keyword
MENU ▼
Read by QxMD icon Read
search

Electron microscopy

keyword
https://www.readbyqxmd.com/read/29141205/investigation-of-alimentary-canal-ultrastructure-following-knockdown-of-the-dicer-2-gene-in-planthoppers-reveals-the-potential-pathogenicity-of-southern-rice-black-streaked-dwarf-virus-to-its-insect-vector
#1
Yuyan Liu, Qianzhuo Mao, Hanhong Lan, Haitao Wang, Taiyun Wei, Qian Chen
An increasing number of studies are suggesting that plant viruses, including southern rice black-streaked dwarf virus (SRBSDV), can adversely affect biological characteristics of insect vectors by unknown mechanisms. To study the adverse effect of SRBSDV at cellular level on the insect vector, we promoted viral infection by the disruption of the small interfering RNA (siRNA) pathway. The transmission electron microscopy was utilized to describe the ultrastructural changes that occurred in insects when the core component of the siRNA pathway, Dicer-2, was knocked down...
November 12, 2017: Virus Research
https://www.readbyqxmd.com/read/29141107/metal-transformation-as-a-strategy-for-bacterial-detoxification-of-heavy-metals
#2
Ashraf M M Essa, Mohamed A Al Abboud, Sayeed I Khatib
Microorganisms can modify the chemical and physical characters of metals leading to an alteration in their speciation, mobility, and toxicity. Aqueous heavy metals solutions (Hg, Cd, Pb, Ag, Cu, and Zn) were treated with the volatile metabolic products (VMPs) of Escherichia coli Z3 for 24 h using aerobic bioreactor. The effect of the metals treated with VMPs in comparison to the untreated metals on the growth of E. coli S1 and Staphylococcus aureus S2 (local isolates) was examined. Moreover, the toxic properties of the treated and untreated metals were monitored using minimum inhibitory concentration assay...
November 15, 2017: Journal of Basic Microbiology
https://www.readbyqxmd.com/read/29140971/effect-of-s-mutans-and-s-sanguinis-on-growth-and-adhesion-of-p-gingivalis-and-their-ability-to-adhere-to-different-dental-materials
#3
Yan Tu, Xiaolong Ling, Yadong Chen, Yuan Wang, Na Zhou, Hui Chen
BACKGROUND Caries and periodontal diseases are caused by the biofilm formed by caries- and periodontal disease-related bacteria. Specific biofilms could be formed on different filling materials in oral cavity. Thus, to explore the inhibition effect of restorative filling materials on biofilm formation is of great significance in the treatment of caries and periodontal disease. MATERIAL AND METHODS The supernatants of S. mutans, S. sanguinis, and P. gingivalis suspension were combined with BHI broth. After 24 h, the live P...
November 15, 2017: Medical Science Monitor: International Medical Journal of Experimental and Clinical Research
https://www.readbyqxmd.com/read/29140895/an-ex-vivo-comparison-of-2-cyanoacrylate-skin-protectants
#4
Daniel J Gibson
PURPOSE: The purpose of these experiments was to compare 2 commercially available skin protectants with different chemical compositions. DESIGN: Two materially different skin protectants were applied to ex vivo pig skin, subjected to stresses, and the resulting skin was observed and analyzed. METHODS: Using ex vivo pig skin, we sought to better understand the physical differences between a cyanoacrylate-based and a mixed cyanoacrylate/acrylic polymer-based skin protectant...
November 14, 2017: Journal of Wound, Ostomy, and Continence Nursing
https://www.readbyqxmd.com/read/29140802/characterization-with-scanning-electron-microscopy-energy-dispersive-x-ray-spectrometry-of-microtraces-from-the-ligature-mean-in-hanging-mechanical-asphyxia-a-series-of-forensic-cases
#5
Francesca Maghin, Salvatore Ambrogio Andreola, Michele Boracchi, Guendalina Gentile, Francesca Maciocco, Riccardo Zoja
The authors applied scanning electron microscopy with energy-dispersive x-ray spectrometry to the furrow derived from hanging means. The study was conducted with the purpose to detect possible extraneous microtraces, deriving from the ligature, that could have had an interaction with the cutaneous biological matrix, thanks to a transfert mechanism, in the proximities of the lesion.Fifteen cutaneous samples of the furrow and an equal number of fragments of graphite tape, directly positioned on the lesion produced by the ligature mean and used as a "conductor" of possible traces, were analyzed using scanning electron microscopy with energy-dispersive x-ray spectrometry...
