Abstract:The "environmental pollution-economic development" circle is a problem in the process of national sustainable development. As a complex concept of environmental protection and technology innovation, green technology innovation is the key to cracking this strange circle. This paper divides green technology innovation into green product innovation and green process innovation and measures green technology innovation based on the perspective of energy saving and emission reduction. Furthermore, we examine the effects of environmental regulation and government R&D funding on green technology innovation. The empirical findings are as follows: (1) from the dynamic point of view, we test whether there is a significant "U-shaped" relationship between environmental regulation and green technological innovation, and we find there exists an "inflection point" in the role of environmental regulation in green technology innovation, and China is at the stage of inhibition before the "inflection point"; (2) direct government funding and tax incentives can promote green technology innovation, but the promotion of government tax incentives to green technology innovation is not significant; (3) the interaction between environmental regulation and government R&D will promote green product innovation and inhibit green process innovation, which is closely related to the imbalance of environmental regulation intensity in energy saving and emission reduction. In addition, this paper also gives out three kinds of control variables (the level of regional development, the proportion of the regional manufacturing industry, and the development level of regional export-oriented economy) and presents their effects on green technology innovation.

It is a challenge to fabricate low-cost and flexible electronic devices with degradable materials. In this work, a flexible and degradable strain sensor was fabricated on a paper substrate by dip-coating in an aqueous suspension of carbon black (CB) and carboxymethyl cellulose (CMC). The composition of CB and CMC in the suspension was first studied for producing a uniform conducting layer on the paper. Then the strain sensor was obtained by assembling the coated paper and wires with silver paste. The sensor exhibits gauge factor of 4.3 and responsive time of approximately 240 ms, demonstrating the capability of monitoring various human motions with high stability >1000 cycles. The microgaps between CB particles and cracks on the surface of the CB layer can account for this resistive-type sensitivity. The degradation test shows that the sensor can be degraded soon under gentle rubbing in wet state, implying it is an environmentally friendly “green” electronic device. Furthermore, the cost of the sensor is quite low (<$0.001/sensor) due to the cheap raw materials used, which provides an opportunity for its future utilization in various intelligent systems.

Unsatisfactory post-stroke recovery has long been a negative factor in the prognosis of ischemic stroke due to the lack of pharmacological treatments. Mesenchymal stem cells (MSCs)-based therapy has recently emerged as a promising strategy redefining stroke treatment; however, its effectiveness has been largely restricted by insufficient therapeutic gene expression and inadequate cell numbers in the ischemic cerebrum. Herein, a non-viral and magnetic field-independent gene transfection approach is reported, using magnetosome-like ferrimagnetic iron oxide nanochains (MFIONs), to genetically engineer MSCs for highly efficient post-stroke recovery. The 1D MFIONs show efficient cellular uptake by MSCs, which results in highly efficient genetic engineering of MSCs to overexpress brainderived neurotrophic factor for treating ischemic cerebrum. Moreover, the internalized MFIONs promote the homing of MSCs to the ischemic cerebrum by upregulating CXCR4. Consequently, a pronounced recovery from ischemic stroke is achieved using MFION-engineered MSCs in a mouse model.

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Aquaporin Z (AqpZ), a typical orthodox aquaporin with six transmembrane domains, was expressed as a fusion protein with TrxA in E. coli in our previous work. In the present study, three fusion partners (DsbA, GST and MBP) were employed to improve the expression level of this channel protein in E. coli. The result showed that, compared with the expression level of TrxA-AqpZ, five- to 40-fold increase in the productivity of AqpZ with fusion proteins was achieved by employing these different fusion partners, and MBP was the most efficient fusion partner to increase the expression level. By using E. coli C43 (DE3)/pMAL-AqpZ, the effects of different expression conditions were investigated systematically to improve the expression level of MBP-AqpZ in E. coli. The high productivity of MBP-AqpZ (200 mg/l) was achieved under optimized conditions. The present work provides a novel approach to improve the expression level of membrane proteins in E. coli.