Construction of Maize Universal Expression Vector PGM-35Sbar and Maize Transformation

[Objective] The paper was to construct maize universal expression vector, in order to provide basis for using transgenic methods to improve abiotic stress tolerance of maize. [Method] Based on the transformation of existing pGreen0229 plant expression vector, phosphinothricin-resistant selectable marker-bar gene driving by CaMv35S promoter was constructed, which could be used to connect target gene of maize expression vector PGM-35Sbar, and transform Ji444 maize inbred lines by pollen tube pathway. [Result] The universal expression vector for PGM-35Sbar maize had been successfully constructed. When the maize plants were transformed, 14 resistant plants were obtained, and 12 plants were identified to be positive plants by PCR detection. [Conclusion] The study provided basis for rapid construction of maize expression vector containing specific target gene.

Optimal Control of a Universal Rotating Magnetic Vector for Petal-shaped Capsule Robot in Curve Environment

Steering control of a capsule robot in curve environment by magnetic navigation is not yet solved completely.A petal-shaped capsule robot with less steering resistance based on multiple wedge effects is presented,and an optimization method with two processes for determining the orientation of a pre-applied universal magnetic spin vector is proposed.To realize quick and non-contact steering swimming,a fuzzy comprehensive evaluation method for optimizing the steering driving angle is presented based on two evaluation indexes including the average steering speed and the average steering trajectory deviation,achieving the initial optimal orientation of a universal magnetic spin vector.To further reduce robotic magnetic vibration,a main target method for optimizing its final orientation,which is used for fine adjustment,is employed under the constrains of the magnetic moments.Swimming experimental results in curve pipe verified the effectiveness of the optimization method,which can be effectively used to realize non-contact steering swimming of the petal-shaped robot and reduce its vibration.

Control theorem of a universal uniform-rotating magnetic vector for capsule robot in curved environment

For realizing non-contact steering swimming of a capsule robot in curved environment filled with viscous liquid, based on spa- tial orthogonal superposition theorem of alternating magnetic vectors, an innovative physical method is proposed, which em- ploys three-axis orthogonal square Helmholtz coils fed with three phase sine currents to create a universal uniform magnetic spin vector as energy source. According to the antiphase sine current superposition theorem generalized in this paper, an effec- tive control method for successively adjusting the orientation and the rotating direction of the universal magnetic spin vector is proposed. For validating its feasibility and controllability, three-axis Helmholtz coils, power source and an innovative capsule robot prototype were manufactured, experiments were conducted in both spiral pipe and animal intestine. It was demonstrated that the orientation and the rotational direction of the universal uniform-magnetic spin vector can be adjusted successively through digital control and steering swimming of the capsule robot in spiral intestine can be achieved successfully. The breakthrough of the universal rotating uniform-magnetic vector will push forward the development of modern physics and biomedical engineering