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Azin Shayganfar Maryam Moradi Roshanak Moshiri Alireza Khosravi Shadi Ebrahimian 《Current problems in diagnostic radiology》2021,50(3):328-331
PurposeRenal Resistive Index (RRI) is a newly introduced sonographic index in predicting contrast-induced nephropathy (CIN) development. It has been suggested that RRI > 0.69 should be considered as a risk factor for CIN development. The present study aimed to calculate the predictive value of RRI using a cutoff point of 0.69.MethodsA total of 90 patients who were a candidate for coronary vessels angiography were enrolled in this study. Color Doppler ultrasonography was performed and RRI was measured. Patients were followed up for 48 hours after contrast media exposure for the CIN development. The diagnosis of CIN was based on a 25% relative rise or 0.5 mg/dL absolute rise in creatinine level. The predictive values of RRI were measured using 0.69 as a cutoff point.ResultsOut of 90 patients, CIN developed in 3 patients and 17 patients had preprocedural RRI > 0.69. Of 3 patients with CIN, 1 had RRI > 0.69. Using 0.69 as the cutoff point, the measured sensitivity and specificity of RRI were 33.3% and 83.9%, respectively.ConclusionsRRI > 0.69 is not a sensitive index in predicting the CIN development and cannot be used as an independent factor. 相似文献
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Linda Broer Veryan Codd Dale R Nyholt Joris Deelen Massimo Mangino Gonneke Willemsen Eva Albrecht Najaf Amin Marian Beekman Eco J C de Geus Anjali Henders Christopher P Nelson Claire J Steves Margie J Wright Anton J M de Craen Aaron Isaacs Mary Matthews Alireza Moayyeri Grant W Montgomery Ben A Oostra Jacqueline M Vink Tim D Spector P Eline Slagboom Nicholas G Martin Nilesh J Samani Cornelia M van Duijn Dorret I Boomsma 《European journal of human genetics : EJHG》2013,21(10):1163-1168
Telomere length (TL) has been associated with aging and mortality, but individual differences are also influenced by genetic factors, with previous studies reporting heritability estimates ranging from 34 to 82%. Here we investigate the heritability, mode of inheritance and the influence of parental age at birth on TL in six large, independent cohort studies with a total of 19 713 participants. The meta-analysis estimate of TL heritability was 0.70 (95% CI 0.64–0.76) and is based on a pattern of results that is highly similar for twins and other family members. We observed a stronger mother–offspring (r=0.42; P-value=3.60 × 10−61) than father–offspring correlation (r=0.33; P-value=7.01 × 10−5), and a significant positive association with paternal age at offspring birth (β=0.005; P-value=7.01 × 10−5). Interestingly, a significant and quite substantial correlation in TL between spouses (r=0.25; P-value=2.82 × 10−30) was seen, which appeared stronger in older spouse pairs (mean age ≥55 years; r=0.31; P-value=4.27 × 10−23) than in younger pairs (mean age<55 years; r=0.20; P-value=3.24 × 10−10). In summary, we find a high and very consistent heritability estimate for TL, evidence for a maternal inheritance component and a positive association with paternal age. 相似文献
74.
Salar Sajedi Alireza Kamal Asl Mohammad R. Ay Mohammad H. Farahani Arman Rahmim 《Medical engineering & physics》2013,35(6):754-764
Applications in imaging and spectroscopy rely on pulse processing methods for appropriate data generation. Often, the particular method utilized does not highly impact data quality, whereas in some scenarios, such as in the presence of high count rates or high frequency pulses, this issue merits extra consideration. In the present study, a new approach for pulse processing in nuclear medicine imaging and spectroscopy is introduced and evaluated. The new non-linear recursive filter (NLRF) performs nonlinear processing of the input signal and extracts the main pulse characteristics, having the powerful ability to recover pulses that would ordinarily result in pulse pile-up. The filter design defines sampling frequencies lower than the Nyquist frequency.In the literature, for systems involving NaI(Tl) detectors and photomultiplier tubes (PMTs), with a signal bandwidth considered as 15 MHz, the sampling frequency should be at least 30 MHz (the Nyquist rate), whereas in the present work, a sampling rate of 3.3 MHz was shown to yield very promising results. This was obtained by exploiting the known shape feature instead of utilizing a general sampling algorithm. The simulation and experimental results show that the proposed filter enhances count rates in spectroscopy. With this filter, the system behaves almost identically as a general pulse detection system with a dead time considerably reduced to the new sampling time (300 ns). Furthermore, because of its unique feature for determining exact event times, the method could prove very useful in time-of-flight PET imaging. 相似文献
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Chen Vincent Barker Alex J. Golan Rotem Scott Michael B. Huh Hyungkyu Wei Qiao Sojoudi Alireza Markl Michael 《The international journal of cardiovascular imaging》2021,37(12):3539-3547
The International Journal of Cardiovascular Imaging - Deep learning algorithms for left ventricle (LV) segmentation are prone to bias towards the training dataset. This study assesses sex- and... 相似文献
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In this paper, a new approach for fixed‐structure H2 controller design in terms of solutions to a set of linear matrix inequalities are given. Both discrete‐time and continuous‐time SISO time‐invariant systems are considered. Then the results are extended to systems with polytopic uncertainty. The presented methods are based on an inner convex approximation of the non‐convex set of fixed‐structure H2 controllers. The designed procedures are initialized either with a stable polynomial or with a stabilizing controller. An iterative procedure for robust controller design is given that converges to a suboptimal solution. The monotonic decreasing of the upper bound on the H2 norm is established theoretically for both nominal and robust controller design. Copyright © 2014 John Wiley & Sons, Ltd. 相似文献
80.
Alireza Tavassoli Reza Bagheri Behzad Feizzadeh Fatemeh Tavassoli Neusha Barekati 《The Indian journal of surgery》2015,77(2):245-247
Port site hernias are one of the most serious complications associated with laparoscopic surgery. In this study, we present a simple and reliable method for port site closure in laparoscopic surgery. From 2005 to 2011, 500 patients who underwent laparoscopic surgery were enrolled for the study. They were evaluated considering age, sex, indication of laparoscopic surgery, and early and late complications of port site and were followed up at least for 1 year after the surgery. In our study, 180 males and 320 females with mean age of 36 years were enrolled. The most common indication for laparoscopic surgery was cholecystectomy in 320 patients (64 %). There were no early or late complications of port site after surgery. Our method is a new modification of the procedure presented by Spalding. Using Allis forceps and putting it under the fascia seems to be a more suitable technique which facilitates the laparoscopic port repair. We found it to be extremely safe, simple, and easy to teach. 相似文献