Cardiac multidetector computed tomography (MDCT) of spontaneously closed ventricular septal defect

WOS: 000266092200003PubMed ID: 19444383The authors present the findings of contrastenhanced electrocardiogram (ECG)-gated cardiac computed tomography (CT) in 18 patients with probably spontaneous closure of muscular ventricular septal defect (VSD). The study included 2,725 consecutive patients referred to our hospitals for multidetector computed tomography (MDCT) coronary angiography. The patients were between the ages of 5 and 78 [mean +/- standard deviation (SD) 59 +/- 13.86] years, and 1,816 (66.6%) were male. Evaluating the images for coronary artery pathologies revealed pouches or sacs in the central muscular location of the septa of some patients. All patient records were retrospectively reviewed, and 18 patients were found to have pouches or sacs in the interventricular septum location likely to be spontaneous closure of muscular VSD (0.66% prevalence). MDCT findings of these 18 patients correlated with their echocardiographic findings. Of the patients with muscular VSD, 13 were male and five were female. These 18 patients were initially referred due to indications such as chest pain (n=11), risk-factor assessment (n=3), coronary artery anomaly (n=1), suspected aberrant right subclavian artery due to dysphagia (n=1) and coronary artery bypass graft (n=2). Our study shows that the incidence of spontaneous closure of muscular VSD with central septum location is probably higher than expected. Thus, some patients initially diagnosed with ventricular diverticula with an apical and marginal septum location may actually have spontaneously closed muscular VSD. This finding may affect previously reported rates of both ventricular diverticula and spontaneous closure of muscular VSD

Analyzing the effects of special washing processes on characteristics of sewing threads

In recent years, wet (washing, bleaching, etc.) and dry (abrasive, laser shaping, rodeo, etc.) operations applied on fashion denim products have become an important factor to increase the added value. However, these wet and dry processes applied to the denim products may have adverse effects on the strength of the fabric and other supplementary materials of denim products. For example, thread breakages affect the repair ratios and quality of products, which causes time and profitability losses in companies. The main objective of this study is to analyse how the types of washing affect the strength of the sewing threads that are commonly used in the production of denim trousers. In this study, 100% cotton denim fabric with a weight of 11.5 ounces and two different sewing threads were used. The fabrics are sewn as trouser legs with chain and lock stitch. Five different washes were applied to the trouser legs. The obtained data were evaluated in the R statistical program. As a result of the analyses made it is proven that the washing techniques used have an effect on the sewing threads’ tensile strength and elongation at break. The tensile strengths of lock stitch and chain stitch decrease averagely 35% and elongation at break of lock stitch decreases %22 and chain stitch decreases 29.8%

Investigation of the effects of inlet system configuration on the airflow characteristics

The effort towards the development of an engine that is efficient and green has become one of the biggest efforts of the major part of the automotive industry. The contribution of air quality to the engine plays an important role to increase power while minimizing the exhaust emission. The main purpose of this article is to investigate the characteristic of the air intake system of a naturally aspirated engine on a steady flow bench. The experiment was conducted using an industrial flow bench apparatus where the pressure different test pressures can be set and, at every test pressure, the valve is lifted at an increment of 1mm until the maximum possible valve lift where the flow rate is obtained in terms of cubic foot per minute or CFM. The experiment process was then repeated at different configuration. The experimental result shows that the flow rate increases with each valve lift in a linear pattern until at a certain point where the value becomes constant. The result also indicated that the flow rate increases as the different pressure increases