45 results match your criteria Aip Advances[Journal]

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determination of exerted forces in magnetic pulling cytometry.

AIP Adv 2019 Mar 14;9(3):035221. Epub 2019 Mar 14.

Mechanical & Aerospace Engineering, Old Dominion University, Kaufman 238e, 1 Old Dominion University, Norfolk, Virginia 23529, USA.

Localized application of exogenous forces on soft biomaterials and cells is often essential for the study of their response to external mechanical stimuli. Magnetic means of applying forces, particularly those based on permanent magnets and magnetic beads coupled to substrates or cells provide an accessible means of exerting forces of appropriate magnitude. The amount of force exerted, however, is often inferred from calibration performed , with typically similar but different magnetic beads. Read More

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http://dx.doi.org/10.1063/1.5084261DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6417906PMC

Investigation of femtosecond laser induced ripple formation on copper for varying incident angle.

AIP Adv 2018 10;8(1):015212. Epub 2018 Jan 10.

Department of Electrical and Computer Engineering, University of Nebraska-Lincoln, Lincoln, Nebraska 68588, USA.

The hydrodynamic mechanisms associated with the formation of femtosecond laser induced ripples on copper for two angles of incidence are reported. Laser pulse length used for this work is 35 fs. A revised two-temperature model is presented that comprises transient changes of optical characteristics during the irradiation with femtosecond pulses to model relaxation processes and thermal response in bulk copper. Read More

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http://aip.scitation.org/doi/10.1063/1.5020029
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http://dx.doi.org/10.1063/1.5020029DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6220345PMC
January 2018
15 Reads

Relationship between permeability and diffusivity in polyethylene glycol hydrogels.

AIP Adv 2018 Oct 4;8(10):105006. Epub 2018 Oct 4.

The Nanoscience Centre, Department of Engineering, University of Cambridge, Cambridge CB3 0FF, United Kingdom.

The transport properties of hydrogels largely affect their performance in biomedical applications ranging from cell culture scaffolds to drug delivery systems. Solutes can move through the polymer mesh as a result of concentration gradients in the interstitial fluid or pressure gradients that move the fluid and solutes simultaneously. The relationship between the two modalities of transport in hydrogels can provide insight for the design of materials that can function effectively in the dynamic conditions experienced and , yet this correlation has not been previously elucidated. Read More

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http://dx.doi.org/10.1063/1.5036999DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6172138PMC
October 2018
1 Read

Chip-scale high Q-factor glassblown microspherical shells for magnetic sensing.

AIP Adv 2018 Jun 14;8(6):065214. Epub 2018 Jun 14.

Department of Electrical and Computer Engineering, Northeastern University, Boston, MA 02115, USA.

A whispering gallery mode resonator based magnetometer using chip-scale glass microspherical shells is described. A neodynium micro-magnet is elastically coupled and integrated on top of the microspherical shell structure that enables transduction of the magnetic force experienced by the magnet in external magnetic fields into an optical resonance frequency shift. High quality factor optical microspherical shell resonators with ultra-smooth surfaces have been successfully fabricated and integrated with magnets to achieve Q-factors of greater than 1. Read More

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http://dx.doi.org/10.1063/1.5030460DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6002270PMC

magnetization/heating electron holography to study the magnetic ordering in arrays of nickel metallic nanowires.

AIP Adv 2018 May 9;8(5):056813. Epub 2018 Jan 9.

Physics and Astronomy, University of Texas at San Antonio, San Antonio, TX, 78249, United States.

Magnetic nanostructures of different size, shape, and composition possess a great potential to improve current technologies like data storage and electromagnetic sensing. In thin ferromagnetic nanowires, their magnetization behavior is dominated by the competition between magnetocrystalline anisotropy (related to the crystalline structure) and shape anisotropy. In this way electron diffraction methods like precession electron diffraction (PED) can be used to link the magnetic behavior observed by Electron Holography (EH) with its crystallinity. Read More

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http://dx.doi.org/10.1063/1.5007671DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5760265PMC
May 2018
3 Reads

Force fields of charged particles in micro-nanofluidic preconcentration systems.

AIP Adv 2017 Dec 21;7(12):125020. Epub 2017 Dec 21.

Institute of Laser and Optoelectronic Intelligent Manufacturing, College of Mechanical and Electrical Engineering, Wenzhou University, Wenzhou 325035, P.R. China.

