Research on Personalized Recommender System for Tourism Information Service

Since the development in the 1990s, Recommender system has been widely applied in various fields. The conflict between the expansion of tourism information and difficulty of tourists obtaining tourism information allows Tourism Information Recommender System to have a practical significance. Based on the existing online tourism information service and the mature recommendation algorithms, Personal Recommender System can be used to solve present problems of the key recommendation algorithms. In the first place, this research presents an overview of researches on this issue both at home and abroad, and analyzes the applications of main stream recommendation algorithms. Secondly, a comparative study of domestic and international tourism information service websites is conducted. Drawbacks in their applications are defined and advantages are adopted in the settings of Recommender System. Finally, this research provides the framework of Recommender System, which combines the design and test of algorithms and the existing tourism information recommendation websites. This system allows customers to broaden experience of tourism information service and make tourism decisions more accurately and rapidly. Keywords: Tourism information service, Personalized recommendation, Intelligence recommendation module, Apriori algorith

Dysbiosis of gut microbiota and decreased propionic acid associated with metabolic abnormality in Cushing’s syndrome

ObjectiveChronic hypercortisolism leads to a phenotype resembling metabolic syndrome. We aimed to investigate the association between gut microbiota and metabolic abnormalities in endogenous hypercortisolism (Cushing’s syndrome).MethodsA total of 23 patients with Cushing’s syndrome (18 female and 5 men, aged 47.24 ± 12.99 years) and 30 age-, sex-and BMI-matched healthy controls (18 female and 12 men, aged 45.03 ± 6.69 years) were consecutively recruited. Differences in gut microbiota and plasma short-chain fatty acid (SCFAs) concentrations between the Cushing’s syndrome patients and controls were analyzed by 16S rRNA sequencing and gas chromatography-mass spectrometry (GC-MS).ResultsCompared to the controls, the Simpson and Pielou indices of α diversity were dramatically decreased in Cushing’s syndrome (P < 0.05). The gut microbiota community structure differed significantly between Cushing’s syndrome patients and controls. Compared to controls, the bacterial communities of the Cushing’s syndrome patients were enriched in Proteobacteria and Escherichia-Shigella, and depleted in Firmicutes, including Agathobacter, Blautia, Anaerostipes, Eubacterium_eligens_group, and Lachnospira. Spearman analysis demonstrated that HbA1c, SBP, DBP, and cortisol levels were significantly positively correlated with Proteobacteria and Escherichia-Shigella, whereas negatively correlated with Agathobacter, Blautia, Anaerostipes, Eubacterium_hallii_group, and Lachnospira, etc. Cushing’s syndrome patients also had a lower propionic acid concentration (0.151±0.054 vs. 0.205±0.032 µg/mL, P=0.039) than controls. Furthermore, the level of propionic acid was negatively correlated with systolic pressure and cortisol levels (P<0.05).ConclusionGut microbiota dysbiosis and decreased propionic acid levels were observed in patients with Cushing’s, suggesting that the gut microbiota may be a potential therapeutic intervention target to improve hypercortisolism-related metabolic abnormalities

Regulatory effect of extracellular matrix stiffness on the plasticity of human prostate cancer cells

