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J Yang, J Zhu, R Pei, J A Oliver, D W Landry, M N Stojanovic, Q Lin
We present a microfluidic aptamer-based biosensor for detection of low-molecular-weight biomarkers in patient samples. Using a microfluidic device that integrates aptamer-based specific analyte extraction, isocratic elution, and detection by matrix-assisted laser desorption/ionization time-of-flight (MALDI-TOF) mass spectrometry, we demonstrate rapid, sensitive and label-free detection of arginine vasopressin (AVP) in human plasma ultrafiltrate. AVP molecules in complex matrices are specifically captured by an aptamer that is immobilized on microbeads via affinity binding in a microchamber...
July 14, 2016: Analytical Methods: Advancing Methods and Applications
Haitao Li, Han Dai, Yihe Zhang, Wangshu Tong, Hua Gao, Qi An
Electrochemically up-regulated surface-enhanced Raman spectroscopy (E-SERS) effectively increases Raman signal intensities. However, the instrumental requirements and the conventional measurement conditions in an electrolyte cell have hampered its application in fast and on-site detection. To circumvent the inconveniences of E-SERS, we propose a self-energizing substrate that provides electrical potential by converting film deformation from a finger press into stored electrical energy. The substrate combines an energy conversion film and a SERS-active Ag nanowire layer...
January 12, 2017: Angewandte Chemie
Soma Khanra, Kartik Ghosh, Fabio F Ferreira, Wendel A Alves, Francesco Punzo, Ping Yu, Suchismita Guha
Self-assembled l,l-diphenylalanine (FF) peptide micro/nanotubes represent a class of biomimetic materials with a non-centrosymmetric crystal structure and strong piezoelectricity. The peptide nanotubes synthesized by a liquid phase method yield tube lengths in the hundreds of micron range, inner diameters in the few hundred nanometer range, and outer diameters in the 5-15 μm range. Second harmonic generation (SHG) polarimetry from individual self-assembled FF nanotubes is used to obtain the nonlinear (NLO) optical coefficients as a function of the tube diameter and thermal treatment...
January 12, 2017: Physical Chemistry Chemical Physics: PCCP
Minwei Zhang, Chengyi Hou, Arnab Halder, Qijin Chi
Thanks to their versatile functionality, metal oxides (MOs) constitute one of the key family materials in a variety of current demands for sensor, catalysis, energy storage and conversion, optical electronics and piezoelectric mechanics. Much effort has focused on engineering specific nanostructure and macroscopic morphology of MOs that aims to enhance their performances, but the design and controlled synthesis of ultrafine nanostructured MOs in a cost-effective and facile way remains a challenge. In this work, we have exploited the advantages of intrinsic structures of graphene oxide (GO) papers, serving as a sacrificial template, to design and synthesize two-dimensional (2D) layered and free-standing MO papers with ultrafine nanostructures...
January 10, 2017: ACS Applied Materials & Interfaces
Haribabu Palneedi, Deepam Maurya, Gi-Yeop Kim, Venkateswarlu Annapureddy, Myoung-Sub Noh, Chong-Yun Kang, Jong-Woo Kim, Jong-Jin Choi, Si-Young Choi, Sung-Yoon Chung, Suk-Joong L Kang, Shashank Priya, Jungho Ryu
A record-high, near-theoretical intrinsic magnetoelectric (ME) coupling of 7 V cm(-1) Oe(-1) is achieved in a heterostructure of piezoelectric Pb(Zr,Ti)O3 (PZT) film deposited on magnetostrictive Metglas (FeBSi). The anchor-like, nanostructured interface between PZT and Metglas, improved crystallinity of PZT by laser annealing, and optimum volume of crystalline PZT are found to be the key factors in realizing such a giant strain-mediated ME coupling.
January 9, 2017: Advanced Materials
Rymantas J Kazys, Reimondas Sliteris, Justina Sestoke
Air-coupled ultrasonic techniques are being increasingly used for material characterization, non-destructive evaluation of composite materials using guided waves as well as for distance measurements. Application of those techniques is mainly limited by the big losses of ultrasonic signals due to attenuation and mismatch of the acoustic impedances of ultrasonic transducers and air. One of the ways to solve this problem is by application of novel more efficient piezoelectric materials like lead magnesium niobate-lead titanate (PMN-PT) type crystals...