Electrokinetic concentration devices based on the ion concentration polarization (ICP) phenomenon have drawn much attention due to their simple setup, high enrichment factor, and easy integration with many subsequent processes, such as separation, reaction, and extraction etc. Despite significant progress in the experimental research, fundamental understanding and detailed modeling of the preconcentration systems is still lacking. The mechanism of the electrokinetic trapping of charged particles is currently limited to the force balance analysis between the electric force and fluid drag force in an over-simplified one-dimensional (1D) model, which misses many signatures of the actual system. Read More

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http://dx.doi.org/10.1063/1.5008365DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5739909PMC
December 2017
2 Reads

A polarization-insensitive plasmonic photoconductive terahertz emitter.

AIP Adv 2017 Nov 16;7(11):115113. Epub 2017 Nov 16.

Electrical Engineering Department, University of California - Los Angeles, Los Angeles, California 90095, USA.

We present a polarization-insensitive plasmonic photoconductive terahertz emitter that uses a two-dimensional array of nanoscale cross-shaped apertures as the plasmonic contact electrodes. The geometry of the cross-shaped apertures is set to maximize optical pump absorption in close proximity to the contact electrodes. The two-dimensional symmetry of the cross-shaped apertures offers a polarization-insensitive interaction between the plasmonic contact electrodes and optical pump beam. Read More

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http://dx.doi.org/10.1063/1.5006273DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5690658PMC
November 2017
1 Read

Artifacts in magnetic measurements of fluid samples.

AIP Adv 2016 Aug 1;6(8). Epub 2016 Aug 1.

Material Measurement Laboratory, National Institute of Standards and Technology, Gaithersburg, Maryland 20899, USA.

Applications of magnetic fluids are ever increasing, as well as the corresponding need to be able to characterize these fluids . Commercial magnetometers are accurate and well-characterized for solid and powder samples, but their use with fluid samples is more limited. Here, we describe artifacts which can occur in magnetic measurements of fluid samples and their impact. Read More

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http://dx.doi.org/10.1063/1.4960457DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5531296PMC
August 2016
2 Reads

Enhanced ferromagnetic resonance linewidth of the free layer in perpendicular magnetic tunnel junctions.

AIP Adv 2017 Mar 3;7(5). Epub 2017 Mar 3.

Avalanche Technology, Fremont, CA 95438, USA.

We report the frequency dependence of the ferromagnetic resonance linewidth of the free layer in magnetic tunnel junctions with all perpendicular-to-the-plane magnetized layers. While the magnetic-field-swept linewidth nominally shows a linear growth with frequency in agreement with Gilbert damping, an additional frequency-dependent linewidth broadening occurs that shows a strong asymmetry between the absorption spectra for increasing- and decreasing external magnetic field. Inhomogeneous magnetic fields produced during reversal of the reference and pinned layer complex is demonstrated to be at the origin of the symmetry breaking and the linewidth enhancement. Read More

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http://dx.doi.org/10.1063/1.4977969DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5497521PMC
March 2017
2 Reads

Fabrication of silicon films from patterned protruded seeds.

AIP Adv 2017 May 12;7(5):055307. Epub 2017 May 12.

Shanghai Advanced Research Institute, Chinese Academy of Sciences, 99 Haike Road, Shanghai 201210, China.

Thin, flexible silicon crystals are starting up applications such as light-weighted flexible solar cells, SOI, flexible IC chips, 3D ICs imagers and 3D CMOS imagers on the demand of high performance with low cost. Kerfless wafering technology by direct conversion of source gases into mono-crystalline wafers on reusable substrates is highly cost-effective and feedstock-effective route to cheap wafers with the thickness down to several microns. Here we show a prototype for direct conversion of silicon source gases to wafers by using the substrate with protruded seeds. Read More

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http://dx.doi.org/10.1063/1.4983575DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5429186PMC
May 2017
66 Reads

Crystallographic and electronic properties of AlCrN films that absorb visible light.

AIP Adv 2017 May 10;7(5):055306. Epub 2017 May 10.

Faculty of Electrical Engineering and Electronics, Kyoto Institute of Technology, Kyoto 606-8585, Japan.

We investigate the crystallographic and electronic properties of wurtzite Cr-doped AlN (AlCrN) films (Cr ≤12.0%) that absorb visible light. We confirmed that the films consist of wurtzite columnar single crystals that are densely packed, -axis oriented, and exhibit a random rotation along the -axis in plane by using transmission electron microscopy. Read More

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http://dx.doi.org/10.1063/1.4983491DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5425299PMC

A novel PM motor with hybrid PM excitation and asymmetric rotor structure for high torque performance.