Objective To investigate the regulatory effect of extracellular matrix (ECM) stiffness on the plasticity of human prostate cancer cells (LNCaP). Methods Human LNCaP cells were cultured in ECM culture dishes with four types of stiffness (i.e., Young’s modulus of 3 GPa [group A], 20 kPa [group B], 6 kPa [group C], and 1 kPa [group D]) for one week. The morphology of cells on substrates of different stiffness values was observed for each group using bright-field microscopy and fluorescence microscopy. Reverse transcription-quantitative polymerase chain reaction (RT-qPCR) was used to measure the expression levels of luminal cell marker genes (AR, CK8, CK18, and PSA), basal cell marker genes (CK5 and P63), and proliferative genes (KI67 and PCNA) in each group. Results Bright-field microscopy and fluorescence microscopy showed that human LNCaP cells in group A exhibited typically spread epithelial cell morphology, whereas the cells in groups B to D showed the state of agglomerated small cell sheets, and the cells in group D formed a three-dimensional organ-like structure. RT-qPCR results showed that there were no significant differences between the four groups in the expression levels of KI67 and P63 genes in human LNCaP cells (P>0.05). The expression level of PCNA gene in group B was significantly higher than that in groups A and C (F=34.96,t=8.39,6.37,P<0.05). The expression level of CK5 gene in group B was significantly higher than that in the other three groups (F=29.35,t=4.46-6.73,P<0.05). The expression levels of AR, CK8, CK18, and PSA genes in group D were significantly higher than those in the other three groups (F=13.66-56.43, t=3.03-11.51,P<0.05). Conclusion ECM environment with a lower stiffness value (Young’s modulus of 1 kPa) can better maintain the luminal cell characteristics of human LNCaP cells, whereas ECM with a higher stiffness value (Young’s modulus of 20 kPa) causes human LNCaP cells to exhibit an intermediate state cellular phenotype, which may be one of the factors leading to the development of prostate cancer

Investigation on Mechanism of Coal Burst Induced by the Geological Weak Surface Slip in Coal Seam Bifurcation Area: A Case Study in Zhaolou Coal Mine, China

AbstractThe coal seam bifurcation area (CSBA) exists widely in coal measure strata, where the geological weak surface (GWS) slip in overburden structure is easy to induce coal burst. The coal mass of coal face shows overall instability failure and high-speed throwing characteristics during the coal burst, seriously threatening the safe and efficient coal mine production. In order to understand the GWS-induced coal burst caused by the slip in CSBA and find the main controlling factors of GWS slip, the GWS slip criterion in CSBA was established based on the coal burst case analysis of overburden structure in CSBA of 1305 coal face (1305CF) in Zhaolou Coal Mine. The case study showed that the angle and range of CSBA are the main controlling factors affecting GWS slip. The FLAC3D numerical model of CSBA was established to analyze the influence effect of main control factors. The results show that the increase of angle and range of CSBA will increase the influence scope and degree of coal face mining, improving coal face burst risk. However, the peak point region of abutment pressure will not be affected, gradually reaching its peak within 0 m ~10 m from the coal seam merging area. With the increase of the angle of CSBA, the integrity of the triangular wedged rock mass along the GWS slip will be enhanced, aggravating the dynamic disturbance to the coal mass. With the increase of the range of CSBA, the slip of triangular wedged rock mass along GWS gradually changes from integral slip to phased slip, which will intermittently disturb the coal mass of the coal face. The research results have certain theoretical significance and practical value for preventing and controlling coal bursts in CSBA

Enhanced Photoluminescence Emission and Thermal Stability from Introduced Cation Disorder in Phosphors

Optimizing properties of phosphors for use in white-light-emitting diodes (WLEDs) is an important materials challenge. Most phosphors have a low level of lattice disorder due to mismatch between the host and activator cations. Here we show that deliberate introduction of high levels of cation disorder leads to significant improvements in quantum efficiency, stability to thermal quenching, and emission lifetime in Sr_{1.98–<i>x</i>}(Ca_0.55Ba_0.45)_<i>x</i>Si₅N₈:Eu_0.02 (<i>x</i> = 0–1.5) phosphors. Replacing Sr by a (Ca_0.55Ba_0.45) mixture with the same average radius increases cation size variance, resulting in photoluminescence emission increases of 20–26% for the <i>x</i> = 1.5 sample relative to the <i>x</i> = 0 parent across the 25–200 °C range that spans WLED working temperatures. Cation disorder suppresses nonradiative processes through disruption of lattice vibrations and creates deep traps that release electrons to compensate for thermal quenching. Introduction of high levels of cation disorder may thus be a very useful general approach for improving the efficiency of luminescent materials