Chitosan hydrolysis by chitosanase is one of the most effective methods to produce chitosan oligosaccharides. One of the prerequisites of enzyme fermentation production is to select and breed enzyme-producing cells with good performance. So in the process of fermentation production, the low yield of chitosanase cannot meet the current requirement. In this paper, a strain producing chitosanase was screened and identified, and a novel mutagenesis system (Atmospheric and Room Temperature Plasma (ARTP)) was selected to increase the yield of chitosanase. Then, the fermentation medium was optimized to further improve the enzyme activity of the strain. A strain of Bacillus cereus capable of producing chitosanase was screened and identified from soil samples. A mutant strain of B.cereus was obtained by Atmospheric and Room Temperature Plasma mutagenesis and bioscreening method, and chitosanase activity was 2.49 folds that of the original bacterium. After an optimized fermentation medium, the enzyme activity of the mutant strain was 1.47 folds that of the original bacterium. Combined with all the above optimization experiments, the enzyme activity of mutant strain increased by 3.66 times. The results showed that the Atmospheric and Room Temperature Plasma mutagenesis and bioscreening method could significantly increase the yield of chitosanase in B.cereus, and had little effect on the properties of the enzyme. These findings have potential applications in the mutagenesis of other enzyme-producing microorganisms.

Short-chain fatty acids (SCFAs), which are formed mainly by bacteria fermenting undigested carbohydrates in the colon, they are based on the number of carbon atoms in the carbon chain. Organic fatty acids with less than 6 carbon atoms are called short-chain fatty acids. SCFAs are closely related to various aspects of the human body, so more and more researchers concentrate on SCFAs. This protocol describes, a direct injection gas chromatography detection method with a pretreatment method for extracting SCFA from mice feces by combining acidification. The corresponding sample limit of quantization (LOQ) and limit of detection (LOD) are 0.8-1.0 mg/L and 0.5-0.8 mg/L, respectively. The correlation coefficient of calibration curve is greater than 0.999. The recovery rate of the spiked standard is 80%-102%. This method can be used to analyze and determine SCFAs in mice feces. Therefore, this is an economical, effective and reproducible method for SCFAs measurement in mice samples.

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This is an era where the rapid development of science and technology is accompanied by an aging population. The advancement of computer technology has brought new technologies to the elderly care industry, and related fields of elderly care robots have emerged as the times require. However, the operation of elderly care robots has always been a problem for older users. In view of such problems, this paper attempts to cut into the UI design of the touch screen interface of the elderly care robot. According to the characteristics of older users, aiming at their operational difficulties, and through research, new ideas and optimizations are put forward for the UI design of the existing elderly care service robot touch screen interface. So as to realize the further adaptation of product functions and older users.

In recent years, with the rapid development of artificial intelligence technology, wearable devices have gradually entered the operation stage. [1] The design focus of wearable devices has shifted from technological breakthroughs to personalization and customization in use and experience. Based on the analysis of the development status of wearable devices, this paper puts forward the modular design method of wearable devices. In this paper, React front-end interaction technology is adopted, and MVC development mode in ASP.NET [2] is adopted at the back end. Infrared spectrum sensor module hc-sr501 is used to realize information transmission, realizing a friendly graphical interactive interface. Caretakers (pet owners and linked accounts) are better connected and act as a bridge between the two.

Based on computer digital technology, the paper first uses the method of non-equal interval quantization to quantize the pixels in the 3D image, and introduces the artificial intelligence vision technology HSV colour space to construct the feature vector formula after non-equal interval quantization to calculate the difference between the two images the final distance between. Experiments have shown that the algorithm has better robustness to changes in light intensity while maintaining the lower number of quantized bins in the Tahoun algorithm. At the same time, the algorithm can effectively reduce 3D colours, with better visual effects, and better than the original. The interference of images with large differences on the search results improves the recall rate of the image library used in the experiment.

Computer network technology breaks through the limits of time and space, integrating all the information of the world into a whole. Computer network technology, as a solid guarantee for the rapid development of new media, plays a significant role in its growth. Both the progress of computer networks and the advance of new media technology are ushering in a new development opportunity, and thus the integration of the two is also a major issue at present.

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