Physical activity has been shown to suppress tumor initiation and progression. The neurotransmitter dopamine (DA) is closely related to movement and exhibits antitumor properties. However, whether ...the suppressive effects of physical activity on tumors was mediated by the nervous system via increased DA level remains unknowns. Here we show that regular moderate swimming (8 min/day, 9 weeks) raised DA levels in the prefrontal cortex, serum and tumor tissue, suppressed growth, reduced lung metastasis of transplanted liver cancer, and prolonged survival in a C57BL/6 mouse model, while overload swimming (16 and 32 min/day, 9 weeks) had the opposite effect. In nude mice that were orthotopically implanted with human liver cancer cell lines, DA treatment significantly suppressed growth and lung metastasis by acting on the D2 receptor (DR2). Furthermore, DR2 blockade attenuated the suppressive effect of moderate swimming on liver cancer. Both moderate swimming and DA treatment suppressed the transforming growth factor-beta (TGF-β1)-induced epithelial-mesenchymal transition of transplanted liver cancer cells. At the molecular level, DR2 signaling inhibited extracellular signal-regulated kinase phosphorylation and expression of TGF-β1 in vitro. Together, these findings demonstrated a novel mechanism by which the moderate exercise suppressed liver cancer through boosting DR2 activity, while overload exercise had the opposite effect, highlighting the possible importance of the dopaminergic system in tumor growth and metastasis of liver cancer.
To generate an efficient tool used in Xenopus oocyte expression for in situ investigation of channel receptor expression, distribution and function, the C‐terminus of the honeybee (Apis mellifera L.) ...resistant to dieldrin (RDL) subunit was fused with *FP, including monomeric red, enhanced yellow or enhanced green fluorescent protein (referred to as mRFP, EYFP and EGFP, respectively). In the present study, all fused *FP‐AmRDLs could be visualized using fluorescence and laser confocal microscopy in cRNA‐injected oocytes. Fluorescence was distributed isotropically in the cellular membrane. The potencies of the agonist γ‐aminobutyric acid (GABA), but not β‐alanine, and the test antagonists (fipronil, flufiprole, dieldrin, α‐endosulfan, bifenazate and avermectin B1a) in the *FP‐AmRDL receptor did not significantly differ from that of the untagged receptor with two‐electrode voltage clamp detection. The half maximal effective concentrations (EC50s) of GABA in AmRDL, EGFP‐AmRDL, EYFP‐AmRDL and mRFP‐AmRDL receptors were 11.98, 12.61, 18.92 and 22.11 μM, respectively, and those of β‐alanine were 651.6, 629.6, 1643.0 and 2146.0 μM, respectively. Inhibition percentages of test antagonists against *FP‐AmRDL and AmRDL were not significantly different from each other. Overall, the consistency in functional properties between *FP‐AmRDL and AmRDL receptors makes pGH19‐*FP a promising tool for further in situ investigation of GABA receptors.
Nanoindentation technology is an effective and convenient method for evaluating the mechanical properties of materials at micro and nano scales. Since the complete nanoindentation process is a ...typical non-linear mechanical behavior and the material deformation varies with the indentation depth, it is difficult to analytically obtain plastic parameters of constitutive models which are however important to describe the material properties in finite element simulations. In this study, nanoindentation experiments are carried out on the sintered silver nanoparticle (AgNP) which is one of the advanced die-attach materials for high-power electronic devices working in harsh environment. In order to further stabilize and enhance the thermal conductivity, different weight contents of SiC microparticles are incorporated in the AgNP paste before the sintering process. Finite element simulations are used to simulate the deformation and load resistance of materials in nanoindentation process. Plastic properties of materials are analyzed by proposing a reverse algorithm based on the measurements of nanoindentation responses. Essentially, the proposed reverse algorithm couples the dimensional analysis and trial-and-error fitting technique. The complete constitutive relationship of sintered AgNP with different SiC contents is obtained accordingly after examining the loading and unloading stages of nanoindentation responses. The influence of SiC content on the mechanical properties of sintered AgNP is also discussed by considering the material microstructure observed using a scanning electron microscopy. Finally, the uniqueness of constitutive curve from the proposed reverse algorithm is confirmed by the agreement of predicted and measured load-displacement responses using independent spherical indentations.
