Read by QxMD icon Read


Divya P Narayanan, Sudha Kochiyil Cherikallinmel, Sugunan Sankaran, Binitha N Narayanan
A one pot synthesis of carbon dot incorporated porous coconut shell char derived sulphonated catalyst is reported here for the first time and is effectively used in the multicomponent synthesis of amidoalkyl naphthol. Macroporous nature of the char is revealed from scanning electron microscopic (SEM) analysis, whereas the dispersion of carbon dots (CDs) on the porous coconut shell char is confirmed from the high resolution transmission electron microscopic (HRTEM) analysis. Fluorescence emission spectrum further confirmed the presence of CDs in the catalyst...
March 6, 2018: Journal of Colloid and Interface Science
Emily Penick, Neha A Deshpande, Karissa Hammer, Nancy C Chescheir
No abstract text is available yet for this article.
March 8, 2018: Obstetrics and Gynecology
Xiao-Mei Shi, Li-Ping Mei, Qian Wang, Wei-Wei Zhao, Jing-Juan Xu, Hong-Yuan Chen
We report herein the energy transfer (ET) between semiconducting polymer dots (Pdots) and gold nanoparticles (Au NPs) in a photoelectrochemical (PEC) system and its feasibility for cathodic bioanalysis application. Specifically, COOH-capped Pdots were first fabricated and then assembled onto the indium-tin oxide (ITO) surface, followed by the modification of single-strand (ss) DNA probe (pDNA). After the DNA hybridization with the Au NP-tethered complementary ssDNA (Au NP-tDNA), the Au NPs were brought into the close proximity of Pdots...
March 13, 2018: Analytical Chemistry
F H Wang, K Bae, Z W Huang, J M Xue
For obtaining high-resolution macroscopical anatomical information and high sensitivity microscopical optical signals, it is highly desirable to develop dual-modality magnetic resonance imaging (MRI) and fluorescent probes in medical imaging simultaneously. In this study, Gd2 O3 nanoparticles were modified with two-photon graphene quantum dots (GQD), integrating a magnetic resonance imaging (MRI) contrast agent with two-photon imaging functionality into one nanoprobe. A photoluminescence study indicated that the GQD modification process integrated MRI properties with both one-photon and two-photon imaging properties...
March 12, 2018: Nanoscale
Ouyang Wang, Lei Wang, Zhaohan Li, Qiulei Xu, Qingli Lin, Hongzhe Wang, Zuliang Du, Huaibin Shen, Lin Song Li
We report a facile and robust synthesis of ZnCdS core/shell quantum dots (QDs) with thick Cdx Zn1-x S (x = constant) uniform alloys as an intermediate shell which can provide effective confinement of excitons within the ZnCdS cores and ultrathin ZnS outermost shell to improve the stability by epitaxial growth at a relatively high temperature. The resulting nearly monodisperse ZnCdS/Cdx Zn1-x S/ZnS core/shell QDs have high photoluminescence quantum yield (near to 100%) and high color purity (full width at half maximum (FWHM) < 18 nm)...
March 12, 2018: Nanoscale
Mohammad Mahdi Tavakoli, Fabrizio Giordano, Shaik M Zakeeruddin, Michael Grätzel
The solar to electric power conversion efficiency (PCE) of perovskite solar cells (PSCs) has recently reached 22.7 % exceeding that of competing thin film photovoltaics and the market leader polycrystalline silicon. Further augmentation of the PCE towards the Shockley-Queisser limit of 33.5 % warrants suppression of radiationless carrier recombination by judicious engineering of the interface between the light harvesting perovskite and the charge carrier extraction layers. Here, we introduce a mesoscopic oxide double layer as electron selective contact consisting of a scaffold of TiO2 nanoparticles covered by a thin film of SnO2, either in amorphous (a-SnO2), crystalline (c-SnO2) or nanocrystalline (quantum dot) form (SnO2-NC)...
March 12, 2018: Nano Letters
Dan Yang, Guixin Yang, Qianqian Sun, Shili Gai, Fei He, Yunlu Dai, Chongna Zhong, Piaoping Yang
The use of visible light to produce reactive oxygen species (ROS) from renewable water splitting is a highly promising means in photodynamic therapy (PDT). Up to date, diverse inorganic-organic hybrid materials developed as photosensitizers still undergo low therapeutic efficiency and/or poor stability. Herein, a kind of carbon-nanodot-decorated TiO2 nanotubes (CDots/TiO2 NTs) composite is developed and applied for photodynamic therapy. Upon 650 nm laser light excitation, the emissions with short wavelengths (325-425 nm) from the CDots as a result of upconversion process excite TiO2 NTs to form electron/hole (e- /h+ ) pairs, triggering the reaction with the adsorbed oxidants to produce ROS...
