Preparation, Characterization, and Electrochemical Activation of a Model [Cp*Rh] Hydride

This document is the Accepted Manuscript version of a Published Work that appeared in final form in Inorganic Chemistry, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://doi.org/10.1021/acs.inorgchem.8b02160.Monomeric half-sandwich rhodium hydride complexes are often proposed as intermediates in catalytic cycles, but relatively few such compounds have been isolated and studied, limiting understanding of their properties. Here, we report preparation and isolation of a monomeric rhodium(III) hydride complex bearing the pentamethylcyclopentadienyl (Cp*) and bis(diphenylphosphino)benzene (dppb) ligands. The hydride complex is formed rapidly upon addition of weak acid to a reduced precursor complex, Cp*Rh(dppb). Single-crystal X-ray diffraction data for the [Cp*Rh] hydride, which were previously unavailable for this class of compounds, provide evidence of the direct Rh–H interaction. Complementary infrared spectra show the Rh–H stretching frequency at 1986 cm−1. In contrast to results with other [Cp*Rh] complexes bearing diimine ligands, treatment of the isolated hydride with strong acid does not result in H2 evolution. Electrochemical studies reveal that the hydride complex can be reduced only at very negative potentials (ca. −2.5 V vs. ferrocenium/ferrocene), resulting in Rh–H bond cleavage and H2 generation. These results are discussed in the context of catalytic H2 generation, and development of design rules for improved catalysts bearing the [Cp*] ligand.University of Kansas Undergraduate Research AwardS10OD016360S10RR024664NSF MRI Grant CHE-162592

Efficacy of adalimumab as second-line therapy in a pediatric cohort of crohn’s disease patients who failed infliximab therapy: The Italian society of pediatric gastroenterology, hepatology, and nutrition experience

Background: Adalimumab (Ada) treatment is an available option for pediatric Crohn’s disease (CD) and the published experience as rescue therapy is limited. Objectives: We investigated Ada efficacy in a retrospective, pediatric CD cohort who had failed previous infliximab treatment, with a minimum follow-up of 6 months. Methods: In this multicenter study, data on demographics, clinical activity, growth, laboratory values (CRP) and adverse events were collected from CD patients during follow-up. Clinical remission (CR) and response were defined with Pediatric CD Activity Index (PCDAI) score ≤10 and a decrease in PCDAI score of ≥12.5 from baseline, respectively. Results: A total of 44 patients were consecutively recruited (mean age 14.8 years): 34 of 44 (77%) had active disease (mean PCDAI score 24.5) at the time of Ada administration, with a mean disease duration of 3.4 (range 0.3–11.2) years. At 6, 12, and 18 months, out of the total of the enrolled population, CR rates were 55%, 78%, and 52%, respectively, with a significant decrease in PCDAI scores (P<0.01) and mean CRP values (mean CRP 5.7 and 2.4 mL/dL, respectively; P<0.01) at the end of follow-up. Steroid-free remission rates, considered as the total number of patients in CR who were not using steroids at the end of this study, were 93%, 95%, and 96% in 44 patients at 6, 12, and 18 months, respectively. No significant differences in growth parameters were detected. In univariate analysis of variables related to Ada efficacy, we found that only a disease duration >2 years was negatively correlated with final PCDAI score (P<0.01). Two serious adverse events were recorded: 1 meningitis and 1 medulloblastoma. Conclusion: Our data confirm Ada efficacy in pediatric patients as second-line biological therapy after infliximab failure. Longer-term prospective data are warranted to define general effectiveness and safety in pediatric CD patients

Side Effects of Human Drug Use: An Overview of the Consequences of Eels’ Exposure to Cocaine

The widespread use of drugs is a global problem which affects not only humans but also the environment around them, as research is showing the presence of these substances in different environmental matrices, like air, water, and soil. Above all, due to the remarkable pharmacological properties of drugs, it is discovered that organisms accidentally exposed to them, as aquatic organisms, undergo behavioral and physiological changes that can compromise their health, survival, and reproduction ability. In addition to this, we must consider the ability of some drugs to accumulate within these organisms, thus entering the food chain, and the possible interactions that drugs in water can establish with each other and with other possible pollutants, making the final effects on exposed organisms unpredictable. This article is an overview of the effects of one of these drugs, cocaine, one of the drugs commonly found in the aquatic environment, on European eel, an endangered species and known biomonitor of aquatic contaminatio