January 6, 2017: Sensors
Ian Gilbert, Andres C Chavez, Daniel T Pierce, John Unguris, Wei-Yang Sun, Cheng-Yen Liang, Gregory P Carman
Strain-mediated thin film multiferroics comprising piezoelectric/ferromagnetic heterostructures enable the electrical manipulation of magnetization with much greater efficiency than other methods; however, the investigation of nanostructures fabricated from these materials is limited. Here we characterize ferromagnetic Ni nanostructures grown on a ferroelectric PMN-PT substrate using scanning electron microscopy with polarization analysis (SEMPA) and micromagnetic simulations. The magnetization of the Ni nanostructures can be controlled with a combination of sample geometry and applied electric field, which strains the ferroelectric substrate and changes the magnetization via magnetoelastic coupling...
October 2016: Applied Physics Letters
Shayan Gholizadeh, Fathollah Moztarzadeh, Nooshin Haghighipour, Leila Ghazizadeh, Fatemeh Baghbani, Mohammad Ali Shokrgozar, Zahra Allahyari
A major limitation in current tissue engineering scaffolds is that some of the most important characteristics of the intended tissue are ignored. As piezoelectricity and high mechanical strength are two of the most important characteristics of the bone tissue, carbon nanotubes are getting a lot of attention as a bone tissue scaffold component in recent years. In the present study, composite scaffolds comprised of functionalized Multiwalled Carbon Nanotubes (f-MWCNT), medium molecular weight chitosan and β-Glycerophosphate were fabricated and characterized...
January 4, 2017: International Journal of Biological Macromolecules
Hamdi Ezzin, Morched Ben Amor, Mohamed Hédi Ben Ghozlen
A dynamic solution is presented for the propagation of harmonic waves in magneto-electro-elastic plates composed of piezoelectric BaTiO3(B) and magnetostrictive CoFe2O4(F) material. The state-vector approach is employed to derive the propagator matrix which connects the field variables at the upper interface to those at the lower interface of each layer. The ordinary differential approach is employed to determine the wave propagating characteristics in the plate by imposing the traction-free boundary condition on the top and bottom surfaces of the layered plate...
December 26, 2016: Ultrasonics
Steve J A Majerus, Paul C Fletter, Elizabeth K Ferry, Hui Zhu, Kenneth J Gustafson, Margot S Damaser
AIMS: Managing bladder pressure in patients with neurogenic bladders is needed to improve rehabilitation options, avoid upper tract damage, incontinence, and their associated co-morbidities and mortality. Current methods of determining bladder contractions are not amenable to chronic or ambulatory settings. In this study we evaluated detection of bladder contractions using a novel piezoelectric catheter-free pressure sensor placed in a suburothelial bladder location in animals. METHODS: Wired prototypes of the pressure monitor were implanted into 2 nonsurvival (feline and canine) and one 13-day survival (canine) animal...
2017: PloS One
Jeong-Suong Yang, Yunsung Kang, Inyoung Kang, Seungmo Lim, Seung-Joo Shin, Jungwon Lee, Kangheon Hur
The degradation of Niobium-doped lead zirconate titanate (PZT) and two types of PZT thin films were investigated. Undoped PZT, 2-step PZT and heavily Nb-doped PZT (PNZT) around the morphotropic phase boundary (MPB) were in-situ deposited under optimum condition by RF-magnetron sputtering. All 2 μm thick films had dense perovskite columnar grain structure and self-polarized (100) dominant orientation. PZT thin films were deposited on Pt/TiOx bottom electrode on Si wafer, and Nb doped PZT thin film was on Ir/TiW electrode with help of orientation control...
January 4, 2017: IEEE Transactions on Ultrasonics, Ferroelectrics, and Frequency Control
Patrycja Lach, Piyush Sindhu Sharma, Karolina Golebiewska, Maciej Cieplak, Francis D'Souza, Wlodzimierz Kutner
A molecularly imprinted polymer (MIP)-based chemosensor for the selective determination of a chosen toxin, N-nitroso-l-proline (Pro-NO), was devised and fabricated. By means of DFT, the structure of the pre-polymerization (functional monomer)-template complex was modeled. This complex was then potentiodynamically electropolymerized in the presence of cross-linking monomer to form a MIP-Pro-NO thin film. Next, the Pro-NO template was extracted from MIP-Pro-NO with 0.1 m NaOH. Piezoelectric microgravimetry (PM) on an electrochemical quartz crystal microbalance and electrochemical (differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS)) techniques were used to transduce binding of Pro-NO to molecular cavities of the MIP-Pro-NO...
November 7, 2016: Chemistry: a European Journal
Tian Zheng, Zhilian Yue, Gordon G Wallace, Yi Du, Pedro Martins, Senentxu Lanceros-Mendez, Michael J Higgins
The coupling of magnetic and electric properties in polymer-based magnetoelectric composites offers new opportunities to develop contactless electrodes, effectively without electrical connections, for less-invasive integration into devices such as energy harvesters, sensors, wearable and implantable electrodes. Understanding the macroscale-to-nanoscale conversion of the properties is important, as nanostructured and nanoscale magnetoelectric structures are increasingly fabricated. However, whilst the magnetoelectric effect at the macroscale is well established both theoretically and experimentally, it remains unclear how this effect translates to the nanoscale, or vice versa...
