Myocardial bridge

Myocardial bridging (MB) is an anatomical variant in which an epicardial coronary artery passes under a bridge of myocardium. The most commonly affected vessel is the left anterior descending coronary artery, although other branches such as the marginal branches, diagonal branches and posterior descending right coronary artery may be occasionally involved. Technological advances in radiological techniques have enabled better diagnosis of myocardial bridges especially coronary angiography and coronary computed tomographic angiography (CCTA). During a routine angiography by means of CCTA in a 60-year-old male patient with arrhythmia, a case of MB was found in two segments of the posterior interventricular artery and a small segment of the right coronary artery. Although most cases of myocardial bridges are asymptomatic, knowledge of its pathophysiology is of great clinical importance as some cases of MBs have been associated with acute coronary syndromes, ischaemia, arrhythmias and even sudden death

Unusual arterial supply of the segment IV with interlobar bridge and right replaced hepatic artery: a case report

A replaced right hepatic artery (RHA) arising from the superior mesenteric artery and an interlobar parenchymal bridge over the sagittal fissure have been observed on a 64-year-old formalin-fixed male cadaver in the anatomy laboratory. As we had followed a detailed segmental anatomy, we encountered an arterial distribution of segment IV featuring a different pattern from the literature so far. According to our observations, the segment I is supplied by both left (LHA) and middle (MHA) hepatic arteries; the segments II and III are supplied by the LHA while the segment IV is supplied by both the MHA and replaced RHA. The segments V–VIII are supplied only by the replaced RHA.  The case emphasizes the importance of arterial variations of liver in terms of the surgical procedures during the liver transplantation, hepatic resections, hepatic tumours, and etc. Our discussion focuses to the arterial supply of the segment IV and possible complications it may cause during/after the liver operations.

Sintering and mechanical properties of β‐SiC powder obtained from waste tires

Plasma synthesized SiC powder obtained from quartz and carbonaceous residue of waste tires was successfully sintered at 1925 ℃ by pressureless liquid-phase method using yttria and alumina as sintering aids (T-SiC). Comparison with sintered SiC obtained from commercial powder (C-SiC) put in evidence of similar sintered density (98%T.D.), but much finer microstructure of T-SiC than that of C-SiC. T-SiC also showed higher flexural strength than C-SiC both at room temperature (508 vs. 458 MPa) and at 1500 ℃ (280 vs. 171 MPa). Difference in liquid phase was responsible for the differences in hardness and fracture toughness. The high value of the Young's modulus of T-SiC (427 MPa) confirmed the high degree of sinterability of this powder and that it can be a promising candidate for structural applications with high added value. © 2016, The Author(s)

Comparison of Data Reduction Algorithms for Image-Based Point Cloud Derived Digital Terrain Models

Digital Terrain Model (DTM) is a digital numerical representation of the Earth's surface. DTMs have been applied to a diverse field of tasks, such as urban planning, military, glacier mapping, disaster management. In the expression of the Earth' surface as a mathematical model, an infinite number of point measurements are needed. Because of the impossibility of this case, the points at regular intervals are measured to characterize the Earth's surface and DTM of the Earth is generated. Hitherto, the classical measurement techniques and photogrammetry method have widespread use in the construction of DTM. At present, RADAR, LiDAR, and stereo satellite images are also used for the construction of DTM. In recent years, especially because of its superiorities, Airborne Light Detection and Ranging (LiDAR) has an increased use in DTM applications. A 3D point cloud is created with LiDAR technology by obtaining numerous point data. However recently, by the development in image mapping methods, the use of unmanned aerial vehicles (UAV) for photogrammetric data acquisition has increased DTM generation from image-based point cloud. The accuracy of the DTM depends on various factors such as data collection method, the distribution of elevation points, the point density, properties of the surface and interpolation methods. In this study, the random data reduction method is compared for DTMs generated from image based point cloud data. The original image based point cloud data set (100%) is reduced to a series of subsets by using random algorithm, representing the 75, 50, 25 and 5% of the original image based point cloud data set. Over the ANS campus of Afyon Kocatepe University as the test area, DTM constructed from the original image based point cloud data set is compared with DTMs interpolated from reduced data sets by Kriging interpolation method. The results show that the random data reduction method can be used to reduce the image based point cloud datasets to 50% density level while still maintaining the quality of DTM

Production of dihaploids in durum wheat using Imperata cylindrica L. mediated chromosome elimination

The possibility of obtaining dihaploid durum wheat (Triticum durum L.) plants by interspecific hybridization with Imperata cylindrica L. was studied. Ten local varieties and 1 commercial durum wheat variety (Triticum durum L., 2n = 4x = 28; AABB) were used as maternal lines. Imperata cylindrica L. (2n = 2x = 20) ecotypes sampled from different districts of Hatay were used as the pollen source. Isolated embryos were placed in an MS medium for plant regeneration 14 days after the interspecific hybridization. The highest average seed setting, embryo formation, and dihaploid plant regeneration for the different hybrid combinations were determined as 31.1%, 15.5%, and 11.5%, respectively. Cytological observations revealed that all the regenerants had 2n = 2x = 14 chromosomes. © TÜBİTAK