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https://www.readbyqxmd.com/read/28236741/studying-substrate-effects-on-localized-surface-plasmons-in-an-individual-silver-nanoparticle-using-electron-energy-loss-spectroscopy
#1
Yoshifumi Fujiyoshi, Takashi Nemoto, Hiroki Kurata
In this study, electron energy-loss spectroscopy (EELS) in conjunction with scanning transmission electron microscopy (STEM) was used to investigate surface plasmons in a single silver nanoparticle (NP) on a magnesium oxide substrate, employing an incident electron trajectory parallel to the substrate surface. This parallel irradiation allowed a direct exploration of the substrate effects on localized surface plasmon (LSP) excitations as a function of the distance from the substrate. The presence of the substrate was found to lower the symmetry of the system, such that the resonance energies of LSPs were dependent on the polarization direction relative to the substrate surface...
January 18, 2017: Ultramicroscopy
https://www.readbyqxmd.com/read/28236461/gas-chromatography-vacuum-ultraviolet-detection-for-classification-and-speciation-of-polychlorinated-biphenyls-in-industrial-mixtures
#2
Changling Qiu, Jack Cochran, Jonathan Smuts, Phillip Walsh, Kevin A Schug
Polychlorinated biphenyls (PCBs) are a group of synthetic chlorinated compounds that have been widely used as dielectric fluids in capacitors and transformers. Due to their toxicity, persistence, and bioaccumulation in the food chain, PCBs are an environmental concern and among the most analyzed compounds in environmental analysis. The most common analytical methods for analysis of PCBs are based on gas chromatography-electron capture detection (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). However, the number of possible congeners (209), similarities of physical and chemical properties, and complexity of sample matrices make it difficult to distinguish and accurately speciate PCB congeners using existing methods...
February 16, 2017: Journal of Chromatography. A
https://www.readbyqxmd.com/read/28235382/can-f%C3%A3-rster-theory-describe-stereoselective-energy-transfer-dynamics-in-a-protein-ligand-complex
#3
Silvana Pinheiro, Carles Curutchet
Förster resonance energy transfer (FRET) reactions involving ligands and aromatic amino acids can substantially impact the fluorescence properties of a protein-ligand complex, an impact intimately related to the corresponding binding mode. Structural characterization of such binding events in terms of intermolecular distances can be done through the well-known R-6 distance-dependent Förster rate expression. However, such interpretation suffers from uncertainties underlying Förster theory in the description of the electronic coupling that promotes FRET, mostly related to the dipole-dipole orientation factor, dielectric screening effects and deviations from the ideal dipole approximation...
February 24, 2017: Journal of Physical Chemistry. B
https://www.readbyqxmd.com/read/28231007/molecular-dynamics-recrystallization-behavior-and-water-solubility-of-amorphous-anticancer-agent-bicalutamide-and-its-polyvinylpyrrolidone-mixtures
#4
Justyna Szczurek, Marzena Rams-Baron, Justyna Knapik-Kowalczuk, Agata Antosik, Joanna Szafraniec, Witold Jamroz, Mateusz Dulski, Renata Jachowicz, Marian Paluch
In this paper, we investigated the molecular mobility and physical stability of amorphous bicalutamide, a poorly water-soluble drug widely used in prostate cancer treatment. Our broadband dielectric spectroscopy measurements and differential scanning calorimetry studies revealed that amorphous BIC is a moderately fragile material with strong tendency to recrystallize from amorphous state. However, mixing the drug with polymer polyvinylpyrrolidone results in a substantial improvement of physical stability attributed to antiplasticizing effect governing by polymer additive...
February 23, 2017: Molecular Pharmaceutics
https://www.readbyqxmd.com/read/28230354/chemical-modification-of-semiconductor-surfaces-for-molecular-electronics
#5
Ayelet Vilan, David Cahen
Inserting molecular monolayers within metal/semiconductor interfaces provides one of the most powerful expressions of how minute chemical modifications can affect electronic devices. This topic also has direct importance for technology as it can help improve the efficiency of a variety of electronic devices such as solar cells, LEDs, sensors, and possible future bioelectronic ones. The review covers the main aspects of using chemistry to control the various aspects of interface electrostatics, such as passivation of interface states and alignment of energy levels by intrinsic molecular polarization, as well as charge rearrangement with the adjacent metal and semiconducting contacts...