March 12, 2018: Advanced Healthcare Materials
Nagamalai Vasimalai, Vânia Vilas-Boas, Juan Gallo, María de Fátima Cerqueira, Mario Menéndez-Miranda, José Manuel Costa-Fernández, Lorena Diéguez, Begoña Espiña, María Teresa Fernández-Argüelles
Carbon dots have demonstrated great potential as luminescent nanoparticles in bioapplications. Although such nanoparticles appear to exhibit low toxicity compared to other metal luminescent nanomaterials, today we know that the toxicity of carbon dots (C-dots) strongly depends on the protocol of fabrication. In this work, aqueous fluorescent C-dots have been synthesized from cinnamon, red chilli, turmeric and black pepper, by a one-pot green hydrothermal method. The synthesized C-dots were firstly characterized by means of UV-vis, fluorescence, Fourier transform infrared and Raman spectroscopy, dynamic light scattering and transmission electron microscopy...
2018: Beilstein Journal of Nanotechnology
M Hasanzadeh, H Navay Baghban, N Shadjou
An innovative electrochemical interface for quantitation of L-proline (L-Pro) based on ternary amplification strategy was fabricated. In this work, gold nanoparticles prepared by soft template methodology were immobilized onto green and biocompatible nanocomposite containing poly as a conductive matrix and graphene quantum dots as the amplification element. Therefore, a novel multilayer film based on poly-L-cysteine, graphene quantum dots (GQDs), and gold nanoparticles (GNPs) was exploited to develop a highly sensitive electrochemical sensor for the detection of L-Pro...
2018: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Xue-Ping Cai, Bin Zhang, Xiao-Bo Chen, Hai-Yang Ding, Bing-Ren Gu, Hong-Ping Xie
Cationic poly-diallyldimethylammonium (PDADMAC), green CdTe quantum dots (QDs) or red CdS coated CdTe QDs, and anionic polyacrylic acid (PAA) were respectively assembled on the nano-carrier SiO2 to prepare green fluorescence composite nanoparticles (GF-QDs) and red ones (RF-QDs) with the structure SiO2 /PDADMAC/QD/PDADMAC/PAA. The sandwich structure "PDADMAC/QD/PDADMAC" on the nano-carrier not only realized the protection to fluorescence of QDs but also avoided the fluorescence shielding of silica shell for the assembled QDs...
2018: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Masanori Ando, Vasudevanpillai Biju, Yasushi Shigeri
Ozone (O3 ) gas is widely used as a strong oxidizing agent for many purposes, such as the decomposition/removal of organic contaminants and photoresist, and the deodorization/disinfection of air and water. However, ozone is highly toxic to the human body when the air concentration exceeds about 1 ppm. Therefore, there is increasing demand for simple, sensitive, reliable, and cost-effective techniques for sensing ozone gas. This article describes the features, advantages, and disadvantages of the available, practical techniques for sensing ozone gas in ambient air...
2018: Analytical Sciences: the International Journal of the Japan Society for Analytical Chemistry
Mansooreh Bagheri, Manajid Farvardin
PURPOSE: To review the association of postoperative ocular alignment, sensory outcomes, and need for reoperation after surgical management of infantile exotropia. METHODS: The clinical records of patients who presented with constant infantile exotropia of >25Δ and subsequently underwent strabismus surgery at a single center from 2004 to 2014 were reviewed retrospectively. Postoperative binocular sensory status was assessed using Worth 4-Dot and Titmus stereoacuity tests...
March 8, 2018: Journal of AAPOS: the Official Publication of the American Association for Pediatric Ophthalmology and Strabismus
Vasily Mikhaïlovitch Smirnov, Christina Zeitz, Nagasamy Soumittra, Isabelle Audo, Sabine Defoort-Dhellemmes
INTRODUCTION: CABP4-related retinal dysfunction is a cone-rod synaptic transmission disorder with electronegative electroretinogram (ERG) waveform. It is a rare retinal dysfunction that can be classified into the incomplete form of congenital stationary night blindness. Absent foveal reflex and overall foveal thinning were previously reported, but in most cases the fundus appearance was described as nearly normal. We report here peculiar macular changes in a patient of French ancestry harbouring CABP4 mutations...
March 10, 2018: Documenta Ophthalmologica. Advances in Ophthalmology
Xuejiao Chen, Fuchun Gong, Zhong Cao, Wu Zou, Tingting Gu
Strongly green fluorescent carbon dots (CQDs) have been directly synthesized from 2,4-diaminophenylhydrazine and 2-hydroxy-5-methylisophthalaldehyde through a facile solvothermal method. The novel CQDs exhibit high fluorescence quantum yield and excellent water solubility due to the abundant amino and hydroxy groups on their surface. The use of the as-prepared CQDs combined with Cu2+ constructed a "turn-on" switch cysteine-responsive nanoprobe. In the CQDs-Cu2+ assemblies, the binding of Cu2+ to CQDs results in the fluorescence quenching of CQDs by electron transfer mechanism, while the addition of cysteine leads to the fluorescence recovery because of the competitive binding between cysteine and CQDs to Cu2+ ...
