Надежность стержневых конструкций мостов (ферм)

Rationale: The chemokine CXCL12 (CXC motif ligand 12) and its receptor CXCR 4 (CXC motif receptor 4) direct the recruitment of smooth muscle progenitor cells (SPCs) in neointima formation after vascular injury. Lysophosphatidic acid (LPA) induces CXCL12 and neointimal accumulation of smooth muscle cells (SMCs) in uninjured arteries. Thus, we hypothesize that LPA may regulate CXCL12-mediated vascular remodelling. Objectives: We evaluated the role of LPA receptors in initiating CXCL12-dependent vascular repair by SPCs. Methods and Results: Wire-induced carotid injury was performed in apolipoprotein E(-/-) mice on western-type diet. LPA receptor expression was studied by immunostaining and quantitative RT-PCR. LPA receptors LPA(1) and LPA(3) were detected in the media of uninjured arteries and in the injury-induced neointima. LPA(3) mRNA was upregulated and LPA(1) mRNA downregulated at one week after injury. The LPA(1/3) antagonist Ki16425 inhibited neointima formation by 71% and reduced both relative neointimal SMCs and the macrophage content. Additionally, neointimal hypoxia-inducible factor-1 alpha and CXCL12 expression, the injury-induced peripheral stem cell antigen-1 (Sca-1)(+)/Lin(-) SPC mobilization, and the neointimal recruitment of Sca-1(+)SMCs were inhibited by Ki16425. In wild type mice, LPA20:4 increased CXCL12 and hypoxia-inducible factor-1 alpha expression in carotid arteries as early as 1 day following short-term endoluminal incubation. LPA20: 4-induced SPC mobilization and neointima formation were blocked by Ki16425, LPA(1)- and LPA(3)-specific small interfering (si) RNA, and the CXCR4 antagonist POL5551. Ki16425 reduced LPA20: 4-mediated neointimal recruitment of SPC as demonstrated by 2-photon microscopy in bone marrow chimeric mice after repopulation with SM22-LacZ transgenic, hematopoietic cells. Moreover, POL5551 decreased the neointimal accumulation of CXCR4(+) SMCs. Conclusions: LPA(1) and LPA(3) promote neointima formation through activation of CXCL12-mediated mobilization and recruitment of SPCs. (Circ Res. 2010; 107: 96-105.

Анализ современных методов диагностики магистральных нефтепроводов в условиях Западно-Сибирского региона

В работе проведен анализ внутритрубного диагностирования трубопроводов специализированным снарядом-дефектоскопом UT Piglet. Рассмотрен основной процесс проведения работ по диагностике данным снарядом, представлены аналитические данные диагностирования напорного нефтепровода, приведены расчеты проведенные согласно ОСТ 153-39.4-010-2002. Так же приведена расчетная модель и алгоритм определения остаточного ресурса трубопровода в условиях периодических изменений напряжений и коррозии.In the work, an analysis of the in-pipe diagnostics of pipelines by a specialized UT Piglet flaw detector was carried out. The main process of diagnostics work with this projectile is considered, analytical data of pressure pipeline diagnostics are presented, calculations are carried out according to OST 153-39.4-010-2002. The calculation model and the algorithm for determining the remaining life of the pipeline under conditions of periodic changes in stress and corrosion are also given

Lysophosphatidic acid receptors LPA1 and LPA3 promote CXCL12-mediated smooth muscle progenitor cell recruitment in neointima formation

2013 IEEE Intelligent Vehicles Symposium (IV) on 23-26 June, Gold Coast City, AustraliaThe original publication is available at http://ieeexplore.ieee.org/xpl/mostRecentIssue.jsp?punumber=6601112Efficient medium access in Vehicular Ad-hoc NETworks (VANETs) remains a significant challenge. Two types of Media Access Control (MAC) approaches have been proposed, namely contention-based and contention-free. We propose a novel MAC approach called Discretized RAndom Medium Access (DRAMA) for VANET. DRAMA is based on a contentionfree MAC, but unlike existing contention-free approaches, it is neighbor-agnostic. We evaluate the effect on performance of taking away all forms of channel coordination, thereby essentially removing neighbor awareness from an existing MAC approach. The evaluation is performed in terms of packet delivery ratio, receiver throughput, and end-to-end latency. We also present a performance evaluation of DRAMA and compare it to the IEEE 802.11p standard for various traffic scenarios. The results show that removing awareness from a MAC has a similar effect on performance to reducing awareness, in terms of number of hops used. Our performance results demonstrate performance improvements of 48%, 130%, and 73% over IEEE 802.11p in terms of packet delivery ratio, receiver throughput, and end-to-end latency, respectively.Post-prin