Relativistic and quantum electrodynamics effects on NMR shielding tensors of TlX (X = H, F, Cl, Br, I, At) molecules.

The results of relativistic calculations of nuclear magnetic resonance shielding tensors (σ) for the thallium monocation (Tl+), thallium hydride (TlH), and thallium halides (TlF, TlCl, TlBr, TlI, and TlAt) are presented as obtained within a four-component polarization propagator formalism and a two-component linear response approach within the zeroth-order regular approximation. In addition to a detailed analysis of relativistic effects performed in this work, some quantum electrodynamical (QED) effects on those nuclear magnetic resonance shieldings and other small contributions are estimated. A strong dependence of σ(Tl) on the bonding partner is found, together with a very weak dependence of QED effects with them.

Opportunities for fundamental physics research with radioactive molecules.

Molecules containing short-lived, radioactive nuclei are uniquely positioned to enable a wide range of scientific discoveries in the areas of fundamental symmetries, astrophysics, nuclear structure, and chemistry. Recent advances in the ability to create, cool, and control complex molecules down to the quantum level, along with recent and upcoming advances in radioactive species production at several facilities around the world, create a compelling opportunity to coordinate and combine these efforts to bring precision measurement and control to molecules containing extreme nuclei. In this manuscript, we review the scientific case for studying radioactive molecules, discuss recent atomic, molecular, nuclear, astrophysical, and chemical advances which provide the foundation for their study, describe the facilities where these species are and will be produced, and provide an outlook for the future of this nascent field.

Quasi-relativistic approach to analytical gradients of parity violating potentials.

An analytic gradient approach for the computation of derivatives of parity-violating (PV) potentials with respect to displacements of the nuclei in chiral molecules is described and implemented within a quasirelativistic mean-field framework. Calculated PV potential gradients are utilized for estimating PV frequency splittings between enantiomers in rotational and vibrational spectra of four chiral polyhalomethanes, i.e.

Relativistic and QED corrections to one-bond indirect nuclear spin-spin couplings in X and X ions (X = Zn, Cd, Hg).

The indirect spin-spin coupling tensor, J, between mercury nuclei in systems containing this element can be of the order of a few kHz and one of the largest measured. We analyzed the physics behind the electronic mechanisms that contribute to the one- and two-bond couplings J (n = 1, 2). For doing so, we performed calculations for J-couplings in the ionized X and X linear molecules (X = Zn, Cd, Hg) within polarization propagator theory using the random phase approximation and the pure zeroth-order approximation with Dirac-Hartree-Fock and Dirac-Kohn-Sham orbitals, both at four-component and zeroth-order regular approximation levels.

Isotope Shifts of Radium Monofluoride Molecules.

Isotope shifts of ^{223-226,228}Ra^{19}F were measured for different vibrational levels in the electronic transition A^{2}Π_{1/2}←X^{2}Σ^{+}. The observed isotope shifts demonstrate the particularly high sensitivity of radium monofluoride to nuclear size effects, offering a stringent test of models describing the electronic density within the radium nucleus. Ab initio quantum chemical calculations are in excellent agreement with experimental observations.

Chiral Molecules as Sensitive Probes for Direct Detection of P-Odd Cosmic Fields.

Potential advantages of chiral molecules for a sensitive search for parity violating cosmic fields are highlighted. Such fields are invoked in different models for cold dark matter or in the Lorentz-invariance violating standard model extensions and thus are signatures of physics beyond the standard model. The sensitivity of a 20-year-old experiment with the molecule CHBrClF to pseudovector cosmic fields as characterized by the parameter |b_{0}^{e}| is estimated to be O(10^{-12}  GeV) employing ab initio calculations.

Toolbox approach for quasi-relativistic calculation of molecular properties for precision tests of fundamental physics.

A generally applicable approach for the calculation of relativistic properties described by one-electron operators within a two-component wave function approach is presented. The formalism is explicitly evaluated for the example of quasirelativistic wave functions obtained within the zeroth order regular approximation (ZORA). The wide applicability of the scheme is demonstrated for the calculation of parity (P) and time-reversal (T  ) symmetry violating properties, which are important for searches of physics beyond the standard model of particle physics.

