Many research groups have attained slow, persistent, continuous release of silver ions through careful experimental design using existing methods. Such methods effectively kill planktonic bacteria and therefore prevent surface adhesion of pathogens. However, the resultant modified coatings cannot provide long-term antibacterial efficacy due to sustained anti-microbial release. In this study, the anti-infection activity of AgNP immobilized biomaterials was evaluated, facilitated by argon plasma grafting technology and activated by bacterial colonization. The modified materials generated in this study showed excellent specificity and were active against both Gram-positive and Gram-negative biofilm forming bacteria, including methicillin-resistant Staphylococcus aureus, Staphylococcus epidermidis, and Escherichia coli. The anti-infection biomaterials developed in this study demonstrate several attractive advantages in comparison to traditional anti-bacterial surfaces loaded with antibiotics or other types of antibacterial agents and include (1) broad spectrum of activity against antibiotic resistant bacteria, (2) the unlikelihood of bacterial resistance, (3) specificity, (4) biocompatibility, and (5) stability.

Global calibration methods for multi-camera system are critical to the accuracy of vision measurement. Proposed in this paper is such a method based on several groups of sphere targets and a precision auxiliary camera. Each camera to be calibrated observes a group of spheres (at least three), while the auxiliary camera observes all the spheres. The global calibration can be achieved after each camera reconstructs the sphere centers in its field of view. In the process of reconstructing a sphere center, a parameter equation is used to describe the sphere projection model. Theoretical analysis and computer simulation are carried out to analyze the factors that affect the calibration accuracy. Simulation results show that the parameter equation can largely improve the reconstruction accuracy. In the experiments, a two-camera system calibrated by our method is used to measure a distance about 578 mm, and the root mean squared error is within 0.14 mm. Furthermore, the experiments indicate that the method has simple operation and good flexibility, especially for the onsite multiple cameras without common field of view.

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