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Two-dimensional nanomaterials have the characteristics of high aspect ratio and high space utilization, which has huge potential advantages in gas separation. In this work, g-C3N4 two-dimensional nanosheets with sieving pore structure were selected as templates and combined with ZIF-90 to construct a 0-dimensional/2-dimensional composite material ZIF-90@C3N4 (ZCN). The complete two-dimensional g-C3N4 nanosheets were stripped under acid etching conditions at 25 °C. ZIF-90 was distributed in an orderly manner on the two-dimensional nanosheets, and the nanosheets were spread out due to the growth of ZIF-90 to provide more free volume. The gas permeation experiment proved that the ZCN has a better CO2/N2 separation performance. The ZCN/Pebax mixed matrix membrane (MMM) with the optimized 8.0 wt% ZCN loading showed an improved CO2 permeability of 110.5 Barrer and a CO2 /N2 selectivity of 84.4, surpassing the Robeson upper bound (2008). The results demonstrated that the designed composite filler with 2D nanosheets is an effective strategy to enhance gas separation performance of MMMs and verified the application potential in gas purification industry.

Whether GDF11 is a systemic factor from young animals’circulation that mediates the rejuvenation process in old animals during heterochronic parabiosis has been debated. We carried out transcriptomic analyses of young versus old monkey and human blood samples demonstrating negative correlations between GDF11 expression and old age, which is further confirmed by quantitative RT-PCR of GDF11 mRNA from more than 400 young and old human blood samples. Reduced GDF11 expression is also correlated with age-dependent cognitive decline. Tail vein injection of recombinant mature GDF11 into aged mice led to increased numbers of cerebral blood vessels and cerebral blood flow, enhanced neurogenesis and spatial learning. Objective and systemic transcriptomic analyses of GDF11-treated brains revealed and subsequently confirmed through biological assays, that rGDF11 regulated angiogenesis, neurogenesis, cell cycle, energy metabolism, clearance of senescent cells, as well as increased telomere length and GDF11 gene expression in neural stem cells via the Smad2/3-PI3K-AKT-mTOR pathway.

The wind environments in real urban areas, which consist of various significantly non-uniform buildings, are completely different from those in regular building arrays or homogeneous underlying surface areas. Through boundary layer wind tunnel experimental studies, the present work aimed to investigate the possible effects of non-uniformity morphological parameters of buildings on the drag coefficient, with consideration given to the non-uniformity of the frontal area, density, shape, and layout of buildings. And a novel non-intrusive approach to drag measurement, based on wind pressure tests performed on three single buildings, was developed and compared with the direct measurement method. The experimental analyses indicate that among different cases, in general, the variation tendency of the drag coefficient of individual blocks positioned along a wind direction over a large planar area was approximated as an attenuation curve. Moreover, the drag coefficient results from the wind pressure tests vary by 10–20% from those based on direct measurements. Furthermore, when the layout was a diagonal-square network, which is considered for buildings that have better ventilation conditions, it was observed that the wind pressure difference coefficient of those pressure modules would increase. There are clear differences between an H-shaped building and a rectangular one, such as their distributions of the wind pressure difference coefficient and the fact that the H-shaped structure induces flow more intensely. In addition, the effect of changes in terrain roughness on the distribution of the surface wind pressure difference coefficient is not significant.

This paper presents an acoustofluidics platform for elastic characterization of biological samples using ultra high frequency (∼1 GHz) ultrasonic bulk acoustic waves (BAW). The propagation of bulk acoustic waves in a plane parallel to the surface of a silicon wafer was controlled using 45° acoustic mirrors, thus leading to the development of real time biosensing applications in a microchannel fabricated using ICP technology. To validate the design and technology of the silicon and PDMS-based platform, the propagation of bulk acoustic waves through the microfluidic channel was studied. This lab-on-a-chip platform was used to characterize different concentrations of chemical solutions in the microfluidic channel and detect latex particles passing through the channel.