2,631 research outputs found

    From single-molecule spectroscopy to super-resolution imaging of the neuron: a review.

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    For more than 20 years, single-molecule spectroscopy has been providing invaluable insights into nature at the molecular level. The field has received a powerful boost with the development of the technique into super-resolution imaging methods, ca. 10 years ago, which overcome the limitations imposed by optical diffraction. Today, single molecule super-resolution imaging is routinely used in the study of macromolecular function and structure in the cell. Concomitantly, computational methods have been developed that provide information on numbers and positions of molecules at the nanometer-scale. In this overview, we outline the technical developments that have led to the emergence of localization microscopy techniques from single-molecule spectroscopy. We then provide a comprehensive review on the application of the technique in the field of neuroscience research.This work was supported by grants from the UK Engineering and Physical Sciences Research Council (EPSRC), The Wellcome Trust, Alzheimer’s Research UK, the Medical Research Council (MRC), and the Biotechnology and Biological Sciences Resesarch Council (BBSRC)

    Connected pathway relative permeability from pore-scale imaging of imbibition

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    Pore-scale images obtained from a synchrotron-based X-ray computed micro-tomography (µCT) imbibition experiment in sandstone rock were used to conduct Navier–Stokes flow simulations on the connected pathways of water and oil phases. The resulting relative permeability was compared with steady-state Darcy-scale imbibition experiments on 5 cm large twin samples from the same outcrop sandstone material. While the relative permeability curves display a large degree of similarity, the endpoint saturations for the µCT data are 10% in saturation units higher than the experimental data. However, the two datasets match well when normalizing to the mobile saturation range. The agreement is particularly good at low water saturations, where the oil is predominantly connected. Apart from different saturation endpoints, in this particular experiment where connected pathway flow dominates, the discrepancies between pore-scale connected pathway flow simulations and Darcy-scale steady-state data are minor overall and have very little impact on fractional flow. The results also indicate that if the pore-scale fluid distributions are available and the amount of disconnected non-wetting phase is low, quasi-static flow simulations may be sufficient to compute relative permeability. When pore-scale fluid distributions are not available, fluid distributions can be obtained from a morphological approach, which approximates capillary-dominated displacement. The relative permeability obtained from the morphological approach compare well to drainage steady state whereas major discrepancies to the imbibition steady-state experimental data are observed. The morphological approach does not represent the imbibition process very well and experimental data for the spatial arrangement of the phases are required. Presumably for modeling imbibition relative permeability an approach is needed that captures moving liquid-liquid interfaces, which requires viscous and capillary forces simultaneously

    Antihypertensive drug concentration measurement combined with personalized feedback in resistant hypertension:a randomized controlled trial

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    Background:Adherence to antihypertensive drugs (AHDs) is crucial for controlling blood pressure (BP). We aimed to determine the effectiveness of measuring AHD concentrations using a dried blood spot (DBS) sampling method to identify nonadherence, combined with personalized feedback, in reducing resistant hypertension.Methods:We conducted a multicenter, randomized, controlled trial (RHYME-RCT, ICTRP NTR6914) in patients with established resistant hypertension. Patients were randomized to receive either an intervention with standard of care (SoC) or SoC alone. SoC consisted of BP measurement and DBS sampling at baseline, 3 months (t3), 6 months (t6), and 12 months (t12); AHD concentrations were measured but not reported in this arm. In the intervention arm, results on AHD concentrations were discussed during a personalized feedback conversation at baseline and t3. Study endpoints included the proportion of patients with RH and AHD adherence at t12.Results:Forty-nine patients were randomized to receive the intervention+SoC, and 51 were randomized to receive SoC alone. The proportion of adherent patients improved from 70.0 to 92.5% in the intervention+SoC arm (P = 0.008, n = 40) and remained the same in the SoC arm (71.4%, n = 42). The difference in adherence between the arms was statistically significant (P = 0.014). The prevalence of resistant hypertension decreased to 75.0% in the intervention+SoC arm (P &lt; 0.001, n = 40) and 59.5% in the SoC arm (P &lt; 0.001, n = 42) at t12; the difference between the arms was statistically nonsignificant (P = 0.14).Conclusion:Personalized feedback conversations based on DBS-derived AHD concentrations improved AHD adherence but did not reduce the prevalence of RH.</p

    EP-1179: What the gamma? The correlation between QA and clinical risk estimates for prostate RapidArc plans

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    Influenza virus infection can be accompanied by life-threatening immune pathology most likely due to excessive antiviral responses. Inhibitory immune receptors may restrain such overactive immune responses. To study the role of the inhibitory immune receptor CD200R and its ligand CD200 during influenza infection, we challenged wild-type and CD200(-/-) mice with influenza virus. We found that CD200(-/-) mice in comparison to wild-type controls when inoculated with influenza virus developed more severe disease, associated with increased lung infiltration and lung endothelium damage. CD200(-/-) mice did develop adequate adaptive immune responses and were able to control viral load, suggesting that the severe disease was caused by a lack of control of the immune response. Interestingly, development of disease was completely prevented by depletion of T cells before infection, despite dramatically increased viral load, indicating that T cells are essential for the development of disease symptoms. Our data show that lack of CD200-CD200R signaling increases immune pathology during influenza infection, which can be reduced by T cell depletion. The Journal of Immunology, 2009, 183: 1990-1996

    Topical Imiquimod Treatment of High-grade Cervical Intraepithelial Neoplasia (TOPIC-3):A Nonrandomized Multicenter Study

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    Topical imiquimod could be an alternative, noninvasive, treatment modality for high-grade cervical intraepithelial neoplasia (CIN). However, evidence is limited, and there are no studies that compared treatment effectiveness and side effects of topical imiquimod cream to standard large loop excision of the transformation zone (LLETZ) treatment. A multi-center, nonrandomized controlled trial was performed among women with a histologic diagnosis of CIN 2/3. Women were treated with either vaginal imiquimod (6.25 mg 3 times weekly for 8 to 16 wk) or LLETZ according to their own preference. Successful treatment was defined as the absence of high-grade dysplasia at the first follow-up interval after treatment (at 20 wk for the imiquimod group and at 26 wk for the LLETZ group). Secondary outcome measures were high-risk human papillomavirus (hrHPV) clearance, side effects, and predictive factors for successful imiquimod treatment. Imiquimod treatment was successful in 60% of women who completed imiquimod treatment and 95% of women treated with LLETZ. hrHPV clearance occurred in 69% and 67% in the imiquimod group and LLETZ group, respectively. This study provides further evidence on topical imiquimod cream as a feasible and safe treatment modality for high-grade CIN. Although the effectiveness is considerably lower than LLETZ treatment, imiquimod treatment could prevent initial surgical treatment in over 40% of women and should be offered to a selected population of women who wish to avoid (repeated) surgical treatment of high-grade CIN
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