Analysis of the Cross Talk Mechanism in Capacitive Micromachined Ultrasonic Transducers

Rho, Yongrae,Khuri-Yakub, Butrus T. The Acoustical Society of Korea 2001 韓國音響學會誌 Vol.20 No.e3

Finite element model of a cMUT is constructed using the commercial code ANSYS to analyze the cross talk mechanism. Calculation results of the complex load impedance seen by single capacitor cells are presented, and then followed by a calculation of the plane wave real load impedance seen by a parallel combination of many cells that are used to make a transducer. Cross talk between 1-D array elements is found to be due to two main sources: coupling through a Stoneley wave propagating at the transducer-water interface and coupling through Lamb waves propagating in the substrate. To reduce the cross talk level, the effect of various structural variations of the substrate are investigated, which include a change of its thickness and etched trenches or polymer walls between array elements.

On the size of the F-test for the one-way random model with heterogeneous error variances

Lee, Juneyoung,Khuri, André,I.,Kim, Kee Whan,Lee, Sangkon Taylor Francis 2007 JOURNAL OF STATISTICAL COMPUTATION AND SIMULATION Vol.77 No.6

<P> Traditional analysis of variance tests are based on the assumption of homogeneous error variances, which often fails in real experimental situations. Violation of this assumption affects not only the power of the standard F-test, but also its size. When a design is unbalanced, the effect of unequal error variances is even more complex. In this paper, we study the effect of heterogeneous error variances on the size of the F-test concerning the among-group variance component in an unbalanced random one-way model. We also provide a method for computing the true critical value of the F-test for a given level of significance.</P>

Financial Burden of Cancer Drug Treatment in Lebanon

Elias, Fadia,Khuri, Fadlo R,Adib, Salim M,Karam, Rita,Harb, Hilda,Awar, May,Zalloua, Pierre,Ammar, Walid Asian Pacific Journal of Cancer Prevention 2016 Asian Pacific journal of cancer prevention Vol.17 No.7

Background: The Ministry of Public Health (MOPH) in Lebanon provides cancer drugs free of charge for uninsured patients who account for more than half the total case-load. Other categories of cancer care are subsidized under more stringent eligibility criteria. MOPH's large database offers an excellent opportunity to analyze the cost of cancer treatment in Lebanon. Materials and Methods: Using utilization and spending data accumulated at MOPH during 2008-2013, the cost to the public budget of cancer drugs was assessed per case and per drug type. Results: The average annual cost of cancer drugs was 6,475$ per patient. Total cancer drug costs were highest for breast cancer, followed by chronic myeloid leukemia (CML), colorectal cancer, lung cancer, and Non-Hodgkin's lymphoma (NHL), which together represented 74% of total MOPH cancer drug expenditure. The annual average cancer drug cost per case was highest for CML ($31,037), followed by NHL ($11,566). Trastuzumab represented 26% and Imatinib 15% of total MOPH cancer drug expenditure over six years. Conclusions: Sustained increase in cancer drug cost threatens the sustainability of MOPH coverage, so crucial for socially vulnerable citizens. To enhance the bargaining position with pharmaceutical firms for drug cost containment in a small market like Lebanon, drug price comparisons with neighboring countries which have already obtained lower prices may succeed in lowering drug costs.

Comparison of designs for the three-fold nested random model

Cheol Jung, B.,Khuri, A.,Lee, J. Taylor Francis 2008 Journal of applied statistics Vol.35 No.6

Laser-Acoustic Techniques for Temperature Measurements in Semiconductor Processing

Lee, Y. J.,Yakud, B. T. Khuri,Saraswat, K. C. 대한전자공학회 1991 ICVC : International Conference on VLSI and CAD Vol.2 No.1

An acoustics-based technique for measuring temperature in a rapid thermal processing environment is investigated. A silicon wafer is placed in a rapid thermal processor with the back side facing the heating lamp. A transducer designed to provide a 170 kHz acoustic signal is placed perpendicular to the plane of the wafer. An acoustic wave launched parallel to the wafer surface is detected at two areas using two probe-beam deflection detectors. By measuring the attenuation and phase difference between the signals detected at the two points, the velocity of the acoustic wave can be accurately determined. The strong temperature dependence of the acoustic wave velocity can be exploited to obtain temperature measurements.

