keyword
MENU ▼
Read by QxMD icon Read
search

Single molecule imaging

keyword
https://www.readbyqxmd.com/read/29772044/a-phase-1-open-label-dose-escalation-trial-to-investigate-safety-and-tolerability-of-single-intravitreous-injections-of-icon-1-targeting-tissue-factor-in-wet-amd
#1
John A Wells, Christine R Gonzales, Brian B Berger, Victor H Gonzalez, Brian D Sippy, Gabriela Burian
BACKGROUND AND OBJECTIVE: This phase 1 study evaluated the safety and tolerability of single intravitreous injections (IVIs) of ICON-1 (Iconic Therapeutics, South San Francisco, CA) in patients with neovascular age-related macular degeneration (nAMD). ICON-1 is a modified factor VIIa protein linked with the Fc portion of a human immunoglobulin G1. The molecule binds tissue factor overexpressed on choroidal neovascularization (CNV) in AMD. PATIENTS AND METHODS: Open-label, interventional, dose-escalation trial in 18 patients with CNV due to AMD, with six patients per dose cohort...
May 1, 2018: Ophthalmic Surgery, Lasers & Imaging Retina
https://www.readbyqxmd.com/read/29771911/asymmetric-polar-localization-dynamics-of-the-serine-chemoreceptor-protein-tsr-in-escherichia-coli
#2
Dongmyung Oh, Yang Yu, Hochan Lee, Jae-Hyung Jeon, Barry L Wanner, Ken Ritchie
The spatial location of proteins in living cells can be critical for their function. For example, the E. coli chemotaxis machinery is localized to the cell poles. Here we describe the polar localization of the serine chemoreceptor Tsr using a strain synthesizing a fluorescent Tsr-Venus fusion at a low level from a single-copy chromosomal construct. Using photobleaching and imaging during recovery by new synthesis, we observed distinct asymmetry between a bright (old) pole and a dim (new) pole. The old pole was shown to be a more stable cluster and to recover after photobleaching faster, which is consistent with the hypothesis that newly synthesized Tsr proteins are inserted directly at or near the old pole...
2018: PloS One
https://www.readbyqxmd.com/read/29771534/nitroxyl-modified-tobacco-mosaic-virus-as-a-metal-free-high-relaxivity-mri-and-epr-active-superoxide-sensor
#3
Madushani Dharmarwardana, Andre F Martins, Zhuo Chen, Philip Palacios, Chance M Nowak, Raymond P Welch, Shaobo Li, Michael Andrew Luzuriaga, Leonidas Bleris, Brad S Pierce, A Dean Sherry, Jeremiah J Gassensmith
Superoxide overproduction is known to occur in multiple disease states requiring critical care yet non-invasive detection of superoxide in deep tissue remains a challenge. Herein, we report a metal-free magnetic resonance imaging (MRI) and electron paramagnetic resonance (EPR) active contrast agent prepared by "click conjugating" paramagnetic organic radical contrast agents (ORCAs) to the surface of tobacco mosaic virus (TMV). While ORCAs are known to be reduced in vivo to an MRI/EPR silent state, their oxidation is facilitated specifically by reactive oxygen species-in particular superoxide-and are largely unaffected by peroxides and molecular oxygen...
May 17, 2018: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/29767969/single-molecule-imaging-reveals-conformational-manipulation-of-holliday-junction-dna-by-the-junction-processing-protein-ruva
#4
Dalton Gibbs, Soma Dhakal
Interactions between DNA and motor proteins regulate nearly all biological functions of DNA such as gene expression, DNA replication and repair, and transcription. During the late stages of homologous recombination (HR), the Escherichia coli recombination machinery, RuvABC, resolves the four-way DNA motifs called Holliday junctions (HJs) that are formed during exchange of nucleotide sequences between two homologous duplex DNA. Although the formation of RuvA-HJ complex is known to be the first critical step in the RuvABC pathway, the mechanism for the binding interaction between RuvA and HJ has remained elusive...
May 16, 2018: Biochemistry
https://www.readbyqxmd.com/read/29767633/nanopatterning-on-calixarene-thin-films-via-low-energy-field-emission-scanning-probe-lithography
#5
Xiaoyue He, Peng Li, Pengchong Liu, Xiaoxian Zhang, Xiangqian Zhou, Wei Liu, Xiaohui Qiu
Field-emitted, low-energy electrons from the conducting tip of an atomic force microscope were adopted for nanolithography on calixarene ultrathin films coated on silicon wafers. A structural evolution from protrusion to depression down to a 30 nm spatial resolution was reproducibly obtained by tuning the sample voltage and exposure current in the lithography process. Close analyses of the profiles showed that the nanostructures formed by a single exposure with a high current are almost identical to those created by cumulative exposure with a lower current but an equal number of injected electrons...
