Read by QxMD icon Read


Shu Zhang, Paul N Williams, Chun-Yang Zhou, Lena Q Ma, Jun Luo
The monitoring of oxyanions in waters, presents significant challenges due to their relatively low concentrations, and a characteristically changeable/unstable/reactive geochemistry with high spatial and temporal turnover. This results in a very heterogeneous pattern of mobility and bioavailability, which is difficult to capture reliably and in a cost effective manner. The diffusive gradients in thin-films (DGT) technique is a popular analytical tool for testing water quality, primarily because it provides a time-integrated measurement...
June 18, 2017: Chemosphere
Jiancheng Wang, Zhouqing Xie, Feiyue Wang, Hui Kang
Gaseous elemental mercury (GEM) in the marine boundary layer (MBL), and dissolved gaseous mercury (DGM) in surface seawater of the Southern Ocean were measured in the austral summer from December 13, 2014 to February 1, 2015. GEM concentrations in the MBL ranged from 0.4 to 1.9ngm(-3) (mean±standard deviation: 0.9±0.2ngm(-3)), whereas DGM concentrations in surface seawater ranged from 7.0 to 75.9pgL(-1) (mean±standard deviation: 23.7±13.2pgL(-1)). The occasionally observed low GEM in the MBL suggested either the occurrence of atmospheric mercury depletion in summer, or the transport of GEM-depleted air from the Antarctic Plateau...
June 20, 2017: Science of the Total Environment
Hicham Bakkali, Eduardo Blanco, Manuel Dominguez, Jose S Garitaonandia
Discontinuous multilayer (DML) thin films, which consist of nano-granular metals (NGMs) embedded in a dielectric matrix, have attracted significant interest as engineered plasmonic metamaterials. In this study, a systematic layer-by-layer deposition of three-dimensional sub-wavelength periodic plasmonic DML structures via the radio frequency sputtering of a composite target has been reported. The overall optical response of the DML films composed of AuAl2O3 NGM homogenous layers, which are periodically sandwiched between two amorphous Al2O3 layers, are studied using reflection spectroscopic ellipsometry and transmission spectroscopy techniques...
June 23, 2017: Nanotechnology
Vasilii I Popov, Danil Nikolaev, Vladimir B Timofeev, Svetlana Smagulova, Irina Antonova
The response of graphene based humidity sensor is considered as a function of film structures. Analysis of resistance changes due to water molecule adsorption on graphene or multigraphene (MLG) surface is performed for films with a different resistivity from hundreds of Ohm/sq to hundreds of kOhm/sq. It has revealed a possible increase, decrease and non monotonous behavior of resistance. Adsorption of water molecules at grain boundary defects is supposed to lead to an increase in film resistivity due to the donor property of water and p-type conductivity of graphene...
June 23, 2017: Nanotechnology
Xie Zhang, Tilmann Hickel, Jutta Rogal, Jörg Neugebauer
Employing ab initio calculations we demonstrate that the complex structural modulations experimentally observed in ultrathin Fe films on Cu(001) originate from Fe bulk phases that arise under extreme deformations. Specifically, we show that the structural modulations correspond to the motifs observed when transforming fcc Fe to bcc Fe in the Pitsch orientation relationship [(001)_{fcc}||(11[over ¯]0)_{bcc}]. The observed structural equivalence between surface and unstable bulk structures naturally explains the experimentally reported magnetic and structural transitions when going from low (two to four MLs) to intermediate (four to ten MLs) film coverages...
June 9, 2017: Physical Review Letters
Pankaj Kumar, Charles H Patterson
First-principles calculations of the dielectric anisotropy of the GaP/Si(001) interface are compared to the anisotropy extracted from reflectance measurements on GaP thin films on Si(001) [O. Supplie et al., Phys. Rev. B 86, 035308 (2012)PRBMDO1098-012110.1103/PhysRevB.86.035308]. Optical excitations from two states localized in several Si layers adjacent to the interface result in the observed anisotropy of the interface. The calculations show excellent agreement with experiment only for a gapped interface with a P layer in contact with Si and show that a combination of theory and experiment can reveal localized electronic states and the atomic structure at buried interfaces...
June 9, 2017: Physical Review Letters
Dmytro A Bozhko, Peter Clausen, Gennadii A Melkov, Victor S L'vov, Anna Pomyalov, Vitaliy I Vasyuchka, Andrii V Chumak, Burkard Hillebrands, Alexander A Serga
An ensemble of magnons, quanta of spin waves, can be prepared as a Bose gas of weakly interacting quasiparticles. Furthermore, the thermalization of the overpopulated magnon gas through magnon-magnon scattering processes, which conserve the number of particles, can lead to the formation of a Bose-Einstein condensate at the bottom of a spin-wave spectrum. However, magnon-phonon scattering can significantly modify this scenario and new quasiparticles are formed-magnetoelastic bosons. Our observations of a parametrically populated magnon gas in a single-crystal film of yttrium iron garnet by means of wave-vector-resolved Brillouin light scattering spectroscopy evidence a novel condensation phenomenon: A spontaneous accumulation of hybrid magnetoelastic bosonic quasiparticles at the intersection of the lowest magnon mode and a transversal acoustic wave...
