Cilostazol after endovascular therapy for femoropopliteal peripheral arterial disease: A systematic review and meta-analysis.

Background: Endovascular therapy (ET) outcomes for femoropopliteal peripheral arterial disease (FP-PAD) remain suboptimal. Cilostazol therapy may improve patency rates and decrease major adverse limb events after ET for FP-PAD. Our goal was to analyze published studies evaluating the use of cilostazol after ET for FP-PAD.

Characterization and genome sequence of phage Morrigan, of cluster EA6 with siphovirus morphology.

Bacteriophage Morrigan, which was isolated from soil using NRRL B-24224, is lytic with siphovirus morphology. Morrigan's 40,509-bp genome has a GC content of 62.8% and 66 putative protein-coding genes, of which 31 could be assigned putative functions.

Hearing abnormalities in multiple sclerosis: clinical semiology and pathophysiologic mechanisms.

Auditory manifestations from multiple sclerosis (MS) are not as common as the well-recognized sentinel exacerbations of optic neuritis, partial myelitis, motor weakness, vertiginous episodes, heat intolerance, and eye movement abnormalities. This paper discusses four cases of auditory changes, secondary to MS, and describes the first case, to our knowledge, of palinacousis, the perseveration of hearing, despite cessation of the sound stimulus. For each we characterize the initial complaint, the diagnostic work up, and ultimately, underscore the individualized treatment interventions, that allowed us to achieve a remission in all four cases.

Heterogenized Pyridine-Substituted Cobalt(II) Phthalocyanine Yields Reduction of CO by Tuning the Electron Affinity of the Co Center.

Conversion of CO to reduced products is a promising route to alleviate irreversible climate change. Here we report the synthesis of a Co-based phthalocyanine with pyridine moieties (CoPc-Pyr), which is supported on a carbon electrode and shows Faradaic efficiency ∼90% for CO at 490 mV of overpotential (-0.6 V vs reversible hydrogen electrode (RHE)).

Solvation Entropy Made Simple.

The entropies of molecules in solution are often calculated using gas phase formulas. It is assumed that, because implicit solvation models are fitted to reproduce free energies, this is sufficient for modeling reactions in solution. However, this procedure exaggerates entropic effects in processes that change molecularity.

Explaining the Incorporation of Oxygen Derived from Solvent Water into the Oxygenated Products of CO Reduction over Cu.

The electrochemical reduction of CO and CO over Cu produces a variety of multicarbon products. Interestingly, recent isotope experiments have suggested that the oxygen atoms contained in the multicarbon alcohols produced over Cu are derived from solvent water. This observation has brought into question many of the proposed reaction mechanisms by which these multicarbon alcohols are produced over Cu.

Reaction mechanism of the selective reduction of CO to CO by a tetraaza [CoNH] complex in the presence of protons.

The tetraaza [CoIIN4H]2+ complex (1) is remarkable for its ability to selectively reduce CO2 to CO with 45% Faradaic efficiency and a CO to H2 ratio of 3 : 2. We employ density functional theory (DFT) to determine the reasons behind the unusual catalytic properties of 1 and the most likely mechanism for CO2 reduction. The selectivity for CO2 over proton reduction is explained by analyzing the catalyst's affinity for the possible ligands present under typical reaction conditions: acetonitrile, water, CO2, and bicarbonate.

Nonempirical Meta-Generalized Gradient Approximations for Modeling Chemisorption at Metal Surfaces.

We assess the accuracy of popular nonempirical GGAs (PBE, PBEsol, RPBE) and meta-GGAs (TPSS, revTPSS, and SCAN) for describing chemisorption reactions at metal surfaces. Except for RPBE, all the functionals tend to overbind the adsorbate significantly. We then propose a nonempirical meta-GGA, denoted as RTPSS, that is based on RPBE in the same way that TPSS is based on PBE.

Is Subsurface Oxygen Necessary for the Electrochemical Reduction of CO on Copper?

It has recently been proposed that subsurface oxygen is crucial for the adsorption and subsequent electroreduction of CO on copper. Using density functional theory, we have studied the stability and diffusion of subsurface oxygen in single crystals of copper exposing (111) and (100) facets. Oxygen is at least 1.

Electronic Structure and Properties of Berkelium Iodates.

The reaction of Bk(OH) with iodate under hydrothermal conditions results in the formation of Bk(IO) as the major product with trace amounts of Bk(IO) also crystallizing from the reaction mixture. The structure of Bk(IO) consists of nine-coordinate Bk cations that are bridged by iodate anions to yield layers that are isomorphous with those found for Am, Cf, and with lanthanides that possess similar ionic radii. Bk(IO) was expected to adopt the same structure as M(IO) (M = Ce, Np, Pu), but instead parallels the structural chemistry of the smaller Zr cation.

Actinide chemistry using singlet-paired coupled cluster and its combinations with density functionals.

Singlet-paired coupled cluster doubles (CCD0) is a simplification of CCD that relinquishes a fraction of dynamic correlation in order to be able to describe static correlation. Combinations of CCD0 with density functionals that recover specifically the dynamic correlation missing in the former have also been developed recently. Here, we assess the accuracy of CCD0 and CCD0+DFT (and variants of these using Brueckner orbitals) as compared to well-established quantum chemical methods for describing ground-state properties of singlet actinide molecules.

Range separated hybrids of pair coupled cluster doubles and density functionals.

