Biomedical Engineering and Bioengineering Commons^™

Reviewing The American University Law Review On Extraterritoriality: A Critical Response To Viki Economides, Note, Tianrui Group Co. V. Itc: The Dubious Status Of Extraterritoriality And The Domestic Industry Requirement Requirement Of Section 337(Link), Jonathan R. K. Stroud

Jonathan R. K. Stroud

Recently, the Federal Circuit upheld the Commission’s decision to exclude goods based on a trade secret violation that largely happened abroad. The American University Law Review critiqued that decision on two grounds: First, that a presumption against extraterritorial application of U.S. law applied; and second, that licensing alone could not establish a domestic industry. The American University Law Review's critique remains incomplete, however, as the Federal Circuit correctly decided the case for at least two reasons. first, the Federal Circuit correctly applied the “extraterritorial presumption” canon of construction; and second, the recent Federal Circuit decision in InterDigital Communications LLC v. …

Comparison Of Phenolic Compounds And Antioxidant Capacities Of Traditional Sorghum Beers With Other Alcoholic Beverages, Fatouma Abdoul-Latif, Romaric G. Bayili, Louis C. Obame, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Thirty samples of sorghum beers “dolo” were selected from traditionally fermented household manufacturers from Burkina Faso. Dolo samples were screened for their total phenolic content, proanthocyanidins and putative antioxidant capacities, and were compared with industrial beers and wines. Total phenols were measured using the Folin-Ciocalteu method. Proanthocyanidins content were determined by the method of HCl-butanol hydrolysis. Antioxidant activities were evaluated both with 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and by the trolox equivalent antioxidant capacity (TEAC) using 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid radical) (ABTS•+). The average contents of total phenols and proanthocyanidins were 506 μg GAE/ml of dolo and 45 μg APE/ml of dolo, respectively. An …

تمرين سري اول, Dr Alireza Zolfaghari

Dr Alireza Zolfaghari

No abstract provided.

Perfusion Improves Tissue Architecture Of Engineered Cardiac Muscle, Rebecca L. Carrier, Maria Rupnick, Robert Langer, Frederick J. Schoen, Lisa E. Freed, Gordana Vunjak-Novakovic

Rebecca L. Carrier

Cardiac muscle with a certain threshold thickness, uniformity of tissue architecture, and functionality would expand the therapeutic options currently available to patients with congenital or acquired cardiac defects. Cardiac constructs cultured in well-mixed medium had an approximately 100-μm-thick peripheral tissue-like region around a relatively cell-free interior, a structure consistent with the presence of concentration gradients within the tissue. We hypothesized that direct perfusion of cultured constructs can reduce diffusional distances for mass transport, improve control of oxygen, pH, nutrients and metabolites in the cell microenvironment, and thereby increase the thickness and spatial uniformity of engineered cardiac muscle. To test this …

Toxicity Assessment And Analgesic Activity Investigation Of Aqueous Acetone Extracts Of Sida Acuta Burn F. And Sida Cordifolia L. (Malvaceae), Medicinal Plants Of Burkina Faso, Kiessoum Konate, Adama Hilou, Raïssa Rr Aworet-Samseny, Alain Souza, Nicolas Barro, Mamoudou H. Dicko Prof., Jacques Datté, Bertrand M’Batchi

Pr. Mamoudou H. DICKO, PhD

Background Sida acuta Burn f. and Sida cordifolia L. (Malvaceae) are traditionally used in Burkina Faso to treat several ailments, mainly pains, including abdominal infections and associated diseases. Despite the extensive use of these plants in traditional health care, literature provides little information regarding their toxicity and the pharmacology. This work was therefore designed to investigate the toxicological effects of aqueous acetone extracts of Sida acuta Burn f. and Sida cordifolia L. Furthermore, their analgesic capacity was assessed, in order to assess the efficiency of the traditional use of these two medicinal plants from Burkina Faso. Method For acute toxicity …

