Read by QxMD icon Read


M Z Mo, X Shen, Z Chen, R K Li, M Dunning, K Sokolowski-Tinten, Q Zheng, S P Weathersby, A H Reid, R Coffee, I Makasyuk, S Edstrom, D McCormick, K Jobe, C Hast, S H Glenzer, X Wang
We have developed a single-shot mega-electronvolt ultrafast-electron-diffraction system to measure the structural dynamics of warm dense matter. The electron probe in this system is featured by a kinetic energy of 3.2 MeV and a total charge of 20 fC, with the FWHM pulse duration and spot size at sample of 350 fs and 120 μm respectively. We demonstrate its unique capability by visualizing the atomic structural changes of warm dense gold formed from a laser-excited 35-nm freestanding single-crystal gold foil...
November 2016: Review of Scientific Instruments
Seok Min Yoon, Jun Heuk Park, Bartosz A Grzybowski
Freestanding MOF films up to six-inches across and replicating various surface (micro)patterns are prepared via a templated growth method. When grown on copper supports, these films have preferred orientation of the constituent crystallites, translating into markedly different wetting properties of the film's two surfaces (water-pinning vs. water repellant). In addition, the films exhibit differential sorption of various organic solvents, can recover oil spills from seawater, and can also act as active layers of chemical sensors...
November 30, 2016: Angewandte Chemie
Gregg R Klein, Jason M Posner, Harlan B Levine, Mark A Hartzband
BACKGROUND: There is an increasing interest in outpatient total hip arthroplasty (THA), as there are perceived benefits to the patient, insurer, and overall healthcare system. However, the safety of outpatient total joint arthroplasty has not been studied. METHODS: Five hundred forty-nine patients who underwent mini-posterior THA at a freestanding independent ambulatory surgical center (ASC) were reviewed. All patients were discharged to home on the day of surgery...
October 20, 2016: Journal of Arthroplasty
Jianfeng Bao, Wataru Norimatsu, Hiroshi Iwata, Keita Matsuda, Takahiro Ito, Michiko Kusunoki
Graphene has a negative thermal expansion coefficient; that is, when heated, the graphene lattice shrinks. On the other hand, the substrates typically used for graphene growth, such as silicon carbide, have a positive thermal expansion coefficient. Hence, on cooling graphene on SiC, graphene expands but SiC shrinks. This mismatch will physically break the atomic bonds between graphene and SiC. We have demonstrated that a graphenelike buffer layer on SiC can be converted to a quasifreestanding monolayer graphene by a rapid-cooling treatment...
November 11, 2016: Physical Review Letters
Angela K Saettele, Jacob L Christensen, Kelly L Chilson, David J Murray
STUDY OBJECTIVE: Children with congenital or acquired heart disease have an increased risk of anesthesia related morbidity and mortality. The child's anesthetic risk is related to the severity of their underlying cardiac disease, associated comorbidities, and surgical procedure. The goal of this project was to determine the ease of use of a preoperative risk stratification tool for assigning pediatric cardiac staff and to determine the relative frequency that children with low, moderate, and high risk cardiac disease present for non-cardiac surgery at a tertiary pediatric hospital...
December 2016: Journal of Clinical Anesthesia
Mohammad Vatankhah-Varnoosfaderani, William F M Daniel, Alexandr P Zhushma, Qiaoxi Li, Benjamin J Morgan, Krzysztof Matyjaszewski, Daniel P Armstrong, Richard J Spontak, Andrey V Dobrynin, Sergei S Sheiko
Freestanding, single-component dielectric actuators are designed based on bottlebrush elastomers that enable giant reversible strokes at relatively low electric fields and altogether avoid preactuation mechanical manipulation. This materials design platform allows for independent tuning of actuator rigidity and elasticity over broad ranges without changing chemical composition, which opens new opportunities in soft-matter robotics.
November 8, 2016: Advanced Materials
Anthony D Slonim, Max J Coppes
No abstract text is available yet for this article.
December 2016: Critical Care Medicine
O D Supekar, J J Brown, N T Eigenfeld, J C Gertsch, V M Bright
Focused ion beam (FIB) micromachining is a powerful tool for maskless lithography and in recent years FIB has been explored as a tool for strain engineering. Ion beam induced deformation can be utilized as a means for folding freestanding thin films into complex 3D structures. FIB of high energy gallium (Ga(+)) ions induces stress by generation of dislocations and ion implantation within material layers, which create creases or folds upon mechanical relaxation enabled by motion of the material layers. One limitation on such processing is the ability to fabricate flat freestanding thin film structures...