June 9, 2017: Physical Review Letters
Lun Peng, Shenglin Zhou, Bo Yang, Meimei Bao, Gaojian Chen, Xiaohua Zhang
This report describes a technique for fabricating dual-structured hierarchical surface topography on the surface of polydimethylsiloxane (PDMS) films through simply replicating prefabricated patterns and wrinkling PDMS films. To enhance the biocompatibility of PDMS films we synthesize a biocompatible dopamine-glycopolymer, which is utilized to modify the chemical feature of the PDMS surface. Dopamine component in this copolymer is introduced for the formation of a carbohydrate layer on the surface of PDMS films due to its excellent adhesion...
June 23, 2017: ACS Applied Materials & Interfaces
Fabrício Mezzomo Collares, Vicente Castelo Branco Leitune, Fernando Freitas Portella, Paula Dapper Santos, Gabriela de Souza Balbinot, Luís Alberto Dos Santos, Clarissa Cavalcanti Fatturi Parolo, Susana Maria Werner Samuel
The aim of this study was to develop and to characterize a methacrylate-based root canal sealer containing chlorhexidine (CHX) and α-tricalcium phosphate (α-TCP). Experimental dual cure methacrylate-based sealer was produced containing 0, 2.5, or 5 wt% of CHX and 0, 25, or 50 wt% of α-TCP. Experimental sealers were evaluated based on flow, film thickness, radiopacity, degree of conversion (DC), degradation in water, pH and antibacterial activity. Flow ranged from 15.09 ± 0.11 to 17.47 ± 0.42 mm...
June 23, 2017: Journal of Biomedical Materials Research. Part B, Applied Biomaterials
Joerg Lahann, Florence Bally-Le Gall, Christoph Hussal, Joshua Kramer, Kenneth Chang, Ramya Kumar, Vanessa Trouillet, Martin Nieger, Stefan Braese, Thomas Eyster, Amy Baek
We report a new class of functionalized polylutidine polymers that are prepared via chemical vapor deposition polymerization of substituted [2](1,4)benzeno[2](2,5)pyridinophanes. To prepare sufficient monomer for CVD polymerization, a new synthesis route for ethynylpyridinophane has been developed in three steps with an overall yield of 59%. Subsequent CVD polymerization yielded well-defined films of poly(2,5-lutidinylene-co-p-xylylene) and poly(4-ethynyl-2,5-lutidinylene-co-p-xylylene). All polymers were characterized by IRRAS, ellipsometry, contact angle and XPS...
June 23, 2017: Chemistry: a European Journal
Yaping He, Xiaohui Yang, Quan Han, Jianbin Zheng
A novel catechol (CA) biosensor was developed by embedding tyrosinase (Tyr) onto in situ electrochemical reduction graphene (EGR) on choline-functionalized gold nanoparticle (AuNPs-Ch) film. The results of UV-Vis spectra indicated that Tyr retained its original structure in the film, and an electrochemical investigation of the biosensor showed a pair of well-defined, quasi-reversible redox peaks with Epa = -0.0744 V and Epc = -0.114 V (vs. SCE) in 0.1 M, pH 7.0 sodium phosphate-buffered saline at a scan rate of 100 mV/s...
June 23, 2017: Molecules: a Journal of Synthetic Chemistry and Natural Product Chemistry
Xuan-Hung Pham, Eunil Hahm, Tae Han Kim, Hyung-Mo Kim, Sang Hun Lee, Yoon-Sik Lee, Dae Hong Jeong, Bong-Hyun Jun
In this study, we prepared adenosine triphosphate (ATP) encapsulated liposomes, and assessed their applicability for the surface enhanced Raman scattering (SERS)-based assays with gold-silver alloy (Au@Ag)-assembled silica nanoparticles (NPs; SiO₂@Au@Ag). The liposomes were prepared by the thin film hydration method from a mixture of l-α-phosphatidylcholine, cholesterol, and PE-PEG2000 in chloroform; evaporating the solvent, followed by hydration of the resulting thin film with ATP in phosphate-buffered saline (PBS)...
June 23, 2017: Sensors
Thomas A K Susanto, Rajat Bhattacharyya
Dimorphism in peripheral blood film was noted in a 16 year old Malay boy with anemia who was eventually diagnosed with X-linked sideroblastic anemia. A mutation in ALAS2 S568G was identified which has not been described previously in a Malay ethnic group.
July 2017: Journal of Pediatric Hematology/oncology
Yuhai Zhang, Jun Yin, Manas R Parida, Ghada H Ahmed, Jun Pan, Osman M Bakr, Jean-Luc Bredas, Omar F Mohammed
With record efficiencies achieved in lead halide perovskite-based photovoltaics, urgency has shifted towards finding alternative materials that are stable and less-toxic. Bismuth-based perovskite materials are currently one of the most promising candidates amongst those alternatives. However, the band structures of these materials, including the nature of the bandgaps, remain elusive due to extremely low photoluminescence quantum yield (PLQY) and scattering issues in their thin-film or bulk form. Here, we overcome those limitations and reveal the specific nature of the material's electronic transitions by realizing monodisperse colloidal nanocrystals (NCs) of hexagonal-phase Cs3Bi2X9 perovskites, which afford well-resolved PL features...