February 23, 2017: Chemical Reviews
https://www.readbyqxmd.com/read/28230215/graphene-modulated-photo-absorption-in-adsorbed-azobenzene-monolayers
#6
Qiang Fu, Caterina Cocchi, Dmitrii Nabok, Andris Gulans, Claudia Draxl
The impact of graphene on the photo-absorption properties of trans- and cis-azobenzene monolayers is studied in the framework of density-functional theory and many-body perturbation theory. We find that, despite the weak hybridization between the electronic bands of graphene and those of the azobenzene monolayers, graphene remarkably modulates the absorption spectra of the adsorbates. The excitation energies are affected via two counteracting mechanisms: substrate polarization reduces the band-gap of azobenzene, and enhanced dielectric screening weakens the attractive interaction between electrons and holes...
February 22, 2017: Physical Chemistry Chemical Physics: PCCP
https://www.readbyqxmd.com/read/28230204/high-resolution-imaging-of-living-mammalian-cells-bound-by-nanobeads-connected-antibodies-in-a-medium-using-scanning-electron-assisted-dielectric-microscopy
#7
Tomoko Okada, Toshihiko Ogura
Nanometre-scale-resolution imaging technologies for liquid-phase specimens are indispensable tools in various scientific fields. In biology, observing untreated living cells in a medium is essential for analysing cellular functions. However, nanoparticles that bind living cells in a medium are hard to detect directly using traditional optical or electron microscopy. Therefore, we previously developed a novel scanning electron-assisted dielectric microscope (SE-ADM) capable of nanoscale observations. This method enables observation of intact cells in aqueous conditions...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28230178/large-area-growth-of-multi-layer-hexagonal-boron-nitride-on-polished-cobalt-foils-by-plasma-assisted-molecular-beam-epitaxy
#8
Zhongguang Xu, Hao Tian, Alireza Khanaki, Renjing Zheng, Mohammad Suja, Jianlin Liu
Two-dimensional (2D) hexagonal boron nitride (h-BN), which has a similar honeycomb lattice structure to graphene, is promising as a dielectric material for a wide variety of potential applications based on 2D materials. Synthesis of high-quality, large-size and single-crystalline h-BN domains is of vital importance for fundamental research as well as practical applications. In this work, we report the growth of h-BN films on mechanically polished cobalt (Co) foils using plasma-assisted molecular beam epitaxy...
February 23, 2017: Scientific Reports
https://www.readbyqxmd.com/read/28229531/homogeneous-inhomogeneous-structured-dielectrics-and-their-energy-storage-performances
#9
REVIEW
Zhonghua Yao, Zhe Song, Hua Hao, Zhiyong Yu, Minghe Cao, Shujun Zhang, Michael T Lanagan, Hanxing Liu
The demand for dielectric capacitors with higher energy-storage capability is increasing for power electronic devices due to the rapid development of electronic industry. Existing dielectrics for high-energy-storage capacitors and potential new capacitor technologies are reviewed toward realizing these goals. Various dielectric materials with desirable permittivity and dielectric breakdown strength potentially meeting the device requirements are discussed. However, some significant limitations for current dielectrics can be ascribed to their low permittivity, low breakdown strength, and high hysteresis loss, which will decrease their energy density and efficiency...
February 23, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28229499/advanced-materials-for-use-in-soft-self-healing-devices
#10
REVIEW
Tan-Phat Huynh, Prashant Sonar, Hossam Haick
Devices integrated with self-healing ability can benefit from long-term use as well as enhanced reliability, maintenance and durability. This progress report reviews the developments in the field of self-healing polymers/composites and wearable devices thereof. One part of the progress report presents and discusses several aspects of the self-healing materials chemistry (from non-covalent to reversible covalent-based mechanisms), as well as the required main approaches used for functionalizing the composites to enhance their electrical conductivity, magnetic, dielectric, electroactive and/or photoactive properties...
February 23, 2017: Advanced Materials
https://www.readbyqxmd.com/read/28228005/strained-germanium-quantum-well-pmosfets-on-soi-with-mobility-enhancement-by-external-uniaxial-stress
#11
Yan Liu, Jiebin Niu, Hongjuan Wang, Genquan Han, Chunfu Zhang, Qian Feng, Jincheng Zhang, Yue Hao
Well-behaved Ge quantum well (QW) p-channel metal-oxide-semiconductor field-effect transistors (pMOSFETs) were fabricated on silicon-on-insulator (SOI) substrate. By optimizing the growth conditions, ultrathin fully strained Ge film was directly epitaxially grown on SOI at about 450 °C using ultra-high vacuum chemical vapor deposition. In situ Si2H6 passivation of Ge was utilized to form a high-quality SiO2/Si interfacial layer between the high-κ dielectric and channels. Strained Ge QW pMOSFETs achieve the significantly improved effective hole mobility μ eff as compared with the relaxed Si and Ge control devices...
