In Vivo Detection of Gold Nanoshells in Tumors Using Diffuse Optical Spectroscopy

This study demonstrates the use of diffuse optical spectroscopy (DOS) for the noninvasive measurement of gold nanoshell concentrations in tumors of live mice. We measured the diffuse optical spectra (500-800 nm) using an optical fiber probe placed in contact with the tissue surface. We performed in vitro studies on tissue phantoms illustrating an accurate measurement of gold-silica nanoshell concentration within 12.6% of the known concentration. In vivo studies were performed on a mouse xenograft tumor model. DOS spectra were measured at preinjection, immediately postinjection, 1 and 24 h postinjection times, and the nanoshell concentrations were verified using neutron activation analysis.     

In Vivo Cell Tracking With Video Rate Multimodality Laser Scanning Microscopy

Studies of biological processes, such as disease progression and response to therapy, call for live imaging methods that allow continuous observation without terminating the study subject for histological tissue processing. Among all current imaging modalities, optical microscopy is the only method capable of probing live tissue with cellular and subcellular resolution. We present a video-rate (30 frames/s), multimodality imaging system that is designed specifically for live animal imaging and cell tracking. In vivo depth-sectioned, high-resolution images are obtained using confocal and nonlinear optical techniques that extract structural, functional, and molecular information by combining multiple contrast mechanisms, including back scattering, fluorescence (from single- and two-photon excitation), second harmonic generation, and coherent anti-Stokes Raman scattering. Simultaneous use of up to three modalities is possible and eliminates the need for coregistration, especially on large-scale images. A real-time movement correction algorithm was developed to extend integration times in cases where the image needs to be stabilized against subject movement. Finally, imaging of fast moving leukocytes in blood vessels is made possible with a modification that permits operation at 120 frames/s over a smaller area. Sample imagery obtained in vivo with the microscope is presented to illustrate the capabilities.     

Recognition of 2006 Transactions and Magazine Papers Reviewers

Lists, by department and committee, the reviewers who contributed to the IEEE Transactions on Industry Applications and the IEEE Industry Applications Magazine in 2006.     

Recognition of 2007 Transactions and Magazine Papers Reviewers

Lists the reviewers who contributed to the IEEE Transactions on Industry Applications and the IEEE Industry Applications Magazine for 2007.     

A Silicon Central Pattern Generator Controls Locomotion in Vivo

We present a neuromorphic silicon chip that emulates the activity of the biological spinal central pattern generator (CPG) and creates locomotor patterns to support walking. The chip implements ten integrate-and-fire silicon neurons and 190 programmable digital-to-analog converters that act as synapses. This architecture allows for each neuron to make synaptic connections to any of the other neurons as well as to any of eight external input signals and one tonic bias input. The chip's functionality is confirmed by a series of experiments in which it controls the motor output of a paralyzed animal in real-time and enables it to walk along a three-meter platform. The walking is controlled under closed-loop conditions with the aide of sensory feedback that is recorded from the animal's legs and fed into the silicon CPG. Although we and others have previously described biomimetic silicon locomotor control systems for robots, this is the first demonstration of a neuromorphic device that can replace some functions of the central nervous system in vivo.      

Optical Diffuse Imaging of an Ex Vivo Model Cancerous Human Breast Using Independent Component Analysis

Optical imaging using independent component analysis (OPTICA) has been used for detection, 3D localization, and cross-section imaging of a tumor inside a model human breast composed of ex vivo human breast tissues. OPTICA uses a multisource target illumination and multidetector signal acquisition scheme to obtain multiple spatial and angular views of the sample for target localization. Independent component analysis of the perturbations in the spatial light intensity distribution measured on the sample boundary sorts out the signal originating from individual targets. A back-projection technique estimates the cross-section of each target. The approach correctly provided the positions of a tumor located at the mid-plane and two glandular structures located at different positions within the 33-mm thick model breast. The reconstructed cross-section images are in good agreement with known dimensions of the structures, and pathological findings.     

Identification and Imaging of the Nerves Responsible for Erectile Function in Rat Prostate, In Vivo, Using Optical Nerve Stimulation and Optical Coherence Tomography

The cavernous nerves on the prostate surface are responsible for erectile function. Optical diagnostic tools such as optical coherence tomography and laser nerve stimulation may assist in the identification, imaging, and preservation of these microscopic nerves during prostate cancer surgery, and thus, help preserve sexual function after surgery. The feasibility of noncontact laser stimulation of the cavernous nerves is demonstrated in an in vivo rat prostate model with comparison to conventional electrical nerve stimulation. High-resolution optical coherence tomographic images of the nerves are also obtained and compared with histology. These optical technologies may be suitable as surgical guidance tools during laparoscopic and robotic nerve-sparing prostate cancer surgery.     

