48 research outputs found

    Differential Expression Profile and Genetic Variants of MicroRNAs Sequences in Breast Cancer Patients

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    The technology available for cancer diagnosis and prognosis is not yet satisfactory at the molecular level, and requires further improvements. Micro RNAs (miRNAs) have been recently reported as useful biomarkers in diseases including cancer. We performed a miRNA expression profiling study using peripheral blood from breast cancer patients to detect and identify characteristic patterns. A total of 100 breast cancer patients and 89 healthy patients were recruited for miRNA genotyping and expression profiling. We found that hs-miR-196a2 in premenopausal patients, and hs-miR-499, hs-miR-146a and hs-miR-196a2 in postmenopausal patients, may discriminate breast cancer patients from healthy individuals. In addition, we found a significant association between two microRNA polymorphisms (hs-miR-196a2 and hs-miR-499) and breast cancer risk. However, no significant association between the hs-miR-146a gene and breast cancer risk was found. In summary, the study demonstrates that peripheral blood miRNAs and their expression and genotypic profiles can be developed as biomarkers for early diagnosis and prognosis of breast cancer

    Assessment of aortic stiffness by cardiovascular magnetic resonance following the treatment of severe aortic stenosis by TAVI and surgical AVR

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    Aortic stiffness is increasingly used as an independent predictor of adverse cardiovascular outcomes. We sought to compare the impact of transcatheter aortic valve implantation (TAVI) and surgical aortic valve replacement (SAVR) upon aortic vascular function using cardiovascular magnetic resonance (CMR) measurements of aortic distensibility and pulse wave velocity (PWV).A 1.5 T CMR scan was performed pre-operatively and at 6 m post-intervention in 72 patients (32 TAVI, 40 SAVR; age 76 ± 8 years) with high-risk symptomatic severe aortic stenosis. Distensibility of the ascending and descending thoracic aorta and aortic pulse wave velocity were determined at both time points. TAVI and SAVR patients were comparable for gender, blood pressure and left ventricular ejection fraction. The TAVI group were older (81 ± 6.3 vs. 72.8 ± 7.0 years, p < 0.05) with a higher EuroSCORE II (5.7 ± 5.6 vs. 1.5 ± 1.0 %, p < 0.05). At 6 m, SAVR was associated with a significant decrease in distensibility of the ascending aorta (1.95 ± 1.15 vs. 1.57 ± 0.68 × 10(-3)mmHg(-1), p = 0.044) and of the descending thoracic aorta (3.05 ± 1.12 vs. 2.66 ± 1.00 × 10(-3)mmHg(-1), p = 0.018), with a significant increase in PWV (6.38 ± 4.47 vs. 11.01 ± 5.75 ms(-1), p = 0.001). Following TAVI, there was no change in distensibility of the ascending aorta (1.96 ± 1.51 vs. 1.72 ± 0.78 × 10(-3)mmHg(-1), p = 0.380), descending thoracic aorta (2.69 ± 1.79 vs. 2.21 ± 0.79 × 10(-3)mmHg(-1), p = 0.181) nor in PWV (8.69 ± 6.76 vs. 10.23 ± 7.88 ms(-1), p = 0.301) at 6 m.Treatment of symptomatic severe aortic stenosis by SAVR but not TAVI was associated with an increase in aortic stiffness at 6 months. Future work should focus on the prognostic implication of these findings to determine whether improved patient selection and outcomes can be achieved

    Bandwidth requirements for accurate detection of direct path in multipath environment

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    The accurate detection of the direct path in a dense multipath environment is critical in time-based and angle-of-arrival-based location estimation techniques. It is generally assumed that an infinitely large bandwidth is helpful in the accurate detection of the direct path and high-range resolution. It is experimentally demonstrated that, for a wideband system, a bandwidth of up to 4 GHz, centred on 12.5 GHz, is sufficient for accurate detection of direct path in a typical indoor scattering environment. Additionally, the bandwidth gain, incremental range accuracy with bandwidth, is an effective indicator of the bandwidth requirements for accurate detection of the direct path

    Effect of Bandwidth and Antenna Directivity on the Range Estimation Accuracy in a Multipath Environment

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    The accurate detection of the direct path in a dense multipath environment is vital for reliable performance of time-based and angle-of-arrival (AOA) based location estimation techniques. This paper investigates the effect of measurement bandwidth and antenna directivity on the detection of the direct path in a typical indoor scattering environment. It is experimentally shown that the ranging error diminishes with increase in measurement bandwidth and the standard deviation of the root mean square ranging error (RMSRE) is reduced by using directional transmit antennas. The results are obtained in a line-of-sight (LOS) propagation environment and are based on the time-of-arrival (TOA) based ranging technique. © 2006 IEEE

    Effect of Bandwidth and Antenna Directivity on the Range Estimation Accuracy in a Multipath Environment

    No full text
    The accurate detection of the direct path in a dense multipath environment is vital for reliable performance of time-based and angle-of-arrival (AOA) based location estimation techniques. This paper investigates the effect of measurement bandwidth and antenna directivity on the detection of the direct path in a typical indoor scattering environment. It is experimentally shown that the ranging error diminishes with increase in measurement bandwidth and the standard deviation of the root mean square ranging error (RMSRE) is reduced by using directional transmit antennas. The results are obtained in a line-of-sight (LOS) propagation environment and are based on the time-of-arrival (TOA) based ranging technique. © 2006 IEEE

    Signal error analysis of multiple antenna radars

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    In this paper, we analyse various topologies of multiple antenna systems in radars. The results are presented by means of a novel detection theoretic approach to track the detection capability of radars. The new detection approach is more tractable than conventional 'probability of detection analysis' and is based on modelling of radar target as a modulator in an analogous communication system. This method is called the analogous communication system for a radar (ACSR) and quantifies 'detection' as being inversely proportional to bit error rates (BER) of the resulting communications channel
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