AIP Adv 2017 May 7;7(5):056671. Epub 2017 Mar 7.

This paper proposes a novel permanent magnet (PM) motor for high torque performance, in which hybrid PM material and asymmetric rotor design are applied. The hybrid PM material is adopted to reduce the consumption of rare-earth PM because ferrite PM is assisted to enhance the torque production. Meanwhile, the rotor structure is designed to be asymmetric by shifting the surface-insert PM (SPM), which is used to improve the torque performance, including average torque and torque ripple. Read More

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http://dx.doi.org/10.1063/1.4978400DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5346104PMC
May 2017
4 Reads

Design and validation of magnetic particle spectrometer for characterization of magnetic nanoparticle relaxation dynamics.

AIP Adv 2017 May 2;7(5):056730. Epub 2017 Mar 2.

Department of Electrical and Computer Engineering, University of Florida , Gainesville, Florida 32608, USA.

The design and validation of a magnetic particle spectrometer (MPS) system used to study the linear and nonlinear behavior of magnetic nanoparticle suspensions is presented. The MPS characterizes the suspension dynamic response, both due to relaxation and saturation effects, which depends on the magnetic particles and their environment. The system applies sinusoidal excitation magnetic fields varying in amplitude and frequency and can be configured for linear measurements (1 mT at up to 120 kHz) and nonlinear measurements (50 mT at up to 24 kHz). Read More

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http://dx.doi.org/10.1063/1.4978003DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5336471PMC
May 2017
2 Reads

Blood clot detection using magnetic nanoparticles.

AIP Adv 2017 May 16;7(5):056723. Epub 2017 Feb 16.

Department of Radiology, Dartmouth-Hitchcock Medical Center , Lebanon New Hampshire 03756, USA.

Deep vein thrombosis, the development of blood clots in the peripheral veins, is a very serious, life threatening condition that is prevalent in the elderly. To deliver proper treatment that enhances the survival rate, it is very important to detect thrombi early and at the point of care. We explored the ability of magnetic particle spectroscopy (MSB) to detect thrombus via specific binding of aptamer functionalized magnetic nanoparticles with the blood clot. Read More

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http://aip.scitation.org/doi/10.1063/1.4977073
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http://dx.doi.org/10.1063/1.4977073DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5315662PMC
May 2017
6 Reads

Design and analysis of a field modulated magnetic screw for artificial heart.

AIP Adv 2017 May 6;7(5):056717. Epub 2017 Feb 6.

School of Electrical and Information Engineering, Jiangsu University , Zhenjiang 212013, China and Jiangsu Key Laboratory of Drive and Intelligent Control for Electric Vehicle , Zhenjiang 212013, China.

This paper proposes a new electromechanical energy conversion system, called Field Modulated Magnetic Screw (FMMS) as a high force density linear actuator for artificial heart. This device is based on the concept of magnetic screw and linear magnetic gear. The proposed FMMS consists of three parts with the outer and inner carrying the radially magnetized helically permanent-magnet (PM), and the intermediate having a set of helically ferromagnetic pole pieces, which modulate the magnetic fields produced by the PMs. Read More

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http://dx.doi.org/10.1063/1.4975699DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5303166PMC
May 2017
1 Read

Sample MMM manuscript for submission to AIP advances transient line starting analysis of the ultra-high speed PMSM.

AIP Adv 2017 May 11;7(5):056627. Epub 2017 Jan 11.

Institute of Mechatronics and Information Systems, State Key Laboratory for Strength and Vibration of Mechanical Structures, Xi'an Jiaotong University , Xi'an, 710049, China.

Aiming at the ultra high speed permanent magnet synchronous motor (PMSM) supported by gas foil bearings (GFBs), this paper calculates the transient line starting of the motor. Firstly, the start effect of the rotor composed of cylindrical PM and stainless steel sleeve is studied. Then, in order to enhance the start torque, copper ring, nickel ring and copper squirrel-cage are introduced in the rotor and their start effect are analysed, respectively. Read More

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http://dx.doi.org/10.1063/1.4974057DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5236057PMC
May 2017
15 Reads

A 3D contact analysis approach for the visualization of the electrical contact asperities.

AIP Adv 2017 Jan 11;7(1):015023. Epub 2017 Jan 11.

School of Engineering and Physical Sciences, Heriot-Watt University , Edinburgh EH14 4AS, United Kingdom.