November 15, 2017: American Journal of Forensic Medicine and Pathology
https://www.readbyqxmd.com/read/29140718/pem-fitter-a-coarse-grained-method-to-validate-protein-candidate-models
#6
Kamal Al Nasr, Christopher Jones, Feras Yousef, Ruba Jebril
The volumetric images produced by Cryo-Electron Microscopy (cryo-EM) technique are used to model macromolecular assemblies and machines. De novo protein modeling uses these images to computationally model the structure of the molecules. Many candidate conformations are usually generated during the intermediate step. Conventionally, each of these candidates is evaluated by time-consuming approaches such as potential energy. We introduce an initial version of a geometrical screening method that uses the skeleton of the cryo-EM images to evaluate candidate structures...
November 15, 2017: Journal of Computational Biology: a Journal of Computational Molecular Cell Biology
https://www.readbyqxmd.com/read/29140713/direct-observation-of-plasmon-induced-interfacial-charge-separation-in-metal-semiconductor-hybrid-nanostructures-by-measuring-surface-potentials
#7
Seung-Hoon Lee, Seung Woo Lee, Taegon Oh, Sarah Hurst Petrosko, Chad A Mirkin, Jae-Won Jang
Plasmon-induced interfacial charge separation (PICS) is one of the key processes responsible for the improved conversion efficiencies of energy-harvesting devices that incorporate metal nanostructures. In this letter, we reveal a mechanism of PICS by visualizing (with nanometer-scale resolution) and characterizing plasmon-exciton coupling between p-type poly(pyrrole) (PPy) nanowires (NWs) and Ag nanoparticles (NPs) using light-irradiated Kelvin probe force microscopy (KPFM). Under blue-light irradiation, the Ag NPs are expected to donate electrons to the PPy NWs via a hot electron injection process...
November 15, 2017: Nano Letters
https://www.readbyqxmd.com/read/29140694/tyrocidine-a-analogues-bearing-the-planar-d-phe-2-abz-turn-motif-how-conformation-impacts-bioactivity
#8
Alan J Cameron, Patrick J B Edwards, Elena Harjes, Vijayalekshmi Sarojini
The D-Phe-Pro β-turn of the cyclic β-hairpin antimicrobial decapeptide Tyrocidine A, (Tyrc A) was substituted with the D-Phe-2-aminobenzoic acid (2-Abz) motif in a synthetic analogue (1). NMR structure of 1 demonstrated that compound 1 retained the β-hairpin structure of Tyrc A with additional planarity, resulting in approx. 30-fold reduced haemolysis than Tyrc A. Although antibacterial activity was partially compromised, a single Gln to Lys substitution (2) restored activity equivalent to Tyrc A against S...
November 15, 2017: Journal of Medicinal Chemistry
https://www.readbyqxmd.com/read/29140683/nanocomposite-phosphor-consisting-of-cai2-eu-2-single-nanocrystals-embedded-in-crystalline-sio2
#9
Hisayoshi Daicho, Takeshi Iwasaki, Yu Shinomiya, Akitoshi Nakano, Hiroshi Sawa, Wataru Yamada, Satoru Matsuishi, Hideo Hosono
High luminescence efficiency is obtained in halide- and chalcogenide-based phosphors, but they are impractical because of their poor chemical durability. Here we report a halide-based nanocomposite phosphor with excellent luminescence efficiency and sufficient durability for practical use. Our approach was to disperse luminescent single nanocrystals of CaI2:Eu(2+) in a chemically stable, translucent crystalline SiO2 matrix. Using this approach, we successfully prepared a nanocomposite phosphor by means of self-organization through a simple solid-state reaction...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29140682/molecular-patterning-and-directed-self-assembly-of-gold-nanoparticles-on-gaas
#10
Tianhan Liu, Timothy D Keiper, Xiaolei Wang, Guang Yang, Daniel T Hallinan, Jianhua Zhao, Peng Xiong
The ability to create micro/nano patterns of organic self-assembled monolayers (SAMs) on semiconductor surfaces is crucial for fundamental studies and applications in a number of emerging fields in nanoscience. Here, we demonstrate the direct patterning of thiolate SAMs on oxide-free GaAs surface by dip-pen nanolithography (DPN) and micro-contact printing (μCP), facilitated by a process of surface etching and passivation of the GaAs. A quantitative analysis on the molecular diffusion on GaAs was conducted by examining the writing of nanoscale dot and line patterns by DPN, which agrees well with surface diffusion models...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29140680/helicity-inversion-of-supramolecular-hydrogels-induced-by-achiral-substituents
#11
Guofeng Liu, Xin Li, Jianhui Sheng, Pei-Zhou Li, Wee Kong Ong, Soo Zeng Fiona Phua, Hans Ågren, Liangliang Zhu, Yanli Zhao
Probing the supramolecular chirality of assemblies and controlling their handedness are closely related to the origin of chirality at supramolecular level and the development of smart materials with desired handedness. However, it remains unclear how achiral residues covalently bonded to chiral amino acids can function in the chirality inversion of supramolecular assemblies. Herein, we report macroscopic chirality and dynamic manipulation of chiroptical activity of hydrogels self-assembled from phenylalanine derivatives, together with the inversion of their handedness achieved solely by exchanging achiral substituents between oligo(ethylene glycol) and carboxylic acid groups...
