The purpose of this study was to develop a sonosensitizer-loaded multi-functional ultrasound (US) contrast agent for both tumour therapy and imaging. The hematoporphyrin (HP)-encapsulated poly(lactic-co-glycolic acid) microbubbles (HP-PLGA-MBs) were prepared and filled with perfluorocarbon gases. The enhancement of US imaging and its sonodynamically induced anti-tumour effect were evaluated by both in vitro and in vivo experiments. The HP-PLGA-MBs have a narrow size distribution and smooth surface with a mean diameter of 702.6 ± 56.8 nm and HP encapsulation efficiency of 63.50 ± 1.26% and drug-loading efficiency of 2.15 ± 0.13%. The HP-PLGA-MBs could well enhance the ultrasound imaging both in vitro and in vivo. A significant anti-tumour effect was obtained by HP-PLGA-MBs mediated sonodynamic therapy. The tumour growth rate and the tumour proliferation index were the lowest in the HP-PLGA-MBs plus sonication group. And the tumour cell apoptotic index was the biggest in the HP-PLGA-MBs plus sonication group. In conclusion, a sonosensitizer-loaded multi-functional contrast agent was constructed and the feasibility was demonstrated, which might provide a novel strategy for tumour imaging and therapy.

Objective: The oral microbiota is associated with the risk of type 2 diabetes (T2D), but the relationship between the oral microbiota and disease progression in the elderly population remains to be determined. Design: In our study, we recruited 150 elderly Chinese residents and divided them into three groups according to their fasting glucose (FG) level: normal (N), high (H), and very high (VH). Their biochemical indexes were analyzed using blood samples. Saliva samples were collected and the oral microbiome was profiled by high-throughput sequencing of the V3-V4 area of the 16S rRNA gene. Result: Our results revealed that the VH group showed deterioration of the metabolic phenotype and dysbiosis of the oral microbiota simultaneously when compared to the other two groups. Furthermore, potential disease-associated bacterial genera including Leptotrichia, Staphylococcus, Catonella, and Bulleidia were significantly enriched in the VH group. Conclusions: These results suggest that dysbiosis of the oral microbiota may be a typical feature of hyperglycemia and might also contribute to disease aggravation in the progression of hyperglycemias.

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Nighttime light data play an important role in the research on cities, while the urban centers over a large spatial scale are still far from clearly understood. Aiming at the current challenges in monitoring the spatial structure of cities using nighttime light data, this paper proposes a new method for identifying urban centers for massive cities at the large spatial scale based on the brightness information captured by the Suomi National Polar-Orbiting Partnership’s Visible Infrared Imaging Radiometer Suite (NPP-VIIRS) sensor. Based on the method for extracting the peak point based on digital elevation model (DEM) data in terrain analysis, the maximum neighborhood and difference algorithms were applied to the NPP-VIIRS data to extract the pixels with the peak nighttime light intensity to identify the potential locations of urban centers. The results show 7239 urban centers in 2200 cities in China in 2017, with an average of 3.3 urban centers per city. Approximately 68% of the cities had significant polycentric structures. The developed method in this paper is useful for identifying the urban centers and can provide the reference to the city planning and construction.

Acceleration sensor is extensively used in the field of human activity recognition, since it provides better recognition rate of human activity. Based on the principle of molecular attribute, a simple and adaptive activity recognition method is proposed using the acceleration data flow, which constitutes a serial activity, when the acceleration data are treated as the material flow with certain molecular structure. Then five molecular attributes including relative molecular mass, density, internal forces in a molecule, molecule stability, and attraction between molecules are introduced to recognize six human activities, since the closer molecular attribute means the more similar activity. Based on the calculated molecular attributes, a reliability-based voting method for human activity recognition is developed. Since each activity has respective motion cycle, a sliding window with variable sizes is put forward to enhance the recognition rate. Furthermore, adaptive incremental learning is designed to adapt to the different users. The long-time experimental results show that the proposed method is rather accurate and robust for different crowds. The average recognition rate achieves 97.2% for six human activities including walking, jogging, running, going upstairs, going downstairs, and sitting down.

The urban heat island effect has always been one of the hottest issues in urban development. In this study, Landsat images from the summers of 2001, 2004, 2009, 2014 and 2018 were used to identify land cover type in six districts of Chongqing’s main city. Land cover was categorized as water, vegetation or impervious surface with the object-oriented method. Land surface temperature (LST) data was calculated with the atmospheric radiation transfer equation method, and was then divided into different heat island intensity grades. Next, the spatial and temporal changes in land cover type and heat island effect were analyzed in the six districts. Center migration analysis and heat island coefficients were used to quantitatively reflect the spatiotemporal evolution relationship between land cover and heat island effect. All six districts exhibited a trend of expanding impervious surface, with a 419.38% increase from 2001 to 2018, and shrinking vegetation, with a 17.81% decrease from 2001 to 2018. Also from 2001 to 2018, Yuzhong District had the most significant heat island effect, with a heat island coefficient 0.35 higher than the mean value of the whole study area. The impervious surface center migrated in different directions in each district. Both the direction and the corresponding velocity of the impervious surface and heat island centers were tightly correlated, with a correlation coefficient of 0.53. Relative heat island coefficients (the difference from the mean) of water ranged from −2.08 to −1.17 in different districts. That of impervious surface ranged from 1.60 to 1.93, and that of vegetation ranged from −0.22 to 1.09. The internal heterogeneity of land cover and heat island effect in Chongqing’s main city was huge. This study quantitatively analyzed the evolution of the heat island effect in the study area to help provide each district with some targeted suggestions for future urban planning.

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