16 research outputs found

    Carbon nanotubes : from molecular to macroscopic sensors

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    The components that contribute to Raman spectral shifts of single-wall carbon nanotubes (SWNT’s) embedded in polymer systems have been identified. The temperature dependence of the Raman shift can be separated into the temperature dependence of the nanotubes, the cohesive energy density of the polymer, and the buildup of thermal strain. Discounting all components apart from the thermal strain from the Raman shift-temperature data, it is shown that the mechanical response of single-wall carbon nanotubes in tension and compression are identical. The stress-strain response of SWNT’s can explain recent experimental data for carbon nanotube-composite systems

    Mechanical response of carbon nanotubes under molecular and macroscopic pressures

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    High hydrostatic pressures were applied to single-wall carbon nanotubes by means of a diamond anvil cell (DAC), and micro-Raman spectroscopy was simultaneously used to monitor the pressure-induced shift of various nanotube bands. The data confirm recent results independently obtained from internal pressure experiments with various liquids, where the peak shifts were considered to arise from compressive forces imposed by the liquids on the nanotubes. It is also shown that the nanotube peak at 1580 cm-1 (the G band) shifts linearly with pressure up to 20 000 atm and deviates from linearity at higher pressure. This deviation is found to be coincident with a drop in Raman intensity for the disorder-induced peak at 2610 cm-1 (the overtone of the D* band), possibly corresponding to the occurrence of reversible flattening of the nanotubes. The independent results presented here confirm the potential of nanotubes as molecular sensors

    Carbon nanotubes : from molecular to macroscopic sensors

    No full text
    The components that contribute to Raman spectral shifts of single-wall carbon nanotubes (SWNT’s) embedded in polymer systems have been identified. The temperature dependence of the Raman shift can be separated into the temperature dependence of the nanotubes, the cohesive energy density of the polymer, and the buildup of thermal strain. Discounting all components apart from the thermal strain from the Raman shift-temperature data, it is shown that the mechanical response of single-wall carbon nanotubes in tension and compression are identical. The stress-strain response of SWNT’s can explain recent experimental data for carbon nanotube-composite systems

    Berekening van ziekteverzuim : standaard voor verzuimregistratie

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    In juni 1996 is de 'Standaard voor berekening van ziekteverzuim' vastgesteld. Die standaard geeft nieuwe definities en rekenregels voor ziekteverzuim. Veel onduidelijkheid over rekenregels en definities van ziekteverzuim was aanleiding tot vaststelling van een standaard. Individuele bedrijven en traditionele producenten van verzuiminformatie gebruiken bijvoorbeeld uiteenlopende berekeningen. In dit boek wordt de Standaard gepresenteerd en toegelicht met de bedoeling duidelijkheid te scheppen, rekening te houden met actuele wensen en vergelijking van verzuimcijfers mogelijk te maken

    Supplementary Material for: Endothelial Interferon Regulatory Factor 1 Regulates Lipopolysaccharide-Induced VCAM-1 Expression Independent of NFκB

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    Sepsis is a severe systemic inflammatory response to infection. Endothelial activation and dysfunction play a critical role in the pathophysiology of sepsis and represent an important therapeutic target to reduce sepsis mortality. Interferon regulatory factor 1 (IRF-1) was recently identified as a downstream target of TNF-α-mediated signal transduction in endothelial cells. The aim of this study was to explore the importance of IRF-1 as a regulator of lipopolysaccharide (LPS)-induced endothelial proinflammatory activation. We found that renal IRF-1 was upregulated by LPS in vivo as well as in LPS-stimulated endothelial cells in vitro. Furthermore, we identified intracellular retinoic acid inducible gene-I (RIG-I) as a regulator of LPS-mediated IRF-1 induction. IRF-1 depletion specifically resulted in diminished induction of VCAM-1 in response to LPS, but not of E-selectin or ICAM-1, which was independent of NFκB signaling. When both IRF-1 and the RIG-I adapter protein mitochondrial antiviral signaling (MAVS) were absent, VCAM-1 induction was not additionally inhibited, suggesting that MAVS and IRF-1 reside in the same signaling pathway. Surprisingly, E-selectin and IL-6 induction were no longer inhibited by MAVS knockdown when IRF-1 was also absent, revealing a redundant endothelial activation pathway. In summary, we report an IRF-1-mediated proinflammatory signaling pathway that specifically regulates LPS-mediated VCAM-1 expression, independent of NFκB

