The associations of residential greenness with fetal growth in utero and birth weight: A birth cohort study in Beijing, China

Background: Although studies have examined the association between residential greenness and birth weight, there is no evidence regarding the association between residential greenness and fetal growth in utero. We aimed to investigate the associations of residential greenness with both fetal growth in utero and birth weight. Methods: A birth cohort (2014–2017) with 18,665 singleton pregnancies was established in Tongzhou Maternal and Child hospital of Beijing, China. Residential greenness was matched with maternal residential address and estimated from remote satellite data using normalized difference vegetation index with 200 m and 500 m buffers (NDVI-200 and NDVI-500). Fetal parameters including estimated fetal weight (EFW), abdominal circumference (AC), head circumference (HC) an

Nonlinear Time Series Analysis of Partial Discharges in Electrical Trees of XLPE Cable Insulation Samples

This paper presents an investigation into the nonlinear dynamics characteristics of the partial discharge (PD) sequence measured during the propagation of typical electrical trees in XLPE cable insulation. Calculation of the correlation dimension and the largest Lyapunov exponent from the PD sequence is used to illustrate the nonlinear characteristics of the PD behavior in the electrical tree growth. The results provide strong evidence for the existence of deterministic chaos in the PD phenomenon of electrical trees, where the correlation dimension and the largest Lyapunov exponent are related with the PD activity of the tree growth, rather than a presence of random stochastic process. The fluctuating correlation dimension of the PD sequence during the branch-pine tree growth is associated with the transition of PD patterns and the change of the channel conductivity of the tree structure. It is also found that the nonlinear dynamics characteristics of the PD sequence are influenced by the applied voltage, the channel conductivity and the electrical tree shape. A possible mechanism is presented for the formation of different chaotic extents of typical electrical trees in XLPE cable insulation

On the Conducting and Non-conducting Electrical Trees in XLPE Cable Insulation Specimens

The conducting and non-conducting properties of electrical trees in cross-linked polyethylene (XLPE) cable insulation are studied by means of partial discharge (PD) measurement, optical microscope, confocal Raman microprobe spectroscopy and scanning electron microscopy (SEM). Specimens equipped with an embedded electrode system and constituted of a needle separated by approximately 2 mm from the counter electrode were utilized. Various types of electrical trees were produced at a range of voltage levels from 9 to 15 kV. It was found that the electrical trees grown at low voltage levels exhibited very different electrical properties from those grown at higher voltage levels. Branch-pine trees were formed at the low voltage conditions, displaying buildup of conducting main channels composed of disordered graphitic carbon deposited on the tree sidewalls. The average domain of the graphitic residues was estimated at the range of 8-8.4 nm in size, which resulted in a sufficient channel conductivity to suppress the PD activity within the main tree channels and caused growth of the pine structure. The branch trees, grown at higher voltage levels, showed typical characteristics of non-conducting trees, in which continuous discharges eroded the tree sidewalls and the observed intensity of fluorescence decreased evidently with the distance from the needle electrode to the tree tip. The bush trees at high voltage levels also showed the non-conducting characteristics. However, some carbonized residues were formed locally in them near the needle electrode, which can be connected to the long and intensive discharge activity during the tree growth

Investigation of Temperature Effect on Electrical Trees in XLPE Cable Insulation

In this paper, combined with the methods of real-time microscopic digital imaging and partial discharge (PD) continuous measurements, the effect of temperature on electrical tree propagation and PDs characteristics in XLPE cable insulation was investigated using an embedded needle electrode arrangement over a range of applied voltages from 9 to 15 kV rms. The temperature of the experiments varied from 10 C up to 70 C, which lay within the rated operating temperature range of XLPE cables. The results obtained show that temperature has dominant effect on electrical tree shapes and growth time. As the electrical tree shapes at lower voltages are influenced by the change of tree channel conductivity, this process appeared to be accelerated greatly by increase of experimental temperature. The tree growth time at higher voltages was decreased at higher temperatures due to the change of material morphology and it was accompanied by intensive PD activity

Platelets and platelet adhesion molecules: novel mechanisms of thrombosis and anti-thrombotic therapies

Abstract Platelets are central mediators of thrombosis and hemostasis. At the site of vascular injury, platelet accumulation (i.e. adhesion and aggregation) constitutes the first wave of hemostasis. Blood coagulation, initiated by the coagulation cascades, is the second wave of thrombin generation and enhance phosphatidylserine exposure, can markedly potentiate cell-based thrombin generation and enhance blood coagulation. Recently, deposition of plasma fibronectin and other proteins onto the injured vessel wall has been identified as a new “protein wave of hemostasis” that occurs prior to platelet accumulation (i.e. the classical first wave of hemostasis). These three waves of hemostasis, in the event of atherosclerotic plaque rupture, may turn pathogenic, and cause uncontrolled vessel occlusion and thrombotic disorders (e.g. heart attack and stroke). Current anti-platelet therapies have significantly reduced cardiovascular mortality, however, on-treatment thrombotic events, thrombocytopenia, and bleeding complications are still major concerns that continue to motivate innovation and drive therapeutic advances. Emerging evidence has brought platelet adhesion molecules back into the spotlight as targets for the development of novel anti-thrombotic agents. These potential antiplatelet targets mainly include the platelet receptors glycoprotein (GP) Ib-IX-V complex, β3 integrins (αIIb subunit and PSI domain of β3 subunit) and GPVI. Numerous efforts have been made aiming to balance the efficacy of inhibiting thrombosis without compromising hemostasis. This mini-review will update the mechanisms of thrombosis and the current state of antiplatelet therapies, and will focus on platelet adhesion molecules and the novel anti-thrombotic therapies that target them