November 15, 2017: ACS Nano
https://www.readbyqxmd.com/read/29140676/synthesis-of-large-area-tungsten-disulfide-films-on-pre-reduced-tungsten-suboxides-substrates
#12
Soo Ho Choi, Stephen Boandoh, Young Ho Lee, Joo Song Lee, Ji-Hoon Park, Soo Min Kim, Woochul Yang, Ki Kang Kim
We report a facile method for the synthesis of large-area tungsten disulfide (WS2) film by means of chemical vapor deposition (CVD). To promote WS2 film growth, the precursor solution, which includes pre-reduced tungsten suboxides, is prepared by using hydrazine as the strong reduction agent and spin-coated onto the growth substrate. Growth is then carried out in a CVD chamber vaporized with dimethyl disulfide (DMDS) as the sulfur precursor. While only WS2 flakes are grown with un-reduced tungsten precursor under hydrogen atmosphere, WS2 film is readily attained on pre-reduced tungsten suboxide substrates without the need for further reduction by hydrogen, which is noted to induce discontinuity of grown film...
November 15, 2017: ACS Applied Materials & Interfaces
https://www.readbyqxmd.com/read/29140372/cytotoxicity-of-dental-implants-the-effects-of-ultrastructural-elements
#13
Ebru Cal, Vildan Bozok Cetintas, Hayal Boyacioglu, Pelin Güneri
PURPOSE: In this in vitro study, the purpose was to assess the cytotoxicity profiles of seven commercial dental implant materials by using cell culture methods on an osteoblastic cell line. MATERIALS AND METHODS: The microstructure of seven commercial dental implants (each given a letter code) was investigated via scanning electron microscopy and energy-dispersive x-ray analysis. Medium extracts were collected on the first and fifth days for each group and tested using MC3T3-E1 cell line...
November 2017: International Journal of Oral & Maxillofacial Implants
https://www.readbyqxmd.com/read/29140369/wear-at-the-implant-abutment-interface-of-zirconia-abutments-manufactured-by-three-cad-cam-systems
#14
Ana Luiza Pinheiro Tannure, Alfredo Gonçalves Cunha, Luiz Antônio Borges Junior, Laís Regiane da Silva Concílio, Ana Christina Claro Neves
PURPOSE: To evaluate the changes in the external-hexagon surface of the titanium (Ti) implant before and after mechanical cycling, when coupled with zirconia (Zr) abutments (A) manufactured by three computer-aided design/computer-aided manufacturing (CAD/CAM) systems (Neodent Digital, Zirkonzahn, and AmannGirrbach) and the ZrTi abutment manufactured by Neodent. MATERIALS AND METHODS: Four groups were formed (n = 6): titanium implant with Zr AmannGirrbach abutment (AZrAG), with Zr Zirkonzahn abutment (AZrZ), with Zr Neodent abutment (AZrN), and with Zr abutment with infrastructure in Ti Neodent (AZrTiN)...
November 2017: International Journal of Oral & Maxillofacial Implants
https://www.readbyqxmd.com/read/29140304/ultra-fast-microwave-synthesis-of-zno-nanorods-on-cellulose-substrates-for-uv-sensor-applications
#15
Ana Pimentel, Ana Samouco, Daniela Nunes, Andreia Araújo, Rodrigo Martins, Elvira Fortunato
In the present work, tracing and Whatman papers were used as substrates to grow zinc oxide (ZnO) nanostructures. Cellulose-based substrates are cost-efficient, highly sensitive and environmentally friendly. ZnO nanostructures with hexagonal structure were synthesized by hydrothermal under microwave irradiation using an ultrafast approach, that is, a fixed synthesis time of 10 min. The effect of synthesis temperature on ZnO nanostructures was investigated from 70 to 130 °C. An Ultra Violet (UV)/Ozone treatment directly to the ZnO seed layer prior to microwave assisted synthesis revealed expressive differences regarding formation of the ZnO nanostructures...
