Incidence of endodontic implantitis and implant endodontitis occurring with single-tooth implants: a retrospective study.

The purposes of this study were to determine success and survival rates for implants and teeth adjacent to implants and the incidence of endodontic implantitis (E-I) (endodontic involvement in adjacent teeth causing implant failure) and implant endodontitis (I-E) (implant placement causing endodontic failure). The data were from 233 single-tooth implants placed in 116 subjects by postgraduate periodontal students with recall radiographs taken >or=9 months after implant placement. Three groups were analyzed: group A, implants with no adjacent teeth (n = 90); group B, implants with nonendodontically treated adjacent teeth (n = 123); and group C, implants with endodontically treated adjacent teeth (n = 20).

Multiple weak supramolecular interactions stabilize a surprisingly twisted As2L3 assembly.

A combined crystallographic, DFT and NMR spectroscopic study of a flexible As(2)(3) assembly reveals temperature dependent conformational behavior in solution and a highly asymmetric structure stabilized by As-pi and edge-to-face aromatic interactions.

Management of cancer pain: basic principles and neuropathic cancer pain.

Pain is one of the commonest symptoms in patients with cancer occurring in as many as 90% of patients during their illness. Pain is a complex phenomenon, which can be exacerbated by numerous other factors. This paper discusses the common strategies for the management of cancer pain in general and also neuropathic cancer pain.

Assessment of the environmental fate and effects of ivermectin in aquatic mesocosms.

Pharmaceuticals in the environment have been subject to increasing public concern and scientific investigation over the past years. More than 100 active pharmaceutical ingredients have been detected in surface waters worldwide at the ng to microg L(-1) range. At these low levels it is commonly assumed that only chronic and/or mixture toxic effects will be discernible in aquatic ecosystems and that there are orders of magnitude between exposure and effect concentrations.

Gastrointestinal microbes increase arsenic bioaccessibility of ingested mine tailings using the simulator of the human intestinal microbial ecosystem.

It is widely accepted that the use of total metal concentrations in soil overestimates metal risk from human ingestion of contaminated soils. In vitro simulators have been used to estimate the fraction of arsenic present in soil that is bioaccessible in the human digestive track. These approaches assume that the bioaccessible fraction remains constant across soil total metal concentrations and that intestinal microbiota do not contribute to arsenic release.

Toxicity and hazard of a mixture of SSRIs to zooplankton communities evaluated in aquatic microcosms.

The toxicity and hazard of a mixture of selective serotonin reuptake inhibitors (SSRIs), including fluoxetine, fluvoxamine, and sertraline, to zooplankton communities were evaluated using 120,00l outdoor microcosms. Acute (day 4) and chronic (day 35) zooplankton abundance and species richness were assessed for Rotifera, Cladocera, and Copepoda. For acute SSRI exposures, rotifers were the most sensitive zooplankton taxa to changes in abundance (predicted no effect concentration (PNEC)=19 nM); however, no effects in zooplankton species richness were observed for this treatment period.

On the connection between Gaussian statistics and excited-state linear response for time-dependent fluorescence.

Time-dependent fluorescence (TDF) of a chromophore in a polar or nonpolar solvent is frequently simulated using linear-response approximations. It is shown that one such linear-response-type approximation for the TDF Stokes shift derived by Carter and Hynes [J. Chem.

Transport properties of CO2-expanded acetonitrile from molecular dynamics simulations.

Carbon-dioxide-expanded liquids, which are mixtures of organic liquids and compressed CO2, are novel media used in chemical processing. The authors present a molecular simulation study of the transport properties of liquid mixtures formed by acetonitrile and carbon dioxide, in which the CO2 mole fraction is adjusted by changing the pressure, at a constant temperature of 298 K. They report values of translational diffusion coefficients, rotational correlation times, and shear viscosities of the liquids as function of CO2 mole fraction.

Kinetic coefficient for hard-sphere crystal growth from the melt.

Using molecular-dynamics simulation, we determine the magnitude and anisotropy of the kinetic coefficient (mu) for the crystal growth from the melt for the hard-sphere system through an analysis of equilibrium capillary fluctuations in interfacial height. We find mu100 = 1.44(7), mu110 = 1.

The anisotropic hard-sphere crystal-melt interfacial free energy from fluctuations.

We have calculated the interfacial free energy for the hard-sphere system, as a function of crystal interface orientation, using a method that examines the fluctuations in the height of the interface during molecular dynamics simulations. The approach is particularly sensitive for the anisotropy of the interfacial free energy. We find an average interfacial free energy of gamma=0.

Direct calculation of the crystal-melt interfacial free energy via molecular dynamics computer simulation.

