Vagus nerve stimulation (VNS) has been shown to improve left ventricular function and survival in rats with acute myocardial infarction (AMI), and this maneuver has also been adopted clinically for the treatment of patients with chronic heart failure (CHF). Recent in vitro and in vivo studies have suggested that VNS can modulate the level of pro-inflammatory factors. Despite the beneficial effects of VNS, the stimulation parameters for obtaining favorable outcomes appear highly variable. To optimize VNS parameters, we set up different stimulation protocols with different pulse width (1–2 ms), frequency (1–6 Hz), voltage (1–6 V) and duration (40–240 min) of VNS by uniform design (UD). Rats were divided into seven groups with (Group1–Group6) or without VNS (MI group). Our results demonstrate that (1) the parameter sets in Group1, Group2 and Group3 yield the best post-MI protection by VNS, while the protective role were not observed in Group4, Group5 and Group6; (2) baroreflex sensitivity and the α7 nicotinic acetylcholine receptor level were also increased in Group1, Group2 and Group3. (3) the parameter set in Group1 (G1:1 ms, 2 Hz, 3 V, 240 min) is judged the most optimal parameter in this study as rats in this group not only showed a reduced myocardial injury with better-preserved cardiac function compared with other groups, more important, but also exhibited minimal heart rate (HR) reduction. (4) the duration of VNS plays an important role in determining the protection effect of VNS. In conclusion, VNS displays a beneficial role in Group1, Group2 and Group3. Of note, the parameter set in Group1 provides the most optimal cardioprotective effect. These results may provide insight into development of novel treatment for ischemic heart diseases.
Continuous through-porous pure aluminum flat pipes were prepared continuously by a self-developed depoling continuous casting technology. An online measurement and control of mold temperature at free end of graphite core rods was realized, which was critical for the preparation. The quality of flat pipes was characterized. The results show that the flat pipes could be successfully prepared with the following process parameters: melt with temperature of 750 °C, cooling water with temperature of 20 °C and flow volume of 400 L·h-1, heat insulating mattress with thickness of 2 mm, mold temperature ranged from 635°C to 655°C and continuous casting speed ranged from 1 mm∙min-1 to 4 mm∙min-1. The flat pipe had cross-section dimensions of 14 mm×5 mm, which was aligned unidirectional pore diameter of 3 mm, pore number of 3 and smooth internal and external surface. The pore surfaces of flat pipes became smoother with the reduction of the graphite core rod surface roughness. When the surface roughness of graphite core rods was 0.531 μm and 0.124 μm, the corresponding surface roughness of pores was 0.581 μm and 0.184 μm, respectively. The mold temperature at the free end of graphite core rods was kept at a low thermal temperature range which was 5~25 °C lower than the solidification point of pure aluminum that is necessary for stable depoling continuous casting.
Establish the inventory transportation integrated optimization model which is under the best period, and compared with the model of inventory transportation integrated optimization which does not consider best period and compared the model of traditional inventory and the model of transportation optimization. It makes supply chain of lower cost, simple and practical. We can see it from the example.
Digital cameras have been widely used in the areas of road transportation, railway transportation as well as security system. To address the position of digital camera in these fields this paper proposed a geometry calibration method based on feature point extraction of arbitrary target. Under the meaning of the questions, this paper first defines four kinds of coordinate system, that is the world coordinate system. The camera's optical center of the coordinate system is the camera coordinate system, using the same point in different coordinate system of the coordinate transformation to determine the relationship between world coordinate system and camera coordinate. And thus determine the camera's internal parameters and external parameters, available transformation matrix and translation vector indicated by the camera's internal parameters of the external parameters and the establishment of a single camera location model. According to the model, using the camera's external parameters to be on the target circle center point in the image plane coordinates.
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