Review
Copyright ©2014 Baishideng Publishing Group Inc.
World J Gastrointest Endosc. Oct 16, 2014; 6(10): 457-474
Published online Oct 16, 2014. doi: 10.4253/wjge.v6.i10.457
Figure 2
Figure 2 Displayed is the β-lactam ring’s four-membered (i. e., a square) chemical structure.