We review our recent work on the direct calculation of the interfacial free energy, gamma, of the crystal-melt interface via molecular dynamics computer simulation for a number of model systems. The value of gamma as a function of crystal orientation is determined using a thermodynamic integration technique employing moving cleaving walls [Phys. Rev.

Phase equilibria in carbon dioxide expanded solvents: Experiments and molecular simulations.

We present complementary molecular simulations and experimental results of phase equilibria for carbon dioxide expanded acetonitrile, methanol, ethanol, acetone, acetic acid, toluene, and 1-octene. The volume expansion measurements were done using a high-pressure Jerguson view cell. Molecular simulations were performed using the Gibbs ensemble Monte Carlo method.

Calculation of the crystal-melt interfacial free energy of succinonitrile from molecular simulation.

The crystal-metal interfacial free energy for a six-site model of succinonitrile [N triple bond C-(CH(2))(2)-C triple bond N] has been calculated using molecular-dynamics simulation from the power spectrum of capillary fluctuations in interface position. The orientationally averaged magnitude of the interfacial free energy is determined to be (7.0+/-0.

Crystal structure and interaction dependence of the crystal-melt interfacial free energy.

We examine via molecular simulation the dependence of the crystal-melt interfacial free energy gamma on molecular interaction and crystal structure (fcc vs bcc) for systems interacting with inverse-power repulsive potentials, u(r)=epsilon(sigma/r)(n), 6< or =n< or =100. Both the magnitude and anisotropy of gamma are found to increase as the range of the potential increases. Also we find that gamma(bcc) View Article and Find Full Text PDF

Hammers and nails: a report.

A case report where parathyroid bone disease simulates bone metastases. Subsequent treatment of underlying hyperparathyroidism causes a marked improvement in bone disease, leading to a review of the initial diagnosis.

Structure of a soft-sphere fluid at a soft repulsive wall: a comparison of weighted density-functional theories.

Density-functional theory is used to investigate the structure of a soft-sphere fluid at a soft wall. The fluid is modeled by an inverse sixth-power repulsive pair potential and the fluid particles interact with a flat stationary wall defined by an inverse-twelth power repulsive external potential. For comparison we examine results using three weighted density approximations (WDA), namely those due to Phys.

Generalized dynamical thermostating technique.

We demonstrate that the Nosé method for constant-temperature molecular-dynamics simulation [Mol. Phys. 52, 255 (1984)] can be substantially generalized by the addition of auxiliary variables to encompass an infinite variety of Hamiltonian thermostats.

Weighted-density approximation for general nonuniform fluid mixtures.

In order to construct a general density-functional theory for nonuniform fluid mixtures, we propose an extension to multicomponent systems of the weighted-density approximation of Curtin and Ashcroft [Phys. Rev. A 32, 2909 (1985)].

Effects of solution polarity and viscosity on peptide deamidation.

Deamidation kinetics were measured for a model hexapeptide (L-Val-L-Tyr-L-Pro-L-Asn-Gly-L-Ala, 0.02 mg/mL) in aqueous solutions containing glycerol (0-50% w/w) and poly(vinyl pyrrolidone) (PVP, 0-20% w/w) at 37 degrees C and pH 10 to determine the effects of solution polarity and viscosity on reactivity. The observed pseudo-first order deamidation rate constants, k(obs), decreased markedly when the viscosity increased from 0.

Direct calculation of the hard-sphere crystal /Melt interfacial free energy.

We present a direct calculation by molecular-dynamics computer simulation of the crystal/melt interfacial free energy gamma for a system of hard spheres of diameter sigma. The calculation is performed by thermodynamic integration along a reversible path defined by cleaving, using specially constructed movable hard-sphere walls, separate bulk crystal, and fluid systems, which are then merged to form an interface. We find the interfacial free energy to be slightly anisotropic with gamma = 0.

Knowledge, attitudes, and behaviors of Alabama's primary care physicians regarding cancer genetics.

Purpose: To determine Alabama's primary care physicians' knowledge, attitudes, and behaviors regarding cancer genetics.

Method: A questionnaire was mailed to a random sample of 1,148 physicians: family and general practitioners, internists, and obstetrician-gynecologists.

Results: Of the surveyed physicians, 22.

Chemical stability of peptides in polymers. 2. Discriminating between solvent and plasticizing effects of water on peptide deamidation in poly(vinylpyrrolidone).

The mechanistic role of water in the deamidation of a model asparagine-containing hexapeptide (Val-Tyr-Pro-Asn-Gly-Ala) in lyophilized formulations containing poly(vinylpyrrolidone) (PVP) and glycerol was investigated. Glycerol was used as a plasticizer to vary formulation glass transition temperature (T(g)) without significantly changing water content or activity. Increases in moisture and glycerol contents increased the rate of peptide deamidation.