Aim: To investigate the effects of piperine, a major pungent alkaloid present in Piper nigrum and Piper longum, on the tumor growth and metastasis of mouse 4T1 mammary carcinoma in vitro and in vivo, and elucidate the underlying mechanisms. Methods: Growth of 4T1 cells was assessed using MTT assay. Apoptosis and cell cycle of 4T1 cells were evaluated with flow cytometry, and the related proteins were examined using Western blotting. Real-time quantitative PCR was applied to detect the expression of matrix metalloproteinases (MMPs). A highly malignant, spontaneously metastasizing 4T1 mouse mammary carcinoma model was used to evaluate the in vivo antitumor activity. Piperine was injected into tumors every 3 d for 3 times.

Abstract. This paper studies the algorithmic issues of the spanning star forest problem. We prove the following results: (1) There is a polynomial-time approximation scheme for planar graphs; (2) there is a polynomial-time -approximation algorithm for graphs; (3) it is NP-hard to approximate the problem within ratio 259 260 + for graphs; (4) there is a linear-time algorithm to compute the maximum star forest of a weighted tree; (5) there is a polynomial-time -approximation algorithm for weighted graphs. We also show how to apply this spanning star forest model to aligning multiple genomic sequences over a tandem duplication region.

The concept of gauge field is a cornerstone of modern physics and the synthetic gauge field has emerged as a new way to manipulate particles in many disciplines. In optics, several schemes of Abelian synthetic gauge fields have been proposed. Here, we introduce a new platform for realizing synthetic SU(2) non-Abelian gauge fields acting on two-dimensional optical waves in a wide class of anisotropic materials and discover novel phenomena. We show that a virtual non-Abelian Lorentz force arising from material anisotropy can induce light beams to travel along Zitterbewegung trajectories even in homogeneous media. We further design an optical non-Abelian Aharonov–Bohm system which results in the exotic spin density interference effect. We can extract the Wilson loop of an arbitrary closed optical path from a series of gauge fixed points in the interference fringes. Our scheme offers a new route to study SU(2) gauge field related physics using optics.

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Abstract. microRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression by either translational inhibition or mRNA degradation. miRNAs play pivotal roles in physiological functioning and pathological progression. The function of microRNA-99a (miR-99a) in oral squamous cell carcinoma (OSCC) remains unclear. In the present study, we investigated the roles of miR-99a in OSCC development and the underlying mechanisms in 25 cases of primary OSCC tissues and Tca-8113 cells. The cells were analyzed using FACS analysis and western blotting. Results showed that the expression levels of miR-99a were markedly decreased in OSCC tissues compared with the adjacent non-tumor tissues (n=25). The results of in vitro experiments showed that miR-99a mimics significantly inhibited the proliferation of Tca-8113 cells, a tongue squamous carcinoma cell line, and that miR-99a mimics markedly induced the apoptosis of Tca-8113 cells. Furthermore, we demonstrated that mammalian target of rapamycin (mTOR) was directly targeted by miR-99a, as the overexpression of miR-99a in Tca-8113 cells downregulated the protein expression level of mTOR. Thus, our findings suggest that the downregulation of miR-99a in OSCC tissues is associated with tumor development. miR-99a regulates the growth and survival of OSCC cells and may be exploited as a biomarker and therapeutic target for patients with OSCC.