The electrical contact is an important phenomenon that should be given into consideration to achieve better performance and long term reliability for the design of devices. Based upon this importance, the electrical contact interface has been visualized as a ''3D Contact Map'' and used in order to investigate the contact asperities. The contact asperities describe the structures above and below the contact spots (the contact spots define the 3D contact map) to the two conductors which make the contact system. Read More

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http://dx.doi.org/10.1063/1.4974151DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5236058PMC
January 2017
1 Read

First-principles investigation on elastic and thermodynamic properties of -CN under high pressure.

AIP Adv 2016 Dec 16;6(12):125040. Epub 2016 Dec 16.

School of Physics and Electronic Engineering, Sichuan University of Science & Engineering , Zigong 643000, China.

The elastic anisotropy and thermodynamic properties of the recently synthesized -CN have been investigated using first-principles calculations under high temperature and high pressure. The calculated equilibrium crystal parameters and normalized volume dependence of the resulting pressure agree with available experimental and theoretical results. Within the considered pressure range of 0-90 GPa, the dependences of the bulk modulus, Young's modulus, and shear modulus on the crystal orientation for -CN have been systematically studied. Read More

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http://aip.scitation.org/doi/10.1063/1.4972775
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http://dx.doi.org/10.1063/1.4972775DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5193123PMC
December 2016
2 Reads

Observation of Strong Reflection of Electron Waves Exiting a Ballistic Channel at Low Energy.

AIP Adv 2016 Jun 10;6(6). Epub 2016 Jun 10.

National Institute of Standards and Technology, Gaithersburg, MD 20899-8120, USA.

Wave scattering by a potential step is a ubiquitous concept. Thus, it is surprising that theoretical treatments of ballistic transport in nanoscale devices, from quantum point contacts to ballistic transistors, assume no reflection even when the potential step is encountered upon exiting the device. Experiments so far seem to support this even if it is not clear why. Read More

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http://dx.doi.org/10.1063/1.4954083DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5117664PMC
June 2016
1 Read

Seed layer technique for high quality epitaxial manganite films.

AIP Adv 2016 Aug 12;6(8):085109. Epub 2016 Aug 12.

CNR - ISMN, Consiglio Nazionale delle Ricerche - Istituto per lo Studio dei Materiali Nanostrutturati , v. Gobetti 101, 40129 Bologna, Italy.

We introduce an innovative approach to the simultaneous control of growth mode and magnetotransport properties of manganite thin films, based on an easy-to-implement film/substrate interface engineering. The deposition of a manganite seed layer and the optimization of the substrate temperature allows a persistent bi-dimensional epitaxy and robust ferromagnetic properties at the same time. Structural measurements confirm that in such interface-engineered films, the optimal properties are related to improved epitaxy. Read More

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http://dx.doi.org/10.1063/1.4961228DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC5000783PMC

Evaluation of polarization rotation in the scattering responses from individual semiconducting oxide nanorods.

AIP Adv 2016 Apr 22;6(4):045213. Epub 2016 Apr 22.

Department of Chemistry, Georgetown University , 37 & O Sts. NW., Washington, DC 20057, USA.

We investigate the interaction of visible light with the solid matters of semiconducting oxide nanorods (NRs) of zinc oxide (ZnO), indium tin oxide (ITO), and zinc tin oxide (ZTO) at the single nanomaterial level. We subsequently identify an intriguing, material-dependent phenomenon of optical rotation in the electric field oscillation direction of the scattered light by systematically controlling the wavelength and polarization direction of the incident light, the NR tilt angle, and the analyzer angle. This polarization rotation effect in the scattered light is repeatedly observed from the chemically pure and highly crystalline ZnO NRs, but absent on the chemically doped NR variants of ITO and ZTO under all measurement circumstances. Read More

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http://dx.doi.org/10.1063/1.4948267DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4841797PMC
April 2016
15 Reads

Micro-particle manipulation by single beam acoustic tweezers based on hydrothermal PZT thick film.

AIP Adv 2016 Mar 3;6(3):035102. Epub 2016 Mar 3.

Department of Biomedical Engineering and NIH Transducer Resource Center, University of Southern California , Los Angeles, California 90089-1111, USA.

Single-beam acoustic tweezers (SBAT), used in laboratory-on-a-chip (LOC) device has promising implications for an individual micro-particle contactless manipulation. In this study, a freestanding hydrothermal PZT thick film with excellent piezoelectric property (d = 270pC/N and k = 0.51) was employed for SBAT applications and a press-focusing technology was introduced. Read More

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http://dx.doi.org/10.1063/1.4943492DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4788601PMC
March 2016
11 Reads

Effect of boron doping on nanostructure and magnetism of rapidly quenched ZrCo-based alloys.

