Cooperation, hotspots and prospects for tourism environmental impact assessments.

This study aims to identify hot spots, research limitations and future research directions in tourism environmental impact assessment (TEIA). We analyzed studies from the core database of Web of Science (WoS) based on their coauthorship, keyword co-occurrence and timeline with VOSviewer and CiteSpace. It was found that China, the United States, the United Kingdom, Australia and Spain are the major contributors to TEIA, and relatively stable cooperative groups have been formed among the authors. Research hotspots in the past 20 years mainly include: the impact of tourism activities in different tourist destinations on the environment, the approaches to assess the impact of tourism on the environment, and strategies on reducing the negative impact of tourism on the environment. We also found TEIA deficiency in the following five aspects: 1) insufficient studies on macro decision-making; 2) insufficient dynamic interaction analysis; 3) insufficient tourism heat footprint research; 4) insufficient studies on the positive effects of tourism on the environment; and 5) insufficient interdisciplinary innovation. Based on the findings, we suggest that 1) further studies be conducted on tourism activity type, time scale, macro pattern, environmental process and policy effect of tourism impact assessment with more variables and factors considered; 2) the impact of different types of tourism on each subsystem of the environment and the paths of the interaction among subsystems be explored from the perspective of system governance; 3) the study of thermal footprint generated by tourism activities be given more attention, especially large-scale tourism activities; 4) the positive impact of tourism activities on the ecological environment be studied, especially ecotourism; 5) the applicability of TEIA evaluation results be increased by means of interdisciplinary methods such as big data analysis.

Towards sustainable development in China: How do green technology innovation and resource misallocation affect carbon emission performance?

Green technology innovation is an effective way through which to achieve carbon neutrality and sustainable development. Based on provincial panel data of 30 provinces in China from 2005 to 2018, this work examines the tripartite relationship among green technology innovation, resource misallocation, and carbon emission performance by constructing panel regression models and a dynamic threshold panel model. The research results show that green technology innovation significantly improves carbon emission performance. Further analysis shows that both capital and labour misallocation have a negative impact on carbon emission performance and hinder the contribution of green technology innovation to the improvement of carbon emission performance. The regression results show that there is a threshold effect of green technology innovation on carbon emission performance: as the degree of resource misallocation increases, the positive impact of green technology innovation on carbon emission performance gradually decreases. This study provides an important reference for policy-makers in implementing policies to improve carbon emission performance. Policy-makers should continue to promote the level of green technology innovation and improve the efficiency of labour and capital allocation.

Phosphorylated and Phosphonated Low-Complexity Protein Segments for Biomimetic Mineralization and Repair of Tooth Enamel.

Biomimetic mineralization based on self-assembly has made great progress, providing bottom-up strategies for the construction of new organic-inorganic hybrid materials applied in the treatment of hard tissue defects. Herein, inspired by the cooperative effects of key components in biomineralization microenvironments, a new type of biocompatible peptide scaffold based on flexibly self-assembling low-complexity protein segments (LCPSs) containing phosphate or phosphonate groups is developed. These LCPSs can retard the transformation of amorphous calcium phosphate into hydroxyapatite (HAP), leading to merged mineralization structures. Moreover, the application of phosphonated LCPS over phosphorylated LCPS can prevent hydrolysis by phosphatases that are enriched in extracellular mineralization microenvironments. After being coated on the etched tooth enamel, these LCPSs facilitate the growth of HAP to generate new enamel layers comparable to the natural layers and mitigate the adhesion of Streptococcus mutans. In addition, they can effectively stimulate the differentiation pathways of osteoblasts. These results shed light on the potential biomedical applications of two LCPSs in hard tissue repair.

Metal ion and light sequentially induced sol-gel-sol transition of a responsive peptide-hydrogel.

We developed a new responsive peptide hydrogel FmocFFpSC(oNB)-PEG, which could achieve gel formation induced by calcium ions and sequential dissolution stimulated by light. It provides a potential delivery system for the efficient encapsulation of drugs and their controlled release in a spatial and temporal way.

Boosting the catalysis of gold by O2 activation at Au-SiO2 interface.

Supported gold (Au) nanocatalysts have attracted extensive interests in the past decades because of their unique catalytic properties for a number of key chemical reactions, especially in (selective) oxidations. The activation of O2 on Au nanocatalysts is crucial and remains a challenge because only small Au nanoparticles (NPs) can effectively activate O2. This severely limits their practical application because Au NPs inevitably sinter into larger ones during reaction due to their low Taman temperature. Here we construct a Au-SiO2 interface by depositing thin SiO2 layer onto Au/TiO2 and calcination at high temperatures and demonstrate that the interface can be not only highly sintering resistant but also extremely active for O2 activation. This work provides insights into the catalysis of Au nanocatalysts and paves a way for the design and development of highly active supported Au catalysts with excellent thermal stability.

Synthesis of α,α-Difluorinated Phosphonate pSer/pThr Mimetics via Rhodium-Catalyzed Asymmetric Hydrogenation of ß-Difluorophosphonomethyl α-(Acylamino)acrylates.

A novel and facile synthetic strategy for α,α-difluorinated phosphonate mimetics of phosphoserine/phosphothreonine utilizing rhodium-catalyzed asymmetric hydrogenation was developed. The dehydrogenated substrate ß-difluorophosphonomethyl α-(acylamino)acrylates were first prepared from protected serine/threonine followed by asymmetric hydrogenation using the rhodium-DuPhos catalytic system to generate the chiral center(s). These important phosphonate building blocks were successfully incorporated into phosphatase-resistant peptides, which displayed similar inhibition to the 14-3-3 ζ protein as the parent pSer/pThr peptides.