| 1. |
- Mah, KW, et al.
(author)
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Distinct pattern of commensal gut microbiota in toddlers with eczema
- 2006
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In: International archives of allergy and immunology. - : S. Karger AG. - 1018-2438 .- 1423-0097. ; 140:2, s. 157-163
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Journal article (peer-reviewed)abstract
- <i>Background:</i> Recent studies have demonstrated differences in the composition of gut microbiota in infants with and without allergic diseases, particularly eczema. <i>Methods:</i> A case-control study involving 21 toddlers (age 3.0 ± 0.5 years) with and 28 age-matched toddlers without eczema was conducted. Four groups of aerobic gut microbiota were identified and quantitated in stool samples grown on selective media. Three groups of anaerobes were enumerated by fluorescent in situ hybridization followed by quantitative flow cytometry. We also performed molecular typing of lactic-acid-producing bacteria (LAB) and enterococcal isolates to facilitate detailed analysis at species level by bacterial 16S rDNA sequencing. <i>Results:</i> Toddlers with eczema harbored significantly lower counts of <i>Bifidobacterium</i> [(median 0.14 (25th and 75th percentile: 0.04 and 0.47) vs. 0.71% (0.16, 1.79) of cells acquired, p = 0.003)] and <i>Clostridium</i> [(0.28 (0.09, 0.78) vs. 0.83% (0.35, 1.82) of cells acquired, p = 0.012)] but significantly higher counts of total LAB [7.3 (6.1, 8.5) vs. 5.7 (4.4, 7.3) log CFU/g, p = 0.006] in particular enterococci [6.3 (4.8, 7.4) vs. 5.0 (3.4, 6.4) log CFU/g, p = 0.018]. There was no significant correlation between eczema severity score and bifidobacterial counts. <i>Conclusion:</i> The results further confirm previous reports that the gut microecosystem differs between children with and without eczema and extend them beyond infancy.
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| 2. |
- Schael, S, et al.
(author)
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Precision electroweak measurements on the Z resonance
- 2006
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In: Physics Reports. - : Elsevier BV. - 0370-1573 .- 1873-6270. ; 427:5-6, s. 257-454
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Research review (peer-reviewed)abstract
- We report on the final electroweak measurements performed with data taken at the Z resonance by the experiments operating at the electron-positron colliders SLC and LEP. The data consist of 17 million Z decays accumulated by the ALEPH, DELPHI, L3 and OPAL experiments at LEP, and 600 thousand Z decays by the SLID experiment using a polarised beam at SLC. The measurements include cross-sections, forward-backward asymmetries and polarised asymmetries. The mass and width of the Z boson, m(Z) and Gamma(Z), and its couplings to fermions, for example the p parameter and the effective electroweak mixing angle for leptons, are precisely measured: m(Z) = 91.1875 +/- 0.0021 GeV, Gamma(Z) = 2.4952 +/- 0.0023 GeV, rho(l) = 1.0050 +/- 0.0010, sin(2)theta(eff)(lept) = 0.23153 +/- 0.00016. The number of light neutrino species is determined to be 2.9840 +/- 0.0082, in agreement with the three observed generations of fundamental fermions. The results are compared to the predictions of the Standard Model (SM). At the Z-pole, electroweak radiative corrections beyond the running of the QED and QCD coupling constants are observed with a significance of five standard deviations, and in agreement with the Standard Model. Of the many Z-pole measurements, the forward-backward asymmetry in b-quark production shows the largest difference with respect to its SM expectation, at the level of 2.8 standard deviations. Through radiative corrections evaluated in the framework of the Standard Model, the Z-pole data are also used to predict the mass of the top quark, m(t) = 173(+10)(+13) GeV, and the mass of the W boson, m(W) = 80.363 +/- 0.032 GeV. These indirect constraints are compared to the direct measurements, providing a stringent test of the SM. Using in addition the direct measurements of m(t) and m(W), the mass of the as yet unobserved SM Higgs boson is predicted with a relative uncertainty of about 50% and found to be less than 285 GeV at 95% confidence level. (c) 2006 Elsevier B.V. All rights reserved.
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| 3. |
- Patra, Michael, et al.
(author)
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Under the influence of alcohol: The effect of ethanol and methanol on lipid bilayers
- 2006
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In: Biophysical Journal. - : Elsevier BV. - 1542-0086 .- 0006-3495. ; 90:4, s. 1121-1135
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Journal article (peer-reviewed)abstract
- Extensive microscopic molecular dynamics simulations have been performed to study the effects of short-chain alcohols, methanol and ethanol, on two different fully hydrated lipid bilayer systems (POPC and DPPC) in the fluid phase at 323 K. It is found that ethanol has a stronger effect on the structural properties of the membranes. In particular, the bilayers become more fluid and permeable: ethanol molecules are able to penetrate through the membrane in typical timescales of similar to 200 ns, whereas for methanol that timescale is considerably longer, at least of the order of microseconds. A closer examination exposes a number of effects due to ethanol. Hydrogen-bonding analysis reveals that a large fraction of ethanols is involved in hydrogen bonds with lipids. This in turn is intimately coupled to the ordering of hydrocarbon chains: we find that binding to an ethanol decreases the order of the chains. We have also determined the dependence of lipid-chain ordering on ethanol concentration and found that to be nonmonotonous. Overall, we find good agreement with NMR and micropipette studies.
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