Antibacterial Activity Against Beta- Lactamase Producing Methicillin And Ampicillin-Resistants Staphylococcus Aureus: Fractional Inhibitory Concentration Index (Fici) Determination, Kiessoun K Onate, Jacques François Mavoungou, Alexis Nicaise Lepengué, Raïssa Rr Aworet-Samseny, Adama Hilou, Mamoudou H. Dicko Prof., Bertrand M’Batchi

Pr. Mamoudou H. DICKO, PhD

The present study reports the antibacterial capacity of alkaloid compounds in combination with Methicillin and Ampicillin-resistants bacteria isolated from clinical samples. The resistance of different bacteria strains to the current antibacterial agents, their toxicity and the cost of the treatment have led to the development of natural products against the bacteria resistant infections when applied in combination with conventional antimicrobial drugs. The antibacterial assays in this study were performed by using inhibition zone diameters, MIC, MBC methods, the time-kill assay and the Fractional Inhibitory Concentration Index (FICI) determination. On the whole, fifteen Gram-positive bacterial strains (MRSA/ARSA) were used. Negative control …

Computational Analysis Of High Throughput Flow Cytometry Data, Joseph P. Robinson

Joseph P Robinson

Introduction (significance of area discussed) –Flow cytometry has been around for over 40 years, but only recently has the opportunity arisen to move into the high-throughput domain. The technology is now available and is highly competitive with imaging tools under the right conditions.

Areas Covered (research discussed and literature review) The historical perspective of flow cytometry operation is discussed as well as how the field has changed and what the key changes have been. The authors provide a solid background as well as compelling arguments for moving toward HT flow, where there are many innovative opportunities. These opportunities show strong …

Energy And Climate Implications For Agricultural Nutrient Use Efficiency, Adam J. Liska, Richard K. Perrin

Richard K Perrin

Energy and climate change are beginning to dominate the global political agenda and will drive policy formation that will shape the future of agriculture. Energy issues threaten national security and economic stability, as well as access to low-cost nutrient inputs for agriculture. Climate change has the potential to cause serious disruption to agricultural productivity. Paradoxically, nutrient use in agriculture to increase crop yields has the potential to negatively impact climate. This chapter will discuss recent and future energy and climate trends, the relationships between agricultural nutrient use efficiency and biofuels, and how global land limitations will shape agriculture in the …

Robust Dynamic Balance Of Ap-1 Transcription Factors In A Neuronal Gene Regulatory Network., Gregory M Miller, Babatunde A Ogunnaike, James S Schwaber, Rajanikanth Vadigepalli

Rajanikanth Vadigepalli

BACKGROUND: The octapeptide Angiotensin II is a key hormone that acts via its receptor AT1R in the brainstem to modulate the blood pressure control circuits and thus plays a central role in the cardiac and respiratory homeostasis. This modulation occurs via activation of a complex network of signaling proteins and transcription factors, leading to changes in levels of key genes and proteins. AT1R initiated activity in the nucleus tractus solitarius (NTS), which regulates blood pressure, has been the subject of extensive molecular analysis. But the adaptive network interactions in the NTS response to AT1R, plausibly related to the development of …

Controlling Dimensionality In A Systems Approach To Dynamic Multimodal Functional Brain Imaging, Srinivas Laxminarayan, Manu Ben Jonny, Solomon Diamond, Dana Brooks, Gilead Tadmore, Eric Miller, David Boas

Dana Brooks

The complementary spatial, temporal and specificity advantages of MRI, EEG, MEG, PET and DOT for functional brain imaging motivate interest in multimodal functional brain imaging. State-variable dynamical systems modeling of neural activity and its relation to local hemodynamics further coupled with autonomic physiology offers enhanced spatiotemporal resolution and insight into physiological signals and mechanisms. However, such a model also implies an explosion of state dimension. We discuss strategies for controlling this high dimensionality based on subspace approaches applied to the observed data and the model structure, and also describe some implications for understanding human brain function.

