keyword
MENU ▼
Read by QxMD icon Read
search

Single particle electron microscopy

keyword
https://www.readbyqxmd.com/read/29334219/mussel-inspired-conductive-polymer-binder-for-si-alloy-anode-in-lithium-ion-batteries
#1
Hui Zhao, Yang Wei, Cheng Wang, Rui-Min Qiao, Wanli Yang, Phillip B Messersmith, Gao Liu
The excessive volume changes during cell cycling of Si-based anode in lithium ion batteries impeded its application. One major reason for the cell failure is particle isolation during volume shrinkage in delithiation process, which makes strong adhesion between polymer binder and anode active material particles a highly desirable property. Here, a biomimetic side-chain conductive polymer incorporating catechol, a key adhesive component of the mussel holdfast protein, was synthesized. Atomic force microscopy (AFM) based single molecule force measurements of mussel-inspired conductive polymer binder contacting a silica surface revealed similar adhesion toward substrate when compared with an effective Si anode binder, homo-polyacrylic acid (PAA), with the added benefit of being electronically conductive...
January 15, 2018: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29324400/determination-of-atomic-positions-from-time-resolved-high-resolution-transmission-electron-microscopy-images
#2
Zahra Hussaini, Pin Ann Lin, Bharath Natarajan, Wenhui Zhu, Renu Sharma
For many reaction processes, such as catalysis, phase transformations, nanomaterial synthesis etc., nanoscale observations at high spatial (sub-nanometer) and temporal (millisecond) resolution are required to characterize and comprehend the underlying factors that favor one reaction over another. The combination of such spatial and temporal resolution (up to 600 µs), while rich in information, produces a large number of snapshots, each of which must be analyzed to obtain the structural (and thereby chemical) information...
December 28, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/29315633/preferential-adsorption-of-flavonoids-from-peanut-shell-by-amino-modified-fe3-o4-nanoparticles-mnp-nh2
#3
Xuexiao Cao, Meng Wang, Lili Sun, Xiaoliang Ren, Gaosheng Pei
BACKGROUND: The highly selective capture of individual components of complex systems such as Chinese medicine extracts is a great challenge. With the rapid development of nanoscience, magnetic materials have attracted increased attention as suitable candidates for use in drug transport vehicles. RESULTS: In this work, amino-modified Fe3 O4 nanoparticles (MNP-NH2 ) have been synthesized and successfully used to selectively isolate Luteolin, a type of flavonoid, from peanut shell, coupled with high-performance liquid chromatography (HPLC)...
January 9, 2018: Journal of the Science of Food and Agriculture
https://www.readbyqxmd.com/read/29310772/ultrastructural-analysis-of-the-extracellular-matrix
#4
Douglas R Keene, Sara F Tufa
This chapter gives insight into task-specific methodologies for the evaluation of matrix ultrastructure by light and electron microscopy. It separately considers the isolation and preparation of molecular isolates for negative staining, immunolabeling, rotary shadowing, and single particle analysis. Also considered is the preparation of whole tissues and cultured cells by chemical fixation and cryofixation methodologies. Immunoelectron microscopy for immunoidentification of matrix components may be accomplished en bloc or via section-surface protocols; the advantages and pitfalls in both methodologies are described...
2018: Methods in Cell Biology
https://www.readbyqxmd.com/read/29301312/mixed-matrix-membranes-of-boron-icosahedron-and-polymers-of-intrinsic-microporosity-pim-1-for-gas-separation
#5
Muntazim Munir Khan, Sergey Shishatskiy, Volkan Filiz
This work reports on the preparation and gas transport performance of mixed matrix membranes (MMMs) based on the polymer of intrinsic microporosity (PIM-1) and potassium dodecahydrododecaborate (K₂B12H12) as inorganic particles (IPs). The effect of IP loading on the gas separation performance of these MMMs was investigated by varying the IP content (2.5, 5, 10 and 20 wt %) in a PIM-1 polymer matrix. The derived MMMs were characterized by scanning electron microscopy (SEM), thermogravimetric analysis (TGA), single gas permeation tests and sorption measurement...