December 2017: Nanoscale Research Letters
https://www.readbyqxmd.com/read/28227992/modeling-and-design-of-antennas-for-implantable-telemetry-applications
#12
Arun Venkatasubramanian, Brandon Gifford, Arun Venkatasubramanian, Brandon Gifford, Brandon Gifford, Arun Venkatasubramanian
Incorporating an RF communications link in an implanted medical device can increase its range of applicability and improve quality of life for the patient. Developments in support electronics decrease design risk, but the implanted antenna remains a critical component of a communications link that operates at very low received power. Transmitted power is limited both by regulatory restrictions and, for most implanted devices, by power source capacity. Dielectric losses and wave trapping in the body result in transmission losses much greater than seen in free space communications...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227600/modeling-the-debye-dielectric-response-in-the-time-domain-for-a-liquid-crystal-based-biopotential-optrode
#13
Hrishikesh Srinivas, Amr Al Abed, Francois Ladouceur, Nigel H Lovell, Leonardo Silvestri, Hrishikesh Srinivas, Amr Al Abed, Francois Ladouceur, Nigel H Lovell, Leonardo Silvestri, Hrishikesh Srinivas, Nigel H Lovell, Francois Ladouceur, Leonardo Silvestri, Amr Al Abed
Multielectrode arrays (MEAs) are widely used for recording biopotentials, with an ongoing research effort to improve their characteristics and performance. In this spirit, we are currently investigating a novel concept for a liquid crystal-based optical electrode (optrode) that has the potential to overcome some of the limitations of MEAs, including that of wiring complexity. In this paper we present a model to fully describe the electrical response of the proposed optrode to biopotentials, taking into account dielectric relaxation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227475/label-free-detection-of-sex-determining-region-y-sry-via-capacitive-biosensor
#14
Shilpa Sivashankar, Christos Sapsanis, Sumeyra Agambayev, Ulrich Buttner, Khaled Nabil Salama, Shilpa Sivashankar, Christos Sapsanis, Sumeyra Agambayev, Ulrich Buttner, Khaled Nabil Salama, Khaled Nabil Salama, Shilpa Sivashankar, Sumeyra Agambayev, Christos Sapsanis, Ulrich Buttner
In this work, we present for the first time, the use of a simple fractal capacitive biosensor for the quantification and detection of sex-determining region Y (SRY) genes. This section of genetic code, which is found on the Y chromosome, finds importance for study as it causes fetuses to develop characteristics of male sex-like gonads when a mutation occurs. It is also an important genetic code in men, and disorders involving the SRY gene can cause infertility and sexual malfunction that lead to a variety of gene mutational disorders...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227298/extracting-dielectric-spectroscopic-properties-from-microwave-induced-thermoacoustic-signals
#15
Shiyu Liu, Hao Nan, Nemat Dolatsha, Amin Arbabian, Shiyu Liu, Hao Nan, Nemat Dolatsha, Amin Arbabian, Hao Nan, Nemat Dolatsha, Amin Arbabian, Shiyu Liu
Available data on the dielectric properties of biological tissue across a frequency range adds an extra degree of freedom of contrast besides the baseline structural information obtained by conventional imaging techniques. In this paper, we propose a new methodology to non-invasively extract the normalized effective conductivity of samples over a large frequency range using microwave-induced thermoacoustic (TA) signals. Additionally, a calibration approach has been adopted to remove the frequency dependency of the experimental setup errors as well as the RF power variation...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227291/development-of-a-head-phantom-and-measurement-setup-for-lightning-effects
#16
Rene Machts, Alexander Hunold, Carsten Leu, Jens Haueisen, Michael Rock, Rene Machts, Alexander Hunold, Carsten Leu, Jens Haueisen, Michael Rock, Alexander Hunold, Carsten Leu, Jens Haueisen, Michael Rock, Rene Machts
Direct lightning strikes to human heads lead to various effects ranging from Lichtenberg figures, over loss of consciousness to death. The evolution of the induced current distribution in the head is of great interest to understand the effect mechanisms. This work describes a technique to model a simplified head-phantom to investigate effects during direct lightning strike. The head-phantom geometry, conductive and dielectric parameters were chosen similar to that of a human head. Three layers (brain, skull, and scalp) were created for the phantom using agarose hydrogel doped with sodium chloride and carbon...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28227099/a-large-scale-detailed-neuronal-model-of-electrical-stimulation-of-the-dentate-gyrus-and-perforant-path-as-a-platform-for-electrode-design-and-optimization
