Fronts from two-dimensional dispersal kernels: Beyond the nonoverlapping-generations model
Daniel R. Amor and Joaquim Fort
Most integrodifference models of biological invasions are based on the nonoverlapping-generations approximation. However, the effect of multiple reproduction events (overlapping generations) on the front speed can be very important (especially for species with a long life spam). Only in one-dimensio ... [Phys. Rev. E 80, 051918 (2009)] published Mon Nov 23, 2009.
Glutaraldehyde enhanced dielectrophoretic yeast cell separation
Zachary Gagnon, Jill Mazur, and Hsueh-Chia Chang
We introduce a method for improved dielectrophoretic (DEP) discrimination and separation of viable and nonviable yeast cells. Due to the higher cell wall permeability of nonviable yeast cells compared with their viable counterpart, the cross-linking agent glutaraldehyde (GLT) is shown to selectively ... [Biomicrofluidics 3, 044108 (2009)] published Mon Nov 23, 2009.
Scaling and self-organized criticality in proteins: Lysozyme c
J. C. Phillips
Proteins appear to be the most dramatic natural example of self-organized criticality (SOC), a concept that explains many otherwise apparently unlikely phenomena. Protein functionality is often dominated by long-range hydro(phobic/philic) interactions, which both drive protein compaction and mediate ... [Phys. Rev. E 80, 051916 (2009)] published Fri Nov 20, 2009.
Phase statistics approach to human ventricular fibrillation
Ming-Chya Wu, Eiichi Watanabe, Zbigniew R. Struzik, Chin-Kun Hu, and Yoshiharu Yamamoto
Ventricular fibrillation (VF) is known to be the most dangerous cardiac arrhythmia, frequently leading to sudden cardiac death (SCD). During VF, cardiac output drops to nil and, unless the fibrillation is promptly halted, death usually ensues within minutes. While delivering life saving electrical s ... [Phys. Rev. E 80, 051917 (2009)] published Fri Nov 20, 2009.
Cluster approximations for infection dynamics on random networks
G. Rozhnova and A. Nunes
In this paper, we consider a simple stochastic epidemic model on large regular random graphs and the stochastic process that corresponds to this dynamics in the standard pair approximation. Using the fact that the nodes of a pair are unlikely to share neighbors, we derive the master equation for thi ... [Phys. Rev. E 80, 051915 (2009)] published Fri Nov 20, 2009.
Multi-Objective Optimization for the Force System of Orthodontic Retraction Spring Using Genetic Algorithms
Bahaa I. Kazem
In this study, Castigliano's second theorem is applied to predict the force and moment system produced by orthodontics T-spring. The developed analytical formulas include all spring design parameters (material, geometrical shape and wire cross section, type and position of spring end mounting system ... [J. Med. Devices 3, 041006 (2009)] published Fri Nov 20, 2009.
Numerical Investigation of Coil Configurations That Provide Ultrahigh Packing Density of Saccular Aneurysms
Chander Sadasivan and Baruch B. Lieber
The long-term outcome of endovascular coiling of cerebral aneurysms is directly related to the packing density at the time of treatment. In general, the highest packing density achievable is only about 45% due to the quasirandom distribution of currently available coils within aneurysms. We investig ... [J. Med. Devices 3, 041005 (2009)] published Fri Nov 20, 2009.
Novel Stapling Method and Device for Nasal Surgery
Ryan K. Buesseler, David B. Hom, and Arthur G. Erdman
This paper presents the design and prototyping of a novel stapling device and method intended forthough not limited tothe nasal septal mucosa. The pistol shaped device has two long projections: one for each nostril. The internal mechanism pushes the male portion of the rivet, nearly 10 cm down one t ... [J. Med. Devices 3, 041007 (2009)] published Fri Nov 20, 2009.
Characterization of Plastic Hypodermic Needles
Eric Busillo and Jonathan S. Colton
A significant potential for plastic hypodermic needles exists as an alternative to current steel needles. This paper presents the design and testing of one type of plastic hypodermic needle. The buckling and penetration characteristics of the needles were modeled and analyzed analytically and by fin ... [J. Med. Devices 3, 041004 (2009)] published Fri Nov 20, 2009.
Comparison of amorphous silicon photodiodes and photoconductors for detection of quantum dot biomolecular tags
A. C. Pimentel, D. M. F. Prazeres, V. Chu, and J. P. Conde
A comparative study of the performance of hydrogenated amorphous silicon photosensors based on two different device configurations for integration in a microarray platform for biomolecular detection is presented. A perpendicular contact p-i-n photodiode and a parallel contact intrinsic photoconducto ... [J. Appl. Phys. 106, 104904 (2009)] published Fri Nov 20, 2009.