January 2, 2018: Membranes
https://www.readbyqxmd.com/read/29300742/component-tree-analysis-of-cystovirus-%C3%AF-6-nucleocapsid-cryo-em-single-particle-reconstructions
#6
Lucas M Oliveira, Ze Ye, Al Katz, Alexandra Alimova, Hui Wei, Gabor T Herman, Paul Gottlieb
The 3-dimensional structure of the nucleocapsid (NC) of bacteriophage φ6 is described utilizing component tree analysis, a topological and geometric image descriptor. The component trees are derived from density maps of cryo-electron microscopy single particle reconstructions. Analysis determines position and occupancy of structure elements responsible for RNA packaging and transcription. Occupancy of the hexameric nucleotide triphosphorylase (P4) and RNA polymerase (P2) are found to be essentially complete in the NC...
2018: PloS One
https://www.readbyqxmd.com/read/29300333/atomic-resolution-structures-of-human-bufaviruses-determined-by-cryo-electron-microscopy
#7
Maria Ilyas, Mario Mietzsch, Shweta Kailasan, Elina Väisänen, Mengxiao Luo, Paul Chipman, J Kennon Smith, Justin Kurian, Duncan Sousa, Robert McKenna, Maria Söderlund-Venermo, Mavis Agbandje-McKenna
Bufavirus strain 1 (BuV1), a member of the Protoparvovirus genus of the Parvoviridae, was first isolated from fecal samples of children with acute diarrhea in Burkina Faso. Since this initial discovery, BuVs have been isolated in several countries, including Finland, the Netherlands, and Bhutan, in pediatric patients exhibiting similar symptoms. Towards their characterization, the structures of virus-like particles of BuV1, BuV2, and BuV3, the current known genotypes, have been determined by cryo-electron microscopy and image reconstruction to 2...
January 4, 2018: Viruses
https://www.readbyqxmd.com/read/29290041/oligomeric-states-in-sodium-ion-dependent-regulation-of-cyanobacterial-histidine-kinase-2
#8
Iskander M Ibrahim, Liang Wang, Sujith Puthiyaveetil, Norbert Krauß, Jon Nield, John F Allen
Two-component signal transduction systems (TCSs) consist of sensor histidine kinases and response regulators. TCSs mediate adaptation to environmental changes in bacteria, plants, fungi and protists. Histidine kinase 2 (Hik2) is a sensor histidine kinase found in all known cyanobacteria and as chloroplast sensor kinase in eukaryotic algae and plants. Sodium ions have been shown to inhibit the autophosphorylation activity of Hik2 with precedes phosphoryl transfer to response regulators, but the mechanism of inhibition has not been determined...
December 30, 2017: Protoplasma
https://www.readbyqxmd.com/read/29288707/improving-the-skin-penetration-and-antifebrile-activity-of-ibuprofen-by-preparing-nanoparticles-using-emulsion-solvent-evaporation-method
#9
Yiping Deng, Fengjian Yang, Xiuhua Zhao, Lu Wang, Weiwei Wu, Chang Zu, Mingfang Wu
Ibuprofen (IBU) is an effective analgesic, non-steroidal anti-inflammatory drug. Unfortunately, oral IBU can cause adverse gastrointestinal drug reactions, such as bleeding and ulcerations, and increases the risk for stomach or intestinal perforations. In this study, IBU nanoparticles (IBU-NPs) were prepared through emulsion solvent evaporation and freeze-drying to improve their solubility. IBU nanoemulsion and nanosuspension were optimized through a single-factor experiment. IBU-NPs with a mean particle size of 216...
December 27, 2017: European Journal of Pharmaceutical Sciences
https://www.readbyqxmd.com/read/29282985/chemical-structure-ensemble-and-single-particle-spectroscopy-of-thick-shell-inp-znse-quantum-dots
#10
Kemar R Reid, James R McBride, Nathaniel J Freymeyer, Lucas B Thal, Sandra J Rosenthal
Thick-shell (> 5 nm) InP-ZnSe colloidal quantum dots (QDs) grown by a continuous-injection shell growth process are reported. The growth of a thick crystalline shell is attributed to the high temperature of the growth process and the relatively low lattice mismatch between the InP core and ZnSe shell. In addition to a narrow ensemble photoluminescence (PL) line-width (~ 40 nm), ensemble and single particle emission dynamics measurements indicate that blinking and Auger recombination are reduced in these heterostructures...
