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Super resolution

Gordon X Wang, Stephen J Smith, Philippe Mourrain
The distribution of proteins within sub-synaptic compartments is an essential aspect of their neurological function. Current methodology such as electron microscopy (EM) and super-resolution imaging techniques can provide precise localization of proteins, but are often limited to a small number of one-time observations with narrow spatial and molecular coverage. The diversity of synaptic proteins and synapse types demands synapse analysis on a scale that is prohibitive with current methods. Here, we demonstrate SubSynMAP, a fast, multiplexed sub-synaptic protein analysis method using wide-field data from deconvolution array tomography (ATD)...
October 22, 2016: ELife
Ruobing Zhang, Gilbert O Fruhwirth, Oana Coban, James E Barrett, Thomas Burgoyne, Sang Hak Lee, Paul Dennis Simonson, Murat Baday, Boris Kholodenko, Clare E Futter, Tony Ng, Paul R Selvin
Heterogeneity of mitogen-activated protein kinase (MAPK) activation in genetically identical cells, which occurs in response to epidermal growth factor receptor (EGFR) signaling, remains poorly understood. MAPK cascades integrate signals emanating from different EGFR spatial locations, including the plasma membrane and endocytic compartment. We previously hypothesized that in EGF-stimulated cells the MAPK phosphorylation (pMAPK) level and activity are largely determined by the spatial organization of the EGFR clusters within the cell...
October 21, 2016: ACS Nano
Hok Sum Sam Lai, Feifei Wang, Yi Li, Boliang Jia, Lianqing Liu, Wen Jung Li
Microsphere-assisted microscopy has received a lot of attention recently due to its simplicity and its capability to surpass the diffraction limit. However, to date, sub-diffraction-limit features have only been observed in virtual images formed through the microspheres. We show that it is possible to form real, super-resolution images using high-refractive index microspheres. Also, we report on how changes to a microsphere's refractive index and size affect image formation and planes. The relationship between the focus position and the additional magnification factor is also investigated using experimental and theoretical methods...
2016: PloS One
Benoît Roubinet, Mariano L Bossi, Philipp Alt, Marcel Leutenegger, Heydar Shojaei, Sebastian Schnorrenberg, Shamil Nizamov, Masahiro Irie, Vladimir N Belov, Stefan W Hell
Reversibly photoswitchable 1,2-bis(2-ethyl-6-phenyl-1-benzothiophene-1,1-dioxide-3-yl)perfluorocyclopentenes (EBT) having fluorescent "closed" forms were decorated with four or eight carboxylic groups and attached to antibodies. Low aggregation, efficient photoswitching in aqueous buffers, specific staining of cellular structures, and good photophysical properties were demonstrated. Alternating light pulses of UV and blue light induce numerous reversible photochemical transformations between two stables states with distinct structures...
October 21, 2016: Angewandte Chemie
Atsushi Matsuda, Haruhiko Asakawa, Tokuko Haraguchi, Yasushi Hiraoka
The fission yeast Schizosaccharomyces pombe is a useful experimental system for studying the organization of chromosomes within the cell nucleus. S. pombe has a small genome that is organized into three chromosomes. The small size of the genome and the small number of chromosomes are advantageous for cytological and genome-wide studies of chromosomes; however, the small size of the nucleus impedes microscopic observations owing to limits in spatial resolution during imaging. Recent advances in microscopy, such as super-resolution microscopy, have greatly expanded the use of S...
October 21, 2016: Yeast
Oihane Irazoki, Jesús Aranda, Timo Zimmermann, Susana Campoy, Jordi Barbé
In addition to its role in DNA damage repair and recombination, the RecA protein, through its interaction with CheW, is involved in swarming motility, a form of flagella-dependent movement across surfaces. In order to better understand how SOS response modulates swarming, in this work the location of RecA and CheW proteins within the swarming cells has been studied by using super-resolution microscopy. Further, and after in silico docking studies, the specific RecA and CheW regions associated with the RecA-CheW interaction have also been confirmed by site-directed mutagenesis and immunoprecipitation techniques...
