4,896 research outputs found

    Sulfatase 2 facilitates lymphangiogenesis in breast cancer by regulating VEGF-D.

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    In our previous studies, sulfatase 2 (Sulf2) was found to upregulate vascular endothelial growth factor-D (VEGF-D) expression in breast cancer. As VEGF-D plays an important role in lymphangiogenesis, we hypothesized that Sulf2 facilitates lymphangiogenesis in breast cancer by regulating VEGF-D. To evaluate the functions of Sulf2 on lymphangiogenesis in breast cancer, proliferation, apoptosis, cell cycle, cell mobility and tube-formation of lymphatic endothelial cells (LECs) were measured in vitro. Lymphangiogenesis in nude mouse ears and breast cancer xenografts were examined in vivo. Furthermore, the expression levels of related signaling pathway genes were screened and verified in LECs. We found that Sulf2 significantly increased the mobility and tube formation of the LECs, inhibited cisplatin-induced LEC apoptosis, but had no effect on cell proliferation and the cell cycle. Moreover, recombinant Sulf2 (rSulf2) combined with VEGF-D further promoted the proliferation, cell cycle, mobility and tube-like structure formation in the LECs, and at the same time inhibited cisplatin-induced apoptosis especially in the late stage. Sulf2 also significantly increased the density of lymphatic vessels in mouse ears and breast cancer xenografts in vivo. AKT1 was also shown to be upregulated and activated by Sulf2. Our results confirmed that Sulf2 facilitated lymphangiogenesis in breast cancer cells by regulating VEGF-D and that the AKT1‑related signaling pathway was involved

    Link between \emph{Zitterbewegung} and topological phase transition

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    Topological quantum state described by the global invariant has been extensively studied in theory and experiment. In this letter, we investigate the relationship between \emph{Zitterbewegung} and the topology of systems that reflect the properties of the local and whole energy bands, respectively. We generalize the usual two-band effective Hamiltonian to characterize the topological phase transition of the spin-JJ topological insulator. By studying \emph{Zitterbewegung} dynamics before and after topological phase transition, we find that the direction of quasiparticles' oscillation can well reflect topological properties. Furthermore, we develop a quantitative calculation formula for the topological invariant in the spin-JJ Chern insulator and give the selection rule of the corresponding dynamics. Finally, we demonstrate that our theory is valid in different topological systems. The topological invariant can be represented by local dynamical properties of the high-symmetry points in the first Brillouin zone, which provides a new measurement method from the dynamical perspective.Comment: 6 pages, 1 figure. Comments are welcom

    Nonholonomic Motion Planning for a Free-Falling Cat Using Quasi-Newton Method

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    The motion planning problem of a free-falling cat is investigated. Nonholonomicity arises in a free-falling cat subject to nonintegrable velocity constraints or nonintegrable conservation laws. When the total angular momentum is zero, the rotational motion of the cat subjects to nonholonomic constraints. The equation of dynamics of a free-falling cat is obtained by using the model of two symmetric rigid bodies. The control of system can be converted to the motion planning problem for a driftless system. Based on the input parameterization, the continuous optimal control problem is transformed into the discrete one. The quasi-Newton method of motion planning for nonholonomic multibody system is proposed. The effectiveness of the numerical algorithm is demonstrated by numerical simulation

    Sino-European Transcontinental Basic and Clinical High-Tech Acupuncture Studies—Part 1: Auricular Acupuncture Increases Heart Rate Variability in Anesthetized Rats

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    Evidence-based research concerning the effects of high-tech acupuncture on autonomic function was performed by two research teams from China and Austria. This study describes the first transcontinental teleacupuncture measurements in animals. Heart rate (HR) and heart rate variability (HRV) recordings in 10 male Sprague-Dawley anesthetized rats were performed under stable conditions in Beijing, China, and the data analysis was completed in Graz, Austria. The electrocardiograms (ECGs) were recorded by an HRV Medilog AR12 system during acupuncture of the ear and body (PC6 Neiguan, CV12 Zhongwan, ST36 Zusanli). The data were analyzed using specially adapted novel Austrian software. HR did not change significantly during any acupuncture stimulation in anesthetized rats (ear acupuncture, PC6, CV12, or ST36). Total HRV only changed significantly (P = 0.025) during auricular acupuncture (acupoint heart). The low-frequency/high-frequency ratio parameter decreased significantly (P = 0.03) during stimulation of ST36. This change was based on intensification of the related mechanism of blood pressure regulation that has been demonstrated in previous studies in humans. Modernization of acupuncture research performed as a collaboration between China and Austria has also been demonstrated

    Matrine enhances the inhibitory effect of 5-FU on SW480 cells in vitro and in vivo

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    We investigated the antitumor effects of the combination of matrine-a purified alkaloid extracted from Sophora flavescence-and 5-fluorouracil (5-FU) on SW480 cells. This combination inhibited the growth of SW480 cells in a synergistic or additive manner by disrupting their progression through the cell cycle. Exposure of SW480 cells to matrine and 5-FU was followed by an increased rate of expression for caspase-3, caspase-9 and poly-ADP ribose polymerase (PARP) and inhibited the subcutaneous transplantation of SW480 tumors into Balb/c nude mice. Histopathological analysis showed that this effect was most pronounced in the spleens of treated animals. Typical cytotoxic effects observed in 5-FU-treated mice included fibrosis and lymphopenia, whereas in mice treated with 5-FU combined with matrine, the spleen ultrastructure remained intact. These findings indicate that matrine may enhance the therapeutic effectiveness of 5-FU in SW480 tumors by enhancing apoptosis and overcome the threat to immunocompetence associated with 5-FU
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