1,220 research outputs found
Effect of SRP on relation of GCF IL-8 and granulocyte elastase to periodontopathogens
published_or_final_versio
Ordering phenomena in quasi one-dimensional organic conductors
Low-dimensional organic conductors could establish themselves as model
systems for the investigation of the physics in reduced dimensions. In the
metallic state of a one-dimensional solid, Fermi-liquid theory breaks down and
spin and charge degrees of freedom become separated. But the metallic phase is
not stable in one dimension: as the temperature is reduced, the electronic
charge and spin tend to arrange themselves in an ordered fashion due to strong
correlations. The competition of the different interactions is responsible for
which broken-symmetry ground state is eventually realized in a specific
compound and which drives the system towards an insulating state.
Here we review the various ordering phenomena and how they can be identified
by optic and magnetic measurements. While the final results might look very
similar in the case of a charge density wave and a charge-ordered metal, for
instance, the physical cause is completely different. When density waves form,
a gap opens in the density of states at the Fermi energy due to nesting of the
one-dimension Fermi surface sheets. When a one-dimensional metal becomes a
charge-ordered Mott insulator, on the other hand, the short-range Coulomb
repulsion localizes the charge on the lattice sites and even causes certain
charge patterns.
We try to point out the similarities and conceptional differences of these
phenomena and give an example for each of them. Particular emphasis will be put
on collective phenomena which are inherently present as soon as ordering breaks
the symmetry of the system.Comment: Review article Naturwissenschaften 200
An exploratory cluster randomised controlled trial of knowledge translation strategies to support evidence-informed decision-making in local governments (The KT4LG study)
Background: Childhood overweight and obesity is the most prevalent and, arguably, politically complex child health problem internationally. Governments, communities and industry have important roles to play, and are increasingly expected to deliver an evidence-informed system-wide prevention program. However, efforts are impeded by a lack of organisational access to and use of research evidence. This study aims to identify feasible, acceptable and ideally, effective knowledge translation (KT) strategies to increase evidence-informed decision making in local governments, within the context of childhood obesity prevention as a national policy priority.Methods/Design: This paper describes the methods for KT4LG, a cluster randomised controlled trial which is exploratory in nature, given the limited evidence base and methodological advances. KT4LG aims to examine a program of KT strategies to increase the use of research evidence in informing public health decisions in local governments. KT4LG will also assess the feasibility and acceptability of the intervention. The intervention program comprises a facilitated program of evidence awareness, access to tailored research evidence, critical appraisal skills development, networking and evidence summaries and will be compared to provision of evidence summaries alone in the control program. 28 local governments were randomised to intervention or control, using computer generated numbers, stratified by budget tertile (high, medium or low). Questionnaires will be used to measure impact, costs, and outcomes, and key informant interviews will be used to examine processes, feasibility, and experiences. Policy tracer studies will be included to examine impact of intervention on policies within relevant government policy documents.Discussion: Knowledge translation intervention studies with a focus on public health and prevention are very few in number. Thus, this study will provide essential data on the experience of program implementation and evaluation of a system-integrated intervention program employed within the local government public health context. Standardised programs of system, organisational and individual KT strategies have not been described or rigorously evaluated. As such, the findings will make a significant contribution to understanding whether a facilitated program of KT strategies hold promise for facilitating evidence-informed public health decision making within complex multisectoral government organisations.<br /
Minimal change in structural, functional and inflammatory markers of lung disease in newborn screened infants with cystic fibrosis at one year
BACKGROUND: With the widespread introduction of newborn screening for cystic fibrosis (CF), there has been considerable emphasis on the need to develop objective markers of lung health that can be used during infancy. We hypothesised that in a newborn screened (NBS) UK cohort, evidence of airway inflammation and infection at one year would be associated with adverse structural and functional outcomes at the same age. METHODS: Infants underwent lung function testing, chest CT scan and bronchoscopy with bronchoalveolar lavage (BAL) at 1 year of age when clinically well. Microbiology cultures were also available from routine cough swabs. RESULTS: 65 infants had lung function, CT and BAL. Mean (SD) lung clearance index and forced expiratory volume in 0.5 s z-scores were 0.9(1.2) and -0.6(1.1) respectively; median Brody II CF-CT air trapping score on chest CT =0 (interquartile range 0-1, maximum possible score 27). Infants isolating any significant pathogen by 1 yr of age had higher LCI z-score (mean difference 0.9; 95%CI:0.4-1.4; p = 0.001) and a trend towards higher air trapping scores on CT (p = 0.06). BAL neutrophil elastase was detectable in 23% (10/43) infants in whom BAL supernatant was available. This did not relate to air trapping score on CT. CONCLUSIONS: In this UK NBS cohort at one year of age, lung and airway damage is much milder and associations between inflammation, abnormal physiology and structural changes were at best weak, contrary to our hypothesis and previously published reports. Continued follow-up will clarify longer term implications of these very mild structural, functional and inflammatory changes