Hemodynamically Constrained Dynamic Diffuse Optical Tomography Under Mammographic Compression, Eleonora Vidolova, Dana H. Brooks, Eric L. Miller, Stefan Carp, David A. Boas

Dana Brooks

This poster considers these points: DOT taken along x-ray mammogram provide valuable functional information, X-ray mammography only gives structural information hard to distinguish between benign and malignant masses, Oxygen consumption (OC) and blood flow (F) contrasts observed between malignant and normal tissue[3, 4], Blood flow, oxygen saturation(SO2), water and lipid distributions could specify the degree of malignancy of a tumor, Physiological changes in the breast due to mammographic compression are significant and should be taken into account[2].

Matlab-Based Finite Difference Frequency-Domain Method For Microwave Breast Imaging, Qiuzhao Dong, Carey Rappaport

Carey Rappaport

The FDFD electromagnetic model computes wave scattering by directly discretizing 's equations along with specifying the material characteristics in the scattering volume. No boundary conditions are need except for the outer grid termination absorbing boundary. We use a sparse matrix Matlab code with loose generalized minimum residue (LGMRES) Krylov subspace iterative method to solve the large sparse matrix equation, along with the Perfectly Matched Layer (PML) absorbing boundary condition. The PML conductivity profile employs the empirical optimal value from[1-2]. This method is easily manipulated and general-geometry oriented, it is fast comparing to other models for solving the whole 3D computational …

Fdtd Simulation Of A Confocal Microscope Using A Theta Line Scan, Blair Simon, Charles Dimarzio, Milind Rajadhyaksha, Carey Rappaport

Carey Rappaport

We describe a 2-D computational model of the optical propagation in human skin from a confocal reflectance theta microscope. As an effect of decreasing the size of the microscope so that it is more clinically useful, the usual point source and detector with a raster scan is changed to a line source with a 1-D array detector. Because there is only one dimension of scanning, the microscope is confocal in one direction, but not in the other, however, this results in additional localized decreases in signal. We hypothesize that these result from the interaction of the bi-static imaging configuration with …

Field Programmable Gate Arrays To Accelerate Sub-Surface Imaging Problems, Miriam Leeser

Miriam Leeser

No abstract provided.

Fdtd Simulation Of A Confocal Microscope Using A Theta Line Scan, Blair Simon, Charles Dimarzio, Milind Rajadhyaksha, Carey Rappaport

Charles A. DiMarzio

We describe a 2-D computational model of the optical propagation in human skin from a confocal reflectance theta microscope. As an effect of decreasing the size of the microscope so that it is more clinically useful, the usual point source and detector with a raster scan is changed to a line source with a 1-D array detector. Because there is only one dimension of scanning, the microscope is confocal in one direction, but not in the other, however, this results in additional localized decreases in signal. We hypothesize that these result from the interaction of the bi-static imaging configuration with …

Compact Dual Wedge Point Scanning Confocal Reflectance Microscope, William C. Warger Ii, Stephen A. Guerrera, Charles A. Dimarzio

Charles A. DiMarzio

Confocal reflectance microscopy has been shown to provide optical sectioning and resolution sufficient to provide useful information about skin to a depth below the epidermis. However, existing instruments are large and expensive, because of the need for fast twodimensional scanning in the pupil, and the associated relay optics. A more compact scanning system could lead to an affordable hand-held instrument for in vivo imaging. Several approaches are being considered with different advantages and disadvantages. Here we report one approach that incorporates a dual-wedge scanner within a point-scanning configuration. The dual-wedge scanner is implemented by replacing the two scanning mirrors and …

Nonlinear Inverse Scattering And Three-Dimensional Near-Field Optical Imaging, George Y. Panasyuk, Vadim A. Markel, P. Scott Carney, John C. Schotland

Vadim A. Markel

The nonlinear inverse scattering problem for electromagnetic fields with evanescent components is considered. A solution to this problem is obtained in the form of a functional series expansion. The first term in the expansion corresponds to the pseudoinverse solution to the linearized inverse problem. The higher order terms represent nonlinear corrections to this result. Applications to the problem of three-dimensional optical imaging with subwavelength resolution are described and illustrated with numerical simulations.

