4,296 research outputs found

    Primary results of 2-dimensional electrophoresis for protein studies of Gentiana kurroo Royle somatic embryos derived from long-term embryogenic cell suspensions

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    Two-dimensional gel electrophoresis was used to compare protein expression profiles between various stages of Gentiana kurroo Royle somatic embryos. Seven distinct stages (I–VII) were pointed out and measured from long-term embryogenic cell suspension. Isoelectric focusing was done in the pH intervals 3–10, and the second dimension was carried out with 13% SDS-polyacrylamide gel electrophoresis. Dependent on the stage from about 400 (stage IV) to more than 700 (stage II) protein spots were totally detected. The molecular weight of abundant proteins range from 12 to 70 kDa, however, majority of proteins were located between 20–49 kDa spots on the gels. The highest difference in the number of spots appeared in the case of globular embryo (stage I) and elongated cotyledonary stage (stage VII) with differences being about 130 spots. The relevance of embryogenic cell suspension choice for proteomic analysis as well as expediency of the increasing number of particular embryo stages is discussed

    Effective One-Dimensional Coupling in the Highly-Frustrated Square-Lattice Itinerant Magnet CaCo2y_{\mathrm{2}-y}As2_{2}

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    Inelastic neutron scattering measurements on the itinerant antiferromagnet (AFM) CaCo2y_{\mathrm{2}-y}As2_{2} at a temperature of 8 K reveal two orthogonal planes of scattering perpendicular to the Co square lattice in reciprocal space, demonstrating the presence of effective one-dimensional spin interactions. These results are shown to arise from near-perfect bond frustration within the J1J_1-J2J_2 Heisenberg model on a square lattice with ferromagnetic J1J_1, and hence indicate that the extensive previous experimental and theoretical study of the J1J_1-J2J_2 Heisenberg model on local-moment square spin lattices should be expanded to include itinerant spin systems

    The role of septal perforators and "myocardial bridging effect" in atherosclerotic plaque distribution in the coronary artery disease

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    The distribution of atherosclerotic plaque burden in the human coronary arteries is not uniform. Plaques are located mostly in the left anterior descending artery (LAD), then in the right coronary artery (RCA), circumflex branch (LCx) and the left main coronary artery (LM) in a decreasing order of frequency. In the LAD and LCx, plaques tend to cluster within the proximal segment, while in the RCA their distribution is more uniform. Several factors have been involved in this phenomenon, particularly flow patterns in the left and right coronary artery. Nevertheless, it does not explain the difference in lesion frequency between the LAD and the LCx as these are both parts of the left coronary artery. Branching points are considered to be the risk points of atherosclerosis. In the LCx, the number of side branches is lower than in the LAD or RCA and there are no septal perforators with intramuscular courses like in the proximal third of the LAD and the posterior descending artery (PDA). We hypothesized that septal branches generate disturbed flow in the LAD and PDA in a similar fashion to the myocardial bridge (myocardial bridging effect). This coronary architecture determines the non-uniform plaque distribution in coronary arteries and LAD predisposition to plaque formation

    Predominant location of coronary artery atherosclerosis in the left anterior descending artery. The impact of septal perforators and the myocardial bridging effect

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    INTRODUCTION: Coronary artery atherosclerosis presents characteristic patterns of plaque distribution despite systemic exposure to risk factors. We hypothesized that local hemodynamic forces induced by the systolic compression of intramuscular septal perforators could be involved in atherosclerotic processes in the left anterior descending artery (LAD) adjacent to the septal perforators' origin. Therefore we studied the spatial distribution of atherosclerosis in coronary arteries, especially in relation to the septal perforators' origin. MATERIAL AND METHODS: 64-slice computed tomography angiography was performed in 309 consecutive patients (92 male and 217 female) with a mean age of 59.9 years. Spatial plaque distribution in the LAD was analyzed in relation to the septal perforators' origin. Additionally, plaque distribution throughout the coronary artery tree is discussed. RESULTS: The coronary calcium score (CCS) was positive in 164 patients (53.1%). In subjects with a CCS > 0, calcifications were more frequent in the LAD (n = 150, 91.5%) compared with the right coronary artery (RCA) (n = 94, 57.3%), circumflex branch (CX) (n = 76, 46.3%) or the left main stem (n = 42, 25.6%) (p < 0.001). Total CCS was higher in the LAD at 46.1 (IQR: 104.2) and RCA at 34.1 (IQR: 90.7) than in the CX at 16.8 (IQR: 61.3) (p = 0.007). In patients with calcifications restricted to a single vessel (n = 54), the most frequently affected artery was the LAD (n = 42, 77.8%). In patients with lesions limited to the LAD, the plaque was located mostly (n = 37, 88.1%) adjacent to the septal perforators' origin. CONCLUSIONS: We demonstrated that coronary calcifications are most frequently located in the LAD in proximity to the septal branch origin. A possible explanation for this phenomenon could be the dynamic compression of the tunneled septal branches, which may result in disturbed blood flow in the adjacent LAD segment (milking effect)
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