ABSTRACT
Perovskite monocrystalline films are regarded as desirable candidates for the integration of high-performance optoelectronics due to their unique photophysical properties. However, the heterogeneous integration of a perovskite monocrystalline film with other semiconductors is fundamentally limited by the lattice mismatch, which hinders direct epitaxy. Herein, the van der Waals (vdW) integration strategy for 3D perovskites is developed, where perovskite monocrystalline films are epitaxially grown on the mother substrate, followed by its peeling off and transferring to arbitrary semiconductors, forming monocrystalline heterojunctions. The as-achieved CsPbBr3-Nb-doped SrTiO3 (Nb:STO) vdW p-n heterojunction exhibited comparable performance to their directly epitaxial counterpart, demonstrating the feasibility of vdW integration for 3D perovskites. Furthermore, the vdW integration could be extended to silicon substrates, rendering the CsPbBr3-n-Si and CsPbCl3-p-Si p-n heterojunction with apparent rectification behaviors and photoresponse. The vdW integration significantly enriches the selections of semiconductors hybridizing with perovskites and provides opportunities for monocrystalline perovskite optoelectronics with complex configurations and multiple functionalities.
ABSTRACT
ESG has emerged as a prominent method for evaluating enterprises, gaining increasing importance in recent years. It assesses a company's ability to promote sustainable economic development and fulfill its social responsibilities, encompassing three non-financial dimensions: environmental, social, and corporate governance. Regulatory authorities, industry associations, and investment institutions worldwide have placed growing emphasis on a company's ESG performance. From the perspective of career concern, this study conducted a multiple regression analysis using data from Chinese A-share companies listed in Shanghai and Shenzhen from 2011 to 2020. It used CEO shareholding and CEO political affiliation as moderating variables to examine the impact of CEO career concerns on the corporate environment, society, and corporate governance performance. Empirical testing of whether CEO career concerns promote or suppress the ESG performance in enterprises. The findings of this study reveal that CEOs with heightened career concerns tend to impede the ESG performance of their respective enterprises. Additionally, CEO shareholding and political affiliations exert a negative moderating influence on the relationship between CEO career concerns and ESG performance. This research significantly extends the investigation into factors influencing ESG performance, offering fresh perspectives that could inform improved CEO oversight, foster corporate transformation, and enhance ESG performance.
Subject(s)
Economic Development , Humans , China , Industry , Social Responsibility , Conservation of Natural Resources/methodsABSTRACT
Objective: The primary objective of this study is to investigate the mechanism by which Bacillus coagulans TBC169 accelerates intestinal function recovery in patients who have undergone gynecological laparoscopic surgery, using metabolomics and gut microbiota analysis. Methods: A total of 20 subjects were selected and randomly divided into two groups: the intervention group (n = 10) receiving Bacillus coagulans TBC169 Tablets (6 pills, 1.05 × 108 CFU), and the control group (n = 10) receiving placebos (6 pills). After the initial postoperative defecation, fecal samples were collected from each subject to analyze their gut microbiota and metabolic profiles by high-throughput 16S rRNA gene sequencing analysis and untargeted metabonomic. Results: There were no statistically significant differences observed in the α-diversity and ß-diversity between the two groups; however, in the intervention group, there was a significant reduction in the relative abundance of unclassified_Enterobacteriaceae at the genus level. Furthermore, the control group showed increased levels of Holdemanella and Enterobacter, whereas the intervention group exhibited elevated levels of Intestinimonas. And administration of Bacillus coagulans TBC169 led to variations in 2 metabolic pathways: D-glutamine and D-glutamate metabolism, and arginine biosynthesis. Conclusion: This study demonstrated that consuming Bacillus coagulans TBC169 after gynecological laparoscopic surgery might inhibit the proliferation of harmful Enterobacteriaceae; mainly influence 2 pathways including D-glutamine and D-glutamate metabolism, and arginine biosynthesis; and regulate metabolites related to immunity and intestinal motility; which can help regulate immune function, maintain intestinal balance, promote intestinal peristalsis, and thus accelerate the recovery of intestinal function.