Pair coupled cluster doubles (pCCD) is a size-consistent, size-extensive, low-cost simplification of CCD that has been shown to be able to describe static correlation without breaking symmetry. We combine pCCD with Kohn-Sham functionals of the density and the local pair density in order to incorporate dynamic correlation in pCCD while maintaining its low cost. Double counting is eliminated by splitting the (interelectron) Coulomb operator into complementary short- and long-range parts, and evaluating the two-body energy with pCCD in the long-range and with density functionals in the short-range.

On the equivalence of LIST and DIIS methods for convergence acceleration.

Self-consistent field extrapolation methods play a pivotal role in quantum chemistry and electronic structure theory. We, here, demonstrate the mathematical equivalence between the recently proposed family of LIST methods [Wang et al., J.

Synergy between pair coupled cluster doubles and pair density functional theory.

Pair coupled cluster doubles (pCCD) has been recently studied as a method capable of accounting for static correlation with low polynomial cost. We present three combinations of pCCD with Kohn-Sham functionals of the density and on-top pair density (the probability of finding two electrons on top of each other) to add dynamic correlation to pCCD without double counting. With a negligible increase in computational cost, these pCCD+DFT blends greatly improve upon pCCD in the description of typical problems where static and dynamic correlations are both important.

Can short- and middle-range hybrids describe the hyperpolarizabilities of long-range charge-transfer compounds?

The hyperpolarizabilities of five prototypical and four recently synthesized long-range charge-transfer (CT) organic compounds are calculated using short- and middle-range (SR and MR) hybrid functionals. These results are compared with data from MP2 and other DFT methods including GGAs, global hybrids, long-range corrected functionals (LC-DFT), and optimally tuned LC-DFT. Although it is commonly believed that the overestimation of hyperpolarizabilities associated with CT excitations by GGA and global hybrid functionals is the result of their wrong asymptotic exchange potential, and that LC-DFT heals this issue, we show here that SR and MR functionals yield results similar to those from LC-DFT.

Can gap tuning schemes of long-range corrected hybrid functionals improve the description of hyperpolarizabilities?

Long-range corrected hybrid density functionals (LC-DFT), with range separation parameters optimally tuned to obey Koopmans' theorem, are used to calculate the first-order hyperpolarizabilities of prototypical charge-transfer compounds p-nitroaniline (PNA) and dimethylamino nitrostilbene (DANS) in the gas phase and various solvents. It is shown that LC-DFT methods with default range separation parameters tend to underestimate hyperpolarizabilities (most notably in solution) and that the tuning scheme can sharply improve results, especially in the cases when the standard LC-DFT errors are largest. Nonetheless, we also identify pathological cases (two pyrrole derivatives) for which LC-DFT underestimates the hyperpolarizabilities, regardless of tuning.

Electronic correlation without double counting via a combination of spin projected Hartree-Fock and density functional theories.

Several schemes to avoid the double counting of correlations in methods that merge multireference wavefunctions with density functional theory (DFT) are studied and here adapted to a combination of spin-projected Hartree-Fock (SUHF) and DFT. The advantages and limitations of the new method, denoted SUHF+fcDFT, are explored through calculations on benchmark sets in which the accounting of correlations is challenging for pure SUHF or DFT. It is shown that SUHF+fcDFT can greatly improve the description of certain molecular properties (e.

Capturing static and dynamic correlations by a combination of projected Hartree-Fock and density functional theories.

This paper explores the possibility of combining projected Hartree-Fock and density functional theories for treating static and dynamic correlations in molecular systems with mean-field computational cost. The combination of spin-projected unrestricted Hartree-Fock (SUHF) with the TPSS correlation functional (SUHF+TPSS) yields excellent results for non-metallic molecular dissociations and singlet-triplet splittings. However, SUHF+TPSS fails to provide the qualitatively correct dissociation curve for the notoriously difficult case of the chromium dimer.

Comparison of self-consistent field convergence acceleration techniques.

The recently proposed ADIIS and LIST methods for accelerating self-consistent field (SCF) convergence are compared to the previously proposed energy-DIIS (EDIIS) + DIIS technique. We here show mathematically that the ADIIS functional is identical to EDIIS for Hartree-Fock wavefunctions. Convergence failures of EDIIS + DIIS reported in the literature are not reproduced with our codes.

Conformational preferences of trans-1,2- and cis-1,3-cyclohexanedicarboxylic acids in water and dimethyl sulfoxide as a function of the ionization state as determined from NMR spectroscopy and density functional theory quantum mechanical calculations.

The populations of diaxial (aa) and diequatorial (ee) conformers of trans-1,2- and cis-1,3-cyclohexanedicarboxylic acids (CDCAs; 1 and 2, respectively) and their salts were determined in water and dimethyl sulfoxide (DMSO) solutions from vicinal proton-proton NMR J couplings ((3)J(HH)). Optimized geometries and free energies for these compounds were obtained at the M06-2X/cc-pVTZ(-f)++ level. Although carboxylic acid groups in cyclohexane rings are generally believed to be far more stable (~2 kcal/mol) in equatorial than axial positions, this investigation demonstrated that an aa conformation (normally assumed to be completely insignificant for these compounds) can be favored depending on the medium and ionization state: strong ee preferences (>90%) were observed in water and DMSO for both diacids and their salts, except for the dianion of 1 in DMSO, which was found to be substantially aa (~57%).