Dianions from Cyclophanes with Unsaturated Bridges; Cyclic Conjugation in 22-38 n-Electron Perimeter Systems

A series of. new c:yclophanes with unsaturated bridges, formally containing it-systems with 18-48 it-electrons was synthesized. Several of these cyclophanes containing 4n perimeters can be reversibly reduced to their dianions with 4n + 2 perimeters. This reversible two-electron process can conveniently be studied by cyclic voltammetry. The electrochemical data reveal a chemically significant difference between the neutral 4n and 4n+2 systems even for large n. A good correlation between calculated energies of the LUMO orbitals and the reversible reduction potentials has been obtained. Recent theories of resonance energies in neutral molecules and dianions with conjugated perimeters have been tested. The question whether resonance energies or more simply the frontier orbitals should be used to rationalize the behavior of the cyclophanes and their dianions is discussed

Hydroxyl as a Tracer of H2 in the Envelope of MBM40

We observed 51 positions in the OH 1667 MHz main line transitions in the translucent, high latitude cloud MBM40. We detected OH emission in 8 out of 8 positions in the molecular core of the cloud and 24 out of 43 in the surrounding, lower extinction envelope and periphery of the cloud. Using a linear relationship between the integrated OH line intensity and E(B-V), we estimate the mass in the core, the envelope, and the periphery of the cloud to be 4, 8, and 5 solar masses. As much as a third of the total cloud mass may be found in the in the periphery (E(B-V) $<$ 0.12 mag) and about a half in the envelope (0.12 $\le$ E(B-V) $\le$ 0.17 mag). If these results are applicable to other translucent clouds the OH 1667 MHz line is an excellent tracer of gas in very low extinction regions and high-sensitivity mapping of the envelopes of molecular clouds may reveal the presence of significant quantities of molecular mass.Comment: 26 pages, 3 figures, and 5 table

Mobius n-Systems; Links Between Small Cyclic and Large Linear n-Systems

It is found that within the framework of Huckel theory, the\u27 frontier orbital gap in a polymer with an extended n-system, built from simple repeating uni.ts, is the same as that of the reapiting unit closed onto itself to give a ring of either Huckel or Mobius topolog

Subdiffusion and lateral diffusion coefficient of lipid atoms and molecules in phospholipid bilayers

We use a long, all-atom molecular dynamics (MD) simulation combined with theoretical modeling to investigate the dynamics of selected lipid atoms and lipid molecules in a hydrated diyristoyl-phosphatidylcholine (DMPC) lipid bilayer. From the analysis of a 0.1 $\mu$s MD trajectory we find that the time evolution of the mean square displacement, [\delta{r}(t)]^2, of lipid atoms and molecules exhibits three well separated dynamical regions: (i) ballistic, with [\delta{r}(t)]^2 ~ t^2 for t < 10 fs; (ii) subdiffusive, with [\delta{r}(t)]^2 ~ t^{\beta} with \beta<1, for 10 ps < t < 10 ns; and (iii) Fickian diffusion, with [\delta{r}(t)]^2 ~ t for t > 30 ns. We propose a memory function approach for calculating [\delta{r}(t)]^2 over the entire time range extending from the ballistic to the Fickian diffusion regimes. The results are in very good agreement with the ones from the MD simulations. We also examine the implications of the presence of the subdiffusive dynamics of lipids on the self-intermediate scattering function and the incoherent dynamics structure factor measured in neutron scattering experiments.Comment: Submitted to Phys. Rev.

Dianions from Cyclophanes with Unsaturated Bridges; Cyclic Conjugation in 22-38 n-Electron Perimeter Systems

A series of. new c:yclophanes with unsaturated bridges, formally containing it-systems with 18-48 it-electrons was synthesized. Several of these cyclophanes containing 4n perimeters can be reversibly reduced to their dianions with 4n + 2 perimeters. This reversible two-electron process can conveniently be studied by cyclic voltammetry. The electrochemical data reveal a chemically significant difference between the neutral 4n and 4n+2 systems even for large n. A good correlation between calculated energies of the LUMO orbitals and the reversible reduction potentials has been obtained. Recent theories of resonance energies in neutral molecules and dianions with conjugated perimeters have been tested. The question whether resonance energies or more simply the frontier orbitals should be used to rationalize the behavior of the cyclophanes and their dianions is discussed

