Understanding Anharmonicity in fcc Materials: From its Origin to ab initio Strategies beyond the Quasiharmonic Approximation.

We derive the Gibbs energy including the anharmonic contribution due to phonon-phonon interactions for an extensive set of unary fcc metals (Al, Ag, Au, Cu, Ir, Ni, Pb, Pd, Pt, Rh) by combining density-functional-theory (DFT) calculations with efficient statistical sampling approaches. We show that the anharmonicity of the macroscopic system can be traced back to the anharmonicity in local pairwise interactions. Using this insight, we derive and benchmark a highly efficient approach which allows the computation of anharmonic contributions using a few T=0 K DFT calculations only.

Temperature dependent magnon-phonon coupling in bcc Fe from theory and experiment.

An ab initio based framework for quantitatively assessing the phonon contribution due to magnon-phonon interactions and lattice expansion is developed. The theoretical results for bcc Fe are in very good agreement with high-quality phonon frequency measurements. For some phonon branches, the magnon-phonon interaction is an order of magnitude larger than the phonon shift due to lattice expansion, demonstrating the strong impact of magnetic short-range order even significantly above the Curie temperature. The framework closes the previous simulation gap between the ferro- and paramagnetic limits.

Characterization of the Porphyridium cruentum Chl a-binding LHC by in vitro reconstitution: LHCaR1 binds 8 Chl a molecules and proportionately more carotenoids than CAB proteins.

The Porphyridium cruentum light harvesting complex (LHC) binds Chl a, zeaxanthin and beta-carotene and comprises at least 6 polypeptides of a multigene family. We describe the first in vitro reconstitution of a red algal light-harvesting protein (LHCaR1) with Chl a/carotenoid extracts from P. cruentum. The reconstituted pigment complex (rLHCaR1) is spectrally similar to the native LHC I, with an absorption maximum at 670 nm, a 77 K fluorescence emission peak at 677 nm (ex. 440 nm), and similar circular dichroism spectra. Molar ratios of 4.0 zeaxanthin, 0.3 beta-carotene and 8.2 Chl a per polypeptide for rLHCaR1 are similar to those of the native LHC I complex (3.1 zeaxanthin, 0.5 beta-carotene, 8.5 Chl a). The binding of 8 Chl a molecules per apoprotein is consistent with 8 putative Chl-binding sites in the predicted transmembrane helices of LHCaR1. Two of the putative Chl a binding sites (helix 2) in LHCaR1 were assigned to Chl b in Chl a/b-binding (CAB) LHC II [Kühlbrandt et al. (1994) Nature 367: 614-21]. This suggests either that discrimination for binding of Chl a or Chl b is not very specific at these sites or that specificity of binding sites evolved separately in CAB proteins. LHCaR1 can be reconstituted with varying ratios of carotenoids, consistent with our previous observation that the carotenoid to Chl ratio is substantially higher in P. cruentum grown under high irradiance. Also notable is that zeaxanthin does not act as an accessory light-harvesting pigment, even though it is highly likely that it occupies the position assigned to lutein in the CAB LHCs.

Missing medications in a unit-dose system: quality assurance.

A method for the identification, documentation, and resolution of problems related to missing medications is described. In cooperation with nursing, a procedure for dispensing doses needed using a medication request form was implemented. Medications are not dispensed without a written request. This has made it possible to enumerate, quantify, and resolve problems in medication dispensing.

I.V. admixture profiling: a simple system.

The description of an I.V. admixture profile form is presented. Detailed information on the mechanisms of using this form, as well as the advantages of the profiling system, are delineated. Several examples are illustrated for thorough understanding of the system. The authors conclude that the system affords a simple, accurate, and flexible profiling system which can be utilized in hospital I.V. admixture programs of various sizes. The profiling system provides for a mechanism of clinical involvement as well as for quality assurance assessment.

Thermodynamic modeling of chromium: strong and weak magnetic coupling.

As chromium is a decisive ingredient for stainless steels, a reliable understanding of its thermodynamic properties is indispensable. Parameter-free first-principles methods have nowadays evolved to a state allowing such thermodynamic predictions. For materials such as Cr, however, the inclusion of magnetic entropy and higher order contributions such as anharmonic entropy is still a formidable task. Employing state-of-the-art ab initio molecular dynamics simulations and statistical concepts, we compute a set of thermodynamic properties based on quasiharmonic, anharmonic, electronic and magnetic free energy contributions from first principles. The magnetic contribution is modeled by an effective nearest-neighbor Heisenberg model, which itself is solved numerically exactly by means of a quantum Monte Carlo method. We investigate two different scenarios: a weak magnetic coupling scenario for Cr, as usually presumed in empirical thermodynamic models, turns out to be in clear disagreement with experimental observations. We show that instead a mixed Hamiltonian including weak and strong magnetic coupling provides a consistent picture with good agreement to experimental thermodynamic data.

Advancing density functional theory to finite temperatures: methods and applications in steel design.

The performance of materials such as steels, their high strength and formability, is based on an impressive variety of competing mechanisms on the microscopic/atomic scale (e.g. dislocation gliding, solid solution hardening, mechanical twinning or structural phase transformations). Whereas many of the currently available concepts to describe these mechanisms are based on empirical and experimental data, it becomes more and more apparent that further improvement of materials needs to be based on a more fundamental level. Recent progress for methods based on density functional theory (DFT) now makes the exploration of chemical trends, the determination of parameters for phenomenological models and the identification of new routes for the optimization of steel properties feasible. A major challenge in applying these methods to a true materials design is, however, the inclusion of temperature-driven effects on the desired properties. Therefore, a large range of computational tools has been developed in order to improve the capability and accuracy of first-principles methods in determining free energies. These combine electronic, vibrational and magnetic effects as well as structural defects in an integrated approach. Based on these simulation tools, one is now able to successfully predict mechanical and thermodynamic properties of metals with a hitherto not achievable accuracy.

