1,117 research outputs found
Effect of diuretics on the plasma lipid profile
Hypertension, dyslipidaemia, glucose intolerance (associated with insulin resistance and compensatory hyperinsulinaemia) and other abnormalities are complementary coronary risk factors which often occur in association. A familial trait for essential hypertension seems to coexist commonly with defects in carbohydrate and lipoprotein metabolism which can be detected before the appearance of hypertension. Diabetes mellitus as well as obesity promotes the development of hypertension and dyslipidaemia. Moreover, certain drugs used for antihypertensive therapy can further modify lipoprotein and glucose metabolism. Thiazides in high dosage and loop-diuretics can increase serum low-density-lipoprotein cholesterol (LDL-C) and/or verv-LDL-C and the total C/high-density lipoprotein cholesterol (HDL-C) ratio, while HDL-C is largely unchanged; triglycerides (Tg) are also often elevated. Premenopausal women may beprotected from this side effect. Whether diureticinduced dyslipidaemia is dose-dependent and low thiazide doses (i.e. hydrochlorothiazide ≤12·5 mg daily) are less active, awaits clarification. The diuretic-antihypertensive agent, indapamide, given at a dose of 2·5 mg. day−1, seems to exert no relevant effect on serum lipoprotein or glucose metabolism. The potassium-sparing diuretic, spironolactone, also may be largely neutral with regard to lipids. Moreover, potassium sparing diuretics may possibly counteract, at least in part, a dyslipidaemic influence of potassium-loosing diuretics in medium dose. Drug-induced dyslipidaemia, as well as glucose intolerance, represent potentially adverse influences. In the hypertensive population, effective blood pressure control with traditional drug therapy based on thiazide-type diuretics in high dosage led to a distinct decrease in cerebrovascular morbidity and mortality, but a lesser decrease in coronary events. The prognostic relevance of drug-induced metabolic changes such as dyslipidaemia, altered insulin sensitivity, and glucose intolerance awaits further clarification. It is of clinical interest that several of the generally available antihypertensive drugs seem to be metabolically ‘neutral' or sometimes perhaps even potentially beneficial with regard to the lipoprotein and glucose metabolis
Magnetic layers with periodic point perturbations
We study spectral properties of a spinless quantum particle confined to an
infinite planar layer with hard walls which interacts with a periodic lattice
of point perturbations and a homogeneous magnetic field perpendicular to the
layer. It is supposed that the lattice cell contains a finite number of
impurities and the flux through the cell is rational. Using the Landau-Zak
transformation, we convert the problem into investigation of the corresponding
fiber operators which is performed by means of Krein's formula. This yields an
explicit description of the spectral bands which may be absolutely continuous
or degenerate, depending on the parameters of the model.Comment: LaTeX 2e, 30 pages; with minor revisions, to appear in Rep. Math.
Phy
Massive Dirac particles on the background of charged de-Sitter black hole manifolds
We consider the behavior of massive Dirac fields on the background of a
charged de-Sitter black hole. All black hole geometries are taken into account,
including the Reissner-Nordstr\"{o}m-de-Sitter one, the Nariai case and the
ultracold case. Our focus is at first on the existence of bound quantum
mechanical states for the Dirac Hamiltonian on the given backgrounds. In this
respect, we show that in all cases no bound state is allowed, which amounts
also to the non-existence of normalizable time-periodic solutions of the Dirac
equation. This quantum result is in contrast to classical physics, and it is
shown to hold true even for extremal cases. Furthermore, we shift our attention
on the very interesting problem of the quantum discharge of the black holes.
Following Damour-Deruelle-Ruffini approach, we show that the existence of
level-crossing between positive and negative continuous energy states is a
signal of the quantum instability leading to the discharge of the black hole,
and in the cases of the Nariai geometry and of the ultracold geometries we also
calculate in WKB approximation the transmission coefficient related to the
discharge process.Comment: 19 pages, 11 figures. Macro package: Revtex4. Changes concern mainly
the introduction and the final discussion in section VI; moreover, Appendix D
on the evaluation of the Nariai transmission integral has been added.