March 9, 2018: Analytical and Bioanalytical Chemistry
Yu-Ting Gong, Fang Yuan, Yuming Dong, Zaijun Li, Guang-Li Wang
A novel and general strategy of split-type immunoassay is developed based on redox chemical reaction modulated photoelectrochemistry of carbon dots (CDs). Specifically, the photocurrent of the CDs sensitized titanium dioxide nanoparticles (TiO2 NPs) modified fluorine doped indium tin oxide (FTO) (that is the FTO/TiO2 /CDs) electrode was inhibited obviously by KMnO4 due to the oxidation of surface hydroxyl groups of CDs to electron accepting carbonyls. While the inhibited photocurrent of the KMnO4 treated FTO/TiO2 /CDs electrode can be restored by ascorbic acid (AA) because of the regeneration of electron donating hydroxyls to promote electron-hole separation...
July 19, 2018: Analytica Chimica Acta
Tapan Das, B P V Dileep, Pranab K Dutta
Near-infrared imaging (NIRI) is a sub-surface imaging that makes a trade-off in recovery accuracy with depth of penetration. On the other hand, diffuse optical tomography (DOT) images tissue up to several centimeters. However, DOT reconstruction has a stability issue due to the inverse problem. This paper proposes a generalized continuous-wave technique to image objects of dimensions 4-6 cm comparable to DOT. A nonlinear Rosenbrock's banana function is fitted to the approximate photon path, and the fit parameter thus obtained gives the penetration depth of each channel...
March 10, 2018: Applied Optics
Jianru Zhao, Xiaohua Pan, Xiaobo Sun, Wei Pan, Guifeng Yu, Jinping Wang
In this work, carbon dots (CDs) with a high quantum yield (22.3%) were easily prepared by hydrothermal pyrolysis of acid fuchsin 6B and hydrogen peroxide at 180°C for 10 h. The resultant CDs possess a narrow size distribution in the range of 2.6 to 3.2 nm and emit blue fluorescence. Interestingly, the absorption band of metronidazole (MTZ) centered at 318 nm can complementary overlap with the excitation band of the as-prepared CDs centered at 320 nm, resulting in an inner filter effect (IFE) in high efficiency...
March 9, 2018: Luminescence: the Journal of Biological and Chemical Luminescence
Anthony S Barnhart, Mandy J Ehlert, Stephen D Goldinger, Alison D Mackey
Recently, performance magic has become a source of insight into the processes underlying awareness. Magicians have highlighted a set of variables that can create moments of visual attentional suppression, which they call "off-beats." One of these variables is akin to the phenomenon psychologists know as attentional entrainment. The current experiments, inspired by performance magic, explore the extent to which entrainment can occur across sensory modalities. Across two experiments using a difficult dot probe detection task, we find that the mere presence of an auditory rhythm can bias when visual attention is deployed, speeding responses to stimuli appearing in phase with the rhythm...
March 8, 2018: Attention, Perception & Psychophysics
Lili Guo, Lin Li, Meiying Liu, Qing Wan, Jianwen Tian, Qiang Huang, Yuanqing Wen, Shangdong Liang, Xiaoyong Zhang, Yen Wei
Carbon quantum dots (CDs) have standout as one of the most important carbon nanomaterials owing to their small size, optical properties, biocompatibility and low toxicity. These CDs have been extensively explored for various applications especially in the biomedical fields. Although great efforts have been devoted to the fabrication of CDs through both top-down and bottom-up methods, most of these CDs exhibited blue emission under UV light irradiation. In this work, we reported a novel, green, economic approach for preparation of nitrogen doped CDs by directly microwave-assisted heating small organic molecules at 120°C for 5min using Glu and amino group of MPD as the precursors and ethylene glycol as solvent...
March 1, 2018: Materials Science & Engineering. C, Materials for Biological Applications
Charles N Melton, Sheida T Riahinasab, Amir Keshavarz, Benjamin J Stokes, Linda S Hirst
When nanoparticle self-assembly takes place in an anisotropic liquid crystal environment, fascinating new effects can arise. The presence of elastic anisotropy and topological defects can direct spatial organization. An important goal in nanoscience is to direct the assembly of nanoparticles over large length scales to produce macroscopic composite materials; however, limitations on spatial ordering exist due to the inherent disorder of fluid-based methods. In this paper we demonstrate the formation of quantum dot clusters and spherical capsules suspended within spherical liquid crystal droplets as a method to position nanoparticle clusters at defined locations...
March 7, 2018: Nanomaterials
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"