The Peridinin-Chlorophyll a-Protein (PCP) complex has both an exceptionally efficient light-harvesting ability and a highly effective protective capacity against photodynamic reactions involving singlet oxygen. These functions can be attributed to presence of a substantial amount of the highly-substituted and complex carotenoid, peridinin, in the protein and the facts that the low-lying singlet states of peridinin are higher in energy than those of chlorophyll (Chl) a, but the lowest-lying triplet state of peridinin is below that of Chl a. Thus, singlet energy can be transferred from peridinin to Chl a, but the Chl a triplet state is quenched before it can sensitize the formation of singlet oxygen. The present investigation takes advantage of Chl a as an effective triplet state donor to peridinin and explores the triplet state spectra and dynamics of a systematic series of peridinin analogs having different numbers of conjugated carbon-carbon double bonds. The carotenoids investigated are peridinin, which has a C(37) carbon skeleton and eight conjugated carbon-carbon double bonds, and three synthetic analogs: C(33)-peridinin, having two less double bonds than peridinin, C(35)-peridinin which has one less double bond than peridinin, and C(39)-peridinin which has one more double bond than peridinin. In this study, the behavior of the triplet state spectra and kinetics exhibited by these molecules has been investigated in polar and nonpolar solvents and reveals a substantial effect of both pi-electron conjugated chain length and solvent environment on the spectral lineshapes. However, only a small dependence of these factors is observed on the kinetics of triplet energy transfer from Chl a and on carotenoid triplet state deactivation to the ground state.

Much research has shown the benefits of additional anatomical learning and dissection beyond the first year of medical school human gross anatomy, all the way through postgraduate medical training. We have developed an interactive method for teaching eye and orbit anatomy to medical students in their ophthalmology rotation at Duke University School of Medicine. We provide review lectures on the detailed anatomy of the adult human eye and orbit as well as the developmental anatomy of the eye. These lectures are followed by a demonstration of the anatomy of the orbit using conventional frontal and superior exposures on a prosected human cadaver. The anatomy is projected onto a large LCD screen using a mounted overhead camera. Following a brief lecture on clinically relevant anatomy, each student then dissects a fresh porcine (pig) eye under low magnification using a dissecting microscope. These dissections serve to identify structures extrinsic to the eyeball, including extraocular muscle attachments, small vessels, optic nerve stalk, and fascial sheath of the eyeball (Tenon's fascia). Dissection then shifts to the internal anatomy of the eyeball. The size and anatomy of the porcine eye is comparable with that of the human and the dissection provides students with a valuable hands-on learning opportunity that is otherwise not available in embalmed human cadavers. Students and clinical faculty feedback reveal high levels of satisfaction with the presentation of anatomy and its scheduling early during the ophthalmology clerkship. Anat Sci Educ 2: 173-178, 2009.

No abstract

No abstract

Much research has shown the benefits of additional anatomical learning and dissection beyond the first year of human gross anatomy during postgraduate medical training. We have developed an interactive method for teaching second‐year medical students in their ophthalmology rotation at Duke University School of Medicine. We provide review lectures on the detailed anatomy of the adult human eye and orbit as well as the development of the eye. This is followed by an anatomical demonstration of the human orbit and eye on a prosected human cadaver, projecting the dissection of the detailed anatomy onto a computer screen. Each student then dissects a fresh suid eye under a regular‐strength microscope, identifying the external musculature and focusing on the detailed anatomy of the internal eyeball. The anatomy and size of the suid eye is comparable to that of the human and thus this method provides students a valuable learning opportunity to dissect anatomy that is most often not preserved or unidentifiable in the human cadaver.Grant Funding SourceNSF