242 research outputs found

    Spatial Modulation Microscopy for Real-Time Imaging of Plasmonic Nanoparticles and Cells

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    Spatial modulation microscopy is a technique originally developed for quantitative spectroscopy of individual nano-objects. Here, a parallel implementation of the spatial modulation microscopy technique is demonstrated based on a line detector capable of demodulation at kHz frequencies. The capabilities of the imaging system are shown using an array of plasmonic nanoantennas and dendritic cells incubated with gold nanoparticles.Comment: 3 pages, 4 figure

    Las plantas beben agua mineral

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    7 páginas.- Presentación elaborada para las III Jornadas IPErinas, celebradas el 11 de diciembre de 2014.Peer reviewe

    Effect of the Photon's Brownian Doppler Shift on the Weak-Localization Coherent-Backscattering Cone

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    We report the first observation of the dependence of the coherent-backscattering (CBS) enhanced cone with the frequency of the backscattered photon. The experiment is performed on a diffusing liquid suspension and the Doppler broadening of light is induced by the Brownian motion of the scatterers. Heterodyne detection on a CCD camera is used to measure the complex field (i.e., the hologram) of the light that is backscattered at a given frequency. The analysis of the holograms yield the frequency and the propagation direction of the backscattered photons. We observe that the angular CBS cone becomes more narrow in the tail of the Brownian spectrum. The experimental results are in good agreement with a simple theoretical model

    Rapid wide-field heterodyne interferometry with custom 2D CMOS camera

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    © The Institution of Engineering and Technology 2015. A wide-field pseudo-heterodyne interference contrast microscope is described, which employs a complementary metal-oxide semiconductor (CMOS) phase-sensitive camera. The use of multiple wells in the camera enables extremely rapid measurement of a full phase field at high resolution and the modulation frequency is not limited by the camera frame rate. The high data acquisition frequency allows the effects of microphonics to be frozen to mitigate the effect of lowfrequency disturbance

    Evidence for the impact of the 8.2-kyBP climate event on Near Eastern early farmers.

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    The 8.2-thousand years B.P. event is evident in multiple proxy records across the globe, showing generally dry and cold conditions for ca. 160 years. Environmental changes around the event are mainly detected using geochemical or palynological analyses of ice cores, lacustrine, marine, and other sediments often distant from human settlements. The Late Neolithic excavated area of the archaeological site of Çatalhöyük East [Team Poznań (TP) area] was occupied for four centuries in the ninth and eighth millennia B.P., thus encompassing the 8.2-thousand years B.P. climatic event. A Bayesian analysis of 56 radiocarbon dates yielded a high-resolution chronological model comprising six building phases, with dates ranging from before 8325-8205 to 7925-7815 calibrated years (cal) B.P. Here, we correlate an onsite paleoclimate record constructed from δ2H values of lipid biomarkers preserved in pottery vessels recovered from these buildings with changes in architectural, archaeozoological, and consumption records from well-documented archaeological contexts. The overall sequence shows major changes in husbandry and consumption practices at ca. 8.2 thousand years B.P., synchronous with variations in the δ2H values of the animal fat residues. Changes in paleoclimate and archaeological records seem connected with the patterns of atmospheric precipitation during the occupation of the TP area predicted by climate modeling. Our multiproxy approach uses records derived directly from documented archaeological contexts. Through this, we provide compelling evidence for the specific impacts of the 8.2-thousand years B.P. climatic event on the economic and domestic activities of pioneer Neolithic farmers, influencing decisions relating to settlement planning and food procurement strategies

    Endothelial alpha-parvin controls integrity of developing vasculature and is required for maintenance of cell-cell junctions

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    RATIONALE: Angiogenesis and vessel integrity depend on the adhesion of endothelial cells (EC) to the extracellular matrix (ECM) and to adjacent ECs. The focal adhesion protein alpha-parvin (alpha-pv) is essential for vascular development. However, the role of alpha-pv in ECs in vivo is not known. OBJECTIVE: To determine the function of alpha-pv in ECs during vascular development in vivo and the underlying mechanisms. METHODS AND RESULTS: We deleted the alpha-pv gene specifically in ECs of mice to study its role in angiogenesis and vascular development. Here we show that endothelial-specific deletion of alpha-pv in mice results in late embryonic lethality associated with hemorrhages and reduced vascular density. Postnatal induced EC-specific deletion of alpha-pv leads to retinal hypovascularization due to reduced vessel sprouting and excessive vessel regression. In the absence of alpha-pv, blood vessels display impaired VE-cadherin junction morphology. In vitro, alpha-pv deficient ECs show reduced stable adherens junctions, decreased monolayer formation and impaired motility, associated with reduced formation of integrin-mediated cell-ECM adhesion structures and an altered actin cytoskeleton. CONCLUSIONS: Endothelial alpha-pv is essential for vessel sprouting and for vessel stability

