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Super resolution

Aleksandra Gil-Krzewska, Mezida B Saeed, Anna Oszmiana, Elizabeth R Fischer, Kathryn Lagrue, William A Gahl, Wendy J Introne, John E Coligan, Daniel M Davis, Konrad Krzewski
BACKGROUND: Chediak-Higashi syndrome (CHS) is a rare disorder caused by biallelic mutations in the LYST gene, resulting in formation of giant lysosomes or lysosome-related organelles in several cell types. The disease is characterized by immunodeficiency and a fatal hemophagocytic lymphohistiocytosis due to impaired function of cytotoxic lymphocytes, mainly Natural Killer (NK) cells. OBJECTIVE: We sought to determine the underlying biochemical cause of the impaired cytotoxicity of NK cells in CHS...
December 11, 2017: Journal of Allergy and Clinical Immunology
David Unnersjö-Jess, Lena Scott, Sonia Zambrano Sevilla, Jaakko Patrakka, Hans Blom, Hjalmar Brismar
The glomerular filtration barrier, has historically only been spatially resolved using electron microscopy due to the nanometer-scale dimensions of these structures. Recently, it was shown that the nanoscale distribution of proteins in the slit diaphragm can be resolved by fluorescence based stimulated emission depletion microscopy, in combination with optical clearing. Fluorescence microscopy has advantages over electron microscopy in terms of multiplex imaging of different epitopes, and also the amount of volumetric data that can be extracted from thicker samples...
December 11, 2017: Kidney International
Roberto Villaseñor, Michael Schilling, Janani Sundaresan, Yves Lutz, Ludovic Collin
Transcytosis across the blood-brain barrier (BBB) regulates key processes of the brain, but the intracellular sorting mechanisms that determine successful receptor-mediated transcytosis in brain endothelial cells (BECs) remain unidentified. Here, we used Transferrin receptor-based Brain Shuttle constructs to investigate intracellular transport in BECs, and we uncovered a pathway for the regulation of receptor-mediated transcytosis. By combining live-cell imaging and mathematical modeling in vitro with super-resolution microscopy of the BBB, we show that intracellular tubules promote transcytosis across the BBB...
December 12, 2017: Cell Reports
Xi-Hao Chen, Fan-Hui Kong, Qiang Fu, Shao-Ying Meng, Ling-An Wu
A sub-Rayleigh resolution ghost imaging experiment is performed via post-detection spatial low-pass filtering of the instantaneous intensity. A super-resolution reconstructed image has been achieved, in which the spatial resolution can exceed the Rayleigh diffraction limit by more than a factor of two. The resolution depends on the filter threshold, and the Rayleigh limit can be exceeded for a wide choice of threshold values. The setup is simple and easy to implement, which is an advantage for practical applications...
December 15, 2017: Optics Letters
O Bouzid, S Haddadi, M Fromager, E Cagniot, K Ferria, A Forbes, K Ait-Ameur
Binary diffractive optics have been extensively studied to date as tools for arbitrary laser beam shaping and experimentally implemented with etched transparent optics and spatial light modulators. Here we demonstrate that a simple one-step binary optic is able to enhance the intensity of a focused beam, displaying some counterintuitive focusing anomalies. We explain these effects by considering the optical aberrations in binary diffractive optics and outline how this may be exploited for further improvements in refractive/diffractive combinations for super-resolution microscopy...
December 10, 2017: Applied Optics
Yanting Shen, Lijia Liang, Shuqin Zhang, Dianshuai Huang, Jing Zhang, Shuping Xu, Chongyang Liang, Weiqing Xu
The pH value of subcellular organelles in living cells is a significant parameter in the physiological activities of cells. Its abnormal fluctuations are commonly believed to be associated with cancers and other diseases. Herein, a series of surface-enhanced Raman scattering (SERS) nanosensors with high sensitivity and targeting function was prepared for the quantification and monitoring of pH values in mitochondria, nucleus, and lysosome. The nanosensors were composed of gold nanorods (AuNRs) functionalized with a pH-responsive molecule (4-mercaptopyridine, MPy) and peptides that could specifically deliver the AuNRs to the targeting subcellular organelles...
December 14, 2017: Nanoscale
Yang Shi, Li Wang, Jianguo Zhang, Yujia Zhai, Fei Sun
Determining the cellular localization of proteins of interest at nanometer resolution is necessary for elucidating their functions. Besides super-resolution fluorescence microscopy, conventional electron microscopy (EM) combined with immunolabeling or clonable EM tags provides a unique approach to correlate protein localization information and cellular ultrastructural information. However, there are still rare cases of such correlation in three-dimensional (3D) spaces. Here, we developed an approach by combining the focus ion beam scanning electron microscopy (FIB-SEM) and a promising clonable EM tag APEX2 (an enhanced ascorbate peroxidase 2) to determine the target protein localization within 3D cellular ultrastructural context...