Practice guidelines and drug-usage evaluation.

Currently, there is a great deal of interest in the development of practice guidelines for medical care that will be more rigorous and clinically sound than what is available today. With the impetus of federal legislation mandating such an approach, it may continue to develop into a significant movement in the medical arena. Pharmacy managers should be aware of developments in this area, particularly as they relate to appropriateness of drug therapy and drug-utilization review. The result may eventually be an evolution from drug-utilization review programs to diagnosis-based, outcome-focused interdisciplinary systems for QA. Even with the development of practice guidelines as described, there will continue to be a need for competent pharmacy practitioners to ensure appropriate pharmaceutical care. With the increasing acuity of patients in the health care system and the rapid development of new drugs and technologies, the role of the institutional pharmacist in ensuring optimal patient care will be more important than ever.

Pharmacy-based automated medication records: methods, application, and a survey of use.

A literature review of articles describing the development and implementation of automated medication administration records is summarized, and the results of a survey undertaken of all hospitals in Missouri to determine the extent of an automated medication administration record (MAR) are reported. For hospitals with an automated MAR, the survey compiled information about the demographics of responding facilities and production and distribution, design, implementation, and procedures for use of automated MARs. The most frequently reported advantages of an automated MAR were a more legible document, increased accuracy, savings in nursing personnel time, and fewer medication errors. The most frequently reported disadvantages were increases in pharmacy personnel time, different interpretation of orders by pharmacy and nursing, and multiple entries required for a medication order to appear correctly on the MAR.

Staffing for comprehensive pharmaceutical services in a small hospital.

The use of licensed practical nurses as medication administration personnel under the administrative authority of the pharmacy department in a 140-bed hospital is described. The pharmacy department assumed responsibility for medication administration in its efforts to expand the scope and quality of its services and to control drug distribution more completely. A medication administration team (MAT) was developed that involves licensed practical nurses and technicians. The MAT members are trained through programmed instruction, on-the-job experiences, and a 32-hour pharmacology course taught by staff pharmacists. This medication administration team gives the pharmacy department control of the entire drug distribution system.

Autophosphorylation of archaeal Cdc6 homologues is regulated by DNA.

The initiator protein Cdc6 (Cdc18 in fission yeast) plays an essential role in the initiation of eukaryotic DNA replication. In yeast the protein is expressed before initiation of DNA replication and is thought to be essential for loading of the helicase onto origin DNA. The biochemical properties of the protein, however, are largely unknown. Using three archaeal homologues of Cdc6, it was found that the proteins are autophosphorylated on Ser residues. The winged-helix domain at the C terminus of Cdc6 interacts with DNA, which apparently regulates the autophosphorylation reaction. Yeast Cdc18 was also found to autophosphorylate, suggesting that this function of Cdc6 may play a widely conserved and essential role in replication initiation.

Shared pharmaceutical services in small hospitals.

A system of shared pharmaceutical services between two small, rural hospitals is described. A contractural agreement was established between a 140-bed hospital and a 40-bed hospital located 15 miles apart in a rural area of eastern Kentucky. The larger hospital provided comprehensive pharmaceutical services to the smaller hospital for a monthly fee. Procurement of i.v. fluids and supplies was a function of the larger hospital; other drugs and supplies were procured separately. The director of pharmacy at the larger institution also served as the director at the small institution. Staff pharmacists rotated between the two hospitals. Supportive personnel were assigned permanently to each hospital. The shared service arrangement reduced costs associated with the implementation of comprehensive pharmaceutical services and made it easier to recruit and retain skilled pharmacy personnel.

Chlorophyll and carotenoid binding in a simple red algal light-harvesting complex crosses phylogenetic lines.

The membrane proteins of peripheral light-harvesting complexes (LHCs) bind chlorophylls and carotenoids and transfer energy to the reaction centers for photosynthesis. LHCs of chlorophytes, chromophytes, dinophytes, and rhodophytes are similar in that they have three transmembrane regions and several highly conserved Chl-binding residues. All LHCs bind Chl a, but in specific taxa certain characteristic pigments accompany Chl a: Chl b and lutein in chlorophytes, Chl c and fucoxanthin in chromophytes, Chl c and peridinin in dinophytes, and zeaxanthin in rhodophytes. The specificity of pigment binding was examined by in vitro reconstitution of various pigments with a simple light-harvesting protein (LHCaR1), from a red alga (Porphyridium cruentum), that normally has eight Chl a and four zeaxanthin molecules. The pigments typical of a chlorophyte (Spinacea oleracea), a chromophyte (Thallasiosira fluviatilis), and a dinophyte (Prorocentrum micans) were found to functionally bind to this protein as evidenced by their participation in energy transfer to Chl a, the terminal pigment. This is a demonstration of a functional relatedness of rhodophyte and higher plant LHCs. The results suggest that eight Chl-binding sites per polypeptide are an ancestral trait, and that the flexibility to bind various Chl and carotenoid pigments may have been retained throughout the evolution of LHCs.