Search

This study aims to more accurately predict the displacement changes of landslides with nonlinear volatility development.The empirical mode decomposition is first employed to process the time series of monitoring surface displacement of a landslide,and then the irregularly changing displacement series is converted into modal components with regular changes,which generates displacement components at different frequencies.Each component is predicted separately so that the mutual influence of errors can be avoided.The comprehensive prediction of the changing trend of displacement series is based on the prediction of the changing trends of all components.The improved threshold autoregressive model able to well describe non-stationary harmonics is used to predict the landslide displacement components.Finally,the modal superposition yields the final predicted displacement.In this way,a combined prediction model based on empirical mode decomposition and threshold autoregressive model is established,and its prediction accuracy is verified with Baishuihe landslide data.Compared with a BP neural network model and a long short-term memory network model,the proposed model has a high prediction accuracy,which provides a new method for the prediction of landslide displacement.

Objective To study the anti-caries efficacy of arginine dentifrice on early childhood caries in the rural area of Chengdu city in order to explore better early intervention measures on caries.Methods Two schools in Chengdu rural area were randomly chosen. Subjects were chosen according to the inclusion and exclusion criteria. All subjects were randomly divided into 2 groups, the experimental group used toothpaste containing 1.5% arginine and 1 450 F - ppm, control group used toothpaste containing 1 450 F - ppm, a comprehensive inspection of the dental caries of the 2 groups of subjects were recorded. The results were recorded by EpiData software for data entry, using SPSS 13.0 statistical software analysis data.Results 1 years later, the prevalence, the mean decayed missing filled teeth of deciduous teeth (dmft) of the experimental group was significantly lower than the control group. The number of new dmft score (t = 1.58, P = 0.001), the new decayed missing filled teeth surfaces (dmfs) number (t = 1.16, P = 0.001), The new permanent teeth DMFT number (t = 1.02, P = 0.005), new permanent teeth decay missing filling surface number (t = 1.03, P = 0.002) in the experimental group of deciduous teeth were lower than the control group. And the difference was statistically significant.Conclusion Toothpaste containing 1.5% arginine and 1 450 F - ppm is more significant on children’s dental caries prevention effect compared with the toothpaste containing 1 450 F - ppm only.

In single-frequency precise-point positioning of a satellite, ionosphere delay is one of the most important factors impacting the accuracy. Because of the instability of the ionosphere and uncertainty of its physical properties, the positioning accuracy is seriously limited when using a precision-limited model for correction. In order to reduce the error, we propose to introduce some ionosphere parameter for real-time ionosphere-delay estimation by applying various mapping functions. Through calculation with data from the IGS (International GPS Service) tracking station and comparison among results of using several different models and mapping functions, the feasibility and effectiveness of the new method are verified.

Giardia duodenalis and Cryptosporidium spp. are common human and animal pathogens. They have increasingly been reported in dairy calves in recent years; however, multilocus genotyping information for G. duodenalis and Cryptosporidium infecting pre-weaned dairy calves in southwestern China is limited. In the present study, the prevalence of G. duodenalis and Cryptosporidium spp. in pre-weaned dairy calves in central Sichuan province was determined and the pathogens were analyzed molecularly. Of 278 fecal samples from pre-weaned dairy calves, 26 (9.4%) were positive for G. duodenalis and 40 (14.4%) were positive for Cryptosporidium spp. Cryptosporidium bovis (n = 28), Cryptosporidium ryanae (n = 5) and Cryptosporidium parvum (n = 7) were detected. All seven C. parvum isolates were successfully subtyped based on the gp60 gene sequence, and only IIdA15G1 was detected. Multilocus sequence typing of G. duodenalis based on beta-giardin (bg), triose phosphate isomerase (tpi) and glutamate dehydrogenase (gdh) genes revealed 19 different assemblage E multilocus genotypes (two known and 17 unpublished genotypes). Based on eBURST analysis, a high degree of genetic diversity within assemblage E was observed in pre-weaned dairy calves in Sichuan province. To the best of our knowledge, this is the first study using multilocus sequence typing and eBURST analysis to characterize G. duodenalis in pre-weaned dairy calves in southwestern China.

Objective To explore the effects of mechanical ventilation and mechanical ventilation combined with phrenic nerve electrical stimulation on the morphology of the phrenic nerve-diaphragm neuromuscular junction in rats. Methods The rats were divided into a control group (CON group, n = 6); an 18-hour mechanical ventilation group (MV group, n = 6); an 18-hour ventilation combined with sham electrical stimulation group (S-MS group, n = 6); and an 18-hour ventilation combined with electrical stimulation group (MS group, n = 6), in which the diaphragm contraction force was detected through the biological signal acquisition system, the stimulation frequency-contraction curve was fitted, and the muscle fatigue index was calculated. The muscle fiber crosssectional area (CSA) of the diaphragm specimen was observed through HE staining; the endplate membrane area of the neuromuscular junction (NMJ) was observed through immunohistochemistry (IHC) staining of the diaphragm combined with laser confocal technology. Results As compared with the CON group, the contractility of isolated diaphragm muscles in the MV group and S-MS group decreased; the fatigue resistance of isolated diaphragm, as compared with the CON group (0.686 8 ± 0.049 42), decreased in the MV group (0.360 3 ± 0.066 89) and the S-MS group (0.367 9 ± 0.034 94), with a greater decline in the MS group (0.536 2 ± 0.054 38); as compared with the CON group [674.3(523.9, 863.6)], diaphragm CSA was reduced in the MV group [374.5(293.3, 522.7)] and S-MS group [392.8(309.5, 542.6)], with a relatively lower reduction in the MS group [592.7(425.1, 820.0)]; as compared with the CON group [393.7(293.5, 471.3)], the diaphragm endplate membrane area decreased in the MV group [289.7(227.0, 354.2)] and S-MS group [243.1(190.8, 331.7)], with a lower degree of reduction in the MS group [331.0(262.8, 413.7). Conclusions Mechanical ventilation causes diaphragm dysfunction in rats and decreases the endplate membrane area of the diaphragm NMJ. Bilateral phrenic nerve electrical stimulation for 10 min/h can improve diaphragm dysfunction and changes in the endplate membrane area of the diaphragm NMJ caused by mechanical ventilation. [ABSTRACT FROM AUTHOR]