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This article introduces a secure tunnel fast marching tree motion planning algorithm (ST-FMT*) to provide a secure and optimal path quickly for a mobile robot. The proposed ST-FMT* consists of preprocessing and exploring procedures, which are responsible for establishing a secure tunnel and optimizing the path, respectively. In the preprocessing process, the generalized Voronoi graph is adopted to build an equidistant roadmap and generates an initial collision-free solution rapidly. Then, a secure tunnel is established via the minimum distance from the obstacles to the initial solution to facilitate the concentration of sampling. In the exploration process, the FMT* with uniform sampling within the secure tunnel is utilized to find the optimal solution with high computational efficiency. The theoretical analyses of the ST-FMT* are provided. In a series of scenarios evaluation, the ST-FMT* exhibits fast convergence to the optimal solution in different environments. Besides, the effectiveness of the ST-FMT* is verified in a transportation experiment using a Turtlebot2 mobile robot. [ABSTRACT FROM AUTHOR]

Fengyun-4A (FY-4A), the second generation of China's geostationary meteorological satellite, provides high spatiotemporal resolution cloud products over East Asia. In this study, cloud fraction (CFR) and cloud top pressure (CTP) products in August 2017 derived from the Advanced Geosynchronous Radiation Imager (AGRI) aboard FY-4A (AGRI/FY-4A) are retrospectively compared with those from the Moderate Resolution Imaging Spectroradiometer (MODIS) aboard Terra (MODIS/Terra) over East Asia. To avoid possible errors in the comparison caused by the lower temporal coverage of MODIS/Terra products compared to that of AGRI/FY-4A over the same region and to account for time lags between observations of the two instruments, we construct datasets of AGRI/FY-4A CFR and CTP to match those of MODIS/Terra in each scan over East Asia in August 2017. Results show that the CFR and CTP datasets of the two instruments generally agree well, with the linear correlation coefficients (R) between CFR (CTP) data of 0.83 (0.80) regardless of time lags. Though longer time lags contribute to the worse consistency between CFR (CTP) data derived from observations of the two instruments in most cases, large CFR/CTP discrepancies do not always match with long time lags. Large CFR discrepancies appear in the vicinity of the Tibetan Plateau (TP; 28°–45°N, 75°–105°E). These differences in the cloud detection by the two instruments largely occur when MODIS/Terra detects clear-sky while AGRI/FY-4A detects higher values of CFR, and this accounts for 61% of the CFR discrepancy greater than 50% near the TP. In the case of CTP, the largest discrepancies appear in the eastern Iranian Plateau (IP; 25°–45°N, 60°–80°E), where there are some samples with long time lags (20–35 min) and fewer daily data samples are available for computing monthly means compared to other regions since there are many clear-sky data samples there during the study period. [ABSTRACT FROM AUTHOR]

Purpose: To detect the expressions of CD74 and matrix metalloproteinase-9 (MMP-9) in colon adenocarcinomas, and to explore the relationship between the expressions and clinicopathological characteristics and prognosis., Methods: 98 cases of colon adenocarcinoma tissues from patients who underwent colon cancer resection in the Sixth Affiliated Hospital, Sun Yat-sen University from January 2013 to March 2015 comprised the experimental group, while 71 cases of colon mucosa tissues from patients who underwent colon polypectomy during the same period comprised the control group. qRT-PCR was used to detect the expressions of CD44 and MMP-9 mRNAs in the two groups, in order to analyze their correlation in colon adenocarcinomas, and to also analyze their relationship with clinicopathological characteristics and prognosis., Results: The expressions of CD74 and MMP-9 mRNAs in colon adenocarcinoma tissues were significantly higher than those in normal colon mucosa tissues (p<0.05). The expressions of CD74 and MMP-9 mRNAs had no significant relationship with the patient's gender, age, differentiation grade and tumor type in colon adenocarcinoma tissues (p>0.05), but had significant correlation with lymph node metastasis and pathological stage (p<0.05). According to the average expressions of CD74 and MMP-9 mRNAs, the patients were divided into low and high expression groups. The 3-year survival rate of patients in the low expression group was significantly higher than that in the high expression group (p<0.05). Moreover, the expressions of CD74 and MMP-9 were positively correlated (r = 0.853, p<0.001)., Conclusion: CD74 and MMP-9 are highly expressed in colon adenocarcinomas, and their expressions are closely related to the pathological stage, lymph node metastasis and prognosis of colon adenocarcinoma patients. Therefore, they can be used as important biological markers for diagnosis and prognosis prediction of colon adenocarcinoma.