9 research outputs found

    The tangent conoids family which depends on the ruled surface

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    In this study, a new congruence [A**] has been defined by putting a tangent right conoid on each line of a ruled surface (A1(s))(A_1(s)) of a line congruence [A]. Then, by considering special case of the congruence [A**] which has been defined in the previous part, the concepts of tangent congruence, drall and the relation among Blaschke vectors of Blaschke trihedrons, having common line A0A_0, has been examined for this special case. At the end of this study, the concept of tangent congruence for some special congruences has been examined

    On the closed motions and closed space-like ruled surfaces

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    The theorems about closed motion in Euclidean space is given in [2] and [3]. In this paper, using the real Steiner rotation and translation vectors, we have given some theorems about the real pitch and the real angle of pitch which are the integral invariants of the closed space-like ruled surfaces. Taking a space-like line x in Frenet trihedron {t,n,b}, the real angle of pitch of space-like ruled surface, which is drawn by the space- like line x, is calculated by the .real angle of pitchs of space-like ruled surfaces those are drawn by the space-like lines t and b. Then, we give some theorems about dral and harmonic curvature in R13R_1^3 .The theorems about closed motion in Euclidean space is given in [2] and [3]. In this paper, using the real Steiner rotation and translation vectors, we have given some theorems about the real pitch and the real angle of pitch which are the integral invariants of the closed space-like ruled surfaces. Taking a space-like line x in Frenet trihedron {t,n,b}, the real angle of pitch of space-like ruled surface, which is drawn by the space- like line x, is calculated by the .real angle of pitchs of space-like ruled surfaces those are drawn by the space-like lines t and b. Then, we give some theorems about dral and harmonic curvature in R13R_1^3

    Early propranolol treatment ameliorates endothelial dysfunction in experimental septic lung

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    PubMedID: 29969202Background. Recent reports have indicated an improved prognosis in sepsis with beta blocker agents; however, the underlying action mechanism is still under debate. Objectives. The aim of this study was to investigate the potential effect of propranolol on endothelial dysfunction in septic rats. Material and methods. The cecal ligation and puncture model (CLP) was used to generate sepsis. Adult male Wistar-Albino rats were divided into 4 groups: group 1 was a sham group, group 2 received sterile saline, group 3 received 10 mg/kg of propranolol 3 days before the intervention, and group 4 received 10 mg/kg of propranolol 30 min after CLP. Six rats from each group were sacrificed 24 h postoperatively. The remaining rats were followed for survival. We have also evaluated the effects on systemic inflammation, coagulation and the lung tissue with immunohistochemical and electron microscopic evaluation. Results. Serum tumor necrosis factor alpha (TNF-?) and plasminogen activator inhibitor-1 (PAI-1) levels, as well as tissue TNF-? scores were elevated in septic rats. Electron microscopic examination of the lung tissue showed endothelial dysfunction in the sepsis group. Pretreatment significantly improved survival. Moreover, pre-treatment altered serum vascular endothelial growth factor receptor-1 (VEGFR-1) levels and post-treatment reduced serum PAI-1 and VEGFR-1 levels. In both the pre- and post-treatment groups, electron microscopic examination revealed improvement of the destroyed lung endothelium and showed only mild alterations in the cytoplasmic organelles, especially in the mitochondria of the endothelial cells. Conclusions. These results suggest that the improved outcome with beta blockers in sepsis may be due to the ameliorated endothelial dysfunction. Further studies focusing on the potential effect of beta blockers on the endothelium may lead to a better understanding of sepsis. © 2019 by Wroclaw Medical University
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