    Levonorgestrel-releasing intrauterine system versus endometrial ablation for heavy menstrual bleeding

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    BACKGROUND: Heavy menstrual bleeding affects the physical functioning and social well-being of many women. The levonorgestrel-releasing intrauterine system and endometrial ablation are 2 frequently applied treatments in women with heavy menstrual bleeding.OBJECTIVE: This study aimed to compare the effectiveness of the levonorgestrel-releasing intrauterine system with endometrial ablation in women with heavy menstrual bleeding.STUDY DESIGN: This multicenter, randomized controlled, non inferiority trial was performed in 26 hospitals and in a network of general practices in the Netherlands. Women with heavy menstrual bleeding, aged 34 years and older, without a pregnancy wish or intracavitary pathology were randomly allocated to treatment with either the levonorgestrel-releasing intrauterine system (Mirena) or endometrial ablation, performed with a bipolar radiofrequency device (NovaSure). The primary outcome was blood loss at 24 months, measured with a Pictorial Blood Loss Assessment Chart score. Secondary outcomes included reintervention rates, patient satisfaction, quality of life, and sexual function.RESULTS: We registered 645 women as eligible, of whom 270 women provided informed consent. Of these, 132 women were allocated to the levonorgestrel-releasing intrauterine system (baseline Pictorial Blood Loss Assessment Chart score, 616) and 138 women to endometrial ablation (baseline Pictorial Blood Loss Assessment Chart score, 630). At 24 months, mean Pictorial Blood Loss Assessment Chart scores were 64.8 in the levonorgestrel-releasing intrauterine system group and 14.2 in the endometrial ablation group (difference, 50.5 points; 95% confidence interval, 4.3-96.7; noninferiority, P1/4.87 [25 Pictorial Blood Loss Assessment Chart point margin]). Compared with 14 women (10%) in the endometrial ablation group, 34 women (27%) underwent a surgical reintervention in the levonorgestrel-releasing intrauterine system group (relative risk, 2.64; 95% confidence interval, 1.49-4.68). There was no significant difference in patient satisfaction and quality of life between the groups.CONCLUSION: Both the levonorgestrel-releasing intrauterine system and endometrial ablation strategies lead to a large decrease in menstrual blood loss in women with heavy menstrual bleeding, with comparable quality of life scores after treatment. Nevertheless, there was a significant difference in menstrual blood loss in favor of endometrial ablation, and we could not demonstrate noninferiority of starting with the levonorgestrel-releasing intrauterine system. Women who start with the levonorgestrelreleasing intrauterine system, a reversible and less invasive treatment, are at an increased risk of needing additional treatment compared with women who start with endometrial ablation. The results of this study will enable physicians to provide women with heavy menstrual bleeding with the evidence to make a well-informed decision between the 2 treatments

    A variant in MCF2L is associated with osteoarthritis.

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    Osteoarthritis (OA) is a prevalent, heritable degenerative joint disease with a substantial public health impact. We used a 1000-Genomes-Project-based imputation in a genome-wide association scan for osteoarthritis (3177 OA cases and 4894 controls) to detect a previously unidentified risk locus. We discovered a small disease-associated set of variants on chromosome 13. Through large-scale replication, we establish a robust association with SNPs in MCF2L (rs11842874, combined odds ratio [95% confidence interval] 1.17 [1.11-1.23], p = 2.1 × 10(-8)) across a total of 19,041 OA cases and 24,504 controls of European descent. This risk locus represents the third established signal for OA overall. MCF2L regulates a nerve growth factor (NGF), and treatment with a humanized monoclonal antibody against NGF is associated with reduction in pain and improvement in function for knee OA patients
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