Analysis on Lightning Strike Cause of Directly Buried Optical Cable in Wind Farm and Its Prevention Methods

Directly buried metal optical cable is a form of erecting optical fiber ring network communication system in wind farms. Although the directly buried optical cable is much less than the overhead optical cable affected by lightning, sometimes lightning damaging optical cable and flashover discharge accidents of optical cable port occurred. In this paper, the amplitude spectrum of lightning wave, the breakdown depth and breakdown distance of lightning wave to soil, the metal components of optical cable port and the impedance characteristics of grounding wire are systematically analyzed, and the prevention methods of directly buried optical cable in wind farm to avoid lightning damage are proposed.

Self-induced Secretion Expression of Trehalose Synthase in Bacillus subtilis WB800n

Bacillus subtilis is a non-pathogenic Gram-positive bacterium that has been widely used to produce industrially and pharmaceutically relevant proteins. Trehalose, a non reducing disaccharide used as protective agent and additive in foodstuffs and pharmaceutical products, can be prepared by trehalose synthase(TreS). The present work aims to construct a robust recombinant B. subtilis to achieve the secretory expression of TreS. In this study, the treS gene from Pseudomonas putida ATCC47054 was amplified by PCR and further cloned and expressed in B. subtilis WB800 N using pHT01 as expression vector. For avoiding the use of inducer, promoter P_(srfA) was used to replace the promoter P_(grac) in pHT01 and verify the activity of recombinant trehalose synthase. The TreS activity assay was employed to evaluate the performance of recombinant B. subtilis W800 N under different phosphate concentrations, carbon sources, carbon source concentrations, nitrogen sources and pH. The results showed that the P_(srfA) promoter had a good regulation effect under pH 8.0 condition, and the enzyme activity reached 6 000 U/L. Using the PhoD as the secretory signal peptide, TreS was effectively secreted, and the extracellular enzyme activity reached 2 100 U/L, accounting for 35% of the total enzyme activity. By optimizing the medium and fermentation conditions, the extracellular enzyme activity reached 6 900 U/L in 5 L of fermentor, and the proportion reached 48%. The pHT01-P_(srfA)-PhoD-treS secretory recombinant B. subtilis constructed in this study has great potential in trehalose synthase production.

A 3D Measurement Method Based on Coded Image

The binocular stereo vision system is often used to reconstruct 3D point clouds of an object.However,it is challenging to find effective matching points in two object images with similar color or less texture.This will lead to mismatching by using the stereo matching algorithm to calculate the disparity map.In this context,the object can’t be reconstructed precisely.As a countermeasure,this study proposes to combine the Gray code fringe projection with the binocular camera as well as to generate denser point clouds by projecting an active light source to increase the texture of the object,which greatly reduces the reconstruction error caused by the lack of texture.Due to the limitation of the camera viewing angle,a one-perspective binocular camera can only reconstruct the 2.5D model of an object.To obtain the 3D model of an object,point clouds obtained from multiple-view images are processed by coarse registration using the coarse SAC-IA algorithm and fine registration using the ICP algorithm,which is followed by voxel filtering fusion of the point cloud.To improve the reconstruction quality,a polarizer is mounted in front of the cameras to filter out the redundant reflected light.Eventually,the 3D model and the dimension of a vase are obtained after calibration.

Progress in Enzymatic Production of Trehalose

Trehalose is a non-reducing disaccharide, and widespread in nature. It is a typical stress metabolite that can protect macromolecules such as proteins in organisms under extreme conditions. Therefore, trehalose has been widely used in food, medicine and cosmetics. Trehalose is extracted from yeast or synthesized by chemical method. Due to the high cost of traditional methods, trehalose is mainly produced by enzymatic methods. There are mainly three pathways: TPS/TPP, TreY/TreZ and TreS. These enzymatic systems are expressed mainly through heterologous expression.

NLRP3-dependent pyroptosis is required for HIV-1 gp120- induced neuropathology

The human immunodeficiency virus-1(HIV-1)envelope protein gp120 is the major contributor to the pathogenesis of HIVassociated neurocognitive disorder(HAND).Neuroinflammation plays a pivotal role in gp120-induced neuropathology,but how gp120 triggers neuroinflammatory processes and subsequent neuronal death remains unknown.Here,we provide evidence that NLRP3 is required for gp120-induced neuroinflammation and neuropathy.Our results showed that gp120-induced NLRP3-dependent pyroptosis and IL-1βproduction in microglia.Inhibition of microglial NLRP3 inflammasome activation alleviated gp120-mediated neuroinflammatory factor release and neuronal injury.Importantly,we showed that chronic administration of MCC950,a novel selective NLRP3 inhibitor,to gp120 transgenic mice not only attenuated neuroinflammation and neuronal death but also promoted neuronal regeneration and restored the impaired neurocognitive function.In conclusion,our data revealed that the NLRP3 inflammasome is important for gp120-induced neuroinflammation and neuropathology and suggest that NLRP3 is a potential novel target for the treatment of HAND.