Spectroscopic Studies Of Fractal Aggregates Of Silver Nanospheres Undergoing Local Restructuring, Sergei V. Karpov, Valeriy S. Gerasimov, Ivan L. Isaev, Vadim A. Markel

Vadim A. Markel

We present an experimental spectroscopic study of large random colloidal aggregates of silver nanoparticles undergoing local restructuring. We argue that such well-known phenomena as strong fluctuation of local electromagnetic fields, appearance of “hot spots” and enhancement of nonlinear optical responses depend on the local structure on the scales of several nanosphere diameters, rather than the large-scale fractal geometry of the sample.

Can The Imaginary Part Of Permeability Be Negative?, Vadim A. Markel

Vadim A. Markel

When new composite optical materials are developed experimentally or studied in numerical simulations, it is essential to have a set of fundamental constraints that the optical constants of such materials must satisfy. In this paper I argue that positivity of the imaginary part of the magnetic permeability may not be one of such constraints, particularly in naturally occurring diamagnetics and in artificial materials that exhibit diamagnetic response to low-frequency or static magnetic fields.

Single-Scattering Optical Tomography: Simultaneous Reconstruction Of Scattering And Absorption, Lucia Florescu, Vadim A. Markel, John C. Schotland

Vadim A. Markel

We report theory and numerical simulations that demonstrate the feasibility of simultaneous reconstruction of the three-dimensional scattering and absorption coefficients of a mesoscopic system using angularly resolved measurements of scattered light. Image reconstruction is based on the inversion of a generalized (broken ray) Radon transform relating the scattering and absorption coefficients of the medium to angularly resolved intensity measurements. Although the single-scattering approximation to the radiative transport equation (RTE) is used to devise the image reconstruction method, there is no assumption that only singly scattered light is measured. That is, no physical mechanism for separating single-scattered photons from the rest …

Propogation Of Surface Plasmons In Ordered And Disordered Chains Of Metal Nanospheres, Vadim A. Markel, Andrey K. Sarychev

Vadim A. Markel

We report a numerical investigation of surface plasmon (SP) propagation in ordered and disordered linear chains of metal nanospheres. In our simulations, SPs are excited at one end of a chain by a near-field tip. We then find numerically the SP amplitude as a function of propagation distance. Two types of SPs are discovered. The first SP, which we call the ordinary or quasistatic, is mediated by short-range, near-field electromagnetic interaction in the chain. This excitation is strongly affected by Ohmic losses in the metal and by disorder in the chain. These two effects result in spatial decay of the …

Comment On "Optical Response Of Strongly Coupled Metal Nanoparticles In Dimer Arrays", Vadim A. Markel

Vadim A. Markel

I have recalculated the extinction spectra of aggregates of two silver nanospheres shown in Figs. 2 and 3 of the paper by J. J. Xiao, J. P. Huang, and K. W. Yu #3;[Phys. Rev. B 71, 045404 #1;(2005)]#2;#4;. I have used the approximate method of images according to the formulas published in that reference and an exact numerical technique. I have found that the three sets of data #1;those I have obtained by the method of images, the numerical results, and the results published in the reference in question#2; do not coincide. In this Comment, I discuss the reasons for …

Nonlinear Inverse Scattering And Three-Dimensional Near-Field Optical Imaging, George Y. Panasyuk, Vadim A. Markel, P. Scott Carney, John C. Schotland

Vadim A. Markel

The nonlinear inverse scattering problem for electromagnetic fields with evanescent components is considered. A solution to this problem is obtained in the form of a functional series expansion. The first term in the expansion corresponds to the pseudoinverse solution to the linearized inverse problem. The higher order terms represent nonlinear corrections to this result. Applications to the problem of three-dimensional optical imaging with subwavelength resolution are described and illustrated with numerical simulations.