A Multichannel Oscillator for a Resonant Chemical Sensor System

Lee, Hyunjoo Jenny,Kwan Kyu Park,Oralkan, Omer,Kupnik, Mario,Khuri-Yakub, Butrus T. IEEE 2014 IEEE transactions on industrial electronics Vol.61 No.10

<P>Vapor detection using highly sensitive miniaturized resonant sensors is of great interest for many applications, including consumer, industrial, and environmental applications. An operational-amplifier-based multichannel oscillator that interfaces with a 50-MHz capacitive micromachined ultrasonic transducer array is presented for chemical sensing applications. The circuit was implemented in a 0.18-μm CMOS technology to reduce power consumption, number of wires, and active area per channel. The presented integrated circuit also addresses the potential-frequency-locking problem between channels by allowing the open-loop gain to be adjustable off-chip. The feasibility of the developed oscillator for the chemical sensing application is demonstrated. Two channels that were operated simultaneously achieved excellent volume sensitivities of 8.5 × 10<SUP>-4</SUP>%/Hz and 3.9 × 10<SUP>-4</SUP>%/Hz, respectively, to relative humidity in N<SUB>2</SUB>.</P>

Review : Prevention of Lung Cancer: Future Perspective with Natural Compounds

( Johann C Brandes ),( A. R. M. Ruhul Amin ),( Fadlo Khuri ),( Dong Moon Shin ) 대한결핵 및 호흡기학회 2010 Tuberculosis and Respiratory Diseases Vol.69 No.1

Lung cancer remains the most common cause of cancer death in the United States and worldwide. About 80~90% of cases are smoking-related and smoking cessation programs are of great importance in reducing lung cancer risk. However, the lifetime risk for lung cancer remains elevated even in ex-smokers. Chemoprevention holds the promise to further reduce this risk and thus to decrease lung cancer incidence and mortality. Over the last decades, most chemoprevention trials for lung cancer have yielded negative outcomes. Population-based studies suggest that high intake of certain foods such as soy, red wine or green vegetables may be associated with decreased cancer risk. Because of these observations and their general safety, a plethora of natural compounds is currently being studied for the chemoprevention of cancer. In this review we discuss promising in vitro and in vivo data of novel natural compounds, their interference with molecular mechanisms responsible for lung cancer development and potential implications for their further preclinical and clinical investigation.

Prevention of Lung Cancer: Future Perspective with Natural Compounds

Brandes, Johann C.,Amin, A.R.M. Ruhul,Khuri, Fadlo,Shin, Dong-Moon The Korean Academy of Tuberculosis and Respiratory 2010 Tuberculosis and Respiratory Diseases Vol.69 No.1

Lung cancer remains the most common cause of cancer death in the United States and worldwide. About 80~90% of cases are smoking-related and smoking cessation programs are of great importance in reducing lung cancer risk. However, the lifetime risk for lung cancer remains elevated even in ex-smokers. Chemoprevention holds the promise to further reduce this risk and thus to decrease lung cancer incidence and mortality. Over the last decades, most chemoprevention trials for lung cancer have yielded negative outcomes. Population-based studies suggest that high intake of certain foods such as soy, red wine or green vegetables may be associated with decreased cancer risk. Because of these observations and their general safety, a plethora of natural compounds is currently being studied for the chemoprevention of cancer. In this review we discuss promising in vitro and in vivo data of novel natural compounds, their interference with molecular mechanisms responsible for lung cancer development and potential implications for their further preclinical and clinical investigation.

Defining the interval for monitoring potential adverse events following immunization (AEFIs) after receipt of live viral vectored vaccines

Kochhar, Sonali,Excler, Jean-Louis,Bok, Karin,Gurwith, Marc,McNeil, Michael M.,Seligman, Stephen J.,Khuri-Bulos, Najwa,Klug, Bettina,Laderoute, Marian,Robertson, James S.,Singh, Vidisha,Chen, Robert T Elsevier Ltd. 2019 Vaccine Vol. No.

<P><B>Abstract</B></P> <P>Live viral vectors that express heterologous antigens of the target pathogen are being investigated in the development of novel vaccines against serious infectious agents like HIV and Ebola. As some live recombinant vectored vaccines may be replication-competent, a key challenge is defining the length of time for monitoring potential adverse events following immunization (AEFI) in clinical trials and epidemiologic studies. This time period must be chosen with care and based on considerations of pre-clinical and clinical trials data, biological plausibility and practical feasibility. The available options include: (1) adapting from the current relevant regulatory guidelines; (2) convening a panel of experts to review the evidence from a systematic literature search to narrow down a list of likely <I>potential or known</I> AEFI and establish the optimal risk window(s); and (3) conducting “near real-time“ prospective monitoring for <I>unknown</I> clustering’s of AEFI in validated large linked vaccine safety databases using Rapid Cycle Analysis for pre-specified adverse events of special interest (AESI) and Treescan to identify previously unsuspected outcomes. The risk window established by any of these options could be used along with (4) establishing a registry of clinically validated pre-specified AESI to include in case-control studies. Depending on the infrastructure, human resources and databases available in different countries, the appropriate option or combination of options can be determined by regulatory agencies and investigators.</P>