May 16, 2018: Nanotechnology
https://www.readbyqxmd.com/read/29767428/photonic-crystal-enhanced-fluorescence-immunoassay-on-diatom-biosilica
#6
Kenneth Squire, Xianming Kong, Paul LeDuff, Gregory L Rorrer, Alan X Wang
Fluorescence biosensing is one of the most established biosensing methods, particularly fluorescence spectroscopy and microscopy. These are two highly sensitive techniques but require high grade electronics and optics to achieve the desired sensitivity. Efforts have been made to implement these methods using consumer grade electronics and simple optical setups for applications such as point-of-care diagnostics, but the sensitivity inherently suffers. Sensing substrates, capable of enhancing fluorescence are thus needed to achieve high sensitivity for such applications...
May 16, 2018: Journal of Biophotonics
https://www.readbyqxmd.com/read/29767359/simultaneous-multiplexed-detection-of-rna-and-protein-on-the-nanostring-%C3%A2-ncounter-%C3%A2-platform
#7
Sarah Warren
The NanoString nCounter Analysis System uses a digital fluorescent barcode technology that allows for direct multiplexed measurement of gene expression (mRNA), DNA, and protein. The technology uses molecular barcodes and single-molecule imaging to detect and count unique mRNA and protein targets in a single reaction. nCounter-based detection is enzyme-free (no amplification of mRNA is required), fully automated, and allows simultaneous detection of up to 770 mRNA and 30 protein targets from multiple sample types...
2018: Methods in Molecular Biology
https://www.readbyqxmd.com/read/29766713/probing-dna-hybridization-equilibrium-by-cationic-conjugated-polymer-for-highly-selective-detection-and-imaging-of-single-nucleotide-mutation
#8
Zehao Li, Xu Zhou, Lidan Li, Shue Liu, Congshan Wang, Lina Li, Changyuan Yu, Xin Su
Hybridization-based probes emerge as a promising tool for nucleic acid target detection and imaging. However, the single-nucleotide selectivity is still challenging because the specificity of hybridization reaction is typically low at room temperature. We disclose an effective and simple method for highly selective detection and in situ imaging of single-nucleotide mutation (SNM) by taking the advantages of the specific hybridization of short duplex and the signal amplifying effect of cationic conjugated polymer (CCP)...
May 16, 2018: Analytical Chemistry
https://www.readbyqxmd.com/read/29764582/-research-advances-in-the-role-of-aptamers-in-the-diagnosis-and-targeted-therapy-of-pediatric-cancer
#9
Yi-Bin Zhang, Yan-Peng Wang, Jing Liu
Aptamers are single-stranded DNA or RNA which are isolated from synthesized random oligonucleotide library in vitro via systematic evolution of ligands by exponential enrichment (SELEX) and can bind to metal ions, small molecules, carbohydrates, lipids, proteins, and others targets with high affinity and specificity. Aptamers have the advantages of simple preparation, good thermal stability, and low immunogenicity and have great potential in the medical fields such as molecular imaging, biosensing, early diagnosis of diseases, and targeted therapy...
May 2018: Zhongguo Dang Dai Er Ke za Zhi, Chinese Journal of Contemporary Pediatrics
https://www.readbyqxmd.com/read/29761181/self-assembly-and-ring-opening-metathesis-polymerization-of-cyclic-conjugated-molecules-on-highly-ordered-pyrolytic-graphite
#10
Shih-Ting Chiu, Hsin-Yu Chiang, Yen-Jen Lin, Yun-Yung Lu, Hirofumi Tanaka, Takuya Hosokai, Masaki Horie
Cyclic conjugated monomers comprising cyclopentadithiophene-vinylene trimers and their polymers on HOPG are observed using STM and AFM. ROMP of the monomers is performed using a Grubbs catalyst. Their STM images exhibit single chains of planar polymers, whereas their AFM images show elongation of the polymer chains on HOPG.