    Guiding Brain Tumor Resection Using Surface-Enhanced Raman Scattering Nanoparticles and a Hand-Held Raman Scanner

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    The current difficulty in visualizing the true extent of malignant brain tumors during surgical resection represents one of the major reasons for the poor prognosis of brain tumor patients. Here, we evaluated the ability of a hand-held Raman scanner, guided by surface-enhanced Raman scattering (SERS) nanoparticles, to identify the microscopic tumor extent in a genetically engineered RCAS/tv-a glioblastoma mouse model. In a simulated intraoperative scenario, we tested both a static Raman imaging device and a mobile, hand-held Raman scanner. We show that SERS image-guided resection is more accurate than resection using white light visualization alone. Both methods complemented each other, and correlation with histology showed that SERS nanoparticles accurately outlined the extent of the tumors. Importantly, the hand-held Raman probe not only allowed near real-time scanning, but also detected additional microscopic foci of cancer in the resection bed that were not seen on static SERS images and would otherwise have been missed. This technology has a strong potential for clinical translation because it uses inert gold-silica SERS nanoparticles and a hand-held Raman scanner that can guide brain tumor resection in the operating room

    Constructing the digitalized sporting body: black and white masculinity in NBA/NHL internet memes

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    In this article, I examine the ways sport fans construct and circulate discourses of race and masculinity in cyberspace. I do this through an examination of a set of Internet memes that juxtapose the bodies of National Hockey League players with National Basketball Association players in one single image. I argue these memes celebrate White masculinity, while at the same time constructing African American athletes as individualistic, selfish, and unwilling to sacrifice their bodies for the greater good of the team. More so, I argue that these memes construct a form of racial ideology that is representative of White backlash politics

    Common ADRB2 Haplotypes Derived from 26 Polymorphic Sites Direct β2-Adrenergic Receptor Expression and Regulation Phenotypes

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    The beta2-adrenergic receptor (beta2AR) is expressed on numerous cell-types including airway smooth muscle cells and cardiomyocytes. Drugs (agonists or antagonists) acting at these receptors for treatment of asthma, chronic obstructive pulmonary disease, and heart failure show substantial interindividual variability in response. The ADRB2 gene is polymorphic in noncoding and coding regions, but virtually all ADRB2 association studies have utilized the two common nonsynonymous coding SNPs, often reaching discrepant conclusions.We constructed the 8 common ADRB2 haplotypes derived from 26 polymorphisms in the promoter, 5'UTR, coding, and 3'UTR of the intronless ADRB2 gene. These were cloned into an expression construct lacking a vector-based promoter, so that beta2AR expression was driven by its promoter, and steady state expression could be modified by polymorphisms throughout ADRB2 within a haplotype. "Whole-gene" transfections were performed with COS-7 cells and revealed 4 haplotypes with increased cell surface beta2AR protein expression compared to the others. Agonist-promoted downregulation of beta2AR protein expression was also haplotype-dependent, and was found to be increased for 2 haplotypes. A phylogenetic tree of the haplotypes was derived and annotated by cellular phenotypes, revealing a pattern potentially driven by expression.Thus for obstructive lung disease, the initial bronchodilator response from intermittent administration of beta-agonist may be influenced by certain beta2AR haplotypes (expression phenotypes), while other haplotypes may influence tachyphylaxis during the response to chronic therapy (downregulation phenotypes). An ideal clinical outcome of high expression and less downregulation was found for two haplotypes. Haplotypes may also affect heart failure antagonist therapy, where beta2AR increase inotropy and are anti-apoptotic. The haplotype-specific expression and regulation phenotypes found in this transfection-based system suggest that the density of genetic information in the form of these haplotypes, or haplotype-clusters with similar phenotypes can potentially provide greater discrimination of phenotype in human disease and pharmacogenomic association studies
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