1,086 research outputs found

    Pulsed-laser studies on the free-radical polymerization kinetics of styrene in microemulsion

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    A mean value of 339 L mol-1 s-1 was obtained for the propagation const. derived from pulsed-laser polymn. (PLP) of styrene in aq. AOT microemulsions. For accurate detns., simulations accounting for the esp. high radical concn. after the laser pulse in microemulsions were recommended. PLP with microemulsions apparently permitted specific kinetic aspects such as transfer to monomer and influence of droplet size on bimol. termination to be studied in detai

    Organization and dynamics of the SpoVAEa protein and its surrounding inner membrane lipids, upon germination of <i>Bacillus</i> <i>subtilis</i> spores

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    The SpoVA proteins make up a channel in the inner membrane (IM) of Bacillus subtilis spores. This channel responds to signals from activated germinant receptors (GRs), and allows release of Ca(2+)-DPA from the spore core during germination. In the current work, we studied the location and dynamics of SpoVAEa in dormant spores. Notably, the SpoVAEa-SGFP2 proteins were present in a single spot in spores, similar to the IM complex formed by all GRs termed the germinosome. However, while the GRs’ spot remains in one location, the SpoVAEa-SGFP2 spot in the IM moved randomly with high frequency. It seems possible that this movement may be a means of communicating germination signals from the germinosome to the IM SpoVA channel, thus stimulating CaDPA release in germination. The dynamics of the SpoVAEa-SGFP2 and its surrounding IM region as stained by fluorescent dyes were also tracked during spore germination, as the dormant spore IM appeared to have an immobile germination related functional microdomain. This microdomain disappeared around the time of appearance of a germinated spore, and the loss of fluorescence of the IM with fluorescent dyes, as well as the appearance of peak SpoVAEa-SGFP2 fluorescent intensity occurred in parallel. These observed events were highly related to spores’ rapid phase darkening, which is considered as due to rapid Ca(2+)DPA release. We also tested the response of SpoVAEa and the IM to thermal treatments at 40–80 °C. Heat treatment triggered an increase of green autofluorescence, which is speculated to be due to coat protein denaturation, and 80 °C treatments induce the appearance of phase-grey-like spores. These spores presumably have a similar intracellular physical state as the phase grey spores detected in the germination but lack the functional proteins for further germination events

    Satanisme gesien vanuit 'n pastorale perspektief

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    Carbonic anhydrase-9 expression levels and prognosis in human breast cancer: association with treatment outcome

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    Item does not contain fulltextHere, we set out to assess CA9 expression levels by real-time quantitative RT-PCR in breast cancer tissue samples obtained from 253 patients, and correlated those with relapse-free (RFS) survival. The median follow-up time was 75 months (range 2-168 months). CA9 expression was mainly found in high-grade, steroid receptor negative cancer tissues. CA9 levels were not significantly associated with RFS (P=0.926, hazard ratio (HR)=0.99, 95% CI=0.80-1.22) in the total cohort of 253 patients. In multivariate analysis with other clinicopathological factors, CA9 (P=0.018, HR=0.77, 95% CI=0.62-0.96), the interaction of adjuvant chemotherapy with CA9 (P=0.009, HR=1.31, 95% CI=1.07-1.61) and the interaction of adjuvant endocrine therapy with CA9 (P<0.001, HR=1.41, 95% CI=1.20-1.66) all contributed significantly to the final model. These results indicate that patients with low CA9 levels benefit more from adjuvant treatment than do patients with high levels. Thus, the determination of CA9 levels could aid in the selection of patients who will not benefit from adjuvant therapy, and whose prognosis will more likely improve with other treatment modalities
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