Quantum chemistry computations with a semicontinuum (cluster + continuum) solvation model have been used to cure long-standing misprediction of aqueous carbamate anion energies in the industrially important CO2 + aqueous amine reaction. Previous errors of over 10 kcal mol(-1) are revealed. Activation energies were also estimated with semicontinuum modeling, and a refined discussion of the competing hypothetical mechanisms for CO2 + monoethanolamine (MEA) is presented. Further results are also presented to demonstrate that the basicity of an amine (aqueous proton affinity) correlates only with CO2 affinity within an amine class: secondary amines have an extra CO2 affinity that primary amines do not have.

The role of protonated cyclopropane (PCP(+)) structures in carbocation rearrangement is a decades-old topic that continues to confound. Here, quantum-chemical computations (PBE molecular dynamics, PBE and CCSD optimizations, CCSD(T) energies) are used to resolve the issue. PCP(+) intermediates are neither edge-protonated nor corner-protonated (normally) but possess "closed" structures mesomeric between these two. An updated mechanism for hexyl ion rearrangement is presented and shown to resolve past mysteries from isotope-labeling experiments. A new table of elementary-step barrier heights is provided. The mechanism and barrier heights should be useful in understanding and predicting product distributions in organic reactions, including petroleum modification.

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Computational chemistry, with considerable effort, was used to elucidate the reason for regioselectivity (12:1 distal:proximal product distribution) in a published Wacker oxidation of internal alkenes with a homoallylic lactam ring. Such a distribution is reproduced by a non-chelating reaction pathway; chelated intermediates are found to be too high in energy. Despite much speculation of chelation effects in the literature, this particular result is most probably an antiperiplanar field effect with no chelation. Partial charge data is provided to support the proposed antiperiplanar effect. The great care needed in modelling Wacker oxidations is emphasized, but optimism is offered that its various product mysteries can be elucidated on a case-by-case basis.

Quality management is of the utmost importance for providing the best patient care in our healthcare system. Patients rightfully expect the care that they receive to be of sound quality. The medical autopsy has been used as the gold standard of diagnostic medicine and continues to provide insights into strategies for healthcare quality improvement. The discordance and concordance rates between autopsy and clinical diagnoses have been used to identify areas of improvement and provide education opportunities to healthcare professionals. Discordance between autopsy and clinical diagnoses has revealed several areas in which clinicians need to improve their diagnostic skills and implement systemic changes to detect and mitigate diagnostic errors. Unfortunately, the rate of hospital autopsies has declined over the past several decades. The purpose of this study was to expand our previous work and combine the analyses of discordance and concordance between autopsy and clinical diagnoses across a 10-year period from 2002 to 2011 and to assess the role of the medical autopsy as a quality improvement tool in modern healthcare systems. Within our study, the autopsy rate of all in-patient deaths was approximately 6%. Our study indicates that the concordance rate between clinical and autopsy diagnoses was 77.5%, the discordance rate was 19.4%, and 3.1% were inconclusive. The discordance rate varied from as low as 9.7% in 2007 to as high as 27.1% in 2002. These findings suggest that overall, approximately 1 in 5 autopsies revealed discordance between autopsy and clinical diagnoses. This is a significant number of cases for which there exists both quality improvement and educational opportunities, thus, supporting the continued use of autopsy. We suggest these data should be used to encourage residents and physicians to continue using autopsy as an important quality tool to extend our understanding of disease processes. Hospital autopsies are closely associated with quality improvement and better patient care.