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Super resolution

Aoran Xiao, Zhongyuan Wang, Lei Wang, Yexian Ren
Super-resolution for satellite video attaches much significance to earth observation accuracy, and the special imaging and transmission conditions on the video satellite pose great challenges to this task. The existing deep convolutional neural-network-based methods require pre-processing or post-processing to be adapted to a high-resolution size or pixel format, leading to reduced performance and extra complexity. To this end, this paper proposes a five-layer end-to-end network structure without any pre-processing and post-processing, but imposes a reshape or deconvolution layer at the end of the network to retain the distribution of ground objects within the image...
April 13, 2018: Sensors
Manon Rostykus, Mattia Rossi, Christophe Moser
We report on a method to increase the spatial resolution in a compact lensless microscope. A compact side illumination is fabricated to illuminate the sample with a collimated beam by diffraction from a volume phase grating. The wavelength of a semi-conductor laser source (vertical-cavity surface-emitting laser) is tuned with the injection current to alter the illumination direction by wavelength selective diffraction from the volume phase grating. The angle tuning is such that several subpixel shifted digital inline holograms are obtained...
April 15, 2018: Optics Letters
Tuanwei Li, Le Liu, Titao Jing, Zheng Ruan, Pan Yuan, Lifeng Yan
Photobleaching and bio-toxicity are the main bottlenecks for organic fluorescent dyes applied in real-time dynamic monitoring of living cells. Here, an unnatural amino acid (UAA), 4-nitro-3-phenyl-L-alanine (NPA), was used as a scaffold to covalently link a near infrared (NIR) fluorophore Cy5.5, and an amphiphilic polypeptide Poly[oligo(ethylene glycol) methyl ether methacrylate]-block-poly[2-Amino-N4-(2-diisopropylamino-ethyl)-L-Aspartic acid] (P(OEGMA)21-P(Asp)16-iPr) was then conjugated for increasing the photostability and improving the biocompatibility simultaneously...
April 13, 2018: ACS Applied Materials & Interfaces
Katsumi Hagita, Takeshi Higuchi, Hiroshi Jinnai
Scanning electron microscopy equipped with a focused ion beam (FIB-SEM) is a promising three-dimensional (3D) imaging technique for nano- and meso-scale morphologies. In FIB-SEM, the specimen surface is stripped by an ion beam and imaged by an SEM installed orthogonally to the FIB. The lateral resolution is governed by the SEM, while the depth resolution, i.e., the FIB milling direction, is determined by the thickness of the stripped thin layer. In most cases, the lateral resolution is superior to the depth resolution; hence, asymmetric resolution is generated in the 3D image...
April 12, 2018: Scientific Reports
Limin Xiang, Michal Wojcik, Samuel J Kenny, Rui Yan, Seonah Moon, Wan Li, Ke Xu
Under ambient conditions, the behavior of a solid surface is often dominated by a molecularly thin adsorbed layer (adlayer) of small molecules. Here we develop an optical approach to unveil the nanoscale structure and composition of small-molecule adlayers on glass surfaces through spectrally resolved super-resolution microscopy. By recording the images and emission spectra of millions of individual solvatochromic molecules that turn fluorescent in the adlayer phase, we obtain ~30 nm spatial resolution and achieve concurrent measurement of local polarity...
April 12, 2018: Nature Communications
Xiaoshuai Huang, Junchao Fan, Liuju Li, Haosen Liu, Runlong Wu, Yi Wu, Lisi Wei, Heng Mao, Amit Lal, Peng Xi, Liqiang Tang, Yunfeng Zhang, Yanmei Liu, Shan Tan, Liangyi Chen
To increase the temporal resolution and maximal imaging time of super-resolution (SR) microscopy, we have developed a deconvolution algorithm for structured illumination microscopy based on Hessian matrixes (Hessian-SIM). It uses the continuity of biological structures in multiple dimensions as a priori knowledge to guide image reconstruction and attains artifact-minimized SR images with less than 10% of the photon dose used by conventional SIM while substantially outperforming current algorithms at low signal intensities...
April 11, 2018: Nature Biotechnology
Shuying Nong, Wujie Dong, Junwen Yin, Bowei Dong, Yue Lu, Xiaotao Yuan, Xin Wang, Kejun Bu, Mingyang Chen, Shangda Jiang, Li-Min Liu, Manling Sui, Fuqiang Huang
TiO2 mesoporous crystal has been prepared by one-step corroding process via an oriented attachment (OA) mechanism with SrTiO3 as precursor. High resolution transmission electron microscopy (HRTEM) and nitrogen adsorption-desorption isotherms confirm its mesoporous crystal structure. Well-dispersed ruthenium (Ru) in the mesoporous nanocrystal TiO2 can be attained by the same process using Ru-doped precursor SrTi1-x Rux O3 . Ru is doped into lattice of TiO2 , which is identified by HRTEM and super energy dispersive spectrometer (super-EDS) elemental mapping...