2016: Frontiers in Microbiology
Thomas J Younts, Hannah R Monday, Barna Dudok, Matthew E Klein, Bryen A Jordan, István Katona, Pablo E Castillo
Long-term changes of neurotransmitter release are critical for proper brain function. However, the molecular mechanisms underlying these changes are poorly understood. While protein synthesis is crucial for the consolidation of postsynaptic plasticity, whether and how protein synthesis regulates presynaptic plasticity in the mature mammalian brain remain unclear. Here, using paired whole-cell recordings in rodent hippocampal slices, we report that presynaptic protein synthesis is required for long-term, but not short-term, plasticity of GABA release from type 1 cannabinoid receptor (CB1)-expressing axons...
October 19, 2016: Neuron
Nirod Kumar Sarangi, K G Ayappa, Sandhya S Visweswariah, Jaydeep Kumar Basu
Cell membranes are believed to be highly complex dynamical systems having compositional heterogeneity involving several types of lipids and proteins as the major constituents. This dynamical and compositional heterogeneity is suggested to be critical to the maintenance of active functionality and response to chemical, mechanical, electrical and thermal stresses. However, delineating the various factors responsible for the spatio-temporal response of actual cell membranes to stresses can be quite challenging...
October 20, 2016: Physical Chemistry Chemical Physics: PCCP
Wei-Jei Lee
Obesity is a pan-endemic health problem in both developed and developing countries, in both western and eastern countries. It increases risk for many common diseases, including type 2 diabetes, dyslipidemia, hypertension, obstructive sleep apnea, heart disease, stroke, asthma, osteoarthritis, cancers and depression etc.. Although the incidence of obesity in Asia is relatively low, Asian patients tend to have similar incidence of obesity related metabolic syndrome at lower BMI level comparing to Caucasians because of central obesity...
September 2016: Journal of Hypertension
Shilpi Yadav, Jonathan K Williamson, Maria A Aronova, Andrew A Prince, Irina D Pokrovskaya, Richard D Leapman, Brian Storrie
Platelets are small, anucleate cell fragments that are central to hemostasis, thrombosis, and inflammation. They are derived from megakaryocytes from which they inherit their organelles. As platelets can synthesize proteins and contain many of the enzymes of the secretory pathway, one might expect all mature human platelets to contain a stacked Golgi apparatus, the central organelle of the secretory pathway. By thin section electron microscopy, stacked membranes resembling the stacked Golgi compartment in megakaryocytes and other nucleated cells can be detected in both proplatelets and platelets...
October 18, 2016: Platelets
Nelson F Velasco, Andrea Rueda, Cristina Santa Marta, Eduardo Romero
High-quality Cardiac Magnetic Resonance (CMR) images can be hardly obtained when intrinsic noise sources are present, namely heart and breathing movements. Yet heart images may be acquired in real time, the image quality is really limited and most sequences use ECG gating to capture images at each stage of the cardiac cycle during several heart beats. This paper presents a novel super-resolution algorithm that improves the cardiac image quality using a sparse Bayesian approach. The high-resolution version of the cardiac image is constructed by combining the information of the low-resolution series -observations from different non-orthogonal series composed of anisotropic voxels- with a prior distribution of the high-resolution local coefficients that enforces sparsity...
October 11, 2016: Magnetic Resonance Imaging
Takahiro Ogawa, Miki Haseyama
This paper presents adaptive subspace-based inverse projections via division into multiple sub-problems (ASIP-DIMS) for missing image data restoration. In the proposed method, a target problem for estimating missing image data is divided into multiple sub-problems, and each sub-problem is iteratively solved with constraints of other known image data. By projection into a subspace model of image patches, the solution of each subproblem is calculated, where we call this procedure "subspacebased inverse projection" for simplicity...
October 10, 2016: IEEE Transactions on Image Processing: a Publication of the IEEE Signal Processing Society
Wen-Liang Gong, Jie Yan, Ling-Xi Zhao, Chong Li, Zhen-Li Huang, Ben Zhong Tang, Ming-Qiang Zhu
Photoswitchable fluorophores are promising in single-molecule optical devices and super-resolution fluorescence imaging, especially in single-molecule photo-activated localization microscopy (PALM) or stochastic optical reconstruction microscopy (STORM). However, the scarcity of current photoswitchable fluorophores stimulates researchers to develop complicated optical systems and processing software, in accordance with the limited photoswitchable fluorescent proteins and organic fluorophores. Previous efforts to develop synthetic photoswitchable fluorophores have exhibited their promising potential in super-resolution fluorescence imaging...