AIP Adv 2016 May 18;6(5):056002. Epub 2016 Feb 18.

Nebraska Center for Materials and Nanoscience, University of Nebraska , Lincoln, NE 68588, USA.

The role of B on the microstructure and magnetism of ZrCo MoB ribbons prepared by arc melting and melt spinning is investigated. Microstructure analysis show that the ribbons consist of a hard-magnetic rhombohedral ZrCo phase and a minor amount of soft-magnetic Co. We show that the addition of B increases the amount of hard-magnetic phase, reduces the amount of soft-magnetic Co and coarsens the grain size from about 35 nm to 110 nm. Read More

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http://dx.doi.org/10.1063/1.4942556DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4760965PMC
May 2016
3 Reads

Dynamic coherent backscattering mirror.

Authors:
I Zeylikovich M Xu

AIP Adv 2016 Feb 8;6(2):025105. Epub 2016 Feb 8.

Physics Department, Fairfield University , Fairfield, CT 06824, USA.

The phase of multiply scattered light has recently attracted considerable interest. Coherent backscattering is a striking phenomenon of multiple scattered light in which the coherence of light survives multiple scattering in a random medium and is observable in the space as an enhancement of the intensity of backscattered light within a cone around the retroreflection direction. Reciprocity also leads to enhancement of backscattering light in the space. Read More

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http://dx.doi.org/10.1063/1.4941832DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4752535PMC
February 2016

Acousto-plasmofluidics: Acoustic modulation of surface plasmon resonance in microfluidic systems.

AIP Adv 2015 Sep 18;5(9):097161. Epub 2015 Sep 18.

Department of Engineering Science and Mechanics, Department of Biomedical Engineering, The Pennsylvania State University , University Park, PA 16802 USA.

We acoustically modulated the localized surface plasmon resonances (LSPRs) of metal nanostructures integrated within microfluidic systems. An acoustically driven micromixing device based on bubble microstreaming quickly and homogeneously mixes multiple laminar flows of different refractive indices. The altered refractive index of the mixed fluids enables rapid modulation of the LSPRs of gold nanodisk arrays embedded within the microfluidic channel. Read More

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http://dx.doi.org/10.1063/1.4931641DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4575316PMC
September 2015

Ionic charge transport between blockages: Sodium cation conduction in freshly excised bulk brain tissue.

AIP Adv 2015 Aug 11;5(8):087133. Epub 2015 Aug 11.

Department of Neurosurgery, David Geffen School of Medicine, University of California at Los Angeles , Los Angeles, CA 90095, USA.

We analyze the transient-dc and frequency-dependent electrical conductivities between blocking electrodes. We extend this analysis to measurements of ions' transport in freshly excised bulk samples of human brain tissue whose complex cellular structure produces blockages. The associated ionic charge-carrier density and diffusivity are consistent with local values for sodium cations determined non-invasively in brain tissue by MRI (NMR) and diffusion-MRI (spin-echo NMR). Read More

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http://dx.doi.org/10.1063/1.4928652DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4537479PMC
August 2015
1 Read

Spectral behavior of second harmonic signals from organic and non-organic materials in multiphoton microscopy.

AIP Adv 2015 Aug 12;5(8):084903. Epub 2015 Mar 12.

Institute of Quantum Optics, University of Hanover , 30167 Hanover, Germany.

Multimodal nonlinear microscopy allows imaging of highly ordered biological tissue due to spectral separation of nonlinear signals. This requires certain knowledge about the spectral distribution of the different nonlinear signals. In contrast to several publications we demonstrate a factor of [Formula: see text] relating the full width at half maximum of a gaussian laser pulse spectrum to the corresponding second harmonic pulse spectrum in the spatial domain by using a simple theoretical model. Read More

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http://aip.scitation.org/doi/10.1063/1.4915134
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http://dx.doi.org/10.1063/1.4915134DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4513891PMC
August 2015
5 Reads

Confocal fluorescence microscopy: An ultra-sensitive tool used to evaluate intracellular antiretroviral nano-drug delivery in HeLa cells.

AIP Adv 2015 Aug 8;5(8):084803. Epub 2015 Jul 8.

School of Pharmacy and Health Professions, Creighton University , Omaha, NE 68178, USA.

