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https://www.readbyqxmd.com/read/28644668/strong-light-matter-interactions-in-single-open-plasmonic-nanocavities-at-the-quantum-optics-limit
#1
Renming Liu, Zhang-Kai Zhou, Yi-Cong Yu, Tengwei Zhang, Hao Wang, Guanghui Liu, Yuming Wei, Huanjun Chen, Xue-Hua Wang
Reaching the quantum optics limit of strong light-matter interactions between a single exciton and a plasmon mode is highly desirable, because it opens up possibilities to explore room-temperature quantum devices operating at the single-photon level. However, two challenges severely hinder the realization of this limit: the integration of single-exciton emitters with plasmonic nanostructures and making the coupling strength at the single-exciton level overcome the large damping of the plasmon mode. Here, we demonstrate that these two hindrances can be overcome by attaching individual J aggregates to single cuboid Au@Ag nanorods...
June 9, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28643467/a-core-shell-satellite-structured-fe3-o4-g-c3-n4-ucnps-peg-for-t1-t2-weighted-dual-modal-mri-guided-photodynamic-therapy
#2
Lili Feng, Dan Yang, Fei He, Shili Gai, Chunxia Li, Yunlu Dai, Piaoping Yang
Reactive oxygen species (ROS) produced in the specific tumor site plays the key role in photodynamic therapy (PDT). Herein, a multifunctional nanoplatform is designed by absorbing ultrasmall upconversion nanoparticles (UCNPs) on mesoporous graphitic-phase carbon nitride (g-C3 N4 ) coated superparamagnetic iron oxide nanospheres, then further modified with polyethylene glycol (PEG)molecules (abbreviated as Fe3 O4 @g-C3 N4 -UCNPs-PEG). The inert g-C3 N4 layer between Fe3 O4 core and outer UCNPs can substantially depress the quenching effect of Fe3 O4 on the upconversion emission...
June 23, 2017: Advanced Healthcare Materials
https://www.readbyqxmd.com/read/28628326/improved-sodium-ion-storage-performance-of-ultrasmall-iron-selenide-nanoparticles
#3
Feipeng Zhao, Sida Shen, Liang Cheng, Lu Ma, Junhua Zhou, Hualin Ye, Na Han, Tianpin Wu, Yanguang Li, Jun Lu
Sodium-ion batteries are potential low-cost alternatives to current lithium-ion technology, yet their performance still fall short of expectation due to the lack of suitable electrode materials with large capacity, long-term cycling stability and high-rate performance. In this work, we demonstrated that ultrasmall (~5 nm) iron selenide (FeSe2) nanoparticles exhibited a remarkable performance for sodium-ion storage. They were prepared from a high-temperature solution method with a narrow size distribution and high yield, and could be readily redispersed in non-polar organic solvents...
June 19, 2017: Nano Letters
https://www.readbyqxmd.com/read/28621978/self-similar-nanocavity-design-with-ultrasmall-mode-volume-for-single-photon-nonlinearities
#4
Hyeongrak Choi, Mikkel Heuck, Dirk Englund
We propose a photonic crystal nanocavity design with self-similar electromagnetic boundary conditions, achieving ultrasmall mode volume (V_{eff}). The electric energy density of a cavity mode can be maximized in the air or dielectric region, depending on the choice of boundary conditions. We illustrate the design concept with a silicon-air one-dimensional photon crystal cavity that reaches an ultrasmall mode volume of V_{eff}∼7.01×10^{-5}λ^{3} at λ∼1550  nm. We show that the extreme light concentration in our design can enable ultrastrong Kerr nonlinearities, even at the single-photon level...
June 2, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28616141/a-general-strategy-for-colloidal-stable-ultrasmall-amorphous-mineral-clusters-in-organic-solvents
#5
Shengtong Sun, Denis Gebauer, Helmut Cölfen
While nature exerts precise control over the size and chemical composition of minerals, this is still a challenging task for artificial syntheses. Despite its significance, until now, there are still no reports on colloidal mineral nanoparticles in the subnanometer range. Here we developed a general gas diffusion strategy using 10,12-pentacosadiynoic acid as a ligand and ethanol as a solvent to fabricate stable amorphous mineral clusters with a core size of less than 2 nm. First discovered for CaCO3, the method was successfully extended to produce monolayer protected clusters of MgCO3, SrCO3, Eu2(CO3)3, Tb2(CO3)3, Ce2(CO3)3, Ca x (PO4) y , CaC2O4 and their hybrid minerals, Ca x Mg y (CO3) z and Ca x (CO3) y (PO4) z ...
