PMID-sentid Pub_year Sent_text comp_official_name comp_offsetprotein_name organism prot_offset 22849590-3 2012 The pi bonding patterns in these boron nanoladders bear similarities to those in conjugated alkenes: H(2)B(7)(-), H(2)B(8), and H(2)B(9)(-), each with two pi bonds, are similar to butadiene, while H(2)B(10)(2-), H(2)B(11)(-), and H(2)B(12), each with three pi bonds, are analogous to 1,3,5-hexatriene. Alkenes 92-99 H2B clustered histone 21 Homo sapiens 101-106