2017: Biophysics Reports
Xingguo Liu, Liang Yang, Qi Long, David Weaver, György Hajnóczky
Mitochondrial dynamics refers to the processes maintaining mitochondrial homeostasis, including mitochondrial fission, fusion, transport, biogenesis, and mitophagy. Mitochondrial dynamics is essential for maintaining the metabolic function of mitochondria as well as their regulatory roles in cell signaling. In this review, we summarize the recently developed imaging techniques for studying mitochondrial dynamics including: mitochondrial-targeted fluorescent proteins and dyes, live-cell imaging using photoactivation, photoswitching and cell fusion, mitochondrial transcription and replication imaging by in situ hybridization, and imaging mitochondrial dynamics by super-resolution microscopy...
2017: Biophysics Reports
Demetrio Sartiano, Salvador Sales
The aim of this paper is to report the design of a low-cost plastic optical fiber (POF) pressure sensor, embedded in a mattress. We report the design of a multipoint sensor, a cheap alternative to the most common fiber sensors. The sensor is implemented using Arduino board, standard LEDs for optical communication in POF (λ = 645 nm) and a silicon light sensor. The Super ESKA® plastic fibers were used to implement the fiber intensity sensor, arranged in a 4 × 4 matrix. During the breathing cycles, the force transmitted from the lungs to the thorax is in the order of tens of Newtons, and the respiration rate is of one breath every 2-5 s (0...
December 13, 2017: Sensors
Yue-Houng Hu, Joerg Rottmann, Rony Fueglistaller, Marios E Myronakis, Adam Wang, Pascal Huber, Daniel Shedlock, Daniel Morf, Paul Baturin, Josh M Star-Lack, Ross I Berbeco
While megavoltage (MV) cone-beam computed tomography (CBCT) using an electronic portal imaging device (EPID) provides many advantages over kilovoltage (kV) CBCT, clinical adoption is limited by its high doses. Multi-layer imager (MLI) EPIDs increase DQE(0) while maintaining high resolution. However, even well-designed, high-performance MLIs suffer from increased electronic noise from each readout, degrading low-dose image quality. To improve low-dose performance, shift-and-bin addition (ShiBA) imaging is proposed, leveraging the unique architecture of the MLI...
December 13, 2017: Physics in Medicine and Biology
Ilhan Ece, Huseyin Yilmaz, Husnu Alptekin, Serdar Yormaz, Bayram Colak, Farise Yilmaz, Mustafa Sahin
BACKGROUNDS: The management of super-super obese patients is challenging for bariatric surgeons. Laparoscopic sleeve gastrectomy (LSG) is feasible as two-stage treatment for high-risk patients. However, its efficacy as a stand-alone procedure in super-super obese (SSO) patients is controversial. The study objective was to demonstrate the safety and efficacy of LSG in super-obese (SO) and SSO patients. METHODS: A retrospective analysis was performed of consecutive patients undergoing LSG...
December 12, 2017: Obesity Surgery
Douglas B Cowan, Rouan Yao, Jerusha K Thedsanamoorthy, David Zurakowski, Pedro J Del Nido, James D McCully
Tissue ischemia adversely affects the function of mitochondria, which results in impairment of oxidative phosphorylation and compromised recovery of the affected organ. The impact of ischemia on mitochondrial function has been extensively studied in the heart because of the morbidity and mortality associated with injury to this organ. As conventional methods to preserve cardiac cell viability and contractile function following ischemia are limited in their efficacy, we developed a unique approach to protect the heart by transplanting respiration-competent mitochondria to the injured region...
December 12, 2017: Scientific Reports
Florian Schueder, Juanita Lara-Gutiérrez, Brian J Beliveau, Sinem K Saka, Hiroshi M Sasaki, Johannes B Woehrstein, Maximilian T Strauss, Heinrich Grabmayr, Peng Yin, Ralf Jungmann
Single-molecule localization microscopy (SMLM) can visualize biological targets on the nanoscale, but complex hardware is required to perform SMLM in thick samples. Here, we combine 3D DNA points accumulation for imaging in nanoscale topography (DNA-PAINT) with spinning disk confocal (SDC) hardware to overcome this limitation. We assay our achievable resolution with two- and three-dimensional DNA origami structures and demonstrate the general applicability by imaging a large variety of cellular targets including proteins, DNA and RNA deep in cells...
December 12, 2017: Nature Communications
Ricardo Gaspar, Georg Meisl, Alexander K Buell, Laurence Young, Clemens F Kaminski, Tuomas P J Knowles, Emma Sparr, Sara Linse
Parkinson's disease (PD) is characterized by proteinaceous aggregates named Lewy Bodies and Lewy Neurites containing α-synuclein fibrils. The underlying aggregation mechanism of this protein is dominated by a secondary process at mildly acidic pH, as in endosomes and other organelles. This effect manifests as a strong acceleration of the aggregation in the presence of seeds and a weak dependence of the aggregation rate on monomer concentration. The molecular mechanism underlying this process could be nucleation of monomers on fibril surfaces or fibril fragmentation...