February 1, 2017: Chemical Science
https://www.readbyqxmd.com/read/28614660/crystallization-temperature-dependence-of-cavitation-and-plastic-flow-in-the-tensile-deformation-of-poly-%C3%AE%C2%B5-caprolactone
#6
Zhiyong Jiang, Ran Chen, Ying Lu, Ben Whiteside, Phil D Coates, Zhonghua Wu, Yongfeng Men
In situ small-, ultrasmall-, and wide-angle X-ray scattering measurements were performed to investigate the structural evolution of crystalline lamellae and cavities as a function of deformation ratio during tensile deformation of isothermally crystallized poly(ε-caprolactone). The cavities were modelled as cylinder-shaped objects which are oriented along the stretching direction and randomly distributed in the samples, and their dimensions were evaluated by direct model fitting of scattering patterns. At small deformations, the orientation of these cavities at the onset of cavity formation was related to the isothermal crystallization temperature...
June 14, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28613886/electrochemical-size-measurement-and-characterization-of-electrodeposited-platinum-nanoparticles-at-nanometer-resolution-with-scanning-electrochemical-microscopy
#7
Wei Ma, Keke Hu, QianJin Chen, Min Zhou, Michael Mirkin, Allen J Bard
The properties of nanoparticles (NPs) are determined by their size and geometric structure. A reliable determination of NP dimensions is critical for understanding physical and chemical properties, but sizing ultrasmall particles on the nanometer (nm) scale in solution is still challenging. Here, we report the size measurement of PtNPs at nm resolution by in-situ scanning electrochemical microscopy (SECM), performed with the electrochemical generation and removal of H2 bubbles at a small distance between tip and substrate in 200 mM or 500 mM HClO4 solution...
June 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28595000/antimicrobial-gold-nanoclusters
#8
Kaiyuan Zheng, Magdiel I Setyawati, David Tai Leong, Jianping Xie
Bulk gold (Au) is known to be chemically inactive. However, when the size of Au nanoparticles (Au NPs) decreases to close to 1 nm or sub-nanometer dimensions, these ultrasmall Au nanoclusters (Au NCs) begin to possess interesting physical and chemical properties and likewise spawn different applications when working with bulk Au or even Au NPs. In this study, we found that it is possible to confer antimicrobial activity to Au NPs through precise control of their size down to NC dimension (typically less than 2 nm)...
June 13, 2017: ACS Nano
https://www.readbyqxmd.com/read/28570764/controllable-n-doped-cuco2-o4-c-film-as-a-self-supported-anode-for-ultrastable-sodium-ion-batteries
#9
Xiaojun Wang, Kangzhe Cao, Yijing Wang, Lifang Jiao
Rational synthesis of flexible electrodes is crucial to rapid growth of functional materials for energy-storage systems. Herein, a controllable fabrication is reported for the self-supported structure of CuCo2 O4 nanodots (≈3 nm) delicately inserted into N-doped carbon nanofibers (named as 3-CCO@C); this composite is first used as binder-free anode for sodium-ion batteries (SIBs). Benefiting from the synergetic effect of ultrasmall CuCo2 O4 nanoparticles and a tailored N-doped carbon matrix, the 3-CCO@C composite exhibits high cycling stability (capacity of 314 mA h g(-1) at 1000 mA g(-1) after 1000 cycles) and high rate capability (296 mA h g(-1) , even at 5000 mA g(-1) )...
June 1, 2017: Small
https://www.readbyqxmd.com/read/28566330/monitoring-the-vascular-response-and-resistance-to-sunitinib-in-renal-cell-carcinoma-in-vivo-with-susceptibility-contrast-mri
#10
Simon P Robinson, Jessica Kr Boult, Naveen S Vasudev, Andrew R Reynolds
Anti-angiogenic therapy is efficacious in metastatic renal cell carcinoma (mRCC).  However, the ability of anti-angiogenic drugs to delay tumor progression and extend survival is limited, due to either innate or acquired drug resistance.  Furthermore, there are currently no validated biomarkers that predict which mRCC patients will benefit from anti-angiogenic therapy.  Here we exploit susceptibility contrast magnetic resonance imaging (SC-MRI) using intravascular ultrasmall superparamagnetic iron oxide particles to quantify and evaluate tumor fractional blood volume (fBV) as a non-invasive imaging biomarker of response to the anti-angiogenic drug sunitinib...
