72 research outputs found
Direct Observation of Propagating Gigahertz Coherent Guided Acoustic Phonons in Free Standing Single Copper Nanowires
We report on gigahertz acoustic phonon waveguiding in free-standing single
copper nanowires studied by femtosecond transient reflectivity measurements.
The results are discussed on the basis of the semianalytical resolution of the
Pochhammer and Chree equation. The spreading of the generated Gaussian wave
packet of two different modes is derived analytically and compared with the
observed oscillations of the sample reflectivity. These experiments provide a
unique way to independently obtain geometrical and material characterization.
This direct observation of coherent guided acoustic phonons in a single
nano-object is also the first step toward nanolateral size acoustic transducer
and comprehensive studies of the thermal properties of nanowires
Peripheral immune circadian variation, synchronisation and possible dysrhythmia in established type 1 diabetes
Aims/hypothesis: The circadian clock influences both diabetes and immunity. Our goal in this study was to characterise more thoroughly the circadian patterns of immune cell populations and cytokines that are particularly relevant to the immune pathology of type 1 diabetes and thus fill in a current gap in our understanding of this disease.
Methods: Ten individuals with established type 1 diabetes (mean disease duration 11 years, age 18-40 years, six female) participated in a circadian sampling protocol, each providing six blood samples over a 24 h period.
Results: Daily ranges of population frequencies were sometimes large and possibly clinically significant. Several immune populations, such as dendritic cells, CD4 and CD8 T cells and their effector memory subpopulations, CD4 regulatory T cells, B cells and cytokine IL-6, exhibited statistically significant circadian rhythmicity. In a comparison with historical healthy control individuals, but using shipped samples, we observed that participants with type 1 diabetes had statistically significant phase shifts occurring in the time of peak occurrence of B cells (+4.8 h), CD4 and CD8 T cells (~ +5 h) and their naive and effector memory subsets (~ +3.3 to +4.5 h), and regulatory T cells (+4.1 h). An independent streptozotocin murine experiment confirmed the phase shifting of CD8 T cells and suggests that circadian dysrhythmia in type 1 diabetes might be an effect and not a cause of the disease.
Conclusions/interpretation: Future efforts investigating this newly described aspect of type 1 diabetes in human participants are warranted. Peripheral immune populations should be measured near the same time of day in order to reduce circadian-related variation
Effect of synbiotic supplementation in children and adolescents with cystic fibrosis: a randomized controlled clinical trial
BACKGROUND/OBJECTIVES:Cystic fibrosis (CF) is characterized by excessive activation of immune processes. The aim of this study was to evaluate the effect of synbiotic supplementation on the inflammatory response in children/adolescents with CF.
SUBJECTS/METHODS:A randomized, placebo-controlled, double-blind, clinical-trial was conducted with control group (CG, n = 17), placebo-CF-group (PCFG, n = 19), synbiotic CF-group (SCFG, n = 22), PCFG negative (n = 8) and positive (n = 11) bacteriology, and SCFG negative (n = 12) and positive (n = 10) bacteriology. Markers of lung function (FEV1), nutritional status [body mass index-for age (BMI/A), height-for-age (H/A), weight-for-age (W/A), upper-arm fat area (UFA), upper-arm muscle area (UMA), body fat (%BF)], and inflammation [interleukin (IL)-12, tumor necrosis factor-alpha (TNF-α), IL-10, IL-6, IL-1β, IL-8, myeloperoxidase (MPO), nitric oxide metabolites (NOx)] were evaluated before and after 90-day of supplementation with a synbiotic.
RESULTS:No significance difference was found between the baseline and end evaluations of FEV1 and nutricional status markers. A significant interaction (time vs. group) was found for IL-12 (p = 0.010) and myeloperoxidase (p = 0.036) between PCFG and SCFG, however, the difference was not maintained after assessing the groups individually. NOx diminished significantly after supplementation in the SCFG (p = 0.030). In the SCFG with positive bacteriology, reductions were found in IL-6 (p = 0.033) and IL-8 (p = 0.009) after supplementation.
CONCLUSIONS: Synbiotic supplementation shown promise at diminishing the pro-inflammatory markers IL-6, IL-8 in the SCFG with positive bacteriology and NOx in the SCFG in children/adolescents with CF
Chandra and Spitzer unveil heavily obscured quasars in the SWIRE/Chandra Survey
Using the large multi-wavelength data set in the chandra/SWIRE Survey (0.6
square degrees in the Lockman Hole), we show evidence for the existence of
highly obscured (Compton-thick) AGN, estimate a lower limit to their surface
density and characterize their multi-wavelength properties. Two independent
selection methods based on the X-ray and infrared spectral properties are
presented. The two selected samples contain 1) 5 X-ray sources with hard X-ray
spectra and column densities > 10^24 cm-2, and 2) 120 infrared sources with red
and AGN-dominated infrared spectral energy distributions (SEDs). We estimate a
surface density of at least 25 Compton-thick AGN per square degree detected in
the infrared in the chandra/SWIRE field of which ~40% show distinct AGN
signatures in their optical/near-infrared SEDs, the remainings being dominated
by the host-galaxy emission. Only ~33% of all Compton-thick AGN are detected in
the X-rays at our depth (F(0.3-8 keV)>10^-15 erg/cm2/s.
We report the discovery of two sources in our sample of Compton-thick AGN,
SWIRE_J104409.95+585224.8 (z=2.54) and SWIRE_J104406.30+583954.1 (z=2.43),
which are the most luminous Compton-thick AGN at high-z currently known. The
properties of these two sources are discussed in detail with an analysis of
their spectra, SEDs, luminosities and black-hole masses.Comment: ApJ accepted (to appear in May 2006 issue, vol. 642, of ApJ) Figures
2, 3, and 14 have been degraded due to space consideration
199 Baricitinib in patients with systemic lupus erythematosus: results from a phase 2, randomized, double-blind, placebo-controlled study
n/
Productivity in Electricity Retail after Market Liberalisation: Analysing the Effects of Ownership and Firm's Governance Structure
Hydrolyzed collagen (gelatin) decreases food efficiency and the bioavailability of high-quality protein in rats
Reproducibility in the absence of selective reporting : An illustration from large-scale brain asymmetry research
Altres ajuts: Max Planck Society (Germany).The problem of poor reproducibility of scientific findings has received much attention over recent years, in a variety of fields including psychology and neuroscience. The problem has been partly attributed to publication bias and unwanted practices such as p-hacking. Low statistical power in individual studies is also understood to be an important factor. In a recent multisite collaborative study, we mapped brain anatomical left-right asymmetries for regional measures of surface area and cortical thickness, in 99 MRI datasets from around the world, for a total of over 17,000 participants. In the present study, we revisited these hemispheric effects from the perspective of reproducibility. Within each dataset, we considered that an effect had been reproduced when it matched the meta-analytic effect from the 98 other datasets, in terms of effect direction and significance threshold. In this sense, the results within each dataset were viewed as coming from separate studies in an "ideal publishing environment," that is, free from selective reporting and p hacking. We found an average reproducibility rate of 63.2% (SD = 22.9%, min = 22.2%, max = 97.0%). As expected, reproducibility was higher for larger effects and in larger datasets. Reproducibility was not obviously related to the age of participants, scanner field strength, FreeSurfer software version, cortical regional measurement reliability, or regional size. These findings constitute an empirical illustration of reproducibility in the absence of publication bias or p hacking, when assessing realistic biological effects in heterogeneous neuroscience data, and given typically-used sample sizes
Finishing the euchromatic sequence of the human genome
The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead
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