Oxidation of Electron Donor-Substituted Verdazyls: Building Blocks for Molecular Switches.

Species that can undergo changes in electronic configuration as a result of an external stimulus such as pH or solvent polarity can play an important role in sensors, conducting polymers, and molecular switches. One way to achieve such structures is to couple two redox-active fragments, where the redox activity of one of them is strongly dependent upon environment. We report on two new verdazyls, one subsituted with a di-tert-butyl phenol group and the other with a dimethylaminophenyl group, that have the potential for such behavior upon oxidation. Oxidation of both verdazyls with copper(II) triflate in acetonitrile gives diamagnetic verdazylium ions characterized by NMR and UV-vis spectroscopies. Deprotonation of the phenol-verdazylium results in electron transfer and a switch from a singlet state to a paramagnetic triplet diradical identified by electron spin resonance. The dimethylaminoverdazylium 9 has a diamagnetic ground state, in line with predictions from simple empirical methods and supported by density functional theory calculations. These results indicate that verdazyls may complement nitroxides as spin carriers in the design of organic molecular electronics.

Structure-property relationships of stable free radicals: verdazyls with electron-rich aryl substituents.

Substitution of the 3 position of 6-oxoverdazyl free radicals with electron-rich arylamines, phenols, and aryl ethers elicits changes in the UV-vis spectra and in the pK(a) of the aryl substituents consistent with the verdazyl being electron withdrawing. The pK(a) of substituents is decreased: in 80% methanol phenols 3a and 3b have pK(a) of 10.4 and 10.9, respectively, while the ammonium ion from protonation of 3j has pK(a) = 2.4. On the basis of these measurements, Hammett parameters for the verdazyl have been estimated: sigma(p)(-) = +0.48 and sigma(m) = +0.27. The longest wavelength band in the visible spectrum is red-shifted with increasingly electron-rich aromatic rings and with increasingly polar solvents, consistent with a transition from the highest fully occupied orbital to the radical SOMO. Exceptions occur when additional interactions occur between verdazyl and substituent; hydrogen bonding in the case of 3c and steric interference for 3f. Measurements such as ESR and electrochemistry that are dependent largely on the SOMO are relatively insensitive to changes in substituent.

Behavioral medicine perspectives on the design of health information technology to improve decision-making, guideline adherence, and care coordination in chronic pain management.

Development of clinical decision support systems (CDSs) has tended to focus on facilitating medication management. An understanding of behavioral medicine perspectives on the usefulness of a CDS for patient care can expand CDSs to improve management of chronic disease. The purpose of this study is to explore feedback from behavioral medicine providers regarding the potential for CDSs to improve decision-making, care coordination, and guideline adherence in pain management. Qualitative methods were used to analyze semi-structured interview responses from behavioral medicine stakeholders following demonstration of an existing CDS for opioid prescribing, ATHENA-OT. Participants suggested that a CDS could assist with decision-making by educating providers, providing recommendations about behavioral therapy, facilitating risk assessment, and improving referral decisions. They suggested that a CDS could improve care coordination by facilitating division of workload, improving patient education, and increasing consideration and knowledge of options in other disciplines. Clinical decision support systems are promising tools for improving behavioral medicine care for chronic pain.

Natural language processing for lines and devices in portable chest x-rays.

Radiology reports are unstructured free text documents that describe abnormalities in patients that are visible via imaging modalities such as X-ray. The number of imaging examinations performed in clinical care is enormous, and mining large repositories of radiology reports connected with clinical data such as patient outcomes could enable epidemiological studies, such as correlating the frequency of infections to the presence or length of time medical devices are present in patients. We developed a natural language processing (NLP) system to recognize device mentions in radiology reports and information about their state (insertion or removal) to enable epidemiological research. We tested our system using a reference standard of reports that were annotated to indicate this information. Our system performed with high accuracy (recall and precision of 97% and 99% for device mentions and 91-96% for device insertion status). Our methods are generalizable to other types of radiology reports as well as to other information extraction tasks and could provide the foundation for tools that enable epidemiological research exploration based on mining radiology reports.