Corrigendum to “Synthesis and anodic electrochemistry of cymanquine and related complexes” [J. Organomet. Chem. 817 (15 August 2016) 15–20]

The authors regret that the oxidation potentials given for compound 5 in the paper are incorrect. The correct values, referenced to ferrocene, are 0.88 V for the first oxidation and 1.14 V for the second oxidation

Synthesis, Characterization, and Molecular Structure of Bis(tetraphenylcyclopentdienyl)rhodium(II)⊗

A 5 day diglyme reflux of Rh(acac)3 and K(C5HPh4), followed by treatment with aqueous HPF6, produces orange-yellow [(C5HPh4)2Rh]PF66 in 40 - 50% yield. Reduction of [(C5HPh4)2Rh]PF6 with sodium amalgam in THF yields olive green (C5HPh4)2Rh in 70% yield. (C5HPh4)2Rh crystallizes in the triclinic [Error : unloaded OLE object or mail attachment]space group with unit-cell parameters of a = 8.622 (3) Å, b = 10.778 (4) Å, c = 12.894 (5) Å, a = 65.58 (3)°, b = 72.66 (3)°, g = 83.52 (3)°, and Z = 1. The least squares data refined to RF = 7.63% and RwF = 10.12% for the 2479 independent observed reflections with Fo \u3e 5s(Fo ). The metal-centroid distance is 1.904 Å and all other bond lengths and angles are similar to known octaphenylmetallocenes. ESR spectra of (C5HPh4)2Rh in low-temperature glasses display a rhombic g-tensor with resolution of Rh hyperfine splitting on one-g-component. Analysis of the spectral parameters is consistent with a d7 configuration derived from a nearly degenerate dxz, dyz ground state. Voltammetry and coulometry establish the electron-transfer series (C5HPh4)2Rh1+/0/1- with E° values of -1.44 V and -2.13 V vs ferrocene. The heterogeneous charge transfer rate of the second reduction is about three orders of magnitude lower than that of the first

Anodic oxidation of ethynylferrocene derivatives in homogeneous solution and following anodic deposition onto glassy carbon electrodes

Eight ferrocene derivatives linked by either an ether, amine, or phenylacetylene moiety to a terminal ethynyl group were covalently deposited on glassy carbon electrodes by anodic electrochemical methods. The lithio activation method, in which the terminal hydrogen of the ethynyl group is replaced by a lithium atom before anodic oxidation, was successfully employed in all cases. Direct oxidation of the unactivated ethynyl group also resulted in surface deposition. Surface coverages between 1 x 10 ‐10 mol cm ‐2 and 14 x 10 ‐10 mol cm ‐2 were achieved. Cyclic voltammetry scans of the modified electrodes in pure electrolytes differed depending on the size of the supporting electrolyte anion, as little as half the current being measured for a [B(C 6 F 5 ) 4 ] ‐ vs. [PF 6 ] ‐ solution, suggesting differences in ion transport near the electrode surface. An ether‐linked ethynylferrocenium ion ( 5 + ) was isolated after electrolytic and chemical oxidation of 5 and characterized by X‐Ray crystallography as its [SbCl 6 ] ‐ salt

Synthesis, Characterization, and Crystal Structure of the (η5-C5Ph5)Cr(CO)3 Radical

The reaction between Cr(CO)6 and Na(C5Ph5 ) in refluxing diglyme yields [Na(diglyme)3/2][(C5Ph5)Cr(CO)3], 1. Metathesis of 1 with [Ph3P=N=PPh3 ]Cl in CH2Cl2 yields [Ph3P=N=PPh3][(C5Ph5)Cr(CO)3], 2. Oxidation of 1 by AgBF4 in cold THF under an argon atmosphere produces (C5Ph5)Cr(CO)3, 3. Complexes 2 and 3 form a redox pair connected by a quasireversible one-electron process, E0 = -0.69 V vs ferrocene in CH2Cl2, E0 = -0.50 V in CH3CN, ks = 0.12 cm/s. ESR spectra of (C5Ph5)Cr(CO)3 in toluene at 90 K gave a rhombic g-tensor with components 2.1366, 2.0224, and 1.9953, consistent with the expected low-spin d5 electronic configuration. The largest g-tensor component was significantly temperature dependent, suggesting an equilibrium between conformations with 2A´ and 2A˝ ground states. Crystal structures of [Ph3P=N=PPh3][(C5Ph5)Cr(CO)3] and (C5Ph5)Cr(CO)3 were obtained

URBAN WOOD/COAL CO-FIRING IN THE NIOSH BOILERPLANT

During the third quarter, the experimental portion of the project was carried out. Three one-day tests using wood/coal blends of 33% wood by volume (both construction wood and demolition wood) were conducted at the NIOSH Boiler Plant (NBP). Blends using hammer-milled wood were operationally successful and can form the basis of Phase II. Emissions of SO{sub 2} and NOx decreased and that of CO increased when compared with combusting coal alone. Mercury emissions were measured and the mathematical modeling of mercury speciation reactions continued, yielding many interesting results. Material and energy balances for the test periods at the NBP, as well as at the Bellefield Boiler Plant, were prepared. Steps were taken to remove severe constraints from the Pennsylvania Switchgrass Energy and Conservation Project and to organize the supplying of landfill gas to the Bruceton federal complex. Two presentations were made to meetings of the Electric Power Research Institute and the National Energy Technology Laboratory