December 28, 2017: Nano Letters
https://www.readbyqxmd.com/read/29236684/cryo-em-structures-of-the-tmem16a-calcium-activated-chloride-channel
#11
Shangyu Dang, Shengjie Feng, Jason Tien, Christian J Peters, David Bulkley, Marco Lolicato, Jianhua Zhao, Kathrin Zuberbühler, Wenlei Ye, Lijun Qi, Tingxu Chen, Charles S Craik, Yuh Nung Jan, Daniel L Minor, Yifan Cheng, Lily Yeh Jan
Calcium-activated chloride channels (CaCCs) encoded by TMEM16A control neuronal signalling, smooth muscle contraction, airway and exocrine gland secretion, and rhythmic movements of the gastrointestinal system. To understand how CaCCs mediate and control anion permeation to fulfil these physiological functions, knowledge of the mammalian TMEM16A structure and identification of its pore-lining residues are essential. TMEM16A forms a dimer with two pores. Previous CaCC structural analyses have relied on homology modelling of a homologue (nhTMEM16) from the fungus Nectria haematococca that functions primarily as a lipid scramblase, as well as subnanometre-resolution electron cryo-microscopy...
December 13, 2017: Nature
https://www.readbyqxmd.com/read/29232520/controlling-the-dynamic-instability-of-capped-metal-nanoparticles-on-metallic-surfaces
#12
Evangelina Laura Pensa, Tim Albrecht
Small metal nanoparticles (NPs) with core-sizes ranging from 1-3 nm constitute a bridge between molecules and colloids with unique electronic, catalytic and other properties. Many applications entail immobilization onto solid supports, but while NP behavior in solution is well studied, the effect of the interaction between NPs and the substrate surface is understood less. Here, we follow the structural evolution of thiolated monolayer-protected AuNPs on Au(111) substrates at the single-particle level in real-time using high-resolution in situ Scanning Tunneling Microscopy...
December 12, 2017: Journal of Physical Chemistry Letters
https://www.readbyqxmd.com/read/29232109/impact-of-chemical-cross-linking-on-protein-structure-and-function
#13
Daniel Rozbesky, Michal Rosulek, Zdenek Kukacka, Josef Chmelik, Petr Man, Petr Novák
Chemical cross-linking coupled with mass spectrometry is a popular technique for deriving structural information of proteins and protein complexes. Also, cross-linking has become a powerful tool for stabilizing macromolecular complexes for single-particle cryo-electron microscopy. However, an effect of cross-linking on protein structure and function should not be forgotten, and surprisingly it has not been investigated in detail so far. Here, we used kinetic studies, mass spectrometry, and NMR spectroscopy to systematically investigate an impact of cross-linking on structure and function of human carbonic anhydrase and alcohol dehydrogenase 1 from Saccharomyces cerevisiae...
December 12, 2017: Analytical Chemistry
https://www.readbyqxmd.com/read/29229700/flexible-hinges-in-bacterial-chemoreceptors
#14
Narahari Akkaladevi, Filiz Bunyak, David Stalla, Tommi A White, Gerald L Hazelbauer
Transmembrane bacterial chemoreceptors are extended, rod-shaped homodimers with ligand-binding sites at one end and interaction sites for formation of signaling complexes and histidine kinase control at the other. There are atomic-resolution structures of chemoreceptor fragments but not of intact, membrane-inserted receptors. Electron tomography of in vivo signaling complex arrays lack distinct densities for chemoreceptor rods away from the well-ordered base plate region, implying structural heterogeneity. We investigated using negative staining, transmission electron microscopy and image analysis to characterize molecular shapes of intact homodimers of Escherichia coli aspartate receptor Tar rendered functional by insertion into Nanodisc-provided E...
December 11, 2017: Journal of Bacteriology
https://www.readbyqxmd.com/read/29227642/x-rays-in-the-cryo-em-era-structural-biology-s-dynamic-future
#15
Susannah Shoemaker, Nozomi Ando
Over the past several years, single-particle cryo-electron microscopy (cryo-EM) has emerged as a leading method for elucidating macromolecular structures at near-atomic resolution, rivaling even the established technique of X-ray crystallography. Cryo-EM is now able to probe proteins as small as hemoglobin (64 kDa), while avoiding the crystallization bottleneck entirely. The remarkable success of cryo-EM has called into question the continuing relevance of X-ray methods, particularly crystallography. To say that the future of structural biology is either cryo-EM or crystallography, however, would be misguided...