In the last decade, confocal fluorescence microscopy has emerged as an ultra-sensitive tool for real-time study of nanoparticles (NPs) fate at the cellular-level. According to WHO 2007 report, Human Immunodeficiency Virus/Acquired Immunodeficiency Syndrome (HIV/AIDS) is still one of the world's major health threats by claiming approximately 7,000 new infections daily worldwide. Although combination antiretroviral drugs (cARV) therapy has improved the life-expectancy of HIV-infected patients, routine use of high doses of cARV has serious health consequences and requires complete adherence to the regimen for success. Read More

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http://aip.scitation.org/doi/10.1063/1.4926584
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http://dx.doi.org/10.1063/1.4926584DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4499042PMC
August 2015
3 Reads

Non-descanned multifocal multiphoton microscopy with a multianode photomultiplier tube.

AIP Adv 2015 Aug 23;5(8):084802. Epub 2015 Mar 23.

Picower Institute for Learning and Memory, Massachusetts Institute of Technology , Cambridge, MA, USA.

Multifocal multiphoton microscopy (MMM) improves imaging speed over a point scanning approach by parallelizing the excitation process. Early versions of MMM relied on imaging detectors to record emission signals from multiple foci simultaneously. For many turbid biological specimens, the scattering of emission photons results in blurred images and degrades the signal-to-noise ratio (SNR). Read More

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http://dx.doi.org/10.1063/1.4916040DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387602PMC
August 2015
2 Reads

Novel type-II material system for laser applications in the near-infrared regime.

AIP Adv 2015 Apr 3;5(4):047105. Epub 2015 Apr 3.

Nonlinear Control Strategies Inc , 3542 N. Geronimo Ave., Tucson, AZ 85705, USA.

The design and experimental realization of a type-II "W"-multiple quantum well heterostructure for emission in the λ > 1.2 m range is presented. The experimental photoluminescence spectra for different excitation intensities are analyzed using microscopic quantum theory. Read More

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http://dx.doi.org/10.1063/1.4917180DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387595PMC

Investigation of CuGaSe/CuInSe double heterojunction interfaces grown by molecular beam epitaxy.

AIP Adv 2015 Feb 11;5(2):027120. Epub 2015 Feb 11.

School of Advanced Science and Engineering, Waseda University , 3-4-1, Okubo, Shinjuku, Tokyo 169-8555, JAPAN.

In-situ reflection high-energy electron diffraction (RHEED) observation and X-ray diffraction measurements were performed on heterojunction interfaces of CuGaSe/CnInSe/CuGaSe grown on GaAs (001) using migration-enhanced epitaxy. The streaky RHEED pattern and persistent RHEED intensity oscillations caused by the alternate deposition of migration-enhanced epitaxy sequence are observed and the growths of smooth surfaces are confirmed. RHEED observation results also confirmed constituent material interdiffusion at the heterointerface. Read More

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http://dx.doi.org/10.1063/1.4908229DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387601PMC
February 2015
2 Reads

Autoinhibitory mechanisms of ERG studied by molecular dynamics simulations.

AIP Adv 2015 Jan 22;5(1):017130. Epub 2015 Jan 22.

Department of Physics, Wake Forest University , Winston-Salem, NC 27106, USA.

ERG, an ETS-family transcription factor, acts as a regulator of differentiation of early hematopoietic cells. It contains an autoinhibitory domain, which negatively regulates DNA-binding. The mechanism of autoinhibitory is still illusive. Read More

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http://dx.doi.org/10.1063/1.4906572DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387600PMC
January 2015

Generalizing thermodynamic properties of bulk single-walled carbon nanotubes.

AIP Adv 2014 Dec 29;4(12):127149. Epub 2014 Dec 29.

Department of Chemistry, California State University , Dominguez Hills, CA 90747, USA.

The enthalpy and Gibbs free energy thermodynamical potentials of single walled carbon nanotubes were studied of all types (armchairs, zig-zags, chirals (), and chiral ()). Bulk values of these thermodynamic potentials were obtained using a previously demonstrated robust method based on semi-empirical PM3 calculations and an extrapolated cluster approach. Those values were used to study the relationship between the thermodynamic potentials and the diameter of the nanotube. Read More

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http://dx.doi.org/10.1063/1.4905263DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC4387603PMC
December 2014
3 Reads

Low dose hard x-ray contact microscopy assisted by a photoelectric conversion layer.

