Tailored Monolayers of N-Heterocyclic Carbenes by Kinetic Control.

Despite the substantial success of N-heterocyclic carbenes (NHCs) as stable and versatile surface modification ligands, their use in nanoscale applications beyond chemistry is still hampered by the failure to control the carbene binding mode, which complicates the fabrication of monolayers with the desired physicochemical properties. Here, we applied vibrational sum-frequency generation spectroscopy to conduct a pseudokinetic surface analysis of NHC monolayers on Au thin films under ambient conditions. We observe for two frequently used carbene structures that their binding mode is highly dynamic and changes with the adsorption time. In addition, we demonstrate that this transition can be accelerated or decelerated to adjust the binding mode of NHCs, which allows fabrication of tailored monolayers of NHCs simply by kinetic control.

Influence of interfacial water and cations on the oxidation of CO at the platinum/ionic liquid interface.

CO oxidation is fundamental to the development of new catalyst materials for fuel cells and key for complete oxidation of small alcohols like methanol or ethanol on Pt catalysts. So far, room-temperature ionic liquids (RTIL) have been used to modify the selectivity and activity in electrocatalysis. In order to understand the mechanism of CO oxidation in RTIL in more detail we have investigated this reaction at the Pt(111)/1-butyl-3-methylimidazolium trifluorosulfonylimide [BMIM][NTf2] electrode/electrolyte interface as a function of H2O concentration and electrode potential with in situ sum-frequency generation (SFG) spectroscopy and infrared absorption spectroscopy (IRAS). Using SFG spectroscopy, we address the changes of linearly bonded CO molecules on Pt(111), while we monitor the changes in the bulk electrolyte with IRAS through vibrational bands from H2O, CO2 and CO. The presence of water in [BMIM][NTf2] shifts the onset potential for CO oxidation by more than 200 mV when the water concentration is increased from 0.01 to 1.5 M, which we relate to the incorporation and the availability of water at the electrode/electrolyte interface. The nature of the RTIL cation has also a large effect on the surface excess of H2O since RTILs like [BMMIM][NTf2] and [BMPyrr][NTf2] which are prone to form closed-packed structures, can block the incorporation of water and lead to more sluggish CO oxidation with larger overpotentials and oxidation in a much wider potential range for which we provide evidence by additional SFG measurements. These results clearly show that the choice of the RTIL is important for CO oxidation on Pt(111) electrode surfaces - an observation that is likely highly relevant also to other catalysts and catalytic reactions that require the presence of interfacial water.

Somatic Experiencing for Posttraumatic Stress Disorder: A Randomized Controlled Outcome Study.

This study presents the first known randomized controlled study evaluating the effectiveness of somatic experiencing (SE), an integrative body-focused therapy for treating people with posttraumatic stress disorder (PTSD). There were 63 participants meeting DSM-IV-TR full criteria for PTSD included. Baseline clinical interviews and self-report measures were completed by all participants, who were then randomly assigned to study (n = 33) or waitlist (n = 30) groups. Study participants began 15 weekly SE sessions, whereas waitlist participants waited the same period, after which the second evaluation was conducted. All participants were evaluated a third time after an additional 15 weeks, during which time the waitlist group received SE therapy. Pretreatment evaluation showed no significant differences between groups. Mixed model linear regression analysis showed significant intervention effects for posttraumatic symptoms severity (Cohen's d = 0.94 to 1.26) and depression (Cohen's d = 0.7 to 1.08) both pre-post and pre-follow-up. This randomized controlled study of SE shows positive results indicating SE may be an effective therapy method for PTSD. Further research is needed to understand who shall benefit most from this treatment modality.

Composite ganglioneuroma-paraganglioma of the filum terminale.

Extraadrenal paragangliomas are most commonly found in the carotid body and are also found with lower frequency in the CNS. These lesions are derived from the sympathoadrenal lineage of neural crest cells. Here, the authors report a rare case of a composite paraganglioma with ganglioneuromatous components found at the filum terminale in a patient who presented with a brief history of low-back pain and paresthesias in the inguinal region. Immunohistochemical analysis of the resected lesion revealed admixed elements of neuroendocrine and neuroblastoma lineages, indicating the presence of divergent differentiation of sympathoadrenal progenitor cells. This case represents a unique opportunity to understand the cell fate of sympathoadrenal progenitor cells. Here, the authors propose that paragangliomas at the filum terminale can revert to a neural crest cell precursor fate, giving rise to divergent neoplastic populations.