Primary tumors and metastases have been thought to initiate avascularly as multicellular aggregates and later induce angiogenesis or initiate vascularly by co-opting pre-existing host blood vessels without inducing angiogenesis. These two distinct concepts of microtumor vascularization have raised significant controversies. To clarify intratumoral vascularization and tumor cell behaviors at single-cell level during the earliest stage of microtumor initiation, we established primary and metastatic microtumor models in Tg(flk1:EGFP) transgenic zebrafish. We found that tumor cells preferred to initiate avascularly as multicellular aggregates and only later (50-100 cells in size) induced angiogenesis in blood-supply-sufficient microenvironments. In blood-supply-deficient microenvironments, less tumor cells (20-30 cells per fish) managed to co-opt and migrate along host vessels, whereas more tumor cells (100-300 cells per fish) could immediately induce angiogenesis without obvious cell migration. In a metastatic model, we clearly observed that tumor cells co-opted, migrated along and proliferated on the surface of host vessels at an early stage after they extravasated from host vessels and induced angiogenesis later when micromatastases comprised only 15-30 tumor cells. Moreover, the inducement of neovessels accelerated the growth of micromatastases in size, meanwhile, decreased the migration of tumor cells on the surface of host vessels. These results suggest that vessel co-option and angiogenesis have distinct contributions during the initiation of microtumors. Microtumors initiated reasonably through co-opting host vessels or inducing angiogenesis, depending on the differences of local microenvironments and cell numbers in microtumors. The results in this study may have important implications for the therapeutic application of antiangiogenic strategies.

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Background: Hypoxia regulates VEGFA expression at both the transcriptional and post-transcriptional levels. Results: eIf3i is induced by HIF1A under hypoxia and controls VEGFA protein translation. Conclusion: eIF3i controls VEGFA signaling during normal and tumorigenic angiogenesis. Significance: Our data reveal a new mechanism for VEGFA regulation, and eIF3i can be an oncotarget in anticancer therapies.

Highlights• The safety of hydrogen fuel cell ship is researched by a CFD simulation.• The corners of fuel cell cabins are the areas with a higher concentration of hydrogen.• Reasonable ventilation is the most effective solution to hydrogen safety in cabin. AbstractA hydrogen fuel cell has many advantages, such as no pollution, high efficiency, low noise and continuous operation. Therefore, it has the potential to be widely applied in both the power propulsion and power supply of a ship. However, the consequent hydrogen safety and leakage issues have attracted much attention and become key issues that need to be resolved urgently. In this paper, based on the component transportation and chemical reaction modules in Fluent software, a ferry is selected as the research object, and a diffusion model of the high pressure hydrogen leakage in a Corresponding author. Yupeng Yuan cabin is established. The hydrogen concentration distributions at different leakage positions after the leakage occurs are obtained by making transient numerical calculations of the hydrogen leakage diffusion at the corresponding leakage positions in the cabin. At the same time, the effects of different ventilation conditions on the diffusion trend of hydrogen are analyzed. The simulationresults have ascertained the optimal positions for hydrogen sensors and ventilations and it is hoped that these results can provide guidance for the design of a fuel cell ship that uses high pressure gaseous hydrogen.

Due to the increasing demand for energy conservation and the reduction of emissions, renewable energy applications for ships have attracted a great deal of attention. In this paper, a 5000-vehicle space pure car and truck carrier (PCTC) is selected as the research object. Then, on the basis of the existing power system, a unified grid-tied/standalone solar system is designed with a built-in battery energy storage system. The system includes a solar energy generation unit, a battery storage system, a diesel generating set, grid-tied/stand-alone controlled inverters, a battery management system (BMS) and an energy management system. According to an analysis of the experimental data, it can be concluded that the use of solar energy hybrid power can reduce fuel consumption by 4.02% and carbon dioxide (CO2) emissions by 8.55% a year. Thus, the proposed solar-powered hybrid system can reduce both oil consumption and CO2 emissions significantly.

The steady and reliable operation of a ship's diesel engine is important to the ship's electrical power system and the engine's performance, and stable control of rotational speed is crucial to a diesel engine's emission, economy and power performance. A ship's diesel engine is a nonlinear and timevarying system. A traditional proportional-integral-derivative (PID) controller cannot regulate the speed under different working conditions. In this paper, a nonlinear mathematical model for speed regulation of diesel engines is established according to experiments and a multi-sliding surface variable structure controller for speed regulation of diesel engine is established by sliding mode control. A bulk cargo ship 500-I was analysed as an example. The MATLAB/Simulink simulation took the navigation environment and the effect of the ship propeller on the diesel engine into consideration. A simulation model considering the whole ship-engine-propeller system is built and some conclusions can be drawn from the simulation. The multi-sliding surface control can restrain the overshoot and realize a quick track of the targeted value with high accuracy and strong robustness. In addition, the fuel consumption and CO 2 emission of this sliding mode variable structure control is reduced by 4.6% compared with traditional PID control.