December 9, 2016: Nanotechnology
Carolyn A Greene, Julian D Ford, Barbara Ward-Zimmerman, Lisa Honigfeld, Anne E Pidano
BACKGROUND: Collaborative pediatric mental health and primary care is increasingly recognized as optimal for meeting the needs of children with mental health problems. This paper describes the challenges faced by freestanding specialty mental health clinics and pediatric health practices to provide such coordinated mind-and-body treatment. It describes critical elements of a proactive approach to achieving collaborative pediatric care under real-world circumstances using the patient-centered medical home neighborhood (PCMH-N) model...
October 2016: Child & Youth Care Forum
Batu Ghosh, Masaki Takeguchi, Jin Nakamura, Yoshihiro Nemoto, Takumi Hamaoka, Sourov Chandra, Naoto Shirahata
On the basis of the systematic study on temperature dependence of photoluminescence (PL) properties along with relaxation dynamics we revise a long-accepted mechanism for enhancing absolute PL quantum yields (QYs) of freestanding silicon nanocrystals (ncSi). A hydrogen-terminated ncSi (ncSi:H) of 2.1 nm was prepared by thermal disproportination of (HSiO1.5)n, followed by hydrofluoric etching. Room-temperature PL QY of the ncSi:H increased twentyfold only by hydrosilylation of 1-octadecene (ncSi-OD). A combination of PL spectroscopic measurement from cryogenic to room temperature with structural characterization allows us to link the enhanced PL QYs with the notable difference in surface structure between the ncSi:H and the ncSi-OD...
November 10, 2016: Scientific Reports
David Hwang, Benjamin P Yonkee, Burhan Saif Addin, Robert M Farrell, Shuji Nakamura, James S Speck, Steven DenBaars
We demonstrate a thin-film flip-chip (TFFC) process for LEDs grown on freestanding c-plane GaN substrates. LEDs are transferred from a bulk GaN substrate to a sapphire submount via a photoelectrochemical (PEC) undercut etch. This PEC liftoff method allows for substrate reuse and exposes the N-face of the LEDs for additional roughening. The LEDs emitted at a wavelength of 432 nm with a turn on voltage of ~3 V. Etching the LEDs in heated KOH after transferring them to a sapphire submount increased the peak external quantum efficiency (EQE) by 42...
October 3, 2016: Optics Express
Richa Singhal, Vibha Kalra
Efficient, low cost, non-precious metal based, and stable bifunctional electrocatalysts are key to various energy storage and conversion devices such as regenerative fuel cells and metal-air batteries. In this work, we report cobalt nanoparticle-embedded porous carbon nanofibers with inherent N- and F- doping as binder-free bifunctional electrocatalysts with excellent activity for both oxygen reduction and evolution reactions (ORR/OER) in alkaline medium. Single-step electrospinning of a solution of selected polymer mixture (carbon precursor) and the cobalt precursor followed by controlled pyrolysis with an intermediate reduction step in H2 (to reduce cobalt oxides to cobalt) was utilized to synthesize an integrated freestanding catalyst...
November 3, 2016: Chemphyschem: a European Journal of Chemical Physics and Physical Chemistry
Yingchao Yang, Xing Li, Minru Wen, Emily Hacopian, Weibing Chen, Yongji Gong, Jing Zhang, Bo Li, Wu Zhou, Pulickel M Ajayan, Qing Chen, Ting Zhu, Jun Lou
An in situ quantitative tensile testing platform is developed to enable the uniform in-plane loading of a freestanding membrane of 2D materials inside a scanning electron microscope. The in situ tensile testing reveals the brittle fracture of large-area MoSe2 crystals and measures their fracture strength for the first time.
November 3, 2016: Advanced Materials
Xiongwu Zhong, Zhen-Zhong Yang, Yu Jiang, Weihan Li, Lin Gu, Yan Yu
Na3V2(PO4)3 (NVP) has been considered as a most promising cathode materials for sodium ion battery (SIBs). But NVP usually exhibits poor cycling stability and rate performance due to the low intrinsic electrical conductivity. Herein, we prepared carbon coated Na3V2(PO4)3 anchored on freestanding graphite foam (denoted as NVP@C-GF) as cathode for SIBs. The NVP@C-GF exhibits superior sodium-ion storage performance, including rate capability (56 mAhg-1 at 200C) and long cycle life (54 mAhg-1 at 100 C after 20000 cycles)...