January 6, 2017: Nanotechnology
Xuexian Chen, Mengdi Han, Haotian Chen, Xiaoliang Cheng, Yu Song, Zongming Su, Yonggang Jiang, Haixia Zhang
A wave-shaped hybrid nanogenerator (NG) with mutually enhanced piezoelectric and triboelectric output is presented in this work. By sandwiching piezoelectric P(VDF-TrFE) nanofibers between wave-shaped Kapton films, the device forms a three-layer structure, which can generate piezoelectric and triboelectric outputs simultaneously in one press and release cycle. Through systematic situational analysis and experimental validation, the three-layer structure can achieve obvious improvement of the output performance for both parts...
January 5, 2017: Nanoscale
Jizhai Cui, Scott Keller, Cheng-Yen Liang, Greg Carman, Christopher Lynch
Controlling magnetization using piezoelectric strain through the magnetoelectric effect offers several orders of magnitude reduction in energy consumption for spintronic applications. However strain is a uniaxial effect and, unlike directional magnetic field or spin-polarized current, cannot induce a full 180° reorientation of the magnetization vector when acting alone. We have engineered novel "peanut" and "cat-eye" shaped nanomagnets on piezoelectric substrates that undergo repeated deterministic 180° magnetization rotations in response to individual electric-field-induced strain pulses by breaking the uniaxial symmetry using shape anisotropy...
January 5, 2017: Nanotechnology
Sulphi A Basheer, R Jay Govind, Augustine Daniel, George Sam, V J Adarsh, Akshatha Rao
INTRODUCTION: Bone removal is necessary for extracting the third molars that are erupted, partially erupted, and/or impacted in bone. Hence, it is necessary to choose a surgical method or instruments that conform to anatomic landmarks and are based on physiological principles. Many authors have reported injuries to the adjacent tooth, especially the distal part of periodontium after removal of second molar. Hence, the present study was undertaken to assess and compare the surgical and postsurgi-cal outcomes of third molar removal using piezoelectric surgery and rotary bur...
January 1, 2017: Journal of Contemporary Dental Practice
S Yousefi, M Ahmad, L Xiang, S Tang, Y Chen, M Zhang, J Zou, K Umegaki, H Shirato, L Xing
PURPOSE: To report our investigations of proton acoustic imaging, including computer simulations and preliminary experimental studies at clinical facilities. The ultimate achievable accuracy, sensitivity and clinical translation challenges are discussed. METHODS: The acoustic pulse due to pressure rise was estimated using finite element model. Since the ionoacoustic pulse is highly dependent on the proton pulse width and energy, multiple pulse widths were studied...
June 2016: Medical Physics
A Soliman, B Chugh, B Keller, A Sahgal, W Song
PURPOSE: Recent advances in MRI-guided radiotherapy has inspired the development of MRI-compatible motion devices that simulate patient periodic motion in the scanner, particularly respiratory motion. Most commercial devices rely on non MR-safe ferromagnetic stepper motors which are not practical for regular QA testing. This work evaluates the motion performance of a new fully MRI compatible respiratory motion device at 3T. METHODS: The QUASAR™ MRI-compatible respiratory motion phantom has been recently developed by Modus QA Inc...
June 2016: Medical Physics
E Flores-Martinez, J Radtke, L DeWerd
PURPOSE: To develop and implement a high spatial resolution calorimeter methodology to measure absorbed dose to water (ADW) using phase shifts (PSs) of light passing through a water phantom and to compare measurements with theoretical calculations. METHODS: Radiation-induced temperature changes were measured using the PSs of a He-Ne laser beam passing through a (10×10×10) cm(3) water phantom. PSs were measured using a Michelson interferometer and recording the time-dependent fringe patterns on a CCD camera...
June 2016: Medical Physics
K W Li, L M Wang, R Zhang, Z B Wang
A 45° dual-drive symmetric photoelastic modulator is demonstrated. Two piezoelectric actuators are connected to a symmetric photoelastic crystal at an angle of 45°. When the amplitudes of the stress standing waves induced by the two piezoelectric actuators are equal and the phase difference between the two stress standing waves is π2, the modulation axis performs circular motion with a frequency of half of the photoelastic modulator's resonant frequency, while the retardation remains a constant that is determined at the driving voltage amplitudes...
December 2016: Review of Scientific Instruments
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