Recent advances in porous molecular cages for photocatalytic organic conversions.

Photocatalytic organic conversion is considered an efficient, environmentally friendly, and energy-saving strategy for organic synthesis. In recent decades, the molecular cage has emerged as a creative functional material with broad applications in host-guest recognition, drug delivery, catalysis, intelligent materials and other fields. Based on the unique properties of porous molecular cage materials, they provide an ideal platform for leveraging pre-structuring in catalytic reactions and show great potential in various photocatalytic organic reactions. As a result, they have emerged as promising alternatives to conventional molecules or inorganic photocatalysts in redox processes. In this Review, the synthesis strategies based on coordination cages and organic cages, as well as their recent progress in photocatalytic organic conversion, are comprehensively summarized. Finally, we deliver the persistent challenges associated with porous molecular cage compounds that need to be overcome for further development in this field.

Manipulating the Reaction Pathway of CO2 Photoreduction via the Microenvironment of a Re Molecular Catalyst.

Re molecular complexes incorporated into two metal-organic frameworks were investigated to disclose the host-guest interaction by infrared and 1H nuclear magnetic resonance and to explore the microenvironment around the Re complex by absorption and photoluminescence spectra. ZIF-8 provides a confined space to isolated Re via an electrostatic interaction, while UiO-66 exerts a relaxed space to accessible Re via a coordination interaction. For CO2 two-electron photoreduction to CO, the turnover number of 28.6 in Re@ZIF-8 is 10-fold that of 2.7 in Re@UiO-66. The electron transfer is promoted in Re@ZIF-8 by a local electrostatic field with a cross-space pathway, whereas it is retarded in Re@UiO-66 as the solvation shell surrounding Re. In the following CO2 activation, the charged intermediate species could be stabilized in Re@ZIF-8 by spatial confinement, while Re-triethanolamine adducts prevailed in Re@UiO-66 with the accessibility of the Re complex. This work demonstrates a feasibility of diverting the CO2 activation pathway by the microenvironment of a molecular catalyst in the field of artificial photosynthesis.

In Situ Preparation of High-Performance Silicon-Based Integrated Electrodes Using Cross-Linked Cyclodextrins.

The strategy of material modification for improving the stability of silicon electrodes is laborious and costly, while the conventional binders cannot withstand the repeated massive volume variability of silicon-based materials. Hence, there is a demand to settle the silicon-based materials' problems with green and straightforward solutions. This paper presents a high-performance silicon anode with a binder obtained by in situ thermal cross-linking of citric acid (CA) and ß-cyclodextrin (ß-CD) during the electrode preparation process. The Si electrode with a binder synthesized by the one-pot method shows excellent cycling performance. It maintains a specific capacity of 1696 mAh·g-1 after 200 cycles at a high current of 0.5 C. Furthermore, the carbonylation of ß-CD to carbonyl-ß-CD (c-ß-CD) introduced better water solubility, and the c-ß-CD can generate multidimensional connections with CA and Si, which significantly enhances the specific capacity to 1941 mAh·g-1 at 0.5 C. The results demonstrate that the prepared integrated electrode facilitates the formation of a stable and controllable solid electrolyte interface layer of Si and accommodates Si's repeated giant volume variations.

Revisiting the Environment Effect on Mass Transfer for Heterogenized Pd6 Ru8 Metal-Organic Cage Photocatalyst Confined within 3D Matrix.

Artificial light-driven splitting of water into hydrogen involves multiple links to emulate natural photosynthesis, including light absorption, electron or energy transfer, surface catalysis et al., in which, the mass transportation of sacrificial reagent and reactant is always ignored. Metal-organic cage (MOC) of Pd6 Ru8 (MOC-16), assembling multiple photosensitive Ru and catalytic Pd concomitant with directional electron transfer between them, provides an opportunity to explore the environmental effects from the view point of mass transportation without disturbance of other links. Zr-MOF of UiO-66 is used as a matrix to heterogenize MOC-16 and a series of characterizations are carried out to unravel the composition, structure and optical properties. The intact MOC-16 remains with long-term photo-stability and the outstanding photocatalytic activity is obtained by virtue of a long-lived triplet state. Three matrixes of ZIF-8, ZIF-8 derived carbonate CZIF, and UiO-66 are intercompared for mass transfer based on wettability and porous structure. Water molecule directly takes part in the formation of H2 catalyzed by MOC-16@UiO-66, evidenced by a kinetic isotope effect, in addition to the proton delivery thanks to the hydrophilic nature of UiO-66. The porous structure of UiO-66 is essential for the permeation of sacrificial reagent to serve as two-electron donor, in sharp contrast as one-electron donor in nonporous CZIF matrix. These results highlight the importance of microenviroment surrounding molecular catalysts in view of the heterogenization of molecular catalysts, meanwhile, providing a prominent guidance on how to choose 3D support to bridge the homogenous and heterogenous system.