Design and Usability of a Home Telerehabilitation System to Train Hand Recovery Following Stroke
William K. Durfee, Samantha A. Weinstein, Ela Bhatt, Ashima Nagpal, and James R. Carey
Current theories of stroke rehabilitation point toward paradigms of intense concentrated use of the afflicted limb as a means for motor program reorganization and partial function restoration. A home-based system for stroke rehabilitation that trains recovery of hand function by a treatment of conce ... [J. Med. Devices 3, 041003 (2009)] published Thu Nov 19, 2009.
A Sensorized Instrument for Skills Assessment and Training in Minimally Invasive Surgery
A. L. Trejos, R. V. Patel, M. D. Naish, A. C. Lyle, and C. M. Schlachta
Minimally invasive surgery (MIS) is carried out using long, narrow instruments and significantly reduces trauma to the body, postoperative pain, and recovery time. Unfortunately, the restricted access conditions, limited instrument motion, and degraded sense of touch inherent in MIS result in new pe ... [J. Med. Devices 3, 041002 (2009)] published Thu Nov 19, 2009.
Degradation of Staphylococcus aureus bacteria by neutral oxygen atoms
U. Cvelbar, M. Mozetic, N. Hauptman, and M. Klanjsek-Gunde
The degradation of Staphylococcus aureus bacteria during treatment with neutral oxygen atoms was monitored by scanning electron microscopy. Experiments were performed in an afterglow chamber made from borosilicate glass. The source of oxygen atoms was remote inductively coupled radiofrequency oxygen ... [J. Appl. Phys. 106, 103303 (2009)] published Thu Nov 19, 2009.
Response of a Hodgkin-Huxley neuron to a high-frequency input
L. S. Borkowski
We study the response of a Hodgkin-Huxley neuron stimulated by a periodic sequence of conductance pulses arriving through the synapse in the high-frequency regime. In addition to the usual excitation threshold there is a smooth crossover from the firing to the silent regime for increasing pulse ampl ... [Phys. Rev. E 80, 051914 (2009)] published Thu Nov 19, 2009.
All-atom ab initio native structure prediction of a mixed fold (1FME): A comparison of structural and folding characteristics of various betabetaalpha miniproteins
Eunae Kim, Soonmin Jang, and Youngshang Pak
We performed an all-atom ab initio native structure prediction of 1FME, which is one of the computationally challenging mixed fold betabetaalpha miniproteins, by combining a novel conformational search algorithm (multiplexed Q-replica exchange molecular dynamics scheme) with a well-balanced all-atom ... [J. Chem. Phys. 131, 195102 (2009)] published Thu Nov 19, 2009.
Unpinning of a spiral wave anchored around a circular obstacle by an external wave train: Common aspects of a chemical reaction and cardiomyocyte tissue
Masanobu Tanaka, Akihiro Isomura, Marcel Horning, Hiroyuki Kitahata, Konstantin Agladze et al.
It is well known that spiral waves are often stabilized by anchoring to a local heterogeneity (pinning) and that such pinned waves are rather difficult to eliminate. In the present report, we show that pinned spiral waves can be eliminated through collision with a wave train arriving from the outer ... [Chaos 19, 043114 (2009)] published Thu Nov 19, 2009.
Hard x-ray phase contrast imaging of black lipid membranes
A. Beerlink, M. Mell, M. Tolkiehn, and T. Salditt
We report hard x-ray phase contrast imaging of black lipid membranes, freely suspended over a micromachined aperture in an aqueous solution. Biomolecular and organic substances can thus be probed in hydrated environments by parallel beam propagation imaging, using coherent multi-kilo-electronvolt x- ... [Appl. Phys. Lett. 95, 203703 (2009)] published Thu Nov 19, 2009.
Nonlinear optical effects during femtosecond photodisruption
Milan P. Poudel and Jinhai Chen
Several nonlinear effects (i.e., continuum generation, self-focusing, and material damage) were studied during femtosecond photodisruption. Numerical aperture dependence of white-light continuum generation and material damage were determined and a relation between the two effects was shown. We showe ... [Opt. Eng. 48, 114302 (2009)] published Thu Nov 19, 2009.
Carbon nanotube pillar structures for human neural cell culture
Jin Woo Lee, Kyong Soo Lee, Byeong Kwon Ju, Hyun Jin Cho, Nae Sung Lee et al.
