Synthesis, structural characterization and antibacterial activity of diorganotin N-(salicylidene)tyrosinates

O-3-X-5-YC6H2CH=NCH(CH2C6H4OH-4)COO] (R, X, Y = Et, H, H (1); n-Bu, H, Br (2); n-Bu, Br, Br (3)), have been synthesized by the one-pot reaction of diorganotin oxide, (L)-tyrosine and salicylaldehyde, and characterized by elemental analysis, IR, NMR, and X-ray single crystal diffraction. X-Ray analyses of 1-3 show that the tin atoms of the complexes exhibit distorted trigonal-bipyramidal geometries. The intermolecular O-H⋅⋅⋅O hydrogen bonds connect the molecules into one-dimensional supramolecular chain or a R22(20) macrocyclic dimer. Bioassay results show that 1-3 have good in vitro antibacterial activity against Escherichia coli

MicroRNA-322 inhibits inflammatory cytokine expression and promotes cell proliferation in LPS-stimulated murine macrophages by targeting NF-κB1 (p50)

Correspondence : Hanchuan Dai ([email protected]) Inflammation is the body's normal self-protection mechanism to eliminate pathogens and resist pathogen invasion. The excessive inflammatory response may lead to inflammatory lesions. The mechanisms accounting for inflammation remain hazy. miRNAs have been proposed to have crucial effects on inflammation. In the present study, we reported that lipopolysaccharide (LPS)-stimulation increased the expression levels of inflammatory cytokines and the cell-cycle progression was suppressed in RAW264.7 cells. Meanwhile, the expression of miR-322 was significantly down-regulated after LPS treatment. Bioinformatics predictions revealed a potential binding site of miR-322 in 3 -UTR of NF-κB1 (p50) and it was further confirmed by luciferase assay. Moreover, both the mRNA and protein levels of NF-κB1 (p50) were down-regulated by miR-322 in RAW264.7 cells. Subsequently, we demonstrated that miR-322 mimics decrease in the expression levels of inflammatory cytokines and cell-cycle repression can be rescued following LPS treatment in RAW264.7 cells. The anti-inflammatory cytokines expression including IL-4 and IL-10 were significantly up-regulated. Furthermore, miR-322 could also promote RAW264.7 cells proliferation. These results demonstrate that miR-322 is a negative regulator of inflammatory response by targeting NF-κB1 (p50)

Adaptive local basis set for Kohn-Sham density functional theory in a discontinuous Galerkin framework I: Total energy calculation

Kohn-Sham density functional theory is one of the most widely used electronic structure theories. In the pseudopotential framework, uniform discretization of the Kohn-Sham Hamiltonian generally results in a large number of basis functions per atom in order to resolve the rapid oscillations of the Kohn-Sham orbitals around the nuclei. Previous attempts to reduce the number of basis functions per atom include the usage of atomic orbitals and similar objects, but the atomic orbitals generally require fine tuning in order to reach high accuracy. We present a novel discretization scheme that adaptively and systematically builds the rapid oscillations of the Kohn-Sham orbitals around the nuclei as well as environmental effects into the basis functions. The resulting basis functions are localized in the real space, and are discontinuous in the global domain. The continuous Kohn-Sham orbitals and the electron density are evaluated from the discontinuous basis functions using the discontinuous Galerkin (DG) framework. Our method is implemented in parallel and the current implementation is able to handle systems with at least thousands of atoms. Numerical examples indicate that our method can reach very high accuracy (less than 1meV) with a very small number ($4\sim 40$) of basis functions per atom

Hyper-Chaotic Color Image Encryption Based on Transformed Zigzag Diffusion and RNA Operation

With increasing utilization of digital multimedia and the Internet, protection on this digital information from cracks has become a hot topic in the communication field. As a path for protecting digital visual information, image encryption plays a crucial role in modern society. In this paper, a novel six-dimensional (6D) hyper-chaotic encryption scheme with three-dimensional (3D) transformed Zigzag diffusion and RNA operation (HCZRNA) is proposed for color images. For this HCZRNA scheme, four phases are included. First, three pseudo-random matrices are generated from the 6D hyper-chaotic system. Second, plaintext color image would be permuted by using the first pseudo-random matrix to convert to an initial cipher image. Third, the initial cipher image is placed on cube for 3D transformed Zigzag diffusion using the second pseudo-random matrix. Finally, the diffused image is converted to RNA codons array and updated through RNA codons tables, which are generated by codons and the third pseudo-random matrix. After four phases, a cipher image is obtained, and the experimental results show that HCZRNA has high resistance against well-known attacks and it is superior to other schemes

Differential topic models

In applications we may want to compare different document collections: they could have shared content but also different and unique aspects in particular collections. This task has been called comparative text mining or cross-collection modeling. We present a differential topic model for this application that models both topic differences and similarities. For this we use hierarchical Bayesian nonparametric models. Moreover, we found it was important to properly model power-law phenomena in topic-word distributions and thus we used the full Pitman-Yor process rather than just a Dirichlet process. Furthermore, we propose the transformed Pitman-Yor process (TPYP) to incorporate prior knowledge such as vocabulary variations in different collections into the model. To deal with the non-conjugate issue between model prior and likelihood in the TPYP, we thus propose an efficient sampling algorithm using a data augmentation technique based on the multinomial theorem. Experimental results show the model discovers interesting aspects of different collections. We also show the proposed MCMC based algorithm achieves a dramatically reduced test perplexity compared to some existing topic models. Finally, we show our model outperforms the state-of-the-art for document classification/ideology prediction on a number of text collections.13 page(s

Analyzing social media via event facets

Microblog is a prominent information platform for sharing experiences, discussing current events, and exchanging ideas. Many events are first reported in social media, and increasing amounts of rich-media content are associated with the posts, making them more credible and attractive. We design a rich-media analysis system to address the important challenge of sensing and exploring events from social media in real-time. The system includes a novel bilateral correspondence topic model to extract representative content and meaningful facets about events over time. It also includes a digital magazine that anchors user interactions with event facets. We demonstrate several examples from more than 4 million rich media microblogs, showing the effectiveness of key content extraction and natrual interactions with facets