AIP Adv 2013 Apr 18;3(4):42121. Epub 2013 Apr 18.

Imaging Physics Laboratory, Biophysics and Biochemistry Center, National Heart, Lung and Blood Institute, National Institutes of Health, Bethesda, MD, 20892, USA.

Hard x-ray contact microscopy provides images of dense samples at resolutions of tens of nanometers. However, the required beam intensity can only be delivered by synchrotron sources. We report on the use of a gold photoelectric conversion layer to lower the exposure dose by a factor of 40 to 50, allowing hard x-ray contact microscopy to be performed with a compact x-ray tube. Read More

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http://dx.doi.org/10.1063/1.4802886DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3645440PMC
April 2013
6 Reads

Possible room temperature superconductivity in conductors obtained by bringing alkanes into contact with a graphite surface.

AIP Adv 2013 May 24;3(5):52132. Epub 2013 May 24.

Department of Precision Engineering, School of Engineering, Tokai University, Hiratsuka, Kanagawa 259-1292, Japan.

Electrical resistances of conductors obtained by bringing alkanes into contact with a graphite surface have been investigated at room temperatures. Ring current in a ring-shaped container into which n-octane-soaked thin graphite flakes were compressed did not decay for 50 days at room temperature. After two HOPG plates were immersed into n-heptane and n-octane at room temperature, changes in resistances of the two samples were measured by four terminal technique. Read More

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http://dx.doi.org/10.1063/1.4808207DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3676368PMC

Deterministic separation of cancer cells from blood at 10 mL/min.

AIP Adv 2012 Dec 3;2(4):42107. Epub 2012 Oct 3.

Princeton Institute for the Science and Technology of Materials (PRISM), Princeton Universtiy, Princeton, NJ, USA ; Department of Electrical Engineering, Princeton University, Princeton, NJ, USA.

Circulating tumor cells (CTCs) and circulating clusters of cancer and stromal cells have been identified in the blood of patients with malignant cancer and can be used as a diagnostic for disease severity, assess the efficacy of different treatment strategies and possibly determine the eventual location of metastatic invasions for possible treatment. There is thus a critical need to isolate, propagate and characterize viable CTCs and clusters of cancer cells with their associated stroma cells. Here, we present a microfluidic device for mL/min flow rate, continuous-flow capture of viable CTCs from blood using deterministic lateral displacement (DLD) arrays. Read More

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http://dx.doi.org/10.1063/1.4758131DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3477176PMC
December 2012
252 Reads

Photoactivation of neurons by laser-generated local heating.

AIP Adv 2012 Sep 23;2(3):032154. Epub 2012 Aug 23.

Department of Neuroscience, University of California, San Diego. 9500 Gilman Drive, La Jolla, CA, 92037, USA.

We present a method for achieving temporally and spatially precise photoactivation of neurons without the need for genetic expression of photosensitive proteins. Our method depends upon conduction of thermal energy via absorption by chemically inert carbon particles and does not require the presence of voltage-gated channels to create transmembrane currents. We demonstrate photothermal initiation of action potentials in neurons within an intact ganglion and of transmembrane currents in oocytes. Read More

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http://dx.doi.org/10.1063/1.4748955DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3977748PMC
September 2012
2 Reads

Dynamic density functional theory of solid tumor growth: Preliminary models.

AIP Adv 2012 Mar 22;2(1):11210. Epub 2012 Mar 22.

Cancer is a disease that can be seen as a complex system whose dynamics and growth result from nonlinear processes coupled across wide ranges of spatio-temporal scales. The current mathematical modeling literature addresses issues at various scales but the development of theoretical methodologies capable of bridging gaps across scales needs further study. We present a new theoretical framework based on Dynamic Density Functional Theory (DDFT) extended, for the first time, to the dynamics of living tissues by accounting for cell density correlations, different cell types, phenotypes and cell birth/death processes, in order to provide a biophysically consistent description of processes across the scales. Read More

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http://dx.doi.org/10.1063/1.3699065DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321520PMC
March 2012
4 Reads

Integrated intravital microscopy and mathematical modeling to optimize nanotherapeutics delivery to tumors.

AIP Adv 2012 Mar 22;2(1):11208. Epub 2012 Mar 22.