November 3, 2016: ACS Applied Materials & Interfaces
Mark Ilton, Miles M P Couchman, Cedric Gerbelot, Michael Benzaquen, Paul D Fowler, Howard A Stone, Elie Raphaël, Kari Dalnoki-Veress, Thomas Salez
We report on the capillary-driven leveling of a topographical perturbation at the surface of a freestanding liquid nanofilm. The width of a stepped surface profile is found to evolve as the square root of time. The hydrodynamic model is in excellent agreement with the experimental data. In addition to exhibiting an analogy with diffusive processes, this novel system serves as a precise nanoprobe for the rheology of liquids at interfaces in a configuration that avoids substrate effects.
October 14, 2016: Physical Review Letters
J J Brown, N C Moore, O D Supekar, J C Gertsch, V M Bright
The recent development of low-temperature (<200 °C) atomic layer deposition (ALD) for fabrication of freestanding nanostructures has enabled consideration of active device design based on engineered ultrathin films. This paper explores audible sound production from thermoacoustic loudspeakers fabricated from suspended tungsten nanobridges formed by ALD. Additionally, this paper develops an approach to lumped-element modeling for design of thermoacoustic nanodevices and relates the near-field plane wave model of individual transducer beams to the far-field spherical wave sound pressure that can be measured with standard experimental techniques...
November 25, 2016: Nanotechnology
Ali E Aliev, Sahila Perananthan, John P Ferraris
Thermoacoustic performance of thin freestanding sheets of carbonized poly(acrylonitrile) and polybenzimidazole nanofibers are studied as promising candidates for thermophones. We analyze thermodynamic properties of sheets using transport parameters of single nanofibers and their aligned and randomly electrospun thin film assemblies. The electrical and thermal conductivities, thermal diffusivity, heat capacity, and infrared blackbody radiation are investigated to extract the heat exchange coefficient and enhance the energy conversion efficiency...
October 24, 2016: ACS Applied Materials & Interfaces
Emily S Walker, Seung Ryul Na, Daehwan Jung, Stephen D March, Joon-Seok Kim, Tanuj Trivedi, Wei Li, Li Tao, Minjoo L Lee, Kenneth M Liechti, Deji Akinwande, Seth R Bank
We report the first direct dry transfer of a single-crystalline thin film grown by molecular beam epitaxy. A double cantilever beam fracture technique was used to transfer epitaxial bismuth thin films grown on silicon (111) to silicon strips coated with epoxy. The transferred bismuth films retained electrical, optical, and structural properties comparable to the as-grown epitaxial films. Additionally, we isolated the bismuth thin films on freestanding flexible cured-epoxy post-transfer. The adhesion energy at the bismuth/silicon interface was measured to be ∼1 J/m(2), comparable to that of exfoliated and wet transferred graphene...
October 24, 2016: Nano Letters
Søren Ulstrup, Jyoti Katoch, Roland J Koch, Daniel Schwarz, Simranjeet Singh, Kathleen M McCreary, Hyang Keun Yoo, Jinsong Xu, Berend T Jonker, Roland K Kawakami, Aaron Bostwick, Eli Rotenberg, Chris Jozwiak
There is a substantial interest in the heterostructures of semiconducting transition metal dichalcogenides (TMDCs) amongst each other or with arbitrary materials, through which the control of the chemical, structural, electronic, spintronic, and optical properties can lead to a change in device paradigms. A critical need is to understand the interface between TMDCs and insulating substrates, for example high-κ dielectrics, which can strongly impact the electronic properties such as the optical gap. Here we show that the chemical and electronic properties of the single-layer (SL) TMDC, WS2, can be transferred onto high-κ transition metal oxide substrates TiO2 and SrTiO3...
October 21, 2016: ACS Nano
Yang Jie, Huarui Zhu, Xia Cao, Yue Zhang, Ning Wang, Liqun Zhang, Zhong Lin Wang
Tactile sensing is of great importance in developing human-machine interface, remote control and security systems. Here, a self-triggered alarm system based on the one-piece triboelectric nanosensor (TENS) is reported. By using nitrocellulose (NC) membrane as the triboelectric material, the as-designed TENS can not only sensitively respond to physical contacts in a self-triggered mode, but also securely detect the third-level details of latent fingerprint. The self-triggered idea based on the triboelectric nanogenerator is compatible with intelligent interactive interface...
October 21, 2016: ACS Nano
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"