October 14, 2016: Photochemical & Photobiological Sciences
Manuel Maidorn, Silvio O Rizzoli, Felipe Opazo
The synapse is densely packed with proteins involved in various highly regulated processes. Synaptic protein copy numbers and their stoichiometric distribution have a drastic influence on neuronal integrity and function. Therefore, the molecular analysis of synapses is a key element to understand their architecture and function. The overall structure of the synapse has been revealed with an exquisite amount of details by electron microscopy. However, the molecular composition and the localization of proteins are more easily addressed with fluorescence imaging, especially with the improved resolution achieved by super-resolution microscopy techniques...
October 15, 2016: Biochemical Journal
Mako Kamiya
 Fluorescence imaging is one of the most powerful techniques currently available for continuous observation of intracellular processes in living cells and tissues, and so it would be useful to have a large toolset of fluorescence probes suitable for visualizing bioactive molecules or biological phenomena. However, design strategies for small molecule-based fluorescence probes have been limited. Therefore, we are interested in establishing novel rational design strategies for developing functional fluorescence probes...
2016: Yakugaku Zasshi: Journal of the Pharmaceutical Society of Japan
Hefei Ruan, Jianqiang Yu, Jinghe Yuan, Nan Li, Xiaohong Fang
Transforming growth factor-β (TGF-β) type II receptor (TβRII) plays a critical role in the initiation of TGF-β signaling pathway, therefore the study of its synthesis and transport processes is of great important. In this work, we have achieved the super-resolution imaging of a new type of TβRII-containing post-Golgi vesicle by our home-built stimulated emission depletion (STED) microscope. We visualized the ring-shaped structure of these vesicles containing newly synthesized TβRII in the cytoplasm, and characterized their size distribution from 300 nm to 1000 nm...
October 10, 2016: Chemistry, An Asian Journal
Sebastián A Díaz, Florencia Gillanders, Kimihiro Susumo, Eunkeu Oh, Igor L Medintz, Thomas M Jovin
Photoswitchable probes are of great utility in fluorescence microscopy, permitting numerous determinations, including molecular localization for super-resolution, based on their modifiable emission intensity and spectra. We have coated a blue (425 nm) emitting quantum dot (QD) with a diheteroarylethene photochrome (PCf), the closed form isomer of which has absorption and emission maxima at 440 and 520-530 nm, respectively, and thus functions as a fluorescent acceptor for the QD donor in Förster resonance energy transfer (FRET)...
October 9, 2016: Chemistry: a European Journal
Adam S Backer, Maurice Y Lee, W E Moerner
Single-molecule orientation measurements provide unparalleled insight into a multitude of biological and polymeric systems. We report a simple, high-throughput technique for measuring the azimuthal orientation and rotational dynamics of single fluorescent molecules, which is compatible with localization microscopy. Our method involves modulating the polarization of an excitation laser, and analyzing the corresponding intensities emitted by single dye molecules and their modulation amplitudes. To demonstrate our approach, we use intercalating and groove-binding dyes to obtain super-resolved images of stretched DNA strands through binding-induced turn-on of fluorescence...
2016: Optica
Christian Schou Oxvig, Thomas Arildsen, Torben Larsen
The use of compressed sensing in atomic force microscopy (AFM) can potentially speed-up image acquisition, lower probe-specimen interaction, or enable super resolution imaging. The idea in compressed sensing for AFM is to spatially undersample the specimen, i.e. only acquire a small fraction of the full image of it, and then use advanced computational techniques to reconstruct the remaining part of the image whenever this is possible. Our initial experiments have shown that it is possible to leverage inherent structure in acquired AFM images to improve image reconstruction...
September 21, 2016: Ultramicroscopy
Guido Wabnitz, Emre Balta, Yvonne Samstag
T-cells need to be tightly regulated during their activation and effector phase to assure an appropriate defence against cancer or pathogens and - vice versa - to avoid autoimmune reactions. Regulatory signals are provided via the immune synapse between T-cells and antigen-presenting cells (APCs) or target cells. The stability and kinetics of immune synapse formation is critical for proper T-cell functions. It requires dynamic rearrangements of the actin cytoskeleton necessary for organized spatio-temporal redistribution of receptors and adhesion molecules...
September 27, 2016: Advances in Biological Regulation
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