January 2017: Quarterly Reviews of Biophysics
Hirokazu Sakamoto, Tetsuroh Ariyoshi, Naoya Kimpara, Kohtaroh Sugao, Isamu Taiko, Kenji Takikawa, Daisuke Asanuma, Shigeyuki Namiki, Kenzo Hirose
The weight of synaptic connections, which is controlled not only postsynaptically but also presynaptically, is a key determinant in neuronal network dynamics. The mechanisms controlling synaptic weight, especially on the presynaptic side, remain elusive. Using single-synapse imaging of the neurotransmitter glutamate combined with super-resolution imaging of presynaptic proteins, we identify a presynaptic mechanism for setting weight in central glutamatergic synapses. In the presynaptic terminal, Munc13-1 molecules form multiple and discrete supramolecular self-assemblies that serve as independent vesicular release sites by recruiting syntaxin-1, a soluble N-ethylmaleimide-sensitive-factor attachment receptor (SNARE) protein essential for synaptic vesicle exocytosis...
December 11, 2017: Nature Neuroscience
Simon Dersch, Peter L Graumann
We are witnessing a breathtaking development in light (fluorescence) microscopy, where structures can be resolved down to the size of a ribosome within cells. This has already yielded surprising insight into the subcellular structure of cells, including the smallest cells, bacteria. Moreover, it has become possible to visualize and track single fluorescent protein fusions in real time, and quantify molecule numbers within individual cells. Combined, super resolution and single molecule tracking are pushing the limits of our understanding of the spatio-temporal organization even of the smallest cells to an unprecedented depth...
December 8, 2017: Current Opinion in Microbiology
Lucas R Parent, Evangelos Bakalis, Maria Proetto, Yiwen Li, Chiwoo Park, Francesco Zerbetto, Nathan C Gianneschi
Revolutions in science and engineering frequently result from the development, and wide adoption, of a new, powerful characterization or imaging technique. Beginning with the first glass lenses and telescopes in astronomy, to the development of visual-light microscopy, staining techniques, confocal microscopy, and fluorescence super-resolution microscopy in biology, and most recently aberration-corrected, cryogenic, and ultrafast (4D) electron microscopy, X-ray microscopy, and scanning probe microscopy in nanoscience...
December 11, 2017: Accounts of Chemical Research
Janosch P Heller, Dmitri A Rusakov
Synaptic connections between individual nerve cells are fundamental to the process of information transfer and storage in the brain. Over the past decades a third key partner of the synaptic machinery has been unveiled: ultrathin processes of electrically passive astroglia which often surround pre- and postsynaptic structures. The recent advent of super-resolution (SR) microscopy has begun to uncover the dynamic nanoworld of synapses and their astroglial environment. Here we overview and discuss the current progress in our understanding of the synaptic nanoenvironment, as gleaned from the imaging methods that go beyond the diffraction limit of conventional light microscopy...
2017: Frontiers in Cellular Neuroscience
Kyle Kaniecki, Luisina De Tullio, Eric C Greene
Genetic recombination occurs in all organisms and is vital for genome stability. Indeed, in humans, aberrant recombination can lead to diseases such as cancer. Our understanding of homologous recombination is built upon more than a century of scientific inquiry, but achieving a more complete picture using ensemble biochemical and genetic approaches is hampered by population heterogeneity and transient recombination intermediates. Recent advances in single-molecule and super-resolution microscopy methods help to overcome these limitations and have led to new and refined insights into recombination mechanisms, including a detailed understanding of DNA helicase function and synaptonemal complex structure...
December 11, 2017: Nature Reviews. Genetics
Yoshitaka Ishii, Ayesha Wickramasinghe, Isamu Matsuda, Yuki Endo, Yuji Ishii, Yusuke Nishiyama, Takahiro Nemoto, Takayuki Kamihara
Proton-detected solid-state NMR (SSNMR) spectroscopy has attracted much attention due to its excellent sensitivity and effectiveness in the analysis of trace amounts of amyloid proteins and other important biological systems. In this perspective article, we present the recent sensitivity limit of 1H-detected SSNMR using "ultra-fast" magic-angle spinning (MAS) at a spinning rate (νR) of 80-100 kHz. It was demonstrated that the high sensitivity of 1H-detected SSNMR at νR of 100 kHz and fast recycling using the paramagnetic-assisted condensed data collection (PACC) approach permitted "super-fast" collection of 1H-detected 2D protein SSNMR...
November 28, 2017: Journal of Magnetic Resonance
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