How does coal consumption constraint policy affect electrical energy efficiency? Evidence from 30 Chinese provinces.

In recent years, energy efficiency has been considered an extremely cost-effective way to reduce greenhouse gas emissions. China is a country with the world's largest coal consumption and heavy reliance on thermal power generation. Therefore, the relationship between the coal consumption constraint policy (CCCP) in China and electrical energy efficiency is a topic worthy of study. Based on the panel data of 30 provinces in China during 2005-2016, this paper employs the difference-in-differences (DID) to examine the impact of CCCP on electrical energy efficiency in China. The results indicate that the implementation of the CCCP reduces electrical energy efficiency in the pilot provinces. Based on the mechanism tests, the cost effect outweighs the innovation effect, which is why CCCP decreases electrical energy efficiency. The results of the heterogeneity analysis show that the influence of CCCP is more significant in the provinces with weak law enforcement and small hydropower investment and northern provinces. This study suggests that the Chinese government can promote corporate technological innovation by improving the environmental compensation system and increasing environmental law enforcement to improve electrical energy efficiency. Meanwhile, renewable energy projects should be the focus of future investment. Supplementary Information: The online version contains supplementary material available at 10.1007/s12053-022-10023-2.

Cross-linked ß-CD-CMC as an effective aqueous binder for silicon-based anodes in rechargeable lithium-ion batteries.

As a non-active material component, the binder can effectively maintain the integrity of battery electrodes. In this work, based on the inspired structure of fishing nets, a three-dimensional mesh adhesive using widely sourced raw materials CMC and ß-CD was designed. These cross-linked cyclodextrins have the advantage of dispersing the stress at the anchor point and moderating the significant volume changes of the Si anode. The Si/ß-CD-CMC electrode maintains a reversible capacity of 1702 mA h g-1 even after 200 cycles at a high current of 0.5C. This work represents a significant step forward in Si anode binders and enables the cross-linked cyclodextrins to have potential applications in energy storage systems.

Charge State of Au25(SG)18 Nanoclusters Induced by Interaction with a Metal Organic Framework Support and Its Effect on Catalytic Performance.

We investigated the charge transfer between Au25(SG)18 nanoclusters and metal-organic framework (MOF) supports including Mil-101-Cr, Mil-125-Ti, and ZIF-8 by an X-ray photoemission technique and discussed the influence of resulted charge states of supported Au25(SG)18 nanoclusters on the 4-nitrophenol reduction reaction. Charge transfer from Au25(SG)18 to Mil-101-Cr induces positive charge Auδ+ (0 < δ < 1) while charge transfer from ZIF-8 to Au25(SG)18 generates negative charge Auδ- due to different metal-support interactions. Au25(SG)18 on Mil-125 shows metallic Au0, similar to unsupported Au25(SG)18, due to negligible charge transfer. The resulted charge state of Auδ- inhibits the formation of adsorbed hydride (H-) species because of electrostatic repulsion, while Auδ+ impairs the reductive ability of adsorbed hydride (H-) species due to strong affinity between them. In comparison, metallic Au0 in Au25(SG)18/Mil-125 and unsupported Au25(SG)18 presents the optimum catalytic activity. The current work provides guidelines to design effective metal nanoclusters in heterogeneous catalysis through metal-support interaction exerted by metal-oxo/nitric clusters within MOFs.

Genome-wide association studies of callus differentiation for the desert tree, Populus euphratica.

