No abstract

Nanoparticle surfactants (NPSs) assembled at the oil−water interface can significantly lower the interfacial tension and be used to structure liquids. However, to realize the three-dimensional printing of one liquid in another, high-viscosity liquids, for example, silicone oil, have been generally used. Here, we present a simple, low-cost approach to print water in low-viscosity toluene by using a new type of polyelectrolyte surfactant, sodium carboxymethyl cellulose surfactant (CMCS), that forms and assembles at the oil−water interface. The interfacial activity of CMCSs can be enhanced by tuning parameters, such as pH and concentration, and the incorporation of a rigid ligand affords excellent mechanical strength to the resultant assemblies. With CMCS jammed at the interface, liquids can be easily printed or molded to the desired shapes, with biocompatible walls that can be used to encapsulate and adsorb active materials. This study opens a new pathway to generate complex, all-liquid devices with a myriad of potential applications in biology, catalysis, and chemical separation.

No abstract

Biogenic volatile organic compounds (BVOCs) emissions lead to fine particulate matter (PM) and ground-level ozone pollution, and are harmful to human health, especially in urban areas. However, most BVOCs estimations ignored the emissions from urban green spaces, causing inaccuracies in the understanding of regional BVOCs emissions and their environmental and health effects. In this study, we used the latest local vegetation datasets from our field survey and applied an estimation model to analyze the spatial-temporal patterns, air quality impacts, health damage and mitigating strategies of BVOCs emissions in the Greater Beijing Area. Results showed that: (1) the urban core was the hotspot of regional BVOCs emissions for the highest region-based emission intensity (3.0 g C m yr) among the 11 sub-regions; (2) urban green spaces played much more important roles (account for 62% of total health damage) than rural forests in threating human health; (3) BVOCs emissions from green spaces will more than triple by 2050 due to urban area expansion, tree growth and environmental changes; and (4) adopting proactive management (e.g. adjusting tree species composition) can reduce 61% of the BVOCs emissions and 50% of the health damage related to BVOCs emissions by 2050.

To study whether colostrum-borne growth factors are responsible for the rapid GI tissue growth in naturally suckled newborn animals, newborn unsuckled piglets were bottle-fed for 24 h with infant milk formula with or without addition of 2 μg/ml of recombinant human insulin-like growth factor-I (IGF-I) or insulin-like growth factor-II (IGF-II), a level which approximated that of porcine colostrum. The animals were then sacrificed for measurements of their digestive organ weights and contents of protein, RNA and DNA in the organs. The treatment with IGF-I or IGF-II failed to show any significant effect on the weight of the esophagus, stomach, small intestine, large intestine, mandibular glands, kidneys and the spleen, and had no effects on the contents of protein, RNA and DNA in the small intestinal mucosa, the liver and the spleen. However, piglets fed with infant formula containing IGF-I (n = 7) or IGF-II (n = 7) had a heavier pancreas (p < 0.05) compared to formula-fed controls (n = 7). The DNA content in the stomach and the pancreas were greater in animals treated with IGF-I or IGF-II than in controls. Using a cell labelling technique it was shown that both IGF-I and IGF-II stimulated cell proliferation in the small intestinal crypts. The results indicate that the substantial GI tissue growth reported in newborn animals is unlikely due to colostrum-borne IGF-I or IGF-II alone. On the other hand the study does suggest that oral IGF-I and IGF-II are capable of stimulating cell proliferation in the GI tract.

Accurate and timely urban land mapping is fundamental to supporting large area environmental and socio-economic research. Most of the available large-area urban land products are limited to a spatial resolution of 30 m. The fusion of optical and synthetic aperture radar (SAR) data for large-area high-resolution urban land mapping has not yet been widely explored. In this study, we propose a fast and effective urban land extraction method using ascending/descending orbits of Sentinel-1A SAR data and Sentinel-2 MSI (MultiSpectral Instrument, Level 1C) optical data acquired from 1 January 2015 to 30 June 2016. Potential urban land (PUL) was identified first through logical operations on yearly mean and standard deviation composites from a time series of ascending/descending orbits of SAR data. A Yearly Normalized Difference Vegetation Index (NDVI) maximum and modified Normalized Difference Water Index (MNDWI) mean composite were generated from Sentinel-2 imagery. The slope image derived from SRTM DEM data was used to mask mountain pixels and reduce the false positives in SAR data over these regions. We applied a region-specific threshold on PUL to extract the target urban land (TUL) and a global threshold on the MNDWI mean, and slope image to extract water bodies and high-slope regions. A majority filter with a three by three window was applied on previously extracted results and the main processing was carried out on the Google Earth Engine (GEE) platform. China was chosen as the testing region to validate the accuracy and robustness of our proposed method through 224,000 validation points randomly selected from high-resolution Google Earth imagery. Additionally, a total of 735 blocks with a size of 900 × 900 m were randomly selected and used to compare our product’s accuracy with the global human settlement layer (GHSL, 2014), GlobeLand30 (2010), and Liu (2015) products. Our method demonstrated the effectiveness of using a fusion of optical and SAR data for large area urban land extraction especially in areas where optical data fail to distinguish urban land from spectrally similar objects. Results show that the average overall, producer’s and user’s accuracies are 88.03%, 94.50% and 82.22%, respectively.

No abstract

Urban green spaces provide various ecosystem services, especially cultural services. Previous assessment methods depend either on hypothetic payments for ecosystems or real payments not directly related to ecosystems. In this paper, we established a method for assessing the cultural ecosystem services in any location in urban area using only two variables, green space (ecosystem) and land rent (real payment). We integrated the cultural and the regulating services into the total ecosystem services because urban green spaces provide almost no provisioning services. Results showed that the same area of green spaces near the center provided much higher cultural services than that near the urban edge; the regulating services accounted for 5% to 40% of the total ecosystem services from the center to the edge of urban area; along the center-edge gradient, there was a threshold out which the ecosystem services were lower than the maintenance cost of green spaces.