A meta-analysis on the prophylactic use of macrolide antibiotics for the prevention of disease exacerbations in patients with Chronic Obstructive Pulmonary Disease

SummaryIntroductionMacrolides are of unique interest in preventing COPD exacerbations because they possess a variety of antibacterial, antiviral and anti-inflammatory properties. Recent research has generated renewed interest in prophylactic macrolides to reduce the risk of COPD exacerbations. Little is known about how well these recent findings fit within the context of previous research on this subject. The purpose of this article is to evaluate, via exploratory meta-analysis, whether the overall consensus favors prophylactic macrolides for prevention of COPD exacerbations.MethodsEMBASE, Cochrane and Medline databases were searched for all relevant randomized controlled trials (RCTs). Six RCTs were identified. The primary endpoint was incidence of COPD exacerbations. Secondary endpoints including mortality, hospitalization rates, adverse events and likelihood of having at least one COPD exacerbation were also examined.ResultsThere was a 37% relative risk reduction (RR = 0.63, 95% CI: 0.45–0.87, p value = 0.005) in COPD exacerbations among patients taking macrolides compared to placebo. Furthermore, there was a 21% reduced risk of hospitalization (RR = 0.79, 95% CI: 0.69–0.90, p-value = 0.01) and 68% reduced risk of having at least one COPD exacerbation (RR = 0.34, 95% CI 0.21–0.54, p-value = 0.001) among patients taking macrolides versus placebo. There was also a trend toward decreased mortality and increased adverse events among patients taking macrolides but these were not statistically significant.ConclusionsProphylactic macrolides are an effective approach for reducing incident COPD exacerbations. There were several limitations to this study including a lack of consistent adverse event reporting and some degree of clinical and statistical heterogeneity between studies

Investigating the probable consequences of super absorbent polymer and mycorrhizal fungi to reduce detrimental effects of lead on wheat (Triticum aestivum L.)

ArticleIn many parts of the world, agricultural use of soils is restricted due to heavy metal contamination. Absorption of heavy metals, such as (Pb), in the tissue of plants increases the plant’s metabolism and causes physiological disorders or even death. In order to study the potential of super absorbent polymers (SAP) and mycorrhiza fungi application to mitigate adverse effects of lead (Pb) on wheat, a greenhouse experiment was conducted. The experiment was setup as a completely randomized design, with two treatments arranged in a factorial scheme with three levels of lead (0, 100 and 200 mg per kg soil) and four levels of SAP and mycorrhiza fungi application (without SAP and mycorrhiza fungi application, SAP application alone, mycorrhiza fungi application alone, SAP and mycorrhiza fungi application combined). The results showed that Pb significantly affected all parameters measured of wheat. The Pb-contamination caused a significantly decreasing in plant height, total dry weight per plant and total chlorophyll contents. And also, the results indicated that the combined use of superabsorbent and mycorrhiza reduced the amount of superoxide dismutase enzyme. As well as, our results show that the application of super absorbent polymer and mycorrhizal fungi seems to be a promising path to reduce detrimental effects of heavy metal pollution of agricultural soils on plant performance.http://dx.doi.org/10.15159/ar.18.00

Violation of critical universality at the antiferromagnetic phase transition of YbRh2Si2

We report on precise low-temperature specific-heat measurements, C(T), of YbRh2Si2 in the vicinity of the antiferromagnetic phase transition on a single crystal of superior quality (RRR 150). We observe a very sharp peak at T_N=72mK with absolute values as high as C/T=8J/molK^2. A detailed analysis of the critical exponent \alpha around T_N reveals \alpha=0.38 which differs significantly from those of the conventional universality classes in the Ginzburg-Landau theory, where \alpha<0.11. Thermal-expansion measurements corroborate this large positive critical exponent. These results provide insight into the nature of the critical magnetic fluctuations at a temperature-driven phase transition close to a quantum critical point.Comment: Accepted for PR

A tilted grating interferometer for full vector field differential x-ray phase contrast tomography

