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Cells exposed with irradiation can induce different biological effects in non-irradiated cells due to the cell-cell interactions. Herein, we investigated the bystander effect of different types of irradiation including gamma irradiation (GR) and lithium heavy ion irradiation (LR) on the model human neuroblastoma cell line (SH-SY5Y). The gamma and lithium ion irradiation induced different bystander effects on the SH-SY5Y cell line. The bystander effect induced by gamma irradiation promoted the cell proliferation through activating the ERK and AKT signaling pathways, but it could slightly influence the cell cycle of non-irradiated SH-SY5Y cells. Whereas, the bystander effect induced by lithium heavy ion irradiation inhibited the cell proliferation, arrested the cell cycle and activated the process of pro-apoptosis. The findings of this study confirm the diversified bystander effects of various irradiation on the non-irradiated cells, therefore it highlights the importance of revised strategy for clinical radiotherapy and radioprotection to reduce the damages caused by bystander effects. Further, the in-depth mechanism research on the cell proliferation influenced by the bystander effect of radiation will also be useful to understand the biological effects of radiation.

A novel non-contact satellite for drag-free and attitude control is proposed in this paper. The non-contact satellite is separated into a payload module and a service module by non-contact Lorentz actuators. Instead of thrusters, the non-contact Lorentz actuators are used to exerted precise forces and torques, enabling drag-free and attitude control of the payload module, while the service module is designed to track the payload module to avoid collision. On the basis of this new design, the dynamics of drag-free and attitude control can be precisely modeled. Accordingly, a hierarchical control algorithm, consisting of an EKF-based estimation and rejection of environmental acceleration of payload module, attitude control of payload module, minimum norm allocation of non-contact Lorentz actuators, as well as collaborative control of service module, is systematically designed. A numerical simulation is then conducted to demonstrate the validity and effectiveness of the proposed design.

Microwave-assisted catalysis offers great promise as an “intensified” technology for chemical processing. The present study investigates microwave-assisted direct conversion of methane with focus on the design and evaluation of microwave-sensitive H-(Fe)ZSM-5 catalysts for the existence of hotspot formation. Isomorphous substituted H-(Fe)ZSM-5 catalysts are tuned to identify key design parameters that control their microwave sensitivity. Increasing the amount of Al and Fe substitution in the zeolite lattice is found to result in higher microwave sensitivity due to improved dielectric properties and hence facilitated microwave heating of the catalyst bed. Comparison between the performance of these catalysts in a conventional thermally-heated (CH) fixed-bed and a microwave (MW) reactor allows identification of the effect of microwave irradiation on the catalyst activity. Methane conversion is drastically enhanced at MW conditions (from 3% at CH conditions to 40% at MW conditions), indicating accelerated methane activation over the metal site and hence suggesting a hot metal site despite much lower catalyst bulk temperature measured in the microwave reactor. The existence of metal hotspot formation is further supported by the reaction product distribution and spent catalyst analysis. At MW conditions, C2 (ethane and ethylene) and coke (mainly carbon nanotubes and nanofibers) selectivity are much higher at the cost of aromatics make compared to CH conditions. This can be explained by reduced aromatization activity at the Bronsted acid sites of the zeolite due to its lower relative temperature of the zeolite. The much-enhanced metal aggregation observed in the spent catalyst from the MW reactor along with the distribution of coke species further confirms the existence of selective heating (i.e. hotspot formation) occurring at the active metal site in the catalyst at MW conditions.

Based on 5 requirements which are essential for stable OAM mode transmission, we propose an OAM fiber family based on a structure of circular photonic crystal fiber (C-PCF). The proposed C-PCF in the family is made of pure silica, with a big round air hole at the center, several rings of air-hole array as the cladding, and a ring shaped silica area in between as the core where the OAM modes propagate. We also provide a design strategy with which the optimized C-PCF can be obtained with optimum number of high quality OAM modes (up to 42 OAM modes), large effective index separation for corresponding vector modes over a wide bandwidth, relative small and flat dispersion, and low nonlinear coefficient compared with a conventional single mode fiber. The designed fiber can be used in MDM communications and other OAM applications in fibers.

We report herein a transition-metal-free coupling reaction of arylboronic acids with benzyl halides and mesylates for the construction of C(sp2)C(sp3) bonds. A unique feature of this coupling reaction is the formation regioisomers in some cases. Mechanistic studies suggest that this reaction may proceed via an unprecedented Friedel–Crafts-type reaction pathway under base conditions with the assistance of boronic acid moiety.

In this work, the interactive process between separation bubble and impinging leading-edge vortices, which is superimposed in unsteady separated and reattaching flows over a finite blunt plate, was experimentally determined. We used an effective recognition strategy based on an offline data analysis by dynamic mode decomposition (DMD) and online DMD computation in a field-programmable gate array (FPGA). The approach was established for phase-locking particle image velocimetry (PIV) measurements of the underlying vortex dynamics. The DMD mode coefficients of wall-pressure fluctuations following the temporal evolution of the corresponding unsteady events clearly reflected the interactive process, in which three consecutive impinging vortices appeared in one period of the separation bubble. The global interactive process between the separation bubble and the impinging vortices was classified into three consecutive processes: an amplification process, a transition process and a preparation process. The phase-averaged PIV measurements revealed the following: (a) During the amplification process, the separation bubble and impinging vortices are in a synchronous enlargement process beginning from the shortest position of the separation bubble at x / D = 3.00 . (b) In both the transition and preparation processes, the interaction was characterized by a flapping separation bubble (which enlarged in the first half of the period and then shrank in the second half of the period) and by the impinging vortices constantly shedding to the downstream region. Finally, the underlying shear layer instabilities and vortex movements of these three interactive processes were analyzed.