Specificity of Clinical Breast Examination in Community Practice

BACKGROUND: Millions of women receive clinical breast examination (CBE) each year, as either a breast cancer screening test or a diagnostic test for breast symptoms. While screening CBE had moderately high specificity (∼94%) in clinical trials, community clinicians may be comparatively inexperienced and may conduct relatively brief examinations, resulting in even higher specificity but lower sensitivity. OBJECTIVE: To estimate the specificity of screening and diagnostic CBE in clinical practice and identify patient factors associated with specificity. DESIGN: Retrospective cohort study. SUBJECTS: Breast-cancer-free female health plan enrollees in 5 states (WA, OR, CA, MA, and MN) who received CBE (N = 1,484). MEASUREMENTS: Medical charts were abstracted to ascertain breast cancer risk factors, examination purpose (screening vs diagnostic), and results (true-negative vs false-positive). Women were considered “average-risk” if they had neither a family history of breast cancer nor a prior breast biopsy and “increased-risk” otherwise. RESULTS: Among average- and increased-risk women, respectively, the specificity (true-negative proportion) of screening CBE was 99.4% [95% confidence interval (CI): 98.8–99.7%] and 97.1% (95% CI: 95.7–98.0%), and the specificity of diagnostic CBE was 68.7% (95% CI: 59.7–76.5%) and 57.1% (95% CI: 51.1–63.0%). The odds of a true-negative screening CBE (specificity) were significantly lower among women at increased risk of breast cancer (adjusted odds ratio 0.21; 95% CI: 0.10–0.46). CONCLUSIONS: Screening CBE likely has higher specificity among community clinicians compared to examiners in clinical trials of breast cancer screening, even among women at increased breast cancer risk. Highly specific examinations, however, may have relatively low sensitivity for breast cancer. Diagnostic CBE, meanwhile, is relatively nonspecific

Measurement of Angular Distributions and R= sigma_L/sigma_T in Diffractive Electroproduction of rho^0 Mesons

Production and decay angular distributions were extracted from measurements of exclusive electroproduction of the rho^0(770) meson over a range in the virtual photon negative four-momentum squared 0.5< Q^2 <4 GeV^2 and the photon-nucleon invariant mass range 3.8< W <6.5 GeV. The experiment was performed with the HERMES spectrometer, using a longitudinally polarized positron beam and a ^3He gas target internal to the HERA e^{+-} storage ring. The event sample combines rho^0 mesons produced incoherently off individual nucleons and coherently off the nucleus as a whole. The distributions in one production angle and two angles describing the rho^0 -> pi+ pi- decay yielded measurements of eight elements of the spin-density matrix, including one that had not been measured before. The results are consistent with the dominance of helicity-conserving amplitudes and natural parity exchange. The improved precision achieved at 47 GeV, reveals evidence for an energy dependence in the ratio R of the longitudinal to transverse cross sections at constant Q^2.Comment: 15 pages, 15 embedded figures, LaTeX for SVJour(epj) document class Revision: Fig. 15 corrected, recent data added to Figs. 10,12,14,15; minor changes to tex

Determination of the Deep Inelastic Contribution to the Generalised Gerasimov-Drell-Hearn Integral for the Proton and Neutron

The virtual photon absorption cross section differences [sigma_1/2-sigma_3/2] for the proton and neutron have been determined from measurements of polarised cross section asymmetries in deep inelastic scattering of 27.5 GeV longitudinally polarised positrons from polarised 1H and 3He internal gas targets. The data were collected in the region above the nucleon resonances in the kinematic range nu < 23.5 GeV and 0.8 GeV**2 < Q**2 < 12 GeV**2. For the proton the contribution to the generalised Gerasimov-Drell-Hearn integral was found to be substantial and must be included for an accurate determination of the full integral. Furthermore the data are consistent with a QCD next-to-leading order fit based on previous deep inelastic scattering data. Therefore higher twist effects do not appear significant.Comment: 6 pages, 3 figures, 1 table, revte

Cell-selective labeling using amino acid precursors for proteomic studies of multicellular environments.

We report a technique to selectively and continuously label the proteomes of individual cell types in coculture, named cell type-specific labeling using amino acid precursors (CTAP). Through transgenic expression of exogenous amino acid biosynthesis enzymes, vertebrate cells overcome their dependence on supplemented essential amino acids and can be selectively labeled through metabolic incorporation of amino acids produced from heavy isotope-labeled precursors. When testing CTAP in several human and mouse cell lines, we could differentially label the proteomes of distinct cell populations in coculture and determine the relative expression of proteins by quantitative mass spectrometry. In addition, using CTAP we identified the cell of origin of extracellular proteins secreted from cells in coculture. We believe that this method, which allows linking of proteins to their cell source, will be useful in studies of cell-cell communication and potentially for discovery of biomarkers