June 23, 2017: Journal of Physical Chemistry Letters
Jiazhen Sheng, Eun Jung Park, Bonggeun Shong, Jin-Seong Park
Indium gallium oxide (IGO) thin films were deposited via atomic layer deposition (ALD) using [1,1,1-trimethyl-N-(trimethylsilyl)silanaminato]indium (InCA-1) and trimethylgallium (TMGa) as indium and gallium precursors, respectively, and hydrogen peroxide (H2O2) as the reactant. In order to clearly understand the mechanism of multicomponent ALD growth of oxide semiconductor materials, several variations in the precursor-reactant deposition cycles were evaluated. Gallium could be doped into oxide film at 200°C when accompanied by an InCA-1 pulse, and no growth of gallium oxide was observed without the simultaneous deposition of indium oxide...
June 23, 2017: ACS Applied Materials & Interfaces
Miao Wang, Fuyang Xu, Yu Lin, Bing Cao, Linghua Chen, Chinhua Wang, Jianfeng Wang, Ke Xu
We proposed and demonstrated an integrated high energy efficient and high linearly polarized InGaN/GaN green LED grown on (0001) oriented sapphire with combined metasurface polarizing converter and polarizer system. It is different from those conventional polarized light emissions generated with plasmonic metallic grating in which at least 50% high energy loss occurs inherently due to high reflection of the transverse electric (TE) component of an electric field. A reflecting metasurface, with a two dimensional elliptic metal cylinder array (EMCA) that functions as a half-wave plate, was integrated at the bottom of a LED such that the back-reflected TE component, that is otherwise lost by a dielectric/metal bi-layered wire grids (DMBiWG) polarizer on the top emitting surface of the LED, can be converted to desired transverse magnetic (TM) polarized emission after reflecting from the metasurface...
June 23, 2017: Nanoscale
Vezio Bianchi, Tian Carey, Leonardo Viti, Lianhe Li, Edmund H Linfield, A Giles Davies, Alessandro Tredicucci, Duhee Yoon, Panagiotis G Karagiannidis, Lucia Lombardi, Flavia Tomarchio, Andrea C Ferrari, Felice Torrisi, Miriam S Vitiello
Saturable absorbers (SA) operating at terahertz (THz) frequencies can open new frontiers in the development of passively mode-locked THz micro-sources. Here we report the fabrication of THz SAs by transfer coating and inkjet printing single and few-layer graphene films prepared by liquid phase exfoliation of graphite. Open-aperture z-scan measurements with a 3.5 THz quantum cascade laser show a transparency modulation ∼80%, almost one order of magnitude larger than that reported to date at THz frequencies...
June 15, 2017: Nature Communications
Seied Rabie Mahdavi, Ghazale Geraily, Ahmad Mostaar, Arman Zia, Golbarg Esmaili, Somayeh Farahani
AIM OF STUDY: Physical wedges (PWs) are widely used in radiotherapy to obtain tilted isodose curves, but they alter beam quality. Dynamic wedges (DWs) using moving collimator overcome this problem, but measuring their beam data is not simple. The main aim of this study is to obtain all dosimetric parameters of DWs produced by Varian 2100CD with Monte Carlo simulation and compare them to those from PWs. SUBJECTS AND METHODS: To simulate 6 MV photon beams equipped with PW and DW, BEAMnrc code was used...
April 2017: Journal of Cancer Research and Therapeutics
Filiz Keles, Emad O Badraddin, Tansel Karabacak
A critical factor for an efficient light harvesting device is reduced reflectance in order to achieve high optical absorptance. In this regard, refractive index engineering becomes important to minimize reflectance. In this study, a new fabrication approach to obtain the density-modulated CuInxGa(1-x)Se2 (CIGS) thin films with self-anti-reflective properties has been demonstrated. Density-modulated CIGS samples were fabricated by utilizing high pressure sputtering (HIPS) at Ar gas pressure of 2.75 x 10-2 mbar along with the conventional low pressure sputtering (LPS) at Ar gas pressure of 3...
June 23, 2017: Nanotechnology
James F Scott, Donald M Evans, Ram S Katiyar, Raymond G P McQuaid, J Marty Gregg
Since the 1935 work of Landau-Lifshitz and of Kittel in 1946 all ferromagnetic, ferroelectric, and ferroelastic domains have been thought to be straight-sided with domain widths proportional to the square root of the sample thickness. We show in the present work that this is not true. We also discover period doubling domains predicted by Metaxas et al (2008 Phys. Rev. Lett. 99 217208) and modeled by Wang and Zhao (2015 Sci. Rep. 5 8887). We examine non-equilibrium ferroic domain structures in perovskite oxides with respect to folding, wrinkling, and relaxation and suggest that structures are kinetically limited and in the viscous flow regime predicted by Metaxas et al in 2008 but never observed experimentally...
June 23, 2017: Journal of Physics. Condensed Matter: An Institute of Physics Journal
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"