ABSTRACT
The fabrication of perovskite single crystal-based optoelectronics with improved performance is largely hindered by limited processing techniques. Particularly, the local halide composition manipulation, which dominates the bandgap and thus the formation of heterostructures and emission of multiple-wavelength light, is realized via prevalent liquid- or gas-phase anion exchange with the utilization of lithography, while the monocrystalline nature is sacrificed due to polycrystalline transition in exchange with massive defects emerging, impeding carrier separation and transportation. Thus, a damage-free and lithography-free solid-state anion exchange strategy, aiming at in situ halide manipulation in perovskite monocrystalline film, is developed. Typically, CsPbCl3 working as medium to deliver halide is van der Waals (vdW) assembled to specific spots of CsPbBr3, followed by the removal of CsPbCl3 after anion exchange, with the halide composition in contact area modulated and monocrystalline nature of CsPbBr3 preserved. CsPbBr3-CsPbBrxCl3-x monocrystalline heterostructure has been achieved without lithography. Device based on the heterostructure shows apparent rectification behavior and improved photo-response rate. Heterostructure arrays can also be constructed with customized medium crystal. Furthermore, the halide composition can be accurately tuned to enable full coverage of visible spectra. The solid-state exchange enriches the toolbox for processing vulnerable perovskite and paves the way for the integration of monocrystalline perovskite optoelectronics.
ABSTRACT
van der Waals heterostructures (vdWHs) based on two-dimensional (2D) semiconductors have attracted considerable attention. However, the reported vdWHs are largely based on vertical device structure with large overlapping area, while the realization of lateral heterostructures contacted through 2D edges remains challenging and is majorly limited by the difficulties of manipulating the lateral distance of 2D materials at nanometer scale (during transfer process). Here, we demonstrate a simple interfacial sliding approach for realizing an edge-by-edge lateral contact. By stretching a vertical vdWH, two 2D flakes could gradually slide apart or toward each other. Therefore, by applying proper strain, the initial vertical vdWH could be converted into a lateral heterojunction with intimately contacted 2D edges. The lateral contact structure is supported by both microscope characterization and in situ electrical measurements, exhibiting carrier tunneling behavior. Finally, this approach can be extended to 3D thin films, as demonstrated by the lateral 2D/3D and 3D/3D Schottky junction.
ABSTRACT
The electrochemical denitrification of nitrate (NO3 -) in actual wastewater to nitrogen (N2) is an effective approach to reversing the current imbalance of the nitrogen cycle and the eutrophication of water. However, electrostatic repulsion between NO3 - and the cathode results in the low efficiency of NO3 - reduction reaction (NO3RR). Here, density functional theory (DFT) calculations are used as a theoretical guide to design a Pd cluster-loaded multivalent Cu foam (Pd/Cu2O-CF) electrocatalyst, which achieves a splendid 97.8% NO3 - removal rate, 97.9% N2 selectivity, 695.5 mg N g-1 Pd h-1 reduction efficiency, and 60.0% Faradaic efficiency at -1.3 V versus SCE. The projected density of states (pDOS) indicates that NO3 - and Pd/Cu2O-CF are bonded via strong complexation between the O 2p (in NO3 -) and Cu 3d (in Cu2O) with the input of voltage, which reduces the electrostatic repulsion and enhances the enrichment of NO3 - on the cathode. In-situ characterizations demonstrate that Pd[H] can reduce Cu2O to Cu, and subsequently Cu reduces NO3 - to nitrite (NO2 -) accompanied by in situ reconfiguration of multivalent Cu foam. NO2 - is then transferred to the surface of Pd clusters by the cascade catalysis and accelerates the breaking of NâO bonds to form PdâN, and eventually achieves the N≡N bond formation.
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Background: The demand for immediate breast reconstruction with a deep inferior epigastric perforator (DIEP) flap is recovering as coronavirus disease 2019 (COVID-19) transitions from a pandemic to an endemic. This study sought to evaluate the safety of resuming DIEP flap reconstruction in the post-COVID-19 era. Methods: Consecutive breast cancer patients who underwent immediate breast reconstruction with a DIEP flap at the Comprehensive Breast Health Center, Ruijin Hospital were retrospectively included in the study. The patients were divided into a post-pandemic group (Group A) and a pre-pandemic group (Group B). The clinicopathological factors, surgical procedures, and rates of post-operative complications were compared between the two groups using the Mann-Whitney U test and Chi-squared test. Results: A total of 167 patients were included in the study, of whom 119 (71.3%) were in Group A and 48 (28.7%) were in Group B. The two groups had similar clinicopathological features, including age (P=0.988), body mass index (P=0.504), and tumor, node, metastasis (TNM) stage (P=0.932). The Group A patients were more likely to receive single perforator DIEP flap transplantation than the Group B patients (n=28, 22.8% vs. n=3, 5.8%, P=0.007). There was a numerical decrease in the mean operating time of Group A patients compared to Group B patients (9.82 vs. 10.12 hours, P=0.172). The mean length of stay after the surgery was significantly shorter after the pandemic than before the pandemic (11.2 vs. 14.3 days, P<0.001). The complication rates between the two groups were similar. Conclusions: This study provides evidence that resuming DIEP reconstruction is safe in the post-COVID-19 era.