Magnetization transfer in lamellar liquid crystals

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109294/1/mrm25034.pd

Universal reduction of pressure between charged surfaces by long-wavelength surface charge modulation

We predict theoretically that long-wavelength surface charge modulations universally reduce the pressure between the charged surfaces with counterions compared with the case of uniformly charged surfaces with the same average surface charge density. The physical origin of this effect is the fact that surface charge modulations always lead to enhanced counterion localization near the surfaces, and hence, fewer charges at the midplane. We confirm the last prediction with Monte Carlo simulations.Comment: 8 pages 1 figure, Europhys. Lett., in pres

Case Study of Resilient Baton Rouge: Applying Depression Collaborative Care and Community Planning to Disaster Recovery.

BackgroundAddressing behavioral health impacts of major disasters is a priority of increasing national attention, but there are limited examples of implementation strategies to guide new disaster responses. We provide a case study of an effort being applied in response to the 2016 Great Flood in Baton Rouge.MethodsResilient Baton Rouge was designed to support recovery after major flooding by building local capacity to implement an expanded model of depression collaborative care for adults, coupled with identifying and responding to local priorities and assets for recovery. For a descriptive, initial evaluation, we coupled analysis of documents and process notes with descriptive surveys of participants in initial training and orientation, including preliminary comparisons among licensed and non-licensed participants to identify training priorities.ResultsWe expanded local behavioral health service delivery capacity through subgrants to four agencies, provision of training tailored to licensed and non-licensed providers and development of advisory councils and partnerships with grassroots and government agencies. We also undertook initial efforts to enhance national collaboration around post-disaster resilience.ConclusionOur partnered processes and lessons learned may be applicable to other communities that aim to promote resilience, as well as planning for and responding to post-disaster behavioral health needs

Further investigation of confirmed urinary tract infection (UTI) in children under five years: a systematic review.

Background: Further investigation of confirmed UTI in children aims to prevent renal scarring and future complications. Methods: We conducted a systematic review to determine the most effective approach to the further investigation of confirmed urinary tract infection (UTI) in children under five years of age. Results: 73 studies were included. Many studies had methodological limitations or were poorly reported. Effectiveness of further investigations: One study found that routine imaging did not lead to a reduction in recurrent UTIs or renal scarring. Diagnostic accuracy: The studies do not support the use of less invasive tests such as ultrasound as an alternative to renal scintigraphy, either to rule out infection of the upper urinary tract (LR- = 0.57, 95%CI: 0.47, 0.68) and thus to exclude patients from further investigation or to detect renal scarring (LR+ = 3.5, 95% CI: 2.5, 4.8). None of the tests investigated can accurately predict the development of renal scarring. The available evidence supports the consideration of contrast-enhanced ultrasound techniques for detecting vesico-ureteric reflux (VUR), as an alternative to micturating cystourethrography (MCUG) (LR+ = 14.1, 95% CI: 9.5, 20.8; LR- = 0.20, 95%CI: 0.13, 0.29); these techniques have the advantage of not requiring exposure to ionising radiation. Conclusion: There is no evidence to support the clinical effectiveness of routine investigation of children with confirmed UTI. Primary research on the effectiveness, in terms of improved patient outcome, of testing at all stages in the investigation of confirmed urinary tract infection is urgently required

Counterion Condensation and Fluctuation-Induced Attraction

We consider an overall neutral system consisting of two similarly charged plates and their oppositely charged counterions and analyze the electrostatic interaction between the two surfaces beyond the mean-field Poisson-Boltzmann approximation. Our physical picture is based on the fluctuation-driven counterion condensation model, in which a fraction of the counterions is allowed to ``condense'' onto the charged plates. In addition, an expression for the pressure is derived, which includes fluctuation contributions of the whole system. We find that for sufficiently high surface charges, the distance at which the attraction, arising from charge fluctuations, starts to dominate can be large compared to the Gouy-Chapmann length. We also demonstrate that depending on the valency, the system may exhibit a novel first-order binding transition at short distances.Comment: 15 pages, 8 figures, to appear in PR