May 31, 2017: Cancer Research
https://www.readbyqxmd.com/read/28552648/ultrasmall-graphene-oxide-based-t1-mri-contrast-agent-for-in-vitro-and-in-vivo-labeling-of-human-mesenchymal-stem-cells
#11
Mengxin Zhang, Xiaoyun Liu, Jie Huang, Lina Wang, He Shen, Yu Luo, Zhenjun Li, Hailu Zhang, Zongwu Deng, Zhijun Zhang
Herein, we report on development of a two-dimensional nanomaterial graphene oxide (GO)-based T1 magnetic resonance imaging (MRI) contrast agent (CA) for in vitro and in vivo labeling of human mesenchymal stem cells (hMSCs). The CA was synthesized by PEGylation of ultrasmall GO, followed by conjugation with a chelating agent DOTA and then gadolinium(III) to form GO-DOTA-Gd complexes. Thus-prepared GO-DOTA-Gd complexes exhibited significantly improved T1 relaxivity, and the r1 value was 14.2 mM(-1)s(-1) at 11...
May 26, 2017: Nanomedicine: Nanotechnology, Biology, and Medicine
https://www.readbyqxmd.com/read/28552303/in-situ-ionic-liquid-dispersive-liquid-liquid-microextraction-using-a-new-anion-exchange-reagent-combined-fe3o4-magnetic-nanoparticles-for-determination-of-pyrethroid-pesticides-in-water-samples
#12
Chen Fan, You Liang, Hongqiang Dong, Guanglong Ding, Wenbing Zhang, Gang Tang, Jiale Yang, Dandan Kong, Deng Wang, Yongsong Cao
In this work, in-situ ionic liquid dispersive liquid-liquid microextraction combined ultrasmall Fe3O4 magnetic nanoparticles was developed as a kind of pretreatment method to detect pyrethroid pesticides in water samples. New anion-exchange reagents including Na[DDTC] and Na[N(CN)2] were optimized for in-situ extraction pyrethroids, which showed enhanced microextraction performance. Pyrethroids were enriched by hydrophilic ionic liquid [P4448][Br] (aqueous solution, 200 μL, 0.2 mmol mL(-1)) reaction in-situ with anion-exchange reagent Na[N(CN)2] (aqueous solution, 300 μL, 0...
July 4, 2017: Analytica Chimica Acta
https://www.readbyqxmd.com/read/28548515/velocity-fluctuations-in-sedimenting-brownian-particles
#13
Johannes Möller, Theyencheri Narayanan
We report a gradual transition of dynamics in sedimenting suspensions of charge stabilized Brownian particles prior to the onset of the macroscopic sedimentation front. Using multispeckle ultrasmall-angle x-ray photon correlation spectroscopy (USA-XPCS), we show that well-defined advective motions dominate the colloid dynamics during the early stages of sedimentation. With elapsing time, these advective currents decay and diffusive motions become the dominating contribution in the dynamics. Probing the temporal development of these fluctuations at smaller Peclet numbers (<1) provides a new perspective for the mechanism determining the transient nature of velocity fluctuations in sedimentation and demonstrates new experimental capabilities enabled by multispeckle USA-XPCS...
May 12, 2017: Physical Review Letters
https://www.readbyqxmd.com/read/28544617/defect-laden-mose2-quantum-dots-made-by-turbulent-shear-mixing-as-enhanced-electrocatalysts
#14
Chongyang Zhu, Yuan Huang, Feng Xu, Peng Gao, Binghui Ge, Jing Chen, Haibo Zeng, Eli Sutter, Peter Sutter, Litao Sun
A high density of edge sites and other defects can significantly improve the catalytic activity of layered 2D materials. Herein, this study demonstrates a novel top-down strategy to maximize catalytic edge sites of MoSe2 by breaking up bulk MoSe2 into quantum dots (QDs) via "turbulent shear mixing" (TSM). The ultrasmall size of the MoSe2 QDs provides a high fraction of atoms in reactive edge sites, thus significantly improving the catalytic activities. The violent TSM further introduces abundant defects as additional active sites for electrocatalytic reactions...
May 24, 2017: Small
https://www.readbyqxmd.com/read/28539274/the-analgesia-efficiency-of-ultrasmall-magnetic-iron-oxide-nanoparticles-in-mice-chronic-inflammatory-pain-model
#15
Ping-Ching Wu, Hung-Tsung Hsiao, Ya-Chi Lin, Dar-Bin Shieh, Yen-Chin Liu
Few studies have investigated the effects of iron oxide nanoparticles (NPs) on analgesia. We developed inflammatory pain models via complete Freund's adjuvant injection over the hind paw in CD1 mice. Various doses of magnetite (Fe3O4) NPs were injected into the paw. Analgesia behavior was checked with von Frey microfilament and thermal irradiation measurements. Paw skin tissues were harvested at the maximal analgesia time point. The presence of activated white cells (CD68, myeloperoxidase) and free radical (reactive oxygen species, ROS) production was also checked...