Brain–Silicon Interface for High-Resolution in vitro Neural Recording

A 256-channel integrated interface for simultaneous recording of distributed neural activity from acute brain slices is presented. An array of 16 times 16 Au recording electrodes are fabricated directly on the die. Each channel implements differential voltage acquisition, amplification and band-pass filtering. In-channel analog memory stores an electronic image of neural activity. A 3 mm times 4.5 mm integrated prototype fabricated in a 0.35-mum CMOS technology is experimentally validated in single-channel extracellular in vitro recordings from the hippocampus of mice and in multichannel simultaneous recordings in a controlled environment     

Inactivation of Escherichia Coli by a Coaxial Microwave Plasma Flow

An atmospheric low-temperature plasma flow generated by a microwave discharge utilizing a coaxial cable for microwave transmission was utilized for the inactivation of a bacteria. The employed device consists of a cavity, a quartz discharge tube, a coaxial cable, a microwave power source, and a gas supply system. Using this argon plasma source, we attempted to clarify the effects of exposure temperature, exposure time, exposure distance, input power, and gas flow rate on the number of surviving cells of Escherichia coli. A log reduction number of E. coli of at least 2 (10^-2) was obtained at an exposure temperature of 353 K when the exposure time was 600 s with a gas flow rate of 5 Sl/min and an input power of 400 W. The number of surviving cells decreased with an increase of exposure time under any sterilization condition.     

Light Supports Neurite Outgrowth of Human Neural Progenitor Cells In Vitro: The Role of P2Y Receptors

The purpose of this study was to compare the effects of growth factors and 810-nm-wavelength light on the differentiation of normal human neural progenitor cells (NHNPCs) in vitro. Although growth factors are routinely used to study neural stem and progenitor cells in vitro, to date, light has not been used as a replacement for growth factors. This study demonstrates that NHNPCs are not only capable of being sustained by light in the absence of growth factors, but that they are also able to differentiate normally as assessed by neurite formation. The NHNPCs had an up-regulation in the expression of endogenous fibroblast growth factor-2, brain derived neurotrophic factor, and nerve growth factor in response to the light. Suramin, a nonselective P2 receptor antagonist, significantly decreased neurite outgrowth, and P2Y2 and P2Y11 receptors were found to be expressed by the NHNPCs by immunolabeling. Based on these findings, the mechanism by which light supports the NHNPC differentiation is hypothesized to be due to increases in adenosine triphosphate acting via P2Y receptors.     

Local Density Estimation and Dynamic Transmission-Range Assignment in Vehicular Ad Hoc Networks

Vehicular ad hoc networks have several characteristics that distinguish them from other ad hoc networks. Among those is the rapid change in topology due to traffic jams, which also disturbs the homogeneous distribution of vehicles on the road. For this reason, a dynamic transmission range is more effective in maintaining the connectivity while minimizing the adverse effects of a high transmission power. This paper proposes a scheme that allows vehicles to estimate the local density and distinguish between the free-flow and the congested traffic phases. The density estimate is used to develop a dynamic transmission-range-assignment (DTRA) algorithm that sets a vehicle transmission range dynamically according to the local traffic conditions. Simulations of several road configurations validate the quality of the local density estimation and show that the DTRA algorithm is successful in maintaining the connectivity in highly dynamic networks.     

A Quantitative Study of Endurance Characteristics and Its Temperature Dependance of Embedded Flash Memories With 2T-FNFN nor Device Architecture

A quantitative study on the endurance of an embedded Flash memory with 2T-FNFN device architecture in a 0.13-mum technology node has been presented in this paper. Physical insights of 2T-FNFN device degradation have been obtained through stressing and characterizing large parallel arrays of flash transistors (with floating gate connected). Experiments are carried out on large random accessible arrays based on the 2T-FNFN cells, at a wide temperature range and with different program/erase (P/E) voltages. An empirical model has been developed to describe the temperature-dependent degradation of the program window. This model fits the experimental data over the whole temperature range, and the endurance performance with single-shot P/E cycles exceeds 1 million cycles. This paper provides a method for flash endurance characterization and modeling.