal with the nonaffine appearance of the control variables, the mean value theorem (MVT) is employed to transform the systems into a block-triangular strict-feedback form with control coefficients being couplings among various inputs and outputs. A systematic procedure is proposed for the design of a new singularityfree adaptive neural tracking control strategy. Such a design procedure can remove the couplings among subsystems and hence avoids the possible circular control construction problem. As a consequence, all the signals in the closed-loop system are guaranteed to be semiglobally uniformly ultimately bounded (SGUUB). Moreover, the outputs of the systems are ensured to converge to a small neighborhood of the desired trajectories. Simulation studies verify the theoretical findings revealed in this work
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