13,592 research outputs found

    Insight into Solvent Coordination of an Iron Porphyrin Hydroxylamine Complex from Spectroscopy and DFT Calculations

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    The reduction of Fe(OEP)(NO) in the presence of substituted phenols leads to a three‐electron reduction to form Fe(OEP)(NH2OH), which has been characterized by visible spectroscopy and electron stoichiometry. In this work, we have further characterized this species using infrared and 1H NMR spectroscopy, along with DFT calculations. The infrared bands in the 3400–3600 cm–1 region, due to hydroxylamine, were significantly downshifted to the 2500–2700 cm–1 region when 4‐[D1]chlorophenol replaced the normal abundance acid. Using 1H NMR spectroscopy, the hydroxylamine and the meso‐protons were identified. From DFT calculations, the 1H NMR spectra were most consistent with a six‐coordinate complex, Fe(OEP)(NH2OH)(THF)

    Redox and Spectroscopic Properties of Iron Porphyrin Nitroxyl in the Presence of Weak Acids

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    The spectroelectrochemistry and voltammetry of Fe(OEP) (NO) in the presence of substituted phenols was studied. Cyclic voltammetry showed that two closely spaced waves were observed for the reduction of Fe(OEP) (NO) in the presence of substituted phenols. The first wave was a single electron reduction under voltammetric conditions. The second wave was kinetically controlled, multielectron process. Visible spectroelectrochemistry of Fe(OEP) (NO) in the presence of substituted phenols showed that three species were present during the electrolysis. Additional spectroscopic studies indicated that the two reduction species were Fe(OEP) (HNO) and Fe(OEP)(H2NOH). The Fe(OEP) (HNO) species, which can be generated chemically, was stable over a period of hours. Additional acid did not lead to further protonation. Proton NMR spectroscopy confirmed the Fe(OEP) (HNO) species could be deprotonated under basic conditions. The third species, Fe(OEP)(H2NOH), was generated by the further reduction of the chemically generated Fe(OEP) (HNO) complex. Both the Fe(OEP) (HNO) and Fe(OEP)(H2NOH) complexes could be slowly oxidized back to Fe(OEP) (NO). At millimolar concentrations of Fe(OEP) (HNO), there was no evidence for the disproportionation of Fe(OEP) (HNO) to Fe(OEP) (NO) and H2 in the presence of substituted phenols. Nor was there evidence for the generation of N2O. The FTIR spectroelectrochemistry showed changes in the infrared spectra in the presence of substituted phenols, but no isotopic sensitive bands were observed for the reduced species between 1450 and 1200 cm–1. This may be because the νNO band shifted into a region (1500–1450 cm–1) where it would be difficult to observe

    Abdominal intercostal hernia: a rare complication after blunt trauma.

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    Abdominal intercostal hernia (AIH) is uncommonly reported in the literature with only 20 cases reported to date.1–3 We report a case of a delayed incarcerated AIH secondary to blunt trauma from a motor vehicle accident in which the colon and diaphragm herniated through an associated chest defect that was repaired successfully through a transabdominal approach using primary repair of the defect in combination with onlay porcine patch reinforcement

    Collaborative Caring: Stories and Reflections on Teamwork in Health Care

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    [Excerpt] There are many theoretical and conceptual books and countless articles that have explored issues of teamwork in general and teamwork in health care in particular. The editors, and many of the authors in this book, have read most, and have even written some of them. To tackle the issue of teamwork, we have, however, taken a different approach. Rather than write a theoretical book about what teamwork is, what it is not, where it exists in health care, what barriers prevent its implementation and how they can be removed, we have chosen instead to address these questions through narratives and reflections that vividly describe good teamwork as well as problems in creating, leading, and working on genuine teams. What we believe is too often lacking in the literature is a clear and compelling picture of what teamwork looks like on the ground, in the institutions where health care work is delivered and where teams play well, or don\u27t play well, on a daily basis. The question we ask here is thus: What is the state of play in most health care institutions? To describe the state of play, we have asked clinicians to write what we think of as where the rubber hits the road stories or reflections about the nature of teamwork in their own particular work setting. To gather these stories, we talked to many people in different health care disciplines. In the invitation for submissions we wrote the following: We are seeking short, concise narratives that describe a concrete example in which you personally have been involved. The idea here is not to focus so much on the individual doctor-patient, nurse-patient, therapist-patient communication but the teamwork that was involved in ensuring that the standard of care was met or exceeded. If the patient or family was involved, so much the better. Stories can deal with interprofessional or intraprofessional teamwork. On balance, we would prefer to have more stories about interprofessional or occupational teamwork. Nonetheless, we recognize that interprofessional work depends on the ability to create teamwork within an occupation or profession. Stories involving support staff, such as housekeepers who spoke up about a patient safety issue, are definitely within the purview of this book. We would also welcome personal reflections that would enhance our understanding of either how to produce genuine teamwork or the obstacles that stand in its way

    Recurrence of Ganglion Cysts Following Re-excision

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    Previous studies have examined the recurrence of ganglion cysts after surgical excision at a rate of 4 to 40%. However, recurrence after revision surgical excision is unknown. The purpose of this study was to define the incidence of recurrent ganglion cysts in patients who underwent a 2nd excisional procedure.https://jdc.jefferson.edu/cwicposters/1032/thumbnail.jp

    Structural and electronic properties of Si/Ge nanoparticles

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    Results of a theoretical study of the electronic properties of (Si)Ge and (Ge)Si core/shell nanoparticles, homogeneous SiGe clusters, and Ge|Si clusters with an interphase separating the Si and Ge atoms are presented. In general, (Si)Ge particles are more stable than (Ge)Si ones, and SiGe systems are more stable than Ge|Si ones. It is found that the frontier orbitals, that dictate the optical properties, are localized to the surface, meaning that saturating dangling bonds on the surface with ligands may influence the optical properties significantly. In the central parts we identify a weak tendency for the Si atoms to accept electrons, whereas Ge atoms donate electrons.Comment: To appear in Phys. Rev.

    Catalytic Reduction of Bisulfite by Myoglobin/Surfactant Films

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    The voltammetry of bisulfite at a film formed with myoglobin was studied in aqueous solutions. A broad wave was observed for the reduction of bisulfite. Using controlled potential electrolysis, the reduction at potentials positive of the FeII/FeIwave formed dithionite exclusively. As the potential approached the region for the FeII/FeI reduction, bisulfite was reduced primarily to HS−. Even at the negative potentials, some dithionite was still formed, which could then be electrochemically reduced to thiosulfate. Analysis of the formation of HS−, dithionite and thiosulfate during the electrolysis was consistent with the parallel formation of HS−and dithionite, the latter of which was reduced to thiosulfate. Thiosulfate was verified by chemical analysis of the products from controlled potential electrolysis of the solution, and dithionite was observed spectroscopically using spectroelectro−chemistry
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