#17
Clayton S Bingham, Kyle Loizos, Gene Yu, Andrew Gilbert, Jean-Marie Bouteiller, Dong Song, Gianluca Lazzi, Theodore W Berger, Clayton S Bingham, Kyle Loizos, Gene Yu, Andrew Gilbert, Jean-Marie Bouteiller, Dong Song, Gianluca Lazzi, Theodore W Berger, Kyle Loizos, Gene Yu, Theodore W Berger, Gianluca Lazzi, Jean-Marie Bouteiller, Clayton S Bingham, Dong Song, Andrew Gilbert
Owing to the dramatic rise in treatment of neurological disorders with electrical micro-stimulation it has become apparent that the major technological limitation in deploying effective devices lies in the process of designing efficient, safe, and outcome specific electrode arrays. The time-consuming and low-fidelity nature of gathering test data using experimental means and the immense control and flexibility of computational models, has prompted us and others to build models of electrical stimulation of neural networks that can be simulated in a computer...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226994/high-dielectric-material-in-mri-numerical-assessment-of-the-reduction-of-the-induced-local-power-on-implanted-cardiac-leads
#18
Eugenio Mattei, Elena Lucano, Federica Censi, Leonardo M Angelone, Giovanni Calcagnini, Eugenio Mattei, Elena Lucano, Federica Censi, Leonardo M Angelone, Giovanni Calcagnini, Eugenio Mattei, Giovanni Calcagnini, Elena Lucano, Leonardo M Angelone, Federica Censi
High dielectric materials (HDM) have been proposed in magnetic resonance imaging (MRI) to increase the signal-to-noise ratio (SNR) of the images acquired while reducing the radiofrequency (RF) absorption in tissue. The aim of this study is to assess the potential merit of using HDM to reduce power induced at the tip of an endocardial lead in patients undergoing MRI. Numerical simulations were performed using a commercial finite-differences time-domain (FDTD) software to model the RF field generated by a birdcage body coil at 64 MHz on a human body model...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226992/multi-layer-low-frequency-tissue-equivalent-phantoms-for-noninvasive-test-of-shallow-implants-and-evaluating-antenna-body-interaction
#19
Lawrence Fomundam, Jenshan Lin, Lawrence Fomundam, Jenshan Lin, Jenshan Lin, Lawrence Fomundam
In this work, a tissue equivalent compound phantom with dielectric properties equivalent to an average human body surface has been developed for a low frequency operating range of 30 MHz to 200 MHz. The compound phantom consists of skin, fat, and muscle layers respectively. The phantom is simple to fabricate with low cost components. A custom coaxial test fixture has been developed to characteristic phantom dielectric properties, which eliminates use of a specialized expensive dielectric measurement probe. The proposed composite phantom can be used as a noninvasive technique to evaluate shallow biomedical implants, antenna-body interaction, and specific absorption rate of tissue media...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
https://www.readbyqxmd.com/read/28226507/theranostic-microwave-applicator-suitable-for-minimal-invasive-therapy-of-malignant-tissue
#20
Carolin Reimann, Margarita Puentes, Martin Schusler, Frank Hubner, Babak Bazrafshan, Thomas J Vogl, Rolf Jakoby, Carolin Reimann, Margarita Puentes, Martin Schusler, Frank Hubner, Babak Bazrafshan, Thomas J Vogl, Rolf Jakoby, Rolf Jakoby, Carolin Reimann, Babak Bazrafshan, Thomas J Vogl, Frank Hubner, Margarita Puentes
A microwave applicator is presented that realizes the theranostic approach by providing two operation modes to detect and treat tumor cells, exemplary in the liver. The tool is based on a planar sensor structure with Split Ring Resonators (SRR) as key elements. For the detection, changes in dielectric properties caused by tissue abnormalities are evaluated by analyzing shifts in the resonance frequency of the SRR. For the treatment mode, the input power is amplified to the specific resonance frequency and microwave ablation is performed...
August 2016: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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