About the Authors
Department of Biomedical Engineering, Johns Hopkins University School of Medicine, Baltimore, Maryland, United States of America
The authors have declared that no competing interests exist.
FMG, JWJ, and ASP conceived and designed the experiments. FMG and JWJ performed the experiments. FMG, JWJ, and ASP analyzed the data. FMG, JWJ, and ASP contributed reagents/materials/analysis tools. FMG, JWJ, and ASP wrote the paper.