April 12, 2018: Journal of the American Chemical Society
Yiming Li, Markus Mund, Philipp Hoess, Joran Deschamps, Ulf Matti, Bianca Nijmeijer, Vilma Jimenez Sabinina, Jan Ellenberg, Ingmar Schoen, Jonas Ries
We present a real-time fitter for 3D single-molecule localization microscopy using experimental point spread functions (PSFs) that achieves minimal uncertainty in 3D on any microscope and is compatible with any PSF engineering approach. We used this method to image cellular structures and attained unprecedented image quality for astigmatic PSFs. The fitter compensates for most optical aberrations and makes accurate 3D super-resolution microscopy broadly accessible, even on standard microscopes without dedicated 3D optics...
April 9, 2018: Nature Methods
Dominik Novák, Pavol Vadovič, Miroslav Ovečka, Olga Šamajová, George Komis, Jean Colcombet, Jozef Šamaj
Phospholipase D alpha 1 (PLDα1, At3g15730) and its product phosphatidic acid (PA) are involved in a variety of cellular and physiological processes, such as cytoskeletal remodeling, regulation of stomatal closure and opening, as well as biotic and abiotic stress signaling. Here we aimed to study developmental expression patterns and subcellular localization of PLDα1 in Arabidopsis using advanced microscopy methods such as light-sheet fluorescence microscopy (LSFM) and structured illumination microscopy (SIM)...
2018: Frontiers in Plant Science
Paolo Armanetti, Alessandra Flori, Cinzia Avigo, Luca Conti, Barbara Valtancoli, Debora Petroni, Saer Doumett, Laura Cappiello, Costanza Ravagli, Giovanni Baldi, Andrea Bencini, Luca Menichetti
Recently, a number of photoacoustic (PA) agents with increased tissue penetration and fine spatial resolution have been developed for molecular imaging and mapping of pathophysiological features at the molecular level. Here, we present bio-conjugated near-infrared light-absorbing magnetic nanoparticles as a new agent for PA imaging. These nanoparticles exhibit suitable absorption in the near-infrared region, with good photoacoustic signal generation efficiency and high photo-stability. Furthermore, these encapsulated iron oxide nanoparticles exhibit strong super-paramagnetic behavior and nuclear relaxivities that make them useful as magnetic resonance imaging (MRI) contrast media as well...
March 15, 2018: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Simona Amodeo, Martin Jakob, Torsten Ochsenreiter
The unicellular parasite Trypanosoma brucei harbors one mitochondrial organelle with a singular genome called the kinetoplast DNA (kDNA). The kDNA consists of a network of concatenated minicircles and a few maxicircles that form the kDNA disc. More than 30 proteins involved in kDNA replication have been described. However, several mechanistic questions are only poorly understood. Here, we describe and characterize MiRF172, a novel mitochondrial genome replication factor, which is essential for cell growth and kDNA maintenance...
April 6, 2018: Journal of Cell Science
Laura Martínez-Muñoz, José Miguel Rodríguez-Frade, Rubén Barroso, Carlos Óscar S Sorzano, Juan A Torreño-Pina, César A Santiago, Carlo Manzo, Pilar Lucas, Eva M García-Cuesta, Enric Gutierrez, Laura Barrio, Javier Vargas, Graciela Cascio, Yolanda R Carrasco, Francisco Sánchez-Madrid, María F García-Parajo, Mario Mellado
A current challenge in cell motility studies is to understand the molecular and physical mechanisms that govern chemokine receptor nanoscale organization at the cell membrane, and their influence on cell response. Using single-particle tracking and super-resolution microscopy, we found that the chemokine receptor CXCR4 forms basal nanoclusters in resting T cells, whose extent, dynamics, and signaling strength are modulated by the orchestrated action of the actin cytoskeleton, the co-receptor CD4, and its ligand CXCL12...
April 5, 2018: Molecular Cell
Christian Sieben, Kyle M Douglass, Paul Guichard, Suliana Manley
Super-resolution fluorescence microscopy (SRM) is increasingly being applied as a complementary method to resolve the organization of large biomolecular assemblies. One of its main advantages is that it provides information on protein organization and identity simultaneously, within the native cellular milieu. It also extends the accessible range of structures up to the micrometer scale, offering complementary information relative to classical structural biology methods. Furthermore, SRM is capable of resolving the organization of some biomolecular assemblies not accessible to other methods...
