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The effects of confining molecular hydrogen within carbon nanohorns are studied via high-resolution quasielastic and inelastic neutron spectroscopies. Both sets of data are remarkably different from those obtained in bulk samples in the liquid and crystalline states. At temperatures where bulk hydrogen is liquid, the spectra of the confined sample show an elastic component indicating a significant proportion of immobile molecules as well as distinctly narrower quasielastic line widths and a strong distortion of the line shape of the para-->ortho rotational transition. The results show that hydrogen interacts far more strongly with such carbonous structures than it does to carbon nanotubes, suggesting that nanohorns and related nanostructures may offer significantly better prospects as lightweight media for hydrogen storage applications.

We characterized a newly isolated bacterium, designated as IR1, with respect to its ability to degrade polycyclic aromatic hydrocarbons (PAHs) and to produce biosurfactants. Isolated IR1 was identified as Pseudomonas putida by analysis of 16S rRNA sequences (99.6% homology). It was capable of utilizing two-, three- and four-ring PAHs but not hexadecane and octadecane as a sole carbon and energy source. PCR and DNA hybridization studies showed that enzymes involved in PAH metabolism were related to the naphthalene dioxygenase pathway. Observation of both tensio-active and emulsifying activities indicated that biosurfactants were produced by IR1 during growth on both water miscible and immiscible substrates. The biosurfactants lowered the surface tension of medium from 54.9 dN cm−1 to 35.4 dN cm−1 and formed a stable and compact emulsion with an emulsifying activity of 74% with diesel oil, when grown on dextrose. These findings indicate that this isolate may be useful for bioremediation of sites contaminated with aromatic hydrocarbons.

Using the Mainz 48 cm лϫ64 cm NaI͑Tl͒ detector and the segmented Göttingen recoil detector SENECA in coincidence, Compton scattering by the proton at ␥ lab ϭ136°has been measured at MAMI ͑Mainz͒ in the energy range from 200 to 470 MeV. The new data confirm the previous observation that there is a systematic discrepancy between MAMI and LEGS ͑Brookhaven͒ data leading to different spin polarizabilities ␥ ϭ Ϫ38.7Ϯ1.8 and Ϫ27.2Ϯ3.1 (ϫ10 Ϫ4 fm 4 ), respectively.

Background and Purpose-High-sensitivity C-reactive protein (hsCRP) and lipoprotein-associated phospholipase A 2 (Lp-PLA 2 ) are hypothesized to be biomarkers of systemic inflammation and risk of myocardial infarction (MI) and stroke. Little is known, however, about the stability of these markers over time, and in particular, about the effects of acute vascular events on these marker levels. Methods-Serum samples were collected at 4 annual intervals in 52 stroke-free participants from the Northern Manhattan Study (NOMAS) and assayed for hsCRP and Lp-PLA 2 mass and activity levels using standard techniques. Log transformation of levels was performed as needed to stabilize the variance. Stability of marker levels over time was assessed using random effects models unadjusted and adjusted for demographics and other risk factors. In addition, samples from 37 initially stroke-free participants with stroke (nϭ17) or MI (nϭ20) were available for measurement before and after the vascular event (median 5 days, range 2 to 40 days). Levels before and after events were compared using nonparametric tests. Results-HsCRP and Lp-PLA 2 activity levels were stable over time, whereas Lp-PLA 2 mass levels decreased on average 5% per year (Pϭ0.0015). Using accepted thresholds to define risk categories of Lp-PLA 2 mass, there was no significant change over time. HsCRP increased after stroke (from median 2.2 mg/L prestroke to 6.5 mg/L poststroke; Pϭ0.0067) and MI (from median 2.5 mg/L pre-MI to 13.5 mg/L post-MI; PϽ0.0001). Lp-PLA 2 mass and activity levels both decreased significantly after stroke and MI (for Lp-PLA 2 mass, from median 210.0 ng/mL to 169.4 ng/mL poststroke, Pϭ0.0348, and from median 233.0 ng/mL to 153.9 post-MI, PϽ0.0001). Conclusion-Lp-PLA 2 mass levels decrease modestly, whereas hsCRP and Lp-PLA 2 activity appear stable over time.Acutely after stroke and MI, hsCRP increases whereas Lp-PLA 2 mass and activity levels decrease. These changes imply that measurements made soon after stroke and MI are not reflective of prestroke levels and may be less reliable for long-term risk stratification. (Stroke. 2009;40:3233-3237.)

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