Single-Electron Redox Chemistry on the [Cp*Rh] Platform Enabled by a Nitrated Bipyridyl Ligand

This work is licensed under a Creative Commons Attribution 4.0 International License.[Cp*Rh] complexes (Cp* = pentamethylcyclopentadienyl) are attracting renewed interest in coordination chemistry and catalysis, but these useful compounds often undergo net two-electron redox cycling that precludes observation of individual one-electron reduction events. Here, we show that a [Cp*Rh] complex bearing the 4,4′-dinitro-2,2′-bipyridyl ligand (dnbpy) (3) can access a distinctive manifold of five oxidation states in organic electrolytes, contrasting with prior work that found no accessible reductions in aqueous electrolyte. These states are readily generated from a newly isolated and fully characterized rhodium(III) precursor complex 3, formulated as [Cp*Rh(dnbpy)Cl]PF6. Single-crystal X-ray diffraction (XRD) data, previously unavailable for the dnbpy ligand bound to the [Cp*Rh] platform, confirm the presence of both [η5-Cp*] and [κ2-dnbpy]. Four individual one-electron reductions of 3 are observed, contrasting sharply with the single two-electron reductions of other [Cp*Rh] complexes. Chemical preparation and the study of the singly reduced species with electronic absorption and electron paramagnetic resonance spectroscopies indicate that the first reduction is predominantly centered on the dnbpy ligand. Comparative cyclic voltammetry studies with [NBu4][PF6] and [NBu4][Cl] as supporting electrolytes indicate that the chloride ligand can be lost from 3 by ligand exchange upon reduction. Spectroelectrochemical studies with ultraviolet (UV)-visible detection reveal isosbestic behavior, confirming the clean interconversion of the reduced forms of 3 inferred from the voltammetry with [NBu4][PF6] as supporting electrolyte. Electrochemical reduction in the presence of triethylammonium results in an irreversible response, but does not give rise to catalytic H2 evolution, contrasting with the reactivity patterns observed in [Cp*Rh] complexes bearing bipyridyl ligands with less electron-withdrawing substituents.US National Science Foundation award OIA-1833087KU Hall Chemical Research FundCenter for Undergraduate Research at the University of KansasNIH S10OD016360NIH S10RR024664NSF MRI funding (CHE-1625923

Impact of diet in shaping gut microbiota revealed by a comparative study in children from Europe and Rural Africa

peer reviewe

Improving the Measurement of Environmental Sensitivity in Children and Adolescents: The Highly Sensitive Child Scale-21 Item Version

Children differ in their sensitivity to positive and negative environmental influences, which can be measured with the Highly Sensitive Child (HSC) scale. The present study introduces the HSC-21, an adaptation of the original 12 item scale with new items and factor structure that are meant to be more informative than the original ones. The psychometric properties of the HSC-21 were investigated in 1,088 children across Belgium and the Netherlands, including child and mother reports. Results showed evidence for (a) bifactor model with a general sensitivity factor and two specific factors (i.e., Ease of Excitation–Low Sensory Threshold and Aesthetic Sensitivity); (b) (partial) measurement invariance across gender, developmental stage, country, and informants; (c) moderate child–mother agreement; (d) good reliability; (e) normally distributed item scores; and (f) meaningful associations with personality and temperament across both samples. No evidence was found for HSC-21 as a moderator in the relationship between parenting and problem behaviors

Precision NNLO determination of alpha_s(M_Z) using an unbiased global parton set

We determine the strong coupling alpha_s at NNLO in perturbative QCD using the global dataset input to the NNPDF2.1 NNLO parton fit: data from neutral and charged current deep-inelastic scattering, Drell-Yan, vector boson production and inclusive jets. We find alpha_s(M_Z)=0.1173+- 0.0007 (stat), where the statistical uncertainty comes from the underlying data and uncertainties due to the analysis procedure are negligible. We show that the distribution of alpha_s values preferred by different experiments in the global fit is statistically consistent, without need for rescaling uncertainties by a "tolerance" factor. We show that if deep-inelastic data only are used, the best-fit value of alpha_s is somewhat lower, but consistent within one sigma with the global determination. We estimate the dominant theoretical uncertainty, from higher orders corrections, to be Delta alpha_s (pert) ~ 0.0009.Comment: 11 pages, 6 figures. Various small corrections and improvements: Chi2 values for PDF fits provided, discussion of pulls clarified. Final version, to be published in Phys.Lett.