Human neuroblastoma cells were cultured and differentiated over patterned (dot, dash, and square pattern) pillar structures of multiwalled carbon nanotubes vertically grown on a SiO film-coated quartz substrate to observe cytoskeletal responses to the nanotube-based scaffold, especially filopodia ac ... [J. Vac. Sci. Technol. B 27, 2444 (2009)] published Thu Nov 19, 2009.
Protein patterning on the micro- and nanoscale by thermal nanoimprint lithography on a new functionalized copolymer
S. Merino, A. Retolaza, V. Trabadelo, A. Cruz, P. Heredia et al.
The localized depositions such as DNA or proteins at the micron or submicron scale on solids supports are a crucial step in the fabrication of advanced biochips and laboratory on chip devices. The present work shows a new approach: A new biofunctionalized copolymer based on 80% benzyl methacrylate a ... [J. Vac. Sci. Technol. B 27, 2439 (2009)] published Thu Nov 19, 2009.
Analysis of bacterial chemotactic response using dynamic laser speckle
Silvia E. Murialdo, Gonzalo H. Sendra, Lucia I. Passoni, Ricardo Arizaga, J. Froilan Gonzalez et al.
Chemotaxis has a meaningful role in several fields, such as microbial physiology, medicine and biotechnology. We present a new application of dynamic laser speckle (or biospeckle) to detect different degrees of bacterial motility during chemotactic response experiments. Encouraging results showed di ... [J. Biomed. Opt. 14, 064015 (2009)] published Thu Nov 19, 2009.
Drug and light dose responses to focal photodynamic therapy of single blood vessels in vivo
Mamta Khurana, Eduardo H. Moriyama, Adrian Mariampillai, Kimberley Samkoe, David Cramb et al.
As part of an ongoing program to develop two-photon (2-gamma) photodynamic therapy (PDT) for treatment of wet-form age-related macular degeneration (AMD) and other vascular pathologies, we have evaluated the reciprocity of drug-light doses in focal-PDT. We targeted individual arteries in a murine wi ... [J. Biomed. Opt. 14, 064006 (2009)] published Thu Nov 19, 2009.
Dynamical Origin of the Effective Storage Capacity in the Brain's Working Memory
Christian Bick and Mikhail I. Rabinovich
The capacity of working memory (WM), a short-term buffer for information in the brain, is limited. We suggest a model for sequential WM that is based upon winnerless competition amongst representations of available informational items. Analytical results for the underlying mathematical model relate ... [Phys. Rev. Lett. 103, 218101 (2009)] published Thu Nov 19, 2009.
Development and evaluation of an ultrasound-guided tracking and gating system for hepatic radiotherapy
Ferenc Jacso, Alexei Kouznetsov, and Wendy L. Smith
Statistical physics of cerebral embolization leading to stroke
J. P. Hague and E. M. L. Chung
We discuss the physics of embolic stroke using a minimal model of emboli moving through the cerebral arteries. Our model of the blood flow network consists of a bifurcating tree into which we introduce particles (emboli) that halt flow on reaching a node of similar size. Flow is weighted away from b ... [Phys. Rev. E 80, 051912 (2009)] published Wed Nov 18, 2009.
Enhanced low-Reynolds-number propulsion in heterogeneous viscous environments
A. M. Leshansky
It has been known for some time that some microorganisms can swim faster in high-viscosity gel-forming polymer solutions. These gel-like media come to mimic highly viscous heterogeneous environment that these microorganisms encounter in-vivo. The qualitative explanation of this phenomena first offer ... [Phys. Rev. E 80, 051911 (2009)] published Wed Nov 18, 2009.
Arterial wall tethering as a distant boundary condition
S. Hodis and M. Zamir
A standing difficulty in the problem of blood vessel tethering has been that only one of the two required boundary conditions can be fully specified, namely, that at the inner (endothelial) wall surface. The other, at the outer layer of the vessel wall, is not known except in the limiting case where ... [Phys. Rev. E 80, 051913 (2009)] published Wed Nov 18, 2009.
Development and fertility studies on post-bio-electrosprayed Drosophila melanogaster embryos
Pascal Joly, Barbara H. Jennings, and Suwan N. Jayasinghe
Bio-electrosprays (BESs) provide a means of precisely manipulating cells and thus have the potential for many clinical uses such as the generation of artificial tissues/organs. Previously we tested the biological safety of this technology with a variety of living cells and also embryos from the vert ... [Biomicrofluidics 3, 044107 (2009)] published Wed Nov 18, 2009.
Accelerated adhesion of grafted skin by laser-induced stress wavebased gene transfer of hepatocyte growth factor
Kazuya Aizawa, Shunichi Sato, Mitsuhiro Terakawa, Daizoh Saitoh, Hitoshi Tsuda et al.