November 15, 2017: Materials
https://www.readbyqxmd.com/read/29139500/self-assembly-of-wo3-3-clusters-on-a-highly-oriented-pyrolytic-graphite-surface-and-nanowire-formation-a-combined-experimental-and-theoretical-study
#16
Xin Tang, Kit H Bowen, Florent Calvo
Tungsten oxide cluster anions (WO3)3(-) produced from a magnetron source were soft-landed on highly oriented pyrolytic graphite (HOPG) surfaces at different temperatures, and the structures formed upon deposition were analyzed using ex situ atomic force microscopy. Under liquid nitrogen cooling conditions of 100 K, the clusters form small branched nanostructures extending over a few nanometers with a height not exceeding 1 nm. At 673 K, nanowires approximately 100 nm long and less than 10 nm in diameter are observed...
November 15, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/29139396/folic-acid-modified-pluronic-f127-coating-ag2s-quantum-dot-for-photoacoustic-imaging-of-tumor-cell-targeting
#17
Ruo-Yun Zhang, Zhao-Yang Wang, Xiao-Quan Yang, Yang Xuan, Kai Cheng, Cheng Li, Xian-Lin Song, Jie An, Xiao-Lin Hou, Yuan-Di Zhao
In this study, oil-soluble Ag2S quantum dot (QD) was synthesized through thermal decomposition of single-source precursor method, and Pluronic F127 (PF127), a triblock copolymer functionalized with folic acid (FA), was deposited on the surface of QD, then water-soluble PF127-FA@Ag2S nanoprobe with targeting ability was fabricated. The as-prepared PF127-FA@Ag2S exhibited spheroidal morphology and high dispersibility, with average diameters of 115 ± 20.7 nm (as observed by transmission electron microscopy). No obvious toxicity of PF127-FA@Ag2S nanoprobe was found in standard 3-(4, 5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide assay and colony-formation assay, indicating that decent biocompatibility and safety...
November 15, 2017: Nanotechnology
https://www.readbyqxmd.com/read/29139394/thickness-dependent-surface-plasmon-resonance-of-ito-nanoparticles-for-ito-in-sn-bilayer-structure
#18
Wenzuo Wei, Ruijin Hong, Ming Jing, Wen Shao, Chunxian Tao, Dawei Zhang
Tunablity of localized surface plasmon resonance (LSPR) in doped semiconductor nanoparticles (NPs), which represents an important characteristic in LSPR sensor applications, still remains a challenge. Here, indium tin oxide/indium tin alloy (ITO/In-Sn) bilayer films were deposited by electron beam evaporation and the properties, such as LSPR and surface morphology, were investigated by UV-vis-NIR double beam spectrophotometer and atomic force microscopy (AFM), respectively. By simply engineering the thickness of ITO/In-Sn NPs without any microstructure fabrications, LSPR wavelength of ITO NPs can be largely tuned from 858 to 1758 nm...
November 15, 2017: Nanotechnology
https://www.readbyqxmd.com/read/29139338/freeze-drying-of-silica-nanoparticles-redispersibility-toward-nanomedicine-applications
#19
Agustin S Picco, Larissa F Ferreira, Michelle S Liberato, Gabriela B Mondo, Mateus B Cardoso
AIM: To study freeze-drying of silica nanoparticles (SiO2NPs) in order to find suitable conditions to produce lyophilized powders with no aggregation after resuspension and storage. METHODS: SiO2NPs were synthesized using a Stöber-based procedure, and characterized by scanning electron microscopy, dynamic light scattering and nitrogen adsorption/desorption isotherms. SiO2NPs hydrodynamic diameters were compared prior and after freeze-drying in the presence/absence of carbohydrate protectants...
November 15, 2017: Nanomedicine
https://www.readbyqxmd.com/read/29139147/the-development-of-lingual-glands-in-the-domestic-duck-anas-platyrhynchos-f-domestica-3d-reconstruction-lm-and-sem-study
#20
Kinga Skieresz-Szewczyk, Pieter Cornillie, Hanna Jackowiak
The major salivary glands of birds develop by branching or elongation of the epithelial cords. The development of the minor salivary glands in form of the lingual glands has never been described. Among birds, only Anatidae have three types of the lingual glands: rostral, caudo-lateral, and caudo-medial lingual glands. The study aims to characterize the manner and rate of the lingual glands development in the domestic duck and their topographical arrangement relative to the hyoid apparatus. The study reveals that all three types of the lingual glands develop by branching...
November 15, 2017: Journal of Morphology
keyword
keyword
9220
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"