To investigate the role of small nucleolus RNA host gene 14 (SNHG14) in the progression of atherosclerosis (AS), bioinformatics analysis, and other relevant experiments (cell counting kit-8, flow ...cytometry, quantitative real-time polymerase chain reaction, luciferase reporter, RNA immunoprecipitation, RNA pull-down, and western blot assays) were done. The current study revealed that SNHG14 level was high in the serum of AS patients and oxidized low-density lipoprotein (ox-LDL)-induced AS cell lines. Besides, we found that SNHG14 accelerated cell proliferation while inhibited cell apoptosis in ox-LDL-induced AS cell lines. Next, SNHG14 was confirmed to be a sponge for miR-186-5p in AS cells, and it was validated that SNHG14 regulated AS cell proliferation and apoptosis by sponging miR-186-5p. Moreover, we uncovered that WAS-interacting protein family member 2 (WIPF2) was a downstream target of miR-186-5p in AS cells. Finally, it was demonstrated that miR-186-5p modulated AS cell proliferation and apoptosis via targeting WIPF2. To conclude, our research disclosed that SNHG14 affected ox-LDL-induced AS cell proliferation and apoptosis through miR-186-5p/WIPF2 axis, which may provide a theoretical basis for the treatment and diagnosis of AS.
Since the discovery of carbon nanotubes in 1991 by Iijima, there has been great interest in creating long, continuous nanotubes for applications where their properties coupled with extended lengths ...will enable new technology developments. For example, ultralong nanotubes can be spun into fibres that are more than an order of magnitude stronger than any current structural material, allowing revolutionary advances in lightweight, high-strength applications. Long metallic nanotubes will enable new types of micro-electromechanical systems such as micro-electric motors, and can also act as a nanoconducting cable for wiring micro-electronic devices. Here we report the synthesis of 4-cm-long individual single-wall carbon nanotubes (SWNTs) at a high growth rate of 11 μm s−1 by catalytic chemical vapour deposition. Our results suggest the possibility of growing SWNTs continuously without any apparent length limitation.
Ultra-fine grain (UFG) Cu–Cr alloy is prepared by equal-channel angular pressing (ECAP). The microstructure, tensile and fatigue properties of the UFG Cu–Cr alloy were investigated. The bulk ...materials with average grain size of ∼230
nm were obtained through ECAP for 12 times. The cellular subgrains with low-angle grain boundaries were first formed at relatively low strains, and high-angle grain boundaries dominate the microstructure with the increasing of strains. Materials exhibit homogeneous equiaxed subgrains after ECAP processing. The Cu–Cr alloy processed by ECAP has high strength besides high conductivity and sufficient ductility. Fatigue experiments were carried out in terms of stress-controlled for the 4 and 6 passes ECAPed samples. The increase of fatigue limit and prolong of fatigue life are remarkable as compared with those of coarse grain Cu–0.75Cr alloy and ECAPed pure Cu reported in available literatures.
Autologous bone marrow cells (BMCs) transplanted into ventricular scar tissue may differentiate into cardiomyocytes and restore myocardial function. This study evaluated cardiomyogenic ...differentiation of BMCs, their survival in myocardial scar tissue, and the effect of the implanted cells on heart function.
BMCs from adult rats were cultured in cell culture medium (control) and medium with 5-azacytidine (5-aza, 10 micromol/L), TGFbeta1 (10 ng/mL), or insulin (1 nmol/L) (n=6, each group). Only BMCs cultured with 5-aza formed myotubules which stained positively for troponin I and myosin heavy chain. In vivo studies: a cryoinjury-derived scar was formed in the left ventricular free wall. At 3 weeks after injury, fresh BMCs (n=9), cultured BMCs (n=9), 5-aza-induced BMCs (n=12), and medium (control, n=12) were autologously transplanted into the scar. Heart function was measured at 8 weeks after myocardial injury. Cardiac-like muscle cells which stained positively for myosin heavy chain and troponin I were observed in the scar tissue of the 3 groups of BMC transplanted hearts. Only the 5-aza-treated BMC transplanted hearts had systolic and developed pressures which were higher (P<0.05) than that of the control hearts. All transplanted BMCs induced angiogenesis in the scar.
Transplantation of BMCs induced angiogenesis. BMCs cultured with 5-aza differentiated into cardiac-like muscle cells in culture and in vivo in ventricular scar tissue and improved myocardial function.
Low-frequency buffeting is a common problem in automobile wind tunnels, it induces pulsations of pressure and velocity in the test section. A 1:15 3/4 open-jet return-type scaled wind tunnel was used ...for this research, and numerical simulations and tests were implemented to study the flow characteristics of the jet shear layer in a model wind tunnel. The results show that guide devices on the inner wall of the nozzle can effectively reduce the low-frequency buffeting, but the presence of the devices deteriorated the axial static pressure gradient of the flow in the test section. The shape of the guide devices was optimized through the Explorative Gradient Method, and numerical simulations were carried out. An optimal shape can effectively reduce the low-frequency buffeting and ensure flow field uniformity in the test section. Finally, the reliability of the numerical simulation and the practicability of the optimal case were verified through a hot wire test and a microphone test.
PDF