Gene therapy using wound healingassociated growth factor gene has received much attention as a new strategy for improving the outcome of tissue transplantation. We delivered plasmid DNA coding for human hepatocyte growth factor (hHGF) to rat free skin grafts by the use of laser-induced stress waves ... [J. Biomed. Opt. 14, 064043 (2009)] published Wed Nov 18, 2009.
Real-time intraoperative fluorescence imaging system using light-absorption correction
George Themelis, Jung Sun Yoo, Kwang-Sup Soh, Ralf Schulz, and Vasilis Ntziachristos
We present a novel fluorescence imaging system developed for real-time interventional imaging applications. The system implements a correction scheme that improves the accuracy of epi-illumination fluorescence images for light intensity variation in tissues. The implementation is based on the use of ... [J. Biomed. Opt. 14, 064012 (2009)] published Wed Nov 18, 2009.
Whole-body three-dimensional optoacoustic tomography system for small animals
Hans-Peter Brecht, Richard Su, Matthew Fronheiser, Sergey A. Ermilov, Andre Conjusteau et al.
We develop a system for three-dimensional whole-body optoacoustic tomography of small animals for applications in preclinical research. The tomographic images are obtained while the objects of study (phantoms or mice) are rotated within a sphere outlined by a concave arc-shaped array of 64 piezocomp ... [J. Biomed. Opt. 14, 064007 (2009)] published Wed Nov 18, 2009.
Simulation of large x-ray fields using independently measured source and geometry details
D. Sawkey and B. A. Faddegon
Scale and Boundary Conditions Effects on the Apparent Elastic Moduli of Trabecular Bone Modeled as a Periodic Cellular Solid
Congyu Wang, Liang Feng, and Iwona Jasiuk
We study apparent elastic moduli of trabecular bone, which is represented, for simplicity, by a two- or three-dimensional periodic cellular network. The term apparent refers to the case when the region used in calculations (or specimen size) is smaller than a representative volume element and the mo ... [J. Biomech. Eng. 131, 121008 (2009)] published Tue Nov 17, 2009.
Tomographic elastography of contracting skeletal muscles from their natural vibrations
Karim G. Sabra and Akibi Archer
Conventional elastography techniques require an external mechanical or radiation excitation to measure noninvasively the viscoelastic properties of skeletal muscles and thus monitor human motor functions. We developed instead a passive elastography technique using only an array of skin-mounted accel ... [Appl. Phys. Lett. 95, 203701 (2009)] published Mon Nov 16, 2009.
The transition state transit time of WW domain folding is controlled by energy landscape roughness
Feng Liu, Marcelo Nakaema, and Martin Gruebele
Protein folding barriers can be so low that a substantial protein population diffusing in the transition state region can be detected. The very fast kinetic phase contributed by transition state transit is the molecular phase. We detect the molecular phase of the beta-sheet protein FiP35 from 60 to ... [J. Chem. Phys. 131, 195101 (2009)] published Mon Nov 16, 2009.
Detection of protein secondary structures via the discrete wavelet transform
Jesus Pando, Luke Sands, and Sean E. Shaheen
We subject the primary sequence of proteins gathered from the Structural Classification of Proteins (SCOP) database to a discrete wavelet transform (DWT) analysis to search for predictors of secondary structures. We use proteins with both alpha helices and beta sheets (the A/B, A+B databases from SC ... [Phys. Rev. E 80, 051909 (2009)] published Mon Nov 16, 2009.
Growing heterogeneous tumors in silico
Jana Gevertz and S. Torquato
An in silico tool that can be utilized in the clinic to predict neoplastic progression and propose individualized treatment strategies is the holy grail of computational tumor modeling. Building such a tool requires the development and successful integration of a number of biophysical and mathematic ... [Phys. Rev. E 80, 051910 (2009)] published Mon Nov 16, 2009.
Cascade optical chromatography for sample fractionation
Alex Terray, Joseph D. Taylor, and Sean J. Hart
Optical chromatography involves the elegant combination of opposing optical and fluid drag forces on colloidal samples within microfluidic environments to both measure analytical differences and fractionate injected samples. Particles that encounter the focused laser beam are trapped axially along t ... [Biomicrofluidics 3, 044106 (2009)] published Mon Nov 16, 2009.
Magnetic Resonance Imaging with a Dielectric Lens. (arXiv:0911.4116v1 [physics.med-ph])
ePrint arXiv http://arXiv.org/
A wireless lingual feedback device to reduce overpressures in seated posture: a feasibility study. (arXiv:0911.3961v1 [physics.med-ph])
ePrint arXiv http://arXiv.org/