Can The Imaginary Part Of Permeability Be Negative?, Vadim A. Markel

Vadim A. Markel

When new composite optical materials are developed experimentally or studied in numerical simulations, it is essential to have a set of fundamental constraints that the optical constants of such materials must satisfy. In this paper I argue that positivity of the imaginary part of the magnetic permeability may not be one of such constraints, particularly in naturally occurring diamagnetics and in artificial materials that exhibit diamagnetic response to low-frequency or static magnetic fields.

Nonlinear Inverse Scattering And Three-Dimensional Near-Field Optical Imaging, George Y. Panasyuk, Vadim A. Markel, P. Scott Carney, John C. Schotland

Vadim A. Markel

The nonlinear inverse scattering problem for electromagnetic fields with evanescent components is considered. A solution to this problem is obtained in the form of a functional series expansion. The first term in the expansion corresponds to the pseudoinverse solution to the linearized inverse problem. The higher order terms represent nonlinear corrections to this result. Applications to the problem of three-dimensional optical imaging with subwavelength resolution are described and illustrated with numerical simulations.

Spectroscopic Studies Of Fractal Aggregates Of Silver Nanospheres Undergoing Local Restructuring, Sergei V. Karpov, Valeriy S. Gerasimov, Ivan L. Isaev, Vadim A. Markel

Vadim A. Markel

We present an experimental spectroscopic study of large random colloidal aggregates of silver nanoparticles undergoing local restructuring. We argue that such well-known phenomena as strong fluctuation of local electromagnetic fields, appearance of “hot spots” and enhancement of nonlinear optical responses depend on the local structure on the scales of several nanosphere diameters, rather than the large-scale fractal geometry of the sample.

Can The Imaginary Part Of Permeability Be Negative?, Vadim A. Markel

Vadim A. Markel

When new composite optical materials are developed experimentally or studied in numerical simulations, it is essential to have a set of fundamental constraints that the optical constants of such materials must satisfy. In this paper I argue that positivity of the imaginary part of the magnetic permeability may not be one of such constraints, particularly in naturally occurring diamagnetics and in artificial materials that exhibit diamagnetic response to low-frequency or static magnetic fields.

Single-Scattering Optical Tomography: Simultaneous Reconstruction Of Scattering And Absorption, Lucia Florescu, Vadim A. Markel, John C. Schotland

Vadim A. Markel

We report theory and numerical simulations that demonstrate the feasibility of simultaneous reconstruction of the three-dimensional scattering and absorption coefficients of a mesoscopic system using angularly resolved measurements of scattered light. Image reconstruction is based on the inversion of a generalized (broken ray) Radon transform relating the scattering and absorption coefficients of the medium to angularly resolved intensity measurements. Although the single-scattering approximation to the radiative transport equation (RTE) is used to devise the image reconstruction method, there is no assumption that only singly scattered light is measured. That is, no physical mechanism for separating single-scattered photons from the rest …

Propogation Of Surface Plasmons In Ordered And Disordered Chains Of Metal Nanospheres, Vadim A. Markel, Andrey K. Sarychev

Vadim A. Markel

We report a numerical investigation of surface plasmon (SP) propagation in ordered and disordered linear chains of metal nanospheres. In our simulations, SPs are excited at one end of a chain by a near-field tip. We then find numerically the SP amplitude as a function of propagation distance. Two types of SPs are discovered. The first SP, which we call the ordinary or quasistatic, is mediated by short-range, near-field electromagnetic interaction in the chain. This excitation is strongly affected by Ohmic losses in the metal and by disorder in the chain. These two effects result in spatial decay of the …

Comment On "Optical Response Of Strongly Coupled Metal Nanoparticles In Dimer Arrays", Vadim A. Markel

Vadim A. Markel

I have recalculated the extinction spectra of aggregates of two silver nanospheres shown in Figs. 2 and 3 of the paper by J. J. Xiao, J. P. Huang, and K. W. Yu #3;[Phys. Rev. B 71, 045404 #1;(2005)]#2;#4;. I have used the approximate method of images according to the formulas published in that reference and an exact numerical technique. I have found that the three sets of data #1;those I have obtained by the method of images, the numerical results, and the results published in the reference in question#2; do not coincide. In this Comment, I discuss the reasons …