exo-6b2-Methyl-Substituted Pentabenzocorannulene: Synthesis, Structural Analysis, and Properties.

exo-6b2-Methyl-substituted pentabenzocorannulene (exo-PBC-Me) was synthesized by the palladium-catalyzed cyclization of 1,2,3-triaryl-1H-cyclopenta[l]phenanthrene. Its bowl-shaped geometry with an sp3 carbon atom in the backbone and a methyl group located at the convex (exo) face was verified by X-ray crystallography. According to DFT calculations, the observed conformer is energetically more favorable than the endo one by 39.9 kcal/mol. Compared to the nitrogen-doped analogs with intact π-conjugated backbones (see the main text), exo-PBC-Me displayed a deeper bowl depth (avg. 1.93 Å), redshifted and broader absorption (250-620 nm) and emission (from 585 to more than 850 nm) bands and a smaller optical HOMO-LUMO gap (2.01 eV). exo-PBC-Me formed polar crystals where all bowl-in-bowl stacking with close π ⋅ ⋅ ⋅ π contacts is arranged unidirectionally, providing the potential for applications as organic semiconductors and pyroelectric materials. This unusual structural feature, molecular packing, and properties are most likely associated with the assistance of the methyl group and the sp3 carbon atom in the backbone.

Prevention of acute exacerbation of chronic hepatitis B infection in cancer patients receiving chemotherapy in a hepatitis B virus endemic area.

UNLABELLED: Reactivation of hepatitis B viral (HBV) infection in cancer patients undergoing chemotherapy may cause interruption of chemotherapy and lead to liver failure and death. In our institute, a computerized order entry-based alert system was introduced in September 2011 to remind healthcare providers of HBV testing when prescribing chemotherapy. Since August 2012, an order entry-based therapeutic control system has been applied to ensure HBV prophylaxis during chemotherapy. This retrospective cohort study included cancer patients receiving chemotherapy in the Kaohsiung Veterans General Hospital from November 2009 to June 2013. The prechemotherapy HBV screening rate, HBV prophylactic rate, and severe HBV acute exacerbation rate were compared between stages with different order systems. Newly diagnosed cancer patients (n = 2512) were included. The HBV testing rate in the screening reminder stage was higher than that in the educational stage (93.5% versus 40.2%, P < 0.001), whereas the adequate HBV prophylactic rates in the two order entry-based stages were comparable (41.1% versus 39.2%). Patients in the order entry-based therapeutic control stage had a higher HBV screening rate (99.3% versus 40.2%, P < 0.001) and a higher HBV prophylactic rate (95.8% versus 39.2%, P < 0.001) than those in the educational stage. Additionally, the severe HBV acute exacerbation rate in the therapeutic control stage was lower than those in the educational and screening reminder stages (0% versus 1.2% and 1.2%, respectively; both P < 0.01). CONCLUSION: A computerized order entry-based therapeutic control system can provide excellent prechemotherapy HBV screening for cancer patients undergoing chemotherapy and can effectively prevent severe acute exacerbation of HBV infection in hospitals among HBV endemic areas.

Syntheses, Structural Analyses, and Properties of Condensed Arenes with Multihelicity.

A C1-symmetric hexapole helicene (HH) and a C3-symmetric dodecapole helicene (DH) were prepared, and their three-dimensional structures were verified by X-ray crystallography and density functional theory calculations. The molecular geometries and local helical configurations of their most stable diastereomers were correctly predicted by arranging suitable conformations of the peripheral aryl rings. Importantly, the outermost three [5]helicenes with a consistent configuration in DH were observed to increase the thermostability, enantiomerization barrier (ΔH⧧ = 40.5 kcal/mol), specific rotation ([α]24D = -4228°) and absorption dissymmetry factor (gabs = 1.35 × 10-3 at 453 nm).