April 2, 2018: Current Opinion in Structural Biology
Juwei Zhang, Pengbo Zheng, Xiaojiang Tan
The magnetic flux leakage method is widely used for non-destructive testing in wire rope applications. A non-destructive testing device for wire rope based on remanence was designed to solve the problems of large volume, low accuracy, and complex operations seen in traditional devices. A wavelet denoising method based on ensemble empirical mode decomposition was proposed to reduce the system noise in broken wire rope testing. After extracting the defects image, the wavelet super-resolution reconstruction technique was adopted to improve the resolution of defect grayscale...
April 5, 2018: Sensors
Christopher J Rowlands, Florian Ströhl, Pedro P Vallejo Ramirez, Katharina M Scherer, Clemens F Kaminski
Super-resolution single-molecule localization microscopy, often referred to as PALM/STORM, works by ensuring that fewer than one fluorophore in a diffraction-limited volume is emitting at any one time, allowing the observer to infer that the emitter is located at the center of the point-spread function. This requires careful control over the incident light intensity in order to control the rate at which fluorophores are switched on; if too many fluorophores are activated, their point-spread functions overlap, which impedes efficient localization...
April 4, 2018: Scientific Reports
Varun Venkataramani, Markus Kardorff, Frank Herrmannsdörfer, Ralph Wieneke, Alina Klein, Robert Tampé, Mike Heilemann, Thomas Kuner
With continuing advances in the resolving power of super-resolution microscopy, the inefficient labeling of proteins with suitable fluorophores becomes a limiting factor. For example, the low labeling density achieved with antibodies or small molecule tags limits attempts to reveal local protein nano-architecture of cellular compartments. On the other hand, high laser intensities cause photobleaching within and nearby an imaged region, thereby further reducing labeling density and impairing multi-plane whole-cell 3D super-resolution imaging...
April 3, 2018: Scientific Reports
Sebastian Lickert, Simona Sorrentino, Jan-Dirk Studt, Ohad Medalia, Viola Vogel, Ingmar Schoen
Haemostatic platelet function is intimately linked to cellular mechanics and cytoskeletal morphology. How cytoskeletal reorganizations give rise to a highly contractile phenotype that is necessary for clot contraction remains poorly understood. To elucidate this process in vitro, we developed a morphometric screen to quantify the spatial organization of actin fibres and vinculin adhesion sites in single spread platelets. Platelets from healthy donors predominantly adopted a bipolar morphology on fibrinogen and fibronectin, whereas distinguishable, more isotropic phenotypes on collagen type I or laminin...
April 3, 2018: Scientific Reports
Shingo Sotoma, Daiki Terada, Takuya F Segawa, Ryuji Igarashi, Yoshie Harada, Masahiro Shirakawa
The development of sensors to estimate physical properties, and their temporal and spatial variation, has been a central driving force in scientific breakthroughs. In recent years, nanosensors based on quantum measurements, such as nitrogen-vacancy centres (NVCs) in nanodiamonds, have been attracting much attention as ultrastable, sensitive, accurate and versatile physical sensors for quantitative cellular measurements. However, the nanodiamonds currently available for use as sensors have diameters of several tens of nanometres, much larger than the usual size of a protein...
April 3, 2018: Scientific Reports
Ruoqi Gao, Nicolas H Piguel, Alexandria E Melendez-Zaidi, Maria Dolores Martin-de-Saavedra, Sehyoun Yoon, Marc P Forrest, Kristoffer Myczek, Gefei Zhang, Theron A Russell, John G Csernansky, D James Surmeier, Peter Penzes
Contactin associated protein-like 2 (CNTNAP2) has emerged as a prominent susceptibility gene implicated in multiple complex neurodevelopmental disorders, including autism spectrum disorders (ASD), intellectual disability (ID), and schizophrenia (SCZ). The presence of seizure comorbidity in many of these cases, as well as inhibitory neuron dysfunction in Cntnap2 knockout (KO) mice, suggests CNTNAP2 may be crucial for proper inhibitory network function. However, underlying cellular mechanisms are unclear. Here we show that cultured Cntnap2 KO mouse neurons exhibit an inhibitory neuron-specific simplification of the dendritic tree...
April 2, 2018: Molecular Psychiatry
Yongzhuang Zhou, Paul Zammit, Guillem Carles, Andrew R Harvey
A new single-aperture 3D particle-localization and tracking technique is presented that demonstrates an increase in depth range by more than an order of magnitude without compromising optical resolution and throughput. We exploit the extended depth range and depth-dependent translation of an Airy-beam PSF for 3D localization over an extended volume in a single snapshot. The technique is applicable to all bright-field and fluorescence modalities for particle localization and tracking, ranging from super-resolution microscopy through to the tracking of fluorescent beads and endogenous particles within cells...
March 19, 2018: Optics Express
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