May 21, 2017: Nanomedicine: Nanotechnology, Biology, and Medicine
https://www.readbyqxmd.com/read/28535354/high-capacity-and-ultrafast-na-ion-storage-of-a-self-supported-3d-porous-antimony-persulfide-graphene-foam-architecture
#16
Yanying Lu, Ning Zhang, Shuang Jiang, Yudong Zhang, Meng Zhou, Zhanliang Tao, Lynden A Archer, Jun Chen
The key challenge for high-performance sodium-ion batteries is the exploitation of appropriate electrode materials with a long cycling stability and high rate capability. Here, we report Sb2S5 nanoparticles (∼5 nm) uniformly encapsulated in three-dimensional (3D) porous graphene foam, which were fabricated by a facile hydrothermal coassembly strategy, as a high-performance anode material for sodium-ion batteries. The as-prepared composite can be directly used as electrodes without adding a binder or current collector, exhibiting outstanding electrochemical performance with a high reversible capacity (845 mA h g(-1) at 0...
June 14, 2017: Nano Letters
https://www.readbyqxmd.com/read/28531986/biomimicking-synthesis-of-photoluminescent-molecular-lantern-catalyzed-by-in-situ-formation-of-nanogold-catalysts
#17
Yong Yu, Xin Ting Zheng, Boon Wei Yee, Yen Nee Tan
Bioluminescence has been widely recognized as a powerful imaging tool for biological investigations. Synthesis of molecular lanterns that mimic bioluminescence in nature is of great interest. Herein we report a synthesis of molecular lantern by utilizing the catalytic properties of ultrasmall (<2nm) gold nanoclusters (AuNC), which is inspired by the enzymatic light-up of luciferin in the biological system. Small molecules such as hydroquinone and Cys-Gly peptides are used to direct the synthesis of AuNC via a biotemplating approach, while the in-situ formation of AuNC simultaneously catalyze the formation of luciferin-like, brightly fluorescent dye (λem=520nm, QY=0...
August 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
https://www.readbyqxmd.com/read/28525274/metal-nanoparticle-catalyzed-hydrogen-generation-from-formic-acid
#18
Zhangpeng Li, Qiang Xu
To meet the ever-increasing energy demand, the development of effective, renewable, and environmentally friendly sources of alternative energy is imperative. Hydrogen (H2) is a renewable, clean energy carrier, which exhibits a threefold energy density compared to gasoline; H2 is considered one of the most promising alternative energy carriers for enabling a secure, clean energy future. However, the realization of a hydrogen economy is restricted by several unresolved issues. Particularly, one of the most difficult challenges is the development of a safe, efficient hydrogen storage and delivery system...
May 19, 2017: Accounts of Chemical Research
https://www.readbyqxmd.com/read/28508857/controlling-photophysical-properties-of-ultrasmall-conjugated-polymer-nanoparticles-through-polymer-chain-packing
#19
Hubert Piwoński, Tsuyoshi Michinobu, Satoshi Habuchi
Applications of conjugated polymer nanoparticles (Pdots) for imaging and sensing depend on their size, fluorescence brightness and intraparticle energy transfer. The molecular design of conjugated polymers (CPs) has been the main focus of the development of Pdots. Here we demonstrate that proper control of the physical interactions between the chains is as critical as the molecular design. The unique design of twisted CPs and fine-tuning of the reprecipitation conditions allow us to fabricate ultrasmall (3...
May 16, 2017: Nature Communications
https://www.readbyqxmd.com/read/28504415/highly-luminescent-folate-functionalized-au22-nanoclusters-for-bioimaging
#20
Kyunglim Pyo, Nguyen Hoang Ly, Sook Young Yoon, Yiming Shen, Seon Young Choi, So Yeong Lee, Sang-Woo Joo, Dongil Lee
Gold nanoclusters are emerging as new materials for biomedical applications because of promises offered by their ultrasmall size and excellent biocompatibility. Here, the synthesis and optical and biological characterizations of a highly luminescent folate-functionalized Au22 cluster (Au22 -FA) are reported. The Au22 -FA clusters are synthesized by functionalizing the surface of Au22 (SG)18 clusters, where SG is glutathione, with benzyl chloroformate and folate. The functionalized clusters are highly water-soluble and exhibit remarkably bright luminescence with a quantum yield of 42%, significantly higher than any other water-soluble gold clusters protected with thiolate ligands...
May 15, 2017: Advanced Healthcare Materials
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