May 15, 2018: Chemical Communications: Chem Comm
https://www.readbyqxmd.com/read/29756761/digital-microarrays-single-molecule-readout-with-interferometric-detection-of-plasmonic-nanorod-labels
#11
Derin Sevenler, George G Daaboul, Fulya Ekiz Kanik, Nese Lortlar Ünlü, M Selim Ünlu
DNA and protein microarrays are a high-throughput technology that allow the simultaneous quantification of tens of thousands of different biomolecular species. The mediocre sensitivity and limited dynamic range of traditional fluorescence microarrays compared to other detection techniques have been the technology's Achilles' Heel, and prevented their adoption for many biomedical and clinical diagnostic applications. Previous work to enhance the sensitivity of microarray readout to the single-molecule ('digital') regime have either required signal amplifying chemistry or sacrificed throughput, nixing the platform's primary advantages...
May 14, 2018: ACS Nano
https://www.readbyqxmd.com/read/29754821/a-post-transcriptional-feedback-mechanism-for-noise-suppression-and-fate-stabilization
#12
Maike M K Hansen, Winnie Y Wen, Elena Ingerman, Brandon S Razooky, Cassandra E Thompson, Roy D Dar, Charles W Chin, Michael L Simpson, Leor S Weinberger
Diverse biological systems utilize fluctuations ("noise") in gene expression to drive lineage-commitment decisions. However, once a commitment is made, noise becomes detrimental to reliable function, and the mechanisms enabling post-commitment noise suppression are unclear. Here, we find that architectural constraints on noise suppression are overcome to stabilize fate commitment. Using single-molecule and time-lapse imaging, we find that-after a noise-driven event-human immunodeficiency virus (HIV) strongly attenuates expression noise through a non-transcriptional negative-feedback circuit...
May 4, 2018: Cell
https://www.readbyqxmd.com/read/29753778/understanding-protein-mobility-in-bacteria-by-tracking-single-molecules
#13
REVIEW
Achillefs N Kapanidis, Stephan Uphoff, Mathew Stracy
Protein diffusion is crucial for understanding the formation of protein complexes in vivo, and has been the subject of many fluorescence microscopy studies in cells; however, such microscopy efforts are often limited by low sensitivity and resolution. During the past decade, these limitations have been addressed by new super-resolution imaging methods, most of which rely on single-particle tracking and single-molecule detection; these methods are revolutionizing our understanding of molecular diffusion inside bacterial cells by directly visualizing the motion of proteins and the effects of the local and global environment on diffusion...
May 10, 2018: Journal of Molecular Biology
https://www.readbyqxmd.com/read/29753448/widefield-high-frame-rate-single-photon-spad-imagers-for-spim-fcs
#14
Jan Buchholz, Jan Krieger, Claudio Bruschini, Samuel Burri, Andrei Ardelean, Edoardo Charbon, Jörg Langowski
Photon-counting sensors based on standard complementary metal-oxide-semiconductor single-photon avalanche diodes (SPADs) represent an emerging class of imagers that enable the counting and/or timing of single photons at zero readout noise (better than high-speed electron-multiplying charge-coupling devices) and over large arrays. They have seen substantial progress over the last 15 years, increasing their spatial resolution, timing accuracy, and sensitivity while reducing spurious signals such as afterpulsing and dark counts...
May 9, 2018: Biophysical Journal
https://www.readbyqxmd.com/read/29752180/-177-lu-psma-617-radionuclide-treatment-in-patients-with-metastatic-castration-resistant-prostate-cancer-lupsma-trial-a-single-centre-single-arm-phase-2-study
#15
Michael S Hofman, John Violet, Rodney J Hicks, Justin Ferdinandus, Sue Ping Thang, Tim Akhurst, Amir Iravani, Grace Kong, Aravind Ravi Kumar, Declan G Murphy, Peter Eu, Price Jackson, Mark Scalzo, Scott G Williams, Shahneen Sandhu
BACKGROUND: Progressive metastatic castration-resistant prostate cancer is a highly lethal disorder and new effective therapeutic agents that improve patient outcomes are urgently needed. Lutetium-177 [177 Lu]-PSMA-617, a radiolabelled small molecule, binds with high affinity to prostate-specific membrane antigen (PSMA) enabling beta particle therapy targeted to metastatic castration-resistant prostate cancer. We aimed to investigate the safety, efficacy, and effect on quality of life of [177 Lu]-PSMA-617 in men with metastatic castration-resistant prostate cancer who progressed after standard treatments...