Synthesis and Characterization of [Br ][MF ] (M=Sb, Ir), as well as Quantum Chemical Study of [Br ] Structure, Chemical Bonding, and Relativistic Effects Compared with [XBr ] (X=Br, I, At, Ts) and [TsZ ] (Z=F, Cl, Br, I, At, Ts).

[Br ][SbF ] and [Br ][IrF ] were synthesized by interaction of BrF with Sb O or iridium metal, respectively. The former compound crystallizes in the orthorhombic space group Pbcn (No. 60) with a=11.

Zeroth order regular approximation approach to electric dipole moment interactions of the electron.

A quasi-relativistic two-component approach for an efficient calculation of P,T-odd interactions caused by a permanent electric dipole moment of the electron (eEDM) is presented. The approach uses a (two-component) complex generalized Hartree-Fock and a complex generalized Kohn-Sham scheme within the zeroth order regular approximation. In applications to select heavy-elemental polar diatomic molecular radicals, which are promising candidates for an eEDM experiment, the method is compared to relativistic four-component electron-correlation calculations and confirms values for the effective electric field acting on the unpaired electron for RaF, BaF, YbF, and HgF.

A Randomized, Double-Blind, Placebo-Controlled Trial of Low-Dose Sertraline in Young Children With Fragile X Syndrome.

Objective: Observational studies and anecdotal reports suggest that sertraline, a selective serotonin reuptake inhibitor, may improve language development in young children with fragile X syndrome (FXS).

Methods: The authors evaluated the efficacy of 6 months of treatment with low-dose sertraline in a randomized, double-blind, placebo-controlled trial in 52 children with FXS aged 2 to 6 years.

Results: Eighty-one subjects were screened for eligibility, and 57 were randomized to sertraline (27) or placebo (30).

We're not keeping up with the Joneses: North Carolina has fewer dentists per capita than neighboring (and most other) states.

This commentary provides a data-driven analysis that shows that North Carolina faces a geographically maldistributed dentist workforce that is inadequate in supply. Not only has North Carolina consistently lagged behind other states in dentists per capita for over 10 years, but projections of future workforce supply do not show improvement.

Surgical workforce in the American South.

There exists a geographic maldistribution of surgeons with significant regional characteristics, which is associated with surgical access differentials that may be contributing to existing health disparities in the United States. We sought to evaluate the trends in the surgical workforce in southern states of the United States from 1981 to 2006 using the American Medical Association Masterfile data. Our study revealed that the general surgery workforce growth peaked in 1986 and has had negative growth per capita as a result of the consistent population growth, unlike other regions in the country.

Factors affecting attrition from associate degree nursing programs in North Carolina.

Projected nursing shortfalls have spurred the state of North Carolina to initiate a series of strategies to increase the number of graduates from pre-licensure Registered Nurse (RN) programs. These efforts have been largely successful, but attrition rates from Associate Degree Nursing (ADN) programs remain high. Only 58% of students entering ADN programs complete the degree.

Numbers of minority health professionals: where do we stand?

This overview has pointed to a continuing racial and ethnic imbalance in the health professions that applies to North Carolina as well as the nation. Great strides have been made early in the development of programs to enhance racial and ethnic representation, but they have generally reached a plateau in terms of growth and progress. Resistance to affirmative action programs and subsequent uncertainty over their legal standing can be cited as one factor thwarting progress, but that issue has been resolved and schools, professions, and the North Carolina General Assembly can move forward with a clear understanding of how to proceed.

Dynamic moisture permeation through clothing.

Dynamic moisture permeation through clothing often occurs during thermal transience, causing an imbalance between evaporative heat loss from the skin (Esk) and that from the clothing surface (Ecl). A device was designed to observe Esk and Ecl simultaneously. It consists of two relative humidity sensors coupled with thermistors so that densities of water vapor at two points within the boundary layer can be calculated.