Frequency and severity of myocardial perfusion abnormalities using Tc-99m MIBI SPECT in cardiac syndrome X

BACKGROUND: Cardiac syndrome X is defined by a typical angina pectoris with normal or near normal (stenosis <40%) coronary angiogram with or without electrocardiogram (ECG) change or atypical angina pectoris with normal or near normal coronary angiogram plus a positive none-invasive test (exercise tolerance test or myocardial perfusion scan) with or without ECG change. Studies with myocardial perfusion imaging on this syndrome have indicated some abnormal perfusion scan. We evaluated the role of myocardial perfusion imaging (MPI) and also the severity and extent of perfusion abnormality using Tc-99m MIBI Single Photon Emission Computed Tomography (SPECT) in these patients. METHODS: The study group consisted of 36 patients with cardiac syndrome X. The semiquantitative perfusion analysis was performed using exercise Tc-99m MIBI SPECT. The MPI results were analyzed by the number, location and severity of perfusion defects. RESULTS: Abnormal perfusion defects were detected in 13 (36.10%) cases, while the remaining 23 (63.90%) had normal cardiac imaging. Five of 13 (38.4%) abnormal studies showed multiple perfusion defects. The defects were localized in the apex in 3, apical segments in 4, midventricular segments in 12 and basal segments in 6 cases. Fourteen (56%) of all abnormal segments revealed mild, 7(28%) moderate and 4 (16%) severe reduction of tracer uptake. No fixed defects were identified. The vessel territories were approximately the same in all subjects. The Exercise treadmill test (ETT) was positive in 25(69%) and negative in 11(30%) patients. There was no consistent pattern as related to the extent of MPI defects or exercise test results. CONCLUSION: Our study suggests that multiple perfusion abnormalities with different levels of severity are common in cardiac syndrome X, with more than 30 % of these patients having at least one abnormal perfusion segment. Our findings suggest that in these patients microvascular angina is probably more common than is generally believed

A numerical investigation of γ-Al2O3-water nanofluids heat transfer and pressure drop in a shell and tube heat exchanger

The effect of γ-Al2O3 nanoparticles on heat transfer rate, baffle spacing and pressure drop in the shell side of small shell and tube heat exchangers was investigated numerically under turbulent regime. γ-Al2O3-water nanofluids and pure water were used in the shell side and the tube side of heat exchangers, respectively. Since the properties of γ-Al2O3-water nanofluids were variable, they were defined using the user define function. The results revealed that heat transfer and pressure drop were increased with mass flow rate as well as baffle numbers. Adding nanoparticles to the based fluid did not have a significant effect on pressure drop in the shell side. The best heat transfer performance of heat exchangers was for γ-Al2O3-water 1 vol.% and higher nanoparticles concentration was not suitable. The suitable baffle spacing was 43.4% of the shell diameter, showing a good agreement with Bell-Delaware method

Intracranial hemorrhage in normotensive and hypertensive patients receiving streptokinase after decreasing elevated blood pressure

Background: Many patients with suspected acute myocardial infarction (AMI) and eligible for thrombolytic therapy may not be treated because of association between hemorrhagic complications especially intracranial hemorrhage (ICH), and severe hypertension (HTN) at presentation. Unfortunately, this leads to under use or delay in thrombolytic therapy. We assessed effect of decreasing elevated blood pressure before thrombolytic therapy in order to reduce the incidence of ICH without increasing mortality rate.&#13; Methods: This observational and analytical cohort study enrolled 293 patients (215males and 78 female) with STsegment elevation (AMI) that were hospitalized in emergency department of Noor hospital, Isfahan, Iran. Severe hypertension (blood pressure ≥180/110mmHg) was diagnosed in 132 patients. All of them received 1.5 million units streptokinase within one hour intravenously. In the hypertensive group, elevated blood pressure was lowered to less than180/110mmhg before thrombolysis and they were observed to detect development of symptomatic ICH and they underwent Brain CT scan, if required.&#13; Results: The incidence of total stroke, ICH and death were 1.4%, 0.7% and 4.8%, respectively. The incidence of death and ICH in patients with severe hypertension was less than control group (P value=0.13 and 0.59, respectively)&#13; Conclusion: Although we did not find any increase in ICH incidence in severe hypertensive patients treated be streptokinase due to AMI, but we recommend a multi-centric study with more cases and varied thrombolytic protocols.&#13; Key words: Acute myocardial infarction, Intracranial hemorrhage, Thrombolytic therap

A new avenue for classification and prediction of olive cultivars using supervised and unsupervised algorithms.

Various methods have been used to identify cultivares of olive trees; herein we used different bioinformatics algorithms to propose new tools to classify 10 cultivares of olive based on RAPD and ISSR genetic markers datasets generated from PCR reactions. Five RAPD markers (OPA0a21, OPD16a, OP01a1, OPD16a1 and OPA0a8) and five ISSR markers (UBC841a4, UBC868a7, UBC841a14, U12BC807a and UBC810a13) selected as the most important markers by all attribute weighting models. K-Medoids unsupervised clustering run on SVM dataset was fully able to cluster each olive cultivar to the right classes. All trees (176) induced by decision tree models generated meaningful trees and UBC841a4 attribute clearly distinguished between foreign and domestic olive cultivars with 100% accuracy. Predictive machine learning algorithms (SVM and Naïve Bayes) were also able to predict the right class of olive cultivares with 100% accuracy. For the first time, our results showed data mining techniques can be effectively used to distinguish between plant cultivares and proposed machine learning based systems in this study can predict new olive cultivars with the best possible accuracy

A robust fuzzy optimisation for a multi-objective pharmaceutical supply chain network design problem considering reliability and delivery time

© 2020 Informa UK Limited, trading as Taylor & Francis Group. Due to the emergency role of pharmaceutical supply chains, there has been rapid development of optimisation techniques as one of efficient tools to improve pharmaceutical supply chain network design. To improve the pharmaceutical supply chain network, this study proposes a novel location-allocation-inventory model as a multi-objective, multi-echelon, multi-product, multi-period and multi-modal transportation system for pharmaceutical supply chain network design under uncertainty. The proposed model aims to optimise multiple objectives, including minimising the total costs and the delivery time while maximising the transportation system reliability simultaneously. To control the impacts of uncertain parameters including the ordering, delivery, purchase, and transportation costs and the capacity of vehicles, warehouses and of distribution centres, a robust fuzzy optimisation approach is developed. An efficient modification of a state-of-the-art evolutionary algorithm called the red deer algorithm (RDA) in its multi-objective form abbreviated as IMORDA is developed and compared with itself and well-established algorithms in the literature such as non-dominated sorting genetic algorithm (NSGA-II) and multi-objective particle swarm optimisation (MOPSO). The results confirm the applicability and efficiency of the IMORDA for the proposed model and encourage further development of this new metaheuristic

Decision Tree generated from three models ran with <i>Gini Index</i> criterion.

<p>As may be inferred from the figure, UBC841A4 and UBC868A7 fragments were the most important attribute alleles in distinguishing Iranian from foreign cultivars.</p