References adde
On the spectrum of a bent chain graph
We study Schr\"odinger operators on an infinite quantum graph of a chain form
which consists of identical rings connected at the touching points by
-couplings with a parameter . If the graph is "straight",
i.e. periodic with respect to ring shifts, its Hamiltonian has a band spectrum
with all the gaps open whenever . We consider a "bending"
deformation of the chain consisting of changing one position at a single ring
and show that it gives rise to eigenvalues in the open spectral gaps. We
analyze dependence of these eigenvalues on the coupling and the
"bending angle" as well as resonances of the system coming from the bending. We
also discuss the behaviour of the eigenvalues and resonances at the edges of
the spectral bands.Comment: LaTeX, 23 pages with 7 figures; minor changes, references added; to
appear in J. Phys. A: Math. Theo
Bound states in point-interaction star-graphs
We discuss the discrete spectrum of the Hamiltonian describing a
two-dimensional quantum particle interacting with an infinite family of point
interactions. We suppose that the latter are arranged into a star-shaped graph
with N arms and a fixed spacing between the interaction sites. We prove that
the essential spectrum of this system is the same as that of the infinite
straight "polymer", but in addition there are isolated eigenvalues unless N=2
and the graph is a straight line. We also show that the system has many
strongly bound states if at least one of the angles between the star arms is
small enough. Examples of eigenfunctions and eigenvalues are computed
numerically.Comment: 17 pages, LaTeX 2e with 9 eps figure
Relative Oscillation Theory, Weighted Zeros of the Wronskian, and the Spectral Shift Function
We develop an analog of classical oscillation theory for Sturm-Liouville
operators which, rather than measuring the spectrum of one single operator,
measures the difference between the spectra of two different operators.
This is done by replacing zeros of solutions of one operator by weighted
zeros of Wronskians of solutions of two different operators. In particular, we
show that a Sturm-type comparison theorem still holds in this situation and
demonstrate how this can be used to investigate the finiteness of eigenvalues
in essential spectral gaps. Furthermore, the connection with Krein's spectral
shift function is established.Comment: 26 page
Schroedinger operators with singular interactions: a model of tunneling resonances
We discuss a generalized Schr\"odinger operator in , with an attractive singular interaction supported by a
-dimensional hyperplane and a finite family of points. It can be
regarded as a model of a leaky quantum wire and a family of quantum dots if
, or surface waves in presence of a finite number of impurities if .
We analyze the discrete spectrum, and furthermore, we show that the resonance
problem in this setting can be explicitly solved; by Birman-Schwinger method it
is cast into a form similar to the Friedrichs model.Comment: LaTeX2e, 34 page
Facilitating implementation of medication reviews in the community pharmacy setting: an application of the implementation research logic model.
Previous research has identified both determinants and potential strategies to facilitate implementation of medication reviews (MR). A conceptual model which links determinants, strategies to support implementation and mechanisms of change to execute implementation, with projected outcomes is helpful to plan the approach and facilitate MR-implementation. The aim of this research was to apply the Implementation Research Logic Model (ILRM) for the implementation of medication reviews in the German community pharmacy setting, and thus illustrate the links between determinants, strategies, and implementation outcomes. The resulting map is meant to inform and facilitate MR-implementation. The IRLM was populated with determinants (barriers and facilitators structured using the Framework for Implementation of Services in Pharmacy, FISpH), proposed strategies (according to the Expert Recommendations for Implementing Change, ERIC) and mechanisms of change which were identified in an interview study with 21 German pharmacy owners. The research team linked these with 8 implementation outcomes derived from Proctor: acceptability, adoption, appropriateness, cost, feasibility, fidelity, penetration, sustainability. Twenty strategies from the interview study were mapped against 32 determinants. All strategies were hypothesised to impact on one or several of the 8 implementation outcomes. Depending on pharmacies' implementation stage (exploration, preparation, implementation, and sustainment) the importance of strategies was expected to vary. Strategies such as educational meetings and learning collaboratives can increase perceived appropriateness and boost adoption of MRs which is particularly important for pharmacies in the early exploration stage. Strategies such as receiving support from external implementation advisors as well as recruiting and training internal implementation leaders were deemed particularly important for pharmacies at the preparation stage to strengthen feasibility and fidelity. In later stages (implementation and sustainment) pharmacies were thought to benefit from provision of clinical feedback, obtaining and using patient feedback and re-examining implementation to achieve high fidelity, penetration, and sustainability of MR-provision. Some strategies such as fixed payment and stable delivery contracts were deemed pre-requisites for implementation irrespective of the stage the pharmacy was at. The application of the Implementation Research Logic Model illustrated the relations between determinants, strategies, mechanisms, and implementation outcomes. Future research is needed to ascertain that strategies work as planned and achieve the projected implementation outcomes
- …