Callus differentiation is a key developmental process in plant regeneration from cells. A better understanding of the genetic architecture of callus differentiation timing can help improve tissue transformation and the efficiency of artificial propagation. In this study, we investigated genotypic variation in callus differentiation capacity among 297 diverse P. euphratica trees sampled from a natural population. We employed a genome-wide association study (GWAS) of binary and growth-based parameters to identify loci and characterize the genetic architecture and genetic network underlying regulation of callus differentiation in P. euphratica. The results of this GWAS experiment suggested potential associations controlling whether the callus could differentiate and the process of callus differentiation. We identified multiple significant quantitative trait loci (QTLs), including the genes LOG1 and LOG7 and a locus containing WOX1. We reconstructed a genetic network that visualizes how each QTL interacts uniquely with other variants, and several core QTLs were detected that are involved in the degree of callus differentiation, providing potential targets for selection. This study represents one of the first to identify genetic variants affecting callus differentiation in a forest tree. Our results suggest that callus differentiation may be a typical qualitative-quantitative trait controlled by a major gene as well as polygenes across the genome of P. euphratica. This GWAS will help to design more complex and specific molecular tools for systematically manipulating organ regeneration.

How Long Non-Coding RNAs and MicroRNAs Mediate the Endogenous RNA Network of Head and Neck Squamous Cell Carcinoma: a Comprehensive Analysis.

BACKGROUND/AIMS: Long non-coding RNAs (lncRNAs) act as competing endogenous RNAs (ceRNAs) to compete for microRNAs (miRNAs) in cancer metastasis. Head and neck squamous cell carcinoma (HNSCC) is one of the most common human cancers and rare biomarkers could predict the clinical prognosis of this disease and its therapeutic effect. METHODS: Weighted gene co-expression network analysis (WGCNA) was performed to identify differentially expressed mRNAs (DEmRNAs) that might be key genes. GO enrichment and protein-protein interaction (PPI) analyses were performed to identify the principal functions of the DEmRNAs. An lncRNA-miRNA-mRNA network was constructed to understand the regulatory mechanisms in HNSCC. The prognostic signatures of mRNAs, miRNAs, and lncRNAs were determined by Gene Expression Profiling Interactive Analysis (GEPIA) and using Kaplan-Meier survival curves for patients with lung squamous cell carcinoma. RESULTS: We identified 2,023 DEmRNAs, 1,048 differentially expressed lncRNAs (DElncRNAs), and 82 differentially expressed miRNAs (DEmiRNAs). We found that eight DEmRNAs, 53 DElncRNAs, and 16 DEmiRNAs interacted in the ceRNA network. Three ceRNAs (HCG22, LINC00460 and STC2) were significantly correlated with survival. STC2 transcript levels were significantly higher in tumour tissues than in normal tissues, and the STC2 expression was slightly upregulated at different stages of HNSCC. CONCLUSION: LINC00460, HCG22 and STC2 exhibited aberrant levels of expression and may participate in the pathogenesis of HNSCC.

[An automatic extraction algorithm for individual tree crown projection area and volume based on 3D point cloud data].

Tree crown projection area and crown volume are the important parameters for the estimation of biomass, tridimensional green biomass and other forestry science applications. Using conventional measurements of tree crown projection area and crown volume will produce a large area of errors in the view of practical situations referring to complicated tree crown structures or different morphological characteristics. However, it is difficult to measure and validate their accuracy through conventional measurement methods. In view of practical problems which include complicated tree crown structure, different morphological characteristics, so as to implement the objective that tree crown projection and crown volume can be extracted by computer program automatically. This paper proposes an automatic untouched measurement based on terrestrial three-dimensional laser scanner named FARO Photon120 using plane scattered data point convex hull algorithm and slice segmentation and accumulation algorithm to calculate the tree crown projection area. It is exploited on VC+6.0 and Matlab7.0. The experiments are exploited on 22 common tree species of Beijing, China. The results show that the correlation coefficient of the crown projection between Av calculated by new method and conventional method A4 reaches 0.964 (p<0.01); and the correlation coefficient of tree crown volume between V(VC) derived from new method and V(C) by the formula of a regular body is 0.960 (p<0.001). The results also show that the average of V(C) is smaller than that of V(VC) at the rate of 8.03%, and the average of A4 is larger than that of A(V) at the rate of 25.5%. Assumed Av and V(VC) as ture values, the deviations of the new method could be attributed to irregularity of the crowns' silhouettes. Different morphological characteristics of tree crown led to measurement error in forest simple plot survey. Based on the results, the paper proposes that: (1) the use of eight-point or sixteen-point projection with fixed angles to estimate crown projections, and (2) different regular volume formula to simulate crown volume according to the tree crown shapes. Based on the high-resolution 3D LIDAR point cloud data of individual tree, tree crown structure was reconstructed at a high rate of speed with high accuracy, and crown projection and volume of individual tree were extracted by this automatical untouched method, which can provide a reference for tree crown structure studies and be worth to popularize in the field of precision forestry.