Persistent hypertriglyceridemia in statin-treated patients with type 2 diabetes mellitus

Purpose: This paper reports the results of an audit that assessed the prevalence of residual hypertriglyceridemia and the potential need for intensified management among patients with statin-treated type 2 diabetes mellitus (T2DM) in primary care in the UK. Patients and methods: A cross-sectional, observational, systematic audit of patients with diagnosed diabetes from 40 primary care practices was undertaken. The audit collected basic demographic information and data on prescriptions issued during the preceding 4 months. T2DM patients were stratified according to the proportion that attained European Society of Cardiology treatment targets. Results: The audit collected data from 14,652 patients with diagnosed diabetes: 89.5% (n = 13,108) of the total cohort had T2DM. Of the people with T2DM, 22.2% (2916) were not currently receiving lipid-lowering therapy. Up to approximately 80% of these people showed evidence of dyslipidemia. Among the group that received lipid-lowering therapy, 94.7% (9647) were on statin monotherapy, which was usually simvastatin (69.5% of patients receiving statin monotherapy; 6707). The currently available statins were prescribed, with the most common dose being 40 mg simvastatin (44.2%; 4267). Irrespective of the statin used, around half of the patients receiving statin monotherapy did not attain the European Society of Cardiology treatment targets for triglycerides, low-density lipoprotein, high-density lipoprotein, and total cholesterol. Conclusion: T2DM patients managed in UK primary care commonly show persistent lipid abnormalities. Clinicians need to optimize compliance with lipid-lowering and other medications. Clinicians also need to consider intensifying statin regimens, prescribing additional lipid-modifying therapies, and specific treatments aimed at triglyceride lowering to improve dyslipidemia control in statin-treated patients with T2DM

The Bacterial Photosynthetic Reaction Center as a Model for Membrane Proteins

Membrane proteins participate in many fundamental cellular processes. Until recently, an understanding of the function and properties of membrane proteins was hampered by an absence of structural information at the atomic level. A landmark achievement toward understanding the structure of membrane proteins was the crystallization (1) and structure determination (2-5) the photosynthetic reaction center (RC) from the purple bacteria Rhodopseudomonas viridis, followed by that of the RC from Rhodobacter sphaeroides (6-17). The RC is an integral membrane protein-pigment complex, which carries out the initial steps of photosynthesis (reviewed in 18). RCs from the purple bacteria Rps. viridis and Rb. sphaeroides are composed of three membrane-associated protein subunits (designated L, M, and H), and the following cofactors: four bacteriochlorophylls (Bchl or B), two bacteriopheophytins (Bphe or [phi]), two quinones, and a nonheme iron. The cofactors are organized into two symmetrical branches that are approximately related by a twofold rotation axis (2, 8). A central feature of the structural organization of the RC is the presence of 11 hydrophobic [alpha]-helixes, approximately 20-30 residues long, which are believed to represent the membrane-spanning portion of the RC (3, 9). Five membrane-spanning helixes are present in both the L and M subunits, while a single helix is in the H subunit. The folding of the L and M subunits is similar, consistent with significant sequence similarity between the two chains (19-25). The L and M subunits are approximately related by the same twofold rotation axis that relates the two cofactor branches. RCs are the first membrane proteins to be described at atomic resolution; consequently they provide an important model for discussing the folding of membrane proteins. The structure demonstrates that [alpha]-helical structures may be adopted by integral membrane proteins, and provides confirmation of the utility of hydropathy plots in identifying nonpolar membrane-spanning regions from sequence data. An important distinction between the folding environments of water-soluble proteins and membrane proteins is the large difference in water concentration surrounding the proteins. As a result, hydrophobic interactions (26) play very different roles in stabilizing the tertiary structures of these two classes of proteins; this has important structural consequences. There is a striking difference in surface polarity of membrane and water-soluble proteins. However, the characteristic atomic packing and surface area appear quite similar. A computational method is described for defining the position of the RC in the membrane (10). After localization of the RC structure in the membrane, surface residues in contact with the lipid bilayer were identified. As has been found for soluble globular proteins, surface residues are less well conserved in homologous membrane proteins than the buried, interior residues. Methods based on the variability of residues between homologous proteins are described (13); they are useful (a) in defining surface helical regions of membrane and water-soluble proteins and (b) in assigning the side of these helixes that are exposed to the solvent. A unifying view of protein structure suggests that water-soluble proteins may be considered as modified membrane proteins with covalently attached polar groups that solubilize the proteins in aqueous solution

Optical Detection of a Single Nuclear Spin

We propose a method to optically detect the spin state of a 31-P nucleus embedded in a 28-Si matrix. The nuclear-electron hyperfine splitting of the 31-P neutral-donor ground state can be resolved via a direct frequency discrimination measurement of the 31-P bound exciton photoluminescence using single photon detectors. The measurement time is expected to be shorter than the lifetime of the nuclear spin at 4 K and 10 T.Comment: 4 pages, 3 figure

Spinning particles in Taub-NUT space

The geodesic motion of pseudo-classical spinning particles in Euclidean Taub-NUT space is analysed. The constants of motion are expressed in terms of Killing-Yano tensors. Some previous results from the literature are corrected.Comment: LaTeX, 8 page

Generalized Killing equations and Taub-NUT spinning space

The generalized Killing equations for the configuration space of spinning particles (spinning space) are analysed. Simple solutions of the homogeneous part of these equations are expressed in terms of Killing-Yano tensors. The general results are applied to the case of the four-dimensional euclidean Taub-NUT manifold.Comment: 10 pages, late

Fast Non-Adiabatic Two Qubit Gates for the Kane Quantum Computer

In this paper we apply the canonical decomposition of two qubit unitaries to find pulse schemes to control the proposed Kane quantum computer. We explicitly find pulse sequences for the CNOT, swap, square root of swap and controlled Z rotations. We analyze the speed and fidelity of these gates, both of which compare favorably to existing schemes. The pulse sequences presented in this paper are theoretically faster, higher fidelity, and simpler than existing schemes. Any two qubit gate may be easily found and implemented using similar pulse sequences. Numerical simulation is used to verify the accuracy of each pulse scheme

Two-spin measurements in exchange interaction quantum computers

We propose and analyze a method for single shot measurement of the total spin of a two electron system in a coupled quantum dot or donor impurity structure, which can be used for readout in a quantum computer. The spin can be inferred by observing spin-dependent fluctuations of charge between the two sites, via a nearby electrometer. Realistic experimental parameters indicate that the fidelity of the measurement can be larger than 0.999 with existing or near-future technology. We also describe how our scheme can be used to implement various one- and two-qubit measurements, and hence to implement universal quantum computation

A Magnetic Resonance Force Microscopy Quantum Computer with Tellurium Donors in Silicon

We propose a magnetic resonance force microscopy (MRFM)-based nuclear spin quantum computer using tellurium impurities in silicon. This approach to quantum computing combines the well-developed silicon technology with expected advances in MRFM.Comment: 9 pages, 1 figur