Inefficient vascularization hinders the optimal transport of cell nutrients, oxygen, and drugs to cancer cells in solid tumors. Gradients of these substances maintain a heterogeneous cell-scale microenvironment through which drugs and their carriers must travel, significantly limiting optimal drug exposure. In this study, we integrate intravital microscopy with a mathematical model of cancer to evaluate the behavior of nanoparticle-based drug delivery systems designed to circumvent biophysical barriers. Read More

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http://dx.doi.org/10.1063/1.3699060DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321519PMC
March 2012
5 Reads

Physics of cancer propagation: A game theory perspective.

AIP Adv 2012 Mar 22;2(1):11202. Epub 2012 Mar 22.

This is a theoretical paper which examines at a game theoretical perspective the dynamics of cooperators and cheater cells under metabolic stress conditions and high spatial heterogeneity. Although the ultimate aim of this work is to understand the dynamics of cancer tumor evolution under stress, we use a simple bacterial model to gain fundamental insights into the progression of resistance to drugs under high competition and stress conditions. Read More

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http://dx.doi.org/10.1063/1.3699043DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321518PMC
March 2012
28 Reads

Implications of quantum metabolism and natural selection for the origin of cancer cells and tumor progression.

AIP Adv 2012 Mar 19;2(1):11101. Epub 2012 Mar 19.

Empirical studies give increased support for the hypothesis that the sporadic form of cancer is an age-related metabolic disease characterized by: (a) metabolic dysregulation with random abnormalities in mitochondrial DNA, and (b) metabolic alteration - the compensatory upregulation of glycolysis to offset mitochondrial impairments. This paper appeals to the theory of Quantum Metabolism and the principles of natural selection to formulate a conceptual framework for a quantitative analysis of the origin and proliferation of the disease. Quantum Metabolism, an analytical theory of energy transduction in cells inspired by the methodology of the quantum theory of solids, elucidates the molecular basis for differences in metabolic rate between normal cells, utilizing predominantly oxidative phosphorylation, and cancer cells utilizing predominantly glycolysis. Read More

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http://dx.doi.org/10.1063/1.3697850DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321517PMC
March 2012
7 Reads

Diversity of dynamics and morphologies of invasive solid tumors.

AIP Adv 2012 Mar 21;2(1):11003. Epub 2012 Mar 21.

Complex tumor-host interactions can significantly affect the growth dynamics and morphologies of progressing neoplasms. The growth of a confined solid tumor induces mechanical pressure and deformation of the surrounding microenvironment, which in turn influences tumor growth. In this paper, we generalize a recently developed cellular automaton model for invasive tumor growth in heterogeneous microenvironments [Y. Read More

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http://dx.doi.org/10.1063/1.3697959DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3321516PMC
March 2012
1 Read

A novel non-imaging optics based Raman spectroscopy device for transdermal blood analyte measurement.

AIP Adv 2011 Sep 27;1(3):32175. Epub 2011 Sep 27.

George R. Harrison Spectroscopy Laboratory, Massachusetts Institute of Technology, 77 Massachusetts Ave 6-205, Cambridge, Massachusetts 02139, USA.

Due to its high chemical specificity, Raman spectroscopy has been considered to be a promising technique for non-invasive disease diagnosis. However, during Raman excitation, less than one out of a million photons undergo spontaneous Raman scattering and such weakness in Raman scattered light often require highly efficient collection of Raman scattered light for the analysis of biological tissues. We present a novel non-imaging optics based portable Raman spectroscopy instrument designed for enhanced light collection. Read More

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http://dx.doi.org/10.1063/1.3646524DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217291PMC
September 2011
5 Reads

An optical-coding method to measure particle distribution in microfluidic devices.

AIP Adv 2011 Jun 29;1(2):22155. Epub 2011 Jun 29.

We demonstrated an optical coding method to measure the position of each particle in a microfluidic channel. The technique utilizes a specially designed pattern as a spatial mask to encode the forward scattering signal of each particle. From the waveform of the forward scattering signal, one can obtain the information about the particle position and velocity. Read More

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http://dx.doi.org/10.1063/1.3609967DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217293PMC
June 2011
33 Reads

Modification of microneedles using inkjet printing.

AIP Adv 2011 Jun 10;1(2):22139. Epub 2011 Jun 10.

In this study, biodegradable acid anhydride copolymer microneedles containing quantum dots were fabricated by means of visible light dynamic mask micro-stereolithography-micromolding and inkjet printing. Nanoindentation was performed to obtain the hardness and the Young's modulus of the biodegradable acid anhydride copolymer. Imaging of quantum dots within porcine skin was accomplished by means of multiphoton microscopy. Read More

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http://dx.doi.org/10.1063/1.3602461DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3217292PMC
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