December 11, 2017: Biochemistry
https://www.readbyqxmd.com/read/29227481/nafion-particles-doped-with-methyl-viologen-electrochemistry
#16
Haiying Yang, Xiuting Li, Christopher Batchelor-McAuley, Stanislav V Sokolov, Richard G Compton
Nafion sub-micro particles doped with methyl viologen (MV2+) are synthesized using the re-precipitation method and characterized by scanning electron microscopy and UV-Vis spectroscopy. The electrochemical behavior of MV2+ incorporated into Nafion particles was investigated at both the ensemble and single particle levels. The charge transferred to single MV-Nafion particles was observed using the nano-impact method and shown to be quantitative. Finally, the charge transferred via individual MV-Nafion particle was substantially enhanced in the presence of permanganate...
December 11, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29223815/attenuation-of-bacterial-cytotoxicity-of-carbon-nanotubes-by-riverine-suspended-solids-in-water
#17
Baotong Zhu, Xinghui Xia, Sibo Zhang, Yuchen Tang
The impact of solid particles on ecotoxicity of nanomaterials in water environments is poorly understood. This study investigated the effect of natural riverine suspended solids (SPS) on the cytotoxicity of single-walled carbon nanotubes (SWCNTs) towards a bacterium, Ochrobactrum sp. in water. Compared with SWCNT suspension without SPS, the presence of SPS at different concentrations ranging from 20 to 400 mg L-1 markedly increased the survival rates of bacteria exposed to 50 mg L-1 SWCNTs and bacterial survival rates increased with SPS concentrations by a power law...
December 7, 2017: Environmental Pollution
https://www.readbyqxmd.com/read/29218346/the-synthesis-of-a-monodisperse-quaternary-ferrite-fecocro4-from-the-hot-injection-thermolysis-of-the-single-source-precursor-crcofeo-o2ctbu-6-ho2ctbu-3
#18
Khadijat O Abdulwahab, Mohammad A Malik, Paul O'Brien, Iñigo J Vitorica-Yrezabal, Grigore A Timco, Floriana Tuna, Richard E P Winpenny
Monodisperse cobalt chromium ferrite (FeCoCrO4) nanoparticles have been synthesised using the trimetallic pivalate cluster [CrCoFeO(O2CtBu)6(HO2CtBu)3]. The precursor was thermolysed in oleylamine and oleic acid, with diphenyl ether as the solvent at 260 °C. The effect of time and the concentration of the precursor on the stoichiometry of the phase formed and/or the morphology of the nanoparticles was studied. The reaction time was investigated by withdrawing aliquots at different times. No products were formed after 5 minutes and aliquots withdrawn at reaction times of less than 1 hour contain traces of iron oxide (Fe2O3); only cubic cobalt chromium ferrite (FeCoCrO4) was obtained after one hour...
December 8, 2017: Dalton Transactions: An International Journal of Inorganic Chemistry
https://www.readbyqxmd.com/read/29218341/templated-co-assembly-into-nanorods-of-polyanions-and-artificial-virus-capsid-proteins
#19
A Hernandez-Garcia, M A Cohen Stuart, R de Vries
Recombinant triblock polypeptides C-Sn-B, where C is a 400 amino acid long hydrophilic random coil block, Sn is a multimer of the silk-like octapeptide S = (GAGAGAGQ), and B = K12 is an oligolysine, have previously been shown to encapsulate double stranded DNA into rod-shaped, virus-like particles. In order to gain insight of the co-assembly process, and in order to be able to use these proteins for templating other types of nanorods, we here explore their co-assembly with a range of polyanionic templates: poly(acrylic acids) (PAA) of a wide range of lengths, poly(styrene sulphonate) (PSS) and the stiff anionic polysaccharide xanthan...
December 8, 2017: Soft Matter
https://www.readbyqxmd.com/read/29217581/structure-of-the-human-trpm4-ion-channel-in-a-lipid-nanodisc
#20
Henriette E Autzen, Alexander G Myasnikov, Melody G Campbell, Daniel Asarnow, David Julius, Yifan Cheng
Transient receptor potential (TRP) melastatin 4 (TRPM4) is a widely expressed cation channel associated with a variety of cardiovascular disorders. TRPM4 is activated by increased intracellular calcium in a voltage dependent manner, but unlike many other TRP channels is permeable to monovalent cations only. Here we present two structures of full-length human TRPM4 embedded in lipid nanodiscs at ~3Å resolution as determined by single particle electron cryo-microscopy. These structures, with and without calcium bound, reveal a general architecture for this major subfamily of TRP channels and a well-defined calcium binding site within the intracellular side of the S1-S4 domain...
December 7, 2017: Science
keyword
keyword
47515
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"