We report on a setup for differential x-ray phase-contrast imaging and tomography, that measures the full 2D phase-gradient information. The setup uses a simple one-dimensional x-ray grating interferometer, in which the grating structures of the interferometer are oriented at a tilt angle with respect to the sample rotation axis. In such a configuration, the differential phase images from opposing tomography projections can be combined to yield both components of the gradient vector. We show how the refractive index distribution as well as its x, y, and z gradient components can be reconstructed directly from the recorded projection data. The method can equally well be applied at conventional x-ray tube sources, to analyzer based x-ray imaging or neutron imaging. It is demonstrated with measurements of an x-ray phantom and a rat brain using synchrotron radiation

Pressure dependence of the Néel and the superconducting transition temperature of CeCo(In0.9Cd0.1)5 studied by thermal expansion

We present low-temperature thermal expansion measurements on the nominally 10% Cd doped CeCoIn5. While the superconducting transition temperature is monotonically suppressed, an antiferromagnetic phase evolves in CeCoIn5 by Cd-doping. For the uniaxial pressure dependence of the Néel temperature along c, we find (∂ TN / ∂ p)∥ c = 0.206 K / GPa. The magnetic field dependence (for B ∥ c) of TN is stronger compared to CeRhIn5. As no traces of a superconducting transition are resolved in thermal expansion along the c-axis, we estimate a lower limit of the in-plane pressure dependence to (∂ Tc / ∂ p)⊥ c = 0.38 K / GPa. © 2007 Elsevier B.V. All rights reserved

Effect of chemical disorder on NiMnSb investigated by Appearance Potential Spectroscopy: a theoretical study

The half-Heusler alloy NiMnSb is one of the local-moment ferromagnets with unique properties for future applications. Band structure calculations predict exclusively majority bands at the Fermi level, thus indicating {100%} spin polarization there. As one thinks about applications and the design of functional materials, the influence of chemical disorder in these materials must be considered. The magnetization, spin polarization, and electronic structure are expected to be sensitive to structural and stoichiometric changes. In this contribution, we report on an investigation of the spin-dependent electronic structure of NiMnSb. We studied the influence of chemical disorder on the unoccupied electronic density of states by use of the ab-initio Coherent Potential Approximation method. The theoretical analysis is discussed along with corresponding spin-resolved Appearance Potential Spectroscopy measurements. Our theoretical approach describes the spectra as the fully-relativistic self-convolution of the matrix-element weighted, orbitally resolved density of states.Comment: JPD submitte

Quantum criticality in layered CeRhIn_{5-x}Sn_x compared with cubic CeIn$_{3-x}Sn_x

We report low-temperature thermal-expansion measurements on single crystals of the {\it layered} heavy fermion system \cri ($0.3\leq x \leq 0.6$) and compare it with a previous study on the related {\it cubic} system \ci [R. K\"{u}chler {\it et al.}, Phys. Rev. Lett. {\bf 96}, 256403 (2006)]. Both systems display a quantum critical point as proven by a divergent Gr\"uneisen ratio. Most remarkably, the three-dimensional itinerant model explains quantum criticality in {\it both} systems, suggesting that the crystalline anisotropy in \cri is unimportant. This is ascribed to the effect of weak disorder in these doped systems.Comment: Eur. Phys. Lett., to be publishe

Ferromagnetic Kondo-Lattice Model

We present a many-body approach to the electronic and magnetic properties of the (multiband) Kondo-lattice model with ferromagnetic interband exchange. The coupling between itinerant conduction electrons and localized magnetic moments leads, on the one hand, to a distinct temperature-dependence of the electronic quasiparticle spectrum and, on the other hand, to magnetic properties, as e.~g.the Curie temperature T_C or the magnon dispersion, which are strongly influenced by the band electron selfenergy and therewith in particular by the carrier density. We present results for the single-band Kondo-lattice model in terms of quasiparticle densities of states and quasiparticle band structures and demonstrate the density-dependence of the self-consistently derived Curie temperature. The transition from weak-coupling (RKKY) to strong-coupling (double exchange) behaviour is worked out. The multiband model is combined with a tight-binding-LMTO bandstructure calculation to describe real magnetic materials. As an example we present results for the archetypal ferromagnetic local-moment systems EuO and EuS. The proposed method avoids the double counting of relevant interactions and takes into account the correct symmetry of atomic orbitals.Comment: 15 pages, 10 figure