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Bioavailability in soils
The consumption of locally-produced vegetables by humans may be an important exposure pathway for soil contaminants in many urban settings and for agricultural land use. Hence, prediction of metal and metalloid uptake by vegetables from contaminated soils is an important part of the Human Health Risk Assessment procedure. The behaviour of metals (cadmium, chromium, cobalt, copper, mercury, molybdenum, nickel, lead and zinc) and metalloids (arsenic, boron and selenium) in contaminated soils depends to a large extent on the intrinsic charge, valence and speciation of the contaminant ion, and soil properties such as pH, redox status and contents of clay and/or organic matter. However, chemistry and behaviour of the contaminant in soil alone cannot predict soil-to-plant transfer. Root uptake, root selectivity, ion interactions, rhizosphere processes, leaf uptake from the atmosphere, and plant partitioning are important processes that ultimately govern the accumulation ofmetals and metalloids in edible vegetable tissues. Mechanistic models to accurately describe all these processes have not yet been developed, let alone validated under field conditions. Hence, to estimate risks by vegetable consumption, empirical models have been used to correlate concentrations of metals and metalloids in contaminated soils, soil physico-chemical characteristics, and concentrations of elements in vegetable tissues. These models should only be used within the bounds of their calibration, and often need to be re-calibrated or validated using local soil and environmental conditions on a regional or site-specific basis.Mike J. McLaughlin, Erik Smolders, Fien Degryse, and Rene Rietr
Shot noise in mesoscopic systems
This is a review of shot noise, the time-dependent fluctuations in the
electrical current due to the discreteness of the electron charge, in small
conductors. The shot-noise power can be smaller than that of a Poisson process
as a result of correlations in the electron transmission imposed by the Pauli
principle. This suppression takes on simple universal values in a symmetric
double-barrier junction (suppression factor 1/2), a disordered metal (factor
1/3), and a chaotic cavity (factor 1/4). Loss of phase coherence has no effect
on this shot-noise suppression, while thermalization of the electrons due to
electron-electron scattering increases the shot noise slightly. Sub-Poissonian
shot noise has been observed experimentally. So far unobserved phenomena
involve the interplay of shot noise with the Aharonov-Bohm effect, Andreev
reflection, and the fractional quantum Hall effect.Comment: 37 pages, Latex, 10 figures (eps). To be published in "Mesoscopic
Electron Transport," edited by L. P. Kouwenhoven, G. Schoen, and L. L. Sohn,
NATO ASI Series E (Kluwer Academic Publishing, Dordrecht
PABPN1 gene therapy for oculopharyngeal muscular dystrophy
International audienceOculopharyngeal muscular dystrophy (OPMD) is an autosomal dominant, late-onset muscle disorder characterized by ptosis, swallowing difficulties, proximal limb weakness and nuclear aggregates in skeletal muscles. OPMD is caused by a trinucleotide repeat expansion in the PABPN1 gene that results in an N-terminal expanded polyalanine tract in polyA-binding protein nuclear 1 (PABPN1). Here we show that the treatment of a mouse model of OPMD with an adeno-associated virus-based gene therapy combining complete knockdown of endogenous PABPN1 and its replacement by a wild-type PABPN1 substantially reduces the amount of insoluble aggregates, decreases muscle fibrosis, reverts muscle strength to the level of healthy muscles and normalizes the muscle transcriptome. The efficacy of the combined treatment is further confirmed in cells derived from OPMD patients. These results pave the way towards a gene replacement approach for OPMD treatment
Cytochemical techniques and energy-filtering transmission electron microscopy applied to the study of parasitic protozoa
The study of parasitic protozoa plays a major role in cell biology, biochemistry and molecular biology. Numerous cytochemical techniques have been developed in order to unequivocally identify the nature of subcellular compartments. Enzyme and immuno-cytochemistry allow the detection of, respectively, enzymatic activity products and antigens in particular sites within the cell. Energy-filtering transmission electron microscopy permits the detection of specific elements within such compartments. These approaches are particularly useful for studies employing antimicrobial agents where cellular compartments may be destroyed or remarkably altered and thus hardly identified by standard methods of observation. In this regard cytochemical and spectroscopic techniques provide valuable data allowing the determination of the mechanisms of action of such compounds
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