Two of the most important prognostic indicators for breast cancer are tumor size and extent of axillary lymph node involvement. Data on 24,740 cases recorded in the Surveillance, Epidemiology, and End Results (SEER) Program of the National Cancer Institute were used to evaluate the breast cancer survival experience in a representative sample of women from the United States. Actuarial (life table) methods were used to investigate the 5-year relative survival rates in cases with known operative/pathologic axillary lymph node status and primary tumor diameter. Survival rates varied from 45.5% for tumor diameters equal to or greater than 5 cm with positive axillary nodes to 96.3% for tumors less than 2 cm and with no involved nodes. The relation between tumor size and lymph node status was investigated in detail. Tumor diameter and lymph node status were found to act as independent but additive prognostic indicators. As tumor size increased, survival decreased regardless of lymph node status; and as lymph node involvement increased, survival status also decreased regardless of tumor size. A linear relation was found between tumor diameter and the percent of cases with positive lymph node involvement. The results of our analyses suggest that disease progression to distant sites does not occur exclusively via the axillary lymph nodes, but rather that lymph node status serves as an indicator of the tumor's ability to spread.

Relation of tumor size, lymph node status, and survival in 24,740 breast cancer cases

http://ieeexplore.ieee.org/iel5/5/31047/01444179.pdf

Fundamentals of acoustics

Modeling wave propagation in damped waveguides of arbitrary cross-section

Nanoparticle-based contrast agents are quickly becoming valuable and potentially transformative tools for enhancing medical diagnostics for a wide range of in-vivo imaging modalities. Compared with conventional molecular-scale contrast agents, nanoparticles (NPs) promise improved abilities for in-vivo detection and potentially enhanced targeting efficiencies through longer engineered circulation times, designed clearance pathways, and multimeric binding capacities. However, NP contrast agents are not without issues. Difficulties in minimizing batch-to-batch variations and problems with identifying and characterizing key physicochemical properties that define the in-vivo fate and transport of NPs are significant barriers to the introduction of new NP materials as clinical contrast agents. This manuscript reviews the development and application of nanoparticles and their future potential to advance current and emerging clinical bioimaging techniques. A focus is placed on the application of solid, phase-separated materials, for example metals and metal oxides, and their specific application as contrast agents for in-vivo near-infrared fluorescence (NIRF) imaging, magnetic resonance imaging (MRI), positron emission tomography (PET), computed tomography (CT), ultrasound (US), and photoacoustic imaging (PAI). Clinical and preclinical applications of NPs are identified for a broad spectrum of imaging applications, with commentaries on the future promise of these materials. Emerging technologies, for example multifunctional and theranostic NPs, and their potential for clinical advances are also discussed.

https://static.springer.com/sgw/documents/1346325/application/pdf/Nanoparticles%20as%20contrast%20agents.pdf

Nanoparticles as contrast agents for in-vivo bioimaging: current status and future perspectives

流体力学用語集 非線形音響学(Nonlinear acoustics)

We report here on the development of an ultrasound-based particle image velocimetry (PIV) system for measurement of multiple velocity components in opaque flows. The method takes advantage of the non-linear backscatter characteristics of small (1-5 /spl mu/) gas-filled microbubbles used as markers of flow trajectories. PIV algorithms, modified for use with ultrasound data, are applied to calculate the local velocity vector. Preliminary data from in vitro and in vivo studies are presented. The method should be useful for a variety of fluid diagnostics applications where optical access (as is required for conventional PIV techniques) is not available. This includes biomedical imaging and MEMS micro-fluidic applications.

An ultrasound based method for measuring multiple velocity components in opaque macro and micro flows

Ultrasonic non-destructive evaluation (NDE) techniques are widely used for structural health monitoring of concrete/FRP structures. In this study, experimental and processing schemes of surface acoustic waves (SAW) are described for assessing concrete/CFRP specimens subjected to accelerated aging conditions. Ultrasonic waves are generated and received at one side using narrow-band transducers of 110 kHz center frequency. The received signals are filtered and amplified then digitized and processed to extract various parameters in both time and frequency domains. These parameters include ultrasound propagation speed, maximum amplitude, total power, and the slope at maximum power spectrum. Changes in these parameters due to water immersion aging at different temperatures were monitored over 10 weeks. Results indicated a notable decrease in measured ultrasonic parameters over time, particularly after the first 2 weeks. This may indicate a debonding or deterioration in the concrete/FRP samples. This behavior showed good agreement with the findings of a parallel destructive study on Mode-II fracture loading of CFRP-concrete samples, tested to obtain fracture energy and define traction-separation response under temperature and water-immersion aging effects.

Ultrasonic Evaluation of CFRP-Concrete Interface for Specimens under Temperature and Water-Immersion Aging Effects

The number of supporting dental implants is an important criterion for the surgical
outcome of dental bridge fixation, which has considerable impact on biomechanical load transfer
characteristics. Excessive stress at the bone–implant interface by masticatory loading may result in
implant failure. The aim of this study was to evaluate the impact of the number of implants
supporting the dental bridge on stress in neighboring tissues around the implants. Results of the
study will provide useful information on appropriate surgical techniques for dental bridge fixation.
In this study, osseointegrated smooth cylindrical dental implants of same diameter and length were
numerically analyzed, using three-dimensional bone–implant models. The effect of the number of
supporting implants on biomechanical stability of dental bridge was examined, using two, three and
four supporting implants. All materials were assumed to be linearly elastic and isotropic.
Masticatory load was applied in coron-apical direction on the external part of dental bridge. Finite
Element (FE) analyses were run to solve for von Mises stress. Maximum von Mises stresses were
located in the cervical line of cortical bone around dental implants. Peak von Mises stress values
decreased with an increase in the number of implants that support the dental bridge. Results of this
study demonstrate the importance of using the correct number of supporting implants to for dental
bridge fixation.

Numerical Evaluation of Biomechanical Stresses in Dental Bridges Supported by Dental Implants

This study investigates the feasibility of using high-resolution ultrasound imaging echogenicity to quantitatively diagnose gingival inflammation. Gingival samples were extracted from the study par...

Osama M. Mukdadi

Papers

An ultrasound based method for measuring multiple velocity components in opaque macro and micro flows

Ultrasonic Evaluation of CFRP-Concrete Interface for Specimens under Temperature and Water-Immersion Aging Effects

Numerical Evaluation of Biomechanical Stresses in Dental Bridges Supported by Dental Implants

Quantitative assessment of gingival inflammation using high-resolution ultrasound ex-vivo

Resonance frequencies of piezoelectric plates surrounded by solid and fluid half-spaces