May 7, 2018: Lancet Oncology
https://www.readbyqxmd.com/read/29750519/charge-carrier-activity-on-single-particle-photo-electro-catalysts-toward-function-in-solar-energy-conversion
#16
Mahdi Hesari, Xianwen Mao, Peng Chen
Understanding the fundamental properties of charge carriers on the surface of semiconductor photo(electro)catalysts is key to the rational design of efficient photo(electro)catalytic devices for sunlight-driven energy conversion. Here high spatial resolution information is always desirable because of the ubiquitous heterogeneity in semiconductor particles. In this Perspective we review the latest advances in nanoscale imaging and quantitative analysis of charge carrier activities on individual semiconductor particles down to sub-particle resolution, covering the approaches of single-molecule super-resolution fluorescence imaging, scanning electron microscopy, and photoluminescence microscopy...
May 11, 2018: Journal of the American Chemical Society
https://www.readbyqxmd.com/read/29749224/photoactivatable-rhodamine-spiroamides-and-diazoketones-decorated-with-universal-hydrophilizer-or-hydroxyl-groups
#17
Benoit Roubinet, Matthias Bischoff, Shamil Nizamov, Sergey Yan, Claudia Geisler, Stefan Stoldt, Gyuzel Y Mitronova, Vladimir N Belov, Mariano L Bossi, Stefan W Hell
Photoactivatable rhodamine spiroamides and spirocyclic diazoketones emerged recently as synthetic markers applicable in multicolor superresolution microscopy. However, their applicability in single molecule localization microscopy (SMLM) is often limited by aggregation, unspecific adhesion and low reactivity caused by insufficient solubility and precipitation from aqueous solutions. We report here two synthetic modifications increasing the polarity of compact polycyclic and hydrophobic labels decorated with a reactive group: attachment of 3-sulfo-L-alanyl - beta-alanine dipeptide (a "universal hydrophilizer") or allylic hydroxylation in photosensitive rhodamine diazoketones (and spiroamides)...
May 11, 2018: Journal of Organic Chemistry
https://www.readbyqxmd.com/read/29748498/single-viruses-on-the-fluorescence-microscope-imaging-molecular-mobility-interactions-and-structure-sheds-new-light-on-viral-replication
#18
REVIEW
Nagma Parveen, Doortje Borrenberghs, Susana Rocha, Jelle Hendrix
Viruses are simple agents exhibiting complex reproductive mechanisms. Decades of research have provided crucial basic insights, antiviral medication and moderately successful gene therapy trials. The most infectious viral particle is, however, not always the most abundant one in a population, questioning the utility of classic ensemble-averaging virology. Indeed, viral replication is often not particularly efficient, prone to errors or containing parallel routes. Here, we review different single-molecule sensitive fluorescence methods that we employ routinely to investigate viruses...
May 10, 2018: Viruses
https://www.readbyqxmd.com/read/29742413/single-molecule-light-sheet-imaging-of-suspended-t-cells
#19
Aleks Ponjavic, James McColl, Alexander R Carr, Ana Mafalda Santos, Klara Kulenkampff, Anna Lippert, Simon J Davis, David Klenerman, Steven F Lee
Adaptive immune responses are initiated by triggering of the T cell receptor. Single-molecule imaging based on total internal reflection fluorescence microscopy at coverslip/basal cell interfaces is commonly used to study this process. These experiments have suggested, unexpectedly, that the diffusional behavior and organization of signaling proteins and receptors may be constrained before activation. However, it is unclear to what extent the molecular behavior and cell state is affected by the imaging conditions, i...
May 8, 2018: Biophysical Journal
https://www.readbyqxmd.com/read/29741383/design-synthesis-and-isomerization-studies-of-light-driven-molecular-motors-for-single-molecular-imaging
#20
Jiawen Chen, Jérôme Vachon, Ben L Feringa
The design of a multicomponent system that aims at the direct visualization of a synthetic rotary motor at the single molecule level on surfaces is presented. The synthesis of two functional motors enabling photochemical rotation and fluorescent detection, is described. The light-driven molecular motor is found to operate in the presence of a fluorescent tag if a rigid long rod (32 Å) is installed between both photoactive moieties. The photochemical isomerization and subsequent thermal helix inversion steps are confirmed by 1H NMR and UV-vis absorption spectroscopies...
May 9, 2018: